1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Debug_A; use Debug_A;
30 with Einfo; use Einfo;
31 with Elists; use Elists;
32 with Errout; use Errout;
33 with Expander; use Expander;
34 with Exp_Disp; use Exp_Disp;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Tss; use Exp_Tss;
38 with Exp_Util; use Exp_Util;
39 with Fname; use Fname;
40 with Freeze; use Freeze;
41 with Itypes; use Itypes;
43 with Lib.Xref; use Lib.Xref;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
48 with Output; use Output;
49 with Restrict; use Restrict;
50 with Rident; use Rident;
51 with Rtsfind; use Rtsfind;
53 with Sem_Aux; use Sem_Aux;
54 with Sem_Aggr; use Sem_Aggr;
55 with Sem_Attr; use Sem_Attr;
56 with Sem_Cat; use Sem_Cat;
57 with Sem_Ch4; use Sem_Ch4;
58 with Sem_Ch6; use Sem_Ch6;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Disp; use Sem_Disp;
62 with Sem_Dist; use Sem_Dist;
63 with Sem_Elim; use Sem_Elim;
64 with Sem_Elab; use Sem_Elab;
65 with Sem_Eval; use Sem_Eval;
66 with Sem_Intr; use Sem_Intr;
67 with Sem_Util; use Sem_Util;
68 with Sem_Type; use Sem_Type;
69 with Sem_Warn; use Sem_Warn;
70 with Sinfo; use Sinfo;
71 with Snames; use Snames;
72 with Stand; use Stand;
73 with Stringt; use Stringt;
74 with Style; use Style;
75 with Tbuild; use Tbuild;
76 with Uintp; use Uintp;
77 with Urealp; use Urealp;
79 package body Sem_Res is
81 -----------------------
82 -- Local Subprograms --
83 -----------------------
85 -- Second pass (top-down) type checking and overload resolution procedures
86 -- Typ is the type required by context. These procedures propagate the
87 -- type information recursively to the descendants of N. If the node
88 -- is not overloaded, its Etype is established in the first pass. If
89 -- overloaded, the Resolve routines set the correct type. For arith.
90 -- operators, the Etype is the base type of the context.
92 -- Note that Resolve_Attribute is separated off in Sem_Attr
94 procedure Check_Discriminant_Use (N : Node_Id);
95 -- Enforce the restrictions on the use of discriminants when constraining
96 -- a component of a discriminated type (record or concurrent type).
98 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
99 -- Given a node for an operator associated with type T, check that
100 -- the operator is visible. Operators all of whose operands are
101 -- universal must be checked for visibility during resolution
102 -- because their type is not determinable based on their operands.
104 procedure Check_Fully_Declared_Prefix
107 -- Check that the type of the prefix of a dereference is not incomplete
109 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
110 -- Given a call node, N, which is known to occur immediately within the
111 -- subprogram being called, determines whether it is a detectable case of
112 -- an infinite recursion, and if so, outputs appropriate messages. Returns
113 -- True if an infinite recursion is detected, and False otherwise.
115 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
116 -- If the type of the object being initialized uses the secondary stack
117 -- directly or indirectly, create a transient scope for the call to the
118 -- init proc. This is because we do not create transient scopes for the
119 -- initialization of individual components within the init proc itself.
120 -- Could be optimized away perhaps?
122 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
123 -- N is the node for a comparison or logical operator. If the operator
124 -- is predefined, and the root type of the operands is Standard.Boolean,
125 -- then a check is made for restriction No_Direct_Boolean_Operators.
127 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
128 -- Determine whether E is an access type declared by an access
129 -- declaration, and not an (anonymous) allocator type.
131 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
132 -- Utility to check whether the name in the call is a predefined
133 -- operator, in which case the call is made into an operator node.
134 -- An instance of an intrinsic conversion operation may be given
135 -- an operator name, but is not treated like an operator.
137 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
138 -- If a default expression in entry call N depends on the discriminants
139 -- of the task, it must be replaced with a reference to the discriminant
140 -- of the task being called.
142 procedure Resolve_Op_Concat_Arg
147 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
148 -- concatenation operator. The operand is either of the array type or of
149 -- the component type. If the operand is an aggregate, and the component
150 -- type is composite, this is ambiguous if component type has aggregates.
152 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
153 -- Does the first part of the work of Resolve_Op_Concat
155 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
156 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
157 -- has been resolved. See Resolve_Op_Concat for details.
159 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
160 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
161 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
162 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
163 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
164 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
165 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
166 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
167 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
168 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
169 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
170 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
171 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
172 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
173 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
174 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
177 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
178 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
181 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
182 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
184 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
185 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
192 function Operator_Kind
194 Is_Binary : Boolean) return Node_Kind;
195 -- Utility to map the name of an operator into the corresponding Node. Used
196 -- by other node rewriting procedures.
198 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
199 -- Resolve actuals of call, and add default expressions for missing ones.
200 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
201 -- called subprogram.
203 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
204 -- Called from Resolve_Call, when the prefix denotes an entry or element
205 -- of entry family. Actuals are resolved as for subprograms, and the node
206 -- is rebuilt as an entry call. Also called for protected operations. Typ
207 -- is the context type, which is used when the operation is a protected
208 -- function with no arguments, and the return value is indexed.
210 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
211 -- A call to a user-defined intrinsic operator is rewritten as a call
212 -- to the corresponding predefined operator, with suitable conversions.
214 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
215 -- Ditto, for unary operators (only arithmetic ones)
217 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
218 -- If an operator node resolves to a call to a user-defined operator,
219 -- rewrite the node as a function call.
221 procedure Make_Call_Into_Operator
225 -- Inverse transformation: if an operator is given in functional notation,
226 -- then after resolving the node, transform into an operator node, so
227 -- that operands are resolved properly. Recall that predefined operators
228 -- do not have a full signature and special resolution rules apply.
230 procedure Rewrite_Renamed_Operator
234 -- An operator can rename another, e.g. in an instantiation. In that
235 -- case, the proper operator node must be constructed and resolved.
237 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
238 -- The String_Literal_Subtype is built for all strings that are not
239 -- operands of a static concatenation operation. If the argument is
240 -- not a N_String_Literal node, then the call has no effect.
242 procedure Set_Slice_Subtype (N : Node_Id);
243 -- Build subtype of array type, with the range specified by the slice
245 procedure Simplify_Type_Conversion (N : Node_Id);
246 -- Called after N has been resolved and evaluated, but before range checks
247 -- have been applied. Currently simplifies a combination of floating-point
248 -- to integer conversion and Truncation attribute.
250 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
251 -- A universal_fixed expression in an universal context is unambiguous
252 -- if there is only one applicable fixed point type. Determining whether
253 -- there is only one requires a search over all visible entities, and
254 -- happens only in very pathological cases (see 6115-006).
256 function Valid_Conversion
259 Operand : Node_Id) return Boolean;
260 -- Verify legality rules given in 4.6 (8-23). Target is the target
261 -- type of the conversion, which may be an implicit conversion of
262 -- an actual parameter to an anonymous access type (in which case
263 -- N denotes the actual parameter and N = Operand).
265 -------------------------
266 -- Ambiguous_Character --
267 -------------------------
269 procedure Ambiguous_Character (C : Node_Id) is
273 if Nkind (C) = N_Character_Literal then
274 Error_Msg_N ("ambiguous character literal", C);
276 -- First the ones in Standard
279 ("\\possible interpretation: Character!", C);
281 ("\\possible interpretation: Wide_Character!", C);
283 -- Include Wide_Wide_Character in Ada 2005 mode
285 if Ada_Version >= Ada_05 then
287 ("\\possible interpretation: Wide_Wide_Character!", C);
290 -- Now any other types that match
292 E := Current_Entity (C);
293 while Present (E) loop
294 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
298 end Ambiguous_Character;
300 -------------------------
301 -- Analyze_And_Resolve --
302 -------------------------
304 procedure Analyze_And_Resolve (N : Node_Id) is
308 end Analyze_And_Resolve;
310 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
314 end Analyze_And_Resolve;
316 -- Version withs check(s) suppressed
318 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, Typ);
332 Scope_Suppress := Svg;
337 Svg : constant Boolean := Scope_Suppress (Suppress);
340 Scope_Suppress (Suppress) := True;
341 Analyze_And_Resolve (N, Typ);
342 Scope_Suppress (Suppress) := Svg;
346 if Current_Scope /= Scop
347 and then Scope_Is_Transient
349 -- This can only happen if a transient scope was created
350 -- for an inner expression, which will be removed upon
351 -- completion of the analysis of an enclosing construct.
352 -- The transient scope must have the suppress status of
353 -- the enclosing environment, not of this Analyze call.
355 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
358 end Analyze_And_Resolve;
360 procedure Analyze_And_Resolve
364 Scop : constant Entity_Id := Current_Scope;
367 if Suppress = All_Checks then
369 Svg : constant Suppress_Array := Scope_Suppress;
371 Scope_Suppress := (others => True);
372 Analyze_And_Resolve (N);
373 Scope_Suppress := Svg;
378 Svg : constant Boolean := Scope_Suppress (Suppress);
381 Scope_Suppress (Suppress) := True;
382 Analyze_And_Resolve (N);
383 Scope_Suppress (Suppress) := Svg;
387 if Current_Scope /= Scop
388 and then Scope_Is_Transient
390 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
393 end Analyze_And_Resolve;
395 ----------------------------
396 -- Check_Discriminant_Use --
397 ----------------------------
399 procedure Check_Discriminant_Use (N : Node_Id) is
400 PN : constant Node_Id := Parent (N);
401 Disc : constant Entity_Id := Entity (N);
406 -- Any use in a spec-expression is legal
408 if In_Spec_Expression then
411 elsif Nkind (PN) = N_Range then
413 -- Discriminant cannot be used to constrain a scalar type
417 if Nkind (P) = N_Range_Constraint
418 and then Nkind (Parent (P)) = N_Subtype_Indication
419 and then Nkind (Parent (Parent (P))) = N_Component_Definition
421 Error_Msg_N ("discriminant cannot constrain scalar type", N);
423 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
425 -- The following check catches the unusual case where
426 -- a discriminant appears within an index constraint
427 -- that is part of a larger expression within a constraint
428 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
429 -- For now we only check case of record components, and
430 -- note that a similar check should also apply in the
431 -- case of discriminant constraints below. ???
433 -- Note that the check for N_Subtype_Declaration below is to
434 -- detect the valid use of discriminants in the constraints of a
435 -- subtype declaration when this subtype declaration appears
436 -- inside the scope of a record type (which is syntactically
437 -- illegal, but which may be created as part of derived type
438 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
441 if Ekind (Current_Scope) = E_Record_Type
442 and then Scope (Disc) = Current_Scope
444 (Nkind (Parent (P)) = N_Subtype_Indication
446 Nkind_In (Parent (Parent (P)), N_Component_Definition,
447 N_Subtype_Declaration)
448 and then Paren_Count (N) = 0)
451 ("discriminant must appear alone in component constraint", N);
455 -- Detect a common error:
457 -- type R (D : Positive := 100) is record
458 -- Name : String (1 .. D);
461 -- The default value causes an object of type R to be allocated
462 -- with room for Positive'Last characters. The RM does not mandate
463 -- the allocation of the maximum size, but that is what GNAT does
464 -- so we should warn the programmer that there is a problem.
466 Check_Large : declare
472 function Large_Storage_Type (T : Entity_Id) return Boolean;
473 -- Return True if type T has a large enough range that
474 -- any array whose index type covered the whole range of
475 -- the type would likely raise Storage_Error.
477 ------------------------
478 -- Large_Storage_Type --
479 ------------------------
481 function Large_Storage_Type (T : Entity_Id) return Boolean is
483 -- The type is considered large if its bounds are known at
484 -- compile time and if it requires at least as many bits as
485 -- a Positive to store the possible values.
487 return Compile_Time_Known_Value (Type_Low_Bound (T))
488 and then Compile_Time_Known_Value (Type_High_Bound (T))
490 Minimum_Size (T, Biased => True) >=
491 RM_Size (Standard_Positive);
492 end Large_Storage_Type;
494 -- Start of processing for Check_Large
497 -- Check that the Disc has a large range
499 if not Large_Storage_Type (Etype (Disc)) then
503 -- If the enclosing type is limited, we allocate only the
504 -- default value, not the maximum, and there is no need for
507 if Is_Limited_Type (Scope (Disc)) then
511 -- Check that it is the high bound
513 if N /= High_Bound (PN)
514 or else No (Discriminant_Default_Value (Disc))
519 -- Check the array allows a large range at this bound.
520 -- First find the array
524 if Nkind (SI) /= N_Subtype_Indication then
528 T := Entity (Subtype_Mark (SI));
530 if not Is_Array_Type (T) then
534 -- Next, find the dimension
536 TB := First_Index (T);
537 CB := First (Constraints (P));
539 and then Present (TB)
540 and then Present (CB)
551 -- Now, check the dimension has a large range
553 if not Large_Storage_Type (Etype (TB)) then
557 -- Warn about the danger
560 ("?creation of & object may raise Storage_Error!",
569 -- Legal case is in index or discriminant constraint
571 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
572 N_Discriminant_Association)
574 if Paren_Count (N) > 0 then
576 ("discriminant in constraint must appear alone", N);
578 elsif Nkind (N) = N_Expanded_Name
579 and then Comes_From_Source (N)
582 ("discriminant must appear alone as a direct name", N);
587 -- Otherwise, context is an expression. It should not be within
588 -- (i.e. a subexpression of) a constraint for a component.
593 while not Nkind_In (P, N_Component_Declaration,
594 N_Subtype_Indication,
602 -- If the discriminant is used in an expression that is a bound
603 -- of a scalar type, an Itype is created and the bounds are attached
604 -- to its range, not to the original subtype indication. Such use
605 -- is of course a double fault.
607 if (Nkind (P) = N_Subtype_Indication
608 and then Nkind_In (Parent (P), N_Component_Definition,
609 N_Derived_Type_Definition)
610 and then D = Constraint (P))
612 -- The constraint itself may be given by a subtype indication,
613 -- rather than by a more common discrete range.
615 or else (Nkind (P) = N_Subtype_Indication
617 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
618 or else Nkind (P) = N_Entry_Declaration
619 or else Nkind (D) = N_Defining_Identifier
622 ("discriminant in constraint must appear alone", N);
625 end Check_Discriminant_Use;
627 --------------------------------
628 -- Check_For_Visible_Operator --
629 --------------------------------
631 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
633 if Is_Invisible_Operator (N, T) then
635 ("operator for} is not directly visible!", N, First_Subtype (T));
636 Error_Msg_N ("use clause would make operation legal!", N);
638 end Check_For_Visible_Operator;
640 ----------------------------------
641 -- Check_Fully_Declared_Prefix --
642 ----------------------------------
644 procedure Check_Fully_Declared_Prefix
649 -- Check that the designated type of the prefix of a dereference is
650 -- not an incomplete type. This cannot be done unconditionally, because
651 -- dereferences of private types are legal in default expressions. This
652 -- case is taken care of in Check_Fully_Declared, called below. There
653 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
655 -- This consideration also applies to similar checks for allocators,
656 -- qualified expressions, and type conversions.
658 -- An additional exception concerns other per-object expressions that
659 -- are not directly related to component declarations, in particular
660 -- representation pragmas for tasks. These will be per-object
661 -- expressions if they depend on discriminants or some global entity.
662 -- If the task has access discriminants, the designated type may be
663 -- incomplete at the point the expression is resolved. This resolution
664 -- takes place within the body of the initialization procedure, where
665 -- the discriminant is replaced by its discriminal.
667 if Is_Entity_Name (Pref)
668 and then Ekind (Entity (Pref)) = E_In_Parameter
672 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
673 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
674 -- Analyze_Object_Renaming, and Freeze_Entity.
676 elsif Ada_Version >= Ada_05
677 and then Is_Entity_Name (Pref)
678 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
680 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
684 Check_Fully_Declared (Typ, Parent (Pref));
686 end Check_Fully_Declared_Prefix;
688 ------------------------------
689 -- Check_Infinite_Recursion --
690 ------------------------------
692 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
696 function Same_Argument_List return Boolean;
697 -- Check whether list of actuals is identical to list of formals
698 -- of called function (which is also the enclosing scope).
700 ------------------------
701 -- Same_Argument_List --
702 ------------------------
704 function Same_Argument_List return Boolean is
710 if not Is_Entity_Name (Name (N)) then
713 Subp := Entity (Name (N));
716 F := First_Formal (Subp);
717 A := First_Actual (N);
718 while Present (F) and then Present (A) loop
719 if not Is_Entity_Name (A)
720 or else Entity (A) /= F
730 end Same_Argument_List;
732 -- Start of processing for Check_Infinite_Recursion
735 -- Special case, if this is a procedure call and is a call to the
736 -- current procedure with the same argument list, then this is for
737 -- sure an infinite recursion and we insert a call to raise SE.
739 if Is_List_Member (N)
740 and then List_Length (List_Containing (N)) = 1
741 and then Same_Argument_List
744 P : constant Node_Id := Parent (N);
746 if Nkind (P) = N_Handled_Sequence_Of_Statements
747 and then Nkind (Parent (P)) = N_Subprogram_Body
748 and then Is_Empty_List (Declarations (Parent (P)))
750 Error_Msg_N ("!?infinite recursion", N);
751 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
753 Make_Raise_Storage_Error (Sloc (N),
754 Reason => SE_Infinite_Recursion));
760 -- If not that special case, search up tree, quitting if we reach a
761 -- construct (e.g. a conditional) that tells us that this is not a
762 -- case for an infinite recursion warning.
768 -- If no parent, then we were not inside a subprogram, this can for
769 -- example happen when processing certain pragmas in a spec. Just
770 -- return False in this case.
776 -- Done if we get to subprogram body, this is definitely an infinite
777 -- recursion case if we did not find anything to stop us.
779 exit when Nkind (P) = N_Subprogram_Body;
781 -- If appearing in conditional, result is false
783 if Nkind_In (P, N_Or_Else,
790 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
791 and then C /= First (Statements (P))
793 -- If the call is the expression of a return statement and the
794 -- actuals are identical to the formals, it's worth a warning.
795 -- However, we skip this if there is an immediately preceding
796 -- raise statement, since the call is never executed.
798 -- Furthermore, this corresponds to a common idiom:
800 -- function F (L : Thing) return Boolean is
802 -- raise Program_Error;
806 -- for generating a stub function
808 if Nkind (Parent (N)) = N_Simple_Return_Statement
809 and then Same_Argument_List
811 exit when not Is_List_Member (Parent (N));
813 -- OK, return statement is in a statement list, look for raise
819 -- Skip past N_Freeze_Entity nodes generated by expansion
821 Nod := Prev (Parent (N));
823 and then Nkind (Nod) = N_Freeze_Entity
828 -- If no raise statement, give warning
830 exit when Nkind (Nod) /= N_Raise_Statement
832 (Nkind (Nod) not in N_Raise_xxx_Error
833 or else Present (Condition (Nod)));
844 Error_Msg_N ("!?possible infinite recursion", N);
845 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
848 end Check_Infinite_Recursion;
850 -------------------------------
851 -- Check_Initialization_Call --
852 -------------------------------
854 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
855 Typ : constant Entity_Id := Etype (First_Formal (Nam));
857 function Uses_SS (T : Entity_Id) return Boolean;
858 -- Check whether the creation of an object of the type will involve
859 -- use of the secondary stack. If T is a record type, this is true
860 -- if the expression for some component uses the secondary stack, e.g.
861 -- through a call to a function that returns an unconstrained value.
862 -- False if T is controlled, because cleanups occur elsewhere.
868 function Uses_SS (T : Entity_Id) return Boolean is
871 Full_Type : Entity_Id := Underlying_Type (T);
874 -- Normally we want to use the underlying type, but if it's not set
875 -- then continue with T.
877 if not Present (Full_Type) then
881 if Is_Controlled (Full_Type) then
884 elsif Is_Array_Type (Full_Type) then
885 return Uses_SS (Component_Type (Full_Type));
887 elsif Is_Record_Type (Full_Type) then
888 Comp := First_Component (Full_Type);
889 while Present (Comp) loop
890 if Ekind (Comp) = E_Component
891 and then Nkind (Parent (Comp)) = N_Component_Declaration
893 -- The expression for a dynamic component may be rewritten
894 -- as a dereference, so retrieve original node.
896 Expr := Original_Node (Expression (Parent (Comp)));
898 -- Return True if the expression is a call to a function
899 -- (including an attribute function such as Image) with
900 -- a result that requires a transient scope.
902 if (Nkind (Expr) = N_Function_Call
903 or else (Nkind (Expr) = N_Attribute_Reference
904 and then Present (Expressions (Expr))))
905 and then Requires_Transient_Scope (Etype (Expr))
909 elsif Uses_SS (Etype (Comp)) then
914 Next_Component (Comp);
924 -- Start of processing for Check_Initialization_Call
927 -- Establish a transient scope if the type needs it
929 if Uses_SS (Typ) then
930 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
932 end Check_Initialization_Call;
934 ---------------------------------------
935 -- Check_No_Direct_Boolean_Operators --
936 ---------------------------------------
938 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
940 if Scope (Entity (N)) = Standard_Standard
941 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
943 -- Restriction does not apply to generated code
945 if not Comes_From_Source (N) then
948 -- Restriction does not apply for A=False, A=True
950 elsif Nkind (N) = N_Op_Eq
951 and then (Is_Entity_Name (Right_Opnd (N))
952 and then (Entity (Right_Opnd (N)) = Standard_True
954 Entity (Right_Opnd (N)) = Standard_False))
958 -- Otherwise restriction applies
961 Check_Restriction (No_Direct_Boolean_Operators, N);
964 end Check_No_Direct_Boolean_Operators;
966 ------------------------------
967 -- Check_Parameterless_Call --
968 ------------------------------
970 procedure Check_Parameterless_Call (N : Node_Id) is
973 function Prefix_Is_Access_Subp return Boolean;
974 -- If the prefix is of an access_to_subprogram type, the node must be
975 -- rewritten as a call. Ditto if the prefix is overloaded and all its
976 -- interpretations are access to subprograms.
978 ---------------------------
979 -- Prefix_Is_Access_Subp --
980 ---------------------------
982 function Prefix_Is_Access_Subp return Boolean is
987 if not Is_Overloaded (N) then
989 Ekind (Etype (N)) = E_Subprogram_Type
990 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
992 Get_First_Interp (N, I, It);
993 while Present (It.Typ) loop
994 if Ekind (It.Typ) /= E_Subprogram_Type
995 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1000 Get_Next_Interp (I, It);
1005 end Prefix_Is_Access_Subp;
1007 -- Start of processing for Check_Parameterless_Call
1010 -- Defend against junk stuff if errors already detected
1012 if Total_Errors_Detected /= 0 then
1013 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1015 elsif Nkind (N) in N_Has_Chars
1016 and then Chars (N) in Error_Name_Or_No_Name
1024 -- If the context expects a value, and the name is a procedure, this is
1025 -- most likely a missing 'Access. Don't try to resolve the parameterless
1026 -- call, error will be caught when the outer call is analyzed.
1028 if Is_Entity_Name (N)
1029 and then Ekind (Entity (N)) = E_Procedure
1030 and then not Is_Overloaded (N)
1032 Nkind_In (Parent (N), N_Parameter_Association,
1034 N_Procedure_Call_Statement)
1039 -- Rewrite as call if overloadable entity that is (or could be, in the
1040 -- overloaded case) a function call. If we know for sure that the entity
1041 -- is an enumeration literal, we do not rewrite it.
1043 if (Is_Entity_Name (N)
1044 and then Is_Overloadable (Entity (N))
1045 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
1046 or else Is_Overloaded (N)))
1048 -- Rewrite as call if it is an explicit deference of an expression of
1049 -- a subprogram access type, and the subprogram type is not that of a
1050 -- procedure or entry.
1053 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
1055 -- Rewrite as call if it is a selected component which is a function,
1056 -- this is the case of a call to a protected function (which may be
1057 -- overloaded with other protected operations).
1060 (Nkind (N) = N_Selected_Component
1061 and then (Ekind (Entity (Selector_Name (N))) = E_Function
1063 ((Ekind (Entity (Selector_Name (N))) = E_Entry
1065 Ekind (Entity (Selector_Name (N))) = E_Procedure)
1066 and then Is_Overloaded (Selector_Name (N)))))
1068 -- If one of the above three conditions is met, rewrite as call.
1069 -- Apply the rewriting only once.
1072 if Nkind (Parent (N)) /= N_Function_Call
1073 or else N /= Name (Parent (N))
1075 Nam := New_Copy (N);
1077 -- If overloaded, overload set belongs to new copy
1079 Save_Interps (N, Nam);
1081 -- Change node to parameterless function call (note that the
1082 -- Parameter_Associations associations field is left set to Empty,
1083 -- its normal default value since there are no parameters)
1085 Change_Node (N, N_Function_Call);
1087 Set_Sloc (N, Sloc (Nam));
1091 elsif Nkind (N) = N_Parameter_Association then
1092 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
1094 end Check_Parameterless_Call;
1096 -----------------------------
1097 -- Is_Definite_Access_Type --
1098 -----------------------------
1100 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1101 Btyp : constant Entity_Id := Base_Type (E);
1103 return Ekind (Btyp) = E_Access_Type
1104 or else (Ekind (Btyp) = E_Access_Subprogram_Type
1105 and then Comes_From_Source (Btyp));
1106 end Is_Definite_Access_Type;
1108 ----------------------
1109 -- Is_Predefined_Op --
1110 ----------------------
1112 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1114 return Is_Intrinsic_Subprogram (Nam)
1115 and then not Is_Generic_Instance (Nam)
1116 and then Chars (Nam) in Any_Operator_Name
1117 and then (No (Alias (Nam))
1118 or else Is_Predefined_Op (Alias (Nam)));
1119 end Is_Predefined_Op;
1121 -----------------------------
1122 -- Make_Call_Into_Operator --
1123 -----------------------------
1125 procedure Make_Call_Into_Operator
1130 Op_Name : constant Name_Id := Chars (Op_Id);
1131 Act1 : Node_Id := First_Actual (N);
1132 Act2 : Node_Id := Next_Actual (Act1);
1133 Error : Boolean := False;
1134 Func : constant Entity_Id := Entity (Name (N));
1135 Is_Binary : constant Boolean := Present (Act2);
1137 Opnd_Type : Entity_Id;
1138 Orig_Type : Entity_Id := Empty;
1141 type Kind_Test is access function (E : Entity_Id) return Boolean;
1143 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
1144 -- If the operand is not universal, and the operator is given by a
1145 -- expanded name, verify that the operand has an interpretation with
1146 -- a type defined in the given scope of the operator.
1148 function Type_In_P (Test : Kind_Test) return Entity_Id;
1149 -- Find a type of the given class in the package Pack that contains
1152 ---------------------------
1153 -- Operand_Type_In_Scope --
1154 ---------------------------
1156 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1157 Nod : constant Node_Id := Right_Opnd (Op_Node);
1162 if not Is_Overloaded (Nod) then
1163 return Scope (Base_Type (Etype (Nod))) = S;
1166 Get_First_Interp (Nod, I, It);
1167 while Present (It.Typ) loop
1168 if Scope (Base_Type (It.Typ)) = S then
1172 Get_Next_Interp (I, It);
1177 end Operand_Type_In_Scope;
1183 function Type_In_P (Test : Kind_Test) return Entity_Id is
1186 function In_Decl return Boolean;
1187 -- Verify that node is not part of the type declaration for the
1188 -- candidate type, which would otherwise be invisible.
1194 function In_Decl return Boolean is
1195 Decl_Node : constant Node_Id := Parent (E);
1201 if Etype (E) = Any_Type then
1204 elsif No (Decl_Node) then
1209 and then Nkind (N2) /= N_Compilation_Unit
1211 if N2 = Decl_Node then
1222 -- Start of processing for Type_In_P
1225 -- If the context type is declared in the prefix package, this
1226 -- is the desired base type.
1228 if Scope (Base_Type (Typ)) = Pack
1231 return Base_Type (Typ);
1234 E := First_Entity (Pack);
1235 while Present (E) loop
1237 and then not In_Decl
1249 -- Start of processing for Make_Call_Into_Operator
1252 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1257 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1258 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1259 Save_Interps (Act1, Left_Opnd (Op_Node));
1260 Save_Interps (Act2, Right_Opnd (Op_Node));
1261 Act1 := Left_Opnd (Op_Node);
1262 Act2 := Right_Opnd (Op_Node);
1267 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1268 Save_Interps (Act1, Right_Opnd (Op_Node));
1269 Act1 := Right_Opnd (Op_Node);
1272 -- If the operator is denoted by an expanded name, and the prefix is
1273 -- not Standard, but the operator is a predefined one whose scope is
1274 -- Standard, then this is an implicit_operator, inserted as an
1275 -- interpretation by the procedure of the same name. This procedure
1276 -- overestimates the presence of implicit operators, because it does
1277 -- not examine the type of the operands. Verify now that the operand
1278 -- type appears in the given scope. If right operand is universal,
1279 -- check the other operand. In the case of concatenation, either
1280 -- argument can be the component type, so check the type of the result.
1281 -- If both arguments are literals, look for a type of the right kind
1282 -- defined in the given scope. This elaborate nonsense is brought to
1283 -- you courtesy of b33302a. The type itself must be frozen, so we must
1284 -- find the type of the proper class in the given scope.
1286 -- A final wrinkle is the multiplication operator for fixed point
1287 -- types, which is defined in Standard only, and not in the scope of
1288 -- the fixed_point type itself.
1290 if Nkind (Name (N)) = N_Expanded_Name then
1291 Pack := Entity (Prefix (Name (N)));
1293 -- If the entity being called is defined in the given package,
1294 -- it is a renaming of a predefined operator, and known to be
1297 if Scope (Entity (Name (N))) = Pack
1298 and then Pack /= Standard_Standard
1302 -- Visibility does not need to be checked in an instance: if the
1303 -- operator was not visible in the generic it has been diagnosed
1304 -- already, else there is an implicit copy of it in the instance.
1306 elsif In_Instance then
1309 elsif (Op_Name = Name_Op_Multiply
1310 or else Op_Name = Name_Op_Divide)
1311 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1312 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1314 if Pack /= Standard_Standard then
1318 -- Ada 2005, AI-420: Predefined equality on Universal_Access
1321 elsif Ada_Version >= Ada_05
1322 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1323 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1328 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1330 if Op_Name = Name_Op_Concat then
1331 Opnd_Type := Base_Type (Typ);
1333 elsif (Scope (Opnd_Type) = Standard_Standard
1335 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1337 and then not Comes_From_Source (Opnd_Type))
1339 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1342 if Scope (Opnd_Type) = Standard_Standard then
1344 -- Verify that the scope contains a type that corresponds to
1345 -- the given literal. Optimize the case where Pack is Standard.
1347 if Pack /= Standard_Standard then
1349 if Opnd_Type = Universal_Integer then
1350 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1352 elsif Opnd_Type = Universal_Real then
1353 Orig_Type := Type_In_P (Is_Real_Type'Access);
1355 elsif Opnd_Type = Any_String then
1356 Orig_Type := Type_In_P (Is_String_Type'Access);
1358 elsif Opnd_Type = Any_Access then
1359 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1361 elsif Opnd_Type = Any_Composite then
1362 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1364 if Present (Orig_Type) then
1365 if Has_Private_Component (Orig_Type) then
1368 Set_Etype (Act1, Orig_Type);
1371 Set_Etype (Act2, Orig_Type);
1380 Error := No (Orig_Type);
1383 elsif Ekind (Opnd_Type) = E_Allocator_Type
1384 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1388 -- If the type is defined elsewhere, and the operator is not
1389 -- defined in the given scope (by a renaming declaration, e.g.)
1390 -- then this is an error as well. If an extension of System is
1391 -- present, and the type may be defined there, Pack must be
1394 elsif Scope (Opnd_Type) /= Pack
1395 and then Scope (Op_Id) /= Pack
1396 and then (No (System_Aux_Id)
1397 or else Scope (Opnd_Type) /= System_Aux_Id
1398 or else Pack /= Scope (System_Aux_Id))
1400 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1403 Error := not Operand_Type_In_Scope (Pack);
1406 elsif Pack = Standard_Standard
1407 and then not Operand_Type_In_Scope (Standard_Standard)
1414 Error_Msg_Node_2 := Pack;
1416 ("& not declared in&", N, Selector_Name (Name (N)));
1417 Set_Etype (N, Any_Type);
1422 Set_Chars (Op_Node, Op_Name);
1424 if not Is_Private_Type (Etype (N)) then
1425 Set_Etype (Op_Node, Base_Type (Etype (N)));
1427 Set_Etype (Op_Node, Etype (N));
1430 -- If this is a call to a function that renames a predefined equality,
1431 -- the renaming declaration provides a type that must be used to
1432 -- resolve the operands. This must be done now because resolution of
1433 -- the equality node will not resolve any remaining ambiguity, and it
1434 -- assumes that the first operand is not overloaded.
1436 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1437 and then Ekind (Func) = E_Function
1438 and then Is_Overloaded (Act1)
1440 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1441 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1444 Set_Entity (Op_Node, Op_Id);
1445 Generate_Reference (Op_Id, N, ' ');
1447 -- Do rewrite setting Comes_From_Source on the result if the original
1448 -- call came from source. Although it is not strictly the case that the
1449 -- operator as such comes from the source, logically it corresponds
1450 -- exactly to the function call in the source, so it should be marked
1451 -- this way (e.g. to make sure that validity checks work fine).
1454 CS : constant Boolean := Comes_From_Source (N);
1456 Rewrite (N, Op_Node);
1457 Set_Comes_From_Source (N, CS);
1460 -- If this is an arithmetic operator and the result type is private,
1461 -- the operands and the result must be wrapped in conversion to
1462 -- expose the underlying numeric type and expand the proper checks,
1463 -- e.g. on division.
1465 if Is_Private_Type (Typ) then
1467 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1468 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1469 Resolve_Intrinsic_Operator (N, Typ);
1471 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1472 Resolve_Intrinsic_Unary_Operator (N, Typ);
1481 -- For predefined operators on literals, the operation freezes
1484 if Present (Orig_Type) then
1485 Set_Etype (Act1, Orig_Type);
1486 Freeze_Expression (Act1);
1488 end Make_Call_Into_Operator;
1494 function Operator_Kind
1496 Is_Binary : Boolean) return Node_Kind
1502 if Op_Name = Name_Op_And then
1504 elsif Op_Name = Name_Op_Or then
1506 elsif Op_Name = Name_Op_Xor then
1508 elsif Op_Name = Name_Op_Eq then
1510 elsif Op_Name = Name_Op_Ne then
1512 elsif Op_Name = Name_Op_Lt then
1514 elsif Op_Name = Name_Op_Le then
1516 elsif Op_Name = Name_Op_Gt then
1518 elsif Op_Name = Name_Op_Ge then
1520 elsif Op_Name = Name_Op_Add then
1522 elsif Op_Name = Name_Op_Subtract then
1523 Kind := N_Op_Subtract;
1524 elsif Op_Name = Name_Op_Concat then
1525 Kind := N_Op_Concat;
1526 elsif Op_Name = Name_Op_Multiply then
1527 Kind := N_Op_Multiply;
1528 elsif Op_Name = Name_Op_Divide then
1529 Kind := N_Op_Divide;
1530 elsif Op_Name = Name_Op_Mod then
1532 elsif Op_Name = Name_Op_Rem then
1534 elsif Op_Name = Name_Op_Expon then
1537 raise Program_Error;
1543 if Op_Name = Name_Op_Add then
1545 elsif Op_Name = Name_Op_Subtract then
1547 elsif Op_Name = Name_Op_Abs then
1549 elsif Op_Name = Name_Op_Not then
1552 raise Program_Error;
1559 ----------------------------
1560 -- Preanalyze_And_Resolve --
1561 ----------------------------
1563 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1564 Save_Full_Analysis : constant Boolean := Full_Analysis;
1567 Full_Analysis := False;
1568 Expander_Mode_Save_And_Set (False);
1570 -- We suppress all checks for this analysis, since the checks will
1571 -- be applied properly, and in the right location, when the default
1572 -- expression is reanalyzed and reexpanded later on.
1574 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1576 Expander_Mode_Restore;
1577 Full_Analysis := Save_Full_Analysis;
1578 end Preanalyze_And_Resolve;
1580 -- Version without context type
1582 procedure Preanalyze_And_Resolve (N : Node_Id) is
1583 Save_Full_Analysis : constant Boolean := Full_Analysis;
1586 Full_Analysis := False;
1587 Expander_Mode_Save_And_Set (False);
1590 Resolve (N, Etype (N), Suppress => All_Checks);
1592 Expander_Mode_Restore;
1593 Full_Analysis := Save_Full_Analysis;
1594 end Preanalyze_And_Resolve;
1596 ----------------------------------
1597 -- Replace_Actual_Discriminants --
1598 ----------------------------------
1600 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1601 Loc : constant Source_Ptr := Sloc (N);
1602 Tsk : Node_Id := Empty;
1604 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1610 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1614 if Nkind (Nod) = N_Identifier then
1615 Ent := Entity (Nod);
1618 and then Ekind (Ent) = E_Discriminant
1621 Make_Selected_Component (Loc,
1622 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1623 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1625 Set_Etype (Nod, Etype (Ent));
1633 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1635 -- Start of processing for Replace_Actual_Discriminants
1638 if not Expander_Active then
1642 if Nkind (Name (N)) = N_Selected_Component then
1643 Tsk := Prefix (Name (N));
1645 elsif Nkind (Name (N)) = N_Indexed_Component then
1646 Tsk := Prefix (Prefix (Name (N)));
1652 Replace_Discrs (Default);
1654 end Replace_Actual_Discriminants;
1660 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1661 Ambiguous : Boolean := False;
1662 Ctx_Type : Entity_Id := Typ;
1663 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1664 Err_Type : Entity_Id := Empty;
1665 Found : Boolean := False;
1668 I1 : Interp_Index := 0; -- prevent junk warning
1671 Seen : Entity_Id := Empty; -- prevent junk warning
1673 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1674 -- Determine whether a node comes from a predefined library unit or
1677 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1678 -- Try and fix up a literal so that it matches its expected type. New
1679 -- literals are manufactured if necessary to avoid cascaded errors.
1681 procedure Resolution_Failed;
1682 -- Called when attempt at resolving current expression fails
1684 ------------------------------------
1685 -- Comes_From_Predefined_Lib_Unit --
1686 -------------------------------------
1688 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1691 Sloc (Nod) = Standard_Location
1692 or else Is_Predefined_File_Name (Unit_File_Name (
1693 Get_Source_Unit (Sloc (Nod))));
1694 end Comes_From_Predefined_Lib_Unit;
1696 --------------------
1697 -- Patch_Up_Value --
1698 --------------------
1700 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1702 if Nkind (N) = N_Integer_Literal
1703 and then Is_Real_Type (Typ)
1706 Make_Real_Literal (Sloc (N),
1707 Realval => UR_From_Uint (Intval (N))));
1708 Set_Etype (N, Universal_Real);
1709 Set_Is_Static_Expression (N);
1711 elsif Nkind (N) = N_Real_Literal
1712 and then Is_Integer_Type (Typ)
1715 Make_Integer_Literal (Sloc (N),
1716 Intval => UR_To_Uint (Realval (N))));
1717 Set_Etype (N, Universal_Integer);
1718 Set_Is_Static_Expression (N);
1720 elsif Nkind (N) = N_String_Literal
1721 and then Is_Character_Type (Typ)
1723 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1725 Make_Character_Literal (Sloc (N),
1727 Char_Literal_Value =>
1728 UI_From_Int (Character'Pos ('A'))));
1729 Set_Etype (N, Any_Character);
1730 Set_Is_Static_Expression (N);
1732 elsif Nkind (N) /= N_String_Literal
1733 and then Is_String_Type (Typ)
1736 Make_String_Literal (Sloc (N),
1737 Strval => End_String));
1739 elsif Nkind (N) = N_Range then
1740 Patch_Up_Value (Low_Bound (N), Typ);
1741 Patch_Up_Value (High_Bound (N), Typ);
1745 -----------------------
1746 -- Resolution_Failed --
1747 -----------------------
1749 procedure Resolution_Failed is
1751 Patch_Up_Value (N, Typ);
1753 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1754 Set_Is_Overloaded (N, False);
1756 -- The caller will return without calling the expander, so we need
1757 -- to set the analyzed flag. Note that it is fine to set Analyzed
1758 -- to True even if we are in the middle of a shallow analysis,
1759 -- (see the spec of sem for more details) since this is an error
1760 -- situation anyway, and there is no point in repeating the
1761 -- analysis later (indeed it won't work to repeat it later, since
1762 -- we haven't got a clear resolution of which entity is being
1765 Set_Analyzed (N, True);
1767 end Resolution_Failed;
1769 -- Start of processing for Resolve
1776 -- Access attribute on remote subprogram cannot be used for
1777 -- a non-remote access-to-subprogram type.
1779 if Nkind (N) = N_Attribute_Reference
1780 and then (Attribute_Name (N) = Name_Access
1781 or else Attribute_Name (N) = Name_Unrestricted_Access
1782 or else Attribute_Name (N) = Name_Unchecked_Access)
1783 and then Comes_From_Source (N)
1784 and then Is_Entity_Name (Prefix (N))
1785 and then Is_Subprogram (Entity (Prefix (N)))
1786 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1787 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1790 ("prefix must statically denote a non-remote subprogram", N);
1793 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1795 -- If the context is a Remote_Access_To_Subprogram, access attributes
1796 -- must be resolved with the corresponding fat pointer. There is no need
1797 -- to check for the attribute name since the return type of an
1798 -- attribute is never a remote type.
1800 if Nkind (N) = N_Attribute_Reference
1801 and then Comes_From_Source (N)
1802 and then (Is_Remote_Call_Interface (Typ)
1803 or else Is_Remote_Types (Typ))
1806 Attr : constant Attribute_Id :=
1807 Get_Attribute_Id (Attribute_Name (N));
1808 Pref : constant Node_Id := Prefix (N);
1811 Is_Remote : Boolean := True;
1814 -- Check that Typ is a remote access-to-subprogram type
1816 if Is_Remote_Access_To_Subprogram_Type (Typ) then
1817 -- Prefix (N) must statically denote a remote subprogram
1818 -- declared in a package specification.
1820 if Attr = Attribute_Access then
1821 Decl := Unit_Declaration_Node (Entity (Pref));
1823 if Nkind (Decl) = N_Subprogram_Body then
1824 Spec := Corresponding_Spec (Decl);
1826 if not No (Spec) then
1827 Decl := Unit_Declaration_Node (Spec);
1831 Spec := Parent (Decl);
1833 if not Is_Entity_Name (Prefix (N))
1834 or else Nkind (Spec) /= N_Package_Specification
1836 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1840 ("prefix must statically denote a remote subprogram ",
1845 -- If we are generating code for a distributed program.
1846 -- perform semantic checks against the corresponding
1849 if (Attr = Attribute_Access
1850 or else Attr = Attribute_Unchecked_Access
1851 or else Attr = Attribute_Unrestricted_Access)
1852 and then Expander_Active
1853 and then Get_PCS_Name /= Name_No_DSA
1855 Check_Subtype_Conformant
1856 (New_Id => Entity (Prefix (N)),
1857 Old_Id => Designated_Type
1858 (Corresponding_Remote_Type (Typ)),
1862 Process_Remote_AST_Attribute (N, Typ);
1869 Debug_A_Entry ("resolving ", N);
1871 if Comes_From_Source (N) then
1872 if Is_Fixed_Point_Type (Typ) then
1873 Check_Restriction (No_Fixed_Point, N);
1875 elsif Is_Floating_Point_Type (Typ)
1876 and then Typ /= Universal_Real
1877 and then Typ /= Any_Real
1879 Check_Restriction (No_Floating_Point, N);
1883 -- Return if already analyzed
1885 if Analyzed (N) then
1886 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1889 -- Return if type = Any_Type (previous error encountered)
1891 elsif Etype (N) = Any_Type then
1892 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1896 Check_Parameterless_Call (N);
1898 -- If not overloaded, then we know the type, and all that needs doing
1899 -- is to check that this type is compatible with the context.
1901 if not Is_Overloaded (N) then
1902 Found := Covers (Typ, Etype (N));
1903 Expr_Type := Etype (N);
1905 -- In the overloaded case, we must select the interpretation that
1906 -- is compatible with the context (i.e. the type passed to Resolve)
1909 -- Loop through possible interpretations
1911 Get_First_Interp (N, I, It);
1912 Interp_Loop : while Present (It.Typ) loop
1914 -- We are only interested in interpretations that are compatible
1915 -- with the expected type, any other interpretations are ignored.
1917 if not Covers (Typ, It.Typ) then
1918 if Debug_Flag_V then
1919 Write_Str (" interpretation incompatible with context");
1924 -- Skip the current interpretation if it is disabled by an
1925 -- abstract operator. This action is performed only when the
1926 -- type against which we are resolving is the same as the
1927 -- type of the interpretation.
1929 if Ada_Version >= Ada_05
1930 and then It.Typ = Typ
1931 and then Typ /= Universal_Integer
1932 and then Typ /= Universal_Real
1933 and then Present (It.Abstract_Op)
1938 -- First matching interpretation
1944 Expr_Type := It.Typ;
1946 -- Matching interpretation that is not the first, maybe an
1947 -- error, but there are some cases where preference rules are
1948 -- used to choose between the two possibilities. These and
1949 -- some more obscure cases are handled in Disambiguate.
1952 -- If the current statement is part of a predefined library
1953 -- unit, then all interpretations which come from user level
1954 -- packages should not be considered.
1957 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
1962 Error_Msg_Sloc := Sloc (Seen);
1963 It1 := Disambiguate (N, I1, I, Typ);
1965 -- Disambiguation has succeeded. Skip the remaining
1968 if It1 /= No_Interp then
1970 Expr_Type := It1.Typ;
1972 while Present (It.Typ) loop
1973 Get_Next_Interp (I, It);
1977 -- Before we issue an ambiguity complaint, check for
1978 -- the case of a subprogram call where at least one
1979 -- of the arguments is Any_Type, and if so, suppress
1980 -- the message, since it is a cascaded error.
1982 if Nkind_In (N, N_Function_Call,
1983 N_Procedure_Call_Statement)
1990 A := First_Actual (N);
1991 while Present (A) loop
1994 if Nkind (E) = N_Parameter_Association then
1995 E := Explicit_Actual_Parameter (E);
1998 if Etype (E) = Any_Type then
1999 if Debug_Flag_V then
2000 Write_Str ("Any_Type in call");
2011 elsif Nkind (N) in N_Binary_Op
2012 and then (Etype (Left_Opnd (N)) = Any_Type
2013 or else Etype (Right_Opnd (N)) = Any_Type)
2017 elsif Nkind (N) in N_Unary_Op
2018 and then Etype (Right_Opnd (N)) = Any_Type
2023 -- Not that special case, so issue message using the
2024 -- flag Ambiguous to control printing of the header
2025 -- message only at the start of an ambiguous set.
2027 if not Ambiguous then
2028 if Nkind (N) = N_Function_Call
2029 and then Nkind (Name (N)) = N_Explicit_Dereference
2032 ("ambiguous expression "
2033 & "(cannot resolve indirect call)!", N);
2035 Error_Msg_NE -- CODEFIX
2036 ("ambiguous expression (cannot resolve&)!",
2042 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
2044 ("\\possible interpretation (inherited)#!", N);
2046 Error_Msg_N -- CODEFIX
2047 ("\\possible interpretation#!", N);
2051 Error_Msg_Sloc := Sloc (It.Nam);
2053 -- By default, the error message refers to the candidate
2054 -- interpretation. But if it is a predefined operator, it
2055 -- is implicitly declared at the declaration of the type
2056 -- of the operand. Recover the sloc of that declaration
2057 -- for the error message.
2059 if Nkind (N) in N_Op
2060 and then Scope (It.Nam) = Standard_Standard
2061 and then not Is_Overloaded (Right_Opnd (N))
2062 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2065 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2067 if Comes_From_Source (Err_Type)
2068 and then Present (Parent (Err_Type))
2070 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2073 elsif Nkind (N) in N_Binary_Op
2074 and then Scope (It.Nam) = Standard_Standard
2075 and then not Is_Overloaded (Left_Opnd (N))
2076 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2079 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2081 if Comes_From_Source (Err_Type)
2082 and then Present (Parent (Err_Type))
2084 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2087 -- If this is an indirect call, use the subprogram_type
2088 -- in the message, to have a meaningful location.
2089 -- Indicate as well if this is an inherited operation,
2090 -- created by a type declaration.
2092 elsif Nkind (N) = N_Function_Call
2093 and then Nkind (Name (N)) = N_Explicit_Dereference
2094 and then Is_Type (It.Nam)
2098 Sloc (Associated_Node_For_Itype (Err_Type));
2103 if Nkind (N) in N_Op
2104 and then Scope (It.Nam) = Standard_Standard
2105 and then Present (Err_Type)
2107 -- Special-case the message for universal_fixed
2108 -- operators, which are not declared with the type
2109 -- of the operand, but appear forever in Standard.
2111 if It.Typ = Universal_Fixed
2112 and then Scope (It.Nam) = Standard_Standard
2115 ("\\possible interpretation as " &
2116 "universal_fixed operation " &
2117 "(RM 4.5.5 (19))", N);
2120 ("\\possible interpretation (predefined)#!", N);
2124 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2127 ("\\possible interpretation (inherited)#!", N);
2129 Error_Msg_N -- CODEFIX
2130 ("\\possible interpretation#!", N);
2136 -- We have a matching interpretation, Expr_Type is the type
2137 -- from this interpretation, and Seen is the entity.
2139 -- For an operator, just set the entity name. The type will be
2140 -- set by the specific operator resolution routine.
2142 if Nkind (N) in N_Op then
2143 Set_Entity (N, Seen);
2144 Generate_Reference (Seen, N);
2146 elsif Nkind (N) = N_Character_Literal then
2147 Set_Etype (N, Expr_Type);
2149 -- For an explicit dereference, attribute reference, range,
2150 -- short-circuit form (which is not an operator node), or call
2151 -- with a name that is an explicit dereference, there is
2152 -- nothing to be done at this point.
2154 elsif Nkind_In (N, N_Explicit_Dereference,
2155 N_Attribute_Reference,
2157 N_Indexed_Component,
2160 N_Selected_Component,
2162 or else Nkind (Name (N)) = N_Explicit_Dereference
2166 -- For procedure or function calls, set the type of the name,
2167 -- and also the entity pointer for the prefix
2169 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
2170 and then (Is_Entity_Name (Name (N))
2171 or else Nkind (Name (N)) = N_Operator_Symbol)
2173 Set_Etype (Name (N), Expr_Type);
2174 Set_Entity (Name (N), Seen);
2175 Generate_Reference (Seen, Name (N));
2177 elsif Nkind (N) = N_Function_Call
2178 and then Nkind (Name (N)) = N_Selected_Component
2180 Set_Etype (Name (N), Expr_Type);
2181 Set_Entity (Selector_Name (Name (N)), Seen);
2182 Generate_Reference (Seen, Selector_Name (Name (N)));
2184 -- For all other cases, just set the type of the Name
2187 Set_Etype (Name (N), Expr_Type);
2194 -- Move to next interpretation
2196 exit Interp_Loop when No (It.Typ);
2198 Get_Next_Interp (I, It);
2199 end loop Interp_Loop;
2202 -- At this stage Found indicates whether or not an acceptable
2203 -- interpretation exists. If not, then we have an error, except
2204 -- that if the context is Any_Type as a result of some other error,
2205 -- then we suppress the error report.
2208 if Typ /= Any_Type then
2210 -- If type we are looking for is Void, then this is the procedure
2211 -- call case, and the error is simply that what we gave is not a
2212 -- procedure name (we think of procedure calls as expressions with
2213 -- types internally, but the user doesn't think of them this way!)
2215 if Typ = Standard_Void_Type then
2217 -- Special case message if function used as a procedure
2219 if Nkind (N) = N_Procedure_Call_Statement
2220 and then Is_Entity_Name (Name (N))
2221 and then Ekind (Entity (Name (N))) = E_Function
2224 ("cannot use function & in a procedure call",
2225 Name (N), Entity (Name (N)));
2227 -- Otherwise give general message (not clear what cases this
2228 -- covers, but no harm in providing for them!)
2231 Error_Msg_N ("expect procedure name in procedure call", N);
2236 -- Otherwise we do have a subexpression with the wrong type
2238 -- Check for the case of an allocator which uses an access type
2239 -- instead of the designated type. This is a common error and we
2240 -- specialize the message, posting an error on the operand of the
2241 -- allocator, complaining that we expected the designated type of
2244 elsif Nkind (N) = N_Allocator
2245 and then Ekind (Typ) in Access_Kind
2246 and then Ekind (Etype (N)) in Access_Kind
2247 and then Designated_Type (Etype (N)) = Typ
2249 Wrong_Type (Expression (N), Designated_Type (Typ));
2252 -- Check for view mismatch on Null in instances, for which the
2253 -- view-swapping mechanism has no identifier.
2255 elsif (In_Instance or else In_Inlined_Body)
2256 and then (Nkind (N) = N_Null)
2257 and then Is_Private_Type (Typ)
2258 and then Is_Access_Type (Full_View (Typ))
2260 Resolve (N, Full_View (Typ));
2264 -- Check for an aggregate. Sometimes we can get bogus aggregates
2265 -- from misuse of parentheses, and we are about to complain about
2266 -- the aggregate without even looking inside it.
2268 -- Instead, if we have an aggregate of type Any_Composite, then
2269 -- analyze and resolve the component fields, and then only issue
2270 -- another message if we get no errors doing this (otherwise
2271 -- assume that the errors in the aggregate caused the problem).
2273 elsif Nkind (N) = N_Aggregate
2274 and then Etype (N) = Any_Composite
2276 -- Disable expansion in any case. If there is a type mismatch
2277 -- it may be fatal to try to expand the aggregate. The flag
2278 -- would otherwise be set to false when the error is posted.
2280 Expander_Active := False;
2283 procedure Check_Aggr (Aggr : Node_Id);
2284 -- Check one aggregate, and set Found to True if we have a
2285 -- definite error in any of its elements
2287 procedure Check_Elmt (Aelmt : Node_Id);
2288 -- Check one element of aggregate and set Found to True if
2289 -- we definitely have an error in the element.
2295 procedure Check_Aggr (Aggr : Node_Id) is
2299 if Present (Expressions (Aggr)) then
2300 Elmt := First (Expressions (Aggr));
2301 while Present (Elmt) loop
2307 if Present (Component_Associations (Aggr)) then
2308 Elmt := First (Component_Associations (Aggr));
2309 while Present (Elmt) loop
2311 -- If this is a default-initialized component, then
2312 -- there is nothing to check. The box will be
2313 -- replaced by the appropriate call during late
2316 if not Box_Present (Elmt) then
2317 Check_Elmt (Expression (Elmt));
2329 procedure Check_Elmt (Aelmt : Node_Id) is
2331 -- If we have a nested aggregate, go inside it (to
2332 -- attempt a naked analyze-resolve of the aggregate
2333 -- can cause undesirable cascaded errors). Do not
2334 -- resolve expression if it needs a type from context,
2335 -- as for integer * fixed expression.
2337 if Nkind (Aelmt) = N_Aggregate then
2343 if not Is_Overloaded (Aelmt)
2344 and then Etype (Aelmt) /= Any_Fixed
2349 if Etype (Aelmt) = Any_Type then
2360 -- If an error message was issued already, Found got reset
2361 -- to True, so if it is still False, issue the standard
2362 -- Wrong_Type message.
2365 if Is_Overloaded (N)
2366 and then Nkind (N) = N_Function_Call
2369 Subp_Name : Node_Id;
2371 if Is_Entity_Name (Name (N)) then
2372 Subp_Name := Name (N);
2374 elsif Nkind (Name (N)) = N_Selected_Component then
2376 -- Protected operation: retrieve operation name
2378 Subp_Name := Selector_Name (Name (N));
2380 raise Program_Error;
2383 Error_Msg_Node_2 := Typ;
2384 Error_Msg_NE ("no visible interpretation of&" &
2385 " matches expected type&", N, Subp_Name);
2388 if All_Errors_Mode then
2390 Index : Interp_Index;
2394 Error_Msg_N ("\\possible interpretations:", N);
2396 Get_First_Interp (Name (N), Index, It);
2397 while Present (It.Nam) loop
2398 Error_Msg_Sloc := Sloc (It.Nam);
2399 Error_Msg_Node_2 := It.Nam;
2401 ("\\ type& for & declared#", N, It.Typ);
2402 Get_Next_Interp (Index, It);
2407 Error_Msg_N ("\use -gnatf for details", N);
2410 Wrong_Type (N, Typ);
2418 -- Test if we have more than one interpretation for the context
2420 elsif Ambiguous then
2424 -- Here we have an acceptable interpretation for the context
2427 -- Propagate type information and normalize tree for various
2428 -- predefined operations. If the context only imposes a class of
2429 -- types, rather than a specific type, propagate the actual type
2432 if Typ = Any_Integer
2433 or else Typ = Any_Boolean
2434 or else Typ = Any_Modular
2435 or else Typ = Any_Real
2436 or else Typ = Any_Discrete
2438 Ctx_Type := Expr_Type;
2440 -- Any_Fixed is legal in a real context only if a specific
2441 -- fixed point type is imposed. If Norman Cohen can be
2442 -- confused by this, it deserves a separate message.
2445 and then Expr_Type = Any_Fixed
2447 Error_Msg_N ("illegal context for mixed mode operation", N);
2448 Set_Etype (N, Universal_Real);
2449 Ctx_Type := Universal_Real;
2453 -- A user-defined operator is transformed into a function call at
2454 -- this point, so that further processing knows that operators are
2455 -- really operators (i.e. are predefined operators). User-defined
2456 -- operators that are intrinsic are just renamings of the predefined
2457 -- ones, and need not be turned into calls either, but if they rename
2458 -- a different operator, we must transform the node accordingly.
2459 -- Instantiations of Unchecked_Conversion are intrinsic but are
2460 -- treated as functions, even if given an operator designator.
2462 if Nkind (N) in N_Op
2463 and then Present (Entity (N))
2464 and then Ekind (Entity (N)) /= E_Operator
2467 if not Is_Predefined_Op (Entity (N)) then
2468 Rewrite_Operator_As_Call (N, Entity (N));
2470 elsif Present (Alias (Entity (N)))
2472 Nkind (Parent (Parent (Entity (N)))) =
2473 N_Subprogram_Renaming_Declaration
2475 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2477 -- If the node is rewritten, it will be fully resolved in
2478 -- Rewrite_Renamed_Operator.
2480 if Analyzed (N) then
2486 case N_Subexpr'(Nkind (N)) is
2488 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2490 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2492 when N_And_Then | N_Or_Else
2493 => Resolve_Short_Circuit (N, Ctx_Type);
2495 when N_Attribute_Reference
2496 => Resolve_Attribute (N, Ctx_Type);
2498 when N_Character_Literal
2499 => Resolve_Character_Literal (N, Ctx_Type);
2501 when N_Conditional_Expression
2502 => Resolve_Conditional_Expression (N, Ctx_Type);
2504 when N_Expanded_Name
2505 => Resolve_Entity_Name (N, Ctx_Type);
2507 when N_Extension_Aggregate
2508 => Resolve_Extension_Aggregate (N, Ctx_Type);
2510 when N_Explicit_Dereference
2511 => Resolve_Explicit_Dereference (N, Ctx_Type);
2513 when N_Function_Call
2514 => Resolve_Call (N, Ctx_Type);
2517 => Resolve_Entity_Name (N, Ctx_Type);
2519 when N_Indexed_Component
2520 => Resolve_Indexed_Component (N, Ctx_Type);
2522 when N_Integer_Literal
2523 => Resolve_Integer_Literal (N, Ctx_Type);
2525 when N_Membership_Test
2526 => Resolve_Membership_Op (N, Ctx_Type);
2528 when N_Null => Resolve_Null (N, Ctx_Type);
2530 when N_Op_And | N_Op_Or | N_Op_Xor
2531 => Resolve_Logical_Op (N, Ctx_Type);
2533 when N_Op_Eq | N_Op_Ne
2534 => Resolve_Equality_Op (N, Ctx_Type);
2536 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2537 => Resolve_Comparison_Op (N, Ctx_Type);
2539 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2541 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2542 N_Op_Divide | N_Op_Mod | N_Op_Rem
2544 => Resolve_Arithmetic_Op (N, Ctx_Type);
2546 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2548 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2550 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2551 => Resolve_Unary_Op (N, Ctx_Type);
2553 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2555 when N_Procedure_Call_Statement
2556 => Resolve_Call (N, Ctx_Type);
2558 when N_Operator_Symbol
2559 => Resolve_Operator_Symbol (N, Ctx_Type);
2561 when N_Qualified_Expression
2562 => Resolve_Qualified_Expression (N, Ctx_Type);
2564 when N_Raise_xxx_Error
2565 => Set_Etype (N, Ctx_Type);
2567 when N_Range => Resolve_Range (N, Ctx_Type);
2570 => Resolve_Real_Literal (N, Ctx_Type);
2572 when N_Reference => Resolve_Reference (N, Ctx_Type);
2574 when N_Selected_Component
2575 => Resolve_Selected_Component (N, Ctx_Type);
2577 when N_Slice => Resolve_Slice (N, Ctx_Type);
2579 when N_String_Literal
2580 => Resolve_String_Literal (N, Ctx_Type);
2582 when N_Subprogram_Info
2583 => Resolve_Subprogram_Info (N, Ctx_Type);
2585 when N_Type_Conversion
2586 => Resolve_Type_Conversion (N, Ctx_Type);
2588 when N_Unchecked_Expression =>
2589 Resolve_Unchecked_Expression (N, Ctx_Type);
2591 when N_Unchecked_Type_Conversion =>
2592 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2596 -- If the subexpression was replaced by a non-subexpression, then
2597 -- all we do is to expand it. The only legitimate case we know of
2598 -- is converting procedure call statement to entry call statements,
2599 -- but there may be others, so we are making this test general.
2601 if Nkind (N) not in N_Subexpr then
2602 Debug_A_Exit ("resolving ", N, " (done)");
2607 -- The expression is definitely NOT overloaded at this point, so
2608 -- we reset the Is_Overloaded flag to avoid any confusion when
2609 -- reanalyzing the node.
2611 Set_Is_Overloaded (N, False);
2613 -- Freeze expression type, entity if it is a name, and designated
2614 -- type if it is an allocator (RM 13.14(10,11,13)).
2616 -- Now that the resolution of the type of the node is complete,
2617 -- and we did not detect an error, we can expand this node. We
2618 -- skip the expand call if we are in a default expression, see
2619 -- section "Handling of Default Expressions" in Sem spec.
2621 Debug_A_Exit ("resolving ", N, " (done)");
2623 -- We unconditionally freeze the expression, even if we are in
2624 -- default expression mode (the Freeze_Expression routine tests
2625 -- this flag and only freezes static types if it is set).
2627 Freeze_Expression (N);
2629 -- Now we can do the expansion
2639 -- Version with check(s) suppressed
2641 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2643 if Suppress = All_Checks then
2645 Svg : constant Suppress_Array := Scope_Suppress;
2647 Scope_Suppress := (others => True);
2649 Scope_Suppress := Svg;
2654 Svg : constant Boolean := Scope_Suppress (Suppress);
2656 Scope_Suppress (Suppress) := True;
2658 Scope_Suppress (Suppress) := Svg;
2667 -- Version with implicit type
2669 procedure Resolve (N : Node_Id) is
2671 Resolve (N, Etype (N));
2674 ---------------------
2675 -- Resolve_Actuals --
2676 ---------------------
2678 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2679 Loc : constant Source_Ptr := Sloc (N);
2684 Prev : Node_Id := Empty;
2687 procedure Check_Argument_Order;
2688 -- Performs a check for the case where the actuals are all simple
2689 -- identifiers that correspond to the formal names, but in the wrong
2690 -- order, which is considered suspicious and cause for a warning.
2692 procedure Check_Prefixed_Call;
2693 -- If the original node is an overloaded call in prefix notation,
2694 -- insert an 'Access or a dereference as needed over the first actual.
2695 -- Try_Object_Operation has already verified that there is a valid
2696 -- interpretation, but the form of the actual can only be determined
2697 -- once the primitive operation is identified.
2699 procedure Insert_Default;
2700 -- If the actual is missing in a call, insert in the actuals list
2701 -- an instance of the default expression. The insertion is always
2702 -- a named association.
2704 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2705 -- Check whether T1 and T2, or their full views, are derived from a
2706 -- common type. Used to enforce the restrictions on array conversions
2709 function Static_Concatenation (N : Node_Id) return Boolean;
2710 -- Predicate to determine whether an actual that is a concatenation
2711 -- will be evaluated statically and does not need a transient scope.
2712 -- This must be determined before the actual is resolved and expanded
2713 -- because if needed the transient scope must be introduced earlier.
2715 --------------------------
2716 -- Check_Argument_Order --
2717 --------------------------
2719 procedure Check_Argument_Order is
2721 -- Nothing to do if no parameters, or original node is neither a
2722 -- function call nor a procedure call statement (happens in the
2723 -- operator-transformed-to-function call case), or the call does
2724 -- not come from source, or this warning is off.
2726 if not Warn_On_Parameter_Order
2728 No (Parameter_Associations (N))
2730 not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2733 not Comes_From_Source (N)
2739 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2742 -- Nothing to do if only one parameter
2748 -- Here if at least two arguments
2751 Actuals : array (1 .. Nargs) of Node_Id;
2755 Wrong_Order : Boolean := False;
2756 -- Set True if an out of order case is found
2759 -- Collect identifier names of actuals, fail if any actual is
2760 -- not a simple identifier, and record max length of name.
2762 Actual := First (Parameter_Associations (N));
2763 for J in Actuals'Range loop
2764 if Nkind (Actual) /= N_Identifier then
2767 Actuals (J) := Actual;
2772 -- If we got this far, all actuals are identifiers and the list
2773 -- of their names is stored in the Actuals array.
2775 Formal := First_Formal (Nam);
2776 for J in Actuals'Range loop
2778 -- If we ran out of formals, that's odd, probably an error
2779 -- which will be detected elsewhere, but abandon the search.
2785 -- If name matches and is in order OK
2787 if Chars (Formal) = Chars (Actuals (J)) then
2791 -- If no match, see if it is elsewhere in list and if so
2792 -- flag potential wrong order if type is compatible.
2794 for K in Actuals'Range loop
2795 if Chars (Formal) = Chars (Actuals (K))
2797 Has_Compatible_Type (Actuals (K), Etype (Formal))
2799 Wrong_Order := True;
2809 <<Continue>> Next_Formal (Formal);
2812 -- If Formals left over, also probably an error, skip warning
2814 if Present (Formal) then
2818 -- Here we give the warning if something was out of order
2822 ("actuals for this call may be in wrong order?", N);
2826 end Check_Argument_Order;
2828 -------------------------
2829 -- Check_Prefixed_Call --
2830 -------------------------
2832 procedure Check_Prefixed_Call is
2833 Act : constant Node_Id := First_Actual (N);
2834 A_Type : constant Entity_Id := Etype (Act);
2835 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2836 Orig : constant Node_Id := Original_Node (N);
2840 -- Check whether the call is a prefixed call, with or without
2841 -- additional actuals.
2843 if Nkind (Orig) = N_Selected_Component
2845 (Nkind (Orig) = N_Indexed_Component
2846 and then Nkind (Prefix (Orig)) = N_Selected_Component
2847 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2848 and then Is_Entity_Name (Act)
2849 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
2851 if Is_Access_Type (A_Type)
2852 and then not Is_Access_Type (F_Type)
2854 -- Introduce dereference on object in prefix
2857 Make_Explicit_Dereference (Sloc (Act),
2858 Prefix => Relocate_Node (Act));
2859 Rewrite (Act, New_A);
2862 elsif Is_Access_Type (F_Type)
2863 and then not Is_Access_Type (A_Type)
2865 -- Introduce an implicit 'Access in prefix
2867 if not Is_Aliased_View (Act) then
2869 ("object in prefixed call to& must be aliased"
2870 & " (RM-2005 4.3.1 (13))",
2875 Make_Attribute_Reference (Loc,
2876 Attribute_Name => Name_Access,
2877 Prefix => Relocate_Node (Act)));
2882 end Check_Prefixed_Call;
2884 --------------------
2885 -- Insert_Default --
2886 --------------------
2888 procedure Insert_Default is
2893 -- Missing argument in call, nothing to insert
2895 if No (Default_Value (F)) then
2899 -- Note that we do a full New_Copy_Tree, so that any associated
2900 -- Itypes are properly copied. This may not be needed any more,
2901 -- but it does no harm as a safety measure! Defaults of a generic
2902 -- formal may be out of bounds of the corresponding actual (see
2903 -- cc1311b) and an additional check may be required.
2908 New_Scope => Current_Scope,
2911 if Is_Concurrent_Type (Scope (Nam))
2912 and then Has_Discriminants (Scope (Nam))
2914 Replace_Actual_Discriminants (N, Actval);
2917 if Is_Overloadable (Nam)
2918 and then Present (Alias (Nam))
2920 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2921 and then not Is_Tagged_Type (Etype (F))
2923 -- If default is a real literal, do not introduce a
2924 -- conversion whose effect may depend on the run-time
2925 -- size of universal real.
2927 if Nkind (Actval) = N_Real_Literal then
2928 Set_Etype (Actval, Base_Type (Etype (F)));
2930 Actval := Unchecked_Convert_To (Etype (F), Actval);
2934 if Is_Scalar_Type (Etype (F)) then
2935 Enable_Range_Check (Actval);
2938 Set_Parent (Actval, N);
2940 -- Resolve aggregates with their base type, to avoid scope
2941 -- anomalies: the subtype was first built in the subprogram
2942 -- declaration, and the current call may be nested.
2944 if Nkind (Actval) = N_Aggregate
2945 and then Has_Discriminants (Etype (Actval))
2947 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2949 Analyze_And_Resolve (Actval, Etype (Actval));
2953 Set_Parent (Actval, N);
2955 -- See note above concerning aggregates
2957 if Nkind (Actval) = N_Aggregate
2958 and then Has_Discriminants (Etype (Actval))
2960 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2962 -- Resolve entities with their own type, which may differ
2963 -- from the type of a reference in a generic context (the
2964 -- view swapping mechanism did not anticipate the re-analysis
2965 -- of default values in calls).
2967 elsif Is_Entity_Name (Actval) then
2968 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2971 Analyze_And_Resolve (Actval, Etype (Actval));
2975 -- If default is a tag indeterminate function call, propagate
2976 -- tag to obtain proper dispatching.
2978 if Is_Controlling_Formal (F)
2979 and then Nkind (Default_Value (F)) = N_Function_Call
2981 Set_Is_Controlling_Actual (Actval);
2986 -- If the default expression raises constraint error, then just
2987 -- silently replace it with an N_Raise_Constraint_Error node,
2988 -- since we already gave the warning on the subprogram spec.
2990 if Raises_Constraint_Error (Actval) then
2992 Make_Raise_Constraint_Error (Loc,
2993 Reason => CE_Range_Check_Failed));
2994 Set_Raises_Constraint_Error (Actval);
2995 Set_Etype (Actval, Etype (F));
2999 Make_Parameter_Association (Loc,
3000 Explicit_Actual_Parameter => Actval,
3001 Selector_Name => Make_Identifier (Loc, Chars (F)));
3003 -- Case of insertion is first named actual
3005 if No (Prev) or else
3006 Nkind (Parent (Prev)) /= N_Parameter_Association
3008 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3009 Set_First_Named_Actual (N, Actval);
3012 if No (Parameter_Associations (N)) then
3013 Set_Parameter_Associations (N, New_List (Assoc));
3015 Append (Assoc, Parameter_Associations (N));
3019 Insert_After (Prev, Assoc);
3022 -- Case of insertion is not first named actual
3025 Set_Next_Named_Actual
3026 (Assoc, Next_Named_Actual (Parent (Prev)));
3027 Set_Next_Named_Actual (Parent (Prev), Actval);
3028 Append (Assoc, Parameter_Associations (N));
3031 Mark_Rewrite_Insertion (Assoc);
3032 Mark_Rewrite_Insertion (Actval);
3041 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3042 FT1 : Entity_Id := T1;
3043 FT2 : Entity_Id := T2;
3046 if Is_Private_Type (T1)
3047 and then Present (Full_View (T1))
3049 FT1 := Full_View (T1);
3052 if Is_Private_Type (T2)
3053 and then Present (Full_View (T2))
3055 FT2 := Full_View (T2);
3058 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3061 --------------------------
3062 -- Static_Concatenation --
3063 --------------------------
3065 function Static_Concatenation (N : Node_Id) return Boolean is
3068 when N_String_Literal =>
3073 -- Concatenation is static when both operands are static
3074 -- and the concatenation operator is a predefined one.
3076 return Scope (Entity (N)) = Standard_Standard
3078 Static_Concatenation (Left_Opnd (N))
3080 Static_Concatenation (Right_Opnd (N));
3083 if Is_Entity_Name (N) then
3085 Ent : constant Entity_Id := Entity (N);
3087 return Ekind (Ent) = E_Constant
3088 and then Present (Constant_Value (Ent))
3090 Is_Static_Expression (Constant_Value (Ent));
3097 end Static_Concatenation;
3099 -- Start of processing for Resolve_Actuals
3102 Check_Argument_Order;
3104 if Present (First_Actual (N)) then
3105 Check_Prefixed_Call;
3108 A := First_Actual (N);
3109 F := First_Formal (Nam);
3110 while Present (F) loop
3111 if No (A) and then Needs_No_Actuals (Nam) then
3114 -- If we have an error in any actual or formal, indicated by a type
3115 -- of Any_Type, then abandon resolution attempt, and set result type
3118 elsif (Present (A) and then Etype (A) = Any_Type)
3119 or else Etype (F) = Any_Type
3121 Set_Etype (N, Any_Type);
3125 -- Case where actual is present
3127 -- If the actual is an entity, generate a reference to it now. We
3128 -- do this before the actual is resolved, because a formal of some
3129 -- protected subprogram, or a task discriminant, will be rewritten
3130 -- during expansion, and the reference to the source entity may
3134 and then Is_Entity_Name (A)
3135 and then Comes_From_Source (N)
3137 Orig_A := Entity (A);
3139 if Present (Orig_A) then
3140 if Is_Formal (Orig_A)
3141 and then Ekind (F) /= E_In_Parameter
3143 Generate_Reference (Orig_A, A, 'm');
3144 elsif not Is_Overloaded (A) then
3145 Generate_Reference (Orig_A, A);
3151 and then (Nkind (Parent (A)) /= N_Parameter_Association
3153 Chars (Selector_Name (Parent (A))) = Chars (F))
3155 -- If style checking mode on, check match of formal name
3158 if Nkind (Parent (A)) = N_Parameter_Association then
3159 Check_Identifier (Selector_Name (Parent (A)), F);
3163 -- If the formal is Out or In_Out, do not resolve and expand the
3164 -- conversion, because it is subsequently expanded into explicit
3165 -- temporaries and assignments. However, the object of the
3166 -- conversion can be resolved. An exception is the case of tagged
3167 -- type conversion with a class-wide actual. In that case we want
3168 -- the tag check to occur and no temporary will be needed (no
3169 -- representation change can occur) and the parameter is passed by
3170 -- reference, so we go ahead and resolve the type conversion.
3171 -- Another exception is the case of reference to component or
3172 -- subcomponent of a bit-packed array, in which case we want to
3173 -- defer expansion to the point the in and out assignments are
3176 if Ekind (F) /= E_In_Parameter
3177 and then Nkind (A) = N_Type_Conversion
3178 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3180 if Ekind (F) = E_In_Out_Parameter
3181 and then Is_Array_Type (Etype (F))
3183 if Has_Aliased_Components (Etype (Expression (A)))
3184 /= Has_Aliased_Components (Etype (F))
3187 -- In a view conversion, the conversion must be legal in
3188 -- both directions, and thus both component types must be
3189 -- aliased, or neither (4.6 (8)).
3191 -- The additional rule 4.6 (24.9.2) seems unduly
3192 -- restrictive: the privacy requirement should not apply
3193 -- to generic types, and should be checked in an
3194 -- instance. ARG query is in order ???
3197 ("both component types in a view conversion must be"
3198 & " aliased, or neither", A);
3201 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3203 if Is_By_Reference_Type (Etype (F))
3204 or else Is_By_Reference_Type (Etype (Expression (A)))
3207 ("view conversion between unrelated by reference " &
3208 "array types not allowed (\'A'I-00246)", A);
3211 Comp_Type : constant Entity_Id :=
3213 (Etype (Expression (A)));
3215 if Comes_From_Source (A)
3216 and then Ada_Version >= Ada_05
3218 ((Is_Private_Type (Comp_Type)
3219 and then not Is_Generic_Type (Comp_Type))
3220 or else Is_Tagged_Type (Comp_Type)
3221 or else Is_Volatile (Comp_Type))
3224 ("component type of a view conversion cannot"
3225 & " be private, tagged, or volatile"
3234 if (Conversion_OK (A)
3235 or else Valid_Conversion (A, Etype (A), Expression (A)))
3236 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
3238 Resolve (Expression (A));
3241 -- If the actual is a function call that returns a limited
3242 -- unconstrained object that needs finalization, create a
3243 -- transient scope for it, so that it can receive the proper
3244 -- finalization list.
3246 elsif Nkind (A) = N_Function_Call
3247 and then Is_Limited_Record (Etype (F))
3248 and then not Is_Constrained (Etype (F))
3249 and then Expander_Active
3251 (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
3253 Establish_Transient_Scope (A, False);
3255 -- A small optimization: if one of the actuals is a concatenation
3256 -- create a block around a procedure call to recover stack space.
3257 -- This alleviates stack usage when several procedure calls in
3258 -- the same statement list use concatenation. We do not perform
3259 -- this wrapping for code statements, where the argument is a
3260 -- static string, and we want to preserve warnings involving
3261 -- sequences of such statements.
3263 elsif Nkind (A) = N_Op_Concat
3264 and then Nkind (N) = N_Procedure_Call_Statement
3265 and then Expander_Active
3267 not (Is_Intrinsic_Subprogram (Nam)
3268 and then Chars (Nam) = Name_Asm)
3269 and then not Static_Concatenation (A)
3271 Establish_Transient_Scope (A, False);
3272 Resolve (A, Etype (F));
3275 if Nkind (A) = N_Type_Conversion
3276 and then Is_Array_Type (Etype (F))
3277 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3279 (Is_Limited_Type (Etype (F))
3280 or else Is_Limited_Type (Etype (Expression (A))))
3283 ("conversion between unrelated limited array types " &
3284 "not allowed (\A\I-00246)", A);
3286 if Is_Limited_Type (Etype (F)) then
3287 Explain_Limited_Type (Etype (F), A);
3290 if Is_Limited_Type (Etype (Expression (A))) then
3291 Explain_Limited_Type (Etype (Expression (A)), A);
3295 -- (Ada 2005: AI-251): If the actual is an allocator whose
3296 -- directly designated type is a class-wide interface, we build
3297 -- an anonymous access type to use it as the type of the
3298 -- allocator. Later, when the subprogram call is expanded, if
3299 -- the interface has a secondary dispatch table the expander
3300 -- will add a type conversion to force the correct displacement
3303 if Nkind (A) = N_Allocator then
3305 DDT : constant Entity_Id :=
3306 Directly_Designated_Type (Base_Type (Etype (F)));
3308 New_Itype : Entity_Id;
3311 if Is_Class_Wide_Type (DDT)
3312 and then Is_Interface (DDT)
3314 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
3315 Set_Etype (New_Itype, Etype (A));
3316 Set_Directly_Designated_Type (New_Itype,
3317 Directly_Designated_Type (Etype (A)));
3318 Set_Etype (A, New_Itype);
3321 -- Ada 2005, AI-162:If the actual is an allocator, the
3322 -- innermost enclosing statement is the master of the
3323 -- created object. This needs to be done with expansion
3324 -- enabled only, otherwise the transient scope will not
3325 -- be removed in the expansion of the wrapped construct.
3327 if (Is_Controlled (DDT) or else Has_Task (DDT))
3328 and then Expander_Active
3330 Establish_Transient_Scope (A, False);
3335 -- (Ada 2005): The call may be to a primitive operation of
3336 -- a tagged synchronized type, declared outside of the type.
3337 -- In this case the controlling actual must be converted to
3338 -- its corresponding record type, which is the formal type.
3339 -- The actual may be a subtype, either because of a constraint
3340 -- or because it is a generic actual, so use base type to
3341 -- locate concurrent type.
3343 A_Typ := Base_Type (Etype (A));
3344 F_Typ := Base_Type (Etype (F));
3347 Full_A_Typ : Entity_Id;
3350 if Present (Full_View (A_Typ)) then
3351 Full_A_Typ := Base_Type (Full_View (A_Typ));
3353 Full_A_Typ := A_Typ;
3356 -- Tagged synchronized type (case 1): the actual is a
3359 if Is_Concurrent_Type (A_Typ)
3360 and then Corresponding_Record_Type (A_Typ) = F_Typ
3363 Unchecked_Convert_To
3364 (Corresponding_Record_Type (A_Typ), A));
3365 Resolve (A, Etype (F));
3367 -- Tagged synchronized type (case 2): the formal is a
3370 elsif Ekind (Full_A_Typ) = E_Record_Type
3372 (Corresponding_Concurrent_Type (Full_A_Typ))
3373 and then Is_Concurrent_Type (F_Typ)
3374 and then Present (Corresponding_Record_Type (F_Typ))
3375 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3377 Resolve (A, Corresponding_Record_Type (F_Typ));
3382 Resolve (A, Etype (F));
3390 -- For mode IN, if actual is an entity, and the type of the formal
3391 -- has warnings suppressed, then we reset Never_Set_In_Source for
3392 -- the calling entity. The reason for this is to catch cases like
3393 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3394 -- uses trickery to modify an IN parameter.
3396 if Ekind (F) = E_In_Parameter
3397 and then Is_Entity_Name (A)
3398 and then Present (Entity (A))
3399 and then Ekind (Entity (A)) = E_Variable
3400 and then Has_Warnings_Off (F_Typ)
3402 Set_Never_Set_In_Source (Entity (A), False);
3405 -- Perform error checks for IN and IN OUT parameters
3407 if Ekind (F) /= E_Out_Parameter then
3409 -- Check unset reference. For scalar parameters, it is clearly
3410 -- wrong to pass an uninitialized value as either an IN or
3411 -- IN-OUT parameter. For composites, it is also clearly an
3412 -- error to pass a completely uninitialized value as an IN
3413 -- parameter, but the case of IN OUT is trickier. We prefer
3414 -- not to give a warning here. For example, suppose there is
3415 -- a routine that sets some component of a record to False.
3416 -- It is perfectly reasonable to make this IN-OUT and allow
3417 -- either initialized or uninitialized records to be passed
3420 -- For partially initialized composite values, we also avoid
3421 -- warnings, since it is quite likely that we are passing a
3422 -- partially initialized value and only the initialized fields
3423 -- will in fact be read in the subprogram.
3425 if Is_Scalar_Type (A_Typ)
3426 or else (Ekind (F) = E_In_Parameter
3427 and then not Is_Partially_Initialized_Type (A_Typ))
3429 Check_Unset_Reference (A);
3432 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3433 -- actual to a nested call, since this is case of reading an
3434 -- out parameter, which is not allowed.
3436 if Ada_Version = Ada_83
3437 and then Is_Entity_Name (A)
3438 and then Ekind (Entity (A)) = E_Out_Parameter
3440 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3444 -- Case of OUT or IN OUT parameter
3446 if Ekind (F) /= E_In_Parameter then
3448 -- For an Out parameter, check for useless assignment. Note
3449 -- that we can't set Last_Assignment this early, because we may
3450 -- kill current values in Resolve_Call, and that call would
3451 -- clobber the Last_Assignment field.
3453 -- Note: call Warn_On_Useless_Assignment before doing the check
3454 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3455 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3456 -- reflects the last assignment, not this one!
3458 if Ekind (F) = E_Out_Parameter then
3459 if Warn_On_Modified_As_Out_Parameter (F)
3460 and then Is_Entity_Name (A)
3461 and then Present (Entity (A))
3462 and then Comes_From_Source (N)
3464 Warn_On_Useless_Assignment (Entity (A), A);
3468 -- Validate the form of the actual. Note that the call to
3469 -- Is_OK_Variable_For_Out_Formal generates the required
3470 -- reference in this case.
3472 if not Is_OK_Variable_For_Out_Formal (A) then
3473 Error_Msg_NE ("actual for& must be a variable", A, F);
3476 -- What's the following about???
3478 if Is_Entity_Name (A) then
3479 Kill_Checks (Entity (A));
3485 if Etype (A) = Any_Type then
3486 Set_Etype (N, Any_Type);
3490 -- Apply appropriate range checks for in, out, and in-out
3491 -- parameters. Out and in-out parameters also need a separate
3492 -- check, if there is a type conversion, to make sure the return
3493 -- value meets the constraints of the variable before the
3496 -- Gigi looks at the check flag and uses the appropriate types.
3497 -- For now since one flag is used there is an optimization which
3498 -- might not be done in the In Out case since Gigi does not do
3499 -- any analysis. More thought required about this ???
3501 if Ekind (F) = E_In_Parameter
3502 or else Ekind (F) = E_In_Out_Parameter
3504 if Is_Scalar_Type (Etype (A)) then
3505 Apply_Scalar_Range_Check (A, F_Typ);
3507 elsif Is_Array_Type (Etype (A)) then
3508 Apply_Length_Check (A, F_Typ);
3510 elsif Is_Record_Type (F_Typ)
3511 and then Has_Discriminants (F_Typ)
3512 and then Is_Constrained (F_Typ)
3513 and then (not Is_Derived_Type (F_Typ)
3514 or else Comes_From_Source (Nam))
3516 Apply_Discriminant_Check (A, F_Typ);
3518 elsif Is_Access_Type (F_Typ)
3519 and then Is_Array_Type (Designated_Type (F_Typ))
3520 and then Is_Constrained (Designated_Type (F_Typ))
3522 Apply_Length_Check (A, F_Typ);
3524 elsif Is_Access_Type (F_Typ)
3525 and then Has_Discriminants (Designated_Type (F_Typ))
3526 and then Is_Constrained (Designated_Type (F_Typ))
3528 Apply_Discriminant_Check (A, F_Typ);
3531 Apply_Range_Check (A, F_Typ);
3534 -- Ada 2005 (AI-231)
3536 if Ada_Version >= Ada_05
3537 and then Is_Access_Type (F_Typ)
3538 and then Can_Never_Be_Null (F_Typ)
3539 and then Known_Null (A)
3541 Apply_Compile_Time_Constraint_Error
3543 Msg => "(Ada 2005) null not allowed in "
3544 & "null-excluding formal?",
3545 Reason => CE_Null_Not_Allowed);
3549 if Ekind (F) = E_Out_Parameter
3550 or else Ekind (F) = E_In_Out_Parameter
3552 if Nkind (A) = N_Type_Conversion then
3553 if Is_Scalar_Type (A_Typ) then
3554 Apply_Scalar_Range_Check
3555 (Expression (A), Etype (Expression (A)), A_Typ);
3558 (Expression (A), Etype (Expression (A)), A_Typ);
3562 if Is_Scalar_Type (F_Typ) then
3563 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
3565 elsif Is_Array_Type (F_Typ)
3566 and then Ekind (F) = E_Out_Parameter
3568 Apply_Length_Check (A, F_Typ);
3571 Apply_Range_Check (A, A_Typ, F_Typ);
3576 -- An actual associated with an access parameter is implicitly
3577 -- converted to the anonymous access type of the formal and must
3578 -- satisfy the legality checks for access conversions.
3580 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3581 if not Valid_Conversion (A, F_Typ, A) then
3583 ("invalid implicit conversion for access parameter", A);
3587 -- Check bad case of atomic/volatile argument (RM C.6(12))
3589 if Is_By_Reference_Type (Etype (F))
3590 and then Comes_From_Source (N)
3592 if Is_Atomic_Object (A)
3593 and then not Is_Atomic (Etype (F))
3596 ("cannot pass atomic argument to non-atomic formal",
3599 elsif Is_Volatile_Object (A)
3600 and then not Is_Volatile (Etype (F))
3603 ("cannot pass volatile argument to non-volatile formal",
3608 -- Check that subprograms don't have improper controlling
3609 -- arguments (RM 3.9.2 (9)).
3611 -- A primitive operation may have an access parameter of an
3612 -- incomplete tagged type, but a dispatching call is illegal
3613 -- if the type is still incomplete.
3615 if Is_Controlling_Formal (F) then
3616 Set_Is_Controlling_Actual (A);
3618 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3620 Desig : constant Entity_Id := Designated_Type (Etype (F));
3622 if Ekind (Desig) = E_Incomplete_Type
3623 and then No (Full_View (Desig))
3624 and then No (Non_Limited_View (Desig))
3627 ("premature use of incomplete type& " &
3628 "in dispatching call", A, Desig);
3633 elsif Nkind (A) = N_Explicit_Dereference then
3634 Validate_Remote_Access_To_Class_Wide_Type (A);
3637 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3638 and then not Is_Class_Wide_Type (F_Typ)
3639 and then not Is_Controlling_Formal (F)
3641 Error_Msg_N ("class-wide argument not allowed here!", A);
3643 if Is_Subprogram (Nam)
3644 and then Comes_From_Source (Nam)
3646 Error_Msg_Node_2 := F_Typ;
3648 ("& is not a dispatching operation of &!", A, Nam);
3651 elsif Is_Access_Type (A_Typ)
3652 and then Is_Access_Type (F_Typ)
3653 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
3654 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
3655 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
3656 or else (Nkind (A) = N_Attribute_Reference
3658 Is_Class_Wide_Type (Etype (Prefix (A)))))
3659 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3660 and then not Is_Controlling_Formal (F)
3663 ("access to class-wide argument not allowed here!", A);
3665 if Is_Subprogram (Nam)
3666 and then Comes_From_Source (Nam)
3668 Error_Msg_Node_2 := Designated_Type (F_Typ);
3670 ("& is not a dispatching operation of &!", A, Nam);
3676 -- If it is a named association, treat the selector_name as
3677 -- a proper identifier, and mark the corresponding entity.
3679 if Nkind (Parent (A)) = N_Parameter_Association then
3680 Set_Entity (Selector_Name (Parent (A)), F);
3681 Generate_Reference (F, Selector_Name (Parent (A)));
3682 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3683 Generate_Reference (F_Typ, N, ' ');
3688 if Ekind (F) /= E_Out_Parameter then
3689 Check_Unset_Reference (A);
3694 -- Case where actual is not present
3702 end Resolve_Actuals;
3704 -----------------------
3705 -- Resolve_Allocator --
3706 -----------------------
3708 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3709 E : constant Node_Id := Expression (N);
3711 Discrim : Entity_Id;
3714 Assoc : Node_Id := Empty;
3717 procedure Check_Allocator_Discrim_Accessibility
3718 (Disc_Exp : Node_Id;
3719 Alloc_Typ : Entity_Id);
3720 -- Check that accessibility level associated with an access discriminant
3721 -- initialized in an allocator by the expression Disc_Exp is not deeper
3722 -- than the level of the allocator type Alloc_Typ. An error message is
3723 -- issued if this condition is violated. Specialized checks are done for
3724 -- the cases of a constraint expression which is an access attribute or
3725 -- an access discriminant.
3727 function In_Dispatching_Context return Boolean;
3728 -- If the allocator is an actual in a call, it is allowed to be class-
3729 -- wide when the context is not because it is a controlling actual.
3731 procedure Propagate_Coextensions (Root : Node_Id);
3732 -- Propagate all nested coextensions which are located one nesting
3733 -- level down the tree to the node Root. Example:
3736 -- Level_1_Coextension
3737 -- Level_2_Coextension
3739 -- The algorithm is paired with delay actions done by the Expander. In
3740 -- the above example, assume all coextensions are controlled types.
3741 -- The cycle of analysis, resolution and expansion will yield:
3743 -- 1) Analyze Top_Record
3744 -- 2) Analyze Level_1_Coextension
3745 -- 3) Analyze Level_2_Coextension
3746 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3748 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3749 -- generated to capture the allocated object. Temp_1 is attached
3750 -- to the coextension chain of Level_2_Coextension.
3751 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3752 -- coextension. A forward tree traversal is performed which finds
3753 -- Level_2_Coextension's list and copies its contents into its
3755 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3756 -- generated to capture the allocated object. Temp_2 is attached
3757 -- to the coextension chain of Level_1_Coextension. Currently, the
3758 -- contents of the list are [Temp_2, Temp_1].
3759 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3760 -- finds Level_1_Coextension's list and copies its contents into
3762 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3763 -- Temp_2 and attach them to Top_Record's finalization list.
3765 -------------------------------------------
3766 -- Check_Allocator_Discrim_Accessibility --
3767 -------------------------------------------
3769 procedure Check_Allocator_Discrim_Accessibility
3770 (Disc_Exp : Node_Id;
3771 Alloc_Typ : Entity_Id)
3774 if Type_Access_Level (Etype (Disc_Exp)) >
3775 Type_Access_Level (Alloc_Typ)
3778 ("operand type has deeper level than allocator type", Disc_Exp);
3780 -- When the expression is an Access attribute the level of the prefix
3781 -- object must not be deeper than that of the allocator's type.
3783 elsif Nkind (Disc_Exp) = N_Attribute_Reference
3784 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
3786 and then Object_Access_Level (Prefix (Disc_Exp))
3787 > Type_Access_Level (Alloc_Typ)
3790 ("prefix of attribute has deeper level than allocator type",
3793 -- When the expression is an access discriminant the check is against
3794 -- the level of the prefix object.
3796 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
3797 and then Nkind (Disc_Exp) = N_Selected_Component
3798 and then Object_Access_Level (Prefix (Disc_Exp))
3799 > Type_Access_Level (Alloc_Typ)
3802 ("access discriminant has deeper level than allocator type",
3805 -- All other cases are legal
3810 end Check_Allocator_Discrim_Accessibility;
3812 ----------------------------
3813 -- In_Dispatching_Context --
3814 ----------------------------
3816 function In_Dispatching_Context return Boolean is
3817 Par : constant Node_Id := Parent (N);
3819 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
3820 and then Is_Entity_Name (Name (Par))
3821 and then Is_Dispatching_Operation (Entity (Name (Par)));
3822 end In_Dispatching_Context;
3824 ----------------------------
3825 -- Propagate_Coextensions --
3826 ----------------------------
3828 procedure Propagate_Coextensions (Root : Node_Id) is
3830 procedure Copy_List (From : Elist_Id; To : Elist_Id);
3831 -- Copy the contents of list From into list To, preserving the
3832 -- order of elements.
3834 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
3835 -- Recognize an allocator or a rewritten allocator node and add it
3836 -- along with its nested coextensions to the list of Root.
3842 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
3843 From_Elmt : Elmt_Id;
3845 From_Elmt := First_Elmt (From);
3846 while Present (From_Elmt) loop
3847 Append_Elmt (Node (From_Elmt), To);
3848 Next_Elmt (From_Elmt);
3852 -----------------------
3853 -- Process_Allocator --
3854 -----------------------
3856 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
3857 Orig_Nod : Node_Id := Nod;
3860 -- This is a possible rewritten subtype indication allocator. Any
3861 -- nested coextensions will appear as discriminant constraints.
3863 if Nkind (Nod) = N_Identifier
3864 and then Present (Original_Node (Nod))
3865 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
3869 Discr_Elmt : Elmt_Id;
3872 if Is_Record_Type (Entity (Nod)) then
3874 First_Elmt (Discriminant_Constraint (Entity (Nod)));
3875 while Present (Discr_Elmt) loop
3876 Discr := Node (Discr_Elmt);
3878 if Nkind (Discr) = N_Identifier
3879 and then Present (Original_Node (Discr))
3880 and then Nkind (Original_Node (Discr)) = N_Allocator
3881 and then Present (Coextensions (
3882 Original_Node (Discr)))
3884 if No (Coextensions (Root)) then
3885 Set_Coextensions (Root, New_Elmt_List);
3889 (From => Coextensions (Original_Node (Discr)),
3890 To => Coextensions (Root));
3893 Next_Elmt (Discr_Elmt);
3896 -- There is no need to continue the traversal of this
3897 -- subtree since all the information has already been
3904 -- Case of either a stand alone allocator or a rewritten allocator
3905 -- with an aggregate.
3908 if Present (Original_Node (Nod)) then
3909 Orig_Nod := Original_Node (Nod);
3912 if Nkind (Orig_Nod) = N_Allocator then
3914 -- Propagate the list of nested coextensions to the Root
3915 -- allocator. This is done through list copy since a single
3916 -- allocator may have multiple coextensions. Do not touch
3917 -- coextensions roots.
3919 if not Is_Coextension_Root (Orig_Nod)
3920 and then Present (Coextensions (Orig_Nod))
3922 if No (Coextensions (Root)) then
3923 Set_Coextensions (Root, New_Elmt_List);
3927 (From => Coextensions (Orig_Nod),
3928 To => Coextensions (Root));
3931 -- There is no need to continue the traversal of this
3932 -- subtree since all the information has already been
3939 -- Keep on traversing, looking for the next allocator
3942 end Process_Allocator;
3944 procedure Process_Allocators is
3945 new Traverse_Proc (Process_Allocator);
3947 -- Start of processing for Propagate_Coextensions
3950 Process_Allocators (Expression (Root));
3951 end Propagate_Coextensions;
3953 -- Start of processing for Resolve_Allocator
3956 -- Replace general access with specific type
3958 if Ekind (Etype (N)) = E_Allocator_Type then
3959 Set_Etype (N, Base_Type (Typ));
3962 if Is_Abstract_Type (Typ) then
3963 Error_Msg_N ("type of allocator cannot be abstract", N);
3966 -- For qualified expression, resolve the expression using the
3967 -- given subtype (nothing to do for type mark, subtype indication)
3969 if Nkind (E) = N_Qualified_Expression then
3970 if Is_Class_Wide_Type (Etype (E))
3971 and then not Is_Class_Wide_Type (Designated_Type (Typ))
3972 and then not In_Dispatching_Context
3975 ("class-wide allocator not allowed for this access type", N);
3978 Resolve (Expression (E), Etype (E));
3979 Check_Unset_Reference (Expression (E));
3981 -- A qualified expression requires an exact match of the type,
3982 -- class-wide matching is not allowed. We skip this test in a call
3983 -- to a CPP constructor because in such case, although the function
3984 -- profile indicates that it returns a class-wide type, the object
3985 -- returned by the C++ constructor has a concrete type.
3987 if Is_Class_Wide_Type (Etype (Expression (E)))
3988 and then Is_CPP_Constructor_Call (Expression (E))
3992 elsif (Is_Class_Wide_Type (Etype (Expression (E)))
3993 or else Is_Class_Wide_Type (Etype (E)))
3994 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
3996 Wrong_Type (Expression (E), Etype (E));
3999 -- A special accessibility check is needed for allocators that
4000 -- constrain access discriminants. The level of the type of the
4001 -- expression used to constrain an access discriminant cannot be
4002 -- deeper than the type of the allocator (in contrast to access
4003 -- parameters, where the level of the actual can be arbitrary).
4005 -- We can't use Valid_Conversion to perform this check because
4006 -- in general the type of the allocator is unrelated to the type
4007 -- of the access discriminant.
4009 if Ekind (Typ) /= E_Anonymous_Access_Type
4010 or else Is_Local_Anonymous_Access (Typ)
4012 Subtyp := Entity (Subtype_Mark (E));
4014 Aggr := Original_Node (Expression (E));
4016 if Has_Discriminants (Subtyp)
4017 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
4019 Discrim := First_Discriminant (Base_Type (Subtyp));
4021 -- Get the first component expression of the aggregate
4023 if Present (Expressions (Aggr)) then
4024 Disc_Exp := First (Expressions (Aggr));
4026 elsif Present (Component_Associations (Aggr)) then
4027 Assoc := First (Component_Associations (Aggr));
4029 if Present (Assoc) then
4030 Disc_Exp := Expression (Assoc);
4039 while Present (Discrim) and then Present (Disc_Exp) loop
4040 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4041 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4044 Next_Discriminant (Discrim);
4046 if Present (Discrim) then
4047 if Present (Assoc) then
4049 Disc_Exp := Expression (Assoc);
4051 elsif Present (Next (Disc_Exp)) then
4055 Assoc := First (Component_Associations (Aggr));
4057 if Present (Assoc) then
4058 Disc_Exp := Expression (Assoc);
4068 -- For a subtype mark or subtype indication, freeze the subtype
4071 Freeze_Expression (E);
4073 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4075 ("initialization required for access-to-constant allocator", N);
4078 -- A special accessibility check is needed for allocators that
4079 -- constrain access discriminants. The level of the type of the
4080 -- expression used to constrain an access discriminant cannot be
4081 -- deeper than the type of the allocator (in contrast to access
4082 -- parameters, where the level of the actual can be arbitrary).
4083 -- We can't use Valid_Conversion to perform this check because
4084 -- in general the type of the allocator is unrelated to the type
4085 -- of the access discriminant.
4087 if Nkind (Original_Node (E)) = N_Subtype_Indication
4088 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4089 or else Is_Local_Anonymous_Access (Typ))
4091 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4093 if Has_Discriminants (Subtyp) then
4094 Discrim := First_Discriminant (Base_Type (Subtyp));
4095 Constr := First (Constraints (Constraint (Original_Node (E))));
4096 while Present (Discrim) and then Present (Constr) loop
4097 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4098 if Nkind (Constr) = N_Discriminant_Association then
4099 Disc_Exp := Original_Node (Expression (Constr));
4101 Disc_Exp := Original_Node (Constr);
4104 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4107 Next_Discriminant (Discrim);
4114 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4115 -- check that the level of the type of the created object is not deeper
4116 -- than the level of the allocator's access type, since extensions can
4117 -- now occur at deeper levels than their ancestor types. This is a
4118 -- static accessibility level check; a run-time check is also needed in
4119 -- the case of an initialized allocator with a class-wide argument (see
4120 -- Expand_Allocator_Expression).
4122 if Ada_Version >= Ada_05
4123 and then Is_Class_Wide_Type (Designated_Type (Typ))
4126 Exp_Typ : Entity_Id;
4129 if Nkind (E) = N_Qualified_Expression then
4130 Exp_Typ := Etype (E);
4131 elsif Nkind (E) = N_Subtype_Indication then
4132 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4134 Exp_Typ := Entity (E);
4137 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4138 if In_Instance_Body then
4139 Error_Msg_N ("?type in allocator has deeper level than" &
4140 " designated class-wide type", E);
4141 Error_Msg_N ("\?Program_Error will be raised at run time",
4144 Make_Raise_Program_Error (Sloc (N),
4145 Reason => PE_Accessibility_Check_Failed));
4148 -- Do not apply Ada 2005 accessibility checks on a class-wide
4149 -- allocator if the type given in the allocator is a formal
4150 -- type. A run-time check will be performed in the instance.
4152 elsif not Is_Generic_Type (Exp_Typ) then
4153 Error_Msg_N ("type in allocator has deeper level than" &
4154 " designated class-wide type", E);
4160 -- Check for allocation from an empty storage pool
4162 if No_Pool_Assigned (Typ) then
4164 Loc : constant Source_Ptr := Sloc (N);
4166 Error_Msg_N ("?allocation from empty storage pool!", N);
4167 Error_Msg_N ("\?Storage_Error will be raised at run time!", N);
4169 Make_Raise_Storage_Error (Loc,
4170 Reason => SE_Empty_Storage_Pool));
4173 -- If the context is an unchecked conversion, as may happen within
4174 -- an inlined subprogram, the allocator is being resolved with its
4175 -- own anonymous type. In that case, if the target type has a specific
4176 -- storage pool, it must be inherited explicitly by the allocator type.
4178 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4179 and then No (Associated_Storage_Pool (Typ))
4181 Set_Associated_Storage_Pool
4182 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
4185 -- An erroneous allocator may be rewritten as a raise Program_Error
4188 if Nkind (N) = N_Allocator then
4190 -- An anonymous access discriminant is the definition of a
4193 if Ekind (Typ) = E_Anonymous_Access_Type
4194 and then Nkind (Associated_Node_For_Itype (Typ)) =
4195 N_Discriminant_Specification
4197 -- Avoid marking an allocator as a dynamic coextension if it is
4198 -- within a static construct.
4200 if not Is_Static_Coextension (N) then
4201 Set_Is_Dynamic_Coextension (N);
4204 -- Cleanup for potential static coextensions
4207 Set_Is_Dynamic_Coextension (N, False);
4208 Set_Is_Static_Coextension (N, False);
4211 -- There is no need to propagate any nested coextensions if they
4212 -- are marked as static since they will be rewritten on the spot.
4214 if not Is_Static_Coextension (N) then
4215 Propagate_Coextensions (N);
4218 end Resolve_Allocator;
4220 ---------------------------
4221 -- Resolve_Arithmetic_Op --
4222 ---------------------------
4224 -- Used for resolving all arithmetic operators except exponentiation
4226 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
4227 L : constant Node_Id := Left_Opnd (N);
4228 R : constant Node_Id := Right_Opnd (N);
4229 TL : constant Entity_Id := Base_Type (Etype (L));
4230 TR : constant Entity_Id := Base_Type (Etype (R));
4234 B_Typ : constant Entity_Id := Base_Type (Typ);
4235 -- We do the resolution using the base type, because intermediate values
4236 -- in expressions always are of the base type, not a subtype of it.
4238 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4239 -- Returns True if N is in a context that expects "any real type"
4241 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4242 -- Return True iff given type is Integer or universal real/integer
4244 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4245 -- Choose type of integer literal in fixed-point operation to conform
4246 -- to available fixed-point type. T is the type of the other operand,
4247 -- which is needed to determine the expected type of N.
4249 procedure Set_Operand_Type (N : Node_Id);
4250 -- Set operand type to T if universal
4252 -------------------------------
4253 -- Expected_Type_Is_Any_Real --
4254 -------------------------------
4256 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4258 -- N is the expression after "delta" in a fixed_point_definition;
4261 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4262 N_Decimal_Fixed_Point_Definition,
4264 -- N is one of the bounds in a real_range_specification;
4267 N_Real_Range_Specification,
4269 -- N is the expression of a delta_constraint;
4272 N_Delta_Constraint);
4273 end Expected_Type_Is_Any_Real;
4275 -----------------------------
4276 -- Is_Integer_Or_Universal --
4277 -----------------------------
4279 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4281 Index : Interp_Index;
4285 if not Is_Overloaded (N) then
4287 return Base_Type (T) = Base_Type (Standard_Integer)
4288 or else T = Universal_Integer
4289 or else T = Universal_Real;
4291 Get_First_Interp (N, Index, It);
4292 while Present (It.Typ) loop
4293 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4294 or else It.Typ = Universal_Integer
4295 or else It.Typ = Universal_Real
4300 Get_Next_Interp (Index, It);
4305 end Is_Integer_Or_Universal;
4307 ----------------------------
4308 -- Set_Mixed_Mode_Operand --
4309 ----------------------------
4311 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4312 Index : Interp_Index;
4316 if Universal_Interpretation (N) = Universal_Integer then
4318 -- A universal integer literal is resolved as standard integer
4319 -- except in the case of a fixed-point result, where we leave it
4320 -- as universal (to be handled by Exp_Fixd later on)
4322 if Is_Fixed_Point_Type (T) then
4323 Resolve (N, Universal_Integer);
4325 Resolve (N, Standard_Integer);
4328 elsif Universal_Interpretation (N) = Universal_Real
4329 and then (T = Base_Type (Standard_Integer)
4330 or else T = Universal_Integer
4331 or else T = Universal_Real)
4333 -- A universal real can appear in a fixed-type context. We resolve
4334 -- the literal with that context, even though this might raise an
4335 -- exception prematurely (the other operand may be zero).
4339 elsif Etype (N) = Base_Type (Standard_Integer)
4340 and then T = Universal_Real
4341 and then Is_Overloaded (N)
4343 -- Integer arg in mixed-mode operation. Resolve with universal
4344 -- type, in case preference rule must be applied.
4346 Resolve (N, Universal_Integer);
4349 and then B_Typ /= Universal_Fixed
4351 -- Not a mixed-mode operation, resolve with context
4355 elsif Etype (N) = Any_Fixed then
4357 -- N may itself be a mixed-mode operation, so use context type
4361 elsif Is_Fixed_Point_Type (T)
4362 and then B_Typ = Universal_Fixed
4363 and then Is_Overloaded (N)
4365 -- Must be (fixed * fixed) operation, operand must have one
4366 -- compatible interpretation.
4368 Resolve (N, Any_Fixed);
4370 elsif Is_Fixed_Point_Type (B_Typ)
4371 and then (T = Universal_Real
4372 or else Is_Fixed_Point_Type (T))
4373 and then Is_Overloaded (N)
4375 -- C * F(X) in a fixed context, where C is a real literal or a
4376 -- fixed-point expression. F must have either a fixed type
4377 -- interpretation or an integer interpretation, but not both.
4379 Get_First_Interp (N, Index, It);
4380 while Present (It.Typ) loop
4381 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
4383 if Analyzed (N) then
4384 Error_Msg_N ("ambiguous operand in fixed operation", N);
4386 Resolve (N, Standard_Integer);
4389 elsif Is_Fixed_Point_Type (It.Typ) then
4391 if Analyzed (N) then
4392 Error_Msg_N ("ambiguous operand in fixed operation", N);
4394 Resolve (N, It.Typ);
4398 Get_Next_Interp (Index, It);
4401 -- Reanalyze the literal with the fixed type of the context. If
4402 -- context is Universal_Fixed, we are within a conversion, leave
4403 -- the literal as a universal real because there is no usable
4404 -- fixed type, and the target of the conversion plays no role in
4418 if B_Typ = Universal_Fixed
4419 and then Nkind (Op2) = N_Real_Literal
4421 T2 := Universal_Real;
4426 Set_Analyzed (Op2, False);
4433 end Set_Mixed_Mode_Operand;
4435 ----------------------
4436 -- Set_Operand_Type --
4437 ----------------------
4439 procedure Set_Operand_Type (N : Node_Id) is
4441 if Etype (N) = Universal_Integer
4442 or else Etype (N) = Universal_Real
4446 end Set_Operand_Type;
4448 -- Start of processing for Resolve_Arithmetic_Op
4451 if Comes_From_Source (N)
4452 and then Ekind (Entity (N)) = E_Function
4453 and then Is_Imported (Entity (N))
4454 and then Is_Intrinsic_Subprogram (Entity (N))
4456 Resolve_Intrinsic_Operator (N, Typ);
4459 -- Special-case for mixed-mode universal expressions or fixed point
4460 -- type operation: each argument is resolved separately. The same
4461 -- treatment is required if one of the operands of a fixed point
4462 -- operation is universal real, since in this case we don't do a
4463 -- conversion to a specific fixed-point type (instead the expander
4464 -- takes care of the case).
4466 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
4467 and then Present (Universal_Interpretation (L))
4468 and then Present (Universal_Interpretation (R))
4470 Resolve (L, Universal_Interpretation (L));
4471 Resolve (R, Universal_Interpretation (R));
4472 Set_Etype (N, B_Typ);
4474 elsif (B_Typ = Universal_Real
4475 or else Etype (N) = Universal_Fixed
4476 or else (Etype (N) = Any_Fixed
4477 and then Is_Fixed_Point_Type (B_Typ))
4478 or else (Is_Fixed_Point_Type (B_Typ)
4479 and then (Is_Integer_Or_Universal (L)
4481 Is_Integer_Or_Universal (R))))
4482 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4484 if TL = Universal_Integer or else TR = Universal_Integer then
4485 Check_For_Visible_Operator (N, B_Typ);
4488 -- If context is a fixed type and one operand is integer, the
4489 -- other is resolved with the type of the context.
4491 if Is_Fixed_Point_Type (B_Typ)
4492 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4493 or else TL = Universal_Integer)
4498 elsif Is_Fixed_Point_Type (B_Typ)
4499 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4500 or else TR = Universal_Integer)
4506 Set_Mixed_Mode_Operand (L, TR);
4507 Set_Mixed_Mode_Operand (R, TL);
4510 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4511 -- multiplying operators from being used when the expected type is
4512 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4513 -- some cases where the expected type is actually Any_Real;
4514 -- Expected_Type_Is_Any_Real takes care of that case.
4516 if Etype (N) = Universal_Fixed
4517 or else Etype (N) = Any_Fixed
4519 if B_Typ = Universal_Fixed
4520 and then not Expected_Type_Is_Any_Real (N)
4521 and then not Nkind_In (Parent (N), N_Type_Conversion,
4522 N_Unchecked_Type_Conversion)
4524 Error_Msg_N ("type cannot be determined from context!", N);
4525 Error_Msg_N ("\explicit conversion to result type required", N);
4527 Set_Etype (L, Any_Type);
4528 Set_Etype (R, Any_Type);
4531 if Ada_Version = Ada_83
4532 and then Etype (N) = Universal_Fixed
4534 Nkind_In (Parent (N), N_Type_Conversion,
4535 N_Unchecked_Type_Conversion)
4538 ("(Ada 83) fixed-point operation "
4539 & "needs explicit conversion", N);
4542 -- The expected type is "any real type" in contexts like
4543 -- type T is delta <universal_fixed-expression> ...
4544 -- in which case we need to set the type to Universal_Real
4545 -- so that static expression evaluation will work properly.
4547 if Expected_Type_Is_Any_Real (N) then
4548 Set_Etype (N, Universal_Real);
4550 Set_Etype (N, B_Typ);
4554 elsif Is_Fixed_Point_Type (B_Typ)
4555 and then (Is_Integer_Or_Universal (L)
4556 or else Nkind (L) = N_Real_Literal
4557 or else Nkind (R) = N_Real_Literal
4558 or else Is_Integer_Or_Universal (R))
4560 Set_Etype (N, B_Typ);
4562 elsif Etype (N) = Any_Fixed then
4564 -- If no previous errors, this is only possible if one operand
4565 -- is overloaded and the context is universal. Resolve as such.
4567 Set_Etype (N, B_Typ);
4571 if (TL = Universal_Integer or else TL = Universal_Real)
4573 (TR = Universal_Integer or else TR = Universal_Real)
4575 Check_For_Visible_Operator (N, B_Typ);
4578 -- If the context is Universal_Fixed and the operands are also
4579 -- universal fixed, this is an error, unless there is only one
4580 -- applicable fixed_point type (usually duration).
4582 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
4583 T := Unique_Fixed_Point_Type (N);
4585 if T = Any_Type then
4598 -- If one of the arguments was resolved to a non-universal type.
4599 -- label the result of the operation itself with the same type.
4600 -- Do the same for the universal argument, if any.
4602 T := Intersect_Types (L, R);
4603 Set_Etype (N, Base_Type (T));
4604 Set_Operand_Type (L);
4605 Set_Operand_Type (R);
4608 Generate_Operator_Reference (N, Typ);
4609 Eval_Arithmetic_Op (N);
4611 -- Set overflow and division checking bit. Much cleverer code needed
4612 -- here eventually and perhaps the Resolve routines should be separated
4613 -- for the various arithmetic operations, since they will need
4614 -- different processing. ???
4616 if Nkind (N) in N_Op then
4617 if not Overflow_Checks_Suppressed (Etype (N)) then
4618 Enable_Overflow_Check (N);
4621 -- Give warning if explicit division by zero
4623 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
4624 and then not Division_Checks_Suppressed (Etype (N))
4626 Rop := Right_Opnd (N);
4628 if Compile_Time_Known_Value (Rop)
4629 and then ((Is_Integer_Type (Etype (Rop))
4630 and then Expr_Value (Rop) = Uint_0)
4632 (Is_Real_Type (Etype (Rop))
4633 and then Expr_Value_R (Rop) = Ureal_0))
4635 -- Specialize the warning message according to the operation
4639 Apply_Compile_Time_Constraint_Error
4640 (N, "division by zero?", CE_Divide_By_Zero,
4641 Loc => Sloc (Right_Opnd (N)));
4644 Apply_Compile_Time_Constraint_Error
4645 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4646 Loc => Sloc (Right_Opnd (N)));
4649 Apply_Compile_Time_Constraint_Error
4650 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4651 Loc => Sloc (Right_Opnd (N)));
4653 -- Division by zero can only happen with division, rem,
4654 -- and mod operations.
4657 raise Program_Error;
4660 -- Otherwise just set the flag to check at run time
4663 Activate_Division_Check (N);
4667 -- If Restriction No_Implicit_Conditionals is active, then it is
4668 -- violated if either operand can be negative for mod, or for rem
4669 -- if both operands can be negative.
4671 if Restrictions.Set (No_Implicit_Conditionals)
4672 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4681 -- Set if corresponding operand might be negative
4684 Determine_Range (Left_Opnd (N), OK, Lo, Hi);
4685 LNeg := (not OK) or else Lo < 0;
4687 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
4688 RNeg := (not OK) or else Lo < 0;
4690 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4692 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4694 Check_Restriction (No_Implicit_Conditionals, N);
4700 Check_Unset_Reference (L);
4701 Check_Unset_Reference (R);
4702 end Resolve_Arithmetic_Op;
4708 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4709 Loc : constant Source_Ptr := Sloc (N);
4710 Subp : constant Node_Id := Name (N);
4719 -- The context imposes a unique interpretation with type Typ on a
4720 -- procedure or function call. Find the entity of the subprogram that
4721 -- yields the expected type, and propagate the corresponding formal
4722 -- constraints on the actuals. The caller has established that an
4723 -- interpretation exists, and emitted an error if not unique.
4725 -- First deal with the case of a call to an access-to-subprogram,
4726 -- dereference made explicit in Analyze_Call.
4728 if Ekind (Etype (Subp)) = E_Subprogram_Type then
4729 if not Is_Overloaded (Subp) then
4730 Nam := Etype (Subp);
4733 -- Find the interpretation whose type (a subprogram type) has a
4734 -- return type that is compatible with the context. Analysis of
4735 -- the node has established that one exists.
4739 Get_First_Interp (Subp, I, It);
4740 while Present (It.Typ) loop
4741 if Covers (Typ, Etype (It.Typ)) then
4746 Get_Next_Interp (I, It);
4750 raise Program_Error;
4754 -- If the prefix is not an entity, then resolve it
4756 if not Is_Entity_Name (Subp) then
4757 Resolve (Subp, Nam);
4760 -- For an indirect call, we always invalidate checks, since we do not
4761 -- know whether the subprogram is local or global. Yes we could do
4762 -- better here, e.g. by knowing that there are no local subprograms,
4763 -- but it does not seem worth the effort. Similarly, we kill all
4764 -- knowledge of current constant values.
4766 Kill_Current_Values;
4768 -- If this is a procedure call which is really an entry call, do
4769 -- the conversion of the procedure call to an entry call. Protected
4770 -- operations use the same circuitry because the name in the call
4771 -- can be an arbitrary expression with special resolution rules.
4773 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
4774 or else (Is_Entity_Name (Subp)
4775 and then Ekind (Entity (Subp)) = E_Entry)
4777 Resolve_Entry_Call (N, Typ);
4778 Check_Elab_Call (N);
4780 -- Kill checks and constant values, as above for indirect case
4781 -- Who knows what happens when another task is activated?
4783 Kill_Current_Values;
4786 -- Normal subprogram call with name established in Resolve
4788 elsif not (Is_Type (Entity (Subp))) then
4789 Nam := Entity (Subp);
4790 Set_Entity_With_Style_Check (Subp, Nam);
4792 -- Otherwise we must have the case of an overloaded call
4795 pragma Assert (Is_Overloaded (Subp));
4797 -- Initialize Nam to prevent warning (we know it will be assigned
4798 -- in the loop below, but the compiler does not know that).
4802 Get_First_Interp (Subp, I, It);
4803 while Present (It.Typ) loop
4804 if Covers (Typ, It.Typ) then
4806 Set_Entity_With_Style_Check (Subp, Nam);
4810 Get_Next_Interp (I, It);
4814 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
4815 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
4816 and then Nkind (Subp) /= N_Explicit_Dereference
4817 and then Present (Parameter_Associations (N))
4819 -- The prefix is a parameterless function call that returns an access
4820 -- to subprogram. If parameters are present in the current call, add
4821 -- add an explicit dereference. We use the base type here because
4822 -- within an instance these may be subtypes.
4824 -- The dereference is added either in Analyze_Call or here. Should
4825 -- be consolidated ???
4827 Set_Is_Overloaded (Subp, False);
4828 Set_Etype (Subp, Etype (Nam));
4829 Insert_Explicit_Dereference (Subp);
4830 Nam := Designated_Type (Etype (Nam));
4831 Resolve (Subp, Nam);
4834 -- Check that a call to Current_Task does not occur in an entry body
4836 if Is_RTE (Nam, RE_Current_Task) then
4845 -- Exclude calls that occur within the default of a formal
4846 -- parameter of the entry, since those are evaluated outside
4849 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
4851 if Nkind (P) = N_Entry_Body
4852 or else (Nkind (P) = N_Subprogram_Body
4853 and then Is_Entry_Barrier_Function (P))
4857 ("?& should not be used in entry body (RM C.7(17))",
4860 ("\Program_Error will be raised at run time?", N, Nam);
4862 Make_Raise_Program_Error (Loc,
4863 Reason => PE_Current_Task_In_Entry_Body));
4864 Set_Etype (N, Rtype);
4871 -- Check that a procedure call does not occur in the context of the
4872 -- entry call statement of a conditional or timed entry call. Note that
4873 -- the case of a call to a subprogram renaming of an entry will also be
4874 -- rejected. The test for N not being an N_Entry_Call_Statement is
4875 -- defensive, covering the possibility that the processing of entry
4876 -- calls might reach this point due to later modifications of the code
4879 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4880 and then Nkind (N) /= N_Entry_Call_Statement
4881 and then Entry_Call_Statement (Parent (N)) = N
4883 if Ada_Version < Ada_05 then
4884 Error_Msg_N ("entry call required in select statement", N);
4886 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4887 -- for a procedure_or_entry_call, the procedure_name or
4888 -- procedure_prefix of the procedure_call_statement shall denote
4889 -- an entry renamed by a procedure, or (a view of) a primitive
4890 -- subprogram of a limited interface whose first parameter is
4891 -- a controlling parameter.
4893 elsif Nkind (N) = N_Procedure_Call_Statement
4894 and then not Is_Renamed_Entry (Nam)
4895 and then not Is_Controlling_Limited_Procedure (Nam)
4898 ("entry call or dispatching primitive of interface required", N);
4902 -- Check that this is not a call to a protected procedure or entry from
4903 -- within a protected function.
4905 if Ekind (Current_Scope) = E_Function
4906 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
4907 and then Ekind (Nam) /= E_Function
4908 and then Scope (Nam) = Scope (Current_Scope)
4910 Error_Msg_N ("within protected function, protected " &
4911 "object is constant", N);
4912 Error_Msg_N ("\cannot call operation that may modify it", N);
4915 -- Freeze the subprogram name if not in a spec-expression. Note that we
4916 -- freeze procedure calls as well as function calls. Procedure calls are
4917 -- not frozen according to the rules (RM 13.14(14)) because it is
4918 -- impossible to have a procedure call to a non-frozen procedure in pure
4919 -- Ada, but in the code that we generate in the expander, this rule
4920 -- needs extending because we can generate procedure calls that need
4923 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
4924 Freeze_Expression (Subp);
4927 -- For a predefined operator, the type of the result is the type imposed
4928 -- by context, except for a predefined operation on universal fixed.
4929 -- Otherwise The type of the call is the type returned by the subprogram
4932 if Is_Predefined_Op (Nam) then
4933 if Etype (N) /= Universal_Fixed then
4937 -- If the subprogram returns an array type, and the context requires the
4938 -- component type of that array type, the node is really an indexing of
4939 -- the parameterless call. Resolve as such. A pathological case occurs
4940 -- when the type of the component is an access to the array type. In
4941 -- this case the call is truly ambiguous.
4943 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
4945 ((Is_Array_Type (Etype (Nam))
4946 and then Covers (Typ, Component_Type (Etype (Nam))))
4947 or else (Is_Access_Type (Etype (Nam))
4948 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4951 Component_Type (Designated_Type (Etype (Nam))))))
4954 Index_Node : Node_Id;
4956 Ret_Type : constant Entity_Id := Etype (Nam);
4959 if Is_Access_Type (Ret_Type)
4960 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
4963 ("cannot disambiguate function call and indexing", N);
4965 New_Subp := Relocate_Node (Subp);
4966 Set_Entity (Subp, Nam);
4968 if Component_Type (Ret_Type) /= Any_Type then
4969 if Needs_No_Actuals (Nam) then
4971 -- Indexed call to a parameterless function
4974 Make_Indexed_Component (Loc,
4976 Make_Function_Call (Loc,
4978 Expressions => Parameter_Associations (N));
4980 -- An Ada 2005 prefixed call to a primitive operation
4981 -- whose first parameter is the prefix. This prefix was
4982 -- prepended to the parameter list, which is actually a
4983 -- list of indices. Remove the prefix in order to build
4984 -- the proper indexed component.
4987 Make_Indexed_Component (Loc,
4989 Make_Function_Call (Loc,
4991 Parameter_Associations =>
4993 (Remove_Head (Parameter_Associations (N)))),
4994 Expressions => Parameter_Associations (N));
4997 -- Since we are correcting a node classification error made
4998 -- by the parser, we call Replace rather than Rewrite.
5000 Replace (N, Index_Node);
5001 Set_Etype (Prefix (N), Ret_Type);
5003 Resolve_Indexed_Component (N, Typ);
5004 Check_Elab_Call (Prefix (N));
5012 Set_Etype (N, Etype (Nam));
5015 -- In the case where the call is to an overloaded subprogram, Analyze
5016 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5017 -- such a case Normalize_Actuals needs to be called once more to order
5018 -- the actuals correctly. Otherwise the call will have the ordering
5019 -- given by the last overloaded subprogram whether this is the correct
5020 -- one being called or not.
5022 if Is_Overloaded (Subp) then
5023 Normalize_Actuals (N, Nam, False, Norm_OK);
5024 pragma Assert (Norm_OK);
5027 -- In any case, call is fully resolved now. Reset Overload flag, to
5028 -- prevent subsequent overload resolution if node is analyzed again
5030 Set_Is_Overloaded (Subp, False);
5031 Set_Is_Overloaded (N, False);
5033 -- If we are calling the current subprogram from immediately within its
5034 -- body, then that is the case where we can sometimes detect cases of
5035 -- infinite recursion statically. Do not try this in case restriction
5036 -- No_Recursion is in effect anyway, and do it only for source calls.
5038 if Comes_From_Source (N) then
5039 Scop := Current_Scope;
5041 -- Issue warning for possible infinite recursion in the absence
5042 -- of the No_Recursion restriction.
5045 and then not Restriction_Active (No_Recursion)
5046 and then Check_Infinite_Recursion (N)
5048 -- Here we detected and flagged an infinite recursion, so we do
5049 -- not need to test the case below for further warnings. Also if
5050 -- we now have a raise SE node, we are all done.
5052 if Nkind (N) = N_Raise_Storage_Error then
5056 -- If call is to immediately containing subprogram, then check for
5057 -- the case of a possible run-time detectable infinite recursion.
5060 Scope_Loop : while Scop /= Standard_Standard loop
5063 -- Although in general case, recursion is not statically
5064 -- checkable, the case of calling an immediately containing
5065 -- subprogram is easy to catch.
5067 Check_Restriction (No_Recursion, N);
5069 -- If the recursive call is to a parameterless subprogram,
5070 -- then even if we can't statically detect infinite
5071 -- recursion, this is pretty suspicious, and we output a
5072 -- warning. Furthermore, we will try later to detect some
5073 -- cases here at run time by expanding checking code (see
5074 -- Detect_Infinite_Recursion in package Exp_Ch6).
5076 -- If the recursive call is within a handler, do not emit a
5077 -- warning, because this is a common idiom: loop until input
5078 -- is correct, catch illegal input in handler and restart.
5080 if No (First_Formal (Nam))
5081 and then Etype (Nam) = Standard_Void_Type
5082 and then not Error_Posted (N)
5083 and then Nkind (Parent (N)) /= N_Exception_Handler
5085 -- For the case of a procedure call. We give the message
5086 -- only if the call is the first statement in a sequence
5087 -- of statements, or if all previous statements are
5088 -- simple assignments. This is simply a heuristic to
5089 -- decrease false positives, without losing too many good
5090 -- warnings. The idea is that these previous statements
5091 -- may affect global variables the procedure depends on.
5093 if Nkind (N) = N_Procedure_Call_Statement
5094 and then Is_List_Member (N)
5100 while Present (P) loop
5101 if Nkind (P) /= N_Assignment_Statement then
5110 -- Do not give warning if we are in a conditional context
5113 K : constant Node_Kind := Nkind (Parent (N));
5115 if (K = N_Loop_Statement
5116 and then Present (Iteration_Scheme (Parent (N))))
5117 or else K = N_If_Statement
5118 or else K = N_Elsif_Part
5119 or else K = N_Case_Statement_Alternative
5125 -- Here warning is to be issued
5127 Set_Has_Recursive_Call (Nam);
5129 ("?possible infinite recursion!", N);
5131 ("\?Storage_Error may be raised at run time!", N);
5137 Scop := Scope (Scop);
5138 end loop Scope_Loop;
5142 -- If subprogram name is a predefined operator, it was given in
5143 -- functional notation. Replace call node with operator node, so
5144 -- that actuals can be resolved appropriately.
5146 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5147 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5150 elsif Present (Alias (Nam))
5151 and then Is_Predefined_Op (Alias (Nam))
5153 Resolve_Actuals (N, Nam);
5154 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5158 -- Create a transient scope if the resulting type requires it
5160 -- There are several notable exceptions:
5162 -- a) In init procs, the transient scope overhead is not needed, and is
5163 -- even incorrect when the call is a nested initialization call for a
5164 -- component whose expansion may generate adjust calls. However, if the
5165 -- call is some other procedure call within an initialization procedure
5166 -- (for example a call to Create_Task in the init_proc of the task
5167 -- run-time record) a transient scope must be created around this call.
5169 -- b) Enumeration literal pseudo-calls need no transient scope
5171 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5172 -- functions) do not use the secondary stack even though the return
5173 -- type may be unconstrained.
5175 -- d) Calls to a build-in-place function, since such functions may
5176 -- allocate their result directly in a target object, and cases where
5177 -- the result does get allocated in the secondary stack are checked for
5178 -- within the specialized Exp_Ch6 procedures for expanding those
5179 -- build-in-place calls.
5181 -- e) If the subprogram is marked Inline_Always, then even if it returns
5182 -- an unconstrained type the call does not require use of the secondary
5183 -- stack. However, inlining will only take place if the body to inline
5184 -- is already present. It may not be available if e.g. the subprogram is
5185 -- declared in a child instance.
5187 -- If this is an initialization call for a type whose construction
5188 -- uses the secondary stack, and it is not a nested call to initialize
5189 -- a component, we do need to create a transient scope for it. We
5190 -- check for this by traversing the type in Check_Initialization_Call.
5193 and then Has_Pragma_Inline_Always (Nam)
5194 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5195 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
5199 elsif Ekind (Nam) = E_Enumeration_Literal
5200 or else Is_Build_In_Place_Function (Nam)
5201 or else Is_Intrinsic_Subprogram (Nam)
5205 elsif Expander_Active
5206 and then Is_Type (Etype (Nam))
5207 and then Requires_Transient_Scope (Etype (Nam))
5209 (not Within_Init_Proc
5211 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
5213 Establish_Transient_Scope (N, Sec_Stack => True);
5215 -- If the call appears within the bounds of a loop, it will
5216 -- be rewritten and reanalyzed, nothing left to do here.
5218 if Nkind (N) /= N_Function_Call then
5222 elsif Is_Init_Proc (Nam)
5223 and then not Within_Init_Proc
5225 Check_Initialization_Call (N, Nam);
5228 -- A protected function cannot be called within the definition of the
5229 -- enclosing protected type.
5231 if Is_Protected_Type (Scope (Nam))
5232 and then In_Open_Scopes (Scope (Nam))
5233 and then not Has_Completion (Scope (Nam))
5236 ("& cannot be called before end of protected definition", N, Nam);
5239 -- Propagate interpretation to actuals, and add default expressions
5242 if Present (First_Formal (Nam)) then
5243 Resolve_Actuals (N, Nam);
5245 -- Overloaded literals are rewritten as function calls, for purpose of
5246 -- resolution. After resolution, we can replace the call with the
5249 elsif Ekind (Nam) = E_Enumeration_Literal then
5250 Copy_Node (Subp, N);
5251 Resolve_Entity_Name (N, Typ);
5253 -- Avoid validation, since it is a static function call
5255 Generate_Reference (Nam, Subp);
5259 -- If the subprogram is not global, then kill all saved values and
5260 -- checks. This is a bit conservative, since in many cases we could do
5261 -- better, but it is not worth the effort. Similarly, we kill constant
5262 -- values. However we do not need to do this for internal entities
5263 -- (unless they are inherited user-defined subprograms), since they
5264 -- are not in the business of molesting local values.
5266 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5267 -- kill all checks and values for calls to global subprograms. This
5268 -- takes care of the case where an access to a local subprogram is
5269 -- taken, and could be passed directly or indirectly and then called
5270 -- from almost any context.
5272 -- Note: we do not do this step till after resolving the actuals. That
5273 -- way we still take advantage of the current value information while
5274 -- scanning the actuals.
5276 -- We suppress killing values if we are processing the nodes associated
5277 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5278 -- type kills all the values as part of analyzing the code that
5279 -- initializes the dispatch tables.
5281 if Inside_Freezing_Actions = 0
5282 and then (not Is_Library_Level_Entity (Nam)
5283 or else Suppress_Value_Tracking_On_Call
5284 (Nearest_Dynamic_Scope (Current_Scope)))
5285 and then (Comes_From_Source (Nam)
5286 or else (Present (Alias (Nam))
5287 and then Comes_From_Source (Alias (Nam))))
5289 Kill_Current_Values;
5292 -- If we are warning about unread OUT parameters, this is the place to
5293 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5294 -- after the above call to Kill_Current_Values (since that call clears
5295 -- the Last_Assignment field of all local variables).
5297 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
5298 and then Comes_From_Source (N)
5299 and then In_Extended_Main_Source_Unit (N)
5306 F := First_Formal (Nam);
5307 A := First_Actual (N);
5308 while Present (F) and then Present (A) loop
5309 if (Ekind (F) = E_Out_Parameter
5311 Ekind (F) = E_In_Out_Parameter)
5312 and then Warn_On_Modified_As_Out_Parameter (F)
5313 and then Is_Entity_Name (A)
5314 and then Present (Entity (A))
5315 and then Comes_From_Source (N)
5316 and then Safe_To_Capture_Value (N, Entity (A))
5318 Set_Last_Assignment (Entity (A), A);
5327 -- If the subprogram is a primitive operation, check whether or not
5328 -- it is a correct dispatching call.
5330 if Is_Overloadable (Nam)
5331 and then Is_Dispatching_Operation (Nam)
5333 Check_Dispatching_Call (N);
5335 elsif Ekind (Nam) /= E_Subprogram_Type
5336 and then Is_Abstract_Subprogram (Nam)
5337 and then not In_Instance
5339 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5342 -- If this is a dispatching call, generate the appropriate reference,
5343 -- for better source navigation in GPS.
5345 if Is_Overloadable (Nam)
5346 and then Present (Controlling_Argument (N))
5348 Generate_Reference (Nam, Subp, 'R');
5350 -- Normal case, not a dispatching call
5353 Generate_Reference (Nam, Subp);
5356 if Is_Intrinsic_Subprogram (Nam) then
5357 Check_Intrinsic_Call (N);
5360 -- Check for violation of restriction No_Specific_Termination_Handlers
5361 -- and warn on a potentially blocking call to Abort_Task.
5363 if Is_RTE (Nam, RE_Set_Specific_Handler)
5365 Is_RTE (Nam, RE_Specific_Handler)
5367 Check_Restriction (No_Specific_Termination_Handlers, N);
5369 elsif Is_RTE (Nam, RE_Abort_Task) then
5370 Check_Potentially_Blocking_Operation (N);
5373 -- Issue an error for a call to an eliminated subprogram
5375 Check_For_Eliminated_Subprogram (Subp, Nam);
5377 -- All done, evaluate call and deal with elaboration issues
5380 Check_Elab_Call (N);
5383 -------------------------------
5384 -- Resolve_Character_Literal --
5385 -------------------------------
5387 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5388 B_Typ : constant Entity_Id := Base_Type (Typ);
5392 -- Verify that the character does belong to the type of the context
5394 Set_Etype (N, B_Typ);
5395 Eval_Character_Literal (N);
5397 -- Wide_Wide_Character literals must always be defined, since the set
5398 -- of wide wide character literals is complete, i.e. if a character
5399 -- literal is accepted by the parser, then it is OK for wide wide
5400 -- character (out of range character literals are rejected).
5402 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5405 -- Always accept character literal for type Any_Character, which
5406 -- occurs in error situations and in comparisons of literals, both
5407 -- of which should accept all literals.
5409 elsif B_Typ = Any_Character then
5412 -- For Standard.Character or a type derived from it, check that
5413 -- the literal is in range
5415 elsif Root_Type (B_Typ) = Standard_Character then
5416 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5420 -- For Standard.Wide_Character or a type derived from it, check
5421 -- that the literal is in range
5423 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5424 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5428 -- For Standard.Wide_Wide_Character or a type derived from it, we
5429 -- know the literal is in range, since the parser checked!
5431 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5434 -- If the entity is already set, this has already been resolved in a
5435 -- generic context, or comes from expansion. Nothing else to do.
5437 elsif Present (Entity (N)) then
5440 -- Otherwise we have a user defined character type, and we can use the
5441 -- standard visibility mechanisms to locate the referenced entity.
5444 C := Current_Entity (N);
5445 while Present (C) loop
5446 if Etype (C) = B_Typ then
5447 Set_Entity_With_Style_Check (N, C);
5448 Generate_Reference (C, N);
5456 -- If we fall through, then the literal does not match any of the
5457 -- entries of the enumeration type. This isn't just a constraint
5458 -- error situation, it is an illegality (see RM 4.2).
5461 ("character not defined for }", N, First_Subtype (B_Typ));
5462 end Resolve_Character_Literal;
5464 ---------------------------
5465 -- Resolve_Comparison_Op --
5466 ---------------------------
5468 -- Context requires a boolean type, and plays no role in resolution.
5469 -- Processing identical to that for equality operators. The result
5470 -- type is the base type, which matters when pathological subtypes of
5471 -- booleans with limited ranges are used.
5473 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5474 L : constant Node_Id := Left_Opnd (N);
5475 R : constant Node_Id := Right_Opnd (N);
5479 Check_No_Direct_Boolean_Operators (N);
5481 -- If this is an intrinsic operation which is not predefined, use the
5482 -- types of its declared arguments to resolve the possibly overloaded
5483 -- operands. Otherwise the operands are unambiguous and specify the
5486 if Scope (Entity (N)) /= Standard_Standard then
5487 T := Etype (First_Entity (Entity (N)));
5490 T := Find_Unique_Type (L, R);
5492 if T = Any_Fixed then
5493 T := Unique_Fixed_Point_Type (L);
5497 Set_Etype (N, Base_Type (Typ));
5498 Generate_Reference (T, N, ' ');
5500 if T /= Any_Type then
5501 if T = Any_String or else
5502 T = Any_Composite or else
5505 if T = Any_Character then
5506 Ambiguous_Character (L);
5508 Error_Msg_N ("ambiguous operands for comparison", N);
5511 Set_Etype (N, Any_Type);
5517 Check_Unset_Reference (L);
5518 Check_Unset_Reference (R);
5519 Generate_Operator_Reference (N, T);
5520 Check_Low_Bound_Tested (N);
5521 Eval_Relational_Op (N);
5524 end Resolve_Comparison_Op;
5526 ------------------------------------
5527 -- Resolve_Conditional_Expression --
5528 ------------------------------------
5530 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5531 Condition : constant Node_Id := First (Expressions (N));
5532 Then_Expr : constant Node_Id := Next (Condition);
5533 Else_Expr : Node_Id := Next (Then_Expr);
5536 Resolve (Condition, Any_Boolean);
5537 Resolve (Then_Expr, Typ);
5539 -- If ELSE expression present, just resolve using the determined type
5541 if Present (Else_Expr) then
5542 Resolve (Else_Expr, Typ);
5544 -- If no ELSE expression is present, root type must be Standard.Boolean
5545 -- and we provide a Standard.True result converted to the appropriate
5546 -- Boolean type (in case it is a derived boolean type).
5548 elsif Root_Type (Typ) = Standard_Boolean then
5550 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
5551 Analyze_And_Resolve (Else_Expr, Typ);
5552 Append_To (Expressions (N), Else_Expr);
5555 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
5556 Append_To (Expressions (N), Error);
5560 Eval_Conditional_Expression (N);
5561 end Resolve_Conditional_Expression;
5563 -----------------------------------------
5564 -- Resolve_Discrete_Subtype_Indication --
5565 -----------------------------------------
5567 procedure Resolve_Discrete_Subtype_Indication
5575 Analyze (Subtype_Mark (N));
5576 S := Entity (Subtype_Mark (N));
5578 if Nkind (Constraint (N)) /= N_Range_Constraint then
5579 Error_Msg_N ("expect range constraint for discrete type", N);
5580 Set_Etype (N, Any_Type);
5583 R := Range_Expression (Constraint (N));
5591 if Base_Type (S) /= Base_Type (Typ) then
5593 ("expect subtype of }", N, First_Subtype (Typ));
5595 -- Rewrite the constraint as a range of Typ
5596 -- to allow compilation to proceed further.
5599 Rewrite (Low_Bound (R),
5600 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5601 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5602 Attribute_Name => Name_First));
5603 Rewrite (High_Bound (R),
5604 Make_Attribute_Reference (Sloc (High_Bound (R)),
5605 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
5606 Attribute_Name => Name_First));
5610 Set_Etype (N, Etype (R));
5612 -- Additionally, we must check that the bounds are compatible
5613 -- with the given subtype, which might be different from the
5614 -- type of the context.
5616 Apply_Range_Check (R, S);
5618 -- ??? If the above check statically detects a Constraint_Error
5619 -- it replaces the offending bound(s) of the range R with a
5620 -- Constraint_Error node. When the itype which uses these bounds
5621 -- is frozen the resulting call to Duplicate_Subexpr generates
5622 -- a new temporary for the bounds.
5624 -- Unfortunately there are other itypes that are also made depend
5625 -- on these bounds, so when Duplicate_Subexpr is called they get
5626 -- a forward reference to the newly created temporaries and Gigi
5627 -- aborts on such forward references. This is probably sign of a
5628 -- more fundamental problem somewhere else in either the order of
5629 -- itype freezing or the way certain itypes are constructed.
5631 -- To get around this problem we call Remove_Side_Effects right
5632 -- away if either bounds of R are a Constraint_Error.
5635 L : constant Node_Id := Low_Bound (R);
5636 H : constant Node_Id := High_Bound (R);
5639 if Nkind (L) = N_Raise_Constraint_Error then
5640 Remove_Side_Effects (L);
5643 if Nkind (H) = N_Raise_Constraint_Error then
5644 Remove_Side_Effects (H);
5648 Check_Unset_Reference (Low_Bound (R));
5649 Check_Unset_Reference (High_Bound (R));
5652 end Resolve_Discrete_Subtype_Indication;
5654 -------------------------
5655 -- Resolve_Entity_Name --
5656 -------------------------
5658 -- Used to resolve identifiers and expanded names
5660 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
5661 E : constant Entity_Id := Entity (N);
5664 -- If garbage from errors, set to Any_Type and return
5666 if No (E) and then Total_Errors_Detected /= 0 then
5667 Set_Etype (N, Any_Type);
5671 -- Replace named numbers by corresponding literals. Note that this is
5672 -- the one case where Resolve_Entity_Name must reset the Etype, since
5673 -- it is currently marked as universal.
5675 if Ekind (E) = E_Named_Integer then
5677 Eval_Named_Integer (N);
5679 elsif Ekind (E) = E_Named_Real then
5681 Eval_Named_Real (N);
5683 -- Allow use of subtype only if it is a concurrent type where we are
5684 -- currently inside the body. This will eventually be expanded into a
5685 -- call to Self (for tasks) or _object (for protected objects). Any
5686 -- other use of a subtype is invalid.
5688 elsif Is_Type (E) then
5689 if Is_Concurrent_Type (E)
5690 and then In_Open_Scopes (E)
5695 ("invalid use of subtype mark in expression or call", N);
5698 -- Check discriminant use if entity is discriminant in current scope,
5699 -- i.e. discriminant of record or concurrent type currently being
5700 -- analyzed. Uses in corresponding body are unrestricted.
5702 elsif Ekind (E) = E_Discriminant
5703 and then Scope (E) = Current_Scope
5704 and then not Has_Completion (Current_Scope)
5706 Check_Discriminant_Use (N);
5708 -- A parameterless generic function cannot appear in a context that
5709 -- requires resolution.
5711 elsif Ekind (E) = E_Generic_Function then
5712 Error_Msg_N ("illegal use of generic function", N);
5714 elsif Ekind (E) = E_Out_Parameter
5715 and then Ada_Version = Ada_83
5716 and then (Nkind (Parent (N)) in N_Op
5717 or else (Nkind (Parent (N)) = N_Assignment_Statement
5718 and then N = Expression (Parent (N)))
5719 or else Nkind (Parent (N)) = N_Explicit_Dereference)
5721 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
5723 -- In all other cases, just do the possible static evaluation
5726 -- A deferred constant that appears in an expression must have a
5727 -- completion, unless it has been removed by in-place expansion of
5730 if Ekind (E) = E_Constant
5731 and then Comes_From_Source (E)
5732 and then No (Constant_Value (E))
5733 and then Is_Frozen (Etype (E))
5734 and then not In_Spec_Expression
5735 and then not Is_Imported (E)
5738 if No_Initialization (Parent (E))
5739 or else (Present (Full_View (E))
5740 and then No_Initialization (Parent (Full_View (E))))
5745 "deferred constant is frozen before completion", N);
5749 Eval_Entity_Name (N);
5751 end Resolve_Entity_Name;
5757 procedure Resolve_Entry (Entry_Name : Node_Id) is
5758 Loc : constant Source_Ptr := Sloc (Entry_Name);
5766 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
5767 -- If the bounds of the entry family being called depend on task
5768 -- discriminants, build a new index subtype where a discriminant is
5769 -- replaced with the value of the discriminant of the target task.
5770 -- The target task is the prefix of the entry name in the call.
5772 -----------------------
5773 -- Actual_Index_Type --
5774 -----------------------
5776 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
5777 Typ : constant Entity_Id := Entry_Index_Type (E);
5778 Tsk : constant Entity_Id := Scope (E);
5779 Lo : constant Node_Id := Type_Low_Bound (Typ);
5780 Hi : constant Node_Id := Type_High_Bound (Typ);
5783 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
5784 -- If the bound is given by a discriminant, replace with a reference
5785 -- to the discriminant of the same name in the target task. If the
5786 -- entry name is the target of a requeue statement and the entry is
5787 -- in the current protected object, the bound to be used is the
5788 -- discriminal of the object (see apply_range_checks for details of
5789 -- the transformation).
5791 -----------------------------
5792 -- Actual_Discriminant_Ref --
5793 -----------------------------
5795 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
5796 Typ : constant Entity_Id := Etype (Bound);
5800 Remove_Side_Effects (Bound);
5802 if not Is_Entity_Name (Bound)
5803 or else Ekind (Entity (Bound)) /= E_Discriminant
5807 elsif Is_Protected_Type (Tsk)
5808 and then In_Open_Scopes (Tsk)
5809 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
5811 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
5815 Make_Selected_Component (Loc,
5816 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
5817 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
5822 end Actual_Discriminant_Ref;
5824 -- Start of processing for Actual_Index_Type
5827 if not Has_Discriminants (Tsk)
5828 or else (not Is_Entity_Name (Lo)
5830 not Is_Entity_Name (Hi))
5832 return Entry_Index_Type (E);
5835 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
5836 Set_Etype (New_T, Base_Type (Typ));
5837 Set_Size_Info (New_T, Typ);
5838 Set_RM_Size (New_T, RM_Size (Typ));
5839 Set_Scalar_Range (New_T,
5840 Make_Range (Sloc (Entry_Name),
5841 Low_Bound => Actual_Discriminant_Ref (Lo),
5842 High_Bound => Actual_Discriminant_Ref (Hi)));
5846 end Actual_Index_Type;
5848 -- Start of processing of Resolve_Entry
5851 -- Find name of entry being called, and resolve prefix of name
5852 -- with its own type. The prefix can be overloaded, and the name
5853 -- and signature of the entry must be taken into account.
5855 if Nkind (Entry_Name) = N_Indexed_Component then
5857 -- Case of dealing with entry family within the current tasks
5859 E_Name := Prefix (Entry_Name);
5862 E_Name := Entry_Name;
5865 if Is_Entity_Name (E_Name) then
5867 -- Entry call to an entry (or entry family) in the current task. This
5868 -- is legal even though the task will deadlock. Rewrite as call to
5871 -- This can also be a call to an entry in an enclosing task. If this
5872 -- is a single task, we have to retrieve its name, because the scope
5873 -- of the entry is the task type, not the object. If the enclosing
5874 -- task is a task type, the identity of the task is given by its own
5877 -- Finally this can be a requeue on an entry of the same task or
5878 -- protected object.
5880 S := Scope (Entity (E_Name));
5882 for J in reverse 0 .. Scope_Stack.Last loop
5883 if Is_Task_Type (Scope_Stack.Table (J).Entity)
5884 and then not Comes_From_Source (S)
5886 -- S is an enclosing task or protected object. The concurrent
5887 -- declaration has been converted into a type declaration, and
5888 -- the object itself has an object declaration that follows
5889 -- the type in the same declarative part.
5891 Tsk := Next_Entity (S);
5892 while Etype (Tsk) /= S loop
5899 elsif S = Scope_Stack.Table (J).Entity then
5901 -- Call to current task. Will be transformed into call to Self
5909 Make_Selected_Component (Loc,
5910 Prefix => New_Occurrence_Of (S, Loc),
5912 New_Occurrence_Of (Entity (E_Name), Loc));
5913 Rewrite (E_Name, New_N);
5916 elsif Nkind (Entry_Name) = N_Selected_Component
5917 and then Is_Overloaded (Prefix (Entry_Name))
5919 -- Use the entry name (which must be unique at this point) to find
5920 -- the prefix that returns the corresponding task type or protected
5924 Pref : constant Node_Id := Prefix (Entry_Name);
5925 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
5930 Get_First_Interp (Pref, I, It);
5931 while Present (It.Typ) loop
5932 if Scope (Ent) = It.Typ then
5933 Set_Etype (Pref, It.Typ);
5937 Get_Next_Interp (I, It);
5942 if Nkind (Entry_Name) = N_Selected_Component then
5943 Resolve (Prefix (Entry_Name));
5945 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
5946 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
5947 Resolve (Prefix (Prefix (Entry_Name)));
5948 Index := First (Expressions (Entry_Name));
5949 Resolve (Index, Entry_Index_Type (Nam));
5951 -- Up to this point the expression could have been the actual in a
5952 -- simple entry call, and be given by a named association.
5954 if Nkind (Index) = N_Parameter_Association then
5955 Error_Msg_N ("expect expression for entry index", Index);
5957 Apply_Range_Check (Index, Actual_Index_Type (Nam));
5962 ------------------------
5963 -- Resolve_Entry_Call --
5964 ------------------------
5966 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
5967 Entry_Name : constant Node_Id := Name (N);
5968 Loc : constant Source_Ptr := Sloc (Entry_Name);
5970 First_Named : Node_Id;
5977 -- We kill all checks here, because it does not seem worth the effort to
5978 -- do anything better, an entry call is a big operation.
5982 -- Processing of the name is similar for entry calls and protected
5983 -- operation calls. Once the entity is determined, we can complete
5984 -- the resolution of the actuals.
5986 -- The selector may be overloaded, in the case of a protected object
5987 -- with overloaded functions. The type of the context is used for
5990 if Nkind (Entry_Name) = N_Selected_Component
5991 and then Is_Overloaded (Selector_Name (Entry_Name))
5992 and then Typ /= Standard_Void_Type
5999 Get_First_Interp (Selector_Name (Entry_Name), I, It);
6000 while Present (It.Typ) loop
6001 if Covers (Typ, It.Typ) then
6002 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6003 Set_Etype (Entry_Name, It.Typ);
6005 Generate_Reference (It.Typ, N, ' ');
6008 Get_Next_Interp (I, It);
6013 Resolve_Entry (Entry_Name);
6015 if Nkind (Entry_Name) = N_Selected_Component then
6017 -- Simple entry call
6019 Nam := Entity (Selector_Name (Entry_Name));
6020 Obj := Prefix (Entry_Name);
6021 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6023 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6025 -- Call to member of entry family
6027 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6028 Obj := Prefix (Prefix (Entry_Name));
6029 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6032 -- We cannot in general check the maximum depth of protected entry
6033 -- calls at compile time. But we can tell that any protected entry
6034 -- call at all violates a specified nesting depth of zero.
6036 if Is_Protected_Type (Scope (Nam)) then
6037 Check_Restriction (Max_Entry_Queue_Length, N);
6040 -- Use context type to disambiguate a protected function that can be
6041 -- called without actuals and that returns an array type, and where
6042 -- the argument list may be an indexing of the returned value.
6044 if Ekind (Nam) = E_Function
6045 and then Needs_No_Actuals (Nam)
6046 and then Present (Parameter_Associations (N))
6048 ((Is_Array_Type (Etype (Nam))
6049 and then Covers (Typ, Component_Type (Etype (Nam))))
6051 or else (Is_Access_Type (Etype (Nam))
6052 and then Is_Array_Type (Designated_Type (Etype (Nam)))
6053 and then Covers (Typ,
6054 Component_Type (Designated_Type (Etype (Nam))))))
6057 Index_Node : Node_Id;
6061 Make_Indexed_Component (Loc,
6063 Make_Function_Call (Loc,
6064 Name => Relocate_Node (Entry_Name)),
6065 Expressions => Parameter_Associations (N));
6067 -- Since we are correcting a node classification error made by
6068 -- the parser, we call Replace rather than Rewrite.
6070 Replace (N, Index_Node);
6071 Set_Etype (Prefix (N), Etype (Nam));
6073 Resolve_Indexed_Component (N, Typ);
6078 -- The operation name may have been overloaded. Order the actuals
6079 -- according to the formals of the resolved entity, and set the
6080 -- return type to that of the operation.
6083 Normalize_Actuals (N, Nam, False, Norm_OK);
6084 pragma Assert (Norm_OK);
6085 Set_Etype (N, Etype (Nam));
6088 Resolve_Actuals (N, Nam);
6089 Generate_Reference (Nam, Entry_Name);
6091 if Ekind (Nam) = E_Entry
6092 or else Ekind (Nam) = E_Entry_Family
6094 Check_Potentially_Blocking_Operation (N);
6097 -- Verify that a procedure call cannot masquerade as an entry
6098 -- call where an entry call is expected.
6100 if Ekind (Nam) = E_Procedure then
6101 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6102 and then N = Entry_Call_Statement (Parent (N))
6104 Error_Msg_N ("entry call required in select statement", N);
6106 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6107 and then N = Triggering_Statement (Parent (N))
6109 Error_Msg_N ("triggering statement cannot be procedure call", N);
6111 elsif Ekind (Scope (Nam)) = E_Task_Type
6112 and then not In_Open_Scopes (Scope (Nam))
6114 Error_Msg_N ("task has no entry with this name", Entry_Name);
6118 -- After resolution, entry calls and protected procedure calls are
6119 -- changed into entry calls, for expansion. The structure of the node
6120 -- does not change, so it can safely be done in place. Protected
6121 -- function calls must keep their structure because they are
6124 if Ekind (Nam) /= E_Function then
6126 -- A protected operation that is not a function may modify the
6127 -- corresponding object, and cannot apply to a constant. If this
6128 -- is an internal call, the prefix is the type itself.
6130 if Is_Protected_Type (Scope (Nam))
6131 and then not Is_Variable (Obj)
6132 and then (not Is_Entity_Name (Obj)
6133 or else not Is_Type (Entity (Obj)))
6136 ("prefix of protected procedure or entry call must be variable",
6140 Actuals := Parameter_Associations (N);
6141 First_Named := First_Named_Actual (N);
6144 Make_Entry_Call_Statement (Loc,
6146 Parameter_Associations => Actuals));
6148 Set_First_Named_Actual (N, First_Named);
6149 Set_Analyzed (N, True);
6151 -- Protected functions can return on the secondary stack, in which
6152 -- case we must trigger the transient scope mechanism.
6154 elsif Expander_Active
6155 and then Requires_Transient_Scope (Etype (Nam))
6157 Establish_Transient_Scope (N, Sec_Stack => True);
6159 end Resolve_Entry_Call;
6161 -------------------------
6162 -- Resolve_Equality_Op --
6163 -------------------------
6165 -- Both arguments must have the same type, and the boolean context does
6166 -- not participate in the resolution. The first pass verifies that the
6167 -- interpretation is not ambiguous, and the type of the left argument is
6168 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6169 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6170 -- though they carry a single (universal) type. Diagnose this case here.
6172 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6173 L : constant Node_Id := Left_Opnd (N);
6174 R : constant Node_Id := Right_Opnd (N);
6175 T : Entity_Id := Find_Unique_Type (L, R);
6177 function Find_Unique_Access_Type return Entity_Id;
6178 -- In the case of allocators, make a last-ditch attempt to find a single
6179 -- access type with the right designated type. This is semantically
6180 -- dubious, and of no interest to any real code, but c48008a makes it
6183 -----------------------------
6184 -- Find_Unique_Access_Type --
6185 -----------------------------
6187 function Find_Unique_Access_Type return Entity_Id is
6193 if Ekind (Etype (R)) = E_Allocator_Type then
6194 Acc := Designated_Type (Etype (R));
6195 elsif Ekind (Etype (L)) = E_Allocator_Type then
6196 Acc := Designated_Type (Etype (L));
6202 while S /= Standard_Standard loop
6203 E := First_Entity (S);
6204 while Present (E) loop
6206 and then Is_Access_Type (E)
6207 and then Ekind (E) /= E_Allocator_Type
6208 and then Designated_Type (E) = Base_Type (Acc)
6220 end Find_Unique_Access_Type;
6222 -- Start of processing for Resolve_Equality_Op
6225 Check_No_Direct_Boolean_Operators (N);
6227 Set_Etype (N, Base_Type (Typ));
6228 Generate_Reference (T, N, ' ');
6230 if T = Any_Fixed then
6231 T := Unique_Fixed_Point_Type (L);
6234 if T /= Any_Type then
6236 or else T = Any_Composite
6237 or else T = Any_Character
6239 if T = Any_Character then
6240 Ambiguous_Character (L);
6242 Error_Msg_N ("ambiguous operands for equality", N);
6245 Set_Etype (N, Any_Type);
6248 elsif T = Any_Access
6249 or else Ekind (T) = E_Allocator_Type
6250 or else Ekind (T) = E_Access_Attribute_Type
6252 T := Find_Unique_Access_Type;
6255 Error_Msg_N ("ambiguous operands for equality", N);
6256 Set_Etype (N, Any_Type);
6264 -- If the unique type is a class-wide type then it will be expanded
6265 -- into a dispatching call to the predefined primitive. Therefore we
6266 -- check here for potential violation of such restriction.
6268 if Is_Class_Wide_Type (T) then
6269 Check_Restriction (No_Dispatching_Calls, N);
6272 if Warn_On_Redundant_Constructs
6273 and then Comes_From_Source (N)
6274 and then Is_Entity_Name (R)
6275 and then Entity (R) = Standard_True
6276 and then Comes_From_Source (R)
6278 Error_Msg_N ("?comparison with True is redundant!", R);
6281 Check_Unset_Reference (L);
6282 Check_Unset_Reference (R);
6283 Generate_Operator_Reference (N, T);
6284 Check_Low_Bound_Tested (N);
6286 -- If this is an inequality, it may be the implicit inequality
6287 -- created for a user-defined operation, in which case the corres-
6288 -- ponding equality operation is not intrinsic, and the operation
6289 -- cannot be constant-folded. Else fold.
6291 if Nkind (N) = N_Op_Eq
6292 or else Comes_From_Source (Entity (N))
6293 or else Ekind (Entity (N)) = E_Operator
6294 or else Is_Intrinsic_Subprogram
6295 (Corresponding_Equality (Entity (N)))
6297 Eval_Relational_Op (N);
6299 elsif Nkind (N) = N_Op_Ne
6300 and then Is_Abstract_Subprogram (Entity (N))
6302 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6305 -- Ada 2005: If one operand is an anonymous access type, convert the
6306 -- other operand to it, to ensure that the underlying types match in
6307 -- the back-end. Same for access_to_subprogram, and the conversion
6308 -- verifies that the types are subtype conformant.
6310 -- We apply the same conversion in the case one of the operands is a
6311 -- private subtype of the type of the other.
6313 -- Why the Expander_Active test here ???
6317 (Ekind (T) = E_Anonymous_Access_Type
6318 or else Ekind (T) = E_Anonymous_Access_Subprogram_Type
6319 or else Is_Private_Type (T))
6321 if Etype (L) /= T then
6323 Make_Unchecked_Type_Conversion (Sloc (L),
6324 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6325 Expression => Relocate_Node (L)));
6326 Analyze_And_Resolve (L, T);
6329 if (Etype (R)) /= T then
6331 Make_Unchecked_Type_Conversion (Sloc (R),
6332 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6333 Expression => Relocate_Node (R)));
6334 Analyze_And_Resolve (R, T);
6338 end Resolve_Equality_Op;
6340 ----------------------------------
6341 -- Resolve_Explicit_Dereference --
6342 ----------------------------------
6344 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
6345 Loc : constant Source_Ptr := Sloc (N);
6347 P : constant Node_Id := Prefix (N);
6352 Check_Fully_Declared_Prefix (Typ, P);
6354 if Is_Overloaded (P) then
6356 -- Use the context type to select the prefix that has the correct
6359 Get_First_Interp (P, I, It);
6360 while Present (It.Typ) loop
6361 exit when Is_Access_Type (It.Typ)
6362 and then Covers (Typ, Designated_Type (It.Typ));
6363 Get_Next_Interp (I, It);
6366 if Present (It.Typ) then
6367 Resolve (P, It.Typ);
6369 -- If no interpretation covers the designated type of the prefix,
6370 -- this is the pathological case where not all implementations of
6371 -- the prefix allow the interpretation of the node as a call. Now
6372 -- that the expected type is known, Remove other interpretations
6373 -- from prefix, rewrite it as a call, and resolve again, so that
6374 -- the proper call node is generated.
6376 Get_First_Interp (P, I, It);
6377 while Present (It.Typ) loop
6378 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6382 Get_Next_Interp (I, It);
6386 Make_Function_Call (Loc,
6388 Make_Explicit_Dereference (Loc,
6390 Parameter_Associations => New_List);
6392 Save_Interps (N, New_N);
6394 Analyze_And_Resolve (N, Typ);
6398 Set_Etype (N, Designated_Type (It.Typ));
6404 if Is_Access_Type (Etype (P)) then
6405 Apply_Access_Check (N);
6408 -- If the designated type is a packed unconstrained array type, and the
6409 -- explicit dereference is not in the context of an attribute reference,
6410 -- then we must compute and set the actual subtype, since it is needed
6411 -- by Gigi. The reason we exclude the attribute case is that this is
6412 -- handled fine by Gigi, and in fact we use such attributes to build the
6413 -- actual subtype. We also exclude generated code (which builds actual
6414 -- subtypes directly if they are needed).
6416 if Is_Array_Type (Etype (N))
6417 and then Is_Packed (Etype (N))
6418 and then not Is_Constrained (Etype (N))
6419 and then Nkind (Parent (N)) /= N_Attribute_Reference
6420 and then Comes_From_Source (N)
6422 Set_Etype (N, Get_Actual_Subtype (N));
6425 -- Note: there is no Eval processing required for an explicit deference,
6426 -- because the type is known to be an allocators, and allocator
6427 -- expressions can never be static.
6429 end Resolve_Explicit_Dereference;
6431 -------------------------------
6432 -- Resolve_Indexed_Component --
6433 -------------------------------
6435 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6436 Name : constant Node_Id := Prefix (N);
6438 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6442 if Is_Overloaded (Name) then
6444 -- Use the context type to select the prefix that yields the correct
6450 I1 : Interp_Index := 0;
6451 P : constant Node_Id := Prefix (N);
6452 Found : Boolean := False;
6455 Get_First_Interp (P, I, It);
6456 while Present (It.Typ) loop
6457 if (Is_Array_Type (It.Typ)
6458 and then Covers (Typ, Component_Type (It.Typ)))
6459 or else (Is_Access_Type (It.Typ)
6460 and then Is_Array_Type (Designated_Type (It.Typ))
6462 (Typ, Component_Type (Designated_Type (It.Typ))))
6465 It := Disambiguate (P, I1, I, Any_Type);
6467 if It = No_Interp then
6468 Error_Msg_N ("ambiguous prefix for indexing", N);
6474 Array_Type := It.Typ;
6480 Array_Type := It.Typ;
6485 Get_Next_Interp (I, It);
6490 Array_Type := Etype (Name);
6493 Resolve (Name, Array_Type);
6494 Array_Type := Get_Actual_Subtype_If_Available (Name);
6496 -- If prefix is access type, dereference to get real array type.
6497 -- Note: we do not apply an access check because the expander always
6498 -- introduces an explicit dereference, and the check will happen there.
6500 if Is_Access_Type (Array_Type) then
6501 Array_Type := Designated_Type (Array_Type);
6504 -- If name was overloaded, set component type correctly now
6505 -- If a misplaced call to an entry family (which has no index types)
6506 -- return. Error will be diagnosed from calling context.
6508 if Is_Array_Type (Array_Type) then
6509 Set_Etype (N, Component_Type (Array_Type));
6514 Index := First_Index (Array_Type);
6515 Expr := First (Expressions (N));
6517 -- The prefix may have resolved to a string literal, in which case its
6518 -- etype has a special representation. This is only possible currently
6519 -- if the prefix is a static concatenation, written in functional
6522 if Ekind (Array_Type) = E_String_Literal_Subtype then
6523 Resolve (Expr, Standard_Positive);
6526 while Present (Index) and Present (Expr) loop
6527 Resolve (Expr, Etype (Index));
6528 Check_Unset_Reference (Expr);
6530 if Is_Scalar_Type (Etype (Expr)) then
6531 Apply_Scalar_Range_Check (Expr, Etype (Index));
6533 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
6541 -- Do not generate the warning on suspicious index if we are analyzing
6542 -- package Ada.Tags; otherwise we will report the warning with the
6543 -- Prims_Ptr field of the dispatch table.
6545 if Scope (Etype (Prefix (N))) = Standard_Standard
6547 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
6550 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
6551 Eval_Indexed_Component (N);
6553 end Resolve_Indexed_Component;
6555 -----------------------------
6556 -- Resolve_Integer_Literal --
6557 -----------------------------
6559 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
6562 Eval_Integer_Literal (N);
6563 end Resolve_Integer_Literal;
6565 --------------------------------
6566 -- Resolve_Intrinsic_Operator --
6567 --------------------------------
6569 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
6570 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6577 while Scope (Op) /= Standard_Standard loop
6579 pragma Assert (Present (Op));
6583 Set_Is_Overloaded (N, False);
6585 -- If the operand type is private, rewrite with suitable conversions on
6586 -- the operands and the result, to expose the proper underlying numeric
6589 if Is_Private_Type (Typ) then
6590 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
6592 if Nkind (N) = N_Op_Expon then
6593 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
6595 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6598 Save_Interps (Left_Opnd (N), Expression (Arg1));
6599 Save_Interps (Right_Opnd (N), Expression (Arg2));
6601 Set_Left_Opnd (N, Arg1);
6602 Set_Right_Opnd (N, Arg2);
6604 Set_Etype (N, Btyp);
6605 Rewrite (N, Unchecked_Convert_To (Typ, N));
6608 elsif Typ /= Etype (Left_Opnd (N))
6609 or else Typ /= Etype (Right_Opnd (N))
6611 -- Add explicit conversion where needed, and save interpretations in
6612 -- case operands are overloaded.
6614 Arg1 := Convert_To (Typ, Left_Opnd (N));
6615 Arg2 := Convert_To (Typ, Right_Opnd (N));
6617 if Nkind (Arg1) = N_Type_Conversion then
6618 Save_Interps (Left_Opnd (N), Expression (Arg1));
6620 Save_Interps (Left_Opnd (N), Arg1);
6623 if Nkind (Arg2) = N_Type_Conversion then
6624 Save_Interps (Right_Opnd (N), Expression (Arg2));
6626 Save_Interps (Right_Opnd (N), Arg2);
6629 Rewrite (Left_Opnd (N), Arg1);
6630 Rewrite (Right_Opnd (N), Arg2);
6633 Resolve_Arithmetic_Op (N, Typ);
6636 Resolve_Arithmetic_Op (N, Typ);
6638 end Resolve_Intrinsic_Operator;
6640 --------------------------------------
6641 -- Resolve_Intrinsic_Unary_Operator --
6642 --------------------------------------
6644 procedure Resolve_Intrinsic_Unary_Operator
6648 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
6654 while Scope (Op) /= Standard_Standard loop
6656 pragma Assert (Present (Op));
6661 if Is_Private_Type (Typ) then
6662 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
6663 Save_Interps (Right_Opnd (N), Expression (Arg2));
6665 Set_Right_Opnd (N, Arg2);
6667 Set_Etype (N, Btyp);
6668 Rewrite (N, Unchecked_Convert_To (Typ, N));
6672 Resolve_Unary_Op (N, Typ);
6674 end Resolve_Intrinsic_Unary_Operator;
6676 ------------------------
6677 -- Resolve_Logical_Op --
6678 ------------------------
6680 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
6684 Check_No_Direct_Boolean_Operators (N);
6686 -- Predefined operations on scalar types yield the base type. On the
6687 -- other hand, logical operations on arrays yield the type of the
6688 -- arguments (and the context).
6690 if Is_Array_Type (Typ) then
6693 B_Typ := Base_Type (Typ);
6696 -- The following test is required because the operands of the operation
6697 -- may be literals, in which case the resulting type appears to be
6698 -- compatible with a signed integer type, when in fact it is compatible
6699 -- only with modular types. If the context itself is universal, the
6700 -- operation is illegal.
6702 if not Valid_Boolean_Arg (Typ) then
6703 Error_Msg_N ("invalid context for logical operation", N);
6704 Set_Etype (N, Any_Type);
6707 elsif Typ = Any_Modular then
6709 ("no modular type available in this context", N);
6710 Set_Etype (N, Any_Type);
6712 elsif Is_Modular_Integer_Type (Typ)
6713 and then Etype (Left_Opnd (N)) = Universal_Integer
6714 and then Etype (Right_Opnd (N)) = Universal_Integer
6716 Check_For_Visible_Operator (N, B_Typ);
6719 Resolve (Left_Opnd (N), B_Typ);
6720 Resolve (Right_Opnd (N), B_Typ);
6722 Check_Unset_Reference (Left_Opnd (N));
6723 Check_Unset_Reference (Right_Opnd (N));
6725 Set_Etype (N, B_Typ);
6726 Generate_Operator_Reference (N, B_Typ);
6727 Eval_Logical_Op (N);
6728 end Resolve_Logical_Op;
6730 ---------------------------
6731 -- Resolve_Membership_Op --
6732 ---------------------------
6734 -- The context can only be a boolean type, and does not determine
6735 -- the arguments. Arguments should be unambiguous, but the preference
6736 -- rule for universal types applies.
6738 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
6739 pragma Warnings (Off, Typ);
6741 L : constant Node_Id := Left_Opnd (N);
6742 R : constant Node_Id := Right_Opnd (N);
6746 if L = Error or else R = Error then
6750 if not Is_Overloaded (R)
6752 (Etype (R) = Universal_Integer or else
6753 Etype (R) = Universal_Real)
6754 and then Is_Overloaded (L)
6758 -- Ada 2005 (AI-251): Support the following case:
6760 -- type I is interface;
6761 -- type T is tagged ...
6763 -- function Test (O : I'Class) is
6765 -- return O in T'Class.
6768 -- In this case we have nothing else to do. The membership test will be
6769 -- done at run-time.
6771 elsif Ada_Version >= Ada_05
6772 and then Is_Class_Wide_Type (Etype (L))
6773 and then Is_Interface (Etype (L))
6774 and then Is_Class_Wide_Type (Etype (R))
6775 and then not Is_Interface (Etype (R))
6780 T := Intersect_Types (L, R);
6784 Check_Unset_Reference (L);
6786 if Nkind (R) = N_Range
6787 and then not Is_Scalar_Type (T)
6789 Error_Msg_N ("scalar type required for range", R);
6792 if Is_Entity_Name (R) then
6793 Freeze_Expression (R);
6796 Check_Unset_Reference (R);
6799 Eval_Membership_Op (N);
6800 end Resolve_Membership_Op;
6806 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
6807 Loc : constant Source_Ptr := Sloc (N);
6810 -- Handle restriction against anonymous null access values This
6811 -- restriction can be turned off using -gnatdj.
6813 -- Ada 2005 (AI-231): Remove restriction
6815 if Ada_Version < Ada_05
6816 and then not Debug_Flag_J
6817 and then Ekind (Typ) = E_Anonymous_Access_Type
6818 and then Comes_From_Source (N)
6820 -- In the common case of a call which uses an explicitly null value
6821 -- for an access parameter, give specialized error message.
6823 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
6827 ("null is not allowed as argument for an access parameter", N);
6829 -- Standard message for all other cases (are there any?)
6833 ("null cannot be of an anonymous access type", N);
6837 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6838 -- assignment to a null-excluding object
6840 if Ada_Version >= Ada_05
6841 and then Can_Never_Be_Null (Typ)
6842 and then Nkind (Parent (N)) = N_Assignment_Statement
6844 if not Inside_Init_Proc then
6846 (Compile_Time_Constraint_Error (N,
6847 "(Ada 2005) null not allowed in null-excluding objects?"),
6848 Make_Raise_Constraint_Error (Loc,
6849 Reason => CE_Access_Check_Failed));
6852 Make_Raise_Constraint_Error (Loc,
6853 Reason => CE_Access_Check_Failed));
6857 -- In a distributed context, null for a remote access to subprogram may
6858 -- need to be replaced with a special record aggregate. In this case,
6859 -- return after having done the transformation.
6861 if (Ekind (Typ) = E_Record_Type
6862 or else Is_Remote_Access_To_Subprogram_Type (Typ))
6863 and then Remote_AST_Null_Value (N, Typ)
6868 -- The null literal takes its type from the context
6873 -----------------------
6874 -- Resolve_Op_Concat --
6875 -----------------------
6877 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
6879 -- We wish to avoid deep recursion, because concatenations are often
6880 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6881 -- operands nonrecursively until we find something that is not a simple
6882 -- concatenation (A in this case). We resolve that, and then walk back
6883 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6884 -- to do the rest of the work at each level. The Parent pointers allow
6885 -- us to avoid recursion, and thus avoid running out of memory. See also
6886 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
6892 -- The following code is equivalent to:
6894 -- Resolve_Op_Concat_First (NN, Typ);
6895 -- Resolve_Op_Concat_Arg (N, ...);
6896 -- Resolve_Op_Concat_Rest (N, Typ);
6898 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6899 -- operand is a concatenation.
6901 -- Walk down left operands
6904 Resolve_Op_Concat_First (NN, Typ);
6905 Op1 := Left_Opnd (NN);
6906 exit when not (Nkind (Op1) = N_Op_Concat
6907 and then not Is_Array_Type (Component_Type (Typ))
6908 and then Entity (Op1) = Entity (NN));
6912 -- Now (given the above example) NN is A&B and Op1 is A
6914 -- First resolve Op1 ...
6916 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
6918 -- ... then walk NN back up until we reach N (where we started), calling
6919 -- Resolve_Op_Concat_Rest along the way.
6922 Resolve_Op_Concat_Rest (NN, Typ);
6926 end Resolve_Op_Concat;
6928 ---------------------------
6929 -- Resolve_Op_Concat_Arg --
6930 ---------------------------
6932 procedure Resolve_Op_Concat_Arg
6938 Btyp : constant Entity_Id := Base_Type (Typ);
6943 or else (not Is_Overloaded (Arg)
6944 and then Etype (Arg) /= Any_Composite
6945 and then Covers (Component_Type (Typ), Etype (Arg)))
6947 Resolve (Arg, Component_Type (Typ));
6949 Resolve (Arg, Btyp);
6952 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
6953 if Nkind (Arg) = N_Aggregate
6954 and then Is_Composite_Type (Component_Type (Typ))
6956 if Is_Private_Type (Component_Type (Typ)) then
6957 Resolve (Arg, Btyp);
6959 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
6960 Set_Etype (Arg, Any_Type);
6964 if Is_Overloaded (Arg)
6965 and then Has_Compatible_Type (Arg, Typ)
6966 and then Etype (Arg) /= Any_Type
6974 Get_First_Interp (Arg, I, It);
6976 Get_Next_Interp (I, It);
6978 -- Special-case the error message when the overloading is
6979 -- caused by a function that yields an array and can be
6980 -- called without parameters.
6982 if It.Nam = Func then
6983 Error_Msg_Sloc := Sloc (Func);
6984 Error_Msg_N ("ambiguous call to function#", Arg);
6986 ("\\interpretation as call yields&", Arg, Typ);
6988 ("\\interpretation as indexing of call yields&",
6989 Arg, Component_Type (Typ));
6993 ("ambiguous operand for concatenation!", Arg);
6994 Get_First_Interp (Arg, I, It);
6995 while Present (It.Nam) loop
6996 Error_Msg_Sloc := Sloc (It.Nam);
6998 if Base_Type (It.Typ) = Base_Type (Typ)
6999 or else Base_Type (It.Typ) =
7000 Base_Type (Component_Type (Typ))
7002 Error_Msg_N -- CODEFIX
7003 ("\\possible interpretation#", Arg);
7006 Get_Next_Interp (I, It);
7012 Resolve (Arg, Component_Type (Typ));
7014 if Nkind (Arg) = N_String_Literal then
7015 Set_Etype (Arg, Component_Type (Typ));
7018 if Arg = Left_Opnd (N) then
7019 Set_Is_Component_Left_Opnd (N);
7021 Set_Is_Component_Right_Opnd (N);
7026 Resolve (Arg, Btyp);
7029 Check_Unset_Reference (Arg);
7030 end Resolve_Op_Concat_Arg;
7032 -----------------------------
7033 -- Resolve_Op_Concat_First --
7034 -----------------------------
7036 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7037 Btyp : constant Entity_Id := Base_Type (Typ);
7038 Op1 : constant Node_Id := Left_Opnd (N);
7039 Op2 : constant Node_Id := Right_Opnd (N);
7042 -- The parser folds an enormous sequence of concatenations of string
7043 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7044 -- in the right operand. If the expression resolves to a predefined "&"
7045 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7046 -- we give an error. See P_Simple_Expression in Par.Ch4.
7048 if Nkind (Op2) = N_String_Literal
7049 and then Is_Folded_In_Parser (Op2)
7050 and then Ekind (Entity (N)) = E_Function
7052 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7053 and then String_Length (Strval (Op1)) = 0);
7054 Error_Msg_N ("too many user-defined concatenations", N);
7058 Set_Etype (N, Btyp);
7060 if Is_Limited_Composite (Btyp) then
7061 Error_Msg_N ("concatenation not available for limited array", N);
7062 Explain_Limited_Type (Btyp, N);
7064 end Resolve_Op_Concat_First;
7066 ----------------------------
7067 -- Resolve_Op_Concat_Rest --
7068 ----------------------------
7070 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7071 Op1 : constant Node_Id := Left_Opnd (N);
7072 Op2 : constant Node_Id := Right_Opnd (N);
7075 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
7077 Generate_Operator_Reference (N, Typ);
7079 if Is_String_Type (Typ) then
7080 Eval_Concatenation (N);
7083 -- If this is not a static concatenation, but the result is a string
7084 -- type (and not an array of strings) ensure that static string operands
7085 -- have their subtypes properly constructed.
7087 if Nkind (N) /= N_String_Literal
7088 and then Is_Character_Type (Component_Type (Typ))
7090 Set_String_Literal_Subtype (Op1, Typ);
7091 Set_String_Literal_Subtype (Op2, Typ);
7093 end Resolve_Op_Concat_Rest;
7095 ----------------------
7096 -- Resolve_Op_Expon --
7097 ----------------------
7099 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7100 B_Typ : constant Entity_Id := Base_Type (Typ);
7103 -- Catch attempts to do fixed-point exponentiation with universal
7104 -- operands, which is a case where the illegality is not caught during
7105 -- normal operator analysis.
7107 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7108 Error_Msg_N ("exponentiation not available for fixed point", N);
7112 if Comes_From_Source (N)
7113 and then Ekind (Entity (N)) = E_Function
7114 and then Is_Imported (Entity (N))
7115 and then Is_Intrinsic_Subprogram (Entity (N))
7117 Resolve_Intrinsic_Operator (N, Typ);
7121 if Etype (Left_Opnd (N)) = Universal_Integer
7122 or else Etype (Left_Opnd (N)) = Universal_Real
7124 Check_For_Visible_Operator (N, B_Typ);
7127 -- We do the resolution using the base type, because intermediate values
7128 -- in expressions always are of the base type, not a subtype of it.
7130 Resolve (Left_Opnd (N), B_Typ);
7131 Resolve (Right_Opnd (N), Standard_Integer);
7133 Check_Unset_Reference (Left_Opnd (N));
7134 Check_Unset_Reference (Right_Opnd (N));
7136 Set_Etype (N, B_Typ);
7137 Generate_Operator_Reference (N, B_Typ);
7140 -- Set overflow checking bit. Much cleverer code needed here eventually
7141 -- and perhaps the Resolve routines should be separated for the various
7142 -- arithmetic operations, since they will need different processing. ???
7144 if Nkind (N) in N_Op then
7145 if not Overflow_Checks_Suppressed (Etype (N)) then
7146 Enable_Overflow_Check (N);
7149 end Resolve_Op_Expon;
7151 --------------------
7152 -- Resolve_Op_Not --
7153 --------------------
7155 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7158 function Parent_Is_Boolean return Boolean;
7159 -- This function determines if the parent node is a boolean operator
7160 -- or operation (comparison op, membership test, or short circuit form)
7161 -- and the not in question is the left operand of this operation.
7162 -- Note that if the not is in parens, then false is returned.
7164 -----------------------
7165 -- Parent_Is_Boolean --
7166 -----------------------
7168 function Parent_Is_Boolean return Boolean is
7170 if Paren_Count (N) /= 0 then
7174 case Nkind (Parent (N)) is
7189 return Left_Opnd (Parent (N)) = N;
7195 end Parent_Is_Boolean;
7197 -- Start of processing for Resolve_Op_Not
7200 -- Predefined operations on scalar types yield the base type. On the
7201 -- other hand, logical operations on arrays yield the type of the
7202 -- arguments (and the context).
7204 if Is_Array_Type (Typ) then
7207 B_Typ := Base_Type (Typ);
7210 -- Straightforward case of incorrect arguments
7212 if not Valid_Boolean_Arg (Typ) then
7213 Error_Msg_N ("invalid operand type for operator&", N);
7214 Set_Etype (N, Any_Type);
7217 -- Special case of probable missing parens
7219 elsif Typ = Universal_Integer or else Typ = Any_Modular then
7220 if Parent_Is_Boolean then
7222 ("operand of not must be enclosed in parentheses",
7226 ("no modular type available in this context", N);
7229 Set_Etype (N, Any_Type);
7232 -- OK resolution of not
7235 -- Warn if non-boolean types involved. This is a case like not a < b
7236 -- where a and b are modular, where we will get (not a) < b and most
7237 -- likely not (a < b) was intended.
7239 if Warn_On_Questionable_Missing_Parens
7240 and then not Is_Boolean_Type (Typ)
7241 and then Parent_Is_Boolean
7243 Error_Msg_N ("?not expression should be parenthesized here!", N);
7246 -- Warn on double negation if checking redundant constructs
7248 if Warn_On_Redundant_Constructs
7249 and then Comes_From_Source (N)
7250 and then Comes_From_Source (Right_Opnd (N))
7251 and then Root_Type (Typ) = Standard_Boolean
7252 and then Nkind (Right_Opnd (N)) = N_Op_Not
7254 Error_Msg_N ("redundant double negation?", N);
7257 -- Complete resolution and evaluation of NOT
7259 Resolve (Right_Opnd (N), B_Typ);
7260 Check_Unset_Reference (Right_Opnd (N));
7261 Set_Etype (N, B_Typ);
7262 Generate_Operator_Reference (N, B_Typ);
7267 -----------------------------
7268 -- Resolve_Operator_Symbol --
7269 -----------------------------
7271 -- Nothing to be done, all resolved already
7273 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
7274 pragma Warnings (Off, N);
7275 pragma Warnings (Off, Typ);
7279 end Resolve_Operator_Symbol;
7281 ----------------------------------
7282 -- Resolve_Qualified_Expression --
7283 ----------------------------------
7285 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
7286 pragma Warnings (Off, Typ);
7288 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7289 Expr : constant Node_Id := Expression (N);
7292 Resolve (Expr, Target_Typ);
7294 -- A qualified expression requires an exact match of the type,
7295 -- class-wide matching is not allowed. However, if the qualifying
7296 -- type is specific and the expression has a class-wide type, it
7297 -- may still be okay, since it can be the result of the expansion
7298 -- of a call to a dispatching function, so we also have to check
7299 -- class-wideness of the type of the expression's original node.
7301 if (Is_Class_Wide_Type (Target_Typ)
7303 (Is_Class_Wide_Type (Etype (Expr))
7304 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
7305 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7307 Wrong_Type (Expr, Target_Typ);
7310 -- If the target type is unconstrained, then we reset the type of
7311 -- the result from the type of the expression. For other cases, the
7312 -- actual subtype of the expression is the target type.
7314 if Is_Composite_Type (Target_Typ)
7315 and then not Is_Constrained (Target_Typ)
7317 Set_Etype (N, Etype (Expr));
7320 Eval_Qualified_Expression (N);
7321 end Resolve_Qualified_Expression;
7327 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7328 L : constant Node_Id := Low_Bound (N);
7329 H : constant Node_Id := High_Bound (N);
7336 Check_Unset_Reference (L);
7337 Check_Unset_Reference (H);
7339 -- We have to check the bounds for being within the base range as
7340 -- required for a non-static context. Normally this is automatic and
7341 -- done as part of evaluating expressions, but the N_Range node is an
7342 -- exception, since in GNAT we consider this node to be a subexpression,
7343 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7344 -- this, but that would put the test on the main evaluation path for
7347 Check_Non_Static_Context (L);
7348 Check_Non_Static_Context (H);
7350 -- Check for an ambiguous range over character literals. This will
7351 -- happen with a membership test involving only literals.
7353 if Typ = Any_Character then
7354 Ambiguous_Character (L);
7355 Set_Etype (N, Any_Type);
7359 -- If bounds are static, constant-fold them, so size computations
7360 -- are identical between front-end and back-end. Do not perform this
7361 -- transformation while analyzing generic units, as type information
7362 -- would then be lost when reanalyzing the constant node in the
7365 if Is_Discrete_Type (Typ) and then Expander_Active then
7366 if Is_OK_Static_Expression (L) then
7367 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
7370 if Is_OK_Static_Expression (H) then
7371 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
7376 --------------------------
7377 -- Resolve_Real_Literal --
7378 --------------------------
7380 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
7381 Actual_Typ : constant Entity_Id := Etype (N);
7384 -- Special processing for fixed-point literals to make sure that the
7385 -- value is an exact multiple of small where this is required. We
7386 -- skip this for the universal real case, and also for generic types.
7388 if Is_Fixed_Point_Type (Typ)
7389 and then Typ /= Universal_Fixed
7390 and then Typ /= Any_Fixed
7391 and then not Is_Generic_Type (Typ)
7394 Val : constant Ureal := Realval (N);
7395 Cintr : constant Ureal := Val / Small_Value (Typ);
7396 Cint : constant Uint := UR_Trunc (Cintr);
7397 Den : constant Uint := Norm_Den (Cintr);
7401 -- Case of literal is not an exact multiple of the Small
7405 -- For a source program literal for a decimal fixed-point
7406 -- type, this is statically illegal (RM 4.9(36)).
7408 if Is_Decimal_Fixed_Point_Type (Typ)
7409 and then Actual_Typ = Universal_Real
7410 and then Comes_From_Source (N)
7412 Error_Msg_N ("value has extraneous low order digits", N);
7415 -- Generate a warning if literal from source
7417 if Is_Static_Expression (N)
7418 and then Warn_On_Bad_Fixed_Value
7421 ("?static fixed-point value is not a multiple of Small!",
7425 -- Replace literal by a value that is the exact representation
7426 -- of a value of the type, i.e. a multiple of the small value,
7427 -- by truncation, since Machine_Rounds is false for all GNAT
7428 -- fixed-point types (RM 4.9(38)).
7430 Stat := Is_Static_Expression (N);
7432 Make_Real_Literal (Sloc (N),
7433 Realval => Small_Value (Typ) * Cint));
7435 Set_Is_Static_Expression (N, Stat);
7438 -- In all cases, set the corresponding integer field
7440 Set_Corresponding_Integer_Value (N, Cint);
7444 -- Now replace the actual type by the expected type as usual
7447 Eval_Real_Literal (N);
7448 end Resolve_Real_Literal;
7450 -----------------------
7451 -- Resolve_Reference --
7452 -----------------------
7454 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
7455 P : constant Node_Id := Prefix (N);
7458 -- Replace general access with specific type
7460 if Ekind (Etype (N)) = E_Allocator_Type then
7461 Set_Etype (N, Base_Type (Typ));
7464 Resolve (P, Designated_Type (Etype (N)));
7466 -- If we are taking the reference of a volatile entity, then treat
7467 -- it as a potential modification of this entity. This is much too
7468 -- conservative, but is necessary because remove side effects can
7469 -- result in transformations of normal assignments into reference
7470 -- sequences that otherwise fail to notice the modification.
7472 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
7473 Note_Possible_Modification (P, Sure => False);
7475 end Resolve_Reference;
7477 --------------------------------
7478 -- Resolve_Selected_Component --
7479 --------------------------------
7481 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
7483 Comp1 : Entity_Id := Empty; -- prevent junk warning
7484 P : constant Node_Id := Prefix (N);
7485 S : constant Node_Id := Selector_Name (N);
7486 T : Entity_Id := Etype (P);
7488 I1 : Interp_Index := 0; -- prevent junk warning
7493 function Init_Component return Boolean;
7494 -- Check whether this is the initialization of a component within an
7495 -- init proc (by assignment or call to another init proc). If true,
7496 -- there is no need for a discriminant check.
7498 --------------------
7499 -- Init_Component --
7500 --------------------
7502 function Init_Component return Boolean is
7504 return Inside_Init_Proc
7505 and then Nkind (Prefix (N)) = N_Identifier
7506 and then Chars (Prefix (N)) = Name_uInit
7507 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
7510 -- Start of processing for Resolve_Selected_Component
7513 if Is_Overloaded (P) then
7515 -- Use the context type to select the prefix that has a selector
7516 -- of the correct name and type.
7519 Get_First_Interp (P, I, It);
7521 Search : while Present (It.Typ) loop
7522 if Is_Access_Type (It.Typ) then
7523 T := Designated_Type (It.Typ);
7528 if Is_Record_Type (T) then
7530 -- The visible components of a class-wide type are those of
7533 if Is_Class_Wide_Type (T) then
7537 Comp := First_Entity (T);
7538 while Present (Comp) loop
7539 if Chars (Comp) = Chars (S)
7540 and then Covers (Etype (Comp), Typ)
7549 It := Disambiguate (P, I1, I, Any_Type);
7551 if It = No_Interp then
7553 ("ambiguous prefix for selected component", N);
7560 -- There may be an implicit dereference. Retrieve
7561 -- designated record type.
7563 if Is_Access_Type (It1.Typ) then
7564 T := Designated_Type (It1.Typ);
7569 if Scope (Comp1) /= T then
7571 -- Resolution chooses the new interpretation.
7572 -- Find the component with the right name.
7574 Comp1 := First_Entity (T);
7575 while Present (Comp1)
7576 and then Chars (Comp1) /= Chars (S)
7578 Comp1 := Next_Entity (Comp1);
7587 Comp := Next_Entity (Comp);
7592 Get_Next_Interp (I, It);
7595 Resolve (P, It1.Typ);
7597 Set_Entity_With_Style_Check (S, Comp1);
7600 -- Resolve prefix with its type
7605 -- Generate cross-reference. We needed to wait until full overloading
7606 -- resolution was complete to do this, since otherwise we can't tell if
7607 -- we are an Lvalue of not.
7609 if May_Be_Lvalue (N) then
7610 Generate_Reference (Entity (S), S, 'm');
7612 Generate_Reference (Entity (S), S, 'r');
7615 -- If prefix is an access type, the node will be transformed into an
7616 -- explicit dereference during expansion. The type of the node is the
7617 -- designated type of that of the prefix.
7619 if Is_Access_Type (Etype (P)) then
7620 T := Designated_Type (Etype (P));
7621 Check_Fully_Declared_Prefix (T, P);
7626 if Has_Discriminants (T)
7627 and then (Ekind (Entity (S)) = E_Component
7629 Ekind (Entity (S)) = E_Discriminant)
7630 and then Present (Original_Record_Component (Entity (S)))
7631 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
7632 and then Present (Discriminant_Checking_Func
7633 (Original_Record_Component (Entity (S))))
7634 and then not Discriminant_Checks_Suppressed (T)
7635 and then not Init_Component
7637 Set_Do_Discriminant_Check (N);
7640 if Ekind (Entity (S)) = E_Void then
7641 Error_Msg_N ("premature use of component", S);
7644 -- If the prefix is a record conversion, this may be a renamed
7645 -- discriminant whose bounds differ from those of the original
7646 -- one, so we must ensure that a range check is performed.
7648 if Nkind (P) = N_Type_Conversion
7649 and then Ekind (Entity (S)) = E_Discriminant
7650 and then Is_Discrete_Type (Typ)
7652 Set_Etype (N, Base_Type (Typ));
7655 -- Note: No Eval processing is required, because the prefix is of a
7656 -- record type, or protected type, and neither can possibly be static.
7658 end Resolve_Selected_Component;
7664 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
7665 B_Typ : constant Entity_Id := Base_Type (Typ);
7666 L : constant Node_Id := Left_Opnd (N);
7667 R : constant Node_Id := Right_Opnd (N);
7670 -- We do the resolution using the base type, because intermediate values
7671 -- in expressions always are of the base type, not a subtype of it.
7674 Resolve (R, Standard_Natural);
7676 Check_Unset_Reference (L);
7677 Check_Unset_Reference (R);
7679 Set_Etype (N, B_Typ);
7680 Generate_Operator_Reference (N, B_Typ);
7684 ---------------------------
7685 -- Resolve_Short_Circuit --
7686 ---------------------------
7688 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
7689 B_Typ : constant Entity_Id := Base_Type (Typ);
7690 L : constant Node_Id := Left_Opnd (N);
7691 R : constant Node_Id := Right_Opnd (N);
7697 -- Check for issuing warning for always False assert/check, this happens
7698 -- when assertions are turned off, in which case the pragma Assert/Check
7699 -- was transformed into:
7701 -- if False and then <condition> then ...
7703 -- and we detect this pattern
7705 if Warn_On_Assertion_Failure
7706 and then Is_Entity_Name (R)
7707 and then Entity (R) = Standard_False
7708 and then Nkind (Parent (N)) = N_If_Statement
7709 and then Nkind (N) = N_And_Then
7710 and then Is_Entity_Name (L)
7711 and then Entity (L) = Standard_False
7714 Orig : constant Node_Id := Original_Node (Parent (N));
7717 if Nkind (Orig) = N_Pragma
7718 and then Pragma_Name (Orig) = Name_Assert
7720 -- Don't want to warn if original condition is explicit False
7723 Expr : constant Node_Id :=
7726 (First (Pragma_Argument_Associations (Orig))));
7728 if Is_Entity_Name (Expr)
7729 and then Entity (Expr) = Standard_False
7733 -- Issue warning. Note that we don't want to make this
7734 -- an unconditional warning, because if the assert is
7735 -- within deleted code we do not want the warning. But
7736 -- we do not want the deletion of the IF/AND-THEN to
7737 -- take this message with it. We achieve this by making
7738 -- sure that the expanded code points to the Sloc of
7739 -- the expression, not the original pragma.
7741 Error_Msg_N ("?assertion would fail at run-time", Orig);
7745 -- Similar processing for Check pragma
7747 elsif Nkind (Orig) = N_Pragma
7748 and then Pragma_Name (Orig) = Name_Check
7750 -- Don't want to warn if original condition is explicit False
7753 Expr : constant Node_Id :=
7757 (Pragma_Argument_Associations (Orig)))));
7759 if Is_Entity_Name (Expr)
7760 and then Entity (Expr) = Standard_False
7764 Error_Msg_N ("?check would fail at run-time", Orig);
7771 -- Continue with processing of short circuit
7773 Check_Unset_Reference (L);
7774 Check_Unset_Reference (R);
7776 Set_Etype (N, B_Typ);
7777 Eval_Short_Circuit (N);
7778 end Resolve_Short_Circuit;
7784 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
7785 Name : constant Node_Id := Prefix (N);
7786 Drange : constant Node_Id := Discrete_Range (N);
7787 Array_Type : Entity_Id := Empty;
7791 if Is_Overloaded (Name) then
7793 -- Use the context type to select the prefix that yields the correct
7798 I1 : Interp_Index := 0;
7800 P : constant Node_Id := Prefix (N);
7801 Found : Boolean := False;
7804 Get_First_Interp (P, I, It);
7805 while Present (It.Typ) loop
7806 if (Is_Array_Type (It.Typ)
7807 and then Covers (Typ, It.Typ))
7808 or else (Is_Access_Type (It.Typ)
7809 and then Is_Array_Type (Designated_Type (It.Typ))
7810 and then Covers (Typ, Designated_Type (It.Typ)))
7813 It := Disambiguate (P, I1, I, Any_Type);
7815 if It = No_Interp then
7816 Error_Msg_N ("ambiguous prefix for slicing", N);
7821 Array_Type := It.Typ;
7826 Array_Type := It.Typ;
7831 Get_Next_Interp (I, It);
7836 Array_Type := Etype (Name);
7839 Resolve (Name, Array_Type);
7841 if Is_Access_Type (Array_Type) then
7842 Apply_Access_Check (N);
7843 Array_Type := Designated_Type (Array_Type);
7845 -- If the prefix is an access to an unconstrained array, we must use
7846 -- the actual subtype of the object to perform the index checks. The
7847 -- object denoted by the prefix is implicit in the node, so we build
7848 -- an explicit representation for it in order to compute the actual
7851 if not Is_Constrained (Array_Type) then
7852 Remove_Side_Effects (Prefix (N));
7855 Obj : constant Node_Id :=
7856 Make_Explicit_Dereference (Sloc (N),
7857 Prefix => New_Copy_Tree (Prefix (N)));
7859 Set_Etype (Obj, Array_Type);
7860 Set_Parent (Obj, Parent (N));
7861 Array_Type := Get_Actual_Subtype (Obj);
7865 elsif Is_Entity_Name (Name)
7866 or else (Nkind (Name) = N_Function_Call
7867 and then not Is_Constrained (Etype (Name)))
7869 Array_Type := Get_Actual_Subtype (Name);
7871 -- If the name is a selected component that depends on discriminants,
7872 -- build an actual subtype for it. This can happen only when the name
7873 -- itself is overloaded; otherwise the actual subtype is created when
7874 -- the selected component is analyzed.
7876 elsif Nkind (Name) = N_Selected_Component
7877 and then Full_Analysis
7878 and then Depends_On_Discriminant (First_Index (Array_Type))
7881 Act_Decl : constant Node_Id :=
7882 Build_Actual_Subtype_Of_Component (Array_Type, Name);
7884 Insert_Action (N, Act_Decl);
7885 Array_Type := Defining_Identifier (Act_Decl);
7889 -- If name was overloaded, set slice type correctly now
7891 Set_Etype (N, Array_Type);
7893 -- If the range is specified by a subtype mark, no resolution is
7894 -- necessary. Else resolve the bounds, and apply needed checks.
7896 if not Is_Entity_Name (Drange) then
7897 Index := First_Index (Array_Type);
7898 Resolve (Drange, Base_Type (Etype (Index)));
7900 if Nkind (Drange) = N_Range
7902 -- Do not apply the range check to nodes associated with the
7903 -- frontend expansion of the dispatch table. We first check
7904 -- if Ada.Tags is already loaded to void the addition of an
7905 -- undesired dependence on such run-time unit.
7908 (not Tagged_Type_Expansion
7910 (RTU_Loaded (Ada_Tags)
7911 and then Nkind (Prefix (N)) = N_Selected_Component
7912 and then Present (Entity (Selector_Name (Prefix (N))))
7913 and then Entity (Selector_Name (Prefix (N))) =
7914 RTE_Record_Component (RE_Prims_Ptr)))
7916 Apply_Range_Check (Drange, Etype (Index));
7920 Set_Slice_Subtype (N);
7922 if Nkind (Drange) = N_Range then
7923 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
7924 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
7930 ----------------------------
7931 -- Resolve_String_Literal --
7932 ----------------------------
7934 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
7935 C_Typ : constant Entity_Id := Component_Type (Typ);
7936 R_Typ : constant Entity_Id := Root_Type (C_Typ);
7937 Loc : constant Source_Ptr := Sloc (N);
7938 Str : constant String_Id := Strval (N);
7939 Strlen : constant Nat := String_Length (Str);
7940 Subtype_Id : Entity_Id;
7941 Need_Check : Boolean;
7944 -- For a string appearing in a concatenation, defer creation of the
7945 -- string_literal_subtype until the end of the resolution of the
7946 -- concatenation, because the literal may be constant-folded away. This
7947 -- is a useful optimization for long concatenation expressions.
7949 -- If the string is an aggregate built for a single character (which
7950 -- happens in a non-static context) or a is null string to which special
7951 -- checks may apply, we build the subtype. Wide strings must also get a
7952 -- string subtype if they come from a one character aggregate. Strings
7953 -- generated by attributes might be static, but it is often hard to
7954 -- determine whether the enclosing context is static, so we generate
7955 -- subtypes for them as well, thus losing some rarer optimizations ???
7956 -- Same for strings that come from a static conversion.
7959 (Strlen = 0 and then Typ /= Standard_String)
7960 or else Nkind (Parent (N)) /= N_Op_Concat
7961 or else (N /= Left_Opnd (Parent (N))
7962 and then N /= Right_Opnd (Parent (N)))
7963 or else ((Typ = Standard_Wide_String
7964 or else Typ = Standard_Wide_Wide_String)
7965 and then Nkind (Original_Node (N)) /= N_String_Literal);
7967 -- If the resolving type is itself a string literal subtype, we can just
7968 -- reuse it, since there is no point in creating another.
7970 if Ekind (Typ) = E_String_Literal_Subtype then
7973 elsif Nkind (Parent (N)) = N_Op_Concat
7974 and then not Need_Check
7975 and then not Nkind_In (Original_Node (N), N_Character_Literal,
7976 N_Attribute_Reference,
7977 N_Qualified_Expression,
7982 -- Otherwise we must create a string literal subtype. Note that the
7983 -- whole idea of string literal subtypes is simply to avoid the need
7984 -- for building a full fledged array subtype for each literal.
7987 Set_String_Literal_Subtype (N, Typ);
7988 Subtype_Id := Etype (N);
7991 if Nkind (Parent (N)) /= N_Op_Concat
7994 Set_Etype (N, Subtype_Id);
7995 Eval_String_Literal (N);
7998 if Is_Limited_Composite (Typ)
7999 or else Is_Private_Composite (Typ)
8001 Error_Msg_N ("string literal not available for private array", N);
8002 Set_Etype (N, Any_Type);
8006 -- The validity of a null string has been checked in the call to
8007 -- Eval_String_Literal.
8012 -- Always accept string literal with component type Any_Character, which
8013 -- occurs in error situations and in comparisons of literals, both of
8014 -- which should accept all literals.
8016 elsif R_Typ = Any_Character then
8019 -- If the type is bit-packed, then we always transform the string
8020 -- literal into a full fledged aggregate.
8022 elsif Is_Bit_Packed_Array (Typ) then
8025 -- Deal with cases of Wide_Wide_String, Wide_String, and String
8028 -- For Standard.Wide_Wide_String, or any other type whose component
8029 -- type is Standard.Wide_Wide_Character, we know that all the
8030 -- characters in the string must be acceptable, since the parser
8031 -- accepted the characters as valid character literals.
8033 if R_Typ = Standard_Wide_Wide_Character then
8036 -- For the case of Standard.String, or any other type whose component
8037 -- type is Standard.Character, we must make sure that there are no
8038 -- wide characters in the string, i.e. that it is entirely composed
8039 -- of characters in range of type Character.
8041 -- If the string literal is the result of a static concatenation, the
8042 -- test has already been performed on the components, and need not be
8045 elsif R_Typ = Standard_Character
8046 and then Nkind (Original_Node (N)) /= N_Op_Concat
8048 for J in 1 .. Strlen loop
8049 if not In_Character_Range (Get_String_Char (Str, J)) then
8051 -- If we are out of range, post error. This is one of the
8052 -- very few places that we place the flag in the middle of
8053 -- a token, right under the offending wide character. Not
8054 -- quite clear if this is right wrt wide character encoding
8055 -- sequences, but it's only an error message!
8058 ("literal out of range of type Standard.Character",
8059 Source_Ptr (Int (Loc) + J));
8064 -- For the case of Standard.Wide_String, or any other type whose
8065 -- component type is Standard.Wide_Character, we must make sure that
8066 -- there are no wide characters in the string, i.e. that it is
8067 -- entirely composed of characters in range of type Wide_Character.
8069 -- If the string literal is the result of a static concatenation,
8070 -- the test has already been performed on the components, and need
8073 elsif R_Typ = Standard_Wide_Character
8074 and then Nkind (Original_Node (N)) /= N_Op_Concat
8076 for J in 1 .. Strlen loop
8077 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8079 -- If we are out of range, post error. This is one of the
8080 -- very few places that we place the flag in the middle of
8081 -- a token, right under the offending wide character.
8083 -- This is not quite right, because characters in general
8084 -- will take more than one character position ???
8087 ("literal out of range of type Standard.Wide_Character",
8088 Source_Ptr (Int (Loc) + J));
8093 -- If the root type is not a standard character, then we will convert
8094 -- the string into an aggregate and will let the aggregate code do
8095 -- the checking. Standard Wide_Wide_Character is also OK here.
8101 -- See if the component type of the array corresponding to the string
8102 -- has compile time known bounds. If yes we can directly check
8103 -- whether the evaluation of the string will raise constraint error.
8104 -- Otherwise we need to transform the string literal into the
8105 -- corresponding character aggregate and let the aggregate
8106 -- code do the checking.
8108 if Is_Standard_Character_Type (R_Typ) then
8110 -- Check for the case of full range, where we are definitely OK
8112 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8116 -- Here the range is not the complete base type range, so check
8119 Comp_Typ_Lo : constant Node_Id :=
8120 Type_Low_Bound (Component_Type (Typ));
8121 Comp_Typ_Hi : constant Node_Id :=
8122 Type_High_Bound (Component_Type (Typ));
8127 if Compile_Time_Known_Value (Comp_Typ_Lo)
8128 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8130 for J in 1 .. Strlen loop
8131 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8133 if Char_Val < Expr_Value (Comp_Typ_Lo)
8134 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8136 Apply_Compile_Time_Constraint_Error
8137 (N, "character out of range?", CE_Range_Check_Failed,
8138 Loc => Source_Ptr (Int (Loc) + J));
8148 -- If we got here we meed to transform the string literal into the
8149 -- equivalent qualified positional array aggregate. This is rather
8150 -- heavy artillery for this situation, but it is hard work to avoid.
8153 Lits : constant List_Id := New_List;
8154 P : Source_Ptr := Loc + 1;
8158 -- Build the character literals, we give them source locations that
8159 -- correspond to the string positions, which is a bit tricky given
8160 -- the possible presence of wide character escape sequences.
8162 for J in 1 .. Strlen loop
8163 C := Get_String_Char (Str, J);
8164 Set_Character_Literal_Name (C);
8167 Make_Character_Literal (P,
8169 Char_Literal_Value => UI_From_CC (C)));
8171 if In_Character_Range (C) then
8174 -- Should we have a call to Skip_Wide here ???
8182 Make_Qualified_Expression (Loc,
8183 Subtype_Mark => New_Reference_To (Typ, Loc),
8185 Make_Aggregate (Loc, Expressions => Lits)));
8187 Analyze_And_Resolve (N, Typ);
8189 end Resolve_String_Literal;
8191 -----------------------------
8192 -- Resolve_Subprogram_Info --
8193 -----------------------------
8195 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8198 end Resolve_Subprogram_Info;
8200 -----------------------------
8201 -- Resolve_Type_Conversion --
8202 -----------------------------
8204 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
8205 Conv_OK : constant Boolean := Conversion_OK (N);
8206 Operand : constant Node_Id := Expression (N);
8207 Operand_Typ : constant Entity_Id := Etype (Operand);
8208 Target_Typ : constant Entity_Id := Etype (N);
8215 and then not Valid_Conversion (N, Target_Typ, Operand)
8220 if Etype (Operand) = Any_Fixed then
8222 -- Mixed-mode operation involving a literal. Context must be a fixed
8223 -- type which is applied to the literal subsequently.
8225 if Is_Fixed_Point_Type (Typ) then
8226 Set_Etype (Operand, Universal_Real);
8228 elsif Is_Numeric_Type (Typ)
8229 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
8230 and then (Etype (Right_Opnd (Operand)) = Universal_Real
8232 Etype (Left_Opnd (Operand)) = Universal_Real)
8234 -- Return if expression is ambiguous
8236 if Unique_Fixed_Point_Type (N) = Any_Type then
8239 -- If nothing else, the available fixed type is Duration
8242 Set_Etype (Operand, Standard_Duration);
8245 -- Resolve the real operand with largest available precision
8247 if Etype (Right_Opnd (Operand)) = Universal_Real then
8248 Rop := New_Copy_Tree (Right_Opnd (Operand));
8250 Rop := New_Copy_Tree (Left_Opnd (Operand));
8253 Resolve (Rop, Universal_Real);
8255 -- If the operand is a literal (it could be a non-static and
8256 -- illegal exponentiation) check whether the use of Duration
8257 -- is potentially inaccurate.
8259 if Nkind (Rop) = N_Real_Literal
8260 and then Realval (Rop) /= Ureal_0
8261 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
8264 ("?universal real operand can only " &
8265 "be interpreted as Duration!",
8268 ("\?precision will be lost in the conversion!", Rop);
8271 elsif Is_Numeric_Type (Typ)
8272 and then Nkind (Operand) in N_Op
8273 and then Unique_Fixed_Point_Type (N) /= Any_Type
8275 Set_Etype (Operand, Standard_Duration);
8278 Error_Msg_N ("invalid context for mixed mode operation", N);
8279 Set_Etype (Operand, Any_Type);
8286 -- Note: we do the Eval_Type_Conversion call before applying the
8287 -- required checks for a subtype conversion. This is important, since
8288 -- both are prepared under certain circumstances to change the type
8289 -- conversion to a constraint error node, but in the case of
8290 -- Eval_Type_Conversion this may reflect an illegality in the static
8291 -- case, and we would miss the illegality (getting only a warning
8292 -- message), if we applied the type conversion checks first.
8294 Eval_Type_Conversion (N);
8296 -- Even when evaluation is not possible, we may be able to simplify the
8297 -- conversion or its expression. This needs to be done before applying
8298 -- checks, since otherwise the checks may use the original expression
8299 -- and defeat the simplifications. This is specifically the case for
8300 -- elimination of the floating-point Truncation attribute in
8301 -- float-to-int conversions.
8303 Simplify_Type_Conversion (N);
8305 -- If after evaluation we still have a type conversion, then we may need
8306 -- to apply checks required for a subtype conversion.
8308 -- Skip these type conversion checks if universal fixed operands
8309 -- operands involved, since range checks are handled separately for
8310 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8312 if Nkind (N) = N_Type_Conversion
8313 and then not Is_Generic_Type (Root_Type (Target_Typ))
8314 and then Target_Typ /= Universal_Fixed
8315 and then Operand_Typ /= Universal_Fixed
8317 Apply_Type_Conversion_Checks (N);
8320 -- Issue warning for conversion of simple object to its own type. We
8321 -- have to test the original nodes, since they may have been rewritten
8322 -- by various optimizations.
8324 Orig_N := Original_Node (N);
8326 if Warn_On_Redundant_Constructs
8327 and then Comes_From_Source (Orig_N)
8328 and then Nkind (Orig_N) = N_Type_Conversion
8329 and then not In_Instance
8331 Orig_N := Original_Node (Expression (Orig_N));
8332 Orig_T := Target_Typ;
8334 -- If the node is part of a larger expression, the Target_Type
8335 -- may not be the original type of the node if the context is a
8336 -- condition. Recover original type to see if conversion is needed.
8338 if Is_Boolean_Type (Orig_T)
8339 and then Nkind (Parent (N)) in N_Op
8341 Orig_T := Etype (Parent (N));
8344 if Is_Entity_Name (Orig_N)
8346 (Etype (Entity (Orig_N)) = Orig_T
8348 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
8349 and then Covers (Orig_T, Etype (Entity (Orig_N)))))
8351 Error_Msg_Node_2 := Orig_T;
8352 Error_Msg_NE -- CODEFIX
8353 ("?redundant conversion, & is of type &!", N, Entity (Orig_N));
8357 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8358 -- No need to perform any interface conversion if the type of the
8359 -- expression coincides with the target type.
8361 if Ada_Version >= Ada_05
8362 and then Expander_Active
8363 and then Operand_Typ /= Target_Typ
8366 Opnd : Entity_Id := Operand_Typ;
8367 Target : Entity_Id := Target_Typ;
8370 if Is_Access_Type (Opnd) then
8371 Opnd := Directly_Designated_Type (Opnd);
8374 if Is_Access_Type (Target_Typ) then
8375 Target := Directly_Designated_Type (Target);
8378 if Opnd = Target then
8381 -- Conversion from interface type
8383 elsif Is_Interface (Opnd) then
8385 -- Ada 2005 (AI-217): Handle entities from limited views
8387 if From_With_Type (Opnd) then
8388 Error_Msg_Qual_Level := 99;
8389 Error_Msg_NE ("missing WITH clause on package &", N,
8390 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
8392 ("type conversions require visibility of the full view",
8395 elsif From_With_Type (Target)
8397 (Is_Access_Type (Target_Typ)
8398 and then Present (Non_Limited_View (Etype (Target))))
8400 Error_Msg_Qual_Level := 99;
8401 Error_Msg_NE ("missing WITH clause on package &", N,
8402 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
8404 ("type conversions require visibility of the full view",
8408 Expand_Interface_Conversion (N, Is_Static => False);
8411 -- Conversion to interface type
8413 elsif Is_Interface (Target) then
8417 if Ekind (Opnd) = E_Protected_Subtype
8418 or else Ekind (Opnd) = E_Task_Subtype
8420 Opnd := Etype (Opnd);
8423 if not Interface_Present_In_Ancestor
8427 if Is_Class_Wide_Type (Opnd) then
8429 -- The static analysis is not enough to know if the
8430 -- interface is implemented or not. Hence we must pass
8431 -- the work to the expander to generate code to evaluate
8432 -- the conversion at run-time.
8434 Expand_Interface_Conversion (N, Is_Static => False);
8437 Error_Msg_Name_1 := Chars (Etype (Target));
8438 Error_Msg_Name_2 := Chars (Opnd);
8440 ("wrong interface conversion (% is not a progenitor " &
8445 Expand_Interface_Conversion (N);
8450 end Resolve_Type_Conversion;
8452 ----------------------
8453 -- Resolve_Unary_Op --
8454 ----------------------
8456 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
8457 B_Typ : constant Entity_Id := Base_Type (Typ);
8458 R : constant Node_Id := Right_Opnd (N);
8464 -- Deal with intrinsic unary operators
8466 if Comes_From_Source (N)
8467 and then Ekind (Entity (N)) = E_Function
8468 and then Is_Imported (Entity (N))
8469 and then Is_Intrinsic_Subprogram (Entity (N))
8471 Resolve_Intrinsic_Unary_Operator (N, Typ);
8475 -- Deal with universal cases
8477 if Etype (R) = Universal_Integer
8479 Etype (R) = Universal_Real
8481 Check_For_Visible_Operator (N, B_Typ);
8484 Set_Etype (N, B_Typ);
8487 -- Generate warning for expressions like abs (x mod 2)
8489 if Warn_On_Redundant_Constructs
8490 and then Nkind (N) = N_Op_Abs
8492 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
8494 if OK and then Hi >= Lo and then Lo >= 0 then
8496 ("?abs applied to known non-negative value has no effect", N);
8500 -- Deal with reference generation
8502 Check_Unset_Reference (R);
8503 Generate_Operator_Reference (N, B_Typ);
8506 -- Set overflow checking bit. Much cleverer code needed here eventually
8507 -- and perhaps the Resolve routines should be separated for the various
8508 -- arithmetic operations, since they will need different processing ???
8510 if Nkind (N) in N_Op then
8511 if not Overflow_Checks_Suppressed (Etype (N)) then
8512 Enable_Overflow_Check (N);
8516 -- Generate warning for expressions like -5 mod 3 for integers. No need
8517 -- to worry in the floating-point case, since parens do not affect the
8518 -- result so there is no point in giving in a warning.
8521 Norig : constant Node_Id := Original_Node (N);
8530 if Warn_On_Questionable_Missing_Parens
8531 and then Comes_From_Source (Norig)
8532 and then Is_Integer_Type (Typ)
8533 and then Nkind (Norig) = N_Op_Minus
8535 Rorig := Original_Node (Right_Opnd (Norig));
8537 -- We are looking for cases where the right operand is not
8538 -- parenthesized, and is a binary operator, multiply, divide, or
8539 -- mod. These are the cases where the grouping can affect results.
8541 if Paren_Count (Rorig) = 0
8542 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
8544 -- For mod, we always give the warning, since the value is
8545 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8546 -- -(5 mod 315)). But for the other cases, the only concern is
8547 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8548 -- overflows, but (-2) * 64 does not). So we try to give the
8549 -- message only when overflow is possible.
8551 if Nkind (Rorig) /= N_Op_Mod
8552 and then Compile_Time_Known_Value (R)
8554 Val := Expr_Value (R);
8556 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
8557 HB := Expr_Value (Type_High_Bound (Typ));
8559 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
8562 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
8563 LB := Expr_Value (Type_Low_Bound (Typ));
8565 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
8568 -- Note that the test below is deliberately excluding the
8569 -- largest negative number, since that is a potentially
8570 -- troublesome case (e.g. -2 * x, where the result is the
8571 -- largest negative integer has an overflow with 2 * x).
8573 if Val > LB and then Val <= HB then
8578 -- For the multiplication case, the only case we have to worry
8579 -- about is when (-a)*b is exactly the largest negative number
8580 -- so that -(a*b) can cause overflow. This can only happen if
8581 -- a is a power of 2, and more generally if any operand is a
8582 -- constant that is not a power of 2, then the parentheses
8583 -- cannot affect whether overflow occurs. We only bother to
8584 -- test the left most operand
8586 -- Loop looking at left operands for one that has known value
8589 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
8590 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
8591 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
8593 -- Operand value of 0 or 1 skips warning
8598 -- Otherwise check power of 2, if power of 2, warn, if
8599 -- anything else, skip warning.
8602 while Lval /= 2 loop
8603 if Lval mod 2 = 1 then
8614 -- Keep looking at left operands
8616 Opnd := Left_Opnd (Opnd);
8619 -- For rem or "/" we can only have a problematic situation
8620 -- if the divisor has a value of minus one or one. Otherwise
8621 -- overflow is impossible (divisor > 1) or we have a case of
8622 -- division by zero in any case.
8624 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
8625 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
8626 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
8631 -- If we fall through warning should be issued
8634 ("?unary minus expression should be parenthesized here!", N);
8638 end Resolve_Unary_Op;
8640 ----------------------------------
8641 -- Resolve_Unchecked_Expression --
8642 ----------------------------------
8644 procedure Resolve_Unchecked_Expression
8649 Resolve (Expression (N), Typ, Suppress => All_Checks);
8651 end Resolve_Unchecked_Expression;
8653 ---------------------------------------
8654 -- Resolve_Unchecked_Type_Conversion --
8655 ---------------------------------------
8657 procedure Resolve_Unchecked_Type_Conversion
8661 pragma Warnings (Off, Typ);
8663 Operand : constant Node_Id := Expression (N);
8664 Opnd_Type : constant Entity_Id := Etype (Operand);
8667 -- Resolve operand using its own type
8669 Resolve (Operand, Opnd_Type);
8670 Eval_Unchecked_Conversion (N);
8672 end Resolve_Unchecked_Type_Conversion;
8674 ------------------------------
8675 -- Rewrite_Operator_As_Call --
8676 ------------------------------
8678 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
8679 Loc : constant Source_Ptr := Sloc (N);
8680 Actuals : constant List_Id := New_List;
8684 if Nkind (N) in N_Binary_Op then
8685 Append (Left_Opnd (N), Actuals);
8688 Append (Right_Opnd (N), Actuals);
8691 Make_Function_Call (Sloc => Loc,
8692 Name => New_Occurrence_Of (Nam, Loc),
8693 Parameter_Associations => Actuals);
8695 Preserve_Comes_From_Source (New_N, N);
8696 Preserve_Comes_From_Source (Name (New_N), N);
8698 Set_Etype (N, Etype (Nam));
8699 end Rewrite_Operator_As_Call;
8701 ------------------------------
8702 -- Rewrite_Renamed_Operator --
8703 ------------------------------
8705 procedure Rewrite_Renamed_Operator
8710 Nam : constant Name_Id := Chars (Op);
8711 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
8715 -- Rewrite the operator node using the real operator, not its renaming.
8716 -- Exclude user-defined intrinsic operations of the same name, which are
8717 -- treated separately and rewritten as calls.
8719 if Ekind (Op) /= E_Function
8720 or else Chars (N) /= Nam
8722 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
8723 Set_Chars (Op_Node, Nam);
8724 Set_Etype (Op_Node, Etype (N));
8725 Set_Entity (Op_Node, Op);
8726 Set_Right_Opnd (Op_Node, Right_Opnd (N));
8728 -- Indicate that both the original entity and its renaming are
8729 -- referenced at this point.
8731 Generate_Reference (Entity (N), N);
8732 Generate_Reference (Op, N);
8735 Set_Left_Opnd (Op_Node, Left_Opnd (N));
8738 Rewrite (N, Op_Node);
8740 -- If the context type is private, add the appropriate conversions
8741 -- so that the operator is applied to the full view. This is done
8742 -- in the routines that resolve intrinsic operators,
8744 if Is_Intrinsic_Subprogram (Op)
8745 and then Is_Private_Type (Typ)
8748 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8749 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
8750 Resolve_Intrinsic_Operator (N, Typ);
8752 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
8753 Resolve_Intrinsic_Unary_Operator (N, Typ);
8760 elsif Ekind (Op) = E_Function
8761 and then Is_Intrinsic_Subprogram (Op)
8763 -- Operator renames a user-defined operator of the same name. Use
8764 -- the original operator in the node, which is the one that Gigi
8768 Set_Is_Overloaded (N, False);
8770 end Rewrite_Renamed_Operator;
8772 -----------------------
8773 -- Set_Slice_Subtype --
8774 -----------------------
8776 -- Build an implicit subtype declaration to represent the type delivered
8777 -- by the slice. This is an abbreviated version of an array subtype. We
8778 -- define an index subtype for the slice, using either the subtype name
8779 -- or the discrete range of the slice. To be consistent with index usage
8780 -- elsewhere, we create a list header to hold the single index. This list
8781 -- is not otherwise attached to the syntax tree.
8783 procedure Set_Slice_Subtype (N : Node_Id) is
8784 Loc : constant Source_Ptr := Sloc (N);
8785 Index_List : constant List_Id := New_List;
8787 Index_Subtype : Entity_Id;
8788 Index_Type : Entity_Id;
8789 Slice_Subtype : Entity_Id;
8790 Drange : constant Node_Id := Discrete_Range (N);
8793 if Is_Entity_Name (Drange) then
8794 Index_Subtype := Entity (Drange);
8797 -- We force the evaluation of a range. This is definitely needed in
8798 -- the renamed case, and seems safer to do unconditionally. Note in
8799 -- any case that since we will create and insert an Itype referring
8800 -- to this range, we must make sure any side effect removal actions
8801 -- are inserted before the Itype definition.
8803 if Nkind (Drange) = N_Range then
8804 Force_Evaluation (Low_Bound (Drange));
8805 Force_Evaluation (High_Bound (Drange));
8808 Index_Type := Base_Type (Etype (Drange));
8810 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8812 Set_Scalar_Range (Index_Subtype, Drange);
8813 Set_Etype (Index_Subtype, Index_Type);
8814 Set_Size_Info (Index_Subtype, Index_Type);
8815 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8818 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
8820 Index := New_Occurrence_Of (Index_Subtype, Loc);
8821 Set_Etype (Index, Index_Subtype);
8822 Append (Index, Index_List);
8824 Set_First_Index (Slice_Subtype, Index);
8825 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
8826 Set_Is_Constrained (Slice_Subtype, True);
8828 Check_Compile_Time_Size (Slice_Subtype);
8830 -- The Etype of the existing Slice node is reset to this slice subtype.
8831 -- Its bounds are obtained from its first index.
8833 Set_Etype (N, Slice_Subtype);
8835 -- In the packed case, this must be immediately frozen
8837 -- Couldn't we always freeze here??? and if we did, then the above
8838 -- call to Check_Compile_Time_Size could be eliminated, which would
8839 -- be nice, because then that routine could be made private to Freeze.
8841 -- Why the test for In_Spec_Expression here ???
8843 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
8844 Freeze_Itype (Slice_Subtype, N);
8847 end Set_Slice_Subtype;
8849 --------------------------------
8850 -- Set_String_Literal_Subtype --
8851 --------------------------------
8853 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
8854 Loc : constant Source_Ptr := Sloc (N);
8855 Low_Bound : constant Node_Id :=
8856 Type_Low_Bound (Etype (First_Index (Typ)));
8857 Subtype_Id : Entity_Id;
8860 if Nkind (N) /= N_String_Literal then
8864 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
8865 Set_String_Literal_Length (Subtype_Id, UI_From_Int
8866 (String_Length (Strval (N))));
8867 Set_Etype (Subtype_Id, Base_Type (Typ));
8868 Set_Is_Constrained (Subtype_Id);
8869 Set_Etype (N, Subtype_Id);
8871 if Is_OK_Static_Expression (Low_Bound) then
8873 -- The low bound is set from the low bound of the corresponding
8874 -- index type. Note that we do not store the high bound in the
8875 -- string literal subtype, but it can be deduced if necessary
8876 -- from the length and the low bound.
8878 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
8881 Set_String_Literal_Low_Bound
8882 (Subtype_Id, Make_Integer_Literal (Loc, 1));
8883 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
8885 -- Build bona fide subtype for the string, and wrap it in an
8886 -- unchecked conversion, because the backend expects the
8887 -- String_Literal_Subtype to have a static lower bound.
8890 Index_List : constant List_Id := New_List;
8891 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
8892 High_Bound : constant Node_Id :=
8894 Left_Opnd => New_Copy_Tree (Low_Bound),
8896 Make_Integer_Literal (Loc,
8897 String_Length (Strval (N)) - 1));
8898 Array_Subtype : Entity_Id;
8899 Index_Subtype : Entity_Id;
8905 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
8906 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
8907 Set_Scalar_Range (Index_Subtype, Drange);
8908 Set_Parent (Drange, N);
8909 Analyze_And_Resolve (Drange, Index_Type);
8911 -- In the context, the Index_Type may already have a constraint,
8912 -- so use common base type on string subtype. The base type may
8913 -- be used when generating attributes of the string, for example
8914 -- in the context of a slice assignment.
8916 Set_Etype (Index_Subtype, Base_Type (Index_Type));
8917 Set_Size_Info (Index_Subtype, Index_Type);
8918 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
8920 Array_Subtype := Create_Itype (E_Array_Subtype, N);
8922 Index := New_Occurrence_Of (Index_Subtype, Loc);
8923 Set_Etype (Index, Index_Subtype);
8924 Append (Index, Index_List);
8926 Set_First_Index (Array_Subtype, Index);
8927 Set_Etype (Array_Subtype, Base_Type (Typ));
8928 Set_Is_Constrained (Array_Subtype, True);
8931 Make_Unchecked_Type_Conversion (Loc,
8932 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
8933 Expression => Relocate_Node (N)));
8934 Set_Etype (N, Array_Subtype);
8937 end Set_String_Literal_Subtype;
8939 ------------------------------
8940 -- Simplify_Type_Conversion --
8941 ------------------------------
8943 procedure Simplify_Type_Conversion (N : Node_Id) is
8945 if Nkind (N) = N_Type_Conversion then
8947 Operand : constant Node_Id := Expression (N);
8948 Target_Typ : constant Entity_Id := Etype (N);
8949 Opnd_Typ : constant Entity_Id := Etype (Operand);
8952 if Is_Floating_Point_Type (Opnd_Typ)
8954 (Is_Integer_Type (Target_Typ)
8955 or else (Is_Fixed_Point_Type (Target_Typ)
8956 and then Conversion_OK (N)))
8957 and then Nkind (Operand) = N_Attribute_Reference
8958 and then Attribute_Name (Operand) = Name_Truncation
8960 -- Special processing required if the conversion is the expression
8961 -- of a Truncation attribute reference. In this case we replace:
8963 -- ityp (ftyp'Truncation (x))
8969 -- with the Float_Truncate flag set, which is more efficient
8973 Relocate_Node (First (Expressions (Operand))));
8974 Set_Float_Truncate (N, True);
8978 end Simplify_Type_Conversion;
8980 -----------------------------
8981 -- Unique_Fixed_Point_Type --
8982 -----------------------------
8984 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
8985 T1 : Entity_Id := Empty;
8990 procedure Fixed_Point_Error;
8991 -- Give error messages for true ambiguity. Messages are posted on node
8992 -- N, and entities T1, T2 are the possible interpretations.
8994 -----------------------
8995 -- Fixed_Point_Error --
8996 -----------------------
8998 procedure Fixed_Point_Error is
9000 Error_Msg_N ("ambiguous universal_fixed_expression", N);
9001 Error_Msg_NE ("\\possible interpretation as}", N, T1);
9002 Error_Msg_NE ("\\possible interpretation as}", N, T2);
9003 end Fixed_Point_Error;
9005 -- Start of processing for Unique_Fixed_Point_Type
9008 -- The operations on Duration are visible, so Duration is always a
9009 -- possible interpretation.
9011 T1 := Standard_Duration;
9013 -- Look for fixed-point types in enclosing scopes
9015 Scop := Current_Scope;
9016 while Scop /= Standard_Standard loop
9017 T2 := First_Entity (Scop);
9018 while Present (T2) loop
9019 if Is_Fixed_Point_Type (T2)
9020 and then Current_Entity (T2) = T2
9021 and then Scope (Base_Type (T2)) = Scop
9023 if Present (T1) then
9034 Scop := Scope (Scop);
9037 -- Look for visible fixed type declarations in the context
9039 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
9040 while Present (Item) loop
9041 if Nkind (Item) = N_With_Clause then
9042 Scop := Entity (Name (Item));
9043 T2 := First_Entity (Scop);
9044 while Present (T2) loop
9045 if Is_Fixed_Point_Type (T2)
9046 and then Scope (Base_Type (T2)) = Scop
9047 and then (Is_Potentially_Use_Visible (T2)
9048 or else In_Use (T2))
9050 if Present (T1) then
9065 if Nkind (N) = N_Real_Literal then
9066 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
9068 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
9072 end Unique_Fixed_Point_Type;
9074 ----------------------
9075 -- Valid_Conversion --
9076 ----------------------
9078 function Valid_Conversion
9081 Operand : Node_Id) return Boolean
9083 Target_Type : constant Entity_Id := Base_Type (Target);
9084 Opnd_Type : Entity_Id := Etype (Operand);
9086 function Conversion_Check
9088 Msg : String) return Boolean;
9089 -- Little routine to post Msg if Valid is False, returns Valid value
9091 function Valid_Tagged_Conversion
9092 (Target_Type : Entity_Id;
9093 Opnd_Type : Entity_Id) return Boolean;
9094 -- Specifically test for validity of tagged conversions
9096 function Valid_Array_Conversion return Boolean;
9097 -- Check index and component conformance, and accessibility levels
9098 -- if the component types are anonymous access types (Ada 2005)
9100 ----------------------
9101 -- Conversion_Check --
9102 ----------------------
9104 function Conversion_Check
9106 Msg : String) return Boolean
9110 Error_Msg_N (Msg, Operand);
9114 end Conversion_Check;
9116 ----------------------------
9117 -- Valid_Array_Conversion --
9118 ----------------------------
9120 function Valid_Array_Conversion return Boolean
9122 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
9123 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
9125 Opnd_Index : Node_Id;
9126 Opnd_Index_Type : Entity_Id;
9128 Target_Comp_Type : constant Entity_Id :=
9129 Component_Type (Target_Type);
9130 Target_Comp_Base : constant Entity_Id :=
9131 Base_Type (Target_Comp_Type);
9133 Target_Index : Node_Id;
9134 Target_Index_Type : Entity_Id;
9137 -- Error if wrong number of dimensions
9140 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9143 ("incompatible number of dimensions for conversion", Operand);
9146 -- Number of dimensions matches
9149 -- Loop through indexes of the two arrays
9151 Target_Index := First_Index (Target_Type);
9152 Opnd_Index := First_Index (Opnd_Type);
9153 while Present (Target_Index) and then Present (Opnd_Index) loop
9154 Target_Index_Type := Etype (Target_Index);
9155 Opnd_Index_Type := Etype (Opnd_Index);
9157 -- Error if index types are incompatible
9159 if not (Is_Integer_Type (Target_Index_Type)
9160 and then Is_Integer_Type (Opnd_Index_Type))
9161 and then (Root_Type (Target_Index_Type)
9162 /= Root_Type (Opnd_Index_Type))
9165 ("incompatible index types for array conversion",
9170 Next_Index (Target_Index);
9171 Next_Index (Opnd_Index);
9174 -- If component types have same base type, all set
9176 if Target_Comp_Base = Opnd_Comp_Base then
9179 -- Here if base types of components are not the same. The only
9180 -- time this is allowed is if we have anonymous access types.
9182 -- The conversion of arrays of anonymous access types can lead
9183 -- to dangling pointers. AI-392 formalizes the accessibility
9184 -- checks that must be applied to such conversions to prevent
9185 -- out-of-scope references.
9188 (Ekind (Target_Comp_Base) = E_Anonymous_Access_Type
9190 Ekind (Target_Comp_Base) = E_Anonymous_Access_Subprogram_Type)
9191 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
9193 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
9195 if Type_Access_Level (Target_Type) <
9196 Type_Access_Level (Opnd_Type)
9198 if In_Instance_Body then
9199 Error_Msg_N ("?source array type " &
9200 "has deeper accessibility level than target", Operand);
9201 Error_Msg_N ("\?Program_Error will be raised at run time",
9204 Make_Raise_Program_Error (Sloc (N),
9205 Reason => PE_Accessibility_Check_Failed));
9206 Set_Etype (N, Target_Type);
9209 -- Conversion not allowed because of accessibility levels
9212 Error_Msg_N ("source array type " &
9213 "has deeper accessibility level than target", Operand);
9220 -- All other cases where component base types do not match
9224 ("incompatible component types for array conversion",
9229 -- Check that component subtypes statically match. For numeric
9230 -- types this means that both must be either constrained or
9231 -- unconstrained. For enumeration types the bounds must match.
9232 -- All of this is checked in Subtypes_Statically_Match.
9234 if not Subtypes_Statically_Match
9235 (Target_Comp_Type, Opnd_Comp_Type)
9238 ("component subtypes must statically match", Operand);
9244 end Valid_Array_Conversion;
9246 -----------------------------
9247 -- Valid_Tagged_Conversion --
9248 -----------------------------
9250 function Valid_Tagged_Conversion
9251 (Target_Type : Entity_Id;
9252 Opnd_Type : Entity_Id) return Boolean
9255 -- Upward conversions are allowed (RM 4.6(22))
9257 if Covers (Target_Type, Opnd_Type)
9258 or else Is_Ancestor (Target_Type, Opnd_Type)
9262 -- Downward conversion are allowed if the operand is class-wide
9265 elsif Is_Class_Wide_Type (Opnd_Type)
9266 and then Covers (Opnd_Type, Target_Type)
9270 elsif Covers (Opnd_Type, Target_Type)
9271 or else Is_Ancestor (Opnd_Type, Target_Type)
9274 Conversion_Check (False,
9275 "downward conversion of tagged objects not allowed");
9277 -- Ada 2005 (AI-251): The conversion to/from interface types is
9280 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
9283 -- If the operand is a class-wide type obtained through a limited_
9284 -- with clause, and the context includes the non-limited view, use
9285 -- it to determine whether the conversion is legal.
9287 elsif Is_Class_Wide_Type (Opnd_Type)
9288 and then From_With_Type (Opnd_Type)
9289 and then Present (Non_Limited_View (Etype (Opnd_Type)))
9290 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
9294 elsif Is_Access_Type (Opnd_Type)
9295 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
9301 ("invalid tagged conversion, not compatible with}",
9302 N, First_Subtype (Opnd_Type));
9305 end Valid_Tagged_Conversion;
9307 -- Start of processing for Valid_Conversion
9310 Check_Parameterless_Call (Operand);
9312 if Is_Overloaded (Operand) then
9321 -- Remove procedure calls, which syntactically cannot appear in
9322 -- this context, but which cannot be removed by type checking,
9323 -- because the context does not impose a type.
9325 -- When compiling for VMS, spurious ambiguities can be produced
9326 -- when arithmetic operations have a literal operand and return
9327 -- System.Address or a descendant of it. These ambiguities are
9328 -- otherwise resolved by the context, but for conversions there
9329 -- is no context type and the removal of the spurious operations
9330 -- must be done explicitly here.
9332 -- The node may be labelled overloaded, but still contain only
9333 -- one interpretation because others were discarded in previous
9334 -- filters. If this is the case, retain the single interpretation
9337 Get_First_Interp (Operand, I, It);
9338 Opnd_Type := It.Typ;
9339 Get_Next_Interp (I, It);
9342 and then Opnd_Type /= Standard_Void_Type
9344 -- More than one candidate interpretation is available
9346 Get_First_Interp (Operand, I, It);
9347 while Present (It.Typ) loop
9348 if It.Typ = Standard_Void_Type then
9352 if Present (System_Aux_Id)
9353 and then Is_Descendent_Of_Address (It.Typ)
9358 Get_Next_Interp (I, It);
9362 Get_First_Interp (Operand, I, It);
9367 Error_Msg_N ("illegal operand in conversion", Operand);
9371 Get_Next_Interp (I, It);
9373 if Present (It.Typ) then
9375 It1 := Disambiguate (Operand, I1, I, Any_Type);
9377 if It1 = No_Interp then
9378 Error_Msg_N ("ambiguous operand in conversion", Operand);
9380 Error_Msg_Sloc := Sloc (It.Nam);
9381 Error_Msg_N -- CODEFIX
9382 ("\\possible interpretation#!", Operand);
9384 Error_Msg_Sloc := Sloc (N1);
9385 Error_Msg_N -- CODEFIX
9386 ("\\possible interpretation#!", Operand);
9392 Set_Etype (Operand, It1.Typ);
9393 Opnd_Type := It1.Typ;
9399 if Is_Numeric_Type (Target_Type) then
9401 -- A universal fixed expression can be converted to any numeric type
9403 if Opnd_Type = Universal_Fixed then
9406 -- Also no need to check when in an instance or inlined body, because
9407 -- the legality has been established when the template was analyzed.
9408 -- Furthermore, numeric conversions may occur where only a private
9409 -- view of the operand type is visible at the instantiation point.
9410 -- This results in a spurious error if we check that the operand type
9411 -- is a numeric type.
9413 -- Note: in a previous version of this unit, the following tests were
9414 -- applied only for generated code (Comes_From_Source set to False),
9415 -- but in fact the test is required for source code as well, since
9416 -- this situation can arise in source code.
9418 elsif In_Instance or else In_Inlined_Body then
9421 -- Otherwise we need the conversion check
9424 return Conversion_Check
9425 (Is_Numeric_Type (Opnd_Type),
9426 "illegal operand for numeric conversion");
9431 elsif Is_Array_Type (Target_Type) then
9432 if not Is_Array_Type (Opnd_Type)
9433 or else Opnd_Type = Any_Composite
9434 or else Opnd_Type = Any_String
9437 ("illegal operand for array conversion", Operand);
9440 return Valid_Array_Conversion;
9443 -- Ada 2005 (AI-251): Anonymous access types where target references an
9446 elsif (Ekind (Target_Type) = E_General_Access_Type
9448 Ekind (Target_Type) = E_Anonymous_Access_Type)
9449 and then Is_Interface (Directly_Designated_Type (Target_Type))
9451 -- Check the static accessibility rule of 4.6(17). Note that the
9452 -- check is not enforced when within an instance body, since the
9453 -- RM requires such cases to be caught at run time.
9455 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
9456 if Type_Access_Level (Opnd_Type) >
9457 Type_Access_Level (Target_Type)
9459 -- In an instance, this is a run-time check, but one we know
9460 -- will fail, so generate an appropriate warning. The raise
9461 -- will be generated by Expand_N_Type_Conversion.
9463 if In_Instance_Body then
9465 ("?cannot convert local pointer to non-local access type",
9468 ("\?Program_Error will be raised at run time", Operand);
9471 ("cannot convert local pointer to non-local access type",
9476 -- Special accessibility checks are needed in the case of access
9477 -- discriminants declared for a limited type.
9479 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9480 and then not Is_Local_Anonymous_Access (Opnd_Type)
9482 -- When the operand is a selected access discriminant the check
9483 -- needs to be made against the level of the object denoted by
9484 -- the prefix of the selected name (Object_Access_Level handles
9485 -- checking the prefix of the operand for this case).
9487 if Nkind (Operand) = N_Selected_Component
9488 and then Object_Access_Level (Operand) >
9489 Type_Access_Level (Target_Type)
9491 -- In an instance, this is a run-time check, but one we know
9492 -- will fail, so generate an appropriate warning. The raise
9493 -- will be generated by Expand_N_Type_Conversion.
9495 if In_Instance_Body then
9497 ("?cannot convert access discriminant to non-local" &
9498 " access type", Operand);
9500 ("\?Program_Error will be raised at run time", Operand);
9503 ("cannot convert access discriminant to non-local" &
9504 " access type", Operand);
9509 -- The case of a reference to an access discriminant from
9510 -- within a limited type declaration (which will appear as
9511 -- a discriminal) is always illegal because the level of the
9512 -- discriminant is considered to be deeper than any (nameable)
9515 if Is_Entity_Name (Operand)
9516 and then not Is_Local_Anonymous_Access (Opnd_Type)
9517 and then (Ekind (Entity (Operand)) = E_In_Parameter
9518 or else Ekind (Entity (Operand)) = E_Constant)
9519 and then Present (Discriminal_Link (Entity (Operand)))
9522 ("discriminant has deeper accessibility level than target",
9531 -- General and anonymous access types
9533 elsif (Ekind (Target_Type) = E_General_Access_Type
9534 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
9537 (Is_Access_Type (Opnd_Type)
9538 and then Ekind (Opnd_Type) /=
9539 E_Access_Subprogram_Type
9540 and then Ekind (Opnd_Type) /=
9541 E_Access_Protected_Subprogram_Type,
9542 "must be an access-to-object type")
9544 if Is_Access_Constant (Opnd_Type)
9545 and then not Is_Access_Constant (Target_Type)
9548 ("access-to-constant operand type not allowed", Operand);
9552 -- Check the static accessibility rule of 4.6(17). Note that the
9553 -- check is not enforced when within an instance body, since the RM
9554 -- requires such cases to be caught at run time.
9556 if Ekind (Target_Type) /= E_Anonymous_Access_Type
9557 or else Is_Local_Anonymous_Access (Target_Type)
9559 if Type_Access_Level (Opnd_Type)
9560 > Type_Access_Level (Target_Type)
9562 -- In an instance, this is a run-time check, but one we know
9563 -- will fail, so generate an appropriate warning. The raise
9564 -- will be generated by Expand_N_Type_Conversion.
9566 if In_Instance_Body then
9568 ("?cannot convert local pointer to non-local access type",
9571 ("\?Program_Error will be raised at run time", Operand);
9574 -- Avoid generation of spurious error message
9576 if not Error_Posted (N) then
9578 ("cannot convert local pointer to non-local access type",
9585 -- Special accessibility checks are needed in the case of access
9586 -- discriminants declared for a limited type.
9588 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
9589 and then not Is_Local_Anonymous_Access (Opnd_Type)
9592 -- When the operand is a selected access discriminant the check
9593 -- needs to be made against the level of the object denoted by
9594 -- the prefix of the selected name (Object_Access_Level handles
9595 -- checking the prefix of the operand for this case).
9597 if Nkind (Operand) = N_Selected_Component
9598 and then Object_Access_Level (Operand) >
9599 Type_Access_Level (Target_Type)
9601 -- In an instance, this is a run-time check, but one we know
9602 -- will fail, so generate an appropriate warning. The raise
9603 -- will be generated by Expand_N_Type_Conversion.
9605 if In_Instance_Body then
9607 ("?cannot convert access discriminant to non-local" &
9608 " access type", Operand);
9610 ("\?Program_Error will be raised at run time",
9615 ("cannot convert access discriminant to non-local" &
9616 " access type", Operand);
9621 -- The case of a reference to an access discriminant from
9622 -- within a limited type declaration (which will appear as
9623 -- a discriminal) is always illegal because the level of the
9624 -- discriminant is considered to be deeper than any (nameable)
9627 if Is_Entity_Name (Operand)
9628 and then (Ekind (Entity (Operand)) = E_In_Parameter
9629 or else Ekind (Entity (Operand)) = E_Constant)
9630 and then Present (Discriminal_Link (Entity (Operand)))
9633 ("discriminant has deeper accessibility level than target",
9640 -- In the presence of limited_with clauses we have to use non-limited
9641 -- views, if available.
9643 Check_Limited : declare
9644 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
9645 -- Helper function to handle limited views
9647 --------------------------
9648 -- Full_Designated_Type --
9649 --------------------------
9651 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
9652 Desig : constant Entity_Id := Designated_Type (T);
9655 -- Handle the limited view of a type
9657 if Is_Incomplete_Type (Desig)
9658 and then From_With_Type (Desig)
9659 and then Present (Non_Limited_View (Desig))
9661 return Available_View (Desig);
9665 end Full_Designated_Type;
9667 -- Local Declarations
9669 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
9670 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
9672 Same_Base : constant Boolean :=
9673 Base_Type (Target) = Base_Type (Opnd);
9675 -- Start of processing for Check_Limited
9678 if Is_Tagged_Type (Target) then
9679 return Valid_Tagged_Conversion (Target, Opnd);
9682 if not Same_Base then
9684 ("target designated type not compatible with }",
9685 N, Base_Type (Opnd));
9688 -- Ada 2005 AI-384: legality rule is symmetric in both
9689 -- designated types. The conversion is legal (with possible
9690 -- constraint check) if either designated type is
9693 elsif Subtypes_Statically_Match (Target, Opnd)
9695 (Has_Discriminants (Target)
9697 (not Is_Constrained (Opnd)
9698 or else not Is_Constrained (Target)))
9700 -- Special case, if Value_Size has been used to make the
9701 -- sizes different, the conversion is not allowed even
9702 -- though the subtypes statically match.
9704 if Known_Static_RM_Size (Target)
9705 and then Known_Static_RM_Size (Opnd)
9706 and then RM_Size (Target) /= RM_Size (Opnd)
9709 ("target designated subtype not compatible with }",
9712 ("\because sizes of the two designated subtypes differ",
9716 -- Normal case where conversion is allowed
9724 ("target designated subtype not compatible with }",
9731 -- Access to subprogram types. If the operand is an access parameter,
9732 -- the type has a deeper accessibility that any master, and cannot
9733 -- be assigned. We must make an exception if the conversion is part
9734 -- of an assignment and the target is the return object of an extended
9735 -- return statement, because in that case the accessibility check
9736 -- takes place after the return.
9738 elsif Is_Access_Subprogram_Type (Target_Type)
9739 and then No (Corresponding_Remote_Type (Opnd_Type))
9741 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
9742 and then Is_Entity_Name (Operand)
9743 and then Ekind (Entity (Operand)) = E_In_Parameter
9745 (Nkind (Parent (N)) /= N_Assignment_Statement
9746 or else not Is_Entity_Name (Name (Parent (N)))
9747 or else not Is_Return_Object (Entity (Name (Parent (N)))))
9750 ("illegal attempt to store anonymous access to subprogram",
9753 ("\value has deeper accessibility than any master " &
9758 ("\use named access type for& instead of access parameter",
9759 Operand, Entity (Operand));
9762 -- Check that the designated types are subtype conformant
9764 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
9765 Old_Id => Designated_Type (Opnd_Type),
9768 -- Check the static accessibility rule of 4.6(20)
9770 if Type_Access_Level (Opnd_Type) >
9771 Type_Access_Level (Target_Type)
9774 ("operand type has deeper accessibility level than target",
9777 -- Check that if the operand type is declared in a generic body,
9778 -- then the target type must be declared within that same body
9779 -- (enforces last sentence of 4.6(20)).
9781 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
9783 O_Gen : constant Node_Id :=
9784 Enclosing_Generic_Body (Opnd_Type);
9789 T_Gen := Enclosing_Generic_Body (Target_Type);
9790 while Present (T_Gen) and then T_Gen /= O_Gen loop
9791 T_Gen := Enclosing_Generic_Body (T_Gen);
9794 if T_Gen /= O_Gen then
9796 ("target type must be declared in same generic body"
9797 & " as operand type", N);
9804 -- Remote subprogram access types
9806 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
9807 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
9809 -- It is valid to convert from one RAS type to another provided
9810 -- that their specification statically match.
9812 Check_Subtype_Conformant
9814 Designated_Type (Corresponding_Remote_Type (Target_Type)),
9816 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
9821 -- If both are tagged types, check legality of view conversions
9823 elsif Is_Tagged_Type (Target_Type)
9824 and then Is_Tagged_Type (Opnd_Type)
9826 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
9828 -- Types derived from the same root type are convertible
9830 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
9833 -- In an instance or an inlined body, there may be inconsistent
9834 -- views of the same type, or of types derived from a common root.
9836 elsif (In_Instance or In_Inlined_Body)
9838 Root_Type (Underlying_Type (Target_Type)) =
9839 Root_Type (Underlying_Type (Opnd_Type))
9843 -- Special check for common access type error case
9845 elsif Ekind (Target_Type) = E_Access_Type
9846 and then Is_Access_Type (Opnd_Type)
9848 Error_Msg_N ("target type must be general access type!", N);
9849 Error_Msg_NE ("add ALL to }!", N, Target_Type);
9853 Error_Msg_NE ("invalid conversion, not compatible with }",
9857 end Valid_Conversion;