1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2004, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree
; use Atree
;
28 with Checks
; use Checks
;
29 with Debug
; use Debug
;
30 with Einfo
; use Einfo
;
31 with Elists
; use Elists
;
32 with Errout
; use Errout
;
33 with Expander
; use Expander
;
34 with Exp_Ch7
; use Exp_Ch7
;
35 with Fname
; use Fname
;
36 with Freeze
; use Freeze
;
37 with Lib
.Xref
; use Lib
.Xref
;
38 with Namet
; use Namet
;
40 with Nlists
; use Nlists
;
41 with Nmake
; use Nmake
;
43 with Output
; use Output
;
44 with Rtsfind
; use Rtsfind
;
46 with Sem_Cat
; use Sem_Cat
;
47 with Sem_Ch3
; use Sem_Ch3
;
48 with Sem_Ch4
; use Sem_Ch4
;
49 with Sem_Ch5
; use Sem_Ch5
;
50 with Sem_Ch8
; use Sem_Ch8
;
51 with Sem_Ch10
; use Sem_Ch10
;
52 with Sem_Ch12
; use Sem_Ch12
;
53 with Sem_Disp
; use Sem_Disp
;
54 with Sem_Dist
; use Sem_Dist
;
55 with Sem_Elim
; use Sem_Elim
;
56 with Sem_Eval
; use Sem_Eval
;
57 with Sem_Mech
; use Sem_Mech
;
58 with Sem_Prag
; use Sem_Prag
;
59 with Sem_Res
; use Sem_Res
;
60 with Sem_Util
; use Sem_Util
;
61 with Sem_Type
; use Sem_Type
;
62 with Sem_Warn
; use Sem_Warn
;
63 with Sinput
; use Sinput
;
64 with Stand
; use Stand
;
65 with Sinfo
; use Sinfo
;
66 with Sinfo
.CN
; use Sinfo
.CN
;
67 with Snames
; use Snames
;
68 with Stringt
; use Stringt
;
70 with Stylesw
; use Stylesw
;
71 with Tbuild
; use Tbuild
;
72 with Uintp
; use Uintp
;
73 with Urealp
; use Urealp
;
74 with Validsw
; use Validsw
;
76 package body Sem_Ch6
is
78 -----------------------
79 -- Local Subprograms --
80 -----------------------
82 procedure Analyze_Generic_Subprogram_Body
(N
: Node_Id
; Gen_Id
: Entity_Id
);
83 -- Analyze a generic subprogram body. N is the body to be analyzed,
84 -- and Gen_Id is the defining entity Id for the corresponding spec.
86 procedure Build_Body_To_Inline
(N
: Node_Id
; Subp
: Entity_Id
);
87 -- If a subprogram has pragma Inline and inlining is active, use generic
88 -- machinery to build an unexpanded body for the subprogram. This body is
89 -- subsequenty used for inline expansions at call sites. If subprogram can
90 -- be inlined (depending on size and nature of local declarations) this
91 -- function returns true. Otherwise subprogram body is treated normally.
92 -- If proper warnings are enabled and the subprogram contains a construct
93 -- that cannot be inlined, the offending construct is flagged accordingly.
95 type Conformance_Type
is
96 (Type_Conformant
, Mode_Conformant
, Subtype_Conformant
, Fully_Conformant
);
97 -- Conformance type used for following call, meaning matches the
98 -- RM definitions of the corresponding terms.
100 procedure Check_Conformance
103 Ctype
: Conformance_Type
;
105 Conforms
: out Boolean;
106 Err_Loc
: Node_Id
:= Empty
;
107 Get_Inst
: Boolean := False);
108 -- Given two entities, this procedure checks that the profiles associated
109 -- with these entities meet the conformance criterion given by the third
110 -- parameter. If they conform, Conforms is set True and control returns
111 -- to the caller. If they do not conform, Conforms is set to False, and
112 -- in addition, if Errmsg is True on the call, proper messages are output
113 -- to complain about the conformance failure. If Err_Loc is non_Empty
114 -- the error messages are placed on Err_Loc, if Err_Loc is empty, then
115 -- error messages are placed on the appropriate part of the construct
116 -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
117 -- against a formal access-to-subprogram type so Get_Instance_Of must
120 procedure Check_Overriding_Operation
123 -- Check that a subprogram with a pragma Overriding or Optional_Overriding
124 -- is legal. This check is performed here rather than in Sem_Prag because
125 -- the pragma must follow immediately the declaration, and can be treated
126 -- as part of the declaration itself, as described in AI-218.
128 procedure Check_Subprogram_Order
(N
: Node_Id
);
129 -- N is the N_Subprogram_Body node for a subprogram. This routine applies
130 -- the alpha ordering rule for N if this ordering requirement applicable.
132 function Is_Non_Overriding_Operation
134 New_E
: Entity_Id
) return Boolean;
135 -- Enforce the rule given in 12.3(18): a private operation in an instance
136 -- overrides an inherited operation only if the corresponding operation
137 -- was overriding in the generic. This can happen for primitive operations
138 -- of types derived (in the generic unit) from formal private or formal
141 procedure Check_Returns
145 -- Called to check for missing return statements in a function body,
146 -- or for returns present in a procedure body which has No_Return set.
147 -- L is the handled statement sequence for the subprogram body. This
148 -- procedure checks all flow paths to make sure they either have a
149 -- return (Mode = 'F') or do not have a return (Mode = 'P'). The flag
150 -- Err is set if there are any control paths not explicitly terminated
151 -- by a return in the function case, and is True otherwise.
153 function Conforming_Types
156 Ctype
: Conformance_Type
;
157 Get_Inst
: Boolean := False) return Boolean;
158 -- Check that two formal parameter types conform, checking both
159 -- for equality of base types, and where required statically
160 -- matching subtypes, depending on the setting of Ctype.
162 procedure Enter_Overloaded_Entity
(S
: Entity_Id
);
163 -- This procedure makes S, a new overloaded entity, into the first
164 -- visible entity with that name.
166 procedure Install_Entity
(E
: Entity_Id
);
167 -- Make single entity visible. Used for generic formals as well.
169 procedure Install_Formals
(Id
: Entity_Id
);
170 -- On entry to a subprogram body, make the formals visible. Note
171 -- that simply placing the subprogram on the scope stack is not
172 -- sufficient: the formals must become the current entities for
175 procedure Make_Inequality_Operator
(S
: Entity_Id
);
176 -- Create the declaration for an inequality operator that is implicitly
177 -- created by a user-defined equality operator that yields a boolean.
179 procedure May_Need_Actuals
(Fun
: Entity_Id
);
180 -- Flag functions that can be called without parameters, i.e. those that
181 -- have no parameters, or those for which defaults exist for all parameters
183 procedure Reference_Body_Formals
(Spec
: Entity_Id
; Bod
: Entity_Id
);
184 -- If there is a separate spec for a subprogram or generic subprogram,
185 -- the formals of the body are treated as references to the corresponding
186 -- formals of the spec. This reference does not count as an actual use of
187 -- the formal, in order to diagnose formals that are unused in the body.
189 procedure Set_Formal_Validity
(Formal_Id
: Entity_Id
);
190 -- Formal_Id is an formal parameter entity. This procedure deals with
191 -- setting the proper validity status for this entity, which depends
192 -- on the kind of parameter and the validity checking mode.
194 ---------------------------------------------
195 -- Analyze_Abstract_Subprogram_Declaration --
196 ---------------------------------------------
198 procedure Analyze_Abstract_Subprogram_Declaration
(N
: Node_Id
) is
199 Designator
: constant Entity_Id
:=
200 Analyze_Subprogram_Specification
(Specification
(N
));
201 Scop
: constant Entity_Id
:= Current_Scope
;
204 Generate_Definition
(Designator
);
205 Set_Is_Abstract
(Designator
);
206 New_Overloaded_Entity
(Designator
);
207 Check_Delayed_Subprogram
(Designator
);
209 Set_Categorization_From_Scope
(Designator
, Scop
);
211 if Ekind
(Scope
(Designator
)) = E_Protected_Type
then
213 ("abstract subprogram not allowed in protected type", N
);
216 Generate_Reference_To_Formals
(Designator
);
217 end Analyze_Abstract_Subprogram_Declaration
;
219 ----------------------------
220 -- Analyze_Function_Call --
221 ----------------------------
223 procedure Analyze_Function_Call
(N
: Node_Id
) is
224 P
: constant Node_Id
:= Name
(N
);
225 L
: constant List_Id
:= Parameter_Associations
(N
);
231 -- If error analyzing name, then set Any_Type as result type and return
233 if Etype
(P
) = Any_Type
then
234 Set_Etype
(N
, Any_Type
);
238 -- Otherwise analyze the parameters
243 while Present
(Actual
) loop
245 Check_Parameterless_Call
(Actual
);
251 end Analyze_Function_Call
;
253 -------------------------------------
254 -- Analyze_Generic_Subprogram_Body --
255 -------------------------------------
257 procedure Analyze_Generic_Subprogram_Body
261 Gen_Decl
: constant Node_Id
:= Unit_Declaration_Node
(Gen_Id
);
262 Kind
: constant Entity_Kind
:= Ekind
(Gen_Id
);
268 -- Copy body and disable expansion while analyzing the generic
269 -- For a stub, do not copy the stub (which would load the proper body),
270 -- this will be done when the proper body is analyzed.
272 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
273 New_N
:= Copy_Generic_Node
(N
, Empty
, Instantiating
=> False);
278 Spec
:= Specification
(N
);
280 -- Within the body of the generic, the subprogram is callable, and
281 -- behaves like the corresponding non-generic unit.
283 Body_Id
:= Defining_Entity
(Spec
);
285 if Kind
= E_Generic_Procedure
286 and then Nkind
(Spec
) /= N_Procedure_Specification
288 Error_Msg_N
("invalid body for generic procedure ", Body_Id
);
291 elsif Kind
= E_Generic_Function
292 and then Nkind
(Spec
) /= N_Function_Specification
294 Error_Msg_N
("invalid body for generic function ", Body_Id
);
298 Set_Corresponding_Body
(Gen_Decl
, Body_Id
);
300 if Has_Completion
(Gen_Id
)
301 and then Nkind
(Parent
(N
)) /= N_Subunit
303 Error_Msg_N
("duplicate generic body", N
);
306 Set_Has_Completion
(Gen_Id
);
309 if Nkind
(N
) = N_Subprogram_Body_Stub
then
310 Set_Ekind
(Defining_Entity
(Specification
(N
)), Kind
);
312 Set_Corresponding_Spec
(N
, Gen_Id
);
315 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
316 Set_Cunit_Entity
(Current_Sem_Unit
, Defining_Entity
(N
));
319 -- Make generic parameters immediately visible in the body. They are
320 -- needed to process the formals declarations. Then make the formals
321 -- visible in a separate step.
327 First_Ent
: Entity_Id
;
330 First_Ent
:= First_Entity
(Gen_Id
);
333 while Present
(E
) and then not Is_Formal
(E
) loop
338 Set_Use
(Generic_Formal_Declarations
(Gen_Decl
));
340 -- Now generic formals are visible, and the specification can be
341 -- analyzed, for subsequent conformance check.
343 Body_Id
:= Analyze_Subprogram_Specification
(Spec
);
345 -- Make formal parameters visible
349 -- E is the first formal parameter, we loop through the formals
350 -- installing them so that they will be visible.
352 Set_First_Entity
(Gen_Id
, E
);
353 while Present
(E
) loop
359 -- Visible generic entity is callable within its own body.
361 Set_Ekind
(Gen_Id
, Ekind
(Body_Id
));
362 Set_Ekind
(Body_Id
, E_Subprogram_Body
);
363 Set_Convention
(Body_Id
, Convention
(Gen_Id
));
364 Set_Scope
(Body_Id
, Scope
(Gen_Id
));
365 Check_Fully_Conformant
(Body_Id
, Gen_Id
, Body_Id
);
367 if Nkind
(N
) = N_Subprogram_Body_Stub
then
369 -- No body to analyze, so restore state of generic unit.
371 Set_Ekind
(Gen_Id
, Kind
);
372 Set_Ekind
(Body_Id
, Kind
);
374 if Present
(First_Ent
) then
375 Set_First_Entity
(Gen_Id
, First_Ent
);
382 -- If this is a compilation unit, it must be made visible
383 -- explicitly, because the compilation of the declaration,
384 -- unlike other library unit declarations, does not. If it
385 -- is not a unit, the following is redundant but harmless.
387 Set_Is_Immediately_Visible
(Gen_Id
);
388 Reference_Body_Formals
(Gen_Id
, Body_Id
);
390 Set_Actual_Subtypes
(N
, Current_Scope
);
391 Analyze_Declarations
(Declarations
(N
));
393 Analyze
(Handled_Statement_Sequence
(N
));
395 Save_Global_References
(Original_Node
(N
));
397 -- Prior to exiting the scope, include generic formals again
398 -- (if any are present) in the set of local entities.
400 if Present
(First_Ent
) then
401 Set_First_Entity
(Gen_Id
, First_Ent
);
404 Check_References
(Gen_Id
);
407 Process_End_Label
(Handled_Statement_Sequence
(N
), 't', Current_Scope
);
409 Check_Subprogram_Order
(N
);
411 -- Outside of its body, unit is generic again.
413 Set_Ekind
(Gen_Id
, Kind
);
414 Generate_Reference
(Gen_Id
, Body_Id
, 'b', Set_Ref
=> False);
415 Style
.Check_Identifier
(Body_Id
, Gen_Id
);
417 end Analyze_Generic_Subprogram_Body
;
419 -----------------------------
420 -- Analyze_Operator_Symbol --
421 -----------------------------
423 -- An operator symbol such as "+" or "and" may appear in context where
424 -- the literal denotes an entity name, such as "+"(x, y) or in a
425 -- context when it is just a string, as in (conjunction = "or"). In
426 -- these cases the parser generates this node, and the semantics does
427 -- the disambiguation. Other such case are actuals in an instantiation,
428 -- the generic unit in an instantiation, and pragma arguments.
430 procedure Analyze_Operator_Symbol
(N
: Node_Id
) is
431 Par
: constant Node_Id
:= Parent
(N
);
434 if (Nkind
(Par
) = N_Function_Call
and then N
= Name
(Par
))
435 or else Nkind
(Par
) = N_Function_Instantiation
436 or else (Nkind
(Par
) = N_Indexed_Component
and then N
= Prefix
(Par
))
437 or else (Nkind
(Par
) = N_Pragma_Argument_Association
438 and then not Is_Pragma_String_Literal
(Par
))
439 or else Nkind
(Par
) = N_Subprogram_Renaming_Declaration
440 or else (Nkind
(Par
) = N_Attribute_Reference
441 and then Attribute_Name
(Par
) /= Name_Value
)
443 Find_Direct_Name
(N
);
446 Change_Operator_Symbol_To_String_Literal
(N
);
449 end Analyze_Operator_Symbol
;
451 -----------------------------------
452 -- Analyze_Parameter_Association --
453 -----------------------------------
455 procedure Analyze_Parameter_Association
(N
: Node_Id
) is
457 Analyze
(Explicit_Actual_Parameter
(N
));
458 end Analyze_Parameter_Association
;
460 ----------------------------
461 -- Analyze_Procedure_Call --
462 ----------------------------
464 procedure Analyze_Procedure_Call
(N
: Node_Id
) is
465 Loc
: constant Source_Ptr
:= Sloc
(N
);
466 P
: constant Node_Id
:= Name
(N
);
467 Actuals
: constant List_Id
:= Parameter_Associations
(N
);
471 procedure Analyze_Call_And_Resolve
;
472 -- Do Analyze and Resolve calls for procedure call
474 ------------------------------
475 -- Analyze_Call_And_Resolve --
476 ------------------------------
478 procedure Analyze_Call_And_Resolve
is
480 if Nkind
(N
) = N_Procedure_Call_Statement
then
482 Resolve
(N
, Standard_Void_Type
);
486 end Analyze_Call_And_Resolve
;
488 -- Start of processing for Analyze_Procedure_Call
491 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
492 -- a procedure call or an entry call. The prefix may denote an access
493 -- to subprogram type, in which case an implicit dereference applies.
494 -- If the prefix is an indexed component (without implicit defererence)
495 -- then the construct denotes a call to a member of an entire family.
496 -- If the prefix is a simple name, it may still denote a call to a
497 -- parameterless member of an entry family. Resolution of these various
498 -- interpretations is delicate.
502 -- If error analyzing prefix, then set Any_Type as result and return
504 if Etype
(P
) = Any_Type
then
505 Set_Etype
(N
, Any_Type
);
509 -- Otherwise analyze the parameters
511 if Present
(Actuals
) then
512 Actual
:= First
(Actuals
);
514 while Present
(Actual
) loop
516 Check_Parameterless_Call
(Actual
);
521 -- Special processing for Elab_Spec and Elab_Body calls
523 if Nkind
(P
) = N_Attribute_Reference
524 and then (Attribute_Name
(P
) = Name_Elab_Spec
525 or else Attribute_Name
(P
) = Name_Elab_Body
)
527 if Present
(Actuals
) then
529 ("no parameters allowed for this call", First
(Actuals
));
533 Set_Etype
(N
, Standard_Void_Type
);
536 elsif Is_Entity_Name
(P
)
537 and then Is_Record_Type
(Etype
(Entity
(P
)))
538 and then Remote_AST_I_Dereference
(P
)
542 elsif Is_Entity_Name
(P
)
543 and then Ekind
(Entity
(P
)) /= E_Entry_Family
545 if Is_Access_Type
(Etype
(P
))
546 and then Ekind
(Designated_Type
(Etype
(P
))) = E_Subprogram_Type
547 and then No
(Actuals
)
548 and then Comes_From_Source
(N
)
550 Error_Msg_N
("missing explicit dereference in call", N
);
553 Analyze_Call_And_Resolve
;
555 -- If the prefix is the simple name of an entry family, this is
556 -- a parameterless call from within the task body itself.
558 elsif Is_Entity_Name
(P
)
559 and then Nkind
(P
) = N_Identifier
560 and then Ekind
(Entity
(P
)) = E_Entry_Family
561 and then Present
(Actuals
)
562 and then No
(Next
(First
(Actuals
)))
564 -- Can be call to parameterless entry family. What appears to be
565 -- the sole argument is in fact the entry index. Rewrite prefix
566 -- of node accordingly. Source representation is unchanged by this
570 Make_Indexed_Component
(Loc
,
572 Make_Selected_Component
(Loc
,
573 Prefix
=> New_Occurrence_Of
(Scope
(Entity
(P
)), Loc
),
574 Selector_Name
=> New_Occurrence_Of
(Entity
(P
), Loc
)),
575 Expressions
=> Actuals
);
577 Set_Etype
(New_N
, Standard_Void_Type
);
578 Set_Parameter_Associations
(N
, No_List
);
579 Analyze_Call_And_Resolve
;
581 elsif Nkind
(P
) = N_Explicit_Dereference
then
582 if Ekind
(Etype
(P
)) = E_Subprogram_Type
then
583 Analyze_Call_And_Resolve
;
585 Error_Msg_N
("expect access to procedure in call", P
);
588 -- The name can be a selected component or an indexed component
589 -- that yields an access to subprogram. Such a prefix is legal if
590 -- the call has parameter associations.
592 elsif Is_Access_Type
(Etype
(P
))
593 and then Ekind
(Designated_Type
(Etype
(P
))) = E_Subprogram_Type
595 if Present
(Actuals
) then
596 Analyze_Call_And_Resolve
;
598 Error_Msg_N
("missing explicit dereference in call ", N
);
601 -- If not an access to subprogram, then the prefix must resolve to
602 -- the name of an entry, entry family, or protected operation.
604 -- For the case of a simple entry call, P is a selected component
605 -- where the prefix is the task and the selector name is the entry.
606 -- A call to a protected procedure will have the same syntax. If
607 -- the protected object contains overloaded operations, the entity
608 -- may appear as a function, the context will select the operation
609 -- whose type is Void.
611 elsif Nkind
(P
) = N_Selected_Component
612 and then (Ekind
(Entity
(Selector_Name
(P
))) = E_Entry
614 Ekind
(Entity
(Selector_Name
(P
))) = E_Procedure
616 Ekind
(Entity
(Selector_Name
(P
))) = E_Function
)
618 Analyze_Call_And_Resolve
;
620 elsif Nkind
(P
) = N_Selected_Component
621 and then Ekind
(Entity
(Selector_Name
(P
))) = E_Entry_Family
622 and then Present
(Actuals
)
623 and then No
(Next
(First
(Actuals
)))
625 -- Can be call to parameterless entry family. What appears to be
626 -- the sole argument is in fact the entry index. Rewrite prefix
627 -- of node accordingly. Source representation is unchanged by this
631 Make_Indexed_Component
(Loc
,
632 Prefix
=> New_Copy
(P
),
633 Expressions
=> Actuals
);
635 Set_Etype
(New_N
, Standard_Void_Type
);
636 Set_Parameter_Associations
(N
, No_List
);
637 Analyze_Call_And_Resolve
;
639 -- For the case of a reference to an element of an entry family, P is
640 -- an indexed component whose prefix is a selected component (task and
641 -- entry family), and whose index is the entry family index.
643 elsif Nkind
(P
) = N_Indexed_Component
644 and then Nkind
(Prefix
(P
)) = N_Selected_Component
645 and then Ekind
(Entity
(Selector_Name
(Prefix
(P
)))) = E_Entry_Family
647 Analyze_Call_And_Resolve
;
649 -- If the prefix is the name of an entry family, it is a call from
650 -- within the task body itself.
652 elsif Nkind
(P
) = N_Indexed_Component
653 and then Nkind
(Prefix
(P
)) = N_Identifier
654 and then Ekind
(Entity
(Prefix
(P
))) = E_Entry_Family
657 Make_Selected_Component
(Loc
,
658 Prefix
=> New_Occurrence_Of
(Scope
(Entity
(Prefix
(P
))), Loc
),
659 Selector_Name
=> New_Occurrence_Of
(Entity
(Prefix
(P
)), Loc
));
660 Rewrite
(Prefix
(P
), New_N
);
662 Analyze_Call_And_Resolve
;
664 -- Anything else is an error.
667 Error_Msg_N
("Invalid procedure or entry call", N
);
669 end Analyze_Procedure_Call
;
671 ------------------------------
672 -- Analyze_Return_Statement --
673 ------------------------------
675 procedure Analyze_Return_Statement
(N
: Node_Id
) is
676 Loc
: constant Source_Ptr
:= Sloc
(N
);
678 Scope_Id
: Entity_Id
;
683 -- Find subprogram or accept statement enclosing the return statement
686 for J
in reverse 0 .. Scope_Stack
.Last
loop
687 Scope_Id
:= Scope_Stack
.Table
(J
).Entity
;
688 exit when Ekind
(Scope_Id
) /= E_Block
and then
689 Ekind
(Scope_Id
) /= E_Loop
;
692 pragma Assert
(Present
(Scope_Id
));
694 Kind
:= Ekind
(Scope_Id
);
695 Expr
:= Expression
(N
);
697 if Kind
/= E_Function
698 and then Kind
/= E_Generic_Function
699 and then Kind
/= E_Procedure
700 and then Kind
/= E_Generic_Procedure
701 and then Kind
/= E_Entry
702 and then Kind
/= E_Entry_Family
704 Error_Msg_N
("illegal context for return statement", N
);
706 elsif Present
(Expr
) then
707 if Kind
= E_Function
or else Kind
= E_Generic_Function
then
708 Set_Return_Present
(Scope_Id
);
709 R_Type
:= Etype
(Scope_Id
);
710 Set_Return_Type
(N
, R_Type
);
711 Analyze_And_Resolve
(Expr
, R_Type
);
713 if (Is_Class_Wide_Type
(Etype
(Expr
))
714 or else Is_Dynamically_Tagged
(Expr
))
715 and then not Is_Class_Wide_Type
(R_Type
)
718 ("dynamically tagged expression not allowed!", Expr
);
721 Apply_Constraint_Check
(Expr
, R_Type
);
723 -- ??? A real run-time accessibility check is needed
724 -- in cases involving dereferences of access parameters.
725 -- For now we just check the static cases.
727 if Is_Return_By_Reference_Type
(Etype
(Scope_Id
))
728 and then Object_Access_Level
(Expr
)
729 > Subprogram_Access_Level
(Scope_Id
)
732 Make_Raise_Program_Error
(Loc
,
733 Reason
=> PE_Accessibility_Check_Failed
));
737 ("cannot return a local value by reference?", N
);
739 ("& will be raised at run time?!",
740 N
, Standard_Program_Error
);
743 elsif Kind
= E_Procedure
or else Kind
= E_Generic_Procedure
then
744 Error_Msg_N
("procedure cannot return value (use function)", N
);
747 Error_Msg_N
("accept statement cannot return value", N
);
750 -- No expression present
753 if Kind
= E_Function
or Kind
= E_Generic_Function
then
754 Error_Msg_N
("missing expression in return from function", N
);
757 if (Ekind
(Scope_Id
) = E_Procedure
758 or else Ekind
(Scope_Id
) = E_Generic_Procedure
)
759 and then No_Return
(Scope_Id
)
762 ("RETURN statement not allowed (No_Return)", N
);
766 Check_Unreachable_Code
(N
);
767 end Analyze_Return_Statement
;
769 -----------------------------
770 -- Analyze_Subprogram_Body --
771 -----------------------------
773 -- This procedure is called for regular subprogram bodies, generic bodies,
774 -- and for subprogram stubs of both kinds. In the case of stubs, only the
775 -- specification matters, and is used to create a proper declaration for
776 -- the subprogram, or to perform conformance checks.
778 procedure Analyze_Subprogram_Body
(N
: Node_Id
) is
779 Loc
: constant Source_Ptr
:= Sloc
(N
);
780 Body_Spec
: constant Node_Id
:= Specification
(N
);
781 Body_Id
: Entity_Id
:= Defining_Entity
(Body_Spec
);
782 Prev_Id
: constant Entity_Id
:= Current_Entity_In_Scope
(Body_Id
);
783 Body_Deleted
: constant Boolean := False;
787 Spec_Decl
: Node_Id
:= Empty
;
788 Last_Formal
: Entity_Id
:= Empty
;
789 Conformant
: Boolean;
790 Missing_Ret
: Boolean;
793 procedure Check_Following_Pragma
;
794 -- If front-end inlining is enabled, look ahead to recognize a pragma
795 -- that may appear after the body.
797 procedure Check_Following_Pragma
is
801 if Front_End_Inlining
802 and then Is_List_Member
(N
)
803 and then Present
(Spec_Decl
)
804 and then List_Containing
(N
) = List_Containing
(Spec_Decl
)
809 and then Nkind
(Prag
) = N_Pragma
810 and then Get_Pragma_Id
(Chars
(Prag
)) = Pragma_Inline
813 (Expression
(First
(Pragma_Argument_Associations
(Prag
))))
819 end Check_Following_Pragma
;
821 -- Start of processing for Analyze_Subprogram_Body
825 Write_Str
("==== Compiling subprogram body ");
826 Write_Name
(Chars
(Body_Id
));
827 Write_Str
(" from ");
828 Write_Location
(Loc
);
832 Trace_Scope
(N
, Body_Id
, " Analyze subprogram");
834 -- Generic subprograms are handled separately. They always have
835 -- a generic specification. Determine whether current scope has
836 -- a previous declaration.
838 -- If the subprogram body is defined within an instance of the
839 -- same name, the instance appears as a package renaming, and
840 -- will be hidden within the subprogram.
843 and then not Is_Overloadable
(Prev_Id
)
844 and then (Nkind
(Parent
(Prev_Id
)) /= N_Package_Renaming_Declaration
845 or else Comes_From_Source
(Prev_Id
))
847 if Is_Generic_Subprogram
(Prev_Id
) then
849 Set_Is_Compilation_Unit
(Body_Id
, Is_Compilation_Unit
(Spec_Id
));
850 Set_Is_Child_Unit
(Body_Id
, Is_Child_Unit
(Spec_Id
));
852 Analyze_Generic_Subprogram_Body
(N
, Spec_Id
);
856 -- Previous entity conflicts with subprogram name.
857 -- Attempting to enter name will post error.
859 Enter_Name
(Body_Id
);
863 -- Non-generic case, find the subprogram declaration, if one was
864 -- seen, or enter new overloaded entity in the current scope.
865 -- If the current_entity is the body_id itself, the unit is being
866 -- analyzed as part of the context of one of its subunits. No need
867 -- to redo the analysis.
869 elsif Prev_Id
= Body_Id
870 and then Has_Completion
(Body_Id
)
875 Body_Id
:= Analyze_Subprogram_Specification
(Body_Spec
);
877 if Nkind
(N
) = N_Subprogram_Body_Stub
878 or else No
(Corresponding_Spec
(N
))
880 Spec_Id
:= Find_Corresponding_Spec
(N
);
882 -- If this is a duplicate body, no point in analyzing it
884 if Error_Posted
(N
) then
888 -- A subprogram body should cause freezing of its own
889 -- declaration, but if there was no previous explicit
890 -- declaration, then the subprogram will get frozen too
891 -- late (there may be code within the body that depends
892 -- on the subprogram having been frozen, such as uses of
893 -- extra formals), so we force it to be frozen here.
894 -- Same holds if the body and the spec are compilation units.
897 Freeze_Before
(N
, Body_Id
);
899 elsif Nkind
(Parent
(N
)) = N_Compilation_Unit
then
900 Freeze_Before
(N
, Spec_Id
);
903 Spec_Id
:= Corresponding_Spec
(N
);
907 -- Do not inline any subprogram that contains nested subprograms,
908 -- since the backend inlining circuit seems to generate uninitialized
909 -- references in this case. We know this happens in the case of front
910 -- end ZCX support, but it also appears it can happen in other cases
911 -- as well. The backend often rejects attempts to inline in the case
912 -- of nested procedures anyway, so little if anything is lost by this.
914 -- Do not do this test if errors have been detected, because in some
915 -- error cases, this code blows up, and we don't need it anyway if
916 -- there have been errors, since we won't get to the linker anyway.
918 if Serious_Errors_Detected
= 0 then
921 P_Ent
:= Scope
(P_Ent
);
922 exit when No
(P_Ent
) or else P_Ent
= Standard_Standard
;
924 if Is_Subprogram
(P_Ent
) then
925 Set_Is_Inlined
(P_Ent
, False);
927 if Comes_From_Source
(P_Ent
)
928 and then Has_Pragma_Inline
(P_Ent
)
931 ("cannot inline& (nested subprogram)?",
938 -- Case of fully private operation in the body of the protected type.
939 -- We must create a declaration for the subprogram, in order to attach
940 -- the protected subprogram that will be used in internal calls.
943 and then Comes_From_Source
(N
)
944 and then Is_Protected_Type
(Current_Scope
)
953 Formal
:= First_Formal
(Body_Id
);
955 -- The protected operation always has at least one formal,
956 -- namely the object itself, but it is only placed in the
957 -- parameter list if expansion is enabled.
960 or else Expander_Active
968 while Present
(Formal
) loop
970 (Make_Parameter_Specification
(Loc
,
971 Defining_Identifier
=>
972 Make_Defining_Identifier
(Sloc
(Formal
),
973 Chars
=> Chars
(Formal
)),
974 In_Present
=> In_Present
(Parent
(Formal
)),
975 Out_Present
=> Out_Present
(Parent
(Formal
)),
977 New_Reference_To
(Etype
(Formal
), Loc
),
979 New_Copy_Tree
(Expression
(Parent
(Formal
)))),
982 Next_Formal
(Formal
);
985 if Nkind
(Body_Spec
) = N_Procedure_Specification
then
987 Make_Procedure_Specification
(Loc
,
988 Defining_Unit_Name
=>
989 Make_Defining_Identifier
(Sloc
(Body_Id
),
990 Chars
=> Chars
(Body_Id
)),
991 Parameter_Specifications
=> Plist
);
994 Make_Function_Specification
(Loc
,
995 Defining_Unit_Name
=>
996 Make_Defining_Identifier
(Sloc
(Body_Id
),
997 Chars
=> Chars
(Body_Id
)),
998 Parameter_Specifications
=> Plist
,
999 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Body_Id
), Loc
));
1003 Make_Subprogram_Declaration
(Loc
,
1004 Specification
=> New_Spec
);
1005 Insert_Before
(N
, Decl
);
1006 Spec_Id
:= Defining_Unit_Name
(New_Spec
);
1008 -- Indicate that the entity comes from source, to ensure that
1009 -- cross-reference information is properly generated.
1010 -- The body itself is rewritten during expansion, and the
1011 -- body entity will not appear in calls to the operation.
1013 Set_Comes_From_Source
(Spec_Id
, True);
1015 Set_Has_Completion
(Spec_Id
);
1016 Set_Convention
(Spec_Id
, Convention_Protected
);
1019 elsif Present
(Spec_Id
) then
1020 Spec_Decl
:= Unit_Declaration_Node
(Spec_Id
);
1023 -- Place subprogram on scope stack, and make formals visible. If there
1024 -- is a spec, the visible entity remains that of the spec.
1026 if Present
(Spec_Id
) then
1027 Generate_Reference
(Spec_Id
, Body_Id
, 'b', Set_Ref
=> False);
1029 Style
.Check_Identifier
(Body_Id
, Spec_Id
);
1032 Set_Is_Compilation_Unit
(Body_Id
, Is_Compilation_Unit
(Spec_Id
));
1033 Set_Is_Child_Unit
(Body_Id
, Is_Child_Unit
(Spec_Id
));
1035 if Is_Abstract
(Spec_Id
) then
1036 Error_Msg_N
("an abstract subprogram cannot have a body", N
);
1039 Set_Convention
(Body_Id
, Convention
(Spec_Id
));
1040 Set_Has_Completion
(Spec_Id
);
1042 if Is_Protected_Type
(Scope
(Spec_Id
)) then
1043 Set_Privals_Chain
(Spec_Id
, New_Elmt_List
);
1046 -- If this is a body generated for a renaming, do not check for
1047 -- full conformance. The check is redundant, because the spec of
1048 -- the body is a copy of the spec in the renaming declaration,
1049 -- and the test can lead to spurious errors on nested defaults.
1051 if Present
(Spec_Decl
)
1052 and then not Comes_From_Source
(N
)
1054 (Nkind
(Original_Node
(Spec_Decl
)) =
1055 N_Subprogram_Renaming_Declaration
1056 or else (Present
(Corresponding_Body
(Spec_Decl
))
1058 Nkind
(Unit_Declaration_Node
1059 (Corresponding_Body
(Spec_Decl
))) =
1060 N_Subprogram_Renaming_Declaration
))
1066 Fully_Conformant
, True, Conformant
, Body_Id
);
1069 -- If the body is not fully conformant, we have to decide if we
1070 -- should analyze it or not. If it has a really messed up profile
1071 -- then we probably should not analyze it, since we will get too
1072 -- many bogus messages.
1074 -- Our decision is to go ahead in the non-fully conformant case
1075 -- only if it is at least mode conformant with the spec. Note
1076 -- that the call to Check_Fully_Conformant has issued the proper
1077 -- error messages to complain about the lack of conformance.
1080 and then not Mode_Conformant
(Body_Id
, Spec_Id
)
1086 if Spec_Id
/= Body_Id
then
1087 Reference_Body_Formals
(Spec_Id
, Body_Id
);
1090 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
1091 Set_Corresponding_Spec
(N
, Spec_Id
);
1092 Install_Formals
(Spec_Id
);
1093 Last_Formal
:= Last_Entity
(Spec_Id
);
1094 New_Scope
(Spec_Id
);
1096 -- Make sure that the subprogram is immediately visible. For
1097 -- child units that have no separate spec this is indispensable.
1098 -- Otherwise it is safe albeit redundant.
1100 Set_Is_Immediately_Visible
(Spec_Id
);
1103 Set_Corresponding_Body
(Unit_Declaration_Node
(Spec_Id
), Body_Id
);
1104 Set_Ekind
(Body_Id
, E_Subprogram_Body
);
1105 Set_Scope
(Body_Id
, Scope
(Spec_Id
));
1107 -- Case of subprogram body with no previous spec
1111 and then Comes_From_Source
(Body_Id
)
1112 and then not Suppress_Style_Checks
(Body_Id
)
1113 and then not In_Instance
1115 Style
.Body_With_No_Spec
(N
);
1118 New_Overloaded_Entity
(Body_Id
);
1120 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
1121 Set_Acts_As_Spec
(N
);
1122 Generate_Definition
(Body_Id
);
1124 (Body_Id
, Body_Id
, 'b', Set_Ref
=> False, Force
=> True);
1125 Generate_Reference_To_Formals
(Body_Id
);
1126 Install_Formals
(Body_Id
);
1127 New_Scope
(Body_Id
);
1131 -- If this is the proper body of a stub, we must verify that the stub
1132 -- conforms to the body, and to the previous spec if one was present.
1133 -- we know already that the body conforms to that spec. This test is
1134 -- only required for subprograms that come from source.
1136 if Nkind
(Parent
(N
)) = N_Subunit
1137 and then Comes_From_Source
(N
)
1138 and then not Error_Posted
(Body_Id
)
1141 Old_Id
: constant Entity_Id
:=
1143 (Specification
(Corresponding_Stub
(Parent
(N
))));
1145 Conformant
: Boolean := False;
1148 if No
(Spec_Id
) then
1149 Check_Fully_Conformant
(Body_Id
, Old_Id
);
1153 (Body_Id
, Old_Id
, Fully_Conformant
, False, Conformant
);
1155 if not Conformant
then
1157 -- The stub was taken to be a new declaration. Indicate
1158 -- that it lacks a body.
1160 Set_Has_Completion
(Old_Id
, False);
1166 Set_Has_Completion
(Body_Id
);
1167 Check_Eliminated
(Body_Id
);
1169 if Nkind
(N
) = N_Subprogram_Body_Stub
then
1172 elsif Present
(Spec_Id
)
1173 and then Expander_Active
1175 Check_Following_Pragma
;
1177 if Is_Always_Inlined
(Spec_Id
)
1178 or else (Has_Pragma_Inline
(Spec_Id
)
1179 and then (Front_End_Inlining
or else Configurable_Run_Time_Mode
))
1181 Build_Body_To_Inline
(N
, Spec_Id
);
1185 -- Ada 0Y (AI-262): In library subprogram bodies, after the analysis
1186 -- if its specification we have to install the private withed units.
1188 if Is_Compilation_Unit
(Body_Id
)
1189 and then Scope
(Body_Id
) = Standard_Standard
1191 Install_Private_With_Clauses
(Body_Id
);
1194 -- Now we can go on to analyze the body
1196 HSS
:= Handled_Statement_Sequence
(N
);
1197 Set_Actual_Subtypes
(N
, Current_Scope
);
1198 Analyze_Declarations
(Declarations
(N
));
1201 Process_End_Label
(HSS
, 't', Current_Scope
);
1203 Check_Subprogram_Order
(N
);
1204 Set_Analyzed
(Body_Id
);
1206 -- If we have a separate spec, then the analysis of the declarations
1207 -- caused the entities in the body to be chained to the spec id, but
1208 -- we want them chained to the body id. Only the formal parameters
1209 -- end up chained to the spec id in this case.
1211 if Present
(Spec_Id
) then
1213 -- If a parent unit is categorized, the context of a subunit
1214 -- must conform to the categorization. Conversely, if a child
1215 -- unit is categorized, the parents themselves must conform.
1217 if Nkind
(Parent
(N
)) = N_Subunit
then
1218 Validate_Categorization_Dependency
(N
, Spec_Id
);
1220 elsif Is_Child_Unit
(Spec_Id
) then
1221 Validate_Categorization_Dependency
1222 (Unit_Declaration_Node
(Spec_Id
), Spec_Id
);
1225 if Present
(Last_Formal
) then
1227 (Last_Entity
(Body_Id
), Next_Entity
(Last_Formal
));
1228 Set_Next_Entity
(Last_Formal
, Empty
);
1229 Set_Last_Entity
(Body_Id
, Last_Entity
(Spec_Id
));
1230 Set_Last_Entity
(Spec_Id
, Last_Formal
);
1233 Set_First_Entity
(Body_Id
, First_Entity
(Spec_Id
));
1234 Set_Last_Entity
(Body_Id
, Last_Entity
(Spec_Id
));
1235 Set_First_Entity
(Spec_Id
, Empty
);
1236 Set_Last_Entity
(Spec_Id
, Empty
);
1240 -- If function, check return statements
1242 if Nkind
(Body_Spec
) = N_Function_Specification
then
1247 if Present
(Spec_Id
) then
1253 if Return_Present
(Id
) then
1254 Check_Returns
(HSS
, 'F', Missing_Ret
);
1257 Set_Has_Missing_Return
(Id
);
1260 elsif not Is_Machine_Code_Subprogram
(Id
)
1261 and then not Body_Deleted
1263 Error_Msg_N
("missing RETURN statement in function body", N
);
1267 -- If procedure with No_Return, check returns
1269 elsif Nkind
(Body_Spec
) = N_Procedure_Specification
1270 and then Present
(Spec_Id
)
1271 and then No_Return
(Spec_Id
)
1273 Check_Returns
(HSS
, 'P', Missing_Ret
);
1276 -- Now we are going to check for variables that are never modified
1277 -- in the body of the procedure. We omit these checks if the first
1278 -- statement of the procedure raises an exception. In particular
1279 -- this deals with the common idiom of a stubbed function, which
1280 -- might appear as something like
1282 -- function F (A : Integer) return Some_Type;
1285 -- raise Program_Error;
1289 -- Here the purpose of X is simply to satisfy the (annoying)
1290 -- requirement in Ada that there be at least one return, and
1291 -- we certainly do not want to go posting warnings on X that
1292 -- it is not initialized!
1295 Stm
: Node_Id
:= First
(Statements
(HSS
));
1298 -- Skip an initial label (for one thing this occurs when we
1299 -- are in front end ZCX mode, but in any case it is irrelevant).
1301 if Nkind
(Stm
) = N_Label
then
1305 -- Do the test on the original statement before expansion
1308 Ostm
: constant Node_Id
:= Original_Node
(Stm
);
1311 -- If explicit raise statement, return with no checks
1313 if Nkind
(Ostm
) = N_Raise_Statement
then
1316 -- Check for explicit call cases which likely raise an exception
1318 elsif Nkind
(Ostm
) = N_Procedure_Call_Statement
then
1319 if Is_Entity_Name
(Name
(Ostm
)) then
1321 Ent
: constant Entity_Id
:= Entity
(Name
(Ostm
));
1324 -- If the procedure is marked No_Return, then likely it
1325 -- raises an exception, but in any case it is not coming
1326 -- back here, so no need to check beyond the call.
1328 if Ekind
(Ent
) = E_Procedure
1329 and then No_Return
(Ent
)
1333 -- If the procedure name is Raise_Exception, then also
1334 -- assume that it raises an exception. The main target
1335 -- here is Ada.Exceptions.Raise_Exception, but this name
1336 -- is pretty evocative in any context! Note that the
1337 -- procedure in Ada.Exceptions is not marked No_Return
1338 -- because of the annoying case of the null exception Id.
1340 elsif Chars
(Ent
) = Name_Raise_Exception
then
1349 -- Check for variables that are never modified
1355 -- If there is a separate spec, then transfer Never_Set_In_Source
1356 -- flags from out parameters to the corresponding entities in the
1357 -- body. The reason we do that is we want to post error flags on
1358 -- the body entities, not the spec entities.
1360 if Present
(Spec_Id
) then
1361 E1
:= First_Entity
(Spec_Id
);
1363 while Present
(E1
) loop
1364 if Ekind
(E1
) = E_Out_Parameter
then
1365 E2
:= First_Entity
(Body_Id
);
1366 while Present
(E2
) loop
1367 exit when Chars
(E1
) = Chars
(E2
);
1371 if Present
(E2
) then
1372 Set_Never_Set_In_Source
(E2
, Never_Set_In_Source
(E1
));
1380 -- Check references in body unless it was deleted. Note that the
1381 -- check of Body_Deleted here is not just for efficiency, it is
1382 -- necessary to avoid junk warnings on formal parameters.
1384 if not Body_Deleted
then
1385 Check_References
(Body_Id
);
1388 end Analyze_Subprogram_Body
;
1390 ------------------------------------
1391 -- Analyze_Subprogram_Declaration --
1392 ------------------------------------
1394 procedure Analyze_Subprogram_Declaration
(N
: Node_Id
) is
1395 Designator
: constant Entity_Id
:=
1396 Analyze_Subprogram_Specification
(Specification
(N
));
1397 Scop
: constant Entity_Id
:= Current_Scope
;
1399 -- Start of processing for Analyze_Subprogram_Declaration
1402 Generate_Definition
(Designator
);
1404 -- Check for RCI unit subprogram declarations against in-lined
1405 -- subprograms and subprograms having access parameter or limited
1406 -- parameter without Read and Write (RM E.2.3(12-13)).
1408 Validate_RCI_Subprogram_Declaration
(N
);
1412 Defining_Entity
(N
),
1413 " Analyze subprogram spec. ");
1415 if Debug_Flag_C
then
1416 Write_Str
("==== Compiling subprogram spec ");
1417 Write_Name
(Chars
(Designator
));
1418 Write_Str
(" from ");
1419 Write_Location
(Sloc
(N
));
1423 New_Overloaded_Entity
(Designator
);
1424 Check_Delayed_Subprogram
(Designator
);
1426 -- What is the following code for, it used to be
1428 -- ??? Set_Suppress_Elaboration_Checks
1429 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator));
1431 -- The following seems equivalent, but a bit dubious
1433 if Elaboration_Checks_Suppressed
(Designator
) then
1434 Set_Kill_Elaboration_Checks
(Designator
);
1437 if Scop
/= Standard_Standard
1438 and then not Is_Child_Unit
(Designator
)
1440 Set_Categorization_From_Scope
(Designator
, Scop
);
1442 -- For a compilation unit, check for library-unit pragmas.
1444 New_Scope
(Designator
);
1445 Set_Categorization_From_Pragmas
(N
);
1446 Validate_Categorization_Dependency
(N
, Designator
);
1450 -- For a compilation unit, set body required. This flag will only be
1451 -- reset if a valid Import or Interface pragma is processed later on.
1453 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
1454 Set_Body_Required
(Parent
(N
), True);
1457 Generate_Reference_To_Formals
(Designator
);
1458 Check_Eliminated
(Designator
);
1460 if Comes_From_Source
(N
)
1461 and then Is_List_Member
(N
)
1463 Check_Overriding_Operation
(N
, Designator
);
1466 end Analyze_Subprogram_Declaration
;
1468 --------------------------------------
1469 -- Analyze_Subprogram_Specification --
1470 --------------------------------------
1472 -- Reminder: N here really is a subprogram specification (not a subprogram
1473 -- declaration). This procedure is called to analyze the specification in
1474 -- both subprogram bodies and subprogram declarations (specs).
1476 function Analyze_Subprogram_Specification
(N
: Node_Id
) return Entity_Id
is
1477 Designator
: constant Entity_Id
:= Defining_Entity
(N
);
1478 Formals
: constant List_Id
:= Parameter_Specifications
(N
);
1482 Generate_Definition
(Designator
);
1484 if Nkind
(N
) = N_Function_Specification
then
1485 Set_Ekind
(Designator
, E_Function
);
1486 Set_Mechanism
(Designator
, Default_Mechanism
);
1488 if Subtype_Mark
(N
) /= Error
then
1489 Find_Type
(Subtype_Mark
(N
));
1490 Typ
:= Entity
(Subtype_Mark
(N
));
1491 Set_Etype
(Designator
, Typ
);
1493 if Ekind
(Typ
) = E_Incomplete_Type
1494 or else (Is_Class_Wide_Type
(Typ
)
1496 Ekind
(Root_Type
(Typ
)) = E_Incomplete_Type
)
1499 ("invalid use of incomplete type", Subtype_Mark
(N
));
1503 Set_Etype
(Designator
, Any_Type
);
1507 Set_Ekind
(Designator
, E_Procedure
);
1508 Set_Etype
(Designator
, Standard_Void_Type
);
1511 if Present
(Formals
) then
1512 Set_Scope
(Designator
, Current_Scope
);
1513 New_Scope
(Designator
);
1514 Process_Formals
(Formals
, N
);
1518 if Nkind
(N
) = N_Function_Specification
then
1519 if Nkind
(Designator
) = N_Defining_Operator_Symbol
then
1520 Valid_Operator_Definition
(Designator
);
1523 May_Need_Actuals
(Designator
);
1525 if Is_Abstract
(Etype
(Designator
))
1526 and then Nkind
(Parent
(N
)) /= N_Abstract_Subprogram_Declaration
1529 ("function that returns abstract type must be abstract", N
);
1534 end Analyze_Subprogram_Specification
;
1536 --------------------------
1537 -- Build_Body_To_Inline --
1538 --------------------------
1540 procedure Build_Body_To_Inline
(N
: Node_Id
; Subp
: Entity_Id
) is
1541 Decl
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
1542 Original_Body
: Node_Id
;
1543 Body_To_Analyze
: Node_Id
;
1544 Max_Size
: constant := 10;
1545 Stat_Count
: Integer := 0;
1547 function Has_Excluded_Declaration
(Decls
: List_Id
) return Boolean;
1548 -- Check for declarations that make inlining not worthwhile.
1550 function Has_Excluded_Statement
(Stats
: List_Id
) return Boolean;
1551 -- Check for statements that make inlining not worthwhile: any
1552 -- tasking statement, nested at any level. Keep track of total
1553 -- number of elementary statements, as a measure of acceptable size.
1555 function Has_Pending_Instantiation
return Boolean;
1556 -- If some enclosing body contains instantiations that appear before
1557 -- the corresponding generic body, the enclosing body has a freeze node
1558 -- so that it can be elaborated after the generic itself. This might
1559 -- conflict with subsequent inlinings, so that it is unsafe to try to
1560 -- inline in such a case.
1562 procedure Remove_Pragmas
;
1563 -- A pragma Unreferenced that mentions a formal parameter has no
1564 -- meaning when the body is inlined and the formals are rewritten.
1565 -- Remove it from body to inline. The analysis of the non-inlined
1566 -- body will handle the pragma properly.
1568 ------------------------------
1569 -- Has_Excluded_Declaration --
1570 ------------------------------
1572 function Has_Excluded_Declaration
(Decls
: List_Id
) return Boolean is
1575 function Is_Unchecked_Conversion
(D
: Node_Id
) return Boolean;
1576 -- Nested subprograms make a given body ineligible for inlining,
1577 -- but we make an exception for instantiations of unchecked
1578 -- conversion. The body has not been analyzed yet, so we check
1579 -- the name, and verify that the visible entity with that name is
1580 -- the predefined unit.
1582 function Is_Unchecked_Conversion
(D
: Node_Id
) return Boolean is
1583 Id
: constant Node_Id
:= Name
(D
);
1587 if Nkind
(Id
) = N_Identifier
1588 and then Chars
(Id
) = Name_Unchecked_Conversion
1590 Conv
:= Current_Entity
(Id
);
1592 elsif Nkind
(Id
) = N_Selected_Component
1593 and then Chars
(Selector_Name
(Id
)) = Name_Unchecked_Conversion
1595 Conv
:= Current_Entity
(Selector_Name
(Id
));
1603 and then Scope
(Conv
) = Standard_Standard
1604 and then Is_Intrinsic_Subprogram
(Conv
);
1605 end Is_Unchecked_Conversion
;
1607 -- Start of processing for Has_Excluded_Declaration
1612 while Present
(D
) loop
1613 if (Nkind
(D
) = N_Function_Instantiation
1614 and then not Is_Unchecked_Conversion
(D
))
1615 or else Nkind
(D
) = N_Protected_Type_Declaration
1616 or else Nkind
(D
) = N_Package_Declaration
1617 or else Nkind
(D
) = N_Package_Instantiation
1618 or else Nkind
(D
) = N_Subprogram_Body
1619 or else Nkind
(D
) = N_Procedure_Instantiation
1620 or else Nkind
(D
) = N_Task_Type_Declaration
1623 ("cannot inline & (non-allowed declaration)?", D
, Subp
);
1631 end Has_Excluded_Declaration
;
1633 ----------------------------
1634 -- Has_Excluded_Statement --
1635 ----------------------------
1637 function Has_Excluded_Statement
(Stats
: List_Id
) return Boolean is
1644 while Present
(S
) loop
1645 Stat_Count
:= Stat_Count
+ 1;
1647 if Nkind
(S
) = N_Abort_Statement
1648 or else Nkind
(S
) = N_Asynchronous_Select
1649 or else Nkind
(S
) = N_Conditional_Entry_Call
1650 or else Nkind
(S
) = N_Delay_Relative_Statement
1651 or else Nkind
(S
) = N_Delay_Until_Statement
1652 or else Nkind
(S
) = N_Selective_Accept
1653 or else Nkind
(S
) = N_Timed_Entry_Call
1656 ("cannot inline & (non-allowed statement)?", S
, Subp
);
1659 elsif Nkind
(S
) = N_Block_Statement
then
1660 if Present
(Declarations
(S
))
1661 and then Has_Excluded_Declaration
(Declarations
(S
))
1665 elsif Present
(Handled_Statement_Sequence
(S
))
1668 (Exception_Handlers
(Handled_Statement_Sequence
(S
)))
1670 Has_Excluded_Statement
1671 (Statements
(Handled_Statement_Sequence
(S
))))
1676 elsif Nkind
(S
) = N_Case_Statement
then
1677 E
:= First
(Alternatives
(S
));
1679 while Present
(E
) loop
1680 if Has_Excluded_Statement
(Statements
(E
)) then
1687 elsif Nkind
(S
) = N_If_Statement
then
1688 if Has_Excluded_Statement
(Then_Statements
(S
)) then
1692 if Present
(Elsif_Parts
(S
)) then
1693 E
:= First
(Elsif_Parts
(S
));
1695 while Present
(E
) loop
1696 if Has_Excluded_Statement
(Then_Statements
(E
)) then
1703 if Present
(Else_Statements
(S
))
1704 and then Has_Excluded_Statement
(Else_Statements
(S
))
1709 elsif Nkind
(S
) = N_Loop_Statement
1710 and then Has_Excluded_Statement
(Statements
(S
))
1719 end Has_Excluded_Statement
;
1721 -------------------------------
1722 -- Has_Pending_Instantiation --
1723 -------------------------------
1725 function Has_Pending_Instantiation
return Boolean is
1726 S
: Entity_Id
:= Current_Scope
;
1729 while Present
(S
) loop
1730 if Is_Compilation_Unit
(S
)
1731 or else Is_Child_Unit
(S
)
1734 elsif Ekind
(S
) = E_Package
1735 and then Has_Forward_Instantiation
(S
)
1744 end Has_Pending_Instantiation
;
1746 --------------------
1747 -- Remove_Pragmas --
1748 --------------------
1750 procedure Remove_Pragmas
is
1755 Decl
:= First
(Declarations
(Body_To_Analyze
));
1756 while Present
(Decl
) loop
1759 if Nkind
(Decl
) = N_Pragma
1760 and then Chars
(Decl
) = Name_Unreferenced
1769 -- Start of processing for Build_Body_To_Inline
1772 if Nkind
(Decl
) = N_Subprogram_Declaration
1773 and then Present
(Body_To_Inline
(Decl
))
1775 return; -- Done already.
1777 -- Functions that return unconstrained composite types will require
1778 -- secondary stack handling, and cannot currently be inlined.
1779 -- Ditto for functions that return controlled types, where controlled
1780 -- actions interfere in complex ways with inlining.
1782 elsif Ekind
(Subp
) = E_Function
1783 and then not Is_Scalar_Type
(Etype
(Subp
))
1784 and then not Is_Access_Type
(Etype
(Subp
))
1785 and then not Is_Constrained
(Etype
(Subp
))
1788 ("cannot inline & (unconstrained return type)?", N
, Subp
);
1791 elsif Ekind
(Subp
) = E_Function
1792 and then Controlled_Type
(Etype
(Subp
))
1795 ("cannot inline & (controlled return type)?", N
, Subp
);
1799 if Present
(Declarations
(N
))
1800 and then Has_Excluded_Declaration
(Declarations
(N
))
1805 if Present
(Handled_Statement_Sequence
(N
)) then
1806 if Present
(Exception_Handlers
(Handled_Statement_Sequence
(N
))) then
1808 ("cannot inline& (exception handler)?",
1809 First
(Exception_Handlers
(Handled_Statement_Sequence
(N
))),
1813 Has_Excluded_Statement
1814 (Statements
(Handled_Statement_Sequence
(N
)))
1820 -- We do not inline a subprogram that is too large, unless it is
1821 -- marked Inline_Always. This pragma does not suppress the other
1822 -- checks on inlining (forbidden declarations, handlers, etc).
1824 if Stat_Count
> Max_Size
1825 and then not Is_Always_Inlined
(Subp
)
1827 Cannot_Inline
("cannot inline& (body too large)?", N
, Subp
);
1831 if Has_Pending_Instantiation
then
1833 ("cannot inline& (forward instance within enclosing body)?",
1838 -- Within an instance, the body to inline must be treated as a nested
1839 -- generic, so that the proper global references are preserved.
1842 Save_Env
(Scope
(Current_Scope
), Scope
(Current_Scope
));
1843 Original_Body
:= Copy_Generic_Node
(N
, Empty
, True);
1845 Original_Body
:= Copy_Separate_Tree
(N
);
1848 -- We need to capture references to the formals in order to substitute
1849 -- the actuals at the point of inlining, i.e. instantiation. To treat
1850 -- the formals as globals to the body to inline, we nest it within
1851 -- a dummy parameterless subprogram, declared within the real one.
1852 -- To avoid generating an internal name (which is never public, and
1853 -- which affects serial numbers of other generated names), we use
1854 -- an internal symbol that cannot conflict with user declarations.
1856 Set_Parameter_Specifications
(Specification
(Original_Body
), No_List
);
1857 Set_Defining_Unit_Name
1858 (Specification
(Original_Body
),
1859 Make_Defining_Identifier
(Sloc
(N
), Name_uParent
));
1860 Set_Corresponding_Spec
(Original_Body
, Empty
);
1862 Body_To_Analyze
:= Copy_Generic_Node
(Original_Body
, Empty
, False);
1864 -- Set return type of function, which is also global and does not need
1867 if Ekind
(Subp
) = E_Function
then
1868 Set_Subtype_Mark
(Specification
(Body_To_Analyze
),
1869 New_Occurrence_Of
(Etype
(Subp
), Sloc
(N
)));
1872 if No
(Declarations
(N
)) then
1873 Set_Declarations
(N
, New_List
(Body_To_Analyze
));
1875 Append
(Body_To_Analyze
, Declarations
(N
));
1878 Expander_Mode_Save_And_Set
(False);
1881 Analyze
(Body_To_Analyze
);
1882 New_Scope
(Defining_Entity
(Body_To_Analyze
));
1883 Save_Global_References
(Original_Body
);
1885 Remove
(Body_To_Analyze
);
1887 Expander_Mode_Restore
;
1888 Set_Body_To_Inline
(Decl
, Original_Body
);
1889 Set_Ekind
(Defining_Entity
(Original_Body
), Ekind
(Subp
));
1890 Set_Is_Inlined
(Subp
);
1895 end Build_Body_To_Inline
;
1901 procedure Cannot_Inline
(Msg
: String; N
: Node_Id
; Subp
: Entity_Id
) is
1903 -- Do not emit warning if this is a predefined unit which is not
1904 -- the main unit. With validity checks enabled, some predefined
1905 -- subprograms may contain nested subprograms and become ineligible
1908 if Is_Predefined_File_Name
(Unit_File_Name
(Get_Source_Unit
(Subp
)))
1909 and then not In_Extended_Main_Source_Unit
(Subp
)
1913 elsif Is_Always_Inlined
(Subp
) then
1914 Error_Msg_NE
(Msg
(1 .. Msg
'Length - 1), N
, Subp
);
1916 elsif Ineffective_Inline_Warnings
then
1917 Error_Msg_NE
(Msg
, N
, Subp
);
1921 -----------------------
1922 -- Check_Conformance --
1923 -----------------------
1925 procedure Check_Conformance
1926 (New_Id
: Entity_Id
;
1928 Ctype
: Conformance_Type
;
1930 Conforms
: out Boolean;
1931 Err_Loc
: Node_Id
:= Empty
;
1932 Get_Inst
: Boolean := False)
1934 Old_Type
: constant Entity_Id
:= Etype
(Old_Id
);
1935 New_Type
: constant Entity_Id
:= Etype
(New_Id
);
1936 Old_Formal
: Entity_Id
;
1937 New_Formal
: Entity_Id
;
1939 procedure Conformance_Error
(Msg
: String; N
: Node_Id
:= New_Id
);
1940 -- Post error message for conformance error on given node.
1941 -- Two messages are output. The first points to the previous
1942 -- declaration with a general "no conformance" message.
1943 -- The second is the detailed reason, supplied as Msg. The
1944 -- parameter N provide information for a possible & insertion
1945 -- in the message, and also provides the location for posting
1946 -- the message in the absence of a specified Err_Loc location.
1948 -----------------------
1949 -- Conformance_Error --
1950 -----------------------
1952 procedure Conformance_Error
(Msg
: String; N
: Node_Id
:= New_Id
) is
1959 if No
(Err_Loc
) then
1965 Error_Msg_Sloc
:= Sloc
(Old_Id
);
1968 when Type_Conformant
=>
1970 ("not type conformant with declaration#!", Enode
);
1972 when Mode_Conformant
=>
1974 ("not mode conformant with declaration#!", Enode
);
1976 when Subtype_Conformant
=>
1978 ("not subtype conformant with declaration#!", Enode
);
1980 when Fully_Conformant
=>
1982 ("not fully conformant with declaration#!", Enode
);
1985 Error_Msg_NE
(Msg
, Enode
, N
);
1987 end Conformance_Error
;
1989 -- Start of processing for Check_Conformance
1994 -- We need a special case for operators, since they don't
1995 -- appear explicitly.
1997 if Ctype
= Type_Conformant
then
1998 if Ekind
(New_Id
) = E_Operator
1999 and then Operator_Matches_Spec
(New_Id
, Old_Id
)
2005 -- If both are functions/operators, check return types conform
2007 if Old_Type
/= Standard_Void_Type
2008 and then New_Type
/= Standard_Void_Type
2010 if not Conforming_Types
(Old_Type
, New_Type
, Ctype
, Get_Inst
) then
2011 Conformance_Error
("return type does not match!", New_Id
);
2015 -- If either is a function/operator and the other isn't, error
2017 elsif Old_Type
/= Standard_Void_Type
2018 or else New_Type
/= Standard_Void_Type
2020 Conformance_Error
("functions can only match functions!", New_Id
);
2024 -- In subtype conformant case, conventions must match (RM 6.3.1(16))
2025 -- If this is a renaming as body, refine error message to indicate that
2026 -- the conflict is with the original declaration. If the entity is not
2027 -- frozen, the conventions don't have to match, the one of the renamed
2028 -- entity is inherited.
2030 if Ctype
>= Subtype_Conformant
then
2031 if Convention
(Old_Id
) /= Convention
(New_Id
) then
2033 if not Is_Frozen
(New_Id
) then
2036 elsif Present
(Err_Loc
)
2037 and then Nkind
(Err_Loc
) = N_Subprogram_Renaming_Declaration
2038 and then Present
(Corresponding_Spec
(Err_Loc
))
2040 Error_Msg_Name_1
:= Chars
(New_Id
);
2042 Name_Ada
+ Convention_Id
'Pos (Convention
(New_Id
));
2044 Conformance_Error
("prior declaration for% has convention %!");
2047 Conformance_Error
("calling conventions do not match!");
2052 elsif Is_Formal_Subprogram
(Old_Id
)
2053 or else Is_Formal_Subprogram
(New_Id
)
2055 Conformance_Error
("formal subprograms not allowed!");
2060 -- Deal with parameters
2062 -- Note: we use the entity information, rather than going directly
2063 -- to the specification in the tree. This is not only simpler, but
2064 -- absolutely necessary for some cases of conformance tests between
2065 -- operators, where the declaration tree simply does not exist!
2067 Old_Formal
:= First_Formal
(Old_Id
);
2068 New_Formal
:= First_Formal
(New_Id
);
2070 while Present
(Old_Formal
) and then Present
(New_Formal
) loop
2071 if Ctype
= Fully_Conformant
then
2073 -- Names must match. Error message is more accurate if we do
2074 -- this before checking that the types of the formals match.
2076 if Chars
(Old_Formal
) /= Chars
(New_Formal
) then
2077 Conformance_Error
("name & does not match!", New_Formal
);
2079 -- Set error posted flag on new formal as well to stop
2080 -- junk cascaded messages in some cases.
2082 Set_Error_Posted
(New_Formal
);
2087 -- Types must always match. In the visible part of an instance,
2088 -- usual overloading rules for dispatching operations apply, and
2089 -- we check base types (not the actual subtypes).
2091 if In_Instance_Visible_Part
2092 and then Is_Dispatching_Operation
(New_Id
)
2094 if not Conforming_Types
2095 (Base_Type
(Etype
(Old_Formal
)),
2096 Base_Type
(Etype
(New_Formal
)), Ctype
, Get_Inst
)
2098 Conformance_Error
("type of & does not match!", New_Formal
);
2102 elsif not Conforming_Types
2103 (Etype
(Old_Formal
), Etype
(New_Formal
), Ctype
, Get_Inst
)
2105 Conformance_Error
("type of & does not match!", New_Formal
);
2109 -- For mode conformance, mode must match
2111 if Ctype
>= Mode_Conformant
2112 and then Parameter_Mode
(Old_Formal
) /= Parameter_Mode
(New_Formal
)
2114 Conformance_Error
("mode of & does not match!", New_Formal
);
2118 -- Full conformance checks
2120 if Ctype
= Fully_Conformant
then
2122 -- We have checked already that names match.
2123 -- Check default expressions for in parameters
2125 if Parameter_Mode
(Old_Formal
) = E_In_Parameter
then
2127 NewD
: constant Boolean :=
2128 Present
(Default_Value
(New_Formal
));
2129 OldD
: constant Boolean :=
2130 Present
(Default_Value
(Old_Formal
));
2132 if NewD
or OldD
then
2134 -- The old default value has been analyzed because
2135 -- the current full declaration will have frozen
2136 -- everything before. The new default values have not
2137 -- been analyzed, so analyze them now before we check
2142 Analyze_Per_Use_Expression
2143 (Default_Value
(New_Formal
), Etype
(New_Formal
));
2147 if not (NewD
and OldD
)
2148 or else not Fully_Conformant_Expressions
2149 (Default_Value
(Old_Formal
),
2150 Default_Value
(New_Formal
))
2153 ("default expression for & does not match!",
2162 -- A couple of special checks for Ada 83 mode. These checks are
2163 -- skipped if either entity is an operator in package Standard.
2164 -- or if either old or new instance is not from the source program.
2167 and then Sloc
(Old_Id
) > Standard_Location
2168 and then Sloc
(New_Id
) > Standard_Location
2169 and then Comes_From_Source
(Old_Id
)
2170 and then Comes_From_Source
(New_Id
)
2173 Old_Param
: constant Node_Id
:= Declaration_Node
(Old_Formal
);
2174 New_Param
: constant Node_Id
:= Declaration_Node
(New_Formal
);
2177 -- Explicit IN must be present or absent in both cases. This
2178 -- test is required only in the full conformance case.
2180 if In_Present
(Old_Param
) /= In_Present
(New_Param
)
2181 and then Ctype
= Fully_Conformant
2184 ("(Ada 83) IN must appear in both declarations",
2189 -- Grouping (use of comma in param lists) must be the same
2190 -- This is where we catch a misconformance like:
2193 -- A : Integer; B : Integer
2195 -- which are represented identically in the tree except
2196 -- for the setting of the flags More_Ids and Prev_Ids.
2198 if More_Ids
(Old_Param
) /= More_Ids
(New_Param
)
2199 or else Prev_Ids
(Old_Param
) /= Prev_Ids
(New_Param
)
2202 ("grouping of & does not match!", New_Formal
);
2208 Next_Formal
(Old_Formal
);
2209 Next_Formal
(New_Formal
);
2212 if Present
(Old_Formal
) then
2213 Conformance_Error
("too few parameters!");
2216 elsif Present
(New_Formal
) then
2217 Conformance_Error
("too many parameters!", New_Formal
);
2221 end Check_Conformance
;
2223 ------------------------------
2224 -- Check_Delayed_Subprogram --
2225 ------------------------------
2227 procedure Check_Delayed_Subprogram
(Designator
: Entity_Id
) is
2230 procedure Possible_Freeze
(T
: Entity_Id
);
2231 -- T is the type of either a formal parameter or of the return type.
2232 -- If T is not yet frozen and needs a delayed freeze, then the
2233 -- subprogram itself must be delayed.
2235 procedure Possible_Freeze
(T
: Entity_Id
) is
2237 if Has_Delayed_Freeze
(T
)
2238 and then not Is_Frozen
(T
)
2240 Set_Has_Delayed_Freeze
(Designator
);
2242 elsif Is_Access_Type
(T
)
2243 and then Has_Delayed_Freeze
(Designated_Type
(T
))
2244 and then not Is_Frozen
(Designated_Type
(T
))
2246 Set_Has_Delayed_Freeze
(Designator
);
2248 end Possible_Freeze
;
2250 -- Start of processing for Check_Delayed_Subprogram
2253 -- Never need to freeze abstract subprogram
2255 if Is_Abstract
(Designator
) then
2258 -- Need delayed freeze if return type itself needs a delayed
2259 -- freeze and is not yet frozen.
2261 Possible_Freeze
(Etype
(Designator
));
2262 Possible_Freeze
(Base_Type
(Etype
(Designator
))); -- needed ???
2264 -- Need delayed freeze if any of the formal types themselves need
2265 -- a delayed freeze and are not yet frozen.
2267 F
:= First_Formal
(Designator
);
2268 while Present
(F
) loop
2269 Possible_Freeze
(Etype
(F
));
2270 Possible_Freeze
(Base_Type
(Etype
(F
))); -- needed ???
2275 -- Mark functions that return by reference. Note that it cannot be
2276 -- done for delayed_freeze subprograms because the underlying
2277 -- returned type may not be known yet (for private types)
2279 if not Has_Delayed_Freeze
(Designator
)
2280 and then Expander_Active
2283 Typ
: constant Entity_Id
:= Etype
(Designator
);
2284 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
2287 if Is_Return_By_Reference_Type
(Typ
) then
2288 Set_Returns_By_Ref
(Designator
);
2290 elsif Present
(Utyp
) and then Controlled_Type
(Utyp
) then
2291 Set_Returns_By_Ref
(Designator
);
2295 end Check_Delayed_Subprogram
;
2297 ------------------------------------
2298 -- Check_Discriminant_Conformance --
2299 ------------------------------------
2301 procedure Check_Discriminant_Conformance
2306 Old_Discr
: Entity_Id
:= First_Discriminant
(Prev
);
2307 New_Discr
: Node_Id
:= First
(Discriminant_Specifications
(N
));
2308 New_Discr_Id
: Entity_Id
;
2309 New_Discr_Type
: Entity_Id
;
2311 procedure Conformance_Error
(Msg
: String; N
: Node_Id
);
2312 -- Post error message for conformance error on given node.
2313 -- Two messages are output. The first points to the previous
2314 -- declaration with a general "no conformance" message.
2315 -- The second is the detailed reason, supplied as Msg. The
2316 -- parameter N provide information for a possible & insertion
2319 -----------------------
2320 -- Conformance_Error --
2321 -----------------------
2323 procedure Conformance_Error
(Msg
: String; N
: Node_Id
) is
2325 Error_Msg_Sloc
:= Sloc
(Prev_Loc
);
2326 Error_Msg_N
("not fully conformant with declaration#!", N
);
2327 Error_Msg_NE
(Msg
, N
, N
);
2328 end Conformance_Error
;
2330 -- Start of processing for Check_Discriminant_Conformance
2333 while Present
(Old_Discr
) and then Present
(New_Discr
) loop
2335 New_Discr_Id
:= Defining_Identifier
(New_Discr
);
2337 -- The subtype mark of the discriminant on the full type
2338 -- has not been analyzed so we do it here. For an access
2339 -- discriminant a new type is created.
2341 if Nkind
(Discriminant_Type
(New_Discr
)) = N_Access_Definition
then
2343 Access_Definition
(N
, Discriminant_Type
(New_Discr
));
2346 Analyze
(Discriminant_Type
(New_Discr
));
2347 New_Discr_Type
:= Etype
(Discriminant_Type
(New_Discr
));
2350 if not Conforming_Types
2351 (Etype
(Old_Discr
), New_Discr_Type
, Fully_Conformant
)
2353 Conformance_Error
("type of & does not match!", New_Discr_Id
);
2356 -- Treat the new discriminant as an occurrence of the old
2357 -- one, for navigation purposes, and fill in some semantic
2358 -- information, for completeness.
2360 Generate_Reference
(Old_Discr
, New_Discr_Id
, 'r');
2361 Set_Etype
(New_Discr_Id
, Etype
(Old_Discr
));
2362 Set_Scope
(New_Discr_Id
, Scope
(Old_Discr
));
2367 if Chars
(Old_Discr
) /= Chars
(Defining_Identifier
(New_Discr
)) then
2368 Conformance_Error
("name & does not match!", New_Discr_Id
);
2372 -- Default expressions must match
2375 NewD
: constant Boolean :=
2376 Present
(Expression
(New_Discr
));
2377 OldD
: constant Boolean :=
2378 Present
(Expression
(Parent
(Old_Discr
)));
2381 if NewD
or OldD
then
2383 -- The old default value has been analyzed and expanded,
2384 -- because the current full declaration will have frozen
2385 -- everything before. The new default values have not
2386 -- been expanded, so expand now to check conformance.
2389 Analyze_Per_Use_Expression
2390 (Expression
(New_Discr
), New_Discr_Type
);
2393 if not (NewD
and OldD
)
2394 or else not Fully_Conformant_Expressions
2395 (Expression
(Parent
(Old_Discr
)),
2396 Expression
(New_Discr
))
2400 ("default expression for & does not match!",
2407 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
2411 Old_Disc
: constant Node_Id
:= Declaration_Node
(Old_Discr
);
2414 -- Grouping (use of comma in param lists) must be the same
2415 -- This is where we catch a misconformance like:
2418 -- A : Integer; B : Integer
2420 -- which are represented identically in the tree except
2421 -- for the setting of the flags More_Ids and Prev_Ids.
2423 if More_Ids
(Old_Disc
) /= More_Ids
(New_Discr
)
2424 or else Prev_Ids
(Old_Disc
) /= Prev_Ids
(New_Discr
)
2427 ("grouping of & does not match!", New_Discr_Id
);
2433 Next_Discriminant
(Old_Discr
);
2437 if Present
(Old_Discr
) then
2438 Conformance_Error
("too few discriminants!", Defining_Identifier
(N
));
2441 elsif Present
(New_Discr
) then
2443 ("too many discriminants!", Defining_Identifier
(New_Discr
));
2446 end Check_Discriminant_Conformance
;
2448 ----------------------------
2449 -- Check_Fully_Conformant --
2450 ----------------------------
2452 procedure Check_Fully_Conformant
2453 (New_Id
: Entity_Id
;
2455 Err_Loc
: Node_Id
:= Empty
)
2461 (New_Id
, Old_Id
, Fully_Conformant
, True, Result
, Err_Loc
);
2462 end Check_Fully_Conformant
;
2464 ---------------------------
2465 -- Check_Mode_Conformant --
2466 ---------------------------
2468 procedure Check_Mode_Conformant
2469 (New_Id
: Entity_Id
;
2471 Err_Loc
: Node_Id
:= Empty
;
2472 Get_Inst
: Boolean := False)
2478 (New_Id
, Old_Id
, Mode_Conformant
, True, Result
, Err_Loc
, Get_Inst
);
2479 end Check_Mode_Conformant
;
2481 --------------------------------
2482 -- Check_Overriding_Operation --
2483 --------------------------------
2485 procedure Check_Overriding_Operation
2491 Has_Pragma
: Boolean := False;
2494 -- See whether there is an overriding pragma immediately following
2495 -- the declaration. Intervening pragmas, such as Inline, are allowed.
2498 while Present
(Decl
)
2499 and then Nkind
(Decl
) = N_Pragma
2501 if Chars
(Decl
) = Name_Overriding
2502 or else Chars
(Decl
) = Name_Optional_Overriding
2504 -- For now disable the use of these pragmas, until the ARG
2505 -- finalizes the design of this feature.
2507 Error_Msg_N
("?unrecognized pragma", Decl
);
2509 if not Is_Overriding_Operation
(Subp
) then
2511 -- Before emitting an error message, check whether this
2512 -- may override an operation that is not yet visible, as
2513 -- in the case of a derivation of a private operation in
2514 -- a child unit. Such an operation is introduced with a
2515 -- different name, but its alias is the parent operation.
2521 E
:= First_Entity
(Current_Scope
);
2523 while Present
(E
) loop
2524 if Ekind
(E
) = Ekind
(Subp
)
2525 and then not Comes_From_Source
(E
)
2526 and then Present
(Alias
(E
))
2527 and then Chars
(Alias
(E
)) = Chars
(Subp
)
2528 and then In_Open_Scopes
(Scope
(Alias
(E
)))
2538 ("& must override an inherited operation",
2544 -- Verify syntax of pragma
2546 Arg1
:= First
(Pragma_Argument_Associations
(Decl
));
2548 if Present
(Arg1
) then
2549 if not Is_Entity_Name
(Expression
(Arg1
)) then
2550 Error_Msg_N
("pragma applies to local subprogram", Decl
);
2552 elsif Chars
(Expression
(Arg1
)) /= Chars
(Subp
) then
2554 ("pragma must apply to preceding subprogram", Decl
);
2556 elsif Present
(Next
(Arg1
)) then
2557 Error_Msg_N
("illegal pragma format", Decl
);
2561 Set_Analyzed
(Decl
);
2570 and then Explicit_Overriding
2571 and then Is_Overriding_Operation
(Subp
)
2573 Error_Msg_NE
("Missing overriding pragma for&", Subp
, Subp
);
2575 end Check_Overriding_Operation
;
2581 procedure Check_Returns
2588 procedure Check_Statement_Sequence
(L
: List_Id
);
2589 -- Internal recursive procedure to check a list of statements for proper
2590 -- termination by a return statement (or a transfer of control or a
2591 -- compound statement that is itself internally properly terminated).
2593 ------------------------------
2594 -- Check_Statement_Sequence --
2595 ------------------------------
2597 procedure Check_Statement_Sequence
(L
: List_Id
) is
2601 Raise_Exception_Call
: Boolean;
2602 -- Set True if statement sequence terminated by Raise_Exception call
2603 -- or a Reraise_Occurrence call.
2606 Raise_Exception_Call
:= False;
2608 -- Get last real statement
2610 Last_Stm
:= Last
(L
);
2612 -- Don't count pragmas
2614 while Nkind
(Last_Stm
) = N_Pragma
2616 -- Don't count call to SS_Release (can happen after Raise_Exception)
2619 (Nkind
(Last_Stm
) = N_Procedure_Call_Statement
2621 Nkind
(Name
(Last_Stm
)) = N_Identifier
2623 Is_RTE
(Entity
(Name
(Last_Stm
)), RE_SS_Release
))
2625 -- Don't count exception junk
2628 ((Nkind
(Last_Stm
) = N_Goto_Statement
2629 or else Nkind
(Last_Stm
) = N_Label
2630 or else Nkind
(Last_Stm
) = N_Object_Declaration
)
2631 and then Exception_Junk
(Last_Stm
))
2636 -- Here we have the "real" last statement
2638 Kind
:= Nkind
(Last_Stm
);
2640 -- Transfer of control, OK. Note that in the No_Return procedure
2641 -- case, we already diagnosed any explicit return statements, so
2642 -- we can treat them as OK in this context.
2644 if Is_Transfer
(Last_Stm
) then
2647 -- Check cases of explicit non-indirect procedure calls
2649 elsif Kind
= N_Procedure_Call_Statement
2650 and then Is_Entity_Name
(Name
(Last_Stm
))
2652 -- Check call to Raise_Exception procedure which is treated
2653 -- specially, as is a call to Reraise_Occurrence.
2655 -- We suppress the warning in these cases since it is likely that
2656 -- the programmer really does not expect to deal with the case
2657 -- of Null_Occurrence, and thus would find a warning about a
2658 -- missing return curious, and raising Program_Error does not
2659 -- seem such a bad behavior if this does occur.
2661 if Is_RTE
(Entity
(Name
(Last_Stm
)), RE_Raise_Exception
)
2663 Is_RTE
(Entity
(Name
(Last_Stm
)), RE_Reraise_Occurrence
)
2665 Raise_Exception_Call
:= True;
2667 -- For Raise_Exception call, test first argument, if it is
2668 -- an attribute reference for a 'Identity call, then we know
2669 -- that the call cannot possibly return.
2672 Arg
: constant Node_Id
:=
2673 Original_Node
(First_Actual
(Last_Stm
));
2676 if Nkind
(Arg
) = N_Attribute_Reference
2677 and then Attribute_Name
(Arg
) = Name_Identity
2684 -- If statement, need to look inside if there is an else and check
2685 -- each constituent statement sequence for proper termination.
2687 elsif Kind
= N_If_Statement
2688 and then Present
(Else_Statements
(Last_Stm
))
2690 Check_Statement_Sequence
(Then_Statements
(Last_Stm
));
2691 Check_Statement_Sequence
(Else_Statements
(Last_Stm
));
2693 if Present
(Elsif_Parts
(Last_Stm
)) then
2695 Elsif_Part
: Node_Id
:= First
(Elsif_Parts
(Last_Stm
));
2698 while Present
(Elsif_Part
) loop
2699 Check_Statement_Sequence
(Then_Statements
(Elsif_Part
));
2707 -- Case statement, check each case for proper termination
2709 elsif Kind
= N_Case_Statement
then
2714 Case_Alt
:= First_Non_Pragma
(Alternatives
(Last_Stm
));
2715 while Present
(Case_Alt
) loop
2716 Check_Statement_Sequence
(Statements
(Case_Alt
));
2717 Next_Non_Pragma
(Case_Alt
);
2723 -- Block statement, check its handled sequence of statements
2725 elsif Kind
= N_Block_Statement
then
2731 (Handled_Statement_Sequence
(Last_Stm
), Mode
, Err1
);
2740 -- Loop statement. If there is an iteration scheme, we can definitely
2741 -- fall out of the loop. Similarly if there is an exit statement, we
2742 -- can fall out. In either case we need a following return.
2744 elsif Kind
= N_Loop_Statement
then
2745 if Present
(Iteration_Scheme
(Last_Stm
))
2746 or else Has_Exit
(Entity
(Identifier
(Last_Stm
)))
2750 -- A loop with no exit statement or iteration scheme if either
2751 -- an inifite loop, or it has some other exit (raise/return).
2752 -- In either case, no warning is required.
2758 -- Timed entry call, check entry call and delay alternatives
2760 -- Note: in expanded code, the timed entry call has been converted
2761 -- to a set of expanded statements on which the check will work
2762 -- correctly in any case.
2764 elsif Kind
= N_Timed_Entry_Call
then
2766 ECA
: constant Node_Id
:= Entry_Call_Alternative
(Last_Stm
);
2767 DCA
: constant Node_Id
:= Delay_Alternative
(Last_Stm
);
2770 -- If statement sequence of entry call alternative is missing,
2771 -- then we can definitely fall through, and we post the error
2772 -- message on the entry call alternative itself.
2774 if No
(Statements
(ECA
)) then
2777 -- If statement sequence of delay alternative is missing, then
2778 -- we can definitely fall through, and we post the error
2779 -- message on the delay alternative itself.
2781 -- Note: if both ECA and DCA are missing the return, then we
2782 -- post only one message, should be enough to fix the bugs.
2783 -- If not we will get a message next time on the DCA when the
2786 elsif No
(Statements
(DCA
)) then
2789 -- Else check both statement sequences
2792 Check_Statement_Sequence
(Statements
(ECA
));
2793 Check_Statement_Sequence
(Statements
(DCA
));
2798 -- Conditional entry call, check entry call and else part
2800 -- Note: in expanded code, the conditional entry call has been
2801 -- converted to a set of expanded statements on which the check
2802 -- will work correctly in any case.
2804 elsif Kind
= N_Conditional_Entry_Call
then
2806 ECA
: constant Node_Id
:= Entry_Call_Alternative
(Last_Stm
);
2809 -- If statement sequence of entry call alternative is missing,
2810 -- then we can definitely fall through, and we post the error
2811 -- message on the entry call alternative itself.
2813 if No
(Statements
(ECA
)) then
2816 -- Else check statement sequence and else part
2819 Check_Statement_Sequence
(Statements
(ECA
));
2820 Check_Statement_Sequence
(Else_Statements
(Last_Stm
));
2826 -- If we fall through, issue appropriate message
2830 if not Raise_Exception_Call
then
2832 ("?RETURN statement missing following this statement!",
2835 ("\?Program_Error may be raised at run time",
2839 -- Note: we set Err even though we have not issued a warning
2840 -- because we still have a case of a missing return. This is
2841 -- an extremely marginal case, probably will never be noticed
2842 -- but we might as well get it right.
2848 ("implied return after this statement not allowed (No_Return)",
2851 end Check_Statement_Sequence
;
2853 -- Start of processing for Check_Returns
2857 Check_Statement_Sequence
(Statements
(HSS
));
2859 if Present
(Exception_Handlers
(HSS
)) then
2860 Handler
:= First_Non_Pragma
(Exception_Handlers
(HSS
));
2861 while Present
(Handler
) loop
2862 Check_Statement_Sequence
(Statements
(Handler
));
2863 Next_Non_Pragma
(Handler
);
2868 ----------------------------
2869 -- Check_Subprogram_Order --
2870 ----------------------------
2872 procedure Check_Subprogram_Order
(N
: Node_Id
) is
2874 function Subprogram_Name_Greater
(S1
, S2
: String) return Boolean;
2875 -- This is used to check if S1 > S2 in the sense required by this
2876 -- test, for example nameab < namec, but name2 < name10.
2878 function Subprogram_Name_Greater
(S1
, S2
: String) return Boolean is
2883 -- Remove trailing numeric parts
2886 while S1
(L1
) in '0' .. '9' loop
2891 while S2
(L2
) in '0' .. '9' loop
2895 -- If non-numeric parts non-equal, that's decisive
2897 if S1
(S1
'First .. L1
) < S2
(S2
'First .. L2
) then
2900 elsif S1
(S1
'First .. L1
) > S2
(S2
'First .. L2
) then
2903 -- If non-numeric parts equal, compare suffixed numeric parts. Note
2904 -- that a missing suffix is treated as numeric zero in this test.
2908 while L1
< S1
'Last loop
2910 N1
:= N1
* 10 + Character'Pos (S1
(L1
)) - Character'Pos ('0');
2914 while L2
< S2
'Last loop
2916 N2
:= N2
* 10 + Character'Pos (S2
(L2
)) - Character'Pos ('0');
2921 end Subprogram_Name_Greater
;
2923 -- Start of processing for Check_Subprogram_Order
2926 -- Check body in alpha order if this is option
2929 and then Style_Check_Subprogram_Order
2930 and then Nkind
(N
) = N_Subprogram_Body
2931 and then Comes_From_Source
(N
)
2932 and then In_Extended_Main_Source_Unit
(N
)
2936 renames Scope_Stack
.Table
2937 (Scope_Stack
.Last
).Last_Subprogram_Name
;
2939 Body_Id
: constant Entity_Id
:=
2940 Defining_Entity
(Specification
(N
));
2943 Get_Decoded_Name_String
(Chars
(Body_Id
));
2946 if Subprogram_Name_Greater
2947 (LSN
.all, Name_Buffer
(1 .. Name_Len
))
2949 Style
.Subprogram_Not_In_Alpha_Order
(Body_Id
);
2955 LSN
:= new String'(Name_Buffer (1 .. Name_Len));
2958 end Check_Subprogram_Order;
2960 ------------------------------
2961 -- Check_Subtype_Conformant --
2962 ------------------------------
2964 procedure Check_Subtype_Conformant
2965 (New_Id : Entity_Id;
2967 Err_Loc : Node_Id := Empty)
2973 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc);
2974 end Check_Subtype_Conformant;
2976 ---------------------------
2977 -- Check_Type_Conformant --
2978 ---------------------------
2980 procedure Check_Type_Conformant
2981 (New_Id : Entity_Id;
2983 Err_Loc : Node_Id := Empty)
2989 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
2990 end Check_Type_Conformant;
2992 ----------------------
2993 -- Conforming_Types --
2994 ----------------------
2996 function Conforming_Types
2999 Ctype : Conformance_Type;
3000 Get_Inst : Boolean := False) return Boolean
3002 Type_1 : Entity_Id := T1;
3003 Type_2 : Entity_Id := T2;
3004 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False;
3006 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
3007 -- If neither T1 nor T2 are generic actual types, or if they are
3008 -- in different scopes (e.g. parent and child instances), then verify
3009 -- that the base types are equal. Otherwise T1 and T2 must be
3010 -- on the same subtype chain. The whole purpose of this procedure
3011 -- is to prevent spurious ambiguities in an instantiation that may
3012 -- arise if two distinct generic types are instantiated with the
3015 ----------------------
3016 -- Base_Types_Match --
3017 ----------------------
3019 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
3024 elsif Base_Type (T1) = Base_Type (T2) then
3026 -- The following is too permissive. A more precise test must
3027 -- check that the generic actual is an ancestor subtype of the
3030 return not Is_Generic_Actual_Type (T1)
3031 or else not Is_Generic_Actual_Type (T2)
3032 or else Scope (T1) /= Scope (T2);
3034 -- In some cases a type imported through a limited_with clause,
3035 -- and its non-limited view are both visible, for example in an
3036 -- anonymous access_to_classwide type in a formal. Both entities
3037 -- designate the same type.
3039 elsif From_With_Type (T1)
3040 and then Ekind (T1) = E_Incomplete_Type
3041 and then T2 = Non_Limited_View (T1)
3048 end Base_Types_Match;
3051 -- The context is an instance association for a formal
3052 -- access-to-subprogram type; the formal parameter types
3053 -- require mapping because they may denote other formal
3054 -- parameters of the generic unit.
3057 Type_1 := Get_Instance_Of (T1);
3058 Type_2 := Get_Instance_Of (T2);
3061 -- First see if base types match
3063 if Base_Types_Match (Type_1, Type_2) then
3064 return Ctype <= Mode_Conformant
3065 or else Subtypes_Statically_Match (Type_1, Type_2);
3067 elsif Is_Incomplete_Or_Private_Type (Type_1)
3068 and then Present (Full_View (Type_1))
3069 and then Base_Types_Match (Full_View (Type_1), Type_2)
3071 return Ctype <= Mode_Conformant
3072 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
3074 elsif Ekind (Type_2) = E_Incomplete_Type
3075 and then Present (Full_View (Type_2))
3076 and then Base_Types_Match (Type_1, Full_View (Type_2))
3078 return Ctype <= Mode_Conformant
3079 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3081 elsif Is_Private_Type (Type_2)
3082 and then In_Instance
3083 and then Present (Full_View (Type_2))
3084 and then Base_Types_Match (Type_1, Full_View (Type_2))
3086 return Ctype <= Mode_Conformant
3087 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3090 -- Ada 0Y (AI-254): Detect anonymous access to subprogram types.
3092 Are_Anonymous_Access_To_Subprogram_Types :=
3094 -- Case 1: Anonymous access to subprogram types
3096 (Ekind (Type_1) = E_Anonymous_Access_Subprogram_Type
3097 and then Ekind (Type_2) = E_Anonymous_Access_Subprogram_Type)
3099 -- Case 2: Anonymous access to PROTECTED subprogram types. In this
3100 -- case the anonymous type_declaration has been replaced by an
3101 -- occurrence of an internal access to subprogram type declaration
3102 -- available through the Original_Access_Type attribute
3105 (Ekind (Type_1) = E_Access_Protected_Subprogram_Type
3106 and then Ekind (Type_2) = E_Access_Protected_Subprogram_Type
3107 and then not Comes_From_Source (Type_1)
3108 and then not Comes_From_Source (Type_2)
3109 and then Present (Original_Access_Type (Type_1))
3110 and then Present (Original_Access_Type (Type_2))
3111 and then Ekind (Original_Access_Type (Type_1)) =
3112 E_Anonymous_Access_Protected_Subprogram_Type
3113 and then Ekind (Original_Access_Type (Type_2)) =
3114 E_Anonymous_Access_Protected_Subprogram_Type);
3116 -- Test anonymous access type case. For this case, static subtype
3117 -- matching is required for mode conformance (RM 6.3.1(15))
3119 if (Ekind (Type_1) = E_Anonymous_Access_Type
3120 and then Ekind (Type_2) = E_Anonymous_Access_Type)
3121 or else Are_Anonymous_Access_To_Subprogram_Types -- Ada 0Y (AI-254)
3124 Desig_1 : Entity_Id;
3125 Desig_2 : Entity_Id;
3128 Desig_1 := Directly_Designated_Type (Type_1);
3130 -- An access parameter can designate an incomplete type
3132 if Ekind (Desig_1) = E_Incomplete_Type
3133 and then Present (Full_View (Desig_1))
3135 Desig_1 := Full_View (Desig_1);
3138 Desig_2 := Directly_Designated_Type (Type_2);
3140 if Ekind (Desig_2) = E_Incomplete_Type
3141 and then Present (Full_View (Desig_2))
3143 Desig_2 := Full_View (Desig_2);
3146 -- The context is an instance association for a formal
3147 -- access-to-subprogram type; formal access parameter
3148 -- designated types require mapping because they may
3149 -- denote other formal parameters of the generic unit.
3152 Desig_1 := Get_Instance_Of (Desig_1);
3153 Desig_2 := Get_Instance_Of (Desig_2);
3156 -- It is possible for a Class_Wide_Type to be introduced for
3157 -- an incomplete type, in which case there is a separate class_
3158 -- wide type for the full view. The types conform if their
3159 -- Etypes conform, i.e. one may be the full view of the other.
3160 -- This can only happen in the context of an access parameter,
3161 -- other uses of an incomplete Class_Wide_Type are illegal.
3163 if Is_Class_Wide_Type (Desig_1)
3164 and then Is_Class_Wide_Type (Desig_2)
3168 (Etype (Base_Type (Desig_1)),
3169 Etype (Base_Type (Desig_2)), Ctype);
3171 elsif Are_Anonymous_Access_To_Subprogram_Types then
3172 return Ctype = Type_Conformant
3174 Subtypes_Statically_Match (Desig_1, Desig_2);
3177 return Base_Type (Desig_1) = Base_Type (Desig_2)
3178 and then (Ctype = Type_Conformant
3180 Subtypes_Statically_Match (Desig_1, Desig_2));
3184 -- Otherwise definitely no match
3190 end Conforming_Types;
3192 --------------------------
3193 -- Create_Extra_Formals --
3194 --------------------------
3196 procedure Create_Extra_Formals (E : Entity_Id) is
3198 Last_Extra : Entity_Id;
3199 Formal_Type : Entity_Id;
3200 P_Formal : Entity_Id := Empty;
3202 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id;
3203 -- Add an extra formal, associated with the current Formal. The
3204 -- extra formal is added to the list of extra formals, and also
3205 -- returned as the result. These formals are always of mode IN.
3207 ----------------------
3208 -- Add_Extra_Formal --
3209 ----------------------
3211 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is
3212 EF : constant Entity_Id :=
3213 Make_Defining_Identifier (Sloc (Formal),
3214 Chars => New_External_Name (Chars (Formal), 'F
'));
3217 -- We never generate extra formals if expansion is not active
3218 -- because we don't need them unless we are generating code.
3220 if not Expander_Active then
3224 -- A little optimization. Never generate an extra formal for
3225 -- the _init operand of an initialization procedure, since it
3226 -- could never be used.
3228 if Chars (Formal) = Name_uInit then
3232 Set_Ekind (EF, E_In_Parameter);
3233 Set_Actual_Subtype (EF, Typ);
3234 Set_Etype (EF, Typ);
3235 Set_Scope (EF, Scope (Formal));
3236 Set_Mechanism (EF, Default_Mechanism);
3237 Set_Formal_Validity (EF);
3239 Set_Extra_Formal (Last_Extra, EF);
3242 end Add_Extra_Formal;
3244 -- Start of processing for Create_Extra_Formals
3247 -- If this is a derived subprogram then the subtypes of the
3248 -- parent subprogram's formal parameters will be used to
3249 -- to determine the need for extra formals.
3251 if Is_Overloadable (E) and then Present (Alias (E)) then
3252 P_Formal := First_Formal (Alias (E));
3255 Last_Extra := Empty;
3256 Formal := First_Formal (E);
3257 while Present (Formal) loop
3258 Last_Extra := Formal;
3259 Next_Formal (Formal);
3262 -- If Extra_formals where already created, don't do it again
3263 -- This situation may arise for subprogram types created as part
3264 -- of dispatching calls (see Expand_Dispatch_Call)
3266 if Present (Last_Extra) and then
3267 Present (Extra_Formal (Last_Extra))
3272 Formal := First_Formal (E);
3274 while Present (Formal) loop
3276 -- Create extra formal for supporting the attribute 'Constrained
.
3277 -- The case of a private type view without discriminants also
3278 -- requires the extra formal if the underlying type has defaulted
3281 if Ekind
(Formal
) /= E_In_Parameter
then
3282 if Present
(P_Formal
) then
3283 Formal_Type
:= Etype
(P_Formal
);
3285 Formal_Type
:= Etype
(Formal
);
3288 if not Has_Discriminants
(Formal_Type
)
3289 and then Ekind
(Formal_Type
) in Private_Kind
3290 and then Present
(Underlying_Type
(Formal_Type
))
3292 Formal_Type
:= Underlying_Type
(Formal_Type
);
3295 if Has_Discriminants
(Formal_Type
)
3297 ((not Is_Constrained
(Formal_Type
)
3298 and then not Is_Indefinite_Subtype
(Formal_Type
))
3299 or else Present
(Extra_Formal
(Formal
)))
3301 Set_Extra_Constrained
3302 (Formal
, Add_Extra_Formal
(Standard_Boolean
));
3306 -- Create extra formal for supporting accessibility checking
3308 -- This is suppressed if we specifically suppress accessibility
3309 -- checks at the pacage level for either the subprogram, or the
3310 -- package in which it resides. However, we do not suppress it
3311 -- simply if the scope has accessibility checks suppressed, since
3312 -- this could cause trouble when clients are compiled with a
3313 -- different suppression setting. The explicit checks at the
3314 -- package level are safe from this point of view.
3316 if Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
3318 (Explicit_Suppress
(E
, Accessibility_Check
)
3320 Explicit_Suppress
(Scope
(E
), Accessibility_Check
))
3322 (not Present
(P_Formal
)
3323 or else Present
(Extra_Accessibility
(P_Formal
)))
3325 -- Temporary kludge: for now we avoid creating the extra
3326 -- formal for access parameters of protected operations
3327 -- because of problem with the case of internal protected
3330 if Nkind
(Parent
(Parent
(Parent
(E
)))) /= N_Protected_Definition
3331 and then Nkind
(Parent
(Parent
(Parent
(E
)))) /= N_Protected_Body
3333 Set_Extra_Accessibility
3334 (Formal
, Add_Extra_Formal
(Standard_Natural
));
3338 if Present
(P_Formal
) then
3339 Next_Formal
(P_Formal
);
3342 Next_Formal
(Formal
);
3344 end Create_Extra_Formals
;
3346 -----------------------------
3347 -- Enter_Overloaded_Entity --
3348 -----------------------------
3350 procedure Enter_Overloaded_Entity
(S
: Entity_Id
) is
3351 E
: Entity_Id
:= Current_Entity_In_Scope
(S
);
3352 C_E
: Entity_Id
:= Current_Entity
(S
);
3356 Set_Has_Homonym
(E
);
3357 Set_Has_Homonym
(S
);
3360 Set_Is_Immediately_Visible
(S
);
3361 Set_Scope
(S
, Current_Scope
);
3363 -- Chain new entity if front of homonym in current scope, so that
3364 -- homonyms are contiguous.
3369 while Homonym
(C_E
) /= E
loop
3370 C_E
:= Homonym
(C_E
);
3373 Set_Homonym
(C_E
, S
);
3377 Set_Current_Entity
(S
);
3382 Append_Entity
(S
, Current_Scope
);
3383 Set_Public_Status
(S
);
3385 if Debug_Flag_E
then
3386 Write_Str
("New overloaded entity chain: ");
3387 Write_Name
(Chars
(S
));
3390 while Present
(E
) loop
3391 Write_Str
(" "); Write_Int
(Int
(E
));
3398 -- Generate warning for hiding
3401 and then Comes_From_Source
(S
)
3402 and then In_Extended_Main_Source_Unit
(S
)
3409 -- Warn unless genuine overloading
3411 if (not Is_Overloadable
(E
))
3412 or else Subtype_Conformant
(E
, S
)
3414 Error_Msg_Sloc
:= Sloc
(E
);
3415 Error_Msg_N
("declaration of & hides one#?", S
);
3419 end Enter_Overloaded_Entity
;
3421 -----------------------------
3422 -- Find_Corresponding_Spec --
3423 -----------------------------
3425 function Find_Corresponding_Spec
(N
: Node_Id
) return Entity_Id
is
3426 Spec
: constant Node_Id
:= Specification
(N
);
3427 Designator
: constant Entity_Id
:= Defining_Entity
(Spec
);
3432 E
:= Current_Entity
(Designator
);
3434 while Present
(E
) loop
3436 -- We are looking for a matching spec. It must have the same scope,
3437 -- and the same name, and either be type conformant, or be the case
3438 -- of a library procedure spec and its body (which belong to one
3439 -- another regardless of whether they are type conformant or not).
3441 if Scope
(E
) = Current_Scope
then
3442 if Current_Scope
= Standard_Standard
3443 or else (Ekind
(E
) = Ekind
(Designator
)
3444 and then Type_Conformant
(E
, Designator
))
3446 -- Within an instantiation, we know that spec and body are
3447 -- subtype conformant, because they were subtype conformant
3448 -- in the generic. We choose the subtype-conformant entity
3449 -- here as well, to resolve spurious ambiguities in the
3450 -- instance that were not present in the generic (i.e. when
3451 -- two different types are given the same actual). If we are
3452 -- looking for a spec to match a body, full conformance is
3456 Set_Convention
(Designator
, Convention
(E
));
3458 if Nkind
(N
) = N_Subprogram_Body
3459 and then Present
(Homonym
(E
))
3460 and then not Fully_Conformant
(E
, Designator
)
3464 elsif not Subtype_Conformant
(E
, Designator
) then
3469 if not Has_Completion
(E
) then
3471 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
3472 Set_Corresponding_Spec
(N
, E
);
3475 Set_Has_Completion
(E
);
3478 elsif Nkind
(Parent
(N
)) = N_Subunit
then
3480 -- If this is the proper body of a subunit, the completion
3481 -- flag is set when analyzing the stub.
3485 -- If body already exists, this is an error unless the
3486 -- previous declaration is the implicit declaration of
3487 -- a derived subprogram, or this is a spurious overloading
3490 elsif No
(Alias
(E
))
3491 and then not Is_Intrinsic_Subprogram
(E
)
3492 and then not In_Instance
3494 Error_Msg_Sloc
:= Sloc
(E
);
3495 if Is_Imported
(E
) then
3497 ("body not allowed for imported subprogram & declared#",
3500 Error_Msg_NE
("duplicate body for & declared#", N
, E
);
3504 elsif Is_Child_Unit
(E
)
3506 Nkind
(Unit_Declaration_Node
(Designator
)) = N_Subprogram_Body
3508 Nkind
(Parent
(Unit_Declaration_Node
(Designator
)))
3509 = N_Compilation_Unit
3512 -- Child units cannot be overloaded, so a conformance mismatch
3513 -- between body and a previous spec is an error.
3516 ("body of child unit does not match previous declaration", N
);
3524 -- On exit, we know that no previous declaration of subprogram exists
3527 end Find_Corresponding_Spec
;
3529 ----------------------
3530 -- Fully_Conformant --
3531 ----------------------
3533 function Fully_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
3537 Check_Conformance
(New_Id
, Old_Id
, Fully_Conformant
, False, Result
);
3539 end Fully_Conformant
;
3541 ----------------------------------
3542 -- Fully_Conformant_Expressions --
3543 ----------------------------------
3545 function Fully_Conformant_Expressions
3546 (Given_E1
: Node_Id
;
3547 Given_E2
: Node_Id
) return Boolean
3549 E1
: constant Node_Id
:= Original_Node
(Given_E1
);
3550 E2
: constant Node_Id
:= Original_Node
(Given_E2
);
3551 -- We always test conformance on original nodes, since it is possible
3552 -- for analysis and/or expansion to make things look as though they
3553 -- conform when they do not, e.g. by converting 1+2 into 3.
3555 function FCE
(Given_E1
, Given_E2
: Node_Id
) return Boolean
3556 renames Fully_Conformant_Expressions
;
3558 function FCL
(L1
, L2
: List_Id
) return Boolean;
3559 -- Compare elements of two lists for conformance. Elements have to
3560 -- be conformant, and actuals inserted as default parameters do not
3561 -- match explicit actuals with the same value.
3563 function FCO
(Op_Node
, Call_Node
: Node_Id
) return Boolean;
3564 -- Compare an operator node with a function call.
3570 function FCL
(L1
, L2
: List_Id
) return Boolean is
3574 if L1
= No_List
then
3580 if L2
= No_List
then
3586 -- Compare two lists, skipping rewrite insertions (we want to
3587 -- compare the original trees, not the expanded versions!)
3590 if Is_Rewrite_Insertion
(N1
) then
3592 elsif Is_Rewrite_Insertion
(N2
) then
3598 elsif not FCE
(N1
, N2
) then
3611 function FCO
(Op_Node
, Call_Node
: Node_Id
) return Boolean is
3612 Actuals
: constant List_Id
:= Parameter_Associations
(Call_Node
);
3617 or else Entity
(Op_Node
) /= Entity
(Name
(Call_Node
))
3622 Act
:= First
(Actuals
);
3624 if Nkind
(Op_Node
) in N_Binary_Op
then
3626 if not FCE
(Left_Opnd
(Op_Node
), Act
) then
3633 return Present
(Act
)
3634 and then FCE
(Right_Opnd
(Op_Node
), Act
)
3635 and then No
(Next
(Act
));
3639 -- Start of processing for Fully_Conformant_Expressions
3642 -- Non-conformant if paren count does not match. Note: if some idiot
3643 -- complains that we don't do this right for more than 3 levels of
3644 -- parentheses, they will be treated with the respect they deserve :-)
3646 if Paren_Count
(E1
) /= Paren_Count
(E2
) then
3649 -- If same entities are referenced, then they are conformant
3650 -- even if they have different forms (RM 8.3.1(19-20)).
3652 elsif Is_Entity_Name
(E1
) and then Is_Entity_Name
(E2
) then
3653 if Present
(Entity
(E1
)) then
3654 return Entity
(E1
) = Entity
(E2
)
3655 or else (Chars
(Entity
(E1
)) = Chars
(Entity
(E2
))
3656 and then Ekind
(Entity
(E1
)) = E_Discriminant
3657 and then Ekind
(Entity
(E2
)) = E_In_Parameter
);
3659 elsif Nkind
(E1
) = N_Expanded_Name
3660 and then Nkind
(E2
) = N_Expanded_Name
3661 and then Nkind
(Selector_Name
(E1
)) = N_Character_Literal
3662 and then Nkind
(Selector_Name
(E2
)) = N_Character_Literal
3664 return Chars
(Selector_Name
(E1
)) = Chars
(Selector_Name
(E2
));
3667 -- Identifiers in component associations don't always have
3668 -- entities, but their names must conform.
3670 return Nkind
(E1
) = N_Identifier
3671 and then Nkind
(E2
) = N_Identifier
3672 and then Chars
(E1
) = Chars
(E2
);
3675 elsif Nkind
(E1
) = N_Character_Literal
3676 and then Nkind
(E2
) = N_Expanded_Name
3678 return Nkind
(Selector_Name
(E2
)) = N_Character_Literal
3679 and then Chars
(E1
) = Chars
(Selector_Name
(E2
));
3681 elsif Nkind
(E2
) = N_Character_Literal
3682 and then Nkind
(E1
) = N_Expanded_Name
3684 return Nkind
(Selector_Name
(E1
)) = N_Character_Literal
3685 and then Chars
(E2
) = Chars
(Selector_Name
(E1
));
3687 elsif Nkind
(E1
) in N_Op
3688 and then Nkind
(E2
) = N_Function_Call
3690 return FCO
(E1
, E2
);
3692 elsif Nkind
(E2
) in N_Op
3693 and then Nkind
(E1
) = N_Function_Call
3695 return FCO
(E2
, E1
);
3697 -- Otherwise we must have the same syntactic entity
3699 elsif Nkind
(E1
) /= Nkind
(E2
) then
3702 -- At this point, we specialize by node type
3709 FCL
(Expressions
(E1
), Expressions
(E2
))
3710 and then FCL
(Component_Associations
(E1
),
3711 Component_Associations
(E2
));
3714 if Nkind
(Expression
(E1
)) = N_Qualified_Expression
3716 Nkind
(Expression
(E2
)) = N_Qualified_Expression
3718 return FCE
(Expression
(E1
), Expression
(E2
));
3720 -- Check that the subtype marks and any constraints
3725 Indic1
: constant Node_Id
:= Expression
(E1
);
3726 Indic2
: constant Node_Id
:= Expression
(E2
);
3731 if Nkind
(Indic1
) /= N_Subtype_Indication
then
3733 Nkind
(Indic2
) /= N_Subtype_Indication
3734 and then Entity
(Indic1
) = Entity
(Indic2
);
3736 elsif Nkind
(Indic2
) /= N_Subtype_Indication
then
3738 Nkind
(Indic1
) /= N_Subtype_Indication
3739 and then Entity
(Indic1
) = Entity
(Indic2
);
3742 if Entity
(Subtype_Mark
(Indic1
)) /=
3743 Entity
(Subtype_Mark
(Indic2
))
3748 Elt1
:= First
(Constraints
(Constraint
(Indic1
)));
3749 Elt2
:= First
(Constraints
(Constraint
(Indic2
)));
3751 while Present
(Elt1
) and then Present
(Elt2
) loop
3752 if not FCE
(Elt1
, Elt2
) then
3765 when N_Attribute_Reference
=>
3767 Attribute_Name
(E1
) = Attribute_Name
(E2
)
3768 and then FCL
(Expressions
(E1
), Expressions
(E2
));
3772 Entity
(E1
) = Entity
(E2
)
3773 and then FCE
(Left_Opnd
(E1
), Left_Opnd
(E2
))
3774 and then FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
3776 when N_And_Then | N_Or_Else | N_In | N_Not_In
=>
3778 FCE
(Left_Opnd
(E1
), Left_Opnd
(E2
))
3780 FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
3782 when N_Character_Literal
=>
3784 Char_Literal_Value
(E1
) = Char_Literal_Value
(E2
);
3786 when N_Component_Association
=>
3788 FCL
(Choices
(E1
), Choices
(E2
))
3789 and then FCE
(Expression
(E1
), Expression
(E2
));
3791 when N_Conditional_Expression
=>
3793 FCL
(Expressions
(E1
), Expressions
(E2
));
3795 when N_Explicit_Dereference
=>
3797 FCE
(Prefix
(E1
), Prefix
(E2
));
3799 when N_Extension_Aggregate
=>
3801 FCL
(Expressions
(E1
), Expressions
(E2
))
3802 and then Null_Record_Present
(E1
) =
3803 Null_Record_Present
(E2
)
3804 and then FCL
(Component_Associations
(E1
),
3805 Component_Associations
(E2
));
3807 when N_Function_Call
=>
3809 FCE
(Name
(E1
), Name
(E2
))
3810 and then FCL
(Parameter_Associations
(E1
),
3811 Parameter_Associations
(E2
));
3813 when N_Indexed_Component
=>
3815 FCE
(Prefix
(E1
), Prefix
(E2
))
3816 and then FCL
(Expressions
(E1
), Expressions
(E2
));
3818 when N_Integer_Literal
=>
3819 return (Intval
(E1
) = Intval
(E2
));
3824 when N_Operator_Symbol
=>
3826 Chars
(E1
) = Chars
(E2
);
3828 when N_Others_Choice
=>
3831 when N_Parameter_Association
=>
3833 Chars
(Selector_Name
(E1
)) = Chars
(Selector_Name
(E2
))
3834 and then FCE
(Explicit_Actual_Parameter
(E1
),
3835 Explicit_Actual_Parameter
(E2
));
3837 when N_Qualified_Expression
=>
3839 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
3840 and then FCE
(Expression
(E1
), Expression
(E2
));
3844 FCE
(Low_Bound
(E1
), Low_Bound
(E2
))
3845 and then FCE
(High_Bound
(E1
), High_Bound
(E2
));
3847 when N_Real_Literal
=>
3848 return (Realval
(E1
) = Realval
(E2
));
3850 when N_Selected_Component
=>
3852 FCE
(Prefix
(E1
), Prefix
(E2
))
3853 and then FCE
(Selector_Name
(E1
), Selector_Name
(E2
));
3857 FCE
(Prefix
(E1
), Prefix
(E2
))
3858 and then FCE
(Discrete_Range
(E1
), Discrete_Range
(E2
));
3860 when N_String_Literal
=>
3862 S1
: constant String_Id
:= Strval
(E1
);
3863 S2
: constant String_Id
:= Strval
(E2
);
3864 L1
: constant Nat
:= String_Length
(S1
);
3865 L2
: constant Nat
:= String_Length
(S2
);
3872 for J
in 1 .. L1
loop
3873 if Get_String_Char
(S1
, J
) /=
3874 Get_String_Char
(S2
, J
)
3884 when N_Type_Conversion
=>
3886 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
3887 and then FCE
(Expression
(E1
), Expression
(E2
));
3891 Entity
(E1
) = Entity
(E2
)
3892 and then FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
3894 when N_Unchecked_Type_Conversion
=>
3896 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
3897 and then FCE
(Expression
(E1
), Expression
(E2
));
3899 -- All other node types cannot appear in this context. Strictly
3900 -- we should raise a fatal internal error. Instead we just ignore
3901 -- the nodes. This means that if anyone makes a mistake in the
3902 -- expander and mucks an expression tree irretrievably, the
3903 -- result will be a failure to detect a (probably very obscure)
3904 -- case of non-conformance, which is better than bombing on some
3905 -- case where two expressions do in fact conform.
3912 end Fully_Conformant_Expressions
;
3914 ----------------------------------------
3915 -- Fully_Conformant_Discrete_Subtypes --
3916 ----------------------------------------
3918 function Fully_Conformant_Discrete_Subtypes
3919 (Given_S1
: Node_Id
;
3920 Given_S2
: Node_Id
) return Boolean
3922 S1
: constant Node_Id
:= Original_Node
(Given_S1
);
3923 S2
: constant Node_Id
:= Original_Node
(Given_S2
);
3925 function Conforming_Bounds
(B1
, B2
: Node_Id
) return Boolean;
3926 -- Special-case for a bound given by a discriminant, which in the
3927 -- body is replaced with the discriminal of the enclosing type.
3929 function Conforming_Ranges
(R1
, R2
: Node_Id
) return Boolean;
3930 -- Check both bounds.
3932 function Conforming_Bounds
(B1
, B2
: Node_Id
) return Boolean is
3934 if Is_Entity_Name
(B1
)
3935 and then Is_Entity_Name
(B2
)
3936 and then Ekind
(Entity
(B1
)) = E_Discriminant
3938 return Chars
(B1
) = Chars
(B2
);
3941 return Fully_Conformant_Expressions
(B1
, B2
);
3943 end Conforming_Bounds
;
3945 function Conforming_Ranges
(R1
, R2
: Node_Id
) return Boolean is
3948 Conforming_Bounds
(Low_Bound
(R1
), Low_Bound
(R2
))
3950 Conforming_Bounds
(High_Bound
(R1
), High_Bound
(R2
));
3951 end Conforming_Ranges
;
3953 -- Start of processing for Fully_Conformant_Discrete_Subtypes
3956 if Nkind
(S1
) /= Nkind
(S2
) then
3959 elsif Is_Entity_Name
(S1
) then
3960 return Entity
(S1
) = Entity
(S2
);
3962 elsif Nkind
(S1
) = N_Range
then
3963 return Conforming_Ranges
(S1
, S2
);
3965 elsif Nkind
(S1
) = N_Subtype_Indication
then
3967 Entity
(Subtype_Mark
(S1
)) = Entity
(Subtype_Mark
(S2
))
3970 (Range_Expression
(Constraint
(S1
)),
3971 Range_Expression
(Constraint
(S2
)));
3975 end Fully_Conformant_Discrete_Subtypes
;
3977 --------------------
3978 -- Install_Entity --
3979 --------------------
3981 procedure Install_Entity
(E
: Entity_Id
) is
3982 Prev
: constant Entity_Id
:= Current_Entity
(E
);
3985 Set_Is_Immediately_Visible
(E
);
3986 Set_Current_Entity
(E
);
3987 Set_Homonym
(E
, Prev
);
3990 ---------------------
3991 -- Install_Formals --
3992 ---------------------
3994 procedure Install_Formals
(Id
: Entity_Id
) is
3998 F
:= First_Formal
(Id
);
4000 while Present
(F
) loop
4004 end Install_Formals
;
4006 ---------------------------------
4007 -- Is_Non_Overriding_Operation --
4008 ---------------------------------
4010 function Is_Non_Overriding_Operation
4011 (Prev_E
: Entity_Id
;
4012 New_E
: Entity_Id
) return Boolean
4016 G_Typ
: Entity_Id
:= Empty
;
4018 function Get_Generic_Parent_Type
(F_Typ
: Entity_Id
) return Entity_Id
;
4019 -- If F_Type is a derived type associated with a generic actual
4020 -- subtype, then return its Generic_Parent_Type attribute, else
4023 function Types_Correspond
4024 (P_Type
: Entity_Id
;
4025 N_Type
: Entity_Id
) return Boolean;
4026 -- Returns true if and only if the types (or designated types
4027 -- in the case of anonymous access types) are the same or N_Type
4028 -- is derived directly or indirectly from P_Type.
4030 -----------------------------
4031 -- Get_Generic_Parent_Type --
4032 -----------------------------
4034 function Get_Generic_Parent_Type
(F_Typ
: Entity_Id
) return Entity_Id
is
4039 if Is_Derived_Type
(F_Typ
)
4040 and then Nkind
(Parent
(F_Typ
)) = N_Full_Type_Declaration
4042 -- The tree must be traversed to determine the parent
4043 -- subtype in the generic unit, which unfortunately isn't
4044 -- always available via semantic attributes. ???
4045 -- (Note: The use of Original_Node is needed for cases
4046 -- where a full derived type has been rewritten.)
4048 Indic
:= Subtype_Indication
4049 (Type_Definition
(Original_Node
(Parent
(F_Typ
))));
4051 if Nkind
(Indic
) = N_Subtype_Indication
then
4052 G_Typ
:= Entity
(Subtype_Mark
(Indic
));
4054 G_Typ
:= Entity
(Indic
);
4057 if Nkind
(Parent
(G_Typ
)) = N_Subtype_Declaration
4058 and then Present
(Generic_Parent_Type
(Parent
(G_Typ
)))
4060 return Generic_Parent_Type
(Parent
(G_Typ
));
4065 end Get_Generic_Parent_Type
;
4067 ----------------------
4068 -- Types_Correspond --
4069 ----------------------
4071 function Types_Correspond
4072 (P_Type
: Entity_Id
;
4073 N_Type
: Entity_Id
) return Boolean
4075 Prev_Type
: Entity_Id
:= Base_Type
(P_Type
);
4076 New_Type
: Entity_Id
:= Base_Type
(N_Type
);
4079 if Ekind
(Prev_Type
) = E_Anonymous_Access_Type
then
4080 Prev_Type
:= Designated_Type
(Prev_Type
);
4083 if Ekind
(New_Type
) = E_Anonymous_Access_Type
then
4084 New_Type
:= Designated_Type
(New_Type
);
4087 if Prev_Type
= New_Type
then
4090 elsif not Is_Class_Wide_Type
(New_Type
) then
4091 while Etype
(New_Type
) /= New_Type
loop
4092 New_Type
:= Etype
(New_Type
);
4093 if New_Type
= Prev_Type
then
4099 end Types_Correspond
;
4101 -- Start of processing for Is_Non_Overriding_Operation
4104 -- In the case where both operations are implicit derived
4105 -- subprograms then neither overrides the other. This can
4106 -- only occur in certain obscure cases (e.g., derivation
4107 -- from homographs created in a generic instantiation).
4109 if Present
(Alias
(Prev_E
)) and then Present
(Alias
(New_E
)) then
4112 elsif Ekind
(Current_Scope
) = E_Package
4113 and then Is_Generic_Instance
(Current_Scope
)
4114 and then In_Private_Part
(Current_Scope
)
4115 and then Comes_From_Source
(New_E
)
4117 -- We examine the formals and result subtype of the inherited
4118 -- operation, to determine whether their type is derived from
4119 -- (the instance of) a generic type.
4121 Formal
:= First_Formal
(Prev_E
);
4123 while Present
(Formal
) loop
4124 F_Typ
:= Base_Type
(Etype
(Formal
));
4126 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
4127 F_Typ
:= Designated_Type
(F_Typ
);
4130 G_Typ
:= Get_Generic_Parent_Type
(F_Typ
);
4132 Next_Formal
(Formal
);
4135 if not Present
(G_Typ
) and then Ekind
(Prev_E
) = E_Function
then
4136 G_Typ
:= Get_Generic_Parent_Type
(Base_Type
(Etype
(Prev_E
)));
4143 -- If the generic type is a private type, then the original
4144 -- operation was not overriding in the generic, because there was
4145 -- no primitive operation to override.
4147 if Nkind
(Parent
(G_Typ
)) = N_Formal_Type_Declaration
4148 and then Nkind
(Formal_Type_Definition
(Parent
(G_Typ
))) =
4149 N_Formal_Private_Type_Definition
4153 -- The generic parent type is the ancestor of a formal derived
4154 -- type declaration. We need to check whether it has a primitive
4155 -- operation that should be overridden by New_E in the generic.
4159 P_Formal
: Entity_Id
;
4160 N_Formal
: Entity_Id
;
4164 Prim_Elt
: Elmt_Id
:= First_Elmt
(Primitive_Operations
(G_Typ
));
4167 while Present
(Prim_Elt
) loop
4168 P_Prim
:= Node
(Prim_Elt
);
4170 if Chars
(P_Prim
) = Chars
(New_E
)
4171 and then Ekind
(P_Prim
) = Ekind
(New_E
)
4173 P_Formal
:= First_Formal
(P_Prim
);
4174 N_Formal
:= First_Formal
(New_E
);
4175 while Present
(P_Formal
) and then Present
(N_Formal
) loop
4176 P_Typ
:= Etype
(P_Formal
);
4177 N_Typ
:= Etype
(N_Formal
);
4179 if not Types_Correspond
(P_Typ
, N_Typ
) then
4183 Next_Entity
(P_Formal
);
4184 Next_Entity
(N_Formal
);
4187 -- Found a matching primitive operation belonging to
4188 -- the formal ancestor type, so the new subprogram
4191 if not Present
(P_Formal
)
4192 and then not Present
(N_Formal
)
4193 and then (Ekind
(New_E
) /= E_Function
4196 (Etype
(P_Prim
), Etype
(New_E
)))
4202 Next_Elmt
(Prim_Elt
);
4205 -- If no match found, then the new subprogram does
4206 -- not override in the generic (nor in the instance).
4214 end Is_Non_Overriding_Operation
;
4216 ------------------------------
4217 -- Make_Inequality_Operator --
4218 ------------------------------
4220 -- S is the defining identifier of an equality operator. We build a
4221 -- subprogram declaration with the right signature. This operation is
4222 -- intrinsic, because it is always expanded as the negation of the
4223 -- call to the equality function.
4225 procedure Make_Inequality_Operator
(S
: Entity_Id
) is
4226 Loc
: constant Source_Ptr
:= Sloc
(S
);
4229 Op_Name
: Entity_Id
;
4235 -- Check that equality was properly defined.
4237 if No
(Next_Formal
(First_Formal
(S
))) then
4241 A
:= Make_Defining_Identifier
(Loc
, Chars
(First_Formal
(S
)));
4242 B
:= Make_Defining_Identifier
(Loc
,
4243 Chars
(Next_Formal
(First_Formal
(S
))));
4245 Op_Name
:= Make_Defining_Operator_Symbol
(Loc
, Name_Op_Ne
);
4247 Formals
:= New_List
(
4248 Make_Parameter_Specification
(Loc
,
4249 Defining_Identifier
=> A
,
4251 New_Reference_To
(Etype
(First_Formal
(S
)), Loc
)),
4253 Make_Parameter_Specification
(Loc
,
4254 Defining_Identifier
=> B
,
4256 New_Reference_To
(Etype
(Next_Formal
(First_Formal
(S
))), Loc
)));
4259 Make_Subprogram_Declaration
(Loc
,
4261 Make_Function_Specification
(Loc
,
4262 Defining_Unit_Name
=> Op_Name
,
4263 Parameter_Specifications
=> Formals
,
4264 Subtype_Mark
=> New_Reference_To
(Standard_Boolean
, Loc
)));
4266 -- Insert inequality right after equality if it is explicit or after
4267 -- the derived type when implicit. These entities are created only
4268 -- for visibility purposes, and eventually replaced in the course of
4269 -- expansion, so they do not need to be attached to the tree and seen
4270 -- by the back-end. Keeping them internal also avoids spurious freezing
4271 -- problems. The parent field is set simply to make analysis safe.
4273 if No
(Alias
(S
)) then
4274 Set_Parent
(Decl
, Parent
(Unit_Declaration_Node
(S
)));
4276 Set_Parent
(Decl
, Parent
(Parent
(Etype
(First_Formal
(S
)))));
4279 Mark_Rewrite_Insertion
(Decl
);
4280 Set_Is_Intrinsic_Subprogram
(Op_Name
);
4282 Set_Has_Completion
(Op_Name
);
4283 Set_Corresponding_Equality
(Op_Name
, S
);
4284 Set_Is_Abstract
(Op_Name
, Is_Abstract
(S
));
4286 end Make_Inequality_Operator
;
4288 ----------------------
4289 -- May_Need_Actuals --
4290 ----------------------
4292 procedure May_Need_Actuals
(Fun
: Entity_Id
) is
4297 F
:= First_Formal
(Fun
);
4300 while Present
(F
) loop
4301 if No
(Default_Value
(F
)) then
4309 Set_Needs_No_Actuals
(Fun
, B
);
4310 end May_Need_Actuals
;
4312 ---------------------
4313 -- Mode_Conformant --
4314 ---------------------
4316 function Mode_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
4320 Check_Conformance
(New_Id
, Old_Id
, Mode_Conformant
, False, Result
);
4322 end Mode_Conformant
;
4324 ---------------------------
4325 -- New_Overloaded_Entity --
4326 ---------------------------
4328 procedure New_Overloaded_Entity
4330 Derived_Type
: Entity_Id
:= Empty
)
4333 -- Entity that S overrides
4335 Prev_Vis
: Entity_Id
:= Empty
;
4336 -- Needs comment ???
4338 function Is_Private_Declaration
(E
: Entity_Id
) return Boolean;
4339 -- Check that E is declared in the private part of the current package,
4340 -- or in the package body, where it may hide a previous declaration.
4341 -- We can't use In_Private_Part by itself because this flag is also
4342 -- set when freezing entities, so we must examine the place of the
4343 -- declaration in the tree, and recognize wrapper packages as well.
4345 procedure Maybe_Primitive_Operation
(Overriding
: Boolean := False);
4346 -- If the subprogram being analyzed is a primitive operation of
4347 -- the type of one of its formals, set the corresponding flag.
4349 ----------------------------
4350 -- Is_Private_Declaration --
4351 ----------------------------
4353 function Is_Private_Declaration
(E
: Entity_Id
) return Boolean is
4354 Priv_Decls
: List_Id
;
4355 Decl
: constant Node_Id
:= Unit_Declaration_Node
(E
);
4358 if Is_Package
(Current_Scope
)
4359 and then In_Private_Part
(Current_Scope
)
4362 Private_Declarations
(
4363 Specification
(Unit_Declaration_Node
(Current_Scope
)));
4365 return In_Package_Body
(Current_Scope
)
4366 or else List_Containing
(Decl
) = Priv_Decls
4367 or else (Nkind
(Parent
(Decl
)) = N_Package_Specification
4368 and then not Is_Compilation_Unit
(
4369 Defining_Entity
(Parent
(Decl
)))
4370 and then List_Containing
(Parent
(Parent
(Decl
)))
4375 end Is_Private_Declaration
;
4377 -------------------------------
4378 -- Maybe_Primitive_Operation --
4379 -------------------------------
4381 procedure Maybe_Primitive_Operation
(Overriding
: Boolean := False) is
4386 function Visible_Part_Type
(T
: Entity_Id
) return Boolean;
4387 -- Returns true if T is declared in the visible part of
4388 -- the current package scope; otherwise returns false.
4389 -- Assumes that T is declared in a package.
4391 procedure Check_Private_Overriding
(T
: Entity_Id
);
4392 -- Checks that if a primitive abstract subprogram of a visible
4393 -- abstract type is declared in a private part, then it must
4394 -- override an abstract subprogram declared in the visible part.
4395 -- Also checks that if a primitive function with a controlling
4396 -- result is declared in a private part, then it must override
4397 -- a function declared in the visible part.
4399 ------------------------------
4400 -- Check_Private_Overriding --
4401 ------------------------------
4403 procedure Check_Private_Overriding
(T
: Entity_Id
) is
4405 if Ekind
(Current_Scope
) = E_Package
4406 and then In_Private_Part
(Current_Scope
)
4407 and then Visible_Part_Type
(T
)
4408 and then not In_Instance
4411 and then Is_Abstract
(S
)
4412 and then (not Overriding
or else not Is_Abstract
(E
))
4414 Error_Msg_N
("abstract subprograms must be visible "
4415 & "('R'M 3.9.3(10))!", S
);
4417 elsif Ekind
(S
) = E_Function
4418 and then Is_Tagged_Type
(T
)
4419 and then T
= Base_Type
(Etype
(S
))
4420 and then not Overriding
4423 ("private function with tagged result must"
4424 & " override visible-part function", S
);
4426 ("\move subprogram to the visible part"
4427 & " ('R'M 3.9.3(10))", S
);
4430 end Check_Private_Overriding
;
4432 -----------------------
4433 -- Visible_Part_Type --
4434 -----------------------
4436 function Visible_Part_Type
(T
: Entity_Id
) return Boolean is
4437 P
: constant Node_Id
:= Unit_Declaration_Node
(Scope
(T
));
4441 -- If the entity is a private type, then it must be
4442 -- declared in a visible part.
4444 if Ekind
(T
) in Private_Kind
then
4448 -- Otherwise, we traverse the visible part looking for its
4449 -- corresponding declaration. We cannot use the declaration
4450 -- node directly because in the private part the entity of a
4451 -- private type is the one in the full view, which does not
4452 -- indicate that it is the completion of something visible.
4454 N
:= First
(Visible_Declarations
(Specification
(P
)));
4455 while Present
(N
) loop
4456 if Nkind
(N
) = N_Full_Type_Declaration
4457 and then Present
(Defining_Identifier
(N
))
4458 and then T
= Defining_Identifier
(N
)
4462 elsif (Nkind
(N
) = N_Private_Type_Declaration
4464 Nkind
(N
) = N_Private_Extension_Declaration
)
4465 and then Present
(Defining_Identifier
(N
))
4466 and then T
= Full_View
(Defining_Identifier
(N
))
4475 end Visible_Part_Type
;
4477 -- Start of processing for Maybe_Primitive_Operation
4480 if not Comes_From_Source
(S
) then
4483 elsif (Ekind
(Current_Scope
) = E_Package
4484 and then not In_Package_Body
(Current_Scope
))
4487 -- For function, check return type
4489 if Ekind
(S
) = E_Function
then
4490 B_Typ
:= Base_Type
(Etype
(S
));
4492 if Scope
(B_Typ
) = Current_Scope
then
4493 Set_Has_Primitive_Operations
(B_Typ
);
4494 Check_Private_Overriding
(B_Typ
);
4498 -- For all subprograms, check formals
4500 Formal
:= First_Formal
(S
);
4501 while Present
(Formal
) loop
4502 if Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
then
4503 F_Typ
:= Designated_Type
(Etype
(Formal
));
4505 F_Typ
:= Etype
(Formal
);
4508 B_Typ
:= Base_Type
(F_Typ
);
4510 if Scope
(B_Typ
) = Current_Scope
then
4511 Set_Has_Primitive_Operations
(B_Typ
);
4512 Check_Private_Overriding
(B_Typ
);
4515 Next_Formal
(Formal
);
4518 end Maybe_Primitive_Operation
;
4520 -- Start of processing for New_Overloaded_Entity
4523 -- We need to look for an entity that S may override. This must be a
4524 -- homonym in the current scope, so we look for the first homonym of
4525 -- S in the current scope as the starting point for the search.
4527 E
:= Current_Entity_In_Scope
(S
);
4529 -- If there is no homonym then this is definitely not overriding
4532 Enter_Overloaded_Entity
(S
);
4533 Check_Dispatching_Operation
(S
, Empty
);
4534 Maybe_Primitive_Operation
;
4536 -- If there is a homonym that is not overloadable, then we have an
4537 -- error, except for the special cases checked explicitly below.
4539 elsif not Is_Overloadable
(E
) then
4541 -- Check for spurious conflict produced by a subprogram that has the
4542 -- same name as that of the enclosing generic package. The conflict
4543 -- occurs within an instance, between the subprogram and the renaming
4544 -- declaration for the package. After the subprogram, the package
4545 -- renaming declaration becomes hidden.
4547 if Ekind
(E
) = E_Package
4548 and then Present
(Renamed_Object
(E
))
4549 and then Renamed_Object
(E
) = Current_Scope
4550 and then Nkind
(Parent
(Renamed_Object
(E
))) =
4551 N_Package_Specification
4552 and then Present
(Generic_Parent
(Parent
(Renamed_Object
(E
))))
4555 Set_Is_Immediately_Visible
(E
, False);
4556 Enter_Overloaded_Entity
(S
);
4557 Set_Homonym
(S
, Homonym
(E
));
4558 Check_Dispatching_Operation
(S
, Empty
);
4560 -- If the subprogram is implicit it is hidden by the previous
4561 -- declaration. However if it is dispatching, it must appear in
4562 -- the dispatch table anyway, because it can be dispatched to
4563 -- even if it cannot be called directly.
4565 elsif Present
(Alias
(S
))
4566 and then not Comes_From_Source
(S
)
4568 Set_Scope
(S
, Current_Scope
);
4570 if Is_Dispatching_Operation
(Alias
(S
)) then
4571 Check_Dispatching_Operation
(S
, Empty
);
4577 Error_Msg_Sloc
:= Sloc
(E
);
4578 Error_Msg_N
("& conflicts with declaration#", S
);
4580 -- Useful additional warning
4582 if Is_Generic_Unit
(E
) then
4583 Error_Msg_N
("\previous generic unit cannot be overloaded", S
);
4589 -- E exists and is overloadable
4592 -- Loop through E and its homonyms to determine if any of them
4593 -- is the candidate for overriding by S.
4595 while Present
(E
) loop
4597 -- Definitely not interesting if not in the current scope
4599 if Scope
(E
) /= Current_Scope
then
4602 -- Check if we have type conformance
4604 elsif Type_Conformant
(E
, S
) then
4606 -- If the old and new entities have the same profile and
4607 -- one is not the body of the other, then this is an error,
4608 -- unless one of them is implicitly declared.
4610 -- There are some cases when both can be implicit, for example
4611 -- when both a literal and a function that overrides it are
4612 -- inherited in a derivation, or when an inhertited operation
4613 -- of a tagged full type overrides the ineherited operation of
4614 -- a private extension. Ada 83 had a special rule for the
4615 -- the literal case. In Ada95, the later implicit operation
4616 -- hides the former, and the literal is always the former.
4617 -- In the odd case where both are derived operations declared
4618 -- at the same point, both operations should be declared,
4619 -- and in that case we bypass the following test and proceed
4620 -- to the next part (this can only occur for certain obscure
4621 -- cases involving homographs in instances and can't occur for
4622 -- dispatching operations ???). Note that the following
4623 -- condition is less than clear. For example, it's not at
4624 -- all clear why there's a test for E_Entry here. ???
4626 if Present
(Alias
(S
))
4627 and then (No
(Alias
(E
))
4628 or else Comes_From_Source
(E
)
4629 or else Is_Dispatching_Operation
(E
))
4631 (Ekind
(E
) = E_Entry
4632 or else Ekind
(E
) /= E_Enumeration_Literal
)
4634 -- When an derived operation is overloaded it may be due
4635 -- to the fact that the full view of a private extension
4636 -- re-inherits. It has to be dealt with.
4638 if Is_Package
(Current_Scope
)
4639 and then In_Private_Part
(Current_Scope
)
4641 Check_Operation_From_Private_View
(S
, E
);
4644 -- In any case the implicit operation remains hidden by
4645 -- the existing declaration, which is overriding.
4647 Set_Is_Overriding_Operation
(E
);
4650 -- Within an instance, the renaming declarations for
4651 -- actual subprograms may become ambiguous, but they do
4652 -- not hide each other.
4654 elsif Ekind
(E
) /= E_Entry
4655 and then not Comes_From_Source
(E
)
4656 and then not Is_Generic_Instance
(E
)
4657 and then (Present
(Alias
(E
))
4658 or else Is_Intrinsic_Subprogram
(E
))
4659 and then (not In_Instance
4660 or else No
(Parent
(E
))
4661 or else Nkind
(Unit_Declaration_Node
(E
)) /=
4662 N_Subprogram_Renaming_Declaration
)
4664 -- A subprogram child unit is not allowed to override
4665 -- an inherited subprogram (10.1.1(20)).
4667 if Is_Child_Unit
(S
) then
4669 ("child unit overrides inherited subprogram in parent",
4674 if Is_Non_Overriding_Operation
(E
, S
) then
4675 Enter_Overloaded_Entity
(S
);
4676 if not Present
(Derived_Type
)
4677 or else Is_Tagged_Type
(Derived_Type
)
4679 Check_Dispatching_Operation
(S
, Empty
);
4685 -- E is a derived operation or an internal operator which
4686 -- is being overridden. Remove E from further visibility.
4687 -- Furthermore, if E is a dispatching operation, it must be
4688 -- replaced in the list of primitive operations of its type
4689 -- (see Override_Dispatching_Operation).
4695 Prev
:= First_Entity
(Current_Scope
);
4697 while Present
(Prev
)
4698 and then Next_Entity
(Prev
) /= E
4703 -- It is possible for E to be in the current scope and
4704 -- yet not in the entity chain. This can only occur in a
4705 -- generic context where E is an implicit concatenation
4706 -- in the formal part, because in a generic body the
4707 -- entity chain starts with the formals.
4710 (Present
(Prev
) or else Chars
(E
) = Name_Op_Concat
);
4712 -- E must be removed both from the entity_list of the
4713 -- current scope, and from the visibility chain
4715 if Debug_Flag_E
then
4716 Write_Str
("Override implicit operation ");
4717 Write_Int
(Int
(E
));
4721 -- If E is a predefined concatenation, it stands for four
4722 -- different operations. As a result, a single explicit
4723 -- declaration does not hide it. In a possible ambiguous
4724 -- situation, Disambiguate chooses the user-defined op,
4725 -- so it is correct to retain the previous internal one.
4727 if Chars
(E
) /= Name_Op_Concat
4728 or else Ekind
(E
) /= E_Operator
4730 -- For nondispatching derived operations that are
4731 -- overridden by a subprogram declared in the private
4732 -- part of a package, we retain the derived subprogram
4733 -- but mark it as not immediately visible. If the
4734 -- derived operation was declared in the visible part
4735 -- then this ensures that it will still be visible
4736 -- outside the package with the proper signature
4737 -- (calls from outside must also be directed to this
4738 -- version rather than the overriding one, unlike the
4739 -- dispatching case). Calls from inside the package
4740 -- will still resolve to the overriding subprogram
4741 -- since the derived one is marked as not visible
4742 -- within the package.
4744 -- If the private operation is dispatching, we achieve
4745 -- the overriding by keeping the implicit operation
4746 -- but setting its alias to be the overring one. In
4747 -- this fashion the proper body is executed in all
4748 -- cases, but the original signature is used outside
4751 -- If the overriding is not in the private part, we
4752 -- remove the implicit operation altogether.
4754 if Is_Private_Declaration
(S
) then
4756 if not Is_Dispatching_Operation
(E
) then
4757 Set_Is_Immediately_Visible
(E
, False);
4760 -- work done in Override_Dispatching_Operation.
4766 -- Find predecessor of E in Homonym chain
4768 if E
= Current_Entity
(E
) then
4771 Prev_Vis
:= Current_Entity
(E
);
4772 while Homonym
(Prev_Vis
) /= E
loop
4773 Prev_Vis
:= Homonym
(Prev_Vis
);
4777 if Prev_Vis
/= Empty
then
4779 -- Skip E in the visibility chain
4781 Set_Homonym
(Prev_Vis
, Homonym
(E
));
4784 Set_Name_Entity_Id
(Chars
(E
), Homonym
(E
));
4787 Set_Next_Entity
(Prev
, Next_Entity
(E
));
4789 if No
(Next_Entity
(Prev
)) then
4790 Set_Last_Entity
(Current_Scope
, Prev
);
4796 Enter_Overloaded_Entity
(S
);
4797 Set_Is_Overriding_Operation
(S
);
4799 if Is_Dispatching_Operation
(E
) then
4801 -- An overriding dispatching subprogram inherits
4802 -- the convention of the overridden subprogram
4805 Set_Convention
(S
, Convention
(E
));
4807 Check_Dispatching_Operation
(S
, E
);
4809 Check_Dispatching_Operation
(S
, Empty
);
4812 Maybe_Primitive_Operation
(Overriding
=> True);
4813 goto Check_Inequality
;
4816 -- Apparent redeclarations in instances can occur when two
4817 -- formal types get the same actual type. The subprograms in
4818 -- in the instance are legal, even if not callable from the
4819 -- outside. Calls from within are disambiguated elsewhere.
4820 -- For dispatching operations in the visible part, the usual
4821 -- rules apply, and operations with the same profile are not
4824 elsif (In_Instance_Visible_Part
4825 and then not Is_Dispatching_Operation
(E
))
4826 or else In_Instance_Not_Visible
4830 -- Here we have a real error (identical profile)
4833 Error_Msg_Sloc
:= Sloc
(E
);
4835 -- Avoid cascaded errors if the entity appears in
4836 -- subsequent calls.
4838 Set_Scope
(S
, Current_Scope
);
4840 Error_Msg_N
("& conflicts with declaration#", S
);
4842 if Is_Generic_Instance
(S
)
4843 and then not Has_Completion
(E
)
4846 ("\instantiation cannot provide body for it", S
);
4860 -- On exit, we know that S is a new entity
4862 Enter_Overloaded_Entity
(S
);
4863 Maybe_Primitive_Operation
;
4865 -- If S is a derived operation for an untagged type then
4866 -- by definition it's not a dispatching operation (even
4867 -- if the parent operation was dispatching), so we don't
4868 -- call Check_Dispatching_Operation in that case.
4870 if not Present
(Derived_Type
)
4871 or else Is_Tagged_Type
(Derived_Type
)
4873 Check_Dispatching_Operation
(S
, Empty
);
4877 -- If this is a user-defined equality operator that is not
4878 -- a derived subprogram, create the corresponding inequality.
4879 -- If the operation is dispatching, the expansion is done
4880 -- elsewhere, and we do not create an explicit inequality
4883 <<Check_Inequality
>>
4884 if Chars
(S
) = Name_Op_Eq
4885 and then Etype
(S
) = Standard_Boolean
4886 and then Present
(Parent
(S
))
4887 and then not Is_Dispatching_Operation
(S
)
4889 Make_Inequality_Operator
(S
);
4891 end New_Overloaded_Entity
;
4893 ---------------------
4894 -- Process_Formals --
4895 ---------------------
4897 procedure Process_Formals
4899 Related_Nod
: Node_Id
)
4901 Param_Spec
: Node_Id
;
4903 Formal_Type
: Entity_Id
;
4907 function Is_Class_Wide_Default
(D
: Node_Id
) return Boolean;
4908 -- Check whether the default has a class-wide type. After analysis
4909 -- the default has the type of the formal, so we must also check
4910 -- explicitly for an access attribute.
4912 ---------------------------
4913 -- Is_Class_Wide_Default --
4914 ---------------------------
4916 function Is_Class_Wide_Default
(D
: Node_Id
) return Boolean is
4918 return Is_Class_Wide_Type
(Designated_Type
(Etype
(D
)))
4919 or else (Nkind
(D
) = N_Attribute_Reference
4920 and then Attribute_Name
(D
) = Name_Access
4921 and then Is_Class_Wide_Type
(Etype
(Prefix
(D
))));
4922 end Is_Class_Wide_Default
;
4924 -- Start of processing for Process_Formals
4927 -- In order to prevent premature use of the formals in the same formal
4928 -- part, the Ekind is left undefined until all default expressions are
4929 -- analyzed. The Ekind is established in a separate loop at the end.
4931 Param_Spec
:= First
(T
);
4933 while Present
(Param_Spec
) loop
4935 Formal
:= Defining_Identifier
(Param_Spec
);
4936 Enter_Name
(Formal
);
4938 -- Case of ordinary parameters
4940 if Nkind
(Parameter_Type
(Param_Spec
)) /= N_Access_Definition
then
4941 Find_Type
(Parameter_Type
(Param_Spec
));
4942 Ptype
:= Parameter_Type
(Param_Spec
);
4944 if Ptype
= Error
then
4948 Formal_Type
:= Entity
(Ptype
);
4950 if Ekind
(Formal_Type
) = E_Incomplete_Type
4951 or else (Is_Class_Wide_Type
(Formal_Type
)
4952 and then Ekind
(Root_Type
(Formal_Type
)) =
4955 -- Ada 0Y (AI-50217): Incomplete tagged types that are made
4956 -- visible through a limited with_clause are valid formal
4959 if From_With_Type
(Formal_Type
)
4960 and then Is_Tagged_Type
(Formal_Type
)
4964 elsif Nkind
(Parent
(T
)) /= N_Access_Function_Definition
4965 and then Nkind
(Parent
(T
)) /= N_Access_Procedure_Definition
4967 Error_Msg_N
("invalid use of incomplete type", Param_Spec
);
4970 elsif Ekind
(Formal_Type
) = E_Void
then
4971 Error_Msg_NE
("premature use of&",
4972 Parameter_Type
(Param_Spec
), Formal_Type
);
4975 -- Ada 0Y (AI-231): Create and decorate an internal subtype
4976 -- declaration corresponding to the null-excluding type of the
4977 -- formal in the enclosing scope. In addition, replace the
4978 -- parameter type of the formal to this internal subtype.
4980 if Null_Exclusion_Present
(Param_Spec
) then
4982 Loc
: constant Source_Ptr
:= Sloc
(Param_Spec
);
4984 Anon
: constant Entity_Id
:=
4985 Make_Defining_Identifier
(Loc
,
4986 Chars
=> New_Internal_Name
('S'));
4988 Curr_Scope
: constant Scope_Stack_Entry
:=
4989 Scope_Stack
.Table
(Scope_Stack
.Last
);
4991 Ptype
: constant Node_Id
:= Parameter_Type
(Param_Spec
);
4993 P
: Node_Id
:= Parent
(Parent
(Related_Nod
));
4996 Set_Is_Internal
(Anon
);
4999 Make_Subtype_Declaration
(Loc
,
5000 Defining_Identifier
=> Anon
,
5001 Null_Exclusion_Present
=> True,
5002 Subtype_Indication
=>
5003 New_Occurrence_Of
(Etype
(Ptype
), Loc
));
5005 -- Propagate the null-excluding attribute to the new entity
5007 if Null_Exclusion_Present
(Param_Spec
) then
5008 Set_Null_Exclusion_Present
(Param_Spec
, False);
5009 Set_Can_Never_Be_Null
(Anon
);
5012 Mark_Rewrite_Insertion
(Decl
);
5014 -- Insert the new declaration in the nearest enclosing scope
5016 while not Has_Declarations
(P
) loop
5020 Prepend
(Decl
, Declarations
(P
));
5022 Rewrite
(Ptype
, New_Occurrence_Of
(Anon
, Loc
));
5023 Mark_Rewrite_Insertion
(Ptype
);
5025 -- Analyze the new declaration in the context of the
5028 Scope_Stack
.Decrement_Last
;
5030 Scope_Stack
.Append
(Curr_Scope
);
5032 Formal_Type
:= Anon
;
5036 -- Ada 0Y (AI-231): Static checks
5038 if Null_Exclusion_Present
(Param_Spec
)
5039 or else Can_Never_Be_Null
(Entity
(Ptype
))
5041 Null_Exclusion_Static_Checks
(Param_Spec
);
5044 -- An access formal type
5048 Access_Definition
(Related_Nod
, Parameter_Type
(Param_Spec
));
5053 AD
: constant Node_Id
:=
5054 Access_To_Subprogram_Definition
5055 (Parameter_Type
(Param_Spec
));
5057 if Present
(AD
) and then Protected_Present
(AD
) then
5059 Replace_Anonymous_Access_To_Protected_Subprogram
5060 (Param_Spec
, Formal_Type
);
5065 Set_Etype
(Formal
, Formal_Type
);
5066 Default
:= Expression
(Param_Spec
);
5068 if Present
(Default
) then
5069 if Out_Present
(Param_Spec
) then
5071 ("default initialization only allowed for IN parameters",
5075 -- Do the special preanalysis of the expression (see section on
5076 -- "Handling of Default Expressions" in the spec of package Sem).
5078 Analyze_Per_Use_Expression
(Default
, Formal_Type
);
5080 -- Check that the designated type of an access parameter's
5081 -- default is not a class-wide type unless the parameter's
5082 -- designated type is also class-wide.
5084 if Ekind
(Formal_Type
) = E_Anonymous_Access_Type
5085 and then Is_Class_Wide_Default
(Default
)
5086 and then not Is_Class_Wide_Type
(Designated_Type
(Formal_Type
))
5089 ("access to class-wide expression not allowed here", Default
);
5097 -- Now set the kind (mode) of each formal
5099 Param_Spec
:= First
(T
);
5101 while Present
(Param_Spec
) loop
5102 Formal
:= Defining_Identifier
(Param_Spec
);
5103 Set_Formal_Mode
(Formal
);
5105 if Ekind
(Formal
) = E_In_Parameter
then
5106 Set_Default_Value
(Formal
, Expression
(Param_Spec
));
5108 if Present
(Expression
(Param_Spec
)) then
5109 Default
:= Expression
(Param_Spec
);
5111 if Is_Scalar_Type
(Etype
(Default
)) then
5113 (Parameter_Type
(Param_Spec
)) /= N_Access_Definition
5115 Formal_Type
:= Entity
(Parameter_Type
(Param_Spec
));
5118 Formal_Type
:= Access_Definition
5119 (Related_Nod
, Parameter_Type
(Param_Spec
));
5122 Apply_Scalar_Range_Check
(Default
, Formal_Type
);
5130 end Process_Formals
;
5132 ----------------------------
5133 -- Reference_Body_Formals --
5134 ----------------------------
5136 procedure Reference_Body_Formals
(Spec
: Entity_Id
; Bod
: Entity_Id
) is
5141 if Error_Posted
(Spec
) then
5145 Fs
:= First_Formal
(Spec
);
5146 Fb
:= First_Formal
(Bod
);
5148 while Present
(Fs
) loop
5149 Generate_Reference
(Fs
, Fb
, 'b');
5152 Style
.Check_Identifier
(Fb
, Fs
);
5155 Set_Spec_Entity
(Fb
, Fs
);
5156 Set_Referenced
(Fs
, False);
5160 end Reference_Body_Formals
;
5162 -------------------------
5163 -- Set_Actual_Subtypes --
5164 -------------------------
5166 procedure Set_Actual_Subtypes
(N
: Node_Id
; Subp
: Entity_Id
) is
5167 Loc
: constant Source_Ptr
:= Sloc
(N
);
5171 First_Stmt
: Node_Id
:= Empty
;
5172 AS_Needed
: Boolean;
5175 -- If this is an emtpy initialization procedure, no need to create
5176 -- actual subtypes (small optimization).
5178 if Ekind
(Subp
) = E_Procedure
5179 and then Is_Null_Init_Proc
(Subp
)
5184 Formal
:= First_Formal
(Subp
);
5185 while Present
(Formal
) loop
5186 T
:= Etype
(Formal
);
5188 -- We never need an actual subtype for a constrained formal.
5190 if Is_Constrained
(T
) then
5193 -- If we have unknown discriminants, then we do not need an
5194 -- actual subtype, or more accurately we cannot figure it out!
5195 -- Note that all class-wide types have unknown discriminants.
5197 elsif Has_Unknown_Discriminants
(T
) then
5200 -- At this stage we have an unconstrained type that may need
5201 -- an actual subtype. For sure the actual subtype is needed
5202 -- if we have an unconstrained array type.
5204 elsif Is_Array_Type
(T
) then
5207 -- The only other case which needs an actual subtype is an
5208 -- unconstrained record type which is an IN parameter (we
5209 -- cannot generate actual subtypes for the OUT or IN OUT case,
5210 -- since an assignment can change the discriminant values.
5211 -- However we exclude the case of initialization procedures,
5212 -- since discriminants are handled very specially in this context,
5213 -- see the section entitled "Handling of Discriminants" in Einfo.
5214 -- We also exclude the case of Discrim_SO_Functions (functions
5215 -- used in front end layout mode for size/offset values), since
5216 -- in such functions only discriminants are referenced, and not
5217 -- only are such subtypes not needed, but they cannot always
5218 -- be generated, because of order of elaboration issues.
5220 elsif Is_Record_Type
(T
)
5221 and then Ekind
(Formal
) = E_In_Parameter
5222 and then Chars
(Formal
) /= Name_uInit
5223 and then not Is_Discrim_SO_Function
(Subp
)
5227 -- All other cases do not need an actual subtype
5233 -- Generate actual subtypes for unconstrained arrays and
5234 -- unconstrained discriminated records.
5237 if Nkind
(N
) = N_Accept_Statement
then
5239 -- If expansion is active, The formal is replaced by a local
5240 -- variable that renames the corresponding entry of the
5241 -- parameter block, and it is this local variable that may
5242 -- require an actual subtype.
5244 if Expander_Active
then
5245 Decl
:= Build_Actual_Subtype
(T
, Renamed_Object
(Formal
));
5247 Decl
:= Build_Actual_Subtype
(T
, Formal
);
5250 if Present
(Handled_Statement_Sequence
(N
)) then
5252 First
(Statements
(Handled_Statement_Sequence
(N
)));
5253 Prepend
(Decl
, Statements
(Handled_Statement_Sequence
(N
)));
5254 Mark_Rewrite_Insertion
(Decl
);
5256 -- If the accept statement has no body, there will be
5257 -- no reference to the actuals, so no need to compute
5264 Decl
:= Build_Actual_Subtype
(T
, Formal
);
5265 Prepend
(Decl
, Declarations
(N
));
5266 Mark_Rewrite_Insertion
(Decl
);
5269 -- The declaration uses the bounds of an existing object,
5270 -- and therefore needs no constraint checks.
5272 Analyze
(Decl
, Suppress
=> All_Checks
);
5274 -- We need to freeze manually the generated type when it is
5275 -- inserted anywhere else than in a declarative part.
5277 if Present
(First_Stmt
) then
5278 Insert_List_Before_And_Analyze
(First_Stmt
,
5279 Freeze_Entity
(Defining_Identifier
(Decl
), Loc
));
5282 if Nkind
(N
) = N_Accept_Statement
5283 and then Expander_Active
5285 Set_Actual_Subtype
(Renamed_Object
(Formal
),
5286 Defining_Identifier
(Decl
));
5288 Set_Actual_Subtype
(Formal
, Defining_Identifier
(Decl
));
5292 Next_Formal
(Formal
);
5294 end Set_Actual_Subtypes
;
5296 ---------------------
5297 -- Set_Formal_Mode --
5298 ---------------------
5300 procedure Set_Formal_Mode
(Formal_Id
: Entity_Id
) is
5301 Spec
: constant Node_Id
:= Parent
(Formal_Id
);
5304 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
5305 -- since we ensure that corresponding actuals are always valid at the
5306 -- point of the call.
5308 if Out_Present
(Spec
) then
5309 if Ekind
(Scope
(Formal_Id
)) = E_Function
5310 or else Ekind
(Scope
(Formal_Id
)) = E_Generic_Function
5312 Error_Msg_N
("functions can only have IN parameters", Spec
);
5313 Set_Ekind
(Formal_Id
, E_In_Parameter
);
5315 elsif In_Present
(Spec
) then
5316 Set_Ekind
(Formal_Id
, E_In_Out_Parameter
);
5319 Set_Ekind
(Formal_Id
, E_Out_Parameter
);
5320 Set_Never_Set_In_Source
(Formal_Id
, True);
5321 Set_Is_True_Constant
(Formal_Id
, False);
5322 Set_Current_Value
(Formal_Id
, Empty
);
5326 Set_Ekind
(Formal_Id
, E_In_Parameter
);
5329 -- Set Is_Known_Non_Null for access parameters since the language
5330 -- guarantees that access parameters are always non-null. We also
5331 -- set Can_Never_Be_Null, since there is no way to change the value.
5333 if Nkind
(Parameter_Type
(Spec
)) = N_Access_Definition
then
5335 -- Ada 0Y (AI-231): This behaviour has been modified in Ada 0Y.
5336 -- It is only forced if the null_exclusion appears.
5338 if not Extensions_Allowed
5339 or else Null_Exclusion_Present
(Spec
)
5341 Set_Is_Known_Non_Null
(Formal_Id
);
5342 Set_Can_Never_Be_Null
(Formal_Id
);
5346 Set_Mechanism
(Formal_Id
, Default_Mechanism
);
5347 Set_Formal_Validity
(Formal_Id
);
5348 end Set_Formal_Mode
;
5350 -------------------------
5351 -- Set_Formal_Validity --
5352 -------------------------
5354 procedure Set_Formal_Validity
(Formal_Id
: Entity_Id
) is
5356 -- If no validity checking, then we cannot assume anything about
5357 -- the validity of parameters, since we do not know there is any
5358 -- checking of the validity on the call side.
5360 if not Validity_Checks_On
then
5363 -- If validity checking for parameters is enabled, this means we are
5364 -- not supposed to make any assumptions about argument values.
5366 elsif Validity_Check_Parameters
then
5369 -- If we are checking in parameters, we will assume that the caller is
5370 -- also checking parameters, so we can assume the parameter is valid.
5372 elsif Ekind
(Formal_Id
) = E_In_Parameter
5373 and then Validity_Check_In_Params
5375 Set_Is_Known_Valid
(Formal_Id
, True);
5377 -- Similar treatment for IN OUT parameters
5379 elsif Ekind
(Formal_Id
) = E_In_Out_Parameter
5380 and then Validity_Check_In_Out_Params
5382 Set_Is_Known_Valid
(Formal_Id
, True);
5384 end Set_Formal_Validity
;
5386 ------------------------
5387 -- Subtype_Conformant --
5388 ------------------------
5390 function Subtype_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
5394 Check_Conformance
(New_Id
, Old_Id
, Subtype_Conformant
, False, Result
);
5396 end Subtype_Conformant
;
5398 ---------------------
5399 -- Type_Conformant --
5400 ---------------------
5402 function Type_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
5405 Check_Conformance
(New_Id
, Old_Id
, Type_Conformant
, False, Result
);
5407 end Type_Conformant
;
5409 -------------------------------
5410 -- Valid_Operator_Definition --
5411 -------------------------------
5413 procedure Valid_Operator_Definition
(Designator
: Entity_Id
) is
5416 Id
: constant Name_Id
:= Chars
(Designator
);
5420 F
:= First_Formal
(Designator
);
5422 while Present
(F
) loop
5425 if Present
(Default_Value
(F
)) then
5427 ("default values not allowed for operator parameters",
5434 -- Verify that user-defined operators have proper number of arguments
5435 -- First case of operators which can only be unary
5438 or else Id
= Name_Op_Abs
5442 -- Case of operators which can be unary or binary
5444 elsif Id
= Name_Op_Add
5445 or Id
= Name_Op_Subtract
5447 N_OK
:= (N
in 1 .. 2);
5449 -- All other operators can only be binary
5457 ("incorrect number of arguments for operator", Designator
);
5461 and then Base_Type
(Etype
(Designator
)) = Standard_Boolean
5462 and then not Is_Intrinsic_Subprogram
(Designator
)
5465 ("explicit definition of inequality not allowed", Designator
);
5467 end Valid_Operator_Definition
;