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 procedure Check_Returns
136 -- Called to check for missing return statements in a function body,
137 -- or for returns present in a procedure body which has No_Return set.
138 -- L is the handled statement sequence for the subprogram body. This
139 -- procedure checks all flow paths to make sure they either have a
140 -- return (Mode = 'F') or do not have a return (Mode = 'P'). The flag
141 -- Err is set if there are any control paths not explicitly terminated
142 -- by a return in the function case, and is True otherwise.
144 function Conforming_Types
147 Ctype
: Conformance_Type
;
148 Get_Inst
: Boolean := False) return Boolean;
149 -- Check that two formal parameter types conform, checking both
150 -- for equality of base types, and where required statically
151 -- matching subtypes, depending on the setting of Ctype.
153 procedure Enter_Overloaded_Entity
(S
: Entity_Id
);
154 -- This procedure makes S, a new overloaded entity, into the first
155 -- visible entity with that name.
157 procedure Install_Entity
(E
: Entity_Id
);
158 -- Make single entity visible. Used for generic formals as well
160 procedure Install_Formals
(Id
: Entity_Id
);
161 -- On entry to a subprogram body, make the formals visible. Note
162 -- that simply placing the subprogram on the scope stack is not
163 -- sufficient: the formals must become the current entities for
166 function Is_Non_Overriding_Operation
168 New_E
: Entity_Id
) return Boolean;
169 -- Enforce the rule given in 12.3(18): a private operation in an instance
170 -- overrides an inherited operation only if the corresponding operation
171 -- was overriding in the generic. This can happen for primitive operations
172 -- of types derived (in the generic unit) from formal private or formal
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
)
1139 and then Nkind
(Corresponding_Stub
(Parent
(N
))) =
1140 N_Subprogram_Body_Stub
1143 Old_Id
: constant Entity_Id
:=
1145 (Specification
(Corresponding_Stub
(Parent
(N
))));
1147 Conformant
: Boolean := False;
1150 if No
(Spec_Id
) then
1151 Check_Fully_Conformant
(Body_Id
, Old_Id
);
1155 (Body_Id
, Old_Id
, Fully_Conformant
, False, Conformant
);
1157 if not Conformant
then
1159 -- The stub was taken to be a new declaration. Indicate
1160 -- that it lacks a body.
1162 Set_Has_Completion
(Old_Id
, False);
1168 Set_Has_Completion
(Body_Id
);
1169 Check_Eliminated
(Body_Id
);
1171 if Nkind
(N
) = N_Subprogram_Body_Stub
then
1174 elsif Present
(Spec_Id
)
1175 and then Expander_Active
1177 Check_Following_Pragma
;
1179 if Is_Always_Inlined
(Spec_Id
)
1180 or else (Has_Pragma_Inline
(Spec_Id
) and then Front_End_Inlining
)
1182 Build_Body_To_Inline
(N
, Spec_Id
);
1186 -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis
1187 -- if its specification we have to install the private withed units.
1189 if Is_Compilation_Unit
(Body_Id
)
1190 and then Scope
(Body_Id
) = Standard_Standard
1192 Install_Private_With_Clauses
(Body_Id
);
1195 -- Now we can go on to analyze the body
1197 HSS
:= Handled_Statement_Sequence
(N
);
1198 Set_Actual_Subtypes
(N
, Current_Scope
);
1199 Analyze_Declarations
(Declarations
(N
));
1202 Process_End_Label
(HSS
, 't', Current_Scope
);
1204 Check_Subprogram_Order
(N
);
1205 Set_Analyzed
(Body_Id
);
1207 -- If we have a separate spec, then the analysis of the declarations
1208 -- caused the entities in the body to be chained to the spec id, but
1209 -- we want them chained to the body id. Only the formal parameters
1210 -- end up chained to the spec id in this case.
1212 if Present
(Spec_Id
) then
1214 -- If a parent unit is categorized, the context of a subunit
1215 -- must conform to the categorization. Conversely, if a child
1216 -- unit is categorized, the parents themselves must conform.
1218 if Nkind
(Parent
(N
)) = N_Subunit
then
1219 Validate_Categorization_Dependency
(N
, Spec_Id
);
1221 elsif Is_Child_Unit
(Spec_Id
) then
1222 Validate_Categorization_Dependency
1223 (Unit_Declaration_Node
(Spec_Id
), Spec_Id
);
1226 if Present
(Last_Formal
) then
1228 (Last_Entity
(Body_Id
), Next_Entity
(Last_Formal
));
1229 Set_Next_Entity
(Last_Formal
, Empty
);
1230 Set_Last_Entity
(Body_Id
, Last_Entity
(Spec_Id
));
1231 Set_Last_Entity
(Spec_Id
, Last_Formal
);
1234 Set_First_Entity
(Body_Id
, First_Entity
(Spec_Id
));
1235 Set_Last_Entity
(Body_Id
, Last_Entity
(Spec_Id
));
1236 Set_First_Entity
(Spec_Id
, Empty
);
1237 Set_Last_Entity
(Spec_Id
, Empty
);
1241 -- If function, check return statements
1243 if Nkind
(Body_Spec
) = N_Function_Specification
then
1248 if Present
(Spec_Id
) then
1254 if Return_Present
(Id
) then
1255 Check_Returns
(HSS
, 'F', Missing_Ret
);
1258 Set_Has_Missing_Return
(Id
);
1261 elsif not Is_Machine_Code_Subprogram
(Id
)
1262 and then not Body_Deleted
1264 Error_Msg_N
("missing RETURN statement in function body", N
);
1268 -- If procedure with No_Return, check returns
1270 elsif Nkind
(Body_Spec
) = N_Procedure_Specification
1271 and then Present
(Spec_Id
)
1272 and then No_Return
(Spec_Id
)
1274 Check_Returns
(HSS
, 'P', Missing_Ret
);
1277 -- Now we are going to check for variables that are never modified
1278 -- in the body of the procedure. We omit these checks if the first
1279 -- statement of the procedure raises an exception. In particular
1280 -- this deals with the common idiom of a stubbed function, which
1281 -- might appear as something like
1283 -- function F (A : Integer) return Some_Type;
1286 -- raise Program_Error;
1290 -- Here the purpose of X is simply to satisfy the (annoying)
1291 -- requirement in Ada that there be at least one return, and
1292 -- we certainly do not want to go posting warnings on X that
1293 -- it is not initialized!
1296 Stm
: Node_Id
:= First
(Statements
(HSS
));
1299 -- Skip an initial label (for one thing this occurs when we
1300 -- are in front end ZCX mode, but in any case it is irrelevant).
1302 if Nkind
(Stm
) = N_Label
then
1306 -- Do the test on the original statement before expansion
1309 Ostm
: constant Node_Id
:= Original_Node
(Stm
);
1312 -- If explicit raise statement, return with no checks
1314 if Nkind
(Ostm
) = N_Raise_Statement
then
1317 -- Check for explicit call cases which likely raise an exception
1319 elsif Nkind
(Ostm
) = N_Procedure_Call_Statement
then
1320 if Is_Entity_Name
(Name
(Ostm
)) then
1322 Ent
: constant Entity_Id
:= Entity
(Name
(Ostm
));
1325 -- If the procedure is marked No_Return, then likely it
1326 -- raises an exception, but in any case it is not coming
1327 -- back here, so no need to check beyond the call.
1329 if Ekind
(Ent
) = E_Procedure
1330 and then No_Return
(Ent
)
1334 -- If the procedure name is Raise_Exception, then also
1335 -- assume that it raises an exception. The main target
1336 -- here is Ada.Exceptions.Raise_Exception, but this name
1337 -- is pretty evocative in any context! Note that the
1338 -- procedure in Ada.Exceptions is not marked No_Return
1339 -- because of the annoying case of the null exception Id.
1341 elsif Chars
(Ent
) = Name_Raise_Exception
then
1350 -- Check for variables that are never modified
1356 -- If there is a separate spec, then transfer Never_Set_In_Source
1357 -- flags from out parameters to the corresponding entities in the
1358 -- body. The reason we do that is we want to post error flags on
1359 -- the body entities, not the spec entities.
1361 if Present
(Spec_Id
) then
1362 E1
:= First_Entity
(Spec_Id
);
1364 while Present
(E1
) loop
1365 if Ekind
(E1
) = E_Out_Parameter
then
1366 E2
:= First_Entity
(Body_Id
);
1367 while Present
(E2
) loop
1368 exit when Chars
(E1
) = Chars
(E2
);
1372 if Present
(E2
) then
1373 Set_Never_Set_In_Source
(E2
, Never_Set_In_Source
(E1
));
1381 -- Check references in body unless it was deleted. Note that the
1382 -- check of Body_Deleted here is not just for efficiency, it is
1383 -- necessary to avoid junk warnings on formal parameters.
1385 if not Body_Deleted
then
1386 Check_References
(Body_Id
);
1389 end Analyze_Subprogram_Body
;
1391 ------------------------------------
1392 -- Analyze_Subprogram_Declaration --
1393 ------------------------------------
1395 procedure Analyze_Subprogram_Declaration
(N
: Node_Id
) is
1396 Designator
: constant Entity_Id
:=
1397 Analyze_Subprogram_Specification
(Specification
(N
));
1398 Scop
: constant Entity_Id
:= Current_Scope
;
1400 -- Start of processing for Analyze_Subprogram_Declaration
1403 Generate_Definition
(Designator
);
1405 -- Check for RCI unit subprogram declarations against in-lined
1406 -- subprograms and subprograms having access parameter or limited
1407 -- parameter without Read and Write (RM E.2.3(12-13)).
1409 Validate_RCI_Subprogram_Declaration
(N
);
1413 Defining_Entity
(N
),
1414 " Analyze subprogram spec. ");
1416 if Debug_Flag_C
then
1417 Write_Str
("==== Compiling subprogram spec ");
1418 Write_Name
(Chars
(Designator
));
1419 Write_Str
(" from ");
1420 Write_Location
(Sloc
(N
));
1424 New_Overloaded_Entity
(Designator
);
1425 Check_Delayed_Subprogram
(Designator
);
1427 -- What is the following code for, it used to be
1429 -- ??? Set_Suppress_Elaboration_Checks
1430 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator));
1432 -- The following seems equivalent, but a bit dubious
1434 if Elaboration_Checks_Suppressed
(Designator
) then
1435 Set_Kill_Elaboration_Checks
(Designator
);
1438 if Scop
/= Standard_Standard
1439 and then not Is_Child_Unit
(Designator
)
1441 Set_Categorization_From_Scope
(Designator
, Scop
);
1443 -- For a compilation unit, check for library-unit pragmas
1445 New_Scope
(Designator
);
1446 Set_Categorization_From_Pragmas
(N
);
1447 Validate_Categorization_Dependency
(N
, Designator
);
1451 -- For a compilation unit, set body required. This flag will only be
1452 -- reset if a valid Import or Interface pragma is processed later on.
1454 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
1455 Set_Body_Required
(Parent
(N
), True);
1458 Generate_Reference_To_Formals
(Designator
);
1459 Check_Eliminated
(Designator
);
1461 if Comes_From_Source
(N
)
1462 and then Is_List_Member
(N
)
1464 Check_Overriding_Operation
(N
, Designator
);
1467 end Analyze_Subprogram_Declaration
;
1469 --------------------------------------
1470 -- Analyze_Subprogram_Specification --
1471 --------------------------------------
1473 -- Reminder: N here really is a subprogram specification (not a subprogram
1474 -- declaration). This procedure is called to analyze the specification in
1475 -- both subprogram bodies and subprogram declarations (specs).
1477 function Analyze_Subprogram_Specification
(N
: Node_Id
) return Entity_Id
is
1478 Designator
: constant Entity_Id
:= Defining_Entity
(N
);
1479 Formals
: constant List_Id
:= Parameter_Specifications
(N
);
1483 Generate_Definition
(Designator
);
1485 if Nkind
(N
) = N_Function_Specification
then
1486 Set_Ekind
(Designator
, E_Function
);
1487 Set_Mechanism
(Designator
, Default_Mechanism
);
1489 if Subtype_Mark
(N
) /= Error
then
1490 Find_Type
(Subtype_Mark
(N
));
1491 Typ
:= Entity
(Subtype_Mark
(N
));
1492 Set_Etype
(Designator
, Typ
);
1494 if Ekind
(Typ
) = E_Incomplete_Type
1495 or else (Is_Class_Wide_Type
(Typ
)
1497 Ekind
(Root_Type
(Typ
)) = E_Incomplete_Type
)
1500 ("invalid use of incomplete type", Subtype_Mark
(N
));
1504 Set_Etype
(Designator
, Any_Type
);
1508 Set_Ekind
(Designator
, E_Procedure
);
1509 Set_Etype
(Designator
, Standard_Void_Type
);
1512 if Present
(Formals
) then
1513 Set_Scope
(Designator
, Current_Scope
);
1514 New_Scope
(Designator
);
1515 Process_Formals
(Formals
, N
);
1519 if Nkind
(N
) = N_Function_Specification
then
1520 if Nkind
(Designator
) = N_Defining_Operator_Symbol
then
1521 Valid_Operator_Definition
(Designator
);
1524 May_Need_Actuals
(Designator
);
1526 if Is_Abstract
(Etype
(Designator
))
1527 and then Nkind
(Parent
(N
)) /= N_Abstract_Subprogram_Declaration
1530 ("function that returns abstract type must be abstract", N
);
1535 end Analyze_Subprogram_Specification
;
1537 --------------------------
1538 -- Build_Body_To_Inline --
1539 --------------------------
1541 procedure Build_Body_To_Inline
(N
: Node_Id
; Subp
: Entity_Id
) is
1542 Decl
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
1543 Original_Body
: Node_Id
;
1544 Body_To_Analyze
: Node_Id
;
1545 Max_Size
: constant := 10;
1546 Stat_Count
: Integer := 0;
1548 function Has_Excluded_Declaration
(Decls
: List_Id
) return Boolean;
1549 -- Check for declarations that make inlining not worthwhile
1551 function Has_Excluded_Statement
(Stats
: List_Id
) return Boolean;
1552 -- Check for statements that make inlining not worthwhile: any
1553 -- tasking statement, nested at any level. Keep track of total
1554 -- number of elementary statements, as a measure of acceptable size.
1556 function Has_Pending_Instantiation
return Boolean;
1557 -- If some enclosing body contains instantiations that appear before
1558 -- the corresponding generic body, the enclosing body has a freeze node
1559 -- so that it can be elaborated after the generic itself. This might
1560 -- conflict with subsequent inlinings, so that it is unsafe to try to
1561 -- inline in such a case.
1563 procedure Remove_Pragmas
;
1564 -- A pragma Unreferenced that mentions a formal parameter has no
1565 -- meaning when the body is inlined and the formals are rewritten.
1566 -- Remove it from body to inline. The analysis of the non-inlined
1567 -- body will handle the pragma properly.
1569 function Uses_Secondary_Stack
(Bod
: Node_Id
) return Boolean;
1570 -- If the body of the subprogram includes a call that returns an
1571 -- unconstrained type, the secondary stack is involved, and it
1572 -- is not worth inlining.
1574 ------------------------------
1575 -- Has_Excluded_Declaration --
1576 ------------------------------
1578 function Has_Excluded_Declaration
(Decls
: List_Id
) return Boolean is
1581 function Is_Unchecked_Conversion
(D
: Node_Id
) return Boolean;
1582 -- Nested subprograms make a given body ineligible for inlining,
1583 -- but we make an exception for instantiations of unchecked
1584 -- conversion. The body has not been analyzed yet, so we check
1585 -- the name, and verify that the visible entity with that name is
1586 -- the predefined unit.
1588 function Is_Unchecked_Conversion
(D
: Node_Id
) return Boolean is
1589 Id
: constant Node_Id
:= Name
(D
);
1593 if Nkind
(Id
) = N_Identifier
1594 and then Chars
(Id
) = Name_Unchecked_Conversion
1596 Conv
:= Current_Entity
(Id
);
1598 elsif Nkind
(Id
) = N_Selected_Component
1599 and then Chars
(Selector_Name
(Id
)) = Name_Unchecked_Conversion
1601 Conv
:= Current_Entity
(Selector_Name
(Id
));
1609 and then Scope
(Conv
) = Standard_Standard
1610 and then Is_Intrinsic_Subprogram
(Conv
);
1611 end Is_Unchecked_Conversion
;
1613 -- Start of processing for Has_Excluded_Declaration
1618 while Present
(D
) loop
1619 if (Nkind
(D
) = N_Function_Instantiation
1620 and then not Is_Unchecked_Conversion
(D
))
1621 or else Nkind
(D
) = N_Protected_Type_Declaration
1622 or else Nkind
(D
) = N_Package_Declaration
1623 or else Nkind
(D
) = N_Package_Instantiation
1624 or else Nkind
(D
) = N_Subprogram_Body
1625 or else Nkind
(D
) = N_Procedure_Instantiation
1626 or else Nkind
(D
) = N_Task_Type_Declaration
1629 ("cannot inline & (non-allowed declaration)?", D
, Subp
);
1637 end Has_Excluded_Declaration
;
1639 ----------------------------
1640 -- Has_Excluded_Statement --
1641 ----------------------------
1643 function Has_Excluded_Statement
(Stats
: List_Id
) return Boolean is
1650 while Present
(S
) loop
1651 Stat_Count
:= Stat_Count
+ 1;
1653 if Nkind
(S
) = N_Abort_Statement
1654 or else Nkind
(S
) = N_Asynchronous_Select
1655 or else Nkind
(S
) = N_Conditional_Entry_Call
1656 or else Nkind
(S
) = N_Delay_Relative_Statement
1657 or else Nkind
(S
) = N_Delay_Until_Statement
1658 or else Nkind
(S
) = N_Selective_Accept
1659 or else Nkind
(S
) = N_Timed_Entry_Call
1662 ("cannot inline & (non-allowed statement)?", S
, Subp
);
1665 elsif Nkind
(S
) = N_Block_Statement
then
1666 if Present
(Declarations
(S
))
1667 and then Has_Excluded_Declaration
(Declarations
(S
))
1671 elsif Present
(Handled_Statement_Sequence
(S
))
1674 (Exception_Handlers
(Handled_Statement_Sequence
(S
)))
1676 Has_Excluded_Statement
1677 (Statements
(Handled_Statement_Sequence
(S
))))
1682 elsif Nkind
(S
) = N_Case_Statement
then
1683 E
:= First
(Alternatives
(S
));
1685 while Present
(E
) loop
1686 if Has_Excluded_Statement
(Statements
(E
)) then
1693 elsif Nkind
(S
) = N_If_Statement
then
1694 if Has_Excluded_Statement
(Then_Statements
(S
)) then
1698 if Present
(Elsif_Parts
(S
)) then
1699 E
:= First
(Elsif_Parts
(S
));
1701 while Present
(E
) loop
1702 if Has_Excluded_Statement
(Then_Statements
(E
)) then
1709 if Present
(Else_Statements
(S
))
1710 and then Has_Excluded_Statement
(Else_Statements
(S
))
1715 elsif Nkind
(S
) = N_Loop_Statement
1716 and then Has_Excluded_Statement
(Statements
(S
))
1725 end Has_Excluded_Statement
;
1727 -------------------------------
1728 -- Has_Pending_Instantiation --
1729 -------------------------------
1731 function Has_Pending_Instantiation
return Boolean is
1732 S
: Entity_Id
:= Current_Scope
;
1735 while Present
(S
) loop
1736 if Is_Compilation_Unit
(S
)
1737 or else Is_Child_Unit
(S
)
1740 elsif Ekind
(S
) = E_Package
1741 and then Has_Forward_Instantiation
(S
)
1750 end Has_Pending_Instantiation
;
1752 --------------------
1753 -- Remove_Pragmas --
1754 --------------------
1756 procedure Remove_Pragmas
is
1761 Decl
:= First
(Declarations
(Body_To_Analyze
));
1762 while Present
(Decl
) loop
1765 if Nkind
(Decl
) = N_Pragma
1766 and then Chars
(Decl
) = Name_Unreferenced
1775 --------------------------
1776 -- Uses_Secondary_Stack --
1777 --------------------------
1779 function Uses_Secondary_Stack
(Bod
: Node_Id
) return Boolean is
1780 function Check_Call
(N
: Node_Id
) return Traverse_Result
;
1781 -- Look for function calls that return an unconstrained type
1787 function Check_Call
(N
: Node_Id
) return Traverse_Result
is
1789 if Nkind
(N
) = N_Function_Call
1790 and then Is_Entity_Name
(Name
(N
))
1791 and then Is_Composite_Type
(Etype
(Entity
(Name
(N
))))
1792 and then not Is_Constrained
(Etype
(Entity
(Name
(N
))))
1795 ("cannot inline & (call returns unconstrained type)?",
1803 function Check_Calls
is new Traverse_Func
(Check_Call
);
1806 return Check_Calls
(Bod
) = Abandon
;
1807 end Uses_Secondary_Stack
;
1809 -- Start of processing for Build_Body_To_Inline
1812 if Nkind
(Decl
) = N_Subprogram_Declaration
1813 and then Present
(Body_To_Inline
(Decl
))
1815 return; -- Done already.
1817 -- Functions that return unconstrained composite types will require
1818 -- secondary stack handling, and cannot currently be inlined.
1819 -- Ditto for functions that return controlled types, where controlled
1820 -- actions interfere in complex ways with inlining.
1822 elsif Ekind
(Subp
) = E_Function
1823 and then not Is_Scalar_Type
(Etype
(Subp
))
1824 and then not Is_Access_Type
(Etype
(Subp
))
1825 and then not Is_Constrained
(Etype
(Subp
))
1828 ("cannot inline & (unconstrained return type)?", N
, Subp
);
1831 elsif Ekind
(Subp
) = E_Function
1832 and then Controlled_Type
(Etype
(Subp
))
1835 ("cannot inline & (controlled return type)?", N
, Subp
);
1839 if Present
(Declarations
(N
))
1840 and then Has_Excluded_Declaration
(Declarations
(N
))
1845 if Present
(Handled_Statement_Sequence
(N
)) then
1846 if Present
(Exception_Handlers
(Handled_Statement_Sequence
(N
))) then
1848 ("cannot inline& (exception handler)?",
1849 First
(Exception_Handlers
(Handled_Statement_Sequence
(N
))),
1853 Has_Excluded_Statement
1854 (Statements
(Handled_Statement_Sequence
(N
)))
1860 -- We do not inline a subprogram that is too large, unless it is
1861 -- marked Inline_Always. This pragma does not suppress the other
1862 -- checks on inlining (forbidden declarations, handlers, etc).
1864 if Stat_Count
> Max_Size
1865 and then not Is_Always_Inlined
(Subp
)
1867 Cannot_Inline
("cannot inline& (body too large)?", N
, Subp
);
1871 if Has_Pending_Instantiation
then
1873 ("cannot inline& (forward instance within enclosing body)?",
1878 -- Within an instance, the body to inline must be treated as a nested
1879 -- generic, so that the proper global references are preserved.
1882 Save_Env
(Scope
(Current_Scope
), Scope
(Current_Scope
));
1883 Original_Body
:= Copy_Generic_Node
(N
, Empty
, True);
1885 Original_Body
:= Copy_Separate_Tree
(N
);
1888 -- We need to capture references to the formals in order to substitute
1889 -- the actuals at the point of inlining, i.e. instantiation. To treat
1890 -- the formals as globals to the body to inline, we nest it within
1891 -- a dummy parameterless subprogram, declared within the real one.
1892 -- To avoid generating an internal name (which is never public, and
1893 -- which affects serial numbers of other generated names), we use
1894 -- an internal symbol that cannot conflict with user declarations.
1896 Set_Parameter_Specifications
(Specification
(Original_Body
), No_List
);
1897 Set_Defining_Unit_Name
1898 (Specification
(Original_Body
),
1899 Make_Defining_Identifier
(Sloc
(N
), Name_uParent
));
1900 Set_Corresponding_Spec
(Original_Body
, Empty
);
1902 Body_To_Analyze
:= Copy_Generic_Node
(Original_Body
, Empty
, False);
1904 -- Set return type of function, which is also global and does not need
1907 if Ekind
(Subp
) = E_Function
then
1908 Set_Subtype_Mark
(Specification
(Body_To_Analyze
),
1909 New_Occurrence_Of
(Etype
(Subp
), Sloc
(N
)));
1912 if No
(Declarations
(N
)) then
1913 Set_Declarations
(N
, New_List
(Body_To_Analyze
));
1915 Append
(Body_To_Analyze
, Declarations
(N
));
1918 Expander_Mode_Save_And_Set
(False);
1921 Analyze
(Body_To_Analyze
);
1922 New_Scope
(Defining_Entity
(Body_To_Analyze
));
1923 Save_Global_References
(Original_Body
);
1925 Remove
(Body_To_Analyze
);
1927 Expander_Mode_Restore
;
1933 -- If secondary stk used there is no point in inlining. We have
1934 -- already issued the warning in this case, so nothing to do.
1936 if Uses_Secondary_Stack
(Body_To_Analyze
) then
1940 Set_Body_To_Inline
(Decl
, Original_Body
);
1941 Set_Ekind
(Defining_Entity
(Original_Body
), Ekind
(Subp
));
1942 Set_Is_Inlined
(Subp
);
1943 end Build_Body_To_Inline
;
1949 procedure Cannot_Inline
(Msg
: String; N
: Node_Id
; Subp
: Entity_Id
) is
1951 -- Do not emit warning if this is a predefined unit which is not
1952 -- the main unit. With validity checks enabled, some predefined
1953 -- subprograms may contain nested subprograms and become ineligible
1956 if Is_Predefined_File_Name
(Unit_File_Name
(Get_Source_Unit
(Subp
)))
1957 and then not In_Extended_Main_Source_Unit
(Subp
)
1961 elsif Is_Always_Inlined
(Subp
) then
1963 -- Remove last character (question mark) to make this into an error,
1964 -- because the Inline_Always pragma cannot be obeyed.
1966 Error_Msg_NE
(Msg
(1 .. Msg
'Length - 1), N
, Subp
);
1968 elsif Ineffective_Inline_Warnings
then
1969 Error_Msg_NE
(Msg
, N
, Subp
);
1973 -----------------------
1974 -- Check_Conformance --
1975 -----------------------
1977 procedure Check_Conformance
1978 (New_Id
: Entity_Id
;
1980 Ctype
: Conformance_Type
;
1982 Conforms
: out Boolean;
1983 Err_Loc
: Node_Id
:= Empty
;
1984 Get_Inst
: Boolean := False)
1986 Old_Type
: constant Entity_Id
:= Etype
(Old_Id
);
1987 New_Type
: constant Entity_Id
:= Etype
(New_Id
);
1988 Old_Formal
: Entity_Id
;
1989 New_Formal
: Entity_Id
;
1991 procedure Conformance_Error
(Msg
: String; N
: Node_Id
:= New_Id
);
1992 -- Post error message for conformance error on given node.
1993 -- Two messages are output. The first points to the previous
1994 -- declaration with a general "no conformance" message.
1995 -- The second is the detailed reason, supplied as Msg. The
1996 -- parameter N provide information for a possible & insertion
1997 -- in the message, and also provides the location for posting
1998 -- the message in the absence of a specified Err_Loc location.
2000 -----------------------
2001 -- Conformance_Error --
2002 -----------------------
2004 procedure Conformance_Error
(Msg
: String; N
: Node_Id
:= New_Id
) is
2011 if No
(Err_Loc
) then
2017 Error_Msg_Sloc
:= Sloc
(Old_Id
);
2020 when Type_Conformant
=>
2022 ("not type conformant with declaration#!", Enode
);
2024 when Mode_Conformant
=>
2026 ("not mode conformant with declaration#!", Enode
);
2028 when Subtype_Conformant
=>
2030 ("not subtype conformant with declaration#!", Enode
);
2032 when Fully_Conformant
=>
2034 ("not fully conformant with declaration#!", Enode
);
2037 Error_Msg_NE
(Msg
, Enode
, N
);
2039 end Conformance_Error
;
2041 -- Start of processing for Check_Conformance
2046 -- We need a special case for operators, since they don't
2047 -- appear explicitly.
2049 if Ctype
= Type_Conformant
then
2050 if Ekind
(New_Id
) = E_Operator
2051 and then Operator_Matches_Spec
(New_Id
, Old_Id
)
2057 -- If both are functions/operators, check return types conform
2059 if Old_Type
/= Standard_Void_Type
2060 and then New_Type
/= Standard_Void_Type
2062 if not Conforming_Types
(Old_Type
, New_Type
, Ctype
, Get_Inst
) then
2063 Conformance_Error
("return type does not match!", New_Id
);
2067 -- If either is a function/operator and the other isn't, error
2069 elsif Old_Type
/= Standard_Void_Type
2070 or else New_Type
/= Standard_Void_Type
2072 Conformance_Error
("functions can only match functions!", New_Id
);
2076 -- In subtype conformant case, conventions must match (RM 6.3.1(16))
2077 -- If this is a renaming as body, refine error message to indicate that
2078 -- the conflict is with the original declaration. If the entity is not
2079 -- frozen, the conventions don't have to match, the one of the renamed
2080 -- entity is inherited.
2082 if Ctype
>= Subtype_Conformant
then
2083 if Convention
(Old_Id
) /= Convention
(New_Id
) then
2085 if not Is_Frozen
(New_Id
) then
2088 elsif Present
(Err_Loc
)
2089 and then Nkind
(Err_Loc
) = N_Subprogram_Renaming_Declaration
2090 and then Present
(Corresponding_Spec
(Err_Loc
))
2092 Error_Msg_Name_1
:= Chars
(New_Id
);
2094 Name_Ada
+ Convention_Id
'Pos (Convention
(New_Id
));
2096 Conformance_Error
("prior declaration for% has convention %!");
2099 Conformance_Error
("calling conventions do not match!");
2104 elsif Is_Formal_Subprogram
(Old_Id
)
2105 or else Is_Formal_Subprogram
(New_Id
)
2107 Conformance_Error
("formal subprograms not allowed!");
2112 -- Deal with parameters
2114 -- Note: we use the entity information, rather than going directly
2115 -- to the specification in the tree. This is not only simpler, but
2116 -- absolutely necessary for some cases of conformance tests between
2117 -- operators, where the declaration tree simply does not exist!
2119 Old_Formal
:= First_Formal
(Old_Id
);
2120 New_Formal
:= First_Formal
(New_Id
);
2122 while Present
(Old_Formal
) and then Present
(New_Formal
) loop
2123 if Ctype
= Fully_Conformant
then
2125 -- Names must match. Error message is more accurate if we do
2126 -- this before checking that the types of the formals match.
2128 if Chars
(Old_Formal
) /= Chars
(New_Formal
) then
2129 Conformance_Error
("name & does not match!", New_Formal
);
2131 -- Set error posted flag on new formal as well to stop
2132 -- junk cascaded messages in some cases.
2134 Set_Error_Posted
(New_Formal
);
2139 -- Types must always match. In the visible part of an instance,
2140 -- usual overloading rules for dispatching operations apply, and
2141 -- we check base types (not the actual subtypes).
2143 if In_Instance_Visible_Part
2144 and then Is_Dispatching_Operation
(New_Id
)
2146 if not Conforming_Types
2147 (Base_Type
(Etype
(Old_Formal
)),
2148 Base_Type
(Etype
(New_Formal
)), Ctype
, Get_Inst
)
2150 Conformance_Error
("type of & does not match!", New_Formal
);
2154 elsif not Conforming_Types
2155 (Etype
(Old_Formal
), Etype
(New_Formal
), Ctype
, Get_Inst
)
2157 Conformance_Error
("type of & does not match!", New_Formal
);
2161 -- For mode conformance, mode must match
2163 if Ctype
>= Mode_Conformant
2164 and then Parameter_Mode
(Old_Formal
) /= Parameter_Mode
(New_Formal
)
2166 Conformance_Error
("mode of & does not match!", New_Formal
);
2170 -- Full conformance checks
2172 if Ctype
= Fully_Conformant
then
2174 -- We have checked already that names match.
2175 -- Check default expressions for in parameters
2177 if Parameter_Mode
(Old_Formal
) = E_In_Parameter
then
2179 NewD
: constant Boolean :=
2180 Present
(Default_Value
(New_Formal
));
2181 OldD
: constant Boolean :=
2182 Present
(Default_Value
(Old_Formal
));
2184 if NewD
or OldD
then
2186 -- The old default value has been analyzed because
2187 -- the current full declaration will have frozen
2188 -- everything before. The new default values have not
2189 -- been analyzed, so analyze them now before we check
2194 Analyze_Per_Use_Expression
2195 (Default_Value
(New_Formal
), Etype
(New_Formal
));
2199 if not (NewD
and OldD
)
2200 or else not Fully_Conformant_Expressions
2201 (Default_Value
(Old_Formal
),
2202 Default_Value
(New_Formal
))
2205 ("default expression for & does not match!",
2214 -- A couple of special checks for Ada 83 mode. These checks are
2215 -- skipped if either entity is an operator in package Standard.
2216 -- or if either old or new instance is not from the source program.
2218 if Ada_Version
= Ada_83
2219 and then Sloc
(Old_Id
) > Standard_Location
2220 and then Sloc
(New_Id
) > Standard_Location
2221 and then Comes_From_Source
(Old_Id
)
2222 and then Comes_From_Source
(New_Id
)
2225 Old_Param
: constant Node_Id
:= Declaration_Node
(Old_Formal
);
2226 New_Param
: constant Node_Id
:= Declaration_Node
(New_Formal
);
2229 -- Explicit IN must be present or absent in both cases. This
2230 -- test is required only in the full conformance case.
2232 if In_Present
(Old_Param
) /= In_Present
(New_Param
)
2233 and then Ctype
= Fully_Conformant
2236 ("(Ada 83) IN must appear in both declarations",
2241 -- Grouping (use of comma in param lists) must be the same
2242 -- This is where we catch a misconformance like:
2245 -- A : Integer; B : Integer
2247 -- which are represented identically in the tree except
2248 -- for the setting of the flags More_Ids and Prev_Ids.
2250 if More_Ids
(Old_Param
) /= More_Ids
(New_Param
)
2251 or else Prev_Ids
(Old_Param
) /= Prev_Ids
(New_Param
)
2254 ("grouping of & does not match!", New_Formal
);
2260 Next_Formal
(Old_Formal
);
2261 Next_Formal
(New_Formal
);
2264 if Present
(Old_Formal
) then
2265 Conformance_Error
("too few parameters!");
2268 elsif Present
(New_Formal
) then
2269 Conformance_Error
("too many parameters!", New_Formal
);
2273 end Check_Conformance
;
2275 ------------------------------
2276 -- Check_Delayed_Subprogram --
2277 ------------------------------
2279 procedure Check_Delayed_Subprogram
(Designator
: Entity_Id
) is
2282 procedure Possible_Freeze
(T
: Entity_Id
);
2283 -- T is the type of either a formal parameter or of the return type.
2284 -- If T is not yet frozen and needs a delayed freeze, then the
2285 -- subprogram itself must be delayed.
2287 procedure Possible_Freeze
(T
: Entity_Id
) is
2289 if Has_Delayed_Freeze
(T
)
2290 and then not Is_Frozen
(T
)
2292 Set_Has_Delayed_Freeze
(Designator
);
2294 elsif Is_Access_Type
(T
)
2295 and then Has_Delayed_Freeze
(Designated_Type
(T
))
2296 and then not Is_Frozen
(Designated_Type
(T
))
2298 Set_Has_Delayed_Freeze
(Designator
);
2300 end Possible_Freeze
;
2302 -- Start of processing for Check_Delayed_Subprogram
2305 -- Never need to freeze abstract subprogram
2307 if Is_Abstract
(Designator
) then
2310 -- Need delayed freeze if return type itself needs a delayed
2311 -- freeze and is not yet frozen.
2313 Possible_Freeze
(Etype
(Designator
));
2314 Possible_Freeze
(Base_Type
(Etype
(Designator
))); -- needed ???
2316 -- Need delayed freeze if any of the formal types themselves need
2317 -- a delayed freeze and are not yet frozen.
2319 F
:= First_Formal
(Designator
);
2320 while Present
(F
) loop
2321 Possible_Freeze
(Etype
(F
));
2322 Possible_Freeze
(Base_Type
(Etype
(F
))); -- needed ???
2327 -- Mark functions that return by reference. Note that it cannot be
2328 -- done for delayed_freeze subprograms because the underlying
2329 -- returned type may not be known yet (for private types)
2331 if not Has_Delayed_Freeze
(Designator
)
2332 and then Expander_Active
2335 Typ
: constant Entity_Id
:= Etype
(Designator
);
2336 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
2339 if Is_Return_By_Reference_Type
(Typ
) then
2340 Set_Returns_By_Ref
(Designator
);
2342 elsif Present
(Utyp
) and then Controlled_Type
(Utyp
) then
2343 Set_Returns_By_Ref
(Designator
);
2347 end Check_Delayed_Subprogram
;
2349 ------------------------------------
2350 -- Check_Discriminant_Conformance --
2351 ------------------------------------
2353 procedure Check_Discriminant_Conformance
2358 Old_Discr
: Entity_Id
:= First_Discriminant
(Prev
);
2359 New_Discr
: Node_Id
:= First
(Discriminant_Specifications
(N
));
2360 New_Discr_Id
: Entity_Id
;
2361 New_Discr_Type
: Entity_Id
;
2363 procedure Conformance_Error
(Msg
: String; N
: Node_Id
);
2364 -- Post error message for conformance error on given node.
2365 -- Two messages are output. The first points to the previous
2366 -- declaration with a general "no conformance" message.
2367 -- The second is the detailed reason, supplied as Msg. The
2368 -- parameter N provide information for a possible & insertion
2371 -----------------------
2372 -- Conformance_Error --
2373 -----------------------
2375 procedure Conformance_Error
(Msg
: String; N
: Node_Id
) is
2377 Error_Msg_Sloc
:= Sloc
(Prev_Loc
);
2378 Error_Msg_N
("not fully conformant with declaration#!", N
);
2379 Error_Msg_NE
(Msg
, N
, N
);
2380 end Conformance_Error
;
2382 -- Start of processing for Check_Discriminant_Conformance
2385 while Present
(Old_Discr
) and then Present
(New_Discr
) loop
2387 New_Discr_Id
:= Defining_Identifier
(New_Discr
);
2389 -- The subtype mark of the discriminant on the full type
2390 -- has not been analyzed so we do it here. For an access
2391 -- discriminant a new type is created.
2393 if Nkind
(Discriminant_Type
(New_Discr
)) = N_Access_Definition
then
2395 Access_Definition
(N
, Discriminant_Type
(New_Discr
));
2398 Analyze
(Discriminant_Type
(New_Discr
));
2399 New_Discr_Type
:= Etype
(Discriminant_Type
(New_Discr
));
2402 if not Conforming_Types
2403 (Etype
(Old_Discr
), New_Discr_Type
, Fully_Conformant
)
2405 Conformance_Error
("type of & does not match!", New_Discr_Id
);
2408 -- Treat the new discriminant as an occurrence of the old
2409 -- one, for navigation purposes, and fill in some semantic
2410 -- information, for completeness.
2412 Generate_Reference
(Old_Discr
, New_Discr_Id
, 'r');
2413 Set_Etype
(New_Discr_Id
, Etype
(Old_Discr
));
2414 Set_Scope
(New_Discr_Id
, Scope
(Old_Discr
));
2419 if Chars
(Old_Discr
) /= Chars
(Defining_Identifier
(New_Discr
)) then
2420 Conformance_Error
("name & does not match!", New_Discr_Id
);
2424 -- Default expressions must match
2427 NewD
: constant Boolean :=
2428 Present
(Expression
(New_Discr
));
2429 OldD
: constant Boolean :=
2430 Present
(Expression
(Parent
(Old_Discr
)));
2433 if NewD
or OldD
then
2435 -- The old default value has been analyzed and expanded,
2436 -- because the current full declaration will have frozen
2437 -- everything before. The new default values have not
2438 -- been expanded, so expand now to check conformance.
2441 Analyze_Per_Use_Expression
2442 (Expression
(New_Discr
), New_Discr_Type
);
2445 if not (NewD
and OldD
)
2446 or else not Fully_Conformant_Expressions
2447 (Expression
(Parent
(Old_Discr
)),
2448 Expression
(New_Discr
))
2452 ("default expression for & does not match!",
2459 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
2461 if Ada_Version
= Ada_83
then
2463 Old_Disc
: constant Node_Id
:= Declaration_Node
(Old_Discr
);
2466 -- Grouping (use of comma in param lists) must be the same
2467 -- This is where we catch a misconformance like:
2470 -- A : Integer; B : Integer
2472 -- which are represented identically in the tree except
2473 -- for the setting of the flags More_Ids and Prev_Ids.
2475 if More_Ids
(Old_Disc
) /= More_Ids
(New_Discr
)
2476 or else Prev_Ids
(Old_Disc
) /= Prev_Ids
(New_Discr
)
2479 ("grouping of & does not match!", New_Discr_Id
);
2485 Next_Discriminant
(Old_Discr
);
2489 if Present
(Old_Discr
) then
2490 Conformance_Error
("too few discriminants!", Defining_Identifier
(N
));
2493 elsif Present
(New_Discr
) then
2495 ("too many discriminants!", Defining_Identifier
(New_Discr
));
2498 end Check_Discriminant_Conformance
;
2500 ----------------------------
2501 -- Check_Fully_Conformant --
2502 ----------------------------
2504 procedure Check_Fully_Conformant
2505 (New_Id
: Entity_Id
;
2507 Err_Loc
: Node_Id
:= Empty
)
2513 (New_Id
, Old_Id
, Fully_Conformant
, True, Result
, Err_Loc
);
2514 end Check_Fully_Conformant
;
2516 ---------------------------
2517 -- Check_Mode_Conformant --
2518 ---------------------------
2520 procedure Check_Mode_Conformant
2521 (New_Id
: Entity_Id
;
2523 Err_Loc
: Node_Id
:= Empty
;
2524 Get_Inst
: Boolean := False)
2530 (New_Id
, Old_Id
, Mode_Conformant
, True, Result
, Err_Loc
, Get_Inst
);
2531 end Check_Mode_Conformant
;
2533 --------------------------------
2534 -- Check_Overriding_Operation --
2535 --------------------------------
2537 procedure Check_Overriding_Operation
2543 Has_Pragma
: Boolean := False;
2546 -- See whether there is an overriding pragma immediately following
2547 -- the declaration. Intervening pragmas, such as Inline, are allowed.
2550 while Present
(Decl
)
2551 and then Nkind
(Decl
) = N_Pragma
2553 if Chars
(Decl
) = Name_Overriding
2554 or else Chars
(Decl
) = Name_Optional_Overriding
2556 -- For now disable the use of these pragmas, until the ARG
2557 -- finalizes the design of this feature.
2559 Error_Msg_N
("?unrecognized pragma", Decl
);
2561 if not Is_Overriding_Operation
(Subp
) then
2563 -- Before emitting an error message, check whether this
2564 -- may override an operation that is not yet visible, as
2565 -- in the case of a derivation of a private operation in
2566 -- a child unit. Such an operation is introduced with a
2567 -- different name, but its alias is the parent operation.
2573 E
:= First_Entity
(Current_Scope
);
2575 while Present
(E
) loop
2576 if Ekind
(E
) = Ekind
(Subp
)
2577 and then not Comes_From_Source
(E
)
2578 and then Present
(Alias
(E
))
2579 and then Chars
(Alias
(E
)) = Chars
(Subp
)
2580 and then In_Open_Scopes
(Scope
(Alias
(E
)))
2590 ("& must override an inherited operation",
2596 -- Verify syntax of pragma
2598 Arg1
:= First
(Pragma_Argument_Associations
(Decl
));
2600 if Present
(Arg1
) then
2601 if not Is_Entity_Name
(Expression
(Arg1
)) then
2602 Error_Msg_N
("pragma applies to local subprogram", Decl
);
2604 elsif Chars
(Expression
(Arg1
)) /= Chars
(Subp
) then
2606 ("pragma must apply to preceding subprogram", Decl
);
2608 elsif Present
(Next
(Arg1
)) then
2609 Error_Msg_N
("illegal pragma format", Decl
);
2613 Set_Analyzed
(Decl
);
2622 and then Explicit_Overriding
2623 and then Is_Overriding_Operation
(Subp
)
2625 Error_Msg_NE
("Missing overriding pragma for&", Subp
, Subp
);
2627 end Check_Overriding_Operation
;
2633 procedure Check_Returns
2640 procedure Check_Statement_Sequence
(L
: List_Id
);
2641 -- Internal recursive procedure to check a list of statements for proper
2642 -- termination by a return statement (or a transfer of control or a
2643 -- compound statement that is itself internally properly terminated).
2645 ------------------------------
2646 -- Check_Statement_Sequence --
2647 ------------------------------
2649 procedure Check_Statement_Sequence
(L
: List_Id
) is
2653 Raise_Exception_Call
: Boolean;
2654 -- Set True if statement sequence terminated by Raise_Exception call
2655 -- or a Reraise_Occurrence call.
2658 Raise_Exception_Call
:= False;
2660 -- Get last real statement
2662 Last_Stm
:= Last
(L
);
2664 -- Don't count pragmas
2666 while Nkind
(Last_Stm
) = N_Pragma
2668 -- Don't count call to SS_Release (can happen after Raise_Exception)
2671 (Nkind
(Last_Stm
) = N_Procedure_Call_Statement
2673 Nkind
(Name
(Last_Stm
)) = N_Identifier
2675 Is_RTE
(Entity
(Name
(Last_Stm
)), RE_SS_Release
))
2677 -- Don't count exception junk
2680 ((Nkind
(Last_Stm
) = N_Goto_Statement
2681 or else Nkind
(Last_Stm
) = N_Label
2682 or else Nkind
(Last_Stm
) = N_Object_Declaration
)
2683 and then Exception_Junk
(Last_Stm
))
2688 -- Here we have the "real" last statement
2690 Kind
:= Nkind
(Last_Stm
);
2692 -- Transfer of control, OK. Note that in the No_Return procedure
2693 -- case, we already diagnosed any explicit return statements, so
2694 -- we can treat them as OK in this context.
2696 if Is_Transfer
(Last_Stm
) then
2699 -- Check cases of explicit non-indirect procedure calls
2701 elsif Kind
= N_Procedure_Call_Statement
2702 and then Is_Entity_Name
(Name
(Last_Stm
))
2704 -- Check call to Raise_Exception procedure which is treated
2705 -- specially, as is a call to Reraise_Occurrence.
2707 -- We suppress the warning in these cases since it is likely that
2708 -- the programmer really does not expect to deal with the case
2709 -- of Null_Occurrence, and thus would find a warning about a
2710 -- missing return curious, and raising Program_Error does not
2711 -- seem such a bad behavior if this does occur.
2713 if Is_RTE
(Entity
(Name
(Last_Stm
)), RE_Raise_Exception
)
2715 Is_RTE
(Entity
(Name
(Last_Stm
)), RE_Reraise_Occurrence
)
2717 Raise_Exception_Call
:= True;
2719 -- For Raise_Exception call, test first argument, if it is
2720 -- an attribute reference for a 'Identity call, then we know
2721 -- that the call cannot possibly return.
2724 Arg
: constant Node_Id
:=
2725 Original_Node
(First_Actual
(Last_Stm
));
2728 if Nkind
(Arg
) = N_Attribute_Reference
2729 and then Attribute_Name
(Arg
) = Name_Identity
2736 -- If statement, need to look inside if there is an else and check
2737 -- each constituent statement sequence for proper termination.
2739 elsif Kind
= N_If_Statement
2740 and then Present
(Else_Statements
(Last_Stm
))
2742 Check_Statement_Sequence
(Then_Statements
(Last_Stm
));
2743 Check_Statement_Sequence
(Else_Statements
(Last_Stm
));
2745 if Present
(Elsif_Parts
(Last_Stm
)) then
2747 Elsif_Part
: Node_Id
:= First
(Elsif_Parts
(Last_Stm
));
2750 while Present
(Elsif_Part
) loop
2751 Check_Statement_Sequence
(Then_Statements
(Elsif_Part
));
2759 -- Case statement, check each case for proper termination
2761 elsif Kind
= N_Case_Statement
then
2766 Case_Alt
:= First_Non_Pragma
(Alternatives
(Last_Stm
));
2767 while Present
(Case_Alt
) loop
2768 Check_Statement_Sequence
(Statements
(Case_Alt
));
2769 Next_Non_Pragma
(Case_Alt
);
2775 -- Block statement, check its handled sequence of statements
2777 elsif Kind
= N_Block_Statement
then
2783 (Handled_Statement_Sequence
(Last_Stm
), Mode
, Err1
);
2792 -- Loop statement. If there is an iteration scheme, we can definitely
2793 -- fall out of the loop. Similarly if there is an exit statement, we
2794 -- can fall out. In either case we need a following return.
2796 elsif Kind
= N_Loop_Statement
then
2797 if Present
(Iteration_Scheme
(Last_Stm
))
2798 or else Has_Exit
(Entity
(Identifier
(Last_Stm
)))
2802 -- A loop with no exit statement or iteration scheme if either
2803 -- an inifite loop, or it has some other exit (raise/return).
2804 -- In either case, no warning is required.
2810 -- Timed entry call, check entry call and delay alternatives
2812 -- Note: in expanded code, the timed entry call has been converted
2813 -- to a set of expanded statements on which the check will work
2814 -- correctly in any case.
2816 elsif Kind
= N_Timed_Entry_Call
then
2818 ECA
: constant Node_Id
:= Entry_Call_Alternative
(Last_Stm
);
2819 DCA
: constant Node_Id
:= Delay_Alternative
(Last_Stm
);
2822 -- If statement sequence of entry call alternative is missing,
2823 -- then we can definitely fall through, and we post the error
2824 -- message on the entry call alternative itself.
2826 if No
(Statements
(ECA
)) then
2829 -- If statement sequence of delay alternative is missing, then
2830 -- we can definitely fall through, and we post the error
2831 -- message on the delay alternative itself.
2833 -- Note: if both ECA and DCA are missing the return, then we
2834 -- post only one message, should be enough to fix the bugs.
2835 -- If not we will get a message next time on the DCA when the
2838 elsif No
(Statements
(DCA
)) then
2841 -- Else check both statement sequences
2844 Check_Statement_Sequence
(Statements
(ECA
));
2845 Check_Statement_Sequence
(Statements
(DCA
));
2850 -- Conditional entry call, check entry call and else part
2852 -- Note: in expanded code, the conditional entry call has been
2853 -- converted to a set of expanded statements on which the check
2854 -- will work correctly in any case.
2856 elsif Kind
= N_Conditional_Entry_Call
then
2858 ECA
: constant Node_Id
:= Entry_Call_Alternative
(Last_Stm
);
2861 -- If statement sequence of entry call alternative is missing,
2862 -- then we can definitely fall through, and we post the error
2863 -- message on the entry call alternative itself.
2865 if No
(Statements
(ECA
)) then
2868 -- Else check statement sequence and else part
2871 Check_Statement_Sequence
(Statements
(ECA
));
2872 Check_Statement_Sequence
(Else_Statements
(Last_Stm
));
2878 -- If we fall through, issue appropriate message
2882 if not Raise_Exception_Call
then
2884 ("?RETURN statement missing following this statement!",
2887 ("\?Program_Error may be raised at run time",
2891 -- Note: we set Err even though we have not issued a warning
2892 -- because we still have a case of a missing return. This is
2893 -- an extremely marginal case, probably will never be noticed
2894 -- but we might as well get it right.
2900 ("implied return after this statement not allowed (No_Return)",
2903 end Check_Statement_Sequence
;
2905 -- Start of processing for Check_Returns
2909 Check_Statement_Sequence
(Statements
(HSS
));
2911 if Present
(Exception_Handlers
(HSS
)) then
2912 Handler
:= First_Non_Pragma
(Exception_Handlers
(HSS
));
2913 while Present
(Handler
) loop
2914 Check_Statement_Sequence
(Statements
(Handler
));
2915 Next_Non_Pragma
(Handler
);
2920 ----------------------------
2921 -- Check_Subprogram_Order --
2922 ----------------------------
2924 procedure Check_Subprogram_Order
(N
: Node_Id
) is
2926 function Subprogram_Name_Greater
(S1
, S2
: String) return Boolean;
2927 -- This is used to check if S1 > S2 in the sense required by this
2928 -- test, for example nameab < namec, but name2 < name10.
2930 function Subprogram_Name_Greater
(S1
, S2
: String) return Boolean is
2935 -- Remove trailing numeric parts
2938 while S1
(L1
) in '0' .. '9' loop
2943 while S2
(L2
) in '0' .. '9' loop
2947 -- If non-numeric parts non-equal, that's decisive
2949 if S1
(S1
'First .. L1
) < S2
(S2
'First .. L2
) then
2952 elsif S1
(S1
'First .. L1
) > S2
(S2
'First .. L2
) then
2955 -- If non-numeric parts equal, compare suffixed numeric parts. Note
2956 -- that a missing suffix is treated as numeric zero in this test.
2960 while L1
< S1
'Last loop
2962 N1
:= N1
* 10 + Character'Pos (S1
(L1
)) - Character'Pos ('0');
2966 while L2
< S2
'Last loop
2968 N2
:= N2
* 10 + Character'Pos (S2
(L2
)) - Character'Pos ('0');
2973 end Subprogram_Name_Greater
;
2975 -- Start of processing for Check_Subprogram_Order
2978 -- Check body in alpha order if this is option
2981 and then Style_Check_Order_Subprograms
2982 and then Nkind
(N
) = N_Subprogram_Body
2983 and then Comes_From_Source
(N
)
2984 and then In_Extended_Main_Source_Unit
(N
)
2988 renames Scope_Stack
.Table
2989 (Scope_Stack
.Last
).Last_Subprogram_Name
;
2991 Body_Id
: constant Entity_Id
:=
2992 Defining_Entity
(Specification
(N
));
2995 Get_Decoded_Name_String
(Chars
(Body_Id
));
2998 if Subprogram_Name_Greater
2999 (LSN
.all, Name_Buffer
(1 .. Name_Len
))
3001 Style
.Subprogram_Not_In_Alpha_Order
(Body_Id
);
3007 LSN
:= new String'(Name_Buffer (1 .. Name_Len));
3010 end Check_Subprogram_Order;
3012 ------------------------------
3013 -- Check_Subtype_Conformant --
3014 ------------------------------
3016 procedure Check_Subtype_Conformant
3017 (New_Id : Entity_Id;
3019 Err_Loc : Node_Id := Empty)
3025 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc);
3026 end Check_Subtype_Conformant;
3028 ---------------------------
3029 -- Check_Type_Conformant --
3030 ---------------------------
3032 procedure Check_Type_Conformant
3033 (New_Id : Entity_Id;
3035 Err_Loc : Node_Id := Empty)
3041 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
3042 end Check_Type_Conformant;
3044 ----------------------
3045 -- Conforming_Types --
3046 ----------------------
3048 function Conforming_Types
3051 Ctype : Conformance_Type;
3052 Get_Inst : Boolean := False) return Boolean
3054 Type_1 : Entity_Id := T1;
3055 Type_2 : Entity_Id := T2;
3056 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False;
3058 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
3059 -- If neither T1 nor T2 are generic actual types, or if they are
3060 -- in different scopes (e.g. parent and child instances), then verify
3061 -- that the base types are equal. Otherwise T1 and T2 must be
3062 -- on the same subtype chain. The whole purpose of this procedure
3063 -- is to prevent spurious ambiguities in an instantiation that may
3064 -- arise if two distinct generic types are instantiated with the
3067 ----------------------
3068 -- Base_Types_Match --
3069 ----------------------
3071 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
3076 elsif Base_Type (T1) = Base_Type (T2) then
3078 -- The following is too permissive. A more precise test must
3079 -- check that the generic actual is an ancestor subtype of the
3082 return not Is_Generic_Actual_Type (T1)
3083 or else not Is_Generic_Actual_Type (T2)
3084 or else Scope (T1) /= Scope (T2);
3086 -- In some cases a type imported through a limited_with clause,
3087 -- and its non-limited view are both visible, for example in an
3088 -- anonymous access_to_classwide type in a formal. Both entities
3089 -- designate the same type.
3091 elsif From_With_Type (T1)
3092 and then Ekind (T1) = E_Incomplete_Type
3093 and then T2 = Non_Limited_View (T1)
3100 end Base_Types_Match;
3103 -- The context is an instance association for a formal
3104 -- access-to-subprogram type; the formal parameter types
3105 -- require mapping because they may denote other formal
3106 -- parameters of the generic unit.
3109 Type_1 := Get_Instance_Of (T1);
3110 Type_2 := Get_Instance_Of (T2);
3113 -- First see if base types match
3115 if Base_Types_Match (Type_1, Type_2) then
3116 return Ctype <= Mode_Conformant
3117 or else Subtypes_Statically_Match (Type_1, Type_2);
3119 elsif Is_Incomplete_Or_Private_Type (Type_1)
3120 and then Present (Full_View (Type_1))
3121 and then Base_Types_Match (Full_View (Type_1), Type_2)
3123 return Ctype <= Mode_Conformant
3124 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
3126 elsif Ekind (Type_2) = E_Incomplete_Type
3127 and then Present (Full_View (Type_2))
3128 and then Base_Types_Match (Type_1, Full_View (Type_2))
3130 return Ctype <= Mode_Conformant
3131 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3133 elsif Is_Private_Type (Type_2)
3134 and then In_Instance
3135 and then Present (Full_View (Type_2))
3136 and then Base_Types_Match (Type_1, Full_View (Type_2))
3138 return Ctype <= Mode_Conformant
3139 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3142 -- Ada 2005 (AI-254): Detect anonymous access to subprogram types
3144 Are_Anonymous_Access_To_Subprogram_Types :=
3146 -- Case 1: Anonymous access to subprogram types
3148 (Ekind (Type_1) = E_Anonymous_Access_Subprogram_Type
3149 and then Ekind (Type_2) = E_Anonymous_Access_Subprogram_Type)
3151 -- Case 2: Anonymous access to PROTECTED subprogram types. In this
3152 -- case the anonymous type_declaration has been replaced by an
3153 -- occurrence of an internal access to subprogram type declaration
3154 -- available through the Original_Access_Type attribute
3157 (Ekind (Type_1) = E_Access_Protected_Subprogram_Type
3158 and then Ekind (Type_2) = E_Access_Protected_Subprogram_Type
3159 and then not Comes_From_Source (Type_1)
3160 and then not Comes_From_Source (Type_2)
3161 and then Present (Original_Access_Type (Type_1))
3162 and then Present (Original_Access_Type (Type_2))
3163 and then Ekind (Original_Access_Type (Type_1)) =
3164 E_Anonymous_Access_Protected_Subprogram_Type
3165 and then Ekind (Original_Access_Type (Type_2)) =
3166 E_Anonymous_Access_Protected_Subprogram_Type);
3168 -- Test anonymous access type case. For this case, static subtype
3169 -- matching is required for mode conformance (RM 6.3.1(15))
3171 if (Ekind (Type_1) = E_Anonymous_Access_Type
3172 and then Ekind (Type_2) = E_Anonymous_Access_Type)
3173 or else Are_Anonymous_Access_To_Subprogram_Types -- Ada 2005 (AI-254)
3176 Desig_1 : Entity_Id;
3177 Desig_2 : Entity_Id;
3180 Desig_1 := Directly_Designated_Type (Type_1);
3182 -- An access parameter can designate an incomplete type
3184 if Ekind (Desig_1) = E_Incomplete_Type
3185 and then Present (Full_View (Desig_1))
3187 Desig_1 := Full_View (Desig_1);
3190 Desig_2 := Directly_Designated_Type (Type_2);
3192 if Ekind (Desig_2) = E_Incomplete_Type
3193 and then Present (Full_View (Desig_2))
3195 Desig_2 := Full_View (Desig_2);
3198 -- The context is an instance association for a formal
3199 -- access-to-subprogram type; formal access parameter
3200 -- designated types require mapping because they may
3201 -- denote other formal parameters of the generic unit.
3204 Desig_1 := Get_Instance_Of (Desig_1);
3205 Desig_2 := Get_Instance_Of (Desig_2);
3208 -- It is possible for a Class_Wide_Type to be introduced for
3209 -- an incomplete type, in which case there is a separate class_
3210 -- wide type for the full view. The types conform if their
3211 -- Etypes conform, i.e. one may be the full view of the other.
3212 -- This can only happen in the context of an access parameter,
3213 -- other uses of an incomplete Class_Wide_Type are illegal.
3215 if Is_Class_Wide_Type (Desig_1)
3216 and then Is_Class_Wide_Type (Desig_2)
3220 (Etype (Base_Type (Desig_1)),
3221 Etype (Base_Type (Desig_2)), Ctype);
3223 elsif Are_Anonymous_Access_To_Subprogram_Types then
3224 return Ctype = Type_Conformant
3226 Subtypes_Statically_Match (Desig_1, Desig_2);
3229 return Base_Type (Desig_1) = Base_Type (Desig_2)
3230 and then (Ctype = Type_Conformant
3232 Subtypes_Statically_Match (Desig_1, Desig_2));
3236 -- Otherwise definitely no match
3242 end Conforming_Types;
3244 --------------------------
3245 -- Create_Extra_Formals --
3246 --------------------------
3248 procedure Create_Extra_Formals (E : Entity_Id) is
3250 Last_Extra : Entity_Id;
3251 Formal_Type : Entity_Id;
3252 P_Formal : Entity_Id := Empty;
3254 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id;
3255 -- Add an extra formal, associated with the current Formal. The
3256 -- extra formal is added to the list of extra formals, and also
3257 -- returned as the result. These formals are always of mode IN.
3259 ----------------------
3260 -- Add_Extra_Formal --
3261 ----------------------
3263 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is
3264 EF : constant Entity_Id :=
3265 Make_Defining_Identifier (Sloc (Formal),
3266 Chars => New_External_Name (Chars (Formal), 'F
'));
3269 -- We never generate extra formals if expansion is not active
3270 -- because we don't need them unless we are generating code.
3272 if not Expander_Active then
3276 -- A little optimization. Never generate an extra formal for
3277 -- the _init operand of an initialization procedure, since it
3278 -- could never be used.
3280 if Chars (Formal) = Name_uInit then
3284 Set_Ekind (EF, E_In_Parameter);
3285 Set_Actual_Subtype (EF, Typ);
3286 Set_Etype (EF, Typ);
3287 Set_Scope (EF, Scope (Formal));
3288 Set_Mechanism (EF, Default_Mechanism);
3289 Set_Formal_Validity (EF);
3291 Set_Extra_Formal (Last_Extra, EF);
3294 end Add_Extra_Formal;
3296 -- Start of processing for Create_Extra_Formals
3299 -- If this is a derived subprogram then the subtypes of the
3300 -- parent subprogram's formal parameters will be used to
3301 -- to determine the need for extra formals.
3303 if Is_Overloadable (E) and then Present (Alias (E)) then
3304 P_Formal := First_Formal (Alias (E));
3307 Last_Extra := Empty;
3308 Formal := First_Formal (E);
3309 while Present (Formal) loop
3310 Last_Extra := Formal;
3311 Next_Formal (Formal);
3314 -- If Extra_formals where already created, don't do it again
3315 -- This situation may arise for subprogram types created as part
3316 -- of dispatching calls (see Expand_Dispatch_Call)
3318 if Present (Last_Extra) and then
3319 Present (Extra_Formal (Last_Extra))
3324 Formal := First_Formal (E);
3326 while Present (Formal) loop
3328 -- Create extra formal for supporting the attribute 'Constrained
.
3329 -- The case of a private type view without discriminants also
3330 -- requires the extra formal if the underlying type has defaulted
3333 if Ekind
(Formal
) /= E_In_Parameter
then
3334 if Present
(P_Formal
) then
3335 Formal_Type
:= Etype
(P_Formal
);
3337 Formal_Type
:= Etype
(Formal
);
3340 -- Do not produce extra formals for Unchecked_Union parameters.
3341 -- Jump directly to the end of the loop.
3343 if Is_Unchecked_Union
(Base_Type
(Formal_Type
)) then
3344 goto Skip_Extra_Formal_Generation
;
3347 if not Has_Discriminants
(Formal_Type
)
3348 and then Ekind
(Formal_Type
) in Private_Kind
3349 and then Present
(Underlying_Type
(Formal_Type
))
3351 Formal_Type
:= Underlying_Type
(Formal_Type
);
3354 if Has_Discriminants
(Formal_Type
)
3356 ((not Is_Constrained
(Formal_Type
)
3357 and then not Is_Indefinite_Subtype
(Formal_Type
))
3358 or else Present
(Extra_Formal
(Formal
)))
3360 Set_Extra_Constrained
3361 (Formal
, Add_Extra_Formal
(Standard_Boolean
));
3365 -- Create extra formal for supporting accessibility checking
3367 -- This is suppressed if we specifically suppress accessibility
3368 -- checks at the pacage level for either the subprogram, or the
3369 -- package in which it resides. However, we do not suppress it
3370 -- simply if the scope has accessibility checks suppressed, since
3371 -- this could cause trouble when clients are compiled with a
3372 -- different suppression setting. The explicit checks at the
3373 -- package level are safe from this point of view.
3375 if Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
3377 (Explicit_Suppress
(E
, Accessibility_Check
)
3379 Explicit_Suppress
(Scope
(E
), Accessibility_Check
))
3381 (not Present
(P_Formal
)
3382 or else Present
(Extra_Accessibility
(P_Formal
)))
3384 -- Temporary kludge: for now we avoid creating the extra
3385 -- formal for access parameters of protected operations
3386 -- because of problem with the case of internal protected
3389 if Nkind
(Parent
(Parent
(Parent
(E
)))) /= N_Protected_Definition
3390 and then Nkind
(Parent
(Parent
(Parent
(E
)))) /= N_Protected_Body
3392 Set_Extra_Accessibility
3393 (Formal
, Add_Extra_Formal
(Standard_Natural
));
3397 if Present
(P_Formal
) then
3398 Next_Formal
(P_Formal
);
3401 -- This label is required when skipping extra formal generation for
3402 -- Unchecked_Union parameters.
3404 <<Skip_Extra_Formal_Generation
>>
3406 Next_Formal
(Formal
);
3408 end Create_Extra_Formals
;
3410 -----------------------------
3411 -- Enter_Overloaded_Entity --
3412 -----------------------------
3414 procedure Enter_Overloaded_Entity
(S
: Entity_Id
) is
3415 E
: Entity_Id
:= Current_Entity_In_Scope
(S
);
3416 C_E
: Entity_Id
:= Current_Entity
(S
);
3420 Set_Has_Homonym
(E
);
3421 Set_Has_Homonym
(S
);
3424 Set_Is_Immediately_Visible
(S
);
3425 Set_Scope
(S
, Current_Scope
);
3427 -- Chain new entity if front of homonym in current scope, so that
3428 -- homonyms are contiguous.
3433 while Homonym
(C_E
) /= E
loop
3434 C_E
:= Homonym
(C_E
);
3437 Set_Homonym
(C_E
, S
);
3441 Set_Current_Entity
(S
);
3446 Append_Entity
(S
, Current_Scope
);
3447 Set_Public_Status
(S
);
3449 if Debug_Flag_E
then
3450 Write_Str
("New overloaded entity chain: ");
3451 Write_Name
(Chars
(S
));
3454 while Present
(E
) loop
3455 Write_Str
(" "); Write_Int
(Int
(E
));
3462 -- Generate warning for hiding
3465 and then Comes_From_Source
(S
)
3466 and then In_Extended_Main_Source_Unit
(S
)
3473 -- Warn unless genuine overloading
3475 if (not Is_Overloadable
(E
))
3476 or else Subtype_Conformant
(E
, S
)
3478 Error_Msg_Sloc
:= Sloc
(E
);
3479 Error_Msg_N
("declaration of & hides one#?", S
);
3483 end Enter_Overloaded_Entity
;
3485 -----------------------------
3486 -- Find_Corresponding_Spec --
3487 -----------------------------
3489 function Find_Corresponding_Spec
(N
: Node_Id
) return Entity_Id
is
3490 Spec
: constant Node_Id
:= Specification
(N
);
3491 Designator
: constant Entity_Id
:= Defining_Entity
(Spec
);
3496 E
:= Current_Entity
(Designator
);
3498 while Present
(E
) loop
3500 -- We are looking for a matching spec. It must have the same scope,
3501 -- and the same name, and either be type conformant, or be the case
3502 -- of a library procedure spec and its body (which belong to one
3503 -- another regardless of whether they are type conformant or not).
3505 if Scope
(E
) = Current_Scope
then
3506 if Current_Scope
= Standard_Standard
3507 or else (Ekind
(E
) = Ekind
(Designator
)
3508 and then Type_Conformant
(E
, Designator
))
3510 -- Within an instantiation, we know that spec and body are
3511 -- subtype conformant, because they were subtype conformant
3512 -- in the generic. We choose the subtype-conformant entity
3513 -- here as well, to resolve spurious ambiguities in the
3514 -- instance that were not present in the generic (i.e. when
3515 -- two different types are given the same actual). If we are
3516 -- looking for a spec to match a body, full conformance is
3520 Set_Convention
(Designator
, Convention
(E
));
3522 if Nkind
(N
) = N_Subprogram_Body
3523 and then Present
(Homonym
(E
))
3524 and then not Fully_Conformant
(E
, Designator
)
3528 elsif not Subtype_Conformant
(E
, Designator
) then
3533 if not Has_Completion
(E
) then
3535 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
3536 Set_Corresponding_Spec
(N
, E
);
3539 Set_Has_Completion
(E
);
3542 elsif Nkind
(Parent
(N
)) = N_Subunit
then
3544 -- If this is the proper body of a subunit, the completion
3545 -- flag is set when analyzing the stub.
3549 -- If body already exists, this is an error unless the
3550 -- previous declaration is the implicit declaration of
3551 -- a derived subprogram, or this is a spurious overloading
3554 elsif No
(Alias
(E
))
3555 and then not Is_Intrinsic_Subprogram
(E
)
3556 and then not In_Instance
3558 Error_Msg_Sloc
:= Sloc
(E
);
3559 if Is_Imported
(E
) then
3561 ("body not allowed for imported subprogram & declared#",
3564 Error_Msg_NE
("duplicate body for & declared#", N
, E
);
3568 elsif Is_Child_Unit
(E
)
3570 Nkind
(Unit_Declaration_Node
(Designator
)) = N_Subprogram_Body
3572 Nkind
(Parent
(Unit_Declaration_Node
(Designator
)))
3573 = N_Compilation_Unit
3576 -- Child units cannot be overloaded, so a conformance mismatch
3577 -- between body and a previous spec is an error.
3580 ("body of child unit does not match previous declaration", N
);
3588 -- On exit, we know that no previous declaration of subprogram exists
3591 end Find_Corresponding_Spec
;
3593 ----------------------
3594 -- Fully_Conformant --
3595 ----------------------
3597 function Fully_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
3601 Check_Conformance
(New_Id
, Old_Id
, Fully_Conformant
, False, Result
);
3603 end Fully_Conformant
;
3605 ----------------------------------
3606 -- Fully_Conformant_Expressions --
3607 ----------------------------------
3609 function Fully_Conformant_Expressions
3610 (Given_E1
: Node_Id
;
3611 Given_E2
: Node_Id
) return Boolean
3613 E1
: constant Node_Id
:= Original_Node
(Given_E1
);
3614 E2
: constant Node_Id
:= Original_Node
(Given_E2
);
3615 -- We always test conformance on original nodes, since it is possible
3616 -- for analysis and/or expansion to make things look as though they
3617 -- conform when they do not, e.g. by converting 1+2 into 3.
3619 function FCE
(Given_E1
, Given_E2
: Node_Id
) return Boolean
3620 renames Fully_Conformant_Expressions
;
3622 function FCL
(L1
, L2
: List_Id
) return Boolean;
3623 -- Compare elements of two lists for conformance. Elements have to
3624 -- be conformant, and actuals inserted as default parameters do not
3625 -- match explicit actuals with the same value.
3627 function FCO
(Op_Node
, Call_Node
: Node_Id
) return Boolean;
3628 -- Compare an operator node with a function call
3634 function FCL
(L1
, L2
: List_Id
) return Boolean is
3638 if L1
= No_List
then
3644 if L2
= No_List
then
3650 -- Compare two lists, skipping rewrite insertions (we want to
3651 -- compare the original trees, not the expanded versions!)
3654 if Is_Rewrite_Insertion
(N1
) then
3656 elsif Is_Rewrite_Insertion
(N2
) then
3662 elsif not FCE
(N1
, N2
) then
3675 function FCO
(Op_Node
, Call_Node
: Node_Id
) return Boolean is
3676 Actuals
: constant List_Id
:= Parameter_Associations
(Call_Node
);
3681 or else Entity
(Op_Node
) /= Entity
(Name
(Call_Node
))
3686 Act
:= First
(Actuals
);
3688 if Nkind
(Op_Node
) in N_Binary_Op
then
3690 if not FCE
(Left_Opnd
(Op_Node
), Act
) then
3697 return Present
(Act
)
3698 and then FCE
(Right_Opnd
(Op_Node
), Act
)
3699 and then No
(Next
(Act
));
3703 -- Start of processing for Fully_Conformant_Expressions
3706 -- Non-conformant if paren count does not match. Note: if some idiot
3707 -- complains that we don't do this right for more than 3 levels of
3708 -- parentheses, they will be treated with the respect they deserve :-)
3710 if Paren_Count
(E1
) /= Paren_Count
(E2
) then
3713 -- If same entities are referenced, then they are conformant
3714 -- even if they have different forms (RM 8.3.1(19-20)).
3716 elsif Is_Entity_Name
(E1
) and then Is_Entity_Name
(E2
) then
3717 if Present
(Entity
(E1
)) then
3718 return Entity
(E1
) = Entity
(E2
)
3719 or else (Chars
(Entity
(E1
)) = Chars
(Entity
(E2
))
3720 and then Ekind
(Entity
(E1
)) = E_Discriminant
3721 and then Ekind
(Entity
(E2
)) = E_In_Parameter
);
3723 elsif Nkind
(E1
) = N_Expanded_Name
3724 and then Nkind
(E2
) = N_Expanded_Name
3725 and then Nkind
(Selector_Name
(E1
)) = N_Character_Literal
3726 and then Nkind
(Selector_Name
(E2
)) = N_Character_Literal
3728 return Chars
(Selector_Name
(E1
)) = Chars
(Selector_Name
(E2
));
3731 -- Identifiers in component associations don't always have
3732 -- entities, but their names must conform.
3734 return Nkind
(E1
) = N_Identifier
3735 and then Nkind
(E2
) = N_Identifier
3736 and then Chars
(E1
) = Chars
(E2
);
3739 elsif Nkind
(E1
) = N_Character_Literal
3740 and then Nkind
(E2
) = N_Expanded_Name
3742 return Nkind
(Selector_Name
(E2
)) = N_Character_Literal
3743 and then Chars
(E1
) = Chars
(Selector_Name
(E2
));
3745 elsif Nkind
(E2
) = N_Character_Literal
3746 and then Nkind
(E1
) = N_Expanded_Name
3748 return Nkind
(Selector_Name
(E1
)) = N_Character_Literal
3749 and then Chars
(E2
) = Chars
(Selector_Name
(E1
));
3751 elsif Nkind
(E1
) in N_Op
3752 and then Nkind
(E2
) = N_Function_Call
3754 return FCO
(E1
, E2
);
3756 elsif Nkind
(E2
) in N_Op
3757 and then Nkind
(E1
) = N_Function_Call
3759 return FCO
(E2
, E1
);
3761 -- Otherwise we must have the same syntactic entity
3763 elsif Nkind
(E1
) /= Nkind
(E2
) then
3766 -- At this point, we specialize by node type
3773 FCL
(Expressions
(E1
), Expressions
(E2
))
3774 and then FCL
(Component_Associations
(E1
),
3775 Component_Associations
(E2
));
3778 if Nkind
(Expression
(E1
)) = N_Qualified_Expression
3780 Nkind
(Expression
(E2
)) = N_Qualified_Expression
3782 return FCE
(Expression
(E1
), Expression
(E2
));
3784 -- Check that the subtype marks and any constraints
3789 Indic1
: constant Node_Id
:= Expression
(E1
);
3790 Indic2
: constant Node_Id
:= Expression
(E2
);
3795 if Nkind
(Indic1
) /= N_Subtype_Indication
then
3797 Nkind
(Indic2
) /= N_Subtype_Indication
3798 and then Entity
(Indic1
) = Entity
(Indic2
);
3800 elsif Nkind
(Indic2
) /= N_Subtype_Indication
then
3802 Nkind
(Indic1
) /= N_Subtype_Indication
3803 and then Entity
(Indic1
) = Entity
(Indic2
);
3806 if Entity
(Subtype_Mark
(Indic1
)) /=
3807 Entity
(Subtype_Mark
(Indic2
))
3812 Elt1
:= First
(Constraints
(Constraint
(Indic1
)));
3813 Elt2
:= First
(Constraints
(Constraint
(Indic2
)));
3815 while Present
(Elt1
) and then Present
(Elt2
) loop
3816 if not FCE
(Elt1
, Elt2
) then
3829 when N_Attribute_Reference
=>
3831 Attribute_Name
(E1
) = Attribute_Name
(E2
)
3832 and then FCL
(Expressions
(E1
), Expressions
(E2
));
3836 Entity
(E1
) = Entity
(E2
)
3837 and then FCE
(Left_Opnd
(E1
), Left_Opnd
(E2
))
3838 and then FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
3840 when N_And_Then | N_Or_Else | N_In | N_Not_In
=>
3842 FCE
(Left_Opnd
(E1
), Left_Opnd
(E2
))
3844 FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
3846 when N_Character_Literal
=>
3848 Char_Literal_Value
(E1
) = Char_Literal_Value
(E2
);
3850 when N_Component_Association
=>
3852 FCL
(Choices
(E1
), Choices
(E2
))
3853 and then FCE
(Expression
(E1
), Expression
(E2
));
3855 when N_Conditional_Expression
=>
3857 FCL
(Expressions
(E1
), Expressions
(E2
));
3859 when N_Explicit_Dereference
=>
3861 FCE
(Prefix
(E1
), Prefix
(E2
));
3863 when N_Extension_Aggregate
=>
3865 FCL
(Expressions
(E1
), Expressions
(E2
))
3866 and then Null_Record_Present
(E1
) =
3867 Null_Record_Present
(E2
)
3868 and then FCL
(Component_Associations
(E1
),
3869 Component_Associations
(E2
));
3871 when N_Function_Call
=>
3873 FCE
(Name
(E1
), Name
(E2
))
3874 and then FCL
(Parameter_Associations
(E1
),
3875 Parameter_Associations
(E2
));
3877 when N_Indexed_Component
=>
3879 FCE
(Prefix
(E1
), Prefix
(E2
))
3880 and then FCL
(Expressions
(E1
), Expressions
(E2
));
3882 when N_Integer_Literal
=>
3883 return (Intval
(E1
) = Intval
(E2
));
3888 when N_Operator_Symbol
=>
3890 Chars
(E1
) = Chars
(E2
);
3892 when N_Others_Choice
=>
3895 when N_Parameter_Association
=>
3897 Chars
(Selector_Name
(E1
)) = Chars
(Selector_Name
(E2
))
3898 and then FCE
(Explicit_Actual_Parameter
(E1
),
3899 Explicit_Actual_Parameter
(E2
));
3901 when N_Qualified_Expression
=>
3903 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
3904 and then FCE
(Expression
(E1
), Expression
(E2
));
3908 FCE
(Low_Bound
(E1
), Low_Bound
(E2
))
3909 and then FCE
(High_Bound
(E1
), High_Bound
(E2
));
3911 when N_Real_Literal
=>
3912 return (Realval
(E1
) = Realval
(E2
));
3914 when N_Selected_Component
=>
3916 FCE
(Prefix
(E1
), Prefix
(E2
))
3917 and then FCE
(Selector_Name
(E1
), Selector_Name
(E2
));
3921 FCE
(Prefix
(E1
), Prefix
(E2
))
3922 and then FCE
(Discrete_Range
(E1
), Discrete_Range
(E2
));
3924 when N_String_Literal
=>
3926 S1
: constant String_Id
:= Strval
(E1
);
3927 S2
: constant String_Id
:= Strval
(E2
);
3928 L1
: constant Nat
:= String_Length
(S1
);
3929 L2
: constant Nat
:= String_Length
(S2
);
3936 for J
in 1 .. L1
loop
3937 if Get_String_Char
(S1
, J
) /=
3938 Get_String_Char
(S2
, J
)
3948 when N_Type_Conversion
=>
3950 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
3951 and then FCE
(Expression
(E1
), Expression
(E2
));
3955 Entity
(E1
) = Entity
(E2
)
3956 and then FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
3958 when N_Unchecked_Type_Conversion
=>
3960 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
3961 and then FCE
(Expression
(E1
), Expression
(E2
));
3963 -- All other node types cannot appear in this context. Strictly
3964 -- we should raise a fatal internal error. Instead we just ignore
3965 -- the nodes. This means that if anyone makes a mistake in the
3966 -- expander and mucks an expression tree irretrievably, the
3967 -- result will be a failure to detect a (probably very obscure)
3968 -- case of non-conformance, which is better than bombing on some
3969 -- case where two expressions do in fact conform.
3976 end Fully_Conformant_Expressions
;
3978 ----------------------------------------
3979 -- Fully_Conformant_Discrete_Subtypes --
3980 ----------------------------------------
3982 function Fully_Conformant_Discrete_Subtypes
3983 (Given_S1
: Node_Id
;
3984 Given_S2
: Node_Id
) return Boolean
3986 S1
: constant Node_Id
:= Original_Node
(Given_S1
);
3987 S2
: constant Node_Id
:= Original_Node
(Given_S2
);
3989 function Conforming_Bounds
(B1
, B2
: Node_Id
) return Boolean;
3990 -- Special-case for a bound given by a discriminant, which in the
3991 -- body is replaced with the discriminal of the enclosing type.
3993 function Conforming_Ranges
(R1
, R2
: Node_Id
) return Boolean;
3994 -- Check both bounds
3996 function Conforming_Bounds
(B1
, B2
: Node_Id
) return Boolean is
3998 if Is_Entity_Name
(B1
)
3999 and then Is_Entity_Name
(B2
)
4000 and then Ekind
(Entity
(B1
)) = E_Discriminant
4002 return Chars
(B1
) = Chars
(B2
);
4005 return Fully_Conformant_Expressions
(B1
, B2
);
4007 end Conforming_Bounds
;
4009 function Conforming_Ranges
(R1
, R2
: Node_Id
) return Boolean is
4012 Conforming_Bounds
(Low_Bound
(R1
), Low_Bound
(R2
))
4014 Conforming_Bounds
(High_Bound
(R1
), High_Bound
(R2
));
4015 end Conforming_Ranges
;
4017 -- Start of processing for Fully_Conformant_Discrete_Subtypes
4020 if Nkind
(S1
) /= Nkind
(S2
) then
4023 elsif Is_Entity_Name
(S1
) then
4024 return Entity
(S1
) = Entity
(S2
);
4026 elsif Nkind
(S1
) = N_Range
then
4027 return Conforming_Ranges
(S1
, S2
);
4029 elsif Nkind
(S1
) = N_Subtype_Indication
then
4031 Entity
(Subtype_Mark
(S1
)) = Entity
(Subtype_Mark
(S2
))
4034 (Range_Expression
(Constraint
(S1
)),
4035 Range_Expression
(Constraint
(S2
)));
4039 end Fully_Conformant_Discrete_Subtypes
;
4041 --------------------
4042 -- Install_Entity --
4043 --------------------
4045 procedure Install_Entity
(E
: Entity_Id
) is
4046 Prev
: constant Entity_Id
:= Current_Entity
(E
);
4049 Set_Is_Immediately_Visible
(E
);
4050 Set_Current_Entity
(E
);
4051 Set_Homonym
(E
, Prev
);
4054 ---------------------
4055 -- Install_Formals --
4056 ---------------------
4058 procedure Install_Formals
(Id
: Entity_Id
) is
4062 F
:= First_Formal
(Id
);
4064 while Present
(F
) loop
4068 end Install_Formals
;
4070 ---------------------------------
4071 -- Is_Non_Overriding_Operation --
4072 ---------------------------------
4074 function Is_Non_Overriding_Operation
4075 (Prev_E
: Entity_Id
;
4076 New_E
: Entity_Id
) return Boolean
4080 G_Typ
: Entity_Id
:= Empty
;
4082 function Get_Generic_Parent_Type
(F_Typ
: Entity_Id
) return Entity_Id
;
4083 -- If F_Type is a derived type associated with a generic actual
4084 -- subtype, then return its Generic_Parent_Type attribute, else
4087 function Types_Correspond
4088 (P_Type
: Entity_Id
;
4089 N_Type
: Entity_Id
) return Boolean;
4090 -- Returns true if and only if the types (or designated types
4091 -- in the case of anonymous access types) are the same or N_Type
4092 -- is derived directly or indirectly from P_Type.
4094 -----------------------------
4095 -- Get_Generic_Parent_Type --
4096 -----------------------------
4098 function Get_Generic_Parent_Type
(F_Typ
: Entity_Id
) return Entity_Id
is
4103 if Is_Derived_Type
(F_Typ
)
4104 and then Nkind
(Parent
(F_Typ
)) = N_Full_Type_Declaration
4106 -- The tree must be traversed to determine the parent
4107 -- subtype in the generic unit, which unfortunately isn't
4108 -- always available via semantic attributes. ???
4109 -- (Note: The use of Original_Node is needed for cases
4110 -- where a full derived type has been rewritten.)
4112 Indic
:= Subtype_Indication
4113 (Type_Definition
(Original_Node
(Parent
(F_Typ
))));
4115 if Nkind
(Indic
) = N_Subtype_Indication
then
4116 G_Typ
:= Entity
(Subtype_Mark
(Indic
));
4118 G_Typ
:= Entity
(Indic
);
4121 if Nkind
(Parent
(G_Typ
)) = N_Subtype_Declaration
4122 and then Present
(Generic_Parent_Type
(Parent
(G_Typ
)))
4124 return Generic_Parent_Type
(Parent
(G_Typ
));
4129 end Get_Generic_Parent_Type
;
4131 ----------------------
4132 -- Types_Correspond --
4133 ----------------------
4135 function Types_Correspond
4136 (P_Type
: Entity_Id
;
4137 N_Type
: Entity_Id
) return Boolean
4139 Prev_Type
: Entity_Id
:= Base_Type
(P_Type
);
4140 New_Type
: Entity_Id
:= Base_Type
(N_Type
);
4143 if Ekind
(Prev_Type
) = E_Anonymous_Access_Type
then
4144 Prev_Type
:= Designated_Type
(Prev_Type
);
4147 if Ekind
(New_Type
) = E_Anonymous_Access_Type
then
4148 New_Type
:= Designated_Type
(New_Type
);
4151 if Prev_Type
= New_Type
then
4154 elsif not Is_Class_Wide_Type
(New_Type
) then
4155 while Etype
(New_Type
) /= New_Type
loop
4156 New_Type
:= Etype
(New_Type
);
4157 if New_Type
= Prev_Type
then
4163 end Types_Correspond
;
4165 -- Start of processing for Is_Non_Overriding_Operation
4168 -- In the case where both operations are implicit derived
4169 -- subprograms then neither overrides the other. This can
4170 -- only occur in certain obscure cases (e.g., derivation
4171 -- from homographs created in a generic instantiation).
4173 if Present
(Alias
(Prev_E
)) and then Present
(Alias
(New_E
)) then
4176 elsif Ekind
(Current_Scope
) = E_Package
4177 and then Is_Generic_Instance
(Current_Scope
)
4178 and then In_Private_Part
(Current_Scope
)
4179 and then Comes_From_Source
(New_E
)
4181 -- We examine the formals and result subtype of the inherited
4182 -- operation, to determine whether their type is derived from
4183 -- (the instance of) a generic type.
4185 Formal
:= First_Formal
(Prev_E
);
4187 while Present
(Formal
) loop
4188 F_Typ
:= Base_Type
(Etype
(Formal
));
4190 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
4191 F_Typ
:= Designated_Type
(F_Typ
);
4194 G_Typ
:= Get_Generic_Parent_Type
(F_Typ
);
4196 Next_Formal
(Formal
);
4199 if not Present
(G_Typ
) and then Ekind
(Prev_E
) = E_Function
then
4200 G_Typ
:= Get_Generic_Parent_Type
(Base_Type
(Etype
(Prev_E
)));
4207 -- If the generic type is a private type, then the original
4208 -- operation was not overriding in the generic, because there was
4209 -- no primitive operation to override.
4211 if Nkind
(Parent
(G_Typ
)) = N_Formal_Type_Declaration
4212 and then Nkind
(Formal_Type_Definition
(Parent
(G_Typ
))) =
4213 N_Formal_Private_Type_Definition
4217 -- The generic parent type is the ancestor of a formal derived
4218 -- type declaration. We need to check whether it has a primitive
4219 -- operation that should be overridden by New_E in the generic.
4223 P_Formal
: Entity_Id
;
4224 N_Formal
: Entity_Id
;
4228 Prim_Elt
: Elmt_Id
:= First_Elmt
(Primitive_Operations
(G_Typ
));
4231 while Present
(Prim_Elt
) loop
4232 P_Prim
:= Node
(Prim_Elt
);
4234 if Chars
(P_Prim
) = Chars
(New_E
)
4235 and then Ekind
(P_Prim
) = Ekind
(New_E
)
4237 P_Formal
:= First_Formal
(P_Prim
);
4238 N_Formal
:= First_Formal
(New_E
);
4239 while Present
(P_Formal
) and then Present
(N_Formal
) loop
4240 P_Typ
:= Etype
(P_Formal
);
4241 N_Typ
:= Etype
(N_Formal
);
4243 if not Types_Correspond
(P_Typ
, N_Typ
) then
4247 Next_Entity
(P_Formal
);
4248 Next_Entity
(N_Formal
);
4251 -- Found a matching primitive operation belonging to
4252 -- the formal ancestor type, so the new subprogram
4255 if not Present
(P_Formal
)
4256 and then not Present
(N_Formal
)
4257 and then (Ekind
(New_E
) /= E_Function
4260 (Etype
(P_Prim
), Etype
(New_E
)))
4266 Next_Elmt
(Prim_Elt
);
4269 -- If no match found, then the new subprogram does
4270 -- not override in the generic (nor in the instance).
4278 end Is_Non_Overriding_Operation
;
4280 ------------------------------
4281 -- Make_Inequality_Operator --
4282 ------------------------------
4284 -- S is the defining identifier of an equality operator. We build a
4285 -- subprogram declaration with the right signature. This operation is
4286 -- intrinsic, because it is always expanded as the negation of the
4287 -- call to the equality function.
4289 procedure Make_Inequality_Operator
(S
: Entity_Id
) is
4290 Loc
: constant Source_Ptr
:= Sloc
(S
);
4293 Op_Name
: Entity_Id
;
4299 -- Check that equality was properly defined
4301 if No
(Next_Formal
(First_Formal
(S
))) then
4305 A
:= Make_Defining_Identifier
(Loc
, Chars
(First_Formal
(S
)));
4306 B
:= Make_Defining_Identifier
(Loc
,
4307 Chars
(Next_Formal
(First_Formal
(S
))));
4309 Op_Name
:= Make_Defining_Operator_Symbol
(Loc
, Name_Op_Ne
);
4311 Formals
:= New_List
(
4312 Make_Parameter_Specification
(Loc
,
4313 Defining_Identifier
=> A
,
4315 New_Reference_To
(Etype
(First_Formal
(S
)), Loc
)),
4317 Make_Parameter_Specification
(Loc
,
4318 Defining_Identifier
=> B
,
4320 New_Reference_To
(Etype
(Next_Formal
(First_Formal
(S
))), Loc
)));
4323 Make_Subprogram_Declaration
(Loc
,
4325 Make_Function_Specification
(Loc
,
4326 Defining_Unit_Name
=> Op_Name
,
4327 Parameter_Specifications
=> Formals
,
4328 Subtype_Mark
=> New_Reference_To
(Standard_Boolean
, Loc
)));
4330 -- Insert inequality right after equality if it is explicit or after
4331 -- the derived type when implicit. These entities are created only
4332 -- for visibility purposes, and eventually replaced in the course of
4333 -- expansion, so they do not need to be attached to the tree and seen
4334 -- by the back-end. Keeping them internal also avoids spurious freezing
4335 -- problems. The parent field is set simply to make analysis safe.
4337 if No
(Alias
(S
)) then
4338 Set_Parent
(Decl
, Parent
(Unit_Declaration_Node
(S
)));
4340 Set_Parent
(Decl
, Parent
(Parent
(Etype
(First_Formal
(S
)))));
4343 Mark_Rewrite_Insertion
(Decl
);
4344 Set_Is_Intrinsic_Subprogram
(Op_Name
);
4346 Set_Has_Completion
(Op_Name
);
4347 Set_Corresponding_Equality
(Op_Name
, S
);
4348 Set_Is_Abstract
(Op_Name
, Is_Abstract
(S
));
4350 end Make_Inequality_Operator
;
4352 ----------------------
4353 -- May_Need_Actuals --
4354 ----------------------
4356 procedure May_Need_Actuals
(Fun
: Entity_Id
) is
4361 F
:= First_Formal
(Fun
);
4364 while Present
(F
) loop
4365 if No
(Default_Value
(F
)) then
4373 Set_Needs_No_Actuals
(Fun
, B
);
4374 end May_Need_Actuals
;
4376 ---------------------
4377 -- Mode_Conformant --
4378 ---------------------
4380 function Mode_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
4384 Check_Conformance
(New_Id
, Old_Id
, Mode_Conformant
, False, Result
);
4386 end Mode_Conformant
;
4388 ---------------------------
4389 -- New_Overloaded_Entity --
4390 ---------------------------
4392 procedure New_Overloaded_Entity
4394 Derived_Type
: Entity_Id
:= Empty
)
4397 -- Entity that S overrides
4399 Prev_Vis
: Entity_Id
:= Empty
;
4400 -- Needs comment ???
4402 function Is_Private_Declaration
(E
: Entity_Id
) return Boolean;
4403 -- Check that E is declared in the private part of the current package,
4404 -- or in the package body, where it may hide a previous declaration.
4405 -- We can't use In_Private_Part by itself because this flag is also
4406 -- set when freezing entities, so we must examine the place of the
4407 -- declaration in the tree, and recognize wrapper packages as well.
4409 procedure Maybe_Primitive_Operation
(Overriding
: Boolean := False);
4410 -- If the subprogram being analyzed is a primitive operation of
4411 -- the type of one of its formals, set the corresponding flag.
4413 ----------------------------
4414 -- Is_Private_Declaration --
4415 ----------------------------
4417 function Is_Private_Declaration
(E
: Entity_Id
) return Boolean is
4418 Priv_Decls
: List_Id
;
4419 Decl
: constant Node_Id
:= Unit_Declaration_Node
(E
);
4422 if Is_Package
(Current_Scope
)
4423 and then In_Private_Part
(Current_Scope
)
4426 Private_Declarations
(
4427 Specification
(Unit_Declaration_Node
(Current_Scope
)));
4429 return In_Package_Body
(Current_Scope
)
4430 or else List_Containing
(Decl
) = Priv_Decls
4431 or else (Nkind
(Parent
(Decl
)) = N_Package_Specification
4432 and then not Is_Compilation_Unit
(
4433 Defining_Entity
(Parent
(Decl
)))
4434 and then List_Containing
(Parent
(Parent
(Decl
)))
4439 end Is_Private_Declaration
;
4441 -------------------------------
4442 -- Maybe_Primitive_Operation --
4443 -------------------------------
4445 procedure Maybe_Primitive_Operation
(Overriding
: Boolean := False) is
4450 function Visible_Part_Type
(T
: Entity_Id
) return Boolean;
4451 -- Returns true if T is declared in the visible part of
4452 -- the current package scope; otherwise returns false.
4453 -- Assumes that T is declared in a package.
4455 procedure Check_Private_Overriding
(T
: Entity_Id
);
4456 -- Checks that if a primitive abstract subprogram of a visible
4457 -- abstract type is declared in a private part, then it must
4458 -- override an abstract subprogram declared in the visible part.
4459 -- Also checks that if a primitive function with a controlling
4460 -- result is declared in a private part, then it must override
4461 -- a function declared in the visible part.
4463 ------------------------------
4464 -- Check_Private_Overriding --
4465 ------------------------------
4467 procedure Check_Private_Overriding
(T
: Entity_Id
) is
4469 if Ekind
(Current_Scope
) = E_Package
4470 and then In_Private_Part
(Current_Scope
)
4471 and then Visible_Part_Type
(T
)
4472 and then not In_Instance
4475 and then Is_Abstract
(S
)
4476 and then (not Overriding
or else not Is_Abstract
(E
))
4478 Error_Msg_N
("abstract subprograms must be visible "
4479 & "('R'M 3.9.3(10))!", S
);
4481 elsif Ekind
(S
) = E_Function
4482 and then Is_Tagged_Type
(T
)
4483 and then T
= Base_Type
(Etype
(S
))
4484 and then not Overriding
4487 ("private function with tagged result must"
4488 & " override visible-part function", S
);
4490 ("\move subprogram to the visible part"
4491 & " ('R'M 3.9.3(10))", S
);
4494 end Check_Private_Overriding
;
4496 -----------------------
4497 -- Visible_Part_Type --
4498 -----------------------
4500 function Visible_Part_Type
(T
: Entity_Id
) return Boolean is
4501 P
: constant Node_Id
:= Unit_Declaration_Node
(Scope
(T
));
4505 -- If the entity is a private type, then it must be
4506 -- declared in a visible part.
4508 if Ekind
(T
) in Private_Kind
then
4512 -- Otherwise, we traverse the visible part looking for its
4513 -- corresponding declaration. We cannot use the declaration
4514 -- node directly because in the private part the entity of a
4515 -- private type is the one in the full view, which does not
4516 -- indicate that it is the completion of something visible.
4518 N
:= First
(Visible_Declarations
(Specification
(P
)));
4519 while Present
(N
) loop
4520 if Nkind
(N
) = N_Full_Type_Declaration
4521 and then Present
(Defining_Identifier
(N
))
4522 and then T
= Defining_Identifier
(N
)
4526 elsif (Nkind
(N
) = N_Private_Type_Declaration
4528 Nkind
(N
) = N_Private_Extension_Declaration
)
4529 and then Present
(Defining_Identifier
(N
))
4530 and then T
= Full_View
(Defining_Identifier
(N
))
4539 end Visible_Part_Type
;
4541 -- Start of processing for Maybe_Primitive_Operation
4544 if not Comes_From_Source
(S
) then
4547 -- If the subprogram is at library level, it is not a
4548 -- primitive operation.
4550 elsif Current_Scope
= Standard_Standard
then
4553 elsif (Ekind
(Current_Scope
) = E_Package
4554 and then not In_Package_Body
(Current_Scope
))
4557 -- For function, check return type
4559 if Ekind
(S
) = E_Function
then
4560 B_Typ
:= Base_Type
(Etype
(S
));
4562 if Scope
(B_Typ
) = Current_Scope
then
4563 Set_Has_Primitive_Operations
(B_Typ
);
4564 Check_Private_Overriding
(B_Typ
);
4568 -- For all subprograms, check formals
4570 Formal
:= First_Formal
(S
);
4571 while Present
(Formal
) loop
4572 if Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
then
4573 F_Typ
:= Designated_Type
(Etype
(Formal
));
4575 F_Typ
:= Etype
(Formal
);
4578 B_Typ
:= Base_Type
(F_Typ
);
4580 if Scope
(B_Typ
) = Current_Scope
then
4581 Set_Has_Primitive_Operations
(B_Typ
);
4582 Check_Private_Overriding
(B_Typ
);
4585 Next_Formal
(Formal
);
4588 end Maybe_Primitive_Operation
;
4590 -- Start of processing for New_Overloaded_Entity
4593 -- We need to look for an entity that S may override. This must be a
4594 -- homonym in the current scope, so we look for the first homonym of
4595 -- S in the current scope as the starting point for the search.
4597 E
:= Current_Entity_In_Scope
(S
);
4599 -- If there is no homonym then this is definitely not overriding
4602 Enter_Overloaded_Entity
(S
);
4603 Check_Dispatching_Operation
(S
, Empty
);
4604 Maybe_Primitive_Operation
;
4606 -- If there is a homonym that is not overloadable, then we have an
4607 -- error, except for the special cases checked explicitly below.
4609 elsif not Is_Overloadable
(E
) then
4611 -- Check for spurious conflict produced by a subprogram that has the
4612 -- same name as that of the enclosing generic package. The conflict
4613 -- occurs within an instance, between the subprogram and the renaming
4614 -- declaration for the package. After the subprogram, the package
4615 -- renaming declaration becomes hidden.
4617 if Ekind
(E
) = E_Package
4618 and then Present
(Renamed_Object
(E
))
4619 and then Renamed_Object
(E
) = Current_Scope
4620 and then Nkind
(Parent
(Renamed_Object
(E
))) =
4621 N_Package_Specification
4622 and then Present
(Generic_Parent
(Parent
(Renamed_Object
(E
))))
4625 Set_Is_Immediately_Visible
(E
, False);
4626 Enter_Overloaded_Entity
(S
);
4627 Set_Homonym
(S
, Homonym
(E
));
4628 Check_Dispatching_Operation
(S
, Empty
);
4630 -- If the subprogram is implicit it is hidden by the previous
4631 -- declaration. However if it is dispatching, it must appear in
4632 -- the dispatch table anyway, because it can be dispatched to
4633 -- even if it cannot be called directly.
4635 elsif Present
(Alias
(S
))
4636 and then not Comes_From_Source
(S
)
4638 Set_Scope
(S
, Current_Scope
);
4640 if Is_Dispatching_Operation
(Alias
(S
)) then
4641 Check_Dispatching_Operation
(S
, Empty
);
4647 Error_Msg_Sloc
:= Sloc
(E
);
4648 Error_Msg_N
("& conflicts with declaration#", S
);
4650 -- Useful additional warning
4652 if Is_Generic_Unit
(E
) then
4653 Error_Msg_N
("\previous generic unit cannot be overloaded", S
);
4659 -- E exists and is overloadable
4662 -- Loop through E and its homonyms to determine if any of them
4663 -- is the candidate for overriding by S.
4665 while Present
(E
) loop
4667 -- Definitely not interesting if not in the current scope
4669 if Scope
(E
) /= Current_Scope
then
4672 -- Check if we have type conformance
4674 elsif Type_Conformant
(E
, S
) then
4676 -- If the old and new entities have the same profile and
4677 -- one is not the body of the other, then this is an error,
4678 -- unless one of them is implicitly declared.
4680 -- There are some cases when both can be implicit, for example
4681 -- when both a literal and a function that overrides it are
4682 -- inherited in a derivation, or when an inhertited operation
4683 -- of a tagged full type overrides the ineherited operation of
4684 -- a private extension. Ada 83 had a special rule for the
4685 -- the literal case. In Ada95, the later implicit operation
4686 -- hides the former, and the literal is always the former.
4687 -- In the odd case where both are derived operations declared
4688 -- at the same point, both operations should be declared,
4689 -- and in that case we bypass the following test and proceed
4690 -- to the next part (this can only occur for certain obscure
4691 -- cases involving homographs in instances and can't occur for
4692 -- dispatching operations ???). Note that the following
4693 -- condition is less than clear. For example, it's not at
4694 -- all clear why there's a test for E_Entry here. ???
4696 if Present
(Alias
(S
))
4697 and then (No
(Alias
(E
))
4698 or else Comes_From_Source
(E
)
4699 or else Is_Dispatching_Operation
(E
))
4701 (Ekind
(E
) = E_Entry
4702 or else Ekind
(E
) /= E_Enumeration_Literal
)
4704 -- When an derived operation is overloaded it may be due
4705 -- to the fact that the full view of a private extension
4706 -- re-inherits. It has to be dealt with.
4708 if Is_Package
(Current_Scope
)
4709 and then In_Private_Part
(Current_Scope
)
4711 Check_Operation_From_Private_View
(S
, E
);
4714 -- In any case the implicit operation remains hidden by
4715 -- the existing declaration, which is overriding.
4717 Set_Is_Overriding_Operation
(E
);
4720 -- Within an instance, the renaming declarations for
4721 -- actual subprograms may become ambiguous, but they do
4722 -- not hide each other.
4724 elsif Ekind
(E
) /= E_Entry
4725 and then not Comes_From_Source
(E
)
4726 and then not Is_Generic_Instance
(E
)
4727 and then (Present
(Alias
(E
))
4728 or else Is_Intrinsic_Subprogram
(E
))
4729 and then (not In_Instance
4730 or else No
(Parent
(E
))
4731 or else Nkind
(Unit_Declaration_Node
(E
)) /=
4732 N_Subprogram_Renaming_Declaration
)
4734 -- A subprogram child unit is not allowed to override
4735 -- an inherited subprogram (10.1.1(20)).
4737 if Is_Child_Unit
(S
) then
4739 ("child unit overrides inherited subprogram in parent",
4744 if Is_Non_Overriding_Operation
(E
, S
) then
4745 Enter_Overloaded_Entity
(S
);
4746 if not Present
(Derived_Type
)
4747 or else Is_Tagged_Type
(Derived_Type
)
4749 Check_Dispatching_Operation
(S
, Empty
);
4755 -- E is a derived operation or an internal operator which
4756 -- is being overridden. Remove E from further visibility.
4757 -- Furthermore, if E is a dispatching operation, it must be
4758 -- replaced in the list of primitive operations of its type
4759 -- (see Override_Dispatching_Operation).
4765 Prev
:= First_Entity
(Current_Scope
);
4767 while Present
(Prev
)
4768 and then Next_Entity
(Prev
) /= E
4773 -- It is possible for E to be in the current scope and
4774 -- yet not in the entity chain. This can only occur in a
4775 -- generic context where E is an implicit concatenation
4776 -- in the formal part, because in a generic body the
4777 -- entity chain starts with the formals.
4780 (Present
(Prev
) or else Chars
(E
) = Name_Op_Concat
);
4782 -- E must be removed both from the entity_list of the
4783 -- current scope, and from the visibility chain
4785 if Debug_Flag_E
then
4786 Write_Str
("Override implicit operation ");
4787 Write_Int
(Int
(E
));
4791 -- If E is a predefined concatenation, it stands for four
4792 -- different operations. As a result, a single explicit
4793 -- declaration does not hide it. In a possible ambiguous
4794 -- situation, Disambiguate chooses the user-defined op,
4795 -- so it is correct to retain the previous internal one.
4797 if Chars
(E
) /= Name_Op_Concat
4798 or else Ekind
(E
) /= E_Operator
4800 -- For nondispatching derived operations that are
4801 -- overridden by a subprogram declared in the private
4802 -- part of a package, we retain the derived subprogram
4803 -- but mark it as not immediately visible. If the
4804 -- derived operation was declared in the visible part
4805 -- then this ensures that it will still be visible
4806 -- outside the package with the proper signature
4807 -- (calls from outside must also be directed to this
4808 -- version rather than the overriding one, unlike the
4809 -- dispatching case). Calls from inside the package
4810 -- will still resolve to the overriding subprogram
4811 -- since the derived one is marked as not visible
4812 -- within the package.
4814 -- If the private operation is dispatching, we achieve
4815 -- the overriding by keeping the implicit operation
4816 -- but setting its alias to be the overring one. In
4817 -- this fashion the proper body is executed in all
4818 -- cases, but the original signature is used outside
4821 -- If the overriding is not in the private part, we
4822 -- remove the implicit operation altogether.
4824 if Is_Private_Declaration
(S
) then
4826 if not Is_Dispatching_Operation
(E
) then
4827 Set_Is_Immediately_Visible
(E
, False);
4829 -- Work done in Override_Dispatching_Operation,
4830 -- so nothing else need to be done here.
4836 -- Find predecessor of E in Homonym chain
4838 if E
= Current_Entity
(E
) then
4841 Prev_Vis
:= Current_Entity
(E
);
4842 while Homonym
(Prev_Vis
) /= E
loop
4843 Prev_Vis
:= Homonym
(Prev_Vis
);
4847 if Prev_Vis
/= Empty
then
4849 -- Skip E in the visibility chain
4851 Set_Homonym
(Prev_Vis
, Homonym
(E
));
4854 Set_Name_Entity_Id
(Chars
(E
), Homonym
(E
));
4857 Set_Next_Entity
(Prev
, Next_Entity
(E
));
4859 if No
(Next_Entity
(Prev
)) then
4860 Set_Last_Entity
(Current_Scope
, Prev
);
4866 Enter_Overloaded_Entity
(S
);
4867 Set_Is_Overriding_Operation
(S
);
4869 if Is_Dispatching_Operation
(E
) then
4871 -- An overriding dispatching subprogram inherits
4872 -- the convention of the overridden subprogram
4875 Set_Convention
(S
, Convention
(E
));
4877 Check_Dispatching_Operation
(S
, E
);
4879 Check_Dispatching_Operation
(S
, Empty
);
4882 Maybe_Primitive_Operation
(Overriding
=> True);
4883 goto Check_Inequality
;
4886 -- Apparent redeclarations in instances can occur when two
4887 -- formal types get the same actual type. The subprograms in
4888 -- in the instance are legal, even if not callable from the
4889 -- outside. Calls from within are disambiguated elsewhere.
4890 -- For dispatching operations in the visible part, the usual
4891 -- rules apply, and operations with the same profile are not
4894 elsif (In_Instance_Visible_Part
4895 and then not Is_Dispatching_Operation
(E
))
4896 or else In_Instance_Not_Visible
4900 -- Here we have a real error (identical profile)
4903 Error_Msg_Sloc
:= Sloc
(E
);
4905 -- Avoid cascaded errors if the entity appears in
4906 -- subsequent calls.
4908 Set_Scope
(S
, Current_Scope
);
4910 Error_Msg_N
("& conflicts with declaration#", S
);
4912 if Is_Generic_Instance
(S
)
4913 and then not Has_Completion
(E
)
4916 ("\instantiation cannot provide body for it", S
);
4930 -- On exit, we know that S is a new entity
4932 Enter_Overloaded_Entity
(S
);
4933 Maybe_Primitive_Operation
;
4935 -- If S is a derived operation for an untagged type then
4936 -- by definition it's not a dispatching operation (even
4937 -- if the parent operation was dispatching), so we don't
4938 -- call Check_Dispatching_Operation in that case.
4940 if not Present
(Derived_Type
)
4941 or else Is_Tagged_Type
(Derived_Type
)
4943 Check_Dispatching_Operation
(S
, Empty
);
4947 -- If this is a user-defined equality operator that is not
4948 -- a derived subprogram, create the corresponding inequality.
4949 -- If the operation is dispatching, the expansion is done
4950 -- elsewhere, and we do not create an explicit inequality
4953 <<Check_Inequality
>>
4954 if Chars
(S
) = Name_Op_Eq
4955 and then Etype
(S
) = Standard_Boolean
4956 and then Present
(Parent
(S
))
4957 and then not Is_Dispatching_Operation
(S
)
4959 Make_Inequality_Operator
(S
);
4961 end New_Overloaded_Entity
;
4963 ---------------------
4964 -- Process_Formals --
4965 ---------------------
4967 procedure Process_Formals
4969 Related_Nod
: Node_Id
)
4971 Param_Spec
: Node_Id
;
4973 Formal_Type
: Entity_Id
;
4977 function Is_Class_Wide_Default
(D
: Node_Id
) return Boolean;
4978 -- Check whether the default has a class-wide type. After analysis
4979 -- the default has the type of the formal, so we must also check
4980 -- explicitly for an access attribute.
4982 ---------------------------
4983 -- Is_Class_Wide_Default --
4984 ---------------------------
4986 function Is_Class_Wide_Default
(D
: Node_Id
) return Boolean is
4988 return Is_Class_Wide_Type
(Designated_Type
(Etype
(D
)))
4989 or else (Nkind
(D
) = N_Attribute_Reference
4990 and then Attribute_Name
(D
) = Name_Access
4991 and then Is_Class_Wide_Type
(Etype
(Prefix
(D
))));
4992 end Is_Class_Wide_Default
;
4994 -- Start of processing for Process_Formals
4997 -- In order to prevent premature use of the formals in the same formal
4998 -- part, the Ekind is left undefined until all default expressions are
4999 -- analyzed. The Ekind is established in a separate loop at the end.
5001 Param_Spec
:= First
(T
);
5003 while Present
(Param_Spec
) loop
5005 Formal
:= Defining_Identifier
(Param_Spec
);
5006 Enter_Name
(Formal
);
5008 -- Case of ordinary parameters
5010 if Nkind
(Parameter_Type
(Param_Spec
)) /= N_Access_Definition
then
5011 Find_Type
(Parameter_Type
(Param_Spec
));
5012 Ptype
:= Parameter_Type
(Param_Spec
);
5014 if Ptype
= Error
then
5018 Formal_Type
:= Entity
(Ptype
);
5020 if Ekind
(Formal_Type
) = E_Incomplete_Type
5021 or else (Is_Class_Wide_Type
(Formal_Type
)
5022 and then Ekind
(Root_Type
(Formal_Type
)) =
5025 -- Ada 2005 (AI-50217): Incomplete tagged types that are made
5026 -- visible by a limited with_clause are valid formal types.
5028 if From_With_Type
(Formal_Type
)
5029 and then Is_Tagged_Type
(Formal_Type
)
5033 elsif Nkind
(Parent
(T
)) /= N_Access_Function_Definition
5034 and then Nkind
(Parent
(T
)) /= N_Access_Procedure_Definition
5036 Error_Msg_N
("invalid use of incomplete type", Param_Spec
);
5039 elsif Ekind
(Formal_Type
) = E_Void
then
5040 Error_Msg_NE
("premature use of&",
5041 Parameter_Type
(Param_Spec
), Formal_Type
);
5044 -- Ada 2005 (AI-231): Create and decorate an internal subtype
5045 -- declaration corresponding to the null-excluding type of the
5046 -- formal in the enclosing scope. In addition, replace the
5047 -- parameter type of the formal to this internal subtype.
5049 if Null_Exclusion_Present
(Param_Spec
) then
5051 Loc
: constant Source_Ptr
:= Sloc
(Param_Spec
);
5053 Anon
: constant Entity_Id
:=
5054 Make_Defining_Identifier
(Loc
,
5055 Chars
=> New_Internal_Name
('S'));
5057 Curr_Scope
: constant Scope_Stack_Entry
:=
5058 Scope_Stack
.Table
(Scope_Stack
.Last
);
5060 Ptype
: constant Node_Id
:= Parameter_Type
(Param_Spec
);
5062 P
: Node_Id
:= Parent
(Parent
(Related_Nod
));
5065 Set_Is_Internal
(Anon
);
5068 Make_Subtype_Declaration
(Loc
,
5069 Defining_Identifier
=> Anon
,
5070 Null_Exclusion_Present
=> True,
5071 Subtype_Indication
=>
5072 New_Occurrence_Of
(Etype
(Ptype
), Loc
));
5074 -- Propagate the null-excluding attribute to the new entity
5076 if Null_Exclusion_Present
(Param_Spec
) then
5077 Set_Null_Exclusion_Present
(Param_Spec
, False);
5078 Set_Can_Never_Be_Null
(Anon
);
5081 Mark_Rewrite_Insertion
(Decl
);
5083 -- Insert the new declaration in the nearest enclosing scope
5085 while not Has_Declarations
(P
) loop
5089 Prepend
(Decl
, Declarations
(P
));
5091 Rewrite
(Ptype
, New_Occurrence_Of
(Anon
, Loc
));
5092 Mark_Rewrite_Insertion
(Ptype
);
5094 -- Analyze the new declaration in the context of the
5097 Scope_Stack
.Decrement_Last
;
5099 Scope_Stack
.Append
(Curr_Scope
);
5101 Formal_Type
:= Anon
;
5105 -- Ada 2005 (AI-231): Static checks
5107 if Null_Exclusion_Present
(Param_Spec
)
5108 or else Can_Never_Be_Null
(Entity
(Ptype
))
5110 Null_Exclusion_Static_Checks
(Param_Spec
);
5113 -- An access formal type
5117 Access_Definition
(Related_Nod
, Parameter_Type
(Param_Spec
));
5119 -- Ada 2005 (AI-254)
5122 AD
: constant Node_Id
:=
5123 Access_To_Subprogram_Definition
5124 (Parameter_Type
(Param_Spec
));
5126 if Present
(AD
) and then Protected_Present
(AD
) then
5128 Replace_Anonymous_Access_To_Protected_Subprogram
5129 (Param_Spec
, Formal_Type
);
5134 Set_Etype
(Formal
, Formal_Type
);
5135 Default
:= Expression
(Param_Spec
);
5137 if Present
(Default
) then
5138 if Out_Present
(Param_Spec
) then
5140 ("default initialization only allowed for IN parameters",
5144 -- Do the special preanalysis of the expression (see section on
5145 -- "Handling of Default Expressions" in the spec of package Sem).
5147 Analyze_Per_Use_Expression
(Default
, Formal_Type
);
5149 -- Check that the designated type of an access parameter's
5150 -- default is not a class-wide type unless the parameter's
5151 -- designated type is also class-wide.
5153 if Ekind
(Formal_Type
) = E_Anonymous_Access_Type
5154 and then Is_Class_Wide_Default
(Default
)
5155 and then not Is_Class_Wide_Type
(Designated_Type
(Formal_Type
))
5158 ("access to class-wide expression not allowed here", Default
);
5166 -- Now set the kind (mode) of each formal
5168 Param_Spec
:= First
(T
);
5170 while Present
(Param_Spec
) loop
5171 Formal
:= Defining_Identifier
(Param_Spec
);
5172 Set_Formal_Mode
(Formal
);
5174 if Ekind
(Formal
) = E_In_Parameter
then
5175 Set_Default_Value
(Formal
, Expression
(Param_Spec
));
5177 if Present
(Expression
(Param_Spec
)) then
5178 Default
:= Expression
(Param_Spec
);
5180 if Is_Scalar_Type
(Etype
(Default
)) then
5182 (Parameter_Type
(Param_Spec
)) /= N_Access_Definition
5184 Formal_Type
:= Entity
(Parameter_Type
(Param_Spec
));
5187 Formal_Type
:= Access_Definition
5188 (Related_Nod
, Parameter_Type
(Param_Spec
));
5191 Apply_Scalar_Range_Check
(Default
, Formal_Type
);
5199 end Process_Formals
;
5201 ----------------------------
5202 -- Reference_Body_Formals --
5203 ----------------------------
5205 procedure Reference_Body_Formals
(Spec
: Entity_Id
; Bod
: Entity_Id
) is
5210 if Error_Posted
(Spec
) then
5214 Fs
:= First_Formal
(Spec
);
5215 Fb
:= First_Formal
(Bod
);
5217 while Present
(Fs
) loop
5218 Generate_Reference
(Fs
, Fb
, 'b');
5221 Style
.Check_Identifier
(Fb
, Fs
);
5224 Set_Spec_Entity
(Fb
, Fs
);
5225 Set_Referenced
(Fs
, False);
5229 end Reference_Body_Formals
;
5231 -------------------------
5232 -- Set_Actual_Subtypes --
5233 -------------------------
5235 procedure Set_Actual_Subtypes
(N
: Node_Id
; Subp
: Entity_Id
) is
5236 Loc
: constant Source_Ptr
:= Sloc
(N
);
5240 First_Stmt
: Node_Id
:= Empty
;
5241 AS_Needed
: Boolean;
5244 -- If this is an emtpy initialization procedure, no need to create
5245 -- actual subtypes (small optimization).
5247 if Ekind
(Subp
) = E_Procedure
5248 and then Is_Null_Init_Proc
(Subp
)
5253 Formal
:= First_Formal
(Subp
);
5254 while Present
(Formal
) loop
5255 T
:= Etype
(Formal
);
5257 -- We never need an actual subtype for a constrained formal
5259 if Is_Constrained
(T
) then
5262 -- If we have unknown discriminants, then we do not need an
5263 -- actual subtype, or more accurately we cannot figure it out!
5264 -- Note that all class-wide types have unknown discriminants.
5266 elsif Has_Unknown_Discriminants
(T
) then
5269 -- At this stage we have an unconstrained type that may need
5270 -- an actual subtype. For sure the actual subtype is needed
5271 -- if we have an unconstrained array type.
5273 elsif Is_Array_Type
(T
) then
5276 -- The only other case which needs an actual subtype is an
5277 -- unconstrained record type which is an IN parameter (we
5278 -- cannot generate actual subtypes for the OUT or IN OUT case,
5279 -- since an assignment can change the discriminant values.
5280 -- However we exclude the case of initialization procedures,
5281 -- since discriminants are handled very specially in this context,
5282 -- see the section entitled "Handling of Discriminants" in Einfo.
5283 -- We also exclude the case of Discrim_SO_Functions (functions
5284 -- used in front end layout mode for size/offset values), since
5285 -- in such functions only discriminants are referenced, and not
5286 -- only are such subtypes not needed, but they cannot always
5287 -- be generated, because of order of elaboration issues.
5289 elsif Is_Record_Type
(T
)
5290 and then Ekind
(Formal
) = E_In_Parameter
5291 and then Chars
(Formal
) /= Name_uInit
5292 and then not Is_Unchecked_Union
(T
)
5293 and then not Is_Discrim_SO_Function
(Subp
)
5297 -- All other cases do not need an actual subtype
5303 -- Generate actual subtypes for unconstrained arrays and
5304 -- unconstrained discriminated records.
5307 if Nkind
(N
) = N_Accept_Statement
then
5309 -- If expansion is active, The formal is replaced by a local
5310 -- variable that renames the corresponding entry of the
5311 -- parameter block, and it is this local variable that may
5312 -- require an actual subtype.
5314 if Expander_Active
then
5315 Decl
:= Build_Actual_Subtype
(T
, Renamed_Object
(Formal
));
5317 Decl
:= Build_Actual_Subtype
(T
, Formal
);
5320 if Present
(Handled_Statement_Sequence
(N
)) then
5322 First
(Statements
(Handled_Statement_Sequence
(N
)));
5323 Prepend
(Decl
, Statements
(Handled_Statement_Sequence
(N
)));
5324 Mark_Rewrite_Insertion
(Decl
);
5326 -- If the accept statement has no body, there will be
5327 -- no reference to the actuals, so no need to compute
5334 Decl
:= Build_Actual_Subtype
(T
, Formal
);
5335 Prepend
(Decl
, Declarations
(N
));
5336 Mark_Rewrite_Insertion
(Decl
);
5339 -- The declaration uses the bounds of an existing object,
5340 -- and therefore needs no constraint checks.
5342 Analyze
(Decl
, Suppress
=> All_Checks
);
5344 -- We need to freeze manually the generated type when it is
5345 -- inserted anywhere else than in a declarative part.
5347 if Present
(First_Stmt
) then
5348 Insert_List_Before_And_Analyze
(First_Stmt
,
5349 Freeze_Entity
(Defining_Identifier
(Decl
), Loc
));
5352 if Nkind
(N
) = N_Accept_Statement
5353 and then Expander_Active
5355 Set_Actual_Subtype
(Renamed_Object
(Formal
),
5356 Defining_Identifier
(Decl
));
5358 Set_Actual_Subtype
(Formal
, Defining_Identifier
(Decl
));
5362 Next_Formal
(Formal
);
5364 end Set_Actual_Subtypes
;
5366 ---------------------
5367 -- Set_Formal_Mode --
5368 ---------------------
5370 procedure Set_Formal_Mode
(Formal_Id
: Entity_Id
) is
5371 Spec
: constant Node_Id
:= Parent
(Formal_Id
);
5374 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
5375 -- since we ensure that corresponding actuals are always valid at the
5376 -- point of the call.
5378 if Out_Present
(Spec
) then
5379 if Ekind
(Scope
(Formal_Id
)) = E_Function
5380 or else Ekind
(Scope
(Formal_Id
)) = E_Generic_Function
5382 Error_Msg_N
("functions can only have IN parameters", Spec
);
5383 Set_Ekind
(Formal_Id
, E_In_Parameter
);
5385 elsif In_Present
(Spec
) then
5386 Set_Ekind
(Formal_Id
, E_In_Out_Parameter
);
5389 Set_Ekind
(Formal_Id
, E_Out_Parameter
);
5390 Set_Never_Set_In_Source
(Formal_Id
, True);
5391 Set_Is_True_Constant
(Formal_Id
, False);
5392 Set_Current_Value
(Formal_Id
, Empty
);
5396 Set_Ekind
(Formal_Id
, E_In_Parameter
);
5399 -- Set Is_Known_Non_Null for access parameters since the language
5400 -- guarantees that access parameters are always non-null. We also
5401 -- set Can_Never_Be_Null, since there is no way to change the value.
5403 if Nkind
(Parameter_Type
(Spec
)) = N_Access_Definition
then
5405 -- Ada 2005 (AI-231): This behaviour has been modified in Ada 2005.
5406 -- It is only forced if the null_exclusion appears.
5408 if Ada_Version
< Ada_05
5409 or else Null_Exclusion_Present
(Spec
)
5411 Set_Is_Known_Non_Null
(Formal_Id
);
5412 Set_Can_Never_Be_Null
(Formal_Id
);
5416 Set_Mechanism
(Formal_Id
, Default_Mechanism
);
5417 Set_Formal_Validity
(Formal_Id
);
5418 end Set_Formal_Mode
;
5420 -------------------------
5421 -- Set_Formal_Validity --
5422 -------------------------
5424 procedure Set_Formal_Validity
(Formal_Id
: Entity_Id
) is
5426 -- If no validity checking, then we cannot assume anything about
5427 -- the validity of parameters, since we do not know there is any
5428 -- checking of the validity on the call side.
5430 if not Validity_Checks_On
then
5433 -- If validity checking for parameters is enabled, this means we are
5434 -- not supposed to make any assumptions about argument values.
5436 elsif Validity_Check_Parameters
then
5439 -- If we are checking in parameters, we will assume that the caller is
5440 -- also checking parameters, so we can assume the parameter is valid.
5442 elsif Ekind
(Formal_Id
) = E_In_Parameter
5443 and then Validity_Check_In_Params
5445 Set_Is_Known_Valid
(Formal_Id
, True);
5447 -- Similar treatment for IN OUT parameters
5449 elsif Ekind
(Formal_Id
) = E_In_Out_Parameter
5450 and then Validity_Check_In_Out_Params
5452 Set_Is_Known_Valid
(Formal_Id
, True);
5454 end Set_Formal_Validity
;
5456 ------------------------
5457 -- Subtype_Conformant --
5458 ------------------------
5460 function Subtype_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
5464 Check_Conformance
(New_Id
, Old_Id
, Subtype_Conformant
, False, Result
);
5466 end Subtype_Conformant
;
5468 ---------------------
5469 -- Type_Conformant --
5470 ---------------------
5472 function Type_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
5475 Check_Conformance
(New_Id
, Old_Id
, Type_Conformant
, False, Result
);
5477 end Type_Conformant
;
5479 -------------------------------
5480 -- Valid_Operator_Definition --
5481 -------------------------------
5483 procedure Valid_Operator_Definition
(Designator
: Entity_Id
) is
5486 Id
: constant Name_Id
:= Chars
(Designator
);
5490 F
:= First_Formal
(Designator
);
5492 while Present
(F
) loop
5495 if Present
(Default_Value
(F
)) then
5497 ("default values not allowed for operator parameters",
5504 -- Verify that user-defined operators have proper number of arguments
5505 -- First case of operators which can only be unary
5508 or else Id
= Name_Op_Abs
5512 -- Case of operators which can be unary or binary
5514 elsif Id
= Name_Op_Add
5515 or Id
= Name_Op_Subtract
5517 N_OK
:= (N
in 1 .. 2);
5519 -- All other operators can only be binary
5527 ("incorrect number of arguments for operator", Designator
);
5531 and then Base_Type
(Etype
(Designator
)) = Standard_Boolean
5532 and then not Is_Intrinsic_Subprogram
(Designator
)
5535 ("explicit definition of inequality not allowed", Designator
);
5537 end Valid_Operator_Definition
;