1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2005, 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_Return_Type
(N
: Node_Id
);
83 -- Subsidiary to Process_Formals: analyze subtype mark in function
84 -- specification, in a context where the formals are visible and hide
87 procedure Analyze_Generic_Subprogram_Body
(N
: Node_Id
; Gen_Id
: Entity_Id
);
88 -- Analyze a generic subprogram body. N is the body to be analyzed, and
89 -- Gen_Id is the defining entity Id for the corresponding spec.
91 procedure Build_Body_To_Inline
(N
: Node_Id
; Subp
: Entity_Id
);
92 -- If a subprogram has pragma Inline and inlining is active, use generic
93 -- machinery to build an unexpanded body for the subprogram. This body is
94 -- subsequenty used for inline expansions at call sites. If subprogram can
95 -- be inlined (depending on size and nature of local declarations) this
96 -- function returns true. Otherwise subprogram body is treated normally.
97 -- If proper warnings are enabled and the subprogram contains a construct
98 -- that cannot be inlined, the offending construct is flagged accordingly.
100 type Conformance_Type
is
101 (Type_Conformant
, Mode_Conformant
, Subtype_Conformant
, Fully_Conformant
);
102 -- Conformance type used for following call, meaning matches the
103 -- RM definitions of the corresponding terms.
105 procedure Check_Conformance
108 Ctype
: Conformance_Type
;
110 Conforms
: out Boolean;
111 Err_Loc
: Node_Id
:= Empty
;
112 Get_Inst
: Boolean := False);
113 -- Given two entities, this procedure checks that the profiles associated
114 -- with these entities meet the conformance criterion given by the third
115 -- parameter. If they conform, Conforms is set True and control returns
116 -- to the caller. If they do not conform, Conforms is set to False, and
117 -- in addition, if Errmsg is True on the call, proper messages are output
118 -- to complain about the conformance failure. If Err_Loc is non_Empty
119 -- the error messages are placed on Err_Loc, if Err_Loc is empty, then
120 -- error messages are placed on the appropriate part of the construct
121 -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
122 -- against a formal access-to-subprogram type so Get_Instance_Of must
125 procedure Check_Overriding_Operation
128 -- Check that a subprogram with a pragma Overriding or Optional_Overriding
129 -- is legal. This check is performed here rather than in Sem_Prag because
130 -- the pragma must follow immediately the declaration, and can be treated
131 -- as part of the declaration itself, as described in AI-218.
133 procedure Check_Subprogram_Order
(N
: Node_Id
);
134 -- N is the N_Subprogram_Body node for a subprogram. This routine applies
135 -- the alpha ordering rule for N if this ordering requirement applicable.
137 procedure Check_Returns
141 -- Called to check for missing return statements in a function body, or
142 -- for returns present in a procedure body which has No_Return set. L is
143 -- the handled statement sequence for the subprogram body. This procedure
144 -- checks all flow paths to make sure they either have return (Mode = 'F')
145 -- or do not have a return (Mode = 'P'). The flag Err is set if there are
146 -- any control paths not explicitly terminated by a return in the function
147 -- case, and is True otherwise.
149 function Conforming_Types
152 Ctype
: Conformance_Type
;
153 Get_Inst
: Boolean := False) return Boolean;
154 -- Check that two formal parameter types conform, checking both for
155 -- equality of base types, and where required statically matching
156 -- subtypes, depending on the setting of Ctype.
158 procedure Enter_Overloaded_Entity
(S
: Entity_Id
);
159 -- This procedure makes S, a new overloaded entity, into the first visible
160 -- entity with that name.
162 procedure Install_Entity
(E
: Entity_Id
);
163 -- Make single entity visible. Used for generic formals as well
165 procedure Install_Formals
(Id
: Entity_Id
);
166 -- On entry to a subprogram body, make the formals visible. Note that
167 -- simply placing the subprogram on the scope stack is not sufficient:
168 -- the formals must become the current entities for their names.
170 function Is_Non_Overriding_Operation
172 New_E
: Entity_Id
) return Boolean;
173 -- Enforce the rule given in 12.3(18): a private operation in an instance
174 -- overrides an inherited operation only if the corresponding operation
175 -- was overriding in the generic. This can happen for primitive operations
176 -- of types derived (in the generic unit) from formal private or formal
179 procedure Make_Inequality_Operator
(S
: Entity_Id
);
180 -- Create the declaration for an inequality operator that is implicitly
181 -- created by a user-defined equality operator that yields a boolean.
183 procedure May_Need_Actuals
(Fun
: Entity_Id
);
184 -- Flag functions that can be called without parameters, i.e. those that
185 -- have no parameters, or those for which defaults exist for all parameters
187 procedure Reference_Body_Formals
(Spec
: Entity_Id
; Bod
: Entity_Id
);
188 -- If there is a separate spec for a subprogram or generic subprogram, the
189 -- formals of the body are treated as references to the corresponding
190 -- formals of the spec. This reference does not count as an actual use of
191 -- the formal, in order to diagnose formals that are unused in the body.
193 procedure Set_Formal_Validity
(Formal_Id
: Entity_Id
);
194 -- Formal_Id is an formal parameter entity. This procedure deals with
195 -- setting the proper validity status for this entity, which depends
196 -- on the kind of parameter and the validity checking mode.
198 ---------------------------------------------
199 -- Analyze_Abstract_Subprogram_Declaration --
200 ---------------------------------------------
202 procedure Analyze_Abstract_Subprogram_Declaration
(N
: Node_Id
) is
203 Designator
: constant Entity_Id
:=
204 Analyze_Subprogram_Specification
(Specification
(N
));
205 Scop
: constant Entity_Id
:= Current_Scope
;
208 Generate_Definition
(Designator
);
209 Set_Is_Abstract
(Designator
);
210 New_Overloaded_Entity
(Designator
);
211 Check_Delayed_Subprogram
(Designator
);
213 Set_Categorization_From_Scope
(Designator
, Scop
);
215 if Ekind
(Scope
(Designator
)) = E_Protected_Type
then
217 ("abstract subprogram not allowed in protected type", N
);
220 Generate_Reference_To_Formals
(Designator
);
221 end Analyze_Abstract_Subprogram_Declaration
;
223 ----------------------------
224 -- Analyze_Function_Call --
225 ----------------------------
227 procedure Analyze_Function_Call
(N
: Node_Id
) is
228 P
: constant Node_Id
:= Name
(N
);
229 L
: constant List_Id
:= Parameter_Associations
(N
);
235 -- A call of the form A.B (X) may be an Ada05 call, which is rewritten
236 -- as B(A, X). If the rewriting is successful, the call has been
237 -- analyzed and we just return.
239 if Nkind
(P
) = N_Selected_Component
240 and then Name
(N
) /= P
241 and then Is_Rewrite_Substitution
(N
)
242 and then Present
(Etype
(N
))
247 -- If error analyzing name, then set Any_Type as result type and return
249 if Etype
(P
) = Any_Type
then
250 Set_Etype
(N
, Any_Type
);
254 -- Otherwise analyze the parameters
259 while Present
(Actual
) loop
261 Check_Parameterless_Call
(Actual
);
267 end Analyze_Function_Call
;
269 -------------------------------------
270 -- Analyze_Generic_Subprogram_Body --
271 -------------------------------------
273 procedure Analyze_Generic_Subprogram_Body
277 Gen_Decl
: constant Node_Id
:= Unit_Declaration_Node
(Gen_Id
);
278 Kind
: constant Entity_Kind
:= Ekind
(Gen_Id
);
284 -- Copy body and disable expansion while analyzing the generic For a
285 -- stub, do not copy the stub (which would load the proper body), this
286 -- will be done when the proper body is analyzed.
288 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
289 New_N
:= Copy_Generic_Node
(N
, Empty
, Instantiating
=> False);
294 Spec
:= Specification
(N
);
296 -- Within the body of the generic, the subprogram is callable, and
297 -- behaves like the corresponding non-generic unit.
299 Body_Id
:= Defining_Entity
(Spec
);
301 if Kind
= E_Generic_Procedure
302 and then Nkind
(Spec
) /= N_Procedure_Specification
304 Error_Msg_N
("invalid body for generic procedure ", Body_Id
);
307 elsif Kind
= E_Generic_Function
308 and then Nkind
(Spec
) /= N_Function_Specification
310 Error_Msg_N
("invalid body for generic function ", Body_Id
);
314 Set_Corresponding_Body
(Gen_Decl
, Body_Id
);
316 if Has_Completion
(Gen_Id
)
317 and then Nkind
(Parent
(N
)) /= N_Subunit
319 Error_Msg_N
("duplicate generic body", N
);
322 Set_Has_Completion
(Gen_Id
);
325 if Nkind
(N
) = N_Subprogram_Body_Stub
then
326 Set_Ekind
(Defining_Entity
(Specification
(N
)), Kind
);
328 Set_Corresponding_Spec
(N
, Gen_Id
);
331 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
332 Set_Cunit_Entity
(Current_Sem_Unit
, Defining_Entity
(N
));
335 -- Make generic parameters immediately visible in the body. They are
336 -- needed to process the formals declarations. Then make the formals
337 -- visible in a separate step.
343 First_Ent
: Entity_Id
;
346 First_Ent
:= First_Entity
(Gen_Id
);
349 while Present
(E
) and then not Is_Formal
(E
) loop
354 Set_Use
(Generic_Formal_Declarations
(Gen_Decl
));
356 -- Now generic formals are visible, and the specification can be
357 -- analyzed, for subsequent conformance check.
359 Body_Id
:= Analyze_Subprogram_Specification
(Spec
);
361 -- Make formal parameters visible
365 -- E is the first formal parameter, we loop through the formals
366 -- installing them so that they will be visible.
368 Set_First_Entity
(Gen_Id
, E
);
369 while Present
(E
) loop
375 -- Visible generic entity is callable within its own body
377 Set_Ekind
(Gen_Id
, Ekind
(Body_Id
));
378 Set_Ekind
(Body_Id
, E_Subprogram_Body
);
379 Set_Convention
(Body_Id
, Convention
(Gen_Id
));
380 Set_Scope
(Body_Id
, Scope
(Gen_Id
));
381 Check_Fully_Conformant
(Body_Id
, Gen_Id
, Body_Id
);
383 if Nkind
(N
) = N_Subprogram_Body_Stub
then
385 -- No body to analyze, so restore state of generic unit
387 Set_Ekind
(Gen_Id
, Kind
);
388 Set_Ekind
(Body_Id
, Kind
);
390 if Present
(First_Ent
) then
391 Set_First_Entity
(Gen_Id
, First_Ent
);
398 -- If this is a compilation unit, it must be made visible explicitly,
399 -- because the compilation of the declaration, unlike other library
400 -- unit declarations, does not. If it is not a unit, the following
401 -- is redundant but harmless.
403 Set_Is_Immediately_Visible
(Gen_Id
);
404 Reference_Body_Formals
(Gen_Id
, Body_Id
);
406 Set_Actual_Subtypes
(N
, Current_Scope
);
407 Analyze_Declarations
(Declarations
(N
));
409 Analyze
(Handled_Statement_Sequence
(N
));
411 Save_Global_References
(Original_Node
(N
));
413 -- Prior to exiting the scope, include generic formals again (if any
414 -- are present) in the set of local entities.
416 if Present
(First_Ent
) then
417 Set_First_Entity
(Gen_Id
, First_Ent
);
420 Check_References
(Gen_Id
);
423 Process_End_Label
(Handled_Statement_Sequence
(N
), 't', Current_Scope
);
425 Check_Subprogram_Order
(N
);
427 -- Outside of its body, unit is generic again
429 Set_Ekind
(Gen_Id
, Kind
);
430 Generate_Reference
(Gen_Id
, Body_Id
, 'b', Set_Ref
=> False);
431 Style
.Check_Identifier
(Body_Id
, Gen_Id
);
433 end Analyze_Generic_Subprogram_Body
;
435 -----------------------------
436 -- Analyze_Operator_Symbol --
437 -----------------------------
439 -- An operator symbol such as "+" or "and" may appear in context where the
440 -- literal denotes an entity name, such as "+"(x, y) or in context when it
441 -- is just a string, as in (conjunction = "or"). In these cases the parser
442 -- generates this node, and the semantics does the disambiguation. Other
443 -- such case are actuals in an instantiation, the generic unit in an
444 -- instantiation, and pragma arguments.
446 procedure Analyze_Operator_Symbol
(N
: Node_Id
) is
447 Par
: constant Node_Id
:= Parent
(N
);
450 if (Nkind
(Par
) = N_Function_Call
and then N
= Name
(Par
))
451 or else Nkind
(Par
) = N_Function_Instantiation
452 or else (Nkind
(Par
) = N_Indexed_Component
and then N
= Prefix
(Par
))
453 or else (Nkind
(Par
) = N_Pragma_Argument_Association
454 and then not Is_Pragma_String_Literal
(Par
))
455 or else Nkind
(Par
) = N_Subprogram_Renaming_Declaration
456 or else (Nkind
(Par
) = N_Attribute_Reference
457 and then Attribute_Name
(Par
) /= Name_Value
)
459 Find_Direct_Name
(N
);
462 Change_Operator_Symbol_To_String_Literal
(N
);
465 end Analyze_Operator_Symbol
;
467 -----------------------------------
468 -- Analyze_Parameter_Association --
469 -----------------------------------
471 procedure Analyze_Parameter_Association
(N
: Node_Id
) is
473 Analyze
(Explicit_Actual_Parameter
(N
));
474 end Analyze_Parameter_Association
;
476 ----------------------------
477 -- Analyze_Procedure_Call --
478 ----------------------------
480 procedure Analyze_Procedure_Call
(N
: Node_Id
) is
481 Loc
: constant Source_Ptr
:= Sloc
(N
);
482 P
: constant Node_Id
:= Name
(N
);
483 Actuals
: constant List_Id
:= Parameter_Associations
(N
);
487 procedure Analyze_Call_And_Resolve
;
488 -- Do Analyze and Resolve calls for procedure call
490 ------------------------------
491 -- Analyze_Call_And_Resolve --
492 ------------------------------
494 procedure Analyze_Call_And_Resolve
is
496 if Nkind
(N
) = N_Procedure_Call_Statement
then
498 Resolve
(N
, Standard_Void_Type
);
502 end Analyze_Call_And_Resolve
;
504 -- Start of processing for Analyze_Procedure_Call
507 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
508 -- a procedure call or an entry call. The prefix may denote an access
509 -- to subprogram type, in which case an implicit dereference applies.
510 -- If the prefix is an indexed component (without implicit defererence)
511 -- then the construct denotes a call to a member of an entire family.
512 -- If the prefix is a simple name, it may still denote a call to a
513 -- parameterless member of an entry family. Resolution of these various
514 -- interpretations is delicate.
518 -- If error analyzing prefix, then set Any_Type as result and return
520 if Etype
(P
) = Any_Type
then
521 Set_Etype
(N
, Any_Type
);
525 -- Otherwise analyze the parameters
527 if Present
(Actuals
) then
528 Actual
:= First
(Actuals
);
530 while Present
(Actual
) loop
532 Check_Parameterless_Call
(Actual
);
537 -- Special processing for Elab_Spec and Elab_Body calls
539 if Nkind
(P
) = N_Attribute_Reference
540 and then (Attribute_Name
(P
) = Name_Elab_Spec
541 or else Attribute_Name
(P
) = Name_Elab_Body
)
543 if Present
(Actuals
) then
545 ("no parameters allowed for this call", First
(Actuals
));
549 Set_Etype
(N
, Standard_Void_Type
);
552 elsif Is_Entity_Name
(P
)
553 and then Is_Record_Type
(Etype
(Entity
(P
)))
554 and then Remote_AST_I_Dereference
(P
)
558 elsif Is_Entity_Name
(P
)
559 and then Ekind
(Entity
(P
)) /= E_Entry_Family
561 if Is_Access_Type
(Etype
(P
))
562 and then Ekind
(Designated_Type
(Etype
(P
))) = E_Subprogram_Type
563 and then No
(Actuals
)
564 and then Comes_From_Source
(N
)
566 Error_Msg_N
("missing explicit dereference in call", N
);
569 Analyze_Call_And_Resolve
;
571 -- If the prefix is the simple name of an entry family, this is
572 -- a parameterless call from within the task body itself.
574 elsif Is_Entity_Name
(P
)
575 and then Nkind
(P
) = N_Identifier
576 and then Ekind
(Entity
(P
)) = E_Entry_Family
577 and then Present
(Actuals
)
578 and then No
(Next
(First
(Actuals
)))
580 -- Can be call to parameterless entry family. What appears to be the
581 -- sole argument is in fact the entry index. Rewrite prefix of node
582 -- accordingly. Source representation is unchanged by this
586 Make_Indexed_Component
(Loc
,
588 Make_Selected_Component
(Loc
,
589 Prefix
=> New_Occurrence_Of
(Scope
(Entity
(P
)), Loc
),
590 Selector_Name
=> New_Occurrence_Of
(Entity
(P
), Loc
)),
591 Expressions
=> Actuals
);
593 Set_Etype
(New_N
, Standard_Void_Type
);
594 Set_Parameter_Associations
(N
, No_List
);
595 Analyze_Call_And_Resolve
;
597 elsif Nkind
(P
) = N_Explicit_Dereference
then
598 if Ekind
(Etype
(P
)) = E_Subprogram_Type
then
599 Analyze_Call_And_Resolve
;
601 Error_Msg_N
("expect access to procedure in call", P
);
604 -- The name can be a selected component or an indexed component that
605 -- yields an access to subprogram. Such a prefix is legal if the call
606 -- has parameter associations.
608 elsif Is_Access_Type
(Etype
(P
))
609 and then Ekind
(Designated_Type
(Etype
(P
))) = E_Subprogram_Type
611 if Present
(Actuals
) then
612 Analyze_Call_And_Resolve
;
614 Error_Msg_N
("missing explicit dereference in call ", N
);
617 -- If not an access to subprogram, then the prefix must resolve to the
618 -- name of an entry, entry family, or protected operation.
620 -- For the case of a simple entry call, P is a selected component where
621 -- the prefix is the task and the selector name is the entry. A call to
622 -- a protected procedure will have the same syntax. If the protected
623 -- object contains overloaded operations, the entity may appear as a
624 -- function, the context will select the operation whose type is Void.
626 elsif Nkind
(P
) = N_Selected_Component
627 and then (Ekind
(Entity
(Selector_Name
(P
))) = E_Entry
629 Ekind
(Entity
(Selector_Name
(P
))) = E_Procedure
631 Ekind
(Entity
(Selector_Name
(P
))) = E_Function
)
633 Analyze_Call_And_Resolve
;
635 elsif Nkind
(P
) = N_Selected_Component
636 and then Ekind
(Entity
(Selector_Name
(P
))) = E_Entry_Family
637 and then Present
(Actuals
)
638 and then No
(Next
(First
(Actuals
)))
640 -- Can be call to parameterless entry family. What appears to be the
641 -- sole argument is in fact the entry index. Rewrite prefix of node
642 -- accordingly. Source representation is unchanged by this
646 Make_Indexed_Component
(Loc
,
647 Prefix
=> New_Copy
(P
),
648 Expressions
=> Actuals
);
650 Set_Etype
(New_N
, Standard_Void_Type
);
651 Set_Parameter_Associations
(N
, No_List
);
652 Analyze_Call_And_Resolve
;
654 -- For the case of a reference to an element of an entry family, P is
655 -- an indexed component whose prefix is a selected component (task and
656 -- entry family), and whose index is the entry family index.
658 elsif Nkind
(P
) = N_Indexed_Component
659 and then Nkind
(Prefix
(P
)) = N_Selected_Component
660 and then Ekind
(Entity
(Selector_Name
(Prefix
(P
)))) = E_Entry_Family
662 Analyze_Call_And_Resolve
;
664 -- If the prefix is the name of an entry family, it is a call from
665 -- within the task body itself.
667 elsif Nkind
(P
) = N_Indexed_Component
668 and then Nkind
(Prefix
(P
)) = N_Identifier
669 and then Ekind
(Entity
(Prefix
(P
))) = E_Entry_Family
672 Make_Selected_Component
(Loc
,
673 Prefix
=> New_Occurrence_Of
(Scope
(Entity
(Prefix
(P
))), Loc
),
674 Selector_Name
=> New_Occurrence_Of
(Entity
(Prefix
(P
)), Loc
));
675 Rewrite
(Prefix
(P
), New_N
);
677 Analyze_Call_And_Resolve
;
679 -- Anything else is an error
682 Error_Msg_N
("Invalid procedure or entry call", N
);
684 end Analyze_Procedure_Call
;
686 ------------------------------
687 -- Analyze_Return_Statement --
688 ------------------------------
690 procedure Analyze_Return_Statement
(N
: Node_Id
) is
691 Loc
: constant Source_Ptr
:= Sloc
(N
);
693 Scope_Id
: Entity_Id
;
698 -- Find subprogram or accept statement enclosing the return statement
701 for J
in reverse 0 .. Scope_Stack
.Last
loop
702 Scope_Id
:= Scope_Stack
.Table
(J
).Entity
;
703 exit when Ekind
(Scope_Id
) /= E_Block
and then
704 Ekind
(Scope_Id
) /= E_Loop
;
707 pragma Assert
(Present
(Scope_Id
));
709 Kind
:= Ekind
(Scope_Id
);
710 Expr
:= Expression
(N
);
712 if Kind
/= E_Function
713 and then Kind
/= E_Generic_Function
714 and then Kind
/= E_Procedure
715 and then Kind
/= E_Generic_Procedure
716 and then Kind
/= E_Entry
717 and then Kind
/= E_Entry_Family
719 Error_Msg_N
("illegal context for return statement", N
);
721 elsif Present
(Expr
) then
722 if Kind
= E_Function
or else Kind
= E_Generic_Function
then
723 Set_Return_Present
(Scope_Id
);
724 R_Type
:= Etype
(Scope_Id
);
725 Set_Return_Type
(N
, R_Type
);
726 Analyze_And_Resolve
(Expr
, R_Type
);
728 if (Is_Class_Wide_Type
(Etype
(Expr
))
729 or else Is_Dynamically_Tagged
(Expr
))
730 and then not Is_Class_Wide_Type
(R_Type
)
733 ("dynamically tagged expression not allowed!", Expr
);
736 Apply_Constraint_Check
(Expr
, R_Type
);
738 -- ??? A real run-time accessibility check is needed in cases
739 -- involving dereferences of access parameters. For now we just
740 -- check the static cases.
742 if Is_Return_By_Reference_Type
(Etype
(Scope_Id
))
743 and then Object_Access_Level
(Expr
)
744 > Subprogram_Access_Level
(Scope_Id
)
747 Make_Raise_Program_Error
(Loc
,
748 Reason
=> PE_Accessibility_Check_Failed
));
752 ("cannot return a local value by reference?", N
);
754 ("& will be raised at run time?!",
755 N
, Standard_Program_Error
);
758 elsif Kind
= E_Procedure
or else Kind
= E_Generic_Procedure
then
759 Error_Msg_N
("procedure cannot return value (use function)", N
);
762 Error_Msg_N
("accept statement cannot return value", N
);
765 -- No expression present
768 if Kind
= E_Function
or Kind
= E_Generic_Function
then
769 Error_Msg_N
("missing expression in return from function", N
);
772 if (Ekind
(Scope_Id
) = E_Procedure
773 or else Ekind
(Scope_Id
) = E_Generic_Procedure
)
774 and then No_Return
(Scope_Id
)
777 ("RETURN statement not allowed (No_Return)", N
);
781 Check_Unreachable_Code
(N
);
782 end Analyze_Return_Statement
;
784 -------------------------
785 -- Analyze_Return_Type --
786 -------------------------
788 procedure Analyze_Return_Type
(N
: Node_Id
) is
789 Designator
: constant Entity_Id
:= Defining_Entity
(N
);
790 Typ
: Entity_Id
:= Empty
;
793 if Subtype_Mark
(N
) /= Error
then
794 Find_Type
(Subtype_Mark
(N
));
795 Typ
:= Entity
(Subtype_Mark
(N
));
796 Set_Etype
(Designator
, Typ
);
798 if Ekind
(Typ
) = E_Incomplete_Type
799 or else (Is_Class_Wide_Type
(Typ
)
801 Ekind
(Root_Type
(Typ
)) = E_Incomplete_Type
)
804 ("invalid use of incomplete type", Subtype_Mark
(N
));
808 Set_Etype
(Designator
, Any_Type
);
810 end Analyze_Return_Type
;
812 -----------------------------
813 -- Analyze_Subprogram_Body --
814 -----------------------------
816 -- This procedure is called for regular subprogram bodies, generic bodies,
817 -- and for subprogram stubs of both kinds. In the case of stubs, only the
818 -- specification matters, and is used to create a proper declaration for
819 -- the subprogram, or to perform conformance checks.
821 procedure Analyze_Subprogram_Body
(N
: Node_Id
) is
822 Loc
: constant Source_Ptr
:= Sloc
(N
);
823 Body_Spec
: constant Node_Id
:= Specification
(N
);
824 Body_Id
: Entity_Id
:= Defining_Entity
(Body_Spec
);
825 Prev_Id
: constant Entity_Id
:= Current_Entity_In_Scope
(Body_Id
);
826 Body_Deleted
: constant Boolean := False;
830 Spec_Decl
: Node_Id
:= Empty
;
831 Last_Formal
: Entity_Id
:= Empty
;
832 Conformant
: Boolean;
833 Missing_Ret
: Boolean;
836 procedure Check_Following_Pragma
;
837 -- If front-end inlining is enabled, look ahead to recognize a pragma
838 -- that may appear after the body.
840 procedure Check_Following_Pragma
is
844 if Front_End_Inlining
845 and then Is_List_Member
(N
)
846 and then Present
(Spec_Decl
)
847 and then List_Containing
(N
) = List_Containing
(Spec_Decl
)
852 and then Nkind
(Prag
) = N_Pragma
853 and then Get_Pragma_Id
(Chars
(Prag
)) = Pragma_Inline
856 (Expression
(First
(Pragma_Argument_Associations
(Prag
))))
862 end Check_Following_Pragma
;
864 -- Start of processing for Analyze_Subprogram_Body
868 Write_Str
("==== Compiling subprogram body ");
869 Write_Name
(Chars
(Body_Id
));
870 Write_Str
(" from ");
871 Write_Location
(Loc
);
875 Trace_Scope
(N
, Body_Id
, " Analyze subprogram");
877 -- Generic subprograms are handled separately. They always have a
878 -- generic specification. Determine whether current scope has a
879 -- previous declaration.
881 -- If the subprogram body is defined within an instance of the same
882 -- name, the instance appears as a package renaming, and will be hidden
883 -- within the subprogram.
886 and then not Is_Overloadable
(Prev_Id
)
887 and then (Nkind
(Parent
(Prev_Id
)) /= N_Package_Renaming_Declaration
888 or else Comes_From_Source
(Prev_Id
))
890 if Is_Generic_Subprogram
(Prev_Id
) then
892 Set_Is_Compilation_Unit
(Body_Id
, Is_Compilation_Unit
(Spec_Id
));
893 Set_Is_Child_Unit
(Body_Id
, Is_Child_Unit
(Spec_Id
));
895 Analyze_Generic_Subprogram_Body
(N
, Spec_Id
);
899 -- Previous entity conflicts with subprogram name. Attempting to
900 -- enter name will post error.
902 Enter_Name
(Body_Id
);
906 -- Non-generic case, find the subprogram declaration, if one was seen,
907 -- or enter new overloaded entity in the current scope. If the
908 -- Current_Entity is the Body_Id itself, the unit is being analyzed as
909 -- part of the context of one of its subunits. No need to redo the
912 elsif Prev_Id
= Body_Id
913 and then Has_Completion
(Body_Id
)
918 Body_Id
:= Analyze_Subprogram_Specification
(Body_Spec
);
920 if Nkind
(N
) = N_Subprogram_Body_Stub
921 or else No
(Corresponding_Spec
(N
))
923 Spec_Id
:= Find_Corresponding_Spec
(N
);
925 -- If this is a duplicate body, no point in analyzing it
927 if Error_Posted
(N
) then
931 -- A subprogram body should cause freezing of its own declaration,
932 -- but if there was no previous explicit declaration, then the
933 -- subprogram will get frozen too late (there may be code within
934 -- the body that depends on the subprogram having been frozen,
935 -- such as uses of extra formals), so we force it to be frozen
936 -- here. Same holds if the body and the spec are compilation
940 Freeze_Before
(N
, Body_Id
);
942 elsif Nkind
(Parent
(N
)) = N_Compilation_Unit
then
943 Freeze_Before
(N
, Spec_Id
);
946 Spec_Id
:= Corresponding_Spec
(N
);
950 -- Do not inline any subprogram that contains nested subprograms, since
951 -- the backend inlining circuit seems to generate uninitialized
952 -- references in this case. We know this happens in the case of front
953 -- end ZCX support, but it also appears it can happen in other cases as
954 -- well. The backend often rejects attempts to inline in the case of
955 -- nested procedures anyway, so little if anything is lost by this.
956 -- Note that this is test is for the benefit of the back-end. There is
957 -- a separate test for front-end inlining that also rejects nested
960 -- Do not do this test if errors have been detected, because in some
961 -- error cases, this code blows up, and we don't need it anyway if
962 -- there have been errors, since we won't get to the linker anyway.
964 if Comes_From_Source
(Body_Id
)
965 and then Serious_Errors_Detected
= 0
969 P_Ent
:= Scope
(P_Ent
);
970 exit when No
(P_Ent
) or else P_Ent
= Standard_Standard
;
972 if Is_Subprogram
(P_Ent
) then
973 Set_Is_Inlined
(P_Ent
, False);
975 if Comes_From_Source
(P_Ent
)
976 and then Has_Pragma_Inline
(P_Ent
)
979 ("cannot inline& (nested subprogram)?",
986 -- Case of fully private operation in the body of the protected type.
987 -- We must create a declaration for the subprogram, in order to attach
988 -- the protected subprogram that will be used in internal calls.
991 and then Comes_From_Source
(N
)
992 and then Is_Protected_Type
(Current_Scope
)
1001 Formal
:= First_Formal
(Body_Id
);
1003 -- The protected operation always has at least one formal, namely
1004 -- the object itself, but it is only placed in the parameter list
1005 -- if expansion is enabled.
1008 or else Expander_Active
1016 while Present
(Formal
) loop
1018 (Make_Parameter_Specification
(Loc
,
1019 Defining_Identifier
=>
1020 Make_Defining_Identifier
(Sloc
(Formal
),
1021 Chars
=> Chars
(Formal
)),
1022 In_Present
=> In_Present
(Parent
(Formal
)),
1023 Out_Present
=> Out_Present
(Parent
(Formal
)),
1025 New_Reference_To
(Etype
(Formal
), Loc
),
1027 New_Copy_Tree
(Expression
(Parent
(Formal
)))),
1030 Next_Formal
(Formal
);
1033 if Nkind
(Body_Spec
) = N_Procedure_Specification
then
1035 Make_Procedure_Specification
(Loc
,
1036 Defining_Unit_Name
=>
1037 Make_Defining_Identifier
(Sloc
(Body_Id
),
1038 Chars
=> Chars
(Body_Id
)),
1039 Parameter_Specifications
=> Plist
);
1042 Make_Function_Specification
(Loc
,
1043 Defining_Unit_Name
=>
1044 Make_Defining_Identifier
(Sloc
(Body_Id
),
1045 Chars
=> Chars
(Body_Id
)),
1046 Parameter_Specifications
=> Plist
,
1047 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Body_Id
), Loc
));
1051 Make_Subprogram_Declaration
(Loc
,
1052 Specification
=> New_Spec
);
1053 Insert_Before
(N
, Decl
);
1054 Spec_Id
:= Defining_Unit_Name
(New_Spec
);
1056 -- Indicate that the entity comes from source, to ensure that
1057 -- cross-reference information is properly generated. The body
1058 -- itself is rewritten during expansion, and the body entity will
1059 -- not appear in calls to the operation.
1061 Set_Comes_From_Source
(Spec_Id
, True);
1063 Set_Has_Completion
(Spec_Id
);
1064 Set_Convention
(Spec_Id
, Convention_Protected
);
1067 elsif Present
(Spec_Id
) then
1068 Spec_Decl
:= Unit_Declaration_Node
(Spec_Id
);
1071 -- Place subprogram on scope stack, and make formals visible. If there
1072 -- is a spec, the visible entity remains that of the spec.
1074 if Present
(Spec_Id
) then
1075 Generate_Reference
(Spec_Id
, Body_Id
, 'b', Set_Ref
=> False);
1077 Style
.Check_Identifier
(Body_Id
, Spec_Id
);
1080 Set_Is_Compilation_Unit
(Body_Id
, Is_Compilation_Unit
(Spec_Id
));
1081 Set_Is_Child_Unit
(Body_Id
, Is_Child_Unit
(Spec_Id
));
1083 if Is_Abstract
(Spec_Id
) then
1084 Error_Msg_N
("an abstract subprogram cannot have a body", N
);
1087 Set_Convention
(Body_Id
, Convention
(Spec_Id
));
1088 Set_Has_Completion
(Spec_Id
);
1090 if Is_Protected_Type
(Scope
(Spec_Id
)) then
1091 Set_Privals_Chain
(Spec_Id
, New_Elmt_List
);
1094 -- If this is a body generated for a renaming, do not check for
1095 -- full conformance. The check is redundant, because the spec of
1096 -- the body is a copy of the spec in the renaming declaration,
1097 -- and the test can lead to spurious errors on nested defaults.
1099 if Present
(Spec_Decl
)
1100 and then not Comes_From_Source
(N
)
1102 (Nkind
(Original_Node
(Spec_Decl
)) =
1103 N_Subprogram_Renaming_Declaration
1104 or else (Present
(Corresponding_Body
(Spec_Decl
))
1106 Nkind
(Unit_Declaration_Node
1107 (Corresponding_Body
(Spec_Decl
))) =
1108 N_Subprogram_Renaming_Declaration
))
1114 Fully_Conformant
, True, Conformant
, Body_Id
);
1117 -- If the body is not fully conformant, we have to decide if we
1118 -- should analyze it or not. If it has a really messed up profile
1119 -- then we probably should not analyze it, since we will get too
1120 -- many bogus messages.
1122 -- Our decision is to go ahead in the non-fully conformant case
1123 -- only if it is at least mode conformant with the spec. Note
1124 -- that the call to Check_Fully_Conformant has issued the proper
1125 -- error messages to complain about the lack of conformance.
1128 and then not Mode_Conformant
(Body_Id
, Spec_Id
)
1134 if Spec_Id
/= Body_Id
then
1135 Reference_Body_Formals
(Spec_Id
, Body_Id
);
1138 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
1139 Set_Corresponding_Spec
(N
, Spec_Id
);
1140 Install_Formals
(Spec_Id
);
1141 Last_Formal
:= Last_Entity
(Spec_Id
);
1142 New_Scope
(Spec_Id
);
1144 -- Make sure that the subprogram is immediately visible. For
1145 -- child units that have no separate spec this is indispensable.
1146 -- Otherwise it is safe albeit redundant.
1148 Set_Is_Immediately_Visible
(Spec_Id
);
1151 Set_Corresponding_Body
(Unit_Declaration_Node
(Spec_Id
), Body_Id
);
1152 Set_Ekind
(Body_Id
, E_Subprogram_Body
);
1153 Set_Scope
(Body_Id
, Scope
(Spec_Id
));
1155 -- Case of subprogram body with no previous spec
1159 and then Comes_From_Source
(Body_Id
)
1160 and then not Suppress_Style_Checks
(Body_Id
)
1161 and then not In_Instance
1163 Style
.Body_With_No_Spec
(N
);
1166 New_Overloaded_Entity
(Body_Id
);
1168 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
1169 Set_Acts_As_Spec
(N
);
1170 Generate_Definition
(Body_Id
);
1172 (Body_Id
, Body_Id
, 'b', Set_Ref
=> False, Force
=> True);
1173 Generate_Reference_To_Formals
(Body_Id
);
1174 Install_Formals
(Body_Id
);
1175 New_Scope
(Body_Id
);
1179 -- If this is the proper body of a stub, we must verify that the stub
1180 -- conforms to the body, and to the previous spec if one was present.
1181 -- we know already that the body conforms to that spec. This test is
1182 -- only required for subprograms that come from source.
1184 if Nkind
(Parent
(N
)) = N_Subunit
1185 and then Comes_From_Source
(N
)
1186 and then not Error_Posted
(Body_Id
)
1187 and then Nkind
(Corresponding_Stub
(Parent
(N
))) =
1188 N_Subprogram_Body_Stub
1191 Old_Id
: constant Entity_Id
:=
1193 (Specification
(Corresponding_Stub
(Parent
(N
))));
1195 Conformant
: Boolean := False;
1198 if No
(Spec_Id
) then
1199 Check_Fully_Conformant
(Body_Id
, Old_Id
);
1203 (Body_Id
, Old_Id
, Fully_Conformant
, False, Conformant
);
1205 if not Conformant
then
1207 -- The stub was taken to be a new declaration. Indicate
1208 -- that it lacks a body.
1210 Set_Has_Completion
(Old_Id
, False);
1216 Set_Has_Completion
(Body_Id
);
1217 Check_Eliminated
(Body_Id
);
1219 if Nkind
(N
) = N_Subprogram_Body_Stub
then
1222 elsif Present
(Spec_Id
)
1223 and then Expander_Active
1225 Check_Following_Pragma
;
1227 if Is_Always_Inlined
(Spec_Id
)
1228 or else (Has_Pragma_Inline
(Spec_Id
) and then Front_End_Inlining
)
1230 Build_Body_To_Inline
(N
, Spec_Id
);
1234 -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis
1235 -- if its specification we have to install the private withed units.
1237 if Is_Compilation_Unit
(Body_Id
)
1238 and then Scope
(Body_Id
) = Standard_Standard
1240 Install_Private_With_Clauses
(Body_Id
);
1243 -- Now we can go on to analyze the body
1245 HSS
:= Handled_Statement_Sequence
(N
);
1246 Set_Actual_Subtypes
(N
, Current_Scope
);
1247 Analyze_Declarations
(Declarations
(N
));
1250 Process_End_Label
(HSS
, 't', Current_Scope
);
1252 Check_Subprogram_Order
(N
);
1253 Set_Analyzed
(Body_Id
);
1255 -- If we have a separate spec, then the analysis of the declarations
1256 -- caused the entities in the body to be chained to the spec id, but
1257 -- we want them chained to the body id. Only the formal parameters
1258 -- end up chained to the spec id in this case.
1260 if Present
(Spec_Id
) then
1262 -- If a parent unit is categorized, the context of a subunit must
1263 -- conform to the categorization. Conversely, if a child unit is
1264 -- categorized, the parents themselves must conform.
1266 if Nkind
(Parent
(N
)) = N_Subunit
then
1267 Validate_Categorization_Dependency
(N
, Spec_Id
);
1269 elsif Is_Child_Unit
(Spec_Id
) then
1270 Validate_Categorization_Dependency
1271 (Unit_Declaration_Node
(Spec_Id
), Spec_Id
);
1274 if Present
(Last_Formal
) then
1276 (Last_Entity
(Body_Id
), Next_Entity
(Last_Formal
));
1277 Set_Next_Entity
(Last_Formal
, Empty
);
1278 Set_Last_Entity
(Body_Id
, Last_Entity
(Spec_Id
));
1279 Set_Last_Entity
(Spec_Id
, Last_Formal
);
1282 Set_First_Entity
(Body_Id
, First_Entity
(Spec_Id
));
1283 Set_Last_Entity
(Body_Id
, Last_Entity
(Spec_Id
));
1284 Set_First_Entity
(Spec_Id
, Empty
);
1285 Set_Last_Entity
(Spec_Id
, Empty
);
1289 -- If function, check return statements
1291 if Nkind
(Body_Spec
) = N_Function_Specification
then
1296 if Present
(Spec_Id
) then
1302 if Return_Present
(Id
) then
1303 Check_Returns
(HSS
, 'F', Missing_Ret
);
1306 Set_Has_Missing_Return
(Id
);
1309 elsif not Is_Machine_Code_Subprogram
(Id
)
1310 and then not Body_Deleted
1312 Error_Msg_N
("missing RETURN statement in function body", N
);
1316 -- If procedure with No_Return, check returns
1318 elsif Nkind
(Body_Spec
) = N_Procedure_Specification
1319 and then Present
(Spec_Id
)
1320 and then No_Return
(Spec_Id
)
1322 Check_Returns
(HSS
, 'P', Missing_Ret
);
1325 -- Now we are going to check for variables that are never modified in
1326 -- the body of the procedure. We omit these checks if the first
1327 -- statement of the procedure raises an exception. In particular this
1328 -- deals with the common idiom of a stubbed function, which might
1329 -- appear as something like
1331 -- function F (A : Integer) return Some_Type;
1334 -- raise Program_Error;
1338 -- Here the purpose of X is simply to satisfy the (annoying)
1339 -- requirement in Ada that there be at least one return, and we
1340 -- certainly do not want to go posting warnings on X that it is not
1344 Stm
: Node_Id
:= First
(Statements
(HSS
));
1347 -- Skip an initial label (for one thing this occurs when we are in
1348 -- front end ZCX mode, but in any case it is irrelevant).
1350 if Nkind
(Stm
) = N_Label
then
1354 -- Do the test on the original statement before expansion
1357 Ostm
: constant Node_Id
:= Original_Node
(Stm
);
1360 -- If explicit raise statement, return with no checks
1362 if Nkind
(Ostm
) = N_Raise_Statement
then
1365 -- Check for explicit call cases which likely raise an exception
1367 elsif Nkind
(Ostm
) = N_Procedure_Call_Statement
then
1368 if Is_Entity_Name
(Name
(Ostm
)) then
1370 Ent
: constant Entity_Id
:= Entity
(Name
(Ostm
));
1373 -- If the procedure is marked No_Return, then likely it
1374 -- raises an exception, but in any case it is not coming
1375 -- back here, so no need to check beyond the call.
1377 if Ekind
(Ent
) = E_Procedure
1378 and then No_Return
(Ent
)
1382 -- If the procedure name is Raise_Exception, then also
1383 -- assume that it raises an exception. The main target
1384 -- here is Ada.Exceptions.Raise_Exception, but this name
1385 -- is pretty evocative in any context! Note that the
1386 -- procedure in Ada.Exceptions is not marked No_Return
1387 -- because of the annoying case of the null exception Id.
1389 elsif Chars
(Ent
) = Name_Raise_Exception
then
1398 -- Check for variables that are never modified
1404 -- If there is a separate spec, then transfer Never_Set_In_Source
1405 -- flags from out parameters to the corresponding entities in the
1406 -- body. The reason we do that is we want to post error flags on
1407 -- the body entities, not the spec entities.
1409 if Present
(Spec_Id
) then
1410 E1
:= First_Entity
(Spec_Id
);
1412 while Present
(E1
) loop
1413 if Ekind
(E1
) = E_Out_Parameter
then
1414 E2
:= First_Entity
(Body_Id
);
1415 while Present
(E2
) loop
1416 exit when Chars
(E1
) = Chars
(E2
);
1420 if Present
(E2
) then
1421 Set_Never_Set_In_Source
(E2
, Never_Set_In_Source
(E1
));
1429 -- Check references in body unless it was deleted. Note that the
1430 -- check of Body_Deleted here is not just for efficiency, it is
1431 -- necessary to avoid junk warnings on formal parameters.
1433 if not Body_Deleted
then
1434 Check_References
(Body_Id
);
1437 end Analyze_Subprogram_Body
;
1439 ------------------------------------
1440 -- Analyze_Subprogram_Declaration --
1441 ------------------------------------
1443 procedure Analyze_Subprogram_Declaration
(N
: Node_Id
) is
1444 Designator
: constant Entity_Id
:=
1445 Analyze_Subprogram_Specification
(Specification
(N
));
1446 Scop
: constant Entity_Id
:= Current_Scope
;
1448 -- Start of processing for Analyze_Subprogram_Declaration
1451 Generate_Definition
(Designator
);
1453 -- Check for RCI unit subprogram declarations against in-lined
1454 -- subprograms and subprograms having access parameter or limited
1455 -- parameter without Read and Write (RM E.2.3(12-13)).
1457 Validate_RCI_Subprogram_Declaration
(N
);
1461 Defining_Entity
(N
),
1462 " Analyze subprogram spec. ");
1464 if Debug_Flag_C
then
1465 Write_Str
("==== Compiling subprogram spec ");
1466 Write_Name
(Chars
(Designator
));
1467 Write_Str
(" from ");
1468 Write_Location
(Sloc
(N
));
1472 New_Overloaded_Entity
(Designator
);
1473 Check_Delayed_Subprogram
(Designator
);
1475 -- What is the following code for, it used to be
1477 -- ??? Set_Suppress_Elaboration_Checks
1478 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator));
1480 -- The following seems equivalent, but a bit dubious
1482 if Elaboration_Checks_Suppressed
(Designator
) then
1483 Set_Kill_Elaboration_Checks
(Designator
);
1486 if Scop
/= Standard_Standard
1487 and then not Is_Child_Unit
(Designator
)
1489 Set_Categorization_From_Scope
(Designator
, Scop
);
1491 -- For a compilation unit, check for library-unit pragmas
1493 New_Scope
(Designator
);
1494 Set_Categorization_From_Pragmas
(N
);
1495 Validate_Categorization_Dependency
(N
, Designator
);
1499 -- For a compilation unit, set body required. This flag will only be
1500 -- reset if a valid Import or Interface pragma is processed later on.
1502 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
1503 Set_Body_Required
(Parent
(N
), True);
1506 Generate_Reference_To_Formals
(Designator
);
1507 Check_Eliminated
(Designator
);
1509 if Comes_From_Source
(N
)
1510 and then Is_List_Member
(N
)
1512 Check_Overriding_Operation
(N
, Designator
);
1515 end Analyze_Subprogram_Declaration
;
1517 --------------------------------------
1518 -- Analyze_Subprogram_Specification --
1519 --------------------------------------
1521 -- Reminder: N here really is a subprogram specification (not a subprogram
1522 -- declaration). This procedure is called to analyze the specification in
1523 -- both subprogram bodies and subprogram declarations (specs).
1525 function Analyze_Subprogram_Specification
(N
: Node_Id
) return Entity_Id
is
1526 Designator
: constant Entity_Id
:= Defining_Entity
(N
);
1527 Formals
: constant List_Id
:= Parameter_Specifications
(N
);
1530 Generate_Definition
(Designator
);
1532 if Nkind
(N
) = N_Function_Specification
then
1533 Set_Ekind
(Designator
, E_Function
);
1534 Set_Mechanism
(Designator
, Default_Mechanism
);
1537 Set_Ekind
(Designator
, E_Procedure
);
1538 Set_Etype
(Designator
, Standard_Void_Type
);
1541 -- Introduce new scope for analysis of the formals and of the
1544 Set_Scope
(Designator
, Current_Scope
);
1546 if Present
(Formals
) then
1547 New_Scope
(Designator
);
1548 Process_Formals
(Formals
, N
);
1551 elsif Nkind
(N
) = N_Function_Specification
then
1552 Analyze_Return_Type
(N
);
1555 if Nkind
(N
) = N_Function_Specification
then
1556 if Nkind
(Designator
) = N_Defining_Operator_Symbol
then
1557 Valid_Operator_Definition
(Designator
);
1560 May_Need_Actuals
(Designator
);
1562 if Is_Abstract
(Etype
(Designator
))
1563 and then Nkind
(Parent
(N
))
1564 /= N_Abstract_Subprogram_Declaration
1565 and then (Nkind
(Parent
(N
)))
1566 /= N_Formal_Abstract_Subprogram_Declaration
1567 and then (Nkind
(Parent
(N
)) /= N_Subprogram_Renaming_Declaration
1568 or else not Is_Entity_Name
(Name
(Parent
(N
)))
1569 or else not Is_Abstract
(Entity
(Name
(Parent
(N
)))))
1572 ("function that returns abstract type must be abstract", N
);
1577 end Analyze_Subprogram_Specification
;
1579 --------------------------
1580 -- Build_Body_To_Inline --
1581 --------------------------
1583 procedure Build_Body_To_Inline
(N
: Node_Id
; Subp
: Entity_Id
) is
1584 Decl
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
1585 Original_Body
: Node_Id
;
1586 Body_To_Analyze
: Node_Id
;
1587 Max_Size
: constant := 10;
1588 Stat_Count
: Integer := 0;
1590 function Has_Excluded_Declaration
(Decls
: List_Id
) return Boolean;
1591 -- Check for declarations that make inlining not worthwhile
1593 function Has_Excluded_Statement
(Stats
: List_Id
) return Boolean;
1594 -- Check for statements that make inlining not worthwhile: any tasking
1595 -- statement, nested at any level. Keep track of total number of
1596 -- elementary statements, as a measure of acceptable size.
1598 function Has_Pending_Instantiation
return Boolean;
1599 -- If some enclosing body contains instantiations that appear before
1600 -- the corresponding generic body, the enclosing body has a freeze node
1601 -- so that it can be elaborated after the generic itself. This might
1602 -- conflict with subsequent inlinings, so that it is unsafe to try to
1603 -- inline in such a case.
1605 procedure Remove_Pragmas
;
1606 -- A pragma Unreferenced that mentions a formal parameter has no
1607 -- meaning when the body is inlined and the formals are rewritten.
1608 -- Remove it from body to inline. The analysis of the non-inlined body
1609 -- will handle the pragma properly.
1611 function Uses_Secondary_Stack
(Bod
: Node_Id
) return Boolean;
1612 -- If the body of the subprogram includes a call that returns an
1613 -- unconstrained type, the secondary stack is involved, and it
1614 -- is not worth inlining.
1616 ------------------------------
1617 -- Has_Excluded_Declaration --
1618 ------------------------------
1620 function Has_Excluded_Declaration
(Decls
: List_Id
) return Boolean is
1623 function Is_Unchecked_Conversion
(D
: Node_Id
) return Boolean;
1624 -- Nested subprograms make a given body ineligible for inlining, but
1625 -- we make an exception for instantiations of unchecked conversion.
1626 -- The body has not been analyzed yet, so check the name, and verify
1627 -- that the visible entity with that name is the predefined unit.
1629 -----------------------------
1630 -- Is_Unchecked_Conversion --
1631 -----------------------------
1633 function Is_Unchecked_Conversion
(D
: Node_Id
) return Boolean is
1634 Id
: constant Node_Id
:= Name
(D
);
1638 if Nkind
(Id
) = N_Identifier
1639 and then Chars
(Id
) = Name_Unchecked_Conversion
1641 Conv
:= Current_Entity
(Id
);
1643 elsif Nkind
(Id
) = N_Selected_Component
1644 and then Chars
(Selector_Name
(Id
)) = Name_Unchecked_Conversion
1646 Conv
:= Current_Entity
(Selector_Name
(Id
));
1654 and then Scope
(Conv
) = Standard_Standard
1655 and then Is_Intrinsic_Subprogram
(Conv
);
1656 end Is_Unchecked_Conversion
;
1658 -- Start of processing for Has_Excluded_Declaration
1663 while Present
(D
) loop
1664 if (Nkind
(D
) = N_Function_Instantiation
1665 and then not Is_Unchecked_Conversion
(D
))
1666 or else Nkind
(D
) = N_Protected_Type_Declaration
1667 or else Nkind
(D
) = N_Package_Declaration
1668 or else Nkind
(D
) = N_Package_Instantiation
1669 or else Nkind
(D
) = N_Subprogram_Body
1670 or else Nkind
(D
) = N_Procedure_Instantiation
1671 or else Nkind
(D
) = N_Task_Type_Declaration
1674 ("cannot inline & (non-allowed declaration)?", D
, Subp
);
1682 end Has_Excluded_Declaration
;
1684 ----------------------------
1685 -- Has_Excluded_Statement --
1686 ----------------------------
1688 function Has_Excluded_Statement
(Stats
: List_Id
) return Boolean is
1695 while Present
(S
) loop
1696 Stat_Count
:= Stat_Count
+ 1;
1698 if Nkind
(S
) = N_Abort_Statement
1699 or else Nkind
(S
) = N_Asynchronous_Select
1700 or else Nkind
(S
) = N_Conditional_Entry_Call
1701 or else Nkind
(S
) = N_Delay_Relative_Statement
1702 or else Nkind
(S
) = N_Delay_Until_Statement
1703 or else Nkind
(S
) = N_Selective_Accept
1704 or else Nkind
(S
) = N_Timed_Entry_Call
1707 ("cannot inline & (non-allowed statement)?", S
, Subp
);
1710 elsif Nkind
(S
) = N_Block_Statement
then
1711 if Present
(Declarations
(S
))
1712 and then Has_Excluded_Declaration
(Declarations
(S
))
1716 elsif Present
(Handled_Statement_Sequence
(S
))
1719 (Exception_Handlers
(Handled_Statement_Sequence
(S
)))
1721 Has_Excluded_Statement
1722 (Statements
(Handled_Statement_Sequence
(S
))))
1727 elsif Nkind
(S
) = N_Case_Statement
then
1728 E
:= First
(Alternatives
(S
));
1729 while Present
(E
) loop
1730 if Has_Excluded_Statement
(Statements
(E
)) then
1737 elsif Nkind
(S
) = N_If_Statement
then
1738 if Has_Excluded_Statement
(Then_Statements
(S
)) then
1742 if Present
(Elsif_Parts
(S
)) then
1743 E
:= First
(Elsif_Parts
(S
));
1744 while Present
(E
) loop
1745 if Has_Excluded_Statement
(Then_Statements
(E
)) then
1752 if Present
(Else_Statements
(S
))
1753 and then Has_Excluded_Statement
(Else_Statements
(S
))
1758 elsif Nkind
(S
) = N_Loop_Statement
1759 and then Has_Excluded_Statement
(Statements
(S
))
1768 end Has_Excluded_Statement
;
1770 -------------------------------
1771 -- Has_Pending_Instantiation --
1772 -------------------------------
1774 function Has_Pending_Instantiation
return Boolean is
1775 S
: Entity_Id
:= Current_Scope
;
1778 while Present
(S
) loop
1779 if Is_Compilation_Unit
(S
)
1780 or else Is_Child_Unit
(S
)
1783 elsif Ekind
(S
) = E_Package
1784 and then Has_Forward_Instantiation
(S
)
1793 end Has_Pending_Instantiation
;
1795 --------------------
1796 -- Remove_Pragmas --
1797 --------------------
1799 procedure Remove_Pragmas
is
1804 Decl
:= First
(Declarations
(Body_To_Analyze
));
1805 while Present
(Decl
) loop
1808 if Nkind
(Decl
) = N_Pragma
1809 and then Chars
(Decl
) = Name_Unreferenced
1818 --------------------------
1819 -- Uses_Secondary_Stack --
1820 --------------------------
1822 function Uses_Secondary_Stack
(Bod
: Node_Id
) return Boolean is
1823 function Check_Call
(N
: Node_Id
) return Traverse_Result
;
1824 -- Look for function calls that return an unconstrained type
1830 function Check_Call
(N
: Node_Id
) return Traverse_Result
is
1832 if Nkind
(N
) = N_Function_Call
1833 and then Is_Entity_Name
(Name
(N
))
1834 and then Is_Composite_Type
(Etype
(Entity
(Name
(N
))))
1835 and then not Is_Constrained
(Etype
(Entity
(Name
(N
))))
1838 ("cannot inline & (call returns unconstrained type)?",
1846 function Check_Calls
is new Traverse_Func
(Check_Call
);
1849 return Check_Calls
(Bod
) = Abandon
;
1850 end Uses_Secondary_Stack
;
1852 -- Start of processing for Build_Body_To_Inline
1855 if Nkind
(Decl
) = N_Subprogram_Declaration
1856 and then Present
(Body_To_Inline
(Decl
))
1858 return; -- Done already.
1860 -- Functions that return unconstrained composite types will require
1861 -- secondary stack handling, and cannot currently be inlined.
1862 -- Ditto for functions that return controlled types, where controlled
1863 -- actions interfere in complex ways with inlining.
1865 elsif Ekind
(Subp
) = E_Function
1866 and then not Is_Scalar_Type
(Etype
(Subp
))
1867 and then not Is_Access_Type
(Etype
(Subp
))
1868 and then not Is_Constrained
(Etype
(Subp
))
1871 ("cannot inline & (unconstrained return type)?", N
, Subp
);
1874 elsif Ekind
(Subp
) = E_Function
1875 and then Controlled_Type
(Etype
(Subp
))
1878 ("cannot inline & (controlled return type)?", N
, Subp
);
1882 if Present
(Declarations
(N
))
1883 and then Has_Excluded_Declaration
(Declarations
(N
))
1888 if Present
(Handled_Statement_Sequence
(N
)) then
1889 if Present
(Exception_Handlers
(Handled_Statement_Sequence
(N
))) then
1891 ("cannot inline& (exception handler)?",
1892 First
(Exception_Handlers
(Handled_Statement_Sequence
(N
))),
1896 Has_Excluded_Statement
1897 (Statements
(Handled_Statement_Sequence
(N
)))
1903 -- We do not inline a subprogram that is too large, unless it is
1904 -- marked Inline_Always. This pragma does not suppress the other
1905 -- checks on inlining (forbidden declarations, handlers, etc).
1907 if Stat_Count
> Max_Size
1908 and then not Is_Always_Inlined
(Subp
)
1910 Cannot_Inline
("cannot inline& (body too large)?", N
, Subp
);
1914 if Has_Pending_Instantiation
then
1916 ("cannot inline& (forward instance within enclosing body)?",
1921 -- Within an instance, the body to inline must be treated as a nested
1922 -- generic, so that the proper global references are preserved.
1925 Save_Env
(Scope
(Current_Scope
), Scope
(Current_Scope
));
1926 Original_Body
:= Copy_Generic_Node
(N
, Empty
, True);
1928 Original_Body
:= Copy_Separate_Tree
(N
);
1931 -- We need to capture references to the formals in order to substitute
1932 -- the actuals at the point of inlining, i.e. instantiation. To treat
1933 -- the formals as globals to the body to inline, we nest it within
1934 -- a dummy parameterless subprogram, declared within the real one.
1935 -- To avoid generating an internal name (which is never public, and
1936 -- which affects serial numbers of other generated names), we use
1937 -- an internal symbol that cannot conflict with user declarations.
1939 Set_Parameter_Specifications
(Specification
(Original_Body
), No_List
);
1940 Set_Defining_Unit_Name
1941 (Specification
(Original_Body
),
1942 Make_Defining_Identifier
(Sloc
(N
), Name_uParent
));
1943 Set_Corresponding_Spec
(Original_Body
, Empty
);
1945 Body_To_Analyze
:= Copy_Generic_Node
(Original_Body
, Empty
, False);
1947 -- Set return type of function, which is also global and does not need
1950 if Ekind
(Subp
) = E_Function
then
1951 Set_Subtype_Mark
(Specification
(Body_To_Analyze
),
1952 New_Occurrence_Of
(Etype
(Subp
), Sloc
(N
)));
1955 if No
(Declarations
(N
)) then
1956 Set_Declarations
(N
, New_List
(Body_To_Analyze
));
1958 Append
(Body_To_Analyze
, Declarations
(N
));
1961 Expander_Mode_Save_And_Set
(False);
1964 Analyze
(Body_To_Analyze
);
1965 New_Scope
(Defining_Entity
(Body_To_Analyze
));
1966 Save_Global_References
(Original_Body
);
1968 Remove
(Body_To_Analyze
);
1970 Expander_Mode_Restore
;
1976 -- If secondary stk used there is no point in inlining. We have
1977 -- already issued the warning in this case, so nothing to do.
1979 if Uses_Secondary_Stack
(Body_To_Analyze
) then
1983 Set_Body_To_Inline
(Decl
, Original_Body
);
1984 Set_Ekind
(Defining_Entity
(Original_Body
), Ekind
(Subp
));
1985 Set_Is_Inlined
(Subp
);
1986 end Build_Body_To_Inline
;
1992 procedure Cannot_Inline
(Msg
: String; N
: Node_Id
; Subp
: Entity_Id
) is
1994 -- Do not emit warning if this is a predefined unit which is not
1995 -- the main unit. With validity checks enabled, some predefined
1996 -- subprograms may contain nested subprograms and become ineligible
1999 if Is_Predefined_File_Name
(Unit_File_Name
(Get_Source_Unit
(Subp
)))
2000 and then not In_Extended_Main_Source_Unit
(Subp
)
2004 elsif Is_Always_Inlined
(Subp
) then
2006 -- Remove last character (question mark) to make this into an error,
2007 -- because the Inline_Always pragma cannot be obeyed.
2009 Error_Msg_NE
(Msg
(1 .. Msg
'Length - 1), N
, Subp
);
2011 elsif Ineffective_Inline_Warnings
then
2012 Error_Msg_NE
(Msg
, N
, Subp
);
2016 -----------------------
2017 -- Check_Conformance --
2018 -----------------------
2020 procedure Check_Conformance
2021 (New_Id
: Entity_Id
;
2023 Ctype
: Conformance_Type
;
2025 Conforms
: out Boolean;
2026 Err_Loc
: Node_Id
:= Empty
;
2027 Get_Inst
: Boolean := False)
2029 Old_Type
: constant Entity_Id
:= Etype
(Old_Id
);
2030 New_Type
: constant Entity_Id
:= Etype
(New_Id
);
2031 Old_Formal
: Entity_Id
;
2032 New_Formal
: Entity_Id
;
2034 procedure Conformance_Error
(Msg
: String; N
: Node_Id
:= New_Id
);
2035 -- Post error message for conformance error on given node. Two messages
2036 -- are output. The first points to the previous declaration with a
2037 -- general "no conformance" message. The second is the detailed reason,
2038 -- supplied as Msg. The parameter N provide information for a possible
2039 -- & insertion in the message, and also provides the location for
2040 -- posting the message in the absence of a specified Err_Loc location.
2042 -----------------------
2043 -- Conformance_Error --
2044 -----------------------
2046 procedure Conformance_Error
(Msg
: String; N
: Node_Id
:= New_Id
) is
2053 if No
(Err_Loc
) then
2059 Error_Msg_Sloc
:= Sloc
(Old_Id
);
2062 when Type_Conformant
=>
2064 ("not type conformant with declaration#!", Enode
);
2066 when Mode_Conformant
=>
2068 ("not mode conformant with declaration#!", Enode
);
2070 when Subtype_Conformant
=>
2072 ("not subtype conformant with declaration#!", Enode
);
2074 when Fully_Conformant
=>
2076 ("not fully conformant with declaration#!", Enode
);
2079 Error_Msg_NE
(Msg
, Enode
, N
);
2081 end Conformance_Error
;
2083 -- Start of processing for Check_Conformance
2088 -- We need a special case for operators, since they don't appear
2091 if Ctype
= Type_Conformant
then
2092 if Ekind
(New_Id
) = E_Operator
2093 and then Operator_Matches_Spec
(New_Id
, Old_Id
)
2099 -- If both are functions/operators, check return types conform
2101 if Old_Type
/= Standard_Void_Type
2102 and then New_Type
/= Standard_Void_Type
2104 if not Conforming_Types
(Old_Type
, New_Type
, Ctype
, Get_Inst
) then
2105 Conformance_Error
("return type does not match!", New_Id
);
2109 -- If either is a function/operator and the other isn't, error
2111 elsif Old_Type
/= Standard_Void_Type
2112 or else New_Type
/= Standard_Void_Type
2114 Conformance_Error
("functions can only match functions!", New_Id
);
2118 -- In subtype conformant case, conventions must match (RM 6.3.1(16))
2119 -- If this is a renaming as body, refine error message to indicate that
2120 -- the conflict is with the original declaration. If the entity is not
2121 -- frozen, the conventions don't have to match, the one of the renamed
2122 -- entity is inherited.
2124 if Ctype
>= Subtype_Conformant
then
2125 if Convention
(Old_Id
) /= Convention
(New_Id
) then
2127 if not Is_Frozen
(New_Id
) then
2130 elsif Present
(Err_Loc
)
2131 and then Nkind
(Err_Loc
) = N_Subprogram_Renaming_Declaration
2132 and then Present
(Corresponding_Spec
(Err_Loc
))
2134 Error_Msg_Name_1
:= Chars
(New_Id
);
2136 Name_Ada
+ Convention_Id
'Pos (Convention
(New_Id
));
2138 Conformance_Error
("prior declaration for% has convention %!");
2141 Conformance_Error
("calling conventions do not match!");
2146 elsif Is_Formal_Subprogram
(Old_Id
)
2147 or else Is_Formal_Subprogram
(New_Id
)
2149 Conformance_Error
("formal subprograms not allowed!");
2154 -- Deal with parameters
2156 -- Note: we use the entity information, rather than going directly
2157 -- to the specification in the tree. This is not only simpler, but
2158 -- absolutely necessary for some cases of conformance tests between
2159 -- operators, where the declaration tree simply does not exist!
2161 Old_Formal
:= First_Formal
(Old_Id
);
2162 New_Formal
:= First_Formal
(New_Id
);
2164 while Present
(Old_Formal
) and then Present
(New_Formal
) loop
2165 if Ctype
= Fully_Conformant
then
2167 -- Names must match. Error message is more accurate if we do
2168 -- this before checking that the types of the formals match.
2170 if Chars
(Old_Formal
) /= Chars
(New_Formal
) then
2171 Conformance_Error
("name & does not match!", New_Formal
);
2173 -- Set error posted flag on new formal as well to stop
2174 -- junk cascaded messages in some cases.
2176 Set_Error_Posted
(New_Formal
);
2181 -- Types must always match. In the visible part of an instance,
2182 -- usual overloading rules for dispatching operations apply, and
2183 -- we check base types (not the actual subtypes).
2185 if In_Instance_Visible_Part
2186 and then Is_Dispatching_Operation
(New_Id
)
2188 if not Conforming_Types
2189 (Base_Type
(Etype
(Old_Formal
)),
2190 Base_Type
(Etype
(New_Formal
)), Ctype
, Get_Inst
)
2192 Conformance_Error
("type of & does not match!", New_Formal
);
2196 elsif not Conforming_Types
2197 (Etype
(Old_Formal
), Etype
(New_Formal
), Ctype
, Get_Inst
)
2199 Conformance_Error
("type of & does not match!", New_Formal
);
2203 -- For mode conformance, mode must match
2205 if Ctype
>= Mode_Conformant
2206 and then Parameter_Mode
(Old_Formal
) /= Parameter_Mode
(New_Formal
)
2208 Conformance_Error
("mode of & does not match!", New_Formal
);
2212 -- Full conformance checks
2214 if Ctype
= Fully_Conformant
then
2216 -- We have checked already that names match. Check default
2217 -- expressions for in parameters
2219 if Parameter_Mode
(Old_Formal
) = E_In_Parameter
then
2221 NewD
: constant Boolean :=
2222 Present
(Default_Value
(New_Formal
));
2223 OldD
: constant Boolean :=
2224 Present
(Default_Value
(Old_Formal
));
2226 if NewD
or OldD
then
2228 -- The old default value has been analyzed because the
2229 -- current full declaration will have frozen everything
2230 -- before. The new default values have not been
2231 -- analyzed, so analyze them now before we check for
2236 Analyze_Per_Use_Expression
2237 (Default_Value
(New_Formal
), Etype
(New_Formal
));
2241 if not (NewD
and OldD
)
2242 or else not Fully_Conformant_Expressions
2243 (Default_Value
(Old_Formal
),
2244 Default_Value
(New_Formal
))
2247 ("default expression for & does not match!",
2256 -- A couple of special checks for Ada 83 mode. These checks are
2257 -- skipped if either entity is an operator in package Standard.
2258 -- or if either old or new instance is not from the source program.
2260 if Ada_Version
= Ada_83
2261 and then Sloc
(Old_Id
) > Standard_Location
2262 and then Sloc
(New_Id
) > Standard_Location
2263 and then Comes_From_Source
(Old_Id
)
2264 and then Comes_From_Source
(New_Id
)
2267 Old_Param
: constant Node_Id
:= Declaration_Node
(Old_Formal
);
2268 New_Param
: constant Node_Id
:= Declaration_Node
(New_Formal
);
2271 -- Explicit IN must be present or absent in both cases. This
2272 -- test is required only in the full conformance case.
2274 if In_Present
(Old_Param
) /= In_Present
(New_Param
)
2275 and then Ctype
= Fully_Conformant
2278 ("(Ada 83) IN must appear in both declarations",
2283 -- Grouping (use of comma in param lists) must be the same
2284 -- This is where we catch a misconformance like:
2287 -- A : Integer; B : Integer
2289 -- which are represented identically in the tree except
2290 -- for the setting of the flags More_Ids and Prev_Ids.
2292 if More_Ids
(Old_Param
) /= More_Ids
(New_Param
)
2293 or else Prev_Ids
(Old_Param
) /= Prev_Ids
(New_Param
)
2296 ("grouping of & does not match!", New_Formal
);
2302 Next_Formal
(Old_Formal
);
2303 Next_Formal
(New_Formal
);
2306 if Present
(Old_Formal
) then
2307 Conformance_Error
("too few parameters!");
2310 elsif Present
(New_Formal
) then
2311 Conformance_Error
("too many parameters!", New_Formal
);
2315 end Check_Conformance
;
2317 ------------------------------
2318 -- Check_Delayed_Subprogram --
2319 ------------------------------
2321 procedure Check_Delayed_Subprogram
(Designator
: Entity_Id
) is
2324 procedure Possible_Freeze
(T
: Entity_Id
);
2325 -- T is the type of either a formal parameter or of the return type.
2326 -- If T is not yet frozen and needs a delayed freeze, then the
2327 -- subprogram itself must be delayed.
2329 ---------------------
2330 -- Possible_Freeze --
2331 ---------------------
2333 procedure Possible_Freeze
(T
: Entity_Id
) is
2335 if Has_Delayed_Freeze
(T
)
2336 and then not Is_Frozen
(T
)
2338 Set_Has_Delayed_Freeze
(Designator
);
2340 elsif Is_Access_Type
(T
)
2341 and then Has_Delayed_Freeze
(Designated_Type
(T
))
2342 and then not Is_Frozen
(Designated_Type
(T
))
2344 Set_Has_Delayed_Freeze
(Designator
);
2346 end Possible_Freeze
;
2348 -- Start of processing for Check_Delayed_Subprogram
2351 -- Never need to freeze abstract subprogram
2353 if Is_Abstract
(Designator
) then
2356 -- Need delayed freeze if return type itself needs a delayed
2357 -- freeze and is not yet frozen.
2359 Possible_Freeze
(Etype
(Designator
));
2360 Possible_Freeze
(Base_Type
(Etype
(Designator
))); -- needed ???
2362 -- Need delayed freeze if any of the formal types themselves need
2363 -- a delayed freeze and are not yet frozen.
2365 F
:= First_Formal
(Designator
);
2366 while Present
(F
) loop
2367 Possible_Freeze
(Etype
(F
));
2368 Possible_Freeze
(Base_Type
(Etype
(F
))); -- needed ???
2373 -- Mark functions that return by reference. Note that it cannot be
2374 -- done for delayed_freeze subprograms because the underlying
2375 -- returned type may not be known yet (for private types)
2377 if not Has_Delayed_Freeze
(Designator
)
2378 and then Expander_Active
2381 Typ
: constant Entity_Id
:= Etype
(Designator
);
2382 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
2385 if Is_Return_By_Reference_Type
(Typ
) then
2386 Set_Returns_By_Ref
(Designator
);
2388 elsif Present
(Utyp
) and then Controlled_Type
(Utyp
) then
2389 Set_Returns_By_Ref
(Designator
);
2393 end Check_Delayed_Subprogram
;
2395 ------------------------------------
2396 -- Check_Discriminant_Conformance --
2397 ------------------------------------
2399 procedure Check_Discriminant_Conformance
2404 Old_Discr
: Entity_Id
:= First_Discriminant
(Prev
);
2405 New_Discr
: Node_Id
:= First
(Discriminant_Specifications
(N
));
2406 New_Discr_Id
: Entity_Id
;
2407 New_Discr_Type
: Entity_Id
;
2409 procedure Conformance_Error
(Msg
: String; N
: Node_Id
);
2410 -- Post error message for conformance error on given node. Two messages
2411 -- are output. The first points to the previous declaration with a
2412 -- general "no conformance" message. The second is the detailed reason,
2413 -- supplied as Msg. The parameter N provide information for a possible
2414 -- & insertion in the message.
2416 -----------------------
2417 -- Conformance_Error --
2418 -----------------------
2420 procedure Conformance_Error
(Msg
: String; N
: Node_Id
) is
2422 Error_Msg_Sloc
:= Sloc
(Prev_Loc
);
2423 Error_Msg_N
("not fully conformant with declaration#!", N
);
2424 Error_Msg_NE
(Msg
, N
, N
);
2425 end Conformance_Error
;
2427 -- Start of processing for Check_Discriminant_Conformance
2430 while Present
(Old_Discr
) and then Present
(New_Discr
) loop
2432 New_Discr_Id
:= Defining_Identifier
(New_Discr
);
2434 -- The subtype mark of the discriminant on the full type has not
2435 -- been analyzed so we do it here. For an access discriminant a new
2438 if Nkind
(Discriminant_Type
(New_Discr
)) = N_Access_Definition
then
2440 Access_Definition
(N
, Discriminant_Type
(New_Discr
));
2443 Analyze
(Discriminant_Type
(New_Discr
));
2444 New_Discr_Type
:= Etype
(Discriminant_Type
(New_Discr
));
2447 if not Conforming_Types
2448 (Etype
(Old_Discr
), New_Discr_Type
, Fully_Conformant
)
2450 Conformance_Error
("type of & does not match!", New_Discr_Id
);
2453 -- Treat the new discriminant as an occurrence of the old one,
2454 -- for navigation purposes, and fill in some semantic
2455 -- information, for completeness.
2457 Generate_Reference
(Old_Discr
, New_Discr_Id
, 'r');
2458 Set_Etype
(New_Discr_Id
, Etype
(Old_Discr
));
2459 Set_Scope
(New_Discr_Id
, Scope
(Old_Discr
));
2464 if Chars
(Old_Discr
) /= Chars
(Defining_Identifier
(New_Discr
)) then
2465 Conformance_Error
("name & does not match!", New_Discr_Id
);
2469 -- Default expressions must match
2472 NewD
: constant Boolean :=
2473 Present
(Expression
(New_Discr
));
2474 OldD
: constant Boolean :=
2475 Present
(Expression
(Parent
(Old_Discr
)));
2478 if NewD
or OldD
then
2480 -- The old default value has been analyzed and expanded,
2481 -- because the current full declaration will have frozen
2482 -- everything before. The new default values have not been
2483 -- expanded, so expand now to check conformance.
2486 Analyze_Per_Use_Expression
2487 (Expression
(New_Discr
), New_Discr_Type
);
2490 if not (NewD
and OldD
)
2491 or else not Fully_Conformant_Expressions
2492 (Expression
(Parent
(Old_Discr
)),
2493 Expression
(New_Discr
))
2497 ("default expression for & does not match!",
2504 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
2506 if Ada_Version
= Ada_83
then
2508 Old_Disc
: constant Node_Id
:= Declaration_Node
(Old_Discr
);
2511 -- Grouping (use of comma in param lists) must be the same
2512 -- This is where we catch a misconformance like:
2515 -- A : Integer; B : Integer
2517 -- which are represented identically in the tree except
2518 -- for the setting of the flags More_Ids and Prev_Ids.
2520 if More_Ids
(Old_Disc
) /= More_Ids
(New_Discr
)
2521 or else Prev_Ids
(Old_Disc
) /= Prev_Ids
(New_Discr
)
2524 ("grouping of & does not match!", New_Discr_Id
);
2530 Next_Discriminant
(Old_Discr
);
2534 if Present
(Old_Discr
) then
2535 Conformance_Error
("too few discriminants!", Defining_Identifier
(N
));
2538 elsif Present
(New_Discr
) then
2540 ("too many discriminants!", Defining_Identifier
(New_Discr
));
2543 end Check_Discriminant_Conformance
;
2545 ----------------------------
2546 -- Check_Fully_Conformant --
2547 ----------------------------
2549 procedure Check_Fully_Conformant
2550 (New_Id
: Entity_Id
;
2552 Err_Loc
: Node_Id
:= Empty
)
2558 (New_Id
, Old_Id
, Fully_Conformant
, True, Result
, Err_Loc
);
2559 end Check_Fully_Conformant
;
2561 ---------------------------
2562 -- Check_Mode_Conformant --
2563 ---------------------------
2565 procedure Check_Mode_Conformant
2566 (New_Id
: Entity_Id
;
2568 Err_Loc
: Node_Id
:= Empty
;
2569 Get_Inst
: Boolean := False)
2575 (New_Id
, Old_Id
, Mode_Conformant
, True, Result
, Err_Loc
, Get_Inst
);
2576 end Check_Mode_Conformant
;
2578 --------------------------------
2579 -- Check_Overriding_Operation --
2580 --------------------------------
2582 procedure Check_Overriding_Operation
2588 Has_Pragma
: Boolean := False;
2591 -- See whether there is an overriding pragma immediately following
2592 -- the declaration. Intervening pragmas, such as Inline, are allowed.
2595 while Present
(Decl
)
2596 and then Nkind
(Decl
) = N_Pragma
2598 if Chars
(Decl
) = Name_Overriding
2599 or else Chars
(Decl
) = Name_Optional_Overriding
2601 -- For now disable the use of these pragmas, until the ARG
2602 -- finalizes the design of this feature.
2604 Error_Msg_N
("?unrecognized pragma", Decl
);
2606 if not Is_Overriding_Operation
(Subp
) then
2608 -- Before emitting an error message, check whether this
2609 -- may override an operation that is not yet visible, as
2610 -- in the case of a derivation of a private operation in
2611 -- a child unit. Such an operation is introduced with a
2612 -- different name, but its alias is the parent operation.
2618 E
:= First_Entity
(Current_Scope
);
2620 while Present
(E
) loop
2621 if Ekind
(E
) = Ekind
(Subp
)
2622 and then not Comes_From_Source
(E
)
2623 and then Present
(Alias
(E
))
2624 and then Chars
(Alias
(E
)) = Chars
(Subp
)
2625 and then In_Open_Scopes
(Scope
(Alias
(E
)))
2635 ("& must override an inherited operation",
2641 -- Verify syntax of pragma
2643 Arg1
:= First
(Pragma_Argument_Associations
(Decl
));
2645 if Present
(Arg1
) then
2646 if not Is_Entity_Name
(Expression
(Arg1
)) then
2647 Error_Msg_N
("pragma applies to local subprogram", Decl
);
2649 elsif Chars
(Expression
(Arg1
)) /= Chars
(Subp
) then
2651 ("pragma must apply to preceding subprogram", Decl
);
2653 elsif Present
(Next
(Arg1
)) then
2654 Error_Msg_N
("illegal pragma format", Decl
);
2658 Set_Analyzed
(Decl
);
2667 and then Explicit_Overriding
2668 and then Is_Overriding_Operation
(Subp
)
2670 Error_Msg_NE
("Missing overriding pragma for&", Subp
, Subp
);
2672 end Check_Overriding_Operation
;
2678 procedure Check_Returns
2685 procedure Check_Statement_Sequence
(L
: List_Id
);
2686 -- Internal recursive procedure to check a list of statements for proper
2687 -- termination by a return statement (or a transfer of control or a
2688 -- compound statement that is itself internally properly terminated).
2690 ------------------------------
2691 -- Check_Statement_Sequence --
2692 ------------------------------
2694 procedure Check_Statement_Sequence
(L
: List_Id
) is
2698 Raise_Exception_Call
: Boolean;
2699 -- Set True if statement sequence terminated by Raise_Exception call
2700 -- or a Reraise_Occurrence call.
2703 Raise_Exception_Call
:= False;
2705 -- Get last real statement
2707 Last_Stm
:= Last
(L
);
2709 -- Don't count pragmas
2711 while Nkind
(Last_Stm
) = N_Pragma
2713 -- Don't count call to SS_Release (can happen after Raise_Exception)
2716 (Nkind
(Last_Stm
) = N_Procedure_Call_Statement
2718 Nkind
(Name
(Last_Stm
)) = N_Identifier
2720 Is_RTE
(Entity
(Name
(Last_Stm
)), RE_SS_Release
))
2722 -- Don't count exception junk
2725 ((Nkind
(Last_Stm
) = N_Goto_Statement
2726 or else Nkind
(Last_Stm
) = N_Label
2727 or else Nkind
(Last_Stm
) = N_Object_Declaration
)
2728 and then Exception_Junk
(Last_Stm
))
2733 -- Here we have the "real" last statement
2735 Kind
:= Nkind
(Last_Stm
);
2737 -- Transfer of control, OK. Note that in the No_Return procedure
2738 -- case, we already diagnosed any explicit return statements, so
2739 -- we can treat them as OK in this context.
2741 if Is_Transfer
(Last_Stm
) then
2744 -- Check cases of explicit non-indirect procedure calls
2746 elsif Kind
= N_Procedure_Call_Statement
2747 and then Is_Entity_Name
(Name
(Last_Stm
))
2749 -- Check call to Raise_Exception procedure which is treated
2750 -- specially, as is a call to Reraise_Occurrence.
2752 -- We suppress the warning in these cases since it is likely that
2753 -- the programmer really does not expect to deal with the case
2754 -- of Null_Occurrence, and thus would find a warning about a
2755 -- missing return curious, and raising Program_Error does not
2756 -- seem such a bad behavior if this does occur.
2758 if Is_RTE
(Entity
(Name
(Last_Stm
)), RE_Raise_Exception
)
2760 Is_RTE
(Entity
(Name
(Last_Stm
)), RE_Reraise_Occurrence
)
2762 Raise_Exception_Call
:= True;
2764 -- For Raise_Exception call, test first argument, if it is
2765 -- an attribute reference for a 'Identity call, then we know
2766 -- that the call cannot possibly return.
2769 Arg
: constant Node_Id
:=
2770 Original_Node
(First_Actual
(Last_Stm
));
2773 if Nkind
(Arg
) = N_Attribute_Reference
2774 and then Attribute_Name
(Arg
) = Name_Identity
2781 -- If statement, need to look inside if there is an else and check
2782 -- each constituent statement sequence for proper termination.
2784 elsif Kind
= N_If_Statement
2785 and then Present
(Else_Statements
(Last_Stm
))
2787 Check_Statement_Sequence
(Then_Statements
(Last_Stm
));
2788 Check_Statement_Sequence
(Else_Statements
(Last_Stm
));
2790 if Present
(Elsif_Parts
(Last_Stm
)) then
2792 Elsif_Part
: Node_Id
:= First
(Elsif_Parts
(Last_Stm
));
2795 while Present
(Elsif_Part
) loop
2796 Check_Statement_Sequence
(Then_Statements
(Elsif_Part
));
2804 -- Case statement, check each case for proper termination
2806 elsif Kind
= N_Case_Statement
then
2811 Case_Alt
:= First_Non_Pragma
(Alternatives
(Last_Stm
));
2812 while Present
(Case_Alt
) loop
2813 Check_Statement_Sequence
(Statements
(Case_Alt
));
2814 Next_Non_Pragma
(Case_Alt
);
2820 -- Block statement, check its handled sequence of statements
2822 elsif Kind
= N_Block_Statement
then
2828 (Handled_Statement_Sequence
(Last_Stm
), Mode
, Err1
);
2837 -- Loop statement. If there is an iteration scheme, we can definitely
2838 -- fall out of the loop. Similarly if there is an exit statement, we
2839 -- can fall out. In either case we need a following return.
2841 elsif Kind
= N_Loop_Statement
then
2842 if Present
(Iteration_Scheme
(Last_Stm
))
2843 or else Has_Exit
(Entity
(Identifier
(Last_Stm
)))
2847 -- A loop with no exit statement or iteration scheme if either
2848 -- an inifite loop, or it has some other exit (raise/return).
2849 -- In either case, no warning is required.
2855 -- Timed entry call, check entry call and delay alternatives
2857 -- Note: in expanded code, the timed entry call has been converted
2858 -- to a set of expanded statements on which the check will work
2859 -- correctly in any case.
2861 elsif Kind
= N_Timed_Entry_Call
then
2863 ECA
: constant Node_Id
:= Entry_Call_Alternative
(Last_Stm
);
2864 DCA
: constant Node_Id
:= Delay_Alternative
(Last_Stm
);
2867 -- If statement sequence of entry call alternative is missing,
2868 -- then we can definitely fall through, and we post the error
2869 -- message on the entry call alternative itself.
2871 if No
(Statements
(ECA
)) then
2874 -- If statement sequence of delay alternative is missing, then
2875 -- we can definitely fall through, and we post the error
2876 -- message on the delay alternative itself.
2878 -- Note: if both ECA and DCA are missing the return, then we
2879 -- post only one message, should be enough to fix the bugs.
2880 -- If not we will get a message next time on the DCA when the
2883 elsif No
(Statements
(DCA
)) then
2886 -- Else check both statement sequences
2889 Check_Statement_Sequence
(Statements
(ECA
));
2890 Check_Statement_Sequence
(Statements
(DCA
));
2895 -- Conditional entry call, check entry call and else part
2897 -- Note: in expanded code, the conditional entry call has been
2898 -- converted to a set of expanded statements on which the check
2899 -- will work correctly in any case.
2901 elsif Kind
= N_Conditional_Entry_Call
then
2903 ECA
: constant Node_Id
:= Entry_Call_Alternative
(Last_Stm
);
2906 -- If statement sequence of entry call alternative is missing,
2907 -- then we can definitely fall through, and we post the error
2908 -- message on the entry call alternative itself.
2910 if No
(Statements
(ECA
)) then
2913 -- Else check statement sequence and else part
2916 Check_Statement_Sequence
(Statements
(ECA
));
2917 Check_Statement_Sequence
(Else_Statements
(Last_Stm
));
2923 -- If we fall through, issue appropriate message
2927 if not Raise_Exception_Call
then
2929 ("?RETURN statement missing following this statement!",
2932 ("\?Program_Error may be raised at run time",
2936 -- Note: we set Err even though we have not issued a warning
2937 -- because we still have a case of a missing return. This is
2938 -- an extremely marginal case, probably will never be noticed
2939 -- but we might as well get it right.
2945 ("implied return after this statement not allowed (No_Return)",
2948 end Check_Statement_Sequence
;
2950 -- Start of processing for Check_Returns
2954 Check_Statement_Sequence
(Statements
(HSS
));
2956 if Present
(Exception_Handlers
(HSS
)) then
2957 Handler
:= First_Non_Pragma
(Exception_Handlers
(HSS
));
2958 while Present
(Handler
) loop
2959 Check_Statement_Sequence
(Statements
(Handler
));
2960 Next_Non_Pragma
(Handler
);
2965 ----------------------------
2966 -- Check_Subprogram_Order --
2967 ----------------------------
2969 procedure Check_Subprogram_Order
(N
: Node_Id
) is
2971 function Subprogram_Name_Greater
(S1
, S2
: String) return Boolean;
2972 -- This is used to check if S1 > S2 in the sense required by this
2973 -- test, for example nameab < namec, but name2 < name10.
2975 -----------------------------
2976 -- Subprogram_Name_Greater --
2977 -----------------------------
2979 function Subprogram_Name_Greater
(S1
, S2
: String) return Boolean is
2984 -- Remove trailing numeric parts
2987 while S1
(L1
) in '0' .. '9' loop
2992 while S2
(L2
) in '0' .. '9' loop
2996 -- If non-numeric parts non-equal, that's decisive
2998 if S1
(S1
'First .. L1
) < S2
(S2
'First .. L2
) then
3001 elsif S1
(S1
'First .. L1
) > S2
(S2
'First .. L2
) then
3004 -- If non-numeric parts equal, compare suffixed numeric parts. Note
3005 -- that a missing suffix is treated as numeric zero in this test.
3009 while L1
< S1
'Last loop
3011 N1
:= N1
* 10 + Character'Pos (S1
(L1
)) - Character'Pos ('0');
3015 while L2
< S2
'Last loop
3017 N2
:= N2
* 10 + Character'Pos (S2
(L2
)) - Character'Pos ('0');
3022 end Subprogram_Name_Greater
;
3024 -- Start of processing for Check_Subprogram_Order
3027 -- Check body in alpha order if this is option
3030 and then Style_Check_Order_Subprograms
3031 and then Nkind
(N
) = N_Subprogram_Body
3032 and then Comes_From_Source
(N
)
3033 and then In_Extended_Main_Source_Unit
(N
)
3037 renames Scope_Stack
.Table
3038 (Scope_Stack
.Last
).Last_Subprogram_Name
;
3040 Body_Id
: constant Entity_Id
:=
3041 Defining_Entity
(Specification
(N
));
3044 Get_Decoded_Name_String
(Chars
(Body_Id
));
3047 if Subprogram_Name_Greater
3048 (LSN
.all, Name_Buffer
(1 .. Name_Len
))
3050 Style
.Subprogram_Not_In_Alpha_Order
(Body_Id
);
3056 LSN
:= new String'(Name_Buffer (1 .. Name_Len));
3059 end Check_Subprogram_Order;
3061 ------------------------------
3062 -- Check_Subtype_Conformant --
3063 ------------------------------
3065 procedure Check_Subtype_Conformant
3066 (New_Id : Entity_Id;
3068 Err_Loc : Node_Id := Empty)
3073 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc);
3074 end Check_Subtype_Conformant;
3076 ---------------------------
3077 -- Check_Type_Conformant --
3078 ---------------------------
3080 procedure Check_Type_Conformant
3081 (New_Id : Entity_Id;
3083 Err_Loc : Node_Id := Empty)
3088 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
3089 end Check_Type_Conformant;
3091 ----------------------
3092 -- Conforming_Types --
3093 ----------------------
3095 function Conforming_Types
3098 Ctype : Conformance_Type;
3099 Get_Inst : Boolean := False) return Boolean
3101 Type_1 : Entity_Id := T1;
3102 Type_2 : Entity_Id := T2;
3103 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False;
3105 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
3106 -- If neither T1 nor T2 are generic actual types, or if they are
3107 -- in different scopes (e.g. parent and child instances), then verify
3108 -- that the base types are equal. Otherwise T1 and T2 must be
3109 -- on the same subtype chain. The whole purpose of this procedure
3110 -- is to prevent spurious ambiguities in an instantiation that may
3111 -- arise if two distinct generic types are instantiated with the
3114 ----------------------
3115 -- Base_Types_Match --
3116 ----------------------
3118 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
3123 elsif Base_Type (T1) = Base_Type (T2) then
3125 -- The following is too permissive. A more precise test must
3126 -- check that the generic actual is an ancestor subtype of the
3129 return not Is_Generic_Actual_Type (T1)
3130 or else not Is_Generic_Actual_Type (T2)
3131 or else Scope (T1) /= Scope (T2);
3133 -- In some cases a type imported through a limited_with clause,
3134 -- and its non-limited view are both visible, for example in an
3135 -- anonymous access_to_classwide type in a formal. Both entities
3136 -- designate the same type.
3138 elsif From_With_Type (T1)
3139 and then Ekind (T1) = E_Incomplete_Type
3140 and then T2 = Non_Limited_View (T1)
3147 end Base_Types_Match;
3150 -- The context is an instance association for a formal
3151 -- access-to-subprogram type; the formal parameter types require
3152 -- mapping because they may denote other formal parameters of the
3156 Type_1 := Get_Instance_Of (T1);
3157 Type_2 := Get_Instance_Of (T2);
3160 -- First see if base types match
3162 if Base_Types_Match (Type_1, Type_2) then
3163 return Ctype <= Mode_Conformant
3164 or else Subtypes_Statically_Match (Type_1, Type_2);
3166 elsif Is_Incomplete_Or_Private_Type (Type_1)
3167 and then Present (Full_View (Type_1))
3168 and then Base_Types_Match (Full_View (Type_1), Type_2)
3170 return Ctype <= Mode_Conformant
3171 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
3173 elsif Ekind (Type_2) = E_Incomplete_Type
3174 and then Present (Full_View (Type_2))
3175 and then Base_Types_Match (Type_1, Full_View (Type_2))
3177 return Ctype <= Mode_Conformant
3178 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3180 elsif Is_Private_Type (Type_2)
3181 and then In_Instance
3182 and then Present (Full_View (Type_2))
3183 and then Base_Types_Match (Type_1, Full_View (Type_2))
3185 return Ctype <= Mode_Conformant
3186 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3189 -- Ada 2005 (AI-254): Detect anonymous access to subprogram types
3191 Are_Anonymous_Access_To_Subprogram_Types :=
3193 -- Case 1: Anonymous access to subprogram types
3195 (Ekind (Type_1) = E_Anonymous_Access_Subprogram_Type
3196 and then Ekind (Type_2) = E_Anonymous_Access_Subprogram_Type)
3198 -- Case 2: Anonymous access to PROTECTED subprogram types. In this
3199 -- case the anonymous type_declaration has been replaced by an
3200 -- occurrence of an internal access to subprogram type declaration
3201 -- available through the Original_Access_Type attribute
3204 (Ekind (Type_1) = E_Access_Protected_Subprogram_Type
3205 and then Ekind (Type_2) = E_Access_Protected_Subprogram_Type
3206 and then not Comes_From_Source (Type_1)
3207 and then not Comes_From_Source (Type_2)
3208 and then Present (Original_Access_Type (Type_1))
3209 and then Present (Original_Access_Type (Type_2))
3210 and then Ekind (Original_Access_Type (Type_1)) =
3211 E_Anonymous_Access_Protected_Subprogram_Type
3212 and then Ekind (Original_Access_Type (Type_2)) =
3213 E_Anonymous_Access_Protected_Subprogram_Type);
3215 -- Test anonymous access type case. For this case, static subtype
3216 -- matching is required for mode conformance (RM 6.3.1(15))
3218 if (Ekind (Type_1) = E_Anonymous_Access_Type
3219 and then Ekind (Type_2) = E_Anonymous_Access_Type)
3220 or else Are_Anonymous_Access_To_Subprogram_Types -- Ada 2005 (AI-254)
3223 Desig_1 : Entity_Id;
3224 Desig_2 : Entity_Id;
3227 Desig_1 := Directly_Designated_Type (Type_1);
3229 -- An access parameter can designate an incomplete type
3231 if Ekind (Desig_1) = E_Incomplete_Type
3232 and then Present (Full_View (Desig_1))
3234 Desig_1 := Full_View (Desig_1);
3237 Desig_2 := Directly_Designated_Type (Type_2);
3239 if Ekind (Desig_2) = E_Incomplete_Type
3240 and then Present (Full_View (Desig_2))
3242 Desig_2 := Full_View (Desig_2);
3245 -- The context is an instance association for a formal
3246 -- access-to-subprogram type; formal access parameter designated
3247 -- types require mapping because they may denote other formal
3248 -- parameters of the generic unit.
3251 Desig_1 := Get_Instance_Of (Desig_1);
3252 Desig_2 := Get_Instance_Of (Desig_2);
3255 -- It is possible for a Class_Wide_Type to be introduced for an
3256 -- incomplete type, in which case there is a separate class_ wide
3257 -- type for the full view. The types conform if their Etypes
3258 -- conform, i.e. one may be the full view of the other. This can
3259 -- only happen in the context of an access parameter, other uses
3260 -- of an incomplete Class_Wide_Type are illegal.
3262 if Is_Class_Wide_Type (Desig_1)
3263 and then Is_Class_Wide_Type (Desig_2)
3267 (Etype (Base_Type (Desig_1)),
3268 Etype (Base_Type (Desig_2)), Ctype);
3270 elsif Are_Anonymous_Access_To_Subprogram_Types then
3271 return Ctype = Type_Conformant
3273 Subtypes_Statically_Match (Desig_1, Desig_2);
3276 return Base_Type (Desig_1) = Base_Type (Desig_2)
3277 and then (Ctype = Type_Conformant
3279 Subtypes_Statically_Match (Desig_1, Desig_2));
3283 -- Otherwise definitely no match
3289 end Conforming_Types;
3291 --------------------------
3292 -- Create_Extra_Formals --
3293 --------------------------
3295 procedure Create_Extra_Formals (E : Entity_Id) is
3297 Last_Extra : Entity_Id;
3298 Formal_Type : Entity_Id;
3299 P_Formal : Entity_Id := Empty;
3301 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id;
3302 -- Add an extra formal, associated with the current Formal. The extra
3303 -- formal is added to the list of extra formals, and also returned as
3304 -- the result. These formals are always of mode IN.
3306 ----------------------
3307 -- Add_Extra_Formal --
3308 ----------------------
3310 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is
3311 EF : constant Entity_Id :=
3312 Make_Defining_Identifier (Sloc (Formal),
3313 Chars => New_External_Name (Chars (Formal), 'F
'));
3316 -- We never generate extra formals if expansion is not active
3317 -- because we don't need them unless we are generating code.
3319 if not Expander_Active then
3323 -- A little optimization. Never generate an extra formal for the
3324 -- _init operand of an initialization procedure, since it could
3327 if Chars (Formal) = Name_uInit then
3331 Set_Ekind (EF, E_In_Parameter);
3332 Set_Actual_Subtype (EF, Typ);
3333 Set_Etype (EF, Typ);
3334 Set_Scope (EF, Scope (Formal));
3335 Set_Mechanism (EF, Default_Mechanism);
3336 Set_Formal_Validity (EF);
3338 Set_Extra_Formal (Last_Extra, EF);
3341 end Add_Extra_Formal;
3343 -- Start of processing for Create_Extra_Formals
3346 -- If this is a derived subprogram then the subtypes of the parent
3347 -- subprogram's formal parameters will be used to to determine the need
3348 -- for extra formals.
3350 if Is_Overloadable (E) and then Present (Alias (E)) then
3351 P_Formal := First_Formal (Alias (E));
3354 Last_Extra := Empty;
3355 Formal := First_Formal (E);
3356 while Present (Formal) loop
3357 Last_Extra := Formal;
3358 Next_Formal (Formal);
3361 -- If Extra_formals where already created, don't do it again. This
3362 -- situation may arise for subprogram types created as part of
3363 -- dispatching calls (see Expand_Dispatching_Call)
3365 if Present (Last_Extra) and then
3366 Present (Extra_Formal (Last_Extra))
3371 Formal := First_Formal (E);
3373 while Present (Formal) loop
3375 -- Create extra formal for supporting the attribute 'Constrained
.
3376 -- The case of a private type view without discriminants also
3377 -- requires the extra formal if the underlying type has defaulted
3380 if Ekind
(Formal
) /= E_In_Parameter
then
3381 if Present
(P_Formal
) then
3382 Formal_Type
:= Etype
(P_Formal
);
3384 Formal_Type
:= Etype
(Formal
);
3387 -- Do not produce extra formals for Unchecked_Union parameters.
3388 -- Jump directly to the end of the loop.
3390 if Is_Unchecked_Union
(Base_Type
(Formal_Type
)) then
3391 goto Skip_Extra_Formal_Generation
;
3394 if not Has_Discriminants
(Formal_Type
)
3395 and then Ekind
(Formal_Type
) in Private_Kind
3396 and then Present
(Underlying_Type
(Formal_Type
))
3398 Formal_Type
:= Underlying_Type
(Formal_Type
);
3401 if Has_Discriminants
(Formal_Type
)
3403 ((not Is_Constrained
(Formal_Type
)
3404 and then not Is_Indefinite_Subtype
(Formal_Type
))
3405 or else Present
(Extra_Formal
(Formal
)))
3407 Set_Extra_Constrained
3408 (Formal
, Add_Extra_Formal
(Standard_Boolean
));
3412 -- Create extra formal for supporting accessibility checking
3414 -- This is suppressed if we specifically suppress accessibility
3415 -- checks at the pacage level for either the subprogram, or the
3416 -- package in which it resides. However, we do not suppress it
3417 -- simply if the scope has accessibility checks suppressed, since
3418 -- this could cause trouble when clients are compiled with a
3419 -- different suppression setting. The explicit checks at the
3420 -- package level are safe from this point of view.
3422 if Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
3424 (Explicit_Suppress
(E
, Accessibility_Check
)
3426 Explicit_Suppress
(Scope
(E
), Accessibility_Check
))
3428 (not Present
(P_Formal
)
3429 or else Present
(Extra_Accessibility
(P_Formal
)))
3431 -- Temporary kludge: for now we avoid creating the extra formal
3432 -- for access parameters of protected operations because of
3433 -- problem with the case of internal protected calls. ???
3435 if Nkind
(Parent
(Parent
(Parent
(E
)))) /= N_Protected_Definition
3436 and then Nkind
(Parent
(Parent
(Parent
(E
)))) /= N_Protected_Body
3438 Set_Extra_Accessibility
3439 (Formal
, Add_Extra_Formal
(Standard_Natural
));
3443 if Present
(P_Formal
) then
3444 Next_Formal
(P_Formal
);
3447 -- This label is required when skipping extra formal generation for
3448 -- Unchecked_Union parameters.
3450 <<Skip_Extra_Formal_Generation
>>
3452 Next_Formal
(Formal
);
3454 end Create_Extra_Formals
;
3456 -----------------------------
3457 -- Enter_Overloaded_Entity --
3458 -----------------------------
3460 procedure Enter_Overloaded_Entity
(S
: Entity_Id
) is
3461 E
: Entity_Id
:= Current_Entity_In_Scope
(S
);
3462 C_E
: Entity_Id
:= Current_Entity
(S
);
3466 Set_Has_Homonym
(E
);
3467 Set_Has_Homonym
(S
);
3470 Set_Is_Immediately_Visible
(S
);
3471 Set_Scope
(S
, Current_Scope
);
3473 -- Chain new entity if front of homonym in current scope, so that
3474 -- homonyms are contiguous.
3479 while Homonym
(C_E
) /= E
loop
3480 C_E
:= Homonym
(C_E
);
3483 Set_Homonym
(C_E
, S
);
3487 Set_Current_Entity
(S
);
3492 Append_Entity
(S
, Current_Scope
);
3493 Set_Public_Status
(S
);
3495 if Debug_Flag_E
then
3496 Write_Str
("New overloaded entity chain: ");
3497 Write_Name
(Chars
(S
));
3500 while Present
(E
) loop
3501 Write_Str
(" "); Write_Int
(Int
(E
));
3508 -- Generate warning for hiding
3511 and then Comes_From_Source
(S
)
3512 and then In_Extended_Main_Source_Unit
(S
)
3519 -- Warn unless genuine overloading
3521 if (not Is_Overloadable
(E
))
3522 or else Subtype_Conformant
(E
, S
)
3524 Error_Msg_Sloc
:= Sloc
(E
);
3525 Error_Msg_N
("declaration of & hides one#?", S
);
3529 end Enter_Overloaded_Entity
;
3531 -----------------------------
3532 -- Find_Corresponding_Spec --
3533 -----------------------------
3535 function Find_Corresponding_Spec
(N
: Node_Id
) return Entity_Id
is
3536 Spec
: constant Node_Id
:= Specification
(N
);
3537 Designator
: constant Entity_Id
:= Defining_Entity
(Spec
);
3542 E
:= Current_Entity
(Designator
);
3544 while Present
(E
) loop
3546 -- We are looking for a matching spec. It must have the same scope,
3547 -- and the same name, and either be type conformant, or be the case
3548 -- of a library procedure spec and its body (which belong to one
3549 -- another regardless of whether they are type conformant or not).
3551 if Scope
(E
) = Current_Scope
then
3552 if Current_Scope
= Standard_Standard
3553 or else (Ekind
(E
) = Ekind
(Designator
)
3554 and then Type_Conformant
(E
, Designator
))
3556 -- Within an instantiation, we know that spec and body are
3557 -- subtype conformant, because they were subtype conformant
3558 -- in the generic. We choose the subtype-conformant entity
3559 -- here as well, to resolve spurious ambiguities in the
3560 -- instance that were not present in the generic (i.e. when
3561 -- two different types are given the same actual). If we are
3562 -- looking for a spec to match a body, full conformance is
3566 Set_Convention
(Designator
, Convention
(E
));
3568 if Nkind
(N
) = N_Subprogram_Body
3569 and then Present
(Homonym
(E
))
3570 and then not Fully_Conformant
(E
, Designator
)
3574 elsif not Subtype_Conformant
(E
, Designator
) then
3579 if not Has_Completion
(E
) then
3581 if Nkind
(N
) /= N_Subprogram_Body_Stub
then
3582 Set_Corresponding_Spec
(N
, E
);
3585 Set_Has_Completion
(E
);
3588 elsif Nkind
(Parent
(N
)) = N_Subunit
then
3590 -- If this is the proper body of a subunit, the completion
3591 -- flag is set when analyzing the stub.
3595 -- If body already exists, this is an error unless the
3596 -- previous declaration is the implicit declaration of
3597 -- a derived subprogram, or this is a spurious overloading
3600 elsif No
(Alias
(E
))
3601 and then not Is_Intrinsic_Subprogram
(E
)
3602 and then not In_Instance
3604 Error_Msg_Sloc
:= Sloc
(E
);
3605 if Is_Imported
(E
) then
3607 ("body not allowed for imported subprogram & declared#",
3610 Error_Msg_NE
("duplicate body for & declared#", N
, E
);
3614 elsif Is_Child_Unit
(E
)
3616 Nkind
(Unit_Declaration_Node
(Designator
)) = N_Subprogram_Body
3618 Nkind
(Parent
(Unit_Declaration_Node
(Designator
)))
3619 = N_Compilation_Unit
3622 -- Child units cannot be overloaded, so a conformance mismatch
3623 -- between body and a previous spec is an error.
3626 ("body of child unit does not match previous declaration", N
);
3634 -- On exit, we know that no previous declaration of subprogram exists
3637 end Find_Corresponding_Spec
;
3639 ----------------------
3640 -- Fully_Conformant --
3641 ----------------------
3643 function Fully_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
3647 Check_Conformance
(New_Id
, Old_Id
, Fully_Conformant
, False, Result
);
3649 end Fully_Conformant
;
3651 ----------------------------------
3652 -- Fully_Conformant_Expressions --
3653 ----------------------------------
3655 function Fully_Conformant_Expressions
3656 (Given_E1
: Node_Id
;
3657 Given_E2
: Node_Id
) return Boolean
3659 E1
: constant Node_Id
:= Original_Node
(Given_E1
);
3660 E2
: constant Node_Id
:= Original_Node
(Given_E2
);
3661 -- We always test conformance on original nodes, since it is possible
3662 -- for analysis and/or expansion to make things look as though they
3663 -- conform when they do not, e.g. by converting 1+2 into 3.
3665 function FCE
(Given_E1
, Given_E2
: Node_Id
) return Boolean
3666 renames Fully_Conformant_Expressions
;
3668 function FCL
(L1
, L2
: List_Id
) return Boolean;
3669 -- Compare elements of two lists for conformance. Elements have to
3670 -- be conformant, and actuals inserted as default parameters do not
3671 -- match explicit actuals with the same value.
3673 function FCO
(Op_Node
, Call_Node
: Node_Id
) return Boolean;
3674 -- Compare an operator node with a function call
3680 function FCL
(L1
, L2
: List_Id
) return Boolean is
3684 if L1
= No_List
then
3690 if L2
= No_List
then
3696 -- Compare two lists, skipping rewrite insertions (we want to
3697 -- compare the original trees, not the expanded versions!)
3700 if Is_Rewrite_Insertion
(N1
) then
3702 elsif Is_Rewrite_Insertion
(N2
) then
3708 elsif not FCE
(N1
, N2
) then
3721 function FCO
(Op_Node
, Call_Node
: Node_Id
) return Boolean is
3722 Actuals
: constant List_Id
:= Parameter_Associations
(Call_Node
);
3727 or else Entity
(Op_Node
) /= Entity
(Name
(Call_Node
))
3732 Act
:= First
(Actuals
);
3734 if Nkind
(Op_Node
) in N_Binary_Op
then
3736 if not FCE
(Left_Opnd
(Op_Node
), Act
) then
3743 return Present
(Act
)
3744 and then FCE
(Right_Opnd
(Op_Node
), Act
)
3745 and then No
(Next
(Act
));
3749 -- Start of processing for Fully_Conformant_Expressions
3752 -- Non-conformant if paren count does not match. Note: if some idiot
3753 -- complains that we don't do this right for more than 3 levels of
3754 -- parentheses, they will be treated with the respect they deserve :-)
3756 if Paren_Count
(E1
) /= Paren_Count
(E2
) then
3759 -- If same entities are referenced, then they are conformant even if
3760 -- they have different forms (RM 8.3.1(19-20)).
3762 elsif Is_Entity_Name
(E1
) and then Is_Entity_Name
(E2
) then
3763 if Present
(Entity
(E1
)) then
3764 return Entity
(E1
) = Entity
(E2
)
3765 or else (Chars
(Entity
(E1
)) = Chars
(Entity
(E2
))
3766 and then Ekind
(Entity
(E1
)) = E_Discriminant
3767 and then Ekind
(Entity
(E2
)) = E_In_Parameter
);
3769 elsif Nkind
(E1
) = N_Expanded_Name
3770 and then Nkind
(E2
) = N_Expanded_Name
3771 and then Nkind
(Selector_Name
(E1
)) = N_Character_Literal
3772 and then Nkind
(Selector_Name
(E2
)) = N_Character_Literal
3774 return Chars
(Selector_Name
(E1
)) = Chars
(Selector_Name
(E2
));
3777 -- Identifiers in component associations don't always have
3778 -- entities, but their names must conform.
3780 return Nkind
(E1
) = N_Identifier
3781 and then Nkind
(E2
) = N_Identifier
3782 and then Chars
(E1
) = Chars
(E2
);
3785 elsif Nkind
(E1
) = N_Character_Literal
3786 and then Nkind
(E2
) = N_Expanded_Name
3788 return Nkind
(Selector_Name
(E2
)) = N_Character_Literal
3789 and then Chars
(E1
) = Chars
(Selector_Name
(E2
));
3791 elsif Nkind
(E2
) = N_Character_Literal
3792 and then Nkind
(E1
) = N_Expanded_Name
3794 return Nkind
(Selector_Name
(E1
)) = N_Character_Literal
3795 and then Chars
(E2
) = Chars
(Selector_Name
(E1
));
3797 elsif Nkind
(E1
) in N_Op
3798 and then Nkind
(E2
) = N_Function_Call
3800 return FCO
(E1
, E2
);
3802 elsif Nkind
(E2
) in N_Op
3803 and then Nkind
(E1
) = N_Function_Call
3805 return FCO
(E2
, E1
);
3807 -- Otherwise we must have the same syntactic entity
3809 elsif Nkind
(E1
) /= Nkind
(E2
) then
3812 -- At this point, we specialize by node type
3819 FCL
(Expressions
(E1
), Expressions
(E2
))
3820 and then FCL
(Component_Associations
(E1
),
3821 Component_Associations
(E2
));
3824 if Nkind
(Expression
(E1
)) = N_Qualified_Expression
3826 Nkind
(Expression
(E2
)) = N_Qualified_Expression
3828 return FCE
(Expression
(E1
), Expression
(E2
));
3830 -- Check that the subtype marks and any constraints
3835 Indic1
: constant Node_Id
:= Expression
(E1
);
3836 Indic2
: constant Node_Id
:= Expression
(E2
);
3841 if Nkind
(Indic1
) /= N_Subtype_Indication
then
3843 Nkind
(Indic2
) /= N_Subtype_Indication
3844 and then Entity
(Indic1
) = Entity
(Indic2
);
3846 elsif Nkind
(Indic2
) /= N_Subtype_Indication
then
3848 Nkind
(Indic1
) /= N_Subtype_Indication
3849 and then Entity
(Indic1
) = Entity
(Indic2
);
3852 if Entity
(Subtype_Mark
(Indic1
)) /=
3853 Entity
(Subtype_Mark
(Indic2
))
3858 Elt1
:= First
(Constraints
(Constraint
(Indic1
)));
3859 Elt2
:= First
(Constraints
(Constraint
(Indic2
)));
3861 while Present
(Elt1
) and then Present
(Elt2
) loop
3862 if not FCE
(Elt1
, Elt2
) then
3875 when N_Attribute_Reference
=>
3877 Attribute_Name
(E1
) = Attribute_Name
(E2
)
3878 and then FCL
(Expressions
(E1
), Expressions
(E2
));
3882 Entity
(E1
) = Entity
(E2
)
3883 and then FCE
(Left_Opnd
(E1
), Left_Opnd
(E2
))
3884 and then FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
3886 when N_And_Then | N_Or_Else | N_In | N_Not_In
=>
3888 FCE
(Left_Opnd
(E1
), Left_Opnd
(E2
))
3890 FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
3892 when N_Character_Literal
=>
3894 Char_Literal_Value
(E1
) = Char_Literal_Value
(E2
);
3896 when N_Component_Association
=>
3898 FCL
(Choices
(E1
), Choices
(E2
))
3899 and then FCE
(Expression
(E1
), Expression
(E2
));
3901 when N_Conditional_Expression
=>
3903 FCL
(Expressions
(E1
), Expressions
(E2
));
3905 when N_Explicit_Dereference
=>
3907 FCE
(Prefix
(E1
), Prefix
(E2
));
3909 when N_Extension_Aggregate
=>
3911 FCL
(Expressions
(E1
), Expressions
(E2
))
3912 and then Null_Record_Present
(E1
) =
3913 Null_Record_Present
(E2
)
3914 and then FCL
(Component_Associations
(E1
),
3915 Component_Associations
(E2
));
3917 when N_Function_Call
=>
3919 FCE
(Name
(E1
), Name
(E2
))
3920 and then FCL
(Parameter_Associations
(E1
),
3921 Parameter_Associations
(E2
));
3923 when N_Indexed_Component
=>
3925 FCE
(Prefix
(E1
), Prefix
(E2
))
3926 and then FCL
(Expressions
(E1
), Expressions
(E2
));
3928 when N_Integer_Literal
=>
3929 return (Intval
(E1
) = Intval
(E2
));
3934 when N_Operator_Symbol
=>
3936 Chars
(E1
) = Chars
(E2
);
3938 when N_Others_Choice
=>
3941 when N_Parameter_Association
=>
3943 Chars
(Selector_Name
(E1
)) = Chars
(Selector_Name
(E2
))
3944 and then FCE
(Explicit_Actual_Parameter
(E1
),
3945 Explicit_Actual_Parameter
(E2
));
3947 when N_Qualified_Expression
=>
3949 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
3950 and then FCE
(Expression
(E1
), Expression
(E2
));
3954 FCE
(Low_Bound
(E1
), Low_Bound
(E2
))
3955 and then FCE
(High_Bound
(E1
), High_Bound
(E2
));
3957 when N_Real_Literal
=>
3958 return (Realval
(E1
) = Realval
(E2
));
3960 when N_Selected_Component
=>
3962 FCE
(Prefix
(E1
), Prefix
(E2
))
3963 and then FCE
(Selector_Name
(E1
), Selector_Name
(E2
));
3967 FCE
(Prefix
(E1
), Prefix
(E2
))
3968 and then FCE
(Discrete_Range
(E1
), Discrete_Range
(E2
));
3970 when N_String_Literal
=>
3972 S1
: constant String_Id
:= Strval
(E1
);
3973 S2
: constant String_Id
:= Strval
(E2
);
3974 L1
: constant Nat
:= String_Length
(S1
);
3975 L2
: constant Nat
:= String_Length
(S2
);
3982 for J
in 1 .. L1
loop
3983 if Get_String_Char
(S1
, J
) /=
3984 Get_String_Char
(S2
, J
)
3994 when N_Type_Conversion
=>
3996 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
3997 and then FCE
(Expression
(E1
), Expression
(E2
));
4001 Entity
(E1
) = Entity
(E2
)
4002 and then FCE
(Right_Opnd
(E1
), Right_Opnd
(E2
));
4004 when N_Unchecked_Type_Conversion
=>
4006 FCE
(Subtype_Mark
(E1
), Subtype_Mark
(E2
))
4007 and then FCE
(Expression
(E1
), Expression
(E2
));
4009 -- All other node types cannot appear in this context. Strictly
4010 -- we should raise a fatal internal error. Instead we just ignore
4011 -- the nodes. This means that if anyone makes a mistake in the
4012 -- expander and mucks an expression tree irretrievably, the
4013 -- result will be a failure to detect a (probably very obscure)
4014 -- case of non-conformance, which is better than bombing on some
4015 -- case where two expressions do in fact conform.
4022 end Fully_Conformant_Expressions
;
4024 ----------------------------------------
4025 -- Fully_Conformant_Discrete_Subtypes --
4026 ----------------------------------------
4028 function Fully_Conformant_Discrete_Subtypes
4029 (Given_S1
: Node_Id
;
4030 Given_S2
: Node_Id
) return Boolean
4032 S1
: constant Node_Id
:= Original_Node
(Given_S1
);
4033 S2
: constant Node_Id
:= Original_Node
(Given_S2
);
4035 function Conforming_Bounds
(B1
, B2
: Node_Id
) return Boolean;
4036 -- Special-case for a bound given by a discriminant, which in the body
4037 -- is replaced with the discriminal of the enclosing type.
4039 function Conforming_Ranges
(R1
, R2
: Node_Id
) return Boolean;
4040 -- Check both bounds
4042 function Conforming_Bounds
(B1
, B2
: Node_Id
) return Boolean is
4044 if Is_Entity_Name
(B1
)
4045 and then Is_Entity_Name
(B2
)
4046 and then Ekind
(Entity
(B1
)) = E_Discriminant
4048 return Chars
(B1
) = Chars
(B2
);
4051 return Fully_Conformant_Expressions
(B1
, B2
);
4053 end Conforming_Bounds
;
4055 function Conforming_Ranges
(R1
, R2
: Node_Id
) return Boolean is
4058 Conforming_Bounds
(Low_Bound
(R1
), Low_Bound
(R2
))
4060 Conforming_Bounds
(High_Bound
(R1
), High_Bound
(R2
));
4061 end Conforming_Ranges
;
4063 -- Start of processing for Fully_Conformant_Discrete_Subtypes
4066 if Nkind
(S1
) /= Nkind
(S2
) then
4069 elsif Is_Entity_Name
(S1
) then
4070 return Entity
(S1
) = Entity
(S2
);
4072 elsif Nkind
(S1
) = N_Range
then
4073 return Conforming_Ranges
(S1
, S2
);
4075 elsif Nkind
(S1
) = N_Subtype_Indication
then
4077 Entity
(Subtype_Mark
(S1
)) = Entity
(Subtype_Mark
(S2
))
4080 (Range_Expression
(Constraint
(S1
)),
4081 Range_Expression
(Constraint
(S2
)));
4085 end Fully_Conformant_Discrete_Subtypes
;
4087 --------------------
4088 -- Install_Entity --
4089 --------------------
4091 procedure Install_Entity
(E
: Entity_Id
) is
4092 Prev
: constant Entity_Id
:= Current_Entity
(E
);
4095 Set_Is_Immediately_Visible
(E
);
4096 Set_Current_Entity
(E
);
4097 Set_Homonym
(E
, Prev
);
4100 ---------------------
4101 -- Install_Formals --
4102 ---------------------
4104 procedure Install_Formals
(Id
: Entity_Id
) is
4108 F
:= First_Formal
(Id
);
4110 while Present
(F
) loop
4114 end Install_Formals
;
4116 ---------------------------------
4117 -- Is_Non_Overriding_Operation --
4118 ---------------------------------
4120 function Is_Non_Overriding_Operation
4121 (Prev_E
: Entity_Id
;
4122 New_E
: Entity_Id
) return Boolean
4126 G_Typ
: Entity_Id
:= Empty
;
4128 function Get_Generic_Parent_Type
(F_Typ
: Entity_Id
) return Entity_Id
;
4129 -- If F_Type is a derived type associated with a generic actual
4130 -- subtype, then return its Generic_Parent_Type attribute, else return
4133 function Types_Correspond
4134 (P_Type
: Entity_Id
;
4135 N_Type
: Entity_Id
) return Boolean;
4136 -- Returns true if and only if the types (or designated types in the
4137 -- case of anonymous access types) are the same or N_Type is derived
4138 -- directly or indirectly from P_Type.
4140 -----------------------------
4141 -- Get_Generic_Parent_Type --
4142 -----------------------------
4144 function Get_Generic_Parent_Type
(F_Typ
: Entity_Id
) return Entity_Id
is
4149 if Is_Derived_Type
(F_Typ
)
4150 and then Nkind
(Parent
(F_Typ
)) = N_Full_Type_Declaration
4152 -- The tree must be traversed to determine the parent subtype in
4153 -- the generic unit, which unfortunately isn't always available
4154 -- via semantic attributes. ??? (Note: The use of Original_Node
4155 -- is needed for cases where a full derived type has been
4158 Indic
:= Subtype_Indication
4159 (Type_Definition
(Original_Node
(Parent
(F_Typ
))));
4161 if Nkind
(Indic
) = N_Subtype_Indication
then
4162 G_Typ
:= Entity
(Subtype_Mark
(Indic
));
4164 G_Typ
:= Entity
(Indic
);
4167 if Nkind
(Parent
(G_Typ
)) = N_Subtype_Declaration
4168 and then Present
(Generic_Parent_Type
(Parent
(G_Typ
)))
4170 return Generic_Parent_Type
(Parent
(G_Typ
));
4175 end Get_Generic_Parent_Type
;
4177 ----------------------
4178 -- Types_Correspond --
4179 ----------------------
4181 function Types_Correspond
4182 (P_Type
: Entity_Id
;
4183 N_Type
: Entity_Id
) return Boolean
4185 Prev_Type
: Entity_Id
:= Base_Type
(P_Type
);
4186 New_Type
: Entity_Id
:= Base_Type
(N_Type
);
4189 if Ekind
(Prev_Type
) = E_Anonymous_Access_Type
then
4190 Prev_Type
:= Designated_Type
(Prev_Type
);
4193 if Ekind
(New_Type
) = E_Anonymous_Access_Type
then
4194 New_Type
:= Designated_Type
(New_Type
);
4197 if Prev_Type
= New_Type
then
4200 elsif not Is_Class_Wide_Type
(New_Type
) then
4201 while Etype
(New_Type
) /= New_Type
loop
4202 New_Type
:= Etype
(New_Type
);
4203 if New_Type
= Prev_Type
then
4209 end Types_Correspond
;
4211 -- Start of processing for Is_Non_Overriding_Operation
4214 -- In the case where both operations are implicit derived subprograms
4215 -- then neither overrides the other. This can only occur in certain
4216 -- obscure cases (e.g., derivation from homographs created in a generic
4219 if Present
(Alias
(Prev_E
)) and then Present
(Alias
(New_E
)) then
4222 elsif Ekind
(Current_Scope
) = E_Package
4223 and then Is_Generic_Instance
(Current_Scope
)
4224 and then In_Private_Part
(Current_Scope
)
4225 and then Comes_From_Source
(New_E
)
4227 -- We examine the formals and result subtype of the inherited
4228 -- operation, to determine whether their type is derived from (the
4229 -- instance of) a generic type.
4231 Formal
:= First_Formal
(Prev_E
);
4233 while Present
(Formal
) loop
4234 F_Typ
:= Base_Type
(Etype
(Formal
));
4236 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
4237 F_Typ
:= Designated_Type
(F_Typ
);
4240 G_Typ
:= Get_Generic_Parent_Type
(F_Typ
);
4242 Next_Formal
(Formal
);
4245 if not Present
(G_Typ
) and then Ekind
(Prev_E
) = E_Function
then
4246 G_Typ
:= Get_Generic_Parent_Type
(Base_Type
(Etype
(Prev_E
)));
4253 -- If the generic type is a private type, then the original
4254 -- operation was not overriding in the generic, because there was
4255 -- no primitive operation to override.
4257 if Nkind
(Parent
(G_Typ
)) = N_Formal_Type_Declaration
4258 and then Nkind
(Formal_Type_Definition
(Parent
(G_Typ
))) =
4259 N_Formal_Private_Type_Definition
4263 -- The generic parent type is the ancestor of a formal derived
4264 -- type declaration. We need to check whether it has a primitive
4265 -- operation that should be overridden by New_E in the generic.
4269 P_Formal
: Entity_Id
;
4270 N_Formal
: Entity_Id
;
4274 Prim_Elt
: Elmt_Id
:= First_Elmt
(Primitive_Operations
(G_Typ
));
4277 while Present
(Prim_Elt
) loop
4278 P_Prim
:= Node
(Prim_Elt
);
4280 if Chars
(P_Prim
) = Chars
(New_E
)
4281 and then Ekind
(P_Prim
) = Ekind
(New_E
)
4283 P_Formal
:= First_Formal
(P_Prim
);
4284 N_Formal
:= First_Formal
(New_E
);
4285 while Present
(P_Formal
) and then Present
(N_Formal
) loop
4286 P_Typ
:= Etype
(P_Formal
);
4287 N_Typ
:= Etype
(N_Formal
);
4289 if not Types_Correspond
(P_Typ
, N_Typ
) then
4293 Next_Entity
(P_Formal
);
4294 Next_Entity
(N_Formal
);
4297 -- Found a matching primitive operation belonging to the
4298 -- formal ancestor type, so the new subprogram is
4301 if not Present
(P_Formal
)
4302 and then not Present
(N_Formal
)
4303 and then (Ekind
(New_E
) /= E_Function
4306 (Etype
(P_Prim
), Etype
(New_E
)))
4312 Next_Elmt
(Prim_Elt
);
4315 -- If no match found, then the new subprogram does not
4316 -- override in the generic (nor in the instance).
4324 end Is_Non_Overriding_Operation
;
4326 ------------------------------
4327 -- Make_Inequality_Operator --
4328 ------------------------------
4330 -- S is the defining identifier of an equality operator. We build a
4331 -- subprogram declaration with the right signature. This operation is
4332 -- intrinsic, because it is always expanded as the negation of the
4333 -- call to the equality function.
4335 procedure Make_Inequality_Operator
(S
: Entity_Id
) is
4336 Loc
: constant Source_Ptr
:= Sloc
(S
);
4339 Op_Name
: Entity_Id
;
4345 -- Check that equality was properly defined
4347 if No
(Next_Formal
(First_Formal
(S
))) then
4351 A
:= Make_Defining_Identifier
(Loc
, Chars
(First_Formal
(S
)));
4352 B
:= Make_Defining_Identifier
(Loc
,
4353 Chars
(Next_Formal
(First_Formal
(S
))));
4355 Op_Name
:= Make_Defining_Operator_Symbol
(Loc
, Name_Op_Ne
);
4357 Formals
:= New_List
(
4358 Make_Parameter_Specification
(Loc
,
4359 Defining_Identifier
=> A
,
4361 New_Reference_To
(Etype
(First_Formal
(S
)), Loc
)),
4363 Make_Parameter_Specification
(Loc
,
4364 Defining_Identifier
=> B
,
4366 New_Reference_To
(Etype
(Next_Formal
(First_Formal
(S
))), Loc
)));
4369 Make_Subprogram_Declaration
(Loc
,
4371 Make_Function_Specification
(Loc
,
4372 Defining_Unit_Name
=> Op_Name
,
4373 Parameter_Specifications
=> Formals
,
4374 Subtype_Mark
=> New_Reference_To
(Standard_Boolean
, Loc
)));
4376 -- Insert inequality right after equality if it is explicit or after
4377 -- the derived type when implicit. These entities are created only
4378 -- for visibility purposes, and eventually replaced in the course of
4379 -- expansion, so they do not need to be attached to the tree and seen
4380 -- by the back-end. Keeping them internal also avoids spurious freezing
4381 -- problems. The parent field is set simply to make analysis safe.
4383 if No
(Alias
(S
)) then
4384 Set_Parent
(Decl
, Parent
(Unit_Declaration_Node
(S
)));
4386 Set_Parent
(Decl
, Parent
(Parent
(Etype
(First_Formal
(S
)))));
4389 Mark_Rewrite_Insertion
(Decl
);
4390 Set_Is_Intrinsic_Subprogram
(Op_Name
);
4392 Set_Has_Completion
(Op_Name
);
4393 Set_Corresponding_Equality
(Op_Name
, S
);
4394 Set_Is_Abstract
(Op_Name
, Is_Abstract
(S
));
4396 end Make_Inequality_Operator
;
4398 ----------------------
4399 -- May_Need_Actuals --
4400 ----------------------
4402 procedure May_Need_Actuals
(Fun
: Entity_Id
) is
4407 F
:= First_Formal
(Fun
);
4410 while Present
(F
) loop
4411 if No
(Default_Value
(F
)) then
4419 Set_Needs_No_Actuals
(Fun
, B
);
4420 end May_Need_Actuals
;
4422 ---------------------
4423 -- Mode_Conformant --
4424 ---------------------
4426 function Mode_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
4429 Check_Conformance
(New_Id
, Old_Id
, Mode_Conformant
, False, Result
);
4431 end Mode_Conformant
;
4433 ---------------------------
4434 -- New_Overloaded_Entity --
4435 ---------------------------
4437 procedure New_Overloaded_Entity
4439 Derived_Type
: Entity_Id
:= Empty
)
4442 -- Entity that S overrides
4444 Prev_Vis
: Entity_Id
:= Empty
;
4445 -- Needs comment ???
4447 function Is_Private_Declaration
(E
: Entity_Id
) return Boolean;
4448 -- Check that E is declared in the private part of the current package,
4449 -- or in the package body, where it may hide a previous declaration.
4450 -- We can't use In_Private_Part by itself because this flag is also
4451 -- set when freezing entities, so we must examine the place of the
4452 -- declaration in the tree, and recognize wrapper packages as well.
4454 procedure Maybe_Primitive_Operation
(Is_Overriding
: Boolean := False);
4455 -- If the subprogram being analyzed is a primitive operation of
4456 -- the type of one of its formals, set the corresponding flag.
4458 ----------------------------
4459 -- Is_Private_Declaration --
4460 ----------------------------
4462 function Is_Private_Declaration
(E
: Entity_Id
) return Boolean is
4463 Priv_Decls
: List_Id
;
4464 Decl
: constant Node_Id
:= Unit_Declaration_Node
(E
);
4467 if Is_Package
(Current_Scope
)
4468 and then In_Private_Part
(Current_Scope
)
4471 Private_Declarations
(
4472 Specification
(Unit_Declaration_Node
(Current_Scope
)));
4474 return In_Package_Body
(Current_Scope
)
4475 or else List_Containing
(Decl
) = Priv_Decls
4476 or else (Nkind
(Parent
(Decl
)) = N_Package_Specification
4477 and then not Is_Compilation_Unit
(
4478 Defining_Entity
(Parent
(Decl
)))
4479 and then List_Containing
(Parent
(Parent
(Decl
)))
4484 end Is_Private_Declaration
;
4486 -------------------------------
4487 -- Maybe_Primitive_Operation --
4488 -------------------------------
4490 procedure Maybe_Primitive_Operation
(Is_Overriding
: Boolean := False) is
4495 function Visible_Part_Type
(T
: Entity_Id
) return Boolean;
4496 -- Returns true if T is declared in the visible part of
4497 -- the current package scope; otherwise returns false.
4498 -- Assumes that T is declared in a package.
4500 procedure Check_Private_Overriding
(T
: Entity_Id
);
4501 -- Checks that if a primitive abstract subprogram of a visible
4502 -- abstract type is declared in a private part, then it must
4503 -- override an abstract subprogram declared in the visible part.
4504 -- Also checks that if a primitive function with a controlling
4505 -- result is declared in a private part, then it must override
4506 -- a function declared in the visible part.
4508 ------------------------------
4509 -- Check_Private_Overriding --
4510 ------------------------------
4512 procedure Check_Private_Overriding
(T
: Entity_Id
) is
4514 if Ekind
(Current_Scope
) = E_Package
4515 and then In_Private_Part
(Current_Scope
)
4516 and then Visible_Part_Type
(T
)
4517 and then not In_Instance
4520 and then Is_Abstract
(S
)
4521 and then (not Is_Overriding
or else not Is_Abstract
(E
))
4523 Error_Msg_N
("abstract subprograms must be visible "
4524 & "('R'M 3.9.3(10))!", S
);
4526 elsif Ekind
(S
) = E_Function
4527 and then Is_Tagged_Type
(T
)
4528 and then T
= Base_Type
(Etype
(S
))
4529 and then not Is_Overriding
4532 ("private function with tagged result must"
4533 & " override visible-part function", S
);
4535 ("\move subprogram to the visible part"
4536 & " ('R'M 3.9.3(10))", S
);
4539 end Check_Private_Overriding
;
4541 -----------------------
4542 -- Visible_Part_Type --
4543 -----------------------
4545 function Visible_Part_Type
(T
: Entity_Id
) return Boolean is
4546 P
: constant Node_Id
:= Unit_Declaration_Node
(Scope
(T
));
4550 -- If the entity is a private type, then it must be
4551 -- declared in a visible part.
4553 if Ekind
(T
) in Private_Kind
then
4557 -- Otherwise, we traverse the visible part looking for its
4558 -- corresponding declaration. We cannot use the declaration
4559 -- node directly because in the private part the entity of a
4560 -- private type is the one in the full view, which does not
4561 -- indicate that it is the completion of something visible.
4563 N
:= First
(Visible_Declarations
(Specification
(P
)));
4564 while Present
(N
) loop
4565 if Nkind
(N
) = N_Full_Type_Declaration
4566 and then Present
(Defining_Identifier
(N
))
4567 and then T
= Defining_Identifier
(N
)
4571 elsif (Nkind
(N
) = N_Private_Type_Declaration
4573 Nkind
(N
) = N_Private_Extension_Declaration
)
4574 and then Present
(Defining_Identifier
(N
))
4575 and then T
= Full_View
(Defining_Identifier
(N
))
4584 end Visible_Part_Type
;
4586 -- Start of processing for Maybe_Primitive_Operation
4589 if not Comes_From_Source
(S
) then
4592 -- If the subprogram is at library level, it is not primitive
4595 elsif Current_Scope
= Standard_Standard
then
4598 elsif (Ekind
(Current_Scope
) = E_Package
4599 and then not In_Package_Body
(Current_Scope
))
4600 or else Is_Overriding
4602 -- For function, check return type
4604 if Ekind
(S
) = E_Function
then
4605 B_Typ
:= Base_Type
(Etype
(S
));
4607 if Scope
(B_Typ
) = Current_Scope
then
4608 Set_Has_Primitive_Operations
(B_Typ
);
4609 Check_Private_Overriding
(B_Typ
);
4613 -- For all subprograms, check formals
4615 Formal
:= First_Formal
(S
);
4616 while Present
(Formal
) loop
4617 if Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
then
4618 F_Typ
:= Designated_Type
(Etype
(Formal
));
4620 F_Typ
:= Etype
(Formal
);
4623 B_Typ
:= Base_Type
(F_Typ
);
4625 if Scope
(B_Typ
) = Current_Scope
then
4626 Set_Has_Primitive_Operations
(B_Typ
);
4627 Check_Private_Overriding
(B_Typ
);
4630 Next_Formal
(Formal
);
4633 end Maybe_Primitive_Operation
;
4635 -- Start of processing for New_Overloaded_Entity
4638 -- We need to look for an entity that S may override. This must be a
4639 -- homonym in the current scope, so we look for the first homonym of
4640 -- S in the current scope as the starting point for the search.
4642 E
:= Current_Entity_In_Scope
(S
);
4644 -- If there is no homonym then this is definitely not overriding
4647 Enter_Overloaded_Entity
(S
);
4648 Check_Dispatching_Operation
(S
, Empty
);
4649 Maybe_Primitive_Operation
;
4651 -- If there is a homonym that is not overloadable, then we have an
4652 -- error, except for the special cases checked explicitly below.
4654 elsif not Is_Overloadable
(E
) then
4656 -- Check for spurious conflict produced by a subprogram that has the
4657 -- same name as that of the enclosing generic package. The conflict
4658 -- occurs within an instance, between the subprogram and the renaming
4659 -- declaration for the package. After the subprogram, the package
4660 -- renaming declaration becomes hidden.
4662 if Ekind
(E
) = E_Package
4663 and then Present
(Renamed_Object
(E
))
4664 and then Renamed_Object
(E
) = Current_Scope
4665 and then Nkind
(Parent
(Renamed_Object
(E
))) =
4666 N_Package_Specification
4667 and then Present
(Generic_Parent
(Parent
(Renamed_Object
(E
))))
4670 Set_Is_Immediately_Visible
(E
, False);
4671 Enter_Overloaded_Entity
(S
);
4672 Set_Homonym
(S
, Homonym
(E
));
4673 Check_Dispatching_Operation
(S
, Empty
);
4675 -- If the subprogram is implicit it is hidden by the previous
4676 -- declaration. However if it is dispatching, it must appear in the
4677 -- dispatch table anyway, because it can be dispatched to even if it
4678 -- cannot be called directly.
4680 elsif Present
(Alias
(S
))
4681 and then not Comes_From_Source
(S
)
4683 Set_Scope
(S
, Current_Scope
);
4685 if Is_Dispatching_Operation
(Alias
(S
)) then
4686 Check_Dispatching_Operation
(S
, Empty
);
4692 Error_Msg_Sloc
:= Sloc
(E
);
4693 Error_Msg_N
("& conflicts with declaration#", S
);
4695 -- Useful additional warning
4697 if Is_Generic_Unit
(E
) then
4698 Error_Msg_N
("\previous generic unit cannot be overloaded", S
);
4704 -- E exists and is overloadable
4707 -- Loop through E and its homonyms to determine if any of them is
4708 -- the candidate for overriding by S.
4710 while Present
(E
) loop
4712 -- Definitely not interesting if not in the current scope
4714 if Scope
(E
) /= Current_Scope
then
4717 -- Check if we have type conformance
4719 elsif Type_Conformant
(E
, S
) then
4721 -- If the old and new entities have the same profile and one
4722 -- is not the body of the other, then this is an error, unless
4723 -- one of them is implicitly declared.
4725 -- There are some cases when both can be implicit, for example
4726 -- when both a literal and a function that overrides it are
4727 -- inherited in a derivation, or when an inhertited operation
4728 -- of a tagged full type overrides the ineherited operation of
4729 -- a private extension. Ada 83 had a special rule for the the
4730 -- literal case. In Ada95, the later implicit operation hides
4731 -- the former, and the literal is always the former. In the
4732 -- odd case where both are derived operations declared at the
4733 -- same point, both operations should be declared, and in that
4734 -- case we bypass the following test and proceed to the next
4735 -- part (this can only occur for certain obscure cases
4736 -- involving homographs in instances and can't occur for
4737 -- dispatching operations ???). Note that the following
4738 -- condition is less than clear. For example, it's not at all
4739 -- clear why there's a test for E_Entry here. ???
4741 if Present
(Alias
(S
))
4742 and then (No
(Alias
(E
))
4743 or else Comes_From_Source
(E
)
4744 or else Is_Dispatching_Operation
(E
))
4746 (Ekind
(E
) = E_Entry
4747 or else Ekind
(E
) /= E_Enumeration_Literal
)
4749 -- When an derived operation is overloaded it may be due to
4750 -- the fact that the full view of a private extension
4751 -- re-inherits. It has to be dealt with.
4753 if Is_Package
(Current_Scope
)
4754 and then In_Private_Part
(Current_Scope
)
4756 Check_Operation_From_Private_View
(S
, E
);
4759 -- In any case the implicit operation remains hidden by
4760 -- the existing declaration, which is overriding.
4762 Set_Is_Overriding_Operation
(E
);
4765 -- Within an instance, the renaming declarations for
4766 -- actual subprograms may become ambiguous, but they do
4767 -- not hide each other.
4769 elsif Ekind
(E
) /= E_Entry
4770 and then not Comes_From_Source
(E
)
4771 and then not Is_Generic_Instance
(E
)
4772 and then (Present
(Alias
(E
))
4773 or else Is_Intrinsic_Subprogram
(E
))
4774 and then (not In_Instance
4775 or else No
(Parent
(E
))
4776 or else Nkind
(Unit_Declaration_Node
(E
)) /=
4777 N_Subprogram_Renaming_Declaration
)
4779 -- A subprogram child unit is not allowed to override
4780 -- an inherited subprogram (10.1.1(20)).
4782 if Is_Child_Unit
(S
) then
4784 ("child unit overrides inherited subprogram in parent",
4789 if Is_Non_Overriding_Operation
(E
, S
) then
4790 Enter_Overloaded_Entity
(S
);
4791 if not Present
(Derived_Type
)
4792 or else Is_Tagged_Type
(Derived_Type
)
4794 Check_Dispatching_Operation
(S
, Empty
);
4800 -- E is a derived operation or an internal operator which
4801 -- is being overridden. Remove E from further visibility.
4802 -- Furthermore, if E is a dispatching operation, it must be
4803 -- replaced in the list of primitive operations of its type
4804 -- (see Override_Dispatching_Operation).
4810 Prev
:= First_Entity
(Current_Scope
);
4812 while Present
(Prev
)
4813 and then Next_Entity
(Prev
) /= E
4818 -- It is possible for E to be in the current scope and
4819 -- yet not in the entity chain. This can only occur in a
4820 -- generic context where E is an implicit concatenation
4821 -- in the formal part, because in a generic body the
4822 -- entity chain starts with the formals.
4825 (Present
(Prev
) or else Chars
(E
) = Name_Op_Concat
);
4827 -- E must be removed both from the entity_list of the
4828 -- current scope, and from the visibility chain
4830 if Debug_Flag_E
then
4831 Write_Str
("Override implicit operation ");
4832 Write_Int
(Int
(E
));
4836 -- If E is a predefined concatenation, it stands for four
4837 -- different operations. As a result, a single explicit
4838 -- declaration does not hide it. In a possible ambiguous
4839 -- situation, Disambiguate chooses the user-defined op,
4840 -- so it is correct to retain the previous internal one.
4842 if Chars
(E
) /= Name_Op_Concat
4843 or else Ekind
(E
) /= E_Operator
4845 -- For nondispatching derived operations that are
4846 -- overridden by a subprogram declared in the private
4847 -- part of a package, we retain the derived
4848 -- subprogram but mark it as not immediately visible.
4849 -- If the derived operation was declared in the
4850 -- visible part then this ensures that it will still
4851 -- be visible outside the package with the proper
4852 -- signature (calls from outside must also be
4853 -- directed to this version rather than the
4854 -- overriding one, unlike the dispatching case).
4855 -- Calls from inside the package will still resolve
4856 -- to the overriding subprogram since the derived one
4857 -- is marked as not visible within the package.
4859 -- If the private operation is dispatching, we achieve
4860 -- the overriding by keeping the implicit operation
4861 -- but setting its alias to be the overring one. In
4862 -- this fashion the proper body is executed in all
4863 -- cases, but the original signature is used outside
4866 -- If the overriding is not in the private part, we
4867 -- remove the implicit operation altogether.
4869 if Is_Private_Declaration
(S
) then
4871 if not Is_Dispatching_Operation
(E
) then
4872 Set_Is_Immediately_Visible
(E
, False);
4874 -- Work done in Override_Dispatching_Operation,
4875 -- so nothing else need to be done here.
4881 -- Find predecessor of E in Homonym chain
4883 if E
= Current_Entity
(E
) then
4886 Prev_Vis
:= Current_Entity
(E
);
4887 while Homonym
(Prev_Vis
) /= E
loop
4888 Prev_Vis
:= Homonym
(Prev_Vis
);
4892 if Prev_Vis
/= Empty
then
4894 -- Skip E in the visibility chain
4896 Set_Homonym
(Prev_Vis
, Homonym
(E
));
4899 Set_Name_Entity_Id
(Chars
(E
), Homonym
(E
));
4902 Set_Next_Entity
(Prev
, Next_Entity
(E
));
4904 if No
(Next_Entity
(Prev
)) then
4905 Set_Last_Entity
(Current_Scope
, Prev
);
4911 Enter_Overloaded_Entity
(S
);
4912 Set_Is_Overriding_Operation
(S
);
4914 if Is_Dispatching_Operation
(E
) then
4916 -- An overriding dispatching subprogram inherits the
4917 -- convention of the overridden subprogram (by
4920 Set_Convention
(S
, Convention
(E
));
4922 Check_Dispatching_Operation
(S
, E
);
4924 Check_Dispatching_Operation
(S
, Empty
);
4927 Maybe_Primitive_Operation
(Is_Overriding
=> True);
4928 goto Check_Inequality
;
4931 -- Apparent redeclarations in instances can occur when two
4932 -- formal types get the same actual type. The subprograms in
4933 -- in the instance are legal, even if not callable from the
4934 -- outside. Calls from within are disambiguated elsewhere.
4935 -- For dispatching operations in the visible part, the usual
4936 -- rules apply, and operations with the same profile are not
4939 elsif (In_Instance_Visible_Part
4940 and then not Is_Dispatching_Operation
(E
))
4941 or else In_Instance_Not_Visible
4945 -- Here we have a real error (identical profile)
4948 Error_Msg_Sloc
:= Sloc
(E
);
4950 -- Avoid cascaded errors if the entity appears in
4951 -- subsequent calls.
4953 Set_Scope
(S
, Current_Scope
);
4955 Error_Msg_N
("& conflicts with declaration#", S
);
4957 if Is_Generic_Instance
(S
)
4958 and then not Has_Completion
(E
)
4961 ("\instantiation cannot provide body for it", S
);
4975 -- On exit, we know that S is a new entity
4977 Enter_Overloaded_Entity
(S
);
4978 Maybe_Primitive_Operation
;
4980 -- If S is a derived operation for an untagged type then by
4981 -- definition it's not a dispatching operation (even if the parent
4982 -- operation was dispatching), so we don't call
4983 -- Check_Dispatching_Operation in that case.
4985 if not Present
(Derived_Type
)
4986 or else Is_Tagged_Type
(Derived_Type
)
4988 Check_Dispatching_Operation
(S
, Empty
);
4992 -- If this is a user-defined equality operator that is not a derived
4993 -- subprogram, create the corresponding inequality. If the operation is
4994 -- dispatching, the expansion is done elsewhere, and we do not create
4995 -- an explicit inequality operation.
4997 <<Check_Inequality
>>
4998 if Chars
(S
) = Name_Op_Eq
4999 and then Etype
(S
) = Standard_Boolean
5000 and then Present
(Parent
(S
))
5001 and then not Is_Dispatching_Operation
(S
)
5003 Make_Inequality_Operator
(S
);
5005 end New_Overloaded_Entity
;
5007 ---------------------
5008 -- Process_Formals --
5009 ---------------------
5011 procedure Process_Formals
5013 Related_Nod
: Node_Id
)
5015 Param_Spec
: Node_Id
;
5017 Formal_Type
: Entity_Id
;
5021 function Is_Class_Wide_Default
(D
: Node_Id
) return Boolean;
5022 -- Check whether the default has a class-wide type. After analysis the
5023 -- default has the type of the formal, so we must also check explicitly
5024 -- for an access attribute.
5026 ---------------------------
5027 -- Is_Class_Wide_Default --
5028 ---------------------------
5030 function Is_Class_Wide_Default
(D
: Node_Id
) return Boolean is
5032 return Is_Class_Wide_Type
(Designated_Type
(Etype
(D
)))
5033 or else (Nkind
(D
) = N_Attribute_Reference
5034 and then Attribute_Name
(D
) = Name_Access
5035 and then Is_Class_Wide_Type
(Etype
(Prefix
(D
))));
5036 end Is_Class_Wide_Default
;
5038 -- Start of processing for Process_Formals
5041 -- In order to prevent premature use of the formals in the same formal
5042 -- part, the Ekind is left undefined until all default expressions are
5043 -- analyzed. The Ekind is established in a separate loop at the end.
5045 Param_Spec
:= First
(T
);
5047 while Present
(Param_Spec
) loop
5049 Formal
:= Defining_Identifier
(Param_Spec
);
5050 Enter_Name
(Formal
);
5052 -- Case of ordinary parameters
5054 if Nkind
(Parameter_Type
(Param_Spec
)) /= N_Access_Definition
then
5055 Find_Type
(Parameter_Type
(Param_Spec
));
5056 Ptype
:= Parameter_Type
(Param_Spec
);
5058 if Ptype
= Error
then
5062 Formal_Type
:= Entity
(Ptype
);
5064 if Ekind
(Formal_Type
) = E_Incomplete_Type
5065 or else (Is_Class_Wide_Type
(Formal_Type
)
5066 and then Ekind
(Root_Type
(Formal_Type
)) =
5069 -- Ada 2005 (AI-50217): Incomplete tagged types that are made
5070 -- visible by a limited with_clause are valid formal types.
5072 if From_With_Type
(Formal_Type
)
5073 and then Is_Tagged_Type
(Formal_Type
)
5077 elsif Nkind
(Parent
(T
)) /= N_Access_Function_Definition
5078 and then Nkind
(Parent
(T
)) /= N_Access_Procedure_Definition
5080 Error_Msg_N
("invalid use of incomplete type", Param_Spec
);
5083 elsif Ekind
(Formal_Type
) = E_Void
then
5084 Error_Msg_NE
("premature use of&",
5085 Parameter_Type
(Param_Spec
), Formal_Type
);
5088 -- Ada 2005 (AI-231): Create and decorate an internal subtype
5089 -- declaration corresponding to the null-excluding type of the
5090 -- formal in the enclosing scope. In addition, replace the
5091 -- parameter type of the formal to this internal subtype.
5093 if Null_Exclusion_Present
(Param_Spec
) then
5095 Loc
: constant Source_Ptr
:= Sloc
(Param_Spec
);
5097 Anon
: constant Entity_Id
:=
5098 Make_Defining_Identifier
(Loc
,
5099 Chars
=> New_Internal_Name
('S'));
5101 Curr_Scope
: constant Scope_Stack_Entry
:=
5102 Scope_Stack
.Table
(Scope_Stack
.Last
);
5104 Ptype
: constant Node_Id
:= Parameter_Type
(Param_Spec
);
5106 P
: Node_Id
:= Parent
(Parent
(Related_Nod
));
5109 Set_Is_Internal
(Anon
);
5112 Make_Subtype_Declaration
(Loc
,
5113 Defining_Identifier
=> Anon
,
5114 Null_Exclusion_Present
=> True,
5115 Subtype_Indication
=>
5116 New_Occurrence_Of
(Etype
(Ptype
), Loc
));
5118 -- Propagate the null-excluding attribute to the new entity
5120 if Null_Exclusion_Present
(Param_Spec
) then
5121 Set_Null_Exclusion_Present
(Param_Spec
, False);
5122 Set_Can_Never_Be_Null
(Anon
);
5125 Mark_Rewrite_Insertion
(Decl
);
5127 -- Insert the new declaration in the nearest enclosing scope
5129 while not Has_Declarations
(P
) loop
5133 Prepend
(Decl
, Declarations
(P
));
5135 Rewrite
(Ptype
, New_Occurrence_Of
(Anon
, Loc
));
5136 Mark_Rewrite_Insertion
(Ptype
);
5138 -- Analyze the new declaration in the context of the
5141 Scope_Stack
.Decrement_Last
;
5143 Scope_Stack
.Append
(Curr_Scope
);
5145 Formal_Type
:= Anon
;
5149 -- Ada 2005 (AI-231): Static checks
5151 if Null_Exclusion_Present
(Param_Spec
)
5152 or else Can_Never_Be_Null
(Entity
(Ptype
))
5154 Null_Exclusion_Static_Checks
(Param_Spec
);
5157 -- An access formal type
5161 Access_Definition
(Related_Nod
, Parameter_Type
(Param_Spec
));
5163 -- Ada 2005 (AI-254)
5166 AD
: constant Node_Id
:=
5167 Access_To_Subprogram_Definition
5168 (Parameter_Type
(Param_Spec
));
5170 if Present
(AD
) and then Protected_Present
(AD
) then
5172 Replace_Anonymous_Access_To_Protected_Subprogram
5173 (Param_Spec
, Formal_Type
);
5178 Set_Etype
(Formal
, Formal_Type
);
5179 Default
:= Expression
(Param_Spec
);
5181 if Present
(Default
) then
5182 if Out_Present
(Param_Spec
) then
5184 ("default initialization only allowed for IN parameters",
5188 -- Do the special preanalysis of the expression (see section on
5189 -- "Handling of Default Expressions" in the spec of package Sem).
5191 Analyze_Per_Use_Expression
(Default
, Formal_Type
);
5193 -- Check that the designated type of an access parameter's
5194 -- default is not a class-wide type unless the parameter's
5195 -- designated type is also class-wide.
5197 if Ekind
(Formal_Type
) = E_Anonymous_Access_Type
5198 and then Is_Class_Wide_Default
(Default
)
5199 and then not Is_Class_Wide_Type
(Designated_Type
(Formal_Type
))
5202 ("access to class-wide expression not allowed here", Default
);
5210 -- If this is the formal part of a function specification, analyze the
5211 -- subtype mark in the context where the formals are visible but not
5212 -- yet usable, and may hide outer homographs.
5214 if Nkind
(Related_Nod
) = N_Function_Specification
then
5215 Analyze_Return_Type
(Related_Nod
);
5218 -- Now set the kind (mode) of each formal
5220 Param_Spec
:= First
(T
);
5222 while Present
(Param_Spec
) loop
5223 Formal
:= Defining_Identifier
(Param_Spec
);
5224 Set_Formal_Mode
(Formal
);
5226 if Ekind
(Formal
) = E_In_Parameter
then
5227 Set_Default_Value
(Formal
, Expression
(Param_Spec
));
5229 if Present
(Expression
(Param_Spec
)) then
5230 Default
:= Expression
(Param_Spec
);
5232 if Is_Scalar_Type
(Etype
(Default
)) then
5234 (Parameter_Type
(Param_Spec
)) /= N_Access_Definition
5236 Formal_Type
:= Entity
(Parameter_Type
(Param_Spec
));
5239 Formal_Type
:= Access_Definition
5240 (Related_Nod
, Parameter_Type
(Param_Spec
));
5243 Apply_Scalar_Range_Check
(Default
, Formal_Type
);
5251 end Process_Formals
;
5253 ----------------------------
5254 -- Reference_Body_Formals --
5255 ----------------------------
5257 procedure Reference_Body_Formals
(Spec
: Entity_Id
; Bod
: Entity_Id
) is
5262 if Error_Posted
(Spec
) then
5266 Fs
:= First_Formal
(Spec
);
5267 Fb
:= First_Formal
(Bod
);
5269 while Present
(Fs
) loop
5270 Generate_Reference
(Fs
, Fb
, 'b');
5273 Style
.Check_Identifier
(Fb
, Fs
);
5276 Set_Spec_Entity
(Fb
, Fs
);
5277 Set_Referenced
(Fs
, False);
5281 end Reference_Body_Formals
;
5283 -------------------------
5284 -- Set_Actual_Subtypes --
5285 -------------------------
5287 procedure Set_Actual_Subtypes
(N
: Node_Id
; Subp
: Entity_Id
) is
5288 Loc
: constant Source_Ptr
:= Sloc
(N
);
5292 First_Stmt
: Node_Id
:= Empty
;
5293 AS_Needed
: Boolean;
5296 -- If this is an emtpy initialization procedure, no need to create
5297 -- actual subtypes (small optimization).
5299 if Ekind
(Subp
) = E_Procedure
5300 and then Is_Null_Init_Proc
(Subp
)
5305 Formal
:= First_Formal
(Subp
);
5306 while Present
(Formal
) loop
5307 T
:= Etype
(Formal
);
5309 -- We never need an actual subtype for a constrained formal
5311 if Is_Constrained
(T
) then
5314 -- If we have unknown discriminants, then we do not need an actual
5315 -- subtype, or more accurately we cannot figure it out! Note that
5316 -- all class-wide types have unknown discriminants.
5318 elsif Has_Unknown_Discriminants
(T
) then
5321 -- At this stage we have an unconstrained type that may need an
5322 -- actual subtype. For sure the actual subtype is needed if we have
5323 -- an unconstrained array type.
5325 elsif Is_Array_Type
(T
) then
5328 -- The only other case which needs an actual subtype is an
5329 -- unconstrained record type which is an IN parameter (we cannot
5330 -- generate actual subtypes for the OUT or IN OUT case, since an
5331 -- assignment can change the discriminant values. However we exclude
5332 -- the case of initialization procedures, since discriminants are
5333 -- handled very specially in this context, see the section entitled
5334 -- "Handling of Discriminants" in Einfo. We also exclude the case of
5335 -- Discrim_SO_Functions (functions used in front end layout mode for
5336 -- size/offset values), since in such functions only discriminants
5337 -- are referenced, and not only are such subtypes not needed, but
5338 -- they cannot always be generated, because of order of elaboration
5341 elsif Is_Record_Type
(T
)
5342 and then Ekind
(Formal
) = E_In_Parameter
5343 and then Chars
(Formal
) /= Name_uInit
5344 and then not Is_Unchecked_Union
(T
)
5345 and then not Is_Discrim_SO_Function
(Subp
)
5349 -- All other cases do not need an actual subtype
5355 -- Generate actual subtypes for unconstrained arrays and
5356 -- unconstrained discriminated records.
5359 if Nkind
(N
) = N_Accept_Statement
then
5361 -- If expansion is active, The formal is replaced by a local
5362 -- variable that renames the corresponding entry of the
5363 -- parameter block, and it is this local variable that may
5364 -- require an actual subtype.
5366 if Expander_Active
then
5367 Decl
:= Build_Actual_Subtype
(T
, Renamed_Object
(Formal
));
5369 Decl
:= Build_Actual_Subtype
(T
, Formal
);
5372 if Present
(Handled_Statement_Sequence
(N
)) then
5374 First
(Statements
(Handled_Statement_Sequence
(N
)));
5375 Prepend
(Decl
, Statements
(Handled_Statement_Sequence
(N
)));
5376 Mark_Rewrite_Insertion
(Decl
);
5378 -- If the accept statement has no body, there will be no
5379 -- reference to the actuals, so no need to compute actual
5386 Decl
:= Build_Actual_Subtype
(T
, Formal
);
5387 Prepend
(Decl
, Declarations
(N
));
5388 Mark_Rewrite_Insertion
(Decl
);
5391 -- The declaration uses the bounds of an existing object, and
5392 -- therefore needs no constraint checks.
5394 Analyze
(Decl
, Suppress
=> All_Checks
);
5396 -- We need to freeze manually the generated type when it is
5397 -- inserted anywhere else than in a declarative part.
5399 if Present
(First_Stmt
) then
5400 Insert_List_Before_And_Analyze
(First_Stmt
,
5401 Freeze_Entity
(Defining_Identifier
(Decl
), Loc
));
5404 if Nkind
(N
) = N_Accept_Statement
5405 and then Expander_Active
5407 Set_Actual_Subtype
(Renamed_Object
(Formal
),
5408 Defining_Identifier
(Decl
));
5410 Set_Actual_Subtype
(Formal
, Defining_Identifier
(Decl
));
5414 Next_Formal
(Formal
);
5416 end Set_Actual_Subtypes
;
5418 ---------------------
5419 -- Set_Formal_Mode --
5420 ---------------------
5422 procedure Set_Formal_Mode
(Formal_Id
: Entity_Id
) is
5423 Spec
: constant Node_Id
:= Parent
(Formal_Id
);
5426 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
5427 -- since we ensure that corresponding actuals are always valid at the
5428 -- point of the call.
5430 if Out_Present
(Spec
) then
5431 if Ekind
(Scope
(Formal_Id
)) = E_Function
5432 or else Ekind
(Scope
(Formal_Id
)) = E_Generic_Function
5434 Error_Msg_N
("functions can only have IN parameters", Spec
);
5435 Set_Ekind
(Formal_Id
, E_In_Parameter
);
5437 elsif In_Present
(Spec
) then
5438 Set_Ekind
(Formal_Id
, E_In_Out_Parameter
);
5441 Set_Ekind
(Formal_Id
, E_Out_Parameter
);
5442 Set_Never_Set_In_Source
(Formal_Id
, True);
5443 Set_Is_True_Constant
(Formal_Id
, False);
5444 Set_Current_Value
(Formal_Id
, Empty
);
5448 Set_Ekind
(Formal_Id
, E_In_Parameter
);
5451 -- Set Is_Known_Non_Null for access parameters since the language
5452 -- guarantees that access parameters are always non-null. We also set
5453 -- Can_Never_Be_Null, since there is no way to change the value.
5455 if Nkind
(Parameter_Type
(Spec
)) = N_Access_Definition
then
5457 -- Ada 2005 (AI-231): This behaviour has been modified in Ada 2005.
5458 -- It is only forced if the null_exclusion appears.
5460 if Ada_Version
< Ada_05
5461 or else Null_Exclusion_Present
(Spec
)
5463 Set_Is_Known_Non_Null
(Formal_Id
);
5464 Set_Can_Never_Be_Null
(Formal_Id
);
5468 Set_Mechanism
(Formal_Id
, Default_Mechanism
);
5469 Set_Formal_Validity
(Formal_Id
);
5470 end Set_Formal_Mode
;
5472 -------------------------
5473 -- Set_Formal_Validity --
5474 -------------------------
5476 procedure Set_Formal_Validity
(Formal_Id
: Entity_Id
) is
5478 -- If no validity checking, then we cannot assume anything about the
5479 -- validity of parameters, since we do not know there is any checking
5480 -- of the validity on the call side.
5482 if not Validity_Checks_On
then
5485 -- If validity checking for parameters is enabled, this means we are
5486 -- not supposed to make any assumptions about argument values.
5488 elsif Validity_Check_Parameters
then
5491 -- If we are checking in parameters, we will assume that the caller is
5492 -- also checking parameters, so we can assume the parameter is valid.
5494 elsif Ekind
(Formal_Id
) = E_In_Parameter
5495 and then Validity_Check_In_Params
5497 Set_Is_Known_Valid
(Formal_Id
, True);
5499 -- Similar treatment for IN OUT parameters
5501 elsif Ekind
(Formal_Id
) = E_In_Out_Parameter
5502 and then Validity_Check_In_Out_Params
5504 Set_Is_Known_Valid
(Formal_Id
, True);
5506 end Set_Formal_Validity
;
5508 ------------------------
5509 -- Subtype_Conformant --
5510 ------------------------
5512 function Subtype_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
5516 Check_Conformance
(New_Id
, Old_Id
, Subtype_Conformant
, False, Result
);
5518 end Subtype_Conformant
;
5520 ---------------------
5521 -- Type_Conformant --
5522 ---------------------
5524 function Type_Conformant
(New_Id
, Old_Id
: Entity_Id
) return Boolean is
5527 Check_Conformance
(New_Id
, Old_Id
, Type_Conformant
, False, Result
);
5529 end Type_Conformant
;
5531 -------------------------------
5532 -- Valid_Operator_Definition --
5533 -------------------------------
5535 procedure Valid_Operator_Definition
(Designator
: Entity_Id
) is
5538 Id
: constant Name_Id
:= Chars
(Designator
);
5542 F
:= First_Formal
(Designator
);
5544 while Present
(F
) loop
5547 if Present
(Default_Value
(F
)) then
5549 ("default values not allowed for operator parameters",
5556 -- Verify that user-defined operators have proper number of arguments
5557 -- First case of operators which can only be unary
5560 or else Id
= Name_Op_Abs
5564 -- Case of operators which can be unary or binary
5566 elsif Id
= Name_Op_Add
5567 or Id
= Name_Op_Subtract
5569 N_OK
:= (N
in 1 .. 2);
5571 -- All other operators can only be binary
5579 ("incorrect number of arguments for operator", Designator
);
5583 and then Base_Type
(Etype
(Designator
)) = Standard_Boolean
5584 and then not Is_Intrinsic_Subprogram
(Designator
)
5587 ("explicit definition of inequality not allowed", Designator
);
5589 end Valid_Operator_Definition
;