1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2004, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Elists; use Elists;
32 with Errout; use Errout;
33 with Expander; use Expander;
34 with Exp_Ch7; use Exp_Ch7;
35 with Fname; use Fname;
36 with Freeze; use Freeze;
37 with Lib.Xref; use Lib.Xref;
38 with Namet; use Namet;
40 with Nlists; use Nlists;
41 with Nmake; use Nmake;
43 with Output; use Output;
44 with Rtsfind; use Rtsfind;
46 with Sem_Cat; use Sem_Cat;
47 with Sem_Ch3; use Sem_Ch3;
48 with Sem_Ch4; use Sem_Ch4;
49 with Sem_Ch5; use Sem_Ch5;
50 with Sem_Ch8; use Sem_Ch8;
51 with Sem_Ch10; use Sem_Ch10;
52 with Sem_Ch12; use Sem_Ch12;
53 with Sem_Disp; use Sem_Disp;
54 with Sem_Dist; use Sem_Dist;
55 with Sem_Elim; use Sem_Elim;
56 with Sem_Eval; use Sem_Eval;
57 with Sem_Mech; use Sem_Mech;
58 with Sem_Prag; use Sem_Prag;
59 with Sem_Res; use Sem_Res;
60 with Sem_Util; use Sem_Util;
61 with Sem_Type; use Sem_Type;
62 with Sem_Warn; use Sem_Warn;
63 with Sinput; use Sinput;
64 with Stand; use Stand;
65 with Sinfo; use Sinfo;
66 with Sinfo.CN; use Sinfo.CN;
67 with Snames; use Snames;
68 with Stringt; use Stringt;
70 with Stylesw; use Stylesw;
71 with Tbuild; use Tbuild;
72 with Uintp; use Uintp;
73 with Urealp; use Urealp;
74 with Validsw; use Validsw;
76 package body Sem_Ch6 is
78 -----------------------
79 -- Local Subprograms --
80 -----------------------
82 procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id);
83 -- Analyze a generic subprogram body. N is the body to be analyzed,
84 -- and Gen_Id is the defining entity Id for the corresponding spec.
86 procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id);
87 -- If a subprogram has pragma Inline and inlining is active, use generic
88 -- machinery to build an unexpanded body for the subprogram. This body is
89 -- subsequenty used for inline expansions at call sites. If subprogram can
90 -- be inlined (depending on size and nature of local declarations) this
91 -- function returns true. Otherwise subprogram body is treated normally.
92 -- If proper warnings are enabled and the subprogram contains a construct
93 -- that cannot be inlined, the offending construct is flagged accordingly.
95 type Conformance_Type is
96 (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant);
97 -- Conformance type used for following call, meaning matches the
98 -- RM definitions of the corresponding terms.
100 procedure Check_Conformance
103 Ctype : Conformance_Type;
105 Conforms : out Boolean;
106 Err_Loc : Node_Id := Empty;
107 Get_Inst : Boolean := False);
108 -- Given two entities, this procedure checks that the profiles associated
109 -- with these entities meet the conformance criterion given by the third
110 -- parameter. If they conform, Conforms is set True and control returns
111 -- to the caller. If they do not conform, Conforms is set to False, and
112 -- in addition, if Errmsg is True on the call, proper messages are output
113 -- to complain about the conformance failure. If Err_Loc is non_Empty
114 -- the error messages are placed on Err_Loc, if Err_Loc is empty, then
115 -- error messages are placed on the appropriate part of the construct
116 -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
117 -- against a formal access-to-subprogram type so Get_Instance_Of must
120 procedure Check_Overriding_Operation
123 -- Check that a subprogram with a pragma Overriding or Optional_Overriding
124 -- is legal. This check is performed here rather than in Sem_Prag because
125 -- the pragma must follow immediately the declaration, and can be treated
126 -- as part of the declaration itself, as described in AI-218.
128 procedure Check_Subprogram_Order (N : Node_Id);
129 -- N is the N_Subprogram_Body node for a subprogram. This routine applies
130 -- the alpha ordering rule for N if this ordering requirement applicable.
132 function Is_Non_Overriding_Operation
134 New_E : Entity_Id) return Boolean;
135 -- Enforce the rule given in 12.3(18): a private operation in an instance
136 -- overrides an inherited operation only if the corresponding operation
137 -- was overriding in the generic. This can happen for primitive operations
138 -- of types derived (in the generic unit) from formal private or formal
141 procedure Check_Returns
145 -- Called to check for missing return statements in a function body,
146 -- or for returns present in a procedure body which has No_Return set.
147 -- L is the handled statement sequence for the subprogram body. This
148 -- procedure checks all flow paths to make sure they either have a
149 -- return (Mode = 'F') or do not have a return (Mode = 'P'). The flag
150 -- Err is set if there are any control paths not explicitly terminated
151 -- by a return in the function case, and is True otherwise.
153 function Conforming_Types
156 Ctype : Conformance_Type;
157 Get_Inst : Boolean := False) return Boolean;
158 -- Check that two formal parameter types conform, checking both
159 -- for equality of base types, and where required statically
160 -- matching subtypes, depending on the setting of Ctype.
162 procedure Enter_Overloaded_Entity (S : Entity_Id);
163 -- This procedure makes S, a new overloaded entity, into the first
164 -- visible entity with that name.
166 procedure Install_Entity (E : Entity_Id);
167 -- Make single entity visible. Used for generic formals as well.
169 procedure Install_Formals (Id : Entity_Id);
170 -- On entry to a subprogram body, make the formals visible. Note
171 -- that simply placing the subprogram on the scope stack is not
172 -- sufficient: the formals must become the current entities for
175 procedure Make_Inequality_Operator (S : Entity_Id);
176 -- Create the declaration for an inequality operator that is implicitly
177 -- created by a user-defined equality operator that yields a boolean.
179 procedure May_Need_Actuals (Fun : Entity_Id);
180 -- Flag functions that can be called without parameters, i.e. those that
181 -- have no parameters, or those for which defaults exist for all parameters
183 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id);
184 -- If there is a separate spec for a subprogram or generic subprogram,
185 -- the formals of the body are treated as references to the corresponding
186 -- formals of the spec. This reference does not count as an actual use of
187 -- the formal, in order to diagnose formals that are unused in the body.
189 procedure Set_Formal_Validity (Formal_Id : Entity_Id);
190 -- Formal_Id is an formal parameter entity. This procedure deals with
191 -- setting the proper validity status for this entity, which depends
192 -- on the kind of parameter and the validity checking mode.
194 ---------------------------------------------
195 -- Analyze_Abstract_Subprogram_Declaration --
196 ---------------------------------------------
198 procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is
199 Designator : constant Entity_Id :=
200 Analyze_Subprogram_Specification (Specification (N));
201 Scop : constant Entity_Id := Current_Scope;
204 Generate_Definition (Designator);
205 Set_Is_Abstract (Designator);
206 New_Overloaded_Entity (Designator);
207 Check_Delayed_Subprogram (Designator);
209 Set_Categorization_From_Scope (Designator, Scop);
211 if Ekind (Scope (Designator)) = E_Protected_Type then
213 ("abstract subprogram not allowed in protected type", N);
216 Generate_Reference_To_Formals (Designator);
217 end Analyze_Abstract_Subprogram_Declaration;
219 ----------------------------
220 -- Analyze_Function_Call --
221 ----------------------------
223 procedure Analyze_Function_Call (N : Node_Id) is
224 P : constant Node_Id := Name (N);
225 L : constant List_Id := Parameter_Associations (N);
231 -- If error analyzing name, then set Any_Type as result type and return
233 if Etype (P) = Any_Type then
234 Set_Etype (N, Any_Type);
238 -- Otherwise analyze the parameters
243 while Present (Actual) loop
245 Check_Parameterless_Call (Actual);
251 end Analyze_Function_Call;
253 -------------------------------------
254 -- Analyze_Generic_Subprogram_Body --
255 -------------------------------------
257 procedure Analyze_Generic_Subprogram_Body
261 Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id);
262 Kind : constant Entity_Kind := Ekind (Gen_Id);
268 -- Copy body and disable expansion while analyzing the generic
269 -- For a stub, do not copy the stub (which would load the proper body),
270 -- this will be done when the proper body is analyzed.
272 if Nkind (N) /= N_Subprogram_Body_Stub then
273 New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
278 Spec := Specification (N);
280 -- Within the body of the generic, the subprogram is callable, and
281 -- behaves like the corresponding non-generic unit.
283 Body_Id := Defining_Entity (Spec);
285 if Kind = E_Generic_Procedure
286 and then Nkind (Spec) /= N_Procedure_Specification
288 Error_Msg_N ("invalid body for generic procedure ", Body_Id);
291 elsif Kind = E_Generic_Function
292 and then Nkind (Spec) /= N_Function_Specification
294 Error_Msg_N ("invalid body for generic function ", Body_Id);
298 Set_Corresponding_Body (Gen_Decl, Body_Id);
300 if Has_Completion (Gen_Id)
301 and then Nkind (Parent (N)) /= N_Subunit
303 Error_Msg_N ("duplicate generic body", N);
306 Set_Has_Completion (Gen_Id);
309 if Nkind (N) = N_Subprogram_Body_Stub then
310 Set_Ekind (Defining_Entity (Specification (N)), Kind);
312 Set_Corresponding_Spec (N, Gen_Id);
315 if Nkind (Parent (N)) = N_Compilation_Unit then
316 Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N));
319 -- Make generic parameters immediately visible in the body. They are
320 -- needed to process the formals declarations. Then make the formals
321 -- visible in a separate step.
327 First_Ent : Entity_Id;
330 First_Ent := First_Entity (Gen_Id);
333 while Present (E) and then not Is_Formal (E) loop
338 Set_Use (Generic_Formal_Declarations (Gen_Decl));
340 -- Now generic formals are visible, and the specification can be
341 -- analyzed, for subsequent conformance check.
343 Body_Id := Analyze_Subprogram_Specification (Spec);
345 -- Make formal parameters visible
349 -- E is the first formal parameter, we loop through the formals
350 -- installing them so that they will be visible.
352 Set_First_Entity (Gen_Id, E);
353 while Present (E) loop
359 -- Visible generic entity is callable within its own body.
361 Set_Ekind (Gen_Id, Ekind (Body_Id));
362 Set_Ekind (Body_Id, E_Subprogram_Body);
363 Set_Convention (Body_Id, Convention (Gen_Id));
364 Set_Scope (Body_Id, Scope (Gen_Id));
365 Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id);
367 if Nkind (N) = N_Subprogram_Body_Stub then
369 -- No body to analyze, so restore state of generic unit.
371 Set_Ekind (Gen_Id, Kind);
372 Set_Ekind (Body_Id, Kind);
374 if Present (First_Ent) then
375 Set_First_Entity (Gen_Id, First_Ent);
382 -- If this is a compilation unit, it must be made visible
383 -- explicitly, because the compilation of the declaration,
384 -- unlike other library unit declarations, does not. If it
385 -- is not a unit, the following is redundant but harmless.
387 Set_Is_Immediately_Visible (Gen_Id);
388 Reference_Body_Formals (Gen_Id, Body_Id);
390 Set_Actual_Subtypes (N, Current_Scope);
391 Analyze_Declarations (Declarations (N));
393 Analyze (Handled_Statement_Sequence (N));
395 Save_Global_References (Original_Node (N));
397 -- Prior to exiting the scope, include generic formals again
398 -- (if any are present) in the set of local entities.
400 if Present (First_Ent) then
401 Set_First_Entity (Gen_Id, First_Ent);
404 Check_References (Gen_Id);
407 Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope);
409 Check_Subprogram_Order (N);
411 -- Outside of its body, unit is generic again.
413 Set_Ekind (Gen_Id, Kind);
414 Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False);
415 Style.Check_Identifier (Body_Id, Gen_Id);
417 end Analyze_Generic_Subprogram_Body;
419 -----------------------------
420 -- Analyze_Operator_Symbol --
421 -----------------------------
423 -- An operator symbol such as "+" or "and" may appear in context where
424 -- the literal denotes an entity name, such as "+"(x, y) or in a
425 -- context when it is just a string, as in (conjunction = "or"). In
426 -- these cases the parser generates this node, and the semantics does
427 -- the disambiguation. Other such case are actuals in an instantiation,
428 -- the generic unit in an instantiation, and pragma arguments.
430 procedure Analyze_Operator_Symbol (N : Node_Id) is
431 Par : constant Node_Id := Parent (N);
434 if (Nkind (Par) = N_Function_Call and then N = Name (Par))
435 or else Nkind (Par) = N_Function_Instantiation
436 or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par))
437 or else (Nkind (Par) = N_Pragma_Argument_Association
438 and then not Is_Pragma_String_Literal (Par))
439 or else Nkind (Par) = N_Subprogram_Renaming_Declaration
440 or else (Nkind (Par) = N_Attribute_Reference
441 and then Attribute_Name (Par) /= Name_Value)
443 Find_Direct_Name (N);
446 Change_Operator_Symbol_To_String_Literal (N);
449 end Analyze_Operator_Symbol;
451 -----------------------------------
452 -- Analyze_Parameter_Association --
453 -----------------------------------
455 procedure Analyze_Parameter_Association (N : Node_Id) is
457 Analyze (Explicit_Actual_Parameter (N));
458 end Analyze_Parameter_Association;
460 ----------------------------
461 -- Analyze_Procedure_Call --
462 ----------------------------
464 procedure Analyze_Procedure_Call (N : Node_Id) is
465 Loc : constant Source_Ptr := Sloc (N);
466 P : constant Node_Id := Name (N);
467 Actuals : constant List_Id := Parameter_Associations (N);
471 procedure Analyze_Call_And_Resolve;
472 -- Do Analyze and Resolve calls for procedure call
474 ------------------------------
475 -- Analyze_Call_And_Resolve --
476 ------------------------------
478 procedure Analyze_Call_And_Resolve is
480 if Nkind (N) = N_Procedure_Call_Statement then
482 Resolve (N, Standard_Void_Type);
486 end Analyze_Call_And_Resolve;
488 -- Start of processing for Analyze_Procedure_Call
491 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
492 -- a procedure call or an entry call. The prefix may denote an access
493 -- to subprogram type, in which case an implicit dereference applies.
494 -- If the prefix is an indexed component (without implicit defererence)
495 -- then the construct denotes a call to a member of an entire family.
496 -- If the prefix is a simple name, it may still denote a call to a
497 -- parameterless member of an entry family. Resolution of these various
498 -- interpretations is delicate.
502 -- If error analyzing prefix, then set Any_Type as result and return
504 if Etype (P) = Any_Type then
505 Set_Etype (N, Any_Type);
509 -- Otherwise analyze the parameters
511 if Present (Actuals) then
512 Actual := First (Actuals);
514 while Present (Actual) loop
516 Check_Parameterless_Call (Actual);
521 -- Special processing for Elab_Spec and Elab_Body calls
523 if Nkind (P) = N_Attribute_Reference
524 and then (Attribute_Name (P) = Name_Elab_Spec
525 or else Attribute_Name (P) = Name_Elab_Body)
527 if Present (Actuals) then
529 ("no parameters allowed for this call", First (Actuals));
533 Set_Etype (N, Standard_Void_Type);
536 elsif Is_Entity_Name (P)
537 and then Is_Record_Type (Etype (Entity (P)))
538 and then Remote_AST_I_Dereference (P)
542 elsif Is_Entity_Name (P)
543 and then Ekind (Entity (P)) /= E_Entry_Family
545 if Is_Access_Type (Etype (P))
546 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
547 and then No (Actuals)
548 and then Comes_From_Source (N)
550 Error_Msg_N ("missing explicit dereference in call", N);
553 Analyze_Call_And_Resolve;
555 -- If the prefix is the simple name of an entry family, this is
556 -- a parameterless call from within the task body itself.
558 elsif Is_Entity_Name (P)
559 and then Nkind (P) = N_Identifier
560 and then Ekind (Entity (P)) = E_Entry_Family
561 and then Present (Actuals)
562 and then No (Next (First (Actuals)))
564 -- Can be call to parameterless entry family. What appears to be
565 -- the sole argument is in fact the entry index. Rewrite prefix
566 -- of node accordingly. Source representation is unchanged by this
570 Make_Indexed_Component (Loc,
572 Make_Selected_Component (Loc,
573 Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc),
574 Selector_Name => New_Occurrence_Of (Entity (P), Loc)),
575 Expressions => Actuals);
577 Set_Etype (New_N, Standard_Void_Type);
578 Set_Parameter_Associations (N, No_List);
579 Analyze_Call_And_Resolve;
581 elsif Nkind (P) = N_Explicit_Dereference then
582 if Ekind (Etype (P)) = E_Subprogram_Type then
583 Analyze_Call_And_Resolve;
585 Error_Msg_N ("expect access to procedure in call", P);
588 -- The name can be a selected component or an indexed component
589 -- that yields an access to subprogram. Such a prefix is legal if
590 -- the call has parameter associations.
592 elsif Is_Access_Type (Etype (P))
593 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
595 if Present (Actuals) then
596 Analyze_Call_And_Resolve;
598 Error_Msg_N ("missing explicit dereference in call ", N);
601 -- If not an access to subprogram, then the prefix must resolve to
602 -- the name of an entry, entry family, or protected operation.
604 -- For the case of a simple entry call, P is a selected component
605 -- where the prefix is the task and the selector name is the entry.
606 -- A call to a protected procedure will have the same syntax. If
607 -- the protected object contains overloaded operations, the entity
608 -- may appear as a function, the context will select the operation
609 -- whose type is Void.
611 elsif Nkind (P) = N_Selected_Component
612 and then (Ekind (Entity (Selector_Name (P))) = E_Entry
614 Ekind (Entity (Selector_Name (P))) = E_Procedure
616 Ekind (Entity (Selector_Name (P))) = E_Function)
618 Analyze_Call_And_Resolve;
620 elsif Nkind (P) = N_Selected_Component
621 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family
622 and then Present (Actuals)
623 and then No (Next (First (Actuals)))
625 -- Can be call to parameterless entry family. What appears to be
626 -- the sole argument is in fact the entry index. Rewrite prefix
627 -- of node accordingly. Source representation is unchanged by this
631 Make_Indexed_Component (Loc,
632 Prefix => New_Copy (P),
633 Expressions => Actuals);
635 Set_Etype (New_N, Standard_Void_Type);
636 Set_Parameter_Associations (N, No_List);
637 Analyze_Call_And_Resolve;
639 -- For the case of a reference to an element of an entry family, P is
640 -- an indexed component whose prefix is a selected component (task and
641 -- entry family), and whose index is the entry family index.
643 elsif Nkind (P) = N_Indexed_Component
644 and then Nkind (Prefix (P)) = N_Selected_Component
645 and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family
647 Analyze_Call_And_Resolve;
649 -- If the prefix is the name of an entry family, it is a call from
650 -- within the task body itself.
652 elsif Nkind (P) = N_Indexed_Component
653 and then Nkind (Prefix (P)) = N_Identifier
654 and then Ekind (Entity (Prefix (P))) = E_Entry_Family
657 Make_Selected_Component (Loc,
658 Prefix => New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc),
659 Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc));
660 Rewrite (Prefix (P), New_N);
662 Analyze_Call_And_Resolve;
664 -- Anything else is an error.
667 Error_Msg_N ("Invalid procedure or entry call", N);
669 end Analyze_Procedure_Call;
671 ------------------------------
672 -- Analyze_Return_Statement --
673 ------------------------------
675 procedure Analyze_Return_Statement (N : Node_Id) is
676 Loc : constant Source_Ptr := Sloc (N);
678 Scope_Id : Entity_Id;
683 -- Find subprogram or accept statement enclosing the return statement
686 for J in reverse 0 .. Scope_Stack.Last loop
687 Scope_Id := Scope_Stack.Table (J).Entity;
688 exit when Ekind (Scope_Id) /= E_Block and then
689 Ekind (Scope_Id) /= E_Loop;
692 pragma Assert (Present (Scope_Id));
694 Kind := Ekind (Scope_Id);
695 Expr := Expression (N);
697 if Kind /= E_Function
698 and then Kind /= E_Generic_Function
699 and then Kind /= E_Procedure
700 and then Kind /= E_Generic_Procedure
701 and then Kind /= E_Entry
702 and then Kind /= E_Entry_Family
704 Error_Msg_N ("illegal context for return statement", N);
706 elsif Present (Expr) then
707 if Kind = E_Function or else Kind = E_Generic_Function then
708 Set_Return_Present (Scope_Id);
709 R_Type := Etype (Scope_Id);
710 Set_Return_Type (N, R_Type);
711 Analyze_And_Resolve (Expr, R_Type);
713 if (Is_Class_Wide_Type (Etype (Expr))
714 or else Is_Dynamically_Tagged (Expr))
715 and then not Is_Class_Wide_Type (R_Type)
718 ("dynamically tagged expression not allowed!", Expr);
721 Apply_Constraint_Check (Expr, R_Type);
723 -- ??? A real run-time accessibility check is needed
724 -- in cases involving dereferences of access parameters.
725 -- For now we just check the static cases.
727 if Is_Return_By_Reference_Type (Etype (Scope_Id))
728 and then Object_Access_Level (Expr)
729 > Subprogram_Access_Level (Scope_Id)
732 Make_Raise_Program_Error (Loc,
733 Reason => PE_Accessibility_Check_Failed));
737 ("cannot return a local value by reference?", N);
739 ("& will be raised at run time?!",
740 N, Standard_Program_Error);
743 elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then
744 Error_Msg_N ("procedure cannot return value (use function)", N);
747 Error_Msg_N ("accept statement cannot return value", N);
750 -- No expression present
753 if Kind = E_Function or Kind = E_Generic_Function then
754 Error_Msg_N ("missing expression in return from function", N);
757 if (Ekind (Scope_Id) = E_Procedure
758 or else Ekind (Scope_Id) = E_Generic_Procedure)
759 and then No_Return (Scope_Id)
762 ("RETURN statement not allowed (No_Return)", N);
766 Check_Unreachable_Code (N);
767 end Analyze_Return_Statement;
769 -----------------------------
770 -- Analyze_Subprogram_Body --
771 -----------------------------
773 -- This procedure is called for regular subprogram bodies, generic bodies,
774 -- and for subprogram stubs of both kinds. In the case of stubs, only the
775 -- specification matters, and is used to create a proper declaration for
776 -- the subprogram, or to perform conformance checks.
778 procedure Analyze_Subprogram_Body (N : Node_Id) is
779 Loc : constant Source_Ptr := Sloc (N);
780 Body_Spec : constant Node_Id := Specification (N);
781 Body_Id : Entity_Id := Defining_Entity (Body_Spec);
782 Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id);
783 Body_Deleted : constant Boolean := False;
787 Spec_Decl : Node_Id := Empty;
788 Last_Formal : Entity_Id := Empty;
789 Conformant : Boolean;
790 Missing_Ret : Boolean;
793 procedure Check_Following_Pragma;
794 -- If front-end inlining is enabled, look ahead to recognize a pragma
795 -- that may appear after the body.
797 procedure Check_Following_Pragma is
801 if Front_End_Inlining
802 and then Is_List_Member (N)
803 and then Present (Spec_Decl)
804 and then List_Containing (N) = List_Containing (Spec_Decl)
809 and then Nkind (Prag) = N_Pragma
810 and then Get_Pragma_Id (Chars (Prag)) = Pragma_Inline
813 (Expression (First (Pragma_Argument_Associations (Prag))))
819 end Check_Following_Pragma;
821 -- Start of processing for Analyze_Subprogram_Body
825 Write_Str ("==== Compiling subprogram body ");
826 Write_Name (Chars (Body_Id));
827 Write_Str (" from ");
828 Write_Location (Loc);
832 Trace_Scope (N, Body_Id, " Analyze subprogram");
834 -- Generic subprograms are handled separately. They always have
835 -- a generic specification. Determine whether current scope has
836 -- a previous declaration.
838 -- If the subprogram body is defined within an instance of the
839 -- same name, the instance appears as a package renaming, and
840 -- will be hidden within the subprogram.
843 and then not Is_Overloadable (Prev_Id)
844 and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration
845 or else Comes_From_Source (Prev_Id))
847 if Is_Generic_Subprogram (Prev_Id) then
849 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
850 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
852 Analyze_Generic_Subprogram_Body (N, Spec_Id);
856 -- Previous entity conflicts with subprogram name.
857 -- Attempting to enter name will post error.
859 Enter_Name (Body_Id);
863 -- Non-generic case, find the subprogram declaration, if one was
864 -- seen, or enter new overloaded entity in the current scope.
865 -- If the current_entity is the body_id itself, the unit is being
866 -- analyzed as part of the context of one of its subunits. No need
867 -- to redo the analysis.
869 elsif Prev_Id = Body_Id
870 and then Has_Completion (Body_Id)
875 Body_Id := Analyze_Subprogram_Specification (Body_Spec);
877 if Nkind (N) = N_Subprogram_Body_Stub
878 or else No (Corresponding_Spec (N))
880 Spec_Id := Find_Corresponding_Spec (N);
882 -- If this is a duplicate body, no point in analyzing it
884 if Error_Posted (N) then
888 -- A subprogram body should cause freezing of its own
889 -- declaration, but if there was no previous explicit
890 -- declaration, then the subprogram will get frozen too
891 -- late (there may be code within the body that depends
892 -- on the subprogram having been frozen, such as uses of
893 -- extra formals), so we force it to be frozen here.
894 -- Same holds if the body and the spec are compilation units.
897 Freeze_Before (N, Body_Id);
899 elsif Nkind (Parent (N)) = N_Compilation_Unit then
900 Freeze_Before (N, Spec_Id);
903 Spec_Id := Corresponding_Spec (N);
907 -- Do not inline any subprogram that contains nested subprograms,
908 -- since the backend inlining circuit seems to generate uninitialized
909 -- references in this case. We know this happens in the case of front
910 -- end ZCX support, but it also appears it can happen in other cases
911 -- as well. The backend often rejects attempts to inline in the case
912 -- of nested procedures anyway, so little if anything is lost by this.
914 -- Do not do this test if errors have been detected, because in some
915 -- error cases, this code blows up, and we don't need it anyway if
916 -- there have been errors, since we won't get to the linker anyway.
918 if Serious_Errors_Detected = 0 then
921 P_Ent := Scope (P_Ent);
922 exit when No (P_Ent) or else P_Ent = Standard_Standard;
924 if Is_Subprogram (P_Ent) then
925 Set_Is_Inlined (P_Ent, False);
927 if Comes_From_Source (P_Ent)
928 and then Has_Pragma_Inline (P_Ent)
931 ("cannot inline& (nested subprogram)?",
938 -- Case of fully private operation in the body of the protected type.
939 -- We must create a declaration for the subprogram, in order to attach
940 -- the protected subprogram that will be used in internal calls.
943 and then Comes_From_Source (N)
944 and then Is_Protected_Type (Current_Scope)
953 Formal := First_Formal (Body_Id);
955 -- The protected operation always has at least one formal,
956 -- namely the object itself, but it is only placed in the
957 -- parameter list if expansion is enabled.
960 or else Expander_Active
968 while Present (Formal) loop
970 (Make_Parameter_Specification (Loc,
971 Defining_Identifier =>
972 Make_Defining_Identifier (Sloc (Formal),
973 Chars => Chars (Formal)),
974 In_Present => In_Present (Parent (Formal)),
975 Out_Present => Out_Present (Parent (Formal)),
977 New_Reference_To (Etype (Formal), Loc),
979 New_Copy_Tree (Expression (Parent (Formal)))),
982 Next_Formal (Formal);
985 if Nkind (Body_Spec) = N_Procedure_Specification then
987 Make_Procedure_Specification (Loc,
988 Defining_Unit_Name =>
989 Make_Defining_Identifier (Sloc (Body_Id),
990 Chars => Chars (Body_Id)),
991 Parameter_Specifications => Plist);
994 Make_Function_Specification (Loc,
995 Defining_Unit_Name =>
996 Make_Defining_Identifier (Sloc (Body_Id),
997 Chars => Chars (Body_Id)),
998 Parameter_Specifications => Plist,
999 Subtype_Mark => New_Occurrence_Of (Etype (Body_Id), Loc));
1003 Make_Subprogram_Declaration (Loc,
1004 Specification => New_Spec);
1005 Insert_Before (N, Decl);
1006 Spec_Id := Defining_Unit_Name (New_Spec);
1008 -- Indicate that the entity comes from source, to ensure that
1009 -- cross-reference information is properly generated.
1010 -- The body itself is rewritten during expansion, and the
1011 -- body entity will not appear in calls to the operation.
1013 Set_Comes_From_Source (Spec_Id, True);
1015 Set_Has_Completion (Spec_Id);
1016 Set_Convention (Spec_Id, Convention_Protected);
1019 elsif Present (Spec_Id) then
1020 Spec_Decl := Unit_Declaration_Node (Spec_Id);
1023 -- Place subprogram on scope stack, and make formals visible. If there
1024 -- is a spec, the visible entity remains that of the spec.
1026 if Present (Spec_Id) then
1027 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
1029 Style.Check_Identifier (Body_Id, Spec_Id);
1032 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
1033 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
1035 if Is_Abstract (Spec_Id) then
1036 Error_Msg_N ("an abstract subprogram cannot have a body", N);
1039 Set_Convention (Body_Id, Convention (Spec_Id));
1040 Set_Has_Completion (Spec_Id);
1042 if Is_Protected_Type (Scope (Spec_Id)) then
1043 Set_Privals_Chain (Spec_Id, New_Elmt_List);
1046 -- If this is a body generated for a renaming, do not check for
1047 -- full conformance. The check is redundant, because the spec of
1048 -- the body is a copy of the spec in the renaming declaration,
1049 -- and the test can lead to spurious errors on nested defaults.
1051 if Present (Spec_Decl)
1052 and then not Comes_From_Source (N)
1054 (Nkind (Original_Node (Spec_Decl)) =
1055 N_Subprogram_Renaming_Declaration
1056 or else (Present (Corresponding_Body (Spec_Decl))
1058 Nkind (Unit_Declaration_Node
1059 (Corresponding_Body (Spec_Decl))) =
1060 N_Subprogram_Renaming_Declaration))
1066 Fully_Conformant, True, Conformant, Body_Id);
1069 -- If the body is not fully conformant, we have to decide if we
1070 -- should analyze it or not. If it has a really messed up profile
1071 -- then we probably should not analyze it, since we will get too
1072 -- many bogus messages.
1074 -- Our decision is to go ahead in the non-fully conformant case
1075 -- only if it is at least mode conformant with the spec. Note
1076 -- that the call to Check_Fully_Conformant has issued the proper
1077 -- error messages to complain about the lack of conformance.
1080 and then not Mode_Conformant (Body_Id, Spec_Id)
1086 if Spec_Id /= Body_Id then
1087 Reference_Body_Formals (Spec_Id, Body_Id);
1090 if Nkind (N) /= N_Subprogram_Body_Stub then
1091 Set_Corresponding_Spec (N, Spec_Id);
1092 Install_Formals (Spec_Id);
1093 Last_Formal := Last_Entity (Spec_Id);
1094 New_Scope (Spec_Id);
1096 -- Make sure that the subprogram is immediately visible. For
1097 -- child units that have no separate spec this is indispensable.
1098 -- Otherwise it is safe albeit redundant.
1100 Set_Is_Immediately_Visible (Spec_Id);
1103 Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id);
1104 Set_Ekind (Body_Id, E_Subprogram_Body);
1105 Set_Scope (Body_Id, Scope (Spec_Id));
1107 -- Case of subprogram body with no previous spec
1111 and then Comes_From_Source (Body_Id)
1112 and then not Suppress_Style_Checks (Body_Id)
1113 and then not In_Instance
1115 Style.Body_With_No_Spec (N);
1118 New_Overloaded_Entity (Body_Id);
1120 if Nkind (N) /= N_Subprogram_Body_Stub then
1121 Set_Acts_As_Spec (N);
1122 Generate_Definition (Body_Id);
1124 (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True);
1125 Generate_Reference_To_Formals (Body_Id);
1126 Install_Formals (Body_Id);
1127 New_Scope (Body_Id);
1131 -- If this is the proper body of a stub, we must verify that the stub
1132 -- conforms to the body, and to the previous spec if one was present.
1133 -- we know already that the body conforms to that spec. This test is
1134 -- only required for subprograms that come from source.
1136 if Nkind (Parent (N)) = N_Subunit
1137 and then Comes_From_Source (N)
1138 and then not Error_Posted (Body_Id)
1141 Old_Id : constant Entity_Id :=
1143 (Specification (Corresponding_Stub (Parent (N))));
1145 Conformant : Boolean := False;
1148 if No (Spec_Id) then
1149 Check_Fully_Conformant (Body_Id, Old_Id);
1153 (Body_Id, Old_Id, Fully_Conformant, False, Conformant);
1155 if not Conformant then
1157 -- The stub was taken to be a new declaration. Indicate
1158 -- that it lacks a body.
1160 Set_Has_Completion (Old_Id, False);
1166 Set_Has_Completion (Body_Id);
1167 Check_Eliminated (Body_Id);
1169 if Nkind (N) = N_Subprogram_Body_Stub then
1172 elsif Present (Spec_Id)
1173 and then Expander_Active
1175 Check_Following_Pragma;
1177 if Is_Always_Inlined (Spec_Id)
1178 or else (Has_Pragma_Inline (Spec_Id)
1179 and then (Front_End_Inlining or else Configurable_Run_Time_Mode))
1181 Build_Body_To_Inline (N, Spec_Id);
1185 -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis
1186 -- if its specification we have to install the private withed units.
1188 if Is_Compilation_Unit (Body_Id)
1189 and then Scope (Body_Id) = Standard_Standard
1191 Install_Private_With_Clauses (Body_Id);
1194 -- Now we can go on to analyze the body
1196 HSS := Handled_Statement_Sequence (N);
1197 Set_Actual_Subtypes (N, Current_Scope);
1198 Analyze_Declarations (Declarations (N));
1201 Process_End_Label (HSS, 't', Current_Scope);
1203 Check_Subprogram_Order (N);
1204 Set_Analyzed (Body_Id);
1206 -- If we have a separate spec, then the analysis of the declarations
1207 -- caused the entities in the body to be chained to the spec id, but
1208 -- we want them chained to the body id. Only the formal parameters
1209 -- end up chained to the spec id in this case.
1211 if Present (Spec_Id) then
1213 -- If a parent unit is categorized, the context of a subunit
1214 -- must conform to the categorization. Conversely, if a child
1215 -- unit is categorized, the parents themselves must conform.
1217 if Nkind (Parent (N)) = N_Subunit then
1218 Validate_Categorization_Dependency (N, Spec_Id);
1220 elsif Is_Child_Unit (Spec_Id) then
1221 Validate_Categorization_Dependency
1222 (Unit_Declaration_Node (Spec_Id), Spec_Id);
1225 if Present (Last_Formal) then
1227 (Last_Entity (Body_Id), Next_Entity (Last_Formal));
1228 Set_Next_Entity (Last_Formal, Empty);
1229 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
1230 Set_Last_Entity (Spec_Id, Last_Formal);
1233 Set_First_Entity (Body_Id, First_Entity (Spec_Id));
1234 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
1235 Set_First_Entity (Spec_Id, Empty);
1236 Set_Last_Entity (Spec_Id, Empty);
1240 -- If function, check return statements
1242 if Nkind (Body_Spec) = N_Function_Specification then
1247 if Present (Spec_Id) then
1253 if Return_Present (Id) then
1254 Check_Returns (HSS, 'F', Missing_Ret);
1257 Set_Has_Missing_Return (Id);
1260 elsif not Is_Machine_Code_Subprogram (Id)
1261 and then not Body_Deleted
1263 Error_Msg_N ("missing RETURN statement in function body", N);
1267 -- If procedure with No_Return, check returns
1269 elsif Nkind (Body_Spec) = N_Procedure_Specification
1270 and then Present (Spec_Id)
1271 and then No_Return (Spec_Id)
1273 Check_Returns (HSS, 'P', Missing_Ret);
1276 -- Now we are going to check for variables that are never modified
1277 -- in the body of the procedure. We omit these checks if the first
1278 -- statement of the procedure raises an exception. In particular
1279 -- this deals with the common idiom of a stubbed function, which
1280 -- might appear as something like
1282 -- function F (A : Integer) return Some_Type;
1285 -- raise Program_Error;
1289 -- Here the purpose of X is simply to satisfy the (annoying)
1290 -- requirement in Ada that there be at least one return, and
1291 -- we certainly do not want to go posting warnings on X that
1292 -- it is not initialized!
1295 Stm : Node_Id := First (Statements (HSS));
1298 -- Skip an initial label (for one thing this occurs when we
1299 -- are in front end ZCX mode, but in any case it is irrelevant).
1301 if Nkind (Stm) = N_Label then
1305 -- Do the test on the original statement before expansion
1308 Ostm : constant Node_Id := Original_Node (Stm);
1311 -- If explicit raise statement, return with no checks
1313 if Nkind (Ostm) = N_Raise_Statement then
1316 -- Check for explicit call cases which likely raise an exception
1318 elsif Nkind (Ostm) = N_Procedure_Call_Statement then
1319 if Is_Entity_Name (Name (Ostm)) then
1321 Ent : constant Entity_Id := Entity (Name (Ostm));
1324 -- If the procedure is marked No_Return, then likely it
1325 -- raises an exception, but in any case it is not coming
1326 -- back here, so no need to check beyond the call.
1328 if Ekind (Ent) = E_Procedure
1329 and then No_Return (Ent)
1333 -- If the procedure name is Raise_Exception, then also
1334 -- assume that it raises an exception. The main target
1335 -- here is Ada.Exceptions.Raise_Exception, but this name
1336 -- is pretty evocative in any context! Note that the
1337 -- procedure in Ada.Exceptions is not marked No_Return
1338 -- because of the annoying case of the null exception Id.
1340 elsif Chars (Ent) = Name_Raise_Exception then
1349 -- Check for variables that are never modified
1355 -- If there is a separate spec, then transfer Never_Set_In_Source
1356 -- flags from out parameters to the corresponding entities in the
1357 -- body. The reason we do that is we want to post error flags on
1358 -- the body entities, not the spec entities.
1360 if Present (Spec_Id) then
1361 E1 := First_Entity (Spec_Id);
1363 while Present (E1) loop
1364 if Ekind (E1) = E_Out_Parameter then
1365 E2 := First_Entity (Body_Id);
1366 while Present (E2) loop
1367 exit when Chars (E1) = Chars (E2);
1371 if Present (E2) then
1372 Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1));
1380 -- Check references in body unless it was deleted. Note that the
1381 -- check of Body_Deleted here is not just for efficiency, it is
1382 -- necessary to avoid junk warnings on formal parameters.
1384 if not Body_Deleted then
1385 Check_References (Body_Id);
1388 end Analyze_Subprogram_Body;
1390 ------------------------------------
1391 -- Analyze_Subprogram_Declaration --
1392 ------------------------------------
1394 procedure Analyze_Subprogram_Declaration (N : Node_Id) is
1395 Designator : constant Entity_Id :=
1396 Analyze_Subprogram_Specification (Specification (N));
1397 Scop : constant Entity_Id := Current_Scope;
1399 -- Start of processing for Analyze_Subprogram_Declaration
1402 Generate_Definition (Designator);
1404 -- Check for RCI unit subprogram declarations against in-lined
1405 -- subprograms and subprograms having access parameter or limited
1406 -- parameter without Read and Write (RM E.2.3(12-13)).
1408 Validate_RCI_Subprogram_Declaration (N);
1412 Defining_Entity (N),
1413 " Analyze subprogram spec. ");
1415 if Debug_Flag_C then
1416 Write_Str ("==== Compiling subprogram spec ");
1417 Write_Name (Chars (Designator));
1418 Write_Str (" from ");
1419 Write_Location (Sloc (N));
1423 New_Overloaded_Entity (Designator);
1424 Check_Delayed_Subprogram (Designator);
1426 -- What is the following code for, it used to be
1428 -- ??? Set_Suppress_Elaboration_Checks
1429 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator));
1431 -- The following seems equivalent, but a bit dubious
1433 if Elaboration_Checks_Suppressed (Designator) then
1434 Set_Kill_Elaboration_Checks (Designator);
1437 if Scop /= Standard_Standard
1438 and then not Is_Child_Unit (Designator)
1440 Set_Categorization_From_Scope (Designator, Scop);
1442 -- For a compilation unit, check for library-unit pragmas.
1444 New_Scope (Designator);
1445 Set_Categorization_From_Pragmas (N);
1446 Validate_Categorization_Dependency (N, Designator);
1450 -- For a compilation unit, set body required. This flag will only be
1451 -- reset if a valid Import or Interface pragma is processed later on.
1453 if Nkind (Parent (N)) = N_Compilation_Unit then
1454 Set_Body_Required (Parent (N), True);
1457 Generate_Reference_To_Formals (Designator);
1458 Check_Eliminated (Designator);
1460 if Comes_From_Source (N)
1461 and then Is_List_Member (N)
1463 Check_Overriding_Operation (N, Designator);
1466 end Analyze_Subprogram_Declaration;
1468 --------------------------------------
1469 -- Analyze_Subprogram_Specification --
1470 --------------------------------------
1472 -- Reminder: N here really is a subprogram specification (not a subprogram
1473 -- declaration). This procedure is called to analyze the specification in
1474 -- both subprogram bodies and subprogram declarations (specs).
1476 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is
1477 Designator : constant Entity_Id := Defining_Entity (N);
1478 Formals : constant List_Id := Parameter_Specifications (N);
1482 Generate_Definition (Designator);
1484 if Nkind (N) = N_Function_Specification then
1485 Set_Ekind (Designator, E_Function);
1486 Set_Mechanism (Designator, Default_Mechanism);
1488 if Subtype_Mark (N) /= Error then
1489 Find_Type (Subtype_Mark (N));
1490 Typ := Entity (Subtype_Mark (N));
1491 Set_Etype (Designator, Typ);
1493 if Ekind (Typ) = E_Incomplete_Type
1494 or else (Is_Class_Wide_Type (Typ)
1496 Ekind (Root_Type (Typ)) = E_Incomplete_Type)
1499 ("invalid use of incomplete type", Subtype_Mark (N));
1503 Set_Etype (Designator, Any_Type);
1507 Set_Ekind (Designator, E_Procedure);
1508 Set_Etype (Designator, Standard_Void_Type);
1511 if Present (Formals) then
1512 Set_Scope (Designator, Current_Scope);
1513 New_Scope (Designator);
1514 Process_Formals (Formals, N);
1518 if Nkind (N) = N_Function_Specification then
1519 if Nkind (Designator) = N_Defining_Operator_Symbol then
1520 Valid_Operator_Definition (Designator);
1523 May_Need_Actuals (Designator);
1525 if Is_Abstract (Etype (Designator))
1526 and then Nkind (Parent (N)) /= N_Abstract_Subprogram_Declaration
1529 ("function that returns abstract type must be abstract", N);
1534 end Analyze_Subprogram_Specification;
1536 --------------------------
1537 -- Build_Body_To_Inline --
1538 --------------------------
1540 procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id) is
1541 Decl : constant Node_Id := Unit_Declaration_Node (Subp);
1542 Original_Body : Node_Id;
1543 Body_To_Analyze : Node_Id;
1544 Max_Size : constant := 10;
1545 Stat_Count : Integer := 0;
1547 function Has_Excluded_Declaration (Decls : List_Id) return Boolean;
1548 -- Check for declarations that make inlining not worthwhile.
1550 function Has_Excluded_Statement (Stats : List_Id) return Boolean;
1551 -- Check for statements that make inlining not worthwhile: any
1552 -- tasking statement, nested at any level. Keep track of total
1553 -- number of elementary statements, as a measure of acceptable size.
1555 function Has_Pending_Instantiation return Boolean;
1556 -- If some enclosing body contains instantiations that appear before
1557 -- the corresponding generic body, the enclosing body has a freeze node
1558 -- so that it can be elaborated after the generic itself. This might
1559 -- conflict with subsequent inlinings, so that it is unsafe to try to
1560 -- inline in such a case.
1562 procedure Remove_Pragmas;
1563 -- A pragma Unreferenced that mentions a formal parameter has no
1564 -- meaning when the body is inlined and the formals are rewritten.
1565 -- Remove it from body to inline. The analysis of the non-inlined
1566 -- body will handle the pragma properly.
1568 ------------------------------
1569 -- Has_Excluded_Declaration --
1570 ------------------------------
1572 function Has_Excluded_Declaration (Decls : List_Id) return Boolean is
1575 function Is_Unchecked_Conversion (D : Node_Id) return Boolean;
1576 -- Nested subprograms make a given body ineligible for inlining,
1577 -- but we make an exception for instantiations of unchecked
1578 -- conversion. The body has not been analyzed yet, so we check
1579 -- the name, and verify that the visible entity with that name is
1580 -- the predefined unit.
1582 function Is_Unchecked_Conversion (D : Node_Id) return Boolean is
1583 Id : constant Node_Id := Name (D);
1587 if Nkind (Id) = N_Identifier
1588 and then Chars (Id) = Name_Unchecked_Conversion
1590 Conv := Current_Entity (Id);
1592 elsif Nkind (Id) = N_Selected_Component
1593 and then Chars (Selector_Name (Id)) = Name_Unchecked_Conversion
1595 Conv := Current_Entity (Selector_Name (Id));
1603 and then Scope (Conv) = Standard_Standard
1604 and then Is_Intrinsic_Subprogram (Conv);
1605 end Is_Unchecked_Conversion;
1607 -- Start of processing for Has_Excluded_Declaration
1612 while Present (D) loop
1613 if (Nkind (D) = N_Function_Instantiation
1614 and then not Is_Unchecked_Conversion (D))
1615 or else Nkind (D) = N_Protected_Type_Declaration
1616 or else Nkind (D) = N_Package_Declaration
1617 or else Nkind (D) = N_Package_Instantiation
1618 or else Nkind (D) = N_Subprogram_Body
1619 or else Nkind (D) = N_Procedure_Instantiation
1620 or else Nkind (D) = N_Task_Type_Declaration
1623 ("cannot inline & (non-allowed declaration)?", D, Subp);
1631 end Has_Excluded_Declaration;
1633 ----------------------------
1634 -- Has_Excluded_Statement --
1635 ----------------------------
1637 function Has_Excluded_Statement (Stats : List_Id) return Boolean is
1644 while Present (S) loop
1645 Stat_Count := Stat_Count + 1;
1647 if Nkind (S) = N_Abort_Statement
1648 or else Nkind (S) = N_Asynchronous_Select
1649 or else Nkind (S) = N_Conditional_Entry_Call
1650 or else Nkind (S) = N_Delay_Relative_Statement
1651 or else Nkind (S) = N_Delay_Until_Statement
1652 or else Nkind (S) = N_Selective_Accept
1653 or else Nkind (S) = N_Timed_Entry_Call
1656 ("cannot inline & (non-allowed statement)?", S, Subp);
1659 elsif Nkind (S) = N_Block_Statement then
1660 if Present (Declarations (S))
1661 and then Has_Excluded_Declaration (Declarations (S))
1665 elsif Present (Handled_Statement_Sequence (S))
1668 (Exception_Handlers (Handled_Statement_Sequence (S)))
1670 Has_Excluded_Statement
1671 (Statements (Handled_Statement_Sequence (S))))
1676 elsif Nkind (S) = N_Case_Statement then
1677 E := First (Alternatives (S));
1679 while Present (E) loop
1680 if Has_Excluded_Statement (Statements (E)) then
1687 elsif Nkind (S) = N_If_Statement then
1688 if Has_Excluded_Statement (Then_Statements (S)) then
1692 if Present (Elsif_Parts (S)) then
1693 E := First (Elsif_Parts (S));
1695 while Present (E) loop
1696 if Has_Excluded_Statement (Then_Statements (E)) then
1703 if Present (Else_Statements (S))
1704 and then Has_Excluded_Statement (Else_Statements (S))
1709 elsif Nkind (S) = N_Loop_Statement
1710 and then Has_Excluded_Statement (Statements (S))
1719 end Has_Excluded_Statement;
1721 -------------------------------
1722 -- Has_Pending_Instantiation --
1723 -------------------------------
1725 function Has_Pending_Instantiation return Boolean is
1726 S : Entity_Id := Current_Scope;
1729 while Present (S) loop
1730 if Is_Compilation_Unit (S)
1731 or else Is_Child_Unit (S)
1734 elsif Ekind (S) = E_Package
1735 and then Has_Forward_Instantiation (S)
1744 end Has_Pending_Instantiation;
1746 --------------------
1747 -- Remove_Pragmas --
1748 --------------------
1750 procedure Remove_Pragmas is
1755 Decl := First (Declarations (Body_To_Analyze));
1756 while Present (Decl) loop
1759 if Nkind (Decl) = N_Pragma
1760 and then Chars (Decl) = Name_Unreferenced
1769 -- Start of processing for Build_Body_To_Inline
1772 if Nkind (Decl) = N_Subprogram_Declaration
1773 and then Present (Body_To_Inline (Decl))
1775 return; -- Done already.
1777 -- Functions that return unconstrained composite types will require
1778 -- secondary stack handling, and cannot currently be inlined.
1779 -- Ditto for functions that return controlled types, where controlled
1780 -- actions interfere in complex ways with inlining.
1782 elsif Ekind (Subp) = E_Function
1783 and then not Is_Scalar_Type (Etype (Subp))
1784 and then not Is_Access_Type (Etype (Subp))
1785 and then not Is_Constrained (Etype (Subp))
1788 ("cannot inline & (unconstrained return type)?", N, Subp);
1791 elsif Ekind (Subp) = E_Function
1792 and then Controlled_Type (Etype (Subp))
1795 ("cannot inline & (controlled return type)?", N, Subp);
1799 if Present (Declarations (N))
1800 and then Has_Excluded_Declaration (Declarations (N))
1805 if Present (Handled_Statement_Sequence (N)) then
1806 if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then
1808 ("cannot inline& (exception handler)?",
1809 First (Exception_Handlers (Handled_Statement_Sequence (N))),
1813 Has_Excluded_Statement
1814 (Statements (Handled_Statement_Sequence (N)))
1820 -- We do not inline a subprogram that is too large, unless it is
1821 -- marked Inline_Always. This pragma does not suppress the other
1822 -- checks on inlining (forbidden declarations, handlers, etc).
1824 if Stat_Count > Max_Size
1825 and then not Is_Always_Inlined (Subp)
1827 Cannot_Inline ("cannot inline& (body too large)?", N, Subp);
1831 if Has_Pending_Instantiation then
1833 ("cannot inline& (forward instance within enclosing body)?",
1838 -- Within an instance, the body to inline must be treated as a nested
1839 -- generic, so that the proper global references are preserved.
1842 Save_Env (Scope (Current_Scope), Scope (Current_Scope));
1843 Original_Body := Copy_Generic_Node (N, Empty, True);
1845 Original_Body := Copy_Separate_Tree (N);
1848 -- We need to capture references to the formals in order to substitute
1849 -- the actuals at the point of inlining, i.e. instantiation. To treat
1850 -- the formals as globals to the body to inline, we nest it within
1851 -- a dummy parameterless subprogram, declared within the real one.
1852 -- To avoid generating an internal name (which is never public, and
1853 -- which affects serial numbers of other generated names), we use
1854 -- an internal symbol that cannot conflict with user declarations.
1856 Set_Parameter_Specifications (Specification (Original_Body), No_List);
1857 Set_Defining_Unit_Name
1858 (Specification (Original_Body),
1859 Make_Defining_Identifier (Sloc (N), Name_uParent));
1860 Set_Corresponding_Spec (Original_Body, Empty);
1862 Body_To_Analyze := Copy_Generic_Node (Original_Body, Empty, False);
1864 -- Set return type of function, which is also global and does not need
1867 if Ekind (Subp) = E_Function then
1868 Set_Subtype_Mark (Specification (Body_To_Analyze),
1869 New_Occurrence_Of (Etype (Subp), Sloc (N)));
1872 if No (Declarations (N)) then
1873 Set_Declarations (N, New_List (Body_To_Analyze));
1875 Append (Body_To_Analyze, Declarations (N));
1878 Expander_Mode_Save_And_Set (False);
1881 Analyze (Body_To_Analyze);
1882 New_Scope (Defining_Entity (Body_To_Analyze));
1883 Save_Global_References (Original_Body);
1885 Remove (Body_To_Analyze);
1887 Expander_Mode_Restore;
1888 Set_Body_To_Inline (Decl, Original_Body);
1889 Set_Ekind (Defining_Entity (Original_Body), Ekind (Subp));
1890 Set_Is_Inlined (Subp);
1895 end Build_Body_To_Inline;
1901 procedure Cannot_Inline (Msg : String; N : Node_Id; Subp : Entity_Id) is
1903 -- Do not emit warning if this is a predefined unit which is not
1904 -- the main unit. With validity checks enabled, some predefined
1905 -- subprograms may contain nested subprograms and become ineligible
1908 if Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Subp)))
1909 and then not In_Extended_Main_Source_Unit (Subp)
1913 elsif Is_Always_Inlined (Subp) then
1914 Error_Msg_NE (Msg (1 .. Msg'Length - 1), N, Subp);
1916 elsif Ineffective_Inline_Warnings then
1917 Error_Msg_NE (Msg, N, Subp);
1921 -----------------------
1922 -- Check_Conformance --
1923 -----------------------
1925 procedure Check_Conformance
1926 (New_Id : Entity_Id;
1928 Ctype : Conformance_Type;
1930 Conforms : out Boolean;
1931 Err_Loc : Node_Id := Empty;
1932 Get_Inst : Boolean := False)
1934 Old_Type : constant Entity_Id := Etype (Old_Id);
1935 New_Type : constant Entity_Id := Etype (New_Id);
1936 Old_Formal : Entity_Id;
1937 New_Formal : Entity_Id;
1939 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id);
1940 -- Post error message for conformance error on given node.
1941 -- Two messages are output. The first points to the previous
1942 -- declaration with a general "no conformance" message.
1943 -- The second is the detailed reason, supplied as Msg. The
1944 -- parameter N provide information for a possible & insertion
1945 -- in the message, and also provides the location for posting
1946 -- the message in the absence of a specified Err_Loc location.
1948 -----------------------
1949 -- Conformance_Error --
1950 -----------------------
1952 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is
1959 if No (Err_Loc) then
1965 Error_Msg_Sloc := Sloc (Old_Id);
1968 when Type_Conformant =>
1970 ("not type conformant with declaration#!", Enode);
1972 when Mode_Conformant =>
1974 ("not mode conformant with declaration#!", Enode);
1976 when Subtype_Conformant =>
1978 ("not subtype conformant with declaration#!", Enode);
1980 when Fully_Conformant =>
1982 ("not fully conformant with declaration#!", Enode);
1985 Error_Msg_NE (Msg, Enode, N);
1987 end Conformance_Error;
1989 -- Start of processing for Check_Conformance
1994 -- We need a special case for operators, since they don't
1995 -- appear explicitly.
1997 if Ctype = Type_Conformant then
1998 if Ekind (New_Id) = E_Operator
1999 and then Operator_Matches_Spec (New_Id, Old_Id)
2005 -- If both are functions/operators, check return types conform
2007 if Old_Type /= Standard_Void_Type
2008 and then New_Type /= Standard_Void_Type
2010 if not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then
2011 Conformance_Error ("return type does not match!", New_Id);
2015 -- If either is a function/operator and the other isn't, error
2017 elsif Old_Type /= Standard_Void_Type
2018 or else New_Type /= Standard_Void_Type
2020 Conformance_Error ("functions can only match functions!", New_Id);
2024 -- In subtype conformant case, conventions must match (RM 6.3.1(16))
2025 -- If this is a renaming as body, refine error message to indicate that
2026 -- the conflict is with the original declaration. If the entity is not
2027 -- frozen, the conventions don't have to match, the one of the renamed
2028 -- entity is inherited.
2030 if Ctype >= Subtype_Conformant then
2031 if Convention (Old_Id) /= Convention (New_Id) then
2033 if not Is_Frozen (New_Id) then
2036 elsif Present (Err_Loc)
2037 and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration
2038 and then Present (Corresponding_Spec (Err_Loc))
2040 Error_Msg_Name_1 := Chars (New_Id);
2042 Name_Ada + Convention_Id'Pos (Convention (New_Id));
2044 Conformance_Error ("prior declaration for% has convention %!");
2047 Conformance_Error ("calling conventions do not match!");
2052 elsif Is_Formal_Subprogram (Old_Id)
2053 or else Is_Formal_Subprogram (New_Id)
2055 Conformance_Error ("formal subprograms not allowed!");
2060 -- Deal with parameters
2062 -- Note: we use the entity information, rather than going directly
2063 -- to the specification in the tree. This is not only simpler, but
2064 -- absolutely necessary for some cases of conformance tests between
2065 -- operators, where the declaration tree simply does not exist!
2067 Old_Formal := First_Formal (Old_Id);
2068 New_Formal := First_Formal (New_Id);
2070 while Present (Old_Formal) and then Present (New_Formal) loop
2071 if Ctype = Fully_Conformant then
2073 -- Names must match. Error message is more accurate if we do
2074 -- this before checking that the types of the formals match.
2076 if Chars (Old_Formal) /= Chars (New_Formal) then
2077 Conformance_Error ("name & does not match!", New_Formal);
2079 -- Set error posted flag on new formal as well to stop
2080 -- junk cascaded messages in some cases.
2082 Set_Error_Posted (New_Formal);
2087 -- Types must always match. In the visible part of an instance,
2088 -- usual overloading rules for dispatching operations apply, and
2089 -- we check base types (not the actual subtypes).
2091 if In_Instance_Visible_Part
2092 and then Is_Dispatching_Operation (New_Id)
2094 if not Conforming_Types
2095 (Base_Type (Etype (Old_Formal)),
2096 Base_Type (Etype (New_Formal)), Ctype, Get_Inst)
2098 Conformance_Error ("type of & does not match!", New_Formal);
2102 elsif not Conforming_Types
2103 (Etype (Old_Formal), Etype (New_Formal), Ctype, Get_Inst)
2105 Conformance_Error ("type of & does not match!", New_Formal);
2109 -- For mode conformance, mode must match
2111 if Ctype >= Mode_Conformant
2112 and then Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal)
2114 Conformance_Error ("mode of & does not match!", New_Formal);
2118 -- Full conformance checks
2120 if Ctype = Fully_Conformant then
2122 -- We have checked already that names match.
2123 -- Check default expressions for in parameters
2125 if Parameter_Mode (Old_Formal) = E_In_Parameter then
2127 NewD : constant Boolean :=
2128 Present (Default_Value (New_Formal));
2129 OldD : constant Boolean :=
2130 Present (Default_Value (Old_Formal));
2132 if NewD or OldD then
2134 -- The old default value has been analyzed because
2135 -- the current full declaration will have frozen
2136 -- everything before. The new default values have not
2137 -- been analyzed, so analyze them now before we check
2142 Analyze_Per_Use_Expression
2143 (Default_Value (New_Formal), Etype (New_Formal));
2147 if not (NewD and OldD)
2148 or else not Fully_Conformant_Expressions
2149 (Default_Value (Old_Formal),
2150 Default_Value (New_Formal))
2153 ("default expression for & does not match!",
2162 -- A couple of special checks for Ada 83 mode. These checks are
2163 -- skipped if either entity is an operator in package Standard.
2164 -- or if either old or new instance is not from the source program.
2166 if Ada_Version = Ada_83
2167 and then Sloc (Old_Id) > Standard_Location
2168 and then Sloc (New_Id) > Standard_Location
2169 and then Comes_From_Source (Old_Id)
2170 and then Comes_From_Source (New_Id)
2173 Old_Param : constant Node_Id := Declaration_Node (Old_Formal);
2174 New_Param : constant Node_Id := Declaration_Node (New_Formal);
2177 -- Explicit IN must be present or absent in both cases. This
2178 -- test is required only in the full conformance case.
2180 if In_Present (Old_Param) /= In_Present (New_Param)
2181 and then Ctype = Fully_Conformant
2184 ("(Ada 83) IN must appear in both declarations",
2189 -- Grouping (use of comma in param lists) must be the same
2190 -- This is where we catch a misconformance like:
2193 -- A : Integer; B : Integer
2195 -- which are represented identically in the tree except
2196 -- for the setting of the flags More_Ids and Prev_Ids.
2198 if More_Ids (Old_Param) /= More_Ids (New_Param)
2199 or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param)
2202 ("grouping of & does not match!", New_Formal);
2208 Next_Formal (Old_Formal);
2209 Next_Formal (New_Formal);
2212 if Present (Old_Formal) then
2213 Conformance_Error ("too few parameters!");
2216 elsif Present (New_Formal) then
2217 Conformance_Error ("too many parameters!", New_Formal);
2221 end Check_Conformance;
2223 ------------------------------
2224 -- Check_Delayed_Subprogram --
2225 ------------------------------
2227 procedure Check_Delayed_Subprogram (Designator : Entity_Id) is
2230 procedure Possible_Freeze (T : Entity_Id);
2231 -- T is the type of either a formal parameter or of the return type.
2232 -- If T is not yet frozen and needs a delayed freeze, then the
2233 -- subprogram itself must be delayed.
2235 procedure Possible_Freeze (T : Entity_Id) is
2237 if Has_Delayed_Freeze (T)
2238 and then not Is_Frozen (T)
2240 Set_Has_Delayed_Freeze (Designator);
2242 elsif Is_Access_Type (T)
2243 and then Has_Delayed_Freeze (Designated_Type (T))
2244 and then not Is_Frozen (Designated_Type (T))
2246 Set_Has_Delayed_Freeze (Designator);
2248 end Possible_Freeze;
2250 -- Start of processing for Check_Delayed_Subprogram
2253 -- Never need to freeze abstract subprogram
2255 if Is_Abstract (Designator) then
2258 -- Need delayed freeze if return type itself needs a delayed
2259 -- freeze and is not yet frozen.
2261 Possible_Freeze (Etype (Designator));
2262 Possible_Freeze (Base_Type (Etype (Designator))); -- needed ???
2264 -- Need delayed freeze if any of the formal types themselves need
2265 -- a delayed freeze and are not yet frozen.
2267 F := First_Formal (Designator);
2268 while Present (F) loop
2269 Possible_Freeze (Etype (F));
2270 Possible_Freeze (Base_Type (Etype (F))); -- needed ???
2275 -- Mark functions that return by reference. Note that it cannot be
2276 -- done for delayed_freeze subprograms because the underlying
2277 -- returned type may not be known yet (for private types)
2279 if not Has_Delayed_Freeze (Designator)
2280 and then Expander_Active
2283 Typ : constant Entity_Id := Etype (Designator);
2284 Utyp : constant Entity_Id := Underlying_Type (Typ);
2287 if Is_Return_By_Reference_Type (Typ) then
2288 Set_Returns_By_Ref (Designator);
2290 elsif Present (Utyp) and then Controlled_Type (Utyp) then
2291 Set_Returns_By_Ref (Designator);
2295 end Check_Delayed_Subprogram;
2297 ------------------------------------
2298 -- Check_Discriminant_Conformance --
2299 ------------------------------------
2301 procedure Check_Discriminant_Conformance
2306 Old_Discr : Entity_Id := First_Discriminant (Prev);
2307 New_Discr : Node_Id := First (Discriminant_Specifications (N));
2308 New_Discr_Id : Entity_Id;
2309 New_Discr_Type : Entity_Id;
2311 procedure Conformance_Error (Msg : String; N : Node_Id);
2312 -- Post error message for conformance error on given node.
2313 -- Two messages are output. The first points to the previous
2314 -- declaration with a general "no conformance" message.
2315 -- The second is the detailed reason, supplied as Msg. The
2316 -- parameter N provide information for a possible & insertion
2319 -----------------------
2320 -- Conformance_Error --
2321 -----------------------
2323 procedure Conformance_Error (Msg : String; N : Node_Id) is
2325 Error_Msg_Sloc := Sloc (Prev_Loc);
2326 Error_Msg_N ("not fully conformant with declaration#!", N);
2327 Error_Msg_NE (Msg, N, N);
2328 end Conformance_Error;
2330 -- Start of processing for Check_Discriminant_Conformance
2333 while Present (Old_Discr) and then Present (New_Discr) loop
2335 New_Discr_Id := Defining_Identifier (New_Discr);
2337 -- The subtype mark of the discriminant on the full type
2338 -- has not been analyzed so we do it here. For an access
2339 -- discriminant a new type is created.
2341 if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then
2343 Access_Definition (N, Discriminant_Type (New_Discr));
2346 Analyze (Discriminant_Type (New_Discr));
2347 New_Discr_Type := Etype (Discriminant_Type (New_Discr));
2350 if not Conforming_Types
2351 (Etype (Old_Discr), New_Discr_Type, Fully_Conformant)
2353 Conformance_Error ("type of & does not match!", New_Discr_Id);
2356 -- Treat the new discriminant as an occurrence of the old
2357 -- one, for navigation purposes, and fill in some semantic
2358 -- information, for completeness.
2360 Generate_Reference (Old_Discr, New_Discr_Id, 'r');
2361 Set_Etype (New_Discr_Id, Etype (Old_Discr));
2362 Set_Scope (New_Discr_Id, Scope (Old_Discr));
2367 if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then
2368 Conformance_Error ("name & does not match!", New_Discr_Id);
2372 -- Default expressions must match
2375 NewD : constant Boolean :=
2376 Present (Expression (New_Discr));
2377 OldD : constant Boolean :=
2378 Present (Expression (Parent (Old_Discr)));
2381 if NewD or OldD then
2383 -- The old default value has been analyzed and expanded,
2384 -- because the current full declaration will have frozen
2385 -- everything before. The new default values have not
2386 -- been expanded, so expand now to check conformance.
2389 Analyze_Per_Use_Expression
2390 (Expression (New_Discr), New_Discr_Type);
2393 if not (NewD and OldD)
2394 or else not Fully_Conformant_Expressions
2395 (Expression (Parent (Old_Discr)),
2396 Expression (New_Discr))
2400 ("default expression for & does not match!",
2407 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
2409 if Ada_Version = Ada_83 then
2411 Old_Disc : constant Node_Id := Declaration_Node (Old_Discr);
2414 -- Grouping (use of comma in param lists) must be the same
2415 -- This is where we catch a misconformance like:
2418 -- A : Integer; B : Integer
2420 -- which are represented identically in the tree except
2421 -- for the setting of the flags More_Ids and Prev_Ids.
2423 if More_Ids (Old_Disc) /= More_Ids (New_Discr)
2424 or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr)
2427 ("grouping of & does not match!", New_Discr_Id);
2433 Next_Discriminant (Old_Discr);
2437 if Present (Old_Discr) then
2438 Conformance_Error ("too few discriminants!", Defining_Identifier (N));
2441 elsif Present (New_Discr) then
2443 ("too many discriminants!", Defining_Identifier (New_Discr));
2446 end Check_Discriminant_Conformance;
2448 ----------------------------
2449 -- Check_Fully_Conformant --
2450 ----------------------------
2452 procedure Check_Fully_Conformant
2453 (New_Id : Entity_Id;
2455 Err_Loc : Node_Id := Empty)
2461 (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc);
2462 end Check_Fully_Conformant;
2464 ---------------------------
2465 -- Check_Mode_Conformant --
2466 ---------------------------
2468 procedure Check_Mode_Conformant
2469 (New_Id : Entity_Id;
2471 Err_Loc : Node_Id := Empty;
2472 Get_Inst : Boolean := False)
2478 (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst);
2479 end Check_Mode_Conformant;
2481 --------------------------------
2482 -- Check_Overriding_Operation --
2483 --------------------------------
2485 procedure Check_Overriding_Operation
2491 Has_Pragma : Boolean := False;
2494 -- See whether there is an overriding pragma immediately following
2495 -- the declaration. Intervening pragmas, such as Inline, are allowed.
2498 while Present (Decl)
2499 and then Nkind (Decl) = N_Pragma
2501 if Chars (Decl) = Name_Overriding
2502 or else Chars (Decl) = Name_Optional_Overriding
2504 -- For now disable the use of these pragmas, until the ARG
2505 -- finalizes the design of this feature.
2507 Error_Msg_N ("?unrecognized pragma", Decl);
2509 if not Is_Overriding_Operation (Subp) then
2511 -- Before emitting an error message, check whether this
2512 -- may override an operation that is not yet visible, as
2513 -- in the case of a derivation of a private operation in
2514 -- a child unit. Such an operation is introduced with a
2515 -- different name, but its alias is the parent operation.
2521 E := First_Entity (Current_Scope);
2523 while Present (E) loop
2524 if Ekind (E) = Ekind (Subp)
2525 and then not Comes_From_Source (E)
2526 and then Present (Alias (E))
2527 and then Chars (Alias (E)) = Chars (Subp)
2528 and then In_Open_Scopes (Scope (Alias (E)))
2538 ("& must override an inherited operation",
2544 -- Verify syntax of pragma
2546 Arg1 := First (Pragma_Argument_Associations (Decl));
2548 if Present (Arg1) then
2549 if not Is_Entity_Name (Expression (Arg1)) then
2550 Error_Msg_N ("pragma applies to local subprogram", Decl);
2552 elsif Chars (Expression (Arg1)) /= Chars (Subp) then
2554 ("pragma must apply to preceding subprogram", Decl);
2556 elsif Present (Next (Arg1)) then
2557 Error_Msg_N ("illegal pragma format", Decl);
2561 Set_Analyzed (Decl);
2570 and then Explicit_Overriding
2571 and then Is_Overriding_Operation (Subp)
2573 Error_Msg_NE ("Missing overriding pragma for&", Subp, Subp);
2575 end Check_Overriding_Operation;
2581 procedure Check_Returns
2588 procedure Check_Statement_Sequence (L : List_Id);
2589 -- Internal recursive procedure to check a list of statements for proper
2590 -- termination by a return statement (or a transfer of control or a
2591 -- compound statement that is itself internally properly terminated).
2593 ------------------------------
2594 -- Check_Statement_Sequence --
2595 ------------------------------
2597 procedure Check_Statement_Sequence (L : List_Id) is
2601 Raise_Exception_Call : Boolean;
2602 -- Set True if statement sequence terminated by Raise_Exception call
2603 -- or a Reraise_Occurrence call.
2606 Raise_Exception_Call := False;
2608 -- Get last real statement
2610 Last_Stm := Last (L);
2612 -- Don't count pragmas
2614 while Nkind (Last_Stm) = N_Pragma
2616 -- Don't count call to SS_Release (can happen after Raise_Exception)
2619 (Nkind (Last_Stm) = N_Procedure_Call_Statement
2621 Nkind (Name (Last_Stm)) = N_Identifier
2623 Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release))
2625 -- Don't count exception junk
2628 ((Nkind (Last_Stm) = N_Goto_Statement
2629 or else Nkind (Last_Stm) = N_Label
2630 or else Nkind (Last_Stm) = N_Object_Declaration)
2631 and then Exception_Junk (Last_Stm))
2636 -- Here we have the "real" last statement
2638 Kind := Nkind (Last_Stm);
2640 -- Transfer of control, OK. Note that in the No_Return procedure
2641 -- case, we already diagnosed any explicit return statements, so
2642 -- we can treat them as OK in this context.
2644 if Is_Transfer (Last_Stm) then
2647 -- Check cases of explicit non-indirect procedure calls
2649 elsif Kind = N_Procedure_Call_Statement
2650 and then Is_Entity_Name (Name (Last_Stm))
2652 -- Check call to Raise_Exception procedure which is treated
2653 -- specially, as is a call to Reraise_Occurrence.
2655 -- We suppress the warning in these cases since it is likely that
2656 -- the programmer really does not expect to deal with the case
2657 -- of Null_Occurrence, and thus would find a warning about a
2658 -- missing return curious, and raising Program_Error does not
2659 -- seem such a bad behavior if this does occur.
2661 if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception)
2663 Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence)
2665 Raise_Exception_Call := True;
2667 -- For Raise_Exception call, test first argument, if it is
2668 -- an attribute reference for a 'Identity call, then we know
2669 -- that the call cannot possibly return.
2672 Arg : constant Node_Id :=
2673 Original_Node (First_Actual (Last_Stm));
2676 if Nkind (Arg) = N_Attribute_Reference
2677 and then Attribute_Name (Arg) = Name_Identity
2684 -- If statement, need to look inside if there is an else and check
2685 -- each constituent statement sequence for proper termination.
2687 elsif Kind = N_If_Statement
2688 and then Present (Else_Statements (Last_Stm))
2690 Check_Statement_Sequence (Then_Statements (Last_Stm));
2691 Check_Statement_Sequence (Else_Statements (Last_Stm));
2693 if Present (Elsif_Parts (Last_Stm)) then
2695 Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm));
2698 while Present (Elsif_Part) loop
2699 Check_Statement_Sequence (Then_Statements (Elsif_Part));
2707 -- Case statement, check each case for proper termination
2709 elsif Kind = N_Case_Statement then
2714 Case_Alt := First_Non_Pragma (Alternatives (Last_Stm));
2715 while Present (Case_Alt) loop
2716 Check_Statement_Sequence (Statements (Case_Alt));
2717 Next_Non_Pragma (Case_Alt);
2723 -- Block statement, check its handled sequence of statements
2725 elsif Kind = N_Block_Statement then
2731 (Handled_Statement_Sequence (Last_Stm), Mode, Err1);
2740 -- Loop statement. If there is an iteration scheme, we can definitely
2741 -- fall out of the loop. Similarly if there is an exit statement, we
2742 -- can fall out. In either case we need a following return.
2744 elsif Kind = N_Loop_Statement then
2745 if Present (Iteration_Scheme (Last_Stm))
2746 or else Has_Exit (Entity (Identifier (Last_Stm)))
2750 -- A loop with no exit statement or iteration scheme if either
2751 -- an inifite loop, or it has some other exit (raise/return).
2752 -- In either case, no warning is required.
2758 -- Timed entry call, check entry call and delay alternatives
2760 -- Note: in expanded code, the timed entry call has been converted
2761 -- to a set of expanded statements on which the check will work
2762 -- correctly in any case.
2764 elsif Kind = N_Timed_Entry_Call then
2766 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
2767 DCA : constant Node_Id := Delay_Alternative (Last_Stm);
2770 -- If statement sequence of entry call alternative is missing,
2771 -- then we can definitely fall through, and we post the error
2772 -- message on the entry call alternative itself.
2774 if No (Statements (ECA)) then
2777 -- If statement sequence of delay alternative is missing, then
2778 -- we can definitely fall through, and we post the error
2779 -- message on the delay alternative itself.
2781 -- Note: if both ECA and DCA are missing the return, then we
2782 -- post only one message, should be enough to fix the bugs.
2783 -- If not we will get a message next time on the DCA when the
2786 elsif No (Statements (DCA)) then
2789 -- Else check both statement sequences
2792 Check_Statement_Sequence (Statements (ECA));
2793 Check_Statement_Sequence (Statements (DCA));
2798 -- Conditional entry call, check entry call and else part
2800 -- Note: in expanded code, the conditional entry call has been
2801 -- converted to a set of expanded statements on which the check
2802 -- will work correctly in any case.
2804 elsif Kind = N_Conditional_Entry_Call then
2806 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
2809 -- If statement sequence of entry call alternative is missing,
2810 -- then we can definitely fall through, and we post the error
2811 -- message on the entry call alternative itself.
2813 if No (Statements (ECA)) then
2816 -- Else check statement sequence and else part
2819 Check_Statement_Sequence (Statements (ECA));
2820 Check_Statement_Sequence (Else_Statements (Last_Stm));
2826 -- If we fall through, issue appropriate message
2830 if not Raise_Exception_Call then
2832 ("?RETURN statement missing following this statement!",
2835 ("\?Program_Error may be raised at run time",
2839 -- Note: we set Err even though we have not issued a warning
2840 -- because we still have a case of a missing return. This is
2841 -- an extremely marginal case, probably will never be noticed
2842 -- but we might as well get it right.
2848 ("implied return after this statement not allowed (No_Return)",
2851 end Check_Statement_Sequence;
2853 -- Start of processing for Check_Returns
2857 Check_Statement_Sequence (Statements (HSS));
2859 if Present (Exception_Handlers (HSS)) then
2860 Handler := First_Non_Pragma (Exception_Handlers (HSS));
2861 while Present (Handler) loop
2862 Check_Statement_Sequence (Statements (Handler));
2863 Next_Non_Pragma (Handler);
2868 ----------------------------
2869 -- Check_Subprogram_Order --
2870 ----------------------------
2872 procedure Check_Subprogram_Order (N : Node_Id) is
2874 function Subprogram_Name_Greater (S1, S2 : String) return Boolean;
2875 -- This is used to check if S1 > S2 in the sense required by this
2876 -- test, for example nameab < namec, but name2 < name10.
2878 function Subprogram_Name_Greater (S1, S2 : String) return Boolean is
2883 -- Remove trailing numeric parts
2886 while S1 (L1) in '0' .. '9' loop
2891 while S2 (L2) in '0' .. '9' loop
2895 -- If non-numeric parts non-equal, that's decisive
2897 if S1 (S1'First .. L1) < S2 (S2'First .. L2) then
2900 elsif S1 (S1'First .. L1) > S2 (S2'First .. L2) then
2903 -- If non-numeric parts equal, compare suffixed numeric parts. Note
2904 -- that a missing suffix is treated as numeric zero in this test.
2908 while L1 < S1'Last loop
2910 N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0');
2914 while L2 < S2'Last loop
2916 N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0');
2921 end Subprogram_Name_Greater;
2923 -- Start of processing for Check_Subprogram_Order
2926 -- Check body in alpha order if this is option
2929 and then Style_Check_Subprogram_Order
2930 and then Nkind (N) = N_Subprogram_Body
2931 and then Comes_From_Source (N)
2932 and then In_Extended_Main_Source_Unit (N)
2936 renames Scope_Stack.Table
2937 (Scope_Stack.Last).Last_Subprogram_Name;
2939 Body_Id : constant Entity_Id :=
2940 Defining_Entity (Specification (N));
2943 Get_Decoded_Name_String (Chars (Body_Id));
2946 if Subprogram_Name_Greater
2947 (LSN.all, Name_Buffer (1 .. Name_Len))
2949 Style.Subprogram_Not_In_Alpha_Order (Body_Id);
2955 LSN := new String'(Name_Buffer (1 .. Name_Len));
2958 end Check_Subprogram_Order;
2960 ------------------------------
2961 -- Check_Subtype_Conformant --
2962 ------------------------------
2964 procedure Check_Subtype_Conformant
2965 (New_Id : Entity_Id;
2967 Err_Loc : Node_Id := Empty)
2973 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc);
2974 end Check_Subtype_Conformant;
2976 ---------------------------
2977 -- Check_Type_Conformant --
2978 ---------------------------
2980 procedure Check_Type_Conformant
2981 (New_Id : Entity_Id;
2983 Err_Loc : Node_Id := Empty)
2989 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
2990 end Check_Type_Conformant;
2992 ----------------------
2993 -- Conforming_Types --
2994 ----------------------
2996 function Conforming_Types
2999 Ctype : Conformance_Type;
3000 Get_Inst : Boolean := False) return Boolean
3002 Type_1 : Entity_Id := T1;
3003 Type_2 : Entity_Id := T2;
3004 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False;
3006 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
3007 -- If neither T1 nor T2 are generic actual types, or if they are
3008 -- in different scopes (e.g. parent and child instances), then verify
3009 -- that the base types are equal. Otherwise T1 and T2 must be
3010 -- on the same subtype chain. The whole purpose of this procedure
3011 -- is to prevent spurious ambiguities in an instantiation that may
3012 -- arise if two distinct generic types are instantiated with the
3015 ----------------------
3016 -- Base_Types_Match --
3017 ----------------------
3019 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
3024 elsif Base_Type (T1) = Base_Type (T2) then
3026 -- The following is too permissive. A more precise test must
3027 -- check that the generic actual is an ancestor subtype of the
3030 return not Is_Generic_Actual_Type (T1)
3031 or else not Is_Generic_Actual_Type (T2)
3032 or else Scope (T1) /= Scope (T2);
3034 -- In some cases a type imported through a limited_with clause,
3035 -- and its non-limited view are both visible, for example in an
3036 -- anonymous access_to_classwide type in a formal. Both entities
3037 -- designate the same type.
3039 elsif From_With_Type (T1)
3040 and then Ekind (T1) = E_Incomplete_Type
3041 and then T2 = Non_Limited_View (T1)
3048 end Base_Types_Match;
3051 -- The context is an instance association for a formal
3052 -- access-to-subprogram type; the formal parameter types
3053 -- require mapping because they may denote other formal
3054 -- parameters of the generic unit.
3057 Type_1 := Get_Instance_Of (T1);
3058 Type_2 := Get_Instance_Of (T2);
3061 -- First see if base types match
3063 if Base_Types_Match (Type_1, Type_2) then
3064 return Ctype <= Mode_Conformant
3065 or else Subtypes_Statically_Match (Type_1, Type_2);
3067 elsif Is_Incomplete_Or_Private_Type (Type_1)
3068 and then Present (Full_View (Type_1))
3069 and then Base_Types_Match (Full_View (Type_1), Type_2)
3071 return Ctype <= Mode_Conformant
3072 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
3074 elsif Ekind (Type_2) = E_Incomplete_Type
3075 and then Present (Full_View (Type_2))
3076 and then Base_Types_Match (Type_1, Full_View (Type_2))
3078 return Ctype <= Mode_Conformant
3079 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3081 elsif Is_Private_Type (Type_2)
3082 and then In_Instance
3083 and then Present (Full_View (Type_2))
3084 and then Base_Types_Match (Type_1, Full_View (Type_2))
3086 return Ctype <= Mode_Conformant
3087 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3090 -- Ada 2005 (AI-254): Detect anonymous access to subprogram types
3092 Are_Anonymous_Access_To_Subprogram_Types :=
3094 -- Case 1: Anonymous access to subprogram types
3096 (Ekind (Type_1) = E_Anonymous_Access_Subprogram_Type
3097 and then Ekind (Type_2) = E_Anonymous_Access_Subprogram_Type)
3099 -- Case 2: Anonymous access to PROTECTED subprogram types. In this
3100 -- case the anonymous type_declaration has been replaced by an
3101 -- occurrence of an internal access to subprogram type declaration
3102 -- available through the Original_Access_Type attribute
3105 (Ekind (Type_1) = E_Access_Protected_Subprogram_Type
3106 and then Ekind (Type_2) = E_Access_Protected_Subprogram_Type
3107 and then not Comes_From_Source (Type_1)
3108 and then not Comes_From_Source (Type_2)
3109 and then Present (Original_Access_Type (Type_1))
3110 and then Present (Original_Access_Type (Type_2))
3111 and then Ekind (Original_Access_Type (Type_1)) =
3112 E_Anonymous_Access_Protected_Subprogram_Type
3113 and then Ekind (Original_Access_Type (Type_2)) =
3114 E_Anonymous_Access_Protected_Subprogram_Type);
3116 -- Test anonymous access type case. For this case, static subtype
3117 -- matching is required for mode conformance (RM 6.3.1(15))
3119 if (Ekind (Type_1) = E_Anonymous_Access_Type
3120 and then Ekind (Type_2) = E_Anonymous_Access_Type)
3121 or else Are_Anonymous_Access_To_Subprogram_Types -- Ada 2005 (AI-254)
3124 Desig_1 : Entity_Id;
3125 Desig_2 : Entity_Id;
3128 Desig_1 := Directly_Designated_Type (Type_1);
3130 -- An access parameter can designate an incomplete type
3132 if Ekind (Desig_1) = E_Incomplete_Type
3133 and then Present (Full_View (Desig_1))
3135 Desig_1 := Full_View (Desig_1);
3138 Desig_2 := Directly_Designated_Type (Type_2);
3140 if Ekind (Desig_2) = E_Incomplete_Type
3141 and then Present (Full_View (Desig_2))
3143 Desig_2 := Full_View (Desig_2);
3146 -- The context is an instance association for a formal
3147 -- access-to-subprogram type; formal access parameter
3148 -- designated types require mapping because they may
3149 -- denote other formal parameters of the generic unit.
3152 Desig_1 := Get_Instance_Of (Desig_1);
3153 Desig_2 := Get_Instance_Of (Desig_2);
3156 -- It is possible for a Class_Wide_Type to be introduced for
3157 -- an incomplete type, in which case there is a separate class_
3158 -- wide type for the full view. The types conform if their
3159 -- Etypes conform, i.e. one may be the full view of the other.
3160 -- This can only happen in the context of an access parameter,
3161 -- other uses of an incomplete Class_Wide_Type are illegal.
3163 if Is_Class_Wide_Type (Desig_1)
3164 and then Is_Class_Wide_Type (Desig_2)
3168 (Etype (Base_Type (Desig_1)),
3169 Etype (Base_Type (Desig_2)), Ctype);
3171 elsif Are_Anonymous_Access_To_Subprogram_Types then
3172 return Ctype = Type_Conformant
3174 Subtypes_Statically_Match (Desig_1, Desig_2);
3177 return Base_Type (Desig_1) = Base_Type (Desig_2)
3178 and then (Ctype = Type_Conformant
3180 Subtypes_Statically_Match (Desig_1, Desig_2));
3184 -- Otherwise definitely no match
3190 end Conforming_Types;
3192 --------------------------
3193 -- Create_Extra_Formals --
3194 --------------------------
3196 procedure Create_Extra_Formals (E : Entity_Id) is
3198 Last_Extra : Entity_Id;
3199 Formal_Type : Entity_Id;
3200 P_Formal : Entity_Id := Empty;
3202 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id;
3203 -- Add an extra formal, associated with the current Formal. The
3204 -- extra formal is added to the list of extra formals, and also
3205 -- returned as the result. These formals are always of mode IN.
3207 ----------------------
3208 -- Add_Extra_Formal --
3209 ----------------------
3211 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is
3212 EF : constant Entity_Id :=
3213 Make_Defining_Identifier (Sloc (Formal),
3214 Chars => New_External_Name (Chars (Formal), 'F'));
3217 -- We never generate extra formals if expansion is not active
3218 -- because we don't need them unless we are generating code.
3220 if not Expander_Active then
3224 -- A little optimization. Never generate an extra formal for
3225 -- the _init operand of an initialization procedure, since it
3226 -- could never be used.
3228 if Chars (Formal) = Name_uInit then
3232 Set_Ekind (EF, E_In_Parameter);
3233 Set_Actual_Subtype (EF, Typ);
3234 Set_Etype (EF, Typ);
3235 Set_Scope (EF, Scope (Formal));
3236 Set_Mechanism (EF, Default_Mechanism);
3237 Set_Formal_Validity (EF);
3239 Set_Extra_Formal (Last_Extra, EF);
3242 end Add_Extra_Formal;
3244 -- Start of processing for Create_Extra_Formals
3247 -- If this is a derived subprogram then the subtypes of the
3248 -- parent subprogram's formal parameters will be used to
3249 -- to determine the need for extra formals.
3251 if Is_Overloadable (E) and then Present (Alias (E)) then
3252 P_Formal := First_Formal (Alias (E));
3255 Last_Extra := Empty;
3256 Formal := First_Formal (E);
3257 while Present (Formal) loop
3258 Last_Extra := Formal;
3259 Next_Formal (Formal);
3262 -- If Extra_formals where already created, don't do it again
3263 -- This situation may arise for subprogram types created as part
3264 -- of dispatching calls (see Expand_Dispatch_Call)
3266 if Present (Last_Extra) and then
3267 Present (Extra_Formal (Last_Extra))
3272 Formal := First_Formal (E);
3274 while Present (Formal) loop
3276 -- Create extra formal for supporting the attribute 'Constrained.
3277 -- The case of a private type view without discriminants also
3278 -- requires the extra formal if the underlying type has defaulted
3281 if Ekind (Formal) /= E_In_Parameter then
3282 if Present (P_Formal) then
3283 Formal_Type := Etype (P_Formal);
3285 Formal_Type := Etype (Formal);
3288 -- Do not produce extra formals for Unchecked_Union parameters.
3289 -- Jump directly to the end of the loop.
3291 if Is_Unchecked_Union (Base_Type (Formal_Type)) then
3292 goto Skip_Extra_Formal_Generation;
3295 if not Has_Discriminants (Formal_Type)
3296 and then Ekind (Formal_Type) in Private_Kind
3297 and then Present (Underlying_Type (Formal_Type))
3299 Formal_Type := Underlying_Type (Formal_Type);
3302 if Has_Discriminants (Formal_Type)
3304 ((not Is_Constrained (Formal_Type)
3305 and then not Is_Indefinite_Subtype (Formal_Type))
3306 or else Present (Extra_Formal (Formal)))
3308 Set_Extra_Constrained
3309 (Formal, Add_Extra_Formal (Standard_Boolean));
3313 -- Create extra formal for supporting accessibility checking
3315 -- This is suppressed if we specifically suppress accessibility
3316 -- checks at the pacage level for either the subprogram, or the
3317 -- package in which it resides. However, we do not suppress it
3318 -- simply if the scope has accessibility checks suppressed, since
3319 -- this could cause trouble when clients are compiled with a
3320 -- different suppression setting. The explicit checks at the
3321 -- package level are safe from this point of view.
3323 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
3325 (Explicit_Suppress (E, Accessibility_Check)
3327 Explicit_Suppress (Scope (E), Accessibility_Check))
3329 (not Present (P_Formal)
3330 or else Present (Extra_Accessibility (P_Formal)))
3332 -- Temporary kludge: for now we avoid creating the extra
3333 -- formal for access parameters of protected operations
3334 -- because of problem with the case of internal protected
3337 if Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Definition
3338 and then Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Body
3340 Set_Extra_Accessibility
3341 (Formal, Add_Extra_Formal (Standard_Natural));
3345 if Present (P_Formal) then
3346 Next_Formal (P_Formal);
3349 -- This label is required when skipping extra formal generation for
3350 -- Unchecked_Union parameters.
3352 <<Skip_Extra_Formal_Generation>>
3354 Next_Formal (Formal);
3356 end Create_Extra_Formals;
3358 -----------------------------
3359 -- Enter_Overloaded_Entity --
3360 -----------------------------
3362 procedure Enter_Overloaded_Entity (S : Entity_Id) is
3363 E : Entity_Id := Current_Entity_In_Scope (S);
3364 C_E : Entity_Id := Current_Entity (S);
3368 Set_Has_Homonym (E);
3369 Set_Has_Homonym (S);
3372 Set_Is_Immediately_Visible (S);
3373 Set_Scope (S, Current_Scope);
3375 -- Chain new entity if front of homonym in current scope, so that
3376 -- homonyms are contiguous.
3381 while Homonym (C_E) /= E loop
3382 C_E := Homonym (C_E);
3385 Set_Homonym (C_E, S);
3389 Set_Current_Entity (S);
3394 Append_Entity (S, Current_Scope);
3395 Set_Public_Status (S);
3397 if Debug_Flag_E then
3398 Write_Str ("New overloaded entity chain: ");
3399 Write_Name (Chars (S));
3402 while Present (E) loop
3403 Write_Str (" "); Write_Int (Int (E));
3410 -- Generate warning for hiding
3413 and then Comes_From_Source (S)
3414 and then In_Extended_Main_Source_Unit (S)
3421 -- Warn unless genuine overloading
3423 if (not Is_Overloadable (E))
3424 or else Subtype_Conformant (E, S)
3426 Error_Msg_Sloc := Sloc (E);
3427 Error_Msg_N ("declaration of & hides one#?", S);
3431 end Enter_Overloaded_Entity;
3433 -----------------------------
3434 -- Find_Corresponding_Spec --
3435 -----------------------------
3437 function Find_Corresponding_Spec (N : Node_Id) return Entity_Id is
3438 Spec : constant Node_Id := Specification (N);
3439 Designator : constant Entity_Id := Defining_Entity (Spec);
3444 E := Current_Entity (Designator);
3446 while Present (E) loop
3448 -- We are looking for a matching spec. It must have the same scope,
3449 -- and the same name, and either be type conformant, or be the case
3450 -- of a library procedure spec and its body (which belong to one
3451 -- another regardless of whether they are type conformant or not).
3453 if Scope (E) = Current_Scope then
3454 if Current_Scope = Standard_Standard
3455 or else (Ekind (E) = Ekind (Designator)
3456 and then Type_Conformant (E, Designator))
3458 -- Within an instantiation, we know that spec and body are
3459 -- subtype conformant, because they were subtype conformant
3460 -- in the generic. We choose the subtype-conformant entity
3461 -- here as well, to resolve spurious ambiguities in the
3462 -- instance that were not present in the generic (i.e. when
3463 -- two different types are given the same actual). If we are
3464 -- looking for a spec to match a body, full conformance is
3468 Set_Convention (Designator, Convention (E));
3470 if Nkind (N) = N_Subprogram_Body
3471 and then Present (Homonym (E))
3472 and then not Fully_Conformant (E, Designator)
3476 elsif not Subtype_Conformant (E, Designator) then
3481 if not Has_Completion (E) then
3483 if Nkind (N) /= N_Subprogram_Body_Stub then
3484 Set_Corresponding_Spec (N, E);
3487 Set_Has_Completion (E);
3490 elsif Nkind (Parent (N)) = N_Subunit then
3492 -- If this is the proper body of a subunit, the completion
3493 -- flag is set when analyzing the stub.
3497 -- If body already exists, this is an error unless the
3498 -- previous declaration is the implicit declaration of
3499 -- a derived subprogram, or this is a spurious overloading
3502 elsif No (Alias (E))
3503 and then not Is_Intrinsic_Subprogram (E)
3504 and then not In_Instance
3506 Error_Msg_Sloc := Sloc (E);
3507 if Is_Imported (E) then
3509 ("body not allowed for imported subprogram & declared#",
3512 Error_Msg_NE ("duplicate body for & declared#", N, E);
3516 elsif Is_Child_Unit (E)
3518 Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body
3520 Nkind (Parent (Unit_Declaration_Node (Designator)))
3521 = N_Compilation_Unit
3524 -- Child units cannot be overloaded, so a conformance mismatch
3525 -- between body and a previous spec is an error.
3528 ("body of child unit does not match previous declaration", N);
3536 -- On exit, we know that no previous declaration of subprogram exists
3539 end Find_Corresponding_Spec;
3541 ----------------------
3542 -- Fully_Conformant --
3543 ----------------------
3545 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
3549 Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result);
3551 end Fully_Conformant;
3553 ----------------------------------
3554 -- Fully_Conformant_Expressions --
3555 ----------------------------------
3557 function Fully_Conformant_Expressions
3558 (Given_E1 : Node_Id;
3559 Given_E2 : Node_Id) return Boolean
3561 E1 : constant Node_Id := Original_Node (Given_E1);
3562 E2 : constant Node_Id := Original_Node (Given_E2);
3563 -- We always test conformance on original nodes, since it is possible
3564 -- for analysis and/or expansion to make things look as though they
3565 -- conform when they do not, e.g. by converting 1+2 into 3.
3567 function FCE (Given_E1, Given_E2 : Node_Id) return Boolean
3568 renames Fully_Conformant_Expressions;
3570 function FCL (L1, L2 : List_Id) return Boolean;
3571 -- Compare elements of two lists for conformance. Elements have to
3572 -- be conformant, and actuals inserted as default parameters do not
3573 -- match explicit actuals with the same value.
3575 function FCO (Op_Node, Call_Node : Node_Id) return Boolean;
3576 -- Compare an operator node with a function call.
3582 function FCL (L1, L2 : List_Id) return Boolean is
3586 if L1 = No_List then
3592 if L2 = No_List then
3598 -- Compare two lists, skipping rewrite insertions (we want to
3599 -- compare the original trees, not the expanded versions!)
3602 if Is_Rewrite_Insertion (N1) then
3604 elsif Is_Rewrite_Insertion (N2) then
3610 elsif not FCE (N1, N2) then
3623 function FCO (Op_Node, Call_Node : Node_Id) return Boolean is
3624 Actuals : constant List_Id := Parameter_Associations (Call_Node);
3629 or else Entity (Op_Node) /= Entity (Name (Call_Node))
3634 Act := First (Actuals);
3636 if Nkind (Op_Node) in N_Binary_Op then
3638 if not FCE (Left_Opnd (Op_Node), Act) then
3645 return Present (Act)
3646 and then FCE (Right_Opnd (Op_Node), Act)
3647 and then No (Next (Act));
3651 -- Start of processing for Fully_Conformant_Expressions
3654 -- Non-conformant if paren count does not match. Note: if some idiot
3655 -- complains that we don't do this right for more than 3 levels of
3656 -- parentheses, they will be treated with the respect they deserve :-)
3658 if Paren_Count (E1) /= Paren_Count (E2) then
3661 -- If same entities are referenced, then they are conformant
3662 -- even if they have different forms (RM 8.3.1(19-20)).
3664 elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then
3665 if Present (Entity (E1)) then
3666 return Entity (E1) = Entity (E2)
3667 or else (Chars (Entity (E1)) = Chars (Entity (E2))
3668 and then Ekind (Entity (E1)) = E_Discriminant
3669 and then Ekind (Entity (E2)) = E_In_Parameter);
3671 elsif Nkind (E1) = N_Expanded_Name
3672 and then Nkind (E2) = N_Expanded_Name
3673 and then Nkind (Selector_Name (E1)) = N_Character_Literal
3674 and then Nkind (Selector_Name (E2)) = N_Character_Literal
3676 return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2));
3679 -- Identifiers in component associations don't always have
3680 -- entities, but their names must conform.
3682 return Nkind (E1) = N_Identifier
3683 and then Nkind (E2) = N_Identifier
3684 and then Chars (E1) = Chars (E2);
3687 elsif Nkind (E1) = N_Character_Literal
3688 and then Nkind (E2) = N_Expanded_Name
3690 return Nkind (Selector_Name (E2)) = N_Character_Literal
3691 and then Chars (E1) = Chars (Selector_Name (E2));
3693 elsif Nkind (E2) = N_Character_Literal
3694 and then Nkind (E1) = N_Expanded_Name
3696 return Nkind (Selector_Name (E1)) = N_Character_Literal
3697 and then Chars (E2) = Chars (Selector_Name (E1));
3699 elsif Nkind (E1) in N_Op
3700 and then Nkind (E2) = N_Function_Call
3702 return FCO (E1, E2);
3704 elsif Nkind (E2) in N_Op
3705 and then Nkind (E1) = N_Function_Call
3707 return FCO (E2, E1);
3709 -- Otherwise we must have the same syntactic entity
3711 elsif Nkind (E1) /= Nkind (E2) then
3714 -- At this point, we specialize by node type
3721 FCL (Expressions (E1), Expressions (E2))
3722 and then FCL (Component_Associations (E1),
3723 Component_Associations (E2));
3726 if Nkind (Expression (E1)) = N_Qualified_Expression
3728 Nkind (Expression (E2)) = N_Qualified_Expression
3730 return FCE (Expression (E1), Expression (E2));
3732 -- Check that the subtype marks and any constraints
3737 Indic1 : constant Node_Id := Expression (E1);
3738 Indic2 : constant Node_Id := Expression (E2);
3743 if Nkind (Indic1) /= N_Subtype_Indication then
3745 Nkind (Indic2) /= N_Subtype_Indication
3746 and then Entity (Indic1) = Entity (Indic2);
3748 elsif Nkind (Indic2) /= N_Subtype_Indication then
3750 Nkind (Indic1) /= N_Subtype_Indication
3751 and then Entity (Indic1) = Entity (Indic2);
3754 if Entity (Subtype_Mark (Indic1)) /=
3755 Entity (Subtype_Mark (Indic2))
3760 Elt1 := First (Constraints (Constraint (Indic1)));
3761 Elt2 := First (Constraints (Constraint (Indic2)));
3763 while Present (Elt1) and then Present (Elt2) loop
3764 if not FCE (Elt1, Elt2) then
3777 when N_Attribute_Reference =>
3779 Attribute_Name (E1) = Attribute_Name (E2)
3780 and then FCL (Expressions (E1), Expressions (E2));
3784 Entity (E1) = Entity (E2)
3785 and then FCE (Left_Opnd (E1), Left_Opnd (E2))
3786 and then FCE (Right_Opnd (E1), Right_Opnd (E2));
3788 when N_And_Then | N_Or_Else | N_In | N_Not_In =>
3790 FCE (Left_Opnd (E1), Left_Opnd (E2))
3792 FCE (Right_Opnd (E1), Right_Opnd (E2));
3794 when N_Character_Literal =>
3796 Char_Literal_Value (E1) = Char_Literal_Value (E2);
3798 when N_Component_Association =>
3800 FCL (Choices (E1), Choices (E2))
3801 and then FCE (Expression (E1), Expression (E2));
3803 when N_Conditional_Expression =>
3805 FCL (Expressions (E1), Expressions (E2));
3807 when N_Explicit_Dereference =>
3809 FCE (Prefix (E1), Prefix (E2));
3811 when N_Extension_Aggregate =>
3813 FCL (Expressions (E1), Expressions (E2))
3814 and then Null_Record_Present (E1) =
3815 Null_Record_Present (E2)
3816 and then FCL (Component_Associations (E1),
3817 Component_Associations (E2));
3819 when N_Function_Call =>
3821 FCE (Name (E1), Name (E2))
3822 and then FCL (Parameter_Associations (E1),
3823 Parameter_Associations (E2));
3825 when N_Indexed_Component =>
3827 FCE (Prefix (E1), Prefix (E2))
3828 and then FCL (Expressions (E1), Expressions (E2));
3830 when N_Integer_Literal =>
3831 return (Intval (E1) = Intval (E2));
3836 when N_Operator_Symbol =>
3838 Chars (E1) = Chars (E2);
3840 when N_Others_Choice =>
3843 when N_Parameter_Association =>
3845 Chars (Selector_Name (E1)) = Chars (Selector_Name (E2))
3846 and then FCE (Explicit_Actual_Parameter (E1),
3847 Explicit_Actual_Parameter (E2));
3849 when N_Qualified_Expression =>
3851 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3852 and then FCE (Expression (E1), Expression (E2));
3856 FCE (Low_Bound (E1), Low_Bound (E2))
3857 and then FCE (High_Bound (E1), High_Bound (E2));
3859 when N_Real_Literal =>
3860 return (Realval (E1) = Realval (E2));
3862 when N_Selected_Component =>
3864 FCE (Prefix (E1), Prefix (E2))
3865 and then FCE (Selector_Name (E1), Selector_Name (E2));
3869 FCE (Prefix (E1), Prefix (E2))
3870 and then FCE (Discrete_Range (E1), Discrete_Range (E2));
3872 when N_String_Literal =>
3874 S1 : constant String_Id := Strval (E1);
3875 S2 : constant String_Id := Strval (E2);
3876 L1 : constant Nat := String_Length (S1);
3877 L2 : constant Nat := String_Length (S2);
3884 for J in 1 .. L1 loop
3885 if Get_String_Char (S1, J) /=
3886 Get_String_Char (S2, J)
3896 when N_Type_Conversion =>
3898 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3899 and then FCE (Expression (E1), Expression (E2));
3903 Entity (E1) = Entity (E2)
3904 and then FCE (Right_Opnd (E1), Right_Opnd (E2));
3906 when N_Unchecked_Type_Conversion =>
3908 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3909 and then FCE (Expression (E1), Expression (E2));
3911 -- All other node types cannot appear in this context. Strictly
3912 -- we should raise a fatal internal error. Instead we just ignore
3913 -- the nodes. This means that if anyone makes a mistake in the
3914 -- expander and mucks an expression tree irretrievably, the
3915 -- result will be a failure to detect a (probably very obscure)
3916 -- case of non-conformance, which is better than bombing on some
3917 -- case where two expressions do in fact conform.
3924 end Fully_Conformant_Expressions;
3926 ----------------------------------------
3927 -- Fully_Conformant_Discrete_Subtypes --
3928 ----------------------------------------
3930 function Fully_Conformant_Discrete_Subtypes
3931 (Given_S1 : Node_Id;
3932 Given_S2 : Node_Id) return Boolean
3934 S1 : constant Node_Id := Original_Node (Given_S1);
3935 S2 : constant Node_Id := Original_Node (Given_S2);
3937 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean;
3938 -- Special-case for a bound given by a discriminant, which in the
3939 -- body is replaced with the discriminal of the enclosing type.
3941 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean;
3942 -- Check both bounds.
3944 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is
3946 if Is_Entity_Name (B1)
3947 and then Is_Entity_Name (B2)
3948 and then Ekind (Entity (B1)) = E_Discriminant
3950 return Chars (B1) = Chars (B2);
3953 return Fully_Conformant_Expressions (B1, B2);
3955 end Conforming_Bounds;
3957 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is
3960 Conforming_Bounds (Low_Bound (R1), Low_Bound (R2))
3962 Conforming_Bounds (High_Bound (R1), High_Bound (R2));
3963 end Conforming_Ranges;
3965 -- Start of processing for Fully_Conformant_Discrete_Subtypes
3968 if Nkind (S1) /= Nkind (S2) then
3971 elsif Is_Entity_Name (S1) then
3972 return Entity (S1) = Entity (S2);
3974 elsif Nkind (S1) = N_Range then
3975 return Conforming_Ranges (S1, S2);
3977 elsif Nkind (S1) = N_Subtype_Indication then
3979 Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2))
3982 (Range_Expression (Constraint (S1)),
3983 Range_Expression (Constraint (S2)));
3987 end Fully_Conformant_Discrete_Subtypes;
3989 --------------------
3990 -- Install_Entity --
3991 --------------------
3993 procedure Install_Entity (E : Entity_Id) is
3994 Prev : constant Entity_Id := Current_Entity (E);
3997 Set_Is_Immediately_Visible (E);
3998 Set_Current_Entity (E);
3999 Set_Homonym (E, Prev);
4002 ---------------------
4003 -- Install_Formals --
4004 ---------------------
4006 procedure Install_Formals (Id : Entity_Id) is
4010 F := First_Formal (Id);
4012 while Present (F) loop
4016 end Install_Formals;
4018 ---------------------------------
4019 -- Is_Non_Overriding_Operation --
4020 ---------------------------------
4022 function Is_Non_Overriding_Operation
4023 (Prev_E : Entity_Id;
4024 New_E : Entity_Id) return Boolean
4028 G_Typ : Entity_Id := Empty;
4030 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id;
4031 -- If F_Type is a derived type associated with a generic actual
4032 -- subtype, then return its Generic_Parent_Type attribute, else
4035 function Types_Correspond
4036 (P_Type : Entity_Id;
4037 N_Type : Entity_Id) return Boolean;
4038 -- Returns true if and only if the types (or designated types
4039 -- in the case of anonymous access types) are the same or N_Type
4040 -- is derived directly or indirectly from P_Type.
4042 -----------------------------
4043 -- Get_Generic_Parent_Type --
4044 -----------------------------
4046 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is
4051 if Is_Derived_Type (F_Typ)
4052 and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration
4054 -- The tree must be traversed to determine the parent
4055 -- subtype in the generic unit, which unfortunately isn't
4056 -- always available via semantic attributes. ???
4057 -- (Note: The use of Original_Node is needed for cases
4058 -- where a full derived type has been rewritten.)
4060 Indic := Subtype_Indication
4061 (Type_Definition (Original_Node (Parent (F_Typ))));
4063 if Nkind (Indic) = N_Subtype_Indication then
4064 G_Typ := Entity (Subtype_Mark (Indic));
4066 G_Typ := Entity (Indic);
4069 if Nkind (Parent (G_Typ)) = N_Subtype_Declaration
4070 and then Present (Generic_Parent_Type (Parent (G_Typ)))
4072 return Generic_Parent_Type (Parent (G_Typ));
4077 end Get_Generic_Parent_Type;
4079 ----------------------
4080 -- Types_Correspond --
4081 ----------------------
4083 function Types_Correspond
4084 (P_Type : Entity_Id;
4085 N_Type : Entity_Id) return Boolean
4087 Prev_Type : Entity_Id := Base_Type (P_Type);
4088 New_Type : Entity_Id := Base_Type (N_Type);
4091 if Ekind (Prev_Type) = E_Anonymous_Access_Type then
4092 Prev_Type := Designated_Type (Prev_Type);
4095 if Ekind (New_Type) = E_Anonymous_Access_Type then
4096 New_Type := Designated_Type (New_Type);
4099 if Prev_Type = New_Type then
4102 elsif not Is_Class_Wide_Type (New_Type) then
4103 while Etype (New_Type) /= New_Type loop
4104 New_Type := Etype (New_Type);
4105 if New_Type = Prev_Type then
4111 end Types_Correspond;
4113 -- Start of processing for Is_Non_Overriding_Operation
4116 -- In the case where both operations are implicit derived
4117 -- subprograms then neither overrides the other. This can
4118 -- only occur in certain obscure cases (e.g., derivation
4119 -- from homographs created in a generic instantiation).
4121 if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then
4124 elsif Ekind (Current_Scope) = E_Package
4125 and then Is_Generic_Instance (Current_Scope)
4126 and then In_Private_Part (Current_Scope)
4127 and then Comes_From_Source (New_E)
4129 -- We examine the formals and result subtype of the inherited
4130 -- operation, to determine whether their type is derived from
4131 -- (the instance of) a generic type.
4133 Formal := First_Formal (Prev_E);
4135 while Present (Formal) loop
4136 F_Typ := Base_Type (Etype (Formal));
4138 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4139 F_Typ := Designated_Type (F_Typ);
4142 G_Typ := Get_Generic_Parent_Type (F_Typ);
4144 Next_Formal (Formal);
4147 if not Present (G_Typ) and then Ekind (Prev_E) = E_Function then
4148 G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E)));
4155 -- If the generic type is a private type, then the original
4156 -- operation was not overriding in the generic, because there was
4157 -- no primitive operation to override.
4159 if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration
4160 and then Nkind (Formal_Type_Definition (Parent (G_Typ))) =
4161 N_Formal_Private_Type_Definition
4165 -- The generic parent type is the ancestor of a formal derived
4166 -- type declaration. We need to check whether it has a primitive
4167 -- operation that should be overridden by New_E in the generic.
4171 P_Formal : Entity_Id;
4172 N_Formal : Entity_Id;
4176 Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ));
4179 while Present (Prim_Elt) loop
4180 P_Prim := Node (Prim_Elt);
4182 if Chars (P_Prim) = Chars (New_E)
4183 and then Ekind (P_Prim) = Ekind (New_E)
4185 P_Formal := First_Formal (P_Prim);
4186 N_Formal := First_Formal (New_E);
4187 while Present (P_Formal) and then Present (N_Formal) loop
4188 P_Typ := Etype (P_Formal);
4189 N_Typ := Etype (N_Formal);
4191 if not Types_Correspond (P_Typ, N_Typ) then
4195 Next_Entity (P_Formal);
4196 Next_Entity (N_Formal);
4199 -- Found a matching primitive operation belonging to
4200 -- the formal ancestor type, so the new subprogram
4203 if not Present (P_Formal)
4204 and then not Present (N_Formal)
4205 and then (Ekind (New_E) /= E_Function
4208 (Etype (P_Prim), Etype (New_E)))
4214 Next_Elmt (Prim_Elt);
4217 -- If no match found, then the new subprogram does
4218 -- not override in the generic (nor in the instance).
4226 end Is_Non_Overriding_Operation;
4228 ------------------------------
4229 -- Make_Inequality_Operator --
4230 ------------------------------
4232 -- S is the defining identifier of an equality operator. We build a
4233 -- subprogram declaration with the right signature. This operation is
4234 -- intrinsic, because it is always expanded as the negation of the
4235 -- call to the equality function.
4237 procedure Make_Inequality_Operator (S : Entity_Id) is
4238 Loc : constant Source_Ptr := Sloc (S);
4241 Op_Name : Entity_Id;
4247 -- Check that equality was properly defined.
4249 if No (Next_Formal (First_Formal (S))) then
4253 A := Make_Defining_Identifier (Loc, Chars (First_Formal (S)));
4254 B := Make_Defining_Identifier (Loc,
4255 Chars (Next_Formal (First_Formal (S))));
4257 Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne);
4259 Formals := New_List (
4260 Make_Parameter_Specification (Loc,
4261 Defining_Identifier => A,
4263 New_Reference_To (Etype (First_Formal (S)), Loc)),
4265 Make_Parameter_Specification (Loc,
4266 Defining_Identifier => B,
4268 New_Reference_To (Etype (Next_Formal (First_Formal (S))), Loc)));
4271 Make_Subprogram_Declaration (Loc,
4273 Make_Function_Specification (Loc,
4274 Defining_Unit_Name => Op_Name,
4275 Parameter_Specifications => Formals,
4276 Subtype_Mark => New_Reference_To (Standard_Boolean, Loc)));
4278 -- Insert inequality right after equality if it is explicit or after
4279 -- the derived type when implicit. These entities are created only
4280 -- for visibility purposes, and eventually replaced in the course of
4281 -- expansion, so they do not need to be attached to the tree and seen
4282 -- by the back-end. Keeping them internal also avoids spurious freezing
4283 -- problems. The parent field is set simply to make analysis safe.
4285 if No (Alias (S)) then
4286 Set_Parent (Decl, Parent (Unit_Declaration_Node (S)));
4288 Set_Parent (Decl, Parent (Parent (Etype (First_Formal (S)))));
4291 Mark_Rewrite_Insertion (Decl);
4292 Set_Is_Intrinsic_Subprogram (Op_Name);
4294 Set_Has_Completion (Op_Name);
4295 Set_Corresponding_Equality (Op_Name, S);
4296 Set_Is_Abstract (Op_Name, Is_Abstract (S));
4298 end Make_Inequality_Operator;
4300 ----------------------
4301 -- May_Need_Actuals --
4302 ----------------------
4304 procedure May_Need_Actuals (Fun : Entity_Id) is
4309 F := First_Formal (Fun);
4312 while Present (F) loop
4313 if No (Default_Value (F)) then
4321 Set_Needs_No_Actuals (Fun, B);
4322 end May_Need_Actuals;
4324 ---------------------
4325 -- Mode_Conformant --
4326 ---------------------
4328 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
4332 Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result);
4334 end Mode_Conformant;
4336 ---------------------------
4337 -- New_Overloaded_Entity --
4338 ---------------------------
4340 procedure New_Overloaded_Entity
4342 Derived_Type : Entity_Id := Empty)
4345 -- Entity that S overrides
4347 Prev_Vis : Entity_Id := Empty;
4348 -- Needs comment ???
4350 function Is_Private_Declaration (E : Entity_Id) return Boolean;
4351 -- Check that E is declared in the private part of the current package,
4352 -- or in the package body, where it may hide a previous declaration.
4353 -- We can't use In_Private_Part by itself because this flag is also
4354 -- set when freezing entities, so we must examine the place of the
4355 -- declaration in the tree, and recognize wrapper packages as well.
4357 procedure Maybe_Primitive_Operation (Overriding : Boolean := False);
4358 -- If the subprogram being analyzed is a primitive operation of
4359 -- the type of one of its formals, set the corresponding flag.
4361 ----------------------------
4362 -- Is_Private_Declaration --
4363 ----------------------------
4365 function Is_Private_Declaration (E : Entity_Id) return Boolean is
4366 Priv_Decls : List_Id;
4367 Decl : constant Node_Id := Unit_Declaration_Node (E);
4370 if Is_Package (Current_Scope)
4371 and then In_Private_Part (Current_Scope)
4374 Private_Declarations (
4375 Specification (Unit_Declaration_Node (Current_Scope)));
4377 return In_Package_Body (Current_Scope)
4378 or else List_Containing (Decl) = Priv_Decls
4379 or else (Nkind (Parent (Decl)) = N_Package_Specification
4380 and then not Is_Compilation_Unit (
4381 Defining_Entity (Parent (Decl)))
4382 and then List_Containing (Parent (Parent (Decl)))
4387 end Is_Private_Declaration;
4389 -------------------------------
4390 -- Maybe_Primitive_Operation --
4391 -------------------------------
4393 procedure Maybe_Primitive_Operation (Overriding : Boolean := False) is
4398 function Visible_Part_Type (T : Entity_Id) return Boolean;
4399 -- Returns true if T is declared in the visible part of
4400 -- the current package scope; otherwise returns false.
4401 -- Assumes that T is declared in a package.
4403 procedure Check_Private_Overriding (T : Entity_Id);
4404 -- Checks that if a primitive abstract subprogram of a visible
4405 -- abstract type is declared in a private part, then it must
4406 -- override an abstract subprogram declared in the visible part.
4407 -- Also checks that if a primitive function with a controlling
4408 -- result is declared in a private part, then it must override
4409 -- a function declared in the visible part.
4411 ------------------------------
4412 -- Check_Private_Overriding --
4413 ------------------------------
4415 procedure Check_Private_Overriding (T : Entity_Id) is
4417 if Ekind (Current_Scope) = E_Package
4418 and then In_Private_Part (Current_Scope)
4419 and then Visible_Part_Type (T)
4420 and then not In_Instance
4423 and then Is_Abstract (S)
4424 and then (not Overriding or else not Is_Abstract (E))
4426 Error_Msg_N ("abstract subprograms must be visible "
4427 & "('R'M 3.9.3(10))!", S);
4429 elsif Ekind (S) = E_Function
4430 and then Is_Tagged_Type (T)
4431 and then T = Base_Type (Etype (S))
4432 and then not Overriding
4435 ("private function with tagged result must"
4436 & " override visible-part function", S);
4438 ("\move subprogram to the visible part"
4439 & " ('R'M 3.9.3(10))", S);
4442 end Check_Private_Overriding;
4444 -----------------------
4445 -- Visible_Part_Type --
4446 -----------------------
4448 function Visible_Part_Type (T : Entity_Id) return Boolean is
4449 P : constant Node_Id := Unit_Declaration_Node (Scope (T));
4453 -- If the entity is a private type, then it must be
4454 -- declared in a visible part.
4456 if Ekind (T) in Private_Kind then
4460 -- Otherwise, we traverse the visible part looking for its
4461 -- corresponding declaration. We cannot use the declaration
4462 -- node directly because in the private part the entity of a
4463 -- private type is the one in the full view, which does not
4464 -- indicate that it is the completion of something visible.
4466 N := First (Visible_Declarations (Specification (P)));
4467 while Present (N) loop
4468 if Nkind (N) = N_Full_Type_Declaration
4469 and then Present (Defining_Identifier (N))
4470 and then T = Defining_Identifier (N)
4474 elsif (Nkind (N) = N_Private_Type_Declaration
4476 Nkind (N) = N_Private_Extension_Declaration)
4477 and then Present (Defining_Identifier (N))
4478 and then T = Full_View (Defining_Identifier (N))
4487 end Visible_Part_Type;
4489 -- Start of processing for Maybe_Primitive_Operation
4492 if not Comes_From_Source (S) then
4495 -- If the subprogram is at library level, it is not a
4496 -- primitive operation.
4498 elsif Current_Scope = Standard_Standard then
4501 elsif (Ekind (Current_Scope) = E_Package
4502 and then not In_Package_Body (Current_Scope))
4505 -- For function, check return type
4507 if Ekind (S) = E_Function then
4508 B_Typ := Base_Type (Etype (S));
4510 if Scope (B_Typ) = Current_Scope then
4511 Set_Has_Primitive_Operations (B_Typ);
4512 Check_Private_Overriding (B_Typ);
4516 -- For all subprograms, check formals
4518 Formal := First_Formal (S);
4519 while Present (Formal) loop
4520 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
4521 F_Typ := Designated_Type (Etype (Formal));
4523 F_Typ := Etype (Formal);
4526 B_Typ := Base_Type (F_Typ);
4528 if Scope (B_Typ) = Current_Scope then
4529 Set_Has_Primitive_Operations (B_Typ);
4530 Check_Private_Overriding (B_Typ);
4533 Next_Formal (Formal);
4536 end Maybe_Primitive_Operation;
4538 -- Start of processing for New_Overloaded_Entity
4541 -- We need to look for an entity that S may override. This must be a
4542 -- homonym in the current scope, so we look for the first homonym of
4543 -- S in the current scope as the starting point for the search.
4545 E := Current_Entity_In_Scope (S);
4547 -- If there is no homonym then this is definitely not overriding
4550 Enter_Overloaded_Entity (S);
4551 Check_Dispatching_Operation (S, Empty);
4552 Maybe_Primitive_Operation;
4554 -- If there is a homonym that is not overloadable, then we have an
4555 -- error, except for the special cases checked explicitly below.
4557 elsif not Is_Overloadable (E) then
4559 -- Check for spurious conflict produced by a subprogram that has the
4560 -- same name as that of the enclosing generic package. The conflict
4561 -- occurs within an instance, between the subprogram and the renaming
4562 -- declaration for the package. After the subprogram, the package
4563 -- renaming declaration becomes hidden.
4565 if Ekind (E) = E_Package
4566 and then Present (Renamed_Object (E))
4567 and then Renamed_Object (E) = Current_Scope
4568 and then Nkind (Parent (Renamed_Object (E))) =
4569 N_Package_Specification
4570 and then Present (Generic_Parent (Parent (Renamed_Object (E))))
4573 Set_Is_Immediately_Visible (E, False);
4574 Enter_Overloaded_Entity (S);
4575 Set_Homonym (S, Homonym (E));
4576 Check_Dispatching_Operation (S, Empty);
4578 -- If the subprogram is implicit it is hidden by the previous
4579 -- declaration. However if it is dispatching, it must appear in
4580 -- the dispatch table anyway, because it can be dispatched to
4581 -- even if it cannot be called directly.
4583 elsif Present (Alias (S))
4584 and then not Comes_From_Source (S)
4586 Set_Scope (S, Current_Scope);
4588 if Is_Dispatching_Operation (Alias (S)) then
4589 Check_Dispatching_Operation (S, Empty);
4595 Error_Msg_Sloc := Sloc (E);
4596 Error_Msg_N ("& conflicts with declaration#", S);
4598 -- Useful additional warning
4600 if Is_Generic_Unit (E) then
4601 Error_Msg_N ("\previous generic unit cannot be overloaded", S);
4607 -- E exists and is overloadable
4610 -- Loop through E and its homonyms to determine if any of them
4611 -- is the candidate for overriding by S.
4613 while Present (E) loop
4615 -- Definitely not interesting if not in the current scope
4617 if Scope (E) /= Current_Scope then
4620 -- Check if we have type conformance
4622 elsif Type_Conformant (E, S) then
4624 -- If the old and new entities have the same profile and
4625 -- one is not the body of the other, then this is an error,
4626 -- unless one of them is implicitly declared.
4628 -- There are some cases when both can be implicit, for example
4629 -- when both a literal and a function that overrides it are
4630 -- inherited in a derivation, or when an inhertited operation
4631 -- of a tagged full type overrides the ineherited operation of
4632 -- a private extension. Ada 83 had a special rule for the
4633 -- the literal case. In Ada95, the later implicit operation
4634 -- hides the former, and the literal is always the former.
4635 -- In the odd case where both are derived operations declared
4636 -- at the same point, both operations should be declared,
4637 -- and in that case we bypass the following test and proceed
4638 -- to the next part (this can only occur for certain obscure
4639 -- cases involving homographs in instances and can't occur for
4640 -- dispatching operations ???). Note that the following
4641 -- condition is less than clear. For example, it's not at
4642 -- all clear why there's a test for E_Entry here. ???
4644 if Present (Alias (S))
4645 and then (No (Alias (E))
4646 or else Comes_From_Source (E)
4647 or else Is_Dispatching_Operation (E))
4649 (Ekind (E) = E_Entry
4650 or else Ekind (E) /= E_Enumeration_Literal)
4652 -- When an derived operation is overloaded it may be due
4653 -- to the fact that the full view of a private extension
4654 -- re-inherits. It has to be dealt with.
4656 if Is_Package (Current_Scope)
4657 and then In_Private_Part (Current_Scope)
4659 Check_Operation_From_Private_View (S, E);
4662 -- In any case the implicit operation remains hidden by
4663 -- the existing declaration, which is overriding.
4665 Set_Is_Overriding_Operation (E);
4668 -- Within an instance, the renaming declarations for
4669 -- actual subprograms may become ambiguous, but they do
4670 -- not hide each other.
4672 elsif Ekind (E) /= E_Entry
4673 and then not Comes_From_Source (E)
4674 and then not Is_Generic_Instance (E)
4675 and then (Present (Alias (E))
4676 or else Is_Intrinsic_Subprogram (E))
4677 and then (not In_Instance
4678 or else No (Parent (E))
4679 or else Nkind (Unit_Declaration_Node (E)) /=
4680 N_Subprogram_Renaming_Declaration)
4682 -- A subprogram child unit is not allowed to override
4683 -- an inherited subprogram (10.1.1(20)).
4685 if Is_Child_Unit (S) then
4687 ("child unit overrides inherited subprogram in parent",
4692 if Is_Non_Overriding_Operation (E, S) then
4693 Enter_Overloaded_Entity (S);
4694 if not Present (Derived_Type)
4695 or else Is_Tagged_Type (Derived_Type)
4697 Check_Dispatching_Operation (S, Empty);
4703 -- E is a derived operation or an internal operator which
4704 -- is being overridden. Remove E from further visibility.
4705 -- Furthermore, if E is a dispatching operation, it must be
4706 -- replaced in the list of primitive operations of its type
4707 -- (see Override_Dispatching_Operation).
4713 Prev := First_Entity (Current_Scope);
4715 while Present (Prev)
4716 and then Next_Entity (Prev) /= E
4721 -- It is possible for E to be in the current scope and
4722 -- yet not in the entity chain. This can only occur in a
4723 -- generic context where E is an implicit concatenation
4724 -- in the formal part, because in a generic body the
4725 -- entity chain starts with the formals.
4728 (Present (Prev) or else Chars (E) = Name_Op_Concat);
4730 -- E must be removed both from the entity_list of the
4731 -- current scope, and from the visibility chain
4733 if Debug_Flag_E then
4734 Write_Str ("Override implicit operation ");
4735 Write_Int (Int (E));
4739 -- If E is a predefined concatenation, it stands for four
4740 -- different operations. As a result, a single explicit
4741 -- declaration does not hide it. In a possible ambiguous
4742 -- situation, Disambiguate chooses the user-defined op,
4743 -- so it is correct to retain the previous internal one.
4745 if Chars (E) /= Name_Op_Concat
4746 or else Ekind (E) /= E_Operator
4748 -- For nondispatching derived operations that are
4749 -- overridden by a subprogram declared in the private
4750 -- part of a package, we retain the derived subprogram
4751 -- but mark it as not immediately visible. If the
4752 -- derived operation was declared in the visible part
4753 -- then this ensures that it will still be visible
4754 -- outside the package with the proper signature
4755 -- (calls from outside must also be directed to this
4756 -- version rather than the overriding one, unlike the
4757 -- dispatching case). Calls from inside the package
4758 -- will still resolve to the overriding subprogram
4759 -- since the derived one is marked as not visible
4760 -- within the package.
4762 -- If the private operation is dispatching, we achieve
4763 -- the overriding by keeping the implicit operation
4764 -- but setting its alias to be the overring one. In
4765 -- this fashion the proper body is executed in all
4766 -- cases, but the original signature is used outside
4769 -- If the overriding is not in the private part, we
4770 -- remove the implicit operation altogether.
4772 if Is_Private_Declaration (S) then
4774 if not Is_Dispatching_Operation (E) then
4775 Set_Is_Immediately_Visible (E, False);
4778 -- work done in Override_Dispatching_Operation.
4784 -- Find predecessor of E in Homonym chain
4786 if E = Current_Entity (E) then
4789 Prev_Vis := Current_Entity (E);
4790 while Homonym (Prev_Vis) /= E loop
4791 Prev_Vis := Homonym (Prev_Vis);
4795 if Prev_Vis /= Empty then
4797 -- Skip E in the visibility chain
4799 Set_Homonym (Prev_Vis, Homonym (E));
4802 Set_Name_Entity_Id (Chars (E), Homonym (E));
4805 Set_Next_Entity (Prev, Next_Entity (E));
4807 if No (Next_Entity (Prev)) then
4808 Set_Last_Entity (Current_Scope, Prev);
4814 Enter_Overloaded_Entity (S);
4815 Set_Is_Overriding_Operation (S);
4817 if Is_Dispatching_Operation (E) then
4819 -- An overriding dispatching subprogram inherits
4820 -- the convention of the overridden subprogram
4823 Set_Convention (S, Convention (E));
4825 Check_Dispatching_Operation (S, E);
4827 Check_Dispatching_Operation (S, Empty);
4830 Maybe_Primitive_Operation (Overriding => True);
4831 goto Check_Inequality;
4834 -- Apparent redeclarations in instances can occur when two
4835 -- formal types get the same actual type. The subprograms in
4836 -- in the instance are legal, even if not callable from the
4837 -- outside. Calls from within are disambiguated elsewhere.
4838 -- For dispatching operations in the visible part, the usual
4839 -- rules apply, and operations with the same profile are not
4842 elsif (In_Instance_Visible_Part
4843 and then not Is_Dispatching_Operation (E))
4844 or else In_Instance_Not_Visible
4848 -- Here we have a real error (identical profile)
4851 Error_Msg_Sloc := Sloc (E);
4853 -- Avoid cascaded errors if the entity appears in
4854 -- subsequent calls.
4856 Set_Scope (S, Current_Scope);
4858 Error_Msg_N ("& conflicts with declaration#", S);
4860 if Is_Generic_Instance (S)
4861 and then not Has_Completion (E)
4864 ("\instantiation cannot provide body for it", S);
4878 -- On exit, we know that S is a new entity
4880 Enter_Overloaded_Entity (S);
4881 Maybe_Primitive_Operation;
4883 -- If S is a derived operation for an untagged type then
4884 -- by definition it's not a dispatching operation (even
4885 -- if the parent operation was dispatching), so we don't
4886 -- call Check_Dispatching_Operation in that case.
4888 if not Present (Derived_Type)
4889 or else Is_Tagged_Type (Derived_Type)
4891 Check_Dispatching_Operation (S, Empty);
4895 -- If this is a user-defined equality operator that is not
4896 -- a derived subprogram, create the corresponding inequality.
4897 -- If the operation is dispatching, the expansion is done
4898 -- elsewhere, and we do not create an explicit inequality
4901 <<Check_Inequality>>
4902 if Chars (S) = Name_Op_Eq
4903 and then Etype (S) = Standard_Boolean
4904 and then Present (Parent (S))
4905 and then not Is_Dispatching_Operation (S)
4907 Make_Inequality_Operator (S);
4909 end New_Overloaded_Entity;
4911 ---------------------
4912 -- Process_Formals --
4913 ---------------------
4915 procedure Process_Formals
4917 Related_Nod : Node_Id)
4919 Param_Spec : Node_Id;
4921 Formal_Type : Entity_Id;
4925 function Is_Class_Wide_Default (D : Node_Id) return Boolean;
4926 -- Check whether the default has a class-wide type. After analysis
4927 -- the default has the type of the formal, so we must also check
4928 -- explicitly for an access attribute.
4930 ---------------------------
4931 -- Is_Class_Wide_Default --
4932 ---------------------------
4934 function Is_Class_Wide_Default (D : Node_Id) return Boolean is
4936 return Is_Class_Wide_Type (Designated_Type (Etype (D)))
4937 or else (Nkind (D) = N_Attribute_Reference
4938 and then Attribute_Name (D) = Name_Access
4939 and then Is_Class_Wide_Type (Etype (Prefix (D))));
4940 end Is_Class_Wide_Default;
4942 -- Start of processing for Process_Formals
4945 -- In order to prevent premature use of the formals in the same formal
4946 -- part, the Ekind is left undefined until all default expressions are
4947 -- analyzed. The Ekind is established in a separate loop at the end.
4949 Param_Spec := First (T);
4951 while Present (Param_Spec) loop
4953 Formal := Defining_Identifier (Param_Spec);
4954 Enter_Name (Formal);
4956 -- Case of ordinary parameters
4958 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
4959 Find_Type (Parameter_Type (Param_Spec));
4960 Ptype := Parameter_Type (Param_Spec);
4962 if Ptype = Error then
4966 Formal_Type := Entity (Ptype);
4968 if Ekind (Formal_Type) = E_Incomplete_Type
4969 or else (Is_Class_Wide_Type (Formal_Type)
4970 and then Ekind (Root_Type (Formal_Type)) =
4973 -- Ada 2005 (AI-50217): Incomplete tagged types that are made
4974 -- visible by a limited with_clause are valid formal types.
4976 if From_With_Type (Formal_Type)
4977 and then Is_Tagged_Type (Formal_Type)
4981 elsif Nkind (Parent (T)) /= N_Access_Function_Definition
4982 and then Nkind (Parent (T)) /= N_Access_Procedure_Definition
4984 Error_Msg_N ("invalid use of incomplete type", Param_Spec);
4987 elsif Ekind (Formal_Type) = E_Void then
4988 Error_Msg_NE ("premature use of&",
4989 Parameter_Type (Param_Spec), Formal_Type);
4992 -- Ada 2005 (AI-231): Create and decorate an internal subtype
4993 -- declaration corresponding to the null-excluding type of the
4994 -- formal in the enclosing scope. In addition, replace the
4995 -- parameter type of the formal to this internal subtype.
4997 if Null_Exclusion_Present (Param_Spec) then
4999 Loc : constant Source_Ptr := Sloc (Param_Spec);
5001 Anon : constant Entity_Id :=
5002 Make_Defining_Identifier (Loc,
5003 Chars => New_Internal_Name ('S'));
5005 Curr_Scope : constant Scope_Stack_Entry :=
5006 Scope_Stack.Table (Scope_Stack.Last);
5008 Ptype : constant Node_Id := Parameter_Type (Param_Spec);
5010 P : Node_Id := Parent (Parent (Related_Nod));
5013 Set_Is_Internal (Anon);
5016 Make_Subtype_Declaration (Loc,
5017 Defining_Identifier => Anon,
5018 Null_Exclusion_Present => True,
5019 Subtype_Indication =>
5020 New_Occurrence_Of (Etype (Ptype), Loc));
5022 -- Propagate the null-excluding attribute to the new entity
5024 if Null_Exclusion_Present (Param_Spec) then
5025 Set_Null_Exclusion_Present (Param_Spec, False);
5026 Set_Can_Never_Be_Null (Anon);
5029 Mark_Rewrite_Insertion (Decl);
5031 -- Insert the new declaration in the nearest enclosing scope
5033 while not Has_Declarations (P) loop
5037 Prepend (Decl, Declarations (P));
5039 Rewrite (Ptype, New_Occurrence_Of (Anon, Loc));
5040 Mark_Rewrite_Insertion (Ptype);
5042 -- Analyze the new declaration in the context of the
5045 Scope_Stack.Decrement_Last;
5047 Scope_Stack.Append (Curr_Scope);
5049 Formal_Type := Anon;
5053 -- Ada 2005 (AI-231): Static checks
5055 if Null_Exclusion_Present (Param_Spec)
5056 or else Can_Never_Be_Null (Entity (Ptype))
5058 Null_Exclusion_Static_Checks (Param_Spec);
5061 -- An access formal type
5065 Access_Definition (Related_Nod, Parameter_Type (Param_Spec));
5067 -- Ada 2005 (AI-254)
5070 AD : constant Node_Id :=
5071 Access_To_Subprogram_Definition
5072 (Parameter_Type (Param_Spec));
5074 if Present (AD) and then Protected_Present (AD) then
5076 Replace_Anonymous_Access_To_Protected_Subprogram
5077 (Param_Spec, Formal_Type);
5082 Set_Etype (Formal, Formal_Type);
5083 Default := Expression (Param_Spec);
5085 if Present (Default) then
5086 if Out_Present (Param_Spec) then
5088 ("default initialization only allowed for IN parameters",
5092 -- Do the special preanalysis of the expression (see section on
5093 -- "Handling of Default Expressions" in the spec of package Sem).
5095 Analyze_Per_Use_Expression (Default, Formal_Type);
5097 -- Check that the designated type of an access parameter's
5098 -- default is not a class-wide type unless the parameter's
5099 -- designated type is also class-wide.
5101 if Ekind (Formal_Type) = E_Anonymous_Access_Type
5102 and then Is_Class_Wide_Default (Default)
5103 and then not Is_Class_Wide_Type (Designated_Type (Formal_Type))
5106 ("access to class-wide expression not allowed here", Default);
5114 -- Now set the kind (mode) of each formal
5116 Param_Spec := First (T);
5118 while Present (Param_Spec) loop
5119 Formal := Defining_Identifier (Param_Spec);
5120 Set_Formal_Mode (Formal);
5122 if Ekind (Formal) = E_In_Parameter then
5123 Set_Default_Value (Formal, Expression (Param_Spec));
5125 if Present (Expression (Param_Spec)) then
5126 Default := Expression (Param_Spec);
5128 if Is_Scalar_Type (Etype (Default)) then
5130 (Parameter_Type (Param_Spec)) /= N_Access_Definition
5132 Formal_Type := Entity (Parameter_Type (Param_Spec));
5135 Formal_Type := Access_Definition
5136 (Related_Nod, Parameter_Type (Param_Spec));
5139 Apply_Scalar_Range_Check (Default, Formal_Type);
5147 end Process_Formals;
5149 ----------------------------
5150 -- Reference_Body_Formals --
5151 ----------------------------
5153 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is
5158 if Error_Posted (Spec) then
5162 Fs := First_Formal (Spec);
5163 Fb := First_Formal (Bod);
5165 while Present (Fs) loop
5166 Generate_Reference (Fs, Fb, 'b');
5169 Style.Check_Identifier (Fb, Fs);
5172 Set_Spec_Entity (Fb, Fs);
5173 Set_Referenced (Fs, False);
5177 end Reference_Body_Formals;
5179 -------------------------
5180 -- Set_Actual_Subtypes --
5181 -------------------------
5183 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is
5184 Loc : constant Source_Ptr := Sloc (N);
5188 First_Stmt : Node_Id := Empty;
5189 AS_Needed : Boolean;
5192 -- If this is an emtpy initialization procedure, no need to create
5193 -- actual subtypes (small optimization).
5195 if Ekind (Subp) = E_Procedure
5196 and then Is_Null_Init_Proc (Subp)
5201 Formal := First_Formal (Subp);
5202 while Present (Formal) loop
5203 T := Etype (Formal);
5205 -- We never need an actual subtype for a constrained formal.
5207 if Is_Constrained (T) then
5210 -- If we have unknown discriminants, then we do not need an
5211 -- actual subtype, or more accurately we cannot figure it out!
5212 -- Note that all class-wide types have unknown discriminants.
5214 elsif Has_Unknown_Discriminants (T) then
5217 -- At this stage we have an unconstrained type that may need
5218 -- an actual subtype. For sure the actual subtype is needed
5219 -- if we have an unconstrained array type.
5221 elsif Is_Array_Type (T) then
5224 -- The only other case which needs an actual subtype is an
5225 -- unconstrained record type which is an IN parameter (we
5226 -- cannot generate actual subtypes for the OUT or IN OUT case,
5227 -- since an assignment can change the discriminant values.
5228 -- However we exclude the case of initialization procedures,
5229 -- since discriminants are handled very specially in this context,
5230 -- see the section entitled "Handling of Discriminants" in Einfo.
5231 -- We also exclude the case of Discrim_SO_Functions (functions
5232 -- used in front end layout mode for size/offset values), since
5233 -- in such functions only discriminants are referenced, and not
5234 -- only are such subtypes not needed, but they cannot always
5235 -- be generated, because of order of elaboration issues.
5237 elsif Is_Record_Type (T)
5238 and then Ekind (Formal) = E_In_Parameter
5239 and then Chars (Formal) /= Name_uInit
5240 and then not Is_Unchecked_Union (T)
5241 and then not Is_Discrim_SO_Function (Subp)
5245 -- All other cases do not need an actual subtype
5251 -- Generate actual subtypes for unconstrained arrays and
5252 -- unconstrained discriminated records.
5255 if Nkind (N) = N_Accept_Statement then
5257 -- If expansion is active, The formal is replaced by a local
5258 -- variable that renames the corresponding entry of the
5259 -- parameter block, and it is this local variable that may
5260 -- require an actual subtype.
5262 if Expander_Active then
5263 Decl := Build_Actual_Subtype (T, Renamed_Object (Formal));
5265 Decl := Build_Actual_Subtype (T, Formal);
5268 if Present (Handled_Statement_Sequence (N)) then
5270 First (Statements (Handled_Statement_Sequence (N)));
5271 Prepend (Decl, Statements (Handled_Statement_Sequence (N)));
5272 Mark_Rewrite_Insertion (Decl);
5274 -- If the accept statement has no body, there will be
5275 -- no reference to the actuals, so no need to compute
5282 Decl := Build_Actual_Subtype (T, Formal);
5283 Prepend (Decl, Declarations (N));
5284 Mark_Rewrite_Insertion (Decl);
5287 -- The declaration uses the bounds of an existing object,
5288 -- and therefore needs no constraint checks.
5290 Analyze (Decl, Suppress => All_Checks);
5292 -- We need to freeze manually the generated type when it is
5293 -- inserted anywhere else than in a declarative part.
5295 if Present (First_Stmt) then
5296 Insert_List_Before_And_Analyze (First_Stmt,
5297 Freeze_Entity (Defining_Identifier (Decl), Loc));
5300 if Nkind (N) = N_Accept_Statement
5301 and then Expander_Active
5303 Set_Actual_Subtype (Renamed_Object (Formal),
5304 Defining_Identifier (Decl));
5306 Set_Actual_Subtype (Formal, Defining_Identifier (Decl));
5310 Next_Formal (Formal);
5312 end Set_Actual_Subtypes;
5314 ---------------------
5315 -- Set_Formal_Mode --
5316 ---------------------
5318 procedure Set_Formal_Mode (Formal_Id : Entity_Id) is
5319 Spec : constant Node_Id := Parent (Formal_Id);
5322 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
5323 -- since we ensure that corresponding actuals are always valid at the
5324 -- point of the call.
5326 if Out_Present (Spec) then
5327 if Ekind (Scope (Formal_Id)) = E_Function
5328 or else Ekind (Scope (Formal_Id)) = E_Generic_Function
5330 Error_Msg_N ("functions can only have IN parameters", Spec);
5331 Set_Ekind (Formal_Id, E_In_Parameter);
5333 elsif In_Present (Spec) then
5334 Set_Ekind (Formal_Id, E_In_Out_Parameter);
5337 Set_Ekind (Formal_Id, E_Out_Parameter);
5338 Set_Never_Set_In_Source (Formal_Id, True);
5339 Set_Is_True_Constant (Formal_Id, False);
5340 Set_Current_Value (Formal_Id, Empty);
5344 Set_Ekind (Formal_Id, E_In_Parameter);
5347 -- Set Is_Known_Non_Null for access parameters since the language
5348 -- guarantees that access parameters are always non-null. We also
5349 -- set Can_Never_Be_Null, since there is no way to change the value.
5351 if Nkind (Parameter_Type (Spec)) = N_Access_Definition then
5353 -- Ada 2005 (AI-231): This behaviour has been modified in Ada 2005.
5354 -- It is only forced if the null_exclusion appears.
5356 if Ada_Version < Ada_05
5357 or else Null_Exclusion_Present (Spec)
5359 Set_Is_Known_Non_Null (Formal_Id);
5360 Set_Can_Never_Be_Null (Formal_Id);
5364 Set_Mechanism (Formal_Id, Default_Mechanism);
5365 Set_Formal_Validity (Formal_Id);
5366 end Set_Formal_Mode;
5368 -------------------------
5369 -- Set_Formal_Validity --
5370 -------------------------
5372 procedure Set_Formal_Validity (Formal_Id : Entity_Id) is
5374 -- If no validity checking, then we cannot assume anything about
5375 -- the validity of parameters, since we do not know there is any
5376 -- checking of the validity on the call side.
5378 if not Validity_Checks_On then
5381 -- If validity checking for parameters is enabled, this means we are
5382 -- not supposed to make any assumptions about argument values.
5384 elsif Validity_Check_Parameters then
5387 -- If we are checking in parameters, we will assume that the caller is
5388 -- also checking parameters, so we can assume the parameter is valid.
5390 elsif Ekind (Formal_Id) = E_In_Parameter
5391 and then Validity_Check_In_Params
5393 Set_Is_Known_Valid (Formal_Id, True);
5395 -- Similar treatment for IN OUT parameters
5397 elsif Ekind (Formal_Id) = E_In_Out_Parameter
5398 and then Validity_Check_In_Out_Params
5400 Set_Is_Known_Valid (Formal_Id, True);
5402 end Set_Formal_Validity;
5404 ------------------------
5405 -- Subtype_Conformant --
5406 ------------------------
5408 function Subtype_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
5412 Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result);
5414 end Subtype_Conformant;
5416 ---------------------
5417 -- Type_Conformant --
5418 ---------------------
5420 function Type_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
5423 Check_Conformance (New_Id, Old_Id, Type_Conformant, False, Result);
5425 end Type_Conformant;
5427 -------------------------------
5428 -- Valid_Operator_Definition --
5429 -------------------------------
5431 procedure Valid_Operator_Definition (Designator : Entity_Id) is
5434 Id : constant Name_Id := Chars (Designator);
5438 F := First_Formal (Designator);
5440 while Present (F) loop
5443 if Present (Default_Value (F)) then
5445 ("default values not allowed for operator parameters",
5452 -- Verify that user-defined operators have proper number of arguments
5453 -- First case of operators which can only be unary
5456 or else Id = Name_Op_Abs
5460 -- Case of operators which can be unary or binary
5462 elsif Id = Name_Op_Add
5463 or Id = Name_Op_Subtract
5465 N_OK := (N in 1 .. 2);
5467 -- All other operators can only be binary
5475 ("incorrect number of arguments for operator", Designator);
5479 and then Base_Type (Etype (Designator)) = Standard_Boolean
5480 and then not Is_Intrinsic_Subprogram (Designator)
5483 ("explicit definition of inequality not allowed", Designator);
5485 end Valid_Operator_Definition;