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_Ch12; use Sem_Ch12;
52 with Sem_Disp; use Sem_Disp;
53 with Sem_Dist; use Sem_Dist;
54 with Sem_Elim; use Sem_Elim;
55 with Sem_Eval; use Sem_Eval;
56 with Sem_Mech; use Sem_Mech;
57 with Sem_Prag; use Sem_Prag;
58 with Sem_Res; use Sem_Res;
59 with Sem_Util; use Sem_Util;
60 with Sem_Type; use Sem_Type;
61 with Sem_Warn; use Sem_Warn;
62 with Sinput; use Sinput;
63 with Stand; use Stand;
64 with Sinfo; use Sinfo;
65 with Sinfo.CN; use Sinfo.CN;
66 with Snames; use Snames;
67 with Stringt; use Stringt;
69 with Stylesw; use Stylesw;
70 with Tbuild; use Tbuild;
71 with Uintp; use Uintp;
72 with Urealp; use Urealp;
73 with Validsw; use Validsw;
75 package body Sem_Ch6 is
77 -----------------------
78 -- Local Subprograms --
79 -----------------------
81 procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id);
82 -- Analyze a generic subprogram body. N is the body to be analyzed,
83 -- and Gen_Id is the defining entity Id for the corresponding spec.
85 procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id);
86 -- If a subprogram has pragma Inline and inlining is active, use generic
87 -- machinery to build an unexpanded body for the subprogram. This body is
88 -- subsequenty used for inline expansions at call sites. If subprogram can
89 -- be inlined (depending on size and nature of local declarations) this
90 -- function returns true. Otherwise subprogram body is treated normally.
91 -- If proper warnings are enabled and the subprogram contains a construct
92 -- that cannot be inlined, the offending construct is flagged accordingly.
94 type Conformance_Type is
95 (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant);
96 -- Conformance type used for following call, meaning matches the
97 -- RM definitions of the corresponding terms.
99 procedure Check_Conformance
102 Ctype : Conformance_Type;
104 Conforms : out Boolean;
105 Err_Loc : Node_Id := Empty;
106 Get_Inst : Boolean := False);
107 -- Given two entities, this procedure checks that the profiles associated
108 -- with these entities meet the conformance criterion given by the third
109 -- parameter. If they conform, Conforms is set True and control returns
110 -- to the caller. If they do not conform, Conforms is set to False, and
111 -- in addition, if Errmsg is True on the call, proper messages are output
112 -- to complain about the conformance failure. If Err_Loc is non_Empty
113 -- the error messages are placed on Err_Loc, if Err_Loc is empty, then
114 -- error messages are placed on the appropriate part of the construct
115 -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
116 -- against a formal access-to-subprogram type so Get_Instance_Of must
119 procedure Check_Overriding_Operation
122 -- Check that a subprogram with a pragma Overriding or Optional_Overriding
123 -- is legal. This check is performed here rather than in Sem_Prag because
124 -- the pragma must follow immediately the declaration, and can be treated
125 -- as part of the declaration itself, as described in AI-218.
127 procedure Check_Subprogram_Order (N : Node_Id);
128 -- N is the N_Subprogram_Body node for a subprogram. This routine applies
129 -- the alpha ordering rule for N if this ordering requirement applicable.
131 function Is_Non_Overriding_Operation
133 New_E : Entity_Id) return Boolean;
134 -- Enforce the rule given in 12.3(18): a private operation in an instance
135 -- overrides an inherited operation only if the corresponding operation
136 -- was overriding in the generic. This can happen for primitive operations
137 -- of types derived (in the generic unit) from formal private or formal
140 procedure Check_Returns
144 -- Called to check for missing return statements in a function body,
145 -- or for returns present in a procedure body which has No_Return set.
146 -- L is the handled statement sequence for the subprogram body. This
147 -- procedure checks all flow paths to make sure they either have a
148 -- return (Mode = 'F') or do not have a return (Mode = 'P'). The flag
149 -- Err is set if there are any control paths not explicitly terminated
150 -- by a return in the function case, and is True otherwise.
152 function Conforming_Types
155 Ctype : Conformance_Type;
156 Get_Inst : Boolean := False) return Boolean;
157 -- Check that two formal parameter types conform, checking both
158 -- for equality of base types, and where required statically
159 -- matching subtypes, depending on the setting of Ctype.
161 procedure Enter_Overloaded_Entity (S : Entity_Id);
162 -- This procedure makes S, a new overloaded entity, into the first
163 -- visible entity with that name.
165 procedure Install_Entity (E : Entity_Id);
166 -- Make single entity visible. Used for generic formals as well.
168 procedure Install_Formals (Id : Entity_Id);
169 -- On entry to a subprogram body, make the formals visible. Note
170 -- that simply placing the subprogram on the scope stack is not
171 -- sufficient: the formals must become the current entities for
174 procedure Make_Inequality_Operator (S : Entity_Id);
175 -- Create the declaration for an inequality operator that is implicitly
176 -- created by a user-defined equality operator that yields a boolean.
178 procedure May_Need_Actuals (Fun : Entity_Id);
179 -- Flag functions that can be called without parameters, i.e. those that
180 -- have no parameters, or those for which defaults exist for all parameters
182 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id);
183 -- If there is a separate spec for a subprogram or generic subprogram,
184 -- the formals of the body are treated as references to the corresponding
185 -- formals of the spec. This reference does not count as an actual use of
186 -- the formal, in order to diagnose formals that are unused in the body.
188 procedure Set_Formal_Validity (Formal_Id : Entity_Id);
189 -- Formal_Id is an formal parameter entity. This procedure deals with
190 -- setting the proper validity status for this entity, which depends
191 -- on the kind of parameter and the validity checking mode.
193 ---------------------------------------------
194 -- Analyze_Abstract_Subprogram_Declaration --
195 ---------------------------------------------
197 procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is
198 Designator : constant Entity_Id :=
199 Analyze_Subprogram_Specification (Specification (N));
200 Scop : constant Entity_Id := Current_Scope;
203 Generate_Definition (Designator);
204 Set_Is_Abstract (Designator);
205 New_Overloaded_Entity (Designator);
206 Check_Delayed_Subprogram (Designator);
208 Set_Categorization_From_Scope (Designator, Scop);
210 if Ekind (Scope (Designator)) = E_Protected_Type then
212 ("abstract subprogram not allowed in protected type", N);
215 Generate_Reference_To_Formals (Designator);
216 end Analyze_Abstract_Subprogram_Declaration;
218 ----------------------------
219 -- Analyze_Function_Call --
220 ----------------------------
222 procedure Analyze_Function_Call (N : Node_Id) is
223 P : constant Node_Id := Name (N);
224 L : constant List_Id := Parameter_Associations (N);
230 -- If error analyzing name, then set Any_Type as result type and return
232 if Etype (P) = Any_Type then
233 Set_Etype (N, Any_Type);
237 -- Otherwise analyze the parameters
242 while Present (Actual) loop
244 Check_Parameterless_Call (Actual);
250 end Analyze_Function_Call;
252 -------------------------------------
253 -- Analyze_Generic_Subprogram_Body --
254 -------------------------------------
256 procedure Analyze_Generic_Subprogram_Body
260 Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id);
261 Kind : constant Entity_Kind := Ekind (Gen_Id);
267 -- Copy body and disable expansion while analyzing the generic
268 -- For a stub, do not copy the stub (which would load the proper body),
269 -- this will be done when the proper body is analyzed.
271 if Nkind (N) /= N_Subprogram_Body_Stub then
272 New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
277 Spec := Specification (N);
279 -- Within the body of the generic, the subprogram is callable, and
280 -- behaves like the corresponding non-generic unit.
282 Body_Id := Defining_Entity (Spec);
284 if Kind = E_Generic_Procedure
285 and then Nkind (Spec) /= N_Procedure_Specification
287 Error_Msg_N ("invalid body for generic procedure ", Body_Id);
290 elsif Kind = E_Generic_Function
291 and then Nkind (Spec) /= N_Function_Specification
293 Error_Msg_N ("invalid body for generic function ", Body_Id);
297 Set_Corresponding_Body (Gen_Decl, Body_Id);
299 if Has_Completion (Gen_Id)
300 and then Nkind (Parent (N)) /= N_Subunit
302 Error_Msg_N ("duplicate generic body", N);
305 Set_Has_Completion (Gen_Id);
308 if Nkind (N) = N_Subprogram_Body_Stub then
309 Set_Ekind (Defining_Entity (Specification (N)), Kind);
311 Set_Corresponding_Spec (N, Gen_Id);
314 if Nkind (Parent (N)) = N_Compilation_Unit then
315 Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N));
318 -- Make generic parameters immediately visible in the body. They are
319 -- needed to process the formals declarations. Then make the formals
320 -- visible in a separate step.
326 First_Ent : Entity_Id;
329 First_Ent := First_Entity (Gen_Id);
332 while Present (E) and then not Is_Formal (E) loop
337 Set_Use (Generic_Formal_Declarations (Gen_Decl));
339 -- Now generic formals are visible, and the specification can be
340 -- analyzed, for subsequent conformance check.
342 Body_Id := Analyze_Subprogram_Specification (Spec);
344 -- Make formal parameters visible
348 -- E is the first formal parameter, we loop through the formals
349 -- installing them so that they will be visible.
351 Set_First_Entity (Gen_Id, E);
352 while Present (E) loop
358 -- Visible generic entity is callable within its own body.
360 Set_Ekind (Gen_Id, Ekind (Body_Id));
361 Set_Ekind (Body_Id, E_Subprogram_Body);
362 Set_Convention (Body_Id, Convention (Gen_Id));
363 Set_Scope (Body_Id, Scope (Gen_Id));
364 Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id);
366 if Nkind (N) = N_Subprogram_Body_Stub then
368 -- No body to analyze, so restore state of generic unit.
370 Set_Ekind (Gen_Id, Kind);
371 Set_Ekind (Body_Id, Kind);
373 if Present (First_Ent) then
374 Set_First_Entity (Gen_Id, First_Ent);
381 -- If this is a compilation unit, it must be made visible
382 -- explicitly, because the compilation of the declaration,
383 -- unlike other library unit declarations, does not. If it
384 -- is not a unit, the following is redundant but harmless.
386 Set_Is_Immediately_Visible (Gen_Id);
387 Reference_Body_Formals (Gen_Id, Body_Id);
389 Set_Actual_Subtypes (N, Current_Scope);
390 Analyze_Declarations (Declarations (N));
392 Analyze (Handled_Statement_Sequence (N));
394 Save_Global_References (Original_Node (N));
396 -- Prior to exiting the scope, include generic formals again
397 -- (if any are present) in the set of local entities.
399 if Present (First_Ent) then
400 Set_First_Entity (Gen_Id, First_Ent);
403 Check_References (Gen_Id);
406 Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope);
408 Check_Subprogram_Order (N);
410 -- Outside of its body, unit is generic again.
412 Set_Ekind (Gen_Id, Kind);
413 Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False);
414 Style.Check_Identifier (Body_Id, Gen_Id);
416 end Analyze_Generic_Subprogram_Body;
418 -----------------------------
419 -- Analyze_Operator_Symbol --
420 -----------------------------
422 -- An operator symbol such as "+" or "and" may appear in context where
423 -- the literal denotes an entity name, such as "+"(x, y) or in a
424 -- context when it is just a string, as in (conjunction = "or"). In
425 -- these cases the parser generates this node, and the semantics does
426 -- the disambiguation. Other such case are actuals in an instantiation,
427 -- the generic unit in an instantiation, and pragma arguments.
429 procedure Analyze_Operator_Symbol (N : Node_Id) is
430 Par : constant Node_Id := Parent (N);
433 if (Nkind (Par) = N_Function_Call and then N = Name (Par))
434 or else Nkind (Par) = N_Function_Instantiation
435 or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par))
436 or else (Nkind (Par) = N_Pragma_Argument_Association
437 and then not Is_Pragma_String_Literal (Par))
438 or else Nkind (Par) = N_Subprogram_Renaming_Declaration
439 or else (Nkind (Par) = N_Attribute_Reference
440 and then Attribute_Name (Par) /= Name_Value)
442 Find_Direct_Name (N);
445 Change_Operator_Symbol_To_String_Literal (N);
448 end Analyze_Operator_Symbol;
450 -----------------------------------
451 -- Analyze_Parameter_Association --
452 -----------------------------------
454 procedure Analyze_Parameter_Association (N : Node_Id) is
456 Analyze (Explicit_Actual_Parameter (N));
457 end Analyze_Parameter_Association;
459 ----------------------------
460 -- Analyze_Procedure_Call --
461 ----------------------------
463 procedure Analyze_Procedure_Call (N : Node_Id) is
464 Loc : constant Source_Ptr := Sloc (N);
465 P : constant Node_Id := Name (N);
466 Actuals : constant List_Id := Parameter_Associations (N);
470 procedure Analyze_Call_And_Resolve;
471 -- Do Analyze and Resolve calls for procedure call
473 ------------------------------
474 -- Analyze_Call_And_Resolve --
475 ------------------------------
477 procedure Analyze_Call_And_Resolve is
479 if Nkind (N) = N_Procedure_Call_Statement then
481 Resolve (N, Standard_Void_Type);
485 end Analyze_Call_And_Resolve;
487 -- Start of processing for Analyze_Procedure_Call
490 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
491 -- a procedure call or an entry call. The prefix may denote an access
492 -- to subprogram type, in which case an implicit dereference applies.
493 -- If the prefix is an indexed component (without implicit defererence)
494 -- then the construct denotes a call to a member of an entire family.
495 -- If the prefix is a simple name, it may still denote a call to a
496 -- parameterless member of an entry family. Resolution of these various
497 -- interpretations is delicate.
501 -- If error analyzing prefix, then set Any_Type as result and return
503 if Etype (P) = Any_Type then
504 Set_Etype (N, Any_Type);
508 -- Otherwise analyze the parameters
510 if Present (Actuals) then
511 Actual := First (Actuals);
513 while Present (Actual) loop
515 Check_Parameterless_Call (Actual);
520 -- Special processing for Elab_Spec and Elab_Body calls
522 if Nkind (P) = N_Attribute_Reference
523 and then (Attribute_Name (P) = Name_Elab_Spec
524 or else Attribute_Name (P) = Name_Elab_Body)
526 if Present (Actuals) then
528 ("no parameters allowed for this call", First (Actuals));
532 Set_Etype (N, Standard_Void_Type);
535 elsif Is_Entity_Name (P)
536 and then Is_Record_Type (Etype (Entity (P)))
537 and then Remote_AST_I_Dereference (P)
541 elsif Is_Entity_Name (P)
542 and then Ekind (Entity (P)) /= E_Entry_Family
544 if Is_Access_Type (Etype (P))
545 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
546 and then No (Actuals)
547 and then Comes_From_Source (N)
549 Error_Msg_N ("missing explicit dereference in call", N);
552 Analyze_Call_And_Resolve;
554 -- If the prefix is the simple name of an entry family, this is
555 -- a parameterless call from within the task body itself.
557 elsif Is_Entity_Name (P)
558 and then Nkind (P) = N_Identifier
559 and then Ekind (Entity (P)) = E_Entry_Family
560 and then Present (Actuals)
561 and then No (Next (First (Actuals)))
563 -- Can be call to parameterless entry family. What appears to be
564 -- the sole argument is in fact the entry index. Rewrite prefix
565 -- of node accordingly. Source representation is unchanged by this
569 Make_Indexed_Component (Loc,
571 Make_Selected_Component (Loc,
572 Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc),
573 Selector_Name => New_Occurrence_Of (Entity (P), Loc)),
574 Expressions => Actuals);
576 Set_Etype (New_N, Standard_Void_Type);
577 Set_Parameter_Associations (N, No_List);
578 Analyze_Call_And_Resolve;
580 elsif Nkind (P) = N_Explicit_Dereference then
581 if Ekind (Etype (P)) = E_Subprogram_Type then
582 Analyze_Call_And_Resolve;
584 Error_Msg_N ("expect access to procedure in call", P);
587 -- The name can be a selected component or an indexed component
588 -- that yields an access to subprogram. Such a prefix is legal if
589 -- the call has parameter associations.
591 elsif Is_Access_Type (Etype (P))
592 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
594 if Present (Actuals) then
595 Analyze_Call_And_Resolve;
597 Error_Msg_N ("missing explicit dereference in call ", N);
600 -- If not an access to subprogram, then the prefix must resolve to
601 -- the name of an entry, entry family, or protected operation.
603 -- For the case of a simple entry call, P is a selected component
604 -- where the prefix is the task and the selector name is the entry.
605 -- A call to a protected procedure will have the same syntax. If
606 -- the protected object contains overloaded operations, the entity
607 -- may appear as a function, the context will select the operation
608 -- whose type is Void.
610 elsif Nkind (P) = N_Selected_Component
611 and then (Ekind (Entity (Selector_Name (P))) = E_Entry
613 Ekind (Entity (Selector_Name (P))) = E_Procedure
615 Ekind (Entity (Selector_Name (P))) = E_Function)
617 Analyze_Call_And_Resolve;
619 elsif Nkind (P) = N_Selected_Component
620 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family
621 and then Present (Actuals)
622 and then No (Next (First (Actuals)))
624 -- Can be call to parameterless entry family. What appears to be
625 -- the sole argument is in fact the entry index. Rewrite prefix
626 -- of node accordingly. Source representation is unchanged by this
630 Make_Indexed_Component (Loc,
631 Prefix => New_Copy (P),
632 Expressions => Actuals);
634 Set_Etype (New_N, Standard_Void_Type);
635 Set_Parameter_Associations (N, No_List);
636 Analyze_Call_And_Resolve;
638 -- For the case of a reference to an element of an entry family, P is
639 -- an indexed component whose prefix is a selected component (task and
640 -- entry family), and whose index is the entry family index.
642 elsif Nkind (P) = N_Indexed_Component
643 and then Nkind (Prefix (P)) = N_Selected_Component
644 and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family
646 Analyze_Call_And_Resolve;
648 -- If the prefix is the name of an entry family, it is a call from
649 -- within the task body itself.
651 elsif Nkind (P) = N_Indexed_Component
652 and then Nkind (Prefix (P)) = N_Identifier
653 and then Ekind (Entity (Prefix (P))) = E_Entry_Family
656 Make_Selected_Component (Loc,
657 Prefix => New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc),
658 Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc));
659 Rewrite (Prefix (P), New_N);
661 Analyze_Call_And_Resolve;
663 -- Anything else is an error.
666 Error_Msg_N ("Invalid procedure or entry call", N);
668 end Analyze_Procedure_Call;
670 ------------------------------
671 -- Analyze_Return_Statement --
672 ------------------------------
674 procedure Analyze_Return_Statement (N : Node_Id) is
675 Loc : constant Source_Ptr := Sloc (N);
677 Scope_Id : Entity_Id;
682 -- Find subprogram or accept statement enclosing the return statement
685 for J in reverse 0 .. Scope_Stack.Last loop
686 Scope_Id := Scope_Stack.Table (J).Entity;
687 exit when Ekind (Scope_Id) /= E_Block and then
688 Ekind (Scope_Id) /= E_Loop;
691 pragma Assert (Present (Scope_Id));
693 Kind := Ekind (Scope_Id);
694 Expr := Expression (N);
696 if Kind /= E_Function
697 and then Kind /= E_Generic_Function
698 and then Kind /= E_Procedure
699 and then Kind /= E_Generic_Procedure
700 and then Kind /= E_Entry
701 and then Kind /= E_Entry_Family
703 Error_Msg_N ("illegal context for return statement", N);
705 elsif Present (Expr) then
706 if Kind = E_Function or else Kind = E_Generic_Function then
707 Set_Return_Present (Scope_Id);
708 R_Type := Etype (Scope_Id);
709 Set_Return_Type (N, R_Type);
710 Analyze_And_Resolve (Expr, R_Type);
712 if (Is_Class_Wide_Type (Etype (Expr))
713 or else Is_Dynamically_Tagged (Expr))
714 and then not Is_Class_Wide_Type (R_Type)
717 ("dynamically tagged expression not allowed!", Expr);
720 Apply_Constraint_Check (Expr, R_Type);
722 -- ??? A real run-time accessibility check is needed
723 -- in cases involving dereferences of access parameters.
724 -- For now we just check the static cases.
726 if Is_Return_By_Reference_Type (Etype (Scope_Id))
727 and then Object_Access_Level (Expr)
728 > Subprogram_Access_Level (Scope_Id)
731 Make_Raise_Program_Error (Loc,
732 Reason => PE_Accessibility_Check_Failed));
736 ("cannot return a local value by reference?", N);
738 ("& will be raised at run time?!",
739 N, Standard_Program_Error);
742 elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then
743 Error_Msg_N ("procedure cannot return value (use function)", N);
746 Error_Msg_N ("accept statement cannot return value", N);
749 -- No expression present
752 if Kind = E_Function or Kind = E_Generic_Function then
753 Error_Msg_N ("missing expression in return from function", N);
756 if (Ekind (Scope_Id) = E_Procedure
757 or else Ekind (Scope_Id) = E_Generic_Procedure)
758 and then No_Return (Scope_Id)
761 ("RETURN statement not allowed (No_Return)", N);
765 Check_Unreachable_Code (N);
766 end Analyze_Return_Statement;
768 -----------------------------
769 -- Analyze_Subprogram_Body --
770 -----------------------------
772 -- This procedure is called for regular subprogram bodies, generic bodies,
773 -- and for subprogram stubs of both kinds. In the case of stubs, only the
774 -- specification matters, and is used to create a proper declaration for
775 -- the subprogram, or to perform conformance checks.
777 procedure Analyze_Subprogram_Body (N : Node_Id) is
778 Loc : constant Source_Ptr := Sloc (N);
779 Body_Spec : constant Node_Id := Specification (N);
780 Body_Id : Entity_Id := Defining_Entity (Body_Spec);
781 Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id);
782 Body_Deleted : constant Boolean := False;
786 Spec_Decl : Node_Id := Empty;
787 Last_Formal : Entity_Id := Empty;
788 Conformant : Boolean;
789 Missing_Ret : Boolean;
794 Write_Str ("==== Compiling subprogram body ");
795 Write_Name (Chars (Body_Id));
796 Write_Str (" from ");
797 Write_Location (Loc);
801 Trace_Scope (N, Body_Id, " Analyze subprogram");
803 -- Generic subprograms are handled separately. They always have
804 -- a generic specification. Determine whether current scope has
805 -- a previous declaration.
807 -- If the subprogram body is defined within an instance of the
808 -- same name, the instance appears as a package renaming, and
809 -- will be hidden within the subprogram.
812 and then not Is_Overloadable (Prev_Id)
813 and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration
814 or else Comes_From_Source (Prev_Id))
816 if Is_Generic_Subprogram (Prev_Id) then
818 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
819 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
821 Analyze_Generic_Subprogram_Body (N, Spec_Id);
825 -- Previous entity conflicts with subprogram name.
826 -- Attempting to enter name will post error.
828 Enter_Name (Body_Id);
832 -- Non-generic case, find the subprogram declaration, if one was
833 -- seen, or enter new overloaded entity in the current scope.
834 -- If the current_entity is the body_id itself, the unit is being
835 -- analyzed as part of the context of one of its subunits. No need
836 -- to redo the analysis.
838 elsif Prev_Id = Body_Id
839 and then Has_Completion (Body_Id)
844 Body_Id := Analyze_Subprogram_Specification (Body_Spec);
846 if Nkind (N) = N_Subprogram_Body_Stub
847 or else No (Corresponding_Spec (N))
849 Spec_Id := Find_Corresponding_Spec (N);
851 -- If this is a duplicate body, no point in analyzing it
853 if Error_Posted (N) then
857 -- A subprogram body should cause freezing of its own
858 -- declaration, but if there was no previous explicit
859 -- declaration, then the subprogram will get frozen too
860 -- late (there may be code within the body that depends
861 -- on the subprogram having been frozen, such as uses of
862 -- extra formals), so we force it to be frozen here.
863 -- Same holds if the body and the spec are compilation units.
866 Freeze_Before (N, Body_Id);
868 elsif Nkind (Parent (N)) = N_Compilation_Unit then
869 Freeze_Before (N, Spec_Id);
872 Spec_Id := Corresponding_Spec (N);
876 -- Do not inline any subprogram that contains nested subprograms,
877 -- since the backend inlining circuit seems to generate uninitialized
878 -- references in this case. We know this happens in the case of front
879 -- end ZCX support, but it also appears it can happen in other cases
880 -- as well. The backend often rejects attempts to inline in the case
881 -- of nested procedures anyway, so little if anything is lost by this.
883 -- Do not do this test if errors have been detected, because in some
884 -- error cases, this code blows up, and we don't need it anyway if
885 -- there have been errors, since we won't get to the linker anyway.
887 if Serious_Errors_Detected = 0 then
890 P_Ent := Scope (P_Ent);
891 exit when No (P_Ent) or else P_Ent = Standard_Standard;
893 if Is_Subprogram (P_Ent) then
894 Set_Is_Inlined (P_Ent, False);
896 if Comes_From_Source (P_Ent)
897 and then Has_Pragma_Inline (P_Ent)
900 ("cannot inline& (nested subprogram)?",
907 -- Case of fully private operation in the body of the protected type.
908 -- We must create a declaration for the subprogram, in order to attach
909 -- the protected subprogram that will be used in internal calls.
912 and then Comes_From_Source (N)
913 and then Is_Protected_Type (Current_Scope)
922 Formal := First_Formal (Body_Id);
924 -- The protected operation always has at least one formal,
925 -- namely the object itself, but it is only placed in the
926 -- parameter list if expansion is enabled.
929 or else Expander_Active
937 while Present (Formal) loop
939 (Make_Parameter_Specification (Loc,
940 Defining_Identifier =>
941 Make_Defining_Identifier (Sloc (Formal),
942 Chars => Chars (Formal)),
943 In_Present => In_Present (Parent (Formal)),
944 Out_Present => Out_Present (Parent (Formal)),
946 New_Reference_To (Etype (Formal), Loc),
948 New_Copy_Tree (Expression (Parent (Formal)))),
951 Next_Formal (Formal);
954 if Nkind (Body_Spec) = N_Procedure_Specification then
956 Make_Procedure_Specification (Loc,
957 Defining_Unit_Name =>
958 Make_Defining_Identifier (Sloc (Body_Id),
959 Chars => Chars (Body_Id)),
960 Parameter_Specifications => Plist);
963 Make_Function_Specification (Loc,
964 Defining_Unit_Name =>
965 Make_Defining_Identifier (Sloc (Body_Id),
966 Chars => Chars (Body_Id)),
967 Parameter_Specifications => Plist,
968 Subtype_Mark => New_Occurrence_Of (Etype (Body_Id), Loc));
972 Make_Subprogram_Declaration (Loc,
973 Specification => New_Spec);
974 Insert_Before (N, Decl);
975 Spec_Id := Defining_Unit_Name (New_Spec);
977 -- Indicate that the entity comes from source, to ensure that
978 -- cross-reference information is properly generated.
979 -- The body itself is rewritten during expansion, and the
980 -- body entity will not appear in calls to the operation.
982 Set_Comes_From_Source (Spec_Id, True);
984 Set_Has_Completion (Spec_Id);
985 Set_Convention (Spec_Id, Convention_Protected);
988 elsif Present (Spec_Id) then
989 Spec_Decl := Unit_Declaration_Node (Spec_Id);
992 -- Place subprogram on scope stack, and make formals visible. If there
993 -- is a spec, the visible entity remains that of the spec.
995 if Present (Spec_Id) then
996 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
998 Style.Check_Identifier (Body_Id, Spec_Id);
1001 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
1002 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
1004 if Is_Abstract (Spec_Id) then
1005 Error_Msg_N ("an abstract subprogram cannot have a body", N);
1008 Set_Convention (Body_Id, Convention (Spec_Id));
1009 Set_Has_Completion (Spec_Id);
1011 if Is_Protected_Type (Scope (Spec_Id)) then
1012 Set_Privals_Chain (Spec_Id, New_Elmt_List);
1015 -- If this is a body generated for a renaming, do not check for
1016 -- full conformance. The check is redundant, because the spec of
1017 -- the body is a copy of the spec in the renaming declaration,
1018 -- and the test can lead to spurious errors on nested defaults.
1020 if Present (Spec_Decl)
1021 and then not Comes_From_Source (N)
1023 (Nkind (Original_Node (Spec_Decl)) =
1024 N_Subprogram_Renaming_Declaration
1025 or else (Present (Corresponding_Body (Spec_Decl))
1027 Nkind (Unit_Declaration_Node
1028 (Corresponding_Body (Spec_Decl))) =
1029 N_Subprogram_Renaming_Declaration))
1035 Fully_Conformant, True, Conformant, Body_Id);
1038 -- If the body is not fully conformant, we have to decide if we
1039 -- should analyze it or not. If it has a really messed up profile
1040 -- then we probably should not analyze it, since we will get too
1041 -- many bogus messages.
1043 -- Our decision is to go ahead in the non-fully conformant case
1044 -- only if it is at least mode conformant with the spec. Note
1045 -- that the call to Check_Fully_Conformant has issued the proper
1046 -- error messages to complain about the lack of conformance.
1049 and then not Mode_Conformant (Body_Id, Spec_Id)
1055 if Spec_Id /= Body_Id then
1056 Reference_Body_Formals (Spec_Id, Body_Id);
1059 if Nkind (N) /= N_Subprogram_Body_Stub then
1060 Set_Corresponding_Spec (N, Spec_Id);
1061 Install_Formals (Spec_Id);
1062 Last_Formal := Last_Entity (Spec_Id);
1063 New_Scope (Spec_Id);
1065 -- Make sure that the subprogram is immediately visible. For
1066 -- child units that have no separate spec this is indispensable.
1067 -- Otherwise it is safe albeit redundant.
1069 Set_Is_Immediately_Visible (Spec_Id);
1072 Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id);
1073 Set_Ekind (Body_Id, E_Subprogram_Body);
1074 Set_Scope (Body_Id, Scope (Spec_Id));
1076 -- Case of subprogram body with no previous spec
1080 and then Comes_From_Source (Body_Id)
1081 and then not Suppress_Style_Checks (Body_Id)
1082 and then not In_Instance
1084 Style.Body_With_No_Spec (N);
1087 New_Overloaded_Entity (Body_Id);
1089 if Nkind (N) /= N_Subprogram_Body_Stub then
1090 Set_Acts_As_Spec (N);
1091 Generate_Definition (Body_Id);
1093 (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True);
1094 Generate_Reference_To_Formals (Body_Id);
1095 Install_Formals (Body_Id);
1096 New_Scope (Body_Id);
1100 -- If this is the proper body of a stub, we must verify that the stub
1101 -- conforms to the body, and to the previous spec if one was present.
1102 -- we know already that the body conforms to that spec. This test is
1103 -- only required for subprograms that come from source.
1105 if Nkind (Parent (N)) = N_Subunit
1106 and then Comes_From_Source (N)
1107 and then not Error_Posted (Body_Id)
1110 Old_Id : constant Entity_Id :=
1112 (Specification (Corresponding_Stub (Parent (N))));
1114 Conformant : Boolean := False;
1117 if No (Spec_Id) then
1118 Check_Fully_Conformant (Body_Id, Old_Id);
1122 (Body_Id, Old_Id, Fully_Conformant, False, Conformant);
1124 if not Conformant then
1126 -- The stub was taken to be a new declaration. Indicate
1127 -- that it lacks a body.
1129 Set_Has_Completion (Old_Id, False);
1135 Set_Has_Completion (Body_Id);
1136 Check_Eliminated (Body_Id);
1138 if Nkind (N) = N_Subprogram_Body_Stub then
1141 elsif Present (Spec_Id)
1142 and then Expander_Active
1143 and then (Is_Always_Inlined (Spec_Id)
1144 or else (Has_Pragma_Inline (Spec_Id)
1147 or else Configurable_Run_Time_Mode)))
1149 Build_Body_To_Inline (N, Spec_Id);
1152 -- Now we can go on to analyze the body
1154 HSS := Handled_Statement_Sequence (N);
1155 Set_Actual_Subtypes (N, Current_Scope);
1156 Analyze_Declarations (Declarations (N));
1159 Process_End_Label (HSS, 't', Current_Scope);
1161 Check_Subprogram_Order (N);
1163 -- If we have a separate spec, then the analysis of the declarations
1164 -- caused the entities in the body to be chained to the spec id, but
1165 -- we want them chained to the body id. Only the formal parameters
1166 -- end up chained to the spec id in this case.
1168 if Present (Spec_Id) then
1170 -- If a parent unit is categorized, the context of a subunit
1171 -- must conform to the categorization. Conversely, if a child
1172 -- unit is categorized, the parents themselves must conform.
1174 if Nkind (Parent (N)) = N_Subunit then
1175 Validate_Categorization_Dependency (N, Spec_Id);
1177 elsif Is_Child_Unit (Spec_Id) then
1178 Validate_Categorization_Dependency
1179 (Unit_Declaration_Node (Spec_Id), Spec_Id);
1182 if Present (Last_Formal) then
1184 (Last_Entity (Body_Id), Next_Entity (Last_Formal));
1185 Set_Next_Entity (Last_Formal, Empty);
1186 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
1187 Set_Last_Entity (Spec_Id, Last_Formal);
1190 Set_First_Entity (Body_Id, First_Entity (Spec_Id));
1191 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
1192 Set_First_Entity (Spec_Id, Empty);
1193 Set_Last_Entity (Spec_Id, Empty);
1197 -- If function, check return statements
1199 if Nkind (Body_Spec) = N_Function_Specification then
1204 if Present (Spec_Id) then
1210 if Return_Present (Id) then
1211 Check_Returns (HSS, 'F', Missing_Ret);
1214 Set_Has_Missing_Return (Id);
1217 elsif not Is_Machine_Code_Subprogram (Id)
1218 and then not Body_Deleted
1220 Error_Msg_N ("missing RETURN statement in function body", N);
1224 -- If procedure with No_Return, check returns
1226 elsif Nkind (Body_Spec) = N_Procedure_Specification
1227 and then Present (Spec_Id)
1228 and then No_Return (Spec_Id)
1230 Check_Returns (HSS, 'P', Missing_Ret);
1233 -- Now we are going to check for variables that are never modified
1234 -- in the body of the procedure. We omit these checks if the first
1235 -- statement of the procedure raises an exception. In particular
1236 -- this deals with the common idiom of a stubbed function, which
1237 -- might appear as something like
1239 -- function F (A : Integer) return Some_Type;
1242 -- raise Program_Error;
1246 -- Here the purpose of X is simply to satisfy the (annoying)
1247 -- requirement in Ada that there be at least one return, and
1248 -- we certainly do not want to go posting warnings on X that
1249 -- it is not initialized!
1252 Stm : Node_Id := First (Statements (HSS));
1255 -- Skip an initial label (for one thing this occurs when we
1256 -- are in front end ZCX mode, but in any case it is irrelevant).
1258 if Nkind (Stm) = N_Label then
1262 -- Do the test on the original statement before expansion
1265 Ostm : constant Node_Id := Original_Node (Stm);
1268 -- If explicit raise statement, return with no checks
1270 if Nkind (Ostm) = N_Raise_Statement then
1273 -- Check for explicit call cases which likely raise an exception
1275 elsif Nkind (Ostm) = N_Procedure_Call_Statement then
1276 if Is_Entity_Name (Name (Ostm)) then
1278 Ent : constant Entity_Id := Entity (Name (Ostm));
1281 -- If the procedure is marked No_Return, then likely it
1282 -- raises an exception, but in any case it is not coming
1283 -- back here, so no need to check beyond the call.
1285 if Ekind (Ent) = E_Procedure
1286 and then No_Return (Ent)
1290 -- If the procedure name is Raise_Exception, then also
1291 -- assume that it raises an exception. The main target
1292 -- here is Ada.Exceptions.Raise_Exception, but this name
1293 -- is pretty evocative in any context! Note that the
1294 -- procedure in Ada.Exceptions is not marked No_Return
1295 -- because of the annoying case of the null exception Id.
1297 elsif Chars (Ent) = Name_Raise_Exception then
1306 -- Check for variables that are never modified
1312 -- If there is a separate spec, then transfer Never_Set_In_Source
1313 -- flags from out parameters to the corresponding entities in the
1314 -- body. The reason we do that is we want to post error flags on
1315 -- the body entities, not the spec entities.
1317 if Present (Spec_Id) then
1318 E1 := First_Entity (Spec_Id);
1320 while Present (E1) loop
1321 if Ekind (E1) = E_Out_Parameter then
1322 E2 := First_Entity (Body_Id);
1323 while Present (E2) loop
1324 exit when Chars (E1) = Chars (E2);
1328 if Present (E2) then
1329 Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1));
1337 -- Check references in body unless it was deleted. Note that the
1338 -- check of Body_Deleted here is not just for efficiency, it is
1339 -- necessary to avoid junk warnings on formal parameters.
1341 if not Body_Deleted then
1342 Check_References (Body_Id);
1345 end Analyze_Subprogram_Body;
1347 ------------------------------------
1348 -- Analyze_Subprogram_Declaration --
1349 ------------------------------------
1351 procedure Analyze_Subprogram_Declaration (N : Node_Id) is
1352 Designator : constant Entity_Id :=
1353 Analyze_Subprogram_Specification (Specification (N));
1354 Scop : constant Entity_Id := Current_Scope;
1356 -- Start of processing for Analyze_Subprogram_Declaration
1359 Generate_Definition (Designator);
1361 -- Check for RCI unit subprogram declarations against in-lined
1362 -- subprograms and subprograms having access parameter or limited
1363 -- parameter without Read and Write (RM E.2.3(12-13)).
1365 Validate_RCI_Subprogram_Declaration (N);
1369 Defining_Entity (N),
1370 " Analyze subprogram spec. ");
1372 if Debug_Flag_C then
1373 Write_Str ("==== Compiling subprogram spec ");
1374 Write_Name (Chars (Designator));
1375 Write_Str (" from ");
1376 Write_Location (Sloc (N));
1380 New_Overloaded_Entity (Designator);
1381 Check_Delayed_Subprogram (Designator);
1383 -- What is the following code for, it used to be
1385 -- ??? Set_Suppress_Elaboration_Checks
1386 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator));
1388 -- The following seems equivalent, but a bit dubious
1390 if Elaboration_Checks_Suppressed (Designator) then
1391 Set_Kill_Elaboration_Checks (Designator);
1394 if Scop /= Standard_Standard
1395 and then not Is_Child_Unit (Designator)
1397 Set_Categorization_From_Scope (Designator, Scop);
1399 -- For a compilation unit, check for library-unit pragmas.
1401 New_Scope (Designator);
1402 Set_Categorization_From_Pragmas (N);
1403 Validate_Categorization_Dependency (N, Designator);
1407 -- For a compilation unit, set body required. This flag will only be
1408 -- reset if a valid Import or Interface pragma is processed later on.
1410 if Nkind (Parent (N)) = N_Compilation_Unit then
1411 Set_Body_Required (Parent (N), True);
1414 Generate_Reference_To_Formals (Designator);
1415 Check_Eliminated (Designator);
1417 if Comes_From_Source (N)
1418 and then Is_List_Member (N)
1420 Check_Overriding_Operation (N, Designator);
1423 end Analyze_Subprogram_Declaration;
1425 --------------------------------------
1426 -- Analyze_Subprogram_Specification --
1427 --------------------------------------
1429 -- Reminder: N here really is a subprogram specification (not a subprogram
1430 -- declaration). This procedure is called to analyze the specification in
1431 -- both subprogram bodies and subprogram declarations (specs).
1433 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is
1434 Designator : constant Entity_Id := Defining_Entity (N);
1435 Formals : constant List_Id := Parameter_Specifications (N);
1439 Generate_Definition (Designator);
1441 if Nkind (N) = N_Function_Specification then
1442 Set_Ekind (Designator, E_Function);
1443 Set_Mechanism (Designator, Default_Mechanism);
1445 if Subtype_Mark (N) /= Error then
1446 Find_Type (Subtype_Mark (N));
1447 Typ := Entity (Subtype_Mark (N));
1448 Set_Etype (Designator, Typ);
1450 if Ekind (Typ) = E_Incomplete_Type
1451 or else (Is_Class_Wide_Type (Typ)
1453 Ekind (Root_Type (Typ)) = E_Incomplete_Type)
1456 ("invalid use of incomplete type", Subtype_Mark (N));
1460 Set_Etype (Designator, Any_Type);
1464 Set_Ekind (Designator, E_Procedure);
1465 Set_Etype (Designator, Standard_Void_Type);
1468 if Present (Formals) then
1469 Set_Scope (Designator, Current_Scope);
1470 New_Scope (Designator);
1471 Process_Formals (Formals, N);
1475 if Nkind (N) = N_Function_Specification then
1476 if Nkind (Designator) = N_Defining_Operator_Symbol then
1477 Valid_Operator_Definition (Designator);
1480 May_Need_Actuals (Designator);
1482 if Is_Abstract (Etype (Designator))
1483 and then Nkind (Parent (N)) /= N_Abstract_Subprogram_Declaration
1486 ("function that returns abstract type must be abstract", N);
1491 end Analyze_Subprogram_Specification;
1493 --------------------------
1494 -- Build_Body_To_Inline --
1495 --------------------------
1497 procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id) is
1498 Decl : constant Node_Id := Unit_Declaration_Node (Subp);
1499 Original_Body : Node_Id;
1500 Body_To_Analyze : Node_Id;
1501 Max_Size : constant := 10;
1502 Stat_Count : Integer := 0;
1504 function Has_Excluded_Declaration (Decls : List_Id) return Boolean;
1505 -- Check for declarations that make inlining not worthwhile.
1507 function Has_Excluded_Statement (Stats : List_Id) return Boolean;
1508 -- Check for statements that make inlining not worthwhile: any
1509 -- tasking statement, nested at any level. Keep track of total
1510 -- number of elementary statements, as a measure of acceptable size.
1512 function Has_Pending_Instantiation return Boolean;
1513 -- If some enclosing body contains instantiations that appear before
1514 -- the corresponding generic body, the enclosing body has a freeze node
1515 -- so that it can be elaborated after the generic itself. This might
1516 -- conflict with subsequent inlinings, so that it is unsafe to try to
1517 -- inline in such a case.
1519 procedure Remove_Pragmas;
1520 -- A pragma Unreferenced that mentions a formal parameter has no
1521 -- meaning when the body is inlined and the formals are rewritten.
1522 -- Remove it from body to inline. The analysis of the non-inlined
1523 -- body will handle the pragma properly.
1525 ------------------------------
1526 -- Has_Excluded_Declaration --
1527 ------------------------------
1529 function Has_Excluded_Declaration (Decls : List_Id) return Boolean is
1532 function Is_Unchecked_Conversion (D : Node_Id) return Boolean;
1533 -- Nested subprograms make a given body ineligible for inlining,
1534 -- but we make an exception for instantiations of unchecked
1535 -- conversion. The body has not been analyzed yet, so we check
1536 -- the name, and verify that the visible entity with that name is
1537 -- the predefined unit.
1539 function Is_Unchecked_Conversion (D : Node_Id) return Boolean is
1540 Id : constant Node_Id := Name (D);
1544 if Nkind (Id) = N_Identifier
1545 and then Chars (Id) = Name_Unchecked_Conversion
1547 Conv := Current_Entity (Id);
1549 elsif Nkind (Id) = N_Selected_Component
1550 and then Chars (Selector_Name (Id)) = Name_Unchecked_Conversion
1552 Conv := Current_Entity (Selector_Name (Id));
1560 and then Scope (Conv) = Standard_Standard
1561 and then Is_Intrinsic_Subprogram (Conv);
1562 end Is_Unchecked_Conversion;
1564 -- Start of processing for Has_Excluded_Declaration
1569 while Present (D) loop
1570 if (Nkind (D) = N_Function_Instantiation
1571 and then not Is_Unchecked_Conversion (D))
1572 or else Nkind (D) = N_Protected_Type_Declaration
1573 or else Nkind (D) = N_Package_Declaration
1574 or else Nkind (D) = N_Package_Instantiation
1575 or else Nkind (D) = N_Subprogram_Body
1576 or else Nkind (D) = N_Procedure_Instantiation
1577 or else Nkind (D) = N_Task_Type_Declaration
1580 ("cannot inline & (non-allowed declaration)?", D, Subp);
1588 end Has_Excluded_Declaration;
1590 ----------------------------
1591 -- Has_Excluded_Statement --
1592 ----------------------------
1594 function Has_Excluded_Statement (Stats : List_Id) return Boolean is
1601 while Present (S) loop
1602 Stat_Count := Stat_Count + 1;
1604 if Nkind (S) = N_Abort_Statement
1605 or else Nkind (S) = N_Asynchronous_Select
1606 or else Nkind (S) = N_Conditional_Entry_Call
1607 or else Nkind (S) = N_Delay_Relative_Statement
1608 or else Nkind (S) = N_Delay_Until_Statement
1609 or else Nkind (S) = N_Selective_Accept
1610 or else Nkind (S) = N_Timed_Entry_Call
1613 ("cannot inline & (non-allowed statement)?", S, Subp);
1616 elsif Nkind (S) = N_Block_Statement then
1617 if Present (Declarations (S))
1618 and then Has_Excluded_Declaration (Declarations (S))
1622 elsif Present (Handled_Statement_Sequence (S))
1625 (Exception_Handlers (Handled_Statement_Sequence (S)))
1627 Has_Excluded_Statement
1628 (Statements (Handled_Statement_Sequence (S))))
1633 elsif Nkind (S) = N_Case_Statement then
1634 E := First (Alternatives (S));
1636 while Present (E) loop
1637 if Has_Excluded_Statement (Statements (E)) then
1644 elsif Nkind (S) = N_If_Statement then
1645 if Has_Excluded_Statement (Then_Statements (S)) then
1649 if Present (Elsif_Parts (S)) then
1650 E := First (Elsif_Parts (S));
1652 while Present (E) loop
1653 if Has_Excluded_Statement (Then_Statements (E)) then
1660 if Present (Else_Statements (S))
1661 and then Has_Excluded_Statement (Else_Statements (S))
1666 elsif Nkind (S) = N_Loop_Statement
1667 and then Has_Excluded_Statement (Statements (S))
1676 end Has_Excluded_Statement;
1678 -------------------------------
1679 -- Has_Pending_Instantiation --
1680 -------------------------------
1682 function Has_Pending_Instantiation return Boolean is
1683 S : Entity_Id := Current_Scope;
1686 while Present (S) loop
1687 if Is_Compilation_Unit (S)
1688 or else Is_Child_Unit (S)
1691 elsif Ekind (S) = E_Package
1692 and then Has_Forward_Instantiation (S)
1701 end Has_Pending_Instantiation;
1703 --------------------
1704 -- Remove_Pragmas --
1705 --------------------
1707 procedure Remove_Pragmas is
1712 Decl := First (Declarations (Body_To_Analyze));
1713 while Present (Decl) loop
1716 if Nkind (Decl) = N_Pragma
1717 and then Chars (Decl) = Name_Unreferenced
1726 -- Start of processing for Build_Body_To_Inline
1729 if Nkind (Decl) = N_Subprogram_Declaration
1730 and then Present (Body_To_Inline (Decl))
1732 return; -- Done already.
1734 -- Functions that return unconstrained composite types will require
1735 -- secondary stack handling, and cannot currently be inlined.
1736 -- Ditto for functions that return controlled types, where controlled
1737 -- actions interfere in complex ways with inlining.
1739 elsif Ekind (Subp) = E_Function
1740 and then not Is_Scalar_Type (Etype (Subp))
1741 and then not Is_Access_Type (Etype (Subp))
1742 and then not Is_Constrained (Etype (Subp))
1745 ("cannot inline & (unconstrained return type)?", N, Subp);
1748 elsif Ekind (Subp) = E_Function
1749 and then Controlled_Type (Etype (Subp))
1752 ("cannot inline & (controlled return type)?", N, Subp);
1756 if Present (Declarations (N))
1757 and then Has_Excluded_Declaration (Declarations (N))
1762 if Present (Handled_Statement_Sequence (N)) then
1763 if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then
1765 ("cannot inline& (exception handler)?",
1766 First (Exception_Handlers (Handled_Statement_Sequence (N))),
1770 Has_Excluded_Statement
1771 (Statements (Handled_Statement_Sequence (N)))
1777 -- We do not inline a subprogram that is too large, unless it is
1778 -- marked Inline_Always. This pragma does not suppress the other
1779 -- checks on inlining (forbidden declarations, handlers, etc).
1781 if Stat_Count > Max_Size
1782 and then not Is_Always_Inlined (Subp)
1784 Cannot_Inline ("cannot inline& (body too large)?", N, Subp);
1788 if Has_Pending_Instantiation then
1790 ("cannot inline& (forward instance within enclosing body)?",
1795 -- Within an instance, the body to inline must be treated as a nested
1796 -- generic, so that the proper global references are preserved.
1799 Save_Env (Scope (Current_Scope), Scope (Current_Scope));
1800 Original_Body := Copy_Generic_Node (N, Empty, True);
1802 Original_Body := Copy_Separate_Tree (N);
1805 -- We need to capture references to the formals in order to substitute
1806 -- the actuals at the point of inlining, i.e. instantiation. To treat
1807 -- the formals as globals to the body to inline, we nest it within
1808 -- a dummy parameterless subprogram, declared within the real one.
1809 -- To avoid generating an internal name (which is never public, and
1810 -- which affects serial numbers of other generated names), we use
1811 -- an internal symbol that cannot conflict with user declarations.
1813 Set_Parameter_Specifications (Specification (Original_Body), No_List);
1814 Set_Defining_Unit_Name
1815 (Specification (Original_Body),
1816 Make_Defining_Identifier (Sloc (N), Name_uParent));
1817 Set_Corresponding_Spec (Original_Body, Empty);
1819 Body_To_Analyze := Copy_Generic_Node (Original_Body, Empty, False);
1821 -- Set return type of function, which is also global and does not need
1824 if Ekind (Subp) = E_Function then
1825 Set_Subtype_Mark (Specification (Body_To_Analyze),
1826 New_Occurrence_Of (Etype (Subp), Sloc (N)));
1829 if No (Declarations (N)) then
1830 Set_Declarations (N, New_List (Body_To_Analyze));
1832 Append (Body_To_Analyze, Declarations (N));
1835 Expander_Mode_Save_And_Set (False);
1838 Analyze (Body_To_Analyze);
1839 New_Scope (Defining_Entity (Body_To_Analyze));
1840 Save_Global_References (Original_Body);
1842 Remove (Body_To_Analyze);
1844 Expander_Mode_Restore;
1845 Set_Body_To_Inline (Decl, Original_Body);
1846 Set_Ekind (Defining_Entity (Original_Body), Ekind (Subp));
1847 Set_Is_Inlined (Subp);
1852 end Build_Body_To_Inline;
1858 procedure Cannot_Inline (Msg : String; N : Node_Id; Subp : Entity_Id) is
1860 -- Do not emit warning if this is a predefined unit which is not
1861 -- the main unit. With validity checks enabled, some predefined
1862 -- subprograms may contain nested subprograms and become ineligible
1865 if Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Subp)))
1866 and then not In_Extended_Main_Source_Unit (Subp)
1870 elsif Is_Always_Inlined (Subp) then
1871 Error_Msg_NE (Msg (1 .. Msg'Length - 1), N, Subp);
1873 elsif Ineffective_Inline_Warnings then
1874 Error_Msg_NE (Msg, N, Subp);
1878 -----------------------
1879 -- Check_Conformance --
1880 -----------------------
1882 procedure Check_Conformance
1883 (New_Id : Entity_Id;
1885 Ctype : Conformance_Type;
1887 Conforms : out Boolean;
1888 Err_Loc : Node_Id := Empty;
1889 Get_Inst : Boolean := False)
1891 Old_Type : constant Entity_Id := Etype (Old_Id);
1892 New_Type : constant Entity_Id := Etype (New_Id);
1893 Old_Formal : Entity_Id;
1894 New_Formal : Entity_Id;
1896 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id);
1897 -- Post error message for conformance error on given node.
1898 -- Two messages are output. The first points to the previous
1899 -- declaration with a general "no conformance" message.
1900 -- The second is the detailed reason, supplied as Msg. The
1901 -- parameter N provide information for a possible & insertion
1902 -- in the message, and also provides the location for posting
1903 -- the message in the absence of a specified Err_Loc location.
1905 -----------------------
1906 -- Conformance_Error --
1907 -----------------------
1909 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is
1916 if No (Err_Loc) then
1922 Error_Msg_Sloc := Sloc (Old_Id);
1925 when Type_Conformant =>
1927 ("not type conformant with declaration#!", Enode);
1929 when Mode_Conformant =>
1931 ("not mode conformant with declaration#!", Enode);
1933 when Subtype_Conformant =>
1935 ("not subtype conformant with declaration#!", Enode);
1937 when Fully_Conformant =>
1939 ("not fully conformant with declaration#!", Enode);
1942 Error_Msg_NE (Msg, Enode, N);
1944 end Conformance_Error;
1946 -- Start of processing for Check_Conformance
1951 -- We need a special case for operators, since they don't
1952 -- appear explicitly.
1954 if Ctype = Type_Conformant then
1955 if Ekind (New_Id) = E_Operator
1956 and then Operator_Matches_Spec (New_Id, Old_Id)
1962 -- If both are functions/operators, check return types conform
1964 if Old_Type /= Standard_Void_Type
1965 and then New_Type /= Standard_Void_Type
1967 if not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then
1968 Conformance_Error ("return type does not match!", New_Id);
1972 -- If either is a function/operator and the other isn't, error
1974 elsif Old_Type /= Standard_Void_Type
1975 or else New_Type /= Standard_Void_Type
1977 Conformance_Error ("functions can only match functions!", New_Id);
1981 -- In subtype conformant case, conventions must match (RM 6.3.1(16))
1982 -- If this is a renaming as body, refine error message to indicate that
1983 -- the conflict is with the original declaration. If the entity is not
1984 -- frozen, the conventions don't have to match, the one of the renamed
1985 -- entity is inherited.
1987 if Ctype >= Subtype_Conformant then
1988 if Convention (Old_Id) /= Convention (New_Id) then
1990 if not Is_Frozen (New_Id) then
1993 elsif Present (Err_Loc)
1994 and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration
1995 and then Present (Corresponding_Spec (Err_Loc))
1997 Error_Msg_Name_1 := Chars (New_Id);
1999 Name_Ada + Convention_Id'Pos (Convention (New_Id));
2001 Conformance_Error ("prior declaration for% has convention %!");
2004 Conformance_Error ("calling conventions do not match!");
2009 elsif Is_Formal_Subprogram (Old_Id)
2010 or else Is_Formal_Subprogram (New_Id)
2012 Conformance_Error ("formal subprograms not allowed!");
2017 -- Deal with parameters
2019 -- Note: we use the entity information, rather than going directly
2020 -- to the specification in the tree. This is not only simpler, but
2021 -- absolutely necessary for some cases of conformance tests between
2022 -- operators, where the declaration tree simply does not exist!
2024 Old_Formal := First_Formal (Old_Id);
2025 New_Formal := First_Formal (New_Id);
2027 while Present (Old_Formal) and then Present (New_Formal) loop
2028 if Ctype = Fully_Conformant then
2030 -- Names must match. Error message is more accurate if we do
2031 -- this before checking that the types of the formals match.
2033 if Chars (Old_Formal) /= Chars (New_Formal) then
2034 Conformance_Error ("name & does not match!", New_Formal);
2036 -- Set error posted flag on new formal as well to stop
2037 -- junk cascaded messages in some cases.
2039 Set_Error_Posted (New_Formal);
2044 -- Types must always match. In the visible part of an instance,
2045 -- usual overloading rules for dispatching operations apply, and
2046 -- we check base types (not the actual subtypes).
2048 if In_Instance_Visible_Part
2049 and then Is_Dispatching_Operation (New_Id)
2051 if not Conforming_Types
2052 (Base_Type (Etype (Old_Formal)),
2053 Base_Type (Etype (New_Formal)), Ctype, Get_Inst)
2055 Conformance_Error ("type of & does not match!", New_Formal);
2059 elsif not Conforming_Types
2060 (Etype (Old_Formal), Etype (New_Formal), Ctype, Get_Inst)
2062 Conformance_Error ("type of & does not match!", New_Formal);
2066 -- For mode conformance, mode must match
2068 if Ctype >= Mode_Conformant
2069 and then Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal)
2071 Conformance_Error ("mode of & does not match!", New_Formal);
2075 -- Full conformance checks
2077 if Ctype = Fully_Conformant then
2079 -- We have checked already that names match.
2080 -- Check default expressions for in parameters
2082 if Parameter_Mode (Old_Formal) = E_In_Parameter then
2084 NewD : constant Boolean :=
2085 Present (Default_Value (New_Formal));
2086 OldD : constant Boolean :=
2087 Present (Default_Value (Old_Formal));
2089 if NewD or OldD then
2091 -- The old default value has been analyzed because
2092 -- the current full declaration will have frozen
2093 -- everything before. The new default values have not
2094 -- been analyzed, so analyze them now before we check
2099 Analyze_Per_Use_Expression
2100 (Default_Value (New_Formal), Etype (New_Formal));
2104 if not (NewD and OldD)
2105 or else not Fully_Conformant_Expressions
2106 (Default_Value (Old_Formal),
2107 Default_Value (New_Formal))
2110 ("default expression for & does not match!",
2119 -- A couple of special checks for Ada 83 mode. These checks are
2120 -- skipped if either entity is an operator in package Standard.
2121 -- or if either old or new instance is not from the source program.
2124 and then Sloc (Old_Id) > Standard_Location
2125 and then Sloc (New_Id) > Standard_Location
2126 and then Comes_From_Source (Old_Id)
2127 and then Comes_From_Source (New_Id)
2130 Old_Param : constant Node_Id := Declaration_Node (Old_Formal);
2131 New_Param : constant Node_Id := Declaration_Node (New_Formal);
2134 -- Explicit IN must be present or absent in both cases. This
2135 -- test is required only in the full conformance case.
2137 if In_Present (Old_Param) /= In_Present (New_Param)
2138 and then Ctype = Fully_Conformant
2141 ("(Ada 83) IN must appear in both declarations",
2146 -- Grouping (use of comma in param lists) must be the same
2147 -- This is where we catch a misconformance like:
2150 -- A : Integer; B : Integer
2152 -- which are represented identically in the tree except
2153 -- for the setting of the flags More_Ids and Prev_Ids.
2155 if More_Ids (Old_Param) /= More_Ids (New_Param)
2156 or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param)
2159 ("grouping of & does not match!", New_Formal);
2165 Next_Formal (Old_Formal);
2166 Next_Formal (New_Formal);
2169 if Present (Old_Formal) then
2170 Conformance_Error ("too few parameters!");
2173 elsif Present (New_Formal) then
2174 Conformance_Error ("too many parameters!", New_Formal);
2178 end Check_Conformance;
2180 ------------------------------
2181 -- Check_Delayed_Subprogram --
2182 ------------------------------
2184 procedure Check_Delayed_Subprogram (Designator : Entity_Id) is
2187 procedure Possible_Freeze (T : Entity_Id);
2188 -- T is the type of either a formal parameter or of the return type.
2189 -- If T is not yet frozen and needs a delayed freeze, then the
2190 -- subprogram itself must be delayed.
2192 procedure Possible_Freeze (T : Entity_Id) is
2194 if Has_Delayed_Freeze (T)
2195 and then not Is_Frozen (T)
2197 Set_Has_Delayed_Freeze (Designator);
2199 elsif Is_Access_Type (T)
2200 and then Has_Delayed_Freeze (Designated_Type (T))
2201 and then not Is_Frozen (Designated_Type (T))
2203 Set_Has_Delayed_Freeze (Designator);
2205 end Possible_Freeze;
2207 -- Start of processing for Check_Delayed_Subprogram
2210 -- Never need to freeze abstract subprogram
2212 if Is_Abstract (Designator) then
2215 -- Need delayed freeze if return type itself needs a delayed
2216 -- freeze and is not yet frozen.
2218 Possible_Freeze (Etype (Designator));
2219 Possible_Freeze (Base_Type (Etype (Designator))); -- needed ???
2221 -- Need delayed freeze if any of the formal types themselves need
2222 -- a delayed freeze and are not yet frozen.
2224 F := First_Formal (Designator);
2225 while Present (F) loop
2226 Possible_Freeze (Etype (F));
2227 Possible_Freeze (Base_Type (Etype (F))); -- needed ???
2232 -- Mark functions that return by reference. Note that it cannot be
2233 -- done for delayed_freeze subprograms because the underlying
2234 -- returned type may not be known yet (for private types)
2236 if not Has_Delayed_Freeze (Designator)
2237 and then Expander_Active
2240 Typ : constant Entity_Id := Etype (Designator);
2241 Utyp : constant Entity_Id := Underlying_Type (Typ);
2244 if Is_Return_By_Reference_Type (Typ) then
2245 Set_Returns_By_Ref (Designator);
2247 elsif Present (Utyp) and then Controlled_Type (Utyp) then
2248 Set_Returns_By_Ref (Designator);
2252 end Check_Delayed_Subprogram;
2254 ------------------------------------
2255 -- Check_Discriminant_Conformance --
2256 ------------------------------------
2258 procedure Check_Discriminant_Conformance
2263 Old_Discr : Entity_Id := First_Discriminant (Prev);
2264 New_Discr : Node_Id := First (Discriminant_Specifications (N));
2265 New_Discr_Id : Entity_Id;
2266 New_Discr_Type : Entity_Id;
2268 procedure Conformance_Error (Msg : String; N : Node_Id);
2269 -- Post error message for conformance error on given node.
2270 -- Two messages are output. The first points to the previous
2271 -- declaration with a general "no conformance" message.
2272 -- The second is the detailed reason, supplied as Msg. The
2273 -- parameter N provide information for a possible & insertion
2276 -----------------------
2277 -- Conformance_Error --
2278 -----------------------
2280 procedure Conformance_Error (Msg : String; N : Node_Id) is
2282 Error_Msg_Sloc := Sloc (Prev_Loc);
2283 Error_Msg_N ("not fully conformant with declaration#!", N);
2284 Error_Msg_NE (Msg, N, N);
2285 end Conformance_Error;
2287 -- Start of processing for Check_Discriminant_Conformance
2290 while Present (Old_Discr) and then Present (New_Discr) loop
2292 New_Discr_Id := Defining_Identifier (New_Discr);
2294 -- The subtype mark of the discriminant on the full type
2295 -- has not been analyzed so we do it here. For an access
2296 -- discriminant a new type is created.
2298 if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then
2300 Access_Definition (N, Discriminant_Type (New_Discr));
2303 Analyze (Discriminant_Type (New_Discr));
2304 New_Discr_Type := Etype (Discriminant_Type (New_Discr));
2307 if not Conforming_Types
2308 (Etype (Old_Discr), New_Discr_Type, Fully_Conformant)
2310 Conformance_Error ("type of & does not match!", New_Discr_Id);
2313 -- Treat the new discriminant as an occurrence of the old
2314 -- one, for navigation purposes, and fill in some semantic
2315 -- information, for completeness.
2317 Generate_Reference (Old_Discr, New_Discr_Id, 'r');
2318 Set_Etype (New_Discr_Id, Etype (Old_Discr));
2319 Set_Scope (New_Discr_Id, Scope (Old_Discr));
2324 if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then
2325 Conformance_Error ("name & does not match!", New_Discr_Id);
2329 -- Default expressions must match
2332 NewD : constant Boolean :=
2333 Present (Expression (New_Discr));
2334 OldD : constant Boolean :=
2335 Present (Expression (Parent (Old_Discr)));
2338 if NewD or OldD then
2340 -- The old default value has been analyzed and expanded,
2341 -- because the current full declaration will have frozen
2342 -- everything before. The new default values have not
2343 -- been expanded, so expand now to check conformance.
2346 Analyze_Per_Use_Expression
2347 (Expression (New_Discr), New_Discr_Type);
2350 if not (NewD and OldD)
2351 or else not Fully_Conformant_Expressions
2352 (Expression (Parent (Old_Discr)),
2353 Expression (New_Discr))
2357 ("default expression for & does not match!",
2364 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
2368 Old_Disc : constant Node_Id := Declaration_Node (Old_Discr);
2371 -- Grouping (use of comma in param lists) must be the same
2372 -- This is where we catch a misconformance like:
2375 -- A : Integer; B : Integer
2377 -- which are represented identically in the tree except
2378 -- for the setting of the flags More_Ids and Prev_Ids.
2380 if More_Ids (Old_Disc) /= More_Ids (New_Discr)
2381 or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr)
2384 ("grouping of & does not match!", New_Discr_Id);
2390 Next_Discriminant (Old_Discr);
2394 if Present (Old_Discr) then
2395 Conformance_Error ("too few discriminants!", Defining_Identifier (N));
2398 elsif Present (New_Discr) then
2400 ("too many discriminants!", Defining_Identifier (New_Discr));
2403 end Check_Discriminant_Conformance;
2405 ----------------------------
2406 -- Check_Fully_Conformant --
2407 ----------------------------
2409 procedure Check_Fully_Conformant
2410 (New_Id : Entity_Id;
2412 Err_Loc : Node_Id := Empty)
2418 (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc);
2419 end Check_Fully_Conformant;
2421 ---------------------------
2422 -- Check_Mode_Conformant --
2423 ---------------------------
2425 procedure Check_Mode_Conformant
2426 (New_Id : Entity_Id;
2428 Err_Loc : Node_Id := Empty;
2429 Get_Inst : Boolean := False)
2435 (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst);
2436 end Check_Mode_Conformant;
2438 --------------------------------
2439 -- Check_Overriding_Operation --
2440 --------------------------------
2442 procedure Check_Overriding_Operation
2448 Has_Pragma : Boolean := False;
2451 -- See whether there is an overriding pragma immediately following
2452 -- the declaration. Intervening pragmas, such as Inline, are allowed.
2455 while Present (Decl)
2456 and then Nkind (Decl) = N_Pragma
2458 if Chars (Decl) = Name_Overriding
2459 or else Chars (Decl) = Name_Optional_Overriding
2461 -- For now disable the use of these pragmas, until the ARG
2462 -- finalizes the design of this feature.
2464 Error_Msg_N ("?unrecognized pragma", Decl);
2466 if not Is_Overriding_Operation (Subp) then
2468 -- Before emitting an error message, check whether this
2469 -- may override an operation that is not yet visible, as
2470 -- in the case of a derivation of a private operation in
2471 -- a child unit. Such an operation is introduced with a
2472 -- different name, but its alias is the parent operation.
2478 E := First_Entity (Current_Scope);
2480 while Present (E) loop
2481 if Ekind (E) = Ekind (Subp)
2482 and then not Comes_From_Source (E)
2483 and then Present (Alias (E))
2484 and then Chars (Alias (E)) = Chars (Subp)
2485 and then In_Open_Scopes (Scope (Alias (E)))
2495 ("& must override an inherited operation",
2501 -- Verify syntax of pragma
2503 Arg1 := First (Pragma_Argument_Associations (Decl));
2505 if Present (Arg1) then
2506 if not Is_Entity_Name (Expression (Arg1)) then
2507 Error_Msg_N ("pragma applies to local subprogram", Decl);
2509 elsif Chars (Expression (Arg1)) /= Chars (Subp) then
2511 ("pragma must apply to preceding subprogram", Decl);
2513 elsif Present (Next (Arg1)) then
2514 Error_Msg_N ("illegal pragma format", Decl);
2518 Set_Analyzed (Decl);
2527 and then Explicit_Overriding
2528 and then Is_Overriding_Operation (Subp)
2530 Error_Msg_NE ("Missing overriding pragma for&", Subp, Subp);
2532 end Check_Overriding_Operation;
2538 procedure Check_Returns
2545 procedure Check_Statement_Sequence (L : List_Id);
2546 -- Internal recursive procedure to check a list of statements for proper
2547 -- termination by a return statement (or a transfer of control or a
2548 -- compound statement that is itself internally properly terminated).
2550 ------------------------------
2551 -- Check_Statement_Sequence --
2552 ------------------------------
2554 procedure Check_Statement_Sequence (L : List_Id) is
2558 Raise_Exception_Call : Boolean;
2559 -- Set True if statement sequence terminated by Raise_Exception call
2560 -- or a Reraise_Occurrence call.
2563 Raise_Exception_Call := False;
2565 -- Get last real statement
2567 Last_Stm := Last (L);
2569 -- Don't count pragmas
2571 while Nkind (Last_Stm) = N_Pragma
2573 -- Don't count call to SS_Release (can happen after Raise_Exception)
2576 (Nkind (Last_Stm) = N_Procedure_Call_Statement
2578 Nkind (Name (Last_Stm)) = N_Identifier
2580 Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release))
2582 -- Don't count exception junk
2585 ((Nkind (Last_Stm) = N_Goto_Statement
2586 or else Nkind (Last_Stm) = N_Label
2587 or else Nkind (Last_Stm) = N_Object_Declaration)
2588 and then Exception_Junk (Last_Stm))
2593 -- Here we have the "real" last statement
2595 Kind := Nkind (Last_Stm);
2597 -- Transfer of control, OK. Note that in the No_Return procedure
2598 -- case, we already diagnosed any explicit return statements, so
2599 -- we can treat them as OK in this context.
2601 if Is_Transfer (Last_Stm) then
2604 -- Check cases of explicit non-indirect procedure calls
2606 elsif Kind = N_Procedure_Call_Statement
2607 and then Is_Entity_Name (Name (Last_Stm))
2609 -- Check call to Raise_Exception procedure which is treated
2610 -- specially, as is a call to Reraise_Occurrence.
2612 -- We suppress the warning in these cases since it is likely that
2613 -- the programmer really does not expect to deal with the case
2614 -- of Null_Occurrence, and thus would find a warning about a
2615 -- missing return curious, and raising Program_Error does not
2616 -- seem such a bad behavior if this does occur.
2618 if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception)
2620 Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence)
2622 Raise_Exception_Call := True;
2624 -- For Raise_Exception call, test first argument, if it is
2625 -- an attribute reference for a 'Identity call, then we know
2626 -- that the call cannot possibly return.
2629 Arg : constant Node_Id :=
2630 Original_Node (First_Actual (Last_Stm));
2633 if Nkind (Arg) = N_Attribute_Reference
2634 and then Attribute_Name (Arg) = Name_Identity
2641 -- If statement, need to look inside if there is an else and check
2642 -- each constituent statement sequence for proper termination.
2644 elsif Kind = N_If_Statement
2645 and then Present (Else_Statements (Last_Stm))
2647 Check_Statement_Sequence (Then_Statements (Last_Stm));
2648 Check_Statement_Sequence (Else_Statements (Last_Stm));
2650 if Present (Elsif_Parts (Last_Stm)) then
2652 Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm));
2655 while Present (Elsif_Part) loop
2656 Check_Statement_Sequence (Then_Statements (Elsif_Part));
2664 -- Case statement, check each case for proper termination
2666 elsif Kind = N_Case_Statement then
2671 Case_Alt := First_Non_Pragma (Alternatives (Last_Stm));
2672 while Present (Case_Alt) loop
2673 Check_Statement_Sequence (Statements (Case_Alt));
2674 Next_Non_Pragma (Case_Alt);
2680 -- Block statement, check its handled sequence of statements
2682 elsif Kind = N_Block_Statement then
2688 (Handled_Statement_Sequence (Last_Stm), Mode, Err1);
2697 -- Loop statement. If there is an iteration scheme, we can definitely
2698 -- fall out of the loop. Similarly if there is an exit statement, we
2699 -- can fall out. In either case we need a following return.
2701 elsif Kind = N_Loop_Statement then
2702 if Present (Iteration_Scheme (Last_Stm))
2703 or else Has_Exit (Entity (Identifier (Last_Stm)))
2707 -- A loop with no exit statement or iteration scheme if either
2708 -- an inifite loop, or it has some other exit (raise/return).
2709 -- In either case, no warning is required.
2715 -- Timed entry call, check entry call and delay alternatives
2717 -- Note: in expanded code, the timed entry call has been converted
2718 -- to a set of expanded statements on which the check will work
2719 -- correctly in any case.
2721 elsif Kind = N_Timed_Entry_Call then
2723 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
2724 DCA : constant Node_Id := Delay_Alternative (Last_Stm);
2727 -- If statement sequence of entry call alternative is missing,
2728 -- then we can definitely fall through, and we post the error
2729 -- message on the entry call alternative itself.
2731 if No (Statements (ECA)) then
2734 -- If statement sequence of delay alternative is missing, then
2735 -- we can definitely fall through, and we post the error
2736 -- message on the delay alternative itself.
2738 -- Note: if both ECA and DCA are missing the return, then we
2739 -- post only one message, should be enough to fix the bugs.
2740 -- If not we will get a message next time on the DCA when the
2743 elsif No (Statements (DCA)) then
2746 -- Else check both statement sequences
2749 Check_Statement_Sequence (Statements (ECA));
2750 Check_Statement_Sequence (Statements (DCA));
2755 -- Conditional entry call, check entry call and else part
2757 -- Note: in expanded code, the conditional entry call has been
2758 -- converted to a set of expanded statements on which the check
2759 -- will work correctly in any case.
2761 elsif Kind = N_Conditional_Entry_Call then
2763 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
2766 -- If statement sequence of entry call alternative is missing,
2767 -- then we can definitely fall through, and we post the error
2768 -- message on the entry call alternative itself.
2770 if No (Statements (ECA)) then
2773 -- Else check statement sequence and else part
2776 Check_Statement_Sequence (Statements (ECA));
2777 Check_Statement_Sequence (Else_Statements (Last_Stm));
2783 -- If we fall through, issue appropriate message
2787 if not Raise_Exception_Call then
2789 ("?RETURN statement missing following this statement!",
2792 ("\?Program_Error may be raised at run time",
2796 -- Note: we set Err even though we have not issued a warning
2797 -- because we still have a case of a missing return. This is
2798 -- an extremely marginal case, probably will never be noticed
2799 -- but we might as well get it right.
2805 ("implied return after this statement not allowed (No_Return)",
2808 end Check_Statement_Sequence;
2810 -- Start of processing for Check_Returns
2814 Check_Statement_Sequence (Statements (HSS));
2816 if Present (Exception_Handlers (HSS)) then
2817 Handler := First_Non_Pragma (Exception_Handlers (HSS));
2818 while Present (Handler) loop
2819 Check_Statement_Sequence (Statements (Handler));
2820 Next_Non_Pragma (Handler);
2825 ----------------------------
2826 -- Check_Subprogram_Order --
2827 ----------------------------
2829 procedure Check_Subprogram_Order (N : Node_Id) is
2831 function Subprogram_Name_Greater (S1, S2 : String) return Boolean;
2832 -- This is used to check if S1 > S2 in the sense required by this
2833 -- test, for example nameab < namec, but name2 < name10.
2835 function Subprogram_Name_Greater (S1, S2 : String) return Boolean is
2840 -- Remove trailing numeric parts
2843 while S1 (L1) in '0' .. '9' loop
2848 while S2 (L2) in '0' .. '9' loop
2852 -- If non-numeric parts non-equal, that's decisive
2854 if S1 (S1'First .. L1) < S2 (S2'First .. L2) then
2857 elsif S1 (S1'First .. L1) > S2 (S2'First .. L2) then
2860 -- If non-numeric parts equal, compare suffixed numeric parts. Note
2861 -- that a missing suffix is treated as numeric zero in this test.
2865 while L1 < S1'Last loop
2867 N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0');
2871 while L2 < S2'Last loop
2873 N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0');
2878 end Subprogram_Name_Greater;
2880 -- Start of processing for Check_Subprogram_Order
2883 -- Check body in alpha order if this is option
2886 and then Style_Check_Subprogram_Order
2887 and then Nkind (N) = N_Subprogram_Body
2888 and then Comes_From_Source (N)
2889 and then In_Extended_Main_Source_Unit (N)
2893 renames Scope_Stack.Table
2894 (Scope_Stack.Last).Last_Subprogram_Name;
2896 Body_Id : constant Entity_Id :=
2897 Defining_Entity (Specification (N));
2900 Get_Decoded_Name_String (Chars (Body_Id));
2903 if Subprogram_Name_Greater
2904 (LSN.all, Name_Buffer (1 .. Name_Len))
2906 Style.Subprogram_Not_In_Alpha_Order (Body_Id);
2912 LSN := new String'(Name_Buffer (1 .. Name_Len));
2915 end Check_Subprogram_Order;
2917 ------------------------------
2918 -- Check_Subtype_Conformant --
2919 ------------------------------
2921 procedure Check_Subtype_Conformant
2922 (New_Id : Entity_Id;
2924 Err_Loc : Node_Id := Empty)
2930 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc);
2931 end Check_Subtype_Conformant;
2933 ---------------------------
2934 -- Check_Type_Conformant --
2935 ---------------------------
2937 procedure Check_Type_Conformant
2938 (New_Id : Entity_Id;
2940 Err_Loc : Node_Id := Empty)
2946 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
2947 end Check_Type_Conformant;
2949 ----------------------
2950 -- Conforming_Types --
2951 ----------------------
2953 function Conforming_Types
2956 Ctype : Conformance_Type;
2957 Get_Inst : Boolean := False) return Boolean
2959 Type_1 : Entity_Id := T1;
2960 Type_2 : Entity_Id := T2;
2961 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False;
2963 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
2964 -- If neither T1 nor T2 are generic actual types, or if they are
2965 -- in different scopes (e.g. parent and child instances), then verify
2966 -- that the base types are equal. Otherwise T1 and T2 must be
2967 -- on the same subtype chain. The whole purpose of this procedure
2968 -- is to prevent spurious ambiguities in an instantiation that may
2969 -- arise if two distinct generic types are instantiated with the
2972 ----------------------
2973 -- Base_Types_Match --
2974 ----------------------
2976 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
2981 elsif Base_Type (T1) = Base_Type (T2) then
2983 -- The following is too permissive. A more precise test must
2984 -- check that the generic actual is an ancestor subtype of the
2987 return not Is_Generic_Actual_Type (T1)
2988 or else not Is_Generic_Actual_Type (T2)
2989 or else Scope (T1) /= Scope (T2);
2991 -- In some cases a type imported through a limited_with clause,
2992 -- and its non-limited view are both visible, for example in an
2993 -- anonymous access_to_classwide type in a formal. Both entities
2994 -- designate the same type.
2996 elsif From_With_Type (T1)
2997 and then Ekind (T1) = E_Incomplete_Type
2998 and then T2 = Non_Limited_View (T1)
3005 end Base_Types_Match;
3008 -- The context is an instance association for a formal
3009 -- access-to-subprogram type; the formal parameter types
3010 -- require mapping because they may denote other formal
3011 -- parameters of the generic unit.
3014 Type_1 := Get_Instance_Of (T1);
3015 Type_2 := Get_Instance_Of (T2);
3018 -- First see if base types match
3020 if Base_Types_Match (Type_1, Type_2) then
3021 return Ctype <= Mode_Conformant
3022 or else Subtypes_Statically_Match (Type_1, Type_2);
3024 elsif Is_Incomplete_Or_Private_Type (Type_1)
3025 and then Present (Full_View (Type_1))
3026 and then Base_Types_Match (Full_View (Type_1), Type_2)
3028 return Ctype <= Mode_Conformant
3029 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
3031 elsif Ekind (Type_2) = E_Incomplete_Type
3032 and then Present (Full_View (Type_2))
3033 and then Base_Types_Match (Type_1, Full_View (Type_2))
3035 return Ctype <= Mode_Conformant
3036 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3038 elsif Is_Private_Type (Type_2)
3039 and then In_Instance
3040 and then Present (Full_View (Type_2))
3041 and then Base_Types_Match (Type_1, Full_View (Type_2))
3043 return Ctype <= Mode_Conformant
3044 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3047 -- Ada 0Y (AI-254): Detect anonymous access to subprogram types.
3049 Are_Anonymous_Access_To_Subprogram_Types :=
3051 -- Case 1: Anonymous access to subprogram types
3053 (Ekind (Type_1) = E_Anonymous_Access_Subprogram_Type
3054 and then Ekind (Type_2) = E_Anonymous_Access_Subprogram_Type)
3056 -- Case 2: Anonymous access to PROTECTED subprogram types. In this
3057 -- case the anonymous type_declaration has been replaced by an
3058 -- occurrence of an internal access to subprogram type declaration
3059 -- available through the Original_Access_Type attribute
3062 (Ekind (Type_1) = E_Access_Protected_Subprogram_Type
3063 and then Ekind (Type_2) = E_Access_Protected_Subprogram_Type
3064 and then not Comes_From_Source (Type_1)
3065 and then not Comes_From_Source (Type_2)
3066 and then Present (Original_Access_Type (Type_1))
3067 and then Present (Original_Access_Type (Type_2))
3068 and then Ekind (Original_Access_Type (Type_1)) =
3069 E_Anonymous_Access_Protected_Subprogram_Type
3070 and then Ekind (Original_Access_Type (Type_2)) =
3071 E_Anonymous_Access_Protected_Subprogram_Type);
3073 -- Test anonymous access type case. For this case, static subtype
3074 -- matching is required for mode conformance (RM 6.3.1(15))
3076 if (Ekind (Type_1) = E_Anonymous_Access_Type
3077 and then Ekind (Type_2) = E_Anonymous_Access_Type)
3078 or else Are_Anonymous_Access_To_Subprogram_Types -- Ada 0Y (AI-254)
3081 Desig_1 : Entity_Id;
3082 Desig_2 : Entity_Id;
3085 Desig_1 := Directly_Designated_Type (Type_1);
3087 -- An access parameter can designate an incomplete type
3089 if Ekind (Desig_1) = E_Incomplete_Type
3090 and then Present (Full_View (Desig_1))
3092 Desig_1 := Full_View (Desig_1);
3095 Desig_2 := Directly_Designated_Type (Type_2);
3097 if Ekind (Desig_2) = E_Incomplete_Type
3098 and then Present (Full_View (Desig_2))
3100 Desig_2 := Full_View (Desig_2);
3103 -- The context is an instance association for a formal
3104 -- access-to-subprogram type; formal access parameter
3105 -- designated types require mapping because they may
3106 -- denote other formal parameters of the generic unit.
3109 Desig_1 := Get_Instance_Of (Desig_1);
3110 Desig_2 := Get_Instance_Of (Desig_2);
3113 -- It is possible for a Class_Wide_Type to be introduced for
3114 -- an incomplete type, in which case there is a separate class_
3115 -- wide type for the full view. The types conform if their
3116 -- Etypes conform, i.e. one may be the full view of the other.
3117 -- This can only happen in the context of an access parameter,
3118 -- other uses of an incomplete Class_Wide_Type are illegal.
3120 if Is_Class_Wide_Type (Desig_1)
3121 and then Is_Class_Wide_Type (Desig_2)
3125 (Etype (Base_Type (Desig_1)),
3126 Etype (Base_Type (Desig_2)), Ctype);
3128 elsif Are_Anonymous_Access_To_Subprogram_Types then
3129 return Ctype = Type_Conformant
3131 Subtypes_Statically_Match (Desig_1, Desig_2);
3134 return Base_Type (Desig_1) = Base_Type (Desig_2)
3135 and then (Ctype = Type_Conformant
3137 Subtypes_Statically_Match (Desig_1, Desig_2));
3141 -- Otherwise definitely no match
3147 end Conforming_Types;
3149 --------------------------
3150 -- Create_Extra_Formals --
3151 --------------------------
3153 procedure Create_Extra_Formals (E : Entity_Id) is
3155 Last_Extra : Entity_Id;
3156 Formal_Type : Entity_Id;
3157 P_Formal : Entity_Id := Empty;
3159 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id;
3160 -- Add an extra formal, associated with the current Formal. The
3161 -- extra formal is added to the list of extra formals, and also
3162 -- returned as the result. These formals are always of mode IN.
3164 ----------------------
3165 -- Add_Extra_Formal --
3166 ----------------------
3168 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is
3169 EF : constant Entity_Id :=
3170 Make_Defining_Identifier (Sloc (Formal),
3171 Chars => New_External_Name (Chars (Formal), 'F'));
3174 -- We never generate extra formals if expansion is not active
3175 -- because we don't need them unless we are generating code.
3177 if not Expander_Active then
3181 -- A little optimization. Never generate an extra formal for
3182 -- the _init operand of an initialization procedure, since it
3183 -- could never be used.
3185 if Chars (Formal) = Name_uInit then
3189 Set_Ekind (EF, E_In_Parameter);
3190 Set_Actual_Subtype (EF, Typ);
3191 Set_Etype (EF, Typ);
3192 Set_Scope (EF, Scope (Formal));
3193 Set_Mechanism (EF, Default_Mechanism);
3194 Set_Formal_Validity (EF);
3196 Set_Extra_Formal (Last_Extra, EF);
3199 end Add_Extra_Formal;
3201 -- Start of processing for Create_Extra_Formals
3204 -- If this is a derived subprogram then the subtypes of the
3205 -- parent subprogram's formal parameters will be used to
3206 -- to determine the need for extra formals.
3208 if Is_Overloadable (E) and then Present (Alias (E)) then
3209 P_Formal := First_Formal (Alias (E));
3212 Last_Extra := Empty;
3213 Formal := First_Formal (E);
3214 while Present (Formal) loop
3215 Last_Extra := Formal;
3216 Next_Formal (Formal);
3219 -- If Extra_formals where already created, don't do it again
3220 -- This situation may arise for subprogram types created as part
3221 -- of dispatching calls (see Expand_Dispatch_Call)
3223 if Present (Last_Extra) and then
3224 Present (Extra_Formal (Last_Extra))
3229 Formal := First_Formal (E);
3231 while Present (Formal) loop
3233 -- Create extra formal for supporting the attribute 'Constrained.
3234 -- The case of a private type view without discriminants also
3235 -- requires the extra formal if the underlying type has defaulted
3238 if Ekind (Formal) /= E_In_Parameter then
3239 if Present (P_Formal) then
3240 Formal_Type := Etype (P_Formal);
3242 Formal_Type := Etype (Formal);
3245 if not Has_Discriminants (Formal_Type)
3246 and then Ekind (Formal_Type) in Private_Kind
3247 and then Present (Underlying_Type (Formal_Type))
3249 Formal_Type := Underlying_Type (Formal_Type);
3252 if Has_Discriminants (Formal_Type)
3254 ((not Is_Constrained (Formal_Type)
3255 and then not Is_Indefinite_Subtype (Formal_Type))
3256 or else Present (Extra_Formal (Formal)))
3258 Set_Extra_Constrained
3259 (Formal, Add_Extra_Formal (Standard_Boolean));
3263 -- Create extra formal for supporting accessibility checking
3265 -- This is suppressed if we specifically suppress accessibility
3266 -- checks at the pacage level for either the subprogram, or the
3267 -- package in which it resides. However, we do not suppress it
3268 -- simply if the scope has accessibility checks suppressed, since
3269 -- this could cause trouble when clients are compiled with a
3270 -- different suppression setting. The explicit checks at the
3271 -- package level are safe from this point of view.
3273 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
3275 (Explicit_Suppress (E, Accessibility_Check)
3277 Explicit_Suppress (Scope (E), Accessibility_Check))
3279 (not Present (P_Formal)
3280 or else Present (Extra_Accessibility (P_Formal)))
3282 -- Temporary kludge: for now we avoid creating the extra
3283 -- formal for access parameters of protected operations
3284 -- because of problem with the case of internal protected
3287 if Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Definition
3288 and then Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Body
3290 Set_Extra_Accessibility
3291 (Formal, Add_Extra_Formal (Standard_Natural));
3295 if Present (P_Formal) then
3296 Next_Formal (P_Formal);
3299 Next_Formal (Formal);
3301 end Create_Extra_Formals;
3303 -----------------------------
3304 -- Enter_Overloaded_Entity --
3305 -----------------------------
3307 procedure Enter_Overloaded_Entity (S : Entity_Id) is
3308 E : Entity_Id := Current_Entity_In_Scope (S);
3309 C_E : Entity_Id := Current_Entity (S);
3313 Set_Has_Homonym (E);
3314 Set_Has_Homonym (S);
3317 Set_Is_Immediately_Visible (S);
3318 Set_Scope (S, Current_Scope);
3320 -- Chain new entity if front of homonym in current scope, so that
3321 -- homonyms are contiguous.
3326 while Homonym (C_E) /= E loop
3327 C_E := Homonym (C_E);
3330 Set_Homonym (C_E, S);
3334 Set_Current_Entity (S);
3339 Append_Entity (S, Current_Scope);
3340 Set_Public_Status (S);
3342 if Debug_Flag_E then
3343 Write_Str ("New overloaded entity chain: ");
3344 Write_Name (Chars (S));
3347 while Present (E) loop
3348 Write_Str (" "); Write_Int (Int (E));
3355 -- Generate warning for hiding
3358 and then Comes_From_Source (S)
3359 and then In_Extended_Main_Source_Unit (S)
3366 -- Warn unless genuine overloading
3368 if (not Is_Overloadable (E))
3369 or else Subtype_Conformant (E, S)
3371 Error_Msg_Sloc := Sloc (E);
3372 Error_Msg_N ("declaration of & hides one#?", S);
3376 end Enter_Overloaded_Entity;
3378 -----------------------------
3379 -- Find_Corresponding_Spec --
3380 -----------------------------
3382 function Find_Corresponding_Spec (N : Node_Id) return Entity_Id is
3383 Spec : constant Node_Id := Specification (N);
3384 Designator : constant Entity_Id := Defining_Entity (Spec);
3389 E := Current_Entity (Designator);
3391 while Present (E) loop
3393 -- We are looking for a matching spec. It must have the same scope,
3394 -- and the same name, and either be type conformant, or be the case
3395 -- of a library procedure spec and its body (which belong to one
3396 -- another regardless of whether they are type conformant or not).
3398 if Scope (E) = Current_Scope then
3399 if Current_Scope = Standard_Standard
3400 or else (Ekind (E) = Ekind (Designator)
3401 and then Type_Conformant (E, Designator))
3403 -- Within an instantiation, we know that spec and body are
3404 -- subtype conformant, because they were subtype conformant
3405 -- in the generic. We choose the subtype-conformant entity
3406 -- here as well, to resolve spurious ambiguities in the
3407 -- instance that were not present in the generic (i.e. when
3408 -- two different types are given the same actual). If we are
3409 -- looking for a spec to match a body, full conformance is
3413 Set_Convention (Designator, Convention (E));
3415 if Nkind (N) = N_Subprogram_Body
3416 and then Present (Homonym (E))
3417 and then not Fully_Conformant (E, Designator)
3421 elsif not Subtype_Conformant (E, Designator) then
3426 if not Has_Completion (E) then
3428 if Nkind (N) /= N_Subprogram_Body_Stub then
3429 Set_Corresponding_Spec (N, E);
3432 Set_Has_Completion (E);
3435 elsif Nkind (Parent (N)) = N_Subunit then
3437 -- If this is the proper body of a subunit, the completion
3438 -- flag is set when analyzing the stub.
3442 -- If body already exists, this is an error unless the
3443 -- previous declaration is the implicit declaration of
3444 -- a derived subprogram, or this is a spurious overloading
3447 elsif No (Alias (E))
3448 and then not Is_Intrinsic_Subprogram (E)
3449 and then not In_Instance
3451 Error_Msg_Sloc := Sloc (E);
3452 if Is_Imported (E) then
3454 ("body not allowed for imported subprogram & declared#",
3457 Error_Msg_NE ("duplicate body for & declared#", N, E);
3461 elsif Is_Child_Unit (E)
3463 Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body
3465 Nkind (Parent (Unit_Declaration_Node (Designator)))
3466 = N_Compilation_Unit
3469 -- Child units cannot be overloaded, so a conformance mismatch
3470 -- between body and a previous spec is an error.
3473 ("body of child unit does not match previous declaration", N);
3481 -- On exit, we know that no previous declaration of subprogram exists
3484 end Find_Corresponding_Spec;
3486 ----------------------
3487 -- Fully_Conformant --
3488 ----------------------
3490 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
3494 Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result);
3496 end Fully_Conformant;
3498 ----------------------------------
3499 -- Fully_Conformant_Expressions --
3500 ----------------------------------
3502 function Fully_Conformant_Expressions
3503 (Given_E1 : Node_Id;
3504 Given_E2 : Node_Id) return Boolean
3506 E1 : constant Node_Id := Original_Node (Given_E1);
3507 E2 : constant Node_Id := Original_Node (Given_E2);
3508 -- We always test conformance on original nodes, since it is possible
3509 -- for analysis and/or expansion to make things look as though they
3510 -- conform when they do not, e.g. by converting 1+2 into 3.
3512 function FCE (Given_E1, Given_E2 : Node_Id) return Boolean
3513 renames Fully_Conformant_Expressions;
3515 function FCL (L1, L2 : List_Id) return Boolean;
3516 -- Compare elements of two lists for conformance. Elements have to
3517 -- be conformant, and actuals inserted as default parameters do not
3518 -- match explicit actuals with the same value.
3520 function FCO (Op_Node, Call_Node : Node_Id) return Boolean;
3521 -- Compare an operator node with a function call.
3527 function FCL (L1, L2 : List_Id) return Boolean is
3531 if L1 = No_List then
3537 if L2 = No_List then
3543 -- Compare two lists, skipping rewrite insertions (we want to
3544 -- compare the original trees, not the expanded versions!)
3547 if Is_Rewrite_Insertion (N1) then
3549 elsif Is_Rewrite_Insertion (N2) then
3555 elsif not FCE (N1, N2) then
3568 function FCO (Op_Node, Call_Node : Node_Id) return Boolean is
3569 Actuals : constant List_Id := Parameter_Associations (Call_Node);
3574 or else Entity (Op_Node) /= Entity (Name (Call_Node))
3579 Act := First (Actuals);
3581 if Nkind (Op_Node) in N_Binary_Op then
3583 if not FCE (Left_Opnd (Op_Node), Act) then
3590 return Present (Act)
3591 and then FCE (Right_Opnd (Op_Node), Act)
3592 and then No (Next (Act));
3596 -- Start of processing for Fully_Conformant_Expressions
3599 -- Non-conformant if paren count does not match. Note: if some idiot
3600 -- complains that we don't do this right for more than 3 levels of
3601 -- parentheses, they will be treated with the respect they deserve :-)
3603 if Paren_Count (E1) /= Paren_Count (E2) then
3606 -- If same entities are referenced, then they are conformant
3607 -- even if they have different forms (RM 8.3.1(19-20)).
3609 elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then
3610 if Present (Entity (E1)) then
3611 return Entity (E1) = Entity (E2)
3612 or else (Chars (Entity (E1)) = Chars (Entity (E2))
3613 and then Ekind (Entity (E1)) = E_Discriminant
3614 and then Ekind (Entity (E2)) = E_In_Parameter);
3616 elsif Nkind (E1) = N_Expanded_Name
3617 and then Nkind (E2) = N_Expanded_Name
3618 and then Nkind (Selector_Name (E1)) = N_Character_Literal
3619 and then Nkind (Selector_Name (E2)) = N_Character_Literal
3621 return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2));
3624 -- Identifiers in component associations don't always have
3625 -- entities, but their names must conform.
3627 return Nkind (E1) = N_Identifier
3628 and then Nkind (E2) = N_Identifier
3629 and then Chars (E1) = Chars (E2);
3632 elsif Nkind (E1) = N_Character_Literal
3633 and then Nkind (E2) = N_Expanded_Name
3635 return Nkind (Selector_Name (E2)) = N_Character_Literal
3636 and then Chars (E1) = Chars (Selector_Name (E2));
3638 elsif Nkind (E2) = N_Character_Literal
3639 and then Nkind (E1) = N_Expanded_Name
3641 return Nkind (Selector_Name (E1)) = N_Character_Literal
3642 and then Chars (E2) = Chars (Selector_Name (E1));
3644 elsif Nkind (E1) in N_Op
3645 and then Nkind (E2) = N_Function_Call
3647 return FCO (E1, E2);
3649 elsif Nkind (E2) in N_Op
3650 and then Nkind (E1) = N_Function_Call
3652 return FCO (E2, E1);
3654 -- Otherwise we must have the same syntactic entity
3656 elsif Nkind (E1) /= Nkind (E2) then
3659 -- At this point, we specialize by node type
3666 FCL (Expressions (E1), Expressions (E2))
3667 and then FCL (Component_Associations (E1),
3668 Component_Associations (E2));
3671 if Nkind (Expression (E1)) = N_Qualified_Expression
3673 Nkind (Expression (E2)) = N_Qualified_Expression
3675 return FCE (Expression (E1), Expression (E2));
3677 -- Check that the subtype marks and any constraints
3682 Indic1 : constant Node_Id := Expression (E1);
3683 Indic2 : constant Node_Id := Expression (E2);
3688 if Nkind (Indic1) /= N_Subtype_Indication then
3690 Nkind (Indic2) /= N_Subtype_Indication
3691 and then Entity (Indic1) = Entity (Indic2);
3693 elsif Nkind (Indic2) /= N_Subtype_Indication then
3695 Nkind (Indic1) /= N_Subtype_Indication
3696 and then Entity (Indic1) = Entity (Indic2);
3699 if Entity (Subtype_Mark (Indic1)) /=
3700 Entity (Subtype_Mark (Indic2))
3705 Elt1 := First (Constraints (Constraint (Indic1)));
3706 Elt2 := First (Constraints (Constraint (Indic2)));
3708 while Present (Elt1) and then Present (Elt2) loop
3709 if not FCE (Elt1, Elt2) then
3722 when N_Attribute_Reference =>
3724 Attribute_Name (E1) = Attribute_Name (E2)
3725 and then FCL (Expressions (E1), Expressions (E2));
3729 Entity (E1) = Entity (E2)
3730 and then FCE (Left_Opnd (E1), Left_Opnd (E2))
3731 and then FCE (Right_Opnd (E1), Right_Opnd (E2));
3733 when N_And_Then | N_Or_Else | N_In | N_Not_In =>
3735 FCE (Left_Opnd (E1), Left_Opnd (E2))
3737 FCE (Right_Opnd (E1), Right_Opnd (E2));
3739 when N_Character_Literal =>
3741 Char_Literal_Value (E1) = Char_Literal_Value (E2);
3743 when N_Component_Association =>
3745 FCL (Choices (E1), Choices (E2))
3746 and then FCE (Expression (E1), Expression (E2));
3748 when N_Conditional_Expression =>
3750 FCL (Expressions (E1), Expressions (E2));
3752 when N_Explicit_Dereference =>
3754 FCE (Prefix (E1), Prefix (E2));
3756 when N_Extension_Aggregate =>
3758 FCL (Expressions (E1), Expressions (E2))
3759 and then Null_Record_Present (E1) =
3760 Null_Record_Present (E2)
3761 and then FCL (Component_Associations (E1),
3762 Component_Associations (E2));
3764 when N_Function_Call =>
3766 FCE (Name (E1), Name (E2))
3767 and then FCL (Parameter_Associations (E1),
3768 Parameter_Associations (E2));
3770 when N_Indexed_Component =>
3772 FCE (Prefix (E1), Prefix (E2))
3773 and then FCL (Expressions (E1), Expressions (E2));
3775 when N_Integer_Literal =>
3776 return (Intval (E1) = Intval (E2));
3781 when N_Operator_Symbol =>
3783 Chars (E1) = Chars (E2);
3785 when N_Others_Choice =>
3788 when N_Parameter_Association =>
3790 Chars (Selector_Name (E1)) = Chars (Selector_Name (E2))
3791 and then FCE (Explicit_Actual_Parameter (E1),
3792 Explicit_Actual_Parameter (E2));
3794 when N_Qualified_Expression =>
3796 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3797 and then FCE (Expression (E1), Expression (E2));
3801 FCE (Low_Bound (E1), Low_Bound (E2))
3802 and then FCE (High_Bound (E1), High_Bound (E2));
3804 when N_Real_Literal =>
3805 return (Realval (E1) = Realval (E2));
3807 when N_Selected_Component =>
3809 FCE (Prefix (E1), Prefix (E2))
3810 and then FCE (Selector_Name (E1), Selector_Name (E2));
3814 FCE (Prefix (E1), Prefix (E2))
3815 and then FCE (Discrete_Range (E1), Discrete_Range (E2));
3817 when N_String_Literal =>
3819 S1 : constant String_Id := Strval (E1);
3820 S2 : constant String_Id := Strval (E2);
3821 L1 : constant Nat := String_Length (S1);
3822 L2 : constant Nat := String_Length (S2);
3829 for J in 1 .. L1 loop
3830 if Get_String_Char (S1, J) /=
3831 Get_String_Char (S2, J)
3841 when N_Type_Conversion =>
3843 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3844 and then FCE (Expression (E1), Expression (E2));
3848 Entity (E1) = Entity (E2)
3849 and then FCE (Right_Opnd (E1), Right_Opnd (E2));
3851 when N_Unchecked_Type_Conversion =>
3853 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3854 and then FCE (Expression (E1), Expression (E2));
3856 -- All other node types cannot appear in this context. Strictly
3857 -- we should raise a fatal internal error. Instead we just ignore
3858 -- the nodes. This means that if anyone makes a mistake in the
3859 -- expander and mucks an expression tree irretrievably, the
3860 -- result will be a failure to detect a (probably very obscure)
3861 -- case of non-conformance, which is better than bombing on some
3862 -- case where two expressions do in fact conform.
3869 end Fully_Conformant_Expressions;
3871 ----------------------------------------
3872 -- Fully_Conformant_Discrete_Subtypes --
3873 ----------------------------------------
3875 function Fully_Conformant_Discrete_Subtypes
3876 (Given_S1 : Node_Id;
3877 Given_S2 : Node_Id) return Boolean
3879 S1 : constant Node_Id := Original_Node (Given_S1);
3880 S2 : constant Node_Id := Original_Node (Given_S2);
3882 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean;
3883 -- Special-case for a bound given by a discriminant, which in the
3884 -- body is replaced with the discriminal of the enclosing type.
3886 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean;
3887 -- Check both bounds.
3889 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is
3891 if Is_Entity_Name (B1)
3892 and then Is_Entity_Name (B2)
3893 and then Ekind (Entity (B1)) = E_Discriminant
3895 return Chars (B1) = Chars (B2);
3898 return Fully_Conformant_Expressions (B1, B2);
3900 end Conforming_Bounds;
3902 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is
3905 Conforming_Bounds (Low_Bound (R1), Low_Bound (R2))
3907 Conforming_Bounds (High_Bound (R1), High_Bound (R2));
3908 end Conforming_Ranges;
3910 -- Start of processing for Fully_Conformant_Discrete_Subtypes
3913 if Nkind (S1) /= Nkind (S2) then
3916 elsif Is_Entity_Name (S1) then
3917 return Entity (S1) = Entity (S2);
3919 elsif Nkind (S1) = N_Range then
3920 return Conforming_Ranges (S1, S2);
3922 elsif Nkind (S1) = N_Subtype_Indication then
3924 Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2))
3927 (Range_Expression (Constraint (S1)),
3928 Range_Expression (Constraint (S2)));
3932 end Fully_Conformant_Discrete_Subtypes;
3934 --------------------
3935 -- Install_Entity --
3936 --------------------
3938 procedure Install_Entity (E : Entity_Id) is
3939 Prev : constant Entity_Id := Current_Entity (E);
3942 Set_Is_Immediately_Visible (E);
3943 Set_Current_Entity (E);
3944 Set_Homonym (E, Prev);
3947 ---------------------
3948 -- Install_Formals --
3949 ---------------------
3951 procedure Install_Formals (Id : Entity_Id) is
3955 F := First_Formal (Id);
3957 while Present (F) loop
3961 end Install_Formals;
3963 ---------------------------------
3964 -- Is_Non_Overriding_Operation --
3965 ---------------------------------
3967 function Is_Non_Overriding_Operation
3968 (Prev_E : Entity_Id;
3969 New_E : Entity_Id) return Boolean
3973 G_Typ : Entity_Id := Empty;
3975 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id;
3976 -- If F_Type is a derived type associated with a generic actual
3977 -- subtype, then return its Generic_Parent_Type attribute, else
3980 function Types_Correspond
3981 (P_Type : Entity_Id;
3982 N_Type : Entity_Id) return Boolean;
3983 -- Returns true if and only if the types (or designated types
3984 -- in the case of anonymous access types) are the same or N_Type
3985 -- is derived directly or indirectly from P_Type.
3987 -----------------------------
3988 -- Get_Generic_Parent_Type --
3989 -----------------------------
3991 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is
3996 if Is_Derived_Type (F_Typ)
3997 and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration
3999 -- The tree must be traversed to determine the parent
4000 -- subtype in the generic unit, which unfortunately isn't
4001 -- always available via semantic attributes. ???
4002 -- (Note: The use of Original_Node is needed for cases
4003 -- where a full derived type has been rewritten.)
4005 Indic := Subtype_Indication
4006 (Type_Definition (Original_Node (Parent (F_Typ))));
4008 if Nkind (Indic) = N_Subtype_Indication then
4009 G_Typ := Entity (Subtype_Mark (Indic));
4011 G_Typ := Entity (Indic);
4014 if Nkind (Parent (G_Typ)) = N_Subtype_Declaration
4015 and then Present (Generic_Parent_Type (Parent (G_Typ)))
4017 return Generic_Parent_Type (Parent (G_Typ));
4022 end Get_Generic_Parent_Type;
4024 ----------------------
4025 -- Types_Correspond --
4026 ----------------------
4028 function Types_Correspond
4029 (P_Type : Entity_Id;
4030 N_Type : Entity_Id) return Boolean
4032 Prev_Type : Entity_Id := Base_Type (P_Type);
4033 New_Type : Entity_Id := Base_Type (N_Type);
4036 if Ekind (Prev_Type) = E_Anonymous_Access_Type then
4037 Prev_Type := Designated_Type (Prev_Type);
4040 if Ekind (New_Type) = E_Anonymous_Access_Type then
4041 New_Type := Designated_Type (New_Type);
4044 if Prev_Type = New_Type then
4047 elsif not Is_Class_Wide_Type (New_Type) then
4048 while Etype (New_Type) /= New_Type loop
4049 New_Type := Etype (New_Type);
4050 if New_Type = Prev_Type then
4056 end Types_Correspond;
4058 -- Start of processing for Is_Non_Overriding_Operation
4061 -- In the case where both operations are implicit derived
4062 -- subprograms then neither overrides the other. This can
4063 -- only occur in certain obscure cases (e.g., derivation
4064 -- from homographs created in a generic instantiation).
4066 if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then
4069 elsif Ekind (Current_Scope) = E_Package
4070 and then Is_Generic_Instance (Current_Scope)
4071 and then In_Private_Part (Current_Scope)
4072 and then Comes_From_Source (New_E)
4074 -- We examine the formals and result subtype of the inherited
4075 -- operation, to determine whether their type is derived from
4076 -- (the instance of) a generic type.
4078 Formal := First_Formal (Prev_E);
4080 while Present (Formal) loop
4081 F_Typ := Base_Type (Etype (Formal));
4083 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4084 F_Typ := Designated_Type (F_Typ);
4087 G_Typ := Get_Generic_Parent_Type (F_Typ);
4089 Next_Formal (Formal);
4092 if not Present (G_Typ) and then Ekind (Prev_E) = E_Function then
4093 G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E)));
4100 -- If the generic type is a private type, then the original
4101 -- operation was not overriding in the generic, because there was
4102 -- no primitive operation to override.
4104 if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration
4105 and then Nkind (Formal_Type_Definition (Parent (G_Typ))) =
4106 N_Formal_Private_Type_Definition
4110 -- The generic parent type is the ancestor of a formal derived
4111 -- type declaration. We need to check whether it has a primitive
4112 -- operation that should be overridden by New_E in the generic.
4116 P_Formal : Entity_Id;
4117 N_Formal : Entity_Id;
4121 Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ));
4124 while Present (Prim_Elt) loop
4125 P_Prim := Node (Prim_Elt);
4127 if Chars (P_Prim) = Chars (New_E)
4128 and then Ekind (P_Prim) = Ekind (New_E)
4130 P_Formal := First_Formal (P_Prim);
4131 N_Formal := First_Formal (New_E);
4132 while Present (P_Formal) and then Present (N_Formal) loop
4133 P_Typ := Etype (P_Formal);
4134 N_Typ := Etype (N_Formal);
4136 if not Types_Correspond (P_Typ, N_Typ) then
4140 Next_Entity (P_Formal);
4141 Next_Entity (N_Formal);
4144 -- Found a matching primitive operation belonging to
4145 -- the formal ancestor type, so the new subprogram
4148 if not Present (P_Formal)
4149 and then not Present (N_Formal)
4150 and then (Ekind (New_E) /= E_Function
4153 (Etype (P_Prim), Etype (New_E)))
4159 Next_Elmt (Prim_Elt);
4162 -- If no match found, then the new subprogram does
4163 -- not override in the generic (nor in the instance).
4171 end Is_Non_Overriding_Operation;
4173 ------------------------------
4174 -- Make_Inequality_Operator --
4175 ------------------------------
4177 -- S is the defining identifier of an equality operator. We build a
4178 -- subprogram declaration with the right signature. This operation is
4179 -- intrinsic, because it is always expanded as the negation of the
4180 -- call to the equality function.
4182 procedure Make_Inequality_Operator (S : Entity_Id) is
4183 Loc : constant Source_Ptr := Sloc (S);
4186 Op_Name : Entity_Id;
4192 -- Check that equality was properly defined.
4194 if No (Next_Formal (First_Formal (S))) then
4198 A := Make_Defining_Identifier (Loc, Chars (First_Formal (S)));
4199 B := Make_Defining_Identifier (Loc,
4200 Chars (Next_Formal (First_Formal (S))));
4202 Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne);
4204 Formals := New_List (
4205 Make_Parameter_Specification (Loc,
4206 Defining_Identifier => A,
4208 New_Reference_To (Etype (First_Formal (S)), Loc)),
4210 Make_Parameter_Specification (Loc,
4211 Defining_Identifier => B,
4213 New_Reference_To (Etype (Next_Formal (First_Formal (S))), Loc)));
4216 Make_Subprogram_Declaration (Loc,
4218 Make_Function_Specification (Loc,
4219 Defining_Unit_Name => Op_Name,
4220 Parameter_Specifications => Formals,
4221 Subtype_Mark => New_Reference_To (Standard_Boolean, Loc)));
4223 -- Insert inequality right after equality if it is explicit or after
4224 -- the derived type when implicit. These entities are created only
4225 -- for visibility purposes, and eventually replaced in the course of
4226 -- expansion, so they do not need to be attached to the tree and seen
4227 -- by the back-end. Keeping them internal also avoids spurious freezing
4228 -- problems. The parent field is set simply to make analysis safe.
4230 if No (Alias (S)) then
4231 Set_Parent (Decl, Parent (Unit_Declaration_Node (S)));
4233 Set_Parent (Decl, Parent (Parent (Etype (First_Formal (S)))));
4236 Mark_Rewrite_Insertion (Decl);
4237 Set_Is_Intrinsic_Subprogram (Op_Name);
4239 Set_Has_Completion (Op_Name);
4240 Set_Corresponding_Equality (Op_Name, S);
4241 Set_Is_Abstract (Op_Name, Is_Abstract (S));
4243 end Make_Inequality_Operator;
4245 ----------------------
4246 -- May_Need_Actuals --
4247 ----------------------
4249 procedure May_Need_Actuals (Fun : Entity_Id) is
4254 F := First_Formal (Fun);
4257 while Present (F) loop
4258 if No (Default_Value (F)) then
4266 Set_Needs_No_Actuals (Fun, B);
4267 end May_Need_Actuals;
4269 ---------------------
4270 -- Mode_Conformant --
4271 ---------------------
4273 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
4277 Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result);
4279 end Mode_Conformant;
4281 ---------------------------
4282 -- New_Overloaded_Entity --
4283 ---------------------------
4285 procedure New_Overloaded_Entity
4287 Derived_Type : Entity_Id := Empty)
4290 -- Entity that S overrides
4292 Prev_Vis : Entity_Id := Empty;
4293 -- Needs comment ???
4295 function Is_Private_Declaration (E : Entity_Id) return Boolean;
4296 -- Check that E is declared in the private part of the current package,
4297 -- or in the package body, where it may hide a previous declaration.
4298 -- We can't use In_Private_Part by itself because this flag is also
4299 -- set when freezing entities, so we must examine the place of the
4300 -- declaration in the tree, and recognize wrapper packages as well.
4302 procedure Maybe_Primitive_Operation (Overriding : Boolean := False);
4303 -- If the subprogram being analyzed is a primitive operation of
4304 -- the type of one of its formals, set the corresponding flag.
4306 ----------------------------
4307 -- Is_Private_Declaration --
4308 ----------------------------
4310 function Is_Private_Declaration (E : Entity_Id) return Boolean is
4311 Priv_Decls : List_Id;
4312 Decl : constant Node_Id := Unit_Declaration_Node (E);
4315 if Is_Package (Current_Scope)
4316 and then In_Private_Part (Current_Scope)
4319 Private_Declarations (
4320 Specification (Unit_Declaration_Node (Current_Scope)));
4322 return In_Package_Body (Current_Scope)
4323 or else List_Containing (Decl) = Priv_Decls
4324 or else (Nkind (Parent (Decl)) = N_Package_Specification
4325 and then not Is_Compilation_Unit (
4326 Defining_Entity (Parent (Decl)))
4327 and then List_Containing (Parent (Parent (Decl)))
4332 end Is_Private_Declaration;
4334 -------------------------------
4335 -- Maybe_Primitive_Operation --
4336 -------------------------------
4338 procedure Maybe_Primitive_Operation (Overriding : Boolean := False) is
4343 function Visible_Part_Type (T : Entity_Id) return Boolean;
4344 -- Returns true if T is declared in the visible part of
4345 -- the current package scope; otherwise returns false.
4346 -- Assumes that T is declared in a package.
4348 procedure Check_Private_Overriding (T : Entity_Id);
4349 -- Checks that if a primitive abstract subprogram of a visible
4350 -- abstract type is declared in a private part, then it must
4351 -- override an abstract subprogram declared in the visible part.
4352 -- Also checks that if a primitive function with a controlling
4353 -- result is declared in a private part, then it must override
4354 -- a function declared in the visible part.
4356 ------------------------------
4357 -- Check_Private_Overriding --
4358 ------------------------------
4360 procedure Check_Private_Overriding (T : Entity_Id) is
4362 if Ekind (Current_Scope) = E_Package
4363 and then In_Private_Part (Current_Scope)
4364 and then Visible_Part_Type (T)
4365 and then not In_Instance
4368 and then Is_Abstract (S)
4369 and then (not Overriding or else not Is_Abstract (E))
4371 Error_Msg_N ("abstract subprograms must be visible "
4372 & "('R'M 3.9.3(10))!", S);
4374 elsif Ekind (S) = E_Function
4375 and then Is_Tagged_Type (T)
4376 and then T = Base_Type (Etype (S))
4377 and then not Overriding
4380 ("private function with tagged result must"
4381 & " override visible-part function", S);
4383 ("\move subprogram to the visible part"
4384 & " ('R'M 3.9.3(10))", S);
4387 end Check_Private_Overriding;
4389 -----------------------
4390 -- Visible_Part_Type --
4391 -----------------------
4393 function Visible_Part_Type (T : Entity_Id) return Boolean is
4394 P : constant Node_Id := Unit_Declaration_Node (Scope (T));
4398 -- If the entity is a private type, then it must be
4399 -- declared in a visible part.
4401 if Ekind (T) in Private_Kind then
4405 -- Otherwise, we traverse the visible part looking for its
4406 -- corresponding declaration. We cannot use the declaration
4407 -- node directly because in the private part the entity of a
4408 -- private type is the one in the full view, which does not
4409 -- indicate that it is the completion of something visible.
4411 N := First (Visible_Declarations (Specification (P)));
4412 while Present (N) loop
4413 if Nkind (N) = N_Full_Type_Declaration
4414 and then Present (Defining_Identifier (N))
4415 and then T = Defining_Identifier (N)
4419 elsif (Nkind (N) = N_Private_Type_Declaration
4421 Nkind (N) = N_Private_Extension_Declaration)
4422 and then Present (Defining_Identifier (N))
4423 and then T = Full_View (Defining_Identifier (N))
4432 end Visible_Part_Type;
4434 -- Start of processing for Maybe_Primitive_Operation
4437 if not Comes_From_Source (S) then
4440 elsif (Ekind (Current_Scope) = E_Package
4441 and then not In_Package_Body (Current_Scope))
4444 -- For function, check return type
4446 if Ekind (S) = E_Function then
4447 B_Typ := Base_Type (Etype (S));
4449 if Scope (B_Typ) = Current_Scope then
4450 Set_Has_Primitive_Operations (B_Typ);
4451 Check_Private_Overriding (B_Typ);
4455 -- For all subprograms, check formals
4457 Formal := First_Formal (S);
4458 while Present (Formal) loop
4459 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
4460 F_Typ := Designated_Type (Etype (Formal));
4462 F_Typ := Etype (Formal);
4465 B_Typ := Base_Type (F_Typ);
4467 if Scope (B_Typ) = Current_Scope then
4468 Set_Has_Primitive_Operations (B_Typ);
4469 Check_Private_Overriding (B_Typ);
4472 Next_Formal (Formal);
4475 end Maybe_Primitive_Operation;
4477 -- Start of processing for New_Overloaded_Entity
4480 -- We need to look for an entity that S may override. This must be a
4481 -- homonym in the current scope, so we look for the first homonym of
4482 -- S in the current scope as the starting point for the search.
4484 E := Current_Entity_In_Scope (S);
4486 -- If there is no homonym then this is definitely not overriding
4489 Enter_Overloaded_Entity (S);
4490 Check_Dispatching_Operation (S, Empty);
4491 Maybe_Primitive_Operation;
4493 -- If there is a homonym that is not overloadable, then we have an
4494 -- error, except for the special cases checked explicitly below.
4496 elsif not Is_Overloadable (E) then
4498 -- Check for spurious conflict produced by a subprogram that has the
4499 -- same name as that of the enclosing generic package. The conflict
4500 -- occurs within an instance, between the subprogram and the renaming
4501 -- declaration for the package. After the subprogram, the package
4502 -- renaming declaration becomes hidden.
4504 if Ekind (E) = E_Package
4505 and then Present (Renamed_Object (E))
4506 and then Renamed_Object (E) = Current_Scope
4507 and then Nkind (Parent (Renamed_Object (E))) =
4508 N_Package_Specification
4509 and then Present (Generic_Parent (Parent (Renamed_Object (E))))
4512 Set_Is_Immediately_Visible (E, False);
4513 Enter_Overloaded_Entity (S);
4514 Set_Homonym (S, Homonym (E));
4515 Check_Dispatching_Operation (S, Empty);
4517 -- If the subprogram is implicit it is hidden by the previous
4518 -- declaration. However if it is dispatching, it must appear in
4519 -- the dispatch table anyway, because it can be dispatched to
4520 -- even if it cannot be called directly.
4522 elsif Present (Alias (S))
4523 and then not Comes_From_Source (S)
4525 Set_Scope (S, Current_Scope);
4527 if Is_Dispatching_Operation (Alias (S)) then
4528 Check_Dispatching_Operation (S, Empty);
4534 Error_Msg_Sloc := Sloc (E);
4535 Error_Msg_N ("& conflicts with declaration#", S);
4537 -- Useful additional warning
4539 if Is_Generic_Unit (E) then
4540 Error_Msg_N ("\previous generic unit cannot be overloaded", S);
4546 -- E exists and is overloadable
4549 -- Loop through E and its homonyms to determine if any of them
4550 -- is the candidate for overriding by S.
4552 while Present (E) loop
4554 -- Definitely not interesting if not in the current scope
4556 if Scope (E) /= Current_Scope then
4559 -- Check if we have type conformance
4561 elsif Type_Conformant (E, S) then
4563 -- If the old and new entities have the same profile and
4564 -- one is not the body of the other, then this is an error,
4565 -- unless one of them is implicitly declared.
4567 -- There are some cases when both can be implicit, for example
4568 -- when both a literal and a function that overrides it are
4569 -- inherited in a derivation, or when an inhertited operation
4570 -- of a tagged full type overrides the ineherited operation of
4571 -- a private extension. Ada 83 had a special rule for the
4572 -- the literal case. In Ada95, the later implicit operation
4573 -- hides the former, and the literal is always the former.
4574 -- In the odd case where both are derived operations declared
4575 -- at the same point, both operations should be declared,
4576 -- and in that case we bypass the following test and proceed
4577 -- to the next part (this can only occur for certain obscure
4578 -- cases involving homographs in instances and can't occur for
4579 -- dispatching operations ???). Note that the following
4580 -- condition is less than clear. For example, it's not at
4581 -- all clear why there's a test for E_Entry here. ???
4583 if Present (Alias (S))
4584 and then (No (Alias (E))
4585 or else Comes_From_Source (E)
4586 or else Is_Dispatching_Operation (E))
4588 (Ekind (E) = E_Entry
4589 or else Ekind (E) /= E_Enumeration_Literal)
4591 -- When an derived operation is overloaded it may be due
4592 -- to the fact that the full view of a private extension
4593 -- re-inherits. It has to be dealt with.
4595 if Is_Package (Current_Scope)
4596 and then In_Private_Part (Current_Scope)
4598 Check_Operation_From_Private_View (S, E);
4601 -- In any case the implicit operation remains hidden by
4602 -- the existing declaration, which is overriding.
4604 Set_Is_Overriding_Operation (E);
4607 -- Within an instance, the renaming declarations for
4608 -- actual subprograms may become ambiguous, but they do
4609 -- not hide each other.
4611 elsif Ekind (E) /= E_Entry
4612 and then not Comes_From_Source (E)
4613 and then not Is_Generic_Instance (E)
4614 and then (Present (Alias (E))
4615 or else Is_Intrinsic_Subprogram (E))
4616 and then (not In_Instance
4617 or else No (Parent (E))
4618 or else Nkind (Unit_Declaration_Node (E)) /=
4619 N_Subprogram_Renaming_Declaration)
4621 -- A subprogram child unit is not allowed to override
4622 -- an inherited subprogram (10.1.1(20)).
4624 if Is_Child_Unit (S) then
4626 ("child unit overrides inherited subprogram in parent",
4631 if Is_Non_Overriding_Operation (E, S) then
4632 Enter_Overloaded_Entity (S);
4633 if not Present (Derived_Type)
4634 or else Is_Tagged_Type (Derived_Type)
4636 Check_Dispatching_Operation (S, Empty);
4642 -- E is a derived operation or an internal operator which
4643 -- is being overridden. Remove E from further visibility.
4644 -- Furthermore, if E is a dispatching operation, it must be
4645 -- replaced in the list of primitive operations of its type
4646 -- (see Override_Dispatching_Operation).
4652 Prev := First_Entity (Current_Scope);
4654 while Present (Prev)
4655 and then Next_Entity (Prev) /= E
4660 -- It is possible for E to be in the current scope and
4661 -- yet not in the entity chain. This can only occur in a
4662 -- generic context where E is an implicit concatenation
4663 -- in the formal part, because in a generic body the
4664 -- entity chain starts with the formals.
4667 (Present (Prev) or else Chars (E) = Name_Op_Concat);
4669 -- E must be removed both from the entity_list of the
4670 -- current scope, and from the visibility chain
4672 if Debug_Flag_E then
4673 Write_Str ("Override implicit operation ");
4674 Write_Int (Int (E));
4678 -- If E is a predefined concatenation, it stands for four
4679 -- different operations. As a result, a single explicit
4680 -- declaration does not hide it. In a possible ambiguous
4681 -- situation, Disambiguate chooses the user-defined op,
4682 -- so it is correct to retain the previous internal one.
4684 if Chars (E) /= Name_Op_Concat
4685 or else Ekind (E) /= E_Operator
4687 -- For nondispatching derived operations that are
4688 -- overridden by a subprogram declared in the private
4689 -- part of a package, we retain the derived subprogram
4690 -- but mark it as not immediately visible. If the
4691 -- derived operation was declared in the visible part
4692 -- then this ensures that it will still be visible
4693 -- outside the package with the proper signature
4694 -- (calls from outside must also be directed to this
4695 -- version rather than the overriding one, unlike the
4696 -- dispatching case). Calls from inside the package
4697 -- will still resolve to the overriding subprogram
4698 -- since the derived one is marked as not visible
4699 -- within the package.
4701 -- If the private operation is dispatching, we achieve
4702 -- the overriding by keeping the implicit operation
4703 -- but setting its alias to be the overring one. In
4704 -- this fashion the proper body is executed in all
4705 -- cases, but the original signature is used outside
4708 -- If the overriding is not in the private part, we
4709 -- remove the implicit operation altogether.
4711 if Is_Private_Declaration (S) then
4713 if not Is_Dispatching_Operation (E) then
4714 Set_Is_Immediately_Visible (E, False);
4717 -- work done in Override_Dispatching_Operation.
4723 -- Find predecessor of E in Homonym chain
4725 if E = Current_Entity (E) then
4728 Prev_Vis := Current_Entity (E);
4729 while Homonym (Prev_Vis) /= E loop
4730 Prev_Vis := Homonym (Prev_Vis);
4734 if Prev_Vis /= Empty then
4736 -- Skip E in the visibility chain
4738 Set_Homonym (Prev_Vis, Homonym (E));
4741 Set_Name_Entity_Id (Chars (E), Homonym (E));
4744 Set_Next_Entity (Prev, Next_Entity (E));
4746 if No (Next_Entity (Prev)) then
4747 Set_Last_Entity (Current_Scope, Prev);
4753 Enter_Overloaded_Entity (S);
4754 Set_Is_Overriding_Operation (S);
4756 if Is_Dispatching_Operation (E) then
4758 -- An overriding dispatching subprogram inherits
4759 -- the convention of the overridden subprogram
4762 Set_Convention (S, Convention (E));
4764 Check_Dispatching_Operation (S, E);
4766 Check_Dispatching_Operation (S, Empty);
4769 Maybe_Primitive_Operation (Overriding => True);
4770 goto Check_Inequality;
4773 -- Apparent redeclarations in instances can occur when two
4774 -- formal types get the same actual type. The subprograms in
4775 -- in the instance are legal, even if not callable from the
4776 -- outside. Calls from within are disambiguated elsewhere.
4777 -- For dispatching operations in the visible part, the usual
4778 -- rules apply, and operations with the same profile are not
4781 elsif (In_Instance_Visible_Part
4782 and then not Is_Dispatching_Operation (E))
4783 or else In_Instance_Not_Visible
4787 -- Here we have a real error (identical profile)
4790 Error_Msg_Sloc := Sloc (E);
4792 -- Avoid cascaded errors if the entity appears in
4793 -- subsequent calls.
4795 Set_Scope (S, Current_Scope);
4797 Error_Msg_N ("& conflicts with declaration#", S);
4799 if Is_Generic_Instance (S)
4800 and then not Has_Completion (E)
4803 ("\instantiation cannot provide body for it", S);
4817 -- On exit, we know that S is a new entity
4819 Enter_Overloaded_Entity (S);
4820 Maybe_Primitive_Operation;
4822 -- If S is a derived operation for an untagged type then
4823 -- by definition it's not a dispatching operation (even
4824 -- if the parent operation was dispatching), so we don't
4825 -- call Check_Dispatching_Operation in that case.
4827 if not Present (Derived_Type)
4828 or else Is_Tagged_Type (Derived_Type)
4830 Check_Dispatching_Operation (S, Empty);
4834 -- If this is a user-defined equality operator that is not
4835 -- a derived subprogram, create the corresponding inequality.
4836 -- If the operation is dispatching, the expansion is done
4837 -- elsewhere, and we do not create an explicit inequality
4840 <<Check_Inequality>>
4841 if Chars (S) = Name_Op_Eq
4842 and then Etype (S) = Standard_Boolean
4843 and then Present (Parent (S))
4844 and then not Is_Dispatching_Operation (S)
4846 Make_Inequality_Operator (S);
4848 end New_Overloaded_Entity;
4850 ---------------------
4851 -- Process_Formals --
4852 ---------------------
4854 procedure Process_Formals
4856 Related_Nod : Node_Id)
4858 Param_Spec : Node_Id;
4860 Formal_Type : Entity_Id;
4864 function Is_Class_Wide_Default (D : Node_Id) return Boolean;
4865 -- Check whether the default has a class-wide type. After analysis
4866 -- the default has the type of the formal, so we must also check
4867 -- explicitly for an access attribute.
4869 ---------------------------
4870 -- Is_Class_Wide_Default --
4871 ---------------------------
4873 function Is_Class_Wide_Default (D : Node_Id) return Boolean is
4875 return Is_Class_Wide_Type (Designated_Type (Etype (D)))
4876 or else (Nkind (D) = N_Attribute_Reference
4877 and then Attribute_Name (D) = Name_Access
4878 and then Is_Class_Wide_Type (Etype (Prefix (D))));
4879 end Is_Class_Wide_Default;
4881 -- Start of processing for Process_Formals
4884 -- In order to prevent premature use of the formals in the same formal
4885 -- part, the Ekind is left undefined until all default expressions are
4886 -- analyzed. The Ekind is established in a separate loop at the end.
4888 Param_Spec := First (T);
4890 while Present (Param_Spec) loop
4892 Formal := Defining_Identifier (Param_Spec);
4893 Enter_Name (Formal);
4895 -- Case of ordinary parameters
4897 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
4898 Find_Type (Parameter_Type (Param_Spec));
4899 Ptype := Parameter_Type (Param_Spec);
4901 if Ptype = Error then
4905 Formal_Type := Entity (Ptype);
4907 if Ekind (Formal_Type) = E_Incomplete_Type
4908 or else (Is_Class_Wide_Type (Formal_Type)
4909 and then Ekind (Root_Type (Formal_Type)) =
4912 -- Ada 0Y (AI-50217): Incomplete tagged types that are made
4913 -- visible through a limited with_clause are valid formal
4916 if From_With_Type (Formal_Type)
4917 and then Is_Tagged_Type (Formal_Type)
4921 elsif Nkind (Parent (T)) /= N_Access_Function_Definition
4922 and then Nkind (Parent (T)) /= N_Access_Procedure_Definition
4924 Error_Msg_N ("invalid use of incomplete type", Param_Spec);
4927 elsif Ekind (Formal_Type) = E_Void then
4928 Error_Msg_NE ("premature use of&",
4929 Parameter_Type (Param_Spec), Formal_Type);
4932 -- Ada 0Y (AI-231): Create and decorate an internal subtype
4933 -- declaration corresponding to the null-excluding type of the
4934 -- formal in the enclosing scope. In addition, replace the
4935 -- parameter type of the formal to this internal subtype.
4937 if Null_Exclusion_Present (Param_Spec) then
4939 Loc : constant Source_Ptr := Sloc (Param_Spec);
4941 Anon : constant Entity_Id :=
4942 Make_Defining_Identifier (Loc,
4943 Chars => New_Internal_Name ('S'));
4945 Curr_Scope : constant Scope_Stack_Entry :=
4946 Scope_Stack.Table (Scope_Stack.Last);
4948 Ptype : constant Node_Id := Parameter_Type (Param_Spec);
4950 P : Node_Id := Parent (Parent (Related_Nod));
4953 Set_Is_Internal (Anon);
4956 Make_Subtype_Declaration (Loc,
4957 Defining_Identifier => Anon,
4958 Null_Exclusion_Present => True,
4959 Subtype_Indication =>
4960 New_Occurrence_Of (Etype (Ptype), Loc));
4962 -- Propagate the null-excluding attribute to the new entity
4964 if Null_Exclusion_Present (Param_Spec) then
4965 Set_Null_Exclusion_Present (Param_Spec, False);
4966 Set_Can_Never_Be_Null (Anon);
4969 Mark_Rewrite_Insertion (Decl);
4971 -- Insert the new declaration in the nearest enclosing scope
4973 while not Has_Declarations (P) loop
4977 Prepend (Decl, Declarations (P));
4979 Rewrite (Ptype, New_Occurrence_Of (Anon, Loc));
4980 Mark_Rewrite_Insertion (Ptype);
4982 -- Analyze the new declaration in the context of the
4985 Scope_Stack.Decrement_Last;
4987 Scope_Stack.Append (Curr_Scope);
4989 Formal_Type := Anon;
4993 -- Ada 0Y (AI-231): Static checks
4995 if Null_Exclusion_Present (Param_Spec)
4996 or else Can_Never_Be_Null (Entity (Ptype))
4998 Null_Exclusion_Static_Checks (Param_Spec);
5001 -- An access formal type
5005 Access_Definition (Related_Nod, Parameter_Type (Param_Spec));
5010 AD : constant Node_Id :=
5011 Access_To_Subprogram_Definition
5012 (Parameter_Type (Param_Spec));
5014 if Present (AD) and then Protected_Present (AD) then
5016 Replace_Anonymous_Access_To_Protected_Subprogram
5017 (Param_Spec, Formal_Type);
5022 Set_Etype (Formal, Formal_Type);
5023 Default := Expression (Param_Spec);
5025 if Present (Default) then
5026 if Out_Present (Param_Spec) then
5028 ("default initialization only allowed for IN parameters",
5032 -- Do the special preanalysis of the expression (see section on
5033 -- "Handling of Default Expressions" in the spec of package Sem).
5035 Analyze_Per_Use_Expression (Default, Formal_Type);
5037 -- Check that the designated type of an access parameter's
5038 -- default is not a class-wide type unless the parameter's
5039 -- designated type is also class-wide.
5041 if Ekind (Formal_Type) = E_Anonymous_Access_Type
5042 and then Is_Class_Wide_Default (Default)
5043 and then not Is_Class_Wide_Type (Designated_Type (Formal_Type))
5046 ("access to class-wide expression not allowed here", Default);
5054 -- Now set the kind (mode) of each formal
5056 Param_Spec := First (T);
5058 while Present (Param_Spec) loop
5059 Formal := Defining_Identifier (Param_Spec);
5060 Set_Formal_Mode (Formal);
5062 if Ekind (Formal) = E_In_Parameter then
5063 Set_Default_Value (Formal, Expression (Param_Spec));
5065 if Present (Expression (Param_Spec)) then
5066 Default := Expression (Param_Spec);
5068 if Is_Scalar_Type (Etype (Default)) then
5070 (Parameter_Type (Param_Spec)) /= N_Access_Definition
5072 Formal_Type := Entity (Parameter_Type (Param_Spec));
5075 Formal_Type := Access_Definition
5076 (Related_Nod, Parameter_Type (Param_Spec));
5079 Apply_Scalar_Range_Check (Default, Formal_Type);
5087 end Process_Formals;
5089 ----------------------------
5090 -- Reference_Body_Formals --
5091 ----------------------------
5093 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is
5098 if Error_Posted (Spec) then
5102 Fs := First_Formal (Spec);
5103 Fb := First_Formal (Bod);
5105 while Present (Fs) loop
5106 Generate_Reference (Fs, Fb, 'b');
5109 Style.Check_Identifier (Fb, Fs);
5112 Set_Spec_Entity (Fb, Fs);
5113 Set_Referenced (Fs, False);
5117 end Reference_Body_Formals;
5119 -------------------------
5120 -- Set_Actual_Subtypes --
5121 -------------------------
5123 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is
5124 Loc : constant Source_Ptr := Sloc (N);
5128 First_Stmt : Node_Id := Empty;
5129 AS_Needed : Boolean;
5132 -- If this is an emtpy initialization procedure, no need to create
5133 -- actual subtypes (small optimization).
5135 if Ekind (Subp) = E_Procedure
5136 and then Is_Null_Init_Proc (Subp)
5141 Formal := First_Formal (Subp);
5142 while Present (Formal) loop
5143 T := Etype (Formal);
5145 -- We never need an actual subtype for a constrained formal.
5147 if Is_Constrained (T) then
5150 -- If we have unknown discriminants, then we do not need an
5151 -- actual subtype, or more accurately we cannot figure it out!
5152 -- Note that all class-wide types have unknown discriminants.
5154 elsif Has_Unknown_Discriminants (T) then
5157 -- At this stage we have an unconstrained type that may need
5158 -- an actual subtype. For sure the actual subtype is needed
5159 -- if we have an unconstrained array type.
5161 elsif Is_Array_Type (T) then
5164 -- The only other case which needs an actual subtype is an
5165 -- unconstrained record type which is an IN parameter (we
5166 -- cannot generate actual subtypes for the OUT or IN OUT case,
5167 -- since an assignment can change the discriminant values.
5168 -- However we exclude the case of initialization procedures,
5169 -- since discriminants are handled very specially in this context,
5170 -- see the section entitled "Handling of Discriminants" in Einfo.
5171 -- We also exclude the case of Discrim_SO_Functions (functions
5172 -- used in front end layout mode for size/offset values), since
5173 -- in such functions only discriminants are referenced, and not
5174 -- only are such subtypes not needed, but they cannot always
5175 -- be generated, because of order of elaboration issues.
5177 elsif Is_Record_Type (T)
5178 and then Ekind (Formal) = E_In_Parameter
5179 and then Chars (Formal) /= Name_uInit
5180 and then not Is_Discrim_SO_Function (Subp)
5184 -- All other cases do not need an actual subtype
5190 -- Generate actual subtypes for unconstrained arrays and
5191 -- unconstrained discriminated records.
5194 if Nkind (N) = N_Accept_Statement then
5196 -- If expansion is active, The formal is replaced by a local
5197 -- variable that renames the corresponding entry of the
5198 -- parameter block, and it is this local variable that may
5199 -- require an actual subtype.
5201 if Expander_Active then
5202 Decl := Build_Actual_Subtype (T, Renamed_Object (Formal));
5204 Decl := Build_Actual_Subtype (T, Formal);
5207 if Present (Handled_Statement_Sequence (N)) then
5209 First (Statements (Handled_Statement_Sequence (N)));
5210 Prepend (Decl, Statements (Handled_Statement_Sequence (N)));
5211 Mark_Rewrite_Insertion (Decl);
5213 -- If the accept statement has no body, there will be
5214 -- no reference to the actuals, so no need to compute
5221 Decl := Build_Actual_Subtype (T, Formal);
5222 Prepend (Decl, Declarations (N));
5223 Mark_Rewrite_Insertion (Decl);
5226 -- The declaration uses the bounds of an existing object,
5227 -- and therefore needs no constraint checks.
5229 Analyze (Decl, Suppress => All_Checks);
5231 -- We need to freeze manually the generated type when it is
5232 -- inserted anywhere else than in a declarative part.
5234 if Present (First_Stmt) then
5235 Insert_List_Before_And_Analyze (First_Stmt,
5236 Freeze_Entity (Defining_Identifier (Decl), Loc));
5239 if Nkind (N) = N_Accept_Statement
5240 and then Expander_Active
5242 Set_Actual_Subtype (Renamed_Object (Formal),
5243 Defining_Identifier (Decl));
5245 Set_Actual_Subtype (Formal, Defining_Identifier (Decl));
5249 Next_Formal (Formal);
5251 end Set_Actual_Subtypes;
5253 ---------------------
5254 -- Set_Formal_Mode --
5255 ---------------------
5257 procedure Set_Formal_Mode (Formal_Id : Entity_Id) is
5258 Spec : constant Node_Id := Parent (Formal_Id);
5261 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
5262 -- since we ensure that corresponding actuals are always valid at the
5263 -- point of the call.
5265 if Out_Present (Spec) then
5266 if Ekind (Scope (Formal_Id)) = E_Function
5267 or else Ekind (Scope (Formal_Id)) = E_Generic_Function
5269 Error_Msg_N ("functions can only have IN parameters", Spec);
5270 Set_Ekind (Formal_Id, E_In_Parameter);
5272 elsif In_Present (Spec) then
5273 Set_Ekind (Formal_Id, E_In_Out_Parameter);
5276 Set_Ekind (Formal_Id, E_Out_Parameter);
5277 Set_Never_Set_In_Source (Formal_Id, True);
5278 Set_Is_True_Constant (Formal_Id, False);
5279 Set_Current_Value (Formal_Id, Empty);
5283 Set_Ekind (Formal_Id, E_In_Parameter);
5286 -- Set Is_Known_Non_Null for access parameters since the language
5287 -- guarantees that access parameters are always non-null. We also
5288 -- set Can_Never_Be_Null, since there is no way to change the value.
5290 if Nkind (Parameter_Type (Spec)) = N_Access_Definition then
5292 -- Ada 0Y (AI-231): This behaviour has been modified in Ada 0Y.
5293 -- It is only forced if the null_exclusion appears.
5295 if not Extensions_Allowed
5296 or else Null_Exclusion_Present (Spec)
5298 Set_Is_Known_Non_Null (Formal_Id);
5299 Set_Can_Never_Be_Null (Formal_Id);
5303 Set_Mechanism (Formal_Id, Default_Mechanism);
5304 Set_Formal_Validity (Formal_Id);
5305 end Set_Formal_Mode;
5307 -------------------------
5308 -- Set_Formal_Validity --
5309 -------------------------
5311 procedure Set_Formal_Validity (Formal_Id : Entity_Id) is
5313 -- If no validity checking, then we cannot assume anything about
5314 -- the validity of parameters, since we do not know there is any
5315 -- checking of the validity on the call side.
5317 if not Validity_Checks_On then
5320 -- If validity checking for parameters is enabled, this means we are
5321 -- not supposed to make any assumptions about argument values.
5323 elsif Validity_Check_Parameters then
5326 -- If we are checking in parameters, we will assume that the caller is
5327 -- also checking parameters, so we can assume the parameter is valid.
5329 elsif Ekind (Formal_Id) = E_In_Parameter
5330 and then Validity_Check_In_Params
5332 Set_Is_Known_Valid (Formal_Id, True);
5334 -- Similar treatment for IN OUT parameters
5336 elsif Ekind (Formal_Id) = E_In_Out_Parameter
5337 and then Validity_Check_In_Out_Params
5339 Set_Is_Known_Valid (Formal_Id, True);
5341 end Set_Formal_Validity;
5343 ------------------------
5344 -- Subtype_Conformant --
5345 ------------------------
5347 function Subtype_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
5351 Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result);
5353 end Subtype_Conformant;
5355 ---------------------
5356 -- Type_Conformant --
5357 ---------------------
5359 function Type_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
5362 Check_Conformance (New_Id, Old_Id, Type_Conformant, False, Result);
5364 end Type_Conformant;
5366 -------------------------------
5367 -- Valid_Operator_Definition --
5368 -------------------------------
5370 procedure Valid_Operator_Definition (Designator : Entity_Id) is
5373 Id : constant Name_Id := Chars (Designator);
5377 F := First_Formal (Designator);
5379 while Present (F) loop
5382 if Present (Default_Value (F)) then
5384 ("default values not allowed for operator parameters",
5391 -- Verify that user-defined operators have proper number of arguments
5392 -- First case of operators which can only be unary
5395 or else Id = Name_Op_Abs
5399 -- Case of operators which can be unary or binary
5401 elsif Id = Name_Op_Add
5402 or Id = Name_Op_Subtract
5404 N_OK := (N in 1 .. 2);
5406 -- All other operators can only be binary
5414 ("incorrect number of arguments for operator", Designator);
5418 and then Base_Type (Etype (Designator)) = Standard_Boolean
5419 and then not Is_Intrinsic_Subprogram (Designator)
5422 ("explicit definition of inequality not allowed", Designator);
5424 end Valid_Operator_Definition;