1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2003, 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.
92 type Conformance_Type is
93 (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant);
94 -- Conformance type used for following call, meaning matches the
95 -- RM definitions of the corresponding terms.
97 procedure Check_Conformance
100 Ctype : Conformance_Type;
102 Conforms : out Boolean;
103 Err_Loc : Node_Id := Empty;
104 Get_Inst : Boolean := False);
105 -- Given two entities, this procedure checks that the profiles associated
106 -- with these entities meet the conformance criterion given by the third
107 -- parameter. If they conform, Conforms is set True and control returns
108 -- to the caller. If they do not conform, Conforms is set to False, and
109 -- in addition, if Errmsg is True on the call, proper messages are output
110 -- to complain about the conformance failure. If Err_Loc is non_Empty
111 -- the error messages are placed on Err_Loc, if Err_Loc is empty, then
112 -- error messages are placed on the appropriate part of the construct
113 -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
114 -- against a formal access-to-subprogram type so Get_Instance_Of must
117 procedure Check_Overriding_Operation
120 -- Check that a subprogram with a pragma Overriding or Optional_Overriding
121 -- is legal. This check is performed here rather than in Sem_Prag because
122 -- the pragma must follow immediately the declaration, and can be treated
123 -- as part of the declaration itself, as described in AI-218.
125 procedure Check_Subprogram_Order (N : Node_Id);
126 -- N is the N_Subprogram_Body node for a subprogram. This routine applies
127 -- the alpha ordering rule for N if this ordering requirement applicable.
129 function Is_Non_Overriding_Operation
131 New_E : Entity_Id) return Boolean;
132 -- Enforce the rule given in 12.3(18): a private operation in an instance
133 -- overrides an inherited operation only if the corresponding operation
134 -- was overriding in the generic. This can happen for primitive operations
135 -- of types derived (in the generic unit) from formal private or formal
138 procedure Check_Returns
142 -- Called to check for missing return statements in a function body,
143 -- or for returns present in a procedure body which has No_Return set.
144 -- L is the handled statement sequence for the subprogram body. This
145 -- procedure checks all flow paths to make sure they either have a
146 -- return (Mode = 'F') or do not have a return (Mode = 'P'). The flag
147 -- Err is set if there are any control paths not explicitly terminated
148 -- by a return in the function case, and is True otherwise.
150 function Conforming_Types
153 Ctype : Conformance_Type;
154 Get_Inst : Boolean := False) return Boolean;
155 -- Check that two formal parameter types conform, checking both
156 -- for equality of base types, and where required statically
157 -- matching subtypes, depending on the setting of Ctype.
159 procedure Enter_Overloaded_Entity (S : Entity_Id);
160 -- This procedure makes S, a new overloaded entity, into the first
161 -- visible entity with that name.
163 procedure Install_Entity (E : Entity_Id);
164 -- Make single entity visible. Used for generic formals as well.
166 procedure Install_Formals (Id : Entity_Id);
167 -- On entry to a subprogram body, make the formals visible. Note
168 -- that simply placing the subprogram on the scope stack is not
169 -- sufficient: the formals must become the current entities for
172 procedure Make_Inequality_Operator (S : Entity_Id);
173 -- Create the declaration for an inequality operator that is implicitly
174 -- created by a user-defined equality operator that yields a boolean.
176 procedure May_Need_Actuals (Fun : Entity_Id);
177 -- Flag functions that can be called without parameters, i.e. those that
178 -- have no parameters, or those for which defaults exist for all parameters
180 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id);
181 -- If there is a separate spec for a subprogram or generic subprogram,
182 -- the formals of the body are treated as references to the corresponding
183 -- formals of the spec. This reference does not count as an actual use of
184 -- the formal, in order to diagnose formals that are unused in the body.
186 procedure Set_Formal_Validity (Formal_Id : Entity_Id);
187 -- Formal_Id is an formal parameter entity. This procedure deals with
188 -- setting the proper validity status for this entity, which depends
189 -- on the kind of parameter and the validity checking mode.
191 ---------------------------------------------
192 -- Analyze_Abstract_Subprogram_Declaration --
193 ---------------------------------------------
195 procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is
196 Designator : constant Entity_Id :=
197 Analyze_Subprogram_Specification (Specification (N));
198 Scop : constant Entity_Id := Current_Scope;
201 Generate_Definition (Designator);
202 Set_Is_Abstract (Designator);
203 New_Overloaded_Entity (Designator);
204 Check_Delayed_Subprogram (Designator);
206 Set_Categorization_From_Scope (Designator, Scop);
208 if Ekind (Scope (Designator)) = E_Protected_Type then
210 ("abstract subprogram not allowed in protected type", N);
213 Generate_Reference_To_Formals (Designator);
214 end Analyze_Abstract_Subprogram_Declaration;
216 ----------------------------
217 -- Analyze_Function_Call --
218 ----------------------------
220 procedure Analyze_Function_Call (N : Node_Id) is
221 P : constant Node_Id := Name (N);
222 L : constant List_Id := Parameter_Associations (N);
228 -- If error analyzing name, then set Any_Type as result type and return
230 if Etype (P) = Any_Type then
231 Set_Etype (N, Any_Type);
235 -- Otherwise analyze the parameters
240 while Present (Actual) loop
242 Check_Parameterless_Call (Actual);
248 end Analyze_Function_Call;
250 -------------------------------------
251 -- Analyze_Generic_Subprogram_Body --
252 -------------------------------------
254 procedure Analyze_Generic_Subprogram_Body
258 Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id);
259 Kind : constant Entity_Kind := Ekind (Gen_Id);
265 -- Copy body and disable expansion while analyzing the generic
266 -- For a stub, do not copy the stub (which would load the proper body),
267 -- this will be done when the proper body is analyzed.
269 if Nkind (N) /= N_Subprogram_Body_Stub then
270 New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
275 Spec := Specification (N);
277 -- Within the body of the generic, the subprogram is callable, and
278 -- behaves like the corresponding non-generic unit.
280 Body_Id := Defining_Entity (Spec);
282 if Kind = E_Generic_Procedure
283 and then Nkind (Spec) /= N_Procedure_Specification
285 Error_Msg_N ("invalid body for generic procedure ", Body_Id);
288 elsif Kind = E_Generic_Function
289 and then Nkind (Spec) /= N_Function_Specification
291 Error_Msg_N ("invalid body for generic function ", Body_Id);
295 Set_Corresponding_Body (Gen_Decl, Body_Id);
297 if Has_Completion (Gen_Id)
298 and then Nkind (Parent (N)) /= N_Subunit
300 Error_Msg_N ("duplicate generic body", N);
303 Set_Has_Completion (Gen_Id);
306 if Nkind (N) = N_Subprogram_Body_Stub then
307 Set_Ekind (Defining_Entity (Specification (N)), Kind);
309 Set_Corresponding_Spec (N, Gen_Id);
312 if Nkind (Parent (N)) = N_Compilation_Unit then
313 Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N));
316 -- Make generic parameters immediately visible in the body. They are
317 -- needed to process the formals declarations. Then make the formals
318 -- visible in a separate step.
324 First_Ent : Entity_Id;
327 First_Ent := First_Entity (Gen_Id);
330 while Present (E) and then not Is_Formal (E) loop
335 Set_Use (Generic_Formal_Declarations (Gen_Decl));
337 -- Now generic formals are visible, and the specification can be
338 -- analyzed, for subsequent conformance check.
340 Body_Id := Analyze_Subprogram_Specification (Spec);
342 -- Make formal parameters visible
346 -- E is the first formal parameter, we loop through the formals
347 -- installing them so that they will be visible.
349 Set_First_Entity (Gen_Id, E);
350 while Present (E) loop
356 -- Visible generic entity is callable within its own body.
358 Set_Ekind (Gen_Id, Ekind (Body_Id));
359 Set_Ekind (Body_Id, E_Subprogram_Body);
360 Set_Convention (Body_Id, Convention (Gen_Id));
361 Set_Scope (Body_Id, Scope (Gen_Id));
362 Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id);
364 if Nkind (N) = N_Subprogram_Body_Stub then
366 -- No body to analyze, so restore state of generic unit.
368 Set_Ekind (Gen_Id, Kind);
369 Set_Ekind (Body_Id, Kind);
371 if Present (First_Ent) then
372 Set_First_Entity (Gen_Id, First_Ent);
379 -- If this is a compilation unit, it must be made visible
380 -- explicitly, because the compilation of the declaration,
381 -- unlike other library unit declarations, does not. If it
382 -- is not a unit, the following is redundant but harmless.
384 Set_Is_Immediately_Visible (Gen_Id);
385 Reference_Body_Formals (Gen_Id, Body_Id);
387 Set_Actual_Subtypes (N, Current_Scope);
388 Analyze_Declarations (Declarations (N));
390 Analyze (Handled_Statement_Sequence (N));
392 Save_Global_References (Original_Node (N));
394 -- Prior to exiting the scope, include generic formals again
395 -- (if any are present) in the set of local entities.
397 if Present (First_Ent) then
398 Set_First_Entity (Gen_Id, First_Ent);
401 Check_References (Gen_Id);
405 Check_Subprogram_Order (N);
407 -- Outside of its body, unit is generic again.
409 Set_Ekind (Gen_Id, Kind);
410 Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False);
411 Style.Check_Identifier (Body_Id, Gen_Id);
413 end Analyze_Generic_Subprogram_Body;
415 -----------------------------
416 -- Analyze_Operator_Symbol --
417 -----------------------------
419 -- An operator symbol such as "+" or "and" may appear in context where
420 -- the literal denotes an entity name, such as "+"(x, y) or in a
421 -- context when it is just a string, as in (conjunction = "or"). In
422 -- these cases the parser generates this node, and the semantics does
423 -- the disambiguation. Other such case are actuals in an instantiation,
424 -- the generic unit in an instantiation, and pragma arguments.
426 procedure Analyze_Operator_Symbol (N : Node_Id) is
427 Par : constant Node_Id := Parent (N);
430 if (Nkind (Par) = N_Function_Call and then N = Name (Par))
431 or else Nkind (Par) = N_Function_Instantiation
432 or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par))
433 or else (Nkind (Par) = N_Pragma_Argument_Association
434 and then not Is_Pragma_String_Literal (Par))
435 or else Nkind (Par) = N_Subprogram_Renaming_Declaration
436 or else (Nkind (Par) = N_Attribute_Reference
437 and then Attribute_Name (Par) /= Name_Value)
439 Find_Direct_Name (N);
442 Change_Operator_Symbol_To_String_Literal (N);
445 end Analyze_Operator_Symbol;
447 -----------------------------------
448 -- Analyze_Parameter_Association --
449 -----------------------------------
451 procedure Analyze_Parameter_Association (N : Node_Id) is
453 Analyze (Explicit_Actual_Parameter (N));
454 end Analyze_Parameter_Association;
456 ----------------------------
457 -- Analyze_Procedure_Call --
458 ----------------------------
460 procedure Analyze_Procedure_Call (N : Node_Id) is
461 Loc : constant Source_Ptr := Sloc (N);
462 P : constant Node_Id := Name (N);
463 Actuals : constant List_Id := Parameter_Associations (N);
467 procedure Analyze_Call_And_Resolve;
468 -- Do Analyze and Resolve calls for procedure call
470 ------------------------------
471 -- Analyze_Call_And_Resolve --
472 ------------------------------
474 procedure Analyze_Call_And_Resolve is
476 if Nkind (N) = N_Procedure_Call_Statement then
478 Resolve (N, Standard_Void_Type);
482 end Analyze_Call_And_Resolve;
484 -- Start of processing for Analyze_Procedure_Call
487 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
488 -- a procedure call or an entry call. The prefix may denote an access
489 -- to subprogram type, in which case an implicit dereference applies.
490 -- If the prefix is an indexed component (without implicit defererence)
491 -- then the construct denotes a call to a member of an entire family.
492 -- If the prefix is a simple name, it may still denote a call to a
493 -- parameterless member of an entry family. Resolution of these various
494 -- interpretations is delicate.
498 -- If error analyzing prefix, then set Any_Type as result and return
500 if Etype (P) = Any_Type then
501 Set_Etype (N, Any_Type);
505 -- Otherwise analyze the parameters
507 if Present (Actuals) then
508 Actual := First (Actuals);
510 while Present (Actual) loop
512 Check_Parameterless_Call (Actual);
517 -- Special processing for Elab_Spec and Elab_Body calls
519 if Nkind (P) = N_Attribute_Reference
520 and then (Attribute_Name (P) = Name_Elab_Spec
521 or else Attribute_Name (P) = Name_Elab_Body)
523 if Present (Actuals) then
525 ("no parameters allowed for this call", First (Actuals));
529 Set_Etype (N, Standard_Void_Type);
532 elsif Is_Entity_Name (P)
533 and then Is_Record_Type (Etype (Entity (P)))
534 and then Remote_AST_I_Dereference (P)
538 elsif Is_Entity_Name (P)
539 and then Ekind (Entity (P)) /= E_Entry_Family
541 if Is_Access_Type (Etype (P))
542 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
543 and then No (Actuals)
544 and then Comes_From_Source (N)
546 Error_Msg_N ("missing explicit dereference in call", N);
549 Analyze_Call_And_Resolve;
551 -- If the prefix is the simple name of an entry family, this is
552 -- a parameterless call from within the task body itself.
554 elsif Is_Entity_Name (P)
555 and then Nkind (P) = N_Identifier
556 and then Ekind (Entity (P)) = E_Entry_Family
557 and then Present (Actuals)
558 and then No (Next (First (Actuals)))
560 -- Can be call to parameterless entry family. What appears to be
561 -- the sole argument is in fact the entry index. Rewrite prefix
562 -- of node accordingly. Source representation is unchanged by this
566 Make_Indexed_Component (Loc,
568 Make_Selected_Component (Loc,
569 Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc),
570 Selector_Name => New_Occurrence_Of (Entity (P), Loc)),
571 Expressions => Actuals);
573 Set_Etype (New_N, Standard_Void_Type);
574 Set_Parameter_Associations (N, No_List);
575 Analyze_Call_And_Resolve;
577 elsif Nkind (P) = N_Explicit_Dereference then
578 if Ekind (Etype (P)) = E_Subprogram_Type then
579 Analyze_Call_And_Resolve;
581 Error_Msg_N ("expect access to procedure in call", P);
584 -- The name can be a selected component or an indexed component
585 -- that yields an access to subprogram. Such a prefix is legal if
586 -- the call has parameter associations.
588 elsif Is_Access_Type (Etype (P))
589 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
591 if Present (Actuals) then
592 Analyze_Call_And_Resolve;
594 Error_Msg_N ("missing explicit dereference in call ", N);
597 -- If not an access to subprogram, then the prefix must resolve to
598 -- the name of an entry, entry family, or protected operation.
600 -- For the case of a simple entry call, P is a selected component
601 -- where the prefix is the task and the selector name is the entry.
602 -- A call to a protected procedure will have the same syntax. If
603 -- the protected object contains overloaded operations, the entity
604 -- may appear as a function, the context will select the operation
605 -- whose type is Void.
607 elsif Nkind (P) = N_Selected_Component
608 and then (Ekind (Entity (Selector_Name (P))) = E_Entry
610 Ekind (Entity (Selector_Name (P))) = E_Procedure
612 Ekind (Entity (Selector_Name (P))) = E_Function)
614 Analyze_Call_And_Resolve;
616 elsif Nkind (P) = N_Selected_Component
617 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family
618 and then Present (Actuals)
619 and then No (Next (First (Actuals)))
621 -- Can be call to parameterless entry family. What appears to be
622 -- the sole argument is in fact the entry index. Rewrite prefix
623 -- of node accordingly. Source representation is unchanged by this
627 Make_Indexed_Component (Loc,
628 Prefix => New_Copy (P),
629 Expressions => Actuals);
631 Set_Etype (New_N, Standard_Void_Type);
632 Set_Parameter_Associations (N, No_List);
633 Analyze_Call_And_Resolve;
635 -- For the case of a reference to an element of an entry family, P is
636 -- an indexed component whose prefix is a selected component (task and
637 -- entry family), and whose index is the entry family index.
639 elsif Nkind (P) = N_Indexed_Component
640 and then Nkind (Prefix (P)) = N_Selected_Component
641 and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family
643 Analyze_Call_And_Resolve;
645 -- If the prefix is the name of an entry family, it is a call from
646 -- within the task body itself.
648 elsif Nkind (P) = N_Indexed_Component
649 and then Nkind (Prefix (P)) = N_Identifier
650 and then Ekind (Entity (Prefix (P))) = E_Entry_Family
653 Make_Selected_Component (Loc,
654 Prefix => New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc),
655 Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc));
656 Rewrite (Prefix (P), New_N);
658 Analyze_Call_And_Resolve;
660 -- Anything else is an error.
663 Error_Msg_N ("Invalid procedure or entry call", N);
665 end Analyze_Procedure_Call;
667 ------------------------------
668 -- Analyze_Return_Statement --
669 ------------------------------
671 procedure Analyze_Return_Statement (N : Node_Id) is
672 Loc : constant Source_Ptr := Sloc (N);
674 Scope_Id : Entity_Id;
679 -- Find subprogram or accept statement enclosing the return statement
682 for J in reverse 0 .. Scope_Stack.Last loop
683 Scope_Id := Scope_Stack.Table (J).Entity;
684 exit when Ekind (Scope_Id) /= E_Block and then
685 Ekind (Scope_Id) /= E_Loop;
688 pragma Assert (Present (Scope_Id));
690 Kind := Ekind (Scope_Id);
691 Expr := Expression (N);
693 if Kind /= E_Function
694 and then Kind /= E_Generic_Function
695 and then Kind /= E_Procedure
696 and then Kind /= E_Generic_Procedure
697 and then Kind /= E_Entry
698 and then Kind /= E_Entry_Family
700 Error_Msg_N ("illegal context for return statement", N);
702 elsif Present (Expr) then
703 if Kind = E_Function or else Kind = E_Generic_Function then
704 Set_Return_Present (Scope_Id);
705 R_Type := Etype (Scope_Id);
706 Set_Return_Type (N, R_Type);
707 Analyze_And_Resolve (Expr, R_Type);
709 if (Is_Class_Wide_Type (Etype (Expr))
710 or else Is_Dynamically_Tagged (Expr))
711 and then not Is_Class_Wide_Type (R_Type)
714 ("dynamically tagged expression not allowed!", Expr);
717 Apply_Constraint_Check (Expr, R_Type);
719 -- ??? A real run-time accessibility check is needed
720 -- in cases involving dereferences of access parameters.
721 -- For now we just check the static cases.
723 if Is_Return_By_Reference_Type (Etype (Scope_Id))
724 and then Object_Access_Level (Expr)
725 > Subprogram_Access_Level (Scope_Id)
728 Make_Raise_Program_Error (Loc,
729 Reason => PE_Accessibility_Check_Failed));
733 ("cannot return a local value by reference?", N);
735 ("& will be raised at run time?!",
736 N, Standard_Program_Error);
739 elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then
740 Error_Msg_N ("procedure cannot return value (use function)", N);
743 Error_Msg_N ("accept statement cannot return value", N);
746 -- No expression present
749 if Kind = E_Function or Kind = E_Generic_Function then
750 Error_Msg_N ("missing expression in return from function", N);
753 if (Ekind (Scope_Id) = E_Procedure
754 or else Ekind (Scope_Id) = E_Generic_Procedure)
755 and then No_Return (Scope_Id)
758 ("RETURN statement not allowed (No_Return)", N);
762 Check_Unreachable_Code (N);
763 end Analyze_Return_Statement;
765 -----------------------------
766 -- Analyze_Subprogram_Body --
767 -----------------------------
769 -- This procedure is called for regular subprogram bodies, generic bodies,
770 -- and for subprogram stubs of both kinds. In the case of stubs, only the
771 -- specification matters, and is used to create a proper declaration for
772 -- the subprogram, or to perform conformance checks.
774 procedure Analyze_Subprogram_Body (N : Node_Id) is
775 Loc : constant Source_Ptr := Sloc (N);
776 Body_Spec : constant Node_Id := Specification (N);
777 Body_Id : Entity_Id := Defining_Entity (Body_Spec);
778 Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id);
779 Body_Deleted : constant Boolean := False;
783 Spec_Decl : Node_Id := Empty;
784 Last_Formal : Entity_Id := Empty;
785 Conformant : Boolean;
786 Missing_Ret : Boolean;
791 Write_Str ("==== Compiling subprogram body ");
792 Write_Name (Chars (Body_Id));
793 Write_Str (" from ");
794 Write_Location (Loc);
798 Trace_Scope (N, Body_Id, " Analyze subprogram");
800 -- Generic subprograms are handled separately. They always have
801 -- a generic specification. Determine whether current scope has
802 -- a previous declaration.
804 -- If the subprogram body is defined within an instance of the
805 -- same name, the instance appears as a package renaming, and
806 -- will be hidden within the subprogram.
809 and then not Is_Overloadable (Prev_Id)
810 and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration
811 or else Comes_From_Source (Prev_Id))
813 if Is_Generic_Subprogram (Prev_Id) then
815 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
816 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
818 Analyze_Generic_Subprogram_Body (N, Spec_Id);
822 -- Previous entity conflicts with subprogram name.
823 -- Attempting to enter name will post error.
825 Enter_Name (Body_Id);
829 -- Non-generic case, find the subprogram declaration, if one was
830 -- seen, or enter new overloaded entity in the current scope.
831 -- If the current_entity is the body_id itself, the unit is being
832 -- analyzed as part of the context of one of its subunits. No need
833 -- to redo the analysis.
835 elsif Prev_Id = Body_Id
836 and then Has_Completion (Body_Id)
841 Body_Id := Analyze_Subprogram_Specification (Body_Spec);
843 if Nkind (N) = N_Subprogram_Body_Stub
844 or else No (Corresponding_Spec (N))
846 Spec_Id := Find_Corresponding_Spec (N);
848 -- If this is a duplicate body, no point in analyzing it
850 if Error_Posted (N) then
854 -- A subprogram body should cause freezing of its own
855 -- declaration, but if there was no previous explicit
856 -- declaration, then the subprogram will get frozen too
857 -- late (there may be code within the body that depends
858 -- on the subprogram having been frozen, such as uses of
859 -- extra formals), so we force it to be frozen here.
860 -- Same holds if the body and the spec are compilation units.
863 Freeze_Before (N, Body_Id);
865 elsif Nkind (Parent (N)) = N_Compilation_Unit then
866 Freeze_Before (N, Spec_Id);
869 Spec_Id := Corresponding_Spec (N);
873 -- Do not inline any subprogram that contains nested subprograms,
874 -- since the backend inlining circuit seems to generate uninitialized
875 -- references in this case. We know this happens in the case of front
876 -- end ZCX support, but it also appears it can happen in other cases
877 -- as well. The backend often rejects attempts to inline in the case
878 -- of nested procedures anyway, so little if anything is lost by this.
880 -- Do not do this test if errors have been detected, because in some
881 -- error cases, this code blows up, and we don't need it anyway if
882 -- there have been errors, since we won't get to the linker anyway.
884 if Serious_Errors_Detected = 0 then
887 P_Ent := Scope (P_Ent);
888 exit when No (P_Ent) or else P_Ent = Standard_Standard;
890 if Is_Subprogram (P_Ent) then
891 Set_Is_Inlined (P_Ent, False);
893 if Comes_From_Source (P_Ent)
894 and then Has_Pragma_Inline (P_Ent)
897 ("cannot inline& (nested subprogram)?",
904 -- Case of fully private operation in the body of the protected type.
905 -- We must create a declaration for the subprogram, in order to attach
906 -- the protected subprogram that will be used in internal calls.
909 and then Comes_From_Source (N)
910 and then Is_Protected_Type (Current_Scope)
919 Formal := First_Formal (Body_Id);
921 -- The protected operation always has at least one formal,
922 -- namely the object itself, but it is only placed in the
923 -- parameter list if expansion is enabled.
926 or else Expander_Active
934 while Present (Formal) loop
936 (Make_Parameter_Specification (Loc,
937 Defining_Identifier =>
938 Make_Defining_Identifier (Sloc (Formal),
939 Chars => Chars (Formal)),
940 In_Present => In_Present (Parent (Formal)),
941 Out_Present => Out_Present (Parent (Formal)),
943 New_Reference_To (Etype (Formal), Loc),
945 New_Copy_Tree (Expression (Parent (Formal)))),
948 Next_Formal (Formal);
951 if Nkind (Body_Spec) = N_Procedure_Specification then
953 Make_Procedure_Specification (Loc,
954 Defining_Unit_Name =>
955 Make_Defining_Identifier (Sloc (Body_Id),
956 Chars => Chars (Body_Id)),
957 Parameter_Specifications => Plist);
960 Make_Function_Specification (Loc,
961 Defining_Unit_Name =>
962 Make_Defining_Identifier (Sloc (Body_Id),
963 Chars => Chars (Body_Id)),
964 Parameter_Specifications => Plist,
965 Subtype_Mark => New_Occurrence_Of (Etype (Body_Id), Loc));
969 Make_Subprogram_Declaration (Loc,
970 Specification => New_Spec);
971 Insert_Before (N, Decl);
973 Spec_Id := Defining_Unit_Name (New_Spec);
974 Set_Has_Completion (Spec_Id);
975 Set_Convention (Spec_Id, Convention_Protected);
978 elsif Present (Spec_Id) then
979 Spec_Decl := Unit_Declaration_Node (Spec_Id);
982 -- Place subprogram on scope stack, and make formals visible. If there
983 -- is a spec, the visible entity remains that of the spec.
985 if Present (Spec_Id) then
986 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
988 Style.Check_Identifier (Body_Id, Spec_Id);
991 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
992 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
994 if Is_Abstract (Spec_Id) then
995 Error_Msg_N ("an abstract subprogram cannot have a body", N);
998 Set_Convention (Body_Id, Convention (Spec_Id));
999 Set_Has_Completion (Spec_Id);
1001 if Is_Protected_Type (Scope (Spec_Id)) then
1002 Set_Privals_Chain (Spec_Id, New_Elmt_List);
1005 -- If this is a body generated for a renaming, do not check for
1006 -- full conformance. The check is redundant, because the spec of
1007 -- the body is a copy of the spec in the renaming declaration,
1008 -- and the test can lead to spurious errors on nested defaults.
1010 if Present (Spec_Decl)
1011 and then not Comes_From_Source (N)
1013 (Nkind (Original_Node (Spec_Decl)) =
1014 N_Subprogram_Renaming_Declaration
1015 or else (Present (Corresponding_Body (Spec_Decl))
1017 Nkind (Unit_Declaration_Node
1018 (Corresponding_Body (Spec_Decl))) =
1019 N_Subprogram_Renaming_Declaration))
1025 Fully_Conformant, True, Conformant, Body_Id);
1028 -- If the body is not fully conformant, we have to decide if we
1029 -- should analyze it or not. If it has a really messed up profile
1030 -- then we probably should not analyze it, since we will get too
1031 -- many bogus messages.
1033 -- Our decision is to go ahead in the non-fully conformant case
1034 -- only if it is at least mode conformant with the spec. Note
1035 -- that the call to Check_Fully_Conformant has issued the proper
1036 -- error messages to complain about the lack of conformance.
1039 and then not Mode_Conformant (Body_Id, Spec_Id)
1045 if Spec_Id /= Body_Id then
1046 Reference_Body_Formals (Spec_Id, Body_Id);
1049 if Nkind (N) /= N_Subprogram_Body_Stub then
1050 Set_Corresponding_Spec (N, Spec_Id);
1051 Install_Formals (Spec_Id);
1052 Last_Formal := Last_Entity (Spec_Id);
1053 New_Scope (Spec_Id);
1055 -- Make sure that the subprogram is immediately visible. For
1056 -- child units that have no separate spec this is indispensable.
1057 -- Otherwise it is safe albeit redundant.
1059 Set_Is_Immediately_Visible (Spec_Id);
1062 Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id);
1063 Set_Ekind (Body_Id, E_Subprogram_Body);
1064 Set_Scope (Body_Id, Scope (Spec_Id));
1066 -- Case of subprogram body with no previous spec
1070 and then Comes_From_Source (Body_Id)
1071 and then not Suppress_Style_Checks (Body_Id)
1072 and then not In_Instance
1074 Style.Body_With_No_Spec (N);
1077 New_Overloaded_Entity (Body_Id);
1079 if Nkind (N) /= N_Subprogram_Body_Stub then
1080 Set_Acts_As_Spec (N);
1081 Generate_Definition (Body_Id);
1083 (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True);
1084 Generate_Reference_To_Formals (Body_Id);
1085 Install_Formals (Body_Id);
1086 New_Scope (Body_Id);
1090 -- If this is the proper body of a stub, we must verify that the stub
1091 -- conforms to the body, and to the previous spec if one was present.
1092 -- we know already that the body conforms to that spec. This test is
1093 -- only required for subprograms that come from source.
1095 if Nkind (Parent (N)) = N_Subunit
1096 and then Comes_From_Source (N)
1097 and then not Error_Posted (Body_Id)
1100 Old_Id : constant Entity_Id :=
1102 (Specification (Corresponding_Stub (Parent (N))));
1104 Conformant : Boolean := False;
1107 if No (Spec_Id) then
1108 Check_Fully_Conformant (Body_Id, Old_Id);
1112 (Body_Id, Old_Id, Fully_Conformant, False, Conformant);
1114 if not Conformant then
1116 -- The stub was taken to be a new declaration. Indicate
1117 -- that it lacks a body.
1119 Set_Has_Completion (Old_Id, False);
1125 Set_Has_Completion (Body_Id);
1126 Check_Eliminated (Body_Id);
1128 if Nkind (N) = N_Subprogram_Body_Stub then
1131 elsif Present (Spec_Id)
1132 and then Expander_Active
1133 and then (Is_Always_Inlined (Spec_Id)
1134 or else (Has_Pragma_Inline (Spec_Id)
1137 or else Configurable_Run_Time_Mode)))
1139 Build_Body_To_Inline (N, Spec_Id);
1142 -- Now we can go on to analyze the body
1144 HSS := Handled_Statement_Sequence (N);
1145 Set_Actual_Subtypes (N, Current_Scope);
1146 Analyze_Declarations (Declarations (N));
1149 Process_End_Label (HSS, 't', Current_Scope);
1151 Check_Subprogram_Order (N);
1153 -- If we have a separate spec, then the analysis of the declarations
1154 -- caused the entities in the body to be chained to the spec id, but
1155 -- we want them chained to the body id. Only the formal parameters
1156 -- end up chained to the spec id in this case.
1158 if Present (Spec_Id) then
1160 -- If a parent unit is categorized, the context of a subunit
1161 -- must conform to the categorization. Conversely, if a child
1162 -- unit is categorized, the parents themselves must conform.
1164 if Nkind (Parent (N)) = N_Subunit then
1165 Validate_Categorization_Dependency (N, Spec_Id);
1167 elsif Is_Child_Unit (Spec_Id) then
1168 Validate_Categorization_Dependency
1169 (Unit_Declaration_Node (Spec_Id), Spec_Id);
1172 if Present (Last_Formal) then
1174 (Last_Entity (Body_Id), Next_Entity (Last_Formal));
1175 Set_Next_Entity (Last_Formal, Empty);
1176 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
1177 Set_Last_Entity (Spec_Id, Last_Formal);
1180 Set_First_Entity (Body_Id, First_Entity (Spec_Id));
1181 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
1182 Set_First_Entity (Spec_Id, Empty);
1183 Set_Last_Entity (Spec_Id, Empty);
1187 -- If function, check return statements
1189 if Nkind (Body_Spec) = N_Function_Specification then
1194 if Present (Spec_Id) then
1200 if Return_Present (Id) then
1201 Check_Returns (HSS, 'F', Missing_Ret);
1204 Set_Has_Missing_Return (Id);
1207 elsif not Is_Machine_Code_Subprogram (Id)
1208 and then not Body_Deleted
1210 Error_Msg_N ("missing RETURN statement in function body", N);
1214 -- If procedure with No_Return, check returns
1216 elsif Nkind (Body_Spec) = N_Procedure_Specification
1217 and then Present (Spec_Id)
1218 and then No_Return (Spec_Id)
1220 Check_Returns (HSS, 'P', Missing_Ret);
1223 -- Now we are going to check for variables that are never modified
1224 -- in the body of the procedure. We omit these checks if the first
1225 -- statement of the procedure raises an exception. In particular
1226 -- this deals with the common idiom of a stubbed function, which
1227 -- might appear as something like
1229 -- function F (A : Integer) return Some_Type;
1232 -- raise Program_Error;
1236 -- Here the purpose of X is simply to satisfy the (annoying)
1237 -- requirement in Ada that there be at least one return, and
1238 -- we certainly do not want to go posting warnings on X that
1239 -- it is not initialized!
1242 Stm : Node_Id := First (Statements (HSS));
1245 -- Skip an initial label (for one thing this occurs when we
1246 -- are in front end ZCX mode, but in any case it is irrelevant).
1248 if Nkind (Stm) = N_Label then
1252 -- Do the test on the original statement before expansion
1255 Ostm : constant Node_Id := Original_Node (Stm);
1258 -- If explicit raise statement, return with no checks
1260 if Nkind (Ostm) = N_Raise_Statement then
1263 -- Check for explicit call cases which likely raise an exception
1265 elsif Nkind (Ostm) = N_Procedure_Call_Statement then
1266 if Is_Entity_Name (Name (Ostm)) then
1268 Ent : constant Entity_Id := Entity (Name (Ostm));
1271 -- If the procedure is marked No_Return, then likely it
1272 -- raises an exception, but in any case it is not coming
1273 -- back here, so no need to check beyond the call.
1275 if Ekind (Ent) = E_Procedure
1276 and then No_Return (Ent)
1280 -- If the procedure name is Raise_Exception, then also
1281 -- assume that it raises an exception. The main target
1282 -- here is Ada.Exceptions.Raise_Exception, but this name
1283 -- is pretty evocative in any context! Note that the
1284 -- procedure in Ada.Exceptions is not marked No_Return
1285 -- because of the annoying case of the null exception Id.
1287 elsif Chars (Ent) = Name_Raise_Exception then
1296 -- Check for variables that are never modified
1302 -- If there is a separate spec, then transfer Never_Set_In_Source
1303 -- flags from out parameters to the corresponding entities in the
1304 -- body. The reason we do that is we want to post error flags on
1305 -- the body entities, not the spec entities.
1307 if Present (Spec_Id) then
1308 E1 := First_Entity (Spec_Id);
1310 while Present (E1) loop
1311 if Ekind (E1) = E_Out_Parameter then
1312 E2 := First_Entity (Body_Id);
1313 while Present (E2) loop
1314 exit when Chars (E1) = Chars (E2);
1318 if Present (E2) then
1319 Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1));
1327 -- Check references in body unless it was deleted. Note that the
1328 -- check of Body_Deleted here is not just for efficiency, it is
1329 -- necessary to avoid junk warnings on formal parameters.
1331 if not Body_Deleted then
1332 Check_References (Body_Id);
1335 end Analyze_Subprogram_Body;
1337 ------------------------------------
1338 -- Analyze_Subprogram_Declaration --
1339 ------------------------------------
1341 procedure Analyze_Subprogram_Declaration (N : Node_Id) is
1342 Designator : constant Entity_Id :=
1343 Analyze_Subprogram_Specification (Specification (N));
1344 Scop : constant Entity_Id := Current_Scope;
1346 -- Start of processing for Analyze_Subprogram_Declaration
1349 Generate_Definition (Designator);
1351 -- Check for RCI unit subprogram declarations against in-lined
1352 -- subprograms and subprograms having access parameter or limited
1353 -- parameter without Read and Write (RM E.2.3(12-13)).
1355 Validate_RCI_Subprogram_Declaration (N);
1359 Defining_Entity (N),
1360 " Analyze subprogram spec. ");
1362 if Debug_Flag_C then
1363 Write_Str ("==== Compiling subprogram spec ");
1364 Write_Name (Chars (Designator));
1365 Write_Str (" from ");
1366 Write_Location (Sloc (N));
1370 New_Overloaded_Entity (Designator);
1371 Check_Delayed_Subprogram (Designator);
1373 -- What is the following code for, it used to be
1375 -- ??? Set_Suppress_Elaboration_Checks
1376 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator));
1378 -- The following seems equivalent, but a bit dubious
1380 if Elaboration_Checks_Suppressed (Designator) then
1381 Set_Kill_Elaboration_Checks (Designator);
1384 if Scop /= Standard_Standard
1385 and then not Is_Child_Unit (Designator)
1387 Set_Categorization_From_Scope (Designator, Scop);
1389 -- For a compilation unit, check for library-unit pragmas.
1391 New_Scope (Designator);
1392 Set_Categorization_From_Pragmas (N);
1393 Validate_Categorization_Dependency (N, Designator);
1397 -- For a compilation unit, set body required. This flag will only be
1398 -- reset if a valid Import or Interface pragma is processed later on.
1400 if Nkind (Parent (N)) = N_Compilation_Unit then
1401 Set_Body_Required (Parent (N), True);
1404 Generate_Reference_To_Formals (Designator);
1405 Check_Eliminated (Designator);
1407 if Comes_From_Source (N)
1408 and then Is_List_Member (N)
1410 Check_Overriding_Operation (N, Designator);
1413 end Analyze_Subprogram_Declaration;
1415 --------------------------------------
1416 -- Analyze_Subprogram_Specification --
1417 --------------------------------------
1419 -- Reminder: N here really is a subprogram specification (not a subprogram
1420 -- declaration). This procedure is called to analyze the specification in
1421 -- both subprogram bodies and subprogram declarations (specs).
1423 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is
1424 Designator : constant Entity_Id := Defining_Entity (N);
1425 Formals : constant List_Id := Parameter_Specifications (N);
1429 Generate_Definition (Designator);
1431 if Nkind (N) = N_Function_Specification then
1432 Set_Ekind (Designator, E_Function);
1433 Set_Mechanism (Designator, Default_Mechanism);
1435 if Subtype_Mark (N) /= Error then
1436 Find_Type (Subtype_Mark (N));
1437 Typ := Entity (Subtype_Mark (N));
1438 Set_Etype (Designator, Typ);
1440 if Ekind (Typ) = E_Incomplete_Type
1441 or else (Is_Class_Wide_Type (Typ)
1443 Ekind (Root_Type (Typ)) = E_Incomplete_Type)
1446 ("invalid use of incomplete type", Subtype_Mark (N));
1450 Set_Etype (Designator, Any_Type);
1454 Set_Ekind (Designator, E_Procedure);
1455 Set_Etype (Designator, Standard_Void_Type);
1458 if Present (Formals) then
1459 Set_Scope (Designator, Current_Scope);
1460 New_Scope (Designator);
1461 Process_Formals (Formals, N);
1465 if Nkind (N) = N_Function_Specification then
1466 if Nkind (Designator) = N_Defining_Operator_Symbol then
1467 Valid_Operator_Definition (Designator);
1470 May_Need_Actuals (Designator);
1472 if Is_Abstract (Etype (Designator))
1473 and then Nkind (Parent (N)) /= N_Abstract_Subprogram_Declaration
1476 ("function that returns abstract type must be abstract", N);
1481 end Analyze_Subprogram_Specification;
1483 --------------------------
1484 -- Build_Body_To_Inline --
1485 --------------------------
1487 procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id) is
1488 Decl : constant Node_Id := Unit_Declaration_Node (Subp);
1489 Original_Body : Node_Id;
1490 Body_To_Analyze : Node_Id;
1491 Max_Size : constant := 10;
1492 Stat_Count : Integer := 0;
1494 function Has_Excluded_Declaration (Decls : List_Id) return Boolean;
1495 -- Check for declarations that make inlining not worthwhile.
1497 function Has_Excluded_Statement (Stats : List_Id) return Boolean;
1498 -- Check for statements that make inlining not worthwhile: any
1499 -- tasking statement, nested at any level. Keep track of total
1500 -- number of elementary statements, as a measure of acceptable size.
1502 function Has_Pending_Instantiation return Boolean;
1503 -- If some enclosing body contains instantiations that appear before
1504 -- the corresponding generic body, the enclosing body has a freeze node
1505 -- so that it can be elaborated after the generic itself. This might
1506 -- conflict with subsequent inlinings, so that it is unsafe to try to
1507 -- inline in such a case.
1509 procedure Remove_Pragmas;
1510 -- A pragma Unreferenced that mentions a formal parameter has no
1511 -- meaning when the body is inlined and the formals are rewritten.
1512 -- Remove it from body to inline. The analysis of the non-inlined
1513 -- body will handle the pragma properly.
1515 ------------------------------
1516 -- Has_Excluded_Declaration --
1517 ------------------------------
1519 function Has_Excluded_Declaration (Decls : List_Id) return Boolean is
1522 function Is_Unchecked_Conversion (D : Node_Id) return Boolean;
1523 -- Nested subprograms make a given body ineligible for inlining,
1524 -- but we make an exception for instantiations of unchecked
1525 -- conversion. The body has not been analyzed yet, so we check
1526 -- the name, and verify that the visible entity with that name is
1527 -- the predefined unit.
1529 function Is_Unchecked_Conversion (D : Node_Id) return Boolean is
1530 Id : constant Node_Id := Name (D);
1534 if Nkind (Id) = N_Identifier
1535 and then Chars (Id) = Name_Unchecked_Conversion
1537 Conv := Current_Entity (Id);
1539 elsif Nkind (Id) = N_Selected_Component
1540 and then Chars (Selector_Name (Id)) = Name_Unchecked_Conversion
1542 Conv := Current_Entity (Selector_Name (Id));
1550 and then Scope (Conv) = Standard_Standard
1551 and then Is_Intrinsic_Subprogram (Conv);
1552 end Is_Unchecked_Conversion;
1554 -- Start of processing for Has_Excluded_Declaration
1559 while Present (D) loop
1560 if (Nkind (D) = N_Function_Instantiation
1561 and then not Is_Unchecked_Conversion (D))
1562 or else Nkind (D) = N_Protected_Type_Declaration
1563 or else Nkind (D) = N_Package_Declaration
1564 or else Nkind (D) = N_Package_Instantiation
1565 or else Nkind (D) = N_Subprogram_Body
1566 or else Nkind (D) = N_Procedure_Instantiation
1567 or else Nkind (D) = N_Task_Type_Declaration
1570 ("cannot inline & (non-allowed declaration)?", D, Subp);
1578 end Has_Excluded_Declaration;
1580 ----------------------------
1581 -- Has_Excluded_Statement --
1582 ----------------------------
1584 function Has_Excluded_Statement (Stats : List_Id) return Boolean is
1591 while Present (S) loop
1592 Stat_Count := Stat_Count + 1;
1594 if Nkind (S) = N_Abort_Statement
1595 or else Nkind (S) = N_Asynchronous_Select
1596 or else Nkind (S) = N_Conditional_Entry_Call
1597 or else Nkind (S) = N_Delay_Relative_Statement
1598 or else Nkind (S) = N_Delay_Until_Statement
1599 or else Nkind (S) = N_Selective_Accept
1600 or else Nkind (S) = N_Timed_Entry_Call
1603 ("cannot inline & (non-allowed statement)?", S, Subp);
1606 elsif Nkind (S) = N_Block_Statement then
1607 if Present (Declarations (S))
1608 and then Has_Excluded_Declaration (Declarations (S))
1612 elsif Present (Handled_Statement_Sequence (S))
1615 (Exception_Handlers (Handled_Statement_Sequence (S)))
1617 Has_Excluded_Statement
1618 (Statements (Handled_Statement_Sequence (S))))
1623 elsif Nkind (S) = N_Case_Statement then
1624 E := First (Alternatives (S));
1626 while Present (E) loop
1627 if Has_Excluded_Statement (Statements (E)) then
1634 elsif Nkind (S) = N_If_Statement then
1635 if Has_Excluded_Statement (Then_Statements (S)) then
1639 if Present (Elsif_Parts (S)) then
1640 E := First (Elsif_Parts (S));
1642 while Present (E) loop
1643 if Has_Excluded_Statement (Then_Statements (E)) then
1650 if Present (Else_Statements (S))
1651 and then Has_Excluded_Statement (Else_Statements (S))
1656 elsif Nkind (S) = N_Loop_Statement
1657 and then Has_Excluded_Statement (Statements (S))
1666 end Has_Excluded_Statement;
1668 -------------------------------
1669 -- Has_Pending_Instantiation --
1670 -------------------------------
1672 function Has_Pending_Instantiation return Boolean is
1673 S : Entity_Id := Current_Scope;
1676 while Present (S) loop
1677 if Is_Compilation_Unit (S)
1678 or else Is_Child_Unit (S)
1681 elsif Ekind (S) = E_Package
1682 and then Has_Forward_Instantiation (S)
1691 end Has_Pending_Instantiation;
1693 --------------------
1694 -- Remove_Pragmas --
1695 --------------------
1697 procedure Remove_Pragmas is
1702 Decl := First (Declarations (Body_To_Analyze));
1703 while Present (Decl) loop
1706 if Nkind (Decl) = N_Pragma
1707 and then Chars (Decl) = Name_Unreferenced
1716 -- Start of processing for Build_Body_To_Inline
1719 if Nkind (Decl) = N_Subprogram_Declaration
1720 and then Present (Body_To_Inline (Decl))
1722 return; -- Done already.
1724 -- Functions that return unconstrained composite types will require
1725 -- secondary stack handling, and cannot currently be inlined.
1727 elsif Ekind (Subp) = E_Function
1728 and then not Is_Scalar_Type (Etype (Subp))
1729 and then not Is_Access_Type (Etype (Subp))
1730 and then not Is_Constrained (Etype (Subp))
1733 ("cannot inline & (unconstrained return type)?", N, Subp);
1737 if Present (Declarations (N))
1738 and then Has_Excluded_Declaration (Declarations (N))
1743 if Present (Handled_Statement_Sequence (N)) then
1744 if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then
1746 ("cannot inline& (exception handler)?",
1747 First (Exception_Handlers (Handled_Statement_Sequence (N))),
1751 Has_Excluded_Statement
1752 (Statements (Handled_Statement_Sequence (N)))
1758 -- We do not inline a subprogram that is too large, unless it is
1759 -- marked Inline_Always. This pragma does not suppress the other
1760 -- checks on inlining (forbidden declarations, handlers, etc).
1762 if Stat_Count > Max_Size
1763 and then not Is_Always_Inlined (Subp)
1765 Cannot_Inline ("cannot inline& (body too large)?", N, Subp);
1769 if Has_Pending_Instantiation then
1771 ("cannot inline& (forward instance within enclosing body)?",
1776 -- Within an instance, the body to inline must be treated as a nested
1777 -- generic, so that the proper global references are preserved.
1780 Save_Env (Scope (Current_Scope), Scope (Current_Scope));
1781 Original_Body := Copy_Generic_Node (N, Empty, True);
1783 Original_Body := Copy_Separate_Tree (N);
1786 -- We need to capture references to the formals in order to substitute
1787 -- the actuals at the point of inlining, i.e. instantiation. To treat
1788 -- the formals as globals to the body to inline, we nest it within
1789 -- a dummy parameterless subprogram, declared within the real one.
1791 Set_Parameter_Specifications (Specification (Original_Body), No_List);
1792 Set_Defining_Unit_Name (Specification (Original_Body),
1793 Make_Defining_Identifier (Sloc (N), New_Internal_Name ('S')));
1794 Set_Corresponding_Spec (Original_Body, Empty);
1796 Body_To_Analyze := Copy_Generic_Node (Original_Body, Empty, False);
1798 -- Set return type of function, which is also global and does not need
1801 if Ekind (Subp) = E_Function then
1802 Set_Subtype_Mark (Specification (Body_To_Analyze),
1803 New_Occurrence_Of (Etype (Subp), Sloc (N)));
1806 if No (Declarations (N)) then
1807 Set_Declarations (N, New_List (Body_To_Analyze));
1809 Append (Body_To_Analyze, Declarations (N));
1812 Expander_Mode_Save_And_Set (False);
1815 Analyze (Body_To_Analyze);
1816 New_Scope (Defining_Entity (Body_To_Analyze));
1817 Save_Global_References (Original_Body);
1819 Remove (Body_To_Analyze);
1821 Expander_Mode_Restore;
1822 Set_Body_To_Inline (Decl, Original_Body);
1823 Set_Ekind (Defining_Entity (Original_Body), Ekind (Subp));
1824 Set_Is_Inlined (Subp);
1829 end Build_Body_To_Inline;
1835 procedure Cannot_Inline (Msg : String; N : Node_Id; Subp : Entity_Id) is
1837 -- Do not emit warning if this is a predefined unit which is not
1838 -- the main unit. With validity checks enabled, some predefined
1839 -- subprograms may contain nested subprograms and become ineligible
1842 if Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Subp)))
1843 and then not In_Extended_Main_Source_Unit (Subp)
1847 elsif Is_Always_Inlined (Subp) then
1848 Error_Msg_NE (Msg (1 .. Msg'Length - 1), N, Subp);
1850 elsif Ineffective_Inline_Warnings then
1851 Error_Msg_NE (Msg, N, Subp);
1855 -----------------------
1856 -- Check_Conformance --
1857 -----------------------
1859 procedure Check_Conformance
1860 (New_Id : Entity_Id;
1862 Ctype : Conformance_Type;
1864 Conforms : out Boolean;
1865 Err_Loc : Node_Id := Empty;
1866 Get_Inst : Boolean := False)
1868 Old_Type : constant Entity_Id := Etype (Old_Id);
1869 New_Type : constant Entity_Id := Etype (New_Id);
1870 Old_Formal : Entity_Id;
1871 New_Formal : Entity_Id;
1873 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id);
1874 -- Post error message for conformance error on given node.
1875 -- Two messages are output. The first points to the previous
1876 -- declaration with a general "no conformance" message.
1877 -- The second is the detailed reason, supplied as Msg. The
1878 -- parameter N provide information for a possible & insertion
1879 -- in the message, and also provides the location for posting
1880 -- the message in the absence of a specified Err_Loc location.
1882 -----------------------
1883 -- Conformance_Error --
1884 -----------------------
1886 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is
1893 if No (Err_Loc) then
1899 Error_Msg_Sloc := Sloc (Old_Id);
1902 when Type_Conformant =>
1904 ("not type conformant with declaration#!", Enode);
1906 when Mode_Conformant =>
1908 ("not mode conformant with declaration#!", Enode);
1910 when Subtype_Conformant =>
1912 ("not subtype conformant with declaration#!", Enode);
1914 when Fully_Conformant =>
1916 ("not fully conformant with declaration#!", Enode);
1919 Error_Msg_NE (Msg, Enode, N);
1921 end Conformance_Error;
1923 -- Start of processing for Check_Conformance
1928 -- We need a special case for operators, since they don't
1929 -- appear explicitly.
1931 if Ctype = Type_Conformant then
1932 if Ekind (New_Id) = E_Operator
1933 and then Operator_Matches_Spec (New_Id, Old_Id)
1939 -- If both are functions/operators, check return types conform
1941 if Old_Type /= Standard_Void_Type
1942 and then New_Type /= Standard_Void_Type
1944 if not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then
1945 Conformance_Error ("return type does not match!", New_Id);
1949 -- If either is a function/operator and the other isn't, error
1951 elsif Old_Type /= Standard_Void_Type
1952 or else New_Type /= Standard_Void_Type
1954 Conformance_Error ("functions can only match functions!", New_Id);
1958 -- In subtype conformant case, conventions must match (RM 6.3.1(16))
1959 -- If this is a renaming as body, refine error message to indicate that
1960 -- the conflict is with the original declaration. If the entity is not
1961 -- frozen, the conventions don't have to match, the one of the renamed
1962 -- entity is inherited.
1964 if Ctype >= Subtype_Conformant then
1965 if Convention (Old_Id) /= Convention (New_Id) then
1967 if not Is_Frozen (New_Id) then
1970 elsif Present (Err_Loc)
1971 and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration
1972 and then Present (Corresponding_Spec (Err_Loc))
1974 Error_Msg_Name_1 := Chars (New_Id);
1976 Name_Ada + Convention_Id'Pos (Convention (New_Id));
1978 Conformance_Error ("prior declaration for% has convention %!");
1981 Conformance_Error ("calling conventions do not match!");
1986 elsif Is_Formal_Subprogram (Old_Id)
1987 or else Is_Formal_Subprogram (New_Id)
1989 Conformance_Error ("formal subprograms not allowed!");
1994 -- Deal with parameters
1996 -- Note: we use the entity information, rather than going directly
1997 -- to the specification in the tree. This is not only simpler, but
1998 -- absolutely necessary for some cases of conformance tests between
1999 -- operators, where the declaration tree simply does not exist!
2001 Old_Formal := First_Formal (Old_Id);
2002 New_Formal := First_Formal (New_Id);
2004 while Present (Old_Formal) and then Present (New_Formal) loop
2005 if Ctype = Fully_Conformant then
2007 -- Names must match. Error message is more accurate if we do
2008 -- this before checking that the types of the formals match.
2010 if Chars (Old_Formal) /= Chars (New_Formal) then
2011 Conformance_Error ("name & does not match!", New_Formal);
2013 -- Set error posted flag on new formal as well to stop
2014 -- junk cascaded messages in some cases.
2016 Set_Error_Posted (New_Formal);
2021 -- Types must always match. In the visible part of an instance,
2022 -- usual overloading rules for dispatching operations apply, and
2023 -- we check base types (not the actual subtypes).
2025 if In_Instance_Visible_Part
2026 and then Is_Dispatching_Operation (New_Id)
2028 if not Conforming_Types
2029 (Base_Type (Etype (Old_Formal)),
2030 Base_Type (Etype (New_Formal)), Ctype, Get_Inst)
2032 Conformance_Error ("type of & does not match!", New_Formal);
2036 elsif not Conforming_Types
2037 (Etype (Old_Formal), Etype (New_Formal), Ctype, Get_Inst)
2039 Conformance_Error ("type of & does not match!", New_Formal);
2043 -- For mode conformance, mode must match
2045 if Ctype >= Mode_Conformant
2046 and then Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal)
2048 Conformance_Error ("mode of & does not match!", New_Formal);
2052 -- Full conformance checks
2054 if Ctype = Fully_Conformant then
2056 -- We have checked already that names match.
2057 -- Check default expressions for in parameters
2059 if Parameter_Mode (Old_Formal) = E_In_Parameter then
2061 NewD : constant Boolean :=
2062 Present (Default_Value (New_Formal));
2063 OldD : constant Boolean :=
2064 Present (Default_Value (Old_Formal));
2066 if NewD or OldD then
2068 -- The old default value has been analyzed because
2069 -- the current full declaration will have frozen
2070 -- everything before. The new default values have not
2071 -- been analyzed, so analyze them now before we check
2076 Analyze_Per_Use_Expression
2077 (Default_Value (New_Formal), Etype (New_Formal));
2081 if not (NewD and OldD)
2082 or else not Fully_Conformant_Expressions
2083 (Default_Value (Old_Formal),
2084 Default_Value (New_Formal))
2087 ("default expression for & does not match!",
2096 -- A couple of special checks for Ada 83 mode. These checks are
2097 -- skipped if either entity is an operator in package Standard.
2098 -- or if either old or new instance is not from the source program.
2101 and then Sloc (Old_Id) > Standard_Location
2102 and then Sloc (New_Id) > Standard_Location
2103 and then Comes_From_Source (Old_Id)
2104 and then Comes_From_Source (New_Id)
2107 Old_Param : constant Node_Id := Declaration_Node (Old_Formal);
2108 New_Param : constant Node_Id := Declaration_Node (New_Formal);
2111 -- Explicit IN must be present or absent in both cases. This
2112 -- test is required only in the full conformance case.
2114 if In_Present (Old_Param) /= In_Present (New_Param)
2115 and then Ctype = Fully_Conformant
2118 ("(Ada 83) IN must appear in both declarations",
2123 -- Grouping (use of comma in param lists) must be the same
2124 -- This is where we catch a misconformance like:
2127 -- A : Integer; B : Integer
2129 -- which are represented identically in the tree except
2130 -- for the setting of the flags More_Ids and Prev_Ids.
2132 if More_Ids (Old_Param) /= More_Ids (New_Param)
2133 or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param)
2136 ("grouping of & does not match!", New_Formal);
2142 Next_Formal (Old_Formal);
2143 Next_Formal (New_Formal);
2146 if Present (Old_Formal) then
2147 Conformance_Error ("too few parameters!");
2150 elsif Present (New_Formal) then
2151 Conformance_Error ("too many parameters!", New_Formal);
2155 end Check_Conformance;
2157 ------------------------------
2158 -- Check_Delayed_Subprogram --
2159 ------------------------------
2161 procedure Check_Delayed_Subprogram (Designator : Entity_Id) is
2164 procedure Possible_Freeze (T : Entity_Id);
2165 -- T is the type of either a formal parameter or of the return type.
2166 -- If T is not yet frozen and needs a delayed freeze, then the
2167 -- subprogram itself must be delayed.
2169 procedure Possible_Freeze (T : Entity_Id) is
2171 if Has_Delayed_Freeze (T)
2172 and then not Is_Frozen (T)
2174 Set_Has_Delayed_Freeze (Designator);
2176 elsif Is_Access_Type (T)
2177 and then Has_Delayed_Freeze (Designated_Type (T))
2178 and then not Is_Frozen (Designated_Type (T))
2180 Set_Has_Delayed_Freeze (Designator);
2182 end Possible_Freeze;
2184 -- Start of processing for Check_Delayed_Subprogram
2187 -- Never need to freeze abstract subprogram
2189 if Is_Abstract (Designator) then
2192 -- Need delayed freeze if return type itself needs a delayed
2193 -- freeze and is not yet frozen.
2195 Possible_Freeze (Etype (Designator));
2196 Possible_Freeze (Base_Type (Etype (Designator))); -- needed ???
2198 -- Need delayed freeze if any of the formal types themselves need
2199 -- a delayed freeze and are not yet frozen.
2201 F := First_Formal (Designator);
2202 while Present (F) loop
2203 Possible_Freeze (Etype (F));
2204 Possible_Freeze (Base_Type (Etype (F))); -- needed ???
2209 -- Mark functions that return by reference. Note that it cannot be
2210 -- done for delayed_freeze subprograms because the underlying
2211 -- returned type may not be known yet (for private types)
2213 if not Has_Delayed_Freeze (Designator)
2214 and then Expander_Active
2217 Typ : constant Entity_Id := Etype (Designator);
2218 Utyp : constant Entity_Id := Underlying_Type (Typ);
2221 if Is_Return_By_Reference_Type (Typ) then
2222 Set_Returns_By_Ref (Designator);
2224 elsif Present (Utyp) and then Controlled_Type (Utyp) then
2225 Set_Returns_By_Ref (Designator);
2229 end Check_Delayed_Subprogram;
2231 ------------------------------------
2232 -- Check_Discriminant_Conformance --
2233 ------------------------------------
2235 procedure Check_Discriminant_Conformance
2240 Old_Discr : Entity_Id := First_Discriminant (Prev);
2241 New_Discr : Node_Id := First (Discriminant_Specifications (N));
2242 New_Discr_Id : Entity_Id;
2243 New_Discr_Type : Entity_Id;
2245 procedure Conformance_Error (Msg : String; N : Node_Id);
2246 -- Post error message for conformance error on given node.
2247 -- Two messages are output. The first points to the previous
2248 -- declaration with a general "no conformance" message.
2249 -- The second is the detailed reason, supplied as Msg. The
2250 -- parameter N provide information for a possible & insertion
2253 -----------------------
2254 -- Conformance_Error --
2255 -----------------------
2257 procedure Conformance_Error (Msg : String; N : Node_Id) is
2259 Error_Msg_Sloc := Sloc (Prev_Loc);
2260 Error_Msg_N ("not fully conformant with declaration#!", N);
2261 Error_Msg_NE (Msg, N, N);
2262 end Conformance_Error;
2264 -- Start of processing for Check_Discriminant_Conformance
2267 while Present (Old_Discr) and then Present (New_Discr) loop
2269 New_Discr_Id := Defining_Identifier (New_Discr);
2271 -- The subtype mark of the discriminant on the full type
2272 -- has not been analyzed so we do it here. For an access
2273 -- discriminant a new type is created.
2275 if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then
2277 Access_Definition (N, Discriminant_Type (New_Discr));
2280 Analyze (Discriminant_Type (New_Discr));
2281 New_Discr_Type := Etype (Discriminant_Type (New_Discr));
2284 if not Conforming_Types
2285 (Etype (Old_Discr), New_Discr_Type, Fully_Conformant)
2287 Conformance_Error ("type of & does not match!", New_Discr_Id);
2290 -- Treat the new discriminant as an occurrence of the old
2291 -- one, for navigation purposes, and fill in some semantic
2292 -- information, for completeness.
2294 Generate_Reference (Old_Discr, New_Discr_Id, 'r');
2295 Set_Etype (New_Discr_Id, Etype (Old_Discr));
2296 Set_Scope (New_Discr_Id, Scope (Old_Discr));
2301 if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then
2302 Conformance_Error ("name & does not match!", New_Discr_Id);
2306 -- Default expressions must match
2309 NewD : constant Boolean :=
2310 Present (Expression (New_Discr));
2311 OldD : constant Boolean :=
2312 Present (Expression (Parent (Old_Discr)));
2315 if NewD or OldD then
2317 -- The old default value has been analyzed and expanded,
2318 -- because the current full declaration will have frozen
2319 -- everything before. The new default values have not
2320 -- been expanded, so expand now to check conformance.
2323 Analyze_Per_Use_Expression
2324 (Expression (New_Discr), New_Discr_Type);
2327 if not (NewD and OldD)
2328 or else not Fully_Conformant_Expressions
2329 (Expression (Parent (Old_Discr)),
2330 Expression (New_Discr))
2334 ("default expression for & does not match!",
2341 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
2345 Old_Disc : constant Node_Id := Declaration_Node (Old_Discr);
2348 -- Grouping (use of comma in param lists) must be the same
2349 -- This is where we catch a misconformance like:
2352 -- A : Integer; B : Integer
2354 -- which are represented identically in the tree except
2355 -- for the setting of the flags More_Ids and Prev_Ids.
2357 if More_Ids (Old_Disc) /= More_Ids (New_Discr)
2358 or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr)
2361 ("grouping of & does not match!", New_Discr_Id);
2367 Next_Discriminant (Old_Discr);
2371 if Present (Old_Discr) then
2372 Conformance_Error ("too few discriminants!", Defining_Identifier (N));
2375 elsif Present (New_Discr) then
2377 ("too many discriminants!", Defining_Identifier (New_Discr));
2380 end Check_Discriminant_Conformance;
2382 ----------------------------
2383 -- Check_Fully_Conformant --
2384 ----------------------------
2386 procedure Check_Fully_Conformant
2387 (New_Id : Entity_Id;
2389 Err_Loc : Node_Id := Empty)
2395 (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc);
2396 end Check_Fully_Conformant;
2398 ---------------------------
2399 -- Check_Mode_Conformant --
2400 ---------------------------
2402 procedure Check_Mode_Conformant
2403 (New_Id : Entity_Id;
2405 Err_Loc : Node_Id := Empty;
2406 Get_Inst : Boolean := False)
2412 (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst);
2413 end Check_Mode_Conformant;
2415 --------------------------------
2416 -- Check_Overriding_Operation --
2417 --------------------------------
2419 procedure Check_Overriding_Operation
2425 Has_Pragma : Boolean := False;
2428 -- See whether there is an overriding pragma immediately following
2429 -- the declaration. Intervening pragmas, such as Inline, are allowed.
2432 while Present (Decl)
2433 and then Nkind (Decl) = N_Pragma
2435 if Chars (Decl) = Name_Overriding
2436 or else Chars (Decl) = Name_Optional_Overriding
2438 -- For now disable the use of these pragmas, until the ARG
2439 -- finalizes the design of this feature.
2441 Error_Msg_N ("?unrecognized pragma", Decl);
2443 if not Is_Overriding_Operation (Subp) then
2445 -- Before emitting an error message, check whether this
2446 -- may override an operation that is not yet visible, as
2447 -- in the case of a derivation of a private operation in
2448 -- a child unit. Such an operation is introduced with a
2449 -- different name, but its alias is the parent operation.
2455 E := First_Entity (Current_Scope);
2457 while Present (E) loop
2458 if Ekind (E) = Ekind (Subp)
2459 and then not Comes_From_Source (E)
2460 and then Present (Alias (E))
2461 and then Chars (Alias (E)) = Chars (Subp)
2462 and then In_Open_Scopes (Scope (Alias (E)))
2472 ("& must override an inherited operation",
2478 -- Verify syntax of pragma
2480 Arg1 := First (Pragma_Argument_Associations (Decl));
2482 if Present (Arg1) then
2483 if not Is_Entity_Name (Expression (Arg1)) then
2484 Error_Msg_N ("pragma applies to local subprogram", Decl);
2486 elsif Chars (Expression (Arg1)) /= Chars (Subp) then
2488 ("pragma must apply to preceding subprogram", Decl);
2490 elsif Present (Next (Arg1)) then
2491 Error_Msg_N ("illegal pragma format", Decl);
2495 Set_Analyzed (Decl);
2504 and then Explicit_Overriding
2505 and then Is_Overriding_Operation (Subp)
2507 Error_Msg_NE ("Missing overriding pragma for&", Subp, Subp);
2509 end Check_Overriding_Operation;
2515 procedure Check_Returns
2522 procedure Check_Statement_Sequence (L : List_Id);
2523 -- Internal recursive procedure to check a list of statements for proper
2524 -- termination by a return statement (or a transfer of control or a
2525 -- compound statement that is itself internally properly terminated).
2527 ------------------------------
2528 -- Check_Statement_Sequence --
2529 ------------------------------
2531 procedure Check_Statement_Sequence (L : List_Id) is
2535 Raise_Exception_Call : Boolean;
2536 -- Set True if statement sequence terminated by Raise_Exception call
2537 -- or a Reraise_Occurrence call.
2540 Raise_Exception_Call := False;
2542 -- Get last real statement
2544 Last_Stm := Last (L);
2546 -- Don't count pragmas
2548 while Nkind (Last_Stm) = N_Pragma
2550 -- Don't count call to SS_Release (can happen after Raise_Exception)
2553 (Nkind (Last_Stm) = N_Procedure_Call_Statement
2555 Nkind (Name (Last_Stm)) = N_Identifier
2557 Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release))
2559 -- Don't count exception junk
2562 ((Nkind (Last_Stm) = N_Goto_Statement
2563 or else Nkind (Last_Stm) = N_Label
2564 or else Nkind (Last_Stm) = N_Object_Declaration)
2565 and then Exception_Junk (Last_Stm))
2570 -- Here we have the "real" last statement
2572 Kind := Nkind (Last_Stm);
2574 -- Transfer of control, OK. Note that in the No_Return procedure
2575 -- case, we already diagnosed any explicit return statements, so
2576 -- we can treat them as OK in this context.
2578 if Is_Transfer (Last_Stm) then
2581 -- Check cases of explicit non-indirect procedure calls
2583 elsif Kind = N_Procedure_Call_Statement
2584 and then Is_Entity_Name (Name (Last_Stm))
2586 -- Check call to Raise_Exception procedure which is treated
2587 -- specially, as is a call to Reraise_Occurrence.
2589 -- We suppress the warning in these cases since it is likely that
2590 -- the programmer really does not expect to deal with the case
2591 -- of Null_Occurrence, and thus would find a warning about a
2592 -- missing return curious, and raising Program_Error does not
2593 -- seem such a bad behavior if this does occur.
2595 if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception)
2597 Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence)
2599 Raise_Exception_Call := True;
2601 -- For Raise_Exception call, test first argument, if it is
2602 -- an attribute reference for a 'Identity call, then we know
2603 -- that the call cannot possibly return.
2606 Arg : constant Node_Id :=
2607 Original_Node (First_Actual (Last_Stm));
2610 if Nkind (Arg) = N_Attribute_Reference
2611 and then Attribute_Name (Arg) = Name_Identity
2618 -- If statement, need to look inside if there is an else and check
2619 -- each constituent statement sequence for proper termination.
2621 elsif Kind = N_If_Statement
2622 and then Present (Else_Statements (Last_Stm))
2624 Check_Statement_Sequence (Then_Statements (Last_Stm));
2625 Check_Statement_Sequence (Else_Statements (Last_Stm));
2627 if Present (Elsif_Parts (Last_Stm)) then
2629 Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm));
2632 while Present (Elsif_Part) loop
2633 Check_Statement_Sequence (Then_Statements (Elsif_Part));
2641 -- Case statement, check each case for proper termination
2643 elsif Kind = N_Case_Statement then
2648 Case_Alt := First_Non_Pragma (Alternatives (Last_Stm));
2649 while Present (Case_Alt) loop
2650 Check_Statement_Sequence (Statements (Case_Alt));
2651 Next_Non_Pragma (Case_Alt);
2657 -- Block statement, check its handled sequence of statements
2659 elsif Kind = N_Block_Statement then
2665 (Handled_Statement_Sequence (Last_Stm), Mode, Err1);
2674 -- Loop statement. If there is an iteration scheme, we can definitely
2675 -- fall out of the loop. Similarly if there is an exit statement, we
2676 -- can fall out. In either case we need a following return.
2678 elsif Kind = N_Loop_Statement then
2679 if Present (Iteration_Scheme (Last_Stm))
2680 or else Has_Exit (Entity (Identifier (Last_Stm)))
2684 -- A loop with no exit statement or iteration scheme if either
2685 -- an inifite loop, or it has some other exit (raise/return).
2686 -- In either case, no warning is required.
2692 -- Timed entry call, check entry call and delay alternatives
2694 -- Note: in expanded code, the timed entry call has been converted
2695 -- to a set of expanded statements on which the check will work
2696 -- correctly in any case.
2698 elsif Kind = N_Timed_Entry_Call then
2700 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
2701 DCA : constant Node_Id := Delay_Alternative (Last_Stm);
2704 -- If statement sequence of entry call alternative is missing,
2705 -- then we can definitely fall through, and we post the error
2706 -- message on the entry call alternative itself.
2708 if No (Statements (ECA)) then
2711 -- If statement sequence of delay alternative is missing, then
2712 -- we can definitely fall through, and we post the error
2713 -- message on the delay alternative itself.
2715 -- Note: if both ECA and DCA are missing the return, then we
2716 -- post only one message, should be enough to fix the bugs.
2717 -- If not we will get a message next time on the DCA when the
2720 elsif No (Statements (DCA)) then
2723 -- Else check both statement sequences
2726 Check_Statement_Sequence (Statements (ECA));
2727 Check_Statement_Sequence (Statements (DCA));
2732 -- Conditional entry call, check entry call and else part
2734 -- Note: in expanded code, the conditional entry call has been
2735 -- converted to a set of expanded statements on which the check
2736 -- will work correctly in any case.
2738 elsif Kind = N_Conditional_Entry_Call then
2740 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
2743 -- If statement sequence of entry call alternative is missing,
2744 -- then we can definitely fall through, and we post the error
2745 -- message on the entry call alternative itself.
2747 if No (Statements (ECA)) then
2750 -- Else check statement sequence and else part
2753 Check_Statement_Sequence (Statements (ECA));
2754 Check_Statement_Sequence (Else_Statements (Last_Stm));
2760 -- If we fall through, issue appropriate message
2764 if not Raise_Exception_Call then
2766 ("?RETURN statement missing following this statement!",
2769 ("\?Program_Error may be raised at run time",
2773 -- Note: we set Err even though we have not issued a warning
2774 -- because we still have a case of a missing return. This is
2775 -- an extremely marginal case, probably will never be noticed
2776 -- but we might as well get it right.
2782 ("implied return after this statement not allowed (No_Return)",
2785 end Check_Statement_Sequence;
2787 -- Start of processing for Check_Returns
2791 Check_Statement_Sequence (Statements (HSS));
2793 if Present (Exception_Handlers (HSS)) then
2794 Handler := First_Non_Pragma (Exception_Handlers (HSS));
2795 while Present (Handler) loop
2796 Check_Statement_Sequence (Statements (Handler));
2797 Next_Non_Pragma (Handler);
2802 ----------------------------
2803 -- Check_Subprogram_Order --
2804 ----------------------------
2806 procedure Check_Subprogram_Order (N : Node_Id) is
2808 function Subprogram_Name_Greater (S1, S2 : String) return Boolean;
2809 -- This is used to check if S1 > S2 in the sense required by this
2810 -- test, for example nameab < namec, but name2 < name10.
2812 function Subprogram_Name_Greater (S1, S2 : String) return Boolean is
2817 -- Remove trailing numeric parts
2820 while S1 (L1) in '0' .. '9' loop
2825 while S2 (L2) in '0' .. '9' loop
2829 -- If non-numeric parts non-equal, that's decisive
2831 if S1 (S1'First .. L1) < S2 (S2'First .. L2) then
2834 elsif S1 (S1'First .. L1) > S2 (S2'First .. L2) then
2837 -- If non-numeric parts equal, compare suffixed numeric parts. Note
2838 -- that a missing suffix is treated as numeric zero in this test.
2842 while L1 < S1'Last loop
2844 N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0');
2848 while L2 < S2'Last loop
2850 N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0');
2855 end Subprogram_Name_Greater;
2857 -- Start of processing for Check_Subprogram_Order
2860 -- Check body in alpha order if this is option
2863 and then Style_Check_Subprogram_Order
2864 and then Nkind (N) = N_Subprogram_Body
2865 and then Comes_From_Source (N)
2866 and then In_Extended_Main_Source_Unit (N)
2870 renames Scope_Stack.Table
2871 (Scope_Stack.Last).Last_Subprogram_Name;
2873 Body_Id : constant Entity_Id :=
2874 Defining_Entity (Specification (N));
2877 Get_Decoded_Name_String (Chars (Body_Id));
2880 if Subprogram_Name_Greater
2881 (LSN.all, Name_Buffer (1 .. Name_Len))
2883 Style.Subprogram_Not_In_Alpha_Order (Body_Id);
2889 LSN := new String'(Name_Buffer (1 .. Name_Len));
2892 end Check_Subprogram_Order;
2894 ------------------------------
2895 -- Check_Subtype_Conformant --
2896 ------------------------------
2898 procedure Check_Subtype_Conformant
2899 (New_Id : Entity_Id;
2901 Err_Loc : Node_Id := Empty)
2907 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc);
2908 end Check_Subtype_Conformant;
2910 ---------------------------
2911 -- Check_Type_Conformant --
2912 ---------------------------
2914 procedure Check_Type_Conformant
2915 (New_Id : Entity_Id;
2917 Err_Loc : Node_Id := Empty)
2923 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
2924 end Check_Type_Conformant;
2926 ----------------------
2927 -- Conforming_Types --
2928 ----------------------
2930 function Conforming_Types
2933 Ctype : Conformance_Type;
2934 Get_Inst : Boolean := False) return Boolean
2936 Type_1 : Entity_Id := T1;
2937 Type_2 : Entity_Id := T2;
2939 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
2940 -- If neither T1 nor T2 are generic actual types, or if they are
2941 -- in different scopes (e.g. parent and child instances), then verify
2942 -- that the base types are equal. Otherwise T1 and T2 must be
2943 -- on the same subtype chain. The whole purpose of this procedure
2944 -- is to prevent spurious ambiguities in an instantiation that may
2945 -- arise if two distinct generic types are instantiated with the
2948 ----------------------
2949 -- Base_Types_Match --
2950 ----------------------
2952 function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
2957 elsif Base_Type (T1) = Base_Type (T2) then
2959 -- The following is too permissive. A more precise test must
2960 -- check that the generic actual is an ancestor subtype of the
2963 return not Is_Generic_Actual_Type (T1)
2964 or else not Is_Generic_Actual_Type (T2)
2965 or else Scope (T1) /= Scope (T2);
2970 end Base_Types_Match;
2973 -- The context is an instance association for a formal
2974 -- access-to-subprogram type; the formal parameter types
2975 -- require mapping because they may denote other formal
2976 -- parameters of the generic unit.
2979 Type_1 := Get_Instance_Of (T1);
2980 Type_2 := Get_Instance_Of (T2);
2983 -- First see if base types match
2985 if Base_Types_Match (Type_1, Type_2) then
2986 return Ctype <= Mode_Conformant
2987 or else Subtypes_Statically_Match (Type_1, Type_2);
2989 elsif Is_Incomplete_Or_Private_Type (Type_1)
2990 and then Present (Full_View (Type_1))
2991 and then Base_Types_Match (Full_View (Type_1), Type_2)
2993 return Ctype <= Mode_Conformant
2994 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
2996 elsif Ekind (Type_2) = E_Incomplete_Type
2997 and then Present (Full_View (Type_2))
2998 and then Base_Types_Match (Type_1, Full_View (Type_2))
3000 return Ctype <= Mode_Conformant
3001 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3003 elsif Is_Private_Type (Type_2)
3004 and then In_Instance
3005 and then Present (Full_View (Type_2))
3006 and then Base_Types_Match (Type_1, Full_View (Type_2))
3008 return Ctype <= Mode_Conformant
3009 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
3012 -- Test anonymous access type case. For this case, static subtype
3013 -- matching is required for mode conformance (RM 6.3.1(15))
3015 if Ekind (Type_1) = E_Anonymous_Access_Type
3016 and then Ekind (Type_2) = E_Anonymous_Access_Type
3019 Desig_1 : Entity_Id;
3020 Desig_2 : Entity_Id;
3023 Desig_1 := Directly_Designated_Type (Type_1);
3025 -- An access parameter can designate an incomplete type.
3027 if Ekind (Desig_1) = E_Incomplete_Type
3028 and then Present (Full_View (Desig_1))
3030 Desig_1 := Full_View (Desig_1);
3033 Desig_2 := Directly_Designated_Type (Type_2);
3035 if Ekind (Desig_2) = E_Incomplete_Type
3036 and then Present (Full_View (Desig_2))
3038 Desig_2 := Full_View (Desig_2);
3041 -- The context is an instance association for a formal
3042 -- access-to-subprogram type; formal access parameter
3043 -- designated types require mapping because they may
3044 -- denote other formal parameters of the generic unit.
3047 Desig_1 := Get_Instance_Of (Desig_1);
3048 Desig_2 := Get_Instance_Of (Desig_2);
3051 -- It is possible for a Class_Wide_Type to be introduced for
3052 -- an incomplete type, in which case there is a separate class_
3053 -- wide type for the full view. The types conform if their
3054 -- Etypes conform, i.e. one may be the full view of the other.
3055 -- This can only happen in the context of an access parameter,
3056 -- other uses of an incomplete Class_Wide_Type are illegal.
3058 if Is_Class_Wide_Type (Desig_1)
3059 and then Is_Class_Wide_Type (Desig_2)
3063 (Etype (Base_Type (Desig_1)),
3064 Etype (Base_Type (Desig_2)), Ctype);
3066 return Base_Type (Desig_1) = Base_Type (Desig_2)
3067 and then (Ctype = Type_Conformant
3069 Subtypes_Statically_Match (Desig_1, Desig_2));
3073 -- Otherwise definitely no match
3079 end Conforming_Types;
3081 --------------------------
3082 -- Create_Extra_Formals --
3083 --------------------------
3085 procedure Create_Extra_Formals (E : Entity_Id) is
3087 Last_Extra : Entity_Id;
3088 Formal_Type : Entity_Id;
3089 P_Formal : Entity_Id := Empty;
3091 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id;
3092 -- Add an extra formal, associated with the current Formal. The
3093 -- extra formal is added to the list of extra formals, and also
3094 -- returned as the result. These formals are always of mode IN.
3096 ----------------------
3097 -- Add_Extra_Formal --
3098 ----------------------
3100 function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is
3101 EF : constant Entity_Id :=
3102 Make_Defining_Identifier (Sloc (Formal),
3103 Chars => New_External_Name (Chars (Formal), 'F'));
3106 -- We never generate extra formals if expansion is not active
3107 -- because we don't need them unless we are generating code.
3109 if not Expander_Active then
3113 -- A little optimization. Never generate an extra formal for
3114 -- the _init operand of an initialization procedure, since it
3115 -- could never be used.
3117 if Chars (Formal) = Name_uInit then
3121 Set_Ekind (EF, E_In_Parameter);
3122 Set_Actual_Subtype (EF, Typ);
3123 Set_Etype (EF, Typ);
3124 Set_Scope (EF, Scope (Formal));
3125 Set_Mechanism (EF, Default_Mechanism);
3126 Set_Formal_Validity (EF);
3128 Set_Extra_Formal (Last_Extra, EF);
3131 end Add_Extra_Formal;
3133 -- Start of processing for Create_Extra_Formals
3136 -- If this is a derived subprogram then the subtypes of the
3137 -- parent subprogram's formal parameters will be used to
3138 -- to determine the need for extra formals.
3140 if Is_Overloadable (E) and then Present (Alias (E)) then
3141 P_Formal := First_Formal (Alias (E));
3144 Last_Extra := Empty;
3145 Formal := First_Formal (E);
3146 while Present (Formal) loop
3147 Last_Extra := Formal;
3148 Next_Formal (Formal);
3151 -- If Extra_formals where already created, don't do it again
3152 -- This situation may arise for subprogram types created as part
3153 -- of dispatching calls (see Expand_Dispatch_Call)
3155 if Present (Last_Extra) and then
3156 Present (Extra_Formal (Last_Extra))
3161 Formal := First_Formal (E);
3163 while Present (Formal) loop
3165 -- Create extra formal for supporting the attribute 'Constrained.
3166 -- The case of a private type view without discriminants also
3167 -- requires the extra formal if the underlying type has defaulted
3170 if Ekind (Formal) /= E_In_Parameter then
3171 if Present (P_Formal) then
3172 Formal_Type := Etype (P_Formal);
3174 Formal_Type := Etype (Formal);
3177 if not Has_Discriminants (Formal_Type)
3178 and then Ekind (Formal_Type) in Private_Kind
3179 and then Present (Underlying_Type (Formal_Type))
3181 Formal_Type := Underlying_Type (Formal_Type);
3184 if Has_Discriminants (Formal_Type)
3186 ((not Is_Constrained (Formal_Type)
3187 and then not Is_Indefinite_Subtype (Formal_Type))
3188 or else Present (Extra_Formal (Formal)))
3190 Set_Extra_Constrained
3191 (Formal, Add_Extra_Formal (Standard_Boolean));
3195 -- Create extra formal for supporting accessibility checking
3197 -- This is suppressed if we specifically suppress accessibility
3198 -- checks at the pacage level for either the subprogram, or the
3199 -- package in which it resides. However, we do not suppress it
3200 -- simply if the scope has accessibility checks suppressed, since
3201 -- this could cause trouble when clients are compiled with a
3202 -- different suppression setting. The explicit checks at the
3203 -- package level are safe from this point of view.
3205 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
3207 (Explicit_Suppress (E, Accessibility_Check)
3209 Explicit_Suppress (Scope (E), Accessibility_Check))
3211 (not Present (P_Formal)
3212 or else Present (Extra_Accessibility (P_Formal)))
3214 -- Temporary kludge: for now we avoid creating the extra
3215 -- formal for access parameters of protected operations
3216 -- because of problem with the case of internal protected
3219 if Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Definition
3220 and then Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Body
3222 Set_Extra_Accessibility
3223 (Formal, Add_Extra_Formal (Standard_Natural));
3227 if Present (P_Formal) then
3228 Next_Formal (P_Formal);
3231 Next_Formal (Formal);
3233 end Create_Extra_Formals;
3235 -----------------------------
3236 -- Enter_Overloaded_Entity --
3237 -----------------------------
3239 procedure Enter_Overloaded_Entity (S : Entity_Id) is
3240 E : Entity_Id := Current_Entity_In_Scope (S);
3241 C_E : Entity_Id := Current_Entity (S);
3245 Set_Has_Homonym (E);
3246 Set_Has_Homonym (S);
3249 Set_Is_Immediately_Visible (S);
3250 Set_Scope (S, Current_Scope);
3252 -- Chain new entity if front of homonym in current scope, so that
3253 -- homonyms are contiguous.
3258 while Homonym (C_E) /= E loop
3259 C_E := Homonym (C_E);
3262 Set_Homonym (C_E, S);
3266 Set_Current_Entity (S);
3271 Append_Entity (S, Current_Scope);
3272 Set_Public_Status (S);
3274 if Debug_Flag_E then
3275 Write_Str ("New overloaded entity chain: ");
3276 Write_Name (Chars (S));
3279 while Present (E) loop
3280 Write_Str (" "); Write_Int (Int (E));
3287 -- Generate warning for hiding
3290 and then Comes_From_Source (S)
3291 and then In_Extended_Main_Source_Unit (S)
3298 -- Warn unless genuine overloading
3300 if (not Is_Overloadable (E))
3301 or else Subtype_Conformant (E, S)
3303 Error_Msg_Sloc := Sloc (E);
3304 Error_Msg_N ("declaration of & hides one#?", S);
3308 end Enter_Overloaded_Entity;
3310 -----------------------------
3311 -- Find_Corresponding_Spec --
3312 -----------------------------
3314 function Find_Corresponding_Spec (N : Node_Id) return Entity_Id is
3315 Spec : constant Node_Id := Specification (N);
3316 Designator : constant Entity_Id := Defining_Entity (Spec);
3321 E := Current_Entity (Designator);
3323 while Present (E) loop
3325 -- We are looking for a matching spec. It must have the same scope,
3326 -- and the same name, and either be type conformant, or be the case
3327 -- of a library procedure spec and its body (which belong to one
3328 -- another regardless of whether they are type conformant or not).
3330 if Scope (E) = Current_Scope then
3331 if Current_Scope = Standard_Standard
3332 or else (Ekind (E) = Ekind (Designator)
3333 and then Type_Conformant (E, Designator))
3335 -- Within an instantiation, we know that spec and body are
3336 -- subtype conformant, because they were subtype conformant
3337 -- in the generic. We choose the subtype-conformant entity
3338 -- here as well, to resolve spurious ambiguities in the
3339 -- instance that were not present in the generic (i.e. when
3340 -- two different types are given the same actual). If we are
3341 -- looking for a spec to match a body, full conformance is
3345 Set_Convention (Designator, Convention (E));
3347 if Nkind (N) = N_Subprogram_Body
3348 and then Present (Homonym (E))
3349 and then not Fully_Conformant (E, Designator)
3353 elsif not Subtype_Conformant (E, Designator) then
3358 if not Has_Completion (E) then
3360 if Nkind (N) /= N_Subprogram_Body_Stub then
3361 Set_Corresponding_Spec (N, E);
3364 Set_Has_Completion (E);
3367 elsif Nkind (Parent (N)) = N_Subunit then
3369 -- If this is the proper body of a subunit, the completion
3370 -- flag is set when analyzing the stub.
3374 -- If body already exists, this is an error unless the
3375 -- previous declaration is the implicit declaration of
3376 -- a derived subprogram, or this is a spurious overloading
3379 elsif No (Alias (E))
3380 and then not Is_Intrinsic_Subprogram (E)
3381 and then not In_Instance
3383 Error_Msg_Sloc := Sloc (E);
3384 if Is_Imported (E) then
3386 ("body not allowed for imported subprogram & declared#",
3389 Error_Msg_NE ("duplicate body for & declared#", N, E);
3393 elsif Is_Child_Unit (E)
3395 Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body
3397 Nkind (Parent (Unit_Declaration_Node (Designator)))
3398 = N_Compilation_Unit
3401 -- Child units cannot be overloaded, so a conformance mismatch
3402 -- between body and a previous spec is an error.
3405 ("body of child unit does not match previous declaration", N);
3413 -- On exit, we know that no previous declaration of subprogram exists
3416 end Find_Corresponding_Spec;
3418 ----------------------
3419 -- Fully_Conformant --
3420 ----------------------
3422 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
3426 Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result);
3428 end Fully_Conformant;
3430 ----------------------------------
3431 -- Fully_Conformant_Expressions --
3432 ----------------------------------
3434 function Fully_Conformant_Expressions
3435 (Given_E1 : Node_Id;
3436 Given_E2 : Node_Id) return Boolean
3438 E1 : constant Node_Id := Original_Node (Given_E1);
3439 E2 : constant Node_Id := Original_Node (Given_E2);
3440 -- We always test conformance on original nodes, since it is possible
3441 -- for analysis and/or expansion to make things look as though they
3442 -- conform when they do not, e.g. by converting 1+2 into 3.
3444 function FCE (Given_E1, Given_E2 : Node_Id) return Boolean
3445 renames Fully_Conformant_Expressions;
3447 function FCL (L1, L2 : List_Id) return Boolean;
3448 -- Compare elements of two lists for conformance. Elements have to
3449 -- be conformant, and actuals inserted as default parameters do not
3450 -- match explicit actuals with the same value.
3452 function FCO (Op_Node, Call_Node : Node_Id) return Boolean;
3453 -- Compare an operator node with a function call.
3459 function FCL (L1, L2 : List_Id) return Boolean is
3463 if L1 = No_List then
3469 if L2 = No_List then
3475 -- Compare two lists, skipping rewrite insertions (we want to
3476 -- compare the original trees, not the expanded versions!)
3479 if Is_Rewrite_Insertion (N1) then
3481 elsif Is_Rewrite_Insertion (N2) then
3487 elsif not FCE (N1, N2) then
3500 function FCO (Op_Node, Call_Node : Node_Id) return Boolean is
3501 Actuals : constant List_Id := Parameter_Associations (Call_Node);
3506 or else Entity (Op_Node) /= Entity (Name (Call_Node))
3511 Act := First (Actuals);
3513 if Nkind (Op_Node) in N_Binary_Op then
3515 if not FCE (Left_Opnd (Op_Node), Act) then
3522 return Present (Act)
3523 and then FCE (Right_Opnd (Op_Node), Act)
3524 and then No (Next (Act));
3528 -- Start of processing for Fully_Conformant_Expressions
3531 -- Non-conformant if paren count does not match. Note: if some idiot
3532 -- complains that we don't do this right for more than 3 levels of
3533 -- parentheses, they will be treated with the respect they deserve :-)
3535 if Paren_Count (E1) /= Paren_Count (E2) then
3538 -- If same entities are referenced, then they are conformant
3539 -- even if they have different forms (RM 8.3.1(19-20)).
3541 elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then
3542 if Present (Entity (E1)) then
3543 return Entity (E1) = Entity (E2)
3544 or else (Chars (Entity (E1)) = Chars (Entity (E2))
3545 and then Ekind (Entity (E1)) = E_Discriminant
3546 and then Ekind (Entity (E2)) = E_In_Parameter);
3548 elsif Nkind (E1) = N_Expanded_Name
3549 and then Nkind (E2) = N_Expanded_Name
3550 and then Nkind (Selector_Name (E1)) = N_Character_Literal
3551 and then Nkind (Selector_Name (E2)) = N_Character_Literal
3553 return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2));
3556 -- Identifiers in component associations don't always have
3557 -- entities, but their names must conform.
3559 return Nkind (E1) = N_Identifier
3560 and then Nkind (E2) = N_Identifier
3561 and then Chars (E1) = Chars (E2);
3564 elsif Nkind (E1) = N_Character_Literal
3565 and then Nkind (E2) = N_Expanded_Name
3567 return Nkind (Selector_Name (E2)) = N_Character_Literal
3568 and then Chars (E1) = Chars (Selector_Name (E2));
3570 elsif Nkind (E2) = N_Character_Literal
3571 and then Nkind (E1) = N_Expanded_Name
3573 return Nkind (Selector_Name (E1)) = N_Character_Literal
3574 and then Chars (E2) = Chars (Selector_Name (E1));
3576 elsif Nkind (E1) in N_Op
3577 and then Nkind (E2) = N_Function_Call
3579 return FCO (E1, E2);
3581 elsif Nkind (E2) in N_Op
3582 and then Nkind (E1) = N_Function_Call
3584 return FCO (E2, E1);
3586 -- Otherwise we must have the same syntactic entity
3588 elsif Nkind (E1) /= Nkind (E2) then
3591 -- At this point, we specialize by node type
3598 FCL (Expressions (E1), Expressions (E2))
3599 and then FCL (Component_Associations (E1),
3600 Component_Associations (E2));
3603 if Nkind (Expression (E1)) = N_Qualified_Expression
3605 Nkind (Expression (E2)) = N_Qualified_Expression
3607 return FCE (Expression (E1), Expression (E2));
3609 -- Check that the subtype marks and any constraints
3614 Indic1 : constant Node_Id := Expression (E1);
3615 Indic2 : constant Node_Id := Expression (E2);
3620 if Nkind (Indic1) /= N_Subtype_Indication then
3622 Nkind (Indic2) /= N_Subtype_Indication
3623 and then Entity (Indic1) = Entity (Indic2);
3625 elsif Nkind (Indic2) /= N_Subtype_Indication then
3627 Nkind (Indic1) /= N_Subtype_Indication
3628 and then Entity (Indic1) = Entity (Indic2);
3631 if Entity (Subtype_Mark (Indic1)) /=
3632 Entity (Subtype_Mark (Indic2))
3637 Elt1 := First (Constraints (Constraint (Indic1)));
3638 Elt2 := First (Constraints (Constraint (Indic2)));
3640 while Present (Elt1) and then Present (Elt2) loop
3641 if not FCE (Elt1, Elt2) then
3654 when N_Attribute_Reference =>
3656 Attribute_Name (E1) = Attribute_Name (E2)
3657 and then FCL (Expressions (E1), Expressions (E2));
3661 Entity (E1) = Entity (E2)
3662 and then FCE (Left_Opnd (E1), Left_Opnd (E2))
3663 and then FCE (Right_Opnd (E1), Right_Opnd (E2));
3665 when N_And_Then | N_Or_Else | N_In | N_Not_In =>
3667 FCE (Left_Opnd (E1), Left_Opnd (E2))
3669 FCE (Right_Opnd (E1), Right_Opnd (E2));
3671 when N_Character_Literal =>
3673 Char_Literal_Value (E1) = Char_Literal_Value (E2);
3675 when N_Component_Association =>
3677 FCL (Choices (E1), Choices (E2))
3678 and then FCE (Expression (E1), Expression (E2));
3680 when N_Conditional_Expression =>
3682 FCL (Expressions (E1), Expressions (E2));
3684 when N_Explicit_Dereference =>
3686 FCE (Prefix (E1), Prefix (E2));
3688 when N_Extension_Aggregate =>
3690 FCL (Expressions (E1), Expressions (E2))
3691 and then Null_Record_Present (E1) =
3692 Null_Record_Present (E2)
3693 and then FCL (Component_Associations (E1),
3694 Component_Associations (E2));
3696 when N_Function_Call =>
3698 FCE (Name (E1), Name (E2))
3699 and then FCL (Parameter_Associations (E1),
3700 Parameter_Associations (E2));
3702 when N_Indexed_Component =>
3704 FCE (Prefix (E1), Prefix (E2))
3705 and then FCL (Expressions (E1), Expressions (E2));
3707 when N_Integer_Literal =>
3708 return (Intval (E1) = Intval (E2));
3713 when N_Operator_Symbol =>
3715 Chars (E1) = Chars (E2);
3717 when N_Others_Choice =>
3720 when N_Parameter_Association =>
3722 Chars (Selector_Name (E1)) = Chars (Selector_Name (E2))
3723 and then FCE (Explicit_Actual_Parameter (E1),
3724 Explicit_Actual_Parameter (E2));
3726 when N_Qualified_Expression =>
3728 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3729 and then FCE (Expression (E1), Expression (E2));
3733 FCE (Low_Bound (E1), Low_Bound (E2))
3734 and then FCE (High_Bound (E1), High_Bound (E2));
3736 when N_Real_Literal =>
3737 return (Realval (E1) = Realval (E2));
3739 when N_Selected_Component =>
3741 FCE (Prefix (E1), Prefix (E2))
3742 and then FCE (Selector_Name (E1), Selector_Name (E2));
3746 FCE (Prefix (E1), Prefix (E2))
3747 and then FCE (Discrete_Range (E1), Discrete_Range (E2));
3749 when N_String_Literal =>
3751 S1 : constant String_Id := Strval (E1);
3752 S2 : constant String_Id := Strval (E2);
3753 L1 : constant Nat := String_Length (S1);
3754 L2 : constant Nat := String_Length (S2);
3761 for J in 1 .. L1 loop
3762 if Get_String_Char (S1, J) /=
3763 Get_String_Char (S2, J)
3773 when N_Type_Conversion =>
3775 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3776 and then FCE (Expression (E1), Expression (E2));
3780 Entity (E1) = Entity (E2)
3781 and then FCE (Right_Opnd (E1), Right_Opnd (E2));
3783 when N_Unchecked_Type_Conversion =>
3785 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
3786 and then FCE (Expression (E1), Expression (E2));
3788 -- All other node types cannot appear in this context. Strictly
3789 -- we should raise a fatal internal error. Instead we just ignore
3790 -- the nodes. This means that if anyone makes a mistake in the
3791 -- expander and mucks an expression tree irretrievably, the
3792 -- result will be a failure to detect a (probably very obscure)
3793 -- case of non-conformance, which is better than bombing on some
3794 -- case where two expressions do in fact conform.
3801 end Fully_Conformant_Expressions;
3803 ----------------------------------------
3804 -- Fully_Conformant_Discrete_Subtypes --
3805 ----------------------------------------
3807 function Fully_Conformant_Discrete_Subtypes
3808 (Given_S1 : Node_Id;
3809 Given_S2 : Node_Id) return Boolean
3811 S1 : constant Node_Id := Original_Node (Given_S1);
3812 S2 : constant Node_Id := Original_Node (Given_S2);
3814 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean;
3815 -- Special-case for a bound given by a discriminant, which in the
3816 -- body is replaced with the discriminal of the enclosing type.
3818 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean;
3819 -- Check both bounds.
3821 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is
3823 if Is_Entity_Name (B1)
3824 and then Is_Entity_Name (B2)
3825 and then Ekind (Entity (B1)) = E_Discriminant
3827 return Chars (B1) = Chars (B2);
3830 return Fully_Conformant_Expressions (B1, B2);
3832 end Conforming_Bounds;
3834 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is
3837 Conforming_Bounds (Low_Bound (R1), Low_Bound (R2))
3839 Conforming_Bounds (High_Bound (R1), High_Bound (R2));
3840 end Conforming_Ranges;
3842 -- Start of processing for Fully_Conformant_Discrete_Subtypes
3845 if Nkind (S1) /= Nkind (S2) then
3848 elsif Is_Entity_Name (S1) then
3849 return Entity (S1) = Entity (S2);
3851 elsif Nkind (S1) = N_Range then
3852 return Conforming_Ranges (S1, S2);
3854 elsif Nkind (S1) = N_Subtype_Indication then
3856 Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2))
3859 (Range_Expression (Constraint (S1)),
3860 Range_Expression (Constraint (S2)));
3864 end Fully_Conformant_Discrete_Subtypes;
3866 --------------------
3867 -- Install_Entity --
3868 --------------------
3870 procedure Install_Entity (E : Entity_Id) is
3871 Prev : constant Entity_Id := Current_Entity (E);
3874 Set_Is_Immediately_Visible (E);
3875 Set_Current_Entity (E);
3876 Set_Homonym (E, Prev);
3879 ---------------------
3880 -- Install_Formals --
3881 ---------------------
3883 procedure Install_Formals (Id : Entity_Id) is
3887 F := First_Formal (Id);
3889 while Present (F) loop
3893 end Install_Formals;
3895 ---------------------------------
3896 -- Is_Non_Overriding_Operation --
3897 ---------------------------------
3899 function Is_Non_Overriding_Operation
3900 (Prev_E : Entity_Id;
3901 New_E : Entity_Id) return Boolean
3905 G_Typ : Entity_Id := Empty;
3907 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id;
3908 -- If F_Type is a derived type associated with a generic actual
3909 -- subtype, then return its Generic_Parent_Type attribute, else
3912 function Types_Correspond
3913 (P_Type : Entity_Id;
3914 N_Type : Entity_Id) return Boolean;
3915 -- Returns true if and only if the types (or designated types
3916 -- in the case of anonymous access types) are the same or N_Type
3917 -- is derived directly or indirectly from P_Type.
3919 -----------------------------
3920 -- Get_Generic_Parent_Type --
3921 -----------------------------
3923 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is
3928 if Is_Derived_Type (F_Typ)
3929 and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration
3931 -- The tree must be traversed to determine the parent
3932 -- subtype in the generic unit, which unfortunately isn't
3933 -- always available via semantic attributes. ???
3934 -- (Note: The use of Original_Node is needed for cases
3935 -- where a full derived type has been rewritten.)
3937 Indic := Subtype_Indication
3938 (Type_Definition (Original_Node (Parent (F_Typ))));
3940 if Nkind (Indic) = N_Subtype_Indication then
3941 G_Typ := Entity (Subtype_Mark (Indic));
3943 G_Typ := Entity (Indic);
3946 if Nkind (Parent (G_Typ)) = N_Subtype_Declaration
3947 and then Present (Generic_Parent_Type (Parent (G_Typ)))
3949 return Generic_Parent_Type (Parent (G_Typ));
3954 end Get_Generic_Parent_Type;
3956 ----------------------
3957 -- Types_Correspond --
3958 ----------------------
3960 function Types_Correspond
3961 (P_Type : Entity_Id;
3962 N_Type : Entity_Id) return Boolean
3964 Prev_Type : Entity_Id := Base_Type (P_Type);
3965 New_Type : Entity_Id := Base_Type (N_Type);
3968 if Ekind (Prev_Type) = E_Anonymous_Access_Type then
3969 Prev_Type := Designated_Type (Prev_Type);
3972 if Ekind (New_Type) = E_Anonymous_Access_Type then
3973 New_Type := Designated_Type (New_Type);
3976 if Prev_Type = New_Type then
3979 elsif not Is_Class_Wide_Type (New_Type) then
3980 while Etype (New_Type) /= New_Type loop
3981 New_Type := Etype (New_Type);
3982 if New_Type = Prev_Type then
3988 end Types_Correspond;
3990 -- Start of processing for Is_Non_Overriding_Operation
3993 -- In the case where both operations are implicit derived
3994 -- subprograms then neither overrides the other. This can
3995 -- only occur in certain obscure cases (e.g., derivation
3996 -- from homographs created in a generic instantiation).
3998 if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then
4001 elsif Ekind (Current_Scope) = E_Package
4002 and then Is_Generic_Instance (Current_Scope)
4003 and then In_Private_Part (Current_Scope)
4004 and then Comes_From_Source (New_E)
4006 -- We examine the formals and result subtype of the inherited
4007 -- operation, to determine whether their type is derived from
4008 -- (the instance of) a generic type.
4010 Formal := First_Formal (Prev_E);
4012 while Present (Formal) loop
4013 F_Typ := Base_Type (Etype (Formal));
4015 if Ekind (F_Typ) = E_Anonymous_Access_Type then
4016 F_Typ := Designated_Type (F_Typ);
4019 G_Typ := Get_Generic_Parent_Type (F_Typ);
4021 Next_Formal (Formal);
4024 if not Present (G_Typ) and then Ekind (Prev_E) = E_Function then
4025 G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E)));
4032 -- If the generic type is a private type, then the original
4033 -- operation was not overriding in the generic, because there was
4034 -- no primitive operation to override.
4036 if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration
4037 and then Nkind (Formal_Type_Definition (Parent (G_Typ))) =
4038 N_Formal_Private_Type_Definition
4042 -- The generic parent type is the ancestor of a formal derived
4043 -- type declaration. We need to check whether it has a primitive
4044 -- operation that should be overridden by New_E in the generic.
4048 P_Formal : Entity_Id;
4049 N_Formal : Entity_Id;
4053 Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ));
4056 while Present (Prim_Elt) loop
4057 P_Prim := Node (Prim_Elt);
4059 if Chars (P_Prim) = Chars (New_E)
4060 and then Ekind (P_Prim) = Ekind (New_E)
4062 P_Formal := First_Formal (P_Prim);
4063 N_Formal := First_Formal (New_E);
4064 while Present (P_Formal) and then Present (N_Formal) loop
4065 P_Typ := Etype (P_Formal);
4066 N_Typ := Etype (N_Formal);
4068 if not Types_Correspond (P_Typ, N_Typ) then
4072 Next_Entity (P_Formal);
4073 Next_Entity (N_Formal);
4076 -- Found a matching primitive operation belonging to
4077 -- the formal ancestor type, so the new subprogram
4080 if not Present (P_Formal)
4081 and then not Present (N_Formal)
4082 and then (Ekind (New_E) /= E_Function
4085 (Etype (P_Prim), Etype (New_E)))
4091 Next_Elmt (Prim_Elt);
4094 -- If no match found, then the new subprogram does
4095 -- not override in the generic (nor in the instance).
4103 end Is_Non_Overriding_Operation;
4105 ------------------------------
4106 -- Make_Inequality_Operator --
4107 ------------------------------
4109 -- S is the defining identifier of an equality operator. We build a
4110 -- subprogram declaration with the right signature. This operation is
4111 -- intrinsic, because it is always expanded as the negation of the
4112 -- call to the equality function.
4114 procedure Make_Inequality_Operator (S : Entity_Id) is
4115 Loc : constant Source_Ptr := Sloc (S);
4118 Op_Name : Entity_Id;
4124 -- Check that equality was properly defined.
4126 if No (Next_Formal (First_Formal (S))) then
4130 A := Make_Defining_Identifier (Loc, Chars (First_Formal (S)));
4131 B := Make_Defining_Identifier (Loc,
4132 Chars (Next_Formal (First_Formal (S))));
4134 Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne);
4136 Formals := New_List (
4137 Make_Parameter_Specification (Loc,
4138 Defining_Identifier => A,
4140 New_Reference_To (Etype (First_Formal (S)), Loc)),
4142 Make_Parameter_Specification (Loc,
4143 Defining_Identifier => B,
4145 New_Reference_To (Etype (Next_Formal (First_Formal (S))), Loc)));
4148 Make_Subprogram_Declaration (Loc,
4150 Make_Function_Specification (Loc,
4151 Defining_Unit_Name => Op_Name,
4152 Parameter_Specifications => Formals,
4153 Subtype_Mark => New_Reference_To (Standard_Boolean, Loc)));
4155 -- Insert inequality right after equality if it is explicit or after
4156 -- the derived type when implicit. These entities are created only
4157 -- for visibility purposes, and eventually replaced in the course of
4158 -- expansion, so they do not need to be attached to the tree and seen
4159 -- by the back-end. Keeping them internal also avoids spurious freezing
4160 -- problems. The parent field is set simply to make analysis safe.
4162 if No (Alias (S)) then
4163 Set_Parent (Decl, Parent (Unit_Declaration_Node (S)));
4165 Set_Parent (Decl, Parent (Parent (Etype (First_Formal (S)))));
4168 Mark_Rewrite_Insertion (Decl);
4169 Set_Is_Intrinsic_Subprogram (Op_Name);
4171 Set_Has_Completion (Op_Name);
4172 Set_Corresponding_Equality (Op_Name, S);
4173 Set_Is_Abstract (Op_Name, Is_Abstract (S));
4175 end Make_Inequality_Operator;
4177 ----------------------
4178 -- May_Need_Actuals --
4179 ----------------------
4181 procedure May_Need_Actuals (Fun : Entity_Id) is
4186 F := First_Formal (Fun);
4189 while Present (F) loop
4190 if No (Default_Value (F)) then
4198 Set_Needs_No_Actuals (Fun, B);
4199 end May_Need_Actuals;
4201 ---------------------
4202 -- Mode_Conformant --
4203 ---------------------
4205 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
4209 Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result);
4211 end Mode_Conformant;
4213 ---------------------------
4214 -- New_Overloaded_Entity --
4215 ---------------------------
4217 procedure New_Overloaded_Entity
4219 Derived_Type : Entity_Id := Empty)
4222 -- Entity that S overrides
4224 Prev_Vis : Entity_Id := Empty;
4225 -- Needs comment ???
4227 function Is_Private_Declaration (E : Entity_Id) return Boolean;
4228 -- Check that E is declared in the private part of the current package,
4229 -- or in the package body, where it may hide a previous declaration.
4230 -- We can't use In_Private_Part by itself because this flag is also
4231 -- set when freezing entities, so we must examine the place of the
4232 -- declaration in the tree, and recognize wrapper packages as well.
4234 procedure Maybe_Primitive_Operation (Overriding : Boolean := False);
4235 -- If the subprogram being analyzed is a primitive operation of
4236 -- the type of one of its formals, set the corresponding flag.
4238 ----------------------------
4239 -- Is_Private_Declaration --
4240 ----------------------------
4242 function Is_Private_Declaration (E : Entity_Id) return Boolean is
4243 Priv_Decls : List_Id;
4244 Decl : constant Node_Id := Unit_Declaration_Node (E);
4247 if Is_Package (Current_Scope)
4248 and then In_Private_Part (Current_Scope)
4251 Private_Declarations (
4252 Specification (Unit_Declaration_Node (Current_Scope)));
4254 return In_Package_Body (Current_Scope)
4255 or else List_Containing (Decl) = Priv_Decls
4256 or else (Nkind (Parent (Decl)) = N_Package_Specification
4257 and then not Is_Compilation_Unit (
4258 Defining_Entity (Parent (Decl)))
4259 and then List_Containing (Parent (Parent (Decl)))
4264 end Is_Private_Declaration;
4266 -------------------------------
4267 -- Maybe_Primitive_Operation --
4268 -------------------------------
4270 procedure Maybe_Primitive_Operation (Overriding : Boolean := False) is
4275 function Visible_Part_Type (T : Entity_Id) return Boolean;
4276 -- Returns true if T is declared in the visible part of
4277 -- the current package scope; otherwise returns false.
4278 -- Assumes that T is declared in a package.
4280 procedure Check_Private_Overriding (T : Entity_Id);
4281 -- Checks that if a primitive abstract subprogram of a visible
4282 -- abstract type is declared in a private part, then it must
4283 -- override an abstract subprogram declared in the visible part.
4284 -- Also checks that if a primitive function with a controlling
4285 -- result is declared in a private part, then it must override
4286 -- a function declared in the visible part.
4288 ------------------------------
4289 -- Check_Private_Overriding --
4290 ------------------------------
4292 procedure Check_Private_Overriding (T : Entity_Id) is
4294 if Ekind (Current_Scope) = E_Package
4295 and then In_Private_Part (Current_Scope)
4296 and then Visible_Part_Type (T)
4297 and then not In_Instance
4300 and then Is_Abstract (S)
4301 and then (not Overriding or else not Is_Abstract (E))
4303 Error_Msg_N ("abstract subprograms must be visible "
4304 & "('R'M 3.9.3(10))!", S);
4306 elsif Ekind (S) = E_Function
4307 and then Is_Tagged_Type (T)
4308 and then T = Base_Type (Etype (S))
4309 and then not Overriding
4312 ("private function with tagged result must"
4313 & " override visible-part function", S);
4315 ("\move subprogram to the visible part"
4316 & " ('R'M 3.9.3(10))", S);
4319 end Check_Private_Overriding;
4321 -----------------------
4322 -- Visible_Part_Type --
4323 -----------------------
4325 function Visible_Part_Type (T : Entity_Id) return Boolean is
4326 P : constant Node_Id := Unit_Declaration_Node (Scope (T));
4330 -- If the entity is a private type, then it must be
4331 -- declared in a visible part.
4333 if Ekind (T) in Private_Kind then
4337 -- Otherwise, we traverse the visible part looking for its
4338 -- corresponding declaration. We cannot use the declaration
4339 -- node directly because in the private part the entity of a
4340 -- private type is the one in the full view, which does not
4341 -- indicate that it is the completion of something visible.
4343 N := First (Visible_Declarations (Specification (P)));
4344 while Present (N) loop
4345 if Nkind (N) = N_Full_Type_Declaration
4346 and then Present (Defining_Identifier (N))
4347 and then T = Defining_Identifier (N)
4351 elsif (Nkind (N) = N_Private_Type_Declaration
4353 Nkind (N) = N_Private_Extension_Declaration)
4354 and then Present (Defining_Identifier (N))
4355 and then T = Full_View (Defining_Identifier (N))
4364 end Visible_Part_Type;
4366 -- Start of processing for Maybe_Primitive_Operation
4369 if not Comes_From_Source (S) then
4372 elsif (Ekind (Current_Scope) = E_Package
4373 and then not In_Package_Body (Current_Scope))
4376 -- For function, check return type
4378 if Ekind (S) = E_Function then
4379 B_Typ := Base_Type (Etype (S));
4381 if Scope (B_Typ) = Current_Scope then
4382 Set_Has_Primitive_Operations (B_Typ);
4383 Check_Private_Overriding (B_Typ);
4387 -- For all subprograms, check formals
4389 Formal := First_Formal (S);
4390 while Present (Formal) loop
4391 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
4392 F_Typ := Designated_Type (Etype (Formal));
4394 F_Typ := Etype (Formal);
4397 B_Typ := Base_Type (F_Typ);
4399 if Scope (B_Typ) = Current_Scope then
4400 Set_Has_Primitive_Operations (B_Typ);
4401 Check_Private_Overriding (B_Typ);
4404 Next_Formal (Formal);
4407 end Maybe_Primitive_Operation;
4409 -- Start of processing for New_Overloaded_Entity
4412 -- We need to look for an entity that S may override. This must be a
4413 -- homonym in the current scope, so we look for the first homonym of
4414 -- S in the current scope as the starting point for the search.
4416 E := Current_Entity_In_Scope (S);
4418 -- If there is no homonym then this is definitely not overriding
4421 Enter_Overloaded_Entity (S);
4422 Check_Dispatching_Operation (S, Empty);
4423 Maybe_Primitive_Operation;
4425 -- If there is a homonym that is not overloadable, then we have an
4426 -- error, except for the special cases checked explicitly below.
4428 elsif not Is_Overloadable (E) then
4430 -- Check for spurious conflict produced by a subprogram that has the
4431 -- same name as that of the enclosing generic package. The conflict
4432 -- occurs within an instance, between the subprogram and the renaming
4433 -- declaration for the package. After the subprogram, the package
4434 -- renaming declaration becomes hidden.
4436 if Ekind (E) = E_Package
4437 and then Present (Renamed_Object (E))
4438 and then Renamed_Object (E) = Current_Scope
4439 and then Nkind (Parent (Renamed_Object (E))) =
4440 N_Package_Specification
4441 and then Present (Generic_Parent (Parent (Renamed_Object (E))))
4444 Set_Is_Immediately_Visible (E, False);
4445 Enter_Overloaded_Entity (S);
4446 Set_Homonym (S, Homonym (E));
4447 Check_Dispatching_Operation (S, Empty);
4449 -- If the subprogram is implicit it is hidden by the previous
4450 -- declaration. However if it is dispatching, it must appear in
4451 -- the dispatch table anyway, because it can be dispatched to
4452 -- even if it cannot be called directly.
4454 elsif Present (Alias (S))
4455 and then not Comes_From_Source (S)
4457 Set_Scope (S, Current_Scope);
4459 if Is_Dispatching_Operation (Alias (S)) then
4460 Check_Dispatching_Operation (S, Empty);
4466 Error_Msg_Sloc := Sloc (E);
4467 Error_Msg_N ("& conflicts with declaration#", S);
4469 -- Useful additional warning
4471 if Is_Generic_Unit (E) then
4472 Error_Msg_N ("\previous generic unit cannot be overloaded", S);
4478 -- E exists and is overloadable
4481 -- Loop through E and its homonyms to determine if any of them
4482 -- is the candidate for overriding by S.
4484 while Present (E) loop
4486 -- Definitely not interesting if not in the current scope
4488 if Scope (E) /= Current_Scope then
4491 -- Check if we have type conformance
4493 elsif Type_Conformant (E, S) then
4495 -- If the old and new entities have the same profile and
4496 -- one is not the body of the other, then this is an error,
4497 -- unless one of them is implicitly declared.
4499 -- There are some cases when both can be implicit, for example
4500 -- when both a literal and a function that overrides it are
4501 -- inherited in a derivation, or when an inhertited operation
4502 -- of a tagged full type overrides the ineherited operation of
4503 -- a private extension. Ada 83 had a special rule for the
4504 -- the literal case. In Ada95, the later implicit operation
4505 -- hides the former, and the literal is always the former.
4506 -- In the odd case where both are derived operations declared
4507 -- at the same point, both operations should be declared,
4508 -- and in that case we bypass the following test and proceed
4509 -- to the next part (this can only occur for certain obscure
4510 -- cases involving homographs in instances and can't occur for
4511 -- dispatching operations ???). Note that the following
4512 -- condition is less than clear. For example, it's not at
4513 -- all clear why there's a test for E_Entry here. ???
4515 if Present (Alias (S))
4516 and then (No (Alias (E))
4517 or else Comes_From_Source (E)
4518 or else Is_Dispatching_Operation (E))
4520 (Ekind (E) = E_Entry
4521 or else Ekind (E) /= E_Enumeration_Literal)
4523 -- When an derived operation is overloaded it may be due
4524 -- to the fact that the full view of a private extension
4525 -- re-inherits. It has to be dealt with.
4527 if Is_Package (Current_Scope)
4528 and then In_Private_Part (Current_Scope)
4530 Check_Operation_From_Private_View (S, E);
4533 -- In any case the implicit operation remains hidden by
4534 -- the existing declaration.
4538 -- Within an instance, the renaming declarations for
4539 -- actual subprograms may become ambiguous, but they do
4540 -- not hide each other.
4542 elsif Ekind (E) /= E_Entry
4543 and then not Comes_From_Source (E)
4544 and then not Is_Generic_Instance (E)
4545 and then (Present (Alias (E))
4546 or else Is_Intrinsic_Subprogram (E))
4547 and then (not In_Instance
4548 or else No (Parent (E))
4549 or else Nkind (Unit_Declaration_Node (E)) /=
4550 N_Subprogram_Renaming_Declaration)
4552 -- A subprogram child unit is not allowed to override
4553 -- an inherited subprogram (10.1.1(20)).
4555 if Is_Child_Unit (S) then
4557 ("child unit overrides inherited subprogram in parent",
4562 if Is_Non_Overriding_Operation (E, S) then
4563 Enter_Overloaded_Entity (S);
4564 if not Present (Derived_Type)
4565 or else Is_Tagged_Type (Derived_Type)
4567 Check_Dispatching_Operation (S, Empty);
4573 -- E is a derived operation or an internal operator which
4574 -- is being overridden. Remove E from further visibility.
4575 -- Furthermore, if E is a dispatching operation, it must be
4576 -- replaced in the list of primitive operations of its type
4577 -- (see Override_Dispatching_Operation).
4583 Prev := First_Entity (Current_Scope);
4585 while Present (Prev)
4586 and then Next_Entity (Prev) /= E
4591 -- It is possible for E to be in the current scope and
4592 -- yet not in the entity chain. This can only occur in a
4593 -- generic context where E is an implicit concatenation
4594 -- in the formal part, because in a generic body the
4595 -- entity chain starts with the formals.
4598 (Present (Prev) or else Chars (E) = Name_Op_Concat);
4600 -- E must be removed both from the entity_list of the
4601 -- current scope, and from the visibility chain
4603 if Debug_Flag_E then
4604 Write_Str ("Override implicit operation ");
4605 Write_Int (Int (E));
4609 -- If E is a predefined concatenation, it stands for four
4610 -- different operations. As a result, a single explicit
4611 -- declaration does not hide it. In a possible ambiguous
4612 -- situation, Disambiguate chooses the user-defined op,
4613 -- so it is correct to retain the previous internal one.
4615 if Chars (E) /= Name_Op_Concat
4616 or else Ekind (E) /= E_Operator
4618 -- For nondispatching derived operations that are
4619 -- overridden by a subprogram declared in the private
4620 -- part of a package, we retain the derived subprogram
4621 -- but mark it as not immediately visible. If the
4622 -- derived operation was declared in the visible part
4623 -- then this ensures that it will still be visible
4624 -- outside the package with the proper signature
4625 -- (calls from outside must also be directed to this
4626 -- version rather than the overriding one, unlike the
4627 -- dispatching case). Calls from inside the package
4628 -- will still resolve to the overriding subprogram
4629 -- since the derived one is marked as not visible
4630 -- within the package.
4632 -- If the private operation is dispatching, we achieve
4633 -- the overriding by keeping the implicit operation
4634 -- but setting its alias to be the overring one. In
4635 -- this fashion the proper body is executed in all
4636 -- cases, but the original signature is used outside
4639 -- If the overriding is not in the private part, we
4640 -- remove the implicit operation altogether.
4642 if Is_Private_Declaration (S) then
4644 if not Is_Dispatching_Operation (E) then
4645 Set_Is_Immediately_Visible (E, False);
4648 -- work done in Override_Dispatching_Operation.
4654 -- Find predecessor of E in Homonym chain
4656 if E = Current_Entity (E) then
4659 Prev_Vis := Current_Entity (E);
4660 while Homonym (Prev_Vis) /= E loop
4661 Prev_Vis := Homonym (Prev_Vis);
4665 if Prev_Vis /= Empty then
4667 -- Skip E in the visibility chain
4669 Set_Homonym (Prev_Vis, Homonym (E));
4672 Set_Name_Entity_Id (Chars (E), Homonym (E));
4675 Set_Next_Entity (Prev, Next_Entity (E));
4677 if No (Next_Entity (Prev)) then
4678 Set_Last_Entity (Current_Scope, Prev);
4684 Enter_Overloaded_Entity (S);
4685 Set_Is_Overriding_Operation (S);
4687 if Is_Dispatching_Operation (E) then
4689 -- An overriding dispatching subprogram inherits
4690 -- the convention of the overridden subprogram
4693 Set_Convention (S, Convention (E));
4695 Check_Dispatching_Operation (S, E);
4697 Check_Dispatching_Operation (S, Empty);
4700 Maybe_Primitive_Operation (Overriding => True);
4701 goto Check_Inequality;
4704 -- Apparent redeclarations in instances can occur when two
4705 -- formal types get the same actual type. The subprograms in
4706 -- in the instance are legal, even if not callable from the
4707 -- outside. Calls from within are disambiguated elsewhere.
4708 -- For dispatching operations in the visible part, the usual
4709 -- rules apply, and operations with the same profile are not
4712 elsif (In_Instance_Visible_Part
4713 and then not Is_Dispatching_Operation (E))
4714 or else In_Instance_Not_Visible
4718 -- Here we have a real error (identical profile)
4721 Error_Msg_Sloc := Sloc (E);
4723 -- Avoid cascaded errors if the entity appears in
4724 -- subsequent calls.
4726 Set_Scope (S, Current_Scope);
4728 Error_Msg_N ("& conflicts with declaration#", S);
4730 if Is_Generic_Instance (S)
4731 and then not Has_Completion (E)
4734 ("\instantiation cannot provide body for it", S);
4748 -- On exit, we know that S is a new entity
4750 Enter_Overloaded_Entity (S);
4751 Maybe_Primitive_Operation;
4753 -- If S is a derived operation for an untagged type then
4754 -- by definition it's not a dispatching operation (even
4755 -- if the parent operation was dispatching), so we don't
4756 -- call Check_Dispatching_Operation in that case.
4758 if not Present (Derived_Type)
4759 or else Is_Tagged_Type (Derived_Type)
4761 Check_Dispatching_Operation (S, Empty);
4765 -- If this is a user-defined equality operator that is not
4766 -- a derived subprogram, create the corresponding inequality.
4767 -- If the operation is dispatching, the expansion is done
4768 -- elsewhere, and we do not create an explicit inequality
4771 <<Check_Inequality>>
4772 if Chars (S) = Name_Op_Eq
4773 and then Etype (S) = Standard_Boolean
4774 and then Present (Parent (S))
4775 and then not Is_Dispatching_Operation (S)
4777 Make_Inequality_Operator (S);
4779 end New_Overloaded_Entity;
4781 ---------------------
4782 -- Process_Formals --
4783 ---------------------
4785 procedure Process_Formals
4787 Related_Nod : Node_Id)
4789 Param_Spec : Node_Id;
4791 Formal_Type : Entity_Id;
4795 function Is_Class_Wide_Default (D : Node_Id) return Boolean;
4796 -- Check whether the default has a class-wide type. After analysis
4797 -- the default has the type of the formal, so we must also check
4798 -- explicitly for an access attribute.
4800 ---------------------------
4801 -- Is_Class_Wide_Default --
4802 ---------------------------
4804 function Is_Class_Wide_Default (D : Node_Id) return Boolean is
4806 return Is_Class_Wide_Type (Designated_Type (Etype (D)))
4807 or else (Nkind (D) = N_Attribute_Reference
4808 and then Attribute_Name (D) = Name_Access
4809 and then Is_Class_Wide_Type (Etype (Prefix (D))));
4810 end Is_Class_Wide_Default;
4812 -- Start of processing for Process_Formals
4815 -- In order to prevent premature use of the formals in the same formal
4816 -- part, the Ekind is left undefined until all default expressions are
4817 -- analyzed. The Ekind is established in a separate loop at the end.
4819 Param_Spec := First (T);
4821 while Present (Param_Spec) loop
4823 Formal := Defining_Identifier (Param_Spec);
4824 Enter_Name (Formal);
4826 -- Case of ordinary parameters
4828 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
4829 Find_Type (Parameter_Type (Param_Spec));
4830 Ptype := Parameter_Type (Param_Spec);
4832 if Ptype = Error then
4836 Formal_Type := Entity (Ptype);
4838 if Ekind (Formal_Type) = E_Incomplete_Type
4839 or else (Is_Class_Wide_Type (Formal_Type)
4840 and then Ekind (Root_Type (Formal_Type)) =
4843 -- Ada0Y (AI-50217): Incomplete tagged types that are made
4844 -- visible through a limited with_clause are valid formal
4847 if From_With_Type (Formal_Type)
4848 and then Is_Tagged_Type (Formal_Type)
4852 elsif Nkind (Parent (T)) /= N_Access_Function_Definition
4853 and then Nkind (Parent (T)) /= N_Access_Procedure_Definition
4855 Error_Msg_N ("invalid use of incomplete type", Param_Spec);
4858 elsif Ekind (Formal_Type) = E_Void then
4859 Error_Msg_NE ("premature use of&",
4860 Parameter_Type (Param_Spec), Formal_Type);
4863 -- An access formal type
4867 Access_Definition (Related_Nod, Parameter_Type (Param_Spec));
4870 Set_Etype (Formal, Formal_Type);
4872 Default := Expression (Param_Spec);
4874 if Present (Default) then
4875 if Out_Present (Param_Spec) then
4877 ("default initialization only allowed for IN parameters",
4881 -- Do the special preanalysis of the expression (see section on
4882 -- "Handling of Default Expressions" in the spec of package Sem).
4884 Analyze_Per_Use_Expression (Default, Formal_Type);
4886 -- Check that the designated type of an access parameter's
4887 -- default is not a class-wide type unless the parameter's
4888 -- designated type is also class-wide.
4890 if Ekind (Formal_Type) = E_Anonymous_Access_Type
4891 and then Is_Class_Wide_Default (Default)
4892 and then not Is_Class_Wide_Type (Designated_Type (Formal_Type))
4895 ("access to class-wide expression not allowed here", Default);
4903 -- Now set the kind (mode) of each formal
4905 Param_Spec := First (T);
4907 while Present (Param_Spec) loop
4908 Formal := Defining_Identifier (Param_Spec);
4909 Set_Formal_Mode (Formal);
4911 if Ekind (Formal) = E_In_Parameter then
4912 Set_Default_Value (Formal, Expression (Param_Spec));
4914 if Present (Expression (Param_Spec)) then
4915 Default := Expression (Param_Spec);
4917 if Is_Scalar_Type (Etype (Default)) then
4919 (Parameter_Type (Param_Spec)) /= N_Access_Definition
4921 Formal_Type := Entity (Parameter_Type (Param_Spec));
4924 Formal_Type := Access_Definition
4925 (Related_Nod, Parameter_Type (Param_Spec));
4928 Apply_Scalar_Range_Check (Default, Formal_Type);
4937 end Process_Formals;
4939 ----------------------------
4940 -- Reference_Body_Formals --
4941 ----------------------------
4943 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is
4948 if Error_Posted (Spec) then
4952 Fs := First_Formal (Spec);
4953 Fb := First_Formal (Bod);
4955 while Present (Fs) loop
4956 Generate_Reference (Fs, Fb, 'b');
4959 Style.Check_Identifier (Fb, Fs);
4962 Set_Spec_Entity (Fb, Fs);
4963 Set_Referenced (Fs, False);
4967 end Reference_Body_Formals;
4969 -------------------------
4970 -- Set_Actual_Subtypes --
4971 -------------------------
4973 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is
4974 Loc : constant Source_Ptr := Sloc (N);
4978 First_Stmt : Node_Id := Empty;
4979 AS_Needed : Boolean;
4982 -- If this is an emtpy initialization procedure, no need to create
4983 -- actual subtypes (small optimization).
4985 if Ekind (Subp) = E_Procedure
4986 and then Is_Null_Init_Proc (Subp)
4991 Formal := First_Formal (Subp);
4992 while Present (Formal) loop
4993 T := Etype (Formal);
4995 -- We never need an actual subtype for a constrained formal.
4997 if Is_Constrained (T) then
5000 -- If we have unknown discriminants, then we do not need an
5001 -- actual subtype, or more accurately we cannot figure it out!
5002 -- Note that all class-wide types have unknown discriminants.
5004 elsif Has_Unknown_Discriminants (T) then
5007 -- At this stage we have an unconstrained type that may need
5008 -- an actual subtype. For sure the actual subtype is needed
5009 -- if we have an unconstrained array type.
5011 elsif Is_Array_Type (T) then
5014 -- The only other case which needs an actual subtype is an
5015 -- unconstrained record type which is an IN parameter (we
5016 -- cannot generate actual subtypes for the OUT or IN OUT case,
5017 -- since an assignment can change the discriminant values.
5018 -- However we exclude the case of initialization procedures,
5019 -- since discriminants are handled very specially in this context,
5020 -- see the section entitled "Handling of Discriminants" in Einfo.
5021 -- We also exclude the case of Discrim_SO_Functions (functions
5022 -- used in front end layout mode for size/offset values), since
5023 -- in such functions only discriminants are referenced, and not
5024 -- only are such subtypes not needed, but they cannot always
5025 -- be generated, because of order of elaboration issues.
5027 elsif Is_Record_Type (T)
5028 and then Ekind (Formal) = E_In_Parameter
5029 and then Chars (Formal) /= Name_uInit
5030 and then not Is_Discrim_SO_Function (Subp)
5034 -- All other cases do not need an actual subtype
5040 -- Generate actual subtypes for unconstrained arrays and
5041 -- unconstrained discriminated records.
5045 if Nkind (N) = N_Accept_Statement then
5047 -- If expansion is active, The formal is replaced by a local
5048 -- variable that renames the corresponding entry of the
5049 -- parameter block, and it is this local variable that may
5050 -- require an actual subtype.
5052 if Expander_Active then
5053 Decl := Build_Actual_Subtype (T, Renamed_Object (Formal));
5055 Decl := Build_Actual_Subtype (T, Formal);
5058 if Present (Handled_Statement_Sequence (N)) then
5060 First (Statements (Handled_Statement_Sequence (N)));
5061 Prepend (Decl, Statements (Handled_Statement_Sequence (N)));
5062 Mark_Rewrite_Insertion (Decl);
5064 -- If the accept statement has no body, there will be
5065 -- no reference to the actuals, so no need to compute
5072 Decl := Build_Actual_Subtype (T, Formal);
5073 Prepend (Decl, Declarations (N));
5074 Mark_Rewrite_Insertion (Decl);
5079 -- We need to freeze manually the generated type when it is
5080 -- inserted anywhere else than in a declarative part.
5082 if Present (First_Stmt) then
5083 Insert_List_Before_And_Analyze (First_Stmt,
5084 Freeze_Entity (Defining_Identifier (Decl), Loc));
5087 if Nkind (N) = N_Accept_Statement
5088 and then Expander_Active
5090 Set_Actual_Subtype (Renamed_Object (Formal),
5091 Defining_Identifier (Decl));
5093 Set_Actual_Subtype (Formal, Defining_Identifier (Decl));
5097 Next_Formal (Formal);
5099 end Set_Actual_Subtypes;
5101 ---------------------
5102 -- Set_Formal_Mode --
5103 ---------------------
5105 procedure Set_Formal_Mode (Formal_Id : Entity_Id) is
5106 Spec : constant Node_Id := Parent (Formal_Id);
5109 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
5110 -- since we ensure that corresponding actuals are always valid at the
5111 -- point of the call.
5113 if Out_Present (Spec) then
5114 if Ekind (Scope (Formal_Id)) = E_Function
5115 or else Ekind (Scope (Formal_Id)) = E_Generic_Function
5117 Error_Msg_N ("functions can only have IN parameters", Spec);
5118 Set_Ekind (Formal_Id, E_In_Parameter);
5120 elsif In_Present (Spec) then
5121 Set_Ekind (Formal_Id, E_In_Out_Parameter);
5124 Set_Ekind (Formal_Id, E_Out_Parameter);
5125 Set_Never_Set_In_Source (Formal_Id, True);
5126 Set_Is_True_Constant (Formal_Id, False);
5127 Set_Current_Value (Formal_Id, Empty);
5131 Set_Ekind (Formal_Id, E_In_Parameter);
5134 -- Set Is_Known_Non_Null for access parameters since the language
5135 -- guarantees that access parameters are always non-null. We also
5136 -- set Can_Never_Be_Null, since there is no way to change the value.
5138 if Nkind (Parameter_Type (Spec)) = N_Access_Definition then
5139 Set_Is_Known_Non_Null (Formal_Id);
5140 Set_Can_Never_Be_Null (Formal_Id);
5143 Set_Mechanism (Formal_Id, Default_Mechanism);
5144 Set_Formal_Validity (Formal_Id);
5145 end Set_Formal_Mode;
5147 -------------------------
5148 -- Set_Formal_Validity --
5149 -------------------------
5151 procedure Set_Formal_Validity (Formal_Id : Entity_Id) is
5153 -- If no validity checking, then we cannot assume anything about
5154 -- the validity of parameters, since we do not know there is any
5155 -- checking of the validity on the call side.
5157 if not Validity_Checks_On then
5160 -- If validity checking for parameters is enabled, this means we are
5161 -- not supposed to make any assumptions about argument values.
5163 elsif Validity_Check_Parameters then
5166 -- If we are checking in parameters, we will assume that the caller is
5167 -- also checking parameters, so we can assume the parameter is valid.
5169 elsif Ekind (Formal_Id) = E_In_Parameter
5170 and then Validity_Check_In_Params
5172 Set_Is_Known_Valid (Formal_Id, True);
5174 -- Similar treatment for IN OUT parameters
5176 elsif Ekind (Formal_Id) = E_In_Out_Parameter
5177 and then Validity_Check_In_Out_Params
5179 Set_Is_Known_Valid (Formal_Id, True);
5181 end Set_Formal_Validity;
5183 ------------------------
5184 -- Subtype_Conformant --
5185 ------------------------
5187 function Subtype_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
5191 Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result);
5193 end Subtype_Conformant;
5195 ---------------------
5196 -- Type_Conformant --
5197 ---------------------
5199 function Type_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
5202 Check_Conformance (New_Id, Old_Id, Type_Conformant, False, Result);
5204 end Type_Conformant;
5206 -------------------------------
5207 -- Valid_Operator_Definition --
5208 -------------------------------
5210 procedure Valid_Operator_Definition (Designator : Entity_Id) is
5213 Id : constant Name_Id := Chars (Designator);
5217 F := First_Formal (Designator);
5219 while Present (F) loop
5222 if Present (Default_Value (F)) then
5224 ("default values not allowed for operator parameters",
5231 -- Verify that user-defined operators have proper number of arguments
5232 -- First case of operators which can only be unary
5235 or else Id = Name_Op_Abs
5239 -- Case of operators which can be unary or binary
5241 elsif Id = Name_Op_Add
5242 or Id = Name_Op_Subtract
5244 N_OK := (N in 1 .. 2);
5246 -- All other operators can only be binary
5254 ("incorrect number of arguments for operator", Designator);
5258 and then Base_Type (Etype (Designator)) = Standard_Boolean
5259 and then not Is_Intrinsic_Subprogram (Designator)
5262 ("explicit definition of inequality not allowed", Designator);
5264 end Valid_Operator_Definition;