1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2017, 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 3, 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Contracts; use Contracts;
30 with Debug; use Debug;
31 with Einfo; use Einfo;
32 with Elists; use Elists;
33 with Errout; use Errout;
34 with Expander; use Expander;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Ch9; use Exp_Ch9;
38 with Exp_Dbug; use Exp_Dbug;
39 with Exp_Disp; use Exp_Disp;
40 with Exp_Tss; use Exp_Tss;
41 with Exp_Util; use Exp_Util;
42 with Freeze; use Freeze;
43 with Ghost; use Ghost;
44 with Inline; use Inline;
45 with Itypes; use Itypes;
46 with Lib.Xref; use Lib.Xref;
47 with Layout; use Layout;
48 with Namet; use Namet;
50 with Nlists; use Nlists;
51 with Nmake; use Nmake;
53 with Output; use Output;
54 with Restrict; use Restrict;
55 with Rident; use Rident;
56 with Rtsfind; use Rtsfind;
58 with Sem_Aux; use Sem_Aux;
59 with Sem_Cat; use Sem_Cat;
60 with Sem_Ch3; use Sem_Ch3;
61 with Sem_Ch4; use Sem_Ch4;
62 with Sem_Ch5; use Sem_Ch5;
63 with Sem_Ch8; use Sem_Ch8;
64 with Sem_Ch9; use Sem_Ch9;
65 with Sem_Ch10; use Sem_Ch10;
66 with Sem_Ch12; use Sem_Ch12;
67 with Sem_Ch13; use Sem_Ch13;
68 with Sem_Dim; use Sem_Dim;
69 with Sem_Disp; use Sem_Disp;
70 with Sem_Dist; use Sem_Dist;
71 with Sem_Elim; use Sem_Elim;
72 with Sem_Eval; use Sem_Eval;
73 with Sem_Mech; use Sem_Mech;
74 with Sem_Prag; use Sem_Prag;
75 with Sem_Res; use Sem_Res;
76 with Sem_Util; use Sem_Util;
77 with Sem_Type; use Sem_Type;
78 with Sem_Warn; use Sem_Warn;
79 with Sinput; use Sinput;
80 with Stand; use Stand;
81 with Sinfo; use Sinfo;
82 with Sinfo.CN; use Sinfo.CN;
83 with Snames; use Snames;
84 with Stringt; use Stringt;
86 with Stylesw; use Stylesw;
87 with Tbuild; use Tbuild;
88 with Uintp; use Uintp;
89 with Urealp; use Urealp;
90 with Validsw; use Validsw;
92 package body Sem_Ch6 is
94 May_Hide_Profile : Boolean := False;
95 -- This flag is used to indicate that two formals in two subprograms being
96 -- checked for conformance differ only in that one is an access parameter
97 -- while the other is of a general access type with the same designated
98 -- type. In this case, if the rest of the signatures match, a call to
99 -- either subprogram may be ambiguous, which is worth a warning. The flag
100 -- is set in Compatible_Types, and the warning emitted in
101 -- New_Overloaded_Entity.
103 -----------------------
104 -- Local Subprograms --
105 -----------------------
107 procedure Analyze_Function_Return (N : Node_Id);
108 -- Subsidiary to Analyze_Return_Statement. Called when the return statement
109 -- applies to a [generic] function.
111 procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id);
112 -- Analyze a generic subprogram body. N is the body to be analyzed, and
113 -- Gen_Id is the defining entity Id for the corresponding spec.
115 procedure Analyze_Null_Procedure
117 Is_Completion : out Boolean);
118 -- A null procedure can be a declaration or (Ada 2012) a completion
120 procedure Analyze_Return_Statement (N : Node_Id);
121 -- Common processing for simple and extended return statements
123 procedure Analyze_Return_Type (N : Node_Id);
124 -- Subsidiary to Process_Formals: analyze subtype mark in function
125 -- specification in a context where the formals are visible and hide
128 procedure Analyze_Subprogram_Body_Helper (N : Node_Id);
129 -- Does all the real work of Analyze_Subprogram_Body. This is split out so
130 -- that we can use RETURN but not skip the debug output at the end.
132 function Can_Override_Operator (Subp : Entity_Id) return Boolean;
133 -- Returns true if Subp can override a predefined operator.
135 procedure Check_Conformance
138 Ctype : Conformance_Type;
140 Conforms : out Boolean;
141 Err_Loc : Node_Id := Empty;
142 Get_Inst : Boolean := False;
143 Skip_Controlling_Formals : Boolean := False);
144 -- Given two entities, this procedure checks that the profiles associated
145 -- with these entities meet the conformance criterion given by the third
146 -- parameter. If they conform, Conforms is set True and control returns
147 -- to the caller. If they do not conform, Conforms is set to False, and
148 -- in addition, if Errmsg is True on the call, proper messages are output
149 -- to complain about the conformance failure. If Err_Loc is non_Empty
150 -- the error messages are placed on Err_Loc, if Err_Loc is empty, then
151 -- error messages are placed on the appropriate part of the construct
152 -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
153 -- against a formal access-to-subprogram type so Get_Instance_Of must
156 procedure Check_Limited_Return
160 -- Check the appropriate (Ada 95 or Ada 2005) rules for returning limited
161 -- types. Used only for simple return statements. Expr is the expression
164 procedure Check_Subprogram_Order (N : Node_Id);
165 -- N is the N_Subprogram_Body node for a subprogram. This routine applies
166 -- the alpha ordering rule for N if this ordering requirement applicable.
168 procedure Check_Returns
172 Proc : Entity_Id := Empty);
173 -- Called to check for missing return statements in a function body, or for
174 -- returns present in a procedure body which has No_Return set. HSS is the
175 -- handled statement sequence for the subprogram body. This procedure
176 -- checks all flow paths to make sure they either have return (Mode = 'F',
177 -- used for functions) or do not have a return (Mode = 'P', used for
178 -- No_Return procedures). The flag Err is set if there are any control
179 -- paths not explicitly terminated by a return in the function case, and is
180 -- True otherwise. Proc is the entity for the procedure case and is used
181 -- in posting the warning message.
183 procedure Check_Untagged_Equality (Eq_Op : Entity_Id);
184 -- In Ada 2012, a primitive equality operator on an untagged record type
185 -- must appear before the type is frozen, and have the same visibility as
186 -- that of the type. This procedure checks that this rule is met, and
187 -- otherwise emits an error on the subprogram declaration and a warning
188 -- on the earlier freeze point if it is easy to locate. In Ada 2012 mode,
189 -- this routine outputs errors (or warnings if -gnatd.E is set). In earlier
190 -- versions of Ada, warnings are output if Warn_On_Ada_2012_Incompatibility
191 -- is set, otherwise the call has no effect.
193 procedure Enter_Overloaded_Entity (S : Entity_Id);
194 -- This procedure makes S, a new overloaded entity, into the first visible
195 -- entity with that name.
197 function Is_Non_Overriding_Operation
199 New_E : Entity_Id) return Boolean;
200 -- Enforce the rule given in 12.3(18): a private operation in an instance
201 -- overrides an inherited operation only if the corresponding operation
202 -- was overriding in the generic. This needs to be checked for primitive
203 -- operations of types derived (in the generic unit) from formal private
204 -- or formal derived types.
206 procedure Make_Inequality_Operator (S : Entity_Id);
207 -- Create the declaration for an inequality operator that is implicitly
208 -- created by a user-defined equality operator that yields a boolean.
210 procedure Set_Formal_Validity (Formal_Id : Entity_Id);
211 -- Formal_Id is an formal parameter entity. This procedure deals with
212 -- setting the proper validity status for this entity, which depends on
213 -- the kind of parameter and the validity checking mode.
215 ---------------------------------------------
216 -- Analyze_Abstract_Subprogram_Declaration --
217 ---------------------------------------------
219 procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is
220 Scop : constant Entity_Id := Current_Scope;
221 Subp_Id : constant Entity_Id :=
222 Analyze_Subprogram_Specification (Specification (N));
225 Check_SPARK_05_Restriction ("abstract subprogram is not allowed", N);
227 Generate_Definition (Subp_Id);
229 Set_Is_Abstract_Subprogram (Subp_Id);
230 New_Overloaded_Entity (Subp_Id);
231 Check_Delayed_Subprogram (Subp_Id);
233 Set_Categorization_From_Scope (Subp_Id, Scop);
235 if Ekind (Scope (Subp_Id)) = E_Protected_Type then
236 Error_Msg_N ("abstract subprogram not allowed in protected type", N);
238 -- Issue a warning if the abstract subprogram is neither a dispatching
239 -- operation nor an operation that overrides an inherited subprogram or
240 -- predefined operator, since this most likely indicates a mistake.
242 elsif Warn_On_Redundant_Constructs
243 and then not Is_Dispatching_Operation (Subp_Id)
244 and then not Present (Overridden_Operation (Subp_Id))
245 and then (not Is_Operator_Symbol_Name (Chars (Subp_Id))
246 or else Scop /= Scope (Etype (First_Formal (Subp_Id))))
249 ("abstract subprogram is not dispatching or overriding?r?", N);
252 Generate_Reference_To_Formals (Subp_Id);
253 Check_Eliminated (Subp_Id);
255 if Has_Aspects (N) then
256 Analyze_Aspect_Specifications (N, Subp_Id);
258 end Analyze_Abstract_Subprogram_Declaration;
260 ---------------------------------
261 -- Analyze_Expression_Function --
262 ---------------------------------
264 procedure Analyze_Expression_Function (N : Node_Id) is
265 Expr : constant Node_Id := Expression (N);
266 Loc : constant Source_Ptr := Sloc (N);
267 LocX : constant Source_Ptr := Sloc (Expr);
268 Spec : constant Node_Id := Specification (N);
276 Ret_Type : Entity_Id;
279 -- If the expression is a completion, Prev is the entity whose
280 -- declaration is completed. Def_Id is needed to analyze the spec.
283 -- This is one of the occasions on which we transform the tree during
284 -- semantic analysis. If this is a completion, transform the expression
285 -- function into an equivalent subprogram body, and analyze it.
287 -- Expression functions are inlined unconditionally. The back-end will
288 -- determine whether this is possible.
290 Inline_Processing_Required := True;
292 -- Create a specification for the generated body. This must be done
293 -- prior to the analysis of the initial declaration.
295 New_Spec := Copy_Subprogram_Spec (Spec);
296 Prev := Current_Entity_In_Scope (Defining_Entity (Spec));
298 -- If there are previous overloadable entities with the same name,
299 -- check whether any of them is completed by the expression function.
300 -- In a generic context a formal subprogram has no completion.
303 and then Is_Overloadable (Prev)
304 and then not Is_Formal_Subprogram (Prev)
306 Def_Id := Analyze_Subprogram_Specification (Spec);
307 Prev := Find_Corresponding_Spec (N);
309 -- The previous entity may be an expression function as well, in
310 -- which case the redeclaration is illegal.
313 and then Nkind (Original_Node (Unit_Declaration_Node (Prev))) =
314 N_Expression_Function
316 Error_Msg_Sloc := Sloc (Prev);
317 Error_Msg_N ("& conflicts with declaration#", Def_Id);
322 Ret := Make_Simple_Return_Statement (LocX, Expression (N));
325 Make_Subprogram_Body (Loc,
326 Specification => New_Spec,
327 Declarations => Empty_List,
328 Handled_Statement_Sequence =>
329 Make_Handled_Sequence_Of_Statements (LocX,
330 Statements => New_List (Ret)));
331 Set_Was_Expression_Function (New_Body);
333 -- If the expression completes a generic subprogram, we must create a
334 -- separate node for the body, because at instantiation the original
335 -- node of the generic copy must be a generic subprogram body, and
336 -- cannot be a expression function. Otherwise we just rewrite the
337 -- expression with the non-generic body.
339 if Present (Prev) and then Ekind (Prev) = E_Generic_Function then
340 Insert_After (N, New_Body);
342 -- Propagate any aspects or pragmas that apply to the expression
343 -- function to the proper body when the expression function acts
346 if Has_Aspects (N) then
347 Move_Aspects (N, To => New_Body);
350 Relocate_Pragmas_To_Body (New_Body);
352 Rewrite (N, Make_Null_Statement (Loc));
353 Set_Has_Completion (Prev, False);
356 Set_Is_Inlined (Prev);
358 -- If the expression function is a completion, the previous declaration
359 -- must come from source. We know already that it appears in the current
360 -- scope. The entity itself may be internally created if within a body
364 and then Comes_From_Source (Parent (Prev))
365 and then not Is_Formal_Subprogram (Prev)
367 Set_Has_Completion (Prev, False);
368 Set_Is_Inlined (Prev);
369 Ret_Type := Etype (Prev);
371 -- An expression function which acts as a completion freezes the
372 -- expression. This means freezing the return type, and if it is
373 -- an access type, freezing its designated type as well.
375 -- Note that we cannot defer this freezing to the analysis of the
376 -- expression itself, because a freeze node might appear in a nested
377 -- scope, leading to an elaboration order issue in gigi.
379 Freeze_Before (N, Ret_Type);
381 -- An entity can only be frozen if it is complete, so if the type
382 -- is still unfrozen it must still be incomplete in some way, e.g.
383 -- a private type without a full view, or a type derived from such
384 -- in an enclosing scope. Except in a generic context (where the
385 -- type may be a generic formal or derived from such), such use of
386 -- an incomplete type is an error. On the other hand, if this is a
387 -- limited view of a type, the type is declared in another unit and
388 -- frozen there. We must be in a context seeing the nonlimited view
389 -- of the type, which will be installed when the body is compiled.
391 if not Is_Frozen (Ret_Type)
392 and then not Is_Generic_Type (Root_Type (Ret_Type))
393 and then not Inside_A_Generic
395 if From_Limited_With (Ret_Type)
396 and then Present (Non_Limited_View (Ret_Type))
401 ("premature use of private type&",
402 Result_Definition (Specification (N)), Ret_Type);
406 -- For navigation purposes, indicate that the function is a body
408 Generate_Reference (Prev, Defining_Entity (N), 'b', Force => True);
409 Rewrite (N, New_Body);
411 -- Remove any existing aspects from the original node because the act
412 -- of rewriting causes the list to be shared between the two nodes.
414 Orig_N := Original_Node (N);
415 Remove_Aspects (Orig_N);
417 -- Propagate any pragmas that apply to expression function to the
418 -- proper body when the expression function acts as a completion.
419 -- Aspects are automatically transfered because of node rewriting.
421 Relocate_Pragmas_To_Body (N);
424 -- Once the aspects of the generated body have been analyzed, create
425 -- a copy for ASIS purposes and associate it with the original node.
427 if Has_Aspects (N) then
428 Set_Aspect_Specifications (Orig_N,
429 New_Copy_List_Tree (Aspect_Specifications (N)));
432 -- Prev is the previous entity with the same name, but it is can
433 -- be an unrelated spec that is not completed by the expression
434 -- function. In that case the relevant entity is the one in the body.
435 -- Not clear that the backend can inline it in this case ???
437 if Has_Completion (Prev) then
439 -- The formals of the expression function are body formals,
440 -- and do not appear in the ali file, which will only contain
441 -- references to the formals of the original subprogram spec.
448 F1 := First_Formal (Def_Id);
449 F2 := First_Formal (Prev);
451 while Present (F1) loop
452 Set_Spec_Entity (F1, F2);
459 Set_Is_Inlined (Defining_Entity (New_Body));
462 -- If this is not a completion, create both a declaration and a body, so
463 -- that the expression can be inlined whenever possible.
466 -- An expression function that is not a completion is not a
467 -- subprogram declaration, and thus cannot appear in a protected
470 if Nkind (Parent (N)) = N_Protected_Definition then
472 ("an expression function is not a legal protected operation", N);
475 Rewrite (N, Make_Subprogram_Declaration (Loc, Specification => Spec));
477 -- Remove any existing aspects from the original node because the act
478 -- of rewriting causes the list to be shared between the two nodes.
480 Orig_N := Original_Node (N);
481 Remove_Aspects (Orig_N);
485 -- Once the aspects of the generated spec have been analyzed, create
486 -- a copy for ASIS purposes and associate it with the original node.
488 if Has_Aspects (N) then
489 Set_Aspect_Specifications (Orig_N,
490 New_Copy_List_Tree (Aspect_Specifications (N)));
493 -- If aspect SPARK_Mode was specified on the body, it needs to be
494 -- repeated both on the generated spec and the body.
496 Asp := Find_Aspect (Defining_Unit_Name (Spec), Aspect_SPARK_Mode);
498 if Present (Asp) then
499 Asp := New_Copy_Tree (Asp);
500 Set_Analyzed (Asp, False);
501 Set_Aspect_Specifications (New_Body, New_List (Asp));
504 Def_Id := Defining_Entity (N);
506 -- Within a generic pre-analyze the original expression for name
507 -- capture. The body is also generated but plays no role in
508 -- this because it is not part of the original source.
510 if Inside_A_Generic then
511 Set_Has_Completion (Def_Id);
513 Install_Formals (Def_Id);
514 Preanalyze_Spec_Expression (Expr, Etype (Def_Id));
518 Set_Is_Inlined (Defining_Entity (N));
520 -- Establish the linkages between the spec and the body. These are
521 -- used when the expression function acts as the prefix of attribute
522 -- 'Access in order to freeze the original expression which has been
523 -- moved to the generated body.
525 Set_Corresponding_Body (N, Defining_Entity (New_Body));
526 Set_Corresponding_Spec (New_Body, Defining_Entity (N));
528 -- To prevent premature freeze action, insert the new body at the end
529 -- of the current declarations, or at the end of the package spec.
530 -- However, resolve usage names now, to prevent spurious visibility
531 -- on later entities. Note that the function can now be called in
532 -- the current declarative part, which will appear to be prior to
533 -- the presence of the body in the code. There are nevertheless no
534 -- order of elaboration issues because all name resolution has taken
535 -- place at the point of declaration.
538 Decls : List_Id := List_Containing (N);
539 Expr : constant Node_Id := Expression (Ret);
540 Par : constant Node_Id := Parent (Decls);
541 Typ : constant Entity_Id := Etype (Def_Id);
544 -- If this is a wrapper created for in an instance for a formal
545 -- subprogram, insert body after declaration, to be analyzed when
546 -- the enclosing instance is analyzed.
549 and then Is_Generic_Actual_Subprogram (Defining_Entity (N))
551 Insert_After (N, New_Body);
554 if Nkind (Par) = N_Package_Specification
555 and then Decls = Visible_Declarations (Par)
556 and then Present (Private_Declarations (Par))
557 and then not Is_Empty_List (Private_Declarations (Par))
559 Decls := Private_Declarations (Par);
562 Insert_After (Last (Decls), New_Body);
564 -- Preanalyze the expression for name capture, except in an
565 -- instance, where this has been done during generic analysis,
566 -- and will be redone when analyzing the body.
568 Set_Parent (Expr, Ret);
570 Install_Formals (Def_Id);
572 if not In_Instance then
573 Preanalyze_Spec_Expression (Expr, Typ);
574 Check_Limited_Return (Original_Node (N), Expr, Typ);
582 -- If the return expression is a static constant, we suppress warning
583 -- messages on unused formals, which in most cases will be noise.
585 Set_Is_Trivial_Subprogram
586 (Defining_Entity (New_Body), Is_OK_Static_Expression (Expr));
587 end Analyze_Expression_Function;
589 ----------------------------------------
590 -- Analyze_Extended_Return_Statement --
591 ----------------------------------------
593 procedure Analyze_Extended_Return_Statement (N : Node_Id) is
595 Check_Compiler_Unit ("extended return statement", N);
596 Analyze_Return_Statement (N);
597 end Analyze_Extended_Return_Statement;
599 ----------------------------
600 -- Analyze_Function_Call --
601 ----------------------------
603 procedure Analyze_Function_Call (N : Node_Id) is
604 Actuals : constant List_Id := Parameter_Associations (N);
605 Func_Nam : constant Node_Id := Name (N);
611 -- A call of the form A.B (X) may be an Ada 2005 call, which is
612 -- rewritten as B (A, X). If the rewriting is successful, the call
613 -- has been analyzed and we just return.
615 if Nkind (Func_Nam) = N_Selected_Component
616 and then Name (N) /= Func_Nam
617 and then Is_Rewrite_Substitution (N)
618 and then Present (Etype (N))
623 -- If error analyzing name, then set Any_Type as result type and return
625 if Etype (Func_Nam) = Any_Type then
626 Set_Etype (N, Any_Type);
630 -- Otherwise analyze the parameters
632 if Present (Actuals) then
633 Actual := First (Actuals);
634 while Present (Actual) loop
636 Check_Parameterless_Call (Actual);
642 end Analyze_Function_Call;
644 -----------------------------
645 -- Analyze_Function_Return --
646 -----------------------------
648 procedure Analyze_Function_Return (N : Node_Id) is
649 Loc : constant Source_Ptr := Sloc (N);
650 Stm_Entity : constant Entity_Id := Return_Statement_Entity (N);
651 Scope_Id : constant Entity_Id := Return_Applies_To (Stm_Entity);
653 R_Type : constant Entity_Id := Etype (Scope_Id);
654 -- Function result subtype
656 procedure Check_Aggregate_Accessibility (Aggr : Node_Id);
657 -- Apply legality rule of 6.5 (5.8) to the access discriminants of an
658 -- aggregate in a return statement.
660 procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id);
661 -- Check that the return_subtype_indication properly matches the result
662 -- subtype of the function, as required by RM-6.5(5.1/2-5.3/2).
664 -----------------------------------
665 -- Check_Aggregate_Accessibility --
666 -----------------------------------
668 procedure Check_Aggregate_Accessibility (Aggr : Node_Id) is
669 Typ : constant Entity_Id := Etype (Aggr);
676 if Is_Record_Type (Typ) and then Has_Discriminants (Typ) then
677 Discr := First_Discriminant (Typ);
678 Assoc := First (Component_Associations (Aggr));
679 while Present (Discr) loop
680 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type then
681 Expr := Expression (Assoc);
683 if Nkind (Expr) = N_Attribute_Reference
684 and then Attribute_Name (Expr) /= Name_Unrestricted_Access
686 Obj := Prefix (Expr);
687 while Nkind_In (Obj, N_Indexed_Component,
688 N_Selected_Component)
693 -- Do not check aliased formals or function calls. A
694 -- run-time check may still be needed ???
696 if Is_Entity_Name (Obj)
697 and then Comes_From_Source (Obj)
699 if Is_Formal (Entity (Obj))
700 and then Is_Aliased (Entity (Obj))
704 elsif Object_Access_Level (Obj) >
705 Scope_Depth (Scope (Scope_Id))
708 ("access discriminant in return aggregate would "
709 & "be a dangling reference", Obj);
715 Next_Discriminant (Discr);
718 end Check_Aggregate_Accessibility;
720 -------------------------------------
721 -- Check_Return_Subtype_Indication --
722 -------------------------------------
724 procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id) is
725 Return_Obj : constant Node_Id := Defining_Identifier (Obj_Decl);
727 R_Stm_Type : constant Entity_Id := Etype (Return_Obj);
728 -- Subtype given in the extended return statement (must match R_Type)
730 Subtype_Ind : constant Node_Id :=
731 Object_Definition (Original_Node (Obj_Decl));
733 procedure Error_No_Match (N : Node_Id);
734 -- Output error messages for case where types do not statically
735 -- match. N is the location for the messages.
741 procedure Error_No_Match (N : Node_Id) is
744 ("subtype must statically match function result subtype", N);
746 if not Predicates_Match (R_Stm_Type, R_Type) then
747 Error_Msg_Node_2 := R_Type;
749 ("\predicate of& does not match predicate of&",
754 -- Start of processing for Check_Return_Subtype_Indication
757 -- First, avoid cascaded errors
759 if Error_Posted (Obj_Decl) or else Error_Posted (Subtype_Ind) then
763 -- "return access T" case; check that the return statement also has
764 -- "access T", and that the subtypes statically match:
765 -- if this is an access to subprogram the signatures must match.
767 if Is_Anonymous_Access_Type (R_Type) then
768 if Is_Anonymous_Access_Type (R_Stm_Type) then
769 if Ekind (Designated_Type (R_Stm_Type)) /= E_Subprogram_Type
771 if Base_Type (Designated_Type (R_Stm_Type)) /=
772 Base_Type (Designated_Type (R_Type))
773 or else not Subtypes_Statically_Match (R_Stm_Type, R_Type)
775 Error_No_Match (Subtype_Mark (Subtype_Ind));
779 -- For two anonymous access to subprogram types, the types
780 -- themselves must be type conformant.
782 if not Conforming_Types
783 (R_Stm_Type, R_Type, Fully_Conformant)
785 Error_No_Match (Subtype_Ind);
790 Error_Msg_N ("must use anonymous access type", Subtype_Ind);
793 -- If the return object is of an anonymous access type, then report
794 -- an error if the function's result type is not also anonymous.
796 elsif Is_Anonymous_Access_Type (R_Stm_Type) then
797 pragma Assert (not Is_Anonymous_Access_Type (R_Type));
799 ("anonymous access not allowed for function with named access "
800 & "result", Subtype_Ind);
802 -- Subtype indication case: check that the return object's type is
803 -- covered by the result type, and that the subtypes statically match
804 -- when the result subtype is constrained. Also handle record types
805 -- with unknown discriminants for which we have built the underlying
806 -- record view. Coverage is needed to allow specific-type return
807 -- objects when the result type is class-wide (see AI05-32).
809 elsif Covers (Base_Type (R_Type), Base_Type (R_Stm_Type))
810 or else (Is_Underlying_Record_View (Base_Type (R_Stm_Type))
814 Underlying_Record_View (Base_Type (R_Stm_Type))))
816 -- A null exclusion may be present on the return type, on the
817 -- function specification, on the object declaration or on the
820 if Is_Access_Type (R_Type)
822 (Can_Never_Be_Null (R_Type)
823 or else Null_Exclusion_Present (Parent (Scope_Id))) /=
824 Can_Never_Be_Null (R_Stm_Type)
826 Error_No_Match (Subtype_Ind);
829 -- AI05-103: for elementary types, subtypes must statically match
831 if Is_Constrained (R_Type) or else Is_Access_Type (R_Type) then
832 if not Subtypes_Statically_Match (R_Stm_Type, R_Type) then
833 Error_No_Match (Subtype_Ind);
837 -- All remaining cases are illegal
839 -- Note: previous versions of this subprogram allowed the return
840 -- value to be the ancestor of the return type if the return type
841 -- was a null extension. This was plainly incorrect.
845 ("wrong type for return_subtype_indication", Subtype_Ind);
847 end Check_Return_Subtype_Indication;
849 ---------------------
850 -- Local Variables --
851 ---------------------
856 -- Start of processing for Analyze_Function_Return
859 Set_Return_Present (Scope_Id);
861 if Nkind (N) = N_Simple_Return_Statement then
862 Expr := Expression (N);
864 -- Guard against a malformed expression. The parser may have tried to
865 -- recover but the node is not analyzable.
867 if Nkind (Expr) = N_Error then
868 Set_Etype (Expr, Any_Type);
869 Expander_Mode_Save_And_Set (False);
873 -- The resolution of a controlled [extension] aggregate associated
874 -- with a return statement creates a temporary which needs to be
875 -- finalized on function exit. Wrap the return statement inside a
876 -- block so that the finalization machinery can detect this case.
877 -- This early expansion is done only when the return statement is
878 -- not part of a handled sequence of statements.
880 if Nkind_In (Expr, N_Aggregate,
881 N_Extension_Aggregate)
882 and then Needs_Finalization (R_Type)
883 and then Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements
886 Make_Block_Statement (Loc,
887 Handled_Statement_Sequence =>
888 Make_Handled_Sequence_Of_Statements (Loc,
889 Statements => New_List (Relocate_Node (N)))));
897 -- Ada 2005 (AI-251): If the type of the returned object is
898 -- an access to an interface type then we add an implicit type
899 -- conversion to force the displacement of the "this" pointer to
900 -- reference the secondary dispatch table. We cannot delay the
901 -- generation of this implicit conversion until the expansion
902 -- because in this case the type resolution changes the decoration
903 -- of the expression node to match R_Type; by contrast, if the
904 -- returned object is a class-wide interface type then it is too
905 -- early to generate here the implicit conversion since the return
906 -- statement may be rewritten by the expander into an extended
907 -- return statement whose expansion takes care of adding the
908 -- implicit type conversion to displace the pointer to the object.
911 and then Serious_Errors_Detected = 0
912 and then Is_Access_Type (R_Type)
913 and then Nkind (Expr) /= N_Null
914 and then Is_Interface (Designated_Type (R_Type))
915 and then Is_Progenitor (Designated_Type (R_Type),
916 Designated_Type (Etype (Expr)))
918 Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr)));
922 Resolve (Expr, R_Type);
923 Check_Limited_Return (N, Expr, R_Type);
925 if Present (Expr) and then Nkind (Expr) = N_Aggregate then
926 Check_Aggregate_Accessibility (Expr);
930 -- RETURN only allowed in SPARK as the last statement in function
932 if Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements
934 (Nkind (Parent (Parent (N))) /= N_Subprogram_Body
935 or else Present (Next (N)))
937 Check_SPARK_05_Restriction
938 ("RETURN should be the last statement in function", N);
942 Check_SPARK_05_Restriction ("extended RETURN is not allowed", N);
943 Obj_Decl := Last (Return_Object_Declarations (N));
945 -- Analyze parts specific to extended_return_statement:
948 Has_Aliased : constant Boolean := Aliased_Present (Obj_Decl);
949 HSS : constant Node_Id := Handled_Statement_Sequence (N);
952 Expr := Expression (Obj_Decl);
954 -- Note: The check for OK_For_Limited_Init will happen in
955 -- Analyze_Object_Declaration; we treat it as a normal
956 -- object declaration.
958 Set_Is_Return_Object (Defining_Identifier (Obj_Decl));
961 Check_Return_Subtype_Indication (Obj_Decl);
963 if Present (HSS) then
966 if Present (Exception_Handlers (HSS)) then
968 -- ???Has_Nested_Block_With_Handler needs to be set.
969 -- Probably by creating an actual N_Block_Statement.
970 -- Probably in Expand.
976 -- Mark the return object as referenced, since the return is an
977 -- implicit reference of the object.
979 Set_Referenced (Defining_Identifier (Obj_Decl));
981 Check_References (Stm_Entity);
983 -- Check RM 6.5 (5.9/3)
986 if Ada_Version < Ada_2012 then
988 -- Shouldn't this test Warn_On_Ada_2012_Compatibility ???
989 -- Can it really happen (extended return???)
992 ("aliased only allowed for limited return objects "
993 & "in Ada 2012??", N);
995 elsif not Is_Limited_View (R_Type) then
997 ("aliased only allowed for limited return objects", N);
1003 -- Case of Expr present
1007 -- Defend against previous errors
1009 and then Nkind (Expr) /= N_Empty
1010 and then Present (Etype (Expr))
1012 -- Apply constraint check. Note that this is done before the implicit
1013 -- conversion of the expression done for anonymous access types to
1014 -- ensure correct generation of the null-excluding check associated
1015 -- with null-excluding expressions found in return statements.
1017 Apply_Constraint_Check (Expr, R_Type);
1019 -- Ada 2005 (AI-318-02): When the result type is an anonymous access
1020 -- type, apply an implicit conversion of the expression to that type
1021 -- to force appropriate static and run-time accessibility checks.
1023 if Ada_Version >= Ada_2005
1024 and then Ekind (R_Type) = E_Anonymous_Access_Type
1026 Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr)));
1027 Analyze_And_Resolve (Expr, R_Type);
1029 -- If this is a local anonymous access to subprogram, the
1030 -- accessibility check can be applied statically. The return is
1031 -- illegal if the access type of the return expression is declared
1032 -- inside of the subprogram (except if it is the subtype indication
1033 -- of an extended return statement).
1035 elsif Ekind (R_Type) = E_Anonymous_Access_Subprogram_Type then
1036 if not Comes_From_Source (Current_Scope)
1037 or else Ekind (Current_Scope) = E_Return_Statement
1042 Scope_Depth (Scope (Etype (Expr))) >= Scope_Depth (Scope_Id)
1044 Error_Msg_N ("cannot return local access to subprogram", N);
1047 -- The expression cannot be of a formal incomplete type
1049 elsif Ekind (Etype (Expr)) = E_Incomplete_Type
1050 and then Is_Generic_Type (Etype (Expr))
1053 ("cannot return expression of a formal incomplete type", N);
1056 -- If the result type is class-wide, then check that the return
1057 -- expression's type is not declared at a deeper level than the
1058 -- function (RM05-6.5(5.6/2)).
1060 if Ada_Version >= Ada_2005
1061 and then Is_Class_Wide_Type (R_Type)
1063 if Type_Access_Level (Etype (Expr)) >
1064 Subprogram_Access_Level (Scope_Id)
1067 ("level of return expression type is deeper than "
1068 & "class-wide function!", Expr);
1072 -- Check incorrect use of dynamically tagged expression
1074 if Is_Tagged_Type (R_Type) then
1075 Check_Dynamically_Tagged_Expression
1081 -- ??? A real run-time accessibility check is needed in cases
1082 -- involving dereferences of access parameters. For now we just
1083 -- check the static cases.
1085 if (Ada_Version < Ada_2005 or else Debug_Flag_Dot_L)
1086 and then Is_Limited_View (Etype (Scope_Id))
1087 and then Object_Access_Level (Expr) >
1088 Subprogram_Access_Level (Scope_Id)
1090 -- Suppress the message in a generic, where the rewriting
1093 if Inside_A_Generic then
1098 Make_Raise_Program_Error (Loc,
1099 Reason => PE_Accessibility_Check_Failed));
1102 Error_Msg_Warn := SPARK_Mode /= On;
1103 Error_Msg_N ("cannot return a local value by reference<<", N);
1104 Error_Msg_NE ("\& [<<", N, Standard_Program_Error);
1108 if Known_Null (Expr)
1109 and then Nkind (Parent (Scope_Id)) = N_Function_Specification
1110 and then Null_Exclusion_Present (Parent (Scope_Id))
1112 Apply_Compile_Time_Constraint_Error
1114 Msg => "(Ada 2005) null not allowed for "
1115 & "null-excluding return??",
1116 Reason => CE_Null_Not_Allowed);
1119 -- RM 6.5 (5.4/3): accessibility checks also apply if the return object
1120 -- has no initializing expression.
1122 elsif Ada_Version > Ada_2005 and then Is_Class_Wide_Type (R_Type) then
1123 if Type_Access_Level (Etype (Defining_Identifier (Obj_Decl))) >
1124 Subprogram_Access_Level (Scope_Id)
1127 ("level of return expression type is deeper than "
1128 & "class-wide function!", Obj_Decl);
1131 end Analyze_Function_Return;
1133 -------------------------------------
1134 -- Analyze_Generic_Subprogram_Body --
1135 -------------------------------------
1137 procedure Analyze_Generic_Subprogram_Body
1141 Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id);
1142 Kind : constant Entity_Kind := Ekind (Gen_Id);
1143 Body_Id : Entity_Id;
1148 -- Copy body and disable expansion while analyzing the generic For a
1149 -- stub, do not copy the stub (which would load the proper body), this
1150 -- will be done when the proper body is analyzed.
1152 if Nkind (N) /= N_Subprogram_Body_Stub then
1153 New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
1156 -- Once the contents of the generic copy and the template are
1157 -- swapped, do the same for their respective aspect specifications.
1159 Exchange_Aspects (N, New_N);
1161 -- Collect all contract-related source pragmas found within the
1162 -- template and attach them to the contract of the subprogram body.
1163 -- This contract is used in the capture of global references within
1166 Create_Generic_Contract (N);
1171 Spec := Specification (N);
1173 -- Within the body of the generic, the subprogram is callable, and
1174 -- behaves like the corresponding non-generic unit.
1176 Body_Id := Defining_Entity (Spec);
1178 if Kind = E_Generic_Procedure
1179 and then Nkind (Spec) /= N_Procedure_Specification
1181 Error_Msg_N ("invalid body for generic procedure ", Body_Id);
1184 elsif Kind = E_Generic_Function
1185 and then Nkind (Spec) /= N_Function_Specification
1187 Error_Msg_N ("invalid body for generic function ", Body_Id);
1191 Set_Corresponding_Body (Gen_Decl, Body_Id);
1193 if Has_Completion (Gen_Id)
1194 and then Nkind (Parent (N)) /= N_Subunit
1196 Error_Msg_N ("duplicate generic body", N);
1199 Set_Has_Completion (Gen_Id);
1202 if Nkind (N) = N_Subprogram_Body_Stub then
1203 Set_Ekind (Defining_Entity (Specification (N)), Kind);
1205 Set_Corresponding_Spec (N, Gen_Id);
1208 if Nkind (Parent (N)) = N_Compilation_Unit then
1209 Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N));
1212 -- Make generic parameters immediately visible in the body. They are
1213 -- needed to process the formals declarations. Then make the formals
1214 -- visible in a separate step.
1216 Push_Scope (Gen_Id);
1220 First_Ent : Entity_Id;
1223 First_Ent := First_Entity (Gen_Id);
1226 while Present (E) and then not Is_Formal (E) loop
1231 Set_Use (Generic_Formal_Declarations (Gen_Decl));
1233 -- Now generic formals are visible, and the specification can be
1234 -- analyzed, for subsequent conformance check.
1236 Body_Id := Analyze_Subprogram_Specification (Spec);
1238 -- Make formal parameters visible
1242 -- E is the first formal parameter, we loop through the formals
1243 -- installing them so that they will be visible.
1245 Set_First_Entity (Gen_Id, E);
1246 while Present (E) loop
1252 -- Visible generic entity is callable within its own body
1254 Set_Ekind (Gen_Id, Ekind (Body_Id));
1255 Set_Ekind (Body_Id, E_Subprogram_Body);
1256 Set_Convention (Body_Id, Convention (Gen_Id));
1257 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Gen_Id));
1258 Set_Scope (Body_Id, Scope (Gen_Id));
1260 Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id);
1262 if Nkind (N) = N_Subprogram_Body_Stub then
1264 -- No body to analyze, so restore state of generic unit
1266 Set_Ekind (Gen_Id, Kind);
1267 Set_Ekind (Body_Id, Kind);
1269 if Present (First_Ent) then
1270 Set_First_Entity (Gen_Id, First_Ent);
1277 -- If this is a compilation unit, it must be made visible explicitly,
1278 -- because the compilation of the declaration, unlike other library
1279 -- unit declarations, does not. If it is not a unit, the following
1280 -- is redundant but harmless.
1282 Set_Is_Immediately_Visible (Gen_Id);
1283 Reference_Body_Formals (Gen_Id, Body_Id);
1285 if Is_Child_Unit (Gen_Id) then
1286 Generate_Reference (Gen_Id, Scope (Gen_Id), 'k', False);
1289 Set_Actual_Subtypes (N, Current_Scope);
1291 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma);
1292 Set_SPARK_Pragma_Inherited (Body_Id);
1294 -- Analyze any aspect specifications that appear on the generic
1297 if Has_Aspects (N) then
1298 Analyze_Aspect_Specifications_On_Body_Or_Stub (N);
1301 Analyze_Declarations (Declarations (N));
1304 -- Process the contract of the subprogram body after all declarations
1305 -- have been analyzed. This ensures that any contract-related pragmas
1306 -- are available through the N_Contract node of the body.
1308 Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id);
1310 Analyze (Handled_Statement_Sequence (N));
1311 Save_Global_References (Original_Node (N));
1313 -- Prior to exiting the scope, include generic formals again (if any
1314 -- are present) in the set of local entities.
1316 if Present (First_Ent) then
1317 Set_First_Entity (Gen_Id, First_Ent);
1320 Check_References (Gen_Id);
1323 Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope);
1325 Check_Subprogram_Order (N);
1327 -- Outside of its body, unit is generic again
1329 Set_Ekind (Gen_Id, Kind);
1330 Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False);
1333 Style.Check_Identifier (Body_Id, Gen_Id);
1337 end Analyze_Generic_Subprogram_Body;
1339 ----------------------------
1340 -- Analyze_Null_Procedure --
1341 ----------------------------
1343 procedure Analyze_Null_Procedure
1345 Is_Completion : out Boolean)
1347 Loc : constant Source_Ptr := Sloc (N);
1348 Spec : constant Node_Id := Specification (N);
1349 Designator : Entity_Id;
1351 Null_Body : Node_Id := Empty;
1352 Null_Stmt : Node_Id := Null_Statement (Spec);
1356 -- Capture the profile of the null procedure before analysis, for
1357 -- expansion at the freeze point and at each point of call. The body is
1358 -- used if the procedure has preconditions, or if it is a completion. In
1359 -- the first case the body is analyzed at the freeze point, in the other
1360 -- it replaces the null procedure declaration.
1362 -- For a null procedure that comes from source, a NULL statement is
1363 -- provided by the parser, which carries the source location of the
1364 -- NULL keyword, and has Comes_From_Source set. For a null procedure
1365 -- from expansion, create one now.
1367 if No (Null_Stmt) then
1368 Null_Stmt := Make_Null_Statement (Loc);
1372 Make_Subprogram_Body (Loc,
1373 Specification => New_Copy_Tree (Spec),
1374 Declarations => New_List,
1375 Handled_Statement_Sequence =>
1376 Make_Handled_Sequence_Of_Statements (Loc,
1377 Statements => New_List (Null_Stmt)));
1379 -- Create new entities for body and formals
1381 Set_Defining_Unit_Name (Specification (Null_Body),
1382 Make_Defining_Identifier
1383 (Sloc (Defining_Entity (N)),
1384 Chars (Defining_Entity (N))));
1386 Form := First (Parameter_Specifications (Specification (Null_Body)));
1387 while Present (Form) loop
1388 Set_Defining_Identifier (Form,
1389 Make_Defining_Identifier
1390 (Sloc (Defining_Identifier (Form)),
1391 Chars (Defining_Identifier (Form))));
1395 -- Determine whether the null procedure may be a completion of a generic
1396 -- suprogram, in which case we use the new null body as the completion
1397 -- and set minimal semantic information on the original declaration,
1398 -- which is rewritten as a null statement.
1400 Prev := Current_Entity_In_Scope (Defining_Entity (Spec));
1402 if Present (Prev) and then Is_Generic_Subprogram (Prev) then
1403 Insert_Before (N, Null_Body);
1404 Set_Ekind (Defining_Entity (N), Ekind (Prev));
1406 Rewrite (N, Make_Null_Statement (Loc));
1407 Analyze_Generic_Subprogram_Body (Null_Body, Prev);
1408 Is_Completion := True;
1412 -- Resolve the types of the formals now, because the freeze point may
1413 -- appear in a different context, e.g. an instantiation.
1415 Form := First (Parameter_Specifications (Specification (Null_Body)));
1416 while Present (Form) loop
1417 if Nkind (Parameter_Type (Form)) /= N_Access_Definition then
1418 Find_Type (Parameter_Type (Form));
1420 elsif No (Access_To_Subprogram_Definition
1421 (Parameter_Type (Form)))
1423 Find_Type (Subtype_Mark (Parameter_Type (Form)));
1425 -- The case of a null procedure with a formal that is an
1426 -- access-to-subprogram type, and that is used as an actual
1427 -- in an instantiation is left to the enthusiastic reader.
1437 -- If there are previous overloadable entities with the same name, check
1438 -- whether any of them is completed by the null procedure.
1440 if Present (Prev) and then Is_Overloadable (Prev) then
1441 Designator := Analyze_Subprogram_Specification (Spec);
1442 Prev := Find_Corresponding_Spec (N);
1445 if No (Prev) or else not Comes_From_Source (Prev) then
1446 Designator := Analyze_Subprogram_Specification (Spec);
1447 Set_Has_Completion (Designator);
1449 -- Signal to caller that this is a procedure declaration
1451 Is_Completion := False;
1453 -- Link the body to the null procedure spec
1455 if Nkind (N) = N_Subprogram_Declaration then
1456 Set_Corresponding_Body (N, Defining_Entity (Null_Body));
1459 -- Null procedures are always inlined, but generic formal subprograms
1460 -- which appear as such in the internal instance of formal packages,
1461 -- need no completion and are not marked Inline.
1464 and then Nkind (N) /= N_Formal_Concrete_Subprogram_Declaration
1466 Set_Body_To_Inline (N, Null_Body);
1467 Set_Is_Inlined (Designator);
1471 -- The null procedure is a completion. We unconditionally rewrite
1472 -- this as a null body (even if expansion is not active), because
1473 -- there are various error checks that are applied on this body
1474 -- when it is analyzed (e.g. correct aspect placement).
1476 if Has_Completion (Prev) then
1477 Error_Msg_Sloc := Sloc (Prev);
1478 Error_Msg_NE ("duplicate body for & declared#", N, Prev);
1481 Is_Completion := True;
1482 Rewrite (N, Null_Body);
1485 end Analyze_Null_Procedure;
1487 -----------------------------
1488 -- Analyze_Operator_Symbol --
1489 -----------------------------
1491 -- An operator symbol such as "+" or "and" may appear in context where the
1492 -- literal denotes an entity name, such as "+"(x, y) or in context when it
1493 -- is just a string, as in (conjunction = "or"). In these cases the parser
1494 -- generates this node, and the semantics does the disambiguation. Other
1495 -- such case are actuals in an instantiation, the generic unit in an
1496 -- instantiation, and pragma arguments.
1498 procedure Analyze_Operator_Symbol (N : Node_Id) is
1499 Par : constant Node_Id := Parent (N);
1502 if (Nkind (Par) = N_Function_Call and then N = Name (Par))
1503 or else Nkind (Par) = N_Function_Instantiation
1504 or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par))
1505 or else (Nkind (Par) = N_Pragma_Argument_Association
1506 and then not Is_Pragma_String_Literal (Par))
1507 or else Nkind (Par) = N_Subprogram_Renaming_Declaration
1508 or else (Nkind (Par) = N_Attribute_Reference
1509 and then Attribute_Name (Par) /= Name_Value)
1511 Find_Direct_Name (N);
1514 Change_Operator_Symbol_To_String_Literal (N);
1517 end Analyze_Operator_Symbol;
1519 -----------------------------------
1520 -- Analyze_Parameter_Association --
1521 -----------------------------------
1523 procedure Analyze_Parameter_Association (N : Node_Id) is
1525 Analyze (Explicit_Actual_Parameter (N));
1526 end Analyze_Parameter_Association;
1528 ----------------------------
1529 -- Analyze_Procedure_Call --
1530 ----------------------------
1532 -- WARNING: This routine manages Ghost regions. Return statements must be
1533 -- replaced by gotos which jump to the end of the routine and restore the
1536 procedure Analyze_Procedure_Call (N : Node_Id) is
1537 procedure Analyze_Call_And_Resolve;
1538 -- Do Analyze and Resolve calls for procedure call. At the end, check
1539 -- for illegal order dependence.
1540 -- ??? where is the check for illegal order dependencies?
1542 ------------------------------
1543 -- Analyze_Call_And_Resolve --
1544 ------------------------------
1546 procedure Analyze_Call_And_Resolve is
1548 if Nkind (N) = N_Procedure_Call_Statement then
1550 Resolve (N, Standard_Void_Type);
1554 end Analyze_Call_And_Resolve;
1558 Actuals : constant List_Id := Parameter_Associations (N);
1559 Loc : constant Source_Ptr := Sloc (N);
1560 P : constant Node_Id := Name (N);
1562 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
1563 -- Save the Ghost mode to restore on exit
1568 -- Start of processing for Analyze_Procedure_Call
1571 -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
1572 -- a procedure call or an entry call. The prefix may denote an access
1573 -- to subprogram type, in which case an implicit dereference applies.
1574 -- If the prefix is an indexed component (without implicit dereference)
1575 -- then the construct denotes a call to a member of an entire family.
1576 -- If the prefix is a simple name, it may still denote a call to a
1577 -- parameterless member of an entry family. Resolution of these various
1578 -- interpretations is delicate.
1580 -- Do not analyze machine code statements to avoid rejecting them in
1583 if CodePeer_Mode and then Nkind (P) = N_Qualified_Expression then
1584 Set_Etype (P, Standard_Void_Type);
1589 -- If this is a call of the form Obj.Op, the call may have been analyzed
1590 -- and possibly rewritten into a block, in which case we are done.
1592 if Analyzed (N) then
1596 -- If there is an error analyzing the name (which may have been
1597 -- rewritten if the original call was in prefix notation) then error
1598 -- has been emitted already, mark node and return.
1600 if Error_Posted (N) or else Etype (Name (N)) = Any_Type then
1601 Set_Etype (N, Any_Type);
1605 -- A procedure call is Ghost when its name denotes a Ghost procedure.
1606 -- Set the mode now to ensure that any nodes generated during analysis
1607 -- and expansion are properly marked as Ghost.
1609 Mark_And_Set_Ghost_Procedure_Call (N);
1611 -- Otherwise analyze the parameters
1613 if Present (Actuals) then
1614 Actual := First (Actuals);
1616 while Present (Actual) loop
1618 Check_Parameterless_Call (Actual);
1623 -- Special processing for Elab_Spec, Elab_Body and Elab_Subp_Body calls
1625 if Nkind (P) = N_Attribute_Reference
1626 and then Nam_In (Attribute_Name (P), Name_Elab_Spec,
1628 Name_Elab_Subp_Body)
1630 if Present (Actuals) then
1632 ("no parameters allowed for this call", First (Actuals));
1636 Set_Etype (N, Standard_Void_Type);
1639 elsif Is_Entity_Name (P)
1640 and then Is_Record_Type (Etype (Entity (P)))
1641 and then Remote_AST_I_Dereference (P)
1645 elsif Is_Entity_Name (P)
1646 and then Ekind (Entity (P)) /= E_Entry_Family
1648 if Is_Access_Type (Etype (P))
1649 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
1650 and then No (Actuals)
1651 and then Comes_From_Source (N)
1653 Error_Msg_N ("missing explicit dereference in call", N);
1656 Analyze_Call_And_Resolve;
1658 -- If the prefix is the simple name of an entry family, this is a
1659 -- parameterless call from within the task body itself.
1661 elsif Is_Entity_Name (P)
1662 and then Nkind (P) = N_Identifier
1663 and then Ekind (Entity (P)) = E_Entry_Family
1664 and then Present (Actuals)
1665 and then No (Next (First (Actuals)))
1667 -- Can be call to parameterless entry family. What appears to be the
1668 -- sole argument is in fact the entry index. Rewrite prefix of node
1669 -- accordingly. Source representation is unchanged by this
1673 Make_Indexed_Component (Loc,
1675 Make_Selected_Component (Loc,
1676 Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc),
1677 Selector_Name => New_Occurrence_Of (Entity (P), Loc)),
1678 Expressions => Actuals);
1679 Set_Name (N, New_N);
1680 Set_Etype (New_N, Standard_Void_Type);
1681 Set_Parameter_Associations (N, No_List);
1682 Analyze_Call_And_Resolve;
1684 elsif Nkind (P) = N_Explicit_Dereference then
1685 if Ekind (Etype (P)) = E_Subprogram_Type then
1686 Analyze_Call_And_Resolve;
1688 Error_Msg_N ("expect access to procedure in call", P);
1691 -- The name can be a selected component or an indexed component that
1692 -- yields an access to subprogram. Such a prefix is legal if the call
1693 -- has parameter associations.
1695 elsif Is_Access_Type (Etype (P))
1696 and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
1698 if Present (Actuals) then
1699 Analyze_Call_And_Resolve;
1701 Error_Msg_N ("missing explicit dereference in call ", N);
1704 -- If not an access to subprogram, then the prefix must resolve to the
1705 -- name of an entry, entry family, or protected operation.
1707 -- For the case of a simple entry call, P is a selected component where
1708 -- the prefix is the task and the selector name is the entry. A call to
1709 -- a protected procedure will have the same syntax. If the protected
1710 -- object contains overloaded operations, the entity may appear as a
1711 -- function, the context will select the operation whose type is Void.
1713 elsif Nkind (P) = N_Selected_Component
1714 and then Ekind_In (Entity (Selector_Name (P)), E_Entry,
1718 -- When front-end inlining is enabled, as with SPARK_Mode, a call
1719 -- in prefix notation may still be missing its controlling argument,
1720 -- so perform the transformation now.
1722 if SPARK_Mode = On and then In_Inlined_Body then
1724 Subp : constant Entity_Id := Entity (Selector_Name (P));
1725 Typ : constant Entity_Id := Etype (Prefix (P));
1728 if Is_Tagged_Type (Typ)
1729 and then Present (First_Formal (Subp))
1730 and then Etype (First_Formal (Subp)) = Typ
1731 and then Try_Object_Operation (P)
1736 Analyze_Call_And_Resolve;
1741 Analyze_Call_And_Resolve;
1744 elsif Nkind (P) = N_Selected_Component
1745 and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family
1746 and then Present (Actuals)
1747 and then No (Next (First (Actuals)))
1749 -- Can be call to parameterless entry family. What appears to be the
1750 -- sole argument is in fact the entry index. Rewrite prefix of node
1751 -- accordingly. Source representation is unchanged by this
1755 Make_Indexed_Component (Loc,
1756 Prefix => New_Copy (P),
1757 Expressions => Actuals);
1758 Set_Name (N, New_N);
1759 Set_Etype (New_N, Standard_Void_Type);
1760 Set_Parameter_Associations (N, No_List);
1761 Analyze_Call_And_Resolve;
1763 -- For the case of a reference to an element of an entry family, P is
1764 -- an indexed component whose prefix is a selected component (task and
1765 -- entry family), and whose index is the entry family index.
1767 elsif Nkind (P) = N_Indexed_Component
1768 and then Nkind (Prefix (P)) = N_Selected_Component
1769 and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family
1771 Analyze_Call_And_Resolve;
1773 -- If the prefix is the name of an entry family, it is a call from
1774 -- within the task body itself.
1776 elsif Nkind (P) = N_Indexed_Component
1777 and then Nkind (Prefix (P)) = N_Identifier
1778 and then Ekind (Entity (Prefix (P))) = E_Entry_Family
1781 Make_Selected_Component (Loc,
1782 Prefix => New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc),
1783 Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc));
1784 Rewrite (Prefix (P), New_N);
1786 Analyze_Call_And_Resolve;
1788 -- In Ada 2012. a qualified expression is a name, but it cannot be a
1789 -- procedure name, so the construct can only be a qualified expression.
1791 elsif Nkind (P) = N_Qualified_Expression
1792 and then Ada_Version >= Ada_2012
1794 Rewrite (N, Make_Code_Statement (Loc, Expression => P));
1797 -- Anything else is an error
1800 Error_Msg_N ("invalid procedure or entry call", N);
1804 Restore_Ghost_Mode (Saved_GM);
1805 end Analyze_Procedure_Call;
1807 ------------------------------
1808 -- Analyze_Return_Statement --
1809 ------------------------------
1811 procedure Analyze_Return_Statement (N : Node_Id) is
1812 pragma Assert (Nkind_In (N, N_Extended_Return_Statement,
1813 N_Simple_Return_Statement));
1815 Returns_Object : constant Boolean :=
1816 Nkind (N) = N_Extended_Return_Statement
1818 (Nkind (N) = N_Simple_Return_Statement
1819 and then Present (Expression (N)));
1820 -- True if we're returning something; that is, "return <expression>;"
1821 -- or "return Result : T [:= ...]". False for "return;". Used for error
1822 -- checking: If Returns_Object is True, N should apply to a function
1823 -- body; otherwise N should apply to a procedure body, entry body,
1824 -- accept statement, or extended return statement.
1826 function Find_What_It_Applies_To return Entity_Id;
1827 -- Find the entity representing the innermost enclosing body, accept
1828 -- statement, or extended return statement. If the result is a callable
1829 -- construct or extended return statement, then this will be the value
1830 -- of the Return_Applies_To attribute. Otherwise, the program is
1831 -- illegal. See RM-6.5(4/2).
1833 -----------------------------
1834 -- Find_What_It_Applies_To --
1835 -----------------------------
1837 function Find_What_It_Applies_To return Entity_Id is
1838 Result : Entity_Id := Empty;
1841 -- Loop outward through the Scope_Stack, skipping blocks, loops,
1842 -- and postconditions.
1844 for J in reverse 0 .. Scope_Stack.Last loop
1845 Result := Scope_Stack.Table (J).Entity;
1846 exit when not Ekind_In (Result, E_Block, E_Loop)
1847 and then Chars (Result) /= Name_uPostconditions;
1850 pragma Assert (Present (Result));
1852 end Find_What_It_Applies_To;
1854 -- Local declarations
1856 Scope_Id : constant Entity_Id := Find_What_It_Applies_To;
1857 Kind : constant Entity_Kind := Ekind (Scope_Id);
1858 Loc : constant Source_Ptr := Sloc (N);
1859 Stm_Entity : constant Entity_Id :=
1861 (E_Return_Statement, Current_Scope, Loc, 'R');
1863 -- Start of processing for Analyze_Return_Statement
1866 Set_Return_Statement_Entity (N, Stm_Entity);
1868 Set_Etype (Stm_Entity, Standard_Void_Type);
1869 Set_Return_Applies_To (Stm_Entity, Scope_Id);
1871 -- Place Return entity on scope stack, to simplify enforcement of 6.5
1872 -- (4/2): an inner return statement will apply to this extended return.
1874 if Nkind (N) = N_Extended_Return_Statement then
1875 Push_Scope (Stm_Entity);
1878 -- Check that pragma No_Return is obeyed. Don't complain about the
1879 -- implicitly-generated return that is placed at the end.
1881 if No_Return (Scope_Id) and then Comes_From_Source (N) then
1882 Error_Msg_N ("RETURN statement not allowed (No_Return)", N);
1885 -- Warn on any unassigned OUT parameters if in procedure
1887 if Ekind (Scope_Id) = E_Procedure then
1888 Warn_On_Unassigned_Out_Parameter (N, Scope_Id);
1891 -- Check that functions return objects, and other things do not
1893 if Kind = E_Function or else Kind = E_Generic_Function then
1894 if not Returns_Object then
1895 Error_Msg_N ("missing expression in return from function", N);
1898 elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then
1899 if Returns_Object then
1900 Error_Msg_N ("procedure cannot return value (use function)", N);
1903 elsif Kind = E_Entry or else Kind = E_Entry_Family then
1904 if Returns_Object then
1905 if Is_Protected_Type (Scope (Scope_Id)) then
1906 Error_Msg_N ("entry body cannot return value", N);
1908 Error_Msg_N ("accept statement cannot return value", N);
1912 elsif Kind = E_Return_Statement then
1914 -- We are nested within another return statement, which must be an
1915 -- extended_return_statement.
1917 if Returns_Object then
1918 if Nkind (N) = N_Extended_Return_Statement then
1920 ("extended return statement cannot be nested (use `RETURN;`)",
1923 -- Case of a simple return statement with a value inside extended
1924 -- return statement.
1928 ("return nested in extended return statement cannot return "
1929 & "value (use `RETURN;`)", N);
1934 Error_Msg_N ("illegal context for return statement", N);
1937 if Ekind_In (Kind, E_Function, E_Generic_Function) then
1938 Analyze_Function_Return (N);
1940 elsif Ekind_In (Kind, E_Procedure, E_Generic_Procedure) then
1941 Set_Return_Present (Scope_Id);
1944 if Nkind (N) = N_Extended_Return_Statement then
1948 Kill_Current_Values (Last_Assignment_Only => True);
1949 Check_Unreachable_Code (N);
1951 Analyze_Dimension (N);
1952 end Analyze_Return_Statement;
1954 -------------------------------------
1955 -- Analyze_Simple_Return_Statement --
1956 -------------------------------------
1958 procedure Analyze_Simple_Return_Statement (N : Node_Id) is
1960 if Present (Expression (N)) then
1961 Mark_Coextensions (N, Expression (N));
1964 Analyze_Return_Statement (N);
1965 end Analyze_Simple_Return_Statement;
1967 -------------------------
1968 -- Analyze_Return_Type --
1969 -------------------------
1971 procedure Analyze_Return_Type (N : Node_Id) is
1972 Designator : constant Entity_Id := Defining_Entity (N);
1973 Typ : Entity_Id := Empty;
1976 -- Normal case where result definition does not indicate an error
1978 if Result_Definition (N) /= Error then
1979 if Nkind (Result_Definition (N)) = N_Access_Definition then
1980 Check_SPARK_05_Restriction
1981 ("access result is not allowed", Result_Definition (N));
1983 -- Ada 2005 (AI-254): Handle anonymous access to subprograms
1986 AD : constant Node_Id :=
1987 Access_To_Subprogram_Definition (Result_Definition (N));
1989 if Present (AD) and then Protected_Present (AD) then
1990 Typ := Replace_Anonymous_Access_To_Protected_Subprogram (N);
1992 Typ := Access_Definition (N, Result_Definition (N));
1996 Set_Parent (Typ, Result_Definition (N));
1997 Set_Is_Local_Anonymous_Access (Typ);
1998 Set_Etype (Designator, Typ);
2000 -- Ada 2005 (AI-231): Ensure proper usage of null exclusion
2002 Null_Exclusion_Static_Checks (N);
2004 -- Subtype_Mark case
2007 Find_Type (Result_Definition (N));
2008 Typ := Entity (Result_Definition (N));
2009 Set_Etype (Designator, Typ);
2011 -- Unconstrained array as result is not allowed in SPARK
2013 if Is_Array_Type (Typ) and then not Is_Constrained (Typ) then
2014 Check_SPARK_05_Restriction
2015 ("returning an unconstrained array is not allowed",
2016 Result_Definition (N));
2019 -- Ada 2005 (AI-231): Ensure proper usage of null exclusion
2021 Null_Exclusion_Static_Checks (N);
2023 -- If a null exclusion is imposed on the result type, then create
2024 -- a null-excluding itype (an access subtype) and use it as the
2025 -- function's Etype. Note that the null exclusion checks are done
2026 -- right before this, because they don't get applied to types that
2027 -- do not come from source.
2029 if Is_Access_Type (Typ) and then Null_Exclusion_Present (N) then
2030 Set_Etype (Designator,
2031 Create_Null_Excluding_Itype
2034 Scope_Id => Scope (Current_Scope)));
2036 -- The new subtype must be elaborated before use because
2037 -- it is visible outside of the function. However its base
2038 -- type may not be frozen yet, so the reference that will
2039 -- force elaboration must be attached to the freezing of
2042 -- If the return specification appears on a proper body,
2043 -- the subtype will have been created already on the spec.
2045 if Is_Frozen (Typ) then
2046 if Nkind (Parent (N)) = N_Subprogram_Body
2047 and then Nkind (Parent (Parent (N))) = N_Subunit
2051 Build_Itype_Reference (Etype (Designator), Parent (N));
2055 Ensure_Freeze_Node (Typ);
2058 IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
2060 Set_Itype (IR, Etype (Designator));
2061 Append_Freeze_Actions (Typ, New_List (IR));
2066 Set_Etype (Designator, Typ);
2069 if Ekind (Typ) = E_Incomplete_Type
2070 or else (Is_Class_Wide_Type (Typ)
2071 and then Ekind (Root_Type (Typ)) = E_Incomplete_Type)
2073 -- AI05-0151: Tagged incomplete types are allowed in all formal
2074 -- parts. Untagged incomplete types are not allowed in bodies.
2075 -- As a consequence, limited views cannot appear in a basic
2076 -- declaration that is itself within a body, because there is
2077 -- no point at which the non-limited view will become visible.
2079 if Ada_Version >= Ada_2012 then
2080 if From_Limited_With (Typ) and then In_Package_Body then
2082 ("invalid use of incomplete type&",
2083 Result_Definition (N), Typ);
2085 -- The return type of a subprogram body cannot be of a
2086 -- formal incomplete type.
2088 elsif Is_Generic_Type (Typ)
2089 and then Nkind (Parent (N)) = N_Subprogram_Body
2092 ("return type cannot be a formal incomplete type",
2093 Result_Definition (N));
2095 elsif Is_Class_Wide_Type (Typ)
2096 and then Is_Generic_Type (Root_Type (Typ))
2097 and then Nkind (Parent (N)) = N_Subprogram_Body
2100 ("return type cannot be a formal incomplete type",
2101 Result_Definition (N));
2103 elsif Is_Tagged_Type (Typ) then
2106 -- Use is legal in a thunk generated for an operation
2107 -- inherited from a progenitor.
2109 elsif Is_Thunk (Designator)
2110 and then Present (Non_Limited_View (Typ))
2114 elsif Nkind (Parent (N)) = N_Subprogram_Body
2115 or else Nkind_In (Parent (Parent (N)), N_Accept_Statement,
2119 ("invalid use of untagged incomplete type&",
2123 -- The type must be completed in the current package. This
2124 -- is checked at the end of the package declaration when
2125 -- Taft-amendment types are identified. If the return type
2126 -- is class-wide, there is no required check, the type can
2127 -- be a bona fide TAT.
2129 if Ekind (Scope (Current_Scope)) = E_Package
2130 and then In_Private_Part (Scope (Current_Scope))
2131 and then not Is_Class_Wide_Type (Typ)
2133 Append_Elmt (Designator, Private_Dependents (Typ));
2138 ("invalid use of incomplete type&", Designator, Typ);
2143 -- Case where result definition does indicate an error
2146 Set_Etype (Designator, Any_Type);
2148 end Analyze_Return_Type;
2150 -----------------------------
2151 -- Analyze_Subprogram_Body --
2152 -----------------------------
2154 procedure Analyze_Subprogram_Body (N : Node_Id) is
2155 Loc : constant Source_Ptr := Sloc (N);
2156 Body_Spec : constant Node_Id := Specification (N);
2157 Body_Id : constant Entity_Id := Defining_Entity (Body_Spec);
2160 if Debug_Flag_C then
2161 Write_Str ("==> subprogram body ");
2162 Write_Name (Chars (Body_Id));
2163 Write_Str (" from ");
2164 Write_Location (Loc);
2169 Trace_Scope (N, Body_Id, " Analyze subprogram: ");
2171 -- The real work is split out into the helper, so it can do "return;"
2172 -- without skipping the debug output:
2174 Analyze_Subprogram_Body_Helper (N);
2176 if Debug_Flag_C then
2178 Write_Str ("<== subprogram body ");
2179 Write_Name (Chars (Body_Id));
2180 Write_Str (" from ");
2181 Write_Location (Loc);
2184 end Analyze_Subprogram_Body;
2186 ------------------------------------
2187 -- Analyze_Subprogram_Body_Helper --
2188 ------------------------------------
2190 -- This procedure is called for regular subprogram bodies, generic bodies,
2191 -- and for subprogram stubs of both kinds. In the case of stubs, only the
2192 -- specification matters, and is used to create a proper declaration for
2193 -- the subprogram, or to perform conformance checks.
2195 -- WARNING: This routine manages Ghost regions. Return statements must be
2196 -- replaced by gotos which jump to the end of the routine and restore the
2199 procedure Analyze_Subprogram_Body_Helper (N : Node_Id) is
2200 Body_Spec : Node_Id := Specification (N);
2201 Body_Id : Entity_Id := Defining_Entity (Body_Spec);
2202 Loc : constant Source_Ptr := Sloc (N);
2203 Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id);
2205 Conformant : Boolean;
2206 Desig_View : Entity_Id := Empty;
2207 Exch_Views : Elist_Id := No_Elist;
2209 Prot_Typ : Entity_Id := Empty;
2210 Spec_Decl : Node_Id := Empty;
2211 Spec_Id : Entity_Id;
2213 Last_Real_Spec_Entity : Entity_Id := Empty;
2214 -- When we analyze a separate spec, the entity chain ends up containing
2215 -- the formals, as well as any itypes generated during analysis of the
2216 -- default expressions for parameters, or the arguments of associated
2217 -- precondition/postcondition pragmas (which are analyzed in the context
2218 -- of the spec since they have visibility on formals).
2220 -- These entities belong with the spec and not the body. However we do
2221 -- the analysis of the body in the context of the spec (again to obtain
2222 -- visibility to the formals), and all the entities generated during
2223 -- this analysis end up also chained to the entity chain of the spec.
2224 -- But they really belong to the body, and there is circuitry to move
2225 -- them from the spec to the body.
2227 -- However, when we do this move, we don't want to move the real spec
2228 -- entities (first para above) to the body. The Last_Real_Spec_Entity
2229 -- variable points to the last real spec entity, so we only move those
2230 -- chained beyond that point. It is initialized to Empty to deal with
2231 -- the case where there is no separate spec.
2233 function Body_Has_Contract return Boolean;
2234 -- Check whether unanalyzed body has an aspect or pragma that may
2235 -- generate a SPARK contract.
2237 function Body_Has_SPARK_Mode_On return Boolean;
2238 -- Check whether SPARK_Mode On applies to the subprogram body, either
2239 -- because it is specified directly on the body, or because it is
2240 -- inherited from the enclosing subprogram or package.
2242 procedure Build_Subprogram_Declaration;
2243 -- Create a matching subprogram declaration for subprogram body N
2245 procedure Check_Anonymous_Return;
2246 -- Ada 2005: if a function returns an access type that denotes a task,
2247 -- or a type that contains tasks, we must create a master entity for
2248 -- the anonymous type, which typically will be used in an allocator
2249 -- in the body of the function.
2251 procedure Check_Inline_Pragma (Spec : in out Node_Id);
2252 -- Look ahead to recognize a pragma that may appear after the body.
2253 -- If there is a previous spec, check that it appears in the same
2254 -- declarative part. If the pragma is Inline_Always, perform inlining
2255 -- unconditionally, otherwise only if Front_End_Inlining is requested.
2256 -- If the body acts as a spec, and inlining is required, we create a
2257 -- subprogram declaration for it, in order to attach the body to inline.
2258 -- If pragma does not appear after the body, check whether there is
2259 -- an inline pragma before any local declarations.
2261 procedure Check_Missing_Return;
2262 -- Checks for a function with a no return statements, and also performs
2263 -- the warning checks implemented by Check_Returns. In formal mode, also
2264 -- verify that a function ends with a RETURN and that a procedure does
2265 -- not contain any RETURN.
2267 function Disambiguate_Spec return Entity_Id;
2268 -- When a primitive is declared between the private view and the full
2269 -- view of a concurrent type which implements an interface, a special
2270 -- mechanism is used to find the corresponding spec of the primitive
2273 function Exchange_Limited_Views (Subp_Id : Entity_Id) return Elist_Id;
2274 -- Ada 2012 (AI05-0151): Detect whether the profile of Subp_Id contains
2275 -- incomplete types coming from a limited context and replace their
2276 -- limited views with the non-limited ones. Return the list of changes
2277 -- to be used to undo the transformation.
2279 procedure Freeze_Expr_Types (Spec_Id : Entity_Id);
2280 -- AI12-0103: N is the body associated with an expression function that
2281 -- is a completion, and Spec_Id is its defining entity. Freeze before N
2282 -- all the types referenced by the expression of the function.
2284 function Is_Private_Concurrent_Primitive
2285 (Subp_Id : Entity_Id) return Boolean;
2286 -- Determine whether subprogram Subp_Id is a primitive of a concurrent
2287 -- type that implements an interface and has a private view.
2289 procedure Restore_Limited_Views (Restore_List : Elist_Id);
2290 -- Undo the transformation done by Exchange_Limited_Views.
2292 procedure Set_Trivial_Subprogram (N : Node_Id);
2293 -- Sets the Is_Trivial_Subprogram flag in both spec and body of the
2294 -- subprogram whose body is being analyzed. N is the statement node
2295 -- causing the flag to be set, if the following statement is a return
2296 -- of an entity, we mark the entity as set in source to suppress any
2297 -- warning on the stylized use of function stubs with a dummy return.
2299 procedure Verify_Overriding_Indicator;
2300 -- If there was a previous spec, the entity has been entered in the
2301 -- current scope previously. If the body itself carries an overriding
2302 -- indicator, check that it is consistent with the known status of the
2305 -----------------------
2306 -- Body_Has_Contract --
2307 -----------------------
2309 function Body_Has_Contract return Boolean is
2310 Decls : constant List_Id := Declarations (N);
2314 -- Check for aspects that may generate a contract
2316 if Present (Aspect_Specifications (N)) then
2317 Item := First (Aspect_Specifications (N));
2318 while Present (Item) loop
2319 if Is_Subprogram_Contract_Annotation (Item) then
2327 -- Check for pragmas that may generate a contract
2329 if Present (Decls) then
2330 Item := First (Decls);
2331 while Present (Item) loop
2332 if Nkind (Item) = N_Pragma
2333 and then Is_Subprogram_Contract_Annotation (Item)
2343 end Body_Has_Contract;
2345 ----------------------------
2346 -- Body_Has_SPARK_Mode_On --
2347 ----------------------------
2349 function Body_Has_SPARK_Mode_On return Boolean is
2350 Decls : constant List_Id := Declarations (N);
2354 -- Check for SPARK_Mode aspect
2356 if Present (Aspect_Specifications (N)) then
2357 Item := First (Aspect_Specifications (N));
2358 while Present (Item) loop
2359 if Get_Aspect_Id (Item) = Aspect_SPARK_Mode then
2360 return Get_SPARK_Mode_From_Annotation (Item) = On;
2367 -- Check for SPARK_Mode pragma
2369 if Present (Decls) then
2370 Item := First (Decls);
2371 while Present (Item) loop
2373 -- Pragmas that apply to a subprogram body are usually grouped
2374 -- together. Look for a potential pragma SPARK_Mode among them.
2376 if Nkind (Item) = N_Pragma then
2377 if Get_Pragma_Id (Item) = Pragma_SPARK_Mode then
2378 return Get_SPARK_Mode_From_Annotation (Item) = On;
2381 -- Otherwise the first non-pragma declarative item terminates
2382 -- the region where pragma SPARK_Mode may appear.
2392 -- Otherwise, the applicable SPARK_Mode is inherited from the
2393 -- enclosing subprogram or package.
2395 return SPARK_Mode = On;
2396 end Body_Has_SPARK_Mode_On;
2398 ----------------------------------
2399 -- Build_Subprogram_Declaration --
2400 ----------------------------------
2402 procedure Build_Subprogram_Declaration is
2403 procedure Move_Pragmas (From : Node_Id; To : Node_Id);
2404 -- Relocate certain categorization pragmas from the declarative list
2405 -- of subprogram body From and insert them after node To. The pragmas
2408 -- Volatile_Function
2409 -- Also copy pragma SPARK_Mode if present in the declarative list
2410 -- of subprogram body From and insert it after node To. This pragma
2411 -- should not be moved, as it applies to the body too.
2417 procedure Move_Pragmas (From : Node_Id; To : Node_Id) is
2419 Next_Decl : Node_Id;
2422 pragma Assert (Nkind (From) = N_Subprogram_Body);
2424 -- The destination node must be part of a list, as the pragmas are
2425 -- inserted after it.
2427 pragma Assert (Is_List_Member (To));
2429 -- Inspect the declarations of the subprogram body looking for
2430 -- specific pragmas.
2432 Decl := First (Declarations (N));
2433 while Present (Decl) loop
2434 Next_Decl := Next (Decl);
2436 if Nkind (Decl) = N_Pragma then
2437 if Pragma_Name_Unmapped (Decl) = Name_SPARK_Mode then
2438 Insert_After (To, New_Copy_Tree (Decl));
2440 elsif Nam_In (Pragma_Name_Unmapped (Decl),
2442 Name_Volatile_Function)
2445 Insert_After (To, Decl);
2456 Subp_Decl : Node_Id;
2458 -- Start of processing for Build_Subprogram_Declaration
2461 -- Create a matching subprogram spec using the profile of the body.
2462 -- The structure of the tree is identical, but has new entities for
2463 -- the defining unit name and formal parameters.
2466 Make_Subprogram_Declaration (Loc,
2467 Specification => Copy_Subprogram_Spec (Body_Spec));
2468 Set_Comes_From_Source (Subp_Decl, True);
2470 -- Relocate the aspects and relevant pragmas from the subprogram body
2471 -- to the generated spec because it acts as the initial declaration.
2473 Insert_Before (N, Subp_Decl);
2474 Move_Aspects (N, To => Subp_Decl);
2475 Move_Pragmas (N, To => Subp_Decl);
2477 -- Ensure that the generated corresponding spec and original body
2478 -- share the same SPARK_Mode pragma or aspect. As a result, both have
2479 -- the same SPARK_Mode attributes, and the global SPARK_Mode value is
2480 -- correctly set for local subprograms.
2482 Copy_SPARK_Mode_Aspect (Subp_Decl, To => N);
2484 Analyze (Subp_Decl);
2486 -- Propagate the attributes Rewritten_For_C and Corresponding_Proc to
2487 -- the body since the expander may generate calls using that entity.
2488 -- Required to ensure that Expand_Call rewrites calls to this
2489 -- function by calls to the built procedure.
2491 if Modify_Tree_For_C
2492 and then Nkind (Body_Spec) = N_Function_Specification
2494 Rewritten_For_C (Defining_Entity (Specification (Subp_Decl)))
2496 Set_Rewritten_For_C (Defining_Entity (Body_Spec));
2497 Set_Corresponding_Procedure (Defining_Entity (Body_Spec),
2498 Corresponding_Procedure
2499 (Defining_Entity (Specification (Subp_Decl))));
2502 -- Analyze any relocated source pragmas or pragmas created for aspect
2505 Decl := Next (Subp_Decl);
2506 while Present (Decl) loop
2508 -- Stop the search for pragmas once the body has been reached as
2509 -- this terminates the region where pragmas may appear.
2514 elsif Nkind (Decl) = N_Pragma then
2521 Spec_Id := Defining_Entity (Subp_Decl);
2522 Set_Corresponding_Spec (N, Spec_Id);
2524 -- Mark the generated spec as a source construct to ensure that all
2525 -- calls to it are properly registered in ALI files for GNATprove.
2527 Set_Comes_From_Source (Spec_Id, True);
2529 -- Ensure that the specs of the subprogram declaration and its body
2530 -- are identical, otherwise they will appear non-conformant due to
2531 -- rewritings in the default values of formal parameters.
2533 Body_Spec := Copy_Subprogram_Spec (Body_Spec);
2534 Set_Specification (N, Body_Spec);
2535 Body_Id := Analyze_Subprogram_Specification (Body_Spec);
2536 end Build_Subprogram_Declaration;
2538 ----------------------------
2539 -- Check_Anonymous_Return --
2540 ----------------------------
2542 procedure Check_Anonymous_Return is
2548 if Present (Spec_Id) then
2554 if Ekind (Scop) = E_Function
2555 and then Ekind (Etype (Scop)) = E_Anonymous_Access_Type
2556 and then not Is_Thunk (Scop)
2558 -- Skip internally built functions which handle the case of
2559 -- a null access (see Expand_Interface_Conversion)
2561 and then not (Is_Interface (Designated_Type (Etype (Scop)))
2562 and then not Comes_From_Source (Parent (Scop)))
2564 and then (Has_Task (Designated_Type (Etype (Scop)))
2566 (Is_Class_Wide_Type (Designated_Type (Etype (Scop)))
2568 Is_Limited_Record (Designated_Type (Etype (Scop)))))
2569 and then Expander_Active
2571 -- Avoid cases with no tasking support
2573 and then RTE_Available (RE_Current_Master)
2574 and then not Restriction_Active (No_Task_Hierarchy)
2577 Make_Object_Declaration (Loc,
2578 Defining_Identifier =>
2579 Make_Defining_Identifier (Loc, Name_uMaster),
2580 Constant_Present => True,
2581 Object_Definition =>
2582 New_Occurrence_Of (RTE (RE_Master_Id), Loc),
2584 Make_Explicit_Dereference (Loc,
2585 New_Occurrence_Of (RTE (RE_Current_Master), Loc)));
2587 if Present (Declarations (N)) then
2588 Prepend (Decl, Declarations (N));
2590 Set_Declarations (N, New_List (Decl));
2593 Set_Master_Id (Etype (Scop), Defining_Identifier (Decl));
2594 Set_Has_Master_Entity (Scop);
2596 -- Now mark the containing scope as a task master
2599 while Nkind (Par) /= N_Compilation_Unit loop
2600 Par := Parent (Par);
2601 pragma Assert (Present (Par));
2603 -- If we fall off the top, we are at the outer level, and
2604 -- the environment task is our effective master, so nothing
2608 (Par, N_Task_Body, N_Block_Statement, N_Subprogram_Body)
2610 Set_Is_Task_Master (Par, True);
2615 end Check_Anonymous_Return;
2617 -------------------------
2618 -- Check_Inline_Pragma --
2619 -------------------------
2621 procedure Check_Inline_Pragma (Spec : in out Node_Id) is
2625 function Is_Inline_Pragma (N : Node_Id) return Boolean;
2626 -- True when N is a pragma Inline or Inline_Always that applies
2627 -- to this subprogram.
2629 -----------------------
2630 -- Is_Inline_Pragma --
2631 -----------------------
2633 function Is_Inline_Pragma (N : Node_Id) return Boolean is
2635 if Nkind (N) = N_Pragma
2637 (Pragma_Name_Unmapped (N) = Name_Inline_Always
2638 or else (Pragma_Name_Unmapped (N) = Name_Inline
2640 (Front_End_Inlining or else Optimization_Level > 0)))
2641 and then Present (Pragma_Argument_Associations (N))
2644 Pragma_Arg : Node_Id :=
2645 Expression (First (Pragma_Argument_Associations (N)));
2647 if Nkind (Pragma_Arg) = N_Selected_Component then
2648 Pragma_Arg := Selector_Name (Pragma_Arg);
2651 return Chars (Pragma_Arg) = Chars (Body_Id);
2657 end Is_Inline_Pragma;
2659 -- Start of processing for Check_Inline_Pragma
2662 if not Expander_Active then
2666 if Is_List_Member (N)
2667 and then Present (Next (N))
2668 and then Is_Inline_Pragma (Next (N))
2672 elsif Nkind (N) /= N_Subprogram_Body_Stub
2673 and then Present (Declarations (N))
2674 and then Is_Inline_Pragma (First (Declarations (N)))
2676 Prag := First (Declarations (N));
2682 if Present (Prag) then
2683 if Present (Spec_Id) then
2684 if Is_List_Member (N)
2685 and then Is_List_Member (Unit_Declaration_Node (Spec_Id))
2686 and then In_Same_List (N, Unit_Declaration_Node (Spec_Id))
2692 -- Create a subprogram declaration, to make treatment uniform.
2693 -- Make the sloc of the subprogram name that of the entity in
2694 -- the body, so that style checks find identical strings.
2697 Subp : constant Entity_Id :=
2698 Make_Defining_Identifier
2699 (Sloc (Body_Id), Chars (Body_Id));
2700 Decl : constant Node_Id :=
2701 Make_Subprogram_Declaration (Loc,
2703 New_Copy_Tree (Specification (N)));
2706 Set_Defining_Unit_Name (Specification (Decl), Subp);
2708 -- To ensure proper coverage when body is inlined, indicate
2709 -- whether the subprogram comes from source.
2711 Set_Comes_From_Source (Subp, Comes_From_Source (N));
2713 if Present (First_Formal (Body_Id)) then
2714 Plist := Copy_Parameter_List (Body_Id);
2715 Set_Parameter_Specifications
2716 (Specification (Decl), Plist);
2719 -- Move aspects to the new spec
2721 if Has_Aspects (N) then
2722 Move_Aspects (N, To => Decl);
2725 Insert_Before (N, Decl);
2728 Set_Has_Pragma_Inline (Subp);
2730 if Pragma_Name (Prag) = Name_Inline_Always then
2731 Set_Is_Inlined (Subp);
2732 Set_Has_Pragma_Inline_Always (Subp);
2735 -- Prior to copying the subprogram body to create a template
2736 -- for it for subsequent inlining, remove the pragma from
2737 -- the current body so that the copy that will produce the
2738 -- new body will start from a completely unanalyzed tree.
2740 if Nkind (Parent (Prag)) = N_Subprogram_Body then
2741 Rewrite (Prag, Make_Null_Statement (Sloc (Prag)));
2748 end Check_Inline_Pragma;
2750 --------------------------
2751 -- Check_Missing_Return --
2752 --------------------------
2754 procedure Check_Missing_Return is
2756 Missing_Ret : Boolean;
2759 if Nkind (Body_Spec) = N_Function_Specification then
2760 if Present (Spec_Id) then
2766 if Return_Present (Id) then
2767 Check_Returns (HSS, 'F', Missing_Ret);
2770 Set_Has_Missing_Return (Id);
2773 -- Within a premature instantiation of a package with no body, we
2774 -- build completions of the functions therein, with a Raise
2775 -- statement. No point in complaining about a missing return in
2778 elsif Ekind (Id) = E_Function
2779 and then In_Instance
2780 and then Present (Statements (HSS))
2781 and then Nkind (First (Statements (HSS))) = N_Raise_Program_Error
2785 elsif Is_Generic_Subprogram (Id)
2786 or else not Is_Machine_Code_Subprogram (Id)
2788 Error_Msg_N ("missing RETURN statement in function body", N);
2791 -- If procedure with No_Return, check returns
2793 elsif Nkind (Body_Spec) = N_Procedure_Specification
2794 and then Present (Spec_Id)
2795 and then No_Return (Spec_Id)
2797 Check_Returns (HSS, 'P', Missing_Ret, Spec_Id);
2800 -- Special checks in SPARK mode
2802 if Nkind (Body_Spec) = N_Function_Specification then
2804 -- In SPARK mode, last statement of a function should be a return
2807 Stat : constant Node_Id := Last_Source_Statement (HSS);
2810 and then not Nkind_In (Stat, N_Simple_Return_Statement,
2811 N_Extended_Return_Statement)
2813 Check_SPARK_05_Restriction
2814 ("last statement in function should be RETURN", Stat);
2818 -- In SPARK mode, verify that a procedure has no return
2820 elsif Nkind (Body_Spec) = N_Procedure_Specification then
2821 if Present (Spec_Id) then
2827 -- Would be nice to point to return statement here, can we
2828 -- borrow the Check_Returns procedure here ???
2830 if Return_Present (Id) then
2831 Check_SPARK_05_Restriction
2832 ("procedure should not have RETURN", N);
2835 end Check_Missing_Return;
2837 -----------------------
2838 -- Disambiguate_Spec --
2839 -----------------------
2841 function Disambiguate_Spec return Entity_Id is
2842 Priv_Spec : Entity_Id;
2845 procedure Replace_Types (To_Corresponding : Boolean);
2846 -- Depending on the flag, replace the type of formal parameters of
2847 -- Body_Id if it is a concurrent type implementing interfaces with
2848 -- the corresponding record type or the other way around.
2850 procedure Replace_Types (To_Corresponding : Boolean) is
2852 Formal_Typ : Entity_Id;
2855 Formal := First_Formal (Body_Id);
2856 while Present (Formal) loop
2857 Formal_Typ := Etype (Formal);
2859 if Is_Class_Wide_Type (Formal_Typ) then
2860 Formal_Typ := Root_Type (Formal_Typ);
2863 -- From concurrent type to corresponding record
2865 if To_Corresponding then
2866 if Is_Concurrent_Type (Formal_Typ)
2867 and then Present (Corresponding_Record_Type (Formal_Typ))
2870 (Corresponding_Record_Type (Formal_Typ)))
2873 Corresponding_Record_Type (Formal_Typ));
2876 -- From corresponding record to concurrent type
2879 if Is_Concurrent_Record_Type (Formal_Typ)
2880 and then Present (Interfaces (Formal_Typ))
2883 Corresponding_Concurrent_Type (Formal_Typ));
2887 Next_Formal (Formal);
2891 -- Start of processing for Disambiguate_Spec
2894 -- Try to retrieve the specification of the body as is. All error
2895 -- messages are suppressed because the body may not have a spec in
2896 -- its current state.
2898 Spec_N := Find_Corresponding_Spec (N, False);
2900 -- It is possible that this is the body of a primitive declared
2901 -- between a private and a full view of a concurrent type. The
2902 -- controlling parameter of the spec carries the concurrent type,
2903 -- not the corresponding record type as transformed by Analyze_
2904 -- Subprogram_Specification. In such cases, we undo the change
2905 -- made by the analysis of the specification and try to find the
2908 -- Note that wrappers already have their corresponding specs and
2909 -- bodies set during their creation, so if the candidate spec is
2910 -- a wrapper, then we definitely need to swap all types to their
2911 -- original concurrent status.
2914 or else Is_Primitive_Wrapper (Spec_N)
2916 -- Restore all references of corresponding record types to the
2917 -- original concurrent types.
2919 Replace_Types (To_Corresponding => False);
2920 Priv_Spec := Find_Corresponding_Spec (N, False);
2922 -- The current body truly belongs to a primitive declared between
2923 -- a private and a full view. We leave the modified body as is,
2924 -- and return the true spec.
2926 if Present (Priv_Spec)
2927 and then Is_Private_Primitive (Priv_Spec)
2932 -- In case that this is some sort of error, restore the original
2933 -- state of the body.
2935 Replace_Types (To_Corresponding => True);
2939 end Disambiguate_Spec;
2941 ----------------------------
2942 -- Exchange_Limited_Views --
2943 ----------------------------
2945 function Exchange_Limited_Views (Subp_Id : Entity_Id) return Elist_Id is
2946 Result : Elist_Id := No_Elist;
2948 procedure Detect_And_Exchange (Id : Entity_Id);
2949 -- Determine whether Id's type denotes an incomplete type associated
2950 -- with a limited with clause and exchange the limited view with the
2951 -- non-limited one when available. Note that the non-limited view
2952 -- may exist because of a with_clause in another unit in the context,
2953 -- but cannot be used because the current view of the enclosing unit
2954 -- is still a limited view.
2956 -------------------------
2957 -- Detect_And_Exchange --
2958 -------------------------
2960 procedure Detect_And_Exchange (Id : Entity_Id) is
2961 Typ : constant Entity_Id := Etype (Id);
2963 if From_Limited_With (Typ)
2964 and then Has_Non_Limited_View (Typ)
2965 and then not From_Limited_With (Scope (Typ))
2968 Result := New_Elmt_List;
2971 Prepend_Elmt (Typ, Result);
2972 Prepend_Elmt (Id, Result);
2973 Set_Etype (Id, Non_Limited_View (Typ));
2975 end Detect_And_Exchange;
2981 -- Start of processing for Exchange_Limited_Views
2984 -- Do not process subprogram bodies as they already use the non-
2985 -- limited view of types.
2987 if not Ekind_In (Subp_Id, E_Function, E_Procedure) then
2991 -- Examine all formals and swap views when applicable
2993 Formal := First_Formal (Subp_Id);
2994 while Present (Formal) loop
2995 Detect_And_Exchange (Formal);
2997 Next_Formal (Formal);
3000 -- Process the return type of a function
3002 if Ekind (Subp_Id) = E_Function then
3003 Detect_And_Exchange (Subp_Id);
3007 end Exchange_Limited_Views;
3009 -----------------------
3010 -- Freeze_Expr_Types --
3011 -----------------------
3013 procedure Freeze_Expr_Types (Spec_Id : Entity_Id) is
3014 function Cloned_Expression return Node_Id;
3015 -- Build a duplicate of the expression of the return statement that
3016 -- has no defining entities shared with the original expression.
3018 function Freeze_Type_Refs (Node : Node_Id) return Traverse_Result;
3019 -- Freeze all types referenced in the subtree rooted at Node
3021 -----------------------
3022 -- Cloned_Expression --
3023 -----------------------
3025 function Cloned_Expression return Node_Id is
3026 function Clone_Id (Node : Node_Id) return Traverse_Result;
3027 -- Tree traversal routine that clones the defining identifier of
3028 -- iterator and loop parameter specification nodes.
3034 function Clone_Id (Node : Node_Id) return Traverse_Result is
3036 if Nkind_In (Node, N_Iterator_Specification,
3037 N_Loop_Parameter_Specification)
3039 Set_Defining_Identifier (Node,
3040 New_Copy (Defining_Identifier (Node)));
3050 procedure Clone_Def_Ids is new Traverse_Proc (Clone_Id);
3054 Return_Stmt : constant Node_Id :=
3056 (Statements (Handled_Statement_Sequence (N)));
3059 -- Start of processing for Cloned_Expression
3062 pragma Assert (Nkind (Return_Stmt) = N_Simple_Return_Statement);
3064 -- We must duplicate the expression with semantic information to
3065 -- inherit the decoration of global entities in generic instances.
3067 Dup_Expr := New_Copy_Tree (Expression (Return_Stmt));
3069 -- Replace the defining identifier of iterators and loop param
3070 -- specifications by a clone to ensure that the cloned expression
3071 -- and the original expression don't have shared identifiers;
3072 -- otherwise, as part of the preanalysis of the expression, these
3073 -- shared identifiers may be left decorated with itypes which
3074 -- will not be available in the tree passed to the backend.
3076 Clone_Def_Ids (Dup_Expr);
3079 end Cloned_Expression;
3081 ----------------------
3082 -- Freeze_Type_Refs --
3083 ----------------------
3085 function Freeze_Type_Refs (Node : Node_Id) return Traverse_Result is
3087 if Nkind (Node) = N_Identifier
3088 and then Present (Entity (Node))
3090 if Is_Type (Entity (Node)) then
3091 Freeze_Before (N, Entity (Node));
3093 elsif Ekind_In (Entity (Node), E_Component,
3097 Rec : constant Entity_Id := Scope (Entity (Node));
3100 -- Check that the enclosing record type can be frozen.
3101 -- This provides a better error message than generating
3102 -- primitives whose compilation fails much later. Refine
3103 -- the error message if possible.
3105 Check_Fully_Declared (Rec, Node);
3107 if Error_Posted (Node) then
3108 if Has_Private_Component (Rec) then
3110 ("\type& has private component", Node, Rec);
3114 Freeze_Before (N, Rec);
3119 -- Freezing an access type does not freeze the designated type,
3120 -- but freezing conversions between access to interfaces requires
3121 -- that the interface types themselves be frozen, so that dispatch
3122 -- table entities are properly created.
3124 -- Unclear whether a more general rule is needed ???
3126 elsif Nkind (Node) = N_Type_Conversion
3127 and then Is_Access_Type (Etype (Node))
3128 and then Is_Interface (Designated_Type (Etype (Node)))
3130 Freeze_Before (N, Designated_Type (Etype (Node)));
3134 end Freeze_Type_Refs;
3136 procedure Freeze_References is new Traverse_Proc (Freeze_Type_Refs);
3140 Saved_First_Entity : constant Entity_Id := First_Entity (Spec_Id);
3141 Saved_Last_Entity : constant Entity_Id := Last_Entity (Spec_Id);
3142 Dup_Expr : constant Node_Id := Cloned_Expression;
3144 -- Start of processing for Freeze_Expr_Types
3147 -- Preanalyze a duplicate of the expression to have available the
3148 -- minimum decoration needed to locate referenced unfrozen types
3149 -- without adding any decoration to the function expression. This
3150 -- preanalysis is performed with errors disabled to avoid reporting
3151 -- spurious errors on Ghost entities (since the expression is not
3154 Push_Scope (Spec_Id);
3155 Install_Formals (Spec_Id);
3156 Ignore_Errors_Enable := Ignore_Errors_Enable + 1;
3158 Preanalyze_Spec_Expression (Dup_Expr, Etype (Spec_Id));
3160 Ignore_Errors_Enable := Ignore_Errors_Enable - 1;
3163 -- Restore certain attributes of Spec_Id since the preanalysis may
3164 -- have introduced itypes to this scope, thus modifying attributes
3165 -- First_Entity and Last_Entity.
3167 Set_First_Entity (Spec_Id, Saved_First_Entity);
3168 Set_Last_Entity (Spec_Id, Saved_Last_Entity);
3170 if Present (Last_Entity (Spec_Id)) then
3171 Set_Next_Entity (Last_Entity (Spec_Id), Empty);
3174 -- Freeze all types referenced in the expression
3176 Freeze_References (Dup_Expr);
3177 end Freeze_Expr_Types;
3179 -------------------------------------
3180 -- Is_Private_Concurrent_Primitive --
3181 -------------------------------------
3183 function Is_Private_Concurrent_Primitive
3184 (Subp_Id : Entity_Id) return Boolean
3186 Formal_Typ : Entity_Id;
3189 if Present (First_Formal (Subp_Id)) then
3190 Formal_Typ := Etype (First_Formal (Subp_Id));
3192 if Is_Concurrent_Record_Type (Formal_Typ) then
3193 if Is_Class_Wide_Type (Formal_Typ) then
3194 Formal_Typ := Root_Type (Formal_Typ);
3197 Formal_Typ := Corresponding_Concurrent_Type (Formal_Typ);
3200 -- The type of the first formal is a concurrent tagged type with
3204 Is_Concurrent_Type (Formal_Typ)
3205 and then Is_Tagged_Type (Formal_Typ)
3206 and then Has_Private_Declaration (Formal_Typ);
3210 end Is_Private_Concurrent_Primitive;
3212 ---------------------------
3213 -- Restore_Limited_Views --
3214 ---------------------------
3216 procedure Restore_Limited_Views (Restore_List : Elist_Id) is
3217 Elmt : Elmt_Id := First_Elmt (Restore_List);
3221 while Present (Elmt) loop
3224 Set_Etype (Id, Node (Elmt));
3227 end Restore_Limited_Views;
3229 ----------------------------
3230 -- Set_Trivial_Subprogram --
3231 ----------------------------
3233 procedure Set_Trivial_Subprogram (N : Node_Id) is
3234 Nxt : constant Node_Id := Next (N);
3237 Set_Is_Trivial_Subprogram (Body_Id);
3239 if Present (Spec_Id) then
3240 Set_Is_Trivial_Subprogram (Spec_Id);
3244 and then Nkind (Nxt) = N_Simple_Return_Statement
3245 and then No (Next (Nxt))
3246 and then Present (Expression (Nxt))
3247 and then Is_Entity_Name (Expression (Nxt))
3249 Set_Never_Set_In_Source (Entity (Expression (Nxt)), False);
3251 end Set_Trivial_Subprogram;
3253 ---------------------------------
3254 -- Verify_Overriding_Indicator --
3255 ---------------------------------
3257 procedure Verify_Overriding_Indicator is
3259 if Must_Override (Body_Spec) then
3260 if Nkind (Spec_Id) = N_Defining_Operator_Symbol
3261 and then Operator_Matches_Spec (Spec_Id, Spec_Id)
3265 elsif not Present (Overridden_Operation (Spec_Id)) then
3267 ("subprogram& is not overriding", Body_Spec, Spec_Id);
3269 -- Overriding indicators aren't allowed for protected subprogram
3270 -- bodies (see the Confirmation in Ada Comment AC95-00213). Change
3271 -- this to a warning if -gnatd.E is enabled.
3273 elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then
3274 Error_Msg_Warn := Error_To_Warning;
3276 ("<<overriding indicator not allowed for protected "
3277 & "subprogram body", Body_Spec);
3280 elsif Must_Not_Override (Body_Spec) then
3281 if Present (Overridden_Operation (Spec_Id)) then
3283 ("subprogram& overrides inherited operation",
3284 Body_Spec, Spec_Id);
3286 elsif Nkind (Spec_Id) = N_Defining_Operator_Symbol
3287 and then Operator_Matches_Spec (Spec_Id, Spec_Id)
3290 ("subprogram& overrides predefined operator ",
3291 Body_Spec, Spec_Id);
3293 -- Overriding indicators aren't allowed for protected subprogram
3294 -- bodies (see the Confirmation in Ada Comment AC95-00213). Change
3295 -- this to a warning if -gnatd.E is enabled.
3297 elsif Ekind (Scope (Spec_Id)) = E_Protected_Type then
3298 Error_Msg_Warn := Error_To_Warning;
3301 ("<<overriding indicator not allowed "
3302 & "for protected subprogram body", Body_Spec);
3304 -- If this is not a primitive operation, then the overriding
3305 -- indicator is altogether illegal.
3307 elsif not Is_Primitive (Spec_Id) then
3309 ("overriding indicator only allowed "
3310 & "if subprogram is primitive", Body_Spec);
3313 -- If checking the style rule and the operation overrides, then
3314 -- issue a warning about a missing overriding_indicator. Protected
3315 -- subprogram bodies are excluded from this style checking, since
3316 -- they aren't primitives (even though their declarations can
3317 -- override) and aren't allowed to have an overriding_indicator.
3320 and then Present (Overridden_Operation (Spec_Id))
3321 and then Ekind (Scope (Spec_Id)) /= E_Protected_Type
3323 pragma Assert (Unit_Declaration_Node (Body_Id) = N);
3324 Style.Missing_Overriding (N, Body_Id);
3327 and then Can_Override_Operator (Spec_Id)
3328 and then not In_Predefined_Unit (Spec_Id)
3330 pragma Assert (Unit_Declaration_Node (Body_Id) = N);
3331 Style.Missing_Overriding (N, Body_Id);
3333 end Verify_Overriding_Indicator;
3337 Saved_GM : constant Ghost_Mode_Type := Ghost_Mode;
3338 Saved_ISMP : constant Boolean :=
3339 Ignore_SPARK_Mode_Pragmas_In_Instance;
3340 -- Save the Ghost and SPARK mode-related data to restore on exit
3342 -- Start of processing for Analyze_Subprogram_Body_Helper
3345 -- A [generic] subprogram body "freezes" the contract of the nearest
3346 -- enclosing package body and all other contracts encountered in the
3347 -- same declarative part up to and excluding the subprogram body:
3349 -- package body Nearest_Enclosing_Package
3350 -- with Refined_State => (State => Constit)
3354 -- procedure Freezes_Enclosing_Package_Body
3355 -- with Refined_Depends => (Input => Constit) ...
3357 -- This ensures that any annotations referenced by the contract of the
3358 -- [generic] subprogram body are available. This form of "freezing" is
3359 -- decoupled from the usual Freeze_xxx mechanism because it must also
3360 -- work in the context of generics where normal freezing is disabled.
3362 -- Only bodies coming from source should cause this type of "freezing".
3363 -- Expression functions that act as bodies and complete an initial
3364 -- declaration must be included in this category, hence the use of
3367 if Comes_From_Source (Original_Node (N)) then
3368 Analyze_Previous_Contracts (N);
3371 -- Generic subprograms are handled separately. They always have a
3372 -- generic specification. Determine whether current scope has a
3373 -- previous declaration.
3375 -- If the subprogram body is defined within an instance of the same
3376 -- name, the instance appears as a package renaming, and will be hidden
3377 -- within the subprogram.
3379 if Present (Prev_Id)
3380 and then not Is_Overloadable (Prev_Id)
3381 and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration
3382 or else Comes_From_Source (Prev_Id))
3384 if Is_Generic_Subprogram (Prev_Id) then
3387 -- A subprogram body is Ghost when it is stand alone and subject
3388 -- to pragma Ghost or when the corresponding spec is Ghost. Set
3389 -- the mode now to ensure that any nodes generated during analysis
3390 -- and expansion are properly marked as Ghost.
3392 Mark_And_Set_Ghost_Body (N, Spec_Id);
3394 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
3395 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
3397 Analyze_Generic_Subprogram_Body (N, Spec_Id);
3399 if Nkind (N) = N_Subprogram_Body then
3400 HSS := Handled_Statement_Sequence (N);
3401 Check_Missing_Return;
3406 -- Otherwise a previous entity conflicts with the subprogram name.
3407 -- Attempting to enter name will post error.
3410 Enter_Name (Body_Id);
3414 -- Non-generic case, find the subprogram declaration, if one was seen,
3415 -- or enter new overloaded entity in the current scope. If the
3416 -- Current_Entity is the Body_Id itself, the unit is being analyzed as
3417 -- part of the context of one of its subunits. No need to redo the
3420 elsif Prev_Id = Body_Id and then Has_Completion (Body_Id) then
3424 Body_Id := Analyze_Subprogram_Specification (Body_Spec);
3426 if Nkind (N) = N_Subprogram_Body_Stub
3427 or else No (Corresponding_Spec (N))
3429 if Is_Private_Concurrent_Primitive (Body_Id) then
3430 Spec_Id := Disambiguate_Spec;
3432 -- A subprogram body is Ghost when it is stand alone and
3433 -- subject to pragma Ghost or when the corresponding spec is
3434 -- Ghost. Set the mode now to ensure that any nodes generated
3435 -- during analysis and expansion are properly marked as Ghost.
3437 Mark_And_Set_Ghost_Body (N, Spec_Id);
3440 Spec_Id := Find_Corresponding_Spec (N);
3442 -- A subprogram body is Ghost when it is stand alone and
3443 -- subject to pragma Ghost or when the corresponding spec is
3444 -- Ghost. Set the mode now to ensure that any nodes generated
3445 -- during analysis and expansion are properly marked as Ghost.
3447 Mark_And_Set_Ghost_Body (N, Spec_Id);
3449 -- In GNATprove mode, if the body has no previous spec, create
3450 -- one so that the inlining machinery can operate properly.
3451 -- Transfer aspects, if any, to the new spec, so that they
3452 -- are legal and can be processed ahead of the body.
3453 -- We make two copies of the given spec, one for the new
3454 -- declaration, and one for the body.
3456 if No (Spec_Id) and then GNATprove_Mode
3458 -- Inlining does not apply during pre-analysis of code
3460 and then Full_Analysis
3462 -- Inlining only applies to full bodies, not stubs
3464 and then Nkind (N) /= N_Subprogram_Body_Stub
3466 -- Inlining only applies to bodies in the source code, not to
3467 -- those generated by the compiler. In particular, expression
3468 -- functions, whose body is generated by the compiler, are
3469 -- treated specially by GNATprove.
3471 and then Comes_From_Source (Body_Id)
3473 -- This cannot be done for a compilation unit, which is not
3474 -- in a context where we can insert a new spec.
3476 and then Is_List_Member (N)
3478 -- Inlining only applies to subprograms without contracts,
3479 -- as a contract is a sign that GNATprove should perform a
3480 -- modular analysis of the subprogram instead of a contextual
3481 -- analysis at each call site. The same test is performed in
3482 -- Inline.Can_Be_Inlined_In_GNATprove_Mode. It is repeated
3483 -- here in another form (because the contract has not been
3484 -- attached to the body) to avoid front-end errors in case
3485 -- pragmas are used instead of aspects, because the
3486 -- corresponding pragmas in the body would not be transferred
3487 -- to the spec, leading to legality errors.
3489 and then not Body_Has_Contract
3490 and then not Inside_A_Generic
3492 Build_Subprogram_Declaration;
3494 -- If this is a function that returns a constrained array, and
3495 -- we are generating SPARK_For_C, create subprogram declaration
3496 -- to simplify subsequent C generation.
3499 and then Modify_Tree_For_C
3500 and then Nkind (Body_Spec) = N_Function_Specification
3501 and then Is_Array_Type (Etype (Body_Id))
3502 and then Is_Constrained (Etype (Body_Id))
3504 Build_Subprogram_Declaration;
3508 -- If this is a duplicate body, no point in analyzing it
3510 if Error_Posted (N) then
3514 -- A subprogram body should cause freezing of its own declaration,
3515 -- but if there was no previous explicit declaration, then the
3516 -- subprogram will get frozen too late (there may be code within
3517 -- the body that depends on the subprogram having been frozen,
3518 -- such as uses of extra formals), so we force it to be frozen
3519 -- here. Same holds if the body and spec are compilation units.
3520 -- Finally, if the return type is an anonymous access to protected
3521 -- subprogram, it must be frozen before the body because its
3522 -- expansion has generated an equivalent type that is used when
3523 -- elaborating the body.
3525 -- An exception in the case of Ada 2012, AI05-177: The bodies
3526 -- created for expression functions do not freeze.
3529 and then Nkind (Original_Node (N)) /= N_Expression_Function
3531 Freeze_Before (N, Body_Id);
3533 elsif Nkind (Parent (N)) = N_Compilation_Unit then
3534 Freeze_Before (N, Spec_Id);
3536 elsif Is_Access_Subprogram_Type (Etype (Body_Id)) then
3537 Freeze_Before (N, Etype (Body_Id));
3541 Spec_Id := Corresponding_Spec (N);
3543 -- A subprogram body is Ghost when it is stand alone and subject
3544 -- to pragma Ghost or when the corresponding spec is Ghost. Set
3545 -- the mode now to ensure that any nodes generated during analysis
3546 -- and expansion are properly marked as Ghost.
3548 Mark_And_Set_Ghost_Body (N, Spec_Id);
3552 -- Previously we scanned the body to look for nested subprograms, and
3553 -- rejected an inline directive if nested subprograms were present,
3554 -- because the back-end would generate conflicting symbols for the
3555 -- nested bodies. This is now unnecessary.
3557 -- Look ahead to recognize a pragma Inline that appears after the body
3559 Check_Inline_Pragma (Spec_Id);
3561 -- Deal with special case of a fully private operation in the body of
3562 -- the protected type. We must create a declaration for the subprogram,
3563 -- in order to attach the protected subprogram that will be used in
3564 -- internal calls. We exclude compiler generated bodies from the
3565 -- expander since the issue does not arise for those cases.
3568 and then Comes_From_Source (N)
3569 and then Is_Protected_Type (Current_Scope)
3571 Spec_Id := Build_Private_Protected_Declaration (N);
3574 -- If we are generating C and this is a function returning a constrained
3575 -- array type for which we must create a procedure with an extra out
3576 -- parameter, build and analyze the body now. The procedure declaration
3577 -- has already been created. We reuse the source body of the function,
3578 -- because in an instance it may contain global references that cannot
3579 -- be reanalyzed. The source function itself is not used any further,
3580 -- so we mark it as having a completion. If the subprogram is a stub the
3581 -- transformation is done later, when the proper body is analyzed.
3584 and then Modify_Tree_For_C
3585 and then Present (Spec_Id)
3586 and then Ekind (Spec_Id) = E_Function
3587 and then Nkind (N) /= N_Subprogram_Body_Stub
3588 and then Rewritten_For_C (Spec_Id)
3590 Set_Has_Completion (Spec_Id);
3592 Rewrite (N, Build_Procedure_Body_Form (Spec_Id, N));
3595 -- The entity for the created procedure must remain invisible, so it
3596 -- does not participate in resolution of subsequent references to the
3599 Set_Is_Immediately_Visible (Corresponding_Spec (N), False);
3603 -- If a separate spec is present, then deal with freezing issues
3605 if Present (Spec_Id) then
3606 Spec_Decl := Unit_Declaration_Node (Spec_Id);
3607 Verify_Overriding_Indicator;
3609 -- In general, the spec will be frozen when we start analyzing the
3610 -- body. However, for internally generated operations, such as
3611 -- wrapper functions for inherited operations with controlling
3612 -- results, the spec may not have been frozen by the time we expand
3613 -- the freeze actions that include the bodies. In particular, extra
3614 -- formals for accessibility or for return-in-place may need to be
3615 -- generated. Freeze nodes, if any, are inserted before the current
3616 -- body. These freeze actions are also needed in ASIS mode and in
3617 -- Compile_Only mode to enable the proper back-end type annotations.
3618 -- They are necessary in any case to insure order of elaboration
3621 if not Is_Frozen (Spec_Id)
3622 and then (Expander_Active
3624 or else (Operating_Mode = Check_Semantics
3625 and then Serious_Errors_Detected = 0))
3627 Set_Has_Delayed_Freeze (Spec_Id);
3628 Freeze_Before (N, Spec_Id);
3630 -- AI12-0103: At the occurrence of an expression function
3631 -- declaration that is a completion, its expression causes
3634 if Has_Completion (Spec_Id)
3635 and then Nkind (N) = N_Subprogram_Body
3636 and then Was_Expression_Function (N)
3638 Freeze_Expr_Types (Spec_Id);
3643 -- If the subprogram has a class-wide clone, build its body as a copy
3644 -- of the original body, and rewrite body of original subprogram as a
3645 -- wrapper that calls the clone.
3647 if Present (Spec_Id)
3648 and then Present (Class_Wide_Clone (Spec_Id))
3649 and then (Comes_From_Source (N) or else Was_Expression_Function (N))
3651 Build_Class_Wide_Clone_Body (Spec_Id, N);
3653 -- This is the new body for the existing primitive operation
3655 Rewrite (N, Build_Class_Wide_Clone_Call
3656 (Sloc (N), New_List, Spec_Id, Parent (Spec_Id)));
3657 Set_Has_Completion (Spec_Id, False);
3662 -- Place subprogram on scope stack, and make formals visible. If there
3663 -- is a spec, the visible entity remains that of the spec.
3665 if Present (Spec_Id) then
3666 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
3668 if Is_Child_Unit (Spec_Id) then
3669 Generate_Reference (Spec_Id, Scope (Spec_Id), 'k', False);
3673 Style.Check_Identifier (Body_Id, Spec_Id);
3676 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
3677 Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
3679 if Is_Abstract_Subprogram (Spec_Id) then
3680 Error_Msg_N ("an abstract subprogram cannot have a body", N);
3684 Set_Convention (Body_Id, Convention (Spec_Id));
3685 Set_Has_Completion (Spec_Id);
3687 if Is_Protected_Type (Scope (Spec_Id)) then
3688 Prot_Typ := Scope (Spec_Id);
3691 -- If this is a body generated for a renaming, do not check for
3692 -- full conformance. The check is redundant, because the spec of
3693 -- the body is a copy of the spec in the renaming declaration,
3694 -- and the test can lead to spurious errors on nested defaults.
3696 if Present (Spec_Decl)
3697 and then not Comes_From_Source (N)
3699 (Nkind (Original_Node (Spec_Decl)) =
3700 N_Subprogram_Renaming_Declaration
3701 or else (Present (Corresponding_Body (Spec_Decl))
3703 Nkind (Unit_Declaration_Node
3704 (Corresponding_Body (Spec_Decl))) =
3705 N_Subprogram_Renaming_Declaration))
3709 -- Conversely, the spec may have been generated for specless body
3710 -- with an inline pragma. The entity comes from source, which is
3711 -- both semantically correct and necessary for proper inlining.
3712 -- The subprogram declaration itself is not in the source.
3714 elsif Comes_From_Source (N)
3715 and then Present (Spec_Decl)
3716 and then not Comes_From_Source (Spec_Decl)
3717 and then Has_Pragma_Inline (Spec_Id)
3724 Fully_Conformant, True, Conformant, Body_Id);
3727 -- If the body is not fully conformant, we have to decide if we
3728 -- should analyze it or not. If it has a really messed up profile
3729 -- then we probably should not analyze it, since we will get too
3730 -- many bogus messages.
3732 -- Our decision is to go ahead in the non-fully conformant case
3733 -- only if it is at least mode conformant with the spec. Note
3734 -- that the call to Check_Fully_Conformant has issued the proper
3735 -- error messages to complain about the lack of conformance.
3738 and then not Mode_Conformant (Body_Id, Spec_Id)
3744 if Spec_Id /= Body_Id then
3745 Reference_Body_Formals (Spec_Id, Body_Id);
3748 Set_Ekind (Body_Id, E_Subprogram_Body);
3750 if Nkind (N) = N_Subprogram_Body_Stub then
3751 Set_Corresponding_Spec_Of_Stub (N, Spec_Id);
3756 Set_Corresponding_Spec (N, Spec_Id);
3758 -- Ada 2005 (AI-345): If the operation is a primitive operation
3759 -- of a concurrent type, the type of the first parameter has been
3760 -- replaced with the corresponding record, which is the proper
3761 -- run-time structure to use. However, within the body there may
3762 -- be uses of the formals that depend on primitive operations
3763 -- of the type (in particular calls in prefixed form) for which
3764 -- we need the original concurrent type. The operation may have
3765 -- several controlling formals, so the replacement must be done
3768 if Comes_From_Source (Spec_Id)
3769 and then Present (First_Entity (Spec_Id))
3770 and then Ekind (Etype (First_Entity (Spec_Id))) = E_Record_Type
3771 and then Is_Tagged_Type (Etype (First_Entity (Spec_Id)))
3772 and then Present (Interfaces (Etype (First_Entity (Spec_Id))))
3773 and then Present (Corresponding_Concurrent_Type
3774 (Etype (First_Entity (Spec_Id))))
3777 Typ : constant Entity_Id := Etype (First_Entity (Spec_Id));
3781 Form := First_Formal (Spec_Id);
3782 while Present (Form) loop
3783 if Etype (Form) = Typ then
3784 Set_Etype (Form, Corresponding_Concurrent_Type (Typ));
3792 -- Make the formals visible, and place subprogram on scope stack.
3793 -- This is also the point at which we set Last_Real_Spec_Entity
3794 -- to mark the entities which will not be moved to the body.
3796 Install_Formals (Spec_Id);
3797 Last_Real_Spec_Entity := Last_Entity (Spec_Id);
3799 -- Within an instance, add local renaming declarations so that
3800 -- gdb can retrieve the values of actuals more easily. This is
3801 -- only relevant if generating code (and indeed we definitely
3802 -- do not want these definitions -gnatc mode, because that would
3805 if Is_Generic_Instance (Spec_Id)
3806 and then Is_Wrapper_Package (Current_Scope)
3807 and then Expander_Active
3809 Build_Subprogram_Instance_Renamings (N, Current_Scope);
3812 Push_Scope (Spec_Id);
3814 -- Make sure that the subprogram is immediately visible. For
3815 -- child units that have no separate spec this is indispensable.
3816 -- Otherwise it is safe albeit redundant.
3818 Set_Is_Immediately_Visible (Spec_Id);
3821 Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id);
3822 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id));
3823 Set_Scope (Body_Id, Scope (Spec_Id));
3825 -- Case of subprogram body with no previous spec
3828 -- Check for style warning required
3832 -- Only apply check for source level subprograms for which checks
3833 -- have not been suppressed.
3835 and then Comes_From_Source (Body_Id)
3836 and then not Suppress_Style_Checks (Body_Id)
3838 -- No warnings within an instance
3840 and then not In_Instance
3842 -- No warnings for expression functions
3844 and then Nkind (Original_Node (N)) /= N_Expression_Function
3846 Style.Body_With_No_Spec (N);
3849 New_Overloaded_Entity (Body_Id);
3851 if Nkind (N) /= N_Subprogram_Body_Stub then
3852 Set_Acts_As_Spec (N);
3853 Generate_Definition (Body_Id);
3855 (Body_Id, Body_Id, 'b', Set_Ref => False, Force => True);
3857 -- If the body is an entry wrapper created for an entry with
3858 -- preconditions, it must be compiled in the context of the
3859 -- enclosing synchronized object, because it may mention other
3860 -- operations of the type.
3862 if Is_Entry_Wrapper (Body_Id) then
3864 Prot : constant Entity_Id := Etype (First_Entity (Body_Id));
3867 Install_Declarations (Prot);
3871 Install_Formals (Body_Id);
3873 Push_Scope (Body_Id);
3876 -- For stubs and bodies with no previous spec, generate references to
3879 Generate_Reference_To_Formals (Body_Id);
3882 -- Entry barrier functions are generated outside the protected type and
3883 -- should not carry the SPARK_Mode of the enclosing context.
3885 if Nkind (N) = N_Subprogram_Body
3886 and then Is_Entry_Barrier_Function (N)
3890 -- The body is generated as part of expression function expansion. When
3891 -- the expression function appears in the visible declarations of a
3892 -- package, the body is added to the private declarations. Since both
3893 -- declarative lists may be subject to a different SPARK_Mode, inherit
3894 -- the mode of the spec.
3896 -- package P with SPARK_Mode is
3897 -- function Expr_Func ... is (...); -- original
3898 -- [function Expr_Func ...;] -- generated spec
3901 -- pragma SPARK_Mode (Off);
3902 -- [function Expr_Func ... is return ...;] -- generated body
3903 -- end P; -- mode is ON
3905 elsif not Comes_From_Source (N)
3906 and then Present (Spec_Id)
3907 and then Is_Expression_Function (Spec_Id)
3909 Set_SPARK_Pragma (Body_Id, SPARK_Pragma (Spec_Id));
3910 Set_SPARK_Pragma_Inherited
3911 (Body_Id, SPARK_Pragma_Inherited (Spec_Id));
3913 -- Set the SPARK_Mode from the current context (may be overwritten later
3914 -- with explicit pragma). Exclude the case where the SPARK_Mode appears
3915 -- initially on a stand-alone subprogram body, but is then relocated to
3916 -- a generated corresponding spec. In this scenario the mode is shared
3917 -- between the spec and body.
3919 elsif No (SPARK_Pragma (Body_Id)) then
3920 Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma);
3921 Set_SPARK_Pragma_Inherited (Body_Id);
3924 -- A subprogram body may be instantiated or inlined at a later pass.
3925 -- Restore the state of Ignore_SPARK_Mode_Pragmas_In_Instance when it
3926 -- applied to the initial declaration of the body.
3928 if Present (Spec_Id) then
3929 if Ignore_SPARK_Mode_Pragmas (Spec_Id) then
3930 Ignore_SPARK_Mode_Pragmas_In_Instance := True;
3934 -- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in
3935 -- case the body is instantiated or inlined later and out of context.
3936 -- The body uses this attribute to restore the value of the global
3939 if Ignore_SPARK_Mode_Pragmas_In_Instance then
3940 Set_Ignore_SPARK_Mode_Pragmas (Body_Id);
3942 elsif Ignore_SPARK_Mode_Pragmas (Body_Id) then
3943 Ignore_SPARK_Mode_Pragmas_In_Instance := True;
3947 -- If this is the proper body of a stub, we must verify that the stub
3948 -- conforms to the body, and to the previous spec if one was present.
3949 -- We know already that the body conforms to that spec. This test is
3950 -- only required for subprograms that come from source.
3952 if Nkind (Parent (N)) = N_Subunit
3953 and then Comes_From_Source (N)
3954 and then not Error_Posted (Body_Id)
3955 and then Nkind (Corresponding_Stub (Parent (N))) =
3956 N_Subprogram_Body_Stub
3959 Old_Id : constant Entity_Id :=
3961 (Specification (Corresponding_Stub (Parent (N))));
3963 Conformant : Boolean := False;
3966 if No (Spec_Id) then
3967 Check_Fully_Conformant (Body_Id, Old_Id);
3971 (Body_Id, Old_Id, Fully_Conformant, False, Conformant);
3973 if not Conformant then
3975 -- The stub was taken to be a new declaration. Indicate that
3978 Set_Has_Completion (Old_Id, False);
3984 Set_Has_Completion (Body_Id);
3985 Check_Eliminated (Body_Id);
3987 -- Analyze any aspect specifications that appear on the subprogram body
3988 -- stub. Stop the analysis now as the stub does not have a declarative
3989 -- or a statement part, and it cannot be inlined.
3991 if Nkind (N) = N_Subprogram_Body_Stub then
3992 if Has_Aspects (N) then
3993 Analyze_Aspect_Specifications_On_Body_Or_Stub (N);
4001 -- Note: Normally we don't do any inlining if expansion is off, since
4002 -- we won't generate code in any case. An exception arises in GNATprove
4003 -- mode where we want to expand some calls in place, even with expansion
4004 -- disabled, since the inlining eases formal verification.
4006 if not GNATprove_Mode
4007 and then Expander_Active
4008 and then Serious_Errors_Detected = 0
4009 and then Present (Spec_Id)
4010 and then Has_Pragma_Inline (Spec_Id)
4012 -- Legacy implementation (relying on front-end inlining)
4014 if not Back_End_Inlining then
4015 if (Has_Pragma_Inline_Always (Spec_Id)
4016 and then not Opt.Disable_FE_Inline_Always)
4017 or else (Front_End_Inlining
4018 and then not Opt.Disable_FE_Inline)
4020 Build_Body_To_Inline (N, Spec_Id);
4023 -- New implementation (relying on back-end inlining)
4026 if Has_Pragma_Inline_Always (Spec_Id)
4027 or else Optimization_Level > 0
4029 -- Handle function returning an unconstrained type
4031 if Comes_From_Source (Body_Id)
4032 and then Ekind (Spec_Id) = E_Function
4033 and then Returns_Unconstrained_Type (Spec_Id)
4035 -- If function builds in place, i.e. returns a limited type,
4036 -- inlining cannot be done.
4038 and then not Is_Limited_Type (Etype (Spec_Id))
4040 Check_And_Split_Unconstrained_Function (N, Spec_Id, Body_Id);
4044 Subp_Body : constant Node_Id :=
4045 Unit_Declaration_Node (Body_Id);
4046 Subp_Decl : constant List_Id := Declarations (Subp_Body);
4049 -- Do not pass inlining to the backend if the subprogram
4050 -- has declarations or statements which cannot be inlined
4051 -- by the backend. This check is done here to emit an
4052 -- error instead of the generic warning message reported
4053 -- by the GCC backend (ie. "function might not be
4056 if Present (Subp_Decl)
4057 and then Has_Excluded_Declaration (Spec_Id, Subp_Decl)
4061 elsif Has_Excluded_Statement
4064 (Handled_Statement_Sequence (Subp_Body)))
4068 -- If the backend inlining is available then at this
4069 -- stage we only have to mark the subprogram as inlined.
4070 -- The expander will take care of registering it in the
4071 -- table of subprograms inlined by the backend a part of
4072 -- processing calls to it (cf. Expand_Call)
4075 Set_Is_Inlined (Spec_Id);
4082 -- In GNATprove mode, inline only when there is a separate subprogram
4083 -- declaration for now, as inlining of subprogram bodies acting as
4084 -- declarations, or subprogram stubs, are not supported by front-end
4085 -- inlining. This inlining should occur after analysis of the body, so
4086 -- that it is known whether the value of SPARK_Mode, which can be
4087 -- defined by a pragma inside the body, is applicable to the body.
4088 -- Inlining can be disabled with switch -gnatdm
4090 elsif GNATprove_Mode
4091 and then Full_Analysis
4092 and then not Inside_A_Generic
4093 and then Present (Spec_Id)
4095 Nkind (Unit_Declaration_Node (Spec_Id)) = N_Subprogram_Declaration
4096 and then Body_Has_SPARK_Mode_On
4097 and then Can_Be_Inlined_In_GNATprove_Mode (Spec_Id, Body_Id)
4098 and then not Body_Has_Contract
4099 and then not Debug_Flag_M
4101 Build_Body_To_Inline (N, Spec_Id);
4104 -- When generating code, inherited pre/postconditions are handled when
4105 -- expanding the corresponding contract.
4107 -- Ada 2005 (AI-262): In library subprogram bodies, after the analysis
4108 -- of the specification we have to install the private withed units.
4109 -- This holds for child units as well.
4111 if Is_Compilation_Unit (Body_Id)
4112 or else Nkind (Parent (N)) = N_Compilation_Unit
4114 Install_Private_With_Clauses (Body_Id);
4117 Check_Anonymous_Return;
4119 -- Set the Protected_Formal field of each extra formal of the protected
4120 -- subprogram to reference the corresponding extra formal of the
4121 -- subprogram that implements it. For regular formals this occurs when
4122 -- the protected subprogram's declaration is expanded, but the extra
4123 -- formals don't get created until the subprogram is frozen. We need to
4124 -- do this before analyzing the protected subprogram's body so that any
4125 -- references to the original subprogram's extra formals will be changed
4126 -- refer to the implementing subprogram's formals (see Expand_Formal).
4128 if Present (Spec_Id)
4129 and then Is_Protected_Type (Scope (Spec_Id))
4130 and then Present (Protected_Body_Subprogram (Spec_Id))
4133 Impl_Subp : constant Entity_Id :=
4134 Protected_Body_Subprogram (Spec_Id);
4135 Prot_Ext_Formal : Entity_Id := Extra_Formals (Spec_Id);
4136 Impl_Ext_Formal : Entity_Id := Extra_Formals (Impl_Subp);
4139 while Present (Prot_Ext_Formal) loop
4140 pragma Assert (Present (Impl_Ext_Formal));
4141 Set_Protected_Formal (Prot_Ext_Formal, Impl_Ext_Formal);
4142 Next_Formal_With_Extras (Prot_Ext_Formal);
4143 Next_Formal_With_Extras (Impl_Ext_Formal);
4148 -- Now we can go on to analyze the body
4150 HSS := Handled_Statement_Sequence (N);
4151 Set_Actual_Subtypes (N, Current_Scope);
4153 -- Add a declaration for the Protection object, renaming declarations
4154 -- for discriminals and privals and finally a declaration for the entry
4155 -- family index (if applicable). This form of early expansion is done
4156 -- when the Expander is active because Install_Private_Data_Declarations
4157 -- references entities which were created during regular expansion. The
4158 -- subprogram entity must come from source, and not be an internally
4159 -- generated subprogram.
4162 and then Present (Prot_Typ)
4163 and then Present (Spec_Id)
4164 and then Comes_From_Source (Spec_Id)
4165 and then not Is_Eliminated (Spec_Id)
4167 Install_Private_Data_Declarations
4168 (Sloc (N), Spec_Id, Prot_Typ, N, Declarations (N));
4171 -- Ada 2012 (AI05-0151): Incomplete types coming from a limited context
4172 -- may now appear in parameter and result profiles. Since the analysis
4173 -- of a subprogram body may use the parameter and result profile of the
4174 -- spec, swap any limited views with their non-limited counterpart.
4176 if Ada_Version >= Ada_2012 and then Present (Spec_Id) then
4177 Exch_Views := Exchange_Limited_Views (Spec_Id);
4180 -- If the return type is an anonymous access type whose designated type
4181 -- is the limited view of a class-wide type and the non-limited view is
4182 -- available, update the return type accordingly.
4184 if Ada_Version >= Ada_2005 and then Present (Spec_Id) then
4190 Rtyp := Etype (Spec_Id);
4192 if Ekind (Rtyp) = E_Anonymous_Access_Type then
4193 Etyp := Directly_Designated_Type (Rtyp);
4195 if Is_Class_Wide_Type (Etyp)
4196 and then From_Limited_With (Etyp)
4199 Set_Directly_Designated_Type (Rtyp, Available_View (Etyp));
4205 -- Analyze any aspect specifications that appear on the subprogram body
4207 if Has_Aspects (N) then
4208 Analyze_Aspect_Specifications_On_Body_Or_Stub (N);
4211 Analyze_Declarations (Declarations (N));
4213 -- Verify that the SPARK_Mode of the body agrees with that of its spec
4215 if Present (Spec_Id) and then Present (SPARK_Pragma (Body_Id)) then
4216 if Present (SPARK_Pragma (Spec_Id)) then
4217 if Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Spec_Id)) = Off
4219 Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Body_Id)) = On
4221 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id));
4222 Error_Msg_N ("incorrect application of SPARK_Mode#", N);
4223 Error_Msg_Sloc := Sloc (SPARK_Pragma (Spec_Id));
4225 ("\value Off was set for SPARK_Mode on & #", N, Spec_Id);
4228 elsif Nkind (Parent (Parent (Spec_Id))) = N_Subprogram_Body_Stub then
4232 Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id));
4233 Error_Msg_N ("incorrect application of SPARK_Mode #", N);
4234 Error_Msg_Sloc := Sloc (Spec_Id);
4236 ("\no value was set for SPARK_Mode on & #", N, Spec_Id);
4240 -- A subprogram body "freezes" its own contract. Analyze the contract
4241 -- after the declarations of the body have been processed as pragmas
4242 -- are now chained on the contract of the subprogram body.
4244 Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id);
4246 -- Check completion, and analyze the statements
4249 Inspect_Deferred_Constant_Completion (Declarations (N));
4252 -- Deal with end of scope processing for the body
4254 Process_End_Label (HSS, 't', Current_Scope);
4257 -- If we are compiling an entry wrapper, remove the enclosing
4258 -- synchronized object from the stack.
4260 if Is_Entry_Wrapper (Body_Id) then
4264 Check_Subprogram_Order (N);
4265 Set_Analyzed (Body_Id);
4267 -- If we have a separate spec, then the analysis of the declarations
4268 -- caused the entities in the body to be chained to the spec id, but
4269 -- we want them chained to the body id. Only the formal parameters
4270 -- end up chained to the spec id in this case.
4272 if Present (Spec_Id) then
4274 -- We must conform to the categorization of our spec
4276 Validate_Categorization_Dependency (N, Spec_Id);
4278 -- And if this is a child unit, the parent units must conform
4280 if Is_Child_Unit (Spec_Id) then
4281 Validate_Categorization_Dependency
4282 (Unit_Declaration_Node (Spec_Id), Spec_Id);
4285 -- Here is where we move entities from the spec to the body
4287 -- Case where there are entities that stay with the spec
4289 if Present (Last_Real_Spec_Entity) then
4291 -- No body entities (happens when the only real spec entities come
4292 -- from precondition and postcondition pragmas).
4294 if No (Last_Entity (Body_Id)) then
4295 Set_First_Entity (Body_Id, Next_Entity (Last_Real_Spec_Entity));
4297 -- Body entities present (formals), so chain stuff past them
4301 (Last_Entity (Body_Id), Next_Entity (Last_Real_Spec_Entity));
4304 Set_Next_Entity (Last_Real_Spec_Entity, Empty);
4305 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
4306 Set_Last_Entity (Spec_Id, Last_Real_Spec_Entity);
4308 -- Case where there are no spec entities, in this case there can be
4309 -- no body entities either, so just move everything.
4311 -- If the body is generated for an expression function, it may have
4312 -- been preanalyzed already, if 'access was applied to it.
4315 if Nkind (Original_Node (Unit_Declaration_Node (Spec_Id))) /=
4316 N_Expression_Function
4318 pragma Assert (No (Last_Entity (Body_Id)));
4322 Set_First_Entity (Body_Id, First_Entity (Spec_Id));
4323 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
4324 Set_First_Entity (Spec_Id, Empty);
4325 Set_Last_Entity (Spec_Id, Empty);
4329 Check_Missing_Return;
4331 -- Now we are going to check for variables that are never modified in
4332 -- the body of the procedure. But first we deal with a special case
4333 -- where we want to modify this check. If the body of the subprogram
4334 -- starts with a raise statement or its equivalent, or if the body
4335 -- consists entirely of a null statement, then it is pretty obvious that
4336 -- it is OK to not reference the parameters. For example, this might be
4337 -- the following common idiom for a stubbed function: statement of the
4338 -- procedure raises an exception. In particular this deals with the
4339 -- common idiom of a stubbed function, which appears something like:
4341 -- function F (A : Integer) return Some_Type;
4344 -- raise Program_Error;
4348 -- Here the purpose of X is simply to satisfy the annoying requirement
4349 -- in Ada that there be at least one return, and we certainly do not
4350 -- want to go posting warnings on X that it is not initialized. On
4351 -- the other hand, if X is entirely unreferenced that should still
4354 -- What we do is to detect these cases, and if we find them, flag the
4355 -- subprogram as being Is_Trivial_Subprogram and then use that flag to
4356 -- suppress unwanted warnings. For the case of the function stub above
4357 -- we have a special test to set X as apparently assigned to suppress
4364 -- Skip initial labels (for one thing this occurs when we are in
4365 -- front-end ZCX mode, but in any case it is irrelevant), and also
4366 -- initial Push_xxx_Error_Label nodes, which are also irrelevant.
4368 Stm := First (Statements (HSS));
4369 while Nkind (Stm) = N_Label
4370 or else Nkind (Stm) in N_Push_xxx_Label
4375 -- Do the test on the original statement before expansion
4378 Ostm : constant Node_Id := Original_Node (Stm);
4381 -- If explicit raise statement, turn on flag
4383 if Nkind (Ostm) = N_Raise_Statement then
4384 Set_Trivial_Subprogram (Stm);
4386 -- If null statement, and no following statements, turn on flag
4388 elsif Nkind (Stm) = N_Null_Statement
4389 and then Comes_From_Source (Stm)
4390 and then No (Next (Stm))
4392 Set_Trivial_Subprogram (Stm);
4394 -- Check for explicit call cases which likely raise an exception
4396 elsif Nkind (Ostm) = N_Procedure_Call_Statement then
4397 if Is_Entity_Name (Name (Ostm)) then
4399 Ent : constant Entity_Id := Entity (Name (Ostm));
4402 -- If the procedure is marked No_Return, then likely it
4403 -- raises an exception, but in any case it is not coming
4404 -- back here, so turn on the flag.
4407 and then Ekind (Ent) = E_Procedure
4408 and then No_Return (Ent)
4410 Set_Trivial_Subprogram (Stm);
4418 -- Check for variables that are never modified
4425 -- If there is a separate spec, then transfer Never_Set_In_Source
4426 -- flags from out parameters to the corresponding entities in the
4427 -- body. The reason we do that is we want to post error flags on
4428 -- the body entities, not the spec entities.
4430 if Present (Spec_Id) then
4431 E1 := First_Entity (Spec_Id);
4432 while Present (E1) loop
4433 if Ekind (E1) = E_Out_Parameter then
4434 E2 := First_Entity (Body_Id);
4435 while Present (E2) loop
4436 exit when Chars (E1) = Chars (E2);
4440 if Present (E2) then
4441 Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1));
4449 -- Check references in body
4451 Check_References (Body_Id);
4454 -- Check for nested subprogram, and mark outer level subprogram if so
4460 if Present (Spec_Id) then
4467 Ent := Enclosing_Subprogram (Ent);
4468 exit when No (Ent) or else Is_Subprogram (Ent);
4471 if Present (Ent) then
4472 Set_Has_Nested_Subprogram (Ent);
4476 -- Restore the limited views in the spec, if any, to let the back end
4477 -- process it without running into circularities.
4479 if Exch_Views /= No_Elist then
4480 Restore_Limited_Views (Exch_Views);
4483 if Present (Desig_View) then
4484 Set_Directly_Designated_Type (Etype (Spec_Id), Desig_View);
4488 Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP;
4489 Restore_Ghost_Mode (Saved_GM);
4490 end Analyze_Subprogram_Body_Helper;
4492 ------------------------------------
4493 -- Analyze_Subprogram_Declaration --
4494 ------------------------------------
4496 procedure Analyze_Subprogram_Declaration (N : Node_Id) is
4497 Scop : constant Entity_Id := Current_Scope;
4498 Designator : Entity_Id;
4500 Is_Completion : Boolean;
4501 -- Indicates whether a null procedure declaration is a completion
4504 -- Null procedures are not allowed in SPARK
4506 if Nkind (Specification (N)) = N_Procedure_Specification
4507 and then Null_Present (Specification (N))
4509 Check_SPARK_05_Restriction ("null procedure is not allowed", N);
4511 -- Null procedures are allowed in protected types, following the
4512 -- recent AI12-0147.
4514 if Is_Protected_Type (Current_Scope)
4515 and then Ada_Version < Ada_2012
4517 Error_Msg_N ("protected operation cannot be a null procedure", N);
4520 Analyze_Null_Procedure (N, Is_Completion);
4522 -- The null procedure acts as a body, nothing further is needed
4524 if Is_Completion then
4529 Designator := Analyze_Subprogram_Specification (Specification (N));
4531 -- A reference may already have been generated for the unit name, in
4532 -- which case the following call is redundant. However it is needed for
4533 -- declarations that are the rewriting of an expression function.
4535 Generate_Definition (Designator);
4537 -- Set the SPARK mode from the current context (may be overwritten later
4538 -- with explicit pragma). This is not done for entry barrier functions
4539 -- because they are generated outside the protected type and should not
4540 -- carry the mode of the enclosing context.
4542 if Nkind (N) = N_Subprogram_Declaration
4543 and then Is_Entry_Barrier_Function (N)
4547 Set_SPARK_Pragma (Designator, SPARK_Mode_Pragma);
4548 Set_SPARK_Pragma_Inherited (Designator);
4551 -- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in case
4552 -- the body of this subprogram is instantiated or inlined later and out
4553 -- of context. The body uses this attribute to restore the value of the
4556 if Ignore_SPARK_Mode_Pragmas_In_Instance then
4557 Set_Ignore_SPARK_Mode_Pragmas (Designator);
4560 if Debug_Flag_C then
4561 Write_Str ("==> subprogram spec ");
4562 Write_Name (Chars (Designator));
4563 Write_Str (" from ");
4564 Write_Location (Sloc (N));
4569 Validate_RCI_Subprogram_Declaration (N);
4570 New_Overloaded_Entity (Designator);
4571 Check_Delayed_Subprogram (Designator);
4573 -- If the type of the first formal of the current subprogram is a non-
4574 -- generic tagged private type, mark the subprogram as being a private
4575 -- primitive. Ditto if this is a function with controlling result, and
4576 -- the return type is currently private. In both cases, the type of the
4577 -- controlling argument or result must be in the current scope for the
4578 -- operation to be primitive.
4580 if Has_Controlling_Result (Designator)
4581 and then Is_Private_Type (Etype (Designator))
4582 and then Scope (Etype (Designator)) = Current_Scope
4583 and then not Is_Generic_Actual_Type (Etype (Designator))
4585 Set_Is_Private_Primitive (Designator);
4587 elsif Present (First_Formal (Designator)) then
4589 Formal_Typ : constant Entity_Id :=
4590 Etype (First_Formal (Designator));
4592 Set_Is_Private_Primitive (Designator,
4593 Is_Tagged_Type (Formal_Typ)
4594 and then Scope (Formal_Typ) = Current_Scope
4595 and then Is_Private_Type (Formal_Typ)
4596 and then not Is_Generic_Actual_Type (Formal_Typ));
4600 -- Ada 2005 (AI-251): Abstract interface primitives must be abstract
4603 if Ada_Version >= Ada_2005
4604 and then Comes_From_Source (N)
4605 and then Is_Dispatching_Operation (Designator)
4612 if Has_Controlling_Result (Designator) then
4613 Etyp := Etype (Designator);
4616 E := First_Entity (Designator);
4618 and then Is_Formal (E)
4619 and then not Is_Controlling_Formal (E)
4627 if Is_Access_Type (Etyp) then
4628 Etyp := Directly_Designated_Type (Etyp);
4631 if Is_Interface (Etyp)
4632 and then not Is_Abstract_Subprogram (Designator)
4633 and then not (Ekind (Designator) = E_Procedure
4634 and then Null_Present (Specification (N)))
4636 Error_Msg_Name_1 := Chars (Defining_Entity (N));
4638 -- Specialize error message based on procedures vs. functions,
4639 -- since functions can't be null subprograms.
4641 if Ekind (Designator) = E_Procedure then
4643 ("interface procedure % must be abstract or null", N);
4646 ("interface function % must be abstract", N);
4652 -- What is the following code for, it used to be
4654 -- ??? Set_Suppress_Elaboration_Checks
4655 -- ??? (Designator, Elaboration_Checks_Suppressed (Designator));
4657 -- The following seems equivalent, but a bit dubious
4659 if Elaboration_Checks_Suppressed (Designator) then
4660 Set_Kill_Elaboration_Checks (Designator);
4663 if Scop /= Standard_Standard and then not Is_Child_Unit (Designator) then
4664 Set_Categorization_From_Scope (Designator, Scop);
4667 -- For a compilation unit, check for library-unit pragmas
4669 Push_Scope (Designator);
4670 Set_Categorization_From_Pragmas (N);
4671 Validate_Categorization_Dependency (N, Designator);
4675 -- For a compilation unit, set body required. This flag will only be
4676 -- reset if a valid Import or Interface pragma is processed later on.
4678 if Nkind (Parent (N)) = N_Compilation_Unit then
4679 Set_Body_Required (Parent (N), True);
4681 if Ada_Version >= Ada_2005
4682 and then Nkind (Specification (N)) = N_Procedure_Specification
4683 and then Null_Present (Specification (N))
4686 ("null procedure cannot be declared at library level", N);
4690 Generate_Reference_To_Formals (Designator);
4691 Check_Eliminated (Designator);
4693 if Debug_Flag_C then
4695 Write_Str ("<== subprogram spec ");
4696 Write_Name (Chars (Designator));
4697 Write_Str (" from ");
4698 Write_Location (Sloc (N));
4702 if Is_Protected_Type (Current_Scope) then
4704 -- Indicate that this is a protected operation, because it may be
4705 -- used in subsequent declarations within the protected type.
4707 Set_Convention (Designator, Convention_Protected);
4710 List_Inherited_Pre_Post_Aspects (Designator);
4712 if Has_Aspects (N) then
4713 Analyze_Aspect_Specifications (N, Designator);
4715 end Analyze_Subprogram_Declaration;
4717 --------------------------------------
4718 -- Analyze_Subprogram_Specification --
4719 --------------------------------------
4721 -- Reminder: N here really is a subprogram specification (not a subprogram
4722 -- declaration). This procedure is called to analyze the specification in
4723 -- both subprogram bodies and subprogram declarations (specs).
4725 function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is
4726 function Is_Invariant_Procedure_Or_Body (E : Entity_Id) return Boolean;
4727 -- Determine whether entity E denotes the spec or body of an invariant
4730 ------------------------------------
4731 -- Is_Invariant_Procedure_Or_Body --
4732 ------------------------------------
4734 function Is_Invariant_Procedure_Or_Body (E : Entity_Id) return Boolean is
4735 Decl : constant Node_Id := Unit_Declaration_Node (E);
4739 if Nkind (Decl) = N_Subprogram_Body then
4740 Spec := Corresponding_Spec (Decl);
4747 and then Ekind (Spec) = E_Procedure
4748 and then (Is_Partial_Invariant_Procedure (Spec)
4749 or else Is_Invariant_Procedure (Spec));
4750 end Is_Invariant_Procedure_Or_Body;
4754 Designator : constant Entity_Id := Defining_Entity (N);
4755 Formals : constant List_Id := Parameter_Specifications (N);
4757 -- Start of processing for Analyze_Subprogram_Specification
4760 -- User-defined operator is not allowed in SPARK, except as a renaming
4762 if Nkind (Defining_Unit_Name (N)) = N_Defining_Operator_Symbol
4763 and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
4765 Check_SPARK_05_Restriction
4766 ("user-defined operator is not allowed", N);
4769 -- Proceed with analysis. Do not emit a cross-reference entry if the
4770 -- specification comes from an expression function, because it may be
4771 -- the completion of a previous declaration. It is not, the cross-
4772 -- reference entry will be emitted for the new subprogram declaration.
4774 if Nkind (Parent (N)) /= N_Expression_Function then
4775 Generate_Definition (Designator);
4778 if Nkind (N) = N_Function_Specification then
4779 Set_Ekind (Designator, E_Function);
4780 Set_Mechanism (Designator, Default_Mechanism);
4782 Set_Ekind (Designator, E_Procedure);
4783 Set_Etype (Designator, Standard_Void_Type);
4786 -- Flag Is_Inlined_Always is True by default, and reversed to False for
4787 -- those subprograms which could be inlined in GNATprove mode (because
4788 -- Body_To_Inline is non-Empty) but should not be inlined.
4790 if GNATprove_Mode then
4791 Set_Is_Inlined_Always (Designator);
4794 -- Introduce new scope for analysis of the formals and the return type
4796 Set_Scope (Designator, Current_Scope);
4798 if Present (Formals) then
4799 Push_Scope (Designator);
4800 Process_Formals (Formals, N);
4802 -- Check dimensions in N for formals with default expression
4804 Analyze_Dimension_Formals (N, Formals);
4806 -- Ada 2005 (AI-345): If this is an overriding operation of an
4807 -- inherited interface operation, and the controlling type is
4808 -- a synchronized type, replace the type with its corresponding
4809 -- record, to match the proper signature of an overriding operation.
4810 -- Same processing for an access parameter whose designated type is
4811 -- derived from a synchronized interface.
4813 -- This modification is not done for invariant procedures because
4814 -- the corresponding record may not necessarely be visible when the
4815 -- concurrent type acts as the full view of a private type.
4818 -- type Prot is private with Type_Invariant => ...;
4819 -- procedure ConcInvariant (Obj : Prot);
4821 -- protected type Prot is ...;
4822 -- type Concurrent_Record_Prot is record ...;
4823 -- procedure ConcInvariant (Obj : Prot) is
4825 -- end ConcInvariant;
4828 -- In the example above, both the spec and body of the invariant
4829 -- procedure must utilize the private type as the controlling type.
4831 if Ada_Version >= Ada_2005
4832 and then not Is_Invariant_Procedure_Or_Body (Designator)
4836 Formal_Typ : Entity_Id;
4837 Rec_Typ : Entity_Id;
4838 Desig_Typ : Entity_Id;
4841 Formal := First_Formal (Designator);
4842 while Present (Formal) loop
4843 Formal_Typ := Etype (Formal);
4845 if Is_Concurrent_Type (Formal_Typ)
4846 and then Present (Corresponding_Record_Type (Formal_Typ))
4848 Rec_Typ := Corresponding_Record_Type (Formal_Typ);
4850 if Present (Interfaces (Rec_Typ)) then
4851 Set_Etype (Formal, Rec_Typ);
4854 elsif Ekind (Formal_Typ) = E_Anonymous_Access_Type then
4855 Desig_Typ := Designated_Type (Formal_Typ);
4857 if Is_Concurrent_Type (Desig_Typ)
4858 and then Present (Corresponding_Record_Type (Desig_Typ))
4860 Rec_Typ := Corresponding_Record_Type (Desig_Typ);
4862 if Present (Interfaces (Rec_Typ)) then
4863 Set_Directly_Designated_Type (Formal_Typ, Rec_Typ);
4868 Next_Formal (Formal);
4875 -- The subprogram scope is pushed and popped around the processing of
4876 -- the return type for consistency with call above to Process_Formals
4877 -- (which itself can call Analyze_Return_Type), and to ensure that any
4878 -- itype created for the return type will be associated with the proper
4881 elsif Nkind (N) = N_Function_Specification then
4882 Push_Scope (Designator);
4883 Analyze_Return_Type (N);
4889 if Nkind (N) = N_Function_Specification then
4891 -- Deal with operator symbol case
4893 if Nkind (Designator) = N_Defining_Operator_Symbol then
4894 Valid_Operator_Definition (Designator);
4897 May_Need_Actuals (Designator);
4899 -- Ada 2005 (AI-251): If the return type is abstract, verify that
4900 -- the subprogram is abstract also. This does not apply to renaming
4901 -- declarations, where abstractness is inherited, and to subprogram
4902 -- bodies generated for stream operations, which become renamings as
4905 -- In case of primitives associated with abstract interface types
4906 -- the check is applied later (see Analyze_Subprogram_Declaration).
4908 if not Nkind_In (Original_Node (Parent (N)),
4909 N_Abstract_Subprogram_Declaration,
4910 N_Formal_Abstract_Subprogram_Declaration,
4911 N_Subprogram_Renaming_Declaration)
4913 if Is_Abstract_Type (Etype (Designator))
4914 and then not Is_Interface (Etype (Designator))
4917 ("function that returns abstract type must be abstract", N);
4919 -- Ada 2012 (AI-0073): Extend this test to subprograms with an
4920 -- access result whose designated type is abstract.
4922 elsif Ada_Version >= Ada_2012
4923 and then Nkind (Result_Definition (N)) = N_Access_Definition
4925 not Is_Class_Wide_Type (Designated_Type (Etype (Designator)))
4926 and then Is_Abstract_Type (Designated_Type (Etype (Designator)))
4929 ("function whose access result designates abstract type "
4930 & "must be abstract", N);
4936 end Analyze_Subprogram_Specification;
4938 -----------------------
4939 -- Check_Conformance --
4940 -----------------------
4942 procedure Check_Conformance
4943 (New_Id : Entity_Id;
4945 Ctype : Conformance_Type;
4947 Conforms : out Boolean;
4948 Err_Loc : Node_Id := Empty;
4949 Get_Inst : Boolean := False;
4950 Skip_Controlling_Formals : Boolean := False)
4952 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id);
4953 -- Sets Conforms to False. If Errmsg is False, then that's all it does.
4954 -- If Errmsg is True, then processing continues to post an error message
4955 -- for conformance error on given node. Two messages are output. The
4956 -- first message points to the previous declaration with a general "no
4957 -- conformance" message. The second is the detailed reason, supplied as
4958 -- Msg. The parameter N provide information for a possible & insertion
4959 -- in the message, and also provides the location for posting the
4960 -- message in the absence of a specified Err_Loc location.
4962 function Conventions_Match
4964 Id2 : Entity_Id) return Boolean;
4965 -- Determine whether the conventions of arbitrary entities Id1 and Id2
4968 -----------------------
4969 -- Conformance_Error --
4970 -----------------------
4972 procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is
4979 if No (Err_Loc) then
4985 Error_Msg_Sloc := Sloc (Old_Id);
4988 when Type_Conformant =>
4989 Error_Msg_N -- CODEFIX
4990 ("not type conformant with declaration#!", Enode);
4992 when Mode_Conformant =>
4993 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
4995 ("not mode conformant with operation inherited#!",
4999 ("not mode conformant with declaration#!", Enode);
5002 when Subtype_Conformant =>
5003 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
5005 ("not subtype conformant with operation inherited#!",
5009 ("not subtype conformant with declaration#!", Enode);
5012 when Fully_Conformant =>
5013 if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
5014 Error_Msg_N -- CODEFIX
5015 ("not fully conformant with operation inherited#!",
5018 Error_Msg_N -- CODEFIX
5019 ("not fully conformant with declaration#!", Enode);
5023 Error_Msg_NE (Msg, Enode, N);
5025 end Conformance_Error;
5027 -----------------------
5028 -- Conventions_Match --
5029 -----------------------
5031 function Conventions_Match
5033 Id2 : Entity_Id) return Boolean
5036 -- Ignore the conventions of anonymous access-to-subprogram types
5037 -- and subprogram types because these are internally generated and
5038 -- the only way these may receive a convention is if they inherit
5039 -- the convention of a related subprogram.
5041 if Ekind_In (Id1, E_Anonymous_Access_Subprogram_Type,
5044 Ekind_In (Id2, E_Anonymous_Access_Subprogram_Type,
5049 -- Otherwise compare the conventions directly
5052 return Convention (Id1) = Convention (Id2);
5054 end Conventions_Match;
5058 Old_Type : constant Entity_Id := Etype (Old_Id);
5059 New_Type : constant Entity_Id := Etype (New_Id);
5060 Old_Formal : Entity_Id;
5061 New_Formal : Entity_Id;
5062 Access_Types_Match : Boolean;
5063 Old_Formal_Base : Entity_Id;
5064 New_Formal_Base : Entity_Id;
5066 -- Start of processing for Check_Conformance
5071 -- We need a special case for operators, since they don't appear
5074 if Ctype = Type_Conformant then
5075 if Ekind (New_Id) = E_Operator
5076 and then Operator_Matches_Spec (New_Id, Old_Id)
5082 -- If both are functions/operators, check return types conform
5084 if Old_Type /= Standard_Void_Type
5086 New_Type /= Standard_Void_Type
5088 -- If we are checking interface conformance we omit controlling
5089 -- arguments and result, because we are only checking the conformance
5090 -- of the remaining parameters.
5092 if Has_Controlling_Result (Old_Id)
5093 and then Has_Controlling_Result (New_Id)
5094 and then Skip_Controlling_Formals
5098 elsif not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then
5099 if Ctype >= Subtype_Conformant
5100 and then not Predicates_Match (Old_Type, New_Type)
5103 ("\predicate of return type does not match!", New_Id);
5106 ("\return type does not match!", New_Id);
5112 -- Ada 2005 (AI-231): In case of anonymous access types check the
5113 -- null-exclusion and access-to-constant attributes match.
5115 if Ada_Version >= Ada_2005
5116 and then Ekind (Etype (Old_Type)) = E_Anonymous_Access_Type
5118 (Can_Never_Be_Null (Old_Type) /= Can_Never_Be_Null (New_Type)
5119 or else Is_Access_Constant (Etype (Old_Type)) /=
5120 Is_Access_Constant (Etype (New_Type)))
5122 Conformance_Error ("\return type does not match!", New_Id);
5126 -- If either is a function/operator and the other isn't, error
5128 elsif Old_Type /= Standard_Void_Type
5129 or else New_Type /= Standard_Void_Type
5131 Conformance_Error ("\functions can only match functions!", New_Id);
5135 -- In subtype conformant case, conventions must match (RM 6.3.1(16)).
5136 -- If this is a renaming as body, refine error message to indicate that
5137 -- the conflict is with the original declaration. If the entity is not
5138 -- frozen, the conventions don't have to match, the one of the renamed
5139 -- entity is inherited.
5141 if Ctype >= Subtype_Conformant then
5142 if not Conventions_Match (Old_Id, New_Id) then
5143 if not Is_Frozen (New_Id) then
5146 elsif Present (Err_Loc)
5147 and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration
5148 and then Present (Corresponding_Spec (Err_Loc))
5150 Error_Msg_Name_1 := Chars (New_Id);
5152 Name_Ada + Convention_Id'Pos (Convention (New_Id));
5153 Conformance_Error ("\prior declaration for% has convention %!");
5156 Conformance_Error ("\calling conventions do not match!");
5161 elsif Is_Formal_Subprogram (Old_Id)
5162 or else Is_Formal_Subprogram (New_Id)
5164 Conformance_Error ("\formal subprograms not allowed!");
5169 -- Deal with parameters
5171 -- Note: we use the entity information, rather than going directly
5172 -- to the specification in the tree. This is not only simpler, but
5173 -- absolutely necessary for some cases of conformance tests between
5174 -- operators, where the declaration tree simply does not exist.
5176 Old_Formal := First_Formal (Old_Id);
5177 New_Formal := First_Formal (New_Id);
5178 while Present (Old_Formal) and then Present (New_Formal) loop
5179 if Is_Controlling_Formal (Old_Formal)
5180 and then Is_Controlling_Formal (New_Formal)
5181 and then Skip_Controlling_Formals
5183 -- The controlling formals will have different types when
5184 -- comparing an interface operation with its match, but both
5185 -- or neither must be access parameters.
5187 if Is_Access_Type (Etype (Old_Formal))
5189 Is_Access_Type (Etype (New_Formal))
5191 goto Skip_Controlling_Formal;
5194 ("\access parameter does not match!", New_Formal);
5198 -- Ada 2012: Mode conformance also requires that formal parameters
5199 -- be both aliased, or neither.
5201 if Ctype >= Mode_Conformant and then Ada_Version >= Ada_2012 then
5202 if Is_Aliased (Old_Formal) /= Is_Aliased (New_Formal) then
5204 ("\aliased parameter mismatch!", New_Formal);
5208 if Ctype = Fully_Conformant then
5210 -- Names must match. Error message is more accurate if we do
5211 -- this before checking that the types of the formals match.
5213 if Chars (Old_Formal) /= Chars (New_Formal) then
5214 Conformance_Error ("\name& does not match!", New_Formal);
5216 -- Set error posted flag on new formal as well to stop
5217 -- junk cascaded messages in some cases.
5219 Set_Error_Posted (New_Formal);
5223 -- Null exclusion must match
5225 if Null_Exclusion_Present (Parent (Old_Formal))
5227 Null_Exclusion_Present (Parent (New_Formal))
5229 -- Only give error if both come from source. This should be
5230 -- investigated some time, since it should not be needed ???
5232 if Comes_From_Source (Old_Formal)
5234 Comes_From_Source (New_Formal)
5237 ("\null exclusion for& does not match", New_Formal);
5239 -- Mark error posted on the new formal to avoid duplicated
5240 -- complaint about types not matching.
5242 Set_Error_Posted (New_Formal);
5247 -- Ada 2005 (AI-423): Possible access [sub]type and itype match. This
5248 -- case occurs whenever a subprogram is being renamed and one of its
5249 -- parameters imposes a null exclusion. For example:
5251 -- type T is null record;
5252 -- type Acc_T is access T;
5253 -- subtype Acc_T_Sub is Acc_T;
5255 -- procedure P (Obj : not null Acc_T_Sub); -- itype
5256 -- procedure Ren_P (Obj : Acc_T_Sub) -- subtype
5259 Old_Formal_Base := Etype (Old_Formal);
5260 New_Formal_Base := Etype (New_Formal);
5263 Old_Formal_Base := Get_Instance_Of (Old_Formal_Base);
5264 New_Formal_Base := Get_Instance_Of (New_Formal_Base);
5267 Access_Types_Match := Ada_Version >= Ada_2005
5269 -- Ensure that this rule is only applied when New_Id is a
5270 -- renaming of Old_Id.
5272 and then Nkind (Parent (Parent (New_Id))) =
5273 N_Subprogram_Renaming_Declaration
5274 and then Nkind (Name (Parent (Parent (New_Id)))) in N_Has_Entity
5275 and then Present (Entity (Name (Parent (Parent (New_Id)))))
5276 and then Entity (Name (Parent (Parent (New_Id)))) = Old_Id
5278 -- Now handle the allowed access-type case
5280 and then Is_Access_Type (Old_Formal_Base)
5281 and then Is_Access_Type (New_Formal_Base)
5283 -- The type kinds must match. The only exception occurs with
5284 -- multiple generics of the form:
5287 -- type F is private; type A is private;
5288 -- type F_Ptr is access F; type A_Ptr is access A;
5289 -- with proc F_P (X : F_Ptr); with proc A_P (X : A_Ptr);
5290 -- package F_Pack is ... package A_Pack is
5291 -- package F_Inst is
5292 -- new F_Pack (A, A_Ptr, A_P);
5294 -- When checking for conformance between the parameters of A_P
5295 -- and F_P, the type kinds of F_Ptr and A_Ptr will not match
5296 -- because the compiler has transformed A_Ptr into a subtype of
5297 -- F_Ptr. We catch this case in the code below.
5299 and then (Ekind (Old_Formal_Base) = Ekind (New_Formal_Base)
5301 (Is_Generic_Type (Old_Formal_Base)
5302 and then Is_Generic_Type (New_Formal_Base)
5303 and then Is_Internal (New_Formal_Base)
5304 and then Etype (Etype (New_Formal_Base)) =
5306 and then Directly_Designated_Type (Old_Formal_Base) =
5307 Directly_Designated_Type (New_Formal_Base)
5308 and then ((Is_Itype (Old_Formal_Base)
5309 and then Can_Never_Be_Null (Old_Formal_Base))
5311 (Is_Itype (New_Formal_Base)
5312 and then Can_Never_Be_Null (New_Formal_Base)));
5314 -- Types must always match. In the visible part of an instance,
5315 -- usual overloading rules for dispatching operations apply, and
5316 -- we check base types (not the actual subtypes).
5318 if In_Instance_Visible_Part
5319 and then Is_Dispatching_Operation (New_Id)
5321 if not Conforming_Types
5322 (T1 => Base_Type (Etype (Old_Formal)),
5323 T2 => Base_Type (Etype (New_Formal)),
5325 Get_Inst => Get_Inst)
5326 and then not Access_Types_Match
5328 Conformance_Error ("\type of & does not match!", New_Formal);
5332 elsif not Conforming_Types
5333 (T1 => Old_Formal_Base,
5334 T2 => New_Formal_Base,
5336 Get_Inst => Get_Inst)
5337 and then not Access_Types_Match
5339 -- Don't give error message if old type is Any_Type. This test
5340 -- avoids some cascaded errors, e.g. in case of a bad spec.
5342 if Errmsg and then Old_Formal_Base = Any_Type then
5345 if Ctype >= Subtype_Conformant
5347 not Predicates_Match (Old_Formal_Base, New_Formal_Base)
5350 ("\predicate of & does not match!", New_Formal);
5353 ("\type of & does not match!", New_Formal);
5355 if not Dimensions_Match (Old_Formal_Base, New_Formal_Base)
5357 Error_Msg_N ("\dimensions mismatch!", New_Formal);
5365 -- For mode conformance, mode must match
5367 if Ctype >= Mode_Conformant then
5368 if Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) then
5369 if not Ekind_In (New_Id, E_Function, E_Procedure)
5370 or else not Is_Primitive_Wrapper (New_Id)
5372 Conformance_Error ("\mode of & does not match!", New_Formal);
5376 T : constant Entity_Id := Find_Dispatching_Type (New_Id);
5378 if Is_Protected_Type (Corresponding_Concurrent_Type (T))
5380 Error_Msg_PT (New_Id, Ultimate_Alias (Old_Id));
5383 ("\mode of & does not match!", New_Formal);
5390 -- Part of mode conformance for access types is having the same
5391 -- constant modifier.
5393 elsif Access_Types_Match
5394 and then Is_Access_Constant (Old_Formal_Base) /=
5395 Is_Access_Constant (New_Formal_Base)
5398 ("\constant modifier does not match!", New_Formal);
5403 if Ctype >= Subtype_Conformant then
5405 -- Ada 2005 (AI-231): In case of anonymous access types check
5406 -- the null-exclusion and access-to-constant attributes must
5407 -- match. For null exclusion, we test the types rather than the
5408 -- formals themselves, since the attribute is only set reliably
5409 -- on the formals in the Ada 95 case, and we exclude the case
5410 -- where Old_Formal is marked as controlling, to avoid errors
5411 -- when matching completing bodies with dispatching declarations
5412 -- (access formals in the bodies aren't marked Can_Never_Be_Null).
5414 if Ada_Version >= Ada_2005
5415 and then Ekind (Etype (Old_Formal)) = E_Anonymous_Access_Type
5416 and then Ekind (Etype (New_Formal)) = E_Anonymous_Access_Type
5418 ((Can_Never_Be_Null (Etype (Old_Formal)) /=
5419 Can_Never_Be_Null (Etype (New_Formal))
5421 not Is_Controlling_Formal (Old_Formal))
5423 Is_Access_Constant (Etype (Old_Formal)) /=
5424 Is_Access_Constant (Etype (New_Formal)))
5426 -- Do not complain if error already posted on New_Formal. This
5427 -- avoids some redundant error messages.
5429 and then not Error_Posted (New_Formal)
5431 -- It is allowed to omit the null-exclusion in case of stream
5432 -- attribute subprograms. We recognize stream subprograms
5433 -- through their TSS-generated suffix.
5436 TSS_Name : constant TSS_Name_Type := Get_TSS_Name (New_Id);
5439 if TSS_Name /= TSS_Stream_Read
5440 and then TSS_Name /= TSS_Stream_Write
5441 and then TSS_Name /= TSS_Stream_Input
5442 and then TSS_Name /= TSS_Stream_Output
5444 -- Here we have a definite conformance error. It is worth
5445 -- special casing the error message for the case of a
5446 -- controlling formal (which excludes null).
5448 if Is_Controlling_Formal (New_Formal) then
5449 Error_Msg_Node_2 := Scope (New_Formal);
5451 ("\controlling formal & of & excludes null, "
5452 & "declaration must exclude null as well",
5455 -- Normal case (couldn't we give more detail here???)
5459 ("\type of & does not match!", New_Formal);
5468 -- Full conformance checks
5470 if Ctype = Fully_Conformant then
5472 -- We have checked already that names match
5474 if Parameter_Mode (Old_Formal) = E_In_Parameter then
5476 -- Check default expressions for in parameters
5479 NewD : constant Boolean :=
5480 Present (Default_Value (New_Formal));
5481 OldD : constant Boolean :=
5482 Present (Default_Value (Old_Formal));
5484 if NewD or OldD then
5486 -- The old default value has been analyzed because the
5487 -- current full declaration will have frozen everything
5488 -- before. The new default value has not been analyzed,
5489 -- so analyze it now before we check for conformance.
5492 Push_Scope (New_Id);
5493 Preanalyze_Spec_Expression
5494 (Default_Value (New_Formal), Etype (New_Formal));
5498 if not (NewD and OldD)
5499 or else not Fully_Conformant_Expressions
5500 (Default_Value (Old_Formal),
5501 Default_Value (New_Formal))
5504 ("\default expression for & does not match!",
5513 -- A couple of special checks for Ada 83 mode. These checks are
5514 -- skipped if either entity is an operator in package Standard,
5515 -- or if either old or new instance is not from the source program.
5517 if Ada_Version = Ada_83
5518 and then Sloc (Old_Id) > Standard_Location
5519 and then Sloc (New_Id) > Standard_Location
5520 and then Comes_From_Source (Old_Id)
5521 and then Comes_From_Source (New_Id)
5524 Old_Param : constant Node_Id := Declaration_Node (Old_Formal);
5525 New_Param : constant Node_Id := Declaration_Node (New_Formal);
5528 -- Explicit IN must be present or absent in both cases. This
5529 -- test is required only in the full conformance case.
5531 if In_Present (Old_Param) /= In_Present (New_Param)
5532 and then Ctype = Fully_Conformant
5535 ("\(Ada 83) IN must appear in both declarations",
5540 -- Grouping (use of comma in param lists) must be the same
5541 -- This is where we catch a misconformance like:
5544 -- A : Integer; B : Integer
5546 -- which are represented identically in the tree except
5547 -- for the setting of the flags More_Ids and Prev_Ids.
5549 if More_Ids (Old_Param) /= More_Ids (New_Param)
5550 or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param)
5553 ("\grouping of & does not match!", New_Formal);
5559 -- This label is required when skipping controlling formals
5561 <<Skip_Controlling_Formal>>
5563 Next_Formal (Old_Formal);
5564 Next_Formal (New_Formal);
5567 if Present (Old_Formal) then
5568 Conformance_Error ("\too few parameters!");
5571 elsif Present (New_Formal) then
5572 Conformance_Error ("\too many parameters!", New_Formal);
5575 end Check_Conformance;
5577 -----------------------
5578 -- Check_Conventions --
5579 -----------------------
5581 procedure Check_Conventions (Typ : Entity_Id) is
5582 Ifaces_List : Elist_Id;
5584 procedure Check_Convention (Op : Entity_Id);
5585 -- Verify that the convention of inherited dispatching operation Op is
5586 -- consistent among all subprograms it overrides. In order to minimize
5587 -- the search, Search_From is utilized to designate a specific point in
5588 -- the list rather than iterating over the whole list once more.
5590 ----------------------
5591 -- Check_Convention --
5592 ----------------------
5594 procedure Check_Convention (Op : Entity_Id) is
5595 Op_Conv : constant Convention_Id := Convention (Op);
5596 Iface_Conv : Convention_Id;
5597 Iface_Elmt : Elmt_Id;
5598 Iface_Prim_Elmt : Elmt_Id;
5599 Iface_Prim : Entity_Id;
5602 Iface_Elmt := First_Elmt (Ifaces_List);
5603 while Present (Iface_Elmt) loop
5605 First_Elmt (Primitive_Operations (Node (Iface_Elmt)));
5606 while Present (Iface_Prim_Elmt) loop
5607 Iface_Prim := Node (Iface_Prim_Elmt);
5608 Iface_Conv := Convention (Iface_Prim);
5610 if Is_Interface_Conformant (Typ, Iface_Prim, Op)
5611 and then Iface_Conv /= Op_Conv
5614 ("inconsistent conventions in primitive operations", Typ);
5616 Error_Msg_Name_1 := Chars (Op);
5617 Error_Msg_Name_2 := Get_Convention_Name (Op_Conv);
5618 Error_Msg_Sloc := Sloc (Op);
5620 if Comes_From_Source (Op) or else No (Alias (Op)) then
5621 if not Present (Overridden_Operation (Op)) then
5622 Error_Msg_N ("\\primitive % defined #", Typ);
5625 ("\\overriding operation % with "
5626 & "convention % defined #", Typ);
5629 else pragma Assert (Present (Alias (Op)));
5630 Error_Msg_Sloc := Sloc (Alias (Op));
5631 Error_Msg_N ("\\inherited operation % with "
5632 & "convention % defined #", Typ);
5635 Error_Msg_Name_1 := Chars (Op);
5636 Error_Msg_Name_2 := Get_Convention_Name (Iface_Conv);
5637 Error_Msg_Sloc := Sloc (Iface_Prim);
5638 Error_Msg_N ("\\overridden operation % with "
5639 & "convention % defined #", Typ);
5641 -- Avoid cascading errors
5646 Next_Elmt (Iface_Prim_Elmt);
5649 Next_Elmt (Iface_Elmt);
5651 end Check_Convention;
5655 Prim_Op : Entity_Id;
5656 Prim_Op_Elmt : Elmt_Id;
5658 -- Start of processing for Check_Conventions
5661 if not Has_Interfaces (Typ) then
5665 Collect_Interfaces (Typ, Ifaces_List);
5667 -- The algorithm checks every overriding dispatching operation against
5668 -- all the corresponding overridden dispatching operations, detecting
5669 -- differences in conventions.
5671 Prim_Op_Elmt := First_Elmt (Primitive_Operations (Typ));
5672 while Present (Prim_Op_Elmt) loop
5673 Prim_Op := Node (Prim_Op_Elmt);
5675 -- A small optimization: skip the predefined dispatching operations
5676 -- since they always have the same convention.
5678 if not Is_Predefined_Dispatching_Operation (Prim_Op) then
5679 Check_Convention (Prim_Op);
5682 Next_Elmt (Prim_Op_Elmt);
5684 end Check_Conventions;
5686 ------------------------------
5687 -- Check_Delayed_Subprogram --
5688 ------------------------------
5690 procedure Check_Delayed_Subprogram (Designator : Entity_Id) is
5693 procedure Possible_Freeze (T : Entity_Id);
5694 -- T is the type of either a formal parameter or of the return type.
5695 -- If T is not yet frozen and needs a delayed freeze, then the
5696 -- subprogram itself must be delayed.
5698 ---------------------
5699 -- Possible_Freeze --
5700 ---------------------
5702 procedure Possible_Freeze (T : Entity_Id) is
5704 if Has_Delayed_Freeze (T) and then not Is_Frozen (T) then
5705 Set_Has_Delayed_Freeze (Designator);
5707 elsif Is_Access_Type (T)
5708 and then Has_Delayed_Freeze (Designated_Type (T))
5709 and then not Is_Frozen (Designated_Type (T))
5711 Set_Has_Delayed_Freeze (Designator);
5714 end Possible_Freeze;
5716 -- Start of processing for Check_Delayed_Subprogram
5719 -- All subprograms, including abstract subprograms, may need a freeze
5720 -- node if some formal type or the return type needs one.
5722 Possible_Freeze (Etype (Designator));
5723 Possible_Freeze (Base_Type (Etype (Designator))); -- needed ???
5725 -- Need delayed freeze if any of the formal types themselves need
5726 -- a delayed freeze and are not yet frozen.
5728 F := First_Formal (Designator);
5729 while Present (F) loop
5730 Possible_Freeze (Etype (F));
5731 Possible_Freeze (Base_Type (Etype (F))); -- needed ???
5735 -- Mark functions that return by reference. Note that it cannot be
5736 -- done for delayed_freeze subprograms because the underlying
5737 -- returned type may not be known yet (for private types)
5739 if not Has_Delayed_Freeze (Designator) and then Expander_Active then
5741 Typ : constant Entity_Id := Etype (Designator);
5742 Utyp : constant Entity_Id := Underlying_Type (Typ);
5744 if Is_Limited_View (Typ) then
5745 Set_Returns_By_Ref (Designator);
5746 elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
5747 Set_Returns_By_Ref (Designator);
5751 end Check_Delayed_Subprogram;
5753 ------------------------------------
5754 -- Check_Discriminant_Conformance --
5755 ------------------------------------
5757 procedure Check_Discriminant_Conformance
5762 Old_Discr : Entity_Id := First_Discriminant (Prev);
5763 New_Discr : Node_Id := First (Discriminant_Specifications (N));
5764 New_Discr_Id : Entity_Id;
5765 New_Discr_Type : Entity_Id;
5767 procedure Conformance_Error (Msg : String; N : Node_Id);
5768 -- Post error message for conformance error on given node. Two messages
5769 -- are output. The first points to the previous declaration with a
5770 -- general "no conformance" message. The second is the detailed reason,
5771 -- supplied as Msg. The parameter N provide information for a possible
5772 -- & insertion in the message.
5774 -----------------------
5775 -- Conformance_Error --
5776 -----------------------
5778 procedure Conformance_Error (Msg : String; N : Node_Id) is
5780 Error_Msg_Sloc := Sloc (Prev_Loc);
5781 Error_Msg_N -- CODEFIX
5782 ("not fully conformant with declaration#!", N);
5783 Error_Msg_NE (Msg, N, N);
5784 end Conformance_Error;
5786 -- Start of processing for Check_Discriminant_Conformance
5789 while Present (Old_Discr) and then Present (New_Discr) loop
5790 New_Discr_Id := Defining_Identifier (New_Discr);
5792 -- The subtype mark of the discriminant on the full type has not
5793 -- been analyzed so we do it here. For an access discriminant a new
5796 if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then
5798 Access_Definition (N, Discriminant_Type (New_Discr));
5801 Analyze (Discriminant_Type (New_Discr));
5802 New_Discr_Type := Etype (Discriminant_Type (New_Discr));
5804 -- Ada 2005: if the discriminant definition carries a null
5805 -- exclusion, create an itype to check properly for consistency
5806 -- with partial declaration.
5808 if Is_Access_Type (New_Discr_Type)
5809 and then Null_Exclusion_Present (New_Discr)
5812 Create_Null_Excluding_Itype
5813 (T => New_Discr_Type,
5814 Related_Nod => New_Discr,
5815 Scope_Id => Current_Scope);
5819 if not Conforming_Types
5820 (Etype (Old_Discr), New_Discr_Type, Fully_Conformant)
5822 Conformance_Error ("type of & does not match!", New_Discr_Id);
5825 -- Treat the new discriminant as an occurrence of the old one,
5826 -- for navigation purposes, and fill in some semantic
5827 -- information, for completeness.
5829 Generate_Reference (Old_Discr, New_Discr_Id, 'r');
5830 Set_Etype (New_Discr_Id, Etype (Old_Discr));
5831 Set_Scope (New_Discr_Id, Scope (Old_Discr));
5836 if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then
5837 Conformance_Error ("name & does not match!", New_Discr_Id);
5841 -- Default expressions must match
5844 NewD : constant Boolean :=
5845 Present (Expression (New_Discr));
5846 OldD : constant Boolean :=
5847 Present (Expression (Parent (Old_Discr)));
5850 if NewD or OldD then
5852 -- The old default value has been analyzed and expanded,
5853 -- because the current full declaration will have frozen
5854 -- everything before. The new default values have not been
5855 -- expanded, so expand now to check conformance.
5858 Preanalyze_Spec_Expression
5859 (Expression (New_Discr), New_Discr_Type);
5862 if not (NewD and OldD)
5863 or else not Fully_Conformant_Expressions
5864 (Expression (Parent (Old_Discr)),
5865 Expression (New_Discr))
5869 ("default expression for & does not match!",
5876 -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
5878 if Ada_Version = Ada_83 then
5880 Old_Disc : constant Node_Id := Declaration_Node (Old_Discr);
5883 -- Grouping (use of comma in param lists) must be the same
5884 -- This is where we catch a misconformance like:
5887 -- A : Integer; B : Integer
5889 -- which are represented identically in the tree except
5890 -- for the setting of the flags More_Ids and Prev_Ids.
5892 if More_Ids (Old_Disc) /= More_Ids (New_Discr)
5893 or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr)
5896 ("grouping of & does not match!", New_Discr_Id);
5902 Next_Discriminant (Old_Discr);
5906 if Present (Old_Discr) then
5907 Conformance_Error ("too few discriminants!", Defining_Identifier (N));
5910 elsif Present (New_Discr) then
5912 ("too many discriminants!", Defining_Identifier (New_Discr));
5915 end Check_Discriminant_Conformance;
5917 ----------------------------
5918 -- Check_Fully_Conformant --
5919 ----------------------------
5921 procedure Check_Fully_Conformant
5922 (New_Id : Entity_Id;
5924 Err_Loc : Node_Id := Empty)
5927 pragma Warnings (Off, Result);
5930 (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc);
5931 end Check_Fully_Conformant;
5933 --------------------------
5934 -- Check_Limited_Return --
5935 --------------------------
5937 procedure Check_Limited_Return
5943 -- Ada 2005 (AI-318-02): Return-by-reference types have been removed and
5944 -- replaced by anonymous access results. This is an incompatibility with
5945 -- Ada 95. Not clear whether this should be enforced yet or perhaps
5946 -- controllable with special switch. ???
5948 -- A limited interface that is not immutably limited is OK
5950 if Is_Limited_Interface (R_Type)
5952 not (Is_Task_Interface (R_Type)
5953 or else Is_Protected_Interface (R_Type)
5954 or else Is_Synchronized_Interface (R_Type))
5958 elsif Is_Limited_Type (R_Type)
5959 and then not Is_Interface (R_Type)
5960 and then Comes_From_Source (N)
5961 and then not In_Instance_Body
5962 and then not OK_For_Limited_Init_In_05 (R_Type, Expr)
5964 -- Error in Ada 2005
5966 if Ada_Version >= Ada_2005
5967 and then not Debug_Flag_Dot_L
5968 and then not GNAT_Mode
5971 ("(Ada 2005) cannot copy object of a limited type "
5972 & "(RM-2005 6.5(5.5/2))", Expr);
5974 if Is_Limited_View (R_Type) then
5976 ("\return by reference not permitted in Ada 2005", Expr);
5979 -- Warn in Ada 95 mode, to give folks a heads up about this
5982 -- In GNAT mode, this is just a warning, to allow it to be evilly
5983 -- turned off. Otherwise it is a real error.
5985 -- In a generic context, simplify the warning because it makes no
5986 -- sense to discuss pass-by-reference or copy.
5988 elsif Warn_On_Ada_2005_Compatibility or GNAT_Mode then
5989 if Inside_A_Generic then
5991 ("return of limited object not permitted in Ada 2005 "
5992 & "(RM-2005 6.5(5.5/2))?y?", Expr);
5994 elsif Is_Limited_View (R_Type) then
5996 ("return by reference not permitted in Ada 2005 "
5997 & "(RM-2005 6.5(5.5/2))?y?", Expr);
6000 ("cannot copy object of a limited type in Ada 2005 "
6001 & "(RM-2005 6.5(5.5/2))?y?", Expr);
6004 -- Ada 95 mode, and compatibility warnings disabled
6007 pragma Assert (Ada_Version <= Ada_95);
6008 pragma Assert (not (Warn_On_Ada_2005_Compatibility or GNAT_Mode));
6009 return; -- skip continuation messages below
6012 if not Inside_A_Generic then
6014 ("\consider switching to return of access type", Expr);
6015 Explain_Limited_Type (R_Type, Expr);
6018 end Check_Limited_Return;
6020 ---------------------------
6021 -- Check_Mode_Conformant --
6022 ---------------------------
6024 procedure Check_Mode_Conformant
6025 (New_Id : Entity_Id;
6027 Err_Loc : Node_Id := Empty;
6028 Get_Inst : Boolean := False)
6031 pragma Warnings (Off, Result);
6034 (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst);
6035 end Check_Mode_Conformant;
6037 --------------------------------
6038 -- Check_Overriding_Indicator --
6039 --------------------------------
6041 procedure Check_Overriding_Indicator
6043 Overridden_Subp : Entity_Id;
6044 Is_Primitive : Boolean)
6050 -- No overriding indicator for literals
6052 if Ekind (Subp) = E_Enumeration_Literal then
6055 elsif Ekind (Subp) = E_Entry then
6056 Decl := Parent (Subp);
6058 -- No point in analyzing a malformed operator
6060 elsif Nkind (Subp) = N_Defining_Operator_Symbol
6061 and then Error_Posted (Subp)
6066 Decl := Unit_Declaration_Node (Subp);
6069 if Nkind_In (Decl, N_Subprogram_Body,
6070 N_Subprogram_Body_Stub,
6071 N_Subprogram_Declaration,
6072 N_Abstract_Subprogram_Declaration,
6073 N_Subprogram_Renaming_Declaration)
6075 Spec := Specification (Decl);
6077 elsif Nkind (Decl) = N_Entry_Declaration then
6084 -- The overriding operation is type conformant with the overridden one,
6085 -- but the names of the formals are not required to match. If the names
6086 -- appear permuted in the overriding operation, this is a possible
6087 -- source of confusion that is worth diagnosing. Controlling formals
6088 -- often carry names that reflect the type, and it is not worthwhile
6089 -- requiring that their names match.
6091 if Present (Overridden_Subp)
6092 and then Nkind (Subp) /= N_Defining_Operator_Symbol
6099 Form1 := First_Formal (Subp);
6100 Form2 := First_Formal (Overridden_Subp);
6102 -- If the overriding operation is a synchronized operation, skip
6103 -- the first parameter of the overridden operation, which is
6104 -- implicit in the new one. If the operation is declared in the
6105 -- body it is not primitive and all formals must match.
6107 if Is_Concurrent_Type (Scope (Subp))
6108 and then Is_Tagged_Type (Scope (Subp))
6109 and then not Has_Completion (Scope (Subp))
6111 Form2 := Next_Formal (Form2);
6114 if Present (Form1) then
6115 Form1 := Next_Formal (Form1);
6116 Form2 := Next_Formal (Form2);
6119 while Present (Form1) loop
6120 if not Is_Controlling_Formal (Form1)
6121 and then Present (Next_Formal (Form2))
6122 and then Chars (Form1) = Chars (Next_Formal (Form2))
6124 Error_Msg_Node_2 := Alias (Overridden_Subp);
6125 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
6127 ("& does not match corresponding formal of&#",
6132 Next_Formal (Form1);
6133 Next_Formal (Form2);
6138 -- If there is an overridden subprogram, then check that there is no
6139 -- "not overriding" indicator, and mark the subprogram as overriding.
6140 -- This is not done if the overridden subprogram is marked as hidden,
6141 -- which can occur for the case of inherited controlled operations
6142 -- (see Derive_Subprogram), unless the inherited subprogram's parent
6143 -- subprogram is not itself hidden. (Note: This condition could probably
6144 -- be simplified, leaving out the testing for the specific controlled
6145 -- cases, but it seems safer and clearer this way, and echoes similar
6146 -- special-case tests of this kind in other places.)
6148 if Present (Overridden_Subp)
6149 and then (not Is_Hidden (Overridden_Subp)
6151 (Nam_In (Chars (Overridden_Subp), Name_Initialize,
6154 and then Present (Alias (Overridden_Subp))
6155 and then not Is_Hidden (Alias (Overridden_Subp))))
6157 if Must_Not_Override (Spec) then
6158 Error_Msg_Sloc := Sloc (Overridden_Subp);
6160 if Ekind (Subp) = E_Entry then
6162 ("entry & overrides inherited operation #", Spec, Subp);
6165 ("subprogram & overrides inherited operation #", Spec, Subp);
6168 -- Special-case to fix a GNAT oddity: Limited_Controlled is declared
6169 -- as an extension of Root_Controlled, and thus has a useless Adjust
6170 -- operation. This operation should not be inherited by other limited
6171 -- controlled types. An explicit Adjust for them is not overriding.
6173 elsif Must_Override (Spec)
6174 and then Chars (Overridden_Subp) = Name_Adjust
6175 and then Is_Limited_Type (Etype (First_Formal (Subp)))
6176 and then Present (Alias (Overridden_Subp))
6177 and then In_Predefined_Unit (Alias (Overridden_Subp))
6180 (Unit_File_Name (Get_Source_Unit (Alias (Overridden_Subp))));
6181 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
6183 elsif Is_Subprogram (Subp) then
6184 if Is_Init_Proc (Subp) then
6187 elsif No (Overridden_Operation (Subp)) then
6189 -- For entities generated by Derive_Subprograms the overridden
6190 -- operation is the inherited primitive (which is available
6191 -- through the attribute alias)
6193 if (Is_Dispatching_Operation (Subp)
6194 or else Is_Dispatching_Operation (Overridden_Subp))
6195 and then not Comes_From_Source (Overridden_Subp)
6196 and then Find_Dispatching_Type (Overridden_Subp) =
6197 Find_Dispatching_Type (Subp)
6198 and then Present (Alias (Overridden_Subp))
6199 and then Comes_From_Source (Alias (Overridden_Subp))
6201 Set_Overridden_Operation (Subp, Alias (Overridden_Subp));
6202 Inherit_Subprogram_Contract (Subp, Alias (Overridden_Subp));
6205 Set_Overridden_Operation (Subp, Overridden_Subp);
6206 Inherit_Subprogram_Contract (Subp, Overridden_Subp);
6211 -- If primitive flag is set or this is a protected operation, then
6212 -- the operation is overriding at the point of its declaration, so
6213 -- warn if necessary. Otherwise it may have been declared before the
6214 -- operation it overrides and no check is required.
6217 and then not Must_Override (Spec)
6218 and then (Is_Primitive
6219 or else Ekind (Scope (Subp)) = E_Protected_Type)
6221 Style.Missing_Overriding (Decl, Subp);
6224 -- If Subp is an operator, it may override a predefined operation, if
6225 -- it is defined in the same scope as the type to which it applies.
6226 -- In that case Overridden_Subp is empty because of our implicit
6227 -- representation for predefined operators. We have to check whether the
6228 -- signature of Subp matches that of a predefined operator. Note that
6229 -- first argument provides the name of the operator, and the second
6230 -- argument the signature that may match that of a standard operation.
6231 -- If the indicator is overriding, then the operator must match a
6232 -- predefined signature, because we know already that there is no
6233 -- explicit overridden operation.
6235 elsif Nkind (Subp) = N_Defining_Operator_Symbol then
6236 if Must_Not_Override (Spec) then
6238 -- If this is not a primitive or a protected subprogram, then
6239 -- "not overriding" is illegal.
6242 and then Ekind (Scope (Subp)) /= E_Protected_Type
6244 Error_Msg_N ("overriding indicator only allowed "
6245 & "if subprogram is primitive", Subp);
6247 elsif Can_Override_Operator (Subp) then
6249 ("subprogram& overrides predefined operator ", Spec, Subp);
6252 elsif Must_Override (Spec) then
6253 if No (Overridden_Operation (Subp))
6254 and then not Can_Override_Operator (Subp)
6256 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
6259 elsif not Error_Posted (Subp)
6260 and then Style_Check
6261 and then Can_Override_Operator (Subp)
6262 and then not In_Predefined_Unit (Subp)
6264 -- If style checks are enabled, indicate that the indicator is
6265 -- missing. However, at the point of declaration, the type of
6266 -- which this is a primitive operation may be private, in which
6267 -- case the indicator would be premature.
6269 if Has_Private_Declaration (Etype (Subp))
6270 or else Has_Private_Declaration (Etype (First_Formal (Subp)))
6274 Style.Missing_Overriding (Decl, Subp);
6278 elsif Must_Override (Spec) then
6279 if Ekind (Subp) = E_Entry then
6280 Error_Msg_NE ("entry & is not overriding", Spec, Subp);
6282 Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
6285 -- If the operation is marked "not overriding" and it's not primitive
6286 -- then an error is issued, unless this is an operation of a task or
6287 -- protected type (RM05-8.3.1(3/2-4/2)). Error cases where "overriding"
6288 -- has been specified have already been checked above.
6290 elsif Must_Not_Override (Spec)
6291 and then not Is_Primitive
6292 and then Ekind (Subp) /= E_Entry
6293 and then Ekind (Scope (Subp)) /= E_Protected_Type
6296 ("overriding indicator only allowed if subprogram is primitive",
6300 end Check_Overriding_Indicator;
6306 -- Note: this procedure needs to know far too much about how the expander
6307 -- messes with exceptions. The use of the flag Exception_Junk and the
6308 -- incorporation of knowledge of Exp_Ch11.Expand_Local_Exception_Handlers
6309 -- works, but is not very clean. It would be better if the expansion
6310 -- routines would leave Original_Node working nicely, and we could use
6311 -- Original_Node here to ignore all the peculiar expander messing ???
6313 procedure Check_Returns
6317 Proc : Entity_Id := Empty)
6321 procedure Check_Statement_Sequence (L : List_Id);
6322 -- Internal recursive procedure to check a list of statements for proper
6323 -- termination by a return statement (or a transfer of control or a
6324 -- compound statement that is itself internally properly terminated).
6326 ------------------------------
6327 -- Check_Statement_Sequence --
6328 ------------------------------
6330 procedure Check_Statement_Sequence (L : List_Id) is
6335 function Assert_False return Boolean;
6336 -- Returns True if Last_Stm is a pragma Assert (False) that has been
6337 -- rewritten as a null statement when assertions are off. The assert
6338 -- is not active, but it is still enough to kill the warning.
6344 function Assert_False return Boolean is
6345 Orig : constant Node_Id := Original_Node (Last_Stm);
6348 if Nkind (Orig) = N_Pragma
6349 and then Pragma_Name (Orig) = Name_Assert
6350 and then not Error_Posted (Orig)
6353 Arg : constant Node_Id :=
6354 First (Pragma_Argument_Associations (Orig));
6355 Exp : constant Node_Id := Expression (Arg);
6357 return Nkind (Exp) = N_Identifier
6358 and then Chars (Exp) = Name_False;
6368 Raise_Exception_Call : Boolean;
6369 -- Set True if statement sequence terminated by Raise_Exception call
6370 -- or a Reraise_Occurrence call.
6372 -- Start of processing for Check_Statement_Sequence
6375 Raise_Exception_Call := False;
6377 -- Get last real statement
6379 Last_Stm := Last (L);
6381 -- Deal with digging out exception handler statement sequences that
6382 -- have been transformed by the local raise to goto optimization.
6383 -- See Exp_Ch11.Expand_Local_Exception_Handlers for details. If this
6384 -- optimization has occurred, we are looking at something like:
6387 -- original stmts in block
6391 -- goto L1; | omitted if No_Exception_Propagation
6396 -- goto L3; -- skip handler when exception not raised
6398 -- <<L1>> -- target label for local exception
6412 -- and what we have to do is to dig out the estmts1 and estmts2
6413 -- sequences (which were the original sequences of statements in
6414 -- the exception handlers) and check them.
6416 if Nkind (Last_Stm) = N_Label and then Exception_Junk (Last_Stm) then
6421 exit when Nkind (Stm) /= N_Block_Statement;
6422 exit when not Exception_Junk (Stm);
6425 exit when Nkind (Stm) /= N_Label;
6426 exit when not Exception_Junk (Stm);
6427 Check_Statement_Sequence
6428 (Statements (Handled_Statement_Sequence (Next (Stm))));
6433 exit when Nkind (Stm) /= N_Goto_Statement;
6434 exit when not Exception_Junk (Stm);
6438 -- Don't count pragmas
6440 while Nkind (Last_Stm) = N_Pragma
6442 -- Don't count call to SS_Release (can happen after Raise_Exception)
6445 (Nkind (Last_Stm) = N_Procedure_Call_Statement
6447 Nkind (Name (Last_Stm)) = N_Identifier
6449 Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release))
6451 -- Don't count exception junk
6454 (Nkind_In (Last_Stm, N_Goto_Statement,
6456 N_Object_Declaration)
6457 and then Exception_Junk (Last_Stm))
6458 or else Nkind (Last_Stm) in N_Push_xxx_Label
6459 or else Nkind (Last_Stm) in N_Pop_xxx_Label
6461 -- Inserted code, such as finalization calls, is irrelevant: we only
6462 -- need to check original source.
6464 or else Is_Rewrite_Insertion (Last_Stm)
6469 -- Here we have the "real" last statement
6471 Kind := Nkind (Last_Stm);
6473 -- Transfer of control, OK. Note that in the No_Return procedure
6474 -- case, we already diagnosed any explicit return statements, so
6475 -- we can treat them as OK in this context.
6477 if Is_Transfer (Last_Stm) then
6480 -- Check cases of explicit non-indirect procedure calls
6482 elsif Kind = N_Procedure_Call_Statement
6483 and then Is_Entity_Name (Name (Last_Stm))
6485 -- Check call to Raise_Exception procedure which is treated
6486 -- specially, as is a call to Reraise_Occurrence.
6488 -- We suppress the warning in these cases since it is likely that
6489 -- the programmer really does not expect to deal with the case
6490 -- of Null_Occurrence, and thus would find a warning about a
6491 -- missing return curious, and raising Program_Error does not
6492 -- seem such a bad behavior if this does occur.
6494 -- Note that in the Ada 2005 case for Raise_Exception, the actual
6495 -- behavior will be to raise Constraint_Error (see AI-329).
6497 if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception)
6499 Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence)
6501 Raise_Exception_Call := True;
6503 -- For Raise_Exception call, test first argument, if it is
6504 -- an attribute reference for a 'Identity call, then we know
6505 -- that the call cannot possibly return.
6508 Arg : constant Node_Id :=
6509 Original_Node (First_Actual (Last_Stm));
6511 if Nkind (Arg) = N_Attribute_Reference
6512 and then Attribute_Name (Arg) = Name_Identity
6519 -- If statement, need to look inside if there is an else and check
6520 -- each constituent statement sequence for proper termination.
6522 elsif Kind = N_If_Statement
6523 and then Present (Else_Statements (Last_Stm))
6525 Check_Statement_Sequence (Then_Statements (Last_Stm));
6526 Check_Statement_Sequence (Else_Statements (Last_Stm));
6528 if Present (Elsif_Parts (Last_Stm)) then
6530 Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm));
6533 while Present (Elsif_Part) loop
6534 Check_Statement_Sequence (Then_Statements (Elsif_Part));
6542 -- Case statement, check each case for proper termination
6544 elsif Kind = N_Case_Statement then
6548 Case_Alt := First_Non_Pragma (Alternatives (Last_Stm));
6549 while Present (Case_Alt) loop
6550 Check_Statement_Sequence (Statements (Case_Alt));
6551 Next_Non_Pragma (Case_Alt);
6557 -- Block statement, check its handled sequence of statements
6559 elsif Kind = N_Block_Statement then
6565 (Handled_Statement_Sequence (Last_Stm), Mode, Err1);
6574 -- Loop statement. If there is an iteration scheme, we can definitely
6575 -- fall out of the loop. Similarly if there is an exit statement, we
6576 -- can fall out. In either case we need a following return.
6578 elsif Kind = N_Loop_Statement then
6579 if Present (Iteration_Scheme (Last_Stm))
6580 or else Has_Exit (Entity (Identifier (Last_Stm)))
6584 -- A loop with no exit statement or iteration scheme is either
6585 -- an infinite loop, or it has some other exit (raise/return).
6586 -- In either case, no warning is required.
6592 -- Timed entry call, check entry call and delay alternatives
6594 -- Note: in expanded code, the timed entry call has been converted
6595 -- to a set of expanded statements on which the check will work
6596 -- correctly in any case.
6598 elsif Kind = N_Timed_Entry_Call then
6600 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
6601 DCA : constant Node_Id := Delay_Alternative (Last_Stm);
6604 -- If statement sequence of entry call alternative is missing,
6605 -- then we can definitely fall through, and we post the error
6606 -- message on the entry call alternative itself.
6608 if No (Statements (ECA)) then
6611 -- If statement sequence of delay alternative is missing, then
6612 -- we can definitely fall through, and we post the error
6613 -- message on the delay alternative itself.
6615 -- Note: if both ECA and DCA are missing the return, then we
6616 -- post only one message, should be enough to fix the bugs.
6617 -- If not we will get a message next time on the DCA when the
6620 elsif No (Statements (DCA)) then
6623 -- Else check both statement sequences
6626 Check_Statement_Sequence (Statements (ECA));
6627 Check_Statement_Sequence (Statements (DCA));
6632 -- Conditional entry call, check entry call and else part
6634 -- Note: in expanded code, the conditional entry call has been
6635 -- converted to a set of expanded statements on which the check
6636 -- will work correctly in any case.
6638 elsif Kind = N_Conditional_Entry_Call then
6640 ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
6643 -- If statement sequence of entry call alternative is missing,
6644 -- then we can definitely fall through, and we post the error
6645 -- message on the entry call alternative itself.
6647 if No (Statements (ECA)) then
6650 -- Else check statement sequence and else part
6653 Check_Statement_Sequence (Statements (ECA));
6654 Check_Statement_Sequence (Else_Statements (Last_Stm));
6660 -- If we fall through, issue appropriate message
6664 -- Kill warning if last statement is a raise exception call,
6665 -- or a pragma Assert (False). Note that with assertions enabled,
6666 -- such a pragma has been converted into a raise exception call
6667 -- already, so the Assert_False is for the assertions off case.
6669 if not Raise_Exception_Call and then not Assert_False then
6671 -- In GNATprove mode, it is an error to have a missing return
6673 Error_Msg_Warn := SPARK_Mode /= On;
6675 -- Issue error message or warning
6678 ("RETURN statement missing following this statement<<!",
6681 ("\Program_Error ]<<!", Last_Stm);
6684 -- Note: we set Err even though we have not issued a warning
6685 -- because we still have a case of a missing return. This is
6686 -- an extremely marginal case, probably will never be noticed
6687 -- but we might as well get it right.
6691 -- Otherwise we have the case of a procedure marked No_Return
6694 if not Raise_Exception_Call then
6695 if GNATprove_Mode then
6697 ("implied return after this statement "
6698 & "would have raised Program_Error", Last_Stm);
6701 ("implied return after this statement "
6702 & "will raise Program_Error??", Last_Stm);
6705 Error_Msg_Warn := SPARK_Mode /= On;
6707 ("\procedure & is marked as No_Return<<!", Last_Stm, Proc);
6711 RE : constant Node_Id :=
6712 Make_Raise_Program_Error (Sloc (Last_Stm),
6713 Reason => PE_Implicit_Return);
6715 Insert_After (Last_Stm, RE);
6719 end Check_Statement_Sequence;
6721 -- Start of processing for Check_Returns
6725 Check_Statement_Sequence (Statements (HSS));
6727 if Present (Exception_Handlers (HSS)) then
6728 Handler := First_Non_Pragma (Exception_Handlers (HSS));
6729 while Present (Handler) loop
6730 Check_Statement_Sequence (Statements (Handler));
6731 Next_Non_Pragma (Handler);
6736 ----------------------------
6737 -- Check_Subprogram_Order --
6738 ----------------------------
6740 procedure Check_Subprogram_Order (N : Node_Id) is
6742 function Subprogram_Name_Greater (S1, S2 : String) return Boolean;
6743 -- This is used to check if S1 > S2 in the sense required by this test,
6744 -- for example nameab < namec, but name2 < name10.
6746 -----------------------------
6747 -- Subprogram_Name_Greater --
6748 -----------------------------
6750 function Subprogram_Name_Greater (S1, S2 : String) return Boolean is
6755 -- Deal with special case where names are identical except for a
6756 -- numerical suffix. These are handled specially, taking the numeric
6757 -- ordering from the suffix into account.
6760 while S1 (L1) in '0' .. '9' loop
6765 while S2 (L2) in '0' .. '9' loop
6769 -- If non-numeric parts non-equal, do straight compare
6771 if S1 (S1'First .. L1) /= S2 (S2'First .. L2) then
6774 -- If non-numeric parts equal, compare suffixed numeric parts. Note
6775 -- that a missing suffix is treated as numeric zero in this test.
6779 while L1 < S1'Last loop
6781 N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0');
6785 while L2 < S2'Last loop
6787 N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0');
6792 end Subprogram_Name_Greater;
6794 -- Start of processing for Check_Subprogram_Order
6797 -- Check body in alpha order if this is option
6800 and then Style_Check_Order_Subprograms
6801 and then Nkind (N) = N_Subprogram_Body
6802 and then Comes_From_Source (N)
6803 and then In_Extended_Main_Source_Unit (N)
6807 renames Scope_Stack.Table
6808 (Scope_Stack.Last).Last_Subprogram_Name;
6810 Body_Id : constant Entity_Id :=
6811 Defining_Entity (Specification (N));
6814 Get_Decoded_Name_String (Chars (Body_Id));
6817 if Subprogram_Name_Greater
6818 (LSN.all, Name_Buffer (1 .. Name_Len))
6820 Style.Subprogram_Not_In_Alpha_Order (Body_Id);
6826 LSN := new String'(Name_Buffer (1 .. Name_Len));
6829 end Check_Subprogram_Order;
6831 ------------------------------
6832 -- Check_Subtype_Conformant --
6833 ------------------------------
6835 procedure Check_Subtype_Conformant
6836 (New_Id : Entity_Id;
6838 Err_Loc : Node_Id := Empty;
6839 Skip_Controlling_Formals : Boolean := False;
6840 Get_Inst : Boolean := False)
6843 pragma Warnings (Off, Result);
6846 (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc,
6847 Skip_Controlling_Formals => Skip_Controlling_Formals,
6848 Get_Inst => Get_Inst);
6849 end Check_Subtype_Conformant;
6851 -----------------------------------
6852 -- Check_Synchronized_Overriding --
6853 -----------------------------------
6855 procedure Check_Synchronized_Overriding
6856 (Def_Id : Entity_Id;
6857 Overridden_Subp : out Entity_Id)
6859 Ifaces_List : Elist_Id;
6863 function Matches_Prefixed_View_Profile
6864 (Prim_Params : List_Id;
6865 Iface_Params : List_Id) return Boolean;
6866 -- Determine whether a subprogram's parameter profile Prim_Params
6867 -- matches that of a potentially overridden interface subprogram
6868 -- Iface_Params. Also determine if the type of first parameter of
6869 -- Iface_Params is an implemented interface.
6871 -----------------------------------
6872 -- Matches_Prefixed_View_Profile --
6873 -----------------------------------
6875 function Matches_Prefixed_View_Profile
6876 (Prim_Params : List_Id;
6877 Iface_Params : List_Id) return Boolean
6879 function Is_Implemented
6880 (Ifaces_List : Elist_Id;
6881 Iface : Entity_Id) return Boolean;
6882 -- Determine if Iface is implemented by the current task or
6885 --------------------
6886 -- Is_Implemented --
6887 --------------------
6889 function Is_Implemented
6890 (Ifaces_List : Elist_Id;
6891 Iface : Entity_Id) return Boolean
6893 Iface_Elmt : Elmt_Id;
6896 Iface_Elmt := First_Elmt (Ifaces_List);
6897 while Present (Iface_Elmt) loop
6898 if Node (Iface_Elmt) = Iface then
6902 Next_Elmt (Iface_Elmt);
6910 Iface_Id : Entity_Id;
6911 Iface_Param : Node_Id;
6912 Iface_Typ : Entity_Id;
6913 Prim_Id : Entity_Id;
6914 Prim_Param : Node_Id;
6915 Prim_Typ : Entity_Id;
6917 -- Start of processing for Matches_Prefixed_View_Profile
6920 Iface_Param := First (Iface_Params);
6921 Iface_Typ := Etype (Defining_Identifier (Iface_Param));
6923 if Is_Access_Type (Iface_Typ) then
6924 Iface_Typ := Designated_Type (Iface_Typ);
6927 Prim_Param := First (Prim_Params);
6929 -- The first parameter of the potentially overridden subprogram must
6930 -- be an interface implemented by Prim.
6932 if not Is_Interface (Iface_Typ)
6933 or else not Is_Implemented (Ifaces_List, Iface_Typ)
6938 -- The checks on the object parameters are done, so move on to the
6939 -- rest of the parameters.
6941 if not In_Scope then
6942 Prim_Param := Next (Prim_Param);
6945 Iface_Param := Next (Iface_Param);
6946 while Present (Iface_Param) and then Present (Prim_Param) loop
6947 Iface_Id := Defining_Identifier (Iface_Param);
6948 Iface_Typ := Find_Parameter_Type (Iface_Param);
6950 Prim_Id := Defining_Identifier (Prim_Param);
6951 Prim_Typ := Find_Parameter_Type (Prim_Param);
6953 if Ekind (Iface_Typ) = E_Anonymous_Access_Type
6954 and then Ekind (Prim_Typ) = E_Anonymous_Access_Type
6955 and then Is_Concurrent_Type (Designated_Type (Prim_Typ))
6957 Iface_Typ := Designated_Type (Iface_Typ);
6958 Prim_Typ := Designated_Type (Prim_Typ);
6961 -- Case of multiple interface types inside a parameter profile
6963 -- (Obj_Param : in out Iface; ...; Param : Iface)
6965 -- If the interface type is implemented, then the matching type in
6966 -- the primitive should be the implementing record type.
6968 if Ekind (Iface_Typ) = E_Record_Type
6969 and then Is_Interface (Iface_Typ)
6970 and then Is_Implemented (Ifaces_List, Iface_Typ)
6972 if Prim_Typ /= Typ then
6976 -- The two parameters must be both mode and subtype conformant
6978 elsif Ekind (Iface_Id) /= Ekind (Prim_Id)
6980 Conforming_Types (Iface_Typ, Prim_Typ, Subtype_Conformant)
6989 -- One of the two lists contains more parameters than the other
6991 if Present (Iface_Param) or else Present (Prim_Param) then
6996 end Matches_Prefixed_View_Profile;
6998 -- Start of processing for Check_Synchronized_Overriding
7001 Overridden_Subp := Empty;
7003 -- Def_Id must be an entry or a subprogram. We should skip predefined
7004 -- primitives internally generated by the front end; however at this
7005 -- stage predefined primitives are still not fully decorated. As a
7006 -- minor optimization we skip here internally generated subprograms.
7008 if (Ekind (Def_Id) /= E_Entry
7009 and then Ekind (Def_Id) /= E_Function
7010 and then Ekind (Def_Id) /= E_Procedure)
7011 or else not Comes_From_Source (Def_Id)
7016 -- Search for the concurrent declaration since it contains the list of
7017 -- all implemented interfaces. In this case, the subprogram is declared
7018 -- within the scope of a protected or a task type.
7020 if Present (Scope (Def_Id))
7021 and then Is_Concurrent_Type (Scope (Def_Id))
7022 and then not Is_Generic_Actual_Type (Scope (Def_Id))
7024 Typ := Scope (Def_Id);
7027 -- The enclosing scope is not a synchronized type and the subprogram
7030 elsif No (First_Formal (Def_Id)) then
7033 -- The subprogram has formals and hence it may be a primitive of a
7037 Typ := Etype (First_Formal (Def_Id));
7039 if Is_Access_Type (Typ) then
7040 Typ := Directly_Designated_Type (Typ);
7043 if Is_Concurrent_Type (Typ)
7044 and then not Is_Generic_Actual_Type (Typ)
7048 -- This case occurs when the concurrent type is declared within a
7049 -- generic unit. As a result the corresponding record has been built
7050 -- and used as the type of the first formal, we just have to retrieve
7051 -- the corresponding concurrent type.
7053 elsif Is_Concurrent_Record_Type (Typ)
7054 and then not Is_Class_Wide_Type (Typ)
7055 and then Present (Corresponding_Concurrent_Type (Typ))
7057 Typ := Corresponding_Concurrent_Type (Typ);
7065 -- There is no overriding to check if this is an inherited operation in
7066 -- a type derivation for a generic actual.
7068 Collect_Interfaces (Typ, Ifaces_List);
7070 if Is_Empty_Elmt_List (Ifaces_List) then
7074 -- Determine whether entry or subprogram Def_Id overrides a primitive
7075 -- operation that belongs to one of the interfaces in Ifaces_List.
7078 Candidate : Entity_Id := Empty;
7079 Hom : Entity_Id := Empty;
7080 Subp : Entity_Id := Empty;
7083 -- Traverse the homonym chain, looking for a potentially overridden
7084 -- subprogram that belongs to an implemented interface.
7086 Hom := Current_Entity_In_Scope (Def_Id);
7087 while Present (Hom) loop
7091 or else not Is_Overloadable (Subp)
7092 or else not Is_Primitive (Subp)
7093 or else not Is_Dispatching_Operation (Subp)
7094 or else not Present (Find_Dispatching_Type (Subp))
7095 or else not Is_Interface (Find_Dispatching_Type (Subp))
7099 -- Entries and procedures can override abstract or null interface
7102 elsif Ekind_In (Def_Id, E_Entry, E_Procedure)
7103 and then Ekind (Subp) = E_Procedure
7104 and then Matches_Prefixed_View_Profile
7105 (Parameter_Specifications (Parent (Def_Id)),
7106 Parameter_Specifications (Parent (Subp)))
7110 -- For an overridden subprogram Subp, check whether the mode
7111 -- of its first parameter is correct depending on the kind of
7112 -- synchronized type.
7115 Formal : constant Node_Id := First_Formal (Candidate);
7118 -- In order for an entry or a protected procedure to
7119 -- override, the first parameter of the overridden routine
7120 -- must be of mode "out", "in out", or access-to-variable.
7122 if Ekind_In (Candidate, E_Entry, E_Procedure)
7123 and then Is_Protected_Type (Typ)
7124 and then Ekind (Formal) /= E_In_Out_Parameter
7125 and then Ekind (Formal) /= E_Out_Parameter
7126 and then Nkind (Parameter_Type (Parent (Formal))) /=
7131 -- All other cases are OK since a task entry or routine does
7132 -- not have a restriction on the mode of the first parameter
7133 -- of the overridden interface routine.
7136 Overridden_Subp := Candidate;
7141 -- Functions can override abstract interface functions
7143 elsif Ekind (Def_Id) = E_Function
7144 and then Ekind (Subp) = E_Function
7145 and then Matches_Prefixed_View_Profile
7146 (Parameter_Specifications (Parent (Def_Id)),
7147 Parameter_Specifications (Parent (Subp)))
7148 and then Etype (Def_Id) = Etype (Subp)
7152 -- If an inherited subprogram is implemented by a protected
7153 -- function, then the first parameter of the inherited
7154 -- subprogram shall be of mode in, but not an access-to-
7155 -- variable parameter (RM 9.4(11/9)).
7157 if Present (First_Formal (Subp))
7158 and then Ekind (First_Formal (Subp)) = E_In_Parameter
7160 (not Is_Access_Type (Etype (First_Formal (Subp)))
7162 Is_Access_Constant (Etype (First_Formal (Subp))))
7164 Overridden_Subp := Subp;
7169 Hom := Homonym (Hom);
7172 -- After examining all candidates for overriding, we are left with
7173 -- the best match, which is a mode-incompatible interface routine.
7175 if In_Scope and then Present (Candidate) then
7176 Error_Msg_PT (Def_Id, Candidate);
7179 Overridden_Subp := Candidate;
7182 end Check_Synchronized_Overriding;
7184 ---------------------------
7185 -- Check_Type_Conformant --
7186 ---------------------------
7188 procedure Check_Type_Conformant
7189 (New_Id : Entity_Id;
7191 Err_Loc : Node_Id := Empty)
7194 pragma Warnings (Off, Result);
7197 (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
7198 end Check_Type_Conformant;
7200 ---------------------------
7201 -- Can_Override_Operator --
7202 ---------------------------
7204 function Can_Override_Operator (Subp : Entity_Id) return Boolean is
7208 if Nkind (Subp) /= N_Defining_Operator_Symbol then
7212 Typ := Base_Type (Etype (First_Formal (Subp)));
7214 -- Check explicitly that the operation is a primitive of the type
7216 return Operator_Matches_Spec (Subp, Subp)
7217 and then not Is_Generic_Type (Typ)
7218 and then Scope (Subp) = Scope (Typ)
7219 and then not Is_Class_Wide_Type (Typ);
7221 end Can_Override_Operator;
7223 ----------------------
7224 -- Conforming_Types --
7225 ----------------------
7227 function Conforming_Types
7230 Ctype : Conformance_Type;
7231 Get_Inst : Boolean := False) return Boolean
7233 function Base_Types_Match
7235 Typ_2 : Entity_Id) return Boolean;
7236 -- If neither Typ_1 nor Typ_2 are generic actual types, or if they are
7237 -- in different scopes (e.g. parent and child instances), then verify
7238 -- that the base types are equal. Otherwise Typ_1 and Typ_2 must be on
7239 -- the same subtype chain. The whole purpose of this procedure is to
7240 -- prevent spurious ambiguities in an instantiation that may arise if
7241 -- two distinct generic types are instantiated with the same actual.
7243 function Find_Designated_Type (Typ : Entity_Id) return Entity_Id;
7244 -- An access parameter can designate an incomplete type. If the
7245 -- incomplete type is the limited view of a type from a limited_
7246 -- with_clause, check whether the non-limited view is available.
7247 -- If it is a (non-limited) incomplete type, get the full view.
7249 function Matches_Limited_With_View
7251 Typ_2 : Entity_Id) return Boolean;
7252 -- Returns True if and only if either Typ_1 denotes a limited view of
7253 -- Typ_2 or Typ_2 denotes a limited view of Typ_1. This can arise when
7254 -- the limited with view of a type is used in a subprogram declaration
7255 -- and the subprogram body is in the scope of a regular with clause for
7256 -- the same unit. In such a case, the two type entities are considered
7257 -- identical for purposes of conformance checking.
7259 ----------------------
7260 -- Base_Types_Match --
7261 ----------------------
7263 function Base_Types_Match
7265 Typ_2 : Entity_Id) return Boolean
7267 Base_1 : constant Entity_Id := Base_Type (Typ_1);
7268 Base_2 : constant Entity_Id := Base_Type (Typ_2);
7271 if Typ_1 = Typ_2 then
7274 elsif Base_1 = Base_2 then
7276 -- The following is too permissive. A more precise test should
7277 -- check that the generic actual is an ancestor subtype of the
7280 -- See code in Find_Corresponding_Spec that applies an additional
7281 -- filter to handle accidental amiguities in instances.
7284 not Is_Generic_Actual_Type (Typ_1)
7285 or else not Is_Generic_Actual_Type (Typ_2)
7286 or else Scope (Typ_1) /= Scope (Typ_2);
7288 -- If Typ_2 is a generic actual type it is declared as the subtype of
7289 -- the actual. If that actual is itself a subtype we need to use its
7290 -- own base type to check for compatibility.
7292 elsif Ekind (Base_2) = Ekind (Typ_2)
7293 and then Base_1 = Base_Type (Base_2)
7297 elsif Ekind (Base_1) = Ekind (Typ_1)
7298 and then Base_2 = Base_Type (Base_1)
7305 end Base_Types_Match;
7307 --------------------------
7308 -- Find_Designated_Type --
7309 --------------------------
7311 function Find_Designated_Type (Typ : Entity_Id) return Entity_Id is
7315 Desig := Directly_Designated_Type (Typ);
7317 if Ekind (Desig) = E_Incomplete_Type then
7319 -- If regular incomplete type, get full view if available
7321 if Present (Full_View (Desig)) then
7322 Desig := Full_View (Desig);
7324 -- If limited view of a type, get non-limited view if available,
7325 -- and check again for a regular incomplete type.
7327 elsif Present (Non_Limited_View (Desig)) then
7328 Desig := Get_Full_View (Non_Limited_View (Desig));
7333 end Find_Designated_Type;
7335 -------------------------------
7336 -- Matches_Limited_With_View --
7337 -------------------------------
7339 function Matches_Limited_With_View
7341 Typ_2 : Entity_Id) return Boolean
7343 function Is_Matching_Limited_View
7345 View : Entity_Id) return Boolean;
7346 -- Determine whether non-limited view View denotes type Typ in some
7347 -- conformant fashion.
7349 ------------------------------
7350 -- Is_Matching_Limited_View --
7351 ------------------------------
7353 function Is_Matching_Limited_View
7355 View : Entity_Id) return Boolean
7357 Root_Typ : Entity_Id;
7358 Root_View : Entity_Id;
7361 -- The non-limited view directly denotes the type
7366 -- The type is a subtype of the non-limited view
7368 elsif Is_Subtype_Of (Typ, View) then
7371 -- Both the non-limited view and the type denote class-wide types
7373 elsif Is_Class_Wide_Type (Typ)
7374 and then Is_Class_Wide_Type (View)
7376 Root_Typ := Root_Type (Typ);
7377 Root_View := Root_Type (View);
7379 if Root_Typ = Root_View then
7382 -- An incomplete tagged type and its full view may receive two
7383 -- distinct class-wide types when the related package has not
7384 -- been analyzed yet.
7387 -- type T is tagged; -- CW_1
7388 -- type T is tagged null record; -- CW_2
7391 -- This is because the package lacks any semantic information
7392 -- that may eventually link both views of T. As a consequence,
7393 -- a client of the limited view of Pack will see CW_2 while a
7394 -- client of the non-limited view of Pack will see CW_1.
7396 elsif Is_Incomplete_Type (Root_Typ)
7397 and then Present (Full_View (Root_Typ))
7398 and then Full_View (Root_Typ) = Root_View
7402 elsif Is_Incomplete_Type (Root_View)
7403 and then Present (Full_View (Root_View))
7404 and then Full_View (Root_View) = Root_Typ
7411 end Is_Matching_Limited_View;
7413 -- Start of processing for Matches_Limited_With_View
7416 -- In some cases a type imported through a limited_with clause, and
7417 -- its non-limited view are both visible, for example in an anonymous
7418 -- access-to-class-wide type in a formal, or when building the body
7419 -- for a subprogram renaming after the subprogram has been frozen.
7420 -- In these cases both entities designate the same type. In addition,
7421 -- if one of them is an actual in an instance, it may be a subtype of
7422 -- the non-limited view of the other.
7424 if From_Limited_With (Typ_1)
7425 and then From_Limited_With (Typ_2)
7426 and then Available_View (Typ_1) = Available_View (Typ_2)
7430 elsif From_Limited_With (Typ_1) then
7431 return Is_Matching_Limited_View (Typ_2, Available_View (Typ_1));
7433 elsif From_Limited_With (Typ_2) then
7434 return Is_Matching_Limited_View (Typ_1, Available_View (Typ_2));
7439 end Matches_Limited_With_View;
7443 Are_Anonymous_Access_To_Subprogram_Types : Boolean := False;
7445 Type_1 : Entity_Id := T1;
7446 Type_2 : Entity_Id := T2;
7448 -- Start of processing for Conforming_Types
7451 -- The context is an instance association for a formal access-to-
7452 -- subprogram type; the formal parameter types require mapping because
7453 -- they may denote other formal parameters of the generic unit.
7456 Type_1 := Get_Instance_Of (T1);
7457 Type_2 := Get_Instance_Of (T2);
7460 -- If one of the types is a view of the other introduced by a limited
7461 -- with clause, treat these as conforming for all purposes.
7463 if Matches_Limited_With_View (T1, T2) then
7466 elsif Base_Types_Match (Type_1, Type_2) then
7467 if Ctype <= Mode_Conformant then
7472 Subtypes_Statically_Match (Type_1, Type_2)
7473 and then Dimensions_Match (Type_1, Type_2);
7476 elsif Is_Incomplete_Or_Private_Type (Type_1)
7477 and then Present (Full_View (Type_1))
7478 and then Base_Types_Match (Full_View (Type_1), Type_2)
7481 Ctype <= Mode_Conformant
7482 or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
7484 elsif Ekind (Type_2) = E_Incomplete_Type
7485 and then Present (Full_View (Type_2))
7486 and then Base_Types_Match (Type_1, Full_View (Type_2))
7489 Ctype <= Mode_Conformant
7490 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
7492 elsif Is_Private_Type (Type_2)
7493 and then In_Instance
7494 and then Present (Full_View (Type_2))
7495 and then Base_Types_Match (Type_1, Full_View (Type_2))
7498 Ctype <= Mode_Conformant
7499 or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
7501 -- Another confusion between views in a nested instance with an
7502 -- actual private type whose full view is not in scope.
7504 elsif Ekind (Type_2) = E_Private_Subtype
7505 and then In_Instance
7506 and then Etype (Type_2) = Type_1
7510 -- In Ada 2012, incomplete types (including limited views) can appear
7511 -- as actuals in instantiations.
7513 elsif Is_Incomplete_Type (Type_1)
7514 and then Is_Incomplete_Type (Type_2)
7515 and then (Used_As_Generic_Actual (Type_1)
7516 or else Used_As_Generic_Actual (Type_2))
7521 -- Ada 2005 (AI-254): Anonymous access-to-subprogram types must be
7522 -- treated recursively because they carry a signature. As far as
7523 -- conformance is concerned, convention plays no role, and either
7524 -- or both could be access to protected subprograms.
7526 Are_Anonymous_Access_To_Subprogram_Types :=
7527 Ekind_In (Type_1, E_Anonymous_Access_Subprogram_Type,
7528 E_Anonymous_Access_Protected_Subprogram_Type)
7530 Ekind_In (Type_2, E_Anonymous_Access_Subprogram_Type,
7531 E_Anonymous_Access_Protected_Subprogram_Type);
7533 -- Test anonymous access type case. For this case, static subtype
7534 -- matching is required for mode conformance (RM 6.3.1(15)). We check
7535 -- the base types because we may have built internal subtype entities
7536 -- to handle null-excluding types (see Process_Formals).
7538 if (Ekind (Base_Type (Type_1)) = E_Anonymous_Access_Type
7540 Ekind (Base_Type (Type_2)) = E_Anonymous_Access_Type)
7542 -- Ada 2005 (AI-254)
7544 or else Are_Anonymous_Access_To_Subprogram_Types
7547 Desig_1 : Entity_Id;
7548 Desig_2 : Entity_Id;
7551 -- In Ada 2005, access constant indicators must match for
7552 -- subtype conformance.
7554 if Ada_Version >= Ada_2005
7555 and then Ctype >= Subtype_Conformant
7557 Is_Access_Constant (Type_1) /= Is_Access_Constant (Type_2)
7562 Desig_1 := Find_Designated_Type (Type_1);
7563 Desig_2 := Find_Designated_Type (Type_2);
7565 -- If the context is an instance association for a formal
7566 -- access-to-subprogram type; formal access parameter designated
7567 -- types require mapping because they may denote other formal
7568 -- parameters of the generic unit.
7571 Desig_1 := Get_Instance_Of (Desig_1);
7572 Desig_2 := Get_Instance_Of (Desig_2);
7575 -- It is possible for a Class_Wide_Type to be introduced for an
7576 -- incomplete type, in which case there is a separate class_ wide
7577 -- type for the full view. The types conform if their Etypes
7578 -- conform, i.e. one may be the full view of the other. This can
7579 -- only happen in the context of an access parameter, other uses
7580 -- of an incomplete Class_Wide_Type are illegal.
7582 if Is_Class_Wide_Type (Desig_1)
7584 Is_Class_Wide_Type (Desig_2)
7588 (Etype (Base_Type (Desig_1)),
7589 Etype (Base_Type (Desig_2)), Ctype);
7591 elsif Are_Anonymous_Access_To_Subprogram_Types then
7592 if Ada_Version < Ada_2005 then
7594 Ctype = Type_Conformant
7595 or else Subtypes_Statically_Match (Desig_1, Desig_2);
7597 -- We must check the conformance of the signatures themselves
7601 Conformant : Boolean;
7604 (Desig_1, Desig_2, Ctype, False, Conformant);
7609 -- A limited view of an actual matches the corresponding
7610 -- incomplete formal.
7612 elsif Ekind (Desig_2) = E_Incomplete_Subtype
7613 and then From_Limited_With (Desig_2)
7614 and then Used_As_Generic_Actual (Etype (Desig_2))
7619 return Base_Type (Desig_1) = Base_Type (Desig_2)
7620 and then (Ctype = Type_Conformant
7622 Subtypes_Statically_Match (Desig_1, Desig_2));
7626 -- Otherwise definitely no match
7629 if ((Ekind (Type_1) = E_Anonymous_Access_Type
7630 and then Is_Access_Type (Type_2))
7631 or else (Ekind (Type_2) = E_Anonymous_Access_Type
7632 and then Is_Access_Type (Type_1)))
7635 (Designated_Type (Type_1), Designated_Type (Type_2), Ctype)
7637 May_Hide_Profile := True;
7642 end Conforming_Types;
7644 --------------------------
7645 -- Create_Extra_Formals --
7646 --------------------------
7648 procedure Create_Extra_Formals (E : Entity_Id) is
7649 First_Extra : Entity_Id := Empty;
7651 Last_Extra : Entity_Id := Empty;
7653 function Add_Extra_Formal
7654 (Assoc_Entity : Entity_Id;
7657 Suffix : String) return Entity_Id;
7658 -- Add an extra formal to the current list of formals and extra formals.
7659 -- The extra formal is added to the end of the list of extra formals,
7660 -- and also returned as the result. These formals are always of mode IN.
7661 -- The new formal has the type Typ, is declared in Scope, and its name
7662 -- is given by a concatenation of the name of Assoc_Entity and Suffix.
7663 -- The following suffixes are currently used. They should not be changed
7664 -- without coordinating with CodePeer, which makes use of these to
7665 -- provide better messages.
7667 -- O denotes the Constrained bit.
7668 -- L denotes the accessibility level.
7669 -- BIP_xxx denotes an extra formal for a build-in-place function. See
7670 -- the full list in exp_ch6.BIP_Formal_Kind.
7672 ----------------------
7673 -- Add_Extra_Formal --
7674 ----------------------
7676 function Add_Extra_Formal
7677 (Assoc_Entity : Entity_Id;
7680 Suffix : String) return Entity_Id
7682 EF : constant Entity_Id :=
7683 Make_Defining_Identifier (Sloc (Assoc_Entity),
7684 Chars => New_External_Name (Chars (Assoc_Entity),
7688 -- A little optimization. Never generate an extra formal for the
7689 -- _init operand of an initialization procedure, since it could
7692 if Chars (Formal) = Name_uInit then
7696 Set_Ekind (EF, E_In_Parameter);
7697 Set_Actual_Subtype (EF, Typ);
7698 Set_Etype (EF, Typ);
7699 Set_Scope (EF, Scope);
7700 Set_Mechanism (EF, Default_Mechanism);
7701 Set_Formal_Validity (EF);
7703 if No (First_Extra) then
7705 Set_Extra_Formals (Scope, First_Extra);
7708 if Present (Last_Extra) then
7709 Set_Extra_Formal (Last_Extra, EF);
7715 end Add_Extra_Formal;
7719 Formal_Type : Entity_Id;
7720 P_Formal : Entity_Id := Empty;
7722 -- Start of processing for Create_Extra_Formals
7725 -- We never generate extra formals if expansion is not active because we
7726 -- don't need them unless we are generating code.
7728 if not Expander_Active then
7732 -- No need to generate extra formals in interface thunks whose target
7733 -- primitive has no extra formals.
7735 if Is_Thunk (E) and then No (Extra_Formals (Thunk_Entity (E))) then
7739 -- If this is a derived subprogram then the subtypes of the parent
7740 -- subprogram's formal parameters will be used to determine the need
7741 -- for extra formals.
7743 if Is_Overloadable (E) and then Present (Alias (E)) then
7744 P_Formal := First_Formal (Alias (E));
7747 Formal := First_Formal (E);
7748 while Present (Formal) loop
7749 Last_Extra := Formal;
7750 Next_Formal (Formal);
7753 -- If Extra_Formals were already created, don't do it again. This
7754 -- situation may arise for subprogram types created as part of
7755 -- dispatching calls (see Expand_Dispatching_Call)
7757 if Present (Last_Extra) and then Present (Extra_Formal (Last_Extra)) then
7761 -- If the subprogram is a predefined dispatching subprogram then don't
7762 -- generate any extra constrained or accessibility level formals. In
7763 -- general we suppress these for internal subprograms (by not calling
7764 -- Freeze_Subprogram and Create_Extra_Formals at all), but internally
7765 -- generated stream attributes do get passed through because extra
7766 -- build-in-place formals are needed in some cases (limited 'Input).
7768 if Is_Predefined_Internal_Operation (E) then
7769 goto Test_For_Func_Result_Extras;
7772 Formal := First_Formal (E);
7773 while Present (Formal) loop
7775 -- Create extra formal for supporting the attribute 'Constrained.
7776 -- The case of a private type view without discriminants also
7777 -- requires the extra formal if the underlying type has defaulted
7780 if Ekind (Formal) /= E_In_Parameter then
7781 if Present (P_Formal) then
7782 Formal_Type := Etype (P_Formal);
7784 Formal_Type := Etype (Formal);
7787 -- Do not produce extra formals for Unchecked_Union parameters.
7788 -- Jump directly to the end of the loop.
7790 if Is_Unchecked_Union (Base_Type (Formal_Type)) then
7791 goto Skip_Extra_Formal_Generation;
7794 if not Has_Discriminants (Formal_Type)
7795 and then Ekind (Formal_Type) in Private_Kind
7796 and then Present (Underlying_Type (Formal_Type))
7798 Formal_Type := Underlying_Type (Formal_Type);
7801 -- Suppress the extra formal if formal's subtype is constrained or
7802 -- indefinite, or we're compiling for Ada 2012 and the underlying
7803 -- type is tagged and limited. In Ada 2012, a limited tagged type
7804 -- can have defaulted discriminants, but 'Constrained is required
7805 -- to return True, so the formal is never needed (see AI05-0214).
7806 -- Note that this ensures consistency of calling sequences for
7807 -- dispatching operations when some types in a class have defaults
7808 -- on discriminants and others do not (and requiring the extra
7809 -- formal would introduce distributed overhead).
7811 -- If the type does not have a completion yet, treat as prior to
7812 -- Ada 2012 for consistency.
7814 if Has_Discriminants (Formal_Type)
7815 and then not Is_Constrained (Formal_Type)
7816 and then Is_Definite_Subtype (Formal_Type)
7817 and then (Ada_Version < Ada_2012
7818 or else No (Underlying_Type (Formal_Type))
7820 (Is_Limited_Type (Formal_Type)
7823 (Underlying_Type (Formal_Type)))))
7825 Set_Extra_Constrained
7826 (Formal, Add_Extra_Formal (Formal, Standard_Boolean, E, "O"));
7830 -- Create extra formal for supporting accessibility checking. This
7831 -- is done for both anonymous access formals and formals of named
7832 -- access types that are marked as controlling formals. The latter
7833 -- case can occur when Expand_Dispatching_Call creates a subprogram
7834 -- type and substitutes the types of access-to-class-wide actuals
7835 -- for the anonymous access-to-specific-type of controlling formals.
7836 -- Base_Type is applied because in cases where there is a null
7837 -- exclusion the formal may have an access subtype.
7839 -- This is suppressed if we specifically suppress accessibility
7840 -- checks at the package level for either the subprogram, or the
7841 -- package in which it resides. However, we do not suppress it
7842 -- simply if the scope has accessibility checks suppressed, since
7843 -- this could cause trouble when clients are compiled with a
7844 -- different suppression setting. The explicit checks at the
7845 -- package level are safe from this point of view.
7847 if (Ekind (Base_Type (Etype (Formal))) = E_Anonymous_Access_Type
7848 or else (Is_Controlling_Formal (Formal)
7849 and then Is_Access_Type (Base_Type (Etype (Formal)))))
7851 (Explicit_Suppress (E, Accessibility_Check)
7853 Explicit_Suppress (Scope (E), Accessibility_Check))
7856 or else Present (Extra_Accessibility (P_Formal)))
7858 Set_Extra_Accessibility
7859 (Formal, Add_Extra_Formal (Formal, Standard_Natural, E, "L"));
7862 -- This label is required when skipping extra formal generation for
7863 -- Unchecked_Union parameters.
7865 <<Skip_Extra_Formal_Generation>>
7867 if Present (P_Formal) then
7868 Next_Formal (P_Formal);
7871 Next_Formal (Formal);
7874 <<Test_For_Func_Result_Extras>>
7876 -- Ada 2012 (AI05-234): "the accessibility level of the result of a
7877 -- function call is ... determined by the point of call ...".
7879 if Needs_Result_Accessibility_Level (E) then
7880 Set_Extra_Accessibility_Of_Result
7881 (E, Add_Extra_Formal (E, Standard_Natural, E, "L"));
7884 -- Ada 2005 (AI-318-02): In the case of build-in-place functions, add
7885 -- appropriate extra formals. See type Exp_Ch6.BIP_Formal_Kind.
7887 if Ada_Version >= Ada_2005 and then Is_Build_In_Place_Function (E) then
7889 Result_Subt : constant Entity_Id := Etype (E);
7890 Full_Subt : constant Entity_Id := Available_View (Result_Subt);
7891 Formal_Typ : Entity_Id;
7892 Subp_Decl : Node_Id;
7894 Discard : Entity_Id;
7895 pragma Warnings (Off, Discard);
7898 -- In the case of functions with unconstrained result subtypes,
7899 -- add a 4-state formal indicating whether the return object is
7900 -- allocated by the caller (1), or should be allocated by the
7901 -- callee on the secondary stack (2), in the global heap (3), or
7902 -- in a user-defined storage pool (4). For the moment we just use
7903 -- Natural for the type of this formal. Note that this formal
7904 -- isn't usually needed in the case where the result subtype is
7905 -- constrained, but it is needed when the function has a tagged
7906 -- result, because generally such functions can be called in a
7907 -- dispatching context and such calls must be handled like calls
7908 -- to a class-wide function.
7910 if Needs_BIP_Alloc_Form (E) then
7913 (E, Standard_Natural,
7914 E, BIP_Formal_Suffix (BIP_Alloc_Form));
7916 -- Add BIP_Storage_Pool, in case BIP_Alloc_Form indicates to
7917 -- use a user-defined pool. This formal is not added on
7918 -- ZFP as those targets do not support pools.
7920 if RTE_Available (RE_Root_Storage_Pool_Ptr) then
7923 (E, RTE (RE_Root_Storage_Pool_Ptr),
7924 E, BIP_Formal_Suffix (BIP_Storage_Pool));
7928 -- In the case of functions whose result type needs finalization,
7929 -- add an extra formal which represents the finalization master.
7931 if Needs_BIP_Finalization_Master (E) then
7934 (E, RTE (RE_Finalization_Master_Ptr),
7935 E, BIP_Formal_Suffix (BIP_Finalization_Master));
7938 -- When the result type contains tasks, add two extra formals: the
7939 -- master of the tasks to be created, and the caller's activation
7942 if Has_Task (Full_Subt) then
7945 (E, RTE (RE_Master_Id),
7946 E, BIP_Formal_Suffix (BIP_Task_Master));
7949 (E, RTE (RE_Activation_Chain_Access),
7950 E, BIP_Formal_Suffix (BIP_Activation_Chain));
7953 -- All build-in-place functions get an extra formal that will be
7954 -- passed the address of the return object within the caller.
7957 Create_Itype (E_Anonymous_Access_Type, E, Scope_Id => Scope (E));
7959 Set_Directly_Designated_Type (Formal_Typ, Result_Subt);
7960 Set_Etype (Formal_Typ, Formal_Typ);
7961 Set_Depends_On_Private
7962 (Formal_Typ, Has_Private_Component (Formal_Typ));
7963 Set_Is_Public (Formal_Typ, Is_Public (Scope (Formal_Typ)));
7964 Set_Is_Access_Constant (Formal_Typ, False);
7966 -- Ada 2005 (AI-50217): Propagate the attribute that indicates
7967 -- the designated type comes from the limited view (for back-end
7970 Set_From_Limited_With
7971 (Formal_Typ, From_Limited_With (Result_Subt));
7973 Layout_Type (Formal_Typ);
7975 -- Force the definition of the Itype in case of internal function
7976 -- calls within the same or nested scope.
7978 if Is_Subprogram_Or_Generic_Subprogram (E) then
7979 Subp_Decl := Parent (E);
7981 -- The insertion point for an Itype reference should be after
7982 -- the unit declaration node of the subprogram. An exception
7983 -- to this are inherited operations from a parent type in which
7984 -- case the derived type acts as their parent.
7986 if Nkind_In (Subp_Decl, N_Function_Specification,
7987 N_Procedure_Specification)
7989 Subp_Decl := Parent (Subp_Decl);
7992 Build_Itype_Reference (Formal_Typ, Subp_Decl);
7997 (E, Formal_Typ, E, BIP_Formal_Suffix (BIP_Object_Access));
8000 end Create_Extra_Formals;
8002 -----------------------------
8003 -- Enter_Overloaded_Entity --
8004 -----------------------------
8006 procedure Enter_Overloaded_Entity (S : Entity_Id) is
8007 function Matches_Predefined_Op return Boolean;
8008 -- This returns an approximation of whether S matches a predefined
8009 -- operator, based on the operator symbol, and the parameter and result
8010 -- types. The rules are scattered throughout chapter 4 of the Ada RM.
8012 ---------------------------
8013 -- Matches_Predefined_Op --
8014 ---------------------------
8016 function Matches_Predefined_Op return Boolean is
8017 Formal_1 : constant Entity_Id := First_Formal (S);
8018 Formal_2 : constant Entity_Id := Next_Formal (Formal_1);
8019 Op : constant Name_Id := Chars (S);
8020 Result_Type : constant Entity_Id := Base_Type (Etype (S));
8021 Type_1 : constant Entity_Id := Base_Type (Etype (Formal_1));
8026 if Present (Formal_2) then
8028 Type_2 : constant Entity_Id := Base_Type (Etype (Formal_2));
8031 -- All but "&" and "**" have same-types parameters
8040 if Type_1 /= Type_2 then
8045 -- Check parameter and result types
8053 Is_Boolean_Type (Result_Type)
8054 and then Result_Type = Type_1;
8060 Is_Integer_Type (Result_Type)
8061 and then Result_Type = Type_1;
8069 Is_Numeric_Type (Result_Type)
8070 and then Result_Type = Type_1;
8076 Is_Boolean_Type (Result_Type)
8077 and then not Is_Limited_Type (Type_1);
8085 Is_Boolean_Type (Result_Type)
8086 and then (Is_Array_Type (Type_1)
8087 or else Is_Scalar_Type (Type_1));
8089 when Name_Op_Concat =>
8090 return Is_Array_Type (Result_Type);
8092 when Name_Op_Expon =>
8094 (Is_Integer_Type (Result_Type)
8095 or else Is_Floating_Point_Type (Result_Type))
8096 and then Result_Type = Type_1
8097 and then Type_2 = Standard_Integer;
8100 raise Program_Error;
8113 Is_Numeric_Type (Result_Type)
8114 and then Result_Type = Type_1;
8118 Is_Boolean_Type (Result_Type)
8119 and then Result_Type = Type_1;
8122 raise Program_Error;
8125 end Matches_Predefined_Op;
8129 E : Entity_Id := Current_Entity_In_Scope (S);
8130 C_E : Entity_Id := Current_Entity (S);
8132 -- Start of processing for Enter_Overloaded_Entity
8136 Set_Has_Homonym (E);
8137 Set_Has_Homonym (S);
8140 Set_Is_Immediately_Visible (S);
8141 Set_Scope (S, Current_Scope);
8143 -- Chain new entity if front of homonym in current scope, so that
8144 -- homonyms are contiguous.
8146 if Present (E) and then E /= C_E then
8147 while Homonym (C_E) /= E loop
8148 C_E := Homonym (C_E);
8151 Set_Homonym (C_E, S);
8155 Set_Current_Entity (S);
8160 if Is_Inherited_Operation (S) then
8161 Append_Inherited_Subprogram (S);
8163 Append_Entity (S, Current_Scope);
8166 Set_Public_Status (S);
8168 if Debug_Flag_E then
8169 Write_Str ("New overloaded entity chain: ");
8170 Write_Name (Chars (S));
8173 while Present (E) loop
8174 Write_Str (" "); Write_Int (Int (E));
8181 -- Generate warning for hiding
8184 and then Comes_From_Source (S)
8185 and then In_Extended_Main_Source_Unit (S)
8192 -- Warn unless genuine overloading. Do not emit warning on
8193 -- hiding predefined operators in Standard (these are either an
8194 -- (artifact of our implicit declarations, or simple noise) but
8195 -- keep warning on a operator defined on a local subtype, because
8196 -- of the real danger that different operators may be applied in
8197 -- various parts of the program.
8199 -- Note that if E and S have the same scope, there is never any
8200 -- hiding. Either the two conflict, and the program is illegal,
8201 -- or S is overriding an implicit inherited subprogram.
8203 if Scope (E) /= Scope (S)
8204 and then (not Is_Overloadable (E)
8205 or else Subtype_Conformant (E, S))
8206 and then (Is_Immediately_Visible (E)
8207 or else Is_Potentially_Use_Visible (S))
8209 if Scope (E) = Standard_Standard then
8210 if Nkind (S) = N_Defining_Operator_Symbol
8211 and then Scope (Base_Type (Etype (First_Formal (S)))) /=
8213 and then Matches_Predefined_Op
8216 ("declaration of & hides predefined operator?h?", S);
8219 -- E not immediately within Standard
8222 Error_Msg_Sloc := Sloc (E);
8223 Error_Msg_N ("declaration of & hides one #?h?", S);
8228 end Enter_Overloaded_Entity;
8230 -----------------------------
8231 -- Check_Untagged_Equality --
8232 -----------------------------
8234 procedure Check_Untagged_Equality (Eq_Op : Entity_Id) is
8235 Typ : constant Entity_Id := Etype (First_Formal (Eq_Op));
8236 Decl : constant Node_Id := Unit_Declaration_Node (Eq_Op);
8240 -- This check applies only if we have a subprogram declaration with an
8241 -- untagged record type.
8243 if Nkind (Decl) /= N_Subprogram_Declaration
8244 or else not Is_Record_Type (Typ)
8245 or else Is_Tagged_Type (Typ)
8250 -- In Ada 2012 case, we will output errors or warnings depending on
8251 -- the setting of debug flag -gnatd.E.
8253 if Ada_Version >= Ada_2012 then
8254 Error_Msg_Warn := Debug_Flag_Dot_EE;
8256 -- In earlier versions of Ada, nothing to do unless we are warning on
8257 -- Ada 2012 incompatibilities (Warn_On_Ada_2012_Incompatibility set).
8260 if not Warn_On_Ada_2012_Compatibility then
8265 -- Cases where the type has already been frozen
8267 if Is_Frozen (Typ) then
8269 -- If the type is not declared in a package, or if we are in the body
8270 -- of the package or in some other scope, the new operation is not
8271 -- primitive, and therefore legal, though suspicious. Should we
8272 -- generate a warning in this case ???
8274 if Ekind (Scope (Typ)) /= E_Package
8275 or else Scope (Typ) /= Current_Scope
8279 -- If the type is a generic actual (sub)type, the operation is not
8280 -- primitive either because the base type is declared elsewhere.
8282 elsif Is_Generic_Actual_Type (Typ) then
8285 -- Here we have a definite error of declaration after freezing
8288 if Ada_Version >= Ada_2012 then
8290 ("equality operator must be declared before type & is "
8291 & "frozen (RM 4.5.2 (9.8)) (Ada 2012)<<", Eq_Op, Typ);
8293 -- In Ada 2012 mode with error turned to warning, output one
8294 -- more warning to warn that the equality operation may not
8295 -- compose. This is the consequence of ignoring the error.
8297 if Error_Msg_Warn then
8298 Error_Msg_N ("\equality operation may not compose??", Eq_Op);
8303 ("equality operator must be declared before type& is "
8304 & "frozen (RM 4.5.2 (9.8)) (Ada 2012)?y?", Eq_Op, Typ);
8307 -- If we are in the package body, we could just move the
8308 -- declaration to the package spec, so add a message saying that.
8310 if In_Package_Body (Scope (Typ)) then
8311 if Ada_Version >= Ada_2012 then
8313 ("\move declaration to package spec<<", Eq_Op);
8316 ("\move declaration to package spec (Ada 2012)?y?", Eq_Op);
8319 -- Otherwise try to find the freezing point
8322 Obj_Decl := Next (Parent (Typ));
8323 while Present (Obj_Decl) and then Obj_Decl /= Decl loop
8324 if Nkind (Obj_Decl) = N_Object_Declaration
8325 and then Etype (Defining_Identifier (Obj_Decl)) = Typ
8327 -- Freezing point, output warnings
8329 if Ada_Version >= Ada_2012 then
8331 ("type& is frozen by declaration??", Obj_Decl, Typ);
8333 ("\an equality operator cannot be declared after "
8338 ("type& is frozen by declaration (Ada 2012)?y?",
8341 ("\an equality operator cannot be declared after "
8342 & "this point (Ada 2012)?y?",
8354 -- Here if type is not frozen yet. It is illegal to have a primitive
8355 -- equality declared in the private part if the type is visible.
8357 elsif not In_Same_List (Parent (Typ), Decl)
8358 and then not Is_Limited_Type (Typ)
8360 -- Shouldn't we give an RM reference here???
8362 if Ada_Version >= Ada_2012 then
8364 ("equality operator appears too late<<", Eq_Op);
8367 ("equality operator appears too late (Ada 2012)?y?", Eq_Op);
8370 -- No error detected
8375 end Check_Untagged_Equality;
8377 -----------------------------
8378 -- Find_Corresponding_Spec --
8379 -----------------------------
8381 function Find_Corresponding_Spec
8383 Post_Error : Boolean := True) return Entity_Id
8385 Spec : constant Node_Id := Specification (N);
8386 Designator : constant Entity_Id := Defining_Entity (Spec);
8390 function Different_Generic_Profile (E : Entity_Id) return Boolean;
8391 -- Even if fully conformant, a body may depend on a generic actual when
8392 -- the spec does not, or vice versa, in which case they were distinct
8393 -- entities in the generic.
8395 -------------------------------
8396 -- Different_Generic_Profile --
8397 -------------------------------
8399 function Different_Generic_Profile (E : Entity_Id) return Boolean is
8402 function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean;
8403 -- Check that the types of corresponding formals have the same
8404 -- generic actual if any. We have to account for subtypes of a
8405 -- generic formal, declared between a spec and a body, which may
8406 -- appear distinct in an instance but matched in the generic, and
8407 -- the subtype may be used either in the spec or the body of the
8408 -- subprogram being checked.
8410 -------------------------
8411 -- Same_Generic_Actual --
8412 -------------------------
8414 function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean is
8416 function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean;
8417 -- Predicate to check whether S1 is a subtype of S2 in the source
8420 -------------------------
8421 -- Is_Declared_Subtype --
8422 -------------------------
8424 function Is_Declared_Subtype (S1, S2 : Entity_Id) return Boolean is
8426 return Comes_From_Source (Parent (S1))
8427 and then Nkind (Parent (S1)) = N_Subtype_Declaration
8428 and then Is_Entity_Name (Subtype_Indication (Parent (S1)))
8429 and then Entity (Subtype_Indication (Parent (S1))) = S2;
8430 end Is_Declared_Subtype;
8432 -- Start of processing for Same_Generic_Actual
8435 return Is_Generic_Actual_Type (T1) = Is_Generic_Actual_Type (T2)
8436 or else Is_Declared_Subtype (T1, T2)
8437 or else Is_Declared_Subtype (T2, T1);
8438 end Same_Generic_Actual;
8440 -- Start of processing for Different_Generic_Profile
8443 if not In_Instance then
8446 elsif Ekind (E) = E_Function
8447 and then not Same_Generic_Actual (Etype (E), Etype (Designator))
8452 F1 := First_Formal (Designator);
8453 F2 := First_Formal (E);
8454 while Present (F1) loop
8455 if not Same_Generic_Actual (Etype (F1), Etype (F2)) then
8464 end Different_Generic_Profile;
8466 -- Start of processing for Find_Corresponding_Spec
8469 E := Current_Entity (Designator);
8470 while Present (E) loop
8472 -- We are looking for a matching spec. It must have the same scope,
8473 -- and the same name, and either be type conformant, or be the case
8474 -- of a library procedure spec and its body (which belong to one
8475 -- another regardless of whether they are type conformant or not).
8477 if Scope (E) = Current_Scope then
8478 if Current_Scope = Standard_Standard
8479 or else (Ekind (E) = Ekind (Designator)
8480 and then Type_Conformant (E, Designator))
8482 -- Within an instantiation, we know that spec and body are
8483 -- subtype conformant, because they were subtype conformant in
8484 -- the generic. We choose the subtype-conformant entity here as
8485 -- well, to resolve spurious ambiguities in the instance that
8486 -- were not present in the generic (i.e. when two different
8487 -- types are given the same actual). If we are looking for a
8488 -- spec to match a body, full conformance is expected.
8492 -- Inherit the convention and "ghostness" of the matching
8493 -- spec to ensure proper full and subtype conformance.
8495 Set_Convention (Designator, Convention (E));
8497 -- Skip past subprogram bodies and subprogram renamings that
8498 -- may appear to have a matching spec, but that aren't fully
8499 -- conformant with it. That can occur in cases where an
8500 -- actual type causes unrelated homographs in the instance.
8502 if Nkind_In (N, N_Subprogram_Body,
8503 N_Subprogram_Renaming_Declaration)
8504 and then Present (Homonym (E))
8505 and then not Fully_Conformant (Designator, E)
8509 elsif not Subtype_Conformant (Designator, E) then
8512 elsif Different_Generic_Profile (E) then
8517 -- Ada 2012 (AI05-0165): For internally generated bodies of
8518 -- null procedures locate the internally generated spec. We
8519 -- enforce mode conformance since a tagged type may inherit
8520 -- from interfaces several null primitives which differ only
8521 -- in the mode of the formals.
8523 if not (Comes_From_Source (E))
8524 and then Is_Null_Procedure (E)
8525 and then not Mode_Conformant (Designator, E)
8529 -- For null procedures coming from source that are completions,
8530 -- analysis of the generated body will establish the link.
8532 elsif Comes_From_Source (E)
8533 and then Nkind (Spec) = N_Procedure_Specification
8534 and then Null_Present (Spec)
8538 -- Expression functions can be completions, but cannot be
8539 -- completed by an explicit body.
8541 elsif Comes_From_Source (E)
8542 and then Comes_From_Source (N)
8543 and then Nkind (N) = N_Subprogram_Body
8544 and then Nkind (Original_Node (Unit_Declaration_Node (E))) =
8545 N_Expression_Function
8547 Error_Msg_Sloc := Sloc (E);
8548 Error_Msg_N ("body conflicts with expression function#", N);
8551 elsif not Has_Completion (E) then
8552 if Nkind (N) /= N_Subprogram_Body_Stub then
8553 Set_Corresponding_Spec (N, E);
8556 Set_Has_Completion (E);
8559 elsif Nkind (Parent (N)) = N_Subunit then
8561 -- If this is the proper body of a subunit, the completion
8562 -- flag is set when analyzing the stub.
8566 -- If E is an internal function with a controlling result that
8567 -- was created for an operation inherited by a null extension,
8568 -- it may be overridden by a body without a previous spec (one
8569 -- more reason why these should be shunned). In that case we
8570 -- remove the generated body if present, because the current
8571 -- one is the explicit overriding.
8573 elsif Ekind (E) = E_Function
8574 and then Ada_Version >= Ada_2005
8575 and then not Comes_From_Source (E)
8576 and then Has_Controlling_Result (E)
8577 and then Is_Null_Extension (Etype (E))
8578 and then Comes_From_Source (Spec)
8580 Set_Has_Completion (E, False);
8583 and then Nkind (Parent (E)) = N_Function_Specification
8586 (Unit_Declaration_Node
8587 (Corresponding_Body (Unit_Declaration_Node (E))));
8591 -- If expansion is disabled, or if the wrapper function has
8592 -- not been generated yet, this a late body overriding an
8593 -- inherited operation, or it is an overriding by some other
8594 -- declaration before the controlling result is frozen. In
8595 -- either case this is a declaration of a new entity.
8601 -- If the body already exists, then this is an error unless
8602 -- the previous declaration is the implicit declaration of a
8603 -- derived subprogram. It is also legal for an instance to
8604 -- contain type conformant overloadable declarations (but the
8605 -- generic declaration may not), per 8.3(26/2).
8607 elsif No (Alias (E))
8608 and then not Is_Intrinsic_Subprogram (E)
8609 and then not In_Instance
8612 Error_Msg_Sloc := Sloc (E);
8614 if Is_Imported (E) then
8616 ("body not allowed for imported subprogram & declared#",
8619 Error_Msg_NE ("duplicate body for & declared#", N, E);
8623 -- Child units cannot be overloaded, so a conformance mismatch
8624 -- between body and a previous spec is an error.
8626 elsif Is_Child_Unit (E)
8628 Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body
8630 Nkind (Parent (Unit_Declaration_Node (Designator))) =
8635 ("body of child unit does not match previous declaration", N);
8643 -- On exit, we know that no previous declaration of subprogram exists
8646 end Find_Corresponding_Spec;
8648 ----------------------
8649 -- Fully_Conformant --
8650 ----------------------
8652 function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
8655 Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result);
8657 end Fully_Conformant;
8659 ----------------------------------
8660 -- Fully_Conformant_Expressions --
8661 ----------------------------------
8663 function Fully_Conformant_Expressions
8664 (Given_E1 : Node_Id;
8665 Given_E2 : Node_Id) return Boolean
8667 E1 : constant Node_Id := Original_Node (Given_E1);
8668 E2 : constant Node_Id := Original_Node (Given_E2);
8669 -- We always test conformance on original nodes, since it is possible
8670 -- for analysis and/or expansion to make things look as though they
8671 -- conform when they do not, e.g. by converting 1+2 into 3.
8673 function FCE (Given_E1, Given_E2 : Node_Id) return Boolean
8674 renames Fully_Conformant_Expressions;
8676 function FCL (L1, L2 : List_Id) return Boolean;
8677 -- Compare elements of two lists for conformance. Elements have to be
8678 -- conformant, and actuals inserted as default parameters do not match
8679 -- explicit actuals with the same value.
8681 function FCO (Op_Node, Call_Node : Node_Id) return Boolean;
8682 -- Compare an operator node with a function call
8688 function FCL (L1, L2 : List_Id) return Boolean is
8692 if L1 = No_List then
8698 if L2 = No_List then
8704 -- Compare two lists, skipping rewrite insertions (we want to compare
8705 -- the original trees, not the expanded versions).
8708 if Is_Rewrite_Insertion (N1) then
8710 elsif Is_Rewrite_Insertion (N2) then
8716 elsif not FCE (N1, N2) then
8729 function FCO (Op_Node, Call_Node : Node_Id) return Boolean is
8730 Actuals : constant List_Id := Parameter_Associations (Call_Node);
8735 or else Entity (Op_Node) /= Entity (Name (Call_Node))
8740 Act := First (Actuals);
8742 if Nkind (Op_Node) in N_Binary_Op then
8743 if not FCE (Left_Opnd (Op_Node), Act) then
8750 return Present (Act)
8751 and then FCE (Right_Opnd (Op_Node), Act)
8752 and then No (Next (Act));
8756 -- Start of processing for Fully_Conformant_Expressions
8759 -- Nonconformant if paren count does not match. Note: if some idiot
8760 -- complains that we don't do this right for more than 3 levels of
8761 -- parentheses, they will be treated with the respect they deserve.
8763 if Paren_Count (E1) /= Paren_Count (E2) then
8766 -- If same entities are referenced, then they are conformant even if
8767 -- they have different forms (RM 8.3.1(19-20)).
8769 elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then
8770 if Present (Entity (E1)) then
8771 return Entity (E1) = Entity (E2)
8773 -- One may be a discriminant that has been replaced by the
8774 -- corresponding discriminal.
8777 (Chars (Entity (E1)) = Chars (Entity (E2))
8778 and then Ekind (Entity (E1)) = E_Discriminant
8779 and then Ekind (Entity (E2)) = E_In_Parameter)
8781 -- The discriminant of a protected type is transformed into
8782 -- a local constant and then into a parameter of a protected
8786 (Ekind (Entity (E1)) = E_Constant
8787 and then Ekind (Entity (E2)) = E_In_Parameter
8788 and then Present (Discriminal_Link (Entity (E1)))
8789 and then Discriminal_Link (Entity (E1)) =
8790 Discriminal_Link (Entity (E2)))
8792 -- AI12-050: The loop variables of quantified expressions
8793 -- match if they have the same identifier, even though they
8794 -- are different entities.
8797 (Chars (Entity (E1)) = Chars (Entity (E2))
8798 and then Ekind (Entity (E1)) = E_Loop_Parameter
8799 and then Ekind (Entity (E2)) = E_Loop_Parameter);
8801 elsif Nkind (E1) = N_Expanded_Name
8802 and then Nkind (E2) = N_Expanded_Name
8803 and then Nkind (Selector_Name (E1)) = N_Character_Literal
8804 and then Nkind (Selector_Name (E2)) = N_Character_Literal
8806 return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2));
8809 -- Identifiers in component associations don't always have
8810 -- entities, but their names must conform.
8812 return Nkind (E1) = N_Identifier
8813 and then Nkind (E2) = N_Identifier
8814 and then Chars (E1) = Chars (E2);
8817 elsif Nkind (E1) = N_Character_Literal
8818 and then Nkind (E2) = N_Expanded_Name
8820 return Nkind (Selector_Name (E2)) = N_Character_Literal
8821 and then Chars (E1) = Chars (Selector_Name (E2));
8823 elsif Nkind (E2) = N_Character_Literal
8824 and then Nkind (E1) = N_Expanded_Name
8826 return Nkind (Selector_Name (E1)) = N_Character_Literal
8827 and then Chars (E2) = Chars (Selector_Name (E1));
8829 elsif Nkind (E1) in N_Op and then Nkind (E2) = N_Function_Call then
8830 return FCO (E1, E2);
8832 elsif Nkind (E2) in N_Op and then Nkind (E1) = N_Function_Call then
8833 return FCO (E2, E1);
8835 -- Otherwise we must have the same syntactic entity
8837 elsif Nkind (E1) /= Nkind (E2) then
8840 -- At this point, we specialize by node type
8846 FCL (Expressions (E1), Expressions (E2))
8848 FCL (Component_Associations (E1),
8849 Component_Associations (E2));
8852 if Nkind (Expression (E1)) = N_Qualified_Expression
8854 Nkind (Expression (E2)) = N_Qualified_Expression
8856 return FCE (Expression (E1), Expression (E2));
8858 -- Check that the subtype marks and any constraints
8863 Indic1 : constant Node_Id := Expression (E1);
8864 Indic2 : constant Node_Id := Expression (E2);
8869 if Nkind (Indic1) /= N_Subtype_Indication then
8871 Nkind (Indic2) /= N_Subtype_Indication
8872 and then Entity (Indic1) = Entity (Indic2);
8874 elsif Nkind (Indic2) /= N_Subtype_Indication then
8876 Nkind (Indic1) /= N_Subtype_Indication
8877 and then Entity (Indic1) = Entity (Indic2);
8880 if Entity (Subtype_Mark (Indic1)) /=
8881 Entity (Subtype_Mark (Indic2))
8886 Elt1 := First (Constraints (Constraint (Indic1)));
8887 Elt2 := First (Constraints (Constraint (Indic2)));
8888 while Present (Elt1) and then Present (Elt2) loop
8889 if not FCE (Elt1, Elt2) then
8902 when N_Attribute_Reference =>
8904 Attribute_Name (E1) = Attribute_Name (E2)
8905 and then FCL (Expressions (E1), Expressions (E2));
8909 Entity (E1) = Entity (E2)
8910 and then FCE (Left_Opnd (E1), Left_Opnd (E2))
8911 and then FCE (Right_Opnd (E1), Right_Opnd (E2));
8913 when N_Membership_Test
8917 FCE (Left_Opnd (E1), Left_Opnd (E2))
8919 FCE (Right_Opnd (E1), Right_Opnd (E2));
8921 when N_Case_Expression =>
8927 if not FCE (Expression (E1), Expression (E2)) then
8931 Alt1 := First (Alternatives (E1));
8932 Alt2 := First (Alternatives (E2));
8934 if Present (Alt1) /= Present (Alt2) then
8936 elsif No (Alt1) then
8940 if not FCE (Expression (Alt1), Expression (Alt2))
8941 or else not FCL (Discrete_Choices (Alt1),
8942 Discrete_Choices (Alt2))
8953 when N_Character_Literal =>
8955 Char_Literal_Value (E1) = Char_Literal_Value (E2);
8957 when N_Component_Association =>
8959 FCL (Choices (E1), Choices (E2))
8961 FCE (Expression (E1), Expression (E2));
8963 when N_Explicit_Dereference =>
8965 FCE (Prefix (E1), Prefix (E2));
8967 when N_Extension_Aggregate =>
8969 FCL (Expressions (E1), Expressions (E2))
8970 and then Null_Record_Present (E1) =
8971 Null_Record_Present (E2)
8972 and then FCL (Component_Associations (E1),
8973 Component_Associations (E2));
8975 when N_Function_Call =>
8977 FCE (Name (E1), Name (E2))
8979 FCL (Parameter_Associations (E1),
8980 Parameter_Associations (E2));
8982 when N_If_Expression =>
8984 FCL (Expressions (E1), Expressions (E2));
8986 when N_Indexed_Component =>
8988 FCE (Prefix (E1), Prefix (E2))
8990 FCL (Expressions (E1), Expressions (E2));
8992 when N_Integer_Literal =>
8993 return (Intval (E1) = Intval (E2));
8998 when N_Operator_Symbol =>
9000 Chars (E1) = Chars (E2);
9002 when N_Others_Choice =>
9005 when N_Parameter_Association =>
9007 Chars (Selector_Name (E1)) = Chars (Selector_Name (E2))
9008 and then FCE (Explicit_Actual_Parameter (E1),
9009 Explicit_Actual_Parameter (E2));
9011 when N_Qualified_Expression
9013 | N_Unchecked_Type_Conversion
9016 FCE (Subtype_Mark (E1), Subtype_Mark (E2))
9018 FCE (Expression (E1), Expression (E2));
9020 when N_Quantified_Expression =>
9021 if not FCE (Condition (E1), Condition (E2)) then
9025 if Present (Loop_Parameter_Specification (E1))
9026 and then Present (Loop_Parameter_Specification (E2))
9029 L1 : constant Node_Id :=
9030 Loop_Parameter_Specification (E1);
9031 L2 : constant Node_Id :=
9032 Loop_Parameter_Specification (E2);
9036 Reverse_Present (L1) = Reverse_Present (L2)
9038 FCE (Defining_Identifier (L1),
9039 Defining_Identifier (L2))
9041 FCE (Discrete_Subtype_Definition (L1),
9042 Discrete_Subtype_Definition (L2));
9045 elsif Present (Iterator_Specification (E1))
9046 and then Present (Iterator_Specification (E2))
9049 I1 : constant Node_Id := Iterator_Specification (E1);
9050 I2 : constant Node_Id := Iterator_Specification (E2);
9054 FCE (Defining_Identifier (I1),
9055 Defining_Identifier (I2))
9057 Of_Present (I1) = Of_Present (I2)
9059 Reverse_Present (I1) = Reverse_Present (I2)
9060 and then FCE (Name (I1), Name (I2))
9061 and then FCE (Subtype_Indication (I1),
9062 Subtype_Indication (I2));
9065 -- The quantified expressions used different specifications to
9066 -- walk their respective ranges.
9074 FCE (Low_Bound (E1), Low_Bound (E2))
9076 FCE (High_Bound (E1), High_Bound (E2));
9078 when N_Real_Literal =>
9079 return (Realval (E1) = Realval (E2));
9081 when N_Selected_Component =>
9083 FCE (Prefix (E1), Prefix (E2))
9085 FCE (Selector_Name (E1), Selector_Name (E2));
9089 FCE (Prefix (E1), Prefix (E2))
9091 FCE (Discrete_Range (E1), Discrete_Range (E2));
9093 when N_String_Literal =>
9095 S1 : constant String_Id := Strval (E1);
9096 S2 : constant String_Id := Strval (E2);
9097 L1 : constant Nat := String_Length (S1);
9098 L2 : constant Nat := String_Length (S2);
9105 for J in 1 .. L1 loop
9106 if Get_String_Char (S1, J) /=
9107 Get_String_Char (S2, J)
9119 Entity (E1) = Entity (E2)
9121 FCE (Right_Opnd (E1), Right_Opnd (E2));
9123 -- All other node types cannot appear in this context. Strictly
9124 -- we should raise a fatal internal error. Instead we just ignore
9125 -- the nodes. This means that if anyone makes a mistake in the
9126 -- expander and mucks an expression tree irretrievably, the result
9127 -- will be a failure to detect a (probably very obscure) case
9128 -- of non-conformance, which is better than bombing on some
9129 -- case where two expressions do in fact conform.
9135 end Fully_Conformant_Expressions;
9137 ----------------------------------------
9138 -- Fully_Conformant_Discrete_Subtypes --
9139 ----------------------------------------
9141 function Fully_Conformant_Discrete_Subtypes
9142 (Given_S1 : Node_Id;
9143 Given_S2 : Node_Id) return Boolean
9145 S1 : constant Node_Id := Original_Node (Given_S1);
9146 S2 : constant Node_Id := Original_Node (Given_S2);
9148 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean;
9149 -- Special-case for a bound given by a discriminant, which in the body
9150 -- is replaced with the discriminal of the enclosing type.
9152 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean;
9153 -- Check both bounds
9155 -----------------------
9156 -- Conforming_Bounds --
9157 -----------------------
9159 function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is
9161 if Is_Entity_Name (B1)
9162 and then Is_Entity_Name (B2)
9163 and then Ekind (Entity (B1)) = E_Discriminant
9165 return Chars (B1) = Chars (B2);
9168 return Fully_Conformant_Expressions (B1, B2);
9170 end Conforming_Bounds;
9172 -----------------------
9173 -- Conforming_Ranges --
9174 -----------------------
9176 function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is
9179 Conforming_Bounds (Low_Bound (R1), Low_Bound (R2))
9181 Conforming_Bounds (High_Bound (R1), High_Bound (R2));
9182 end Conforming_Ranges;
9184 -- Start of processing for Fully_Conformant_Discrete_Subtypes
9187 if Nkind (S1) /= Nkind (S2) then
9190 elsif Is_Entity_Name (S1) then
9191 return Entity (S1) = Entity (S2);
9193 elsif Nkind (S1) = N_Range then
9194 return Conforming_Ranges (S1, S2);
9196 elsif Nkind (S1) = N_Subtype_Indication then
9198 Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2))
9201 (Range_Expression (Constraint (S1)),
9202 Range_Expression (Constraint (S2)));
9206 end Fully_Conformant_Discrete_Subtypes;
9208 --------------------
9209 -- Install_Entity --
9210 --------------------
9212 procedure Install_Entity (E : Entity_Id) is
9213 Prev : constant Entity_Id := Current_Entity (E);
9215 Set_Is_Immediately_Visible (E);
9216 Set_Current_Entity (E);
9217 Set_Homonym (E, Prev);
9220 ---------------------
9221 -- Install_Formals --
9222 ---------------------
9224 procedure Install_Formals (Id : Entity_Id) is
9227 F := First_Formal (Id);
9228 while Present (F) loop
9232 end Install_Formals;
9234 -----------------------------
9235 -- Is_Interface_Conformant --
9236 -----------------------------
9238 function Is_Interface_Conformant
9239 (Tagged_Type : Entity_Id;
9240 Iface_Prim : Entity_Id;
9241 Prim : Entity_Id) return Boolean
9243 -- The operation may in fact be an inherited (implicit) operation
9244 -- rather than the original interface primitive, so retrieve the
9245 -- ultimate ancestor.
9247 Iface : constant Entity_Id :=
9248 Find_Dispatching_Type (Ultimate_Alias (Iface_Prim));
9249 Typ : constant Entity_Id := Find_Dispatching_Type (Prim);
9251 function Controlling_Formal (Prim : Entity_Id) return Entity_Id;
9252 -- Return the controlling formal of Prim
9254 ------------------------
9255 -- Controlling_Formal --
9256 ------------------------
9258 function Controlling_Formal (Prim : Entity_Id) return Entity_Id is
9262 E := First_Entity (Prim);
9263 while Present (E) loop
9264 if Is_Formal (E) and then Is_Controlling_Formal (E) then
9272 end Controlling_Formal;
9276 Iface_Ctrl_F : constant Entity_Id := Controlling_Formal (Iface_Prim);
9277 Prim_Ctrl_F : constant Entity_Id := Controlling_Formal (Prim);
9279 -- Start of processing for Is_Interface_Conformant
9282 pragma Assert (Is_Subprogram (Iface_Prim)
9283 and then Is_Subprogram (Prim)
9284 and then Is_Dispatching_Operation (Iface_Prim)
9285 and then Is_Dispatching_Operation (Prim));
9287 pragma Assert (Is_Interface (Iface)
9288 or else (Present (Alias (Iface_Prim))
9291 (Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)))));
9293 if Prim = Iface_Prim
9294 or else not Is_Subprogram (Prim)
9295 or else Ekind (Prim) /= Ekind (Iface_Prim)
9296 or else not Is_Dispatching_Operation (Prim)
9297 or else Scope (Prim) /= Scope (Tagged_Type)
9299 or else Base_Type (Typ) /= Base_Type (Tagged_Type)
9300 or else not Primitive_Names_Match (Iface_Prim, Prim)
9304 -- The mode of the controlling formals must match
9306 elsif Present (Iface_Ctrl_F)
9307 and then Present (Prim_Ctrl_F)
9308 and then Ekind (Iface_Ctrl_F) /= Ekind (Prim_Ctrl_F)
9312 -- Case of a procedure, or a function whose result type matches the
9313 -- result type of the interface primitive, or a function that has no
9314 -- controlling result (I or access I).
9316 elsif Ekind (Iface_Prim) = E_Procedure
9317 or else Etype (Prim) = Etype (Iface_Prim)
9318 or else not Has_Controlling_Result (Prim)
9320 return Type_Conformant
9321 (Iface_Prim, Prim, Skip_Controlling_Formals => True);
9323 -- Case of a function returning an interface, or an access to one. Check
9324 -- that the return types correspond.
9326 elsif Implements_Interface (Typ, Iface) then
9327 if (Ekind (Etype (Prim)) = E_Anonymous_Access_Type)
9329 (Ekind (Etype (Iface_Prim)) = E_Anonymous_Access_Type)
9334 Type_Conformant (Prim, Ultimate_Alias (Iface_Prim),
9335 Skip_Controlling_Formals => True);
9341 end Is_Interface_Conformant;
9343 ---------------------------------
9344 -- Is_Non_Overriding_Operation --
9345 ---------------------------------
9347 function Is_Non_Overriding_Operation
9348 (Prev_E : Entity_Id;
9349 New_E : Entity_Id) return Boolean
9353 G_Typ : Entity_Id := Empty;
9355 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id;
9356 -- If F_Type is a derived type associated with a generic actual subtype,
9357 -- then return its Generic_Parent_Type attribute, else return Empty.
9359 function Types_Correspond
9360 (P_Type : Entity_Id;
9361 N_Type : Entity_Id) return Boolean;
9362 -- Returns true if and only if the types (or designated types in the
9363 -- case of anonymous access types) are the same or N_Type is derived
9364 -- directly or indirectly from P_Type.
9366 -----------------------------
9367 -- Get_Generic_Parent_Type --
9368 -----------------------------
9370 function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is
9376 if Is_Derived_Type (F_Typ)
9377 and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration
9379 -- The tree must be traversed to determine the parent subtype in
9380 -- the generic unit, which unfortunately isn't always available
9381 -- via semantic attributes. ??? (Note: The use of Original_Node
9382 -- is needed for cases where a full derived type has been
9385 -- If the parent type is a scalar type, the derivation creates
9386 -- an anonymous base type for it, and the source type is its
9389 if Is_Scalar_Type (F_Typ)
9390 and then not Comes_From_Source (F_Typ)
9394 (Original_Node (Parent (First_Subtype (F_Typ))));
9396 Defn := Type_Definition (Original_Node (Parent (F_Typ)));
9398 if Nkind (Defn) = N_Derived_Type_Definition then
9399 Indic := Subtype_Indication (Defn);
9401 if Nkind (Indic) = N_Subtype_Indication then
9402 G_Typ := Entity (Subtype_Mark (Indic));
9404 G_Typ := Entity (Indic);
9407 if Nkind (Parent (G_Typ)) = N_Subtype_Declaration
9408 and then Present (Generic_Parent_Type (Parent (G_Typ)))
9410 return Generic_Parent_Type (Parent (G_Typ));
9416 end Get_Generic_Parent_Type;
9418 ----------------------
9419 -- Types_Correspond --
9420 ----------------------
9422 function Types_Correspond
9423 (P_Type : Entity_Id;
9424 N_Type : Entity_Id) return Boolean
9426 Prev_Type : Entity_Id := Base_Type (P_Type);
9427 New_Type : Entity_Id := Base_Type (N_Type);
9430 if Ekind (Prev_Type) = E_Anonymous_Access_Type then
9431 Prev_Type := Designated_Type (Prev_Type);
9434 if Ekind (New_Type) = E_Anonymous_Access_Type then
9435 New_Type := Designated_Type (New_Type);
9438 if Prev_Type = New_Type then
9441 elsif not Is_Class_Wide_Type (New_Type) then
9442 while Etype (New_Type) /= New_Type loop
9443 New_Type := Etype (New_Type);
9445 if New_Type = Prev_Type then
9451 end Types_Correspond;
9453 -- Start of processing for Is_Non_Overriding_Operation
9456 -- In the case where both operations are implicit derived subprograms
9457 -- then neither overrides the other. This can only occur in certain
9458 -- obscure cases (e.g., derivation from homographs created in a generic
9461 if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then
9464 elsif Ekind (Current_Scope) = E_Package
9465 and then Is_Generic_Instance (Current_Scope)
9466 and then In_Private_Part (Current_Scope)
9467 and then Comes_From_Source (New_E)
9469 -- We examine the formals and result type of the inherited operation,
9470 -- to determine whether their type is derived from (the instance of)
9471 -- a generic type. The first such formal or result type is the one
9474 Formal := First_Formal (Prev_E);
9476 while Present (Formal) loop
9477 F_Typ := Base_Type (Etype (Formal));
9479 if Ekind (F_Typ) = E_Anonymous_Access_Type then
9480 F_Typ := Designated_Type (F_Typ);
9483 G_Typ := Get_Generic_Parent_Type (F_Typ);
9484 exit when Present (G_Typ);
9486 Next_Formal (Formal);
9489 -- If the function dispatches on result check the result type
9491 if No (G_Typ) and then Ekind (Prev_E) = E_Function then
9492 G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E)));
9499 -- If the generic type is a private type, then the original operation
9500 -- was not overriding in the generic, because there was no primitive
9501 -- operation to override.
9503 if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration
9504 and then Nkind (Formal_Type_Definition (Parent (G_Typ))) =
9505 N_Formal_Private_Type_Definition
9509 -- The generic parent type is the ancestor of a formal derived
9510 -- type declaration. We need to check whether it has a primitive
9511 -- operation that should be overridden by New_E in the generic.
9515 P_Formal : Entity_Id;
9516 N_Formal : Entity_Id;
9520 Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ));
9523 while Present (Prim_Elt) loop
9524 P_Prim := Node (Prim_Elt);
9526 if Chars (P_Prim) = Chars (New_E)
9527 and then Ekind (P_Prim) = Ekind (New_E)
9529 P_Formal := First_Formal (P_Prim);
9530 N_Formal := First_Formal (New_E);
9531 while Present (P_Formal) and then Present (N_Formal) loop
9532 P_Typ := Etype (P_Formal);
9533 N_Typ := Etype (N_Formal);
9535 if not Types_Correspond (P_Typ, N_Typ) then
9539 Next_Entity (P_Formal);
9540 Next_Entity (N_Formal);
9543 -- Found a matching primitive operation belonging to the
9544 -- formal ancestor type, so the new subprogram is
9548 and then No (N_Formal)
9549 and then (Ekind (New_E) /= E_Function
9552 (Etype (P_Prim), Etype (New_E)))
9558 Next_Elmt (Prim_Elt);
9561 -- If no match found, then the new subprogram does not override
9562 -- in the generic (nor in the instance).
9564 -- If the type in question is not abstract, and the subprogram
9565 -- is, this will be an error if the new operation is in the
9566 -- private part of the instance. Emit a warning now, which will
9567 -- make the subsequent error message easier to understand.
9569 if Present (F_Typ) and then not Is_Abstract_Type (F_Typ)
9570 and then Is_Abstract_Subprogram (Prev_E)
9571 and then In_Private_Part (Current_Scope)
9573 Error_Msg_Node_2 := F_Typ;
9575 ("private operation& in generic unit does not override "
9576 & "any primitive operation of& (RM 12.3 (18))??",
9586 end Is_Non_Overriding_Operation;
9588 -------------------------------------
9589 -- List_Inherited_Pre_Post_Aspects --
9590 -------------------------------------
9592 procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id) is
9594 if Opt.List_Inherited_Aspects
9595 and then Is_Subprogram_Or_Generic_Subprogram (E)
9598 Subps : constant Subprogram_List := Inherited_Subprograms (E);
9603 for Index in Subps'Range loop
9604 Items := Contract (Subps (Index));
9606 if Present (Items) then
9607 Prag := Pre_Post_Conditions (Items);
9608 while Present (Prag) loop
9609 Error_Msg_Sloc := Sloc (Prag);
9611 if Class_Present (Prag)
9612 and then not Split_PPC (Prag)
9614 if Pragma_Name (Prag) = Name_Precondition then
9616 ("info: & inherits `Pre''Class` aspect from "
9620 ("info: & inherits `Post''Class` aspect from "
9625 Prag := Next_Pragma (Prag);
9631 end List_Inherited_Pre_Post_Aspects;
9633 ------------------------------
9634 -- Make_Inequality_Operator --
9635 ------------------------------
9637 -- S is the defining identifier of an equality operator. We build a
9638 -- subprogram declaration with the right signature. This operation is
9639 -- intrinsic, because it is always expanded as the negation of the
9640 -- call to the equality function.
9642 procedure Make_Inequality_Operator (S : Entity_Id) is
9643 Loc : constant Source_Ptr := Sloc (S);
9646 Op_Name : Entity_Id;
9648 FF : constant Entity_Id := First_Formal (S);
9649 NF : constant Entity_Id := Next_Formal (FF);
9652 -- Check that equality was properly defined, ignore call if not
9659 A : constant Entity_Id :=
9660 Make_Defining_Identifier (Sloc (FF),
9661 Chars => Chars (FF));
9663 B : constant Entity_Id :=
9664 Make_Defining_Identifier (Sloc (NF),
9665 Chars => Chars (NF));
9668 Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne);
9670 Formals := New_List (
9671 Make_Parameter_Specification (Loc,
9672 Defining_Identifier => A,
9674 New_Occurrence_Of (Etype (First_Formal (S)),
9675 Sloc (Etype (First_Formal (S))))),
9677 Make_Parameter_Specification (Loc,
9678 Defining_Identifier => B,
9680 New_Occurrence_Of (Etype (Next_Formal (First_Formal (S))),
9681 Sloc (Etype (Next_Formal (First_Formal (S)))))));
9684 Make_Subprogram_Declaration (Loc,
9686 Make_Function_Specification (Loc,
9687 Defining_Unit_Name => Op_Name,
9688 Parameter_Specifications => Formals,
9689 Result_Definition =>
9690 New_Occurrence_Of (Standard_Boolean, Loc)));
9692 -- Insert inequality right after equality if it is explicit or after
9693 -- the derived type when implicit. These entities are created only
9694 -- for visibility purposes, and eventually replaced in the course
9695 -- of expansion, so they do not need to be attached to the tree and
9696 -- seen by the back-end. Keeping them internal also avoids spurious
9697 -- freezing problems. The declaration is inserted in the tree for
9698 -- analysis, and removed afterwards. If the equality operator comes
9699 -- from an explicit declaration, attach the inequality immediately
9700 -- after. Else the equality is inherited from a derived type
9701 -- declaration, so insert inequality after that declaration.
9703 if No (Alias (S)) then
9704 Insert_After (Unit_Declaration_Node (S), Decl);
9705 elsif Is_List_Member (Parent (S)) then
9706 Insert_After (Parent (S), Decl);
9708 Insert_After (Parent (Etype (First_Formal (S))), Decl);
9711 Mark_Rewrite_Insertion (Decl);
9712 Set_Is_Intrinsic_Subprogram (Op_Name);
9715 Set_Has_Completion (Op_Name);
9716 Set_Corresponding_Equality (Op_Name, S);
9717 Set_Is_Abstract_Subprogram (Op_Name, Is_Abstract_Subprogram (S));
9719 end Make_Inequality_Operator;
9721 ----------------------
9722 -- May_Need_Actuals --
9723 ----------------------
9725 procedure May_Need_Actuals (Fun : Entity_Id) is
9730 F := First_Formal (Fun);
9732 while Present (F) loop
9733 if No (Default_Value (F)) then
9741 Set_Needs_No_Actuals (Fun, B);
9742 end May_Need_Actuals;
9744 ---------------------
9745 -- Mode_Conformant --
9746 ---------------------
9748 function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
9751 Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result);
9753 end Mode_Conformant;
9755 ---------------------------
9756 -- New_Overloaded_Entity --
9757 ---------------------------
9759 procedure New_Overloaded_Entity
9761 Derived_Type : Entity_Id := Empty)
9763 Overridden_Subp : Entity_Id := Empty;
9764 -- Set if the current scope has an operation that is type-conformant
9765 -- with S, and becomes hidden by S.
9767 Is_Primitive_Subp : Boolean;
9768 -- Set to True if the new subprogram is primitive
9771 -- Entity that S overrides
9773 Prev_Vis : Entity_Id := Empty;
9774 -- Predecessor of E in Homonym chain
9776 procedure Check_For_Primitive_Subprogram
9777 (Is_Primitive : out Boolean;
9778 Is_Overriding : Boolean := False);
9779 -- If the subprogram being analyzed is a primitive operation of the type
9780 -- of a formal or result, set the Has_Primitive_Operations flag on the
9781 -- type, and set Is_Primitive to True (otherwise set to False). Set the
9782 -- corresponding flag on the entity itself for later use.
9784 function Has_Matching_Entry_Or_Subprogram (E : Entity_Id) return Boolean;
9785 -- True if a) E is a subprogram whose first formal is a concurrent type
9786 -- defined in the scope of E that has some entry or subprogram whose
9787 -- profile matches E, or b) E is an internally built dispatching
9788 -- subprogram of a protected type and there is a matching subprogram
9789 -- defined in the enclosing scope of the protected type, or c) E is
9790 -- an entry of a synchronized type and a matching procedure has been
9791 -- previously defined in the enclosing scope of the synchronized type.
9793 function Is_Private_Declaration (E : Entity_Id) return Boolean;
9794 -- Check that E is declared in the private part of the current package,
9795 -- or in the package body, where it may hide a previous declaration.
9796 -- We can't use In_Private_Part by itself because this flag is also
9797 -- set when freezing entities, so we must examine the place of the
9798 -- declaration in the tree, and recognize wrapper packages as well.
9800 function Is_Overriding_Alias
9802 New_E : Entity_Id) return Boolean;
9803 -- Check whether new subprogram and old subprogram are both inherited
9804 -- from subprograms that have distinct dispatch table entries. This can
9805 -- occur with derivations from instances with accidental homonyms. The
9806 -- function is conservative given that the converse is only true within
9807 -- instances that contain accidental overloadings.
9809 procedure Report_Conflict (S : Entity_Id; E : Entity_Id);
9810 -- Report conflict between entities S and E
9812 ------------------------------------
9813 -- Check_For_Primitive_Subprogram --
9814 ------------------------------------
9816 procedure Check_For_Primitive_Subprogram
9817 (Is_Primitive : out Boolean;
9818 Is_Overriding : Boolean := False)
9824 function Visible_Part_Type (T : Entity_Id) return Boolean;
9825 -- Returns true if T is declared in the visible part of the current
9826 -- package scope; otherwise returns false. Assumes that T is declared
9829 procedure Check_Private_Overriding (T : Entity_Id);
9830 -- Checks that if a primitive abstract subprogram of a visible
9831 -- abstract type is declared in a private part, then it must override
9832 -- an abstract subprogram declared in the visible part. Also checks
9833 -- that if a primitive function with a controlling result is declared
9834 -- in a private part, then it must override a function declared in
9835 -- the visible part.
9837 ------------------------------
9838 -- Check_Private_Overriding --
9839 ------------------------------
9841 procedure Check_Private_Overriding (T : Entity_Id) is
9842 function Overrides_Private_Part_Op return Boolean;
9843 -- This detects the special case where the overriding subprogram
9844 -- is overriding a subprogram that was declared in the same
9845 -- private part. That case is illegal by 3.9.3(10).
9847 function Overrides_Visible_Function
9848 (Partial_View : Entity_Id) return Boolean;
9849 -- True if S overrides a function in the visible part. The
9850 -- overridden function could be explicitly or implicitly declared.
9852 -------------------------------
9853 -- Overrides_Private_Part_Op --
9854 -------------------------------
9856 function Overrides_Private_Part_Op return Boolean is
9857 Over_Decl : constant Node_Id :=
9858 Unit_Declaration_Node (Overridden_Operation (S));
9859 Subp_Decl : constant Node_Id := Unit_Declaration_Node (S);
9862 pragma Assert (Is_Overriding);
9864 (Nkind (Over_Decl) = N_Abstract_Subprogram_Declaration);
9866 (Nkind (Subp_Decl) = N_Abstract_Subprogram_Declaration);
9868 return In_Same_List (Over_Decl, Subp_Decl);
9869 end Overrides_Private_Part_Op;
9871 --------------------------------
9872 -- Overrides_Visible_Function --
9873 --------------------------------
9875 function Overrides_Visible_Function
9876 (Partial_View : Entity_Id) return Boolean
9879 if not Is_Overriding or else not Has_Homonym (S) then
9883 if not Present (Partial_View) then
9887 -- Search through all the homonyms H of S in the current
9888 -- package spec, and return True if we find one that matches.
9889 -- Note that Parent (H) will be the declaration of the
9890 -- partial view of T for a match.
9897 exit when not Present (H) or else Scope (H) /= Scope (S);
9901 N_Private_Extension_Declaration,
9902 N_Private_Type_Declaration)
9903 and then Defining_Identifier (Parent (H)) = Partial_View
9911 end Overrides_Visible_Function;
9913 -- Start of processing for Check_Private_Overriding
9916 if Is_Package_Or_Generic_Package (Current_Scope)
9917 and then In_Private_Part (Current_Scope)
9918 and then Visible_Part_Type (T)
9919 and then not In_Instance
9921 if Is_Abstract_Type (T)
9922 and then Is_Abstract_Subprogram (S)
9923 and then (not Is_Overriding
9924 or else not Is_Abstract_Subprogram (E)
9925 or else Overrides_Private_Part_Op)
9928 ("abstract subprograms must be visible (RM 3.9.3(10))!",
9931 elsif Ekind (S) = E_Function then
9933 Partial_View : constant Entity_Id :=
9934 Incomplete_Or_Partial_View (T);
9937 if not Overrides_Visible_Function (Partial_View) then
9939 -- Here, S is "function ... return T;" declared in
9940 -- the private part, not overriding some visible
9941 -- operation. That's illegal in the tagged case
9942 -- (but not if the private type is untagged).
9944 if ((Present (Partial_View)
9945 and then Is_Tagged_Type (Partial_View))
9946 or else (not Present (Partial_View)
9947 and then Is_Tagged_Type (T)))
9948 and then T = Base_Type (Etype (S))
9951 ("private function with tagged result must"
9952 & " override visible-part function", S);
9954 ("\move subprogram to the visible part"
9955 & " (RM 3.9.3(10))", S);
9957 -- AI05-0073: extend this test to the case of a
9958 -- function with a controlling access result.
9960 elsif Ekind (Etype (S)) = E_Anonymous_Access_Type
9961 and then Is_Tagged_Type (Designated_Type (Etype (S)))
9963 not Is_Class_Wide_Type
9964 (Designated_Type (Etype (S)))
9965 and then Ada_Version >= Ada_2012
9968 ("private function with controlling access "
9969 & "result must override visible-part function",
9972 ("\move subprogram to the visible part"
9973 & " (RM 3.9.3(10))", S);
9979 end Check_Private_Overriding;
9981 -----------------------
9982 -- Visible_Part_Type --
9983 -----------------------
9985 function Visible_Part_Type (T : Entity_Id) return Boolean is
9986 P : constant Node_Id := Unit_Declaration_Node (Scope (T));
9990 -- If the entity is a private type, then it must be declared in a
9993 if Ekind (T) in Private_Kind then
9997 -- Otherwise, we traverse the visible part looking for its
9998 -- corresponding declaration. We cannot use the declaration
9999 -- node directly because in the private part the entity of a
10000 -- private type is the one in the full view, which does not
10001 -- indicate that it is the completion of something visible.
10003 N := First (Visible_Declarations (Specification (P)));
10004 while Present (N) loop
10005 if Nkind (N) = N_Full_Type_Declaration
10006 and then Present (Defining_Identifier (N))
10007 and then T = Defining_Identifier (N)
10011 elsif Nkind_In (N, N_Private_Type_Declaration,
10012 N_Private_Extension_Declaration)
10013 and then Present (Defining_Identifier (N))
10014 and then T = Full_View (Defining_Identifier (N))
10023 end Visible_Part_Type;
10025 -- Start of processing for Check_For_Primitive_Subprogram
10028 Is_Primitive := False;
10030 if not Comes_From_Source (S) then
10033 -- If subprogram is at library level, it is not primitive operation
10035 elsif Current_Scope = Standard_Standard then
10038 elsif (Is_Package_Or_Generic_Package (Current_Scope)
10039 and then not In_Package_Body (Current_Scope))
10040 or else Is_Overriding
10042 -- For function, check return type
10044 if Ekind (S) = E_Function then
10045 if Ekind (Etype (S)) = E_Anonymous_Access_Type then
10046 F_Typ := Designated_Type (Etype (S));
10048 F_Typ := Etype (S);
10051 B_Typ := Base_Type (F_Typ);
10053 if Scope (B_Typ) = Current_Scope
10054 and then not Is_Class_Wide_Type (B_Typ)
10055 and then not Is_Generic_Type (B_Typ)
10057 Is_Primitive := True;
10058 Set_Has_Primitive_Operations (B_Typ);
10059 Set_Is_Primitive (S);
10060 Check_Private_Overriding (B_Typ);
10062 -- The Ghost policy in effect at the point of declaration
10063 -- or a tagged type and a primitive operation must match
10064 -- (SPARK RM 6.9(16)).
10066 Check_Ghost_Primitive (S, B_Typ);
10070 -- For all subprograms, check formals
10072 Formal := First_Formal (S);
10073 while Present (Formal) loop
10074 if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
10075 F_Typ := Designated_Type (Etype (Formal));
10077 F_Typ := Etype (Formal);
10080 B_Typ := Base_Type (F_Typ);
10082 if Ekind (B_Typ) = E_Access_Subtype then
10083 B_Typ := Base_Type (B_Typ);
10086 if Scope (B_Typ) = Current_Scope
10087 and then not Is_Class_Wide_Type (B_Typ)
10088 and then not Is_Generic_Type (B_Typ)
10090 Is_Primitive := True;
10091 Set_Is_Primitive (S);
10092 Set_Has_Primitive_Operations (B_Typ);
10093 Check_Private_Overriding (B_Typ);
10095 -- The Ghost policy in effect at the point of declaration
10096 -- of a tagged type and a primitive operation must match
10097 -- (SPARK RM 6.9(16)).
10099 Check_Ghost_Primitive (S, B_Typ);
10102 Next_Formal (Formal);
10105 -- Special case: An equality function can be redefined for a type
10106 -- occurring in a declarative part, and won't otherwise be treated as
10107 -- a primitive because it doesn't occur in a package spec and doesn't
10108 -- override an inherited subprogram. It's important that we mark it
10109 -- primitive so it can be returned by Collect_Primitive_Operations
10110 -- and be used in composing the equality operation of later types
10111 -- that have a component of the type.
10113 elsif Chars (S) = Name_Op_Eq
10114 and then Etype (S) = Standard_Boolean
10116 B_Typ := Base_Type (Etype (First_Formal (S)));
10118 if Scope (B_Typ) = Current_Scope
10120 Base_Type (Etype (Next_Formal (First_Formal (S)))) = B_Typ
10121 and then not Is_Limited_Type (B_Typ)
10123 Is_Primitive := True;
10124 Set_Is_Primitive (S);
10125 Set_Has_Primitive_Operations (B_Typ);
10126 Check_Private_Overriding (B_Typ);
10128 -- The Ghost policy in effect at the point of declaration of a
10129 -- tagged type and a primitive operation must match
10130 -- (SPARK RM 6.9(16)).
10132 Check_Ghost_Primitive (S, B_Typ);
10135 end Check_For_Primitive_Subprogram;
10137 --------------------------------------
10138 -- Has_Matching_Entry_Or_Subprogram --
10139 --------------------------------------
10141 function Has_Matching_Entry_Or_Subprogram
10142 (E : Entity_Id) return Boolean
10144 function Check_Conforming_Parameters
10145 (E1_Param : Node_Id;
10146 E2_Param : Node_Id) return Boolean;
10147 -- Starting from the given parameters, check that all the parameters
10148 -- of two entries or subprograms are subtype conformant. Used to skip
10149 -- the check on the controlling argument.
10151 function Matching_Entry_Or_Subprogram
10152 (Conc_Typ : Entity_Id;
10153 Subp : Entity_Id) return Entity_Id;
10154 -- Return the first entry or subprogram of the given concurrent type
10155 -- whose name matches the name of Subp and has a profile conformant
10156 -- with Subp; return Empty if not found.
10158 function Matching_Dispatching_Subprogram
10159 (Conc_Typ : Entity_Id;
10160 Ent : Entity_Id) return Entity_Id;
10161 -- Return the first dispatching primitive of Conc_Type defined in the
10162 -- enclosing scope of Conc_Type (i.e. before the full definition of
10163 -- this concurrent type) whose name matches the entry Ent and has a
10164 -- profile conformant with the profile of the corresponding (not yet
10165 -- built) dispatching primitive of Ent; return Empty if not found.
10167 function Matching_Original_Protected_Subprogram
10168 (Prot_Typ : Entity_Id;
10169 Subp : Entity_Id) return Entity_Id;
10170 -- Return the first subprogram defined in the enclosing scope of
10171 -- Prot_Typ (before the full definition of this protected type)
10172 -- whose name matches the original name of Subp and has a profile
10173 -- conformant with the profile of Subp; return Empty if not found.
10175 ---------------------------------
10176 -- Check_Confirming_Parameters --
10177 ---------------------------------
10179 function Check_Conforming_Parameters
10180 (E1_Param : Node_Id;
10181 E2_Param : Node_Id) return Boolean
10183 Param_E1 : Node_Id := E1_Param;
10184 Param_E2 : Node_Id := E2_Param;
10187 while Present (Param_E1) and then Present (Param_E2) loop
10188 if Ekind (Defining_Identifier (Param_E1)) /=
10189 Ekind (Defining_Identifier (Param_E2))
10192 (Find_Parameter_Type (Param_E1),
10193 Find_Parameter_Type (Param_E2),
10194 Subtype_Conformant)
10203 -- The candidate is not valid if one of the two lists contains
10204 -- more parameters than the other
10206 return No (Param_E1) and then No (Param_E2);
10207 end Check_Conforming_Parameters;
10209 ----------------------------------
10210 -- Matching_Entry_Or_Subprogram --
10211 ----------------------------------
10213 function Matching_Entry_Or_Subprogram
10214 (Conc_Typ : Entity_Id;
10215 Subp : Entity_Id) return Entity_Id
10220 E := First_Entity (Conc_Typ);
10221 while Present (E) loop
10222 if Chars (Subp) = Chars (E)
10223 and then (Ekind (E) = E_Entry or else Is_Subprogram (E))
10225 Check_Conforming_Parameters
10226 (First (Parameter_Specifications (Parent (E))),
10227 Next (First (Parameter_Specifications (Parent (Subp)))))
10236 end Matching_Entry_Or_Subprogram;
10238 -------------------------------------
10239 -- Matching_Dispatching_Subprogram --
10240 -------------------------------------
10242 function Matching_Dispatching_Subprogram
10243 (Conc_Typ : Entity_Id;
10244 Ent : Entity_Id) return Entity_Id
10249 -- Search for entities in the enclosing scope of this synchonized
10252 pragma Assert (Is_Concurrent_Type (Conc_Typ));
10253 Push_Scope (Scope (Conc_Typ));
10254 E := Current_Entity_In_Scope (Ent);
10257 while Present (E) loop
10258 if Scope (E) = Scope (Conc_Typ)
10259 and then Comes_From_Source (E)
10260 and then Ekind (E) = E_Procedure
10261 and then Present (First_Entity (E))
10262 and then Is_Controlling_Formal (First_Entity (E))
10263 and then Etype (First_Entity (E)) = Conc_Typ
10265 Check_Conforming_Parameters
10266 (First (Parameter_Specifications (Parent (Ent))),
10267 Next (First (Parameter_Specifications (Parent (E)))))
10276 end Matching_Dispatching_Subprogram;
10278 --------------------------------------------
10279 -- Matching_Original_Protected_Subprogram --
10280 --------------------------------------------
10282 function Matching_Original_Protected_Subprogram
10283 (Prot_Typ : Entity_Id;
10284 Subp : Entity_Id) return Entity_Id
10286 ICF : constant Boolean :=
10287 Is_Controlling_Formal (First_Entity (Subp));
10291 -- Temporarily decorate the first parameter of Subp as controlling
10292 -- formal, required to invoke Subtype_Conformant.
10294 Set_Is_Controlling_Formal (First_Entity (Subp));
10297 Current_Entity_In_Scope (Original_Protected_Subprogram (Subp));
10299 while Present (E) loop
10300 if Scope (E) = Scope (Prot_Typ)
10301 and then Comes_From_Source (E)
10302 and then Ekind (Subp) = Ekind (E)
10303 and then Present (First_Entity (E))
10304 and then Is_Controlling_Formal (First_Entity (E))
10305 and then Etype (First_Entity (E)) = Prot_Typ
10306 and then Subtype_Conformant (Subp, E,
10307 Skip_Controlling_Formals => True)
10309 Set_Is_Controlling_Formal (First_Entity (Subp), ICF);
10316 Set_Is_Controlling_Formal (First_Entity (Subp), ICF);
10319 end Matching_Original_Protected_Subprogram;
10321 -- Start of processing for Has_Matching_Entry_Or_Subprogram
10324 -- Case 1: E is a subprogram whose first formal is a concurrent type
10325 -- defined in the scope of E that has an entry or subprogram whose
10326 -- profile matches E.
10328 if Comes_From_Source (E)
10329 and then Is_Subprogram (E)
10330 and then Present (First_Entity (E))
10331 and then Is_Concurrent_Record_Type (Etype (First_Entity (E)))
10334 Scope (Corresponding_Concurrent_Type
10335 (Etype (First_Entity (E))))
10338 (Matching_Entry_Or_Subprogram
10339 (Corresponding_Concurrent_Type (Etype (First_Entity (E))),
10342 Report_Conflict (E,
10343 Matching_Entry_Or_Subprogram
10344 (Corresponding_Concurrent_Type (Etype (First_Entity (E))),
10349 -- Case 2: E is an internally built dispatching subprogram of a
10350 -- protected type and there is a subprogram defined in the enclosing
10351 -- scope of the protected type that has the original name of E and
10352 -- its profile is conformant with the profile of E. We check the
10353 -- name of the original protected subprogram associated with E since
10354 -- the expander builds dispatching primitives of protected functions
10355 -- and procedures with other names (see Exp_Ch9.Build_Selected_Name).
10357 elsif not Comes_From_Source (E)
10358 and then Is_Subprogram (E)
10359 and then Present (First_Entity (E))
10360 and then Is_Concurrent_Record_Type (Etype (First_Entity (E)))
10361 and then Present (Original_Protected_Subprogram (E))
10364 (Matching_Original_Protected_Subprogram
10365 (Corresponding_Concurrent_Type (Etype (First_Entity (E))),
10368 Report_Conflict (E,
10369 Matching_Original_Protected_Subprogram
10370 (Corresponding_Concurrent_Type (Etype (First_Entity (E))),
10374 -- Case 3: E is an entry of a synchronized type and a matching
10375 -- procedure has been previously defined in the enclosing scope
10376 -- of the synchronized type.
10378 elsif Comes_From_Source (E)
10379 and then Ekind (E) = E_Entry
10381 Present (Matching_Dispatching_Subprogram (Current_Scope, E))
10383 Report_Conflict (E,
10384 Matching_Dispatching_Subprogram (Current_Scope, E));
10389 end Has_Matching_Entry_Or_Subprogram;
10391 ----------------------------
10392 -- Is_Private_Declaration --
10393 ----------------------------
10395 function Is_Private_Declaration (E : Entity_Id) return Boolean is
10396 Decl : constant Node_Id := Unit_Declaration_Node (E);
10397 Priv_Decls : List_Id;
10400 if Is_Package_Or_Generic_Package (Current_Scope)
10401 and then In_Private_Part (Current_Scope)
10404 Private_Declarations (Package_Specification (Current_Scope));
10406 return In_Package_Body (Current_Scope)
10408 (Is_List_Member (Decl)
10409 and then List_Containing (Decl) = Priv_Decls)
10410 or else (Nkind (Parent (Decl)) = N_Package_Specification
10412 Is_Compilation_Unit
10413 (Defining_Entity (Parent (Decl)))
10414 and then List_Containing (Parent (Parent (Decl))) =
10419 end Is_Private_Declaration;
10421 --------------------------
10422 -- Is_Overriding_Alias --
10423 --------------------------
10425 function Is_Overriding_Alias
10426 (Old_E : Entity_Id;
10427 New_E : Entity_Id) return Boolean
10429 AO : constant Entity_Id := Alias (Old_E);
10430 AN : constant Entity_Id := Alias (New_E);
10433 return Scope (AO) /= Scope (AN)
10434 or else No (DTC_Entity (AO))
10435 or else No (DTC_Entity (AN))
10436 or else DT_Position (AO) = DT_Position (AN);
10437 end Is_Overriding_Alias;
10439 ---------------------
10440 -- Report_Conflict --
10441 ---------------------
10443 procedure Report_Conflict (S : Entity_Id; E : Entity_Id) is
10445 Error_Msg_Sloc := Sloc (E);
10447 -- Generate message, with useful additional warning if in generic
10449 if Is_Generic_Unit (E) then
10450 Error_Msg_N ("previous generic unit cannot be overloaded", S);
10451 Error_Msg_N ("\& conflicts with declaration#", S);
10453 Error_Msg_N ("& conflicts with declaration#", S);
10455 end Report_Conflict;
10457 -- Start of processing for New_Overloaded_Entity
10460 -- We need to look for an entity that S may override. This must be a
10461 -- homonym in the current scope, so we look for the first homonym of
10462 -- S in the current scope as the starting point for the search.
10464 E := Current_Entity_In_Scope (S);
10466 -- Ada 2005 (AI-251): Derivation of abstract interface primitives.
10467 -- They are directly added to the list of primitive operations of
10468 -- Derived_Type, unless this is a rederivation in the private part
10469 -- of an operation that was already derived in the visible part of
10470 -- the current package.
10472 if Ada_Version >= Ada_2005
10473 and then Present (Derived_Type)
10474 and then Present (Alias (S))
10475 and then Is_Dispatching_Operation (Alias (S))
10476 and then Present (Find_Dispatching_Type (Alias (S)))
10477 and then Is_Interface (Find_Dispatching_Type (Alias (S)))
10479 -- For private types, when the full-view is processed we propagate to
10480 -- the full view the non-overridden entities whose attribute "alias"
10481 -- references an interface primitive. These entities were added by
10482 -- Derive_Subprograms to ensure that interface primitives are
10485 -- Inside_Freeze_Actions is non zero when S corresponds with an
10486 -- internal entity that links an interface primitive with its
10487 -- covering primitive through attribute Interface_Alias (see
10488 -- Add_Internal_Interface_Entities).
10490 if Inside_Freezing_Actions = 0
10491 and then Is_Package_Or_Generic_Package (Current_Scope)
10492 and then In_Private_Part (Current_Scope)
10493 and then Nkind (Parent (E)) = N_Private_Extension_Declaration
10494 and then Nkind (Parent (S)) = N_Full_Type_Declaration
10495 and then Full_View (Defining_Identifier (Parent (E)))
10496 = Defining_Identifier (Parent (S))
10497 and then Alias (E) = Alias (S)
10499 Check_Operation_From_Private_View (S, E);
10500 Set_Is_Dispatching_Operation (S);
10505 Enter_Overloaded_Entity (S);
10506 Check_Dispatching_Operation (S, Empty);
10507 Check_For_Primitive_Subprogram (Is_Primitive_Subp);
10513 -- For synchronized types check conflicts of this entity with previously
10514 -- defined entities.
10516 if Ada_Version >= Ada_2005
10517 and then Has_Matching_Entry_Or_Subprogram (S)
10522 -- If there is no homonym then this is definitely not overriding
10525 Enter_Overloaded_Entity (S);
10526 Check_Dispatching_Operation (S, Empty);
10527 Check_For_Primitive_Subprogram (Is_Primitive_Subp);
10529 -- If subprogram has an explicit declaration, check whether it has an
10530 -- overriding indicator.
10532 if Comes_From_Source (S) then
10533 Check_Synchronized_Overriding (S, Overridden_Subp);
10535 -- (Ada 2012: AI05-0125-1): If S is a dispatching operation then
10536 -- it may have overridden some hidden inherited primitive. Update
10537 -- Overridden_Subp to avoid spurious errors when checking the
10538 -- overriding indicator.
10540 if Ada_Version >= Ada_2012
10541 and then No (Overridden_Subp)
10542 and then Is_Dispatching_Operation (S)
10543 and then Present (Overridden_Operation (S))
10545 Overridden_Subp := Overridden_Operation (S);
10548 Check_Overriding_Indicator
10549 (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp);
10551 -- The Ghost policy in effect at the point of declaration of a
10552 -- parent subprogram and an overriding subprogram must match
10553 -- (SPARK RM 6.9(17)).
10555 Check_Ghost_Overriding (S, Overridden_Subp);
10558 -- If there is a homonym that is not overloadable, then we have an
10559 -- error, except for the special cases checked explicitly below.
10561 elsif not Is_Overloadable (E) then
10563 -- Check for spurious conflict produced by a subprogram that has the
10564 -- same name as that of the enclosing generic package. The conflict
10565 -- occurs within an instance, between the subprogram and the renaming
10566 -- declaration for the package. After the subprogram, the package
10567 -- renaming declaration becomes hidden.
10569 if Ekind (E) = E_Package
10570 and then Present (Renamed_Object (E))
10571 and then Renamed_Object (E) = Current_Scope
10572 and then Nkind (Parent (Renamed_Object (E))) =
10573 N_Package_Specification
10574 and then Present (Generic_Parent (Parent (Renamed_Object (E))))
10577 Set_Is_Immediately_Visible (E, False);
10578 Enter_Overloaded_Entity (S);
10579 Set_Homonym (S, Homonym (E));
10580 Check_Dispatching_Operation (S, Empty);
10581 Check_Overriding_Indicator (S, Empty, Is_Primitive => False);
10583 -- If the subprogram is implicit it is hidden by the previous
10584 -- declaration. However if it is dispatching, it must appear in the
10585 -- dispatch table anyway, because it can be dispatched to even if it
10586 -- cannot be called directly.
10588 elsif Present (Alias (S)) and then not Comes_From_Source (S) then
10589 Set_Scope (S, Current_Scope);
10591 if Is_Dispatching_Operation (Alias (S)) then
10592 Check_Dispatching_Operation (S, Empty);
10598 Report_Conflict (S, E);
10602 -- E exists and is overloadable
10605 Check_Synchronized_Overriding (S, Overridden_Subp);
10607 -- Loop through E and its homonyms to determine if any of them is
10608 -- the candidate for overriding by S.
10610 while Present (E) loop
10612 -- Definitely not interesting if not in the current scope
10614 if Scope (E) /= Current_Scope then
10617 -- A function can overload the name of an abstract state. The
10618 -- state can be viewed as a function with a profile that cannot
10619 -- be matched by anything.
10621 elsif Ekind (S) = E_Function
10622 and then Ekind (E) = E_Abstract_State
10624 Enter_Overloaded_Entity (S);
10627 -- Ada 2012 (AI05-0165): For internally generated bodies of null
10628 -- procedures locate the internally generated spec. We enforce
10629 -- mode conformance since a tagged type may inherit from
10630 -- interfaces several null primitives which differ only in
10631 -- the mode of the formals.
10633 elsif not Comes_From_Source (S)
10634 and then Is_Null_Procedure (S)
10635 and then not Mode_Conformant (E, S)
10639 -- Check if we have type conformance
10641 elsif Type_Conformant (E, S) then
10643 -- If the old and new entities have the same profile and one
10644 -- is not the body of the other, then this is an error, unless
10645 -- one of them is implicitly declared.
10647 -- There are some cases when both can be implicit, for example
10648 -- when both a literal and a function that overrides it are
10649 -- inherited in a derivation, or when an inherited operation
10650 -- of a tagged full type overrides the inherited operation of
10651 -- a private extension. Ada 83 had a special rule for the
10652 -- literal case. In Ada 95, the later implicit operation hides
10653 -- the former, and the literal is always the former. In the
10654 -- odd case where both are derived operations declared at the
10655 -- same point, both operations should be declared, and in that
10656 -- case we bypass the following test and proceed to the next
10657 -- part. This can only occur for certain obscure cases in
10658 -- instances, when an operation on a type derived from a formal
10659 -- private type does not override a homograph inherited from
10660 -- the actual. In subsequent derivations of such a type, the
10661 -- DT positions of these operations remain distinct, if they
10664 if Present (Alias (S))
10665 and then (No (Alias (E))
10666 or else Comes_From_Source (E)
10667 or else Is_Abstract_Subprogram (S)
10669 (Is_Dispatching_Operation (E)
10670 and then Is_Overriding_Alias (E, S)))
10671 and then Ekind (E) /= E_Enumeration_Literal
10673 -- When an derived operation is overloaded it may be due to
10674 -- the fact that the full view of a private extension
10675 -- re-inherits. It has to be dealt with.
10677 if Is_Package_Or_Generic_Package (Current_Scope)
10678 and then In_Private_Part (Current_Scope)
10680 Check_Operation_From_Private_View (S, E);
10683 -- In any case the implicit operation remains hidden by the
10684 -- existing declaration, which is overriding. Indicate that
10685 -- E overrides the operation from which S is inherited.
10687 if Present (Alias (S)) then
10688 Set_Overridden_Operation (E, Alias (S));
10689 Inherit_Subprogram_Contract (E, Alias (S));
10692 Set_Overridden_Operation (E, S);
10693 Inherit_Subprogram_Contract (E, S);
10696 if Comes_From_Source (E) then
10697 Check_Overriding_Indicator (E, S, Is_Primitive => False);
10699 -- The Ghost policy in effect at the point of declaration
10700 -- of a parent subprogram and an overriding subprogram
10701 -- must match (SPARK RM 6.9(17)).
10703 Check_Ghost_Overriding (E, S);
10708 -- Within an instance, the renaming declarations for actual
10709 -- subprograms may become ambiguous, but they do not hide each
10712 elsif Ekind (E) /= E_Entry
10713 and then not Comes_From_Source (E)
10714 and then not Is_Generic_Instance (E)
10715 and then (Present (Alias (E))
10716 or else Is_Intrinsic_Subprogram (E))
10717 and then (not In_Instance
10718 or else No (Parent (E))
10719 or else Nkind (Unit_Declaration_Node (E)) /=
10720 N_Subprogram_Renaming_Declaration)
10722 -- A subprogram child unit is not allowed to override an
10723 -- inherited subprogram (10.1.1(20)).
10725 if Is_Child_Unit (S) then
10727 ("child unit overrides inherited subprogram in parent",
10732 if Is_Non_Overriding_Operation (E, S) then
10733 Enter_Overloaded_Entity (S);
10735 if No (Derived_Type)
10736 or else Is_Tagged_Type (Derived_Type)
10738 Check_Dispatching_Operation (S, Empty);
10744 -- E is a derived operation or an internal operator which
10745 -- is being overridden. Remove E from further visibility.
10746 -- Furthermore, if E is a dispatching operation, it must be
10747 -- replaced in the list of primitive operations of its type
10748 -- (see Override_Dispatching_Operation).
10750 Overridden_Subp := E;
10756 Prev := First_Entity (Current_Scope);
10757 while Present (Prev) and then Next_Entity (Prev) /= E loop
10758 Next_Entity (Prev);
10761 -- It is possible for E to be in the current scope and
10762 -- yet not in the entity chain. This can only occur in a
10763 -- generic context where E is an implicit concatenation
10764 -- in the formal part, because in a generic body the
10765 -- entity chain starts with the formals.
10767 -- In GNATprove mode, a wrapper for an operation with
10768 -- axiomatization may be a homonym of another declaration
10769 -- for an actual subprogram (needs refinement ???).
10773 and then GNATprove_Mode
10775 Nkind (Original_Node (Unit_Declaration_Node (S))) =
10776 N_Subprogram_Renaming_Declaration
10780 pragma Assert (Chars (E) = Name_Op_Concat);
10785 -- E must be removed both from the entity_list of the
10786 -- current scope, and from the visibility chain.
10788 if Debug_Flag_E then
10789 Write_Str ("Override implicit operation ");
10790 Write_Int (Int (E));
10794 -- If E is a predefined concatenation, it stands for four
10795 -- different operations. As a result, a single explicit
10796 -- declaration does not hide it. In a possible ambiguous
10797 -- situation, Disambiguate chooses the user-defined op,
10798 -- so it is correct to retain the previous internal one.
10800 if Chars (E) /= Name_Op_Concat
10801 or else Ekind (E) /= E_Operator
10803 -- For nondispatching derived operations that are
10804 -- overridden by a subprogram declared in the private
10805 -- part of a package, we retain the derived subprogram
10806 -- but mark it as not immediately visible. If the
10807 -- derived operation was declared in the visible part
10808 -- then this ensures that it will still be visible
10809 -- outside the package with the proper signature
10810 -- (calls from outside must also be directed to this
10811 -- version rather than the overriding one, unlike the
10812 -- dispatching case). Calls from inside the package
10813 -- will still resolve to the overriding subprogram
10814 -- since the derived one is marked as not visible
10815 -- within the package.
10817 -- If the private operation is dispatching, we achieve
10818 -- the overriding by keeping the implicit operation
10819 -- but setting its alias to be the overriding one. In
10820 -- this fashion the proper body is executed in all
10821 -- cases, but the original signature is used outside
10824 -- If the overriding is not in the private part, we
10825 -- remove the implicit operation altogether.
10827 if Is_Private_Declaration (S) then
10828 if not Is_Dispatching_Operation (E) then
10829 Set_Is_Immediately_Visible (E, False);
10831 -- Work done in Override_Dispatching_Operation,
10832 -- so nothing else needs to be done here.
10838 -- Find predecessor of E in Homonym chain
10840 if E = Current_Entity (E) then
10843 Prev_Vis := Current_Entity (E);
10844 while Homonym (Prev_Vis) /= E loop
10845 Prev_Vis := Homonym (Prev_Vis);
10849 if Prev_Vis /= Empty then
10851 -- Skip E in the visibility chain
10853 Set_Homonym (Prev_Vis, Homonym (E));
10856 Set_Name_Entity_Id (Chars (E), Homonym (E));
10859 Set_Next_Entity (Prev, Next_Entity (E));
10861 if No (Next_Entity (Prev)) then
10862 Set_Last_Entity (Current_Scope, Prev);
10867 Enter_Overloaded_Entity (S);
10869 -- For entities generated by Derive_Subprograms the
10870 -- overridden operation is the inherited primitive
10871 -- (which is available through the attribute alias).
10873 if not (Comes_From_Source (E))
10874 and then Is_Dispatching_Operation (E)
10875 and then Find_Dispatching_Type (E) =
10876 Find_Dispatching_Type (S)
10877 and then Present (Alias (E))
10878 and then Comes_From_Source (Alias (E))
10880 Set_Overridden_Operation (S, Alias (E));
10881 Inherit_Subprogram_Contract (S, Alias (E));
10883 -- Normal case of setting entity as overridden
10885 -- Note: Static_Initialization and Overridden_Operation
10886 -- attributes use the same field in subprogram entities.
10887 -- Static_Initialization is only defined for internal
10888 -- initialization procedures, where Overridden_Operation
10889 -- is irrelevant. Therefore the setting of this attribute
10890 -- must check whether the target is an init_proc.
10892 elsif not Is_Init_Proc (S) then
10893 Set_Overridden_Operation (S, E);
10894 Inherit_Subprogram_Contract (S, E);
10897 Check_Overriding_Indicator (S, E, Is_Primitive => True);
10899 -- The Ghost policy in effect at the point of declaration
10900 -- of a parent subprogram and an overriding subprogram
10901 -- must match (SPARK RM 6.9(17)).
10903 Check_Ghost_Overriding (S, E);
10905 -- If S is a user-defined subprogram or a null procedure
10906 -- expanded to override an inherited null procedure, or a
10907 -- predefined dispatching primitive then indicate that E
10908 -- overrides the operation from which S is inherited.
10910 if Comes_From_Source (S)
10912 (Present (Parent (S))
10914 Nkind (Parent (S)) = N_Procedure_Specification
10916 Null_Present (Parent (S)))
10918 (Present (Alias (E))
10920 Is_Predefined_Dispatching_Operation (Alias (E)))
10922 if Present (Alias (E)) then
10923 Set_Overridden_Operation (S, Alias (E));
10924 Inherit_Subprogram_Contract (S, Alias (E));
10928 if Is_Dispatching_Operation (E) then
10930 -- An overriding dispatching subprogram inherits the
10931 -- convention of the overridden subprogram (AI-117).
10933 Set_Convention (S, Convention (E));
10934 Check_Dispatching_Operation (S, E);
10937 Check_Dispatching_Operation (S, Empty);
10940 Check_For_Primitive_Subprogram
10941 (Is_Primitive_Subp, Is_Overriding => True);
10942 goto Check_Inequality;
10945 -- Apparent redeclarations in instances can occur when two
10946 -- formal types get the same actual type. The subprograms in
10947 -- in the instance are legal, even if not callable from the
10948 -- outside. Calls from within are disambiguated elsewhere.
10949 -- For dispatching operations in the visible part, the usual
10950 -- rules apply, and operations with the same profile are not
10951 -- legal (B830001).
10953 elsif (In_Instance_Visible_Part
10954 and then not Is_Dispatching_Operation (E))
10955 or else In_Instance_Not_Visible
10959 -- Here we have a real error (identical profile)
10962 Error_Msg_Sloc := Sloc (E);
10964 -- Avoid cascaded errors if the entity appears in
10965 -- subsequent calls.
10967 Set_Scope (S, Current_Scope);
10969 -- Generate error, with extra useful warning for the case
10970 -- of a generic instance with no completion.
10972 if Is_Generic_Instance (S)
10973 and then not Has_Completion (E)
10976 ("instantiation cannot provide body for&", S);
10977 Error_Msg_N ("\& conflicts with declaration#", S);
10979 Error_Msg_N ("& conflicts with declaration#", S);
10986 -- If one subprogram has an access parameter and the other
10987 -- a parameter of an access type, calls to either might be
10988 -- ambiguous. Verify that parameters match except for the
10989 -- access parameter.
10991 if May_Hide_Profile then
10997 F1 := First_Formal (S);
10998 F2 := First_Formal (E);
10999 while Present (F1) and then Present (F2) loop
11000 if Is_Access_Type (Etype (F1)) then
11001 if not Is_Access_Type (Etype (F2))
11002 or else not Conforming_Types
11003 (Designated_Type (Etype (F1)),
11004 Designated_Type (Etype (F2)),
11007 May_Hide_Profile := False;
11011 not Conforming_Types
11012 (Etype (F1), Etype (F2), Type_Conformant)
11014 May_Hide_Profile := False;
11021 if May_Hide_Profile
11025 Error_Msg_NE ("calls to& may be ambiguous??", S, S);
11034 -- On exit, we know that S is a new entity
11036 Enter_Overloaded_Entity (S);
11037 Check_For_Primitive_Subprogram (Is_Primitive_Subp);
11038 Check_Overriding_Indicator
11039 (S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp);
11041 -- The Ghost policy in effect at the point of declaration of a parent
11042 -- subprogram and an overriding subprogram must match
11043 -- (SPARK RM 6.9(17)).
11045 Check_Ghost_Overriding (S, Overridden_Subp);
11047 -- Overloading is not allowed in SPARK, except for operators
11049 if Nkind (S) /= N_Defining_Operator_Symbol then
11050 Error_Msg_Sloc := Sloc (Homonym (S));
11051 Check_SPARK_05_Restriction
11052 ("overloading not allowed with entity#", S);
11055 -- If S is a derived operation for an untagged type then by
11056 -- definition it's not a dispatching operation (even if the parent
11057 -- operation was dispatching), so Check_Dispatching_Operation is not
11058 -- called in that case.
11060 if No (Derived_Type)
11061 or else Is_Tagged_Type (Derived_Type)
11063 Check_Dispatching_Operation (S, Empty);
11067 -- If this is a user-defined equality operator that is not a derived
11068 -- subprogram, create the corresponding inequality. If the operation is
11069 -- dispatching, the expansion is done elsewhere, and we do not create
11070 -- an explicit inequality operation.
11072 <<Check_Inequality>>
11073 if Chars (S) = Name_Op_Eq
11074 and then Etype (S) = Standard_Boolean
11075 and then Present (Parent (S))
11076 and then not Is_Dispatching_Operation (S)
11078 Make_Inequality_Operator (S);
11079 Check_Untagged_Equality (S);
11081 end New_Overloaded_Entity;
11083 ---------------------
11084 -- Process_Formals --
11085 ---------------------
11087 procedure Process_Formals
11089 Related_Nod : Node_Id)
11091 function Designates_From_Limited_With (Typ : Entity_Id) return Boolean;
11092 -- Determine whether an access type designates a type coming from a
11095 function Is_Class_Wide_Default (D : Node_Id) return Boolean;
11096 -- Check whether the default has a class-wide type. After analysis the
11097 -- default has the type of the formal, so we must also check explicitly
11098 -- for an access attribute.
11100 ----------------------------------
11101 -- Designates_From_Limited_With --
11102 ----------------------------------
11104 function Designates_From_Limited_With (Typ : Entity_Id) return Boolean is
11105 Desig : Entity_Id := Typ;
11108 if Is_Access_Type (Desig) then
11109 Desig := Directly_Designated_Type (Desig);
11112 if Is_Class_Wide_Type (Desig) then
11113 Desig := Root_Type (Desig);
11117 Ekind (Desig) = E_Incomplete_Type
11118 and then From_Limited_With (Desig);
11119 end Designates_From_Limited_With;
11121 ---------------------------
11122 -- Is_Class_Wide_Default --
11123 ---------------------------
11125 function Is_Class_Wide_Default (D : Node_Id) return Boolean is
11127 return Is_Class_Wide_Type (Designated_Type (Etype (D)))
11128 or else (Nkind (D) = N_Attribute_Reference
11129 and then Attribute_Name (D) = Name_Access
11130 and then Is_Class_Wide_Type (Etype (Prefix (D))));
11131 end Is_Class_Wide_Default;
11135 Context : constant Node_Id := Parent (Parent (T));
11137 Formal : Entity_Id;
11138 Formal_Type : Entity_Id;
11139 Param_Spec : Node_Id;
11142 Num_Out_Params : Nat := 0;
11143 First_Out_Param : Entity_Id := Empty;
11144 -- Used for setting Is_Only_Out_Parameter
11146 -- Start of processing for Process_Formals
11149 -- In order to prevent premature use of the formals in the same formal
11150 -- part, the Ekind is left undefined until all default expressions are
11151 -- analyzed. The Ekind is established in a separate loop at the end.
11153 Param_Spec := First (T);
11154 while Present (Param_Spec) loop
11155 Formal := Defining_Identifier (Param_Spec);
11156 Set_Never_Set_In_Source (Formal, True);
11157 Enter_Name (Formal);
11159 -- Case of ordinary parameters
11161 if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
11162 Find_Type (Parameter_Type (Param_Spec));
11163 Ptype := Parameter_Type (Param_Spec);
11165 if Ptype = Error then
11169 Formal_Type := Entity (Ptype);
11171 if Is_Incomplete_Type (Formal_Type)
11173 (Is_Class_Wide_Type (Formal_Type)
11174 and then Is_Incomplete_Type (Root_Type (Formal_Type)))
11176 -- Ada 2005 (AI-326): Tagged incomplete types allowed in
11177 -- primitive operations, as long as their completion is
11178 -- in the same declarative part. If in the private part
11179 -- this means that the type cannot be a Taft-amendment type.
11180 -- Check is done on package exit. For access to subprograms,
11181 -- the use is legal for Taft-amendment types.
11183 -- Ada 2012: tagged incomplete types are allowed as generic
11184 -- formal types. They do not introduce dependencies and the
11185 -- corresponding generic subprogram does not have a delayed
11186 -- freeze, because it does not need a freeze node. However,
11187 -- it is still the case that untagged incomplete types cannot
11188 -- be Taft-amendment types and must be completed in private
11189 -- part, so the subprogram must appear in the list of private
11190 -- dependents of the type.
11192 if Is_Tagged_Type (Formal_Type)
11193 or else (Ada_Version >= Ada_2012
11194 and then not From_Limited_With (Formal_Type)
11195 and then not Is_Generic_Type (Formal_Type))
11197 if Ekind (Scope (Current_Scope)) = E_Package
11198 and then not Is_Generic_Type (Formal_Type)
11199 and then not Is_Class_Wide_Type (Formal_Type)
11202 (Parent (T), N_Access_Function_Definition,
11203 N_Access_Procedure_Definition)
11205 Append_Elmt (Current_Scope,
11206 Private_Dependents (Base_Type (Formal_Type)));
11208 -- Freezing is delayed to ensure that Register_Prim
11209 -- will get called for this operation, which is needed
11210 -- in cases where static dispatch tables aren't built.
11211 -- (Note that the same is done for controlling access
11212 -- parameter cases in function Access_Definition.)
11214 if not Is_Thunk (Current_Scope) then
11215 Set_Has_Delayed_Freeze (Current_Scope);
11220 elsif not Nkind_In (Parent (T), N_Access_Function_Definition,
11221 N_Access_Procedure_Definition)
11223 -- AI05-0151: Tagged incomplete types are allowed in all
11224 -- formal parts. Untagged incomplete types are not allowed
11225 -- in bodies. Limited views of either kind are not allowed
11226 -- if there is no place at which the non-limited view can
11227 -- become available.
11229 -- Incomplete formal untagged types are not allowed in
11230 -- subprogram bodies (but are legal in their declarations).
11231 -- This excludes bodies created for null procedures, which
11232 -- are basic declarations.
11234 if Is_Generic_Type (Formal_Type)
11235 and then not Is_Tagged_Type (Formal_Type)
11236 and then Nkind (Parent (Related_Nod)) = N_Subprogram_Body
11239 ("invalid use of formal incomplete type", Param_Spec);
11241 elsif Ada_Version >= Ada_2012 then
11242 if Is_Tagged_Type (Formal_Type)
11243 and then (not From_Limited_With (Formal_Type)
11244 or else not In_Package_Body)
11248 elsif Nkind_In (Context, N_Accept_Statement,
11249 N_Accept_Alternative,
11251 or else (Nkind (Context) = N_Subprogram_Body
11252 and then Comes_From_Source (Context))
11255 ("invalid use of untagged incomplete type &",
11256 Ptype, Formal_Type);
11261 ("invalid use of incomplete type&",
11262 Param_Spec, Formal_Type);
11264 -- Further checks on the legality of incomplete types
11265 -- in formal parts are delayed until the freeze point
11266 -- of the enclosing subprogram or access to subprogram.
11270 elsif Ekind (Formal_Type) = E_Void then
11272 ("premature use of&",
11273 Parameter_Type (Param_Spec), Formal_Type);
11276 -- Ada 2012 (AI-142): Handle aliased parameters
11278 if Ada_Version >= Ada_2012
11279 and then Aliased_Present (Param_Spec)
11281 Set_Is_Aliased (Formal);
11284 -- Ada 2005 (AI-231): Create and decorate an internal subtype
11285 -- declaration corresponding to the null-excluding type of the
11286 -- formal in the enclosing scope. Finally, replace the parameter
11287 -- type of the formal with the internal subtype.
11289 if Ada_Version >= Ada_2005
11290 and then Null_Exclusion_Present (Param_Spec)
11292 if not Is_Access_Type (Formal_Type) then
11294 ("`NOT NULL` allowed only for an access type", Param_Spec);
11297 if Can_Never_Be_Null (Formal_Type)
11298 and then Comes_From_Source (Related_Nod)
11301 ("`NOT NULL` not allowed (& already excludes null)",
11302 Param_Spec, Formal_Type);
11306 Create_Null_Excluding_Itype
11308 Related_Nod => Related_Nod,
11309 Scope_Id => Scope (Current_Scope));
11311 -- If the designated type of the itype is an itype that is
11312 -- not frozen yet, we set the Has_Delayed_Freeze attribute
11313 -- on the access subtype, to prevent order-of-elaboration
11314 -- issues in the backend.
11317 -- type T is access procedure;
11318 -- procedure Op (O : not null T);
11320 if Is_Itype (Directly_Designated_Type (Formal_Type))
11322 not Is_Frozen (Directly_Designated_Type (Formal_Type))
11324 Set_Has_Delayed_Freeze (Formal_Type);
11329 -- An access formal type
11333 Access_Definition (Related_Nod, Parameter_Type (Param_Spec));
11335 -- No need to continue if we already notified errors
11337 if not Present (Formal_Type) then
11341 -- Ada 2005 (AI-254)
11344 AD : constant Node_Id :=
11345 Access_To_Subprogram_Definition
11346 (Parameter_Type (Param_Spec));
11348 if Present (AD) and then Protected_Present (AD) then
11350 Replace_Anonymous_Access_To_Protected_Subprogram
11356 Set_Etype (Formal, Formal_Type);
11358 -- Deal with default expression if present
11360 Default := Expression (Param_Spec);
11362 if Present (Default) then
11363 Check_SPARK_05_Restriction
11364 ("default expression is not allowed", Default);
11366 if Out_Present (Param_Spec) then
11368 ("default initialization only allowed for IN parameters",
11372 -- Do the special preanalysis of the expression (see section on
11373 -- "Handling of Default Expressions" in the spec of package Sem).
11375 Preanalyze_Spec_Expression (Default, Formal_Type);
11377 -- An access to constant cannot be the default for
11378 -- an access parameter that is an access to variable.
11380 if Ekind (Formal_Type) = E_Anonymous_Access_Type
11381 and then not Is_Access_Constant (Formal_Type)
11382 and then Is_Access_Type (Etype (Default))
11383 and then Is_Access_Constant (Etype (Default))
11386 ("formal that is access to variable cannot be initialized "
11387 & "with an access-to-constant expression", Default);
11390 -- Check that the designated type of an access parameter's default
11391 -- is not a class-wide type unless the parameter's designated type
11392 -- is also class-wide.
11394 if Ekind (Formal_Type) = E_Anonymous_Access_Type
11395 and then not Designates_From_Limited_With (Formal_Type)
11396 and then Is_Class_Wide_Default (Default)
11397 and then not Is_Class_Wide_Type (Designated_Type (Formal_Type))
11400 ("access to class-wide expression not allowed here", Default);
11403 -- Check incorrect use of dynamically tagged expressions
11405 if Is_Tagged_Type (Formal_Type) then
11406 Check_Dynamically_Tagged_Expression
11408 Typ => Formal_Type,
11409 Related_Nod => Default);
11413 -- Ada 2005 (AI-231): Static checks
11415 if Ada_Version >= Ada_2005
11416 and then Is_Access_Type (Etype (Formal))
11417 and then Can_Never_Be_Null (Etype (Formal))
11419 Null_Exclusion_Static_Checks (Param_Spec);
11422 -- The following checks are relevant only when SPARK_Mode is on as
11423 -- these are not standard Ada legality rules.
11425 if SPARK_Mode = On then
11426 if Ekind_In (Scope (Formal), E_Function, E_Generic_Function) then
11428 -- A function cannot have a parameter of mode IN OUT or OUT
11431 if Ekind_In (Formal, E_In_Out_Parameter, E_Out_Parameter) then
11433 ("function cannot have parameter of mode `OUT` or "
11434 & "`IN OUT`", Formal);
11437 -- A procedure cannot have an effectively volatile formal
11438 -- parameter of mode IN because it behaves as a constant
11439 -- (SPARK RM 7.1.3(6)). -- ??? maybe 7.1.3(4)
11441 elsif Ekind (Scope (Formal)) = E_Procedure
11442 and then Ekind (Formal) = E_In_Parameter
11443 and then Is_Effectively_Volatile (Formal)
11446 ("formal parameter of mode `IN` cannot be volatile", Formal);
11454 -- If this is the formal part of a function specification, analyze the
11455 -- subtype mark in the context where the formals are visible but not
11456 -- yet usable, and may hide outer homographs.
11458 if Nkind (Related_Nod) = N_Function_Specification then
11459 Analyze_Return_Type (Related_Nod);
11462 -- Now set the kind (mode) of each formal
11464 Param_Spec := First (T);
11465 while Present (Param_Spec) loop
11466 Formal := Defining_Identifier (Param_Spec);
11467 Set_Formal_Mode (Formal);
11469 if Ekind (Formal) = E_In_Parameter then
11470 Set_Default_Value (Formal, Expression (Param_Spec));
11472 if Present (Expression (Param_Spec)) then
11473 Default := Expression (Param_Spec);
11475 if Is_Scalar_Type (Etype (Default)) then
11476 if Nkind (Parameter_Type (Param_Spec)) /=
11477 N_Access_Definition
11479 Formal_Type := Entity (Parameter_Type (Param_Spec));
11483 (Related_Nod, Parameter_Type (Param_Spec));
11486 Apply_Scalar_Range_Check (Default, Formal_Type);
11490 elsif Ekind (Formal) = E_Out_Parameter then
11491 Num_Out_Params := Num_Out_Params + 1;
11493 if Num_Out_Params = 1 then
11494 First_Out_Param := Formal;
11497 elsif Ekind (Formal) = E_In_Out_Parameter then
11498 Num_Out_Params := Num_Out_Params + 1;
11501 -- Skip remaining processing if formal type was in error
11503 if Etype (Formal) = Any_Type or else Error_Posted (Formal) then
11504 goto Next_Parameter;
11507 -- Force call by reference if aliased
11510 Conv : constant Convention_Id := Convention (Etype (Formal));
11512 if Is_Aliased (Formal) then
11513 Set_Mechanism (Formal, By_Reference);
11515 -- Warn if user asked this to be passed by copy
11517 if Conv = Convention_Ada_Pass_By_Copy then
11519 ("cannot pass aliased parameter & by copy??", Formal);
11522 -- Force mechanism if type has Convention Ada_Pass_By_Ref/Copy
11524 elsif Conv = Convention_Ada_Pass_By_Copy then
11525 Set_Mechanism (Formal, By_Copy);
11527 elsif Conv = Convention_Ada_Pass_By_Reference then
11528 Set_Mechanism (Formal, By_Reference);
11536 if Present (First_Out_Param) and then Num_Out_Params = 1 then
11537 Set_Is_Only_Out_Parameter (First_Out_Param);
11539 end Process_Formals;
11541 ----------------------------
11542 -- Reference_Body_Formals --
11543 ----------------------------
11545 procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is
11550 if Error_Posted (Spec) then
11554 -- Iterate over both lists. They may be of different lengths if the two
11555 -- specs are not conformant.
11557 Fs := First_Formal (Spec);
11558 Fb := First_Formal (Bod);
11559 while Present (Fs) and then Present (Fb) loop
11560 Generate_Reference (Fs, Fb, 'b');
11562 if Style_Check then
11563 Style.Check_Identifier (Fb, Fs);
11566 Set_Spec_Entity (Fb, Fs);
11567 Set_Referenced (Fs, False);
11571 end Reference_Body_Formals;
11573 -------------------------
11574 -- Set_Actual_Subtypes --
11575 -------------------------
11577 procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is
11579 Formal : Entity_Id;
11581 First_Stmt : Node_Id := Empty;
11582 AS_Needed : Boolean;
11585 -- If this is an empty initialization procedure, no need to create
11586 -- actual subtypes (small optimization).
11588 if Ekind (Subp) = E_Procedure and then Is_Null_Init_Proc (Subp) then
11592 -- The subtype declarations may freeze the formals. The body generated
11593 -- for an expression function is not a freeze point, so do not emit
11594 -- these declarations (small loss of efficiency in rare cases).
11596 if Nkind (N) = N_Subprogram_Body
11597 and then Was_Expression_Function (N)
11602 Formal := First_Formal (Subp);
11603 while Present (Formal) loop
11604 T := Etype (Formal);
11606 -- We never need an actual subtype for a constrained formal
11608 if Is_Constrained (T) then
11609 AS_Needed := False;
11611 -- If we have unknown discriminants, then we do not need an actual
11612 -- subtype, or more accurately we cannot figure it out. Note that
11613 -- all class-wide types have unknown discriminants.
11615 elsif Has_Unknown_Discriminants (T) then
11616 AS_Needed := False;
11618 -- At this stage we have an unconstrained type that may need an
11619 -- actual subtype. For sure the actual subtype is needed if we have
11620 -- an unconstrained array type. However, in an instance, the type
11621 -- may appear as a subtype of the full view, while the actual is
11622 -- in fact private (in which case no actual subtype is needed) so
11623 -- check the kind of the base type.
11625 elsif Is_Array_Type (Base_Type (T)) then
11628 -- The only other case needing an actual subtype is an unconstrained
11629 -- record type which is an IN parameter (we cannot generate actual
11630 -- subtypes for the OUT or IN OUT case, since an assignment can
11631 -- change the discriminant values. However we exclude the case of
11632 -- initialization procedures, since discriminants are handled very
11633 -- specially in this context, see the section entitled "Handling of
11634 -- Discriminants" in Einfo.
11636 -- We also exclude the case of Discrim_SO_Functions (functions used
11637 -- in front-end layout mode for size/offset values), since in such
11638 -- functions only discriminants are referenced, and not only are such
11639 -- subtypes not needed, but they cannot always be generated, because
11640 -- of order of elaboration issues.
11642 elsif Is_Record_Type (T)
11643 and then Ekind (Formal) = E_In_Parameter
11644 and then Chars (Formal) /= Name_uInit
11645 and then not Is_Unchecked_Union (T)
11646 and then not Is_Discrim_SO_Function (Subp)
11650 -- All other cases do not need an actual subtype
11653 AS_Needed := False;
11656 -- Generate actual subtypes for unconstrained arrays and
11657 -- unconstrained discriminated records.
11660 if Nkind (N) = N_Accept_Statement then
11662 -- If expansion is active, the formal is replaced by a local
11663 -- variable that renames the corresponding entry of the
11664 -- parameter block, and it is this local variable that may
11665 -- require an actual subtype.
11667 if Expander_Active then
11668 Decl := Build_Actual_Subtype (T, Renamed_Object (Formal));
11670 Decl := Build_Actual_Subtype (T, Formal);
11673 if Present (Handled_Statement_Sequence (N)) then
11675 First (Statements (Handled_Statement_Sequence (N)));
11676 Prepend (Decl, Statements (Handled_Statement_Sequence (N)));
11677 Mark_Rewrite_Insertion (Decl);
11679 -- If the accept statement has no body, there will be no
11680 -- reference to the actuals, so no need to compute actual
11687 Decl := Build_Actual_Subtype (T, Formal);
11688 Prepend (Decl, Declarations (N));
11689 Mark_Rewrite_Insertion (Decl);
11692 -- The declaration uses the bounds of an existing object, and
11693 -- therefore needs no constraint checks.
11695 Analyze (Decl, Suppress => All_Checks);
11696 Set_Is_Actual_Subtype (Defining_Identifier (Decl));
11698 -- We need to freeze manually the generated type when it is
11699 -- inserted anywhere else than in a declarative part.
11701 if Present (First_Stmt) then
11702 Insert_List_Before_And_Analyze (First_Stmt,
11703 Freeze_Entity (Defining_Identifier (Decl), N));
11705 -- Ditto if the type has a dynamic predicate, because the
11706 -- generated function will mention the actual subtype. The
11707 -- predicate may come from an explicit aspect of be inherited.
11709 elsif Has_Predicates (T) then
11710 Insert_List_Before_And_Analyze (Decl,
11711 Freeze_Entity (Defining_Identifier (Decl), N));
11714 if Nkind (N) = N_Accept_Statement
11715 and then Expander_Active
11717 Set_Actual_Subtype (Renamed_Object (Formal),
11718 Defining_Identifier (Decl));
11720 Set_Actual_Subtype (Formal, Defining_Identifier (Decl));
11724 Next_Formal (Formal);
11726 end Set_Actual_Subtypes;
11728 ---------------------
11729 -- Set_Formal_Mode --
11730 ---------------------
11732 procedure Set_Formal_Mode (Formal_Id : Entity_Id) is
11733 Spec : constant Node_Id := Parent (Formal_Id);
11734 Id : constant Entity_Id := Scope (Formal_Id);
11737 -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
11738 -- since we ensure that corresponding actuals are always valid at the
11739 -- point of the call.
11741 if Out_Present (Spec) then
11742 if Ekind_In (Id, E_Entry, E_Entry_Family)
11743 or else Is_Subprogram_Or_Generic_Subprogram (Id)
11745 Set_Has_Out_Or_In_Out_Parameter (Id, True);
11748 if Ekind_In (Id, E_Function, E_Generic_Function) then
11750 -- [IN] OUT parameters allowed for functions in Ada 2012
11752 if Ada_Version >= Ada_2012 then
11754 -- Even in Ada 2012 operators can only have IN parameters
11756 if Is_Operator_Symbol_Name (Chars (Scope (Formal_Id))) then
11757 Error_Msg_N ("operators can only have IN parameters", Spec);
11760 if In_Present (Spec) then
11761 Set_Ekind (Formal_Id, E_In_Out_Parameter);
11763 Set_Ekind (Formal_Id, E_Out_Parameter);
11766 -- But not in earlier versions of Ada
11769 Error_Msg_N ("functions can only have IN parameters", Spec);
11770 Set_Ekind (Formal_Id, E_In_Parameter);
11773 elsif In_Present (Spec) then
11774 Set_Ekind (Formal_Id, E_In_Out_Parameter);
11777 Set_Ekind (Formal_Id, E_Out_Parameter);
11778 Set_Never_Set_In_Source (Formal_Id, True);
11779 Set_Is_True_Constant (Formal_Id, False);
11780 Set_Current_Value (Formal_Id, Empty);
11784 Set_Ekind (Formal_Id, E_In_Parameter);
11787 -- Set Is_Known_Non_Null for access parameters since the language
11788 -- guarantees that access parameters are always non-null. We also set
11789 -- Can_Never_Be_Null, since there is no way to change the value.
11791 if Nkind (Parameter_Type (Spec)) = N_Access_Definition then
11793 -- Ada 2005 (AI-231): In Ada 95, access parameters are always non-
11794 -- null; In Ada 2005, only if then null_exclusion is explicit.
11796 if Ada_Version < Ada_2005
11797 or else Can_Never_Be_Null (Etype (Formal_Id))
11799 Set_Is_Known_Non_Null (Formal_Id);
11800 Set_Can_Never_Be_Null (Formal_Id);
11803 -- Ada 2005 (AI-231): Null-exclusion access subtype
11805 elsif Is_Access_Type (Etype (Formal_Id))
11806 and then Can_Never_Be_Null (Etype (Formal_Id))
11808 Set_Is_Known_Non_Null (Formal_Id);
11810 -- We can also set Can_Never_Be_Null (thus preventing some junk
11811 -- access checks) for the case of an IN parameter, which cannot
11812 -- be changed, or for an IN OUT parameter, which can be changed but
11813 -- not to a null value. But for an OUT parameter, the initial value
11814 -- passed in can be null, so we can't set this flag in that case.
11816 if Ekind (Formal_Id) /= E_Out_Parameter then
11817 Set_Can_Never_Be_Null (Formal_Id);
11821 Set_Mechanism (Formal_Id, Default_Mechanism);
11822 Set_Formal_Validity (Formal_Id);
11823 end Set_Formal_Mode;
11825 -------------------------
11826 -- Set_Formal_Validity --
11827 -------------------------
11829 procedure Set_Formal_Validity (Formal_Id : Entity_Id) is
11831 -- If no validity checking, then we cannot assume anything about the
11832 -- validity of parameters, since we do not know there is any checking
11833 -- of the validity on the call side.
11835 if not Validity_Checks_On then
11838 -- If validity checking for parameters is enabled, this means we are
11839 -- not supposed to make any assumptions about argument values.
11841 elsif Validity_Check_Parameters then
11844 -- If we are checking in parameters, we will assume that the caller is
11845 -- also checking parameters, so we can assume the parameter is valid.
11847 elsif Ekind (Formal_Id) = E_In_Parameter
11848 and then Validity_Check_In_Params
11850 Set_Is_Known_Valid (Formal_Id, True);
11852 -- Similar treatment for IN OUT parameters
11854 elsif Ekind (Formal_Id) = E_In_Out_Parameter
11855 and then Validity_Check_In_Out_Params
11857 Set_Is_Known_Valid (Formal_Id, True);
11859 end Set_Formal_Validity;
11861 ------------------------
11862 -- Subtype_Conformant --
11863 ------------------------
11865 function Subtype_Conformant
11866 (New_Id : Entity_Id;
11867 Old_Id : Entity_Id;
11868 Skip_Controlling_Formals : Boolean := False) return Boolean
11872 Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result,
11873 Skip_Controlling_Formals => Skip_Controlling_Formals);
11875 end Subtype_Conformant;
11877 ---------------------
11878 -- Type_Conformant --
11879 ---------------------
11881 function Type_Conformant
11882 (New_Id : Entity_Id;
11883 Old_Id : Entity_Id;
11884 Skip_Controlling_Formals : Boolean := False) return Boolean
11888 May_Hide_Profile := False;
11890 (New_Id, Old_Id, Type_Conformant, False, Result,
11891 Skip_Controlling_Formals => Skip_Controlling_Formals);
11893 end Type_Conformant;
11895 -------------------------------
11896 -- Valid_Operator_Definition --
11897 -------------------------------
11899 procedure Valid_Operator_Definition (Designator : Entity_Id) is
11902 Id : constant Name_Id := Chars (Designator);
11906 F := First_Formal (Designator);
11907 while Present (F) loop
11910 if Present (Default_Value (F)) then
11912 ("default values not allowed for operator parameters",
11915 -- For function instantiations that are operators, we must check
11916 -- separately that the corresponding generic only has in-parameters.
11917 -- For subprogram declarations this is done in Set_Formal_Mode. Such
11918 -- an error could not arise in earlier versions of the language.
11920 elsif Ekind (F) /= E_In_Parameter then
11921 Error_Msg_N ("operators can only have IN parameters", F);
11927 -- Verify that user-defined operators have proper number of arguments
11928 -- First case of operators which can only be unary
11930 if Nam_In (Id, Name_Op_Not, Name_Op_Abs) then
11933 -- Case of operators which can be unary or binary
11935 elsif Nam_In (Id, Name_Op_Add, Name_Op_Subtract) then
11936 N_OK := (N in 1 .. 2);
11938 -- All other operators can only be binary
11946 ("incorrect number of arguments for operator", Designator);
11950 and then Base_Type (Etype (Designator)) = Standard_Boolean
11951 and then not Is_Intrinsic_Subprogram (Designator)
11954 ("explicit definition of inequality not allowed", Designator);
11956 end Valid_Operator_Definition;