1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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 -- This package contains the routines to process package specifications and
27 -- bodies. The most important semantic aspects of package processing are the
28 -- handling of private and full declarations, and the construction of
29 -- dispatch tables for tagged types.
31 with Atree; use Atree;
32 with Debug; use Debug;
33 with Einfo; use Einfo;
34 with Elists; use Elists;
35 with Errout; use Errout;
36 with Exp_Disp; use Exp_Disp;
37 with Exp_Dist; use Exp_Dist;
38 with Exp_Dbug; use Exp_Dbug;
40 with Lib.Xref; use Lib.Xref;
41 with Namet; use Namet;
42 with Nmake; use Nmake;
43 with Nlists; use Nlists;
45 with Output; use Output;
47 with Sem_Cat; use Sem_Cat;
48 with Sem_Ch3; use Sem_Ch3;
49 with Sem_Ch6; use Sem_Ch6;
50 with Sem_Ch8; use Sem_Ch8;
51 with Sem_Ch10; use Sem_Ch10;
52 with Sem_Ch12; use Sem_Ch12;
53 with Sem_Disp; use Sem_Disp;
54 with Sem_Prag; use Sem_Prag;
55 with Sem_Util; use Sem_Util;
56 with Sem_Warn; use Sem_Warn;
57 with Snames; use Snames;
58 with Stand; use Stand;
59 with Sinfo; use Sinfo;
60 with Sinput; use Sinput;
62 with Uintp; use Uintp;
64 package body Sem_Ch7 is
66 -----------------------------------
67 -- Handling private declarations --
68 -----------------------------------
70 -- The principle that each entity has a single defining occurrence clashes
71 -- with the presence of two separate definitions for private types: the
72 -- first is the private type declaration, and the second is the full type
73 -- declaration. It is important that all references to the type point to
74 -- the same defining occurrence, namely the first one. To enforce the two
75 -- separate views of the entity, the corresponding information is swapped
76 -- between the two declarations. Outside of the package, the defining
77 -- occurrence only contains the private declaration information, while in
78 -- the private part and the body of the package the defining occurrence
79 -- contains the full declaration. To simplify the swap, the defining
80 -- occurrence that currently holds the private declaration points to the
81 -- full declaration. During semantic processing the defining occurrence
82 -- also points to a list of private dependents, that is to say access types
83 -- or composite types whose designated types or component types are
84 -- subtypes or derived types of the private type in question. After the
85 -- full declaration has been seen, the private dependents are updated to
86 -- indicate that they have full definitions.
88 -----------------------
89 -- Local Subprograms --
90 -----------------------
92 procedure Check_Anonymous_Access_Types
95 -- If the spec of a package has a limited_with_clause, it may declare
96 -- anonymous access types whose designated type is a limited view, such an
97 -- anonymous access return type for a function. This access type cannot be
98 -- elaborated in the spec itself, but it may need an itype reference if it
99 -- is used within a nested scope. In that case the itype reference is
100 -- created at the beginning of the corresponding package body and inserted
101 -- before other body declarations.
103 procedure Install_Package_Entity (Id : Entity_Id);
104 -- Supporting procedure for Install_{Visible,Private}_Declarations.
105 -- Places one entity on its visibility chain, and recurses on the visible
106 -- part if the entity is an inner package.
108 function Is_Private_Base_Type (E : Entity_Id) return Boolean;
109 -- True for a private type that is not a subtype
111 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean;
112 -- If the private dependent is a private type whose full view is derived
113 -- from the parent type, its full properties are revealed only if we are in
114 -- the immediate scope of the private dependent. Should this predicate be
115 -- tightened further???
117 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id);
118 -- Called upon entering the private part of a public child package and the
119 -- body of a nested package, to potentially declare certain inherited
120 -- subprograms that were inherited by types in the visible part, but whose
121 -- declaration was deferred because the parent operation was private and
122 -- not visible at that point. These subprograms are located by traversing
123 -- the visible part declarations looking for non-private type extensions
124 -- and then examining each of the primitive operations of such types to
125 -- find those that were inherited but declared with a special internal
126 -- name. Each such operation is now declared as an operation with a normal
127 -- name (using the name of the parent operation) and replaces the previous
128 -- implicit operation in the primitive operations list of the type. If the
129 -- inherited private operation has been overridden, then it's replaced by
130 -- the overriding operation.
132 --------------------------
133 -- Analyze_Package_Body --
134 --------------------------
136 procedure Analyze_Package_Body (N : Node_Id) is
137 Loc : constant Source_Ptr := Sloc (N);
141 Last_Spec_Entity : Entity_Id;
145 procedure Install_Composite_Operations (P : Entity_Id);
146 -- Composite types declared in the current scope may depend on
147 -- types that were private at the point of declaration, and whose
148 -- full view is now in scope. Indicate that the corresponding
149 -- operations on the composite type are available.
151 ----------------------------------
152 -- Install_Composite_Operations --
153 ----------------------------------
155 procedure Install_Composite_Operations (P : Entity_Id) is
159 Id := First_Entity (P);
160 while Present (Id) loop
162 and then (Is_Limited_Composite (Id)
163 or else Is_Private_Composite (Id))
164 and then No (Private_Component (Id))
166 Set_Is_Limited_Composite (Id, False);
167 Set_Is_Private_Composite (Id, False);
172 end Install_Composite_Operations;
174 -- Start of processing for Analyze_Package_Body
177 -- Find corresponding package specification, and establish the
178 -- current scope. The visible defining entity for the package is the
179 -- defining occurrence in the spec. On exit from the package body, all
180 -- body declarations are attached to the defining entity for the body,
181 -- but the later is never used for name resolution. In this fashion
182 -- there is only one visible entity that denotes the package.
185 Write_Str ("==== Compiling package body ");
186 Write_Name (Chars (Defining_Entity (N)));
187 Write_Str (" from ");
188 Write_Location (Loc);
192 -- Set Body_Id. Note that this Will be reset to point to the
193 -- generic copy later on in the generic case.
195 Body_Id := Defining_Entity (N);
197 if Present (Corresponding_Spec (N)) then
199 -- Body is body of package instantiation. Corresponding spec
200 -- has already been set.
202 Spec_Id := Corresponding_Spec (N);
203 Pack_Decl := Unit_Declaration_Node (Spec_Id);
206 Spec_Id := Current_Entity_In_Scope (Defining_Entity (N));
209 and then Is_Package_Or_Generic_Package (Spec_Id)
211 Pack_Decl := Unit_Declaration_Node (Spec_Id);
213 if Nkind (Pack_Decl) = N_Package_Renaming_Declaration then
214 Error_Msg_N ("cannot supply body for package renaming", N);
217 elsif Present (Corresponding_Body (Pack_Decl)) then
218 Error_Msg_N ("redefinition of package body", N);
223 Error_Msg_N ("missing specification for package body", N);
227 if Is_Package_Or_Generic_Package (Spec_Id)
229 (Scope (Spec_Id) = Standard_Standard
230 or else Is_Child_Unit (Spec_Id))
231 and then not Unit_Requires_Body (Spec_Id)
233 if Ada_Version = Ada_83 then
235 ("optional package body (not allowed in Ada 95)?", N);
238 ("spec of this package does not allow a body", N);
243 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
244 Style.Check_Identifier (Body_Id, Spec_Id);
246 if Is_Child_Unit (Spec_Id) then
247 if Nkind (Parent (N)) /= N_Compilation_Unit then
249 ("body of child unit& cannot be an inner package", N, Spec_Id);
252 Set_Is_Child_Unit (Body_Id);
255 -- Generic package case
257 if Ekind (Spec_Id) = E_Generic_Package then
259 -- Disable expansion and perform semantic analysis on copy.
260 -- The unannotated body will be used in all instantiations.
262 Body_Id := Defining_Entity (N);
263 Set_Ekind (Body_Id, E_Package_Body);
264 Set_Scope (Body_Id, Scope (Spec_Id));
265 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id));
266 Set_Body_Entity (Spec_Id, Body_Id);
267 Set_Spec_Entity (Body_Id, Spec_Id);
269 New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
272 -- Update Body_Id to point to the copied node for the remainder
273 -- of the processing.
275 Body_Id := Defining_Entity (N);
279 -- The Body_Id is that of the copied node in the generic case, the
280 -- current node otherwise. Note that N was rewritten above, so we
281 -- must be sure to get the latest Body_Id value.
283 Set_Ekind (Body_Id, E_Package_Body);
284 Set_Body_Entity (Spec_Id, Body_Id);
285 Set_Spec_Entity (Body_Id, Spec_Id);
287 -- Defining name for the package body is not a visible entity: Only
288 -- the defining name for the declaration is visible.
290 Set_Etype (Body_Id, Standard_Void_Type);
291 Set_Scope (Body_Id, Scope (Spec_Id));
292 Set_Corresponding_Spec (N, Spec_Id);
293 Set_Corresponding_Body (Pack_Decl, Body_Id);
295 -- The body entity is not used for semantics or code generation, but
296 -- it is attached to the entity list of the enclosing scope to simplify
297 -- the listing of back-annotations for the types it main contain.
299 if Scope (Spec_Id) /= Standard_Standard then
300 Append_Entity (Body_Id, Scope (Spec_Id));
303 -- Indicate that we are currently compiling the body of the package
305 Set_In_Package_Body (Spec_Id);
306 Set_Has_Completion (Spec_Id);
307 Last_Spec_Entity := Last_Entity (Spec_Id);
309 Push_Scope (Spec_Id);
311 Set_Categorization_From_Pragmas (N);
313 Install_Visible_Declarations (Spec_Id);
314 Install_Private_Declarations (Spec_Id);
315 Install_Private_With_Clauses (Spec_Id);
316 Install_Composite_Operations (Spec_Id);
318 Check_Anonymous_Access_Types (Spec_Id, N);
320 if Ekind (Spec_Id) = E_Generic_Package then
321 Set_Use (Generic_Formal_Declarations (Pack_Decl));
324 Set_Use (Visible_Declarations (Specification (Pack_Decl)));
325 Set_Use (Private_Declarations (Specification (Pack_Decl)));
327 -- This is a nested package, so it may be necessary to declare certain
328 -- inherited subprograms that are not yet visible because the parent
329 -- type's subprograms are now visible.
331 if Ekind (Scope (Spec_Id)) = E_Package
332 and then Scope (Spec_Id) /= Standard_Standard
334 Declare_Inherited_Private_Subprograms (Spec_Id);
337 if Present (Declarations (N)) then
338 Analyze_Declarations (Declarations (N));
339 Inspect_Deferred_Constant_Completion (Declarations (N));
342 -- Analyze_Declarations has caused freezing of all types; now generate
343 -- bodies for RACW primitives and stream attributes, if any.
345 if Ekind (Spec_Id) = E_Package and then Has_RACW (Spec_Id) then
347 -- Attach subprogram bodies to support RACWs declared in spec
349 Append_RACW_Bodies (Declarations (N), Spec_Id);
350 Analyze_List (Declarations (N));
353 HSS := Handled_Statement_Sequence (N);
355 if Present (HSS) then
356 Process_End_Label (HSS, 't', Spec_Id);
359 -- Check that elaboration code in a preelaborable package body is
360 -- empty other than null statements and labels (RM 10.2.1(6)).
362 Validate_Null_Statement_Sequence (N);
365 Validate_Categorization_Dependency (N, Spec_Id);
366 Check_Completion (Body_Id);
368 -- Generate start of body reference. Note that we do this fairly late,
369 -- because the call will use In_Extended_Main_Source_Unit as a check,
370 -- and we want to make sure that Corresponding_Stub links are set
372 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
374 -- For a generic package, collect global references and mark them on
375 -- the original body so that they are not resolved again at the point
378 if Ekind (Spec_Id) /= E_Package then
379 Save_Global_References (Original_Node (N));
383 -- The entities of the package body have so far been chained onto the
384 -- declaration chain for the spec. That's been fine while we were in the
385 -- body, since we wanted them to be visible, but now that we are leaving
386 -- the package body, they are no longer visible, so we remove them from
387 -- the entity chain of the package spec entity, and copy them to the
388 -- entity chain of the package body entity, where they will never again
391 if Present (Last_Spec_Entity) then
392 Set_First_Entity (Body_Id, Next_Entity (Last_Spec_Entity));
393 Set_Next_Entity (Last_Spec_Entity, Empty);
394 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
395 Set_Last_Entity (Spec_Id, Last_Spec_Entity);
398 Set_First_Entity (Body_Id, First_Entity (Spec_Id));
399 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
400 Set_First_Entity (Spec_Id, Empty);
401 Set_Last_Entity (Spec_Id, Empty);
404 End_Package_Scope (Spec_Id);
406 -- All entities declared in body are not visible
412 E := First_Entity (Body_Id);
413 while Present (E) loop
414 Set_Is_Immediately_Visible (E, False);
415 Set_Is_Potentially_Use_Visible (E, False);
418 -- Child units may appear on the entity list (for example if
419 -- they appear in the context of a subunit) but they are not
422 if not Is_Child_Unit (E) then
423 Set_Is_Package_Body_Entity (E);
430 Check_References (Body_Id);
432 -- For a generic unit, check that the formal parameters are referenced,
433 -- and that local variables are used, as for regular packages.
435 if Ekind (Spec_Id) = E_Generic_Package then
436 Check_References (Spec_Id);
439 -- The processing so far has made all entities of the package body
440 -- public (i.e. externally visible to the linker). This is in general
441 -- necessary, since inlined or generic bodies, for which code is
442 -- generated in other units, may need to see these entities. The
443 -- following loop runs backwards from the end of the entities of the
444 -- package body making these entities invisible until we reach a
445 -- referencer, i.e. a declaration that could reference a previous
446 -- declaration, a generic body or an inlined body, or a stub (which
447 -- may contain either of these). This is of course an approximation,
448 -- but it is conservative and definitely correct.
450 -- We only do this at the outer (library) level non-generic packages.
451 -- The reason is simply to cut down on the number of external symbols
452 -- generated, so this is simply an optimization of the efficiency
453 -- of the compilation process. It has no other effect.
455 if (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id))
456 and then not Is_Generic_Unit (Spec_Id)
457 and then Present (Declarations (N))
459 Make_Non_Public_Where_Possible : declare
461 function Has_Referencer
465 -- Traverse the given list of declarations in reverse order.
466 -- Return True as soon as a referencer is reached. Return
467 -- False if none is found. The Outer parameter is True for
468 -- the outer level call, and False for inner level calls for
469 -- nested packages. If Outer is True, then any entities up
470 -- to the point of hitting a referencer get their Is_Public
471 -- flag cleared, so that the entities will be treated as
472 -- static entities in the C sense, and need not have fully
473 -- qualified names. For inner levels, we need all names to
474 -- be fully qualified to deal with the same name appearing
475 -- in parallel packages (right now this is tied to their
482 function Has_Referencer
498 while Present (D) loop
501 if K in N_Body_Stub then
504 elsif K = N_Subprogram_Body then
505 if Acts_As_Spec (D) then
506 E := Defining_Entity (D);
508 -- An inlined body acts as a referencer. Note also
509 -- that we never reset Is_Public for an inlined
510 -- subprogram. Gigi requires Is_Public to be set.
512 -- Note that we test Has_Pragma_Inline here rather
513 -- than Is_Inlined. We are compiling this for a
514 -- client, and it is the client who will decide
515 -- if actual inlining should occur, so we need to
516 -- assume that the procedure could be inlined for
517 -- the purpose of accessing global entities.
519 if Has_Pragma_Inline (E) then
522 Set_Is_Public (E, False);
526 E := Corresponding_Spec (D);
529 and then (Is_Generic_Unit (E)
530 or else Has_Pragma_Inline (E)
531 or else Is_Inlined (E))
537 -- Processing for package bodies
539 elsif K = N_Package_Body
540 and then Present (Corresponding_Spec (D))
542 E := Corresponding_Spec (D);
544 -- Generic package body is a referencer. It would
545 -- seem that we only have to consider generics that
546 -- can be exported, i.e. where the corresponding spec
547 -- is the spec of the current package, but because of
548 -- nested instantiations, a fully private generic
549 -- body may export other private body entities.
551 if Is_Generic_Unit (E) then
554 -- For non-generic package body, recurse into body
555 -- unless this is an instance, we ignore instances
556 -- since they cannot have references that affect
559 elsif not Is_Generic_Instance (E) then
561 (Declarations (D), Outer => False)
567 -- Processing for package specs, recurse into declarations.
568 -- Again we skip this for the case of generic instances.
570 elsif K = N_Package_Declaration then
571 S := Specification (D);
573 if not Is_Generic_Unit (Defining_Entity (S)) then
575 (Private_Declarations (S), Outer => False)
579 (Visible_Declarations (S), Outer => False)
585 -- Objects and exceptions need not be public if we have
586 -- not encountered a referencer so far. We only reset
587 -- the flag for outer level entities that are not
588 -- imported/exported, and which have no interface name.
590 elsif Nkind_In (K, N_Object_Declaration,
591 N_Exception_Declaration,
592 N_Subprogram_Declaration)
594 E := Defining_Entity (D);
597 and then not Is_Imported (E)
598 and then not Is_Exported (E)
599 and then No (Interface_Name (E))
601 Set_Is_Public (E, False);
611 -- Start of processing for Make_Non_Public_Where_Possible
616 pragma Warnings (Off, Discard);
619 Discard := Has_Referencer (Declarations (N), Outer => True);
621 end Make_Non_Public_Where_Possible;
624 -- If expander is not active, then here is where we turn off the
625 -- In_Package_Body flag, otherwise it is turned off at the end of
626 -- the corresponding expansion routine. If this is an instance body,
627 -- we need to qualify names of local entities, because the body may
628 -- have been compiled as a preliminary to another instantiation.
630 if not Expander_Active then
631 Set_In_Package_Body (Spec_Id, False);
633 if Is_Generic_Instance (Spec_Id)
634 and then Operating_Mode = Generate_Code
636 Qualify_Entity_Names (N);
639 end Analyze_Package_Body;
641 ---------------------------------
642 -- Analyze_Package_Declaration --
643 ---------------------------------
645 procedure Analyze_Package_Declaration (N : Node_Id) is
646 Id : constant Node_Id := Defining_Entity (N);
649 -- True when in the context of a declared pure library unit
651 Body_Required : Boolean;
652 -- True when this package declaration requires a corresponding body
655 -- True when this package declaration is not a nested declaration
658 -- Ada 2005 (AI-217): Check if the package has been erroneously named
659 -- in a limited-with clause of its own context. In this case the error
660 -- has been previously notified by Analyze_Context.
662 -- limited with Pkg; -- ERROR
663 -- package Pkg is ...
665 if From_With_Type (Id) then
669 Generate_Definition (Id);
671 Set_Ekind (Id, E_Package);
672 Set_Etype (Id, Standard_Void_Type);
676 PF := Is_Pure (Enclosing_Lib_Unit_Entity);
677 Set_Is_Pure (Id, PF);
679 Set_Categorization_From_Pragmas (N);
682 Write_Str ("==== Compiling package spec ");
683 Write_Name (Chars (Id));
684 Write_Str (" from ");
685 Write_Location (Sloc (N));
689 Analyze (Specification (N));
690 Validate_Categorization_Dependency (N, Id);
692 Body_Required := Unit_Requires_Body (Id);
694 -- When this spec does not require an explicit body, we know that
695 -- there are no entities requiring completion in the language sense;
696 -- we call Check_Completion here only to ensure that any nested package
697 -- declaration that requires an implicit body gets one. (In the case
698 -- where a body is required, Check_Completion is called at the end of
699 -- the body's declarative part.)
701 if not Body_Required then
705 Comp_Unit := Nkind (Parent (N)) = N_Compilation_Unit;
708 -- Set Body_Required indication on the compilation unit node, and
709 -- determine whether elaboration warnings may be meaningful on it.
711 Set_Body_Required (Parent (N), Body_Required);
713 if not Body_Required then
714 Set_Suppress_Elaboration_Warnings (Id);
719 End_Package_Scope (Id);
721 -- For the declaration of a library unit that is a remote types package,
722 -- check legality rules regarding availability of stream attributes for
723 -- types that contain non-remote access values. This subprogram performs
724 -- visibility tests that rely on the fact that we have exited the scope
728 Validate_RT_RAT_Component (N);
730 end Analyze_Package_Declaration;
732 -----------------------------------
733 -- Analyze_Package_Specification --
734 -----------------------------------
736 -- Note that this code is shared for the analysis of generic package
737 -- specs (see Sem_Ch12.Analyze_Generic_Package_Declaration for details).
739 procedure Analyze_Package_Specification (N : Node_Id) is
740 Id : constant Entity_Id := Defining_Entity (N);
741 Orig_Decl : constant Node_Id := Original_Node (Parent (N));
742 Vis_Decls : constant List_Id := Visible_Declarations (N);
743 Priv_Decls : constant List_Id := Private_Declarations (N);
746 Public_Child : Boolean;
748 Private_With_Clauses_Installed : Boolean := False;
749 -- In Ada 2005, private with_clauses are visible in the private part
750 -- of a nested package, even if it appears in the public part of the
751 -- enclosing package. This requires a separate step to install these
752 -- private_with_clauses, and remove them at the end of the nested
755 procedure Analyze_PPCs (Decls : List_Id);
756 -- Given a list of declarations, go through looking for subprogram
757 -- specs, and for each one found, analyze any pre/postconditions that
758 -- are chained to the spec. This is the implementation of the late
759 -- visibility analysis for preconditions and postconditions in specs.
761 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id);
762 -- Clears constant indications (Never_Set_In_Source, Constant_Value,
763 -- and Is_True_Constant) on all variables that are entities of Id,
764 -- and on the chain whose first element is FE. A recursive call is
765 -- made for all packages and generic packages.
767 procedure Generate_Parent_References;
768 -- For a child unit, generate references to parent units, for
769 -- GPS navigation purposes.
771 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean;
772 -- Child and Unit are entities of compilation units. True if Child
773 -- is a public child of Parent as defined in 10.1.1
775 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id);
776 -- Detects all incomplete or private type declarations having a known
777 -- discriminant part that are completed by an Unchecked_Union. Emits
778 -- the error message "Unchecked_Union may not complete discriminated
781 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id);
782 -- Given the package entity of a generic package instantiation or
783 -- formal package whose corresponding generic is a child unit, installs
784 -- the private declarations of each of the child unit's parents.
785 -- This has to be done at the point of entering the instance package's
786 -- private part rather than being done in Sem_Ch12.Install_Parent
787 -- (which is where the parents' visible declarations are installed).
793 procedure Analyze_PPCs (Decls : List_Id) is
800 Decl := First (Decls);
801 while Present (Decl) loop
802 if Nkind (Original_Node (Decl)) = N_Subprogram_Declaration then
803 Spec := Specification (Original_Node (Decl));
804 Sent := Defining_Unit_Name (Spec);
805 Prag := Spec_PPC_List (Sent);
806 while Present (Prag) loop
807 Analyze_PPC_In_Decl_Part (Prag, Sent);
808 Prag := Next_Pragma (Prag);
816 ---------------------
817 -- Clear_Constants --
818 ---------------------
820 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id) is
824 -- Ignore package renamings, not interesting and they can
825 -- cause self referential loops in the code below.
827 if Nkind (Parent (Id)) = N_Package_Renaming_Declaration then
831 -- Note: in the loop below, the check for Next_Entity pointing
832 -- back to the package entity may seem odd, but it is needed,
833 -- because a package can contain a renaming declaration to itself,
834 -- and such renamings are generated automatically within package
838 while Present (E) and then E /= Id loop
839 if Is_Assignable (E) then
840 Set_Never_Set_In_Source (E, False);
841 Set_Is_True_Constant (E, False);
842 Set_Current_Value (E, Empty);
843 Set_Is_Known_Null (E, False);
844 Set_Last_Assignment (E, Empty);
846 if not Can_Never_Be_Null (E) then
847 Set_Is_Known_Non_Null (E, False);
850 elsif Is_Package_Or_Generic_Package (E) then
851 Clear_Constants (E, First_Entity (E));
852 Clear_Constants (E, First_Private_Entity (E));
859 --------------------------------
860 -- Generate_Parent_References --
861 --------------------------------
863 procedure Generate_Parent_References is
864 Decl : constant Node_Id := Parent (N);
867 if Id = Cunit_Entity (Main_Unit)
868 or else Parent (Decl) = Library_Unit (Cunit (Main_Unit))
870 Generate_Reference (Id, Scope (Id), 'k', False);
872 elsif not Nkind_In (Unit (Cunit (Main_Unit)), N_Subprogram_Body,
875 -- If current unit is an ancestor of main unit, generate
876 -- a reference to its own parent.
880 Main_Spec : Node_Id := Unit (Cunit (Main_Unit));
883 if Nkind (Main_Spec) = N_Package_Body then
884 Main_Spec := Unit (Library_Unit (Cunit (Main_Unit)));
887 U := Parent_Spec (Main_Spec);
888 while Present (U) loop
889 if U = Parent (Decl) then
890 Generate_Reference (Id, Scope (Id), 'k', False);
893 elsif Nkind (Unit (U)) = N_Package_Body then
897 U := Parent_Spec (Unit (U));
902 end Generate_Parent_References;
904 ---------------------
905 -- Is_Public_Child --
906 ---------------------
908 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean is
910 if not Is_Private_Descendant (Child) then
914 return not Private_Present (
915 Parent (Unit_Declaration_Node (Child)));
917 return Is_Public_Child (Scope (Child), Unit);
922 ----------------------------------------
923 -- Inspect_Unchecked_Union_Completion --
924 ----------------------------------------
926 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is
930 Decl := First (Decls);
931 while Present (Decl) loop
933 -- We are looking at an incomplete or private type declaration
934 -- with a known_discriminant_part whose full view is an
937 if Nkind_In (Decl, N_Incomplete_Type_Declaration,
938 N_Private_Type_Declaration)
939 and then Has_Discriminants (Defining_Identifier (Decl))
940 and then Present (Full_View (Defining_Identifier (Decl)))
942 Is_Unchecked_Union (Full_View (Defining_Identifier (Decl)))
945 ("completion of discriminated partial view "
946 & "cannot be an Unchecked_Union",
947 Full_View (Defining_Identifier (Decl)));
952 end Inspect_Unchecked_Union_Completion;
954 -----------------------------------------
955 -- Install_Parent_Private_Declarations --
956 -----------------------------------------
958 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id) is
959 Inst_Par : Entity_Id;
967 Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par)));
968 while Present (Gen_Par) and then Is_Child_Unit (Gen_Par) loop
969 Inst_Node := Get_Package_Instantiation_Node (Inst_Par);
971 if Nkind_In (Inst_Node, N_Package_Instantiation,
972 N_Formal_Package_Declaration)
973 and then Nkind (Name (Inst_Node)) = N_Expanded_Name
975 Inst_Par := Entity (Prefix (Name (Inst_Node)));
977 if Present (Renamed_Entity (Inst_Par)) then
978 Inst_Par := Renamed_Entity (Inst_Par);
983 (Specification (Unit_Declaration_Node (Inst_Par)));
985 -- Install the private declarations and private use clauses
986 -- of a parent instance of the child instance, unless the
987 -- parent instance private declarations have already been
988 -- installed earlier in Analyze_Package_Specification, which
989 -- happens when a generic child is instantiated, and the
990 -- instance is a child of the parent instance.
992 -- Installing the use clauses of the parent instance twice
993 -- is both unnecessary and wrong, because it would cause the
994 -- clauses to be chained to themselves in the use clauses
995 -- list of the scope stack entry. That in turn would cause
996 -- an endless loop from End_Use_Clauses upon scope exit.
998 -- The parent is now fully visible. It may be a hidden open
999 -- scope if we are currently compiling some child instance
1000 -- declared within it, but while the current instance is being
1001 -- compiled the parent is immediately visible. In particular
1002 -- its entities must remain visible if a stack save/restore
1003 -- takes place through a call to Rtsfind.
1005 if Present (Gen_Par) then
1006 if not In_Private_Part (Inst_Par) then
1007 Install_Private_Declarations (Inst_Par);
1008 Set_Use (Private_Declarations
1010 (Unit_Declaration_Node (Inst_Par))));
1011 Set_Is_Hidden_Open_Scope (Inst_Par, False);
1014 -- If we've reached the end of the generic instance parents,
1015 -- then finish off by looping through the nongeneric parents
1016 -- and installing their private declarations.
1019 while Present (Inst_Par)
1020 and then Inst_Par /= Standard_Standard
1021 and then (not In_Open_Scopes (Inst_Par)
1022 or else not In_Private_Part (Inst_Par))
1024 Install_Private_Declarations (Inst_Par);
1025 Set_Use (Private_Declarations
1027 (Unit_Declaration_Node (Inst_Par))));
1028 Inst_Par := Scope (Inst_Par);
1038 end Install_Parent_Private_Declarations;
1040 -- Start of processing for Analyze_Package_Specification
1043 if Present (Vis_Decls) then
1044 Analyze_Declarations (Vis_Decls);
1045 Analyze_PPCs (Vis_Decls);
1048 -- Verify that incomplete types have received full declarations
1050 E := First_Entity (Id);
1051 while Present (E) loop
1052 if Ekind (E) = E_Incomplete_Type
1053 and then No (Full_View (E))
1055 Error_Msg_N ("no declaration in visible part for incomplete}", E);
1061 if Is_Remote_Call_Interface (Id)
1062 and then Nkind (Parent (Parent (N))) = N_Compilation_Unit
1064 Validate_RCI_Declarations (Id);
1067 -- Save global references in the visible declarations, before
1068 -- installing private declarations of parent unit if there is one,
1069 -- because the privacy status of types defined in the parent will
1070 -- change. This is only relevant for generic child units, but is
1071 -- done in all cases for uniformity.
1073 if Ekind (Id) = E_Generic_Package
1074 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1077 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1078 Save_Priv : constant List_Id := Private_Declarations (Orig_Spec);
1081 Set_Private_Declarations (Orig_Spec, Empty_List);
1082 Save_Global_References (Orig_Decl);
1083 Set_Private_Declarations (Orig_Spec, Save_Priv);
1087 -- If package is a public child unit, then make the private declarations
1088 -- of the parent visible.
1090 Public_Child := False;
1094 Pack_Decl : Node_Id;
1099 Par_Spec := Parent_Spec (Parent (N));
1101 -- If the package is formal package of an enclosing generic, it is
1102 -- transformed into a local generic declaration, and compiled to make
1103 -- its spec available. We need to retrieve the original generic to
1104 -- determine whether it is a child unit, and install its parents.
1108 Nkind (Original_Node (Parent (N))) = N_Formal_Package_Declaration
1110 Par := Entity (Name (Original_Node (Parent (N))));
1111 Par_Spec := Parent_Spec (Unit_Declaration_Node (Par));
1114 if Present (Par_Spec) then
1115 Generate_Parent_References;
1117 while Scope (Par) /= Standard_Standard
1118 and then Is_Public_Child (Id, Par)
1119 and then In_Open_Scopes (Par)
1121 Public_Child := True;
1123 Install_Private_Declarations (Par);
1124 Install_Private_With_Clauses (Par);
1125 Pack_Decl := Unit_Declaration_Node (Par);
1126 Set_Use (Private_Declarations (Specification (Pack_Decl)));
1131 if Is_Compilation_Unit (Id) then
1132 Install_Private_With_Clauses (Id);
1135 -- The current compilation unit may include private with_clauses,
1136 -- which are visible in the private part of the current nested
1137 -- package, and have to be installed now. This is not done for
1138 -- nested instantiations, where the private with_clauses of the
1139 -- enclosing unit have no effect once the instantiation info is
1140 -- established and we start analyzing the package declaration.
1143 Comp_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1145 if Is_Package_Or_Generic_Package (Comp_Unit)
1146 and then not In_Private_Part (Comp_Unit)
1147 and then not In_Instance
1149 Install_Private_With_Clauses (Comp_Unit);
1150 Private_With_Clauses_Installed := True;
1155 -- If this is a package associated with a generic instance or formal
1156 -- package, then the private declarations of each of the generic's
1157 -- parents must be installed at this point.
1159 if Is_Generic_Instance (Id) then
1160 Install_Parent_Private_Declarations (Id);
1163 -- Analyze private part if present. The flag In_Private_Part is reset
1164 -- in End_Package_Scope.
1166 L := Last_Entity (Id);
1168 if Present (Priv_Decls) then
1169 Set_In_Private_Part (Id);
1171 -- Upon entering a public child's private part, it may be necessary
1172 -- to declare subprograms that were derived in the package's visible
1173 -- part but not yet made visible.
1175 if Public_Child then
1176 Declare_Inherited_Private_Subprograms (Id);
1179 Analyze_Declarations (Priv_Decls);
1180 Analyze_PPCs (Priv_Decls);
1182 -- Check the private declarations for incomplete deferred constants
1184 Inspect_Deferred_Constant_Completion (Priv_Decls);
1186 -- The first private entity is the immediate follower of the last
1187 -- visible entity, if there was one.
1190 Set_First_Private_Entity (Id, Next_Entity (L));
1192 Set_First_Private_Entity (Id, First_Entity (Id));
1195 -- There may be inherited private subprograms that need to be declared,
1196 -- even in the absence of an explicit private part. If there are any
1197 -- public declarations in the package and the package is a public child
1198 -- unit, then an implicit private part is assumed.
1200 elsif Present (L) and then Public_Child then
1201 Set_In_Private_Part (Id);
1202 Declare_Inherited_Private_Subprograms (Id);
1203 Set_First_Private_Entity (Id, Next_Entity (L));
1206 E := First_Entity (Id);
1207 while Present (E) loop
1209 -- Check rule of 3.6(11), which in general requires waiting till all
1210 -- full types have been seen.
1212 if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then
1213 Check_Aliased_Component_Types (E);
1216 -- Check preelaborable initialization for full type completing a
1217 -- private type for which pragma Preelaborable_Initialization given.
1220 and then Must_Have_Preelab_Init (E)
1221 and then not Has_Preelaborable_Initialization (E)
1224 ("full view of & does not have preelaborable initialization", E);
1230 -- Ada 2005 (AI-216): The completion of an incomplete or private type
1231 -- declaration having a known_discriminant_part shall not be an
1232 -- Unchecked_Union type.
1234 if Present (Vis_Decls) then
1235 Inspect_Unchecked_Union_Completion (Vis_Decls);
1238 if Present (Priv_Decls) then
1239 Inspect_Unchecked_Union_Completion (Priv_Decls);
1242 if Ekind (Id) = E_Generic_Package
1243 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1244 and then Present (Priv_Decls)
1246 -- Save global references in private declarations, ignoring the
1247 -- visible declarations that were processed earlier.
1250 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1251 Save_Vis : constant List_Id := Visible_Declarations (Orig_Spec);
1252 Save_Form : constant List_Id :=
1253 Generic_Formal_Declarations (Orig_Decl);
1256 Set_Visible_Declarations (Orig_Spec, Empty_List);
1257 Set_Generic_Formal_Declarations (Orig_Decl, Empty_List);
1258 Save_Global_References (Orig_Decl);
1259 Set_Generic_Formal_Declarations (Orig_Decl, Save_Form);
1260 Set_Visible_Declarations (Orig_Spec, Save_Vis);
1264 Process_End_Label (N, 'e', Id);
1266 -- Remove private_with_clauses of enclosing compilation unit, if they
1269 if Private_With_Clauses_Installed then
1270 Remove_Private_With_Clauses (Cunit (Current_Sem_Unit));
1273 -- For the case of a library level package, we must go through all the
1274 -- entities clearing the indications that the value may be constant and
1275 -- not modified. Why? Because any client of this package may modify
1276 -- these values freely from anywhere. This also applies to any nested
1277 -- packages or generic packages.
1279 -- For now we unconditionally clear constants for packages that are
1280 -- instances of generic packages. The reason is that we do not have the
1281 -- body yet, and we otherwise think things are unreferenced when they
1282 -- are not. This should be fixed sometime (the effect is not terrible,
1283 -- we just lose some warnings, and also some cases of value propagation)
1286 if Is_Library_Level_Entity (Id)
1287 or else Is_Generic_Instance (Id)
1289 Clear_Constants (Id, First_Entity (Id));
1290 Clear_Constants (Id, First_Private_Entity (Id));
1292 end Analyze_Package_Specification;
1294 --------------------------------------
1295 -- Analyze_Private_Type_Declaration --
1296 --------------------------------------
1298 procedure Analyze_Private_Type_Declaration (N : Node_Id) is
1299 PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity);
1300 Id : constant Entity_Id := Defining_Identifier (N);
1303 Generate_Definition (Id);
1304 Set_Is_Pure (Id, PF);
1305 Init_Size_Align (Id);
1307 if not Is_Package_Or_Generic_Package (Current_Scope)
1308 or else In_Private_Part (Current_Scope)
1310 Error_Msg_N ("invalid context for private declaration", N);
1313 New_Private_Type (N, Id, N);
1314 Set_Depends_On_Private (Id);
1315 end Analyze_Private_Type_Declaration;
1317 ----------------------------------
1318 -- Check_Anonymous_Access_Types --
1319 ----------------------------------
1321 procedure Check_Anonymous_Access_Types
1322 (Spec_Id : Entity_Id;
1329 -- Itype references are only needed by gigi, to force elaboration of
1330 -- itypes. In the absence of code generation, they are not needed.
1332 if not Expander_Active then
1336 E := First_Entity (Spec_Id);
1337 while Present (E) loop
1338 if Ekind (E) = E_Anonymous_Access_Type
1339 and then From_With_Type (E)
1341 IR := Make_Itype_Reference (Sloc (P_Body));
1344 if No (Declarations (P_Body)) then
1345 Set_Declarations (P_Body, New_List (IR));
1347 Prepend (IR, Declarations (P_Body));
1353 end Check_Anonymous_Access_Types;
1355 -------------------------------------------
1356 -- Declare_Inherited_Private_Subprograms --
1357 -------------------------------------------
1359 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is
1361 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean;
1362 -- Check whether an inherited subprogram is an operation of an
1363 -- untagged derived type.
1365 ---------------------
1366 -- Is_Primitive_Of --
1367 ---------------------
1369 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is
1373 -- If the full view is a scalar type, the type is the anonymous
1374 -- base type, but the operation mentions the first subtype, so
1375 -- check the signature against the base type.
1377 if Base_Type (Etype (S)) = Base_Type (T) then
1381 Formal := First_Formal (S);
1382 while Present (Formal) loop
1383 if Base_Type (Etype (Formal)) = Base_Type (T) then
1387 Next_Formal (Formal);
1392 end Is_Primitive_Of;
1399 Op_Elmt_2 : Elmt_Id;
1400 Prim_Op : Entity_Id;
1401 New_Op : Entity_Id := Empty;
1402 Parent_Subp : Entity_Id;
1405 -- Start of processing for Declare_Inherited_Private_Subprograms
1408 E := First_Entity (Id);
1409 while Present (E) loop
1411 -- If the entity is a nonprivate type extension whose parent
1412 -- type is declared in an open scope, then the type may have
1413 -- inherited operations that now need to be made visible.
1414 -- Ditto if the entity is a formal derived type in a child unit.
1416 if ((Is_Derived_Type (E) and then not Is_Private_Type (E))
1418 (Nkind (Parent (E)) = N_Private_Extension_Declaration
1419 and then Is_Generic_Type (E)))
1420 and then In_Open_Scopes (Scope (Etype (E)))
1421 and then E = Base_Type (E)
1423 if Is_Tagged_Type (E) then
1424 Op_List := Primitive_Operations (E);
1426 Tag := First_Tag_Component (E);
1428 Op_Elmt := First_Elmt (Op_List);
1429 while Present (Op_Elmt) loop
1430 Prim_Op := Node (Op_Elmt);
1432 -- Search primitives that are implicit operations with an
1433 -- internal name whose parent operation has a normal name.
1435 if Present (Alias (Prim_Op))
1436 and then Find_Dispatching_Type (Alias (Prim_Op)) /= E
1437 and then not Comes_From_Source (Prim_Op)
1438 and then Is_Internal_Name (Chars (Prim_Op))
1439 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1441 Parent_Subp := Alias (Prim_Op);
1443 -- Case 1: Check if the type has also an explicit
1444 -- overriding for this primitive.
1446 Op_Elmt_2 := Next_Elmt (Op_Elmt);
1447 while Present (Op_Elmt_2) loop
1448 if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp)
1449 and then Type_Conformant (Prim_Op, Node (Op_Elmt_2))
1451 -- The private inherited operation has been
1452 -- overridden by an explicit subprogram: replace
1453 -- the former by the latter.
1455 New_Op := Node (Op_Elmt_2);
1456 Replace_Elmt (Op_Elmt, New_Op);
1457 Remove_Elmt (Op_List, Op_Elmt_2);
1458 Set_Is_Overriding_Operation (New_Op);
1459 Set_Overridden_Operation (New_Op, Parent_Subp);
1461 -- We don't need to inherit its dispatching slot.
1462 -- Set_All_DT_Position has previously ensured that
1463 -- the same slot was assigned to the two primitives
1466 and then Present (DTC_Entity (New_Op))
1467 and then Present (DTC_Entity (Prim_Op))
1469 pragma Assert (DT_Position (New_Op)
1470 = DT_Position (Prim_Op));
1474 goto Next_Primitive;
1477 Next_Elmt (Op_Elmt_2);
1480 -- Case 2: We have not found any explicit overriding and
1481 -- hence we need to declare the operation (i.e., make it
1484 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1486 -- Inherit the dispatching slot if E is already frozen
1489 and then Present (DTC_Entity (Alias (Prim_Op)))
1491 Set_DTC_Entity_Value (E, New_Op);
1492 Set_DT_Position (New_Op,
1493 DT_Position (Alias (Prim_Op)));
1497 (Is_Dispatching_Operation (New_Op)
1498 and then Node (Last_Elmt (Op_List)) = New_Op);
1500 -- Substitute the new operation for the old one
1501 -- in the type's primitive operations list. Since
1502 -- the new operation was also just added to the end
1503 -- of list, the last element must be removed.
1505 -- (Question: is there a simpler way of declaring
1506 -- the operation, say by just replacing the name
1507 -- of the earlier operation, reentering it in the
1508 -- in the symbol table (how?), and marking it as
1511 Replace_Elmt (Op_Elmt, New_Op);
1512 Remove_Last_Elmt (Op_List);
1516 Next_Elmt (Op_Elmt);
1519 -- Generate listing showing the contents of the dispatch table
1521 if Debug_Flag_ZZ then
1526 -- Non-tagged type, scan forward to locate
1527 -- inherited hidden operations.
1529 Prim_Op := Next_Entity (E);
1530 while Present (Prim_Op) loop
1531 if Is_Subprogram (Prim_Op)
1532 and then Present (Alias (Prim_Op))
1533 and then not Comes_From_Source (Prim_Op)
1534 and then Is_Internal_Name (Chars (Prim_Op))
1535 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1536 and then Is_Primitive_Of (E, Prim_Op)
1538 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1541 Next_Entity (Prim_Op);
1548 end Declare_Inherited_Private_Subprograms;
1550 -----------------------
1551 -- End_Package_Scope --
1552 -----------------------
1554 procedure End_Package_Scope (P : Entity_Id) is
1556 Uninstall_Declarations (P);
1558 end End_Package_Scope;
1560 ---------------------------
1561 -- Exchange_Declarations --
1562 ---------------------------
1564 procedure Exchange_Declarations (Id : Entity_Id) is
1565 Full_Id : constant Entity_Id := Full_View (Id);
1566 H1 : constant Entity_Id := Homonym (Id);
1567 Next1 : constant Entity_Id := Next_Entity (Id);
1572 -- If missing full declaration for type, nothing to exchange
1574 if No (Full_Id) then
1578 -- Otherwise complete the exchange, and preserve semantic links
1580 Next2 := Next_Entity (Full_Id);
1581 H2 := Homonym (Full_Id);
1583 -- Reset full declaration pointer to reflect the switched entities
1584 -- and readjust the next entity chains.
1586 Exchange_Entities (Id, Full_Id);
1588 Set_Next_Entity (Id, Next1);
1589 Set_Homonym (Id, H1);
1591 Set_Full_View (Full_Id, Id);
1592 Set_Next_Entity (Full_Id, Next2);
1593 Set_Homonym (Full_Id, H2);
1594 end Exchange_Declarations;
1596 ----------------------------
1597 -- Install_Package_Entity --
1598 ----------------------------
1600 procedure Install_Package_Entity (Id : Entity_Id) is
1602 if not Is_Internal (Id) then
1603 if Debug_Flag_E then
1604 Write_Str ("Install: ");
1605 Write_Name (Chars (Id));
1609 if not Is_Child_Unit (Id) then
1610 Set_Is_Immediately_Visible (Id);
1614 end Install_Package_Entity;
1616 ----------------------------------
1617 -- Install_Private_Declarations --
1618 ----------------------------------
1620 procedure Install_Private_Declarations (P : Entity_Id) is
1622 Priv_Elmt : Elmt_Id;
1627 -- First exchange declarations for private types, so that the
1628 -- full declaration is visible. For each private type, we check
1629 -- its Private_Dependents list and also exchange any subtypes of
1630 -- or derived types from it. Finally, if this is a Taft amendment
1631 -- type, the incomplete declaration is irrelevant, and we want to
1632 -- link the eventual full declaration with the original private
1633 -- one so we also skip the exchange.
1635 Id := First_Entity (P);
1636 while Present (Id) and then Id /= First_Private_Entity (P) loop
1637 if Is_Private_Base_Type (Id)
1638 and then Comes_From_Source (Full_View (Id))
1639 and then Present (Full_View (Id))
1640 and then Scope (Full_View (Id)) = Scope (Id)
1641 and then Ekind (Full_View (Id)) /= E_Incomplete_Type
1643 -- If there is a use-type clause on the private type, set the
1644 -- full view accordingly.
1646 Set_In_Use (Full_View (Id), In_Use (Id));
1647 Full := Full_View (Id);
1649 if Is_Private_Base_Type (Full)
1650 and then Has_Private_Declaration (Full)
1651 and then Nkind (Parent (Full)) = N_Full_Type_Declaration
1652 and then In_Open_Scopes (Scope (Etype (Full)))
1653 and then In_Package_Body (Current_Scope)
1654 and then not Is_Private_Type (Etype (Full))
1656 -- This is the completion of a private type by a derivation
1657 -- from another private type which is not private anymore. This
1658 -- can only happen in a package nested within a child package,
1659 -- when the parent type is defined in the parent unit. At this
1660 -- point the current type is not private either, and we have to
1661 -- install the underlying full view, which is now visible.
1662 -- Save the current full view as well, so that all views can
1663 -- be restored on exit. It may seem that after compiling the
1664 -- child body there are not environments to restore, but the
1665 -- back-end expects those links to be valid, and freeze nodes
1668 if No (Full_View (Full))
1669 and then Present (Underlying_Full_View (Full))
1671 Set_Full_View (Id, Underlying_Full_View (Full));
1672 Set_Underlying_Full_View (Id, Full);
1674 Set_Underlying_Full_View (Full, Empty);
1675 Set_Is_Frozen (Full_View (Id));
1679 Priv_Elmt := First_Elmt (Private_Dependents (Id));
1681 Exchange_Declarations (Id);
1682 Set_Is_Immediately_Visible (Id);
1684 while Present (Priv_Elmt) loop
1685 Priv := Node (Priv_Elmt);
1687 -- Before the exchange, verify that the presence of the
1688 -- Full_View field. It will be empty if the entity
1689 -- has already been installed due to a previous call.
1691 if Present (Full_View (Priv))
1692 and then Is_Visible_Dependent (Priv)
1695 -- For each subtype that is swapped, we also swap the
1696 -- reference to it in Private_Dependents, to allow access
1697 -- to it when we swap them out in End_Package_Scope.
1699 Replace_Elmt (Priv_Elmt, Full_View (Priv));
1700 Exchange_Declarations (Priv);
1701 Set_Is_Immediately_Visible
1702 (Priv, In_Open_Scopes (Scope (Priv)));
1703 Set_Is_Potentially_Use_Visible
1704 (Priv, Is_Potentially_Use_Visible (Node (Priv_Elmt)));
1707 Next_Elmt (Priv_Elmt);
1714 -- Next make other declarations in the private part visible as well
1716 Id := First_Private_Entity (P);
1717 while Present (Id) loop
1718 Install_Package_Entity (Id);
1719 Set_Is_Hidden (Id, False);
1723 -- Indicate that the private part is currently visible, so it can be
1724 -- properly reset on exit.
1726 Set_In_Private_Part (P);
1727 end Install_Private_Declarations;
1729 ----------------------------------
1730 -- Install_Visible_Declarations --
1731 ----------------------------------
1733 procedure Install_Visible_Declarations (P : Entity_Id) is
1735 Last_Entity : Entity_Id;
1739 (Is_Package_Or_Generic_Package (P) or else Is_Record_Type (P));
1741 if Is_Package_Or_Generic_Package (P) then
1742 Last_Entity := First_Private_Entity (P);
1744 Last_Entity := Empty;
1747 Id := First_Entity (P);
1748 while Present (Id) and then Id /= Last_Entity loop
1749 Install_Package_Entity (Id);
1752 end Install_Visible_Declarations;
1754 --------------------------
1755 -- Is_Private_Base_Type --
1756 --------------------------
1758 function Is_Private_Base_Type (E : Entity_Id) return Boolean is
1760 return Ekind (E) = E_Private_Type
1761 or else Ekind (E) = E_Limited_Private_Type
1762 or else Ekind (E) = E_Record_Type_With_Private;
1763 end Is_Private_Base_Type;
1765 --------------------------
1766 -- Is_Visible_Dependent --
1767 --------------------------
1769 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean
1771 S : constant Entity_Id := Scope (Dep);
1774 -- Renamings created for actual types have the visibility of the
1777 if Ekind (S) = E_Package
1778 and then Is_Generic_Instance (S)
1779 and then (Is_Generic_Actual_Type (Dep)
1780 or else Is_Generic_Actual_Type (Full_View (Dep)))
1784 elsif not (Is_Derived_Type (Dep))
1785 and then Is_Derived_Type (Full_View (Dep))
1787 -- When instantiating a package body, the scope stack is empty,
1788 -- so check instead whether the dependent type is defined in
1789 -- the same scope as the instance itself.
1791 return In_Open_Scopes (S)
1792 or else (Is_Generic_Instance (Current_Scope)
1793 and then Scope (Dep) = Scope (Current_Scope));
1797 end Is_Visible_Dependent;
1799 ----------------------------
1800 -- May_Need_Implicit_Body --
1801 ----------------------------
1803 procedure May_Need_Implicit_Body (E : Entity_Id) is
1804 P : constant Node_Id := Unit_Declaration_Node (E);
1805 S : constant Node_Id := Parent (P);
1810 if not Has_Completion (E)
1811 and then Nkind (P) = N_Package_Declaration
1812 and then (Present (Activation_Chain_Entity (P)) or else Has_RACW (E))
1815 Make_Package_Body (Sloc (E),
1816 Defining_Unit_Name => Make_Defining_Identifier (Sloc (E),
1817 Chars => Chars (E)),
1818 Declarations => New_List);
1820 if Nkind (S) = N_Package_Specification then
1821 if Present (Private_Declarations (S)) then
1822 Decls := Private_Declarations (S);
1824 Decls := Visible_Declarations (S);
1827 Decls := Declarations (S);
1833 end May_Need_Implicit_Body;
1835 ----------------------
1836 -- New_Private_Type --
1837 ----------------------
1839 procedure New_Private_Type (N : Node_Id; Id : Entity_Id; Def : Node_Id) is
1843 if Limited_Present (Def) then
1844 Set_Ekind (Id, E_Limited_Private_Type);
1846 Set_Ekind (Id, E_Private_Type);
1850 Set_Has_Delayed_Freeze (Id);
1851 Set_Is_First_Subtype (Id);
1852 Init_Size_Align (Id);
1854 Set_Is_Constrained (Id,
1855 No (Discriminant_Specifications (N))
1856 and then not Unknown_Discriminants_Present (N));
1858 -- Set tagged flag before processing discriminants, to catch
1861 Set_Is_Tagged_Type (Id, Tagged_Present (Def));
1863 Set_Discriminant_Constraint (Id, No_Elist);
1864 Set_Stored_Constraint (Id, No_Elist);
1866 if Present (Discriminant_Specifications (N)) then
1868 Process_Discriminants (N);
1871 elsif Unknown_Discriminants_Present (N) then
1872 Set_Has_Unknown_Discriminants (Id);
1875 Set_Private_Dependents (Id, New_Elmt_List);
1877 if Tagged_Present (Def) then
1878 Set_Ekind (Id, E_Record_Type_With_Private);
1879 Make_Class_Wide_Type (Id);
1880 Set_Primitive_Operations (Id, New_Elmt_List);
1881 Set_Is_Abstract_Type (Id, Abstract_Present (Def));
1882 Set_Is_Limited_Record (Id, Limited_Present (Def));
1883 Set_Has_Delayed_Freeze (Id, True);
1885 elsif Abstract_Present (Def) then
1886 Error_Msg_N ("only a tagged type can be abstract", N);
1888 end New_Private_Type;
1890 ----------------------------
1891 -- Uninstall_Declarations --
1892 ----------------------------
1894 procedure Uninstall_Declarations (P : Entity_Id) is
1895 Decl : constant Node_Id := Unit_Declaration_Node (P);
1898 Priv_Elmt : Elmt_Id;
1899 Priv_Sub : Entity_Id;
1901 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id);
1902 -- Copy to the private declaration the attributes of the full view
1903 -- that need to be available for the partial view also.
1905 function Type_In_Use (T : Entity_Id) return Boolean;
1906 -- Check whether type or base type appear in an active use_type clause
1908 ------------------------------
1909 -- Preserve_Full_Attributes --
1910 ------------------------------
1912 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id) is
1913 Priv_Is_Base_Type : constant Boolean := Priv = Base_Type (Priv);
1916 Set_Size_Info (Priv, (Full));
1917 Set_RM_Size (Priv, RM_Size (Full));
1918 Set_Size_Known_At_Compile_Time
1919 (Priv, Size_Known_At_Compile_Time (Full));
1920 Set_Is_Volatile (Priv, Is_Volatile (Full));
1921 Set_Treat_As_Volatile (Priv, Treat_As_Volatile (Full));
1922 Set_Is_Ada_2005_Only (Priv, Is_Ada_2005_Only (Full));
1923 Set_Has_Pragma_Unreferenced (Priv, Has_Pragma_Unreferenced (Full));
1924 Set_Has_Pragma_Unreferenced_Objects
1925 (Priv, Has_Pragma_Unreferenced_Objects
1927 if Is_Unchecked_Union (Full) then
1928 Set_Is_Unchecked_Union (Base_Type (Priv));
1930 -- Why is atomic not copied here ???
1932 if Referenced (Full) then
1933 Set_Referenced (Priv);
1936 if Priv_Is_Base_Type then
1937 Set_Is_Controlled (Priv, Is_Controlled (Base_Type (Full)));
1938 Set_Finalize_Storage_Only (Priv, Finalize_Storage_Only
1939 (Base_Type (Full)));
1940 Set_Has_Task (Priv, Has_Task (Base_Type (Full)));
1941 Set_Has_Controlled_Component (Priv, Has_Controlled_Component
1942 (Base_Type (Full)));
1945 Set_Freeze_Node (Priv, Freeze_Node (Full));
1947 if Is_Tagged_Type (Priv)
1948 and then Is_Tagged_Type (Full)
1949 and then not Error_Posted (Full)
1951 if Priv_Is_Base_Type then
1953 -- Ada 2005 (AI-345): The full view of a type implementing
1954 -- an interface can be a task type.
1956 -- type T is new I with private;
1958 -- task type T is new I with ...
1960 if Is_Interface (Etype (Priv))
1961 and then Is_Concurrent_Type (Base_Type (Full))
1963 -- Protect the frontend against previous errors
1965 if Present (Corresponding_Record_Type
1968 Set_Access_Disp_Table
1969 (Priv, Access_Disp_Table
1970 (Corresponding_Record_Type (Base_Type (Full))));
1972 -- Generic context, or previous errors
1979 Set_Access_Disp_Table
1980 (Priv, Access_Disp_Table (Base_Type (Full)));
1984 if Is_Tagged_Type (Priv) then
1986 -- If the type is tagged, the tag itself must be available
1987 -- on the partial view, for expansion purposes.
1989 Set_First_Entity (Priv, First_Entity (Full));
1991 -- If there are discriminants in the partial view, these remain
1992 -- visible. Otherwise only the tag itself is visible, and there
1993 -- are no nameable components in the partial view.
1995 if No (Last_Entity (Priv)) then
1996 Set_Last_Entity (Priv, First_Entity (Priv));
2000 Set_Has_Discriminants (Priv, Has_Discriminants (Full));
2002 end Preserve_Full_Attributes;
2008 function Type_In_Use (T : Entity_Id) return Boolean is
2010 return Scope (Base_Type (T)) = P
2011 and then (In_Use (T) or else In_Use (Base_Type (T)));
2014 -- Start of processing for Uninstall_Declarations
2017 Id := First_Entity (P);
2018 while Present (Id) and then Id /= First_Private_Entity (P) loop
2019 if Debug_Flag_E then
2020 Write_Str ("unlinking visible entity ");
2021 Write_Int (Int (Id));
2025 -- On exit from the package scope, we must preserve the visibility
2026 -- established by use clauses in the current scope. Two cases:
2028 -- a) If the entity is an operator, it may be a primitive operator of
2029 -- a type for which there is a visible use-type clause.
2031 -- b) for other entities, their use-visibility is determined by a
2032 -- visible use clause for the package itself. For a generic instance,
2033 -- the instantiation of the formals appears in the visible part,
2034 -- but the formals are private and remain so.
2036 if Ekind (Id) = E_Function
2037 and then Is_Operator_Symbol_Name (Chars (Id))
2038 and then not Is_Hidden (Id)
2039 and then not Error_Posted (Id)
2041 Set_Is_Potentially_Use_Visible (Id,
2043 or else Type_In_Use (Etype (Id))
2044 or else Type_In_Use (Etype (First_Formal (Id)))
2045 or else (Present (Next_Formal (First_Formal (Id)))
2048 (Etype (Next_Formal (First_Formal (Id))))));
2050 if In_Use (P) and then not Is_Hidden (Id) then
2052 -- A child unit of a use-visible package remains use-visible
2053 -- only if it is itself a visible child unit. Otherwise it
2054 -- would remain visible in other contexts where P is use-
2055 -- visible, because once compiled it stays in the entity list
2056 -- of its parent unit.
2058 if Is_Child_Unit (Id) then
2059 Set_Is_Potentially_Use_Visible (Id,
2060 Is_Visible_Child_Unit (Id));
2062 Set_Is_Potentially_Use_Visible (Id);
2066 Set_Is_Potentially_Use_Visible (Id, False);
2070 -- Local entities are not immediately visible outside of the package
2072 Set_Is_Immediately_Visible (Id, False);
2074 -- If this is a private type with a full view (for example a local
2075 -- subtype of a private type declared elsewhere), ensure that the
2076 -- full view is also removed from visibility: it may be exposed when
2077 -- swapping views in an instantiation.
2080 and then Present (Full_View (Id))
2082 Set_Is_Immediately_Visible (Full_View (Id), False);
2085 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2086 Check_Abstract_Overriding (Id);
2087 Check_Conventions (Id);
2090 if (Ekind (Id) = E_Private_Type
2091 or else Ekind (Id) = E_Limited_Private_Type)
2092 and then No (Full_View (Id))
2093 and then not Is_Generic_Type (Id)
2094 and then not Is_Derived_Type (Id)
2096 Error_Msg_N ("missing full declaration for private type&", Id);
2098 elsif Ekind (Id) = E_Record_Type_With_Private
2099 and then not Is_Generic_Type (Id)
2100 and then No (Full_View (Id))
2102 if Nkind (Parent (Id)) = N_Private_Type_Declaration then
2103 Error_Msg_N ("missing full declaration for private type&", Id);
2106 ("missing full declaration for private extension", Id);
2109 elsif Ekind (Id) = E_Constant
2110 and then No (Constant_Value (Id))
2111 and then No (Full_View (Id))
2112 and then not Is_Imported (Id)
2113 and then (Nkind (Parent (Id)) /= N_Object_Declaration
2114 or else not No_Initialization (Parent (Id)))
2116 if not Has_Private_Declaration (Etype (Id)) then
2118 -- We assume that the user did not not intend a deferred
2119 -- constant declaration, and the expression is just missing.
2122 ("constant declaration requires initialization expression",
2125 if Is_Limited_Type (Etype (Id)) then
2127 ("\if variable intended, remove CONSTANT from declaration",
2133 ("missing full declaration for deferred constant (RM 7.4)",
2136 if Is_Limited_Type (Etype (Id)) then
2138 ("\if variable intended, remove CONSTANT from declaration",
2147 -- If the specification was installed as the parent of a public child
2148 -- unit, the private declarations were not installed, and there is
2151 if not In_Private_Part (P) then
2154 Set_In_Private_Part (P, False);
2157 -- Make private entities invisible and exchange full and private
2158 -- declarations for private types. Id is now the first private
2159 -- entity in the package.
2161 while Present (Id) loop
2162 if Debug_Flag_E then
2163 Write_Str ("unlinking private entity ");
2164 Write_Int (Int (Id));
2168 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2169 Check_Abstract_Overriding (Id);
2170 Check_Conventions (Id);
2173 Set_Is_Immediately_Visible (Id, False);
2175 if Is_Private_Base_Type (Id)
2176 and then Present (Full_View (Id))
2178 Full := Full_View (Id);
2180 -- If the partial view is not declared in the visible part
2181 -- of the package (as is the case when it is a type derived
2182 -- from some other private type in the private part of the
2183 -- current package), no exchange takes place.
2186 or else List_Containing (Parent (Id))
2187 /= Visible_Declarations (Specification (Decl))
2192 -- The entry in the private part points to the full declaration,
2193 -- which is currently visible. Exchange them so only the private
2194 -- type declaration remains accessible, and link private and
2195 -- full declaration in the opposite direction. Before the actual
2196 -- exchange, we copy back attributes of the full view that
2197 -- must be available to the partial view too.
2199 Preserve_Full_Attributes (Id, Full);
2201 Set_Is_Potentially_Use_Visible (Id, In_Use (P));
2203 if Is_Indefinite_Subtype (Full)
2204 and then not Is_Indefinite_Subtype (Id)
2207 ("full view of type must be definite subtype", Full);
2210 Priv_Elmt := First_Elmt (Private_Dependents (Id));
2212 -- Swap out the subtypes and derived types of Id that were
2213 -- compiled in this scope, or installed previously by
2214 -- Install_Private_Declarations.
2215 -- Before we do the swap, we verify the presence of the
2216 -- Full_View field which may be empty due to a swap by
2217 -- a previous call to End_Package_Scope (e.g. from the
2218 -- freezing mechanism).
2220 while Present (Priv_Elmt) loop
2221 Priv_Sub := Node (Priv_Elmt);
2223 if Present (Full_View (Priv_Sub)) then
2225 if Scope (Priv_Sub) = P
2226 or else not In_Open_Scopes (Scope (Priv_Sub))
2228 Set_Is_Immediately_Visible (Priv_Sub, False);
2231 if Is_Visible_Dependent (Priv_Sub) then
2232 Preserve_Full_Attributes
2233 (Priv_Sub, Full_View (Priv_Sub));
2234 Replace_Elmt (Priv_Elmt, Full_View (Priv_Sub));
2235 Exchange_Declarations (Priv_Sub);
2239 Next_Elmt (Priv_Elmt);
2242 -- Now restore the type itself to its private view
2244 Exchange_Declarations (Id);
2246 -- If we have installed an underlying full view for a type
2247 -- derived from a private type in a child unit, restore the
2248 -- proper views of private and full view. See corresponding
2249 -- code in Install_Private_Declarations.
2250 -- After the exchange, Full denotes the private type in the
2251 -- visible part of the package.
2253 if Is_Private_Base_Type (Full)
2254 and then Present (Full_View (Full))
2255 and then Present (Underlying_Full_View (Full))
2256 and then In_Package_Body (Current_Scope)
2258 Set_Full_View (Full, Underlying_Full_View (Full));
2259 Set_Underlying_Full_View (Full, Empty);
2262 elsif Ekind (Id) = E_Incomplete_Type
2263 and then No (Full_View (Id))
2265 -- Mark Taft amendment types
2267 Set_Has_Completion_In_Body (Id);
2269 elsif not Is_Child_Unit (Id)
2270 and then (not Is_Private_Type (Id)
2271 or else No (Full_View (Id)))
2274 Set_Is_Potentially_Use_Visible (Id, False);
2280 end Uninstall_Declarations;
2282 ------------------------
2283 -- Unit_Requires_Body --
2284 ------------------------
2286 function Unit_Requires_Body (P : Entity_Id) return Boolean is
2290 -- Imported entity never requires body. Right now, only
2291 -- subprograms can be imported, but perhaps in the future
2292 -- we will allow import of packages.
2294 if Is_Imported (P) then
2297 -- Body required if library package with pragma Elaborate_Body
2299 elsif Has_Pragma_Elaborate_Body (P) then
2302 -- Body required if subprogram
2304 elsif Is_Subprogram (P) or else Is_Generic_Subprogram (P) then
2307 -- Treat a block as requiring a body
2309 elsif Ekind (P) = E_Block then
2312 elsif Ekind (P) = E_Package
2313 and then Nkind (Parent (P)) = N_Package_Specification
2314 and then Present (Generic_Parent (Parent (P)))
2317 G_P : constant Entity_Id := Generic_Parent (Parent (P));
2319 if Has_Pragma_Elaborate_Body (G_P) then
2325 -- Otherwise search entity chain for entity requiring completion
2327 E := First_Entity (P);
2328 while Present (E) loop
2330 -- Always ignore child units. Child units get added to the entity
2331 -- list of a parent unit, but are not original entities of the
2332 -- parent, and so do not affect whether the parent needs a body.
2334 if Is_Child_Unit (E) then
2337 -- Ignore formal packages and their renamings
2339 elsif Ekind (E) = E_Package
2340 and then Nkind (Original_Node (Unit_Declaration_Node (E))) =
2341 N_Formal_Package_Declaration
2345 -- Otherwise test to see if entity requires a completion.
2346 -- Note that subprogram entities whose declaration does not come
2347 -- from source are ignored here on the basis that we assume the
2348 -- expander will provide an implicit completion at some point.
2350 elsif (Is_Overloadable (E)
2351 and then Ekind (E) /= E_Enumeration_Literal
2352 and then Ekind (E) /= E_Operator
2353 and then not Is_Abstract_Subprogram (E)
2354 and then not Has_Completion (E)
2355 and then Comes_From_Source (Parent (E)))
2358 (Ekind (E) = E_Package
2360 and then not Has_Completion (E)
2361 and then Unit_Requires_Body (E))
2364 (Ekind (E) = E_Incomplete_Type and then No (Full_View (E)))
2367 ((Ekind (E) = E_Task_Type or else
2368 Ekind (E) = E_Protected_Type)
2369 and then not Has_Completion (E))
2372 (Ekind (E) = E_Generic_Package and then E /= P
2373 and then not Has_Completion (E)
2374 and then Unit_Requires_Body (E))
2377 (Is_Generic_Subprogram (E)
2378 and then not Has_Completion (E))
2383 -- Entity that does not require completion
2393 end Unit_Requires_Body;