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_Aux; use Sem_Aux;
48 with Sem_Cat; use Sem_Cat;
49 with Sem_Ch3; use Sem_Ch3;
50 with Sem_Ch6; use Sem_Ch6;
51 with Sem_Ch8; use Sem_Ch8;
52 with Sem_Ch10; use Sem_Ch10;
53 with Sem_Ch12; use Sem_Ch12;
54 with Sem_Disp; use Sem_Disp;
55 with Sem_Prag; use Sem_Prag;
56 with Sem_Util; use Sem_Util;
57 with Sem_Warn; use Sem_Warn;
58 with Snames; use Snames;
59 with Stand; use Stand;
60 with Sinfo; use Sinfo;
61 with Sinput; use Sinput;
63 with Uintp; use Uintp;
65 package body Sem_Ch7 is
67 -----------------------------------
68 -- Handling private declarations --
69 -----------------------------------
71 -- The principle that each entity has a single defining occurrence clashes
72 -- with the presence of two separate definitions for private types: the
73 -- first is the private type declaration, and the second is the full type
74 -- declaration. It is important that all references to the type point to
75 -- the same defining occurrence, namely the first one. To enforce the two
76 -- separate views of the entity, the corresponding information is swapped
77 -- between the two declarations. Outside of the package, the defining
78 -- occurrence only contains the private declaration information, while in
79 -- the private part and the body of the package the defining occurrence
80 -- contains the full declaration. To simplify the swap, the defining
81 -- occurrence that currently holds the private declaration points to the
82 -- full declaration. During semantic processing the defining occurrence
83 -- also points to a list of private dependents, that is to say access types
84 -- or composite types whose designated types or component types are
85 -- subtypes or derived types of the private type in question. After the
86 -- full declaration has been seen, the private dependents are updated to
87 -- indicate that they have full definitions.
89 -----------------------
90 -- Local Subprograms --
91 -----------------------
93 procedure Check_Anonymous_Access_Types
96 -- If the spec of a package has a limited_with_clause, it may declare
97 -- anonymous access types whose designated type is a limited view, such an
98 -- anonymous access return type for a function. This access type cannot be
99 -- elaborated in the spec itself, but it may need an itype reference if it
100 -- is used within a nested scope. In that case the itype reference is
101 -- created at the beginning of the corresponding package body and inserted
102 -- before other body declarations.
104 procedure Install_Package_Entity (Id : Entity_Id);
105 -- Supporting procedure for Install_{Visible,Private}_Declarations.
106 -- Places one entity on its visibility chain, and recurses on the visible
107 -- part if the entity is an inner package.
109 function Is_Private_Base_Type (E : Entity_Id) return Boolean;
110 -- True for a private type that is not a subtype
112 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean;
113 -- If the private dependent is a private type whose full view is derived
114 -- from the parent type, its full properties are revealed only if we are in
115 -- the immediate scope of the private dependent. Should this predicate be
116 -- tightened further???
118 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id);
119 -- Called upon entering the private part of a public child package and the
120 -- body of a nested package, to potentially declare certain inherited
121 -- subprograms that were inherited by types in the visible part, but whose
122 -- declaration was deferred because the parent operation was private and
123 -- not visible at that point. These subprograms are located by traversing
124 -- the visible part declarations looking for non-private type extensions
125 -- and then examining each of the primitive operations of such types to
126 -- find those that were inherited but declared with a special internal
127 -- name. Each such operation is now declared as an operation with a normal
128 -- name (using the name of the parent operation) and replaces the previous
129 -- implicit operation in the primitive operations list of the type. If the
130 -- inherited private operation has been overridden, then it's replaced by
131 -- the overriding operation.
133 --------------------------
134 -- Analyze_Package_Body --
135 --------------------------
137 procedure Analyze_Package_Body (N : Node_Id) is
138 Loc : constant Source_Ptr := Sloc (N);
142 Last_Spec_Entity : Entity_Id;
146 procedure Install_Composite_Operations (P : Entity_Id);
147 -- Composite types declared in the current scope may depend on
148 -- types that were private at the point of declaration, and whose
149 -- full view is now in scope. Indicate that the corresponding
150 -- operations on the composite type are available.
152 ----------------------------------
153 -- Install_Composite_Operations --
154 ----------------------------------
156 procedure Install_Composite_Operations (P : Entity_Id) is
160 Id := First_Entity (P);
161 while Present (Id) loop
163 and then (Is_Limited_Composite (Id)
164 or else Is_Private_Composite (Id))
165 and then No (Private_Component (Id))
167 Set_Is_Limited_Composite (Id, False);
168 Set_Is_Private_Composite (Id, False);
173 end Install_Composite_Operations;
175 -- Start of processing for Analyze_Package_Body
178 -- Find corresponding package specification, and establish the
179 -- current scope. The visible defining entity for the package is the
180 -- defining occurrence in the spec. On exit from the package body, all
181 -- body declarations are attached to the defining entity for the body,
182 -- but the later is never used for name resolution. In this fashion
183 -- there is only one visible entity that denotes the package.
186 Write_Str ("==== Compiling package body ");
187 Write_Name (Chars (Defining_Entity (N)));
188 Write_Str (" from ");
189 Write_Location (Loc);
193 -- Set Body_Id. Note that this Will be reset to point to the
194 -- generic copy later on in the generic case.
196 Body_Id := Defining_Entity (N);
198 if Present (Corresponding_Spec (N)) then
200 -- Body is body of package instantiation. Corresponding spec
201 -- has already been set.
203 Spec_Id := Corresponding_Spec (N);
204 Pack_Decl := Unit_Declaration_Node (Spec_Id);
207 Spec_Id := Current_Entity_In_Scope (Defining_Entity (N));
210 and then Is_Package_Or_Generic_Package (Spec_Id)
212 Pack_Decl := Unit_Declaration_Node (Spec_Id);
214 if Nkind (Pack_Decl) = N_Package_Renaming_Declaration then
215 Error_Msg_N ("cannot supply body for package renaming", N);
218 elsif Present (Corresponding_Body (Pack_Decl)) then
219 Error_Msg_N ("redefinition of package body", N);
224 Error_Msg_N ("missing specification for package body", N);
228 if Is_Package_Or_Generic_Package (Spec_Id)
230 (Scope (Spec_Id) = Standard_Standard
231 or else Is_Child_Unit (Spec_Id))
232 and then not Unit_Requires_Body (Spec_Id)
234 if Ada_Version = Ada_83 then
236 ("optional package body (not allowed in Ada 95)?", N);
239 ("spec of this package does not allow a body", N);
244 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
245 Style.Check_Identifier (Body_Id, Spec_Id);
247 if Is_Child_Unit (Spec_Id) then
248 if Nkind (Parent (N)) /= N_Compilation_Unit then
250 ("body of child unit& cannot be an inner package", N, Spec_Id);
253 Set_Is_Child_Unit (Body_Id);
256 -- Generic package case
258 if Ekind (Spec_Id) = E_Generic_Package then
260 -- Disable expansion and perform semantic analysis on copy.
261 -- The unannotated body will be used in all instantiations.
263 Body_Id := Defining_Entity (N);
264 Set_Ekind (Body_Id, E_Package_Body);
265 Set_Scope (Body_Id, Scope (Spec_Id));
266 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id));
267 Set_Body_Entity (Spec_Id, Body_Id);
268 Set_Spec_Entity (Body_Id, Spec_Id);
270 New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
273 -- Update Body_Id to point to the copied node for the remainder
274 -- of the processing.
276 Body_Id := Defining_Entity (N);
280 -- The Body_Id is that of the copied node in the generic case, the
281 -- current node otherwise. Note that N was rewritten above, so we
282 -- must be sure to get the latest Body_Id value.
284 Set_Ekind (Body_Id, E_Package_Body);
285 Set_Body_Entity (Spec_Id, Body_Id);
286 Set_Spec_Entity (Body_Id, Spec_Id);
288 -- Defining name for the package body is not a visible entity: Only
289 -- the defining name for the declaration is visible.
291 Set_Etype (Body_Id, Standard_Void_Type);
292 Set_Scope (Body_Id, Scope (Spec_Id));
293 Set_Corresponding_Spec (N, Spec_Id);
294 Set_Corresponding_Body (Pack_Decl, Body_Id);
296 -- The body entity is not used for semantics or code generation, but
297 -- it is attached to the entity list of the enclosing scope to simplify
298 -- the listing of back-annotations for the types it main contain.
300 if Scope (Spec_Id) /= Standard_Standard then
301 Append_Entity (Body_Id, Scope (Spec_Id));
304 -- Indicate that we are currently compiling the body of the package
306 Set_In_Package_Body (Spec_Id);
307 Set_Has_Completion (Spec_Id);
308 Last_Spec_Entity := Last_Entity (Spec_Id);
310 Push_Scope (Spec_Id);
312 Set_Categorization_From_Pragmas (N);
314 Install_Visible_Declarations (Spec_Id);
315 Install_Private_Declarations (Spec_Id);
316 Install_Private_With_Clauses (Spec_Id);
317 Install_Composite_Operations (Spec_Id);
319 Check_Anonymous_Access_Types (Spec_Id, N);
321 if Ekind (Spec_Id) = E_Generic_Package then
322 Set_Use (Generic_Formal_Declarations (Pack_Decl));
325 Set_Use (Visible_Declarations (Specification (Pack_Decl)));
326 Set_Use (Private_Declarations (Specification (Pack_Decl)));
328 -- This is a nested package, so it may be necessary to declare certain
329 -- inherited subprograms that are not yet visible because the parent
330 -- type's subprograms are now visible.
332 if Ekind (Scope (Spec_Id)) = E_Package
333 and then Scope (Spec_Id) /= Standard_Standard
335 Declare_Inherited_Private_Subprograms (Spec_Id);
338 if Present (Declarations (N)) then
339 Analyze_Declarations (Declarations (N));
340 Inspect_Deferred_Constant_Completion (Declarations (N));
343 -- Analyze_Declarations has caused freezing of all types; now generate
344 -- bodies for RACW primitives and stream attributes, if any.
346 if Ekind (Spec_Id) = E_Package and then Has_RACW (Spec_Id) then
348 -- Attach subprogram bodies to support RACWs declared in spec
350 Append_RACW_Bodies (Declarations (N), Spec_Id);
351 Analyze_List (Declarations (N));
354 HSS := Handled_Statement_Sequence (N);
356 if Present (HSS) then
357 Process_End_Label (HSS, 't', Spec_Id);
360 -- Check that elaboration code in a preelaborable package body is
361 -- empty other than null statements and labels (RM 10.2.1(6)).
363 Validate_Null_Statement_Sequence (N);
366 Validate_Categorization_Dependency (N, Spec_Id);
367 Check_Completion (Body_Id);
369 -- Generate start of body reference. Note that we do this fairly late,
370 -- because the call will use In_Extended_Main_Source_Unit as a check,
371 -- and we want to make sure that Corresponding_Stub links are set
373 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
375 -- For a generic package, collect global references and mark them on
376 -- the original body so that they are not resolved again at the point
379 if Ekind (Spec_Id) /= E_Package then
380 Save_Global_References (Original_Node (N));
384 -- The entities of the package body have so far been chained onto the
385 -- declaration chain for the spec. That's been fine while we were in the
386 -- body, since we wanted them to be visible, but now that we are leaving
387 -- the package body, they are no longer visible, so we remove them from
388 -- the entity chain of the package spec entity, and copy them to the
389 -- entity chain of the package body entity, where they will never again
392 if Present (Last_Spec_Entity) then
393 Set_First_Entity (Body_Id, Next_Entity (Last_Spec_Entity));
394 Set_Next_Entity (Last_Spec_Entity, Empty);
395 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
396 Set_Last_Entity (Spec_Id, Last_Spec_Entity);
399 Set_First_Entity (Body_Id, First_Entity (Spec_Id));
400 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
401 Set_First_Entity (Spec_Id, Empty);
402 Set_Last_Entity (Spec_Id, Empty);
405 End_Package_Scope (Spec_Id);
407 -- All entities declared in body are not visible
413 E := First_Entity (Body_Id);
414 while Present (E) loop
415 Set_Is_Immediately_Visible (E, False);
416 Set_Is_Potentially_Use_Visible (E, False);
419 -- Child units may appear on the entity list (for example if
420 -- they appear in the context of a subunit) but they are not
423 if not Is_Child_Unit (E) then
424 Set_Is_Package_Body_Entity (E);
431 Check_References (Body_Id);
433 -- For a generic unit, check that the formal parameters are referenced,
434 -- and that local variables are used, as for regular packages.
436 if Ekind (Spec_Id) = E_Generic_Package then
437 Check_References (Spec_Id);
440 -- The processing so far has made all entities of the package body
441 -- public (i.e. externally visible to the linker). This is in general
442 -- necessary, since inlined or generic bodies, for which code is
443 -- generated in other units, may need to see these entities. The
444 -- following loop runs backwards from the end of the entities of the
445 -- package body making these entities invisible until we reach a
446 -- referencer, i.e. a declaration that could reference a previous
447 -- declaration, a generic body or an inlined body, or a stub (which
448 -- may contain either of these). This is of course an approximation,
449 -- but it is conservative and definitely correct.
451 -- We only do this at the outer (library) level non-generic packages.
452 -- The reason is simply to cut down on the number of external symbols
453 -- generated, so this is simply an optimization of the efficiency
454 -- of the compilation process. It has no other effect.
456 if (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id))
457 and then not Is_Generic_Unit (Spec_Id)
458 and then Present (Declarations (N))
460 Make_Non_Public_Where_Possible : declare
462 function Has_Referencer
466 -- Traverse the given list of declarations in reverse order.
467 -- Return True as soon as a referencer is reached. Return
468 -- False if none is found. The Outer parameter is True for
469 -- the outer level call, and False for inner level calls for
470 -- nested packages. If Outer is True, then any entities up
471 -- to the point of hitting a referencer get their Is_Public
472 -- flag cleared, so that the entities will be treated as
473 -- static entities in the C sense, and need not have fully
474 -- qualified names. For inner levels, we need all names to
475 -- be fully qualified to deal with the same name appearing
476 -- in parallel packages (right now this is tied to their
483 function Has_Referencer
499 while Present (D) loop
502 if K in N_Body_Stub then
505 elsif K = N_Subprogram_Body then
506 if Acts_As_Spec (D) then
507 E := Defining_Entity (D);
509 -- An inlined body acts as a referencer. Note also
510 -- that we never reset Is_Public for an inlined
511 -- subprogram. Gigi requires Is_Public to be set.
513 -- Note that we test Has_Pragma_Inline here rather
514 -- than Is_Inlined. We are compiling this for a
515 -- client, and it is the client who will decide
516 -- if actual inlining should occur, so we need to
517 -- assume that the procedure could be inlined for
518 -- the purpose of accessing global entities.
520 if Has_Pragma_Inline (E) then
523 Set_Is_Public (E, False);
527 E := Corresponding_Spec (D);
530 and then (Is_Generic_Unit (E)
531 or else Has_Pragma_Inline (E)
532 or else Is_Inlined (E))
538 -- Processing for package bodies
540 elsif K = N_Package_Body
541 and then Present (Corresponding_Spec (D))
543 E := Corresponding_Spec (D);
545 -- Generic package body is a referencer. It would
546 -- seem that we only have to consider generics that
547 -- can be exported, i.e. where the corresponding spec
548 -- is the spec of the current package, but because of
549 -- nested instantiations, a fully private generic
550 -- body may export other private body entities.
552 if Is_Generic_Unit (E) then
555 -- For non-generic package body, recurse into body
556 -- unless this is an instance, we ignore instances
557 -- since they cannot have references that affect
560 elsif not Is_Generic_Instance (E) then
562 (Declarations (D), Outer => False)
568 -- Processing for package specs, recurse into declarations.
569 -- Again we skip this for the case of generic instances.
571 elsif K = N_Package_Declaration then
572 S := Specification (D);
574 if not Is_Generic_Unit (Defining_Entity (S)) then
576 (Private_Declarations (S), Outer => False)
580 (Visible_Declarations (S), Outer => False)
586 -- Objects and exceptions need not be public if we have
587 -- not encountered a referencer so far. We only reset
588 -- the flag for outer level entities that are not
589 -- imported/exported, and which have no interface name.
591 elsif Nkind_In (K, N_Object_Declaration,
592 N_Exception_Declaration,
593 N_Subprogram_Declaration)
595 E := Defining_Entity (D);
598 and then not Is_Imported (E)
599 and then not Is_Exported (E)
600 and then No (Interface_Name (E))
602 Set_Is_Public (E, False);
612 -- Start of processing for Make_Non_Public_Where_Possible
617 pragma Warnings (Off, Discard);
620 Discard := Has_Referencer (Declarations (N), Outer => True);
622 end Make_Non_Public_Where_Possible;
625 -- If expander is not active, then here is where we turn off the
626 -- In_Package_Body flag, otherwise it is turned off at the end of
627 -- the corresponding expansion routine. If this is an instance body,
628 -- we need to qualify names of local entities, because the body may
629 -- have been compiled as a preliminary to another instantiation.
631 if not Expander_Active then
632 Set_In_Package_Body (Spec_Id, False);
634 if Is_Generic_Instance (Spec_Id)
635 and then Operating_Mode = Generate_Code
637 Qualify_Entity_Names (N);
640 end Analyze_Package_Body;
642 ---------------------------------
643 -- Analyze_Package_Declaration --
644 ---------------------------------
646 procedure Analyze_Package_Declaration (N : Node_Id) is
647 Id : constant Node_Id := Defining_Entity (N);
650 -- True when in the context of a declared pure library unit
652 Body_Required : Boolean;
653 -- True when this package declaration requires a corresponding body
656 -- True when this package declaration is not a nested declaration
659 -- Ada 2005 (AI-217): Check if the package has been erroneously named
660 -- in a limited-with clause of its own context. In this case the error
661 -- has been previously notified by Analyze_Context.
663 -- limited with Pkg; -- ERROR
664 -- package Pkg is ...
666 if From_With_Type (Id) then
670 Generate_Definition (Id);
672 Set_Ekind (Id, E_Package);
673 Set_Etype (Id, Standard_Void_Type);
677 PF := Is_Pure (Enclosing_Lib_Unit_Entity);
678 Set_Is_Pure (Id, PF);
680 Set_Categorization_From_Pragmas (N);
683 Write_Str ("==== Compiling package spec ");
684 Write_Name (Chars (Id));
685 Write_Str (" from ");
686 Write_Location (Sloc (N));
690 Analyze (Specification (N));
691 Validate_Categorization_Dependency (N, Id);
693 Body_Required := Unit_Requires_Body (Id);
695 -- When this spec does not require an explicit body, we know that
696 -- there are no entities requiring completion in the language sense;
697 -- we call Check_Completion here only to ensure that any nested package
698 -- declaration that requires an implicit body gets one. (In the case
699 -- where a body is required, Check_Completion is called at the end of
700 -- the body's declarative part.)
702 if not Body_Required then
706 Comp_Unit := Nkind (Parent (N)) = N_Compilation_Unit;
709 -- Set Body_Required indication on the compilation unit node, and
710 -- determine whether elaboration warnings may be meaningful on it.
712 Set_Body_Required (Parent (N), Body_Required);
714 if not Body_Required then
715 Set_Suppress_Elaboration_Warnings (Id);
720 End_Package_Scope (Id);
722 -- For the declaration of a library unit that is a remote types package,
723 -- check legality rules regarding availability of stream attributes for
724 -- types that contain non-remote access values. This subprogram performs
725 -- visibility tests that rely on the fact that we have exited the scope
729 Validate_RT_RAT_Component (N);
731 end Analyze_Package_Declaration;
733 -----------------------------------
734 -- Analyze_Package_Specification --
735 -----------------------------------
737 -- Note that this code is shared for the analysis of generic package
738 -- specs (see Sem_Ch12.Analyze_Generic_Package_Declaration for details).
740 procedure Analyze_Package_Specification (N : Node_Id) is
741 Id : constant Entity_Id := Defining_Entity (N);
742 Orig_Decl : constant Node_Id := Original_Node (Parent (N));
743 Vis_Decls : constant List_Id := Visible_Declarations (N);
744 Priv_Decls : constant List_Id := Private_Declarations (N);
747 Public_Child : Boolean;
749 Private_With_Clauses_Installed : Boolean := False;
750 -- In Ada 2005, private with_clauses are visible in the private part
751 -- of a nested package, even if it appears in the public part of the
752 -- enclosing package. This requires a separate step to install these
753 -- private_with_clauses, and remove them at the end of the nested
756 procedure Analyze_PPCs (Decls : List_Id);
757 -- Given a list of declarations, go through looking for subprogram
758 -- specs, and for each one found, analyze any pre/postconditions that
759 -- are chained to the spec. This is the implementation of the late
760 -- visibility analysis for preconditions and postconditions in specs.
762 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id);
763 -- Clears constant indications (Never_Set_In_Source, Constant_Value,
764 -- and Is_True_Constant) on all variables that are entities of Id,
765 -- and on the chain whose first element is FE. A recursive call is
766 -- made for all packages and generic packages.
768 procedure Generate_Parent_References;
769 -- For a child unit, generate references to parent units, for
770 -- GPS navigation purposes.
772 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean;
773 -- Child and Unit are entities of compilation units. True if Child
774 -- is a public child of Parent as defined in 10.1.1
776 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id);
777 -- Detects all incomplete or private type declarations having a known
778 -- discriminant part that are completed by an Unchecked_Union. Emits
779 -- the error message "Unchecked_Union may not complete discriminated
782 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id);
783 -- Given the package entity of a generic package instantiation or
784 -- formal package whose corresponding generic is a child unit, installs
785 -- the private declarations of each of the child unit's parents.
786 -- This has to be done at the point of entering the instance package's
787 -- private part rather than being done in Sem_Ch12.Install_Parent
788 -- (which is where the parents' visible declarations are installed).
794 procedure Analyze_PPCs (Decls : List_Id) is
801 Decl := First (Decls);
802 while Present (Decl) loop
803 if Nkind (Original_Node (Decl)) = N_Subprogram_Declaration then
804 Spec := Specification (Original_Node (Decl));
805 Sent := Defining_Unit_Name (Spec);
806 Prag := Spec_PPC_List (Sent);
807 while Present (Prag) loop
808 Analyze_PPC_In_Decl_Part (Prag, Sent);
809 Prag := Next_Pragma (Prag);
817 ---------------------
818 -- Clear_Constants --
819 ---------------------
821 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id) is
825 -- Ignore package renamings, not interesting and they can
826 -- cause self referential loops in the code below.
828 if Nkind (Parent (Id)) = N_Package_Renaming_Declaration then
832 -- Note: in the loop below, the check for Next_Entity pointing
833 -- back to the package entity may seem odd, but it is needed,
834 -- because a package can contain a renaming declaration to itself,
835 -- and such renamings are generated automatically within package
839 while Present (E) and then E /= Id loop
840 if Is_Assignable (E) then
841 Set_Never_Set_In_Source (E, False);
842 Set_Is_True_Constant (E, False);
843 Set_Current_Value (E, Empty);
844 Set_Is_Known_Null (E, False);
845 Set_Last_Assignment (E, Empty);
847 if not Can_Never_Be_Null (E) then
848 Set_Is_Known_Non_Null (E, False);
851 elsif Is_Package_Or_Generic_Package (E) then
852 Clear_Constants (E, First_Entity (E));
853 Clear_Constants (E, First_Private_Entity (E));
860 --------------------------------
861 -- Generate_Parent_References --
862 --------------------------------
864 procedure Generate_Parent_References is
865 Decl : constant Node_Id := Parent (N);
868 if Id = Cunit_Entity (Main_Unit)
869 or else Parent (Decl) = Library_Unit (Cunit (Main_Unit))
871 Generate_Reference (Id, Scope (Id), 'k', False);
873 elsif not Nkind_In (Unit (Cunit (Main_Unit)), N_Subprogram_Body,
876 -- If current unit is an ancestor of main unit, generate
877 -- a reference to its own parent.
881 Main_Spec : Node_Id := Unit (Cunit (Main_Unit));
884 if Nkind (Main_Spec) = N_Package_Body then
885 Main_Spec := Unit (Library_Unit (Cunit (Main_Unit)));
888 U := Parent_Spec (Main_Spec);
889 while Present (U) loop
890 if U = Parent (Decl) then
891 Generate_Reference (Id, Scope (Id), 'k', False);
894 elsif Nkind (Unit (U)) = N_Package_Body then
898 U := Parent_Spec (Unit (U));
903 end Generate_Parent_References;
905 ---------------------
906 -- Is_Public_Child --
907 ---------------------
909 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean is
911 if not Is_Private_Descendant (Child) then
915 return not Private_Present (
916 Parent (Unit_Declaration_Node (Child)));
918 return Is_Public_Child (Scope (Child), Unit);
923 ----------------------------------------
924 -- Inspect_Unchecked_Union_Completion --
925 ----------------------------------------
927 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is
931 Decl := First (Decls);
932 while Present (Decl) loop
934 -- We are looking at an incomplete or private type declaration
935 -- with a known_discriminant_part whose full view is an
938 if Nkind_In (Decl, N_Incomplete_Type_Declaration,
939 N_Private_Type_Declaration)
940 and then Has_Discriminants (Defining_Identifier (Decl))
941 and then Present (Full_View (Defining_Identifier (Decl)))
943 Is_Unchecked_Union (Full_View (Defining_Identifier (Decl)))
946 ("completion of discriminated partial view "
947 & "cannot be an Unchecked_Union",
948 Full_View (Defining_Identifier (Decl)));
953 end Inspect_Unchecked_Union_Completion;
955 -----------------------------------------
956 -- Install_Parent_Private_Declarations --
957 -----------------------------------------
959 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id) is
960 Inst_Par : Entity_Id;
968 Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par)));
969 while Present (Gen_Par) and then Is_Child_Unit (Gen_Par) loop
970 Inst_Node := Get_Package_Instantiation_Node (Inst_Par);
972 if Nkind_In (Inst_Node, N_Package_Instantiation,
973 N_Formal_Package_Declaration)
974 and then Nkind (Name (Inst_Node)) = N_Expanded_Name
976 Inst_Par := Entity (Prefix (Name (Inst_Node)));
978 if Present (Renamed_Entity (Inst_Par)) then
979 Inst_Par := Renamed_Entity (Inst_Par);
984 (Specification (Unit_Declaration_Node (Inst_Par)));
986 -- Install the private declarations and private use clauses
987 -- of a parent instance of the child instance, unless the
988 -- parent instance private declarations have already been
989 -- installed earlier in Analyze_Package_Specification, which
990 -- happens when a generic child is instantiated, and the
991 -- instance is a child of the parent instance.
993 -- Installing the use clauses of the parent instance twice
994 -- is both unnecessary and wrong, because it would cause the
995 -- clauses to be chained to themselves in the use clauses
996 -- list of the scope stack entry. That in turn would cause
997 -- an endless loop from End_Use_Clauses upon scope exit.
999 -- The parent is now fully visible. It may be a hidden open
1000 -- scope if we are currently compiling some child instance
1001 -- declared within it, but while the current instance is being
1002 -- compiled the parent is immediately visible. In particular
1003 -- its entities must remain visible if a stack save/restore
1004 -- takes place through a call to Rtsfind.
1006 if Present (Gen_Par) then
1007 if not In_Private_Part (Inst_Par) then
1008 Install_Private_Declarations (Inst_Par);
1009 Set_Use (Private_Declarations
1011 (Unit_Declaration_Node (Inst_Par))));
1012 Set_Is_Hidden_Open_Scope (Inst_Par, False);
1015 -- If we've reached the end of the generic instance parents,
1016 -- then finish off by looping through the nongeneric parents
1017 -- and installing their private declarations.
1020 while Present (Inst_Par)
1021 and then Inst_Par /= Standard_Standard
1022 and then (not In_Open_Scopes (Inst_Par)
1023 or else not In_Private_Part (Inst_Par))
1025 Install_Private_Declarations (Inst_Par);
1026 Set_Use (Private_Declarations
1028 (Unit_Declaration_Node (Inst_Par))));
1029 Inst_Par := Scope (Inst_Par);
1039 end Install_Parent_Private_Declarations;
1041 -- Start of processing for Analyze_Package_Specification
1044 if Present (Vis_Decls) then
1045 Analyze_Declarations (Vis_Decls);
1046 Analyze_PPCs (Vis_Decls);
1049 -- Verify that incomplete types have received full declarations
1051 E := First_Entity (Id);
1052 while Present (E) loop
1053 if Ekind (E) = E_Incomplete_Type
1054 and then No (Full_View (E))
1056 Error_Msg_N ("no declaration in visible part for incomplete}", E);
1062 if Is_Remote_Call_Interface (Id)
1063 and then Nkind (Parent (Parent (N))) = N_Compilation_Unit
1065 Validate_RCI_Declarations (Id);
1068 -- Save global references in the visible declarations, before
1069 -- installing private declarations of parent unit if there is one,
1070 -- because the privacy status of types defined in the parent will
1071 -- change. This is only relevant for generic child units, but is
1072 -- done in all cases for uniformity.
1074 if Ekind (Id) = E_Generic_Package
1075 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1078 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1079 Save_Priv : constant List_Id := Private_Declarations (Orig_Spec);
1082 Set_Private_Declarations (Orig_Spec, Empty_List);
1083 Save_Global_References (Orig_Decl);
1084 Set_Private_Declarations (Orig_Spec, Save_Priv);
1088 -- If package is a public child unit, then make the private declarations
1089 -- of the parent visible.
1091 Public_Child := False;
1095 Pack_Decl : Node_Id;
1100 Par_Spec := Parent_Spec (Parent (N));
1102 -- If the package is formal package of an enclosing generic, it is
1103 -- transformed into a local generic declaration, and compiled to make
1104 -- its spec available. We need to retrieve the original generic to
1105 -- determine whether it is a child unit, and install its parents.
1109 Nkind (Original_Node (Parent (N))) = N_Formal_Package_Declaration
1111 Par := Entity (Name (Original_Node (Parent (N))));
1112 Par_Spec := Parent_Spec (Unit_Declaration_Node (Par));
1115 if Present (Par_Spec) then
1116 Generate_Parent_References;
1118 while Scope (Par) /= Standard_Standard
1119 and then Is_Public_Child (Id, Par)
1120 and then In_Open_Scopes (Par)
1122 Public_Child := True;
1124 Install_Private_Declarations (Par);
1125 Install_Private_With_Clauses (Par);
1126 Pack_Decl := Unit_Declaration_Node (Par);
1127 Set_Use (Private_Declarations (Specification (Pack_Decl)));
1132 if Is_Compilation_Unit (Id) then
1133 Install_Private_With_Clauses (Id);
1136 -- The current compilation unit may include private with_clauses,
1137 -- which are visible in the private part of the current nested
1138 -- package, and have to be installed now. This is not done for
1139 -- nested instantiations, where the private with_clauses of the
1140 -- enclosing unit have no effect once the instantiation info is
1141 -- established and we start analyzing the package declaration.
1144 Comp_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1146 if Is_Package_Or_Generic_Package (Comp_Unit)
1147 and then not In_Private_Part (Comp_Unit)
1148 and then not In_Instance
1150 Install_Private_With_Clauses (Comp_Unit);
1151 Private_With_Clauses_Installed := True;
1156 -- If this is a package associated with a generic instance or formal
1157 -- package, then the private declarations of each of the generic's
1158 -- parents must be installed at this point.
1160 if Is_Generic_Instance (Id) then
1161 Install_Parent_Private_Declarations (Id);
1164 -- Analyze private part if present. The flag In_Private_Part is reset
1165 -- in End_Package_Scope.
1167 L := Last_Entity (Id);
1169 if Present (Priv_Decls) then
1170 Set_In_Private_Part (Id);
1172 -- Upon entering a public child's private part, it may be necessary
1173 -- to declare subprograms that were derived in the package's visible
1174 -- part but not yet made visible.
1176 if Public_Child then
1177 Declare_Inherited_Private_Subprograms (Id);
1180 Analyze_Declarations (Priv_Decls);
1181 Analyze_PPCs (Priv_Decls);
1183 -- Check the private declarations for incomplete deferred constants
1185 Inspect_Deferred_Constant_Completion (Priv_Decls);
1187 -- The first private entity is the immediate follower of the last
1188 -- visible entity, if there was one.
1191 Set_First_Private_Entity (Id, Next_Entity (L));
1193 Set_First_Private_Entity (Id, First_Entity (Id));
1196 -- There may be inherited private subprograms that need to be declared,
1197 -- even in the absence of an explicit private part. If there are any
1198 -- public declarations in the package and the package is a public child
1199 -- unit, then an implicit private part is assumed.
1201 elsif Present (L) and then Public_Child then
1202 Set_In_Private_Part (Id);
1203 Declare_Inherited_Private_Subprograms (Id);
1204 Set_First_Private_Entity (Id, Next_Entity (L));
1207 E := First_Entity (Id);
1208 while Present (E) loop
1210 -- Check rule of 3.6(11), which in general requires waiting till all
1211 -- full types have been seen.
1213 if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then
1214 Check_Aliased_Component_Types (E);
1217 -- Check preelaborable initialization for full type completing a
1218 -- private type for which pragma Preelaborable_Initialization given.
1221 and then Must_Have_Preelab_Init (E)
1222 and then not Has_Preelaborable_Initialization (E)
1225 ("full view of & does not have preelaborable initialization", E);
1231 -- Ada 2005 (AI-216): The completion of an incomplete or private type
1232 -- declaration having a known_discriminant_part shall not be an
1233 -- Unchecked_Union type.
1235 if Present (Vis_Decls) then
1236 Inspect_Unchecked_Union_Completion (Vis_Decls);
1239 if Present (Priv_Decls) then
1240 Inspect_Unchecked_Union_Completion (Priv_Decls);
1243 if Ekind (Id) = E_Generic_Package
1244 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1245 and then Present (Priv_Decls)
1247 -- Save global references in private declarations, ignoring the
1248 -- visible declarations that were processed earlier.
1251 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1252 Save_Vis : constant List_Id := Visible_Declarations (Orig_Spec);
1253 Save_Form : constant List_Id :=
1254 Generic_Formal_Declarations (Orig_Decl);
1257 Set_Visible_Declarations (Orig_Spec, Empty_List);
1258 Set_Generic_Formal_Declarations (Orig_Decl, Empty_List);
1259 Save_Global_References (Orig_Decl);
1260 Set_Generic_Formal_Declarations (Orig_Decl, Save_Form);
1261 Set_Visible_Declarations (Orig_Spec, Save_Vis);
1265 Process_End_Label (N, 'e', Id);
1267 -- Remove private_with_clauses of enclosing compilation unit, if they
1270 if Private_With_Clauses_Installed then
1271 Remove_Private_With_Clauses (Cunit (Current_Sem_Unit));
1274 -- For the case of a library level package, we must go through all the
1275 -- entities clearing the indications that the value may be constant and
1276 -- not modified. Why? Because any client of this package may modify
1277 -- these values freely from anywhere. This also applies to any nested
1278 -- packages or generic packages.
1280 -- For now we unconditionally clear constants for packages that are
1281 -- instances of generic packages. The reason is that we do not have the
1282 -- body yet, and we otherwise think things are unreferenced when they
1283 -- are not. This should be fixed sometime (the effect is not terrible,
1284 -- we just lose some warnings, and also some cases of value propagation)
1287 if Is_Library_Level_Entity (Id)
1288 or else Is_Generic_Instance (Id)
1290 Clear_Constants (Id, First_Entity (Id));
1291 Clear_Constants (Id, First_Private_Entity (Id));
1293 end Analyze_Package_Specification;
1295 --------------------------------------
1296 -- Analyze_Private_Type_Declaration --
1297 --------------------------------------
1299 procedure Analyze_Private_Type_Declaration (N : Node_Id) is
1300 PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity);
1301 Id : constant Entity_Id := Defining_Identifier (N);
1304 Generate_Definition (Id);
1305 Set_Is_Pure (Id, PF);
1306 Init_Size_Align (Id);
1308 if not Is_Package_Or_Generic_Package (Current_Scope)
1309 or else In_Private_Part (Current_Scope)
1311 Error_Msg_N ("invalid context for private declaration", N);
1314 New_Private_Type (N, Id, N);
1315 Set_Depends_On_Private (Id);
1316 end Analyze_Private_Type_Declaration;
1318 ----------------------------------
1319 -- Check_Anonymous_Access_Types --
1320 ----------------------------------
1322 procedure Check_Anonymous_Access_Types
1323 (Spec_Id : Entity_Id;
1330 -- Itype references are only needed by gigi, to force elaboration of
1331 -- itypes. In the absence of code generation, they are not needed.
1333 if not Expander_Active then
1337 E := First_Entity (Spec_Id);
1338 while Present (E) loop
1339 if Ekind (E) = E_Anonymous_Access_Type
1340 and then From_With_Type (E)
1342 IR := Make_Itype_Reference (Sloc (P_Body));
1345 if No (Declarations (P_Body)) then
1346 Set_Declarations (P_Body, New_List (IR));
1348 Prepend (IR, Declarations (P_Body));
1354 end Check_Anonymous_Access_Types;
1356 -------------------------------------------
1357 -- Declare_Inherited_Private_Subprograms --
1358 -------------------------------------------
1360 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is
1362 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean;
1363 -- Check whether an inherited subprogram is an operation of an
1364 -- untagged derived type.
1366 ---------------------
1367 -- Is_Primitive_Of --
1368 ---------------------
1370 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is
1374 -- If the full view is a scalar type, the type is the anonymous
1375 -- base type, but the operation mentions the first subtype, so
1376 -- check the signature against the base type.
1378 if Base_Type (Etype (S)) = Base_Type (T) then
1382 Formal := First_Formal (S);
1383 while Present (Formal) loop
1384 if Base_Type (Etype (Formal)) = Base_Type (T) then
1388 Next_Formal (Formal);
1393 end Is_Primitive_Of;
1400 Op_Elmt_2 : Elmt_Id;
1401 Prim_Op : Entity_Id;
1402 New_Op : Entity_Id := Empty;
1403 Parent_Subp : Entity_Id;
1406 -- Start of processing for Declare_Inherited_Private_Subprograms
1409 E := First_Entity (Id);
1410 while Present (E) loop
1412 -- If the entity is a nonprivate type extension whose parent
1413 -- type is declared in an open scope, then the type may have
1414 -- inherited operations that now need to be made visible.
1415 -- Ditto if the entity is a formal derived type in a child unit.
1417 if ((Is_Derived_Type (E) and then not Is_Private_Type (E))
1419 (Nkind (Parent (E)) = N_Private_Extension_Declaration
1420 and then Is_Generic_Type (E)))
1421 and then In_Open_Scopes (Scope (Etype (E)))
1422 and then E = Base_Type (E)
1424 if Is_Tagged_Type (E) then
1425 Op_List := Primitive_Operations (E);
1427 Tag := First_Tag_Component (E);
1429 Op_Elmt := First_Elmt (Op_List);
1430 while Present (Op_Elmt) loop
1431 Prim_Op := Node (Op_Elmt);
1433 -- Search primitives that are implicit operations with an
1434 -- internal name whose parent operation has a normal name.
1436 if Present (Alias (Prim_Op))
1437 and then Find_Dispatching_Type (Alias (Prim_Op)) /= E
1438 and then not Comes_From_Source (Prim_Op)
1439 and then Is_Internal_Name (Chars (Prim_Op))
1440 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1442 Parent_Subp := Alias (Prim_Op);
1444 -- Case 1: Check if the type has also an explicit
1445 -- overriding for this primitive.
1447 Op_Elmt_2 := Next_Elmt (Op_Elmt);
1448 while Present (Op_Elmt_2) loop
1449 if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp)
1450 and then Type_Conformant (Prim_Op, Node (Op_Elmt_2))
1452 -- The private inherited operation has been
1453 -- overridden by an explicit subprogram: replace
1454 -- the former by the latter.
1456 New_Op := Node (Op_Elmt_2);
1457 Replace_Elmt (Op_Elmt, New_Op);
1458 Remove_Elmt (Op_List, Op_Elmt_2);
1459 Set_Is_Overriding_Operation (New_Op);
1460 Set_Overridden_Operation (New_Op, Parent_Subp);
1462 -- We don't need to inherit its dispatching slot.
1463 -- Set_All_DT_Position has previously ensured that
1464 -- the same slot was assigned to the two primitives
1467 and then Present (DTC_Entity (New_Op))
1468 and then Present (DTC_Entity (Prim_Op))
1470 pragma Assert (DT_Position (New_Op)
1471 = DT_Position (Prim_Op));
1475 goto Next_Primitive;
1478 Next_Elmt (Op_Elmt_2);
1481 -- Case 2: We have not found any explicit overriding and
1482 -- hence we need to declare the operation (i.e., make it
1485 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1487 -- Inherit the dispatching slot if E is already frozen
1490 and then Present (DTC_Entity (Alias (Prim_Op)))
1492 Set_DTC_Entity_Value (E, New_Op);
1493 Set_DT_Position (New_Op,
1494 DT_Position (Alias (Prim_Op)));
1498 (Is_Dispatching_Operation (New_Op)
1499 and then Node (Last_Elmt (Op_List)) = New_Op);
1501 -- Substitute the new operation for the old one
1502 -- in the type's primitive operations list. Since
1503 -- the new operation was also just added to the end
1504 -- of list, the last element must be removed.
1506 -- (Question: is there a simpler way of declaring
1507 -- the operation, say by just replacing the name
1508 -- of the earlier operation, reentering it in the
1509 -- in the symbol table (how?), and marking it as
1512 Replace_Elmt (Op_Elmt, New_Op);
1513 Remove_Last_Elmt (Op_List);
1517 Next_Elmt (Op_Elmt);
1520 -- Generate listing showing the contents of the dispatch table
1522 if Debug_Flag_ZZ then
1527 -- Non-tagged type, scan forward to locate
1528 -- inherited hidden operations.
1530 Prim_Op := Next_Entity (E);
1531 while Present (Prim_Op) loop
1532 if Is_Subprogram (Prim_Op)
1533 and then Present (Alias (Prim_Op))
1534 and then not Comes_From_Source (Prim_Op)
1535 and then Is_Internal_Name (Chars (Prim_Op))
1536 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1537 and then Is_Primitive_Of (E, Prim_Op)
1539 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1542 Next_Entity (Prim_Op);
1549 end Declare_Inherited_Private_Subprograms;
1551 -----------------------
1552 -- End_Package_Scope --
1553 -----------------------
1555 procedure End_Package_Scope (P : Entity_Id) is
1557 Uninstall_Declarations (P);
1559 end End_Package_Scope;
1561 ---------------------------
1562 -- Exchange_Declarations --
1563 ---------------------------
1565 procedure Exchange_Declarations (Id : Entity_Id) is
1566 Full_Id : constant Entity_Id := Full_View (Id);
1567 H1 : constant Entity_Id := Homonym (Id);
1568 Next1 : constant Entity_Id := Next_Entity (Id);
1573 -- If missing full declaration for type, nothing to exchange
1575 if No (Full_Id) then
1579 -- Otherwise complete the exchange, and preserve semantic links
1581 Next2 := Next_Entity (Full_Id);
1582 H2 := Homonym (Full_Id);
1584 -- Reset full declaration pointer to reflect the switched entities
1585 -- and readjust the next entity chains.
1587 Exchange_Entities (Id, Full_Id);
1589 Set_Next_Entity (Id, Next1);
1590 Set_Homonym (Id, H1);
1592 Set_Full_View (Full_Id, Id);
1593 Set_Next_Entity (Full_Id, Next2);
1594 Set_Homonym (Full_Id, H2);
1595 end Exchange_Declarations;
1597 ----------------------------
1598 -- Install_Package_Entity --
1599 ----------------------------
1601 procedure Install_Package_Entity (Id : Entity_Id) is
1603 if not Is_Internal (Id) then
1604 if Debug_Flag_E then
1605 Write_Str ("Install: ");
1606 Write_Name (Chars (Id));
1610 if not Is_Child_Unit (Id) then
1611 Set_Is_Immediately_Visible (Id);
1615 end Install_Package_Entity;
1617 ----------------------------------
1618 -- Install_Private_Declarations --
1619 ----------------------------------
1621 procedure Install_Private_Declarations (P : Entity_Id) is
1623 Priv_Elmt : Elmt_Id;
1628 -- First exchange declarations for private types, so that the
1629 -- full declaration is visible. For each private type, we check
1630 -- its Private_Dependents list and also exchange any subtypes of
1631 -- or derived types from it. Finally, if this is a Taft amendment
1632 -- type, the incomplete declaration is irrelevant, and we want to
1633 -- link the eventual full declaration with the original private
1634 -- one so we also skip the exchange.
1636 Id := First_Entity (P);
1637 while Present (Id) and then Id /= First_Private_Entity (P) loop
1638 if Is_Private_Base_Type (Id)
1639 and then Comes_From_Source (Full_View (Id))
1640 and then Present (Full_View (Id))
1641 and then Scope (Full_View (Id)) = Scope (Id)
1642 and then Ekind (Full_View (Id)) /= E_Incomplete_Type
1644 -- If there is a use-type clause on the private type, set the
1645 -- full view accordingly.
1647 Set_In_Use (Full_View (Id), In_Use (Id));
1648 Full := Full_View (Id);
1650 if Is_Private_Base_Type (Full)
1651 and then Has_Private_Declaration (Full)
1652 and then Nkind (Parent (Full)) = N_Full_Type_Declaration
1653 and then In_Open_Scopes (Scope (Etype (Full)))
1654 and then In_Package_Body (Current_Scope)
1655 and then not Is_Private_Type (Etype (Full))
1657 -- This is the completion of a private type by a derivation
1658 -- from another private type which is not private anymore. This
1659 -- can only happen in a package nested within a child package,
1660 -- when the parent type is defined in the parent unit. At this
1661 -- point the current type is not private either, and we have to
1662 -- install the underlying full view, which is now visible.
1663 -- Save the current full view as well, so that all views can
1664 -- be restored on exit. It may seem that after compiling the
1665 -- child body there are not environments to restore, but the
1666 -- back-end expects those links to be valid, and freeze nodes
1669 if No (Full_View (Full))
1670 and then Present (Underlying_Full_View (Full))
1672 Set_Full_View (Id, Underlying_Full_View (Full));
1673 Set_Underlying_Full_View (Id, Full);
1675 Set_Underlying_Full_View (Full, Empty);
1676 Set_Is_Frozen (Full_View (Id));
1680 Priv_Elmt := First_Elmt (Private_Dependents (Id));
1682 Exchange_Declarations (Id);
1683 Set_Is_Immediately_Visible (Id);
1685 while Present (Priv_Elmt) loop
1686 Priv := Node (Priv_Elmt);
1688 -- Before the exchange, verify that the presence of the
1689 -- Full_View field. It will be empty if the entity
1690 -- has already been installed due to a previous call.
1692 if Present (Full_View (Priv))
1693 and then Is_Visible_Dependent (Priv)
1696 -- For each subtype that is swapped, we also swap the
1697 -- reference to it in Private_Dependents, to allow access
1698 -- to it when we swap them out in End_Package_Scope.
1700 Replace_Elmt (Priv_Elmt, Full_View (Priv));
1701 Exchange_Declarations (Priv);
1702 Set_Is_Immediately_Visible
1703 (Priv, In_Open_Scopes (Scope (Priv)));
1704 Set_Is_Potentially_Use_Visible
1705 (Priv, Is_Potentially_Use_Visible (Node (Priv_Elmt)));
1708 Next_Elmt (Priv_Elmt);
1715 -- Next make other declarations in the private part visible as well
1717 Id := First_Private_Entity (P);
1718 while Present (Id) loop
1719 Install_Package_Entity (Id);
1720 Set_Is_Hidden (Id, False);
1724 -- Indicate that the private part is currently visible, so it can be
1725 -- properly reset on exit.
1727 Set_In_Private_Part (P);
1728 end Install_Private_Declarations;
1730 ----------------------------------
1731 -- Install_Visible_Declarations --
1732 ----------------------------------
1734 procedure Install_Visible_Declarations (P : Entity_Id) is
1736 Last_Entity : Entity_Id;
1740 (Is_Package_Or_Generic_Package (P) or else Is_Record_Type (P));
1742 if Is_Package_Or_Generic_Package (P) then
1743 Last_Entity := First_Private_Entity (P);
1745 Last_Entity := Empty;
1748 Id := First_Entity (P);
1749 while Present (Id) and then Id /= Last_Entity loop
1750 Install_Package_Entity (Id);
1753 end Install_Visible_Declarations;
1755 --------------------------
1756 -- Is_Private_Base_Type --
1757 --------------------------
1759 function Is_Private_Base_Type (E : Entity_Id) return Boolean is
1761 return Ekind (E) = E_Private_Type
1762 or else Ekind (E) = E_Limited_Private_Type
1763 or else Ekind (E) = E_Record_Type_With_Private;
1764 end Is_Private_Base_Type;
1766 --------------------------
1767 -- Is_Visible_Dependent --
1768 --------------------------
1770 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean
1772 S : constant Entity_Id := Scope (Dep);
1775 -- Renamings created for actual types have the visibility of the
1778 if Ekind (S) = E_Package
1779 and then Is_Generic_Instance (S)
1780 and then (Is_Generic_Actual_Type (Dep)
1781 or else Is_Generic_Actual_Type (Full_View (Dep)))
1785 elsif not (Is_Derived_Type (Dep))
1786 and then Is_Derived_Type (Full_View (Dep))
1788 -- When instantiating a package body, the scope stack is empty,
1789 -- so check instead whether the dependent type is defined in
1790 -- the same scope as the instance itself.
1792 return In_Open_Scopes (S)
1793 or else (Is_Generic_Instance (Current_Scope)
1794 and then Scope (Dep) = Scope (Current_Scope));
1798 end Is_Visible_Dependent;
1800 ----------------------------
1801 -- May_Need_Implicit_Body --
1802 ----------------------------
1804 procedure May_Need_Implicit_Body (E : Entity_Id) is
1805 P : constant Node_Id := Unit_Declaration_Node (E);
1806 S : constant Node_Id := Parent (P);
1811 if not Has_Completion (E)
1812 and then Nkind (P) = N_Package_Declaration
1813 and then (Present (Activation_Chain_Entity (P)) or else Has_RACW (E))
1816 Make_Package_Body (Sloc (E),
1817 Defining_Unit_Name => Make_Defining_Identifier (Sloc (E),
1818 Chars => Chars (E)),
1819 Declarations => New_List);
1821 if Nkind (S) = N_Package_Specification then
1822 if Present (Private_Declarations (S)) then
1823 Decls := Private_Declarations (S);
1825 Decls := Visible_Declarations (S);
1828 Decls := Declarations (S);
1834 end May_Need_Implicit_Body;
1836 ----------------------
1837 -- New_Private_Type --
1838 ----------------------
1840 procedure New_Private_Type (N : Node_Id; Id : Entity_Id; Def : Node_Id) is
1844 if Limited_Present (Def) then
1845 Set_Ekind (Id, E_Limited_Private_Type);
1847 Set_Ekind (Id, E_Private_Type);
1851 Set_Has_Delayed_Freeze (Id);
1852 Set_Is_First_Subtype (Id);
1853 Init_Size_Align (Id);
1855 Set_Is_Constrained (Id,
1856 No (Discriminant_Specifications (N))
1857 and then not Unknown_Discriminants_Present (N));
1859 -- Set tagged flag before processing discriminants, to catch
1862 Set_Is_Tagged_Type (Id, Tagged_Present (Def));
1864 Set_Discriminant_Constraint (Id, No_Elist);
1865 Set_Stored_Constraint (Id, No_Elist);
1867 if Present (Discriminant_Specifications (N)) then
1869 Process_Discriminants (N);
1872 elsif Unknown_Discriminants_Present (N) then
1873 Set_Has_Unknown_Discriminants (Id);
1876 Set_Private_Dependents (Id, New_Elmt_List);
1878 if Tagged_Present (Def) then
1879 Set_Ekind (Id, E_Record_Type_With_Private);
1880 Make_Class_Wide_Type (Id);
1881 Set_Primitive_Operations (Id, New_Elmt_List);
1882 Set_Is_Abstract_Type (Id, Abstract_Present (Def));
1883 Set_Is_Limited_Record (Id, Limited_Present (Def));
1884 Set_Has_Delayed_Freeze (Id, True);
1886 elsif Abstract_Present (Def) then
1887 Error_Msg_N ("only a tagged type can be abstract", N);
1889 end New_Private_Type;
1891 ----------------------------
1892 -- Uninstall_Declarations --
1893 ----------------------------
1895 procedure Uninstall_Declarations (P : Entity_Id) is
1896 Decl : constant Node_Id := Unit_Declaration_Node (P);
1899 Priv_Elmt : Elmt_Id;
1900 Priv_Sub : Entity_Id;
1902 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id);
1903 -- Copy to the private declaration the attributes of the full view
1904 -- that need to be available for the partial view also.
1906 function Type_In_Use (T : Entity_Id) return Boolean;
1907 -- Check whether type or base type appear in an active use_type clause
1909 ------------------------------
1910 -- Preserve_Full_Attributes --
1911 ------------------------------
1913 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id) is
1914 Priv_Is_Base_Type : constant Boolean := Priv = Base_Type (Priv);
1917 Set_Size_Info (Priv, (Full));
1918 Set_RM_Size (Priv, RM_Size (Full));
1919 Set_Size_Known_At_Compile_Time
1920 (Priv, Size_Known_At_Compile_Time (Full));
1921 Set_Is_Volatile (Priv, Is_Volatile (Full));
1922 Set_Treat_As_Volatile (Priv, Treat_As_Volatile (Full));
1923 Set_Is_Ada_2005_Only (Priv, Is_Ada_2005_Only (Full));
1924 Set_Has_Pragma_Unreferenced (Priv, Has_Pragma_Unreferenced (Full));
1925 Set_Has_Pragma_Unreferenced_Objects
1926 (Priv, Has_Pragma_Unreferenced_Objects
1928 if Is_Unchecked_Union (Full) then
1929 Set_Is_Unchecked_Union (Base_Type (Priv));
1931 -- Why is atomic not copied here ???
1933 if Referenced (Full) then
1934 Set_Referenced (Priv);
1937 if Priv_Is_Base_Type then
1938 Set_Is_Controlled (Priv, Is_Controlled (Base_Type (Full)));
1939 Set_Finalize_Storage_Only (Priv, Finalize_Storage_Only
1940 (Base_Type (Full)));
1941 Set_Has_Task (Priv, Has_Task (Base_Type (Full)));
1942 Set_Has_Controlled_Component (Priv, Has_Controlled_Component
1943 (Base_Type (Full)));
1946 Set_Freeze_Node (Priv, Freeze_Node (Full));
1948 if Is_Tagged_Type (Priv)
1949 and then Is_Tagged_Type (Full)
1950 and then not Error_Posted (Full)
1952 if Priv_Is_Base_Type then
1954 -- Ada 2005 (AI-345): The full view of a type implementing
1955 -- an interface can be a task type.
1957 -- type T is new I with private;
1959 -- task type T is new I with ...
1961 if Is_Interface (Etype (Priv))
1962 and then Is_Concurrent_Type (Base_Type (Full))
1964 -- Protect the frontend against previous errors
1966 if Present (Corresponding_Record_Type
1969 Set_Access_Disp_Table
1970 (Priv, Access_Disp_Table
1971 (Corresponding_Record_Type (Base_Type (Full))));
1973 -- Generic context, or previous errors
1980 Set_Access_Disp_Table
1981 (Priv, Access_Disp_Table (Base_Type (Full)));
1985 if Is_Tagged_Type (Priv) then
1987 -- If the type is tagged, the tag itself must be available
1988 -- on the partial view, for expansion purposes.
1990 Set_First_Entity (Priv, First_Entity (Full));
1992 -- If there are discriminants in the partial view, these remain
1993 -- visible. Otherwise only the tag itself is visible, and there
1994 -- are no nameable components in the partial view.
1996 if No (Last_Entity (Priv)) then
1997 Set_Last_Entity (Priv, First_Entity (Priv));
2001 Set_Has_Discriminants (Priv, Has_Discriminants (Full));
2003 end Preserve_Full_Attributes;
2009 function Type_In_Use (T : Entity_Id) return Boolean is
2011 return Scope (Base_Type (T)) = P
2012 and then (In_Use (T) or else In_Use (Base_Type (T)));
2015 -- Start of processing for Uninstall_Declarations
2018 Id := First_Entity (P);
2019 while Present (Id) and then Id /= First_Private_Entity (P) loop
2020 if Debug_Flag_E then
2021 Write_Str ("unlinking visible entity ");
2022 Write_Int (Int (Id));
2026 -- On exit from the package scope, we must preserve the visibility
2027 -- established by use clauses in the current scope. Two cases:
2029 -- a) If the entity is an operator, it may be a primitive operator of
2030 -- a type for which there is a visible use-type clause.
2032 -- b) for other entities, their use-visibility is determined by a
2033 -- visible use clause for the package itself. For a generic instance,
2034 -- the instantiation of the formals appears in the visible part,
2035 -- but the formals are private and remain so.
2037 if Ekind (Id) = E_Function
2038 and then Is_Operator_Symbol_Name (Chars (Id))
2039 and then not Is_Hidden (Id)
2040 and then not Error_Posted (Id)
2042 Set_Is_Potentially_Use_Visible (Id,
2044 or else Type_In_Use (Etype (Id))
2045 or else Type_In_Use (Etype (First_Formal (Id)))
2046 or else (Present (Next_Formal (First_Formal (Id)))
2049 (Etype (Next_Formal (First_Formal (Id))))));
2051 if In_Use (P) and then not Is_Hidden (Id) then
2053 -- A child unit of a use-visible package remains use-visible
2054 -- only if it is itself a visible child unit. Otherwise it
2055 -- would remain visible in other contexts where P is use-
2056 -- visible, because once compiled it stays in the entity list
2057 -- of its parent unit.
2059 if Is_Child_Unit (Id) then
2060 Set_Is_Potentially_Use_Visible (Id,
2061 Is_Visible_Child_Unit (Id));
2063 Set_Is_Potentially_Use_Visible (Id);
2067 Set_Is_Potentially_Use_Visible (Id, False);
2071 -- Local entities are not immediately visible outside of the package
2073 Set_Is_Immediately_Visible (Id, False);
2075 -- If this is a private type with a full view (for example a local
2076 -- subtype of a private type declared elsewhere), ensure that the
2077 -- full view is also removed from visibility: it may be exposed when
2078 -- swapping views in an instantiation.
2081 and then Present (Full_View (Id))
2083 Set_Is_Immediately_Visible (Full_View (Id), False);
2086 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2087 Check_Abstract_Overriding (Id);
2088 Check_Conventions (Id);
2091 if (Ekind (Id) = E_Private_Type
2092 or else Ekind (Id) = E_Limited_Private_Type)
2093 and then No (Full_View (Id))
2094 and then not Is_Generic_Type (Id)
2095 and then not Is_Derived_Type (Id)
2097 Error_Msg_N ("missing full declaration for private type&", Id);
2099 elsif Ekind (Id) = E_Record_Type_With_Private
2100 and then not Is_Generic_Type (Id)
2101 and then No (Full_View (Id))
2103 if Nkind (Parent (Id)) = N_Private_Type_Declaration then
2104 Error_Msg_N ("missing full declaration for private type&", Id);
2107 ("missing full declaration for private extension", Id);
2110 elsif Ekind (Id) = E_Constant
2111 and then No (Constant_Value (Id))
2112 and then No (Full_View (Id))
2113 and then not Is_Imported (Id)
2114 and then (Nkind (Parent (Id)) /= N_Object_Declaration
2115 or else not No_Initialization (Parent (Id)))
2117 if not Has_Private_Declaration (Etype (Id)) then
2119 -- We assume that the user did not intend a deferred
2120 -- constant declaration, and the expression is just missing.
2123 ("constant declaration requires initialization expression",
2126 if Is_Limited_Type (Etype (Id)) then
2128 ("\if variable intended, remove CONSTANT from declaration",
2134 ("missing full declaration for deferred constant (RM 7.4)",
2137 if Is_Limited_Type (Etype (Id)) then
2139 ("\if variable intended, remove CONSTANT from declaration",
2148 -- If the specification was installed as the parent of a public child
2149 -- unit, the private declarations were not installed, and there is
2152 if not In_Private_Part (P) then
2155 Set_In_Private_Part (P, False);
2158 -- Make private entities invisible and exchange full and private
2159 -- declarations for private types. Id is now the first private
2160 -- entity in the package.
2162 while Present (Id) loop
2163 if Debug_Flag_E then
2164 Write_Str ("unlinking private entity ");
2165 Write_Int (Int (Id));
2169 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2170 Check_Abstract_Overriding (Id);
2171 Check_Conventions (Id);
2174 Set_Is_Immediately_Visible (Id, False);
2176 if Is_Private_Base_Type (Id)
2177 and then Present (Full_View (Id))
2179 Full := Full_View (Id);
2181 -- If the partial view is not declared in the visible part
2182 -- of the package (as is the case when it is a type derived
2183 -- from some other private type in the private part of the
2184 -- current package), no exchange takes place.
2187 or else List_Containing (Parent (Id))
2188 /= Visible_Declarations (Specification (Decl))
2193 -- The entry in the private part points to the full declaration,
2194 -- which is currently visible. Exchange them so only the private
2195 -- type declaration remains accessible, and link private and
2196 -- full declaration in the opposite direction. Before the actual
2197 -- exchange, we copy back attributes of the full view that
2198 -- must be available to the partial view too.
2200 Preserve_Full_Attributes (Id, Full);
2202 Set_Is_Potentially_Use_Visible (Id, In_Use (P));
2204 if Is_Indefinite_Subtype (Full)
2205 and then not Is_Indefinite_Subtype (Id)
2208 ("full view of type must be definite subtype", Full);
2211 Priv_Elmt := First_Elmt (Private_Dependents (Id));
2213 -- Swap out the subtypes and derived types of Id that were
2214 -- compiled in this scope, or installed previously by
2215 -- Install_Private_Declarations.
2216 -- Before we do the swap, we verify the presence of the
2217 -- Full_View field which may be empty due to a swap by
2218 -- a previous call to End_Package_Scope (e.g. from the
2219 -- freezing mechanism).
2221 while Present (Priv_Elmt) loop
2222 Priv_Sub := Node (Priv_Elmt);
2224 if Present (Full_View (Priv_Sub)) then
2226 if Scope (Priv_Sub) = P
2227 or else not In_Open_Scopes (Scope (Priv_Sub))
2229 Set_Is_Immediately_Visible (Priv_Sub, False);
2232 if Is_Visible_Dependent (Priv_Sub) then
2233 Preserve_Full_Attributes
2234 (Priv_Sub, Full_View (Priv_Sub));
2235 Replace_Elmt (Priv_Elmt, Full_View (Priv_Sub));
2236 Exchange_Declarations (Priv_Sub);
2240 Next_Elmt (Priv_Elmt);
2243 -- Now restore the type itself to its private view
2245 Exchange_Declarations (Id);
2247 -- If we have installed an underlying full view for a type
2248 -- derived from a private type in a child unit, restore the
2249 -- proper views of private and full view. See corresponding
2250 -- code in Install_Private_Declarations.
2251 -- After the exchange, Full denotes the private type in the
2252 -- visible part of the package.
2254 if Is_Private_Base_Type (Full)
2255 and then Present (Full_View (Full))
2256 and then Present (Underlying_Full_View (Full))
2257 and then In_Package_Body (Current_Scope)
2259 Set_Full_View (Full, Underlying_Full_View (Full));
2260 Set_Underlying_Full_View (Full, Empty);
2263 elsif Ekind (Id) = E_Incomplete_Type
2264 and then No (Full_View (Id))
2266 -- Mark Taft amendment types
2268 Set_Has_Completion_In_Body (Id);
2270 elsif not Is_Child_Unit (Id)
2271 and then (not Is_Private_Type (Id)
2272 or else No (Full_View (Id)))
2275 Set_Is_Potentially_Use_Visible (Id, False);
2281 end Uninstall_Declarations;
2283 ------------------------
2284 -- Unit_Requires_Body --
2285 ------------------------
2287 function Unit_Requires_Body (P : Entity_Id) return Boolean is
2291 -- Imported entity never requires body. Right now, only
2292 -- subprograms can be imported, but perhaps in the future
2293 -- we will allow import of packages.
2295 if Is_Imported (P) then
2298 -- Body required if library package with pragma Elaborate_Body
2300 elsif Has_Pragma_Elaborate_Body (P) then
2303 -- Body required if subprogram
2305 elsif Is_Subprogram (P) or else Is_Generic_Subprogram (P) then
2308 -- Treat a block as requiring a body
2310 elsif Ekind (P) = E_Block then
2313 elsif Ekind (P) = E_Package
2314 and then Nkind (Parent (P)) = N_Package_Specification
2315 and then Present (Generic_Parent (Parent (P)))
2318 G_P : constant Entity_Id := Generic_Parent (Parent (P));
2320 if Has_Pragma_Elaborate_Body (G_P) then
2326 -- Otherwise search entity chain for entity requiring completion
2328 E := First_Entity (P);
2329 while Present (E) loop
2331 -- Always ignore child units. Child units get added to the entity
2332 -- list of a parent unit, but are not original entities of the
2333 -- parent, and so do not affect whether the parent needs a body.
2335 if Is_Child_Unit (E) then
2338 -- Ignore formal packages and their renamings
2340 elsif Ekind (E) = E_Package
2341 and then Nkind (Original_Node (Unit_Declaration_Node (E))) =
2342 N_Formal_Package_Declaration
2346 -- Otherwise test to see if entity requires a completion.
2347 -- Note that subprogram entities whose declaration does not come
2348 -- from source are ignored here on the basis that we assume the
2349 -- expander will provide an implicit completion at some point.
2351 elsif (Is_Overloadable (E)
2352 and then Ekind (E) /= E_Enumeration_Literal
2353 and then Ekind (E) /= E_Operator
2354 and then not Is_Abstract_Subprogram (E)
2355 and then not Has_Completion (E)
2356 and then Comes_From_Source (Parent (E)))
2359 (Ekind (E) = E_Package
2361 and then not Has_Completion (E)
2362 and then Unit_Requires_Body (E))
2365 (Ekind (E) = E_Incomplete_Type and then No (Full_View (E)))
2368 ((Ekind (E) = E_Task_Type or else
2369 Ekind (E) = E_Protected_Type)
2370 and then not Has_Completion (E))
2373 (Ekind (E) = E_Generic_Package and then E /= P
2374 and then not Has_Completion (E)
2375 and then Unit_Requires_Body (E))
2378 (Is_Generic_Subprogram (E)
2379 and then not Has_Completion (E))
2384 -- Entity that does not require completion
2394 end Unit_Requires_Body;