1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, 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_Util; use Sem_Util;
55 with Sem_Warn; use Sem_Warn;
56 with Snames; use Snames;
57 with Stand; use Stand;
58 with Sinfo; use Sinfo;
59 with Sinput; use Sinput;
61 with Uintp; use Uintp;
63 package body Sem_Ch7 is
65 -----------------------------------
66 -- Handling private declarations --
67 -----------------------------------
69 -- The principle that each entity has a single defining occurrence clashes
70 -- with the presence of two separate definitions for private types: the
71 -- first is the private type declaration, and the second is the full type
72 -- declaration. It is important that all references to the type point to
73 -- the same defining occurrence, namely the first one. To enforce the two
74 -- separate views of the entity, the corresponding information is swapped
75 -- between the two declarations. Outside of the package, the defining
76 -- occurrence only contains the private declaration information, while in
77 -- the private part and the body of the package the defining occurrence
78 -- contains the full declaration. To simplify the swap, the defining
79 -- occurrence that currently holds the private declaration points to the
80 -- full declaration. During semantic processing the defining occurrence
81 -- also points to a list of private dependents, that is to say access types
82 -- or composite types whose designated types or component types are
83 -- subtypes or derived types of the private type in question. After the
84 -- full declaration has been seen, the private dependents are updated to
85 -- indicate that they have full definitions.
87 -----------------------
88 -- Local Subprograms --
89 -----------------------
91 procedure Check_Anonymous_Access_Types
94 -- If the spec of a package has a limited_with_clause, it may declare
95 -- anonymous access types whose designated type is a limited view, such an
96 -- anonymous access return type for a function. This access type cannot be
97 -- elaborated in the spec itself, but it may need an itype reference if it
98 -- is used within a nested scope. In that case the itype reference is
99 -- created at the beginning of the corresponding package body and inserted
100 -- before other body declarations.
102 procedure Inspect_Deferred_Constant_Completion (Decls : List_Id);
103 -- Examines the deferred constants in the private part of the package
104 -- specification, or in a package body. Emits the error message
105 -- "constant declaration requires initialization expression" if not
106 -- completed by an Import pragma.
108 procedure Install_Package_Entity (Id : Entity_Id);
109 -- Supporting procedure for Install_{Visible,Private}_Declarations.
110 -- Places one entity on its visibility chain, and recurses on the visible
111 -- part if the entity is an inner package.
113 function Is_Private_Base_Type (E : Entity_Id) return Boolean;
114 -- True for a private type that is not a subtype
116 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean;
117 -- If the private dependent is a private type whose full view is derived
118 -- from the parent type, its full properties are revealed only if we are in
119 -- the immediate scope of the private dependent. Should this predicate be
120 -- tightened further???
122 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id);
123 -- Called upon entering the private part of a public child package and the
124 -- body of a nested package, to potentially declare certain inherited
125 -- subprograms that were inherited by types in the visible part, but whose
126 -- declaration was deferred because the parent operation was private and
127 -- not visible at that point. These subprograms are located by traversing
128 -- the visible part declarations looking for non-private type extensions
129 -- and then examining each of the primitive operations of such types to
130 -- find those that were inherited but declared with a special internal
131 -- name. Each such operation is now declared as an operation with a normal
132 -- name (using the name of the parent operation) and replaces the previous
133 -- implicit operation in the primitive operations list of the type. If the
134 -- inherited private operation has been overridden, then it's replaced by
135 -- the overriding operation.
137 --------------------------
138 -- Analyze_Package_Body --
139 --------------------------
141 procedure Analyze_Package_Body (N : Node_Id) is
142 Loc : constant Source_Ptr := Sloc (N);
146 Last_Spec_Entity : Entity_Id;
150 procedure Install_Composite_Operations (P : Entity_Id);
151 -- Composite types declared in the current scope may depend on
152 -- types that were private at the point of declaration, and whose
153 -- full view is now in scope. Indicate that the corresponding
154 -- operations on the composite type are available.
156 ----------------------------------
157 -- Install_Composite_Operations --
158 ----------------------------------
160 procedure Install_Composite_Operations (P : Entity_Id) is
164 Id := First_Entity (P);
165 while Present (Id) loop
167 and then (Is_Limited_Composite (Id)
168 or else Is_Private_Composite (Id))
169 and then No (Private_Component (Id))
171 Set_Is_Limited_Composite (Id, False);
172 Set_Is_Private_Composite (Id, False);
177 end Install_Composite_Operations;
179 -- Start of processing for Analyze_Package_Body
182 -- Find corresponding package specification, and establish the
183 -- current scope. The visible defining entity for the package is the
184 -- defining occurrence in the spec. On exit from the package body, all
185 -- body declarations are attached to the defining entity for the body,
186 -- but the later is never used for name resolution. In this fashion
187 -- there is only one visible entity that denotes the package.
190 Write_Str ("==== Compiling package body ");
191 Write_Name (Chars (Defining_Entity (N)));
192 Write_Str (" from ");
193 Write_Location (Loc);
197 -- Set Body_Id. Note that this Will be reset to point to the
198 -- generic copy later on in the generic case.
200 Body_Id := Defining_Entity (N);
202 if Present (Corresponding_Spec (N)) then
204 -- Body is body of package instantiation. Corresponding spec
205 -- has already been set.
207 Spec_Id := Corresponding_Spec (N);
208 Pack_Decl := Unit_Declaration_Node (Spec_Id);
211 Spec_Id := Current_Entity_In_Scope (Defining_Entity (N));
214 and then Is_Package_Or_Generic_Package (Spec_Id)
216 Pack_Decl := Unit_Declaration_Node (Spec_Id);
218 if Nkind (Pack_Decl) = N_Package_Renaming_Declaration then
219 Error_Msg_N ("cannot supply body for package renaming", N);
222 elsif Present (Corresponding_Body (Pack_Decl)) then
223 Error_Msg_N ("redefinition of package body", N);
228 Error_Msg_N ("missing specification for package body", N);
232 if Is_Package_Or_Generic_Package (Spec_Id)
234 (Scope (Spec_Id) = Standard_Standard
235 or else Is_Child_Unit (Spec_Id))
236 and then not Unit_Requires_Body (Spec_Id)
238 if Ada_Version = Ada_83 then
240 ("optional package body (not allowed in Ada 95)?", N);
243 ("spec of this package does not allow a body", N);
248 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
249 Style.Check_Identifier (Body_Id, Spec_Id);
251 if Is_Child_Unit (Spec_Id) then
252 if Nkind (Parent (N)) /= N_Compilation_Unit then
254 ("body of child unit& cannot be an inner package", N, Spec_Id);
257 Set_Is_Child_Unit (Body_Id);
260 -- Generic package case
262 if Ekind (Spec_Id) = E_Generic_Package then
264 -- Disable expansion and perform semantic analysis on copy.
265 -- The unannotated body will be used in all instantiations.
267 Body_Id := Defining_Entity (N);
268 Set_Ekind (Body_Id, E_Package_Body);
269 Set_Scope (Body_Id, Scope (Spec_Id));
270 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id));
271 Set_Body_Entity (Spec_Id, Body_Id);
272 Set_Spec_Entity (Body_Id, Spec_Id);
274 New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
277 -- Update Body_Id to point to the copied node for the remainder
278 -- of the processing.
280 Body_Id := Defining_Entity (N);
284 -- The Body_Id is that of the copied node in the generic case, the
285 -- current node otherwise. Note that N was rewritten above, so we
286 -- must be sure to get the latest Body_Id value.
288 Set_Ekind (Body_Id, E_Package_Body);
289 Set_Body_Entity (Spec_Id, Body_Id);
290 Set_Spec_Entity (Body_Id, Spec_Id);
292 -- Defining name for the package body is not a visible entity: Only
293 -- the defining name for the declaration is visible.
295 Set_Etype (Body_Id, Standard_Void_Type);
296 Set_Scope (Body_Id, Scope (Spec_Id));
297 Set_Corresponding_Spec (N, Spec_Id);
298 Set_Corresponding_Body (Pack_Decl, Body_Id);
300 -- The body entity is not used for semantics or code generation, but
301 -- it is attached to the entity list of the enclosing scope to simplify
302 -- the listing of back-annotations for the types it main contain.
304 if Scope (Spec_Id) /= Standard_Standard then
305 Append_Entity (Body_Id, Scope (Spec_Id));
308 -- Indicate that we are currently compiling the body of the package
310 Set_In_Package_Body (Spec_Id);
311 Set_Has_Completion (Spec_Id);
312 Last_Spec_Entity := Last_Entity (Spec_Id);
314 Push_Scope (Spec_Id);
316 Set_Categorization_From_Pragmas (N);
318 Install_Visible_Declarations (Spec_Id);
319 Install_Private_Declarations (Spec_Id);
320 Install_Private_With_Clauses (Spec_Id);
321 Install_Composite_Operations (Spec_Id);
323 Check_Anonymous_Access_Types (Spec_Id, N);
325 if Ekind (Spec_Id) = E_Generic_Package then
326 Set_Use (Generic_Formal_Declarations (Pack_Decl));
329 Set_Use (Visible_Declarations (Specification (Pack_Decl)));
330 Set_Use (Private_Declarations (Specification (Pack_Decl)));
332 -- This is a nested package, so it may be necessary to declare certain
333 -- inherited subprograms that are not yet visible because the parent
334 -- type's subprograms are now visible.
336 if Ekind (Scope (Spec_Id)) = E_Package
337 and then Scope (Spec_Id) /= Standard_Standard
339 Declare_Inherited_Private_Subprograms (Spec_Id);
342 if Present (Declarations (N)) then
343 Analyze_Declarations (Declarations (N));
344 Inspect_Deferred_Constant_Completion (Declarations (N));
347 -- Analyze_Declarations has caused freezing of all types; now generate
348 -- bodies for RACW primitives and stream attributes, if any.
350 if Ekind (Spec_Id) = E_Package and then Has_RACW (Spec_Id) then
352 -- Attach subprogram bodies to support RACWs declared in spec
354 Append_RACW_Bodies (Declarations (N), Spec_Id);
355 Analyze_List (Declarations (N));
358 HSS := Handled_Statement_Sequence (N);
360 if Present (HSS) then
361 Process_End_Label (HSS, 't', Spec_Id);
364 -- Check that elaboration code in a preelaborable package body is
365 -- empty other than null statements and labels (RM 10.2.1(6)).
367 Validate_Null_Statement_Sequence (N);
370 Validate_Categorization_Dependency (N, Spec_Id);
371 Check_Completion (Body_Id);
373 -- Generate start of body reference. Note that we do this fairly late,
374 -- because the call will use In_Extended_Main_Source_Unit as a check,
375 -- and we want to make sure that Corresponding_Stub links are set
377 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
379 -- For a generic package, collect global references and mark them on
380 -- the original body so that they are not resolved again at the point
383 if Ekind (Spec_Id) /= E_Package then
384 Save_Global_References (Original_Node (N));
388 -- The entities of the package body have so far been chained onto the
389 -- declaration chain for the spec. That's been fine while we were in the
390 -- body, since we wanted them to be visible, but now that we are leaving
391 -- the package body, they are no longer visible, so we remove them from
392 -- the entity chain of the package spec entity, and copy them to the
393 -- entity chain of the package body entity, where they will never again
396 if Present (Last_Spec_Entity) then
397 Set_First_Entity (Body_Id, Next_Entity (Last_Spec_Entity));
398 Set_Next_Entity (Last_Spec_Entity, Empty);
399 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
400 Set_Last_Entity (Spec_Id, Last_Spec_Entity);
403 Set_First_Entity (Body_Id, First_Entity (Spec_Id));
404 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
405 Set_First_Entity (Spec_Id, Empty);
406 Set_Last_Entity (Spec_Id, Empty);
409 End_Package_Scope (Spec_Id);
411 -- All entities declared in body are not visible
417 E := First_Entity (Body_Id);
418 while Present (E) loop
419 Set_Is_Immediately_Visible (E, False);
420 Set_Is_Potentially_Use_Visible (E, False);
423 -- Child units may appear on the entity list (for example if
424 -- they appear in the context of a subunit) but they are not
427 if not Is_Child_Unit (E) then
428 Set_Is_Package_Body_Entity (E);
435 Check_References (Body_Id);
437 -- For a generic unit, check that the formal parameters are referenced,
438 -- and that local variables are used, as for regular packages.
440 if Ekind (Spec_Id) = E_Generic_Package then
441 Check_References (Spec_Id);
444 -- The processing so far has made all entities of the package body
445 -- public (i.e. externally visible to the linker). This is in general
446 -- necessary, since inlined or generic bodies, for which code is
447 -- generated in other units, may need to see these entities. The
448 -- following loop runs backwards from the end of the entities of the
449 -- package body making these entities invisible until we reach a
450 -- referencer, i.e. a declaration that could reference a previous
451 -- declaration, a generic body or an inlined body, or a stub (which
452 -- may contain either of these). This is of course an approximation,
453 -- but it is conservative and definitely correct.
455 -- We only do this at the outer (library) level non-generic packages.
456 -- The reason is simply to cut down on the number of external symbols
457 -- generated, so this is simply an optimization of the efficiency
458 -- of the compilation process. It has no other effect.
460 if (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id))
461 and then not Is_Generic_Unit (Spec_Id)
462 and then Present (Declarations (N))
464 Make_Non_Public_Where_Possible : declare
466 function Has_Referencer
470 -- Traverse the given list of declarations in reverse order.
471 -- Return True as soon as a referencer is reached. Return
472 -- False if none is found. The Outer parameter is True for
473 -- the outer level call, and False for inner level calls for
474 -- nested packages. If Outer is True, then any entities up
475 -- to the point of hitting a referencer get their Is_Public
476 -- flag cleared, so that the entities will be treated as
477 -- static entities in the C sense, and need not have fully
478 -- qualified names. For inner levels, we need all names to
479 -- be fully qualified to deal with the same name appearing
480 -- in parallel packages (right now this is tied to their
487 function Has_Referencer
503 while Present (D) loop
506 if K in N_Body_Stub then
509 elsif K = N_Subprogram_Body then
510 if Acts_As_Spec (D) then
511 E := Defining_Entity (D);
513 -- An inlined body acts as a referencer. Note also
514 -- that we never reset Is_Public for an inlined
515 -- subprogram. Gigi requires Is_Public to be set.
517 -- Note that we test Has_Pragma_Inline here rather
518 -- than Is_Inlined. We are compiling this for a
519 -- client, and it is the client who will decide
520 -- if actual inlining should occur, so we need to
521 -- assume that the procedure could be inlined for
522 -- the purpose of accessing global entities.
524 if Has_Pragma_Inline (E) then
527 Set_Is_Public (E, False);
531 E := Corresponding_Spec (D);
534 and then (Is_Generic_Unit (E)
535 or else Has_Pragma_Inline (E)
536 or else Is_Inlined (E))
542 -- Processing for package bodies
544 elsif K = N_Package_Body
545 and then Present (Corresponding_Spec (D))
547 E := Corresponding_Spec (D);
549 -- Generic package body is a referencer. It would
550 -- seem that we only have to consider generics that
551 -- can be exported, i.e. where the corresponding spec
552 -- is the spec of the current package, but because of
553 -- nested instantiations, a fully private generic
554 -- body may export other private body entities.
556 if Is_Generic_Unit (E) then
559 -- For non-generic package body, recurse into body
560 -- unless this is an instance, we ignore instances
561 -- since they cannot have references that affect
564 elsif not Is_Generic_Instance (E) then
566 (Declarations (D), Outer => False)
572 -- Processing for package specs, recurse into declarations.
573 -- Again we skip this for the case of generic instances.
575 elsif K = N_Package_Declaration then
576 S := Specification (D);
578 if not Is_Generic_Unit (Defining_Entity (S)) then
580 (Private_Declarations (S), Outer => False)
584 (Visible_Declarations (S), Outer => False)
590 -- Objects and exceptions need not be public if we have
591 -- not encountered a referencer so far. We only reset
592 -- the flag for outer level entities that are not
593 -- imported/exported, and which have no interface name.
595 elsif K = N_Object_Declaration
596 or else K = N_Exception_Declaration
597 or else K = N_Subprogram_Declaration
599 E := Defining_Entity (D);
602 and then not Is_Imported (E)
603 and then not Is_Exported (E)
604 and then No (Interface_Name (E))
606 Set_Is_Public (E, False);
616 -- Start of processing for Make_Non_Public_Where_Possible
621 pragma Warnings (Off, Discard);
624 Discard := Has_Referencer (Declarations (N), Outer => True);
626 end Make_Non_Public_Where_Possible;
629 -- If expander is not active, then here is where we turn off the
630 -- In_Package_Body flag, otherwise it is turned off at the end of
631 -- the corresponding expansion routine. If this is an instance body,
632 -- we need to qualify names of local entities, because the body may
633 -- have been compiled as a preliminary to another instantiation.
635 if not Expander_Active then
636 Set_In_Package_Body (Spec_Id, False);
638 if Is_Generic_Instance (Spec_Id)
639 and then Operating_Mode = Generate_Code
641 Qualify_Entity_Names (N);
644 end Analyze_Package_Body;
646 ---------------------------------
647 -- Analyze_Package_Declaration --
648 ---------------------------------
650 procedure Analyze_Package_Declaration (N : Node_Id) is
651 Id : constant Node_Id := Defining_Entity (N);
654 -- True when in the context of a declared pure library unit
656 Body_Required : Boolean;
657 -- True when this package declaration requires a corresponding body
660 -- True when this package declaration is not a nested declaration
663 -- Ada 2005 (AI-217): Check if the package has been erroneously named
664 -- in a limited-with clause of its own context. In this case the error
665 -- has been previously notified by Analyze_Context.
667 -- limited with Pkg; -- ERROR
668 -- package Pkg is ...
670 if From_With_Type (Id) then
674 Generate_Definition (Id);
676 Set_Ekind (Id, E_Package);
677 Set_Etype (Id, Standard_Void_Type);
681 PF := Is_Pure (Enclosing_Lib_Unit_Entity);
682 Set_Is_Pure (Id, PF);
684 Set_Categorization_From_Pragmas (N);
687 Write_Str ("==== Compiling package spec ");
688 Write_Name (Chars (Id));
689 Write_Str (" from ");
690 Write_Location (Sloc (N));
694 Analyze (Specification (N));
695 Validate_Categorization_Dependency (N, Id);
697 Body_Required := Unit_Requires_Body (Id);
699 -- When this spec does not require an explicit body, we know that
700 -- there are no entities requiring completion in the language sense;
701 -- we call Check_Completion here only to ensure that any nested package
702 -- declaration that requires an implicit body gets one. (In the case
703 -- where a body is required, Check_Completion is called at the end of
704 -- the body's declarative part.)
706 if not Body_Required then
710 Comp_Unit := Nkind (Parent (N)) = N_Compilation_Unit;
713 -- Set Body_Required indication on the compilation unit node, and
714 -- determine whether elaboration warnings may be meaningful on it.
716 Set_Body_Required (Parent (N), Body_Required);
718 if not Body_Required then
719 Set_Suppress_Elaboration_Warnings (Id);
724 End_Package_Scope (Id);
726 -- For the declaration of a library unit that is a remote types package,
727 -- check legality rules regarding availability of stream attributes for
728 -- types that contain non-remote access values. This subprogram performs
729 -- visibility tests that rely on the fact that we have exited the scope
733 Validate_RT_RAT_Component (N);
735 end Analyze_Package_Declaration;
737 -----------------------------------
738 -- Analyze_Package_Specification --
739 -----------------------------------
741 -- Note that this code is shared for the analysis of generic package
742 -- specs (see Sem_Ch12.Analyze_Generic_Package_Declaration for details).
744 procedure Analyze_Package_Specification (N : Node_Id) is
745 Id : constant Entity_Id := Defining_Entity (N);
746 Orig_Decl : constant Node_Id := Original_Node (Parent (N));
747 Vis_Decls : constant List_Id := Visible_Declarations (N);
748 Priv_Decls : constant List_Id := Private_Declarations (N);
751 Public_Child : Boolean;
753 Private_With_Clauses_Installed : Boolean := False;
754 -- In Ada 2005, private with_clauses are visible in the private part
755 -- of a nested package, even if it appears in the public part of the
756 -- enclosing package. This requires a separate step to install these
757 -- private_with_clauses, and remove them at the end of the nested
760 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id);
761 -- Clears constant indications (Never_Set_In_Source, Constant_Value,
762 -- and Is_True_Constant) on all variables that are entities of Id,
763 -- and on the chain whose first element is FE. A recursive call is
764 -- made for all packages and generic packages.
766 procedure Generate_Parent_References;
767 -- For a child unit, generate references to parent units, for
768 -- GPS navigation purposes.
770 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean;
771 -- Child and Unit are entities of compilation units. True if Child
772 -- is a public child of Parent as defined in 10.1.1
774 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id);
775 -- Detects all incomplete or private type declarations having a known
776 -- discriminant part that are completed by an Unchecked_Union. Emits
777 -- the error message "Unchecked_Union may not complete discriminated
780 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id);
781 -- Given the package entity of a generic package instantiation or
782 -- formal package whose corresponding generic is a child unit, installs
783 -- the private declarations of each of the child unit's parents.
784 -- This has to be done at the point of entering the instance package's
785 -- private part rather than being done in Sem_Ch12.Install_Parent
786 -- (which is where the parents' visible declarations are installed).
788 ---------------------
789 -- Clear_Constants --
790 ---------------------
792 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id) is
796 -- Ignore package renamings, not interesting and they can
797 -- cause self referential loops in the code below.
799 if Nkind (Parent (Id)) = N_Package_Renaming_Declaration then
803 -- Note: in the loop below, the check for Next_Entity pointing
804 -- back to the package entity may seem odd, but it is needed,
805 -- because a package can contain a renaming declaration to itself,
806 -- and such renamings are generated automatically within package
810 while Present (E) and then E /= Id loop
811 if Is_Assignable (E) then
812 Set_Never_Set_In_Source (E, False);
813 Set_Is_True_Constant (E, False);
814 Set_Current_Value (E, Empty);
815 Set_Is_Known_Null (E, False);
816 Set_Last_Assignment (E, Empty);
818 if not Can_Never_Be_Null (E) then
819 Set_Is_Known_Non_Null (E, False);
822 elsif Ekind (E) = E_Package
824 Ekind (E) = E_Generic_Package
826 Clear_Constants (E, First_Entity (E));
827 Clear_Constants (E, First_Private_Entity (E));
834 --------------------------------
835 -- Generate_Parent_References --
836 --------------------------------
838 procedure Generate_Parent_References is
839 Decl : constant Node_Id := Parent (N);
842 if Id = Cunit_Entity (Main_Unit)
843 or else Parent (Decl) = Library_Unit (Cunit (Main_Unit))
845 Generate_Reference (Id, Scope (Id), 'k', False);
847 elsif Nkind (Unit (Cunit (Main_Unit))) /= N_Subprogram_Body
848 and then Nkind (Unit (Cunit (Main_Unit))) /= N_Subunit
850 -- If current unit is an ancestor of main unit, generate
851 -- a reference to its own parent.
855 Main_Spec : Node_Id := Unit (Cunit (Main_Unit));
858 if Nkind (Main_Spec) = N_Package_Body then
859 Main_Spec := Unit (Library_Unit (Cunit (Main_Unit)));
862 U := Parent_Spec (Main_Spec);
863 while Present (U) loop
864 if U = Parent (Decl) then
865 Generate_Reference (Id, Scope (Id), 'k', False);
868 elsif Nkind (Unit (U)) = N_Package_Body then
872 U := Parent_Spec (Unit (U));
877 end Generate_Parent_References;
879 ---------------------
880 -- Is_Public_Child --
881 ---------------------
883 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean is
885 if not Is_Private_Descendant (Child) then
889 return not Private_Present (
890 Parent (Unit_Declaration_Node (Child)));
892 return Is_Public_Child (Scope (Child), Unit);
897 ----------------------------------------
898 -- Inspect_Unchecked_Union_Completion --
899 ----------------------------------------
901 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is
905 Decl := First (Decls);
906 while Present (Decl) loop
908 -- We are looking at an incomplete or private type declaration
909 -- with a known_discriminant_part whose full view is an
912 if (Nkind (Decl) = N_Incomplete_Type_Declaration
914 Nkind (Decl) = N_Private_Type_Declaration)
915 and then Has_Discriminants (Defining_Identifier (Decl))
916 and then Present (Full_View (Defining_Identifier (Decl)))
917 and then Is_Unchecked_Union
918 (Full_View (Defining_Identifier (Decl)))
920 Error_Msg_N ("completion of discriminated partial view" &
921 " cannot be an Unchecked_Union",
922 Full_View (Defining_Identifier (Decl)));
927 end Inspect_Unchecked_Union_Completion;
929 -----------------------------------------
930 -- Install_Parent_Private_Declarations --
931 -----------------------------------------
933 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id) is
934 Inst_Par : Entity_Id;
941 Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par)));
942 while Present (Gen_Par) and then Is_Child_Unit (Gen_Par) loop
943 Inst_Node := Get_Package_Instantiation_Node (Inst_Par);
945 if (Nkind (Inst_Node) = N_Package_Instantiation
946 or else Nkind (Inst_Node) = N_Formal_Package_Declaration)
947 and then Nkind (Name (Inst_Node)) = N_Expanded_Name
949 Inst_Par := Entity (Prefix (Name (Inst_Node)));
951 if Present (Renamed_Entity (Inst_Par)) then
952 Inst_Par := Renamed_Entity (Inst_Par);
957 (Specification (Unit_Declaration_Node (Inst_Par)));
959 -- Install the private declarations and private use clauses
960 -- of a parent instance of the child instance, unless the
961 -- parent instance private declarations have already been
962 -- installed earlier in Analyze_Package_Specification, which
963 -- happens when a generic child is instantiated, and the
964 -- instance is a child of the parent instance.
966 -- Installing the use clauses of the parent instance twice is
967 -- both unnecessary and wrong, because it would cause the
968 -- clauses to be chained to themselves in the use clauses list
969 -- of the scope stack entry. That in turn would cause
970 -- End_Use_Clauses to get into an endless look upon scope exit.
972 if Present (Gen_Par) then
973 if not In_Private_Part (Inst_Par) then
974 Install_Private_Declarations (Inst_Par);
975 Set_Use (Private_Declarations
977 (Unit_Declaration_Node (Inst_Par))));
980 -- If we've reached the end of the generic instance parents,
981 -- then finish off by looping through the nongeneric parents
982 -- and installing their private declarations.
985 while Present (Inst_Par)
986 and then Inst_Par /= Standard_Standard
987 and then (not In_Open_Scopes (Inst_Par)
988 or else not In_Private_Part (Inst_Par))
990 Install_Private_Declarations (Inst_Par);
991 Set_Use (Private_Declarations
993 (Unit_Declaration_Node (Inst_Par))));
994 Inst_Par := Scope (Inst_Par);
1004 end Install_Parent_Private_Declarations;
1006 -- Start of processing for Analyze_Package_Specification
1009 if Present (Vis_Decls) then
1010 Analyze_Declarations (Vis_Decls);
1013 -- Verify that incomplete types have received full declarations
1015 E := First_Entity (Id);
1016 while Present (E) loop
1017 if Ekind (E) = E_Incomplete_Type
1018 and then No (Full_View (E))
1020 Error_Msg_N ("no declaration in visible part for incomplete}", E);
1026 if Is_Remote_Call_Interface (Id)
1027 and then Nkind (Parent (Parent (N))) = N_Compilation_Unit
1029 Validate_RCI_Declarations (Id);
1032 -- Save global references in the visible declarations, before
1033 -- installing private declarations of parent unit if there is one,
1034 -- because the privacy status of types defined in the parent will
1035 -- change. This is only relevant for generic child units, but is
1036 -- done in all cases for uniformity.
1038 if Ekind (Id) = E_Generic_Package
1039 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1042 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1043 Save_Priv : constant List_Id := Private_Declarations (Orig_Spec);
1046 Set_Private_Declarations (Orig_Spec, Empty_List);
1047 Save_Global_References (Orig_Decl);
1048 Set_Private_Declarations (Orig_Spec, Save_Priv);
1052 -- If package is a public child unit, then make the private declarations
1053 -- of the parent visible.
1055 Public_Child := False;
1059 Pack_Decl : Node_Id;
1064 Par_Spec := Parent_Spec (Parent (N));
1066 -- If the package is formal package of an enclosing generic, it is
1067 -- transformed into a local generic declaration, and compiled to make
1068 -- its spec available. We need to retrieve the original generic to
1069 -- determine whether it is a child unit, and install its parents.
1073 Nkind (Original_Node (Parent (N))) = N_Formal_Package_Declaration
1075 Par := Entity (Name (Original_Node (Parent (N))));
1076 Par_Spec := Parent_Spec (Unit_Declaration_Node (Par));
1079 if Present (Par_Spec) then
1080 Generate_Parent_References;
1082 while Scope (Par) /= Standard_Standard
1083 and then Is_Public_Child (Id, Par)
1084 and then In_Open_Scopes (Par)
1086 Public_Child := True;
1088 Install_Private_Declarations (Par);
1089 Install_Private_With_Clauses (Par);
1090 Pack_Decl := Unit_Declaration_Node (Par);
1091 Set_Use (Private_Declarations (Specification (Pack_Decl)));
1096 if Is_Compilation_Unit (Id) then
1097 Install_Private_With_Clauses (Id);
1100 -- The current compilation unit may include private with_clauses,
1101 -- which are visible in the private part of the current nested
1102 -- package, and have to be installed now. This is not done for
1103 -- nested instantiations, where the private with_clauses of the
1104 -- enclosing unit have no effect once the instantiation info is
1105 -- established and we start analyzing the package declaration.
1108 Comp_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1110 if (Ekind (Comp_Unit) = E_Package
1111 or else Ekind (Comp_Unit) = E_Generic_Package)
1112 and then not In_Private_Part (Comp_Unit)
1113 and then not In_Instance
1115 Install_Private_With_Clauses (Comp_Unit);
1116 Private_With_Clauses_Installed := True;
1121 -- If this is a package associated with a generic instance or formal
1122 -- package, then the private declarations of each of the generic's
1123 -- parents must be installed at this point.
1125 if Is_Generic_Instance (Id) then
1126 Install_Parent_Private_Declarations (Id);
1129 -- Analyze private part if present. The flag In_Private_Part is reset
1130 -- in End_Package_Scope.
1132 L := Last_Entity (Id);
1134 if Present (Priv_Decls) then
1135 Set_In_Private_Part (Id);
1137 -- Upon entering a public child's private part, it may be necessary
1138 -- to declare subprograms that were derived in the package's visible
1139 -- part but not yet made visible.
1141 if Public_Child then
1142 Declare_Inherited_Private_Subprograms (Id);
1145 Analyze_Declarations (Priv_Decls);
1147 -- Check the private declarations for incomplete deferred constants
1149 Inspect_Deferred_Constant_Completion (Priv_Decls);
1151 -- The first private entity is the immediate follower of the last
1152 -- visible entity, if there was one.
1155 Set_First_Private_Entity (Id, Next_Entity (L));
1157 Set_First_Private_Entity (Id, First_Entity (Id));
1160 -- There may be inherited private subprograms that need to be declared,
1161 -- even in the absence of an explicit private part. If there are any
1162 -- public declarations in the package and the package is a public child
1163 -- unit, then an implicit private part is assumed.
1165 elsif Present (L) and then Public_Child then
1166 Set_In_Private_Part (Id);
1167 Declare_Inherited_Private_Subprograms (Id);
1168 Set_First_Private_Entity (Id, Next_Entity (L));
1171 E := First_Entity (Id);
1172 while Present (E) loop
1174 -- Check rule of 3.6(11), which in general requires waiting till all
1175 -- full types have been seen.
1177 if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then
1178 Check_Aliased_Component_Types (E);
1181 -- Check preelaborable initialization for full type completing a
1182 -- private type for which pragma Preelaborable_Initialization given.
1185 and then Must_Have_Preelab_Init (E)
1186 and then not Has_Preelaborable_Initialization (E)
1189 ("full view of & does not have preelaborable initialization", E);
1195 -- Ada 2005 (AI-216): The completion of an incomplete or private type
1196 -- declaration having a known_discriminant_part shall not be an
1197 -- Unchecked_Union type.
1199 if Present (Vis_Decls) then
1200 Inspect_Unchecked_Union_Completion (Vis_Decls);
1203 if Present (Priv_Decls) then
1204 Inspect_Unchecked_Union_Completion (Priv_Decls);
1207 if Ekind (Id) = E_Generic_Package
1208 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1209 and then Present (Priv_Decls)
1211 -- Save global references in private declarations, ignoring the
1212 -- visible declarations that were processed earlier.
1215 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1216 Save_Vis : constant List_Id := Visible_Declarations (Orig_Spec);
1217 Save_Form : constant List_Id :=
1218 Generic_Formal_Declarations (Orig_Decl);
1221 Set_Visible_Declarations (Orig_Spec, Empty_List);
1222 Set_Generic_Formal_Declarations (Orig_Decl, Empty_List);
1223 Save_Global_References (Orig_Decl);
1224 Set_Generic_Formal_Declarations (Orig_Decl, Save_Form);
1225 Set_Visible_Declarations (Orig_Spec, Save_Vis);
1229 Process_End_Label (N, 'e', Id);
1231 -- Remove private_with_clauses of enclosing compilation unit, if they
1234 if Private_With_Clauses_Installed then
1235 Remove_Private_With_Clauses (Cunit (Current_Sem_Unit));
1238 -- For the case of a library level package, we must go through all the
1239 -- entities clearing the indications that the value may be constant and
1240 -- not modified. Why? Because any client of this package may modify
1241 -- these values freely from anywhere. This also applies to any nested
1242 -- packages or generic packages.
1244 -- For now we unconditionally clear constants for packages that are
1245 -- instances of generic packages. The reason is that we do not have the
1246 -- body yet, and we otherwise think things are unreferenced when they
1247 -- are not. This should be fixed sometime (the effect is not terrible,
1248 -- we just lose some warnings, and also some cases of value propagation)
1251 if Is_Library_Level_Entity (Id)
1252 or else Is_Generic_Instance (Id)
1254 Clear_Constants (Id, First_Entity (Id));
1255 Clear_Constants (Id, First_Private_Entity (Id));
1257 end Analyze_Package_Specification;
1259 --------------------------------------
1260 -- Analyze_Private_Type_Declaration --
1261 --------------------------------------
1263 procedure Analyze_Private_Type_Declaration (N : Node_Id) is
1264 PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity);
1265 Id : constant Entity_Id := Defining_Identifier (N);
1268 Generate_Definition (Id);
1269 Set_Is_Pure (Id, PF);
1270 Init_Size_Align (Id);
1272 if (Ekind (Current_Scope) /= E_Package
1273 and then Ekind (Current_Scope) /= E_Generic_Package)
1274 or else In_Private_Part (Current_Scope)
1276 Error_Msg_N ("invalid context for private declaration", N);
1279 New_Private_Type (N, Id, N);
1280 Set_Depends_On_Private (Id);
1281 end Analyze_Private_Type_Declaration;
1283 ----------------------------------
1284 -- Check_Anonymous_Access_Types --
1285 ----------------------------------
1287 procedure Check_Anonymous_Access_Types
1288 (Spec_Id : Entity_Id;
1295 -- Itype references are only needed by gigi, to force elaboration of
1296 -- itypes. In the absence of code generation, they are not needed.
1298 if not Expander_Active then
1302 E := First_Entity (Spec_Id);
1303 while Present (E) loop
1304 if Ekind (E) = E_Anonymous_Access_Type
1305 and then From_With_Type (E)
1307 IR := Make_Itype_Reference (Sloc (P_Body));
1310 if No (Declarations (P_Body)) then
1311 Set_Declarations (P_Body, New_List (IR));
1313 Prepend (IR, Declarations (P_Body));
1319 end Check_Anonymous_Access_Types;
1321 -------------------------------------------
1322 -- Declare_Inherited_Private_Subprograms --
1323 -------------------------------------------
1325 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is
1327 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean;
1328 -- Check whether an inherited subprogram is an operation of an
1329 -- untagged derived type.
1331 ---------------------
1332 -- Is_Primitive_Of --
1333 ---------------------
1335 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is
1339 if Etype (S) = T then
1343 Formal := First_Formal (S);
1344 while Present (Formal) loop
1345 if Etype (Formal) = T then
1349 Next_Formal (Formal);
1354 end Is_Primitive_Of;
1361 Op_Elmt_2 : Elmt_Id;
1362 Prim_Op : Entity_Id;
1363 New_Op : Entity_Id := Empty;
1364 Parent_Subp : Entity_Id;
1367 -- Start of processing for Declare_Inherited_Private_Subprograms
1370 E := First_Entity (Id);
1371 while Present (E) loop
1373 -- If the entity is a nonprivate type extension whose parent
1374 -- type is declared in an open scope, then the type may have
1375 -- inherited operations that now need to be made visible.
1376 -- Ditto if the entity is a formal derived type in a child unit.
1378 if ((Is_Derived_Type (E) and then not Is_Private_Type (E))
1380 (Nkind (Parent (E)) = N_Private_Extension_Declaration
1381 and then Is_Generic_Type (E)))
1382 and then In_Open_Scopes (Scope (Etype (E)))
1383 and then E = Base_Type (E)
1385 if Is_Tagged_Type (E) then
1386 Op_List := Primitive_Operations (E);
1388 Tag := First_Tag_Component (E);
1390 Op_Elmt := First_Elmt (Op_List);
1391 while Present (Op_Elmt) loop
1392 Prim_Op := Node (Op_Elmt);
1394 -- Search primitives that are implicit operations with an
1395 -- internal name whose parent operation has a normal name.
1397 if Present (Alias (Prim_Op))
1398 and then Find_Dispatching_Type (Alias (Prim_Op)) /= E
1399 and then not Comes_From_Source (Prim_Op)
1400 and then Is_Internal_Name (Chars (Prim_Op))
1401 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1403 Parent_Subp := Alias (Prim_Op);
1405 -- Case 1: Check if the type has also an explicit
1406 -- overriding for this primitive.
1408 Op_Elmt_2 := Next_Elmt (Op_Elmt);
1409 while Present (Op_Elmt_2) loop
1410 if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp)
1411 and then Type_Conformant (Prim_Op, Node (Op_Elmt_2))
1413 -- The private inherited operation has been
1414 -- overridden by an explicit subprogram: replace
1415 -- the former by the latter.
1417 New_Op := Node (Op_Elmt_2);
1418 Replace_Elmt (Op_Elmt, New_Op);
1419 Remove_Elmt (Op_List, Op_Elmt_2);
1420 Set_Is_Overriding_Operation (New_Op);
1422 -- We don't need to inherit its dispatching slot.
1423 -- Set_All_DT_Position has previously ensured that
1424 -- the same slot was assigned to the two primitives
1427 and then Present (DTC_Entity (New_Op))
1428 and then Present (DTC_Entity (Prim_Op))
1430 pragma Assert (DT_Position (New_Op)
1431 = DT_Position (Prim_Op));
1435 goto Next_Primitive;
1438 Next_Elmt (Op_Elmt_2);
1441 -- Case 2: We have not found any explicit overriding and
1442 -- hence we need to declare the operation (i.e., make it
1445 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1447 -- Inherit the dispatching slot if E is already frozen
1450 and then Present (DTC_Entity (Alias (Prim_Op)))
1452 Set_DTC_Entity_Value (E, New_Op);
1453 Set_DT_Position (New_Op,
1454 DT_Position (Alias (Prim_Op)));
1458 (Is_Dispatching_Operation (New_Op)
1459 and then Node (Last_Elmt (Op_List)) = New_Op);
1461 -- Substitute the new operation for the old one
1462 -- in the type's primitive operations list. Since
1463 -- the new operation was also just added to the end
1464 -- of list, the last element must be removed.
1466 -- (Question: is there a simpler way of declaring
1467 -- the operation, say by just replacing the name
1468 -- of the earlier operation, reentering it in the
1469 -- in the symbol table (how?), and marking it as
1472 Replace_Elmt (Op_Elmt, New_Op);
1473 Remove_Last_Elmt (Op_List);
1477 Next_Elmt (Op_Elmt);
1480 -- Generate listing showing the contents of the dispatch table
1482 if Debug_Flag_ZZ then
1487 -- Non-tagged type, scan forward to locate
1488 -- inherited hidden operations.
1490 Prim_Op := Next_Entity (E);
1491 while Present (Prim_Op) loop
1492 if Is_Subprogram (Prim_Op)
1493 and then Present (Alias (Prim_Op))
1494 and then not Comes_From_Source (Prim_Op)
1495 and then Is_Internal_Name (Chars (Prim_Op))
1496 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1497 and then Is_Primitive_Of (E, Prim_Op)
1499 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1502 Next_Entity (Prim_Op);
1509 end Declare_Inherited_Private_Subprograms;
1511 -----------------------
1512 -- End_Package_Scope --
1513 -----------------------
1515 procedure End_Package_Scope (P : Entity_Id) is
1517 Uninstall_Declarations (P);
1519 end End_Package_Scope;
1521 ---------------------------
1522 -- Exchange_Declarations --
1523 ---------------------------
1525 procedure Exchange_Declarations (Id : Entity_Id) is
1526 Full_Id : constant Entity_Id := Full_View (Id);
1527 H1 : constant Entity_Id := Homonym (Id);
1528 Next1 : constant Entity_Id := Next_Entity (Id);
1533 -- If missing full declaration for type, nothing to exchange
1535 if No (Full_Id) then
1539 -- Otherwise complete the exchange, and preserve semantic links
1541 Next2 := Next_Entity (Full_Id);
1542 H2 := Homonym (Full_Id);
1544 -- Reset full declaration pointer to reflect the switched entities
1545 -- and readjust the next entity chains.
1547 Exchange_Entities (Id, Full_Id);
1549 Set_Next_Entity (Id, Next1);
1550 Set_Homonym (Id, H1);
1552 Set_Full_View (Full_Id, Id);
1553 Set_Next_Entity (Full_Id, Next2);
1554 Set_Homonym (Full_Id, H2);
1555 end Exchange_Declarations;
1557 ------------------------------------------
1558 -- Inspect_Deferred_Constant_Completion --
1559 ------------------------------------------
1561 procedure Inspect_Deferred_Constant_Completion (Decls : List_Id) is
1565 Decl := First (Decls);
1566 while Present (Decl) loop
1568 -- Deferred constant signature
1570 if Nkind (Decl) = N_Object_Declaration
1571 and then Constant_Present (Decl)
1572 and then No (Expression (Decl))
1574 -- No need to check internally generated constants
1576 and then Comes_From_Source (Decl)
1578 -- The constant is not completed. A full object declaration
1579 -- or a pragma Import complete a deferred constant.
1581 and then not Has_Completion (Defining_Identifier (Decl))
1584 ("constant declaration requires initialization expression",
1585 Defining_Identifier (Decl));
1588 Decl := Next (Decl);
1590 end Inspect_Deferred_Constant_Completion;
1592 ----------------------------
1593 -- Install_Package_Entity --
1594 ----------------------------
1596 procedure Install_Package_Entity (Id : Entity_Id) is
1598 if not Is_Internal (Id) then
1599 if Debug_Flag_E then
1600 Write_Str ("Install: ");
1601 Write_Name (Chars (Id));
1605 if not Is_Child_Unit (Id) then
1606 Set_Is_Immediately_Visible (Id);
1610 end Install_Package_Entity;
1612 ----------------------------------
1613 -- Install_Private_Declarations --
1614 ----------------------------------
1616 procedure Install_Private_Declarations (P : Entity_Id) is
1618 Priv_Elmt : Elmt_Id;
1623 -- First exchange declarations for private types, so that the
1624 -- full declaration is visible. For each private type, we check
1625 -- its Private_Dependents list and also exchange any subtypes of
1626 -- or derived types from it. Finally, if this is a Taft amendment
1627 -- type, the incomplete declaration is irrelevant, and we want to
1628 -- link the eventual full declaration with the original private
1629 -- one so we also skip the exchange.
1631 Id := First_Entity (P);
1632 while Present (Id) and then Id /= First_Private_Entity (P) loop
1633 if Is_Private_Base_Type (Id)
1634 and then Comes_From_Source (Full_View (Id))
1635 and then Present (Full_View (Id))
1636 and then Scope (Full_View (Id)) = Scope (Id)
1637 and then Ekind (Full_View (Id)) /= E_Incomplete_Type
1639 -- If there is a use-type clause on the private type, set the
1640 -- full view accordingly.
1642 Set_In_Use (Full_View (Id), In_Use (Id));
1643 Full := Full_View (Id);
1645 if Is_Private_Base_Type (Full)
1646 and then Has_Private_Declaration (Full)
1647 and then Nkind (Parent (Full)) = N_Full_Type_Declaration
1648 and then In_Open_Scopes (Scope (Etype (Full)))
1649 and then In_Package_Body (Current_Scope)
1650 and then not Is_Private_Type (Etype (Full))
1652 -- This is the completion of a private type by a derivation
1653 -- from another private type which is not private anymore. This
1654 -- can only happen in a package nested within a child package,
1655 -- when the parent type is defined in the parent unit. At this
1656 -- point the current type is not private either, and we have to
1657 -- install the underlying full view, which is now visible.
1659 if No (Full_View (Full))
1660 and then Present (Underlying_Full_View (Full))
1662 Set_Full_View (Id, Underlying_Full_View (Full));
1663 Set_Underlying_Full_View (Full, Empty);
1664 Set_Is_Frozen (Full_View (Id));
1668 Priv_Elmt := First_Elmt (Private_Dependents (Id));
1670 Exchange_Declarations (Id);
1671 Set_Is_Immediately_Visible (Id);
1673 while Present (Priv_Elmt) loop
1674 Priv := Node (Priv_Elmt);
1676 -- Before the exchange, verify that the presence of the
1677 -- Full_View field. It will be empty if the entity
1678 -- has already been installed due to a previous call.
1680 if Present (Full_View (Priv))
1681 and then Is_Visible_Dependent (Priv)
1684 -- For each subtype that is swapped, we also swap the
1685 -- reference to it in Private_Dependents, to allow access
1686 -- to it when we swap them out in End_Package_Scope.
1688 Replace_Elmt (Priv_Elmt, Full_View (Priv));
1689 Exchange_Declarations (Priv);
1690 Set_Is_Immediately_Visible
1691 (Priv, In_Open_Scopes (Scope (Priv)));
1692 Set_Is_Potentially_Use_Visible
1693 (Priv, Is_Potentially_Use_Visible (Node (Priv_Elmt)));
1696 Next_Elmt (Priv_Elmt);
1703 -- Next make other declarations in the private part visible as well
1705 Id := First_Private_Entity (P);
1706 while Present (Id) loop
1707 Install_Package_Entity (Id);
1708 Set_Is_Hidden (Id, False);
1712 -- Indicate that the private part is currently visible, so it can be
1713 -- properly reset on exit.
1715 Set_In_Private_Part (P);
1716 end Install_Private_Declarations;
1718 ----------------------------------
1719 -- Install_Visible_Declarations --
1720 ----------------------------------
1722 procedure Install_Visible_Declarations (P : Entity_Id) is
1724 Last_Entity : Entity_Id;
1728 (Is_Package_Or_Generic_Package (P) or else Is_Record_Type (P));
1730 if Is_Package_Or_Generic_Package (P) then
1731 Last_Entity := First_Private_Entity (P);
1733 Last_Entity := Empty;
1736 Id := First_Entity (P);
1737 while Present (Id) and then Id /= Last_Entity loop
1738 Install_Package_Entity (Id);
1741 end Install_Visible_Declarations;
1743 --------------------------
1744 -- Is_Private_Base_Type --
1745 --------------------------
1747 function Is_Private_Base_Type (E : Entity_Id) return Boolean is
1749 return Ekind (E) = E_Private_Type
1750 or else Ekind (E) = E_Limited_Private_Type
1751 or else Ekind (E) = E_Record_Type_With_Private;
1752 end Is_Private_Base_Type;
1754 --------------------------
1755 -- Is_Visible_Dependent --
1756 --------------------------
1758 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean
1760 S : constant Entity_Id := Scope (Dep);
1763 -- Renamings created for actual types have the visibility of the
1766 if Ekind (S) = E_Package
1767 and then Is_Generic_Instance (S)
1768 and then (Is_Generic_Actual_Type (Dep)
1769 or else Is_Generic_Actual_Type (Full_View (Dep)))
1773 elsif not (Is_Derived_Type (Dep))
1774 and then Is_Derived_Type (Full_View (Dep))
1776 -- When instantiating a package body, the scope stack is empty,
1777 -- so check instead whether the dependent type is defined in
1778 -- the same scope as the instance itself.
1780 return In_Open_Scopes (S)
1781 or else (Is_Generic_Instance (Current_Scope)
1782 and then Scope (Dep) = Scope (Current_Scope));
1786 end Is_Visible_Dependent;
1788 ----------------------------
1789 -- May_Need_Implicit_Body --
1790 ----------------------------
1792 procedure May_Need_Implicit_Body (E : Entity_Id) is
1793 P : constant Node_Id := Unit_Declaration_Node (E);
1794 S : constant Node_Id := Parent (P);
1799 if not Has_Completion (E)
1800 and then Nkind (P) = N_Package_Declaration
1801 and then (Present (Activation_Chain_Entity (P)) or else Has_RACW (E))
1804 Make_Package_Body (Sloc (E),
1805 Defining_Unit_Name => Make_Defining_Identifier (Sloc (E),
1806 Chars => Chars (E)),
1807 Declarations => New_List);
1809 if Nkind (S) = N_Package_Specification then
1810 if Present (Private_Declarations (S)) then
1811 Decls := Private_Declarations (S);
1813 Decls := Visible_Declarations (S);
1816 Decls := Declarations (S);
1822 end May_Need_Implicit_Body;
1824 ----------------------
1825 -- New_Private_Type --
1826 ----------------------
1828 procedure New_Private_Type (N : Node_Id; Id : Entity_Id; Def : Node_Id) is
1832 if Limited_Present (Def) then
1833 Set_Ekind (Id, E_Limited_Private_Type);
1835 Set_Ekind (Id, E_Private_Type);
1839 Set_Has_Delayed_Freeze (Id);
1840 Set_Is_First_Subtype (Id);
1841 Init_Size_Align (Id);
1843 Set_Is_Constrained (Id,
1844 No (Discriminant_Specifications (N))
1845 and then not Unknown_Discriminants_Present (N));
1847 -- Set tagged flag before processing discriminants, to catch
1850 Set_Is_Tagged_Type (Id, Tagged_Present (Def));
1852 Set_Discriminant_Constraint (Id, No_Elist);
1853 Set_Stored_Constraint (Id, No_Elist);
1855 if Present (Discriminant_Specifications (N)) then
1857 Process_Discriminants (N);
1860 elsif Unknown_Discriminants_Present (N) then
1861 Set_Has_Unknown_Discriminants (Id);
1864 Set_Private_Dependents (Id, New_Elmt_List);
1866 if Tagged_Present (Def) then
1867 Set_Ekind (Id, E_Record_Type_With_Private);
1868 Make_Class_Wide_Type (Id);
1869 Set_Primitive_Operations (Id, New_Elmt_List);
1870 Set_Is_Abstract_Type (Id, Abstract_Present (Def));
1871 Set_Is_Limited_Record (Id, Limited_Present (Def));
1872 Set_Has_Delayed_Freeze (Id, True);
1874 elsif Abstract_Present (Def) then
1875 Error_Msg_N ("only a tagged type can be abstract", N);
1877 end New_Private_Type;
1879 ----------------------------
1880 -- Uninstall_Declarations --
1881 ----------------------------
1883 procedure Uninstall_Declarations (P : Entity_Id) is
1884 Decl : constant Node_Id := Unit_Declaration_Node (P);
1887 Priv_Elmt : Elmt_Id;
1888 Priv_Sub : Entity_Id;
1890 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id);
1891 -- Copy to the private declaration the attributes of the full view
1892 -- that need to be available for the partial view also.
1894 function Type_In_Use (T : Entity_Id) return Boolean;
1895 -- Check whether type or base type appear in an active use_type clause
1897 ------------------------------
1898 -- Preserve_Full_Attributes --
1899 ------------------------------
1901 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id) is
1902 Priv_Is_Base_Type : constant Boolean := Priv = Base_Type (Priv);
1905 Set_Size_Info (Priv, (Full));
1906 Set_RM_Size (Priv, RM_Size (Full));
1907 Set_Size_Known_At_Compile_Time
1908 (Priv, Size_Known_At_Compile_Time (Full));
1909 Set_Is_Volatile (Priv, Is_Volatile (Full));
1910 Set_Treat_As_Volatile (Priv, Treat_As_Volatile (Full));
1911 Set_Is_Ada_2005_Only (Priv, Is_Ada_2005_Only (Full));
1912 Set_Has_Pragma_Unreferenced (Priv, Has_Pragma_Unreferenced (Full));
1913 Set_Has_Pragma_Unreferenced_Objects
1914 (Priv, Has_Pragma_Unreferenced_Objects
1916 if Is_Unchecked_Union (Full) then
1917 Set_Is_Unchecked_Union (Base_Type (Priv));
1919 -- Why is atomic not copied here ???
1921 if Referenced (Full) then
1922 Set_Referenced (Priv);
1925 if Priv_Is_Base_Type then
1926 Set_Is_Controlled (Priv, Is_Controlled (Base_Type (Full)));
1927 Set_Finalize_Storage_Only (Priv, Finalize_Storage_Only
1928 (Base_Type (Full)));
1929 Set_Has_Task (Priv, Has_Task (Base_Type (Full)));
1930 Set_Has_Controlled_Component (Priv, Has_Controlled_Component
1931 (Base_Type (Full)));
1934 Set_Freeze_Node (Priv, Freeze_Node (Full));
1936 if Is_Tagged_Type (Priv)
1937 and then Is_Tagged_Type (Full)
1938 and then not Error_Posted (Full)
1940 if Priv_Is_Base_Type then
1942 -- Ada 2005 (AI-345): The full view of a type implementing
1943 -- an interface can be a task type.
1945 -- type T is new I with private;
1947 -- task type T is new I with ...
1949 if Is_Interface (Etype (Priv))
1950 and then Is_Concurrent_Type (Base_Type (Full))
1952 -- Protect the frontend against previous errors
1954 if Present (Corresponding_Record_Type
1957 Set_Access_Disp_Table
1958 (Priv, Access_Disp_Table
1959 (Corresponding_Record_Type (Base_Type (Full))));
1961 -- Generic context, or previous errors
1968 Set_Access_Disp_Table
1969 (Priv, Access_Disp_Table (Base_Type (Full)));
1973 if Is_Tagged_Type (Priv) then
1975 -- If the type is tagged, the tag itself must be available
1976 -- on the partial view, for expansion purposes.
1978 Set_First_Entity (Priv, First_Entity (Full));
1980 -- If there are discriminants in the partial view, these remain
1981 -- visible. Otherwise only the tag itself is visible, and there
1982 -- are no nameable components in the partial view.
1984 if No (Last_Entity (Priv)) then
1985 Set_Last_Entity (Priv, First_Entity (Priv));
1989 Set_Has_Discriminants (Priv, Has_Discriminants (Full));
1991 end Preserve_Full_Attributes;
1997 function Type_In_Use (T : Entity_Id) return Boolean is
1999 return Scope (Base_Type (T)) = P
2000 and then (In_Use (T) or else In_Use (Base_Type (T)));
2003 -- Start of processing for Uninstall_Declarations
2006 Id := First_Entity (P);
2007 while Present (Id) and then Id /= First_Private_Entity (P) loop
2008 if Debug_Flag_E then
2009 Write_Str ("unlinking visible entity ");
2010 Write_Int (Int (Id));
2014 -- On exit from the package scope, we must preserve the visibility
2015 -- established by use clauses in the current scope. Two cases:
2017 -- a) If the entity is an operator, it may be a primitive operator of
2018 -- a type for which there is a visible use-type clause.
2020 -- b) for other entities, their use-visibility is determined by a
2021 -- visible use clause for the package itself. For a generic instance,
2022 -- the instantiation of the formals appears in the visible part,
2023 -- but the formals are private and remain so.
2025 if Ekind (Id) = E_Function
2026 and then Is_Operator_Symbol_Name (Chars (Id))
2027 and then not Is_Hidden (Id)
2028 and then not Error_Posted (Id)
2030 Set_Is_Potentially_Use_Visible (Id,
2032 or else Type_In_Use (Etype (Id))
2033 or else Type_In_Use (Etype (First_Formal (Id)))
2034 or else (Present (Next_Formal (First_Formal (Id)))
2037 (Etype (Next_Formal (First_Formal (Id))))));
2039 if In_Use (P) and then not Is_Hidden (Id) then
2041 -- A child unit of a use-visible package remains use-visible
2042 -- only if it is itself a visible child unit. Otherwise it
2043 -- would remain visible in other contexts where P is use-
2044 -- visible, because once compiled it stays in the entity list
2045 -- of its parent unit.
2047 if Is_Child_Unit (Id) then
2048 Set_Is_Potentially_Use_Visible (Id,
2049 Is_Visible_Child_Unit (Id));
2051 Set_Is_Potentially_Use_Visible (Id);
2055 Set_Is_Potentially_Use_Visible (Id, False);
2059 -- Local entities are not immediately visible outside of the package
2061 Set_Is_Immediately_Visible (Id, False);
2063 -- If this is a private type with a full view (for example a local
2064 -- subtype of a private type declared elsewhere), ensure that the
2065 -- full view is also removed from visibility: it may be exposed when
2066 -- swapping views in an instantiation.
2069 and then Present (Full_View (Id))
2071 Set_Is_Immediately_Visible (Full_View (Id), False);
2074 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2075 Check_Abstract_Overriding (Id);
2076 Check_Conventions (Id);
2079 if (Ekind (Id) = E_Private_Type
2080 or else Ekind (Id) = E_Limited_Private_Type)
2081 and then No (Full_View (Id))
2082 and then not Is_Generic_Type (Id)
2083 and then not Is_Derived_Type (Id)
2085 Error_Msg_N ("missing full declaration for private type&", Id);
2087 elsif Ekind (Id) = E_Record_Type_With_Private
2088 and then not Is_Generic_Type (Id)
2089 and then No (Full_View (Id))
2091 if Nkind (Parent (Id)) = N_Private_Type_Declaration then
2092 Error_Msg_N ("missing full declaration for private type&", Id);
2095 ("missing full declaration for private extension", Id);
2098 elsif Ekind (Id) = E_Constant
2099 and then No (Constant_Value (Id))
2100 and then No (Full_View (Id))
2101 and then not Is_Imported (Id)
2102 and then (Nkind (Parent (Id)) /= N_Object_Declaration
2103 or else not No_Initialization (Parent (Id)))
2105 if not Has_Private_Declaration (Etype (Id)) then
2107 -- We assume that the user did not not intend a deferred
2108 -- constant declaration, and the expression is just missing.
2111 ("constant declaration requires initialization expression",
2114 if Is_Limited_Type (Etype (Id)) then
2116 ("\if variable intended, remove CONSTANT from declaration",
2122 ("missing full declaration for deferred constant (RM 7.4)",
2125 if Is_Limited_Type (Etype (Id)) then
2127 ("\if variable intended, remove CONSTANT from declaration",
2136 -- If the specification was installed as the parent of a public child
2137 -- unit, the private declarations were not installed, and there is
2140 if not In_Private_Part (P) then
2143 Set_In_Private_Part (P, False);
2146 -- Make private entities invisible and exchange full and private
2147 -- declarations for private types.
2149 while Present (Id) loop
2150 if Debug_Flag_E then
2151 Write_Str ("unlinking private entity ");
2152 Write_Int (Int (Id));
2156 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2157 Check_Abstract_Overriding (Id);
2158 Check_Conventions (Id);
2161 Set_Is_Immediately_Visible (Id, False);
2163 if Is_Private_Base_Type (Id)
2164 and then Present (Full_View (Id))
2166 Full := Full_View (Id);
2168 -- If the partial view is not declared in the visible part
2169 -- of the package (as is the case when it is a type derived
2170 -- from some other private type in the private part of the
2171 -- current package), no exchange takes place.
2174 or else List_Containing (Parent (Id))
2175 /= Visible_Declarations (Specification (Decl))
2180 -- The entry in the private part points to the full declaration,
2181 -- which is currently visible. Exchange them so only the private
2182 -- type declaration remains accessible, and link private and
2183 -- full declaration in the opposite direction. Before the actual
2184 -- exchange, we copy back attributes of the full view that
2185 -- must be available to the partial view too.
2187 Preserve_Full_Attributes (Id, Full);
2189 Set_Is_Potentially_Use_Visible (Id, In_Use (P));
2191 if Is_Indefinite_Subtype (Full)
2192 and then not Is_Indefinite_Subtype (Id)
2195 ("full view of type must be definite subtype", Full);
2198 Priv_Elmt := First_Elmt (Private_Dependents (Id));
2200 -- Swap out the subtypes and derived types of Id that were
2201 -- compiled in this scope, or installed previously by
2202 -- Install_Private_Declarations.
2203 -- Before we do the swap, we verify the presence of the
2204 -- Full_View field which may be empty due to a swap by
2205 -- a previous call to End_Package_Scope (e.g. from the
2206 -- freezing mechanism).
2208 while Present (Priv_Elmt) loop
2209 Priv_Sub := Node (Priv_Elmt);
2211 if Present (Full_View (Priv_Sub)) then
2213 if Scope (Priv_Sub) = P
2214 or else not In_Open_Scopes (Scope (Priv_Sub))
2216 Set_Is_Immediately_Visible (Priv_Sub, False);
2219 if Is_Visible_Dependent (Priv_Sub) then
2220 Preserve_Full_Attributes
2221 (Priv_Sub, Full_View (Priv_Sub));
2222 Replace_Elmt (Priv_Elmt, Full_View (Priv_Sub));
2223 Exchange_Declarations (Priv_Sub);
2227 Next_Elmt (Priv_Elmt);
2230 -- Now restore the type itself to its private view
2232 Exchange_Declarations (Id);
2234 elsif Ekind (Id) = E_Incomplete_Type
2235 and then No (Full_View (Id))
2237 -- Mark Taft amendment types
2239 Set_Has_Completion_In_Body (Id);
2241 elsif not Is_Child_Unit (Id)
2242 and then (not Is_Private_Type (Id)
2243 or else No (Full_View (Id)))
2246 Set_Is_Potentially_Use_Visible (Id, False);
2252 end Uninstall_Declarations;
2254 ------------------------
2255 -- Unit_Requires_Body --
2256 ------------------------
2258 function Unit_Requires_Body (P : Entity_Id) return Boolean is
2262 -- Imported entity never requires body. Right now, only
2263 -- subprograms can be imported, but perhaps in the future
2264 -- we will allow import of packages.
2266 if Is_Imported (P) then
2269 -- Body required if library package with pragma Elaborate_Body
2271 elsif Has_Pragma_Elaborate_Body (P) then
2274 -- Body required if subprogram
2276 elsif Is_Subprogram (P) or else Is_Generic_Subprogram (P) then
2279 -- Treat a block as requiring a body
2281 elsif Ekind (P) = E_Block then
2284 elsif Ekind (P) = E_Package
2285 and then Nkind (Parent (P)) = N_Package_Specification
2286 and then Present (Generic_Parent (Parent (P)))
2289 G_P : constant Entity_Id := Generic_Parent (Parent (P));
2291 if Has_Pragma_Elaborate_Body (G_P) then
2297 -- Otherwise search entity chain for entity requiring completion
2299 E := First_Entity (P);
2300 while Present (E) loop
2302 -- Always ignore child units. Child units get added to the entity
2303 -- list of a parent unit, but are not original entities of the
2304 -- parent, and so do not affect whether the parent needs a body.
2306 if Is_Child_Unit (E) then
2309 -- Ignore formal packages and their renamings
2311 elsif Ekind (E) = E_Package
2312 and then Nkind (Original_Node (Unit_Declaration_Node (E))) =
2313 N_Formal_Package_Declaration
2317 -- Otherwise test to see if entity requires a completion.
2318 -- Note that subprogram entities whose declaration does not come
2319 -- from source are ignored here on the basis that we assume the
2320 -- expander will provide an implicit completion at some point.
2322 elsif (Is_Overloadable (E)
2323 and then Ekind (E) /= E_Enumeration_Literal
2324 and then Ekind (E) /= E_Operator
2325 and then not Is_Abstract_Subprogram (E)
2326 and then not Has_Completion (E)
2327 and then Comes_From_Source (Parent (E)))
2330 (Ekind (E) = E_Package
2332 and then not Has_Completion (E)
2333 and then Unit_Requires_Body (E))
2336 (Ekind (E) = E_Incomplete_Type and then No (Full_View (E)))
2339 ((Ekind (E) = E_Task_Type or else
2340 Ekind (E) = E_Protected_Type)
2341 and then not Has_Completion (E))
2344 (Ekind (E) = E_Generic_Package and then E /= P
2345 and then not Has_Completion (E)
2346 and then Unit_Requires_Body (E))
2349 (Is_Generic_Subprogram (E)
2350 and then not Has_Completion (E))
2355 -- Entity that does not require completion
2365 end Unit_Requires_Body;