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 dispatch
29 -- 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. Places
106 -- one entity on its visibility chain, and recurses on the visible part if
107 -- 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 types
148 -- that were private at the point of declaration, and whose full view
149 -- is now in scope. Indicate that the corresponding operations on the
150 -- 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 current
179 -- scope. The visible defining entity for the package is the defining
180 -- occurrence in the spec. On exit from the package body, all body
181 -- declarations are attached to the defining entity for the body, but
182 -- the later is never used for name resolution. In this fashion there
183 -- 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 generic
194 -- 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 has
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. The
261 -- 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 of
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 must
282 -- 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 the
289 -- 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 (e.g. if they appear
420 -- in the context of a subunit) but they are not body entities.
422 if not Is_Child_Unit (E) then
423 Set_Is_Package_Body_Entity (E);
430 Check_References (Body_Id);
432 -- For a generic unit, check that the formal parameters are referenced,
433 -- and that local variables are used, as for regular packages.
435 if Ekind (Spec_Id) = E_Generic_Package then
436 Check_References (Spec_Id);
439 -- The processing so far has made all entities of the package body
440 -- public (i.e. externally visible to the linker). This is in general
441 -- necessary, since inlined or generic bodies, for which code is
442 -- generated in other units, may need to see these entities. The
443 -- following loop runs backwards from the end of the entities of the
444 -- package body making these entities invisible until we reach a
445 -- referencer, i.e. a declaration that could reference a previous
446 -- declaration, a generic body or an inlined body, or a stub (which may
447 -- contain either of these). This is of course an approximation, but it
448 -- is conservative and definitely correct.
450 -- We only do this at the outer (library) level non-generic packages.
451 -- The reason is simply to cut down on the number of external symbols
452 -- generated, so this is simply an optimization of the efficiency
453 -- of the compilation process. It has no other effect.
455 if (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id))
456 and then not Is_Generic_Unit (Spec_Id)
457 and then Present (Declarations (N))
459 Make_Non_Public_Where_Possible : declare
461 function Has_Referencer
465 -- Traverse the given list of declarations in reverse order.
466 -- Return True as soon as a referencer is reached. Return False if
467 -- none is found. The Outer parameter is True for the outer level
468 -- call, and False for inner level calls for nested packages. If
469 -- Outer is True, then any entities up to the point of hitting a
470 -- referencer get their Is_Public flag cleared, so that the
471 -- entities will be treated as static entities in the C sense, and
472 -- need not have fully qualified names. For inner levels, we need
473 -- all names to be fully qualified to deal with the same name
474 -- appearing in parallel packages (right now this is tied to their
481 function Has_Referencer
497 while Present (D) loop
500 if K in N_Body_Stub then
503 elsif K = N_Subprogram_Body then
504 if Acts_As_Spec (D) then
505 E := Defining_Entity (D);
507 -- An inlined body acts as a referencer. Note also
508 -- that we never reset Is_Public for an inlined
509 -- subprogram. Gigi requires Is_Public to be set.
511 -- Note that we test Has_Pragma_Inline here rather
512 -- than Is_Inlined. We are compiling this for a
513 -- client, and it is the client who will decide if
514 -- actual inlining should occur, so we need to assume
515 -- that the procedure could be inlined for the purpose
516 -- of accessing global entities.
518 if Has_Pragma_Inline (E) then
521 Set_Is_Public (E, False);
525 E := Corresponding_Spec (D);
528 and then (Is_Generic_Unit (E)
529 or else Has_Pragma_Inline (E)
530 or else Is_Inlined (E))
536 -- Processing for package bodies
538 elsif K = N_Package_Body
539 and then Present (Corresponding_Spec (D))
541 E := Corresponding_Spec (D);
543 -- Generic package body is a referencer. It would seem
544 -- that we only have to consider generics that can be
545 -- exported, i.e. where the corresponding spec is the
546 -- spec of the current package, but because of nested
547 -- instantiations, a fully private generic body may
548 -- export other private body entities.
550 if Is_Generic_Unit (E) then
553 -- For non-generic package body, recurse into body unless
554 -- this is an instance, we ignore instances since they
555 -- cannot have references that affect outer entities.
557 elsif not Is_Generic_Instance (E) then
559 (Declarations (D), Outer => False)
565 -- Processing for package specs, recurse into declarations.
566 -- Again we skip this for the case of generic instances.
568 elsif K = N_Package_Declaration then
569 S := Specification (D);
571 if not Is_Generic_Unit (Defining_Entity (S)) then
573 (Private_Declarations (S), Outer => False)
577 (Visible_Declarations (S), Outer => False)
583 -- Objects and exceptions need not be public if we have not
584 -- encountered a referencer so far. We only reset the flag
585 -- for outer level entities that are not imported/exported,
586 -- and which have no interface name.
588 elsif Nkind_In (K, N_Object_Declaration,
589 N_Exception_Declaration,
590 N_Subprogram_Declaration)
592 E := Defining_Entity (D);
595 and then not Is_Imported (E)
596 and then not Is_Exported (E)
597 and then No (Interface_Name (E))
599 Set_Is_Public (E, False);
609 -- Start of processing for Make_Non_Public_Where_Possible
614 pragma Warnings (Off, Discard);
617 Discard := Has_Referencer (Declarations (N), Outer => True);
619 end Make_Non_Public_Where_Possible;
622 -- If expander is not active, then here is where we turn off the
623 -- In_Package_Body flag, otherwise it is turned off at the end of the
624 -- corresponding expansion routine. If this is an instance body, we need
625 -- to qualify names of local entities, because the body may have been
626 -- compiled as a preliminary to another instantiation.
628 if not Expander_Active then
629 Set_In_Package_Body (Spec_Id, False);
631 if Is_Generic_Instance (Spec_Id)
632 and then Operating_Mode = Generate_Code
634 Qualify_Entity_Names (N);
637 end Analyze_Package_Body;
639 ---------------------------------
640 -- Analyze_Package_Declaration --
641 ---------------------------------
643 procedure Analyze_Package_Declaration (N : Node_Id) is
644 Id : constant Node_Id := Defining_Entity (N);
647 -- True when in the context of a declared pure library unit
649 Body_Required : Boolean;
650 -- True when this package declaration requires a corresponding body
653 -- True when this package declaration is not a nested declaration
656 -- Ada 2005 (AI-217): Check if the package has been erroneously named
657 -- in a limited-with clause of its own context. In this case the error
658 -- has been previously notified by Analyze_Context.
660 -- limited with Pkg; -- ERROR
661 -- package Pkg is ...
663 if From_With_Type (Id) then
667 Generate_Definition (Id);
669 Set_Ekind (Id, E_Package);
670 Set_Etype (Id, Standard_Void_Type);
674 PF := Is_Pure (Enclosing_Lib_Unit_Entity);
675 Set_Is_Pure (Id, PF);
677 Set_Categorization_From_Pragmas (N);
680 Write_Str ("==== Compiling package spec ");
681 Write_Name (Chars (Id));
682 Write_Str (" from ");
683 Write_Location (Sloc (N));
687 Analyze (Specification (N));
688 Validate_Categorization_Dependency (N, Id);
690 Body_Required := Unit_Requires_Body (Id);
692 -- When this spec does not require an explicit body, we know that there
693 -- are no entities requiring completion in the language sense; we call
694 -- Check_Completion here only to ensure that any nested package
695 -- declaration that requires an implicit body gets one. (In the case
696 -- where a body is required, Check_Completion is called at the end of
697 -- the body's declarative part.)
699 if not Body_Required then
703 Comp_Unit := Nkind (Parent (N)) = N_Compilation_Unit;
706 -- Set Body_Required indication on the compilation unit node, and
707 -- determine whether elaboration warnings may be meaningful on it.
709 Set_Body_Required (Parent (N), Body_Required);
711 if not Body_Required then
712 Set_Suppress_Elaboration_Warnings (Id);
717 End_Package_Scope (Id);
719 -- For the declaration of a library unit that is a remote types package,
720 -- check legality rules regarding availability of stream attributes for
721 -- types that contain non-remote access values. This subprogram performs
722 -- visibility tests that rely on the fact that we have exited the scope
726 Validate_RT_RAT_Component (N);
728 end Analyze_Package_Declaration;
730 -----------------------------------
731 -- Analyze_Package_Specification --
732 -----------------------------------
734 -- Note that this code is shared for the analysis of generic package specs
735 -- (see Sem_Ch12.Analyze_Generic_Package_Declaration for details).
737 procedure Analyze_Package_Specification (N : Node_Id) is
738 Id : constant Entity_Id := Defining_Entity (N);
739 Orig_Decl : constant Node_Id := Original_Node (Parent (N));
740 Vis_Decls : constant List_Id := Visible_Declarations (N);
741 Priv_Decls : constant List_Id := Private_Declarations (N);
744 Public_Child : Boolean;
746 Private_With_Clauses_Installed : Boolean := False;
747 -- In Ada 2005, private with_clauses are visible in the private part
748 -- of a nested package, even if it appears in the public part of the
749 -- enclosing package. This requires a separate step to install these
750 -- private_with_clauses, and remove them at the end of the nested
753 procedure Analyze_PPCs (Decls : List_Id);
754 -- Given a list of declarations, go through looking for subprogram
755 -- specs, and for each one found, analyze any pre/postconditions that
756 -- are chained to the spec. This is the implementation of the late
757 -- visibility analysis for preconditions and postconditions in specs.
759 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id);
760 -- Clears constant indications (Never_Set_In_Source, Constant_Value, and
761 -- Is_True_Constant) on all variables that are entities of Id, and on
762 -- the chain whose first element is FE. A recursive call is made for all
763 -- packages and generic packages.
765 procedure Generate_Parent_References;
766 -- For a child unit, generate references to parent units, for
767 -- GPS navigation purposes.
769 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean;
770 -- Child and Unit are entities of compilation units. True if Child
771 -- is a public child of Parent as defined in 10.1.1
773 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id);
774 -- Detects all incomplete or private type declarations having a known
775 -- discriminant part that are completed by an Unchecked_Union. Emits
776 -- the error message "Unchecked_Union may not complete discriminated
779 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id);
780 -- Given the package entity of a generic package instantiation or
781 -- formal package whose corresponding generic is a child unit, installs
782 -- the private declarations of each of the child unit's parents.
783 -- This has to be done at the point of entering the instance package's
784 -- private part rather than being done in Sem_Ch12.Install_Parent
785 -- (which is where the parents' visible declarations are installed).
791 procedure Analyze_PPCs (Decls : List_Id) is
798 Decl := First (Decls);
799 while Present (Decl) loop
800 if Nkind (Original_Node (Decl)) = N_Subprogram_Declaration then
801 Spec := Specification (Original_Node (Decl));
802 Sent := Defining_Unit_Name (Spec);
803 Prag := Spec_PPC_List (Sent);
804 while Present (Prag) loop
805 Analyze_PPC_In_Decl_Part (Prag, Sent);
806 Prag := Next_Pragma (Prag);
814 ---------------------
815 -- Clear_Constants --
816 ---------------------
818 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id) is
822 -- Ignore package renamings, not interesting and they can cause self
823 -- referential loops in the code below.
825 if Nkind (Parent (Id)) = N_Package_Renaming_Declaration then
829 -- Note: in the loop below, the check for Next_Entity pointing back
830 -- to the package entity may seem odd, but it is needed, because a
831 -- package can contain a renaming declaration to itself, and such
832 -- renamings are generated automatically within package instances.
835 while Present (E) and then E /= Id loop
836 if Is_Assignable (E) then
837 Set_Never_Set_In_Source (E, False);
838 Set_Is_True_Constant (E, False);
839 Set_Current_Value (E, Empty);
840 Set_Is_Known_Null (E, False);
841 Set_Last_Assignment (E, Empty);
843 if not Can_Never_Be_Null (E) then
844 Set_Is_Known_Non_Null (E, False);
847 elsif Is_Package_Or_Generic_Package (E) then
848 Clear_Constants (E, First_Entity (E));
849 Clear_Constants (E, First_Private_Entity (E));
856 --------------------------------
857 -- Generate_Parent_References --
858 --------------------------------
860 procedure Generate_Parent_References is
861 Decl : constant Node_Id := Parent (N);
864 if Id = Cunit_Entity (Main_Unit)
865 or else Parent (Decl) = Library_Unit (Cunit (Main_Unit))
867 Generate_Reference (Id, Scope (Id), 'k', False);
869 elsif not Nkind_In (Unit (Cunit (Main_Unit)), N_Subprogram_Body,
872 -- If current unit is an ancestor of main unit, generate a
873 -- reference to its own parent.
877 Main_Spec : Node_Id := Unit (Cunit (Main_Unit));
880 if Nkind (Main_Spec) = N_Package_Body then
881 Main_Spec := Unit (Library_Unit (Cunit (Main_Unit)));
884 U := Parent_Spec (Main_Spec);
885 while Present (U) loop
886 if U = Parent (Decl) then
887 Generate_Reference (Id, Scope (Id), 'k', False);
890 elsif Nkind (Unit (U)) = N_Package_Body then
894 U := Parent_Spec (Unit (U));
899 end Generate_Parent_References;
901 ---------------------
902 -- Is_Public_Child --
903 ---------------------
905 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean is
907 if not Is_Private_Descendant (Child) then
911 return not Private_Present (
912 Parent (Unit_Declaration_Node (Child)));
914 return Is_Public_Child (Scope (Child), Unit);
919 ----------------------------------------
920 -- Inspect_Unchecked_Union_Completion --
921 ----------------------------------------
923 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is
927 Decl := First (Decls);
928 while Present (Decl) loop
930 -- We are looking at an incomplete or private type declaration
931 -- with a known_discriminant_part whose full view is an
934 if Nkind_In (Decl, N_Incomplete_Type_Declaration,
935 N_Private_Type_Declaration)
936 and then Has_Discriminants (Defining_Identifier (Decl))
937 and then Present (Full_View (Defining_Identifier (Decl)))
939 Is_Unchecked_Union (Full_View (Defining_Identifier (Decl)))
942 ("completion of discriminated partial view "
943 & "cannot be an Unchecked_Union",
944 Full_View (Defining_Identifier (Decl)));
949 end Inspect_Unchecked_Union_Completion;
951 -----------------------------------------
952 -- Install_Parent_Private_Declarations --
953 -----------------------------------------
955 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id) is
956 Inst_Par : Entity_Id;
964 Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par)));
965 while Present (Gen_Par) and then Is_Child_Unit (Gen_Par) loop
966 Inst_Node := Get_Package_Instantiation_Node (Inst_Par);
968 if Nkind_In (Inst_Node, N_Package_Instantiation,
969 N_Formal_Package_Declaration)
970 and then Nkind (Name (Inst_Node)) = N_Expanded_Name
972 Inst_Par := Entity (Prefix (Name (Inst_Node)));
974 if Present (Renamed_Entity (Inst_Par)) then
975 Inst_Par := Renamed_Entity (Inst_Par);
980 (Specification (Unit_Declaration_Node (Inst_Par)));
982 -- Install the private declarations and private use clauses
983 -- of a parent instance of the child instance, unless the
984 -- parent instance private declarations have already been
985 -- installed earlier in Analyze_Package_Specification, which
986 -- happens when a generic child is instantiated, and the
987 -- instance is a child of the parent instance.
989 -- Installing the use clauses of the parent instance twice
990 -- is both unnecessary and wrong, because it would cause the
991 -- clauses to be chained to themselves in the use clauses
992 -- list of the scope stack entry. That in turn would cause
993 -- an endless loop from End_Use_Clauses upon scope exit.
995 -- The parent is now fully visible. It may be a hidden open
996 -- scope if we are currently compiling some child instance
997 -- declared within it, but while the current instance is being
998 -- compiled the parent is immediately visible. In particular
999 -- its entities must remain visible if a stack save/restore
1000 -- takes place through a call to Rtsfind.
1002 if Present (Gen_Par) then
1003 if not In_Private_Part (Inst_Par) then
1004 Install_Private_Declarations (Inst_Par);
1005 Set_Use (Private_Declarations
1007 (Unit_Declaration_Node (Inst_Par))));
1008 Set_Is_Hidden_Open_Scope (Inst_Par, False);
1011 -- If we've reached the end of the generic instance parents,
1012 -- then finish off by looping through the nongeneric parents
1013 -- and installing their private declarations.
1016 while Present (Inst_Par)
1017 and then Inst_Par /= Standard_Standard
1018 and then (not In_Open_Scopes (Inst_Par)
1019 or else not In_Private_Part (Inst_Par))
1021 Install_Private_Declarations (Inst_Par);
1022 Set_Use (Private_Declarations
1024 (Unit_Declaration_Node (Inst_Par))));
1025 Inst_Par := Scope (Inst_Par);
1035 end Install_Parent_Private_Declarations;
1037 -- Start of processing for Analyze_Package_Specification
1040 if Present (Vis_Decls) then
1041 Analyze_Declarations (Vis_Decls);
1042 Analyze_PPCs (Vis_Decls);
1045 -- Verify that incomplete types have received full declarations
1047 E := First_Entity (Id);
1048 while Present (E) loop
1049 if Ekind (E) = E_Incomplete_Type
1050 and then No (Full_View (E))
1052 Error_Msg_N ("no declaration in visible part for incomplete}", E);
1058 if Is_Remote_Call_Interface (Id)
1059 and then Nkind (Parent (Parent (N))) = N_Compilation_Unit
1061 Validate_RCI_Declarations (Id);
1064 -- Save global references in the visible declarations, before installing
1065 -- private declarations of parent unit if there is one, because the
1066 -- privacy status of types defined in the parent will change. This is
1067 -- only relevant for generic child units, but is done in all cases for
1070 if Ekind (Id) = E_Generic_Package
1071 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1074 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1075 Save_Priv : constant List_Id := Private_Declarations (Orig_Spec);
1078 Set_Private_Declarations (Orig_Spec, Empty_List);
1079 Save_Global_References (Orig_Decl);
1080 Set_Private_Declarations (Orig_Spec, Save_Priv);
1084 -- If package is a public child unit, then make the private declarations
1085 -- of the parent visible.
1087 Public_Child := False;
1091 Pack_Decl : Node_Id;
1096 Par_Spec := Parent_Spec (Parent (N));
1098 -- If the package is formal package of an enclosing generic, it is
1099 -- transformed into a local generic declaration, and compiled to make
1100 -- its spec available. We need to retrieve the original generic to
1101 -- determine whether it is a child unit, and install its parents.
1105 Nkind (Original_Node (Parent (N))) = N_Formal_Package_Declaration
1107 Par := Entity (Name (Original_Node (Parent (N))));
1108 Par_Spec := Parent_Spec (Unit_Declaration_Node (Par));
1111 if Present (Par_Spec) then
1112 Generate_Parent_References;
1114 while Scope (Par) /= Standard_Standard
1115 and then Is_Public_Child (Id, Par)
1116 and then In_Open_Scopes (Par)
1118 Public_Child := True;
1120 Install_Private_Declarations (Par);
1121 Install_Private_With_Clauses (Par);
1122 Pack_Decl := Unit_Declaration_Node (Par);
1123 Set_Use (Private_Declarations (Specification (Pack_Decl)));
1128 if Is_Compilation_Unit (Id) then
1129 Install_Private_With_Clauses (Id);
1132 -- The current compilation unit may include private with_clauses,
1133 -- which are visible in the private part of the current nested
1134 -- package, and have to be installed now. This is not done for
1135 -- nested instantiations, where the private with_clauses of the
1136 -- enclosing unit have no effect once the instantiation info is
1137 -- established and we start analyzing the package declaration.
1140 Comp_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1142 if Is_Package_Or_Generic_Package (Comp_Unit)
1143 and then not In_Private_Part (Comp_Unit)
1144 and then not In_Instance
1146 Install_Private_With_Clauses (Comp_Unit);
1147 Private_With_Clauses_Installed := True;
1152 -- If this is a package associated with a generic instance or formal
1153 -- package, then the private declarations of each of the generic's
1154 -- parents must be installed at this point.
1156 if Is_Generic_Instance (Id) then
1157 Install_Parent_Private_Declarations (Id);
1160 -- Analyze private part if present. The flag In_Private_Part is reset
1161 -- in End_Package_Scope.
1163 L := Last_Entity (Id);
1165 if Present (Priv_Decls) then
1166 Set_In_Private_Part (Id);
1168 -- Upon entering a public child's private part, it may be necessary
1169 -- to declare subprograms that were derived in the package's visible
1170 -- part but not yet made visible.
1172 if Public_Child then
1173 Declare_Inherited_Private_Subprograms (Id);
1176 Analyze_Declarations (Priv_Decls);
1177 Analyze_PPCs (Priv_Decls);
1179 -- Check the private declarations for incomplete deferred constants
1181 Inspect_Deferred_Constant_Completion (Priv_Decls);
1183 -- The first private entity is the immediate follower of the last
1184 -- visible entity, if there was one.
1187 Set_First_Private_Entity (Id, Next_Entity (L));
1189 Set_First_Private_Entity (Id, First_Entity (Id));
1192 -- There may be inherited private subprograms that need to be declared,
1193 -- even in the absence of an explicit private part. If there are any
1194 -- public declarations in the package and the package is a public child
1195 -- unit, then an implicit private part is assumed.
1197 elsif Present (L) and then Public_Child then
1198 Set_In_Private_Part (Id);
1199 Declare_Inherited_Private_Subprograms (Id);
1200 Set_First_Private_Entity (Id, Next_Entity (L));
1203 E := First_Entity (Id);
1204 while Present (E) loop
1206 -- Check rule of 3.6(11), which in general requires waiting till all
1207 -- full types have been seen.
1209 if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then
1210 Check_Aliased_Component_Types (E);
1213 -- Check preelaborable initialization for full type completing a
1214 -- private type for which pragma Preelaborable_Initialization given.
1217 and then Must_Have_Preelab_Init (E)
1218 and then not Has_Preelaborable_Initialization (E)
1221 ("full view of & does not have preelaborable initialization", E);
1227 -- Ada 2005 (AI-216): The completion of an incomplete or private type
1228 -- declaration having a known_discriminant_part shall not be an
1229 -- Unchecked_Union type.
1231 if Present (Vis_Decls) then
1232 Inspect_Unchecked_Union_Completion (Vis_Decls);
1235 if Present (Priv_Decls) then
1236 Inspect_Unchecked_Union_Completion (Priv_Decls);
1239 if Ekind (Id) = E_Generic_Package
1240 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1241 and then Present (Priv_Decls)
1243 -- Save global references in private declarations, ignoring the
1244 -- visible declarations that were processed earlier.
1247 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1248 Save_Vis : constant List_Id := Visible_Declarations (Orig_Spec);
1249 Save_Form : constant List_Id :=
1250 Generic_Formal_Declarations (Orig_Decl);
1253 Set_Visible_Declarations (Orig_Spec, Empty_List);
1254 Set_Generic_Formal_Declarations (Orig_Decl, Empty_List);
1255 Save_Global_References (Orig_Decl);
1256 Set_Generic_Formal_Declarations (Orig_Decl, Save_Form);
1257 Set_Visible_Declarations (Orig_Spec, Save_Vis);
1261 Process_End_Label (N, 'e', Id);
1263 -- Remove private_with_clauses of enclosing compilation unit, if they
1266 if Private_With_Clauses_Installed then
1267 Remove_Private_With_Clauses (Cunit (Current_Sem_Unit));
1270 -- For the case of a library level package, we must go through all the
1271 -- entities clearing the indications that the value may be constant and
1272 -- not modified. Why? Because any client of this package may modify
1273 -- these values freely from anywhere. This also applies to any nested
1274 -- packages or generic packages.
1276 -- For now we unconditionally clear constants for packages that are
1277 -- instances of generic packages. The reason is that we do not have the
1278 -- body yet, and we otherwise think things are unreferenced when they
1279 -- are not. This should be fixed sometime (the effect is not terrible,
1280 -- we just lose some warnings, and also some cases of value propagation)
1283 if Is_Library_Level_Entity (Id)
1284 or else Is_Generic_Instance (Id)
1286 Clear_Constants (Id, First_Entity (Id));
1287 Clear_Constants (Id, First_Private_Entity (Id));
1289 end Analyze_Package_Specification;
1291 --------------------------------------
1292 -- Analyze_Private_Type_Declaration --
1293 --------------------------------------
1295 procedure Analyze_Private_Type_Declaration (N : Node_Id) is
1296 PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity);
1297 Id : constant Entity_Id := Defining_Identifier (N);
1300 Generate_Definition (Id);
1301 Set_Is_Pure (Id, PF);
1302 Init_Size_Align (Id);
1304 if not Is_Package_Or_Generic_Package (Current_Scope)
1305 or else In_Private_Part (Current_Scope)
1307 Error_Msg_N ("invalid context for private declaration", N);
1310 New_Private_Type (N, Id, N);
1311 Set_Depends_On_Private (Id);
1312 end Analyze_Private_Type_Declaration;
1314 ----------------------------------
1315 -- Check_Anonymous_Access_Types --
1316 ----------------------------------
1318 procedure Check_Anonymous_Access_Types
1319 (Spec_Id : Entity_Id;
1326 -- Itype references are only needed by gigi, to force elaboration of
1327 -- itypes. In the absence of code generation, they are not needed.
1329 if not Expander_Active then
1333 E := First_Entity (Spec_Id);
1334 while Present (E) loop
1335 if Ekind (E) = E_Anonymous_Access_Type
1336 and then From_With_Type (E)
1338 IR := Make_Itype_Reference (Sloc (P_Body));
1341 if No (Declarations (P_Body)) then
1342 Set_Declarations (P_Body, New_List (IR));
1344 Prepend (IR, Declarations (P_Body));
1350 end Check_Anonymous_Access_Types;
1352 -------------------------------------------
1353 -- Declare_Inherited_Private_Subprograms --
1354 -------------------------------------------
1356 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is
1358 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean;
1359 -- Check whether an inherited subprogram is an operation of an untagged
1362 ---------------------
1363 -- Is_Primitive_Of --
1364 ---------------------
1366 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is
1370 -- If the full view is a scalar type, the type is the anonymous base
1371 -- type, but the operation mentions the first subtype, so check the
1372 -- signature against the base type.
1374 if Base_Type (Etype (S)) = Base_Type (T) then
1378 Formal := First_Formal (S);
1379 while Present (Formal) loop
1380 if Base_Type (Etype (Formal)) = Base_Type (T) then
1384 Next_Formal (Formal);
1389 end Is_Primitive_Of;
1396 Op_Elmt_2 : Elmt_Id;
1397 Prim_Op : Entity_Id;
1398 New_Op : Entity_Id := Empty;
1399 Parent_Subp : Entity_Id;
1402 -- Start of processing for Declare_Inherited_Private_Subprograms
1405 E := First_Entity (Id);
1406 while Present (E) loop
1408 -- If the entity is a nonprivate type extension whose parent type
1409 -- is declared in an open scope, then the type may have inherited
1410 -- operations that now need to be made visible. Ditto if the entity
1411 -- is a formal derived type in a child unit.
1413 if ((Is_Derived_Type (E) and then not Is_Private_Type (E))
1415 (Nkind (Parent (E)) = N_Private_Extension_Declaration
1416 and then Is_Generic_Type (E)))
1417 and then In_Open_Scopes (Scope (Etype (E)))
1418 and then E = Base_Type (E)
1420 if Is_Tagged_Type (E) then
1421 Op_List := Primitive_Operations (E);
1423 Tag := First_Tag_Component (E);
1425 Op_Elmt := First_Elmt (Op_List);
1426 while Present (Op_Elmt) loop
1427 Prim_Op := Node (Op_Elmt);
1429 -- Search primitives that are implicit operations with an
1430 -- internal name whose parent operation has a normal name.
1432 if Present (Alias (Prim_Op))
1433 and then Find_Dispatching_Type (Alias (Prim_Op)) /= E
1434 and then not Comes_From_Source (Prim_Op)
1435 and then Is_Internal_Name (Chars (Prim_Op))
1436 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1438 Parent_Subp := Alias (Prim_Op);
1440 -- Case 1: Check if the type has also an explicit
1441 -- overriding for this primitive.
1443 Op_Elmt_2 := Next_Elmt (Op_Elmt);
1444 while Present (Op_Elmt_2) loop
1445 if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp)
1446 and then Type_Conformant (Prim_Op, Node (Op_Elmt_2))
1448 -- The private inherited operation has been
1449 -- overridden by an explicit subprogram: replace
1450 -- the former by the latter.
1452 New_Op := Node (Op_Elmt_2);
1453 Replace_Elmt (Op_Elmt, New_Op);
1454 Remove_Elmt (Op_List, Op_Elmt_2);
1455 Set_Is_Overriding_Operation (New_Op);
1456 Set_Overridden_Operation (New_Op, Parent_Subp);
1458 -- We don't need to inherit its dispatching slot.
1459 -- Set_All_DT_Position has previously ensured that
1460 -- the same slot was assigned to the two primitives
1463 and then Present (DTC_Entity (New_Op))
1464 and then Present (DTC_Entity (Prim_Op))
1466 pragma Assert (DT_Position (New_Op)
1467 = DT_Position (Prim_Op));
1471 goto Next_Primitive;
1474 Next_Elmt (Op_Elmt_2);
1477 -- Case 2: We have not found any explicit overriding and
1478 -- hence we need to declare the operation (i.e., make it
1481 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1483 -- Inherit the dispatching slot if E is already frozen
1486 and then Present (DTC_Entity (Alias (Prim_Op)))
1488 Set_DTC_Entity_Value (E, New_Op);
1489 Set_DT_Position (New_Op,
1490 DT_Position (Alias (Prim_Op)));
1494 (Is_Dispatching_Operation (New_Op)
1495 and then Node (Last_Elmt (Op_List)) = New_Op);
1497 -- Substitute the new operation for the old one in the
1498 -- type's primitive operations list. Since the new
1499 -- operation was also just added to the end of list,
1500 -- the last element must be removed.
1502 -- (Question: is there a simpler way of declaring the
1503 -- operation, say by just replacing the name of the
1504 -- earlier operation, reentering it in the in the symbol
1505 -- table (how?), and marking it as private???)
1507 Replace_Elmt (Op_Elmt, New_Op);
1508 Remove_Last_Elmt (Op_List);
1512 Next_Elmt (Op_Elmt);
1515 -- Generate listing showing the contents of the dispatch table
1517 if Debug_Flag_ZZ then
1522 -- Non-tagged type, scan forward to locate inherited hidden
1525 Prim_Op := Next_Entity (E);
1526 while Present (Prim_Op) loop
1527 if Is_Subprogram (Prim_Op)
1528 and then Present (Alias (Prim_Op))
1529 and then not Comes_From_Source (Prim_Op)
1530 and then Is_Internal_Name (Chars (Prim_Op))
1531 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1532 and then Is_Primitive_Of (E, Prim_Op)
1534 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1537 Next_Entity (Prim_Op);
1544 end Declare_Inherited_Private_Subprograms;
1546 -----------------------
1547 -- End_Package_Scope --
1548 -----------------------
1550 procedure End_Package_Scope (P : Entity_Id) is
1552 Uninstall_Declarations (P);
1554 end End_Package_Scope;
1556 ---------------------------
1557 -- Exchange_Declarations --
1558 ---------------------------
1560 procedure Exchange_Declarations (Id : Entity_Id) is
1561 Full_Id : constant Entity_Id := Full_View (Id);
1562 H1 : constant Entity_Id := Homonym (Id);
1563 Next1 : constant Entity_Id := Next_Entity (Id);
1568 -- If missing full declaration for type, nothing to exchange
1570 if No (Full_Id) then
1574 -- Otherwise complete the exchange, and preserve semantic links
1576 Next2 := Next_Entity (Full_Id);
1577 H2 := Homonym (Full_Id);
1579 -- Reset full declaration pointer to reflect the switched entities and
1580 -- readjust the next entity chains.
1582 Exchange_Entities (Id, Full_Id);
1584 Set_Next_Entity (Id, Next1);
1585 Set_Homonym (Id, H1);
1587 Set_Full_View (Full_Id, Id);
1588 Set_Next_Entity (Full_Id, Next2);
1589 Set_Homonym (Full_Id, H2);
1590 end Exchange_Declarations;
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 full
1624 -- declaration is visible. For each private type, we check its
1625 -- Private_Dependents list and also exchange any subtypes of or derived
1626 -- types from it. Finally, if this is a Taft amendment type, the
1627 -- incomplete declaration is irrelevant, and we want to link the
1628 -- eventual full declaration with the original private one so we also
1629 -- 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. Save
1658 -- the current full view as well, so that all views can be
1659 -- restored on exit. It may seem that after compiling the child
1660 -- body there are not environments to restore, but the back-end
1661 -- expects those links to be valid, and freeze nodes depend on
1664 if No (Full_View (Full))
1665 and then Present (Underlying_Full_View (Full))
1667 Set_Full_View (Id, Underlying_Full_View (Full));
1668 Set_Underlying_Full_View (Id, Full);
1670 Set_Underlying_Full_View (Full, Empty);
1671 Set_Is_Frozen (Full_View (Id));
1675 Priv_Elmt := First_Elmt (Private_Dependents (Id));
1677 Exchange_Declarations (Id);
1678 Set_Is_Immediately_Visible (Id);
1680 while Present (Priv_Elmt) loop
1681 Priv := Node (Priv_Elmt);
1683 -- Before the exchange, verify that the presence of the
1684 -- Full_View field. It will be empty if the entity has already
1685 -- been installed due to a previous call.
1687 if Present (Full_View (Priv))
1688 and then Is_Visible_Dependent (Priv)
1691 -- For each subtype that is swapped, we also swap the
1692 -- reference to it in Private_Dependents, to allow access
1693 -- to it when we swap them out in End_Package_Scope.
1695 Replace_Elmt (Priv_Elmt, Full_View (Priv));
1696 Exchange_Declarations (Priv);
1697 Set_Is_Immediately_Visible
1698 (Priv, In_Open_Scopes (Scope (Priv)));
1699 Set_Is_Potentially_Use_Visible
1700 (Priv, Is_Potentially_Use_Visible (Node (Priv_Elmt)));
1703 Next_Elmt (Priv_Elmt);
1710 -- Next make other declarations in the private part visible as well
1712 Id := First_Private_Entity (P);
1713 while Present (Id) loop
1714 Install_Package_Entity (Id);
1715 Set_Is_Hidden (Id, False);
1719 -- Indicate that the private part is currently visible, so it can be
1720 -- properly reset on exit.
1722 Set_In_Private_Part (P);
1723 end Install_Private_Declarations;
1725 ----------------------------------
1726 -- Install_Visible_Declarations --
1727 ----------------------------------
1729 procedure Install_Visible_Declarations (P : Entity_Id) is
1731 Last_Entity : Entity_Id;
1735 (Is_Package_Or_Generic_Package (P) or else Is_Record_Type (P));
1737 if Is_Package_Or_Generic_Package (P) then
1738 Last_Entity := First_Private_Entity (P);
1740 Last_Entity := Empty;
1743 Id := First_Entity (P);
1744 while Present (Id) and then Id /= Last_Entity loop
1745 Install_Package_Entity (Id);
1748 end Install_Visible_Declarations;
1750 --------------------------
1751 -- Is_Private_Base_Type --
1752 --------------------------
1754 function Is_Private_Base_Type (E : Entity_Id) return Boolean is
1756 return Ekind (E) = E_Private_Type
1757 or else Ekind (E) = E_Limited_Private_Type
1758 or else Ekind (E) = E_Record_Type_With_Private;
1759 end Is_Private_Base_Type;
1761 --------------------------
1762 -- Is_Visible_Dependent --
1763 --------------------------
1765 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean
1767 S : constant Entity_Id := Scope (Dep);
1770 -- Renamings created for actual types have the visibility of the actual
1772 if Ekind (S) = E_Package
1773 and then Is_Generic_Instance (S)
1774 and then (Is_Generic_Actual_Type (Dep)
1775 or else Is_Generic_Actual_Type (Full_View (Dep)))
1779 elsif not (Is_Derived_Type (Dep))
1780 and then Is_Derived_Type (Full_View (Dep))
1782 -- When instantiating a package body, the scope stack is empty, so
1783 -- check instead whether the dependent type is defined in the same
1784 -- scope as the instance itself.
1786 return In_Open_Scopes (S)
1787 or else (Is_Generic_Instance (Current_Scope)
1788 and then Scope (Dep) = Scope (Current_Scope));
1792 end Is_Visible_Dependent;
1794 ----------------------------
1795 -- May_Need_Implicit_Body --
1796 ----------------------------
1798 procedure May_Need_Implicit_Body (E : Entity_Id) is
1799 P : constant Node_Id := Unit_Declaration_Node (E);
1800 S : constant Node_Id := Parent (P);
1805 if not Has_Completion (E)
1806 and then Nkind (P) = N_Package_Declaration
1807 and then (Present (Activation_Chain_Entity (P)) or else Has_RACW (E))
1810 Make_Package_Body (Sloc (E),
1811 Defining_Unit_Name => Make_Defining_Identifier (Sloc (E),
1812 Chars => Chars (E)),
1813 Declarations => New_List);
1815 if Nkind (S) = N_Package_Specification then
1816 if Present (Private_Declarations (S)) then
1817 Decls := Private_Declarations (S);
1819 Decls := Visible_Declarations (S);
1822 Decls := Declarations (S);
1828 end May_Need_Implicit_Body;
1830 ----------------------
1831 -- New_Private_Type --
1832 ----------------------
1834 procedure New_Private_Type (N : Node_Id; Id : Entity_Id; Def : Node_Id) is
1838 if Limited_Present (Def) then
1839 Set_Ekind (Id, E_Limited_Private_Type);
1841 Set_Ekind (Id, E_Private_Type);
1845 Set_Has_Delayed_Freeze (Id);
1846 Set_Is_First_Subtype (Id);
1847 Init_Size_Align (Id);
1849 Set_Is_Constrained (Id,
1850 No (Discriminant_Specifications (N))
1851 and then not Unknown_Discriminants_Present (N));
1853 -- Set tagged flag before processing discriminants, to catch illegal
1856 Set_Is_Tagged_Type (Id, Tagged_Present (Def));
1858 Set_Discriminant_Constraint (Id, No_Elist);
1859 Set_Stored_Constraint (Id, No_Elist);
1861 if Present (Discriminant_Specifications (N)) then
1863 Process_Discriminants (N);
1866 elsif Unknown_Discriminants_Present (N) then
1867 Set_Has_Unknown_Discriminants (Id);
1870 Set_Private_Dependents (Id, New_Elmt_List);
1872 if Tagged_Present (Def) then
1873 Set_Ekind (Id, E_Record_Type_With_Private);
1874 Make_Class_Wide_Type (Id);
1875 Set_Primitive_Operations (Id, New_Elmt_List);
1876 Set_Is_Abstract_Type (Id, Abstract_Present (Def));
1877 Set_Is_Limited_Record (Id, Limited_Present (Def));
1878 Set_Has_Delayed_Freeze (Id, True);
1880 elsif Abstract_Present (Def) then
1881 Error_Msg_N ("only a tagged type can be abstract", N);
1883 end New_Private_Type;
1885 ----------------------------
1886 -- Uninstall_Declarations --
1887 ----------------------------
1889 procedure Uninstall_Declarations (P : Entity_Id) is
1890 Decl : constant Node_Id := Unit_Declaration_Node (P);
1893 Priv_Elmt : Elmt_Id;
1894 Priv_Sub : Entity_Id;
1896 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id);
1897 -- Copy to the private declaration the attributes of the full view that
1898 -- need to be available for the partial view also.
1900 function Type_In_Use (T : Entity_Id) return Boolean;
1901 -- Check whether type or base type appear in an active use_type clause
1903 ------------------------------
1904 -- Preserve_Full_Attributes --
1905 ------------------------------
1907 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id) is
1908 Priv_Is_Base_Type : constant Boolean := Priv = Base_Type (Priv);
1911 Set_Size_Info (Priv, (Full));
1912 Set_RM_Size (Priv, RM_Size (Full));
1913 Set_Size_Known_At_Compile_Time
1914 (Priv, Size_Known_At_Compile_Time (Full));
1915 Set_Is_Volatile (Priv, Is_Volatile (Full));
1916 Set_Treat_As_Volatile (Priv, Treat_As_Volatile (Full));
1917 Set_Is_Ada_2005_Only (Priv, Is_Ada_2005_Only (Full));
1918 Set_Has_Pragma_Unreferenced (Priv, Has_Pragma_Unreferenced (Full));
1919 Set_Has_Pragma_Unreferenced_Objects
1920 (Priv, Has_Pragma_Unreferenced_Objects
1922 if Is_Unchecked_Union (Full) then
1923 Set_Is_Unchecked_Union (Base_Type (Priv));
1925 -- Why is atomic not copied here ???
1927 if Referenced (Full) then
1928 Set_Referenced (Priv);
1931 if Priv_Is_Base_Type then
1932 Set_Is_Controlled (Priv, Is_Controlled (Base_Type (Full)));
1933 Set_Finalize_Storage_Only (Priv, Finalize_Storage_Only
1934 (Base_Type (Full)));
1935 Set_Has_Task (Priv, Has_Task (Base_Type (Full)));
1936 Set_Has_Controlled_Component (Priv, Has_Controlled_Component
1937 (Base_Type (Full)));
1940 Set_Freeze_Node (Priv, Freeze_Node (Full));
1942 if Is_Tagged_Type (Priv)
1943 and then Is_Tagged_Type (Full)
1944 and then not Error_Posted (Full)
1946 if Priv_Is_Base_Type then
1948 -- Ada 2005 (AI-345): The full view of a type implementing an
1949 -- interface can be a task type.
1951 -- type T is new I with private;
1953 -- task type T is new I with ...
1955 if Is_Interface (Etype (Priv))
1956 and then Is_Concurrent_Type (Base_Type (Full))
1958 -- Protect the frontend against previous errors
1960 if Present (Corresponding_Record_Type
1963 Set_Access_Disp_Table
1964 (Priv, Access_Disp_Table
1965 (Corresponding_Record_Type (Base_Type (Full))));
1967 -- Generic context, or previous errors
1974 Set_Access_Disp_Table
1975 (Priv, Access_Disp_Table (Base_Type (Full)));
1979 if Is_Tagged_Type (Priv) then
1981 -- If the type is tagged, the tag itself must be available on
1982 -- the partial view, for expansion purposes.
1984 Set_First_Entity (Priv, First_Entity (Full));
1986 -- If there are discriminants in the partial view, these remain
1987 -- visible. Otherwise only the tag itself is visible, and there
1988 -- are no nameable components in the partial view.
1990 if No (Last_Entity (Priv)) then
1991 Set_Last_Entity (Priv, First_Entity (Priv));
1995 Set_Has_Discriminants (Priv, Has_Discriminants (Full));
1997 end Preserve_Full_Attributes;
2003 function Type_In_Use (T : Entity_Id) return Boolean is
2005 return Scope (Base_Type (T)) = P
2006 and then (In_Use (T) or else In_Use (Base_Type (T)));
2009 -- Start of processing for Uninstall_Declarations
2012 Id := First_Entity (P);
2013 while Present (Id) and then Id /= First_Private_Entity (P) loop
2014 if Debug_Flag_E then
2015 Write_Str ("unlinking visible entity ");
2016 Write_Int (Int (Id));
2020 -- On exit from the package scope, we must preserve the visibility
2021 -- established by use clauses in the current scope. Two cases:
2023 -- a) If the entity is an operator, it may be a primitive operator of
2024 -- a type for which there is a visible use-type clause.
2026 -- b) for other entities, their use-visibility is determined by a
2027 -- visible use clause for the package itself. For a generic instance,
2028 -- the instantiation of the formals appears in the visible part,
2029 -- but the formals are private and remain so.
2031 if Ekind (Id) = E_Function
2032 and then Is_Operator_Symbol_Name (Chars (Id))
2033 and then not Is_Hidden (Id)
2034 and then not Error_Posted (Id)
2036 Set_Is_Potentially_Use_Visible (Id,
2038 or else Type_In_Use (Etype (Id))
2039 or else Type_In_Use (Etype (First_Formal (Id)))
2040 or else (Present (Next_Formal (First_Formal (Id)))
2043 (Etype (Next_Formal (First_Formal (Id))))));
2045 if In_Use (P) and then not Is_Hidden (Id) then
2047 -- A child unit of a use-visible package remains use-visible
2048 -- only if it is itself a visible child unit. Otherwise it
2049 -- would remain visible in other contexts where P is use-
2050 -- visible, because once compiled it stays in the entity list
2051 -- of its parent unit.
2053 if Is_Child_Unit (Id) then
2054 Set_Is_Potentially_Use_Visible (Id,
2055 Is_Visible_Child_Unit (Id));
2057 Set_Is_Potentially_Use_Visible (Id);
2061 Set_Is_Potentially_Use_Visible (Id, False);
2065 -- Local entities are not immediately visible outside of the package
2067 Set_Is_Immediately_Visible (Id, False);
2069 -- If this is a private type with a full view (for example a local
2070 -- subtype of a private type declared elsewhere), ensure that the
2071 -- full view is also removed from visibility: it may be exposed when
2072 -- swapping views in an instantiation.
2075 and then Present (Full_View (Id))
2077 Set_Is_Immediately_Visible (Full_View (Id), False);
2080 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2081 Check_Abstract_Overriding (Id);
2082 Check_Conventions (Id);
2085 if (Ekind (Id) = E_Private_Type
2086 or else Ekind (Id) = E_Limited_Private_Type)
2087 and then No (Full_View (Id))
2088 and then not Is_Generic_Type (Id)
2089 and then not Is_Derived_Type (Id)
2091 Error_Msg_N ("missing full declaration for private type&", Id);
2093 elsif Ekind (Id) = E_Record_Type_With_Private
2094 and then not Is_Generic_Type (Id)
2095 and then No (Full_View (Id))
2097 if Nkind (Parent (Id)) = N_Private_Type_Declaration then
2098 Error_Msg_N ("missing full declaration for private type&", Id);
2101 ("missing full declaration for private extension", Id);
2104 elsif Ekind (Id) = E_Constant
2105 and then No (Constant_Value (Id))
2106 and then No (Full_View (Id))
2107 and then not Is_Imported (Id)
2108 and then (Nkind (Parent (Id)) /= N_Object_Declaration
2109 or else not No_Initialization (Parent (Id)))
2111 if not Has_Private_Declaration (Etype (Id)) then
2113 -- We assume that the user did not intend a deferred
2114 -- constant declaration, and the expression is just missing.
2117 ("constant declaration requires initialization expression",
2120 if Is_Limited_Type (Etype (Id)) then
2122 ("\if variable intended, remove CONSTANT from declaration",
2128 ("missing full declaration for deferred constant (RM 7.4)",
2131 if Is_Limited_Type (Etype (Id)) then
2133 ("\if variable intended, remove CONSTANT from declaration",
2142 -- If the specification was installed as the parent of a public child
2143 -- unit, the private declarations were not installed, and there is
2146 if not In_Private_Part (P) then
2149 Set_In_Private_Part (P, False);
2152 -- Make private entities invisible and exchange full and private
2153 -- declarations for private types. Id is now the first private entity
2156 while Present (Id) loop
2157 if Debug_Flag_E then
2158 Write_Str ("unlinking private entity ");
2159 Write_Int (Int (Id));
2163 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2164 Check_Abstract_Overriding (Id);
2165 Check_Conventions (Id);
2168 Set_Is_Immediately_Visible (Id, False);
2170 if Is_Private_Base_Type (Id)
2171 and then Present (Full_View (Id))
2173 Full := Full_View (Id);
2175 -- If the partial view is not declared in the visible part of the
2176 -- package (as is the case when it is a type derived from some
2177 -- other private type in the private part of the current package),
2178 -- no exchange takes place.
2181 or else List_Containing (Parent (Id))
2182 /= Visible_Declarations (Specification (Decl))
2187 -- The entry in the private part points to the full declaration,
2188 -- which is currently visible. Exchange them so only the private
2189 -- type declaration remains accessible, and link private and full
2190 -- declaration in the opposite direction. Before the actual
2191 -- exchange, we copy back attributes of the full view that must
2192 -- be available to the partial view too.
2194 Preserve_Full_Attributes (Id, Full);
2196 Set_Is_Potentially_Use_Visible (Id, In_Use (P));
2198 if Is_Indefinite_Subtype (Full)
2199 and then not Is_Indefinite_Subtype (Id)
2202 ("full view of type must be definite subtype", Full);
2205 Priv_Elmt := First_Elmt (Private_Dependents (Id));
2207 -- Swap out the subtypes and derived types of Id that were
2208 -- compiled in this scope, or installed previously by
2209 -- Install_Private_Declarations.
2211 -- Before we do the swap, we verify the presence of the Full_View
2212 -- field which may be empty due to a swap by a previous call to
2213 -- End_Package_Scope (e.g. from the freezing mechanism).
2215 while Present (Priv_Elmt) loop
2216 Priv_Sub := Node (Priv_Elmt);
2218 if Present (Full_View (Priv_Sub)) then
2220 if Scope (Priv_Sub) = P
2221 or else not In_Open_Scopes (Scope (Priv_Sub))
2223 Set_Is_Immediately_Visible (Priv_Sub, False);
2226 if Is_Visible_Dependent (Priv_Sub) then
2227 Preserve_Full_Attributes
2228 (Priv_Sub, Full_View (Priv_Sub));
2229 Replace_Elmt (Priv_Elmt, Full_View (Priv_Sub));
2230 Exchange_Declarations (Priv_Sub);
2234 Next_Elmt (Priv_Elmt);
2237 -- Now restore the type itself to its private view
2239 Exchange_Declarations (Id);
2241 -- If we have installed an underlying full view for a type derived
2242 -- from a private type in a child unit, restore the proper views
2243 -- of private and full view. See corresponding code in
2244 -- Install_Private_Declarations.
2246 -- After the exchange, Full denotes the private type in the
2247 -- visible part of the package.
2249 if Is_Private_Base_Type (Full)
2250 and then Present (Full_View (Full))
2251 and then Present (Underlying_Full_View (Full))
2252 and then In_Package_Body (Current_Scope)
2254 Set_Full_View (Full, Underlying_Full_View (Full));
2255 Set_Underlying_Full_View (Full, Empty);
2258 elsif Ekind (Id) = E_Incomplete_Type
2259 and then Comes_From_Source (Id)
2260 and then No (Full_View (Id))
2262 -- Mark Taft amendment types. Verify that there are no primitive
2263 -- operations declared for the type (3.10.1 (9)).
2265 Set_Has_Completion_In_Body (Id);
2272 Elmt := First_Elmt (Private_Dependents (Id));
2273 while Present (Elmt) loop
2274 Subp := Node (Elmt);
2276 if Is_Overloadable (Subp) then
2278 ("type& must be completed in the private part",
2281 -- The return type of an access_to_function cannot be a
2282 -- Taft-amendment type.
2284 elsif Ekind (Subp) = E_Subprogram_Type then
2285 if Etype (Subp) = Id
2287 (Is_Class_Wide_Type (Etype (Subp))
2288 and then Etype (Etype (Subp)) = Id)
2291 ("type& must be completed in the private part",
2292 Associated_Node_For_Itype (Subp), Id);
2300 elsif not Is_Child_Unit (Id)
2301 and then (not Is_Private_Type (Id)
2302 or else No (Full_View (Id)))
2305 Set_Is_Potentially_Use_Visible (Id, False);
2311 end Uninstall_Declarations;
2313 ------------------------
2314 -- Unit_Requires_Body --
2315 ------------------------
2317 function Unit_Requires_Body (P : Entity_Id) return Boolean is
2321 -- Imported entity never requires body. Right now, only subprograms can
2322 -- be imported, but perhaps in the future we will allow import of
2325 if Is_Imported (P) then
2328 -- Body required if library package with pragma Elaborate_Body
2330 elsif Has_Pragma_Elaborate_Body (P) then
2333 -- Body required if subprogram
2335 elsif Is_Subprogram (P) or else Is_Generic_Subprogram (P) then
2338 -- Treat a block as requiring a body
2340 elsif Ekind (P) = E_Block then
2343 elsif Ekind (P) = E_Package
2344 and then Nkind (Parent (P)) = N_Package_Specification
2345 and then Present (Generic_Parent (Parent (P)))
2348 G_P : constant Entity_Id := Generic_Parent (Parent (P));
2350 if Has_Pragma_Elaborate_Body (G_P) then
2356 -- Otherwise search entity chain for entity requiring completion
2358 E := First_Entity (P);
2359 while Present (E) loop
2361 -- Always ignore child units. Child units get added to the entity
2362 -- list of a parent unit, but are not original entities of the
2363 -- parent, and so do not affect whether the parent needs a body.
2365 if Is_Child_Unit (E) then
2368 -- Ignore formal packages and their renamings
2370 elsif Ekind (E) = E_Package
2371 and then Nkind (Original_Node (Unit_Declaration_Node (E))) =
2372 N_Formal_Package_Declaration
2376 -- Otherwise test to see if entity requires a completion.
2377 -- Note that subprogram entities whose declaration does not come
2378 -- from source are ignored here on the basis that we assume the
2379 -- expander will provide an implicit completion at some point.
2381 elsif (Is_Overloadable (E)
2382 and then Ekind (E) /= E_Enumeration_Literal
2383 and then Ekind (E) /= E_Operator
2384 and then not Is_Abstract_Subprogram (E)
2385 and then not Has_Completion (E)
2386 and then Comes_From_Source (Parent (E)))
2389 (Ekind (E) = E_Package
2391 and then not Has_Completion (E)
2392 and then Unit_Requires_Body (E))
2395 (Ekind (E) = E_Incomplete_Type and then No (Full_View (E)))
2398 ((Ekind (E) = E_Task_Type or else
2399 Ekind (E) = E_Protected_Type)
2400 and then not Has_Completion (E))
2403 (Ekind (E) = E_Generic_Package and then E /= P
2404 and then not Has_Completion (E)
2405 and then Unit_Requires_Body (E))
2408 (Is_Generic_Subprogram (E)
2409 and then not Has_Completion (E))
2414 -- Entity that does not require completion
2424 end Unit_Requires_Body;