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 Analyze_Package_Body_Helper (N : Node_Id);
94 -- Does all the real work of Analyze_Package_Body
96 procedure Check_Anonymous_Access_Types
99 -- If the spec of a package has a limited_with_clause, it may declare
100 -- anonymous access types whose designated type is a limited view, such an
101 -- anonymous access return type for a function. This access type cannot be
102 -- elaborated in the spec itself, but it may need an itype reference if it
103 -- is used within a nested scope. In that case the itype reference is
104 -- created at the beginning of the corresponding package body and inserted
105 -- before other body declarations.
107 procedure Install_Package_Entity (Id : Entity_Id);
108 -- Supporting procedure for Install_{Visible,Private}_Declarations. Places
109 -- one entity on its visibility chain, and recurses on the visible part if
110 -- the entity is an inner package.
112 function Is_Private_Base_Type (E : Entity_Id) return Boolean;
113 -- True for a private type that is not a subtype
115 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean;
116 -- If the private dependent is a private type whose full view is derived
117 -- from the parent type, its full properties are revealed only if we are in
118 -- the immediate scope of the private dependent. Should this predicate be
119 -- tightened further???
121 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id);
122 -- Called upon entering the private part of a public child package and the
123 -- body of a nested package, to potentially declare certain inherited
124 -- subprograms that were inherited by types in the visible part, but whose
125 -- declaration was deferred because the parent operation was private and
126 -- not visible at that point. These subprograms are located by traversing
127 -- the visible part declarations looking for non-private type extensions
128 -- and then examining each of the primitive operations of such types to
129 -- find those that were inherited but declared with a special internal
130 -- name. Each such operation is now declared as an operation with a normal
131 -- name (using the name of the parent operation) and replaces the previous
132 -- implicit operation in the primitive operations list of the type. If the
133 -- inherited private operation has been overridden, then it's replaced by
134 -- the overriding operation.
136 --------------------------
137 -- Analyze_Package_Body --
138 --------------------------
140 procedure Analyze_Package_Body (N : Node_Id) is
141 Loc : constant Source_Ptr := Sloc (N);
145 Write_Str ("==> package body ");
146 Write_Name (Chars (Defining_Entity (N)));
147 Write_Str (" from ");
148 Write_Location (Loc);
153 -- The real work is split out into the helper, so it can do "return;"
154 -- without skipping the debug output.
156 Analyze_Package_Body_Helper (N);
160 Write_Str ("<== package body ");
161 Write_Name (Chars (Defining_Entity (N)));
162 Write_Str (" from ");
163 Write_Location (Loc);
166 end Analyze_Package_Body;
168 ---------------------------------
169 -- Analyze_Package_Body_Helper --
170 ---------------------------------
172 procedure Analyze_Package_Body_Helper (N : Node_Id) is
176 Last_Spec_Entity : Entity_Id;
180 procedure Install_Composite_Operations (P : Entity_Id);
181 -- Composite types declared in the current scope may depend on types
182 -- that were private at the point of declaration, and whose full view
183 -- is now in scope. Indicate that the corresponding operations on the
184 -- composite type are available.
186 ----------------------------------
187 -- Install_Composite_Operations --
188 ----------------------------------
190 procedure Install_Composite_Operations (P : Entity_Id) is
194 Id := First_Entity (P);
195 while Present (Id) loop
197 and then (Is_Limited_Composite (Id)
198 or else Is_Private_Composite (Id))
199 and then No (Private_Component (Id))
201 Set_Is_Limited_Composite (Id, False);
202 Set_Is_Private_Composite (Id, False);
207 end Install_Composite_Operations;
209 -- Start of processing for Analyze_Package_Body_Helper
212 -- Find corresponding package specification, and establish the current
213 -- scope. The visible defining entity for the package is the defining
214 -- occurrence in the spec. On exit from the package body, all body
215 -- declarations are attached to the defining entity for the body, but
216 -- the later is never used for name resolution. In this fashion there
217 -- is only one visible entity that denotes the package.
219 -- Set Body_Id. Note that this Will be reset to point to the generic
220 -- copy later on in the generic case.
222 Body_Id := Defining_Entity (N);
224 if Present (Corresponding_Spec (N)) then
226 -- Body is body of package instantiation. Corresponding spec has
229 Spec_Id := Corresponding_Spec (N);
230 Pack_Decl := Unit_Declaration_Node (Spec_Id);
233 Spec_Id := Current_Entity_In_Scope (Defining_Entity (N));
236 and then Is_Package_Or_Generic_Package (Spec_Id)
238 Pack_Decl := Unit_Declaration_Node (Spec_Id);
240 if Nkind (Pack_Decl) = N_Package_Renaming_Declaration then
241 Error_Msg_N ("cannot supply body for package renaming", N);
244 elsif Present (Corresponding_Body (Pack_Decl)) then
245 Error_Msg_N ("redefinition of package body", N);
250 Error_Msg_N ("missing specification for package body", N);
254 if Is_Package_Or_Generic_Package (Spec_Id)
256 (Scope (Spec_Id) = Standard_Standard
257 or else Is_Child_Unit (Spec_Id))
258 and then not Unit_Requires_Body (Spec_Id)
260 if Ada_Version = Ada_83 then
262 ("optional package body (not allowed in Ada 95)?", N);
265 ("spec of this package does not allow a body", N);
270 Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
271 Style.Check_Identifier (Body_Id, Spec_Id);
273 if Is_Child_Unit (Spec_Id) then
274 if Nkind (Parent (N)) /= N_Compilation_Unit then
276 ("body of child unit& cannot be an inner package", N, Spec_Id);
279 Set_Is_Child_Unit (Body_Id);
282 -- Generic package case
284 if Ekind (Spec_Id) = E_Generic_Package then
286 -- Disable expansion and perform semantic analysis on copy. The
287 -- unannotated body will be used in all instantiations.
289 Body_Id := Defining_Entity (N);
290 Set_Ekind (Body_Id, E_Package_Body);
291 Set_Scope (Body_Id, Scope (Spec_Id));
292 Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id));
293 Set_Body_Entity (Spec_Id, Body_Id);
294 Set_Spec_Entity (Body_Id, Spec_Id);
296 New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
299 -- Update Body_Id to point to the copied node for the remainder of
302 Body_Id := Defining_Entity (N);
306 -- The Body_Id is that of the copied node in the generic case, the
307 -- current node otherwise. Note that N was rewritten above, so we must
308 -- be sure to get the latest Body_Id value.
310 Set_Ekind (Body_Id, E_Package_Body);
311 Set_Body_Entity (Spec_Id, Body_Id);
312 Set_Spec_Entity (Body_Id, Spec_Id);
314 -- Defining name for the package body is not a visible entity: Only the
315 -- defining name for the declaration is visible.
317 Set_Etype (Body_Id, Standard_Void_Type);
318 Set_Scope (Body_Id, Scope (Spec_Id));
319 Set_Corresponding_Spec (N, Spec_Id);
320 Set_Corresponding_Body (Pack_Decl, Body_Id);
322 -- The body entity is not used for semantics or code generation, but
323 -- it is attached to the entity list of the enclosing scope to simplify
324 -- the listing of back-annotations for the types it main contain.
326 if Scope (Spec_Id) /= Standard_Standard then
327 Append_Entity (Body_Id, Scope (Spec_Id));
330 -- Indicate that we are currently compiling the body of the package
332 Set_In_Package_Body (Spec_Id);
333 Set_Has_Completion (Spec_Id);
334 Last_Spec_Entity := Last_Entity (Spec_Id);
336 Push_Scope (Spec_Id);
338 Set_Categorization_From_Pragmas (N);
340 Install_Visible_Declarations (Spec_Id);
341 Install_Private_Declarations (Spec_Id);
342 Install_Private_With_Clauses (Spec_Id);
343 Install_Composite_Operations (Spec_Id);
345 Check_Anonymous_Access_Types (Spec_Id, N);
347 if Ekind (Spec_Id) = E_Generic_Package then
348 Set_Use (Generic_Formal_Declarations (Pack_Decl));
351 Set_Use (Visible_Declarations (Specification (Pack_Decl)));
352 Set_Use (Private_Declarations (Specification (Pack_Decl)));
354 -- This is a nested package, so it may be necessary to declare certain
355 -- inherited subprograms that are not yet visible because the parent
356 -- type's subprograms are now visible.
358 if Ekind (Scope (Spec_Id)) = E_Package
359 and then Scope (Spec_Id) /= Standard_Standard
361 Declare_Inherited_Private_Subprograms (Spec_Id);
364 if Present (Declarations (N)) then
365 Analyze_Declarations (Declarations (N));
366 Inspect_Deferred_Constant_Completion (Declarations (N));
369 -- Analyze_Declarations has caused freezing of all types. Now generate
370 -- bodies for RACW primitives and stream attributes, if any.
372 if Ekind (Spec_Id) = E_Package and then Has_RACW (Spec_Id) then
374 -- Attach subprogram bodies to support RACWs declared in spec
376 Append_RACW_Bodies (Declarations (N), Spec_Id);
377 Analyze_List (Declarations (N));
380 HSS := Handled_Statement_Sequence (N);
382 if Present (HSS) then
383 Process_End_Label (HSS, 't', Spec_Id);
386 -- Check that elaboration code in a preelaborable package body is
387 -- empty other than null statements and labels (RM 10.2.1(6)).
389 Validate_Null_Statement_Sequence (N);
392 Validate_Categorization_Dependency (N, Spec_Id);
393 Check_Completion (Body_Id);
395 -- Generate start of body reference. Note that we do this fairly late,
396 -- because the call will use In_Extended_Main_Source_Unit as a check,
397 -- and we want to make sure that Corresponding_Stub links are set
399 Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
401 -- For a generic package, collect global references and mark them on
402 -- the original body so that they are not resolved again at the point
405 if Ekind (Spec_Id) /= E_Package then
406 Save_Global_References (Original_Node (N));
410 -- The entities of the package body have so far been chained onto the
411 -- declaration chain for the spec. That's been fine while we were in the
412 -- body, since we wanted them to be visible, but now that we are leaving
413 -- the package body, they are no longer visible, so we remove them from
414 -- the entity chain of the package spec entity, and copy them to the
415 -- entity chain of the package body entity, where they will never again
418 if Present (Last_Spec_Entity) then
419 Set_First_Entity (Body_Id, Next_Entity (Last_Spec_Entity));
420 Set_Next_Entity (Last_Spec_Entity, Empty);
421 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
422 Set_Last_Entity (Spec_Id, Last_Spec_Entity);
425 Set_First_Entity (Body_Id, First_Entity (Spec_Id));
426 Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
427 Set_First_Entity (Spec_Id, Empty);
428 Set_Last_Entity (Spec_Id, Empty);
431 End_Package_Scope (Spec_Id);
433 -- All entities declared in body are not visible
439 E := First_Entity (Body_Id);
440 while Present (E) loop
441 Set_Is_Immediately_Visible (E, False);
442 Set_Is_Potentially_Use_Visible (E, False);
445 -- Child units may appear on the entity list (e.g. if they appear
446 -- in the context of a subunit) but they are not body entities.
448 if not Is_Child_Unit (E) then
449 Set_Is_Package_Body_Entity (E);
456 Check_References (Body_Id);
458 -- For a generic unit, check that the formal parameters are referenced,
459 -- and that local variables are used, as for regular packages.
461 if Ekind (Spec_Id) = E_Generic_Package then
462 Check_References (Spec_Id);
465 -- The processing so far has made all entities of the package body
466 -- public (i.e. externally visible to the linker). This is in general
467 -- necessary, since inlined or generic bodies, for which code is
468 -- generated in other units, may need to see these entities. The
469 -- following loop runs backwards from the end of the entities of the
470 -- package body making these entities invisible until we reach a
471 -- referencer, i.e. a declaration that could reference a previous
472 -- declaration, a generic body or an inlined body, or a stub (which may
473 -- contain either of these). This is of course an approximation, but it
474 -- is conservative and definitely correct.
476 -- We only do this at the outer (library) level non-generic packages.
477 -- The reason is simply to cut down on the number of external symbols
478 -- generated, so this is simply an optimization of the efficiency
479 -- of the compilation process. It has no other effect.
481 if (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id))
482 and then not Is_Generic_Unit (Spec_Id)
483 and then Present (Declarations (N))
485 Make_Non_Public_Where_Possible : declare
487 function Has_Referencer
491 -- Traverse the given list of declarations in reverse order.
492 -- Return True as soon as a referencer is reached. Return False if
493 -- none is found. The Outer parameter is True for the outer level
494 -- call, and False for inner level calls for nested packages. If
495 -- Outer is True, then any entities up to the point of hitting a
496 -- referencer get their Is_Public flag cleared, so that the
497 -- entities will be treated as static entities in the C sense, and
498 -- need not have fully qualified names. For inner levels, we need
499 -- all names to be fully qualified to deal with the same name
500 -- appearing in parallel packages (right now this is tied to their
507 function Has_Referencer
523 while Present (D) loop
526 if K in N_Body_Stub then
529 elsif K = N_Subprogram_Body then
530 if Acts_As_Spec (D) then
531 E := Defining_Entity (D);
533 -- An inlined body acts as a referencer. Note also
534 -- that we never reset Is_Public for an inlined
535 -- subprogram. Gigi requires Is_Public to be set.
537 -- Note that we test Has_Pragma_Inline here rather
538 -- than Is_Inlined. We are compiling this for a
539 -- client, and it is the client who will decide if
540 -- actual inlining should occur, so we need to assume
541 -- that the procedure could be inlined for the purpose
542 -- of accessing global entities.
544 if Has_Pragma_Inline (E) then
547 Set_Is_Public (E, False);
551 E := Corresponding_Spec (D);
554 and then (Is_Generic_Unit (E)
555 or else Has_Pragma_Inline (E)
556 or else Is_Inlined (E))
562 -- Processing for package bodies
564 elsif K = N_Package_Body
565 and then Present (Corresponding_Spec (D))
567 E := Corresponding_Spec (D);
569 -- Generic package body is a referencer. It would seem
570 -- that we only have to consider generics that can be
571 -- exported, i.e. where the corresponding spec is the
572 -- spec of the current package, but because of nested
573 -- instantiations, a fully private generic body may
574 -- export other private body entities.
576 if Is_Generic_Unit (E) then
579 -- For non-generic package body, recurse into body unless
580 -- this is an instance, we ignore instances since they
581 -- cannot have references that affect outer entities.
583 elsif not Is_Generic_Instance (E) then
585 (Declarations (D), Outer => False)
591 -- Processing for package specs, recurse into declarations.
592 -- Again we skip this for the case of generic instances.
594 elsif K = N_Package_Declaration then
595 S := Specification (D);
597 if not Is_Generic_Unit (Defining_Entity (S)) then
599 (Private_Declarations (S), Outer => False)
603 (Visible_Declarations (S), Outer => False)
609 -- Objects and exceptions need not be public if we have not
610 -- encountered a referencer so far. We only reset the flag
611 -- for outer level entities that are not imported/exported,
612 -- and which have no interface name.
614 elsif Nkind_In (K, N_Object_Declaration,
615 N_Exception_Declaration,
616 N_Subprogram_Declaration)
618 E := Defining_Entity (D);
621 and then not Is_Imported (E)
622 and then not Is_Exported (E)
623 and then No (Interface_Name (E))
625 Set_Is_Public (E, False);
635 -- Start of processing for Make_Non_Public_Where_Possible
640 pragma Warnings (Off, Discard);
643 Discard := Has_Referencer (Declarations (N), Outer => True);
645 end Make_Non_Public_Where_Possible;
648 -- If expander is not active, then here is where we turn off the
649 -- In_Package_Body flag, otherwise it is turned off at the end of the
650 -- corresponding expansion routine. If this is an instance body, we need
651 -- to qualify names of local entities, because the body may have been
652 -- compiled as a preliminary to another instantiation.
654 if not Expander_Active then
655 Set_In_Package_Body (Spec_Id, False);
657 if Is_Generic_Instance (Spec_Id)
658 and then Operating_Mode = Generate_Code
660 Qualify_Entity_Names (N);
663 end Analyze_Package_Body_Helper;
665 ---------------------------------
666 -- Analyze_Package_Declaration --
667 ---------------------------------
669 procedure Analyze_Package_Declaration (N : Node_Id) is
670 Id : constant Node_Id := Defining_Entity (N);
673 -- True when in the context of a declared pure library unit
675 Body_Required : Boolean;
676 -- True when this package declaration requires a corresponding body
679 -- True when this package declaration is not a nested declaration
682 -- Ada 2005 (AI-217): Check if the package has been erroneously named
683 -- in a limited-with clause of its own context. In this case the error
684 -- has been previously notified by Analyze_Context.
686 -- limited with Pkg; -- ERROR
687 -- package Pkg is ...
689 if From_With_Type (Id) then
694 Write_Str ("==> package spec ");
695 Write_Name (Chars (Id));
696 Write_Str (" from ");
697 Write_Location (Sloc (N));
702 Generate_Definition (Id);
704 Set_Ekind (Id, E_Package);
705 Set_Etype (Id, Standard_Void_Type);
709 PF := Is_Pure (Enclosing_Lib_Unit_Entity);
710 Set_Is_Pure (Id, PF);
712 Set_Categorization_From_Pragmas (N);
714 Analyze (Specification (N));
715 Validate_Categorization_Dependency (N, Id);
717 Body_Required := Unit_Requires_Body (Id);
719 -- When this spec does not require an explicit body, we know that there
720 -- are no entities requiring completion in the language sense; we call
721 -- Check_Completion here only to ensure that any nested package
722 -- declaration that requires an implicit body gets one. (In the case
723 -- where a body is required, Check_Completion is called at the end of
724 -- the body's declarative part.)
726 if not Body_Required then
730 Comp_Unit := Nkind (Parent (N)) = N_Compilation_Unit;
733 -- Set Body_Required indication on the compilation unit node, and
734 -- determine whether elaboration warnings may be meaningful on it.
736 Set_Body_Required (Parent (N), Body_Required);
738 if not Body_Required then
739 Set_Suppress_Elaboration_Warnings (Id);
744 End_Package_Scope (Id);
746 -- For the declaration of a library unit that is a remote types package,
747 -- check legality rules regarding availability of stream attributes for
748 -- types that contain non-remote access values. This subprogram performs
749 -- visibility tests that rely on the fact that we have exited the scope
753 Validate_RT_RAT_Component (N);
758 Write_Str ("<== package spec ");
759 Write_Name (Chars (Id));
760 Write_Str (" from ");
761 Write_Location (Sloc (N));
764 end Analyze_Package_Declaration;
766 -----------------------------------
767 -- Analyze_Package_Specification --
768 -----------------------------------
770 -- Note that this code is shared for the analysis of generic package specs
771 -- (see Sem_Ch12.Analyze_Generic_Package_Declaration for details).
773 procedure Analyze_Package_Specification (N : Node_Id) is
774 Id : constant Entity_Id := Defining_Entity (N);
775 Orig_Decl : constant Node_Id := Original_Node (Parent (N));
776 Vis_Decls : constant List_Id := Visible_Declarations (N);
777 Priv_Decls : constant List_Id := Private_Declarations (N);
780 Public_Child : Boolean;
782 Private_With_Clauses_Installed : Boolean := False;
783 -- In Ada 2005, private with_clauses are visible in the private part
784 -- of a nested package, even if it appears in the public part of the
785 -- enclosing package. This requires a separate step to install these
786 -- private_with_clauses, and remove them at the end of the nested
789 procedure Analyze_PPCs (Decls : List_Id);
790 -- Given a list of declarations, go through looking for subprogram
791 -- specs, and for each one found, analyze any pre/postconditions that
792 -- are chained to the spec. This is the implementation of the late
793 -- visibility analysis for preconditions and postconditions in specs.
795 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id);
796 -- Clears constant indications (Never_Set_In_Source, Constant_Value, and
797 -- Is_True_Constant) on all variables that are entities of Id, and on
798 -- the chain whose first element is FE. A recursive call is made for all
799 -- packages and generic packages.
801 procedure Generate_Parent_References;
802 -- For a child unit, generate references to parent units, for
803 -- GPS navigation purposes.
805 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean;
806 -- Child and Unit are entities of compilation units. True if Child
807 -- is a public child of Parent as defined in 10.1.1
809 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id);
810 -- Detects all incomplete or private type declarations having a known
811 -- discriminant part that are completed by an Unchecked_Union. Emits
812 -- the error message "Unchecked_Union may not complete discriminated
815 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id);
816 -- Given the package entity of a generic package instantiation or
817 -- formal package whose corresponding generic is a child unit, installs
818 -- the private declarations of each of the child unit's parents.
819 -- This has to be done at the point of entering the instance package's
820 -- private part rather than being done in Sem_Ch12.Install_Parent
821 -- (which is where the parents' visible declarations are installed).
827 procedure Analyze_PPCs (Decls : List_Id) is
834 Decl := First (Decls);
835 while Present (Decl) loop
836 if Nkind (Original_Node (Decl)) = N_Subprogram_Declaration then
837 Spec := Specification (Original_Node (Decl));
838 Sent := Defining_Unit_Name (Spec);
839 Prag := Spec_PPC_List (Sent);
840 while Present (Prag) loop
841 Analyze_PPC_In_Decl_Part (Prag, Sent);
842 Prag := Next_Pragma (Prag);
850 ---------------------
851 -- Clear_Constants --
852 ---------------------
854 procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id) is
858 -- Ignore package renamings, not interesting and they can cause self
859 -- referential loops in the code below.
861 if Nkind (Parent (Id)) = N_Package_Renaming_Declaration then
865 -- Note: in the loop below, the check for Next_Entity pointing back
866 -- to the package entity may seem odd, but it is needed, because a
867 -- package can contain a renaming declaration to itself, and such
868 -- renamings are generated automatically within package instances.
871 while Present (E) and then E /= Id loop
872 if Is_Assignable (E) then
873 Set_Never_Set_In_Source (E, False);
874 Set_Is_True_Constant (E, False);
875 Set_Current_Value (E, Empty);
876 Set_Is_Known_Null (E, False);
877 Set_Last_Assignment (E, Empty);
879 if not Can_Never_Be_Null (E) then
880 Set_Is_Known_Non_Null (E, False);
883 elsif Is_Package_Or_Generic_Package (E) then
884 Clear_Constants (E, First_Entity (E));
885 Clear_Constants (E, First_Private_Entity (E));
892 --------------------------------
893 -- Generate_Parent_References --
894 --------------------------------
896 procedure Generate_Parent_References is
897 Decl : constant Node_Id := Parent (N);
900 if Id = Cunit_Entity (Main_Unit)
901 or else Parent (Decl) = Library_Unit (Cunit (Main_Unit))
903 Generate_Reference (Id, Scope (Id), 'k', False);
905 elsif not Nkind_In (Unit (Cunit (Main_Unit)), N_Subprogram_Body,
908 -- If current unit is an ancestor of main unit, generate a
909 -- reference to its own parent.
913 Main_Spec : Node_Id := Unit (Cunit (Main_Unit));
916 if Nkind (Main_Spec) = N_Package_Body then
917 Main_Spec := Unit (Library_Unit (Cunit (Main_Unit)));
920 U := Parent_Spec (Main_Spec);
921 while Present (U) loop
922 if U = Parent (Decl) then
923 Generate_Reference (Id, Scope (Id), 'k', False);
926 elsif Nkind (Unit (U)) = N_Package_Body then
930 U := Parent_Spec (Unit (U));
935 end Generate_Parent_References;
937 ---------------------
938 -- Is_Public_Child --
939 ---------------------
941 function Is_Public_Child (Child, Unit : Entity_Id) return Boolean is
943 if not Is_Private_Descendant (Child) then
947 return not Private_Present (
948 Parent (Unit_Declaration_Node (Child)));
950 return Is_Public_Child (Scope (Child), Unit);
955 ----------------------------------------
956 -- Inspect_Unchecked_Union_Completion --
957 ----------------------------------------
959 procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is
963 Decl := First (Decls);
964 while Present (Decl) loop
966 -- We are looking at an incomplete or private type declaration
967 -- with a known_discriminant_part whose full view is an
970 if Nkind_In (Decl, N_Incomplete_Type_Declaration,
971 N_Private_Type_Declaration)
972 and then Has_Discriminants (Defining_Identifier (Decl))
973 and then Present (Full_View (Defining_Identifier (Decl)))
975 Is_Unchecked_Union (Full_View (Defining_Identifier (Decl)))
978 ("completion of discriminated partial view "
979 & "cannot be an Unchecked_Union",
980 Full_View (Defining_Identifier (Decl)));
985 end Inspect_Unchecked_Union_Completion;
987 -----------------------------------------
988 -- Install_Parent_Private_Declarations --
989 -----------------------------------------
991 procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id) is
992 Inst_Par : Entity_Id;
1000 Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par)));
1001 while Present (Gen_Par) and then Is_Child_Unit (Gen_Par) loop
1002 Inst_Node := Get_Package_Instantiation_Node (Inst_Par);
1004 if Nkind_In (Inst_Node, N_Package_Instantiation,
1005 N_Formal_Package_Declaration)
1006 and then Nkind (Name (Inst_Node)) = N_Expanded_Name
1008 Inst_Par := Entity (Prefix (Name (Inst_Node)));
1010 if Present (Renamed_Entity (Inst_Par)) then
1011 Inst_Par := Renamed_Entity (Inst_Par);
1016 (Specification (Unit_Declaration_Node (Inst_Par)));
1018 -- Install the private declarations and private use clauses
1019 -- of a parent instance of the child instance, unless the
1020 -- parent instance private declarations have already been
1021 -- installed earlier in Analyze_Package_Specification, which
1022 -- happens when a generic child is instantiated, and the
1023 -- instance is a child of the parent instance.
1025 -- Installing the use clauses of the parent instance twice
1026 -- is both unnecessary and wrong, because it would cause the
1027 -- clauses to be chained to themselves in the use clauses
1028 -- list of the scope stack entry. That in turn would cause
1029 -- an endless loop from End_Use_Clauses upon scope exit.
1031 -- The parent is now fully visible. It may be a hidden open
1032 -- scope if we are currently compiling some child instance
1033 -- declared within it, but while the current instance is being
1034 -- compiled the parent is immediately visible. In particular
1035 -- its entities must remain visible if a stack save/restore
1036 -- takes place through a call to Rtsfind.
1038 if Present (Gen_Par) then
1039 if not In_Private_Part (Inst_Par) then
1040 Install_Private_Declarations (Inst_Par);
1041 Set_Use (Private_Declarations
1043 (Unit_Declaration_Node (Inst_Par))));
1044 Set_Is_Hidden_Open_Scope (Inst_Par, False);
1047 -- If we've reached the end of the generic instance parents,
1048 -- then finish off by looping through the nongeneric parents
1049 -- and installing their private declarations.
1052 while Present (Inst_Par)
1053 and then Inst_Par /= Standard_Standard
1054 and then (not In_Open_Scopes (Inst_Par)
1055 or else not In_Private_Part (Inst_Par))
1057 Install_Private_Declarations (Inst_Par);
1058 Set_Use (Private_Declarations
1060 (Unit_Declaration_Node (Inst_Par))));
1061 Inst_Par := Scope (Inst_Par);
1071 end Install_Parent_Private_Declarations;
1073 -- Start of processing for Analyze_Package_Specification
1076 if Present (Vis_Decls) then
1077 Analyze_Declarations (Vis_Decls);
1078 Analyze_PPCs (Vis_Decls);
1081 -- Verify that incomplete types have received full declarations
1083 E := First_Entity (Id);
1084 while Present (E) loop
1085 if Ekind (E) = E_Incomplete_Type
1086 and then No (Full_View (E))
1088 Error_Msg_N ("no declaration in visible part for incomplete}", E);
1094 if Is_Remote_Call_Interface (Id)
1095 and then Nkind (Parent (Parent (N))) = N_Compilation_Unit
1097 Validate_RCI_Declarations (Id);
1100 -- Save global references in the visible declarations, before installing
1101 -- private declarations of parent unit if there is one, because the
1102 -- privacy status of types defined in the parent will change. This is
1103 -- only relevant for generic child units, but is done in all cases for
1106 if Ekind (Id) = E_Generic_Package
1107 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1110 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1111 Save_Priv : constant List_Id := Private_Declarations (Orig_Spec);
1114 Set_Private_Declarations (Orig_Spec, Empty_List);
1115 Save_Global_References (Orig_Decl);
1116 Set_Private_Declarations (Orig_Spec, Save_Priv);
1120 -- If package is a public child unit, then make the private declarations
1121 -- of the parent visible.
1123 Public_Child := False;
1127 Pack_Decl : Node_Id;
1132 Par_Spec := Parent_Spec (Parent (N));
1134 -- If the package is formal package of an enclosing generic, it is
1135 -- transformed into a local generic declaration, and compiled to make
1136 -- its spec available. We need to retrieve the original generic to
1137 -- determine whether it is a child unit, and install its parents.
1141 Nkind (Original_Node (Parent (N))) = N_Formal_Package_Declaration
1143 Par := Entity (Name (Original_Node (Parent (N))));
1144 Par_Spec := Parent_Spec (Unit_Declaration_Node (Par));
1147 if Present (Par_Spec) then
1148 Generate_Parent_References;
1150 while Scope (Par) /= Standard_Standard
1151 and then Is_Public_Child (Id, Par)
1152 and then In_Open_Scopes (Par)
1154 Public_Child := True;
1156 Install_Private_Declarations (Par);
1157 Install_Private_With_Clauses (Par);
1158 Pack_Decl := Unit_Declaration_Node (Par);
1159 Set_Use (Private_Declarations (Specification (Pack_Decl)));
1164 if Is_Compilation_Unit (Id) then
1165 Install_Private_With_Clauses (Id);
1168 -- The current compilation unit may include private with_clauses,
1169 -- which are visible in the private part of the current nested
1170 -- package, and have to be installed now. This is not done for
1171 -- nested instantiations, where the private with_clauses of the
1172 -- enclosing unit have no effect once the instantiation info is
1173 -- established and we start analyzing the package declaration.
1176 Comp_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
1178 if Is_Package_Or_Generic_Package (Comp_Unit)
1179 and then not In_Private_Part (Comp_Unit)
1180 and then not In_Instance
1182 Install_Private_With_Clauses (Comp_Unit);
1183 Private_With_Clauses_Installed := True;
1188 -- If this is a package associated with a generic instance or formal
1189 -- package, then the private declarations of each of the generic's
1190 -- parents must be installed at this point.
1192 if Is_Generic_Instance (Id) then
1193 Install_Parent_Private_Declarations (Id);
1196 -- Analyze private part if present. The flag In_Private_Part is reset
1197 -- in End_Package_Scope.
1199 L := Last_Entity (Id);
1201 if Present (Priv_Decls) then
1202 Set_In_Private_Part (Id);
1204 -- Upon entering a public child's private part, it may be necessary
1205 -- to declare subprograms that were derived in the package's visible
1206 -- part but not yet made visible.
1208 if Public_Child then
1209 Declare_Inherited_Private_Subprograms (Id);
1212 Analyze_Declarations (Priv_Decls);
1213 Analyze_PPCs (Priv_Decls);
1215 -- Check the private declarations for incomplete deferred constants
1217 Inspect_Deferred_Constant_Completion (Priv_Decls);
1219 -- The first private entity is the immediate follower of the last
1220 -- visible entity, if there was one.
1223 Set_First_Private_Entity (Id, Next_Entity (L));
1225 Set_First_Private_Entity (Id, First_Entity (Id));
1228 -- There may be inherited private subprograms that need to be declared,
1229 -- even in the absence of an explicit private part. If there are any
1230 -- public declarations in the package and the package is a public child
1231 -- unit, then an implicit private part is assumed.
1233 elsif Present (L) and then Public_Child then
1234 Set_In_Private_Part (Id);
1235 Declare_Inherited_Private_Subprograms (Id);
1236 Set_First_Private_Entity (Id, Next_Entity (L));
1239 E := First_Entity (Id);
1240 while Present (E) loop
1242 -- Check rule of 3.6(11), which in general requires waiting till all
1243 -- full types have been seen.
1245 if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then
1246 Check_Aliased_Component_Types (E);
1249 -- Check preelaborable initialization for full type completing a
1250 -- private type for which pragma Preelaborable_Initialization given.
1253 and then Must_Have_Preelab_Init (E)
1254 and then not Has_Preelaborable_Initialization (E)
1257 ("full view of & does not have preelaborable initialization", E);
1263 -- Ada 2005 (AI-216): The completion of an incomplete or private type
1264 -- declaration having a known_discriminant_part shall not be an
1265 -- Unchecked_Union type.
1267 if Present (Vis_Decls) then
1268 Inspect_Unchecked_Union_Completion (Vis_Decls);
1271 if Present (Priv_Decls) then
1272 Inspect_Unchecked_Union_Completion (Priv_Decls);
1275 if Ekind (Id) = E_Generic_Package
1276 and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
1277 and then Present (Priv_Decls)
1279 -- Save global references in private declarations, ignoring the
1280 -- visible declarations that were processed earlier.
1283 Orig_Spec : constant Node_Id := Specification (Orig_Decl);
1284 Save_Vis : constant List_Id := Visible_Declarations (Orig_Spec);
1285 Save_Form : constant List_Id :=
1286 Generic_Formal_Declarations (Orig_Decl);
1289 Set_Visible_Declarations (Orig_Spec, Empty_List);
1290 Set_Generic_Formal_Declarations (Orig_Decl, Empty_List);
1291 Save_Global_References (Orig_Decl);
1292 Set_Generic_Formal_Declarations (Orig_Decl, Save_Form);
1293 Set_Visible_Declarations (Orig_Spec, Save_Vis);
1297 Process_End_Label (N, 'e', Id);
1299 -- Remove private_with_clauses of enclosing compilation unit, if they
1302 if Private_With_Clauses_Installed then
1303 Remove_Private_With_Clauses (Cunit (Current_Sem_Unit));
1306 -- For the case of a library level package, we must go through all the
1307 -- entities clearing the indications that the value may be constant and
1308 -- not modified. Why? Because any client of this package may modify
1309 -- these values freely from anywhere. This also applies to any nested
1310 -- packages or generic packages.
1312 -- For now we unconditionally clear constants for packages that are
1313 -- instances of generic packages. The reason is that we do not have the
1314 -- body yet, and we otherwise think things are unreferenced when they
1315 -- are not. This should be fixed sometime (the effect is not terrible,
1316 -- we just lose some warnings, and also some cases of value propagation)
1319 if Is_Library_Level_Entity (Id)
1320 or else Is_Generic_Instance (Id)
1322 Clear_Constants (Id, First_Entity (Id));
1323 Clear_Constants (Id, First_Private_Entity (Id));
1325 end Analyze_Package_Specification;
1327 --------------------------------------
1328 -- Analyze_Private_Type_Declaration --
1329 --------------------------------------
1331 procedure Analyze_Private_Type_Declaration (N : Node_Id) is
1332 PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity);
1333 Id : constant Entity_Id := Defining_Identifier (N);
1336 Generate_Definition (Id);
1337 Set_Is_Pure (Id, PF);
1338 Init_Size_Align (Id);
1340 if not Is_Package_Or_Generic_Package (Current_Scope)
1341 or else In_Private_Part (Current_Scope)
1343 Error_Msg_N ("invalid context for private declaration", N);
1346 New_Private_Type (N, Id, N);
1347 Set_Depends_On_Private (Id);
1348 end Analyze_Private_Type_Declaration;
1350 ----------------------------------
1351 -- Check_Anonymous_Access_Types --
1352 ----------------------------------
1354 procedure Check_Anonymous_Access_Types
1355 (Spec_Id : Entity_Id;
1362 -- Itype references are only needed by gigi, to force elaboration of
1363 -- itypes. In the absence of code generation, they are not needed.
1365 if not Expander_Active then
1369 E := First_Entity (Spec_Id);
1370 while Present (E) loop
1371 if Ekind (E) = E_Anonymous_Access_Type
1372 and then From_With_Type (E)
1374 IR := Make_Itype_Reference (Sloc (P_Body));
1377 if No (Declarations (P_Body)) then
1378 Set_Declarations (P_Body, New_List (IR));
1380 Prepend (IR, Declarations (P_Body));
1386 end Check_Anonymous_Access_Types;
1388 -------------------------------------------
1389 -- Declare_Inherited_Private_Subprograms --
1390 -------------------------------------------
1392 procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is
1394 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean;
1395 -- Check whether an inherited subprogram is an operation of an untagged
1398 ---------------------
1399 -- Is_Primitive_Of --
1400 ---------------------
1402 function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is
1406 -- If the full view is a scalar type, the type is the anonymous base
1407 -- type, but the operation mentions the first subtype, so check the
1408 -- signature against the base type.
1410 if Base_Type (Etype (S)) = Base_Type (T) then
1414 Formal := First_Formal (S);
1415 while Present (Formal) loop
1416 if Base_Type (Etype (Formal)) = Base_Type (T) then
1420 Next_Formal (Formal);
1425 end Is_Primitive_Of;
1432 Op_Elmt_2 : Elmt_Id;
1433 Prim_Op : Entity_Id;
1434 New_Op : Entity_Id := Empty;
1435 Parent_Subp : Entity_Id;
1438 -- Start of processing for Declare_Inherited_Private_Subprograms
1441 E := First_Entity (Id);
1442 while Present (E) loop
1444 -- If the entity is a nonprivate type extension whose parent type
1445 -- is declared in an open scope, then the type may have inherited
1446 -- operations that now need to be made visible. Ditto if the entity
1447 -- is a formal derived type in a child unit.
1449 if ((Is_Derived_Type (E) and then not Is_Private_Type (E))
1451 (Nkind (Parent (E)) = N_Private_Extension_Declaration
1452 and then Is_Generic_Type (E)))
1453 and then In_Open_Scopes (Scope (Etype (E)))
1454 and then E = Base_Type (E)
1456 if Is_Tagged_Type (E) then
1457 Op_List := Primitive_Operations (E);
1459 Tag := First_Tag_Component (E);
1461 Op_Elmt := First_Elmt (Op_List);
1462 while Present (Op_Elmt) loop
1463 Prim_Op := Node (Op_Elmt);
1465 -- Search primitives that are implicit operations with an
1466 -- internal name whose parent operation has a normal name.
1468 if Present (Alias (Prim_Op))
1469 and then Find_Dispatching_Type (Alias (Prim_Op)) /= E
1470 and then not Comes_From_Source (Prim_Op)
1471 and then Is_Internal_Name (Chars (Prim_Op))
1472 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1474 Parent_Subp := Alias (Prim_Op);
1476 -- Case 1: Check if the type has also an explicit
1477 -- overriding for this primitive.
1479 Op_Elmt_2 := Next_Elmt (Op_Elmt);
1480 while Present (Op_Elmt_2) loop
1481 if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp)
1482 and then Type_Conformant (Prim_Op, Node (Op_Elmt_2))
1484 -- The private inherited operation has been
1485 -- overridden by an explicit subprogram: replace
1486 -- the former by the latter.
1488 New_Op := Node (Op_Elmt_2);
1489 Replace_Elmt (Op_Elmt, New_Op);
1490 Remove_Elmt (Op_List, Op_Elmt_2);
1491 Set_Is_Overriding_Operation (New_Op);
1492 Set_Overridden_Operation (New_Op, Parent_Subp);
1494 -- We don't need to inherit its dispatching slot.
1495 -- Set_All_DT_Position has previously ensured that
1496 -- the same slot was assigned to the two primitives
1499 and then Present (DTC_Entity (New_Op))
1500 and then Present (DTC_Entity (Prim_Op))
1502 pragma Assert (DT_Position (New_Op)
1503 = DT_Position (Prim_Op));
1507 goto Next_Primitive;
1510 Next_Elmt (Op_Elmt_2);
1513 -- Case 2: We have not found any explicit overriding and
1514 -- hence we need to declare the operation (i.e., make it
1517 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1519 -- Inherit the dispatching slot if E is already frozen
1522 and then Present (DTC_Entity (Alias (Prim_Op)))
1524 Set_DTC_Entity_Value (E, New_Op);
1525 Set_DT_Position (New_Op,
1526 DT_Position (Alias (Prim_Op)));
1530 (Is_Dispatching_Operation (New_Op)
1531 and then Node (Last_Elmt (Op_List)) = New_Op);
1533 -- Substitute the new operation for the old one in the
1534 -- type's primitive operations list. Since the new
1535 -- operation was also just added to the end of list,
1536 -- the last element must be removed.
1538 -- (Question: is there a simpler way of declaring the
1539 -- operation, say by just replacing the name of the
1540 -- earlier operation, reentering it in the in the symbol
1541 -- table (how?), and marking it as private???)
1543 Replace_Elmt (Op_Elmt, New_Op);
1544 Remove_Last_Elmt (Op_List);
1548 Next_Elmt (Op_Elmt);
1551 -- Generate listing showing the contents of the dispatch table
1553 if Debug_Flag_ZZ then
1558 -- Non-tagged type, scan forward to locate inherited hidden
1561 Prim_Op := Next_Entity (E);
1562 while Present (Prim_Op) loop
1563 if Is_Subprogram (Prim_Op)
1564 and then Present (Alias (Prim_Op))
1565 and then not Comes_From_Source (Prim_Op)
1566 and then Is_Internal_Name (Chars (Prim_Op))
1567 and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
1568 and then Is_Primitive_Of (E, Prim_Op)
1570 Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
1573 Next_Entity (Prim_Op);
1580 end Declare_Inherited_Private_Subprograms;
1582 -----------------------
1583 -- End_Package_Scope --
1584 -----------------------
1586 procedure End_Package_Scope (P : Entity_Id) is
1588 Uninstall_Declarations (P);
1590 end End_Package_Scope;
1592 ---------------------------
1593 -- Exchange_Declarations --
1594 ---------------------------
1596 procedure Exchange_Declarations (Id : Entity_Id) is
1597 Full_Id : constant Entity_Id := Full_View (Id);
1598 H1 : constant Entity_Id := Homonym (Id);
1599 Next1 : constant Entity_Id := Next_Entity (Id);
1604 -- If missing full declaration for type, nothing to exchange
1606 if No (Full_Id) then
1610 -- Otherwise complete the exchange, and preserve semantic links
1612 Next2 := Next_Entity (Full_Id);
1613 H2 := Homonym (Full_Id);
1615 -- Reset full declaration pointer to reflect the switched entities and
1616 -- readjust the next entity chains.
1618 Exchange_Entities (Id, Full_Id);
1620 Set_Next_Entity (Id, Next1);
1621 Set_Homonym (Id, H1);
1623 Set_Full_View (Full_Id, Id);
1624 Set_Next_Entity (Full_Id, Next2);
1625 Set_Homonym (Full_Id, H2);
1626 end Exchange_Declarations;
1628 ----------------------------
1629 -- Install_Package_Entity --
1630 ----------------------------
1632 procedure Install_Package_Entity (Id : Entity_Id) is
1634 if not Is_Internal (Id) then
1635 if Debug_Flag_E then
1636 Write_Str ("Install: ");
1637 Write_Name (Chars (Id));
1641 if not Is_Child_Unit (Id) then
1642 Set_Is_Immediately_Visible (Id);
1646 end Install_Package_Entity;
1648 ----------------------------------
1649 -- Install_Private_Declarations --
1650 ----------------------------------
1652 procedure Install_Private_Declarations (P : Entity_Id) is
1654 Priv_Elmt : Elmt_Id;
1659 -- First exchange declarations for private types, so that the full
1660 -- declaration is visible. For each private type, we check its
1661 -- Private_Dependents list and also exchange any subtypes of or derived
1662 -- types from it. Finally, if this is a Taft amendment type, the
1663 -- incomplete declaration is irrelevant, and we want to link the
1664 -- eventual full declaration with the original private one so we also
1665 -- skip the exchange.
1667 Id := First_Entity (P);
1668 while Present (Id) and then Id /= First_Private_Entity (P) loop
1669 if Is_Private_Base_Type (Id)
1670 and then Comes_From_Source (Full_View (Id))
1671 and then Present (Full_View (Id))
1672 and then Scope (Full_View (Id)) = Scope (Id)
1673 and then Ekind (Full_View (Id)) /= E_Incomplete_Type
1675 -- If there is a use-type clause on the private type, set the
1676 -- full view accordingly.
1678 Set_In_Use (Full_View (Id), In_Use (Id));
1679 Full := Full_View (Id);
1681 if Is_Private_Base_Type (Full)
1682 and then Has_Private_Declaration (Full)
1683 and then Nkind (Parent (Full)) = N_Full_Type_Declaration
1684 and then In_Open_Scopes (Scope (Etype (Full)))
1685 and then In_Package_Body (Current_Scope)
1686 and then not Is_Private_Type (Etype (Full))
1688 -- This is the completion of a private type by a derivation
1689 -- from another private type which is not private anymore. This
1690 -- can only happen in a package nested within a child package,
1691 -- when the parent type is defined in the parent unit. At this
1692 -- point the current type is not private either, and we have to
1693 -- install the underlying full view, which is now visible. Save
1694 -- the current full view as well, so that all views can be
1695 -- restored on exit. It may seem that after compiling the child
1696 -- body there are not environments to restore, but the back-end
1697 -- expects those links to be valid, and freeze nodes depend on
1700 if No (Full_View (Full))
1701 and then Present (Underlying_Full_View (Full))
1703 Set_Full_View (Id, Underlying_Full_View (Full));
1704 Set_Underlying_Full_View (Id, Full);
1706 Set_Underlying_Full_View (Full, Empty);
1707 Set_Is_Frozen (Full_View (Id));
1711 Priv_Elmt := First_Elmt (Private_Dependents (Id));
1713 Exchange_Declarations (Id);
1714 Set_Is_Immediately_Visible (Id);
1716 while Present (Priv_Elmt) loop
1717 Priv := Node (Priv_Elmt);
1719 -- Before the exchange, verify that the presence of the
1720 -- Full_View field. It will be empty if the entity has already
1721 -- been installed due to a previous call.
1723 if Present (Full_View (Priv))
1724 and then Is_Visible_Dependent (Priv)
1727 -- For each subtype that is swapped, we also swap the
1728 -- reference to it in Private_Dependents, to allow access
1729 -- to it when we swap them out in End_Package_Scope.
1731 Replace_Elmt (Priv_Elmt, Full_View (Priv));
1732 Exchange_Declarations (Priv);
1733 Set_Is_Immediately_Visible
1734 (Priv, In_Open_Scopes (Scope (Priv)));
1735 Set_Is_Potentially_Use_Visible
1736 (Priv, Is_Potentially_Use_Visible (Node (Priv_Elmt)));
1739 Next_Elmt (Priv_Elmt);
1746 -- Next make other declarations in the private part visible as well
1748 Id := First_Private_Entity (P);
1749 while Present (Id) loop
1750 Install_Package_Entity (Id);
1751 Set_Is_Hidden (Id, False);
1755 -- Indicate that the private part is currently visible, so it can be
1756 -- properly reset on exit.
1758 Set_In_Private_Part (P);
1759 end Install_Private_Declarations;
1761 ----------------------------------
1762 -- Install_Visible_Declarations --
1763 ----------------------------------
1765 procedure Install_Visible_Declarations (P : Entity_Id) is
1767 Last_Entity : Entity_Id;
1771 (Is_Package_Or_Generic_Package (P) or else Is_Record_Type (P));
1773 if Is_Package_Or_Generic_Package (P) then
1774 Last_Entity := First_Private_Entity (P);
1776 Last_Entity := Empty;
1779 Id := First_Entity (P);
1780 while Present (Id) and then Id /= Last_Entity loop
1781 Install_Package_Entity (Id);
1784 end Install_Visible_Declarations;
1786 --------------------------
1787 -- Is_Private_Base_Type --
1788 --------------------------
1790 function Is_Private_Base_Type (E : Entity_Id) return Boolean is
1792 return Ekind (E) = E_Private_Type
1793 or else Ekind (E) = E_Limited_Private_Type
1794 or else Ekind (E) = E_Record_Type_With_Private;
1795 end Is_Private_Base_Type;
1797 --------------------------
1798 -- Is_Visible_Dependent --
1799 --------------------------
1801 function Is_Visible_Dependent (Dep : Entity_Id) return Boolean
1803 S : constant Entity_Id := Scope (Dep);
1806 -- Renamings created for actual types have the visibility of the actual
1808 if Ekind (S) = E_Package
1809 and then Is_Generic_Instance (S)
1810 and then (Is_Generic_Actual_Type (Dep)
1811 or else Is_Generic_Actual_Type (Full_View (Dep)))
1815 elsif not (Is_Derived_Type (Dep))
1816 and then Is_Derived_Type (Full_View (Dep))
1818 -- When instantiating a package body, the scope stack is empty, so
1819 -- check instead whether the dependent type is defined in the same
1820 -- scope as the instance itself.
1822 return In_Open_Scopes (S)
1823 or else (Is_Generic_Instance (Current_Scope)
1824 and then Scope (Dep) = Scope (Current_Scope));
1828 end Is_Visible_Dependent;
1830 ----------------------------
1831 -- May_Need_Implicit_Body --
1832 ----------------------------
1834 procedure May_Need_Implicit_Body (E : Entity_Id) is
1835 P : constant Node_Id := Unit_Declaration_Node (E);
1836 S : constant Node_Id := Parent (P);
1841 if not Has_Completion (E)
1842 and then Nkind (P) = N_Package_Declaration
1843 and then (Present (Activation_Chain_Entity (P)) or else Has_RACW (E))
1846 Make_Package_Body (Sloc (E),
1847 Defining_Unit_Name => Make_Defining_Identifier (Sloc (E),
1848 Chars => Chars (E)),
1849 Declarations => New_List);
1851 if Nkind (S) = N_Package_Specification then
1852 if Present (Private_Declarations (S)) then
1853 Decls := Private_Declarations (S);
1855 Decls := Visible_Declarations (S);
1858 Decls := Declarations (S);
1864 end May_Need_Implicit_Body;
1866 ----------------------
1867 -- New_Private_Type --
1868 ----------------------
1870 procedure New_Private_Type (N : Node_Id; Id : Entity_Id; Def : Node_Id) is
1874 if Limited_Present (Def) then
1875 Set_Ekind (Id, E_Limited_Private_Type);
1877 Set_Ekind (Id, E_Private_Type);
1881 Set_Has_Delayed_Freeze (Id);
1882 Set_Is_First_Subtype (Id);
1883 Init_Size_Align (Id);
1885 Set_Is_Constrained (Id,
1886 No (Discriminant_Specifications (N))
1887 and then not Unknown_Discriminants_Present (N));
1889 -- Set tagged flag before processing discriminants, to catch illegal
1892 Set_Is_Tagged_Type (Id, Tagged_Present (Def));
1894 Set_Discriminant_Constraint (Id, No_Elist);
1895 Set_Stored_Constraint (Id, No_Elist);
1897 if Present (Discriminant_Specifications (N)) then
1899 Process_Discriminants (N);
1902 elsif Unknown_Discriminants_Present (N) then
1903 Set_Has_Unknown_Discriminants (Id);
1906 Set_Private_Dependents (Id, New_Elmt_List);
1908 if Tagged_Present (Def) then
1909 Set_Ekind (Id, E_Record_Type_With_Private);
1910 Make_Class_Wide_Type (Id);
1911 Set_Primitive_Operations (Id, New_Elmt_List);
1912 Set_Is_Abstract_Type (Id, Abstract_Present (Def));
1913 Set_Is_Limited_Record (Id, Limited_Present (Def));
1914 Set_Has_Delayed_Freeze (Id, True);
1916 elsif Abstract_Present (Def) then
1917 Error_Msg_N ("only a tagged type can be abstract", N);
1919 end New_Private_Type;
1921 ----------------------------
1922 -- Uninstall_Declarations --
1923 ----------------------------
1925 procedure Uninstall_Declarations (P : Entity_Id) is
1926 Decl : constant Node_Id := Unit_Declaration_Node (P);
1929 Priv_Elmt : Elmt_Id;
1930 Priv_Sub : Entity_Id;
1932 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id);
1933 -- Copy to the private declaration the attributes of the full view that
1934 -- need to be available for the partial view also.
1936 function Type_In_Use (T : Entity_Id) return Boolean;
1937 -- Check whether type or base type appear in an active use_type clause
1939 ------------------------------
1940 -- Preserve_Full_Attributes --
1941 ------------------------------
1943 procedure Preserve_Full_Attributes (Priv, Full : Entity_Id) is
1944 Priv_Is_Base_Type : constant Boolean := Priv = Base_Type (Priv);
1947 Set_Size_Info (Priv, (Full));
1948 Set_RM_Size (Priv, RM_Size (Full));
1949 Set_Size_Known_At_Compile_Time
1950 (Priv, Size_Known_At_Compile_Time (Full));
1951 Set_Is_Volatile (Priv, Is_Volatile (Full));
1952 Set_Treat_As_Volatile (Priv, Treat_As_Volatile (Full));
1953 Set_Is_Ada_2005_Only (Priv, Is_Ada_2005_Only (Full));
1954 Set_Has_Pragma_Unreferenced (Priv, Has_Pragma_Unreferenced (Full));
1955 Set_Has_Pragma_Unreferenced_Objects
1956 (Priv, Has_Pragma_Unreferenced_Objects
1958 if Is_Unchecked_Union (Full) then
1959 Set_Is_Unchecked_Union (Base_Type (Priv));
1961 -- Why is atomic not copied here ???
1963 if Referenced (Full) then
1964 Set_Referenced (Priv);
1967 if Priv_Is_Base_Type then
1968 Set_Is_Controlled (Priv, Is_Controlled (Base_Type (Full)));
1969 Set_Finalize_Storage_Only (Priv, Finalize_Storage_Only
1970 (Base_Type (Full)));
1971 Set_Has_Task (Priv, Has_Task (Base_Type (Full)));
1972 Set_Has_Controlled_Component (Priv, Has_Controlled_Component
1973 (Base_Type (Full)));
1976 Set_Freeze_Node (Priv, Freeze_Node (Full));
1978 if Is_Tagged_Type (Priv)
1979 and then Is_Tagged_Type (Full)
1980 and then not Error_Posted (Full)
1982 if Priv_Is_Base_Type then
1984 -- Ada 2005 (AI-345): The full view of a type implementing an
1985 -- interface can be a task type.
1987 -- type T is new I with private;
1989 -- task type T is new I with ...
1991 if Is_Interface (Etype (Priv))
1992 and then Is_Concurrent_Type (Base_Type (Full))
1994 -- Protect the frontend against previous errors
1996 if Present (Corresponding_Record_Type
1999 Set_Access_Disp_Table
2000 (Priv, Access_Disp_Table
2001 (Corresponding_Record_Type (Base_Type (Full))));
2003 -- Generic context, or previous errors
2010 Set_Access_Disp_Table
2011 (Priv, Access_Disp_Table (Base_Type (Full)));
2015 if Is_Tagged_Type (Priv) then
2017 -- If the type is tagged, the tag itself must be available on
2018 -- the partial view, for expansion purposes.
2020 Set_First_Entity (Priv, First_Entity (Full));
2022 -- If there are discriminants in the partial view, these remain
2023 -- visible. Otherwise only the tag itself is visible, and there
2024 -- are no nameable components in the partial view.
2026 if No (Last_Entity (Priv)) then
2027 Set_Last_Entity (Priv, First_Entity (Priv));
2031 Set_Has_Discriminants (Priv, Has_Discriminants (Full));
2033 end Preserve_Full_Attributes;
2039 function Type_In_Use (T : Entity_Id) return Boolean is
2041 return Scope (Base_Type (T)) = P
2042 and then (In_Use (T) or else In_Use (Base_Type (T)));
2045 -- Start of processing for Uninstall_Declarations
2048 Id := First_Entity (P);
2049 while Present (Id) and then Id /= First_Private_Entity (P) loop
2050 if Debug_Flag_E then
2051 Write_Str ("unlinking visible entity ");
2052 Write_Int (Int (Id));
2056 -- On exit from the package scope, we must preserve the visibility
2057 -- established by use clauses in the current scope. Two cases:
2059 -- a) If the entity is an operator, it may be a primitive operator of
2060 -- a type for which there is a visible use-type clause.
2062 -- b) for other entities, their use-visibility is determined by a
2063 -- visible use clause for the package itself. For a generic instance,
2064 -- the instantiation of the formals appears in the visible part,
2065 -- but the formals are private and remain so.
2067 if Ekind (Id) = E_Function
2068 and then Is_Operator_Symbol_Name (Chars (Id))
2069 and then not Is_Hidden (Id)
2070 and then not Error_Posted (Id)
2072 Set_Is_Potentially_Use_Visible (Id,
2074 or else Type_In_Use (Etype (Id))
2075 or else Type_In_Use (Etype (First_Formal (Id)))
2076 or else (Present (Next_Formal (First_Formal (Id)))
2079 (Etype (Next_Formal (First_Formal (Id))))));
2081 if In_Use (P) and then not Is_Hidden (Id) then
2083 -- A child unit of a use-visible package remains use-visible
2084 -- only if it is itself a visible child unit. Otherwise it
2085 -- would remain visible in other contexts where P is use-
2086 -- visible, because once compiled it stays in the entity list
2087 -- of its parent unit.
2089 if Is_Child_Unit (Id) then
2090 Set_Is_Potentially_Use_Visible (Id,
2091 Is_Visible_Child_Unit (Id));
2093 Set_Is_Potentially_Use_Visible (Id);
2097 Set_Is_Potentially_Use_Visible (Id, False);
2101 -- Local entities are not immediately visible outside of the package
2103 Set_Is_Immediately_Visible (Id, False);
2105 -- If this is a private type with a full view (for example a local
2106 -- subtype of a private type declared elsewhere), ensure that the
2107 -- full view is also removed from visibility: it may be exposed when
2108 -- swapping views in an instantiation.
2111 and then Present (Full_View (Id))
2113 Set_Is_Immediately_Visible (Full_View (Id), False);
2116 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2117 Check_Abstract_Overriding (Id);
2118 Check_Conventions (Id);
2121 if (Ekind (Id) = E_Private_Type
2122 or else Ekind (Id) = E_Limited_Private_Type)
2123 and then No (Full_View (Id))
2124 and then not Is_Generic_Type (Id)
2125 and then not Is_Derived_Type (Id)
2127 Error_Msg_N ("missing full declaration for private type&", Id);
2129 elsif Ekind (Id) = E_Record_Type_With_Private
2130 and then not Is_Generic_Type (Id)
2131 and then No (Full_View (Id))
2133 if Nkind (Parent (Id)) = N_Private_Type_Declaration then
2134 Error_Msg_N ("missing full declaration for private type&", Id);
2137 ("missing full declaration for private extension", Id);
2140 elsif Ekind (Id) = E_Constant
2141 and then No (Constant_Value (Id))
2142 and then No (Full_View (Id))
2143 and then not Is_Imported (Id)
2144 and then (Nkind (Parent (Id)) /= N_Object_Declaration
2145 or else not No_Initialization (Parent (Id)))
2147 if not Has_Private_Declaration (Etype (Id)) then
2149 -- We assume that the user did not intend a deferred
2150 -- constant declaration, and the expression is just missing.
2153 ("constant declaration requires initialization expression",
2156 if Is_Limited_Type (Etype (Id)) then
2158 ("\if variable intended, remove CONSTANT from declaration",
2164 ("missing full declaration for deferred constant (RM 7.4)",
2167 if Is_Limited_Type (Etype (Id)) then
2169 ("\if variable intended, remove CONSTANT from declaration",
2178 -- If the specification was installed as the parent of a public child
2179 -- unit, the private declarations were not installed, and there is
2182 if not In_Private_Part (P) then
2185 Set_In_Private_Part (P, False);
2188 -- Make private entities invisible and exchange full and private
2189 -- declarations for private types. Id is now the first private entity
2192 while Present (Id) loop
2193 if Debug_Flag_E then
2194 Write_Str ("unlinking private entity ");
2195 Write_Int (Int (Id));
2199 if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
2200 Check_Abstract_Overriding (Id);
2201 Check_Conventions (Id);
2204 Set_Is_Immediately_Visible (Id, False);
2206 if Is_Private_Base_Type (Id)
2207 and then Present (Full_View (Id))
2209 Full := Full_View (Id);
2211 -- If the partial view is not declared in the visible part of the
2212 -- package (as is the case when it is a type derived from some
2213 -- other private type in the private part of the current package),
2214 -- no exchange takes place.
2217 or else List_Containing (Parent (Id))
2218 /= Visible_Declarations (Specification (Decl))
2223 -- The entry in the private part points to the full declaration,
2224 -- which is currently visible. Exchange them so only the private
2225 -- type declaration remains accessible, and link private and full
2226 -- declaration in the opposite direction. Before the actual
2227 -- exchange, we copy back attributes of the full view that must
2228 -- be available to the partial view too.
2230 Preserve_Full_Attributes (Id, Full);
2232 Set_Is_Potentially_Use_Visible (Id, In_Use (P));
2234 if Is_Indefinite_Subtype (Full)
2235 and then not Is_Indefinite_Subtype (Id)
2238 ("full view of type must be definite subtype", Full);
2241 Priv_Elmt := First_Elmt (Private_Dependents (Id));
2243 -- Swap out the subtypes and derived types of Id that were
2244 -- compiled in this scope, or installed previously by
2245 -- Install_Private_Declarations.
2247 -- Before we do the swap, we verify the presence of the Full_View
2248 -- field which may be empty due to a swap by a previous call to
2249 -- End_Package_Scope (e.g. from the freezing mechanism).
2251 while Present (Priv_Elmt) loop
2252 Priv_Sub := Node (Priv_Elmt);
2254 if Present (Full_View (Priv_Sub)) then
2256 if Scope (Priv_Sub) = P
2257 or else not In_Open_Scopes (Scope (Priv_Sub))
2259 Set_Is_Immediately_Visible (Priv_Sub, False);
2262 if Is_Visible_Dependent (Priv_Sub) then
2263 Preserve_Full_Attributes
2264 (Priv_Sub, Full_View (Priv_Sub));
2265 Replace_Elmt (Priv_Elmt, Full_View (Priv_Sub));
2266 Exchange_Declarations (Priv_Sub);
2270 Next_Elmt (Priv_Elmt);
2273 -- Now restore the type itself to its private view
2275 Exchange_Declarations (Id);
2277 -- If we have installed an underlying full view for a type derived
2278 -- from a private type in a child unit, restore the proper views
2279 -- of private and full view. See corresponding code in
2280 -- Install_Private_Declarations.
2282 -- After the exchange, Full denotes the private type in the
2283 -- visible part of the package.
2285 if Is_Private_Base_Type (Full)
2286 and then Present (Full_View (Full))
2287 and then Present (Underlying_Full_View (Full))
2288 and then In_Package_Body (Current_Scope)
2290 Set_Full_View (Full, Underlying_Full_View (Full));
2291 Set_Underlying_Full_View (Full, Empty);
2294 elsif Ekind (Id) = E_Incomplete_Type
2295 and then Comes_From_Source (Id)
2296 and then No (Full_View (Id))
2298 -- Mark Taft amendment types. Verify that there are no primitive
2299 -- operations declared for the type (3.10.1 (9)).
2301 Set_Has_Completion_In_Body (Id);
2308 Elmt := First_Elmt (Private_Dependents (Id));
2309 while Present (Elmt) loop
2310 Subp := Node (Elmt);
2312 if Is_Overloadable (Subp) then
2314 ("type& must be completed in the private part",
2317 -- The return type of an access_to_function cannot be a
2318 -- Taft-amendment type.
2320 elsif Ekind (Subp) = E_Subprogram_Type then
2321 if Etype (Subp) = Id
2323 (Is_Class_Wide_Type (Etype (Subp))
2324 and then Etype (Etype (Subp)) = Id)
2327 ("type& must be completed in the private part",
2328 Associated_Node_For_Itype (Subp), Id);
2336 elsif not Is_Child_Unit (Id)
2337 and then (not Is_Private_Type (Id)
2338 or else No (Full_View (Id)))
2341 Set_Is_Potentially_Use_Visible (Id, False);
2347 end Uninstall_Declarations;
2349 ------------------------
2350 -- Unit_Requires_Body --
2351 ------------------------
2353 function Unit_Requires_Body (P : Entity_Id) return Boolean is
2357 -- Imported entity never requires body. Right now, only subprograms can
2358 -- be imported, but perhaps in the future we will allow import of
2361 if Is_Imported (P) then
2364 -- Body required if library package with pragma Elaborate_Body
2366 elsif Has_Pragma_Elaborate_Body (P) then
2369 -- Body required if subprogram
2371 elsif Is_Subprogram (P) or else Is_Generic_Subprogram (P) then
2374 -- Treat a block as requiring a body
2376 elsif Ekind (P) = E_Block then
2379 elsif Ekind (P) = E_Package
2380 and then Nkind (Parent (P)) = N_Package_Specification
2381 and then Present (Generic_Parent (Parent (P)))
2384 G_P : constant Entity_Id := Generic_Parent (Parent (P));
2386 if Has_Pragma_Elaborate_Body (G_P) then
2392 -- Otherwise search entity chain for entity requiring completion
2394 E := First_Entity (P);
2395 while Present (E) loop
2397 -- Always ignore child units. Child units get added to the entity
2398 -- list of a parent unit, but are not original entities of the
2399 -- parent, and so do not affect whether the parent needs a body.
2401 if Is_Child_Unit (E) then
2404 -- Ignore formal packages and their renamings
2406 elsif Ekind (E) = E_Package
2407 and then Nkind (Original_Node (Unit_Declaration_Node (E))) =
2408 N_Formal_Package_Declaration
2412 -- Otherwise test to see if entity requires a completion.
2413 -- Note that subprogram entities whose declaration does not come
2414 -- from source are ignored here on the basis that we assume the
2415 -- expander will provide an implicit completion at some point.
2417 elsif (Is_Overloadable (E)
2418 and then Ekind (E) /= E_Enumeration_Literal
2419 and then Ekind (E) /= E_Operator
2420 and then not Is_Abstract_Subprogram (E)
2421 and then not Has_Completion (E)
2422 and then Comes_From_Source (Parent (E)))
2425 (Ekind (E) = E_Package
2427 and then not Has_Completion (E)
2428 and then Unit_Requires_Body (E))
2431 (Ekind (E) = E_Incomplete_Type and then No (Full_View (E)))
2434 ((Ekind (E) = E_Task_Type or else
2435 Ekind (E) = E_Protected_Type)
2436 and then not Has_Completion (E))
2439 (Ekind (E) = E_Generic_Package and then E /= P
2440 and then not Has_Completion (E)
2441 and then Unit_Requires_Body (E))
2444 (Is_Generic_Subprogram (E)
2445 and then not Has_Completion (E))
2450 -- Entity that does not require completion
2460 end Unit_Requires_Body;