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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 7 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package contains the routines to process package specifications and
-- bodies. The most important semantic aspects of package processing are the
-- handling of private and full declarations, and the construction of dispatch
-- tables for tagged types.
with Aspects; use Aspects;
with Atree; use Atree;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Disp; use Exp_Disp;
with Exp_Dist; use Exp_Dist;
with Exp_Dbug; use Exp_Dbug;
with Ghost; use Ghost;
with Lib; use Lib;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Nmake; use Nmake;
with Nlists; use Nlists;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch10; use Sem_Ch10;
with Sem_Ch12; use Sem_Ch12;
with Sem_Ch13; use Sem_Ch13;
with Sem_Disp; use Sem_Disp;
with Sem_Eval; use Sem_Eval;
with Sem_Prag; use Sem_Prag;
with Sem_Util; use Sem_Util;
with Sem_Warn; use Sem_Warn;
with Snames; use Snames;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinput; use Sinput;
with Style;
with Uintp; use Uintp;
package body Sem_Ch7 is
-----------------------------------
-- Handling private declarations --
-----------------------------------
-- The principle that each entity has a single defining occurrence clashes
-- with the presence of two separate definitions for private types: the
-- first is the private type declaration, and the second is the full type
-- declaration. It is important that all references to the type point to
-- the same defining occurrence, namely the first one. To enforce the two
-- separate views of the entity, the corresponding information is swapped
-- between the two declarations. Outside of the package, the defining
-- occurrence only contains the private declaration information, while in
-- the private part and the body of the package the defining occurrence
-- contains the full declaration. To simplify the swap, the defining
-- occurrence that currently holds the private declaration points to the
-- full declaration. During semantic processing the defining occurrence
-- also points to a list of private dependents, that is to say access types
-- or composite types whose designated types or component types are
-- subtypes or derived types of the private type in question. After the
-- full declaration has been seen, the private dependents are updated to
-- indicate that they have full definitions.
-----------------------
-- Local Subprograms --
-----------------------
procedure Analyze_Package_Body_Helper (N : Node_Id);
-- Does all the real work of Analyze_Package_Body
procedure Check_Anonymous_Access_Types
(Spec_Id : Entity_Id;
P_Body : Node_Id);
-- If the spec of a package has a limited_with_clause, it may declare
-- anonymous access types whose designated type is a limited view, such an
-- anonymous access return type for a function. This access type cannot be
-- elaborated in the spec itself, but it may need an itype reference if it
-- is used within a nested scope. In that case the itype reference is
-- created at the beginning of the corresponding package body and inserted
-- before other body declarations.
procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id);
-- Called upon entering the private part of a public child package and the
-- body of a nested package, to potentially declare certain inherited
-- subprograms that were inherited by types in the visible part, but whose
-- declaration was deferred because the parent operation was private and
-- not visible at that point. These subprograms are located by traversing
-- the visible part declarations looking for non-private type extensions
-- and then examining each of the primitive operations of such types to
-- find those that were inherited but declared with a special internal
-- name. Each such operation is now declared as an operation with a normal
-- name (using the name of the parent operation) and replaces the previous
-- implicit operation in the primitive operations list of the type. If the
-- inherited private operation has been overridden, then it's replaced by
-- the overriding operation.
procedure Install_Package_Entity (Id : Entity_Id);
-- Supporting procedure for Install_{Visible,Private}_Declarations. Places
-- one entity on its visibility chain, and recurses on the visible part if
-- the entity is an inner package.
function Is_Private_Base_Type (E : Entity_Id) return Boolean;
-- True for a private type that is not a subtype
function Is_Visible_Dependent (Dep : Entity_Id) return Boolean;
-- If the private dependent is a private type whose full view is derived
-- from the parent type, its full properties are revealed only if we are in
-- the immediate scope of the private dependent. Should this predicate be
-- tightened further???
function Requires_Completion_In_Body
(Id : Entity_Id;
Pack_Id : Entity_Id) return Boolean;
-- Subsidiary to routines Unit_Requires_Body and Unit_Requires_Body_Info.
-- Determine whether entity Id declared in package spec Pack_Id requires
-- completion in a package body.
procedure Unit_Requires_Body_Info (Pack_Id : Entity_Id);
-- Outputs info messages showing why package Pack_Id requires a body. The
-- caller has checked that the switch requesting this information is set,
-- and that the package does indeed require a body.
--------------------------
-- Analyze_Package_Body --
--------------------------
procedure Analyze_Package_Body (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
begin
if Debug_Flag_C then
Write_Str ("==> package body ");
Write_Name (Chars (Defining_Entity (N)));
Write_Str (" from ");
Write_Location (Loc);
Write_Eol;
Indent;
end if;
-- The real work is split out into the helper, so it can do "return;"
-- without skipping the debug output.
Analyze_Package_Body_Helper (N);
if Debug_Flag_C then
Outdent;
Write_Str ("<== package body ");
Write_Name (Chars (Defining_Entity (N)));
Write_Str (" from ");
Write_Location (Loc);
Write_Eol;
end if;
end Analyze_Package_Body;
-----------------------------------
-- Analyze_Package_Body_Contract --
-----------------------------------
procedure Analyze_Package_Body_Contract (Body_Id : Entity_Id) is
Spec_Id : constant Entity_Id := Spec_Entity (Body_Id);
Mode : SPARK_Mode_Type;
Prag : Node_Id;
begin
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related package body.
Save_SPARK_Mode_And_Set (Body_Id, Mode);
Prag := Get_Pragma (Body_Id, Pragma_Refined_State);
-- The analysis of pragma Refined_State detects whether the spec has
-- abstract states available for refinement.
if Present (Prag) then
Analyze_Refined_State_In_Decl_Part (Prag);
-- State refinement is required when the package declaration defines at
-- least one abstract state. Null states are not considered. Refinement
-- is not envorced when SPARK checks are turned off.
elsif SPARK_Mode /= Off
and then Requires_State_Refinement (Spec_Id, Body_Id)
then
Error_Msg_N ("package & requires state refinement", Spec_Id);
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Mode);
end Analyze_Package_Body_Contract;
---------------------------------
-- Analyze_Package_Body_Helper --
---------------------------------
procedure Analyze_Package_Body_Helper (N : Node_Id) is
procedure Hide_Public_Entities (Decls : List_Id);
-- Attempt to hide all public entities found in declarative list Decls
-- by resetting their Is_Public flag to False depending on whether the
-- entities are not referenced by inlined or generic bodies. This kind
-- of processing is a conservative approximation and may still leave
-- certain entities externally visible.
procedure Install_Composite_Operations (P : Entity_Id);
-- Composite types declared in the current scope may depend on types
-- that were private at the point of declaration, and whose full view
-- is now in scope. Indicate that the corresponding operations on the
-- composite type are available.
--------------------------
-- Hide_Public_Entities --
--------------------------
procedure Hide_Public_Entities (Decls : List_Id) is
function Contains_Subp_Or_Const_Refs (N : Node_Id) return Boolean;
-- Subsidiary to routine Has_Referencer. Determine whether a node
-- contains a reference to a subprogram or a non-static constant.
-- WARNING: this is a very expensive routine as it performs a full
-- tree traversal.
function Has_Referencer
(Decls : List_Id;
Top_Level : Boolean := False) return Boolean;
-- A "referencer" is a construct which may reference a previous
-- declaration. Examine all declarations in list Decls in reverse
-- and determine whether once such referencer exists. All entities
-- in the range Last (Decls) .. Referencer are hidden from external
-- visibility.
---------------------------------
-- Contains_Subp_Or_Const_Refs --
---------------------------------
function Contains_Subp_Or_Const_Refs (N : Node_Id) return Boolean is
Reference_Seen : Boolean := False;
function Is_Subp_Or_Const_Ref
(N : Node_Id) return Traverse_Result;
-- Determine whether a node denotes a reference to a subprogram or
-- a non-static constant.
--------------------------
-- Is_Subp_Or_Const_Ref --
--------------------------
function Is_Subp_Or_Const_Ref
(N : Node_Id) return Traverse_Result
is
Val : Node_Id;
begin
-- Detect a reference of the form
-- Subp_Call
if Nkind (N) in N_Subprogram_Call
and then Is_Entity_Name (Name (N))
then
Reference_Seen := True;
return Abandon;
-- Detect a reference of the form
-- Subp'Some_Attribute
elsif Nkind (N) = N_Attribute_Reference
and then Is_Entity_Name (Prefix (N))
and then Present (Entity (Prefix (N)))
and then Is_Subprogram (Entity (Prefix (N)))
then
Reference_Seen := True;
return Abandon;
-- Detect the use of a non-static constant
elsif Is_Entity_Name (N)
and then Present (Entity (N))
and then Ekind (Entity (N)) = E_Constant
then
Val := Constant_Value (Entity (N));
if Present (Val)
and then not Compile_Time_Known_Value (Val)
then
Reference_Seen := True;
return Abandon;
end if;
end if;
return OK;
end Is_Subp_Or_Const_Ref;
procedure Find_Subp_Or_Const_Ref is
new Traverse_Proc (Is_Subp_Or_Const_Ref);
-- Start of processing for Contains_Subp_Or_Const_Refs
begin
Find_Subp_Or_Const_Ref (N);
return Reference_Seen;
end Contains_Subp_Or_Const_Refs;
--------------------
-- Has_Referencer --
--------------------
function Has_Referencer
(Decls : List_Id;
Top_Level : Boolean := False) return Boolean
is
Decl : Node_Id;
Decl_Id : Entity_Id;
Spec : Node_Id;
Has_Non_Subp_Const_Referencer : Boolean := False;
-- Flag set for inlined subprogram bodies that do not contain
-- references to other subprograms or non-static constants.
begin
if No (Decls) then
return False;
end if;
-- Examine all declarations in reverse order, hiding all entities
-- from external visibility until a referencer has been found. The
-- algorithm recurses into nested packages.
Decl := Last (Decls);
while Present (Decl) loop
-- A stub is always considered a referencer
if Nkind (Decl) in N_Body_Stub then
return True;
-- Package declaration
elsif Nkind (Decl) = N_Package_Declaration
and then not Has_Non_Subp_Const_Referencer
then
Spec := Specification (Decl);
-- Inspect the declarations of a non-generic package to try
-- and hide more entities from external visibility.
if not Is_Generic_Unit (Defining_Entity (Spec)) then
if Has_Referencer (Private_Declarations (Spec))
or else Has_Referencer (Visible_Declarations (Spec))
then
return True;
end if;
end if;
-- Package body
elsif Nkind (Decl) = N_Package_Body
and then Present (Corresponding_Spec (Decl))
then
Decl_Id := Corresponding_Spec (Decl);
-- A generic package body is a referencer. It would seem
-- that we only have to consider generics that can be
-- exported, i.e. where the corresponding spec is the
-- spec of the current package, but because of nested
-- instantiations, a fully private generic body may export
-- other private body entities. Furthermore, regardless of
-- whether there was a previous inlined subprogram, (an
-- instantiation of) the generic package may reference any
-- entity declared before it.
if Is_Generic_Unit (Decl_Id) then
return True;
-- Inspect the declarations of a non-generic package body to
-- try and hide more entities from external visibility.
elsif not Has_Non_Subp_Const_Referencer
and then Has_Referencer (Declarations (Decl))
then
return True;
end if;
-- Subprogram body
elsif Nkind (Decl) = N_Subprogram_Body then
if Present (Corresponding_Spec (Decl)) then
Decl_Id := Corresponding_Spec (Decl);
-- A generic subprogram body acts as a referencer
if Is_Generic_Unit (Decl_Id) then
return True;
end if;
-- An inlined subprogram body acts as a referencer
if Is_Inlined (Decl_Id)
or else Has_Pragma_Inline (Decl_Id)
then
-- Inspect the statements of the subprogram body
-- to determine whether the body references other
-- subprograms and/or non-static constants.
if Top_Level
and then not Contains_Subp_Or_Const_Refs (Decl)
then
Has_Non_Subp_Const_Referencer := True;
else
return True;
end if;
end if;
-- Otherwise this is a stand alone subprogram body
else
Decl_Id := Defining_Entity (Decl);
-- An inlined body acts as a referencer. Note that an
-- inlined subprogram remains Is_Public as gigi requires
-- the flag to be set.
-- Note that we test Has_Pragma_Inline here rather than
-- Is_Inlined. We are compiling this for a client, and
-- it is the client who will decide if actual inlining
-- should occur, so we need to assume that the procedure
-- could be inlined for the purpose of accessing global
-- entities.
if Has_Pragma_Inline (Decl_Id) then
if Top_Level
and then not Contains_Subp_Or_Const_Refs (Decl)
then
Has_Non_Subp_Const_Referencer := True;
else
return True;
end if;
else
Set_Is_Public (Decl_Id, False);
end if;
end if;
-- Exceptions, objects and renamings do not need to be public
-- if they are not followed by a construct which can reference
-- and export them. The Is_Public flag is reset on top level
-- entities only as anything nested is local to its context.
elsif Nkind_In (Decl, N_Exception_Declaration,
N_Object_Declaration,
N_Object_Renaming_Declaration,
N_Subprogram_Declaration,
N_Subprogram_Renaming_Declaration)
then
Decl_Id := Defining_Entity (Decl);
if Top_Level
and then not Is_Imported (Decl_Id)
and then not Is_Exported (Decl_Id)
and then No (Interface_Name (Decl_Id))
and then
(not Has_Non_Subp_Const_Referencer
or else Nkind (Decl) = N_Subprogram_Declaration)
then
Set_Is_Public (Decl_Id, False);
end if;
end if;
Prev (Decl);
end loop;
return Has_Non_Subp_Const_Referencer;
end Has_Referencer;
-- Local variables
Discard : Boolean := True;
pragma Unreferenced (Discard);
-- Start of processing for Hide_Public_Entities
begin
-- The algorithm examines the top level declarations of a package
-- body in reverse looking for a construct that may export entities
-- declared prior to it. If such a scenario is encountered, then all
-- entities in the range Last (Decls) .. construct are hidden from
-- external visibility. Consider:
-- package Pack is
-- generic
-- package Gen is
-- end Gen;
-- end Pack;
-- package body Pack is
-- External_Obj : ...; -- (1)
-- package body Gen is -- (2)
-- ... External_Obj ... -- (3)
-- end Gen;
-- Local_Obj : ...; -- (4)
-- end Pack;
-- In this example Local_Obj (4) must not be externally visible as
-- it cannot be exported by anything in Pack. The body of generic
-- package Gen (2) on the other hand acts as a "referencer" and may
-- export anything declared before it. Since the compiler does not
-- perform flow analysis, it is not possible to determine precisely
-- which entities will be exported when Gen is instantiated. In the
-- example above External_Obj (1) is exported at (3), but this may
-- not always be the case. The algorithm takes a conservative stance
-- and leaves entity External_Obj public.
Discard := Has_Referencer (Decls, Top_Level => True);
end Hide_Public_Entities;
----------------------------------
-- Install_Composite_Operations --
----------------------------------
procedure Install_Composite_Operations (P : Entity_Id) is
Id : Entity_Id;
begin
Id := First_Entity (P);
while Present (Id) loop
if Is_Type (Id)
and then (Is_Limited_Composite (Id)
or else Is_Private_Composite (Id))
and then No (Private_Component (Id))
then
Set_Is_Limited_Composite (Id, False);
Set_Is_Private_Composite (Id, False);
end if;
Next_Entity (Id);
end loop;
end Install_Composite_Operations;
-- Local variables
Body_Id : Entity_Id;
HSS : Node_Id;
Last_Spec_Entity : Entity_Id;
New_N : Node_Id;
Pack_Decl : Node_Id;
Spec_Id : Entity_Id;
-- Start of processing for Analyze_Package_Body_Helper
begin
-- Find corresponding package specification, and establish the current
-- scope. The visible defining entity for the package is the defining
-- occurrence in the spec. On exit from the package body, all body
-- declarations are attached to the defining entity for the body, but
-- the later is never used for name resolution. In this fashion there
-- is only one visible entity that denotes the package.
-- Set Body_Id. Note that this will be reset to point to the generic
-- copy later on in the generic case.
Body_Id := Defining_Entity (N);
-- Body is body of package instantiation. Corresponding spec has already
-- been set.
if Present (Corresponding_Spec (N)) then
Spec_Id := Corresponding_Spec (N);
Pack_Decl := Unit_Declaration_Node (Spec_Id);
else
Spec_Id := Current_Entity_In_Scope (Defining_Entity (N));
if Present (Spec_Id)
and then Is_Package_Or_Generic_Package (Spec_Id)
then
Pack_Decl := Unit_Declaration_Node (Spec_Id);
if Nkind (Pack_Decl) = N_Package_Renaming_Declaration then
Error_Msg_N ("cannot supply body for package renaming", N);
return;
elsif Present (Corresponding_Body (Pack_Decl)) then
Error_Msg_N ("redefinition of package body", N);
return;
end if;
else
Error_Msg_N ("missing specification for package body", N);
return;
end if;
if Is_Package_Or_Generic_Package (Spec_Id)
and then (Scope (Spec_Id) = Standard_Standard
or else Is_Child_Unit (Spec_Id))
and then not Unit_Requires_Body (Spec_Id)
then
if Ada_Version = Ada_83 then
Error_Msg_N
("optional package body (not allowed in Ada 95)??", N);
else
Error_Msg_N ("spec of this package does not allow a body", N);
end if;
end if;
end if;
-- The corresponding spec of the package body may be subject to pragma
-- Ghost with policy Ignore. Set the mode now to ensure that any nodes
-- generated during analysis and expansion are properly flagged as
-- ignored Ghost.
Set_Ghost_Mode (N, Spec_Id);
Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
Style.Check_Identifier (Body_Id, Spec_Id);
if Is_Child_Unit (Spec_Id) then
if Nkind (Parent (N)) /= N_Compilation_Unit then
Error_Msg_NE
("body of child unit& cannot be an inner package", N, Spec_Id);
end if;
Set_Is_Child_Unit (Body_Id);
end if;
-- Generic package case
if Ekind (Spec_Id) = E_Generic_Package then
-- Disable expansion and perform semantic analysis on copy. The
-- unannotated body will be used in all instantiations.
Body_Id := Defining_Entity (N);
Set_Ekind (Body_Id, E_Package_Body);
Set_Scope (Body_Id, Scope (Spec_Id));
Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id));
Set_Body_Entity (Spec_Id, Body_Id);
Set_Spec_Entity (Body_Id, Spec_Id);
New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
Rewrite (N, New_N);
-- Once the contents of the generic copy and the template are
-- swapped, do the same for their respective aspect specifications.
Exchange_Aspects (N, New_N);
-- Update Body_Id to point to the copied node for the remainder of
-- the processing.
Body_Id := Defining_Entity (N);
Start_Generic;
end if;
-- The Body_Id is that of the copied node in the generic case, the
-- current node otherwise. Note that N was rewritten above, so we must
-- be sure to get the latest Body_Id value.
Set_Ekind (Body_Id, E_Package_Body);
Set_Body_Entity (Spec_Id, Body_Id);
Set_Spec_Entity (Body_Id, Spec_Id);
-- Defining name for the package body is not a visible entity: Only the
-- defining name for the declaration is visible.
Set_Etype (Body_Id, Standard_Void_Type);
Set_Scope (Body_Id, Scope (Spec_Id));
Set_Corresponding_Spec (N, Spec_Id);
Set_Corresponding_Body (Pack_Decl, Body_Id);
-- The body entity is not used for semantics or code generation, but
-- it is attached to the entity list of the enclosing scope to simplify
-- the listing of back-annotations for the types it main contain.
if Scope (Spec_Id) /= Standard_Standard then
Append_Entity (Body_Id, Scope (Spec_Id));
end if;
-- Indicate that we are currently compiling the body of the package
Set_In_Package_Body (Spec_Id);
Set_Has_Completion (Spec_Id);
Last_Spec_Entity := Last_Entity (Spec_Id);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Body_Id);
end if;
Push_Scope (Spec_Id);
-- Set SPARK_Mode only for non-generic package
if Ekind (Spec_Id) = E_Package then
-- Set SPARK_Mode from context
Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Body_Id, True);
-- Set elaboration code SPARK mode the same for now
Set_SPARK_Aux_Pragma (Body_Id, SPARK_Pragma (Body_Id));
Set_SPARK_Aux_Pragma_Inherited (Body_Id, True);
end if;
-- Inherit the "ghostness" of the subprogram spec. Note that this
-- property is not directly inherited as the body may be subject to a
-- different Ghost assertion policy.
if Is_Ghost_Entity (Spec_Id) or else Ghost_Mode > None then
Set_Is_Ghost_Entity (Body_Id);
-- The Ghost policy in effect at the point of declaration and at the
-- point of completion must match (SPARK RM 6.9(15)).
Check_Ghost_Completion (Spec_Id, Body_Id);
end if;
Set_Categorization_From_Pragmas (N);
Install_Visible_Declarations (Spec_Id);
Install_Private_Declarations (Spec_Id);
Install_Private_With_Clauses (Spec_Id);
Install_Composite_Operations (Spec_Id);
Check_Anonymous_Access_Types (Spec_Id, N);
if Ekind (Spec_Id) = E_Generic_Package then
Set_Use (Generic_Formal_Declarations (Pack_Decl));
end if;
Set_Use (Visible_Declarations (Specification (Pack_Decl)));
Set_Use (Private_Declarations (Specification (Pack_Decl)));
-- This is a nested package, so it may be necessary to declare certain
-- inherited subprograms that are not yet visible because the parent
-- type's subprograms are now visible.
if Ekind (Scope (Spec_Id)) = E_Package
and then Scope (Spec_Id) /= Standard_Standard
then
Declare_Inherited_Private_Subprograms (Spec_Id);
end if;
if Present (Declarations (N)) then
Analyze_Declarations (Declarations (N));
Inspect_Deferred_Constant_Completion (Declarations (N));
end if;
-- Verify that the SPARK_Mode of the body agrees with that of its spec
if Present (SPARK_Pragma (Body_Id)) then
if Present (SPARK_Aux_Pragma (Spec_Id)) then
if Get_SPARK_Mode_From_Pragma (SPARK_Aux_Pragma (Spec_Id)) = Off
and then
Get_SPARK_Mode_From_Pragma (SPARK_Pragma (Body_Id)) = On
then
Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id));
Error_Msg_N ("incorrect application of SPARK_Mode#", N);
Error_Msg_Sloc := Sloc (SPARK_Aux_Pragma (Spec_Id));
Error_Msg_NE
("\value Off was set for SPARK_Mode on & #", N, Spec_Id);
end if;
else
Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id));
Error_Msg_N ("incorrect application of SPARK_Mode#", N);
Error_Msg_Sloc := Sloc (Spec_Id);
Error_Msg_NE
("\no value was set for SPARK_Mode on & #", N, Spec_Id);
end if;
end if;
-- Analyze_Declarations has caused freezing of all types. Now generate
-- bodies for RACW primitives and stream attributes, if any.
if Ekind (Spec_Id) = E_Package and then Has_RACW (Spec_Id) then
-- Attach subprogram bodies to support RACWs declared in spec
Append_RACW_Bodies (Declarations (N), Spec_Id);
Analyze_List (Declarations (N));
end if;
HSS := Handled_Statement_Sequence (N);
if Present (HSS) then
Process_End_Label (HSS, 't', Spec_Id);
Analyze (HSS);
-- Check that elaboration code in a preelaborable package body is
-- empty other than null statements and labels (RM 10.2.1(6)).
Validate_Null_Statement_Sequence (N);
end if;
Validate_Categorization_Dependency (N, Spec_Id);
Check_Completion (Body_Id);
-- Generate start of body reference. Note that we do this fairly late,
-- because the call will use In_Extended_Main_Source_Unit as a check,
-- and we want to make sure that Corresponding_Stub links are set
Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
-- For a generic package, collect global references and mark them on
-- the original body so that they are not resolved again at the point
-- of instantiation.
if Ekind (Spec_Id) /= E_Package then
Save_Global_References (Original_Node (N));
End_Generic;
end if;
-- The entities of the package body have so far been chained onto the
-- declaration chain for the spec. That's been fine while we were in the
-- body, since we wanted them to be visible, but now that we are leaving
-- the package body, they are no longer visible, so we remove them from
-- the entity chain of the package spec entity, and copy them to the
-- entity chain of the package body entity, where they will never again
-- be visible.
if Present (Last_Spec_Entity) then
Set_First_Entity (Body_Id, Next_Entity (Last_Spec_Entity));
Set_Next_Entity (Last_Spec_Entity, Empty);
Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
Set_Last_Entity (Spec_Id, Last_Spec_Entity);
else
Set_First_Entity (Body_Id, First_Entity (Spec_Id));
Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
Set_First_Entity (Spec_Id, Empty);
Set_Last_Entity (Spec_Id, Empty);
end if;
End_Package_Scope (Spec_Id);
-- All entities declared in body are not visible
declare
E : Entity_Id;
begin
E := First_Entity (Body_Id);
while Present (E) loop
Set_Is_Immediately_Visible (E, False);
Set_Is_Potentially_Use_Visible (E, False);
Set_Is_Hidden (E);
-- Child units may appear on the entity list (e.g. if they appear
-- in the context of a subunit) but they are not body entities.
if not Is_Child_Unit (E) then
Set_Is_Package_Body_Entity (E);
end if;
Next_Entity (E);
end loop;
end;
Check_References (Body_Id);
-- For a generic unit, check that the formal parameters are referenced,
-- and that local variables are used, as for regular packages.
if Ekind (Spec_Id) = E_Generic_Package then
Check_References (Spec_Id);
end if;
-- At this point all entities of the package body are externally visible
-- to the linker as their Is_Public flag is set to True. This proactive
-- approach is necessary because an inlined or a generic body for which
-- code is generated in other units may need to see these entities. Cut
-- down the number of global symbols that do not neet public visibility
-- as this has two beneficial effects:
-- (1) It makes the compilation process more efficient.
-- (2) It gives the code generatormore freedom to optimize within each
-- unit, especially subprograms.
-- This is done only for top level library packages or child units as
-- the algorithm does a top down traversal of the package body.
if (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id))
and then not Is_Generic_Unit (Spec_Id)
then
Hide_Public_Entities (Declarations (N));
end if;
-- If expander is not active, then here is where we turn off the
-- In_Package_Body flag, otherwise it is turned off at the end of the
-- corresponding expansion routine. If this is an instance body, we need
-- to qualify names of local entities, because the body may have been
-- compiled as a preliminary to another instantiation.
if not Expander_Active then
Set_In_Package_Body (Spec_Id, False);
if Is_Generic_Instance (Spec_Id)
and then Operating_Mode = Generate_Code
then
Qualify_Entity_Names (N);
end if;
end if;
end Analyze_Package_Body_Helper;
------------------------------
-- Analyze_Package_Contract --
------------------------------
procedure Analyze_Package_Contract (Pack_Id : Entity_Id) is
Mode : SPARK_Mode_Type;
Prag : Node_Id;
begin
-- Due to the timing of contract analysis, delayed pragmas may be
-- subject to the wrong SPARK_Mode, usually that of the enclosing
-- context. To remedy this, restore the original SPARK_Mode of the
-- related package.
Save_SPARK_Mode_And_Set (Pack_Id, Mode);
-- Analyze the initialization related pragmas. Initializes must come
-- before Initial_Condition due to item dependencies.
Prag := Get_Pragma (Pack_Id, Pragma_Initializes);
if Present (Prag) then
Analyze_Initializes_In_Decl_Part (Prag);
end if;
Prag := Get_Pragma (Pack_Id, Pragma_Initial_Condition);
if Present (Prag) then
Analyze_Initial_Condition_In_Decl_Part (Prag);
end if;
-- Check whether the lack of indicator Part_Of agrees with the placement
-- of the package instantiation with respect to the state space.
if Is_Generic_Instance (Pack_Id) then
Prag := Get_Pragma (Pack_Id, Pragma_Part_Of);
if No (Prag) then
Check_Missing_Part_Of (Pack_Id);
end if;
end if;
-- Restore the SPARK_Mode of the enclosing context after all delayed
-- pragmas have been analyzed.
Restore_SPARK_Mode (Mode);
end Analyze_Package_Contract;
---------------------------------
-- Analyze_Package_Declaration --
---------------------------------
procedure Analyze_Package_Declaration (N : Node_Id) is
Id : constant Node_Id := Defining_Entity (N);
PF : Boolean;
-- True when in the context of a declared pure library unit
Body_Required : Boolean;
-- True when this package declaration requires a corresponding body
Comp_Unit : Boolean;
-- True when this package declaration is not a nested declaration
begin
if Debug_Flag_C then
Write_Str ("==> package spec ");
Write_Name (Chars (Id));
Write_Str (" from ");
Write_Location (Sloc (N));
Write_Eol;
Indent;
end if;
-- The package declaration may be subject to pragma Ghost with policy
-- Ignore. Set the mode now to ensure that any nodes generated during
-- analysis and expansion are properly flagged as ignored Ghost.
Set_Ghost_Mode (N);
Generate_Definition (Id);
Enter_Name (Id);
Set_Ekind (Id, E_Package);
Set_Etype (Id, Standard_Void_Type);
-- Set SPARK_Mode from context only for non-generic package
if Ekind (Id) = E_Package then
Set_SPARK_Pragma (Id, SPARK_Mode_Pragma);
Set_SPARK_Aux_Pragma (Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Id, True);
Set_SPARK_Aux_Pragma_Inherited (Id, True);
end if;
-- Analyze aspect specifications immediately, since we need to recognize
-- things like Pure early enough to diagnose violations during analysis.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
end if;
-- Ada 2005 (AI-217): Check if the package has been illegally named
-- in a limited-with clause of its own context. In this case the error
-- has been previously notified by Analyze_Context.
-- limited with Pkg; -- ERROR
-- package Pkg is ...
if From_Limited_With (Id) then
return;
end if;
Push_Scope (Id);
PF := Is_Pure (Enclosing_Lib_Unit_Entity);
Set_Is_Pure (Id, PF);
Set_Categorization_From_Pragmas (N);
Analyze (Specification (N));
Validate_Categorization_Dependency (N, Id);
Body_Required := Unit_Requires_Body (Id);
-- When this spec does not require an explicit body, we know that there
-- are no entities requiring completion in the language sense; we call
-- Check_Completion here only to ensure that any nested package
-- declaration that requires an implicit body gets one. (In the case
-- where a body is required, Check_Completion is called at the end of
-- the body's declarative part.)
if not Body_Required then
Check_Completion;
end if;
Comp_Unit := Nkind (Parent (N)) = N_Compilation_Unit;
if Comp_Unit then
-- Set Body_Required indication on the compilation unit node, and
-- determine whether elaboration warnings may be meaningful on it.
Set_Body_Required (Parent (N), Body_Required);
if not Body_Required then
Set_Suppress_Elaboration_Warnings (Id);
end if;
end if;
End_Package_Scope (Id);
-- For the declaration of a library unit that is a remote types package,
-- check legality rules regarding availability of stream attributes for
-- types that contain non-remote access values. This subprogram performs
-- visibility tests that rely on the fact that we have exited the scope
-- of Id.
if Comp_Unit then
Validate_RT_RAT_Component (N);
end if;
if Debug_Flag_C then
Outdent;
Write_Str ("<== package spec ");
Write_Name (Chars (Id));
Write_Str (" from ");
Write_Location (Sloc (N));
Write_Eol;
end if;
end Analyze_Package_Declaration;
-----------------------------------
-- Analyze_Package_Specification --
-----------------------------------
-- Note that this code is shared for the analysis of generic package specs
-- (see Sem_Ch12.Analyze_Generic_Package_Declaration for details).
procedure Analyze_Package_Specification (N : Node_Id) is
Id : constant Entity_Id := Defining_Entity (N);
Orig_Decl : constant Node_Id := Original_Node (Parent (N));
Vis_Decls : constant List_Id := Visible_Declarations (N);
Priv_Decls : constant List_Id := Private_Declarations (N);
E : Entity_Id;
L : Entity_Id;
Public_Child : Boolean;
Private_With_Clauses_Installed : Boolean := False;
-- In Ada 2005, private with_clauses are visible in the private part
-- of a nested package, even if it appears in the public part of the
-- enclosing package. This requires a separate step to install these
-- private_with_clauses, and remove them at the end of the nested
-- package.
procedure Check_One_Tagged_Type_Or_Extension_At_Most;
-- Issue an error in SPARK mode if a package specification contains
-- more than one tagged type or type extension.
procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id);
-- Clears constant indications (Never_Set_In_Source, Constant_Value, and
-- Is_True_Constant) on all variables that are entities of Id, and on
-- the chain whose first element is FE. A recursive call is made for all
-- packages and generic packages.
procedure Generate_Parent_References;
-- For a child unit, generate references to parent units, for
-- GPS navigation purposes.
function Is_Public_Child (Child, Unit : Entity_Id) return Boolean;
-- Child and Unit are entities of compilation units. True if Child
-- is a public child of Parent as defined in 10.1.1
procedure Inspect_Unchecked_Union_Completion (Decls : List_Id);
-- Reject completion of an incomplete or private type declarations
-- having a known discriminant part by an unchecked union.
procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id);
-- Given the package entity of a generic package instantiation or
-- formal package whose corresponding generic is a child unit, installs
-- the private declarations of each of the child unit's parents.
-- This has to be done at the point of entering the instance package's
-- private part rather than being done in Sem_Ch12.Install_Parent
-- (which is where the parents' visible declarations are installed).
------------------------------------------------
-- Check_One_Tagged_Type_Or_Extension_At_Most --
------------------------------------------------
procedure Check_One_Tagged_Type_Or_Extension_At_Most is
Previous : Node_Id;
procedure Check_Decls (Decls : List_Id);
-- Check that either Previous is Empty and Decls does not contain
-- more than one tagged type or type extension, or Previous is
-- already set and Decls contains no tagged type or type extension.
-----------------
-- Check_Decls --
-----------------
procedure Check_Decls (Decls : List_Id) is
Decl : Node_Id;
begin
Decl := First (Decls);
while Present (Decl) loop
if Nkind (Decl) = N_Full_Type_Declaration
and then Is_Tagged_Type (Defining_Identifier (Decl))
then
if No (Previous) then
Previous := Decl;
else
Error_Msg_Sloc := Sloc (Previous);
Check_SPARK_05_Restriction
("at most one tagged type or type extension allowed",
"\\ previous declaration#",
Decl);
end if;
end if;
Next (Decl);
end loop;
end Check_Decls;
-- Start of processing for Check_One_Tagged_Type_Or_Extension_At_Most
begin
Previous := Empty;
Check_Decls (Vis_Decls);
if Present (Priv_Decls) then
Check_Decls (Priv_Decls);
end if;
end Check_One_Tagged_Type_Or_Extension_At_Most;
---------------------
-- Clear_Constants --
---------------------
procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id) is
E : Entity_Id;
begin
-- Ignore package renamings, not interesting and they can cause self
-- referential loops in the code below.
if Nkind (Parent (Id)) = N_Package_Renaming_Declaration then
return;
end if;
-- Note: in the loop below, the check for Next_Entity pointing back
-- to the package entity may seem odd, but it is needed, because a
-- package can contain a renaming declaration to itself, and such
-- renamings are generated automatically within package instances.
E := FE;
while Present (E) and then E /= Id loop
if Is_Assignable (E) then
Set_Never_Set_In_Source (E, False);
Set_Is_True_Constant (E, False);
Set_Current_Value (E, Empty);
Set_Is_Known_Null (E, False);
Set_Last_Assignment (E, Empty);
if not Can_Never_Be_Null (E) then
Set_Is_Known_Non_Null (E, False);
end if;
elsif Is_Package_Or_Generic_Package (E) then
Clear_Constants (E, First_Entity (E));
Clear_Constants (E, First_Private_Entity (E));
end if;
Next_Entity (E);
end loop;
end Clear_Constants;
--------------------------------
-- Generate_Parent_References --
--------------------------------
procedure Generate_Parent_References is
Decl : constant Node_Id := Parent (N);
begin
if Id = Cunit_Entity (Main_Unit)
or else Parent (Decl) = Library_Unit (Cunit (Main_Unit))
then
Generate_Reference (Id, Scope (Id), 'k', False);
elsif not Nkind_In (Unit (Cunit (Main_Unit)), N_Subprogram_Body,
N_Subunit)
then
-- If current unit is an ancestor of main unit, generate a
-- reference to its own parent.
declare
U : Node_Id;
Main_Spec : Node_Id := Unit (Cunit (Main_Unit));
begin
if Nkind (Main_Spec) = N_Package_Body then
Main_Spec := Unit (Library_Unit (Cunit (Main_Unit)));
end if;
U := Parent_Spec (Main_Spec);
while Present (U) loop
if U = Parent (Decl) then
Generate_Reference (Id, Scope (Id), 'k', False);
exit;
elsif Nkind (Unit (U)) = N_Package_Body then
exit;
else
U := Parent_Spec (Unit (U));
end if;
end loop;
end;
end if;
end Generate_Parent_References;
---------------------
-- Is_Public_Child --
---------------------
function Is_Public_Child (Child, Unit : Entity_Id) return Boolean is
begin
if not Is_Private_Descendant (Child) then
return True;
else
if Child = Unit then
return not Private_Present (
Parent (Unit_Declaration_Node (Child)));
else
return Is_Public_Child (Scope (Child), Unit);
end if;
end if;
end Is_Public_Child;
----------------------------------------
-- Inspect_Unchecked_Union_Completion --
----------------------------------------
procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is
Decl : Node_Id;
begin
Decl := First (Decls);
while Present (Decl) loop
-- We are looking at an incomplete or private type declaration
-- with a known_discriminant_part whose full view is an
-- Unchecked_Union.
if Nkind_In (Decl, N_Incomplete_Type_Declaration,
N_Private_Type_Declaration)
and then Has_Discriminants (Defining_Identifier (Decl))
and then Present (Full_View (Defining_Identifier (Decl)))
and then
Is_Unchecked_Union (Full_View (Defining_Identifier (Decl)))
then
Error_Msg_N
("completion of discriminated partial view "
& "cannot be an unchecked union",
Full_View (Defining_Identifier (Decl)));
end if;
Next (Decl);
end loop;
end Inspect_Unchecked_Union_Completion;
-----------------------------------------
-- Install_Parent_Private_Declarations --
-----------------------------------------
procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id) is
Inst_Par : Entity_Id;
Gen_Par : Entity_Id;
Inst_Node : Node_Id;
begin
Inst_Par := Inst_Id;
Gen_Par :=
Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par)));
while Present (Gen_Par) and then Is_Child_Unit (Gen_Par) loop
Inst_Node := Get_Package_Instantiation_Node (Inst_Par);
if Nkind_In (Inst_Node, N_Package_Instantiation,
N_Formal_Package_Declaration)
and then Nkind (Name (Inst_Node)) = N_Expanded_Name
then
Inst_Par := Entity (Prefix (Name (Inst_Node)));
if Present (Renamed_Entity (Inst_Par)) then
Inst_Par := Renamed_Entity (Inst_Par);
end if;
Gen_Par :=
Generic_Parent
(Specification (Unit_Declaration_Node (Inst_Par)));
-- Install the private declarations and private use clauses
-- of a parent instance of the child instance, unless the
-- parent instance private declarations have already been
-- installed earlier in Analyze_Package_Specification, which
-- happens when a generic child is instantiated, and the
-- instance is a child of the parent instance.
-- Installing the use clauses of the parent instance twice
-- is both unnecessary and wrong, because it would cause the
-- clauses to be chained to themselves in the use clauses
-- list of the scope stack entry. That in turn would cause
-- an endless loop from End_Use_Clauses upon scope exit.
-- The parent is now fully visible. It may be a hidden open
-- scope if we are currently compiling some child instance
-- declared within it, but while the current instance is being
-- compiled the parent is immediately visible. In particular
-- its entities must remain visible if a stack save/restore
-- takes place through a call to Rtsfind.
if Present (Gen_Par) then
if not In_Private_Part (Inst_Par) then
Install_Private_Declarations (Inst_Par);
Set_Use (Private_Declarations
(Specification
(Unit_Declaration_Node (Inst_Par))));
Set_Is_Hidden_Open_Scope (Inst_Par, False);
end if;
-- If we've reached the end of the generic instance parents,
-- then finish off by looping through the nongeneric parents
-- and installing their private declarations.
-- If one of the non-generic parents is itself on the scope
-- stack, do not install its private declarations: they are
-- installed in due time when the private part of that parent
-- is analyzed. This is delicate ???
else
while Present (Inst_Par)
and then Inst_Par /= Standard_Standard
and then (not In_Open_Scopes (Inst_Par)
or else not In_Private_Part (Inst_Par))
loop
Install_Private_Declarations (Inst_Par);
Set_Use (Private_Declarations
(Specification
(Unit_Declaration_Node (Inst_Par))));
Inst_Par := Scope (Inst_Par);
end loop;
exit;
end if;
else
exit;
end if;
end loop;
end Install_Parent_Private_Declarations;
-- Start of processing for Analyze_Package_Specification
begin
if Present (Vis_Decls) then
Analyze_Declarations (Vis_Decls);
end if;
-- Inspect the entities defined in the package and ensure that all
-- incomplete types have received full declarations. Build default
-- initial condition and invariant procedures for all qualifying types.
E := First_Entity (Id);
while Present (E) loop
-- Check on incomplete types
-- AI05-0213: A formal incomplete type has no completion
if Ekind (E) = E_Incomplete_Type
and then No (Full_View (E))
and then not Is_Generic_Type (E)
then
Error_Msg_N ("no declaration in visible part for incomplete}", E);
end if;
if Is_Type (E) then
-- Each private type subject to pragma Default_Initial_Condition
-- declares a specialized procedure which verifies the assumption
-- of the pragma. The declaration appears in the visible part of
-- the package to allow for being called from the outside.
if Has_Default_Init_Cond (E) then
Build_Default_Init_Cond_Procedure_Declaration (E);
-- A private extension inherits the default initial condition
-- procedure from its parent type.
elsif Has_Inherited_Default_Init_Cond (E) then
Inherit_Default_Init_Cond_Procedure (E);
end if;
-- If invariants are present, build the invariant procedure for a
-- private type, but not any of its subtypes or interface types.
if Has_Invariants (E) then
if Ekind (E) = E_Private_Subtype then
null;
else
Build_Invariant_Procedure (E, N);
end if;
end if;
end if;
Next_Entity (E);
end loop;
if Is_Remote_Call_Interface (Id)
and then Nkind (Parent (Parent (N))) = N_Compilation_Unit
then
Validate_RCI_Declarations (Id);
end if;
-- Save global references in the visible declarations, before installing
-- private declarations of parent unit if there is one, because the
-- privacy status of types defined in the parent will change. This is
-- only relevant for generic child units, but is done in all cases for
-- uniformity.
if Ekind (Id) = E_Generic_Package
and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
then
declare
Orig_Spec : constant Node_Id := Specification (Orig_Decl);
Save_Priv : constant List_Id := Private_Declarations (Orig_Spec);
begin
Set_Private_Declarations (Orig_Spec, Empty_List);
Save_Global_References (Orig_Decl);
Set_Private_Declarations (Orig_Spec, Save_Priv);
end;
end if;
-- If package is a public child unit, then make the private declarations
-- of the parent visible.
Public_Child := False;
declare
Par : Entity_Id;
Pack_Decl : Node_Id;
Par_Spec : Node_Id;
begin
Par := Id;
Par_Spec := Parent_Spec (Parent (N));
-- If the package is formal package of an enclosing generic, it is
-- transformed into a local generic declaration, and compiled to make
-- its spec available. We need to retrieve the original generic to
-- determine whether it is a child unit, and install its parents.
if No (Par_Spec)
and then
Nkind (Original_Node (Parent (N))) = N_Formal_Package_Declaration
then
Par := Entity (Name (Original_Node (Parent (N))));
Par_Spec := Parent_Spec (Unit_Declaration_Node (Par));
end if;
if Present (Par_Spec) then
Generate_Parent_References;
while Scope (Par) /= Standard_Standard
and then Is_Public_Child (Id, Par)
and then In_Open_Scopes (Par)
loop
Public_Child := True;
Par := Scope (Par);
Install_Private_Declarations (Par);
Install_Private_With_Clauses (Par);
Pack_Decl := Unit_Declaration_Node (Par);
Set_Use (Private_Declarations (Specification (Pack_Decl)));
end loop;
end if;
end;
if Is_Compilation_Unit (Id) then
Install_Private_With_Clauses (Id);
else
-- The current compilation unit may include private with_clauses,
-- which are visible in the private part of the current nested
-- package, and have to be installed now. This is not done for
-- nested instantiations, where the private with_clauses of the
-- enclosing unit have no effect once the instantiation info is
-- established and we start analyzing the package declaration.
declare
Comp_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
begin
if Is_Package_Or_Generic_Package (Comp_Unit)
and then not In_Private_Part (Comp_Unit)
and then not In_Instance
then
Install_Private_With_Clauses (Comp_Unit);
Private_With_Clauses_Installed := True;
end if;
end;
end if;
-- If this is a package associated with a generic instance or formal
-- package, then the private declarations of each of the generic's
-- parents must be installed at this point.
if Is_Generic_Instance (Id) then
Install_Parent_Private_Declarations (Id);
end if;
-- Analyze private part if present. The flag In_Private_Part is reset
-- in End_Package_Scope.
L := Last_Entity (Id);
if Present (Priv_Decls) then
Set_In_Private_Part (Id);
-- Upon entering a public child's private part, it may be necessary
-- to declare subprograms that were derived in the package's visible
-- part but not yet made visible.
if Public_Child then
Declare_Inherited_Private_Subprograms (Id);
end if;
Analyze_Declarations (Priv_Decls);
-- Check the private declarations for incomplete deferred constants
Inspect_Deferred_Constant_Completion (Priv_Decls);
-- The first private entity is the immediate follower of the last
-- visible entity, if there was one.
if Present (L) then
Set_First_Private_Entity (Id, Next_Entity (L));
else
Set_First_Private_Entity (Id, First_Entity (Id));
end if;
-- There may be inherited private subprograms that need to be declared,
-- even in the absence of an explicit private part. If there are any
-- public declarations in the package and the package is a public child
-- unit, then an implicit private part is assumed.
elsif Present (L) and then Public_Child then
Set_In_Private_Part (Id);
Declare_Inherited_Private_Subprograms (Id);
Set_First_Private_Entity (Id, Next_Entity (L));
end if;
E := First_Entity (Id);
while Present (E) loop
-- Check rule of 3.6(11), which in general requires waiting till all
-- full types have been seen.
if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then
Check_Aliased_Component_Types (E);
end if;
-- Check preelaborable initialization for full type completing a
-- private type for which pragma Preelaborable_Initialization given.
if Is_Type (E)
and then Must_Have_Preelab_Init (E)
and then not Has_Preelaborable_Initialization (E)
then
Error_Msg_N
("full view of & does not have preelaborable initialization", E);
end if;
-- An invariant may appear on a full view of a type
if Is_Type (E)
and then Has_Private_Declaration (E)
and then Nkind (Parent (E)) = N_Full_Type_Declaration
then
declare
IP_Built : Boolean := False;
begin
if Has_Aspects (Parent (E)) then
declare
ASN : Node_Id;
begin
ASN := First (Aspect_Specifications (Parent (E)));
while Present (ASN) loop
if Nam_In (Chars (Identifier (ASN)),
Name_Invariant,
Name_Type_Invariant)
then
Build_Invariant_Procedure (E, N);
IP_Built := True;
exit;
end if;
Next (ASN);
end loop;
end;
end if;
-- Invariants may have been inherited from progenitors
if not IP_Built
and then Has_Interfaces (E)
and then Has_Inheritable_Invariants (E)
and then not Is_Interface (E)
and then not Is_Class_Wide_Type (E)
then
Build_Invariant_Procedure (E, N);
end if;
end;
end if;
Next_Entity (E);
end loop;
-- Ada 2005 (AI-216): The completion of an incomplete or private type
-- declaration having a known_discriminant_part shall not be an
-- unchecked union type.
if Present (Vis_Decls) then
Inspect_Unchecked_Union_Completion (Vis_Decls);
end if;
if Present (Priv_Decls) then
Inspect_Unchecked_Union_Completion (Priv_Decls);
end if;
if Ekind (Id) = E_Generic_Package
and then Nkind (Orig_Decl) = N_Generic_Package_Declaration
and then Present (Priv_Decls)
then
-- Save global references in private declarations, ignoring the
-- visible declarations that were processed earlier.
declare
Orig_Spec : constant Node_Id := Specification (Orig_Decl);
Save_Vis : constant List_Id := Visible_Declarations (Orig_Spec);
Save_Form : constant List_Id :=
Generic_Formal_Declarations (Orig_Decl);
begin
Set_Visible_Declarations (Orig_Spec, Empty_List);
Set_Generic_Formal_Declarations (Orig_Decl, Empty_List);
Save_Global_References (Orig_Decl);
Set_Generic_Formal_Declarations (Orig_Decl, Save_Form);
Set_Visible_Declarations (Orig_Spec, Save_Vis);
end;
end if;
Process_End_Label (N, 'e', Id);
-- Remove private_with_clauses of enclosing compilation unit, if they
-- were installed.
if Private_With_Clauses_Installed then
Remove_Private_With_Clauses (Cunit (Current_Sem_Unit));
end if;
-- For the case of a library level package, we must go through all the
-- entities clearing the indications that the value may be constant and
-- not modified. Why? Because any client of this package may modify
-- these values freely from anywhere. This also applies to any nested
-- packages or generic packages.
-- For now we unconditionally clear constants for packages that are
-- instances of generic packages. The reason is that we do not have the
-- body yet, and we otherwise think things are unreferenced when they
-- are not. This should be fixed sometime (the effect is not terrible,
-- we just lose some warnings, and also some cases of value propagation)
-- ???
if Is_Library_Level_Entity (Id)
or else Is_Generic_Instance (Id)
then
Clear_Constants (Id, First_Entity (Id));
Clear_Constants (Id, First_Private_Entity (Id));
end if;
-- Issue an error in SPARK mode if a package specification contains
-- more than one tagged type or type extension.
Check_One_Tagged_Type_Or_Extension_At_Most;
-- If switch set, output information on why body required
if List_Body_Required_Info
and then In_Extended_Main_Source_Unit (Id)
and then Unit_Requires_Body (Id)
then
Unit_Requires_Body_Info (Id);
end if;
end Analyze_Package_Specification;
--------------------------------------
-- Analyze_Private_Type_Declaration --
--------------------------------------
procedure Analyze_Private_Type_Declaration (N : Node_Id) is
PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity);
Id : constant Entity_Id := Defining_Identifier (N);
begin
-- The private type declaration may be subject to pragma Ghost with
-- policy Ignore. Set the mode now to ensure that any nodes generated
-- during analysis and expansion are properly flagged as ignored Ghost.
Set_Ghost_Mode (N);
Generate_Definition (Id);
Set_Is_Pure (Id, PF);
Init_Size_Align (Id);
if not Is_Package_Or_Generic_Package (Current_Scope)
or else In_Private_Part (Current_Scope)
then
Error_Msg_N ("invalid context for private declaration", N);
end if;
New_Private_Type (N, Id, N);
Set_Depends_On_Private (Id);
-- A type declared within a Ghost region is automatically Ghost
-- (SPARK RM 6.9(2)).
if Ghost_Mode > None then
Set_Is_Ghost_Entity (Id);
end if;
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
end if;
end Analyze_Private_Type_Declaration;
----------------------------------
-- Check_Anonymous_Access_Types --
----------------------------------
procedure Check_Anonymous_Access_Types
(Spec_Id : Entity_Id;
P_Body : Node_Id)
is
E : Entity_Id;
IR : Node_Id;
begin
-- Itype references are only needed by gigi, to force elaboration of
-- itypes. In the absence of code generation, they are not needed.
if not Expander_Active then
return;
end if;
E := First_Entity (Spec_Id);
while Present (E) loop
if Ekind (E) = E_Anonymous_Access_Type
and then From_Limited_With (E)
then
IR := Make_Itype_Reference (Sloc (P_Body));
Set_Itype (IR, E);
if No (Declarations (P_Body)) then
Set_Declarations (P_Body, New_List (IR));
else
Prepend (IR, Declarations (P_Body));
end if;
end if;
Next_Entity (E);
end loop;
end Check_Anonymous_Access_Types;
-------------------------------------------
-- Declare_Inherited_Private_Subprograms --
-------------------------------------------
procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is
function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean;
-- Check whether an inherited subprogram S is an operation of an
-- untagged derived type T.
---------------------
-- Is_Primitive_Of --
---------------------
function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is
Formal : Entity_Id;
begin
-- If the full view is a scalar type, the type is the anonymous base
-- type, but the operation mentions the first subtype, so check the
-- signature against the base type.
if Base_Type (Etype (S)) = Base_Type (T) then
return True;
else
Formal := First_Formal (S);
while Present (Formal) loop
if Base_Type (Etype (Formal)) = Base_Type (T) then
return True;
end if;
Next_Formal (Formal);
end loop;
return False;
end if;
end Is_Primitive_Of;
-- Local variables
E : Entity_Id;
Op_List : Elist_Id;
Op_Elmt : Elmt_Id;
Op_Elmt_2 : Elmt_Id;
Prim_Op : Entity_Id;
New_Op : Entity_Id := Empty;
Parent_Subp : Entity_Id;
Tag : Entity_Id;
-- Start of processing for Declare_Inherited_Private_Subprograms
begin
E := First_Entity (Id);
while Present (E) loop
-- If the entity is a nonprivate type extension whose parent type
-- is declared in an open scope, then the type may have inherited
-- operations that now need to be made visible. Ditto if the entity
-- is a formal derived type in a child unit.
if ((Is_Derived_Type (E) and then not Is_Private_Type (E))
or else
(Nkind (Parent (E)) = N_Private_Extension_Declaration
and then Is_Generic_Type (E)))
and then In_Open_Scopes (Scope (Etype (E)))
and then Is_Base_Type (E)
then
if Is_Tagged_Type (E) then
Op_List := Primitive_Operations (E);
New_Op := Empty;
Tag := First_Tag_Component (E);
Op_Elmt := First_Elmt (Op_List);
while Present (Op_Elmt) loop
Prim_Op := Node (Op_Elmt);
-- Search primitives that are implicit operations with an
-- internal name whose parent operation has a normal name.
if Present (Alias (Prim_Op))
and then Find_Dispatching_Type (Alias (Prim_Op)) /= E
and then not Comes_From_Source (Prim_Op)
and then Is_Internal_Name (Chars (Prim_Op))
and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
then
Parent_Subp := Alias (Prim_Op);
-- Case 1: Check if the type has also an explicit
-- overriding for this primitive.
Op_Elmt_2 := Next_Elmt (Op_Elmt);
while Present (Op_Elmt_2) loop
-- Skip entities with attribute Interface_Alias since
-- they are not overriding primitives (these entities
-- link an interface primitive with their covering
-- primitive)
if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp)
and then Type_Conformant (Prim_Op, Node (Op_Elmt_2))
and then No (Interface_Alias (Node (Op_Elmt_2)))
then
-- The private inherited operation has been
-- overridden by an explicit subprogram:
-- replace the former by the latter.
New_Op := Node (Op_Elmt_2);
Replace_Elmt (Op_Elmt, New_Op);
Remove_Elmt (Op_List, Op_Elmt_2);
Set_Overridden_Operation (New_Op, Parent_Subp);
-- We don't need to inherit its dispatching slot.
-- Set_All_DT_Position has previously ensured that
-- the same slot was assigned to the two primitives
if Present (Tag)
and then Present (DTC_Entity (New_Op))
and then Present (DTC_Entity (Prim_Op))
then
pragma Assert
(DT_Position (New_Op) = DT_Position (Prim_Op));
null;
end if;
goto Next_Primitive;
end if;
Next_Elmt (Op_Elmt_2);
end loop;
-- Case 2: We have not found any explicit overriding and
-- hence we need to declare the operation (i.e., make it
-- visible).
Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
-- Inherit the dispatching slot if E is already frozen
if Is_Frozen (E)
and then Present (DTC_Entity (Alias (Prim_Op)))
then
Set_DTC_Entity_Value (E, New_Op);
Set_DT_Position_Value (New_Op,
DT_Position (Alias (Prim_Op)));
end if;
pragma Assert
(Is_Dispatching_Operation (New_Op)
and then Node (Last_Elmt (Op_List)) = New_Op);
-- Substitute the new operation for the old one in the
-- type's primitive operations list. Since the new
-- operation was also just added to the end of list,
-- the last element must be removed.
-- (Question: is there a simpler way of declaring the
-- operation, say by just replacing the name of the
-- earlier operation, reentering it in the in the symbol
-- table (how?), and marking it as private???)
Replace_Elmt (Op_Elmt, New_Op);
Remove_Last_Elmt (Op_List);
end if;
<<Next_Primitive>>
Next_Elmt (Op_Elmt);
end loop;
-- Generate listing showing the contents of the dispatch table
if Debug_Flag_ZZ then
Write_DT (E);
end if;
else
-- For untagged type, scan forward to locate inherited hidden
-- operations.
Prim_Op := Next_Entity (E);
while Present (Prim_Op) loop
if Is_Subprogram (Prim_Op)
and then Present (Alias (Prim_Op))
and then not Comes_From_Source (Prim_Op)
and then Is_Internal_Name (Chars (Prim_Op))
and then not Is_Internal_Name (Chars (Alias (Prim_Op)))
and then Is_Primitive_Of (E, Prim_Op)
then
Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E));
end if;
Next_Entity (Prim_Op);
-- Derived operations appear immediately after the type
-- declaration (or the following subtype indication for
-- a derived scalar type). Further declarations cannot
-- include inherited operations of the type.
if Present (Prim_Op) then
exit when Ekind (Prim_Op) not in Overloadable_Kind;
end if;
end loop;
end if;
end if;
Next_Entity (E);
end loop;
end Declare_Inherited_Private_Subprograms;
-----------------------
-- End_Package_Scope --
-----------------------
procedure End_Package_Scope (P : Entity_Id) is
begin
Uninstall_Declarations (P);
Pop_Scope;
end End_Package_Scope;
---------------------------
-- Exchange_Declarations --
---------------------------
procedure Exchange_Declarations (Id : Entity_Id) is
Full_Id : constant Entity_Id := Full_View (Id);
H1 : constant Entity_Id := Homonym (Id);
Next1 : constant Entity_Id := Next_Entity (Id);
H2 : Entity_Id;
Next2 : Entity_Id;
begin
-- If missing full declaration for type, nothing to exchange
if No (Full_Id) then
return;
end if;
-- Otherwise complete the exchange, and preserve semantic links
Next2 := Next_Entity (Full_Id);
H2 := Homonym (Full_Id);
-- Reset full declaration pointer to reflect the switched entities and
-- readjust the next entity chains.
Exchange_Entities (Id, Full_Id);
Set_Next_Entity (Id, Next1);
Set_Homonym (Id, H1);
Set_Full_View (Full_Id, Id);
Set_Next_Entity (Full_Id, Next2);
Set_Homonym (Full_Id, H2);
end Exchange_Declarations;
----------------------------
-- Install_Package_Entity --
----------------------------
procedure Install_Package_Entity (Id : Entity_Id) is
begin
if not Is_Internal (Id) then
if Debug_Flag_E then
Write_Str ("Install: ");
Write_Name (Chars (Id));
Write_Eol;
end if;
if Is_Child_Unit (Id) then
null;
-- Do not enter implicitly inherited non-overridden subprograms of
-- a tagged type back into visibility if they have non-conformant
-- homographs (Ada RM 8.3 12.3/2).
elsif Is_Hidden_Non_Overridden_Subpgm (Id) then
null;
else
Set_Is_Immediately_Visible (Id);
end if;
end if;
end Install_Package_Entity;
----------------------------------
-- Install_Private_Declarations --
----------------------------------
procedure Install_Private_Declarations (P : Entity_Id) is
Id : Entity_Id;
Full : Entity_Id;
Priv_Deps : Elist_Id;
procedure Swap_Private_Dependents (Priv_Deps : Elist_Id);
-- When the full view of a private type is made available, we do the
-- same for its private dependents under proper visibility conditions.
-- When compiling a grand-chid unit this needs to be done recursively.
-----------------------------
-- Swap_Private_Dependents --
-----------------------------
procedure Swap_Private_Dependents (Priv_Deps : Elist_Id) is
Deps : Elist_Id;
Priv : Entity_Id;
Priv_Elmt : Elmt_Id;
Is_Priv : Boolean;
begin
Priv_Elmt := First_Elmt (Priv_Deps);
while Present (Priv_Elmt) loop
Priv := Node (Priv_Elmt);
-- Before the exchange, verify that the presence of the Full_View
-- field. This field will be empty if the entity has already been
-- installed due to a previous call.
if Present (Full_View (Priv)) and then Is_Visible_Dependent (Priv)
then
if Is_Private_Type (Priv) then
Deps := Private_Dependents (Priv);
Is_Priv := True;
else
Is_Priv := False;
end if;
-- For each subtype that is swapped, we also swap the reference
-- to it in Private_Dependents, to allow access to it when we
-- swap them out in End_Package_Scope.
Replace_Elmt (Priv_Elmt, Full_View (Priv));
Exchange_Declarations (Priv);
Set_Is_Immediately_Visible
(Priv, In_Open_Scopes (Scope (Priv)));
Set_Is_Potentially_Use_Visible
(Priv, Is_Potentially_Use_Visible (Node (Priv_Elmt)));
-- Within a child unit, recurse, except in generic child unit,
-- which (unfortunately) handle private_dependents separately.
if Is_Priv
and then Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
and then not Is_Empty_Elmt_List (Deps)
and then not Inside_A_Generic
then
Swap_Private_Dependents (Deps);
end if;
end if;
Next_Elmt (Priv_Elmt);
end loop;
end Swap_Private_Dependents;
-- Start of processing for Install_Private_Declarations
begin
-- First exchange declarations for private types, so that the full
-- declaration is visible. For each private type, we check its
-- Private_Dependents list and also exchange any subtypes of or derived
-- types from it. Finally, if this is a Taft amendment type, the
-- incomplete declaration is irrelevant, and we want to link the
-- eventual full declaration with the original private one so we
-- also skip the exchange.
Id := First_Entity (P);
while Present (Id) and then Id /= First_Private_Entity (P) loop
if Is_Private_Base_Type (Id)
and then Present (Full_View (Id))
and then Comes_From_Source (Full_View (Id))
and then Scope (Full_View (Id)) = Scope (Id)
and then Ekind (Full_View (Id)) /= E_Incomplete_Type
then
-- If there is a use-type clause on the private type, set the full
-- view accordingly.
Set_In_Use (Full_View (Id), In_Use (Id));
Full := Full_View (Id);
if Is_Private_Base_Type (Full)
and then Has_Private_Declaration (Full)
and then Nkind (Parent (Full)) = N_Full_Type_Declaration
and then In_Open_Scopes (Scope (Etype (Full)))
and then In_Package_Body (Current_Scope)
and then not Is_Private_Type (Etype (Full))
then
-- This is the completion of a private type by a derivation
-- from another private type which is not private anymore. This
-- can only happen in a package nested within a child package,
-- when the parent type is defined in the parent unit. At this
-- point the current type is not private either, and we have
-- to install the underlying full view, which is now visible.
-- Save the current full view as well, so that all views can be
-- restored on exit. It may seem that after compiling the child
-- body there are not environments to restore, but the back-end
-- expects those links to be valid, and freeze nodes depend on
-- them.
if No (Full_View (Full))
and then Present (Underlying_Full_View (Full))
then
Set_Full_View (Id, Underlying_Full_View (Full));
Set_Underlying_Full_View (Id, Full);
Set_Underlying_Full_View (Full, Empty);
Set_Is_Frozen (Full_View (Id));
end if;
end if;
Priv_Deps := Private_Dependents (Id);
Exchange_Declarations (Id);
Set_Is_Immediately_Visible (Id);
Swap_Private_Dependents (Priv_Deps);
end if;
Next_Entity (Id);
end loop;
-- Next make other declarations in the private part visible as well
Id := First_Private_Entity (P);
while Present (Id) loop
Install_Package_Entity (Id);
Set_Is_Hidden (Id, False);
Next_Entity (Id);
end loop;
-- Indicate that the private part is currently visible, so it can be
-- properly reset on exit.
Set_In_Private_Part (P);
end Install_Private_Declarations;
----------------------------------
-- Install_Visible_Declarations --
----------------------------------
procedure Install_Visible_Declarations (P : Entity_Id) is
Id : Entity_Id;
Last_Entity : Entity_Id;
begin
pragma Assert
(Is_Package_Or_Generic_Package (P) or else Is_Record_Type (P));
if Is_Package_Or_Generic_Package (P) then
Last_Entity := First_Private_Entity (P);
else
Last_Entity := Empty;
end if;
Id := First_Entity (P);
while Present (Id) and then Id /= Last_Entity loop
Install_Package_Entity (Id);
Next_Entity (Id);
end loop;
end Install_Visible_Declarations;
--------------------------
-- Is_Private_Base_Type --
--------------------------
function Is_Private_Base_Type (E : Entity_Id) return Boolean is
begin
return Ekind (E) = E_Private_Type
or else Ekind (E) = E_Limited_Private_Type
or else Ekind (E) = E_Record_Type_With_Private;
end Is_Private_Base_Type;
--------------------------
-- Is_Visible_Dependent --
--------------------------
function Is_Visible_Dependent (Dep : Entity_Id) return Boolean
is
S : constant Entity_Id := Scope (Dep);
begin
-- Renamings created for actual types have the visibility of the actual
if Ekind (S) = E_Package
and then Is_Generic_Instance (S)
and then (Is_Generic_Actual_Type (Dep)
or else Is_Generic_Actual_Type (Full_View (Dep)))
then
return True;
elsif not (Is_Derived_Type (Dep))
and then Is_Derived_Type (Full_View (Dep))
then
-- When instantiating a package body, the scope stack is empty, so
-- check instead whether the dependent type is defined in the same
-- scope as the instance itself.
return In_Open_Scopes (S)
or else (Is_Generic_Instance (Current_Scope)
and then Scope (Dep) = Scope (Current_Scope));
else
return True;
end if;
end Is_Visible_Dependent;
----------------------------
-- May_Need_Implicit_Body --
----------------------------
procedure May_Need_Implicit_Body (E : Entity_Id) is
P : constant Node_Id := Unit_Declaration_Node (E);
S : constant Node_Id := Parent (P);
B : Node_Id;
Decls : List_Id;
begin
if not Has_Completion (E)
and then Nkind (P) = N_Package_Declaration
and then (Present (Activation_Chain_Entity (P)) or else Has_RACW (E))
then
B :=
Make_Package_Body (Sloc (E),
Defining_Unit_Name => Make_Defining_Identifier (Sloc (E),
Chars => Chars (E)),
Declarations => New_List);
if Nkind (S) = N_Package_Specification then
if Present (Private_Declarations (S)) then
Decls := Private_Declarations (S);
else
Decls := Visible_Declarations (S);
end if;
else
Decls := Declarations (S);
end if;
Append (B, Decls);
Analyze (B);
end if;
end May_Need_Implicit_Body;
----------------------
-- New_Private_Type --
----------------------
procedure New_Private_Type (N : Node_Id; Id : Entity_Id; Def : Node_Id) is
begin
-- For other than Ada 2012, enter the name in the current scope
if Ada_Version < Ada_2012 then
Enter_Name (Id);
-- Ada 2012 (AI05-0162): Enter the name in the current scope. Note that
-- there may be an incomplete previous view.
else
declare
Prev : Entity_Id;
begin
Prev := Find_Type_Name (N);
pragma Assert (Prev = Id
or else (Ekind (Prev) = E_Incomplete_Type
and then Present (Full_View (Prev))
and then Full_View (Prev) = Id));
end;
end if;
if Limited_Present (Def) then
Set_Ekind (Id, E_Limited_Private_Type);
else
Set_Ekind (Id, E_Private_Type);
end if;
Set_Etype (Id, Id);
Set_Has_Delayed_Freeze (Id);
Set_Is_First_Subtype (Id);
Init_Size_Align (Id);
Set_Is_Constrained (Id,
No (Discriminant_Specifications (N))
and then not Unknown_Discriminants_Present (N));
-- Set tagged flag before processing discriminants, to catch illegal
-- usage.
Set_Is_Tagged_Type (Id, Tagged_Present (Def));
Set_Discriminant_Constraint (Id, No_Elist);
Set_Stored_Constraint (Id, No_Elist);
if Present (Discriminant_Specifications (N)) then
Push_Scope (Id);
Process_Discriminants (N);
End_Scope;
elsif Unknown_Discriminants_Present (N) then
Set_Has_Unknown_Discriminants (Id);
end if;
Set_Private_Dependents (Id, New_Elmt_List);
if Tagged_Present (Def) then
Set_Ekind (Id, E_Record_Type_With_Private);
Set_Direct_Primitive_Operations (Id, New_Elmt_List);
Set_Is_Abstract_Type (Id, Abstract_Present (Def));
Set_Is_Limited_Record (Id, Limited_Present (Def));
Set_Has_Delayed_Freeze (Id, True);
-- Create a class-wide type with the same attributes
Make_Class_Wide_Type (Id);
elsif Abstract_Present (Def) then
Error_Msg_N ("only a tagged type can be abstract", N);
end if;
end New_Private_Type;
---------------------------------
-- Requires_Completion_In_Body --
---------------------------------
function Requires_Completion_In_Body
(Id : Entity_Id;
Pack_Id : Entity_Id) return Boolean
is
begin
-- Always ignore child units. Child units get added to the entity list
-- of a parent unit, but are not original entities of the parent, and
-- so do not affect whether the parent needs a body.
if Is_Child_Unit (Id) then
return False;
-- Ignore formal packages and their renamings
elsif Ekind (Id) = E_Package
and then Nkind (Original_Node (Unit_Declaration_Node (Id))) =
N_Formal_Package_Declaration
then
return False;
-- A Ghost entity declared in a non-Ghost package does not force the
-- need for a body (SPARK RM 6.9(11)).
elsif not Is_Ghost_Entity (Pack_Id) and then Is_Ghost_Entity (Id) then
return False;
-- Otherwise test to see if entity requires a completion. Note that
-- subprogram entities whose declaration does not come from source are
-- ignored here on the basis that we assume the expander will provide an
-- implicit completion at some point.
elsif (Is_Overloadable (Id)
and then Ekind (Id) /= E_Enumeration_Literal
and then Ekind (Id) /= E_Operator
and then not Is_Abstract_Subprogram (Id)
and then not Has_Completion (Id)
and then Comes_From_Source (Parent (Id)))
or else
(Ekind (Id) = E_Package
and then Id /= Pack_Id
and then not Has_Completion (Id)
and then Unit_Requires_Body (Id))
or else
(Ekind (Id) = E_Incomplete_Type
and then No (Full_View (Id))
and then not Is_Generic_Type (Id))
or else
(Ekind_In (Id, E_Task_Type, E_Protected_Type)
and then not Has_Completion (Id))
or else
(Ekind (Id) = E_Generic_Package
and then Id /= Pack_Id
and then not Has_Completion (Id)
and then Unit_Requires_Body (Id))
or else
(Is_Generic_Subprogram (Id)
and then not Has_Completion (Id))
then
return True;
-- Otherwise the entity does not require completion in a package body
else
return False;
end if;
end Requires_Completion_In_Body;
----------------------------
-- Uninstall_Declarations --
----------------------------
procedure Uninstall_Declarations (P : Entity_Id) is
Decl : constant Node_Id := Unit_Declaration_Node (P);
Id : Entity_Id;
Full : Entity_Id;
Priv_Elmt : Elmt_Id;
Priv_Sub : Entity_Id;
procedure Preserve_Full_Attributes (Priv, Full : Entity_Id);
-- Copy to the private declaration the attributes of the full view that
-- need to be available for the partial view also.
function Type_In_Use (T : Entity_Id) return Boolean;
-- Check whether type or base type appear in an active use_type clause
------------------------------
-- Preserve_Full_Attributes --
------------------------------
procedure Preserve_Full_Attributes (Priv, Full : Entity_Id) is
Priv_Is_Base_Type : constant Boolean := Is_Base_Type (Priv);
begin
Set_Size_Info (Priv, (Full));
Set_RM_Size (Priv, RM_Size (Full));
Set_Size_Known_At_Compile_Time
(Priv, Size_Known_At_Compile_Time (Full));
Set_Is_Volatile (Priv, Is_Volatile (Full));
Set_Treat_As_Volatile (Priv, Treat_As_Volatile (Full));
Set_Is_Ada_2005_Only (Priv, Is_Ada_2005_Only (Full));
Set_Is_Ada_2012_Only (Priv, Is_Ada_2012_Only (Full));
Set_Has_Pragma_Unmodified (Priv, Has_Pragma_Unmodified (Full));
Set_Has_Pragma_Unreferenced (Priv, Has_Pragma_Unreferenced (Full));
Set_Has_Pragma_Unreferenced_Objects
(Priv, Has_Pragma_Unreferenced_Objects
(Full));
if Is_Unchecked_Union (Full) then
Set_Is_Unchecked_Union (Base_Type (Priv));
end if;
-- Why is atomic not copied here ???
if Referenced (Full) then
Set_Referenced (Priv);
end if;
if Priv_Is_Base_Type then
Set_Is_Controlled (Priv, Is_Controlled (Base_Type (Full)));
Set_Finalize_Storage_Only
(Priv, Finalize_Storage_Only
(Base_Type (Full)));
Set_Has_Task (Priv, Has_Task (Base_Type (Full)));
Set_Has_Protected (Priv, Has_Protected (Base_Type (Full)));
Set_Has_Controlled_Component
(Priv, Has_Controlled_Component
(Base_Type (Full)));
end if;
Set_Freeze_Node (Priv, Freeze_Node (Full));
-- Propagate information of type invariants, which may be specified
-- for the full view.
if Has_Invariants (Full) and not Has_Invariants (Priv) then
Set_Has_Invariants (Priv);
Set_Subprograms_For_Type (Priv, Subprograms_For_Type (Full));
end if;
if Is_Tagged_Type (Priv)
and then Is_Tagged_Type (Full)
and then not Error_Posted (Full)
then
if Is_Tagged_Type (Priv) then
-- If the type is tagged, the tag itself must be available on
-- the partial view, for expansion purposes.
Set_First_Entity (Priv, First_Entity (Full));
-- If there are discriminants in the partial view, these remain
-- visible. Otherwise only the tag itself is visible, and there
-- are no nameable components in the partial view.
if No (Last_Entity (Priv)) then
Set_Last_Entity (Priv, First_Entity (Priv));
end if;
end if;
Set_Has_Discriminants (Priv, Has_Discriminants (Full));
if Has_Discriminants (Full) then
Set_Discriminant_Constraint (Priv,
Discriminant_Constraint (Full));
end if;
end if;
end Preserve_Full_Attributes;
-----------------
-- Type_In_Use --
-----------------
function Type_In_Use (T : Entity_Id) return Boolean is
begin
return Scope (Base_Type (T)) = P
and then (In_Use (T) or else In_Use (Base_Type (T)));
end Type_In_Use;
-- Start of processing for Uninstall_Declarations
begin
Id := First_Entity (P);
while Present (Id) and then Id /= First_Private_Entity (P) loop
if Debug_Flag_E then
Write_Str ("unlinking visible entity ");
Write_Int (Int (Id));
Write_Eol;
end if;
-- On exit from the package scope, we must preserve the visibility
-- established by use clauses in the current scope. Two cases:
-- a) If the entity is an operator, it may be a primitive operator of
-- a type for which there is a visible use-type clause.
-- b) for other entities, their use-visibility is determined by a
-- visible use clause for the package itself. For a generic instance,
-- the instantiation of the formals appears in the visible part,
-- but the formals are private and remain so.
if Ekind (Id) = E_Function
and then Is_Operator_Symbol_Name (Chars (Id))
and then not Is_Hidden (Id)
and then not Error_Posted (Id)
then
Set_Is_Potentially_Use_Visible (Id,
In_Use (P)
or else Type_In_Use (Etype (Id))
or else Type_In_Use (Etype (First_Formal (Id)))
or else (Present (Next_Formal (First_Formal (Id)))
and then
Type_In_Use
(Etype (Next_Formal (First_Formal (Id))))));
else
if In_Use (P) and then not Is_Hidden (Id) then
-- A child unit of a use-visible package remains use-visible
-- only if it is itself a visible child unit. Otherwise it
-- would remain visible in other contexts where P is use-
-- visible, because once compiled it stays in the entity list
-- of its parent unit.
if Is_Child_Unit (Id) then
Set_Is_Potentially_Use_Visible
(Id, Is_Visible_Lib_Unit (Id));
else
Set_Is_Potentially_Use_Visible (Id);
end if;
else
Set_Is_Potentially_Use_Visible (Id, False);
end if;
end if;
-- Local entities are not immediately visible outside of the package
Set_Is_Immediately_Visible (Id, False);
-- If this is a private type with a full view (for example a local
-- subtype of a private type declared elsewhere), ensure that the
-- full view is also removed from visibility: it may be exposed when
-- swapping views in an instantiation.
if Is_Type (Id) and then Present (Full_View (Id)) then
Set_Is_Immediately_Visible (Full_View (Id), False);
end if;
if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
Check_Abstract_Overriding (Id);
Check_Conventions (Id);
end if;
if Ekind_In (Id, E_Private_Type, E_Limited_Private_Type)
and then No (Full_View (Id))
and then not Is_Generic_Type (Id)
and then not Is_Derived_Type (Id)
then
Error_Msg_N ("missing full declaration for private type&", Id);
elsif Ekind (Id) = E_Record_Type_With_Private
and then not Is_Generic_Type (Id)
and then No (Full_View (Id))
then
if Nkind (Parent (Id)) = N_Private_Type_Declaration then
Error_Msg_N ("missing full declaration for private type&", Id);
else
Error_Msg_N
("missing full declaration for private extension", Id);
end if;
-- Case of constant, check for deferred constant declaration with
-- no full view. Likely just a matter of a missing expression, or
-- accidental use of the keyword constant.
elsif Ekind (Id) = E_Constant
-- OK if constant value present
and then No (Constant_Value (Id))
-- OK if full view present
and then No (Full_View (Id))
-- OK if imported, since that provides the completion
and then not Is_Imported (Id)
-- OK if object declaration replaced by renaming declaration as
-- a result of OK_To_Rename processing (e.g. for concatenation)
and then Nkind (Parent (Id)) /= N_Object_Renaming_Declaration
-- OK if object declaration with the No_Initialization flag set
and then not (Nkind (Parent (Id)) = N_Object_Declaration
and then No_Initialization (Parent (Id)))
then
-- If no private declaration is present, we assume the user did
-- not intend a deferred constant declaration and the problem
-- is simply that the initializing expression is missing.
if not Has_Private_Declaration (Etype (Id)) then
-- We assume that the user did not intend a deferred constant
-- declaration, and the expression is just missing.
Error_Msg_N
("constant declaration requires initialization expression",
Parent (Id));
if Is_Limited_Type (Etype (Id)) then
Error_Msg_N
("\if variable intended, remove CONSTANT from declaration",
Parent (Id));
end if;
-- Otherwise if a private declaration is present, then we are
-- missing the full declaration for the deferred constant.
else
Error_Msg_N
("missing full declaration for deferred constant (RM 7.4)",
Id);
if Is_Limited_Type (Etype (Id)) then
Error_Msg_N
("\if variable intended, remove CONSTANT from declaration",
Parent (Id));
end if;
end if;
end if;
Next_Entity (Id);
end loop;
-- If the specification was installed as the parent of a public child
-- unit, the private declarations were not installed, and there is
-- nothing to do.
if not In_Private_Part (P) then
return;
else
Set_In_Private_Part (P, False);
end if;
-- Make private entities invisible and exchange full and private
-- declarations for private types. Id is now the first private entity
-- in the package.
while Present (Id) loop
if Debug_Flag_E then
Write_Str ("unlinking private entity ");
Write_Int (Int (Id));
Write_Eol;
end if;
if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then
Check_Abstract_Overriding (Id);
Check_Conventions (Id);
end if;
Set_Is_Immediately_Visible (Id, False);
if Is_Private_Base_Type (Id) and then Present (Full_View (Id)) then
Full := Full_View (Id);
-- If the partial view is not declared in the visible part of the
-- package (as is the case when it is a type derived from some
-- other private type in the private part of the current package),
-- no exchange takes place.
if No (Parent (Id))
or else List_Containing (Parent (Id)) /=
Visible_Declarations (Specification (Decl))
then
goto Next_Id;
end if;
-- The entry in the private part points to the full declaration,
-- which is currently visible. Exchange them so only the private
-- type declaration remains accessible, and link private and full
-- declaration in the opposite direction. Before the actual
-- exchange, we copy back attributes of the full view that must
-- be available to the partial view too.
Preserve_Full_Attributes (Id, Full);
Set_Is_Potentially_Use_Visible (Id, In_Use (P));
-- The following test may be redundant, as this is already
-- diagnosed in sem_ch3. ???
if Is_Indefinite_Subtype (Full)
and then not Is_Indefinite_Subtype (Id)
then
Error_Msg_Sloc := Sloc (Parent (Id));
Error_Msg_NE
("full view of& not compatible with declaration#", Full, Id);
end if;
-- Swap out the subtypes and derived types of Id that
-- were compiled in this scope, or installed previously
-- by Install_Private_Declarations.
-- Before we do the swap, we verify the presence of the Full_View
-- field which may be empty due to a swap by a previous call to
-- End_Package_Scope (e.g. from the freezing mechanism).
Priv_Elmt := First_Elmt (Private_Dependents (Id));
while Present (Priv_Elmt) loop
Priv_Sub := Node (Priv_Elmt);
if Present (Full_View (Priv_Sub)) then
if Scope (Priv_Sub) = P
or else not In_Open_Scopes (Scope (Priv_Sub))
then
Set_Is_Immediately_Visible (Priv_Sub, False);
end if;
if Is_Visible_Dependent (Priv_Sub) then
Preserve_Full_Attributes
(Priv_Sub, Full_View (Priv_Sub));
Replace_Elmt (Priv_Elmt, Full_View (Priv_Sub));
Exchange_Declarations (Priv_Sub);
end if;
end if;
Next_Elmt (Priv_Elmt);
end loop;
-- Now restore the type itself to its private view
Exchange_Declarations (Id);
-- If we have installed an underlying full view for a type derived
-- from a private type in a child unit, restore the proper views
-- of private and full view. See corresponding code in
-- Install_Private_Declarations.
-- After the exchange, Full denotes the private type in the
-- visible part of the package.
if Is_Private_Base_Type (Full)
and then Present (Full_View (Full))
and then Present (Underlying_Full_View (Full))
and then In_Package_Body (Current_Scope)
then
Set_Full_View (Full, Underlying_Full_View (Full));
Set_Underlying_Full_View (Full, Empty);
end if;
elsif Ekind (Id) = E_Incomplete_Type
and then Comes_From_Source (Id)
and then No (Full_View (Id))
then
-- Mark Taft amendment types. Verify that there are no primitive
-- operations declared for the type (3.10.1(9)).
Set_Has_Completion_In_Body (Id);
declare
Elmt : Elmt_Id;
Subp : Entity_Id;
begin
Elmt := First_Elmt (Private_Dependents (Id));
while Present (Elmt) loop
Subp := Node (Elmt);
-- Is_Primitive is tested because there can be cases where
-- nonprimitive subprograms (in nested packages) are added
-- to the Private_Dependents list.
if Is_Overloadable (Subp) and then Is_Primitive (Subp) then
Error_Msg_NE
("type& must be completed in the private part",
Parent (Subp), Id);
-- The result type of an access-to-function type cannot be a
-- Taft-amendment type, unless the version is Ada 2012 or
-- later (see AI05-151).
elsif Ada_Version < Ada_2012
and then Ekind (Subp) = E_Subprogram_Type
then
if Etype (Subp) = Id
or else
(Is_Class_Wide_Type (Etype (Subp))
and then Etype (Etype (Subp)) = Id)
then
Error_Msg_NE
("type& must be completed in the private part",
Associated_Node_For_Itype (Subp), Id);
end if;
end if;
Next_Elmt (Elmt);
end loop;
end;
elsif not Is_Child_Unit (Id)
and then (not Is_Private_Type (Id) or else No (Full_View (Id)))
then
Set_Is_Hidden (Id);
Set_Is_Potentially_Use_Visible (Id, False);
end if;
<<Next_Id>>
Next_Entity (Id);
end loop;
end Uninstall_Declarations;
------------------------
-- Unit_Requires_Body --
------------------------
function Unit_Requires_Body
(Pack_Id : Entity_Id;
Ignore_Abstract_State : Boolean := False) return Boolean
is
E : Entity_Id;
begin
-- Imported entity never requires body. Right now, only subprograms can
-- be imported, but perhaps in the future we will allow import of
-- packages.
if Is_Imported (Pack_Id) then
return False;
-- Body required if library package with pragma Elaborate_Body
elsif Has_Pragma_Elaborate_Body (Pack_Id) then
return True;
-- Body required if subprogram
elsif Is_Subprogram_Or_Generic_Subprogram (Pack_Id) then
return True;
-- Treat a block as requiring a body
elsif Ekind (Pack_Id) = E_Block then
return True;
elsif Ekind (Pack_Id) = E_Package
and then Nkind (Parent (Pack_Id)) = N_Package_Specification
and then Present (Generic_Parent (Parent (Pack_Id)))
then
declare
G_P : constant Entity_Id := Generic_Parent (Parent (Pack_Id));
begin
if Has_Pragma_Elaborate_Body (G_P) then
return True;
end if;
end;
-- A [generic] package that introduces at least one non-null abstract
-- state requires completion. However, there is a separate rule that
-- requires that such a package have a reason other than this for a
-- body being required (if necessary a pragma Elaborate_Body must be
-- provided). If Ignore_Abstract_State is True, we don't do this check
-- (so we can use Unit_Requires_Body to check for some other reason).
elsif Ekind_In (Pack_Id, E_Generic_Package, E_Package)
and then not Ignore_Abstract_State
and then Present (Abstract_States (Pack_Id))
and then not Is_Null_State
(Node (First_Elmt (Abstract_States (Pack_Id))))
then
return True;
end if;
-- Otherwise search entity chain for entity requiring completion
E := First_Entity (Pack_Id);
while Present (E) loop
if Requires_Completion_In_Body (E, Pack_Id) then
return True;
end if;
Next_Entity (E);
end loop;
return False;
end Unit_Requires_Body;
-----------------------------
-- Unit_Requires_Body_Info --
-----------------------------
procedure Unit_Requires_Body_Info (Pack_Id : Entity_Id) is
E : Entity_Id;
begin
-- An imported entity never requires body. Right now, only subprograms
-- can be imported, but perhaps in the future we will allow import of
-- packages.
if Is_Imported (Pack_Id) then
return;
-- Body required if library package with pragma Elaborate_Body
elsif Has_Pragma_Elaborate_Body (Pack_Id) then
Error_Msg_N ("info: & requires body (Elaborate_Body)?Y?", Pack_Id);
-- Body required if subprogram
elsif Is_Subprogram_Or_Generic_Subprogram (Pack_Id) then
Error_Msg_N ("info: & requires body (subprogram case)?Y?", Pack_Id);
-- Body required if generic parent has Elaborate_Body
elsif Ekind (Pack_Id) = E_Package
and then Nkind (Parent (Pack_Id)) = N_Package_Specification
and then Present (Generic_Parent (Parent (Pack_Id)))
then
declare
G_P : constant Entity_Id := Generic_Parent (Parent (Pack_Id));
begin
if Has_Pragma_Elaborate_Body (G_P) then
Error_Msg_N
("info: & requires body (generic parent Elaborate_Body)?Y?",
Pack_Id);
end if;
end;
-- A [generic] package that introduces at least one non-null abstract
-- state requires completion. However, there is a separate rule that
-- requires that such a package have a reason other than this for a
-- body being required (if necessary a pragma Elaborate_Body must be
-- provided). If Ignore_Abstract_State is True, we don't do this check
-- (so we can use Unit_Requires_Body to check for some other reason).
elsif Ekind_In (Pack_Id, E_Generic_Package, E_Package)
and then Present (Abstract_States (Pack_Id))
and then not Is_Null_State
(Node (First_Elmt (Abstract_States (Pack_Id))))
then
Error_Msg_N
("info: & requires body (non-null abstract state aspect)?Y?",
Pack_Id);
end if;
-- Otherwise search entity chain for entity requiring completion
E := First_Entity (Pack_Id);
while Present (E) loop
if Requires_Completion_In_Body (E, Pack_Id) then
Error_Msg_Node_2 := E;
Error_Msg_NE
("info: & requires body (& requires completion)?Y?", E, Pack_Id);
end if;
Next_Entity (E);
end loop;
end Unit_Requires_Body_Info;
end Sem_Ch7;