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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ S M E M --
-- --
-- B o d y --
-- --
-- Copyright (C) 1998-2015, 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. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Einfo; use Einfo;
with Errout; use Errout;
with Namet; use Namet;
with Sem_Aux; use Sem_Aux;
with Sinfo; use Sinfo;
with Snames; use Snames;
package body Sem_Smem is
function Contains_Access_Type (T : Entity_Id) return Boolean;
-- This function determines if type T is an access type, or contains
-- a component (array, record, protected type cases) that contains
-- an access type (recursively defined in the appropriate manner).
----------------------
-- Check_Shared_Var --
----------------------
procedure Check_Shared_Var
(Id : Entity_Id;
T : Entity_Id;
N : Node_Id)
is
begin
-- We cannot tolerate aliased variables, because they might be
-- modified via an aliased pointer, and we could not detect that
-- this was happening (to update the corresponding shared memory
-- file), so we must disallow all use of Aliased
if Aliased_Present (N) then
Error_Msg_N
("aliased variables " &
"not supported in Shared_Passive partitions",
N);
-- We can't support access types at all, since they are local
-- pointers that cannot in any simple way be transmitted to other
-- partitions.
elsif Is_Access_Type (T) then
Error_Msg_N
("access type variables " &
"not supported in Shared_Passive partitions",
Id);
-- We cannot tolerate types that contain access types, same reasons
elsif Contains_Access_Type (T) then
Error_Msg_N
("types containing access components " &
"not supported in Shared_Passive partitions",
Id);
-- Objects with default-initialized types will be rejected when
-- the initialization code is generated. However we must flag tasks
-- earlier on, to prevent expansion of stream attributes that is
-- bound to fail.
elsif Has_Task (T) then
Error_Msg_N
("Shared_Passive partitions cannot contain tasks", Id);
-- Currently we do not support unconstrained record types, since we
-- use 'Write to write out values. This could probably be special
-- cased and handled in the future if necessary.
elsif Is_Record_Type (T)
and then not Is_Constrained (T)
and then (Nkind (N) /= N_Object_Declaration
or else No (Expression (N)))
then
Error_Msg_N
("unconstrained variant records " &
"not supported in Shared_Passive partitions",
Id);
end if;
end Check_Shared_Var;
--------------------------
-- Contains_Access_Type --
--------------------------
function Contains_Access_Type (T : Entity_Id) return Boolean is
C : Entity_Id;
begin
if Is_Access_Type (T) then
return True;
elsif Is_Array_Type (T) then
return Contains_Access_Type (Component_Type (T));
elsif Is_Record_Type (T) then
if Has_Discriminants (T) then
-- Check for access discriminants.
C := First_Discriminant (T);
while Present (C) loop
if Is_Access_Type (Etype (C)) then
return True;
else
C := Next_Discriminant (C);
end if;
end loop;
end if;
C := First_Component (T);
while Present (C) loop
-- For components, ignore internal components other than _Parent
if Comes_From_Source (T)
and then
(Chars (C) = Name_uParent
or else
not Is_Internal_Name (Chars (C)))
and then Contains_Access_Type (Etype (C))
then
return True;
else
C := Next_Component (C);
end if;
end loop;
return False;
elsif Is_Protected_Type (T) then
return Contains_Access_Type (Corresponding_Record_Type (T));
else
return False;
end if;
end Contains_Access_Type;
end Sem_Smem;
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