163 lines
5.9 KiB
Ada
163 lines
5.9 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- S E M _ S M E M --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1998-2020, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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-- for more details. You should have received a copy of the GNU General --
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-- Public License distributed with GNAT; see file COPYING3. If not, go to --
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-- http://www.gnu.org/licenses for a complete copy of the license. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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with Atree; use Atree;
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with Einfo; use Einfo;
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with Errout; use Errout;
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with Namet; use Namet;
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with Sem_Aux; use Sem_Aux;
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with Sinfo; use Sinfo;
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with Snames; use Snames;
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package body Sem_Smem is
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function Contains_Access_Type (T : Entity_Id) return Boolean;
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-- This function determines if type T is an access type, or contains
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-- a component (array, record, protected type cases) that contains
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-- an access type (recursively defined in the appropriate manner).
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----------------------
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-- Check_Shared_Var --
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----------------------
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procedure Check_Shared_Var
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(Id : Entity_Id;
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T : Entity_Id;
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N : Node_Id)
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is
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begin
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-- We cannot tolerate aliased variables, because they might be
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-- modified via an aliased pointer, and we could not detect that
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-- this was happening (to update the corresponding shared memory
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-- file), so we must disallow all use of Aliased
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if Aliased_Present (N) then
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Error_Msg_N
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("aliased variables " &
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"not supported in Shared_Passive partitions",
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N);
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-- We can't support access types at all, since they are local
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-- pointers that cannot in any simple way be transmitted to other
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-- partitions.
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elsif Is_Access_Type (T) then
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Error_Msg_N
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("access type variables " &
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"not supported in Shared_Passive partitions",
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Id);
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-- We cannot tolerate types that contain access types, same reasons
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elsif Contains_Access_Type (T) then
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Error_Msg_N
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("types containing access components " &
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"not supported in Shared_Passive partitions",
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Id);
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-- Objects with default-initialized types will be rejected when
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-- the initialization code is generated. However we must flag tasks
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-- earlier on, to prevent expansion of stream attributes that is
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-- bound to fail.
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elsif Has_Task (T) then
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Error_Msg_N
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("Shared_Passive partitions cannot contain tasks", Id);
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-- Currently we do not support unconstrained record types, since we
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-- use 'Write to write out values. This could probably be special
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-- cased and handled in the future if necessary.
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elsif Is_Record_Type (T)
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and then not Is_Constrained (T)
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and then (Nkind (N) /= N_Object_Declaration
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or else No (Expression (N)))
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then
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Error_Msg_N
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("unconstrained variant records " &
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"not supported in Shared_Passive partitions",
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Id);
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end if;
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end Check_Shared_Var;
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--------------------------
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-- Contains_Access_Type --
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--------------------------
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function Contains_Access_Type (T : Entity_Id) return Boolean is
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C : Entity_Id;
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begin
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if Is_Access_Type (T) then
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return True;
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elsif Is_Array_Type (T) then
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return Contains_Access_Type (Component_Type (T));
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elsif Is_Record_Type (T) then
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if Has_Discriminants (T) then
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-- Check for access discriminants.
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C := First_Discriminant (T);
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while Present (C) loop
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if Is_Access_Type (Etype (C)) then
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return True;
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else
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Next_Discriminant (C);
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end if;
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end loop;
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end if;
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C := First_Component (T);
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while Present (C) loop
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-- For components, ignore internal components other than _Parent
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if Comes_From_Source (T)
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and then
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(Chars (C) = Name_uParent
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or else
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not Is_Internal_Name (Chars (C)))
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and then Contains_Access_Type (Etype (C))
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then
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return True;
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else
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Next_Component (C);
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end if;
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end loop;
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return False;
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elsif Is_Protected_Type (T) then
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return Contains_Access_Type (Corresponding_Record_Type (T));
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else
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return False;
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end if;
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end Contains_Access_Type;
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end Sem_Smem;
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