1 files changed, 64 insertions, 0 deletions
diff --git a/src/vhdl/iir_chains.adb b/src/vhdl/iir_chains.adb
new file mode 100644
index 000000000..ef47b6485
--- /dev/null
+++ b/src/vhdl/iir_chains.adb
@@ -0,0 +1,64 @@
+--  Chain handling.
+--  Copyright (C) 2002, 2003, 2004, 2005 Tristan Gingold
+--
+--  GHDL is free software; you can redistribute it and/or modify it under
+--  the terms of the GNU General Public License as published by the Free
+--  Software Foundation; either version 2, or (at your option) any later
+--  version.
+--
+--  GHDL is distributed in the hope that it will be useful, but WITHOUT 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
+--  along with GHDL; see the file COPYING.  If not, write to the Free
+--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+--  02111-1307, USA.
+package body Iir_Chains is
+   function Get_Chain_Length (First : Iir) return Natural
+   is
+      Res : Natural := 0;
+      El : Iir := First;
+   begin
+      while El /= Null_Iir loop
+         Res := Res + 1;
+         El := Get_Chain (El);
+      end loop;
+      return Res;
+   end Get_Chain_Length;
+
+   procedure Sub_Chain_Init (First, Last : out Iir) is
+   begin
+      First := Null_Iir;
+      Last := Null_Iir;
+   end Sub_Chain_Init;
+
+   procedure Sub_Chain_Append (First, Last : in out Iir; El : Iir) is
+   begin
+      if First = Null_Iir then
+         First := El;
+      else
+         Set_Chain (Last, El);
+      end if;
+      Last := El;
+   end Sub_Chain_Append;
+
+   function Is_Chain_Length_One (Chain : Iir) return Boolean is
+   begin
+      return Chain /= Null_Iir and then Get_Chain (Chain) = Null_Iir;
+   end Is_Chain_Length_One;
+
+   procedure Insert (Last : Iir; El : Iir) is
+   begin
+      Set_Chain (El, Get_Chain (Last));
+      Set_Chain (Last, El);
+   end Insert;
+
+   procedure Insert_Incr (Last : in out Iir; El : Iir) is
+   begin
+      Set_Chain (El, Get_Chain (Last));
+      Set_Chain (Last, El);
+      Last := El;
+   end Insert_Incr;
+end Iir_Chains;