--vcdz option added,

switched to gcc-4.0.2,
can be compiled with GNAT GPL 2005
ready for ada05 (interface identifier not used anymore)
bug fixes

23 files changed, 327 insertions, 53 deletions

diff --git a/translate/grt/ghwlib.c b/translate/grt/ghwlib.c
index 827e69851..984729246 100644
--- a/translate/grt/ghwlib.c
+++ b/translate/grt/ghwlib.c
@@ -1147,10 +1147,10 @@ ghw_read_cycle_cont (struct ghw_handler *h, int *list)
   list_p = list;
   while (1)
     {
-      int32_t d;
+      uint32_t d;
       
       /* Read delta to next signal.  */
-      if (ghw_read_sleb128 (h, &d) < 0)
+      if (ghw_read_uleb128 (h, &d) < 0)
 	return -1;
       if (d == 0)
 	{
diff --git a/translate/grt/grt-astdio.adb b/translate/grt/grt-astdio.adb
index 3c19cc851..de28094d1 100644
--- a/translate/grt/grt-astdio.adb
+++ b/translate/grt/grt-astdio.adb
@@ -15,6 +15,8 @@
 --  along with GCC; see the file COPYING.  If not, write to the Free
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
+with Grt.C; use Grt.C;
+
 package body Grt.Astdio is
    procedure Put (Stream : FILEs; Str : String)
    is
diff --git a/translate/grt/grt-c.ads b/translate/grt/grt-c.ads
new file mode 100644
index 000000000..33fb36cef
--- /dev/null
+++ b/translate/grt/grt-c.ads
@@ -0,0 +1,36 @@
+--  GHDL Run Time (GRT) - C interface.
+--  Copyright (C) 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 GCC; see the file COPYING.  If not, write to the Free
+--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+--  02111-1307, USA.
+
+--  This package declares C types.
+--  It is a really stripped down version of interfaces.C!
+with System;
+
+package Grt.C is
+   pragma Preelaborate (Grt.C);
+
+   --  Type void * and char *.
+   subtype voids is System.Address;
+   subtype chars is System.Address;
+   subtype long is Long_Integer;
+
+   --  Type size_t.
+   type size_t is mod 2 ** Standard'Address_Size;
+
+   --  Type int.  It is an alias on Integer for simplicity.
+   subtype int is Integer;
+end Grt.C;
diff --git a/translate/grt/grt-disp.adb b/translate/grt/grt-disp.adb
index 9bd803534..a40f0edfe 100644
--- a/translate/grt/grt-disp.adb
+++ b/translate/grt/grt-disp.adb
@@ -15,6 +15,7 @@
 --  along with GCC; see the file COPYING.  If not, write to the Free
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Types; use Grt.Types;
 with Grt.Signals; use Grt.Signals;
 with Grt.Astdio; use Grt.Astdio;
diff --git a/translate/grt/grt-disp_rti.adb b/translate/grt/grt-disp_rti.adb
index 47e5ac6ce..28ad75db5 100644
--- a/translate/grt/grt-disp_rti.adb
+++ b/translate/grt/grt-disp_rti.adb
@@ -21,7 +21,6 @@ with Grt.Stdio; use Grt.Stdio;
 with Grt.Astdio; use Grt.Astdio;
 with Grt.Types; use Grt.Types;
 with Grt.Errors; use Grt.Errors;
---with Grt.Typedesc; use Grt.Typedesc;
 with Grt.Rtis_Addr; use Grt.Rtis_Addr;
 with Grt.Options; use Grt.Options;
 
@@ -649,7 +648,8 @@ package body Grt.Disp_Rti is
       Put (" := ");
 
       --  FIXME: put this into a function.
-      if Obj_Type.Kind = Ghdl_Rtik_Subtype_Array
+      if (Obj_Type.Kind = Ghdl_Rtik_Subtype_Array
+          or Obj_Type.Kind = Ghdl_Rtik_Type_Record)
         and then Obj_Type.Mode = 1
       then
          Addr := To_Addr_Acc (Addr).all;
diff --git a/translate/grt/grt-disp_signals.adb b/translate/grt/grt-disp_signals.adb
index ab73b2d24..0fdf01d23 100644
--- a/translate/grt/grt-disp_signals.adb
+++ b/translate/grt/grt-disp_signals.adb
@@ -16,6 +16,7 @@
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
 with System; use System;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Ada.Unchecked_Conversion;
 with Grt.Types; use Grt.Types;
 with Grt.Rtis; use Grt.Rtis;
diff --git a/translate/grt/grt-files.adb b/translate/grt/grt-files.adb
index d0063226a..151549712 100644
--- a/translate/grt/grt-files.adb
+++ b/translate/grt/grt-files.adb
@@ -17,6 +17,7 @@
 --  02111-1307, USA.
 with Grt.Errors; use Grt.Errors;
 with Grt.Stdio; use Grt.Stdio;
+with Grt.C; use Grt.C;
 with GNAT.Table;
 with System; use System;
 
diff --git a/translate/grt/grt-images.adb b/translate/grt/grt-images.adb
index 8b85d59ec..e322f4775 100644
--- a/translate/grt/grt-images.adb
+++ b/translate/grt/grt-images.adb
@@ -16,6 +16,7 @@
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
 with System; use System;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Ada.Unchecked_Conversion;
 with Grt.Processes; use Grt.Processes;
 with Grt.Vstrings; use Grt.Vstrings;
diff --git a/translate/grt/grt-main.adb b/translate/grt/grt-main.adb
index db57dc81c..99ac86ca8 100644
--- a/translate/grt/grt-main.adb
+++ b/translate/grt/grt-main.adb
@@ -15,9 +15,11 @@
 --  along with GCC; see the file COPYING.  If not, write to the Free
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Types; use Grt.Types;
 with Grt.Errors;
 with Grt.Vcd;
+with Grt.Vcdz;
 with Grt.Vpi;
 with Grt.Waves;
 with Grt.Stacks;
@@ -83,6 +85,7 @@ package body Grt.Main is
    begin
       --  List of modules to be registered.
       Grt.Vcd.Register;
+      Grt.Vcdz.Register;
       Grt.Waves.Register;
       Grt.Vpi.Register;
       Grt.Vital_Annotate.Register;
diff --git a/translate/grt/grt-names.adb b/translate/grt/grt-names.adb
index be4fc8665..46ed04e2d 100644
--- a/translate/grt/grt-names.adb
+++ b/translate/grt/grt-names.adb
@@ -17,6 +17,7 @@
 --  02111-1307, USA.
 --with Grt.Errors; use Grt.Errors;
 with Ada.Unchecked_Conversion;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Processes; use Grt.Processes;
 with Grt.Rtis_Addr; use Grt.Rtis_Addr;
 with Grt.Rtis_Utils; use Grt.Rtis_Utils;
diff --git a/translate/grt/grt-processes.adb b/translate/grt/grt-processes.adb
index a4e269bf9..c0dee2bcb 100644
--- a/translate/grt/grt-processes.adb
+++ b/translate/grt/grt-processes.adb
@@ -18,6 +18,7 @@
 with GNAT.Table;
 with Ada.Unchecked_Conversion;
 with Ada.Unchecked_Deallocation;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Stack2; use Grt.Stack2;
 with Grt.Disp;
 with Grt.Astdio;
diff --git a/translate/grt/grt-sdf.adb b/translate/grt/grt-sdf.adb
index 9d329781c..c7391ccb4 100644
--- a/translate/grt/grt-sdf.adb
+++ b/translate/grt/grt-sdf.adb
@@ -15,8 +15,10 @@
 --  along with GCC; see the file COPYING.  If not, write to the Free
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Types; use Grt.Types;
 with Grt.Stdio; use Grt.Stdio;
+with Grt.C; use Grt.C;
 with Grt.Errors; use Grt.Errors;
 with Ada.Characters.Latin_1;
 with Ada.Unchecked_Deallocation;
diff --git a/translate/grt/grt-signals.adb b/translate/grt/grt-signals.adb
index 9ed8a3227..638c37572 100644
--- a/translate/grt/grt-signals.adb
+++ b/translate/grt/grt-signals.adb
@@ -16,6 +16,7 @@
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
 with System; use System;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Ada.Unchecked_Deallocation;
 with Ada.Unchecked_Conversion;
 with Grt.Errors; use Grt.Errors;
diff --git a/translate/grt/grt-stats.adb b/translate/grt/grt-stats.adb
index 9e3259cd0..284cc6a91 100644
--- a/translate/grt/grt-stats.adb
+++ b/translate/grt/grt-stats.adb
@@ -16,6 +16,7 @@
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
 with System; use System;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Stdio; use Grt.Stdio;
 with Grt.Astdio; use Grt.Astdio;
 with Grt.Signals;
diff --git a/translate/grt/grt-stdio.ads b/translate/grt/grt-stdio.ads
index fad33226b..b600416f2 100644
--- a/translate/grt/grt-stdio.ads
+++ b/translate/grt/grt-stdio.ads
@@ -16,6 +16,7 @@
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
 with System;
+with Grt.C; use Grt.C;
 
 --  This package provides a thin binding to the stdio.h of the C library.
 --  It mimics GNAT package Interfaces.C_Streams.
@@ -35,17 +36,6 @@ package Grt.Stdio is
    function stderr return FILEs;
    function stdin return FILEs;
 
-   --  Type void * and char *.
-   subtype voids is System.Address;
-   subtype chars is System.Address;
-   subtype long is Long_Integer;
-
-   --  Type size_t.
-   type size_t is mod 2 ** Standard'Address_Size;
-
-   --  Type int.  It is an alias on Integer for simplicity.
-   subtype int is Integer;
-
    --  The following subprograms are translation of the C prototypes.
 
    function fopen (path: chars; mode : chars) return FILEs;
diff --git a/translate/grt/grt-vcd.adb b/translate/grt/grt-vcd.adb
index 66f248c5d..f9fd174d2 100644
--- a/translate/grt/grt-vcd.adb
+++ b/translate/grt/grt-vcd.adb
@@ -18,22 +18,52 @@
 with Interfaces;
 with Grt.Stdio; use Grt.Stdio;
 with System; use System;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Errors; use Grt.Errors;
 with Grt.Types; use Grt.Types;
 with Grt.Signals; use Grt.Signals;
 with GNAT.Table;
 with Grt.Astdio; use Grt.Astdio;
+with Grt.C; use Grt.C;
 with Grt.Hooks; use Grt.Hooks;
 with Grt.Avhpi; use Grt.Avhpi;
 with Grt.Rtis; use Grt.Rtis;
 with Grt.Rtis_Addr; use Grt.Rtis_Addr;
 with Grt.Rtis_Types; use Grt.Rtis_Types;
+with Grt.Vstrings;
 
 package body Grt.Vcd is
+   type Vcd_IO_Simple is new Vcd_IO_Handler with record
+      Stream : FILEs;
+   end record;
+   type IO_Simple_Acc is access Vcd_IO_Simple;
+   procedure Vcd_Put (Handler : access Vcd_IO_Simple; Str : String);
+   procedure Vcd_Putc (Handler : access Vcd_IO_Simple; C : Character);
+   procedure Vcd_Close (Handler : access Vcd_IO_Simple);
+
+   procedure Vcd_Put (Handler : access Vcd_IO_Simple; Str : String)
+   is
+      R : size_t;
+   begin
+      R := fwrite (Str'Address, Str'Length, 1, Handler.Stream);
+   end Vcd_Put;
+
+   procedure Vcd_Putc (Handler : access Vcd_IO_Simple; C : Character)
+   is
+      R : int;
+   begin
+      R := fputc (Character'Pos (C), Handler.Stream);
+   end Vcd_Putc;
+
+   procedure Vcd_Close (Handler : access Vcd_IO_Simple) is
+   begin
+      fclose (Handler.Stream);
+      Handler.Stream := NULL_Stream;
+   end Vcd_Close;
+
    --  VCD filename.
-   Vcd_Filename : String_Access := null;
    --  Stream corresponding to the VCD filename.
-   Vcd_Stream : FILEs;
+   --Vcd_Stream : FILEs;
 
    --  Index type of the table of vcd variables to dump.
    type Vcd_Index_Type is new Integer;
@@ -42,15 +72,37 @@ package body Grt.Vcd is
    function Vcd_Option (Opt : String) return Boolean
    is
       F : Natural := Opt'First;
+      Mode : constant String := "wt" & NUL;
+      Handler : IO_Simple_Acc;
+      Vcd_Filename : String_Access;
    begin
       if Opt'Length < 5 or else Opt (F .. F + 4) /= "--vcd" then
          return False;
       end if;
       if Opt'Length > 6 and then Opt (F + 5) = '=' then
+         if H /= null then
+            Error ("--vcd: file already set");
+            return True;
+         end if;
+
          --  Add an extra NUL character.
          Vcd_Filename := new String (1 .. Opt'Length - 6 + 1);
          Vcd_Filename (1 .. Opt'Length - 6) := Opt (F + 6 .. Opt'Last);
          Vcd_Filename (Vcd_Filename'Last) := NUL;
+
+         Handler := new Vcd_IO_Simple;
+         if Vcd_Filename.all = "-" & NUL then
+            Handler.Stream := stdout;
+         else
+            Handler.Stream := fopen (Vcd_Filename.all'Address, Mode'Address);
+            if Handler.Stream = NULL_Stream then
+               Error_C ("cannot open ");
+               Error_E (Vcd_Filename (Vcd_Filename'First
+                                      .. Vcd_Filename'Last - 1));
+               return True;
+            end if;
+         end if;
+         H := Handler_Acc (Handler);
          return True;
       else
          return False;
@@ -62,28 +114,24 @@ package body Grt.Vcd is
       Put_Line (" --vcd=FILENAME     dump signal values into a VCD file");
    end Vcd_Help;
 
-   procedure Vcd_Put (Str : String)
-   is
-      R : size_t;
+   procedure Vcd_Put (Str : String) is
    begin
-      R := fwrite (Str'Address, Str'Length, 1, Vcd_Stream);
+      Vcd_Put (H, Str);
    end Vcd_Put;
 
-   procedure Vcd_Putc (C : Character)
-   is
-      R : int;
+   procedure Vcd_Putc (C : Character) is
    begin
-      R := fputc (Character'Pos (C), Vcd_Stream);
+      Vcd_Putc (H, C);
    end Vcd_Putc;
 
    procedure Vcd_Newline is
    begin
-      Vcd_Putc (Nl);
+      Vcd_Putc (H, Nl);
    end Vcd_Newline;
 
    procedure Vcd_Putline (Str : String) is
    begin
-      Vcd_Put (Str);
+      Vcd_Put (H, Str);
       Vcd_Newline;
    end Vcd_Putline;
 
@@ -95,8 +143,11 @@ package body Grt.Vcd is
 
    procedure Vcd_Put_I32 (V : Ghdl_I32)
    is
+      Str : String (1 .. 11);
+      First : Natural;
    begin
-      Put_I32 (Vcd_Stream, V);
+      Vstrings.To_String (Str, First, V);
+      Vcd_Put (Str (First .. Str'Last));
    end Vcd_Put_I32;
 
    procedure Vcd_Put_Idcode (N : Vcd_Index_Type)
@@ -139,23 +190,10 @@ package body Grt.Vcd is
    --  Called before elaboration.
    procedure Vcd_Init
    is
-      Mode : constant String := "wt" & NUL;
    begin
-      if Vcd_Filename = null then
-         Vcd_Stream := NULL_Stream;
+      if H = null then
          return;
       end if;
-      if Vcd_Filename.all = "-" & NUL then
-         Vcd_Stream := stdout;
-      else
-         Vcd_Stream := fopen (Vcd_Filename.all'Address, Mode'Address);
-         if Vcd_Stream = NULL_Stream then
-            Error_C ("cannot open ");
-            Error_E (Vcd_Filename (Vcd_Filename'First
-                                   .. Vcd_Filename'Last - 1));
-            return;
-         end if;
-      end if;
       Vcd_Putline ("$date");
       Vcd_Put ("  ");
       declare
@@ -165,13 +203,17 @@ package body Grt.Vcd is
          function time (Addr : Address) return time_t;
          pragma Import (C, time);
 
-         function ctime (Timep: Address) return chars;
+         function ctime (Timep: Address) return Ghdl_C_String;
          pragma Import (C, ctime);
 
-         R : int;
+         Ct : Ghdl_C_String;
       begin
          Cur_Time := time (Null_Address);
-         R := fputs (ctime (Cur_Time'Address), Vcd_Stream);
+         Ct := ctime (Cur_Time'Address);
+         for I in Positive loop
+            exit when Ct (I) = NUL;
+            Vcd_Putc (Ct (I));
+         end loop;
          -- Note: ctime already append a LF.
       end;
       Vcd_Put_End;
@@ -639,9 +681,12 @@ package body Grt.Vcd is
 
    procedure Vcd_Put_Time
    is
+      Str : String (1 .. 21);
+      First : Natural;
    begin
       Vcd_Putc ('#');
-      Put_I64 (Vcd_Stream, Ghdl_I64 (Cycle_Time));
+      Vstrings.To_String (Str, First, Ghdl_I64 (Cycle_Time));
+      Vcd_Put (Str (First .. Str'Last));
       Vcd_Newline;
    end Vcd_Put_Time;
 
@@ -653,7 +698,7 @@ package body Grt.Vcd is
       Root : VhpiHandleT;
    begin
       --  Do nothing if there is no VCD file to generate.
-      if Vcd_Stream = NULL_Stream then
+      if H = null then
          return;
       end if;
 
@@ -674,11 +719,6 @@ package body Grt.Vcd is
    --  Called before each non delta cycle.
    procedure Vcd_Cycle is
    begin
-      --  Do nothing if there is no VCD file to generate.
-      if Vcd_Stream = NULL_Stream then
-         return;
-      end if;
-
       --  Disp values.
       Vcd_Put_Time;
       if Cycle_Time = 0 then
@@ -699,7 +739,9 @@ package body Grt.Vcd is
    --  Called at the end of the simulation.
    procedure Vcd_End is
    begin
-      null;
+      if H /= null then
+         Vcd_Close (H);
+      end if;
    end Vcd_End;
 
    Vcd_Hooks : aliased constant Hooks_Type :=
diff --git a/translate/grt/grt-vcd.ads b/translate/grt/grt-vcd.ads
index 40b9d8c5e..a6d79b402 100644
--- a/translate/grt/grt-vcd.ads
+++ b/translate/grt/grt-vcd.ads
@@ -20,6 +20,18 @@ with Grt.Types; use Grt.Types;
 with Grt.Avhpi; use Grt.Avhpi;
 
 package Grt.Vcd is
+   --  Abstract type for IO.
+   type Vcd_IO_Handler is abstract tagged null record;
+   procedure Vcd_Put (Handler : access Vcd_IO_Handler; Str : String)
+      is abstract;
+   procedure Vcd_Putc (Handler : access Vcd_IO_Handler; C : Character)
+      is abstract;
+   procedure Vcd_Close (Handler : access Vcd_IO_Handler)
+      is abstract;
+
+   type Handler_Acc is access all Vcd_IO_Handler'Class;
+   H : Handler_Acc := null;
+
    type Vcd_Var_Kind is (Vcd_Bad,
                          Vcd_Bool,
                          Vcd_Integer32,
diff --git a/translate/grt/grt-vcdz.adb b/translate/grt/grt-vcdz.adb
new file mode 100644
index 000000000..7b5144ee2
--- /dev/null
+++ b/translate/grt/grt-vcdz.adb
@@ -0,0 +1,112 @@
+--  GHDL Run Time (GRT) - VCD .gz module.
+--  Copyright (C) 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 GCC; see the file COPYING.  If not, write to the Free
+--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+--  02111-1307, USA.
+with System.Storage_Elements; --  Work around GNAT bug.
+with Grt.Vcd; use Grt.Vcd;
+with Grt.Errors; use Grt.Errors;
+with Grt.Types; use Grt.Types;
+with Grt.Astdio; use Grt.Astdio;
+with Grt.Hooks; use Grt.Hooks;
+with Grt.Zlib; use Grt.Zlib;
+with Grt.C; use Grt.C;
+
+package body Grt.Vcdz is
+   type Vcd_IO_Gzip is new Vcd_IO_Handler with record
+      Stream : gzFile;
+   end record;
+   type IO_Gzip_Acc is access Vcd_IO_Gzip;
+   procedure Vcd_Put (Handler : access Vcd_IO_Gzip; Str : String);
+   procedure Vcd_Putc (Handler : access Vcd_IO_Gzip; C : Character);
+   procedure Vcd_Close (Handler : access Vcd_IO_Gzip);
+
+   procedure Vcd_Put (Handler : access Vcd_IO_Gzip; Str : String)
+   is
+      R : int;
+   begin
+      R := gzwrite (Handler.Stream, Str'Address, Str'Length);
+   end Vcd_Put;
+
+   procedure Vcd_Putc (Handler : access Vcd_IO_Gzip; C : Character)
+   is
+      R : int;
+   begin
+      R := gzputc (Handler.Stream, Character'Pos (C));
+   end Vcd_Putc;
+
+   procedure Vcd_Close (Handler : access Vcd_IO_Gzip) is
+   begin
+      gzclose (Handler.Stream);
+      Handler.Stream := NULL_gzFile;
+   end Vcd_Close;
+
+   --  VCD filename.
+
+   --  Return TRUE if OPT is an option for VCD.
+   function Vcdz_Option (Opt : String) return Boolean
+   is
+      F : Natural := Opt'First;
+      Vcd_Filename : String_Access := null;
+      Handler : IO_Gzip_Acc;
+      Mode : constant String := "wb" & NUL;
+   begin
+      if Opt'Length < 7 or else Opt (F .. F + 6) /= "--vcdgz" then
+         return False;
+      end if;
+      if Opt'Length > 7 and then Opt (F + 7) = '=' then
+         if H /= null then
+            Error ("--vcdz: file already set");
+            return True;
+         end if;
+
+         --  Add an extra NUL character.
+         Vcd_Filename := new String (1 .. Opt'Length - 8 + 1);
+         Vcd_Filename (1 .. Opt'Length - 8) := Opt (F + 8 .. Opt'Last);
+         Vcd_Filename (Vcd_Filename'Last) := NUL;
+
+         Handler := new Vcd_IO_Gzip;
+         Handler.Stream := gzopen (Vcd_Filename.all'Address, Mode'Address);
+         if Handler.Stream = NULL_gzFile then
+            Error_C ("cannot open ");
+            Error_E (Vcd_Filename (Vcd_Filename'First
+                                   .. Vcd_Filename'Last - 1));
+            return True;
+         end if;
+         H := Handler_Acc (Handler);
+         return True;
+      else
+         return False;
+      end if;
+   end Vcdz_Option;
+
+   procedure Vcdz_Help is
+   begin
+      Put_Line
+        (" --vcdgz=FILENAME   dump signal values into a VCD gzip'ed file");
+   end Vcdz_Help;
+
+   Vcdz_Hooks : aliased constant Hooks_Type :=
+     (Option => Vcdz_Option'Access,
+      Help => Vcdz_Help'Access,
+      Init => Proc_Hook_Nil'Access,
+      Start => Proc_Hook_Nil'Access,
+      Finish => Proc_Hook_Nil'Access);
+
+   procedure Register is
+   begin
+      Register_Hooks (Vcdz_Hooks'Access);
+   end Register;
+end Grt.Vcdz;
diff --git a/translate/grt/grt-vcdz.ads b/translate/grt/grt-vcdz.ads
new file mode 100644
index 000000000..c213efb16
--- /dev/null
+++ b/translate/grt/grt-vcdz.ads
@@ -0,0 +1,21 @@
+--  GHDL Run Time (GRT) - VCD .gz module.
+--  Copyright (C) 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 GCC; see the file COPYING.  If not, write to the Free
+--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+--  02111-1307, USA.
+
+package Grt.Vcdz is
+   procedure Register;
+end Grt.Vcdz;
diff --git a/translate/grt/grt-vpi.adb b/translate/grt/grt-vpi.adb
index 0609d466c..f6c5c56ad 100644
--- a/translate/grt/grt-vpi.adb
+++ b/translate/grt/grt-vpi.adb
@@ -39,7 +39,9 @@
 -------------------------------------------------------------------------------
 
 with Ada.Unchecked_Deallocation;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Stdio; use Grt.Stdio;
+with Grt.C; use Grt.C;
 with Grt.Signals; use Grt.Signals;
 with GNAT.Table;
 with Grt.Astdio; use Grt.Astdio;
diff --git a/translate/grt/grt-vstrings.adb b/translate/grt/grt-vstrings.adb
index 17c64e3da..d17cc87ea 100644
--- a/translate/grt/grt-vstrings.adb
+++ b/translate/grt/grt-vstrings.adb
@@ -15,7 +15,9 @@
 --  along with GCC; see the file COPYING.  If not, write to the Free
 --  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 --  02111-1307, USA.
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Errors; use Grt.Errors;
+with Grt.C; use Grt.C;
 
 package body Grt.Vstrings is
    procedure Free (Fs : Fat_String_Acc);
diff --git a/translate/grt/grt-waves.adb b/translate/grt/grt-waves.adb
index 93f217e82..c571cfabf 100644
--- a/translate/grt/grt-waves.adb
+++ b/translate/grt/grt-waves.adb
@@ -18,9 +18,11 @@
 with Ada.Unchecked_Conversion;
 with Ada.Unchecked_Deallocation;
 with Interfaces; use Interfaces;
+with System.Storage_Elements; --  Work around GNAT bug.
 with Grt.Types; use Grt.Types;
 with Grt.Avhpi; use Grt.Avhpi;
 with Grt.Stdio; use Grt.Stdio;
+with Grt.C; use Grt.C;
 with Grt.Errors; use Grt.Errors;
 with Grt.Types; use Grt.Types;
 with Grt.Astdio; use Grt.Astdio;
diff --git a/translate/grt/grt-zlib.ads b/translate/grt/grt-zlib.ads
new file mode 100644
index 000000000..6b674ca03
--- /dev/null
+++ b/translate/grt/grt-zlib.ads
@@ -0,0 +1,40 @@
+--  GHDL Run Time (GRT) - Zlib binding.
+--  Copyright (C) 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 GCC; see the file COPYING.  If not, write to the Free
+--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+--  02111-1307, USA.
+
+with System; use System;
+with Grt.C; use Grt.C;
+
+package Grt.Zlib is
+   pragma Linker_Options ("-lz");
+
+   type gzFile is new System.Address;
+
+   NULL_gzFile : constant gzFile := gzFile (System'To_Address (0));
+
+   function gzputc (File : gzFile; C : int) return int;
+   pragma Import (C, gzputc);
+
+   function gzwrite (File : gzFile; Buf : voids; Len : int) return int;
+   pragma Import (C, gzwrite);
+
+   function gzopen (Path : chars; Mode : chars) return gzFile;
+   pragma Import (C, gzopen);
+
+   procedure gzclose (File : gzFile);
+   pragma Import (C, gzclose);
+end Grt.Zlib;