3 files changed, 23 insertions, 6 deletions
diff --git a/src/grt/grt-errors.adb b/src/grt/grt-errors.adb
index 9a48de48e..28ee85963 100644
--- a/src/grt/grt-errors.adb
+++ b/src/grt/grt-errors.adb
@@ -29,6 +29,14 @@ with Grt.Hooks; use Grt.Hooks;
 with Grt.Backtraces;
 
 package body Grt.Errors is
+   --  Output stream to send error messages
+   Out_Stream : FILEs;
+
+   procedure Set_Out_Stream (Stream : Grt.Stdio.FILEs) is
+   begin
+      Out_Stream := Stream;
+   end Set_Out_Stream;
+
    --  Called in case of premature exit.
    --  CODE is 0 for success, 1 for failure.
    procedure Ghdl_Exit (Code : Integer);
@@ -74,27 +82,27 @@ package body Grt.Errors is
 
    procedure Put_Err (Str : String) is
    begin
-      Put (stderr, Str);
+      Put (Out_Stream, Str);
    end Put_Err;
 
    procedure Put_Err (C : Character) is
    begin
-      Put (stderr, C);
+      Put (Out_Stream, C);
    end Put_Err;
 
    procedure Put_Err (Str : Ghdl_C_String) is
    begin
-      Put (stderr, Str);
+      Put (Out_Stream, Str);
    end Put_Err;
 
    procedure Put_Err (N : Integer) is
    begin
-      Put_I32 (stderr, Ghdl_I32 (N));
+      Put_I32 (Out_Stream, Ghdl_I32 (N));
    end Put_Err;
 
    procedure Newline_Err is
    begin
-      New_Line (stderr);
+      New_Line (Out_Stream);
    end Newline_Err;
 
 --    procedure Put_Err (Str : Ghdl_Str_Len_Type)
@@ -133,7 +141,7 @@ package body Grt.Errors is
 
    procedure Report_Now_C is
    begin
-      Put_Time (stderr, Grt.Types.Current_Time);
+      Put_Time (Out_Stream, Grt.Types.Current_Time);
    end Report_Now_C;
 
    procedure Report_E (Str : String) is
diff --git a/src/grt/grt-errors.ads b/src/grt/grt-errors.ads
index 974ef3820..b7ee4c24d 100644
--- a/src/grt/grt-errors.ads
+++ b/src/grt/grt-errors.ads
@@ -24,10 +24,15 @@
 --  covered by the GNU Public License.
 with Grt.Types; use Grt.Types;
 with Grt.Hooks;
+with Grt.Stdio;
 
 package Grt.Errors is
    pragma Preelaborate (Grt.Errors);
 
+   --  Set the stream for error messages.  Must be called before using this
+   --  package.
+   procedure Set_Out_Stream (Stream : Grt.Stdio.FILEs);
+
    --  Multi-call error procedure.
    --  Start and continue with Error_C, finish by an Error_E.
    procedure Error_C (Str : String);
diff --git a/src/grt/grt-main.adb b/src/grt/grt-main.adb
index 4c37e1da7..7bc2bd57f 100644
--- a/src/grt/grt-main.adb
+++ b/src/grt/grt-main.adb
@@ -25,6 +25,7 @@
 with System.Storage_Elements; --  Work around GNAT bug.
 pragma Unreferenced (System.Storage_Elements);
 with Grt.Types; use Grt.Types;
+with Grt.Stdio;
 with Grt.Errors;
 with Grt.Processes;
 with Grt.Signals;
@@ -110,6 +111,9 @@ package body Grt.Main is
       Stop : Boolean;
       Status : Integer;
    begin
+      --  Set stream for error messages
+      Grt.Errors.Set_Out_Stream (Grt.Stdio.stdout);
+
       --  Register modules.
       --  They may insert hooks.
       Grt.Modules.Register_Modules;