Re: RFA: Support Windows extended error numbers in safe_strerror

[Daniel Jacobowitz <drow at false dot org>]

On Fri, Feb 03, 2006 at 04:54:55PM -0500, Daniel Jacobowitz wrote:
> This is an improved version of a patch Mark Mitchell submitted last
> year.  If you give strerror() anything above 42 (sys_nerr) on Windows,
> it gives you back "Unknown error" - particularly unfortunate since
> WSAECONNREFUSED is way above there, so connecting to a closed socket
> will give you a generic error message.  This patch lets us try an
> OS-specific interface to fetch an error string.
> 
> [Actually you need my next patch too to get the connection refused message;
> right now you'll get a timeout.]
> 
> Any comments on this patch?

There were plenty :-)  Is this better?

We had finally eliminated the XM files in favor of autoconf checks.
This patch re-adds an xm-*.h header file, but I think it's still
the best of our options.  We can restrict our use of these headers
to things where autoconf is a bad fit - like right here.

Rather than creating a .mh file and setting XM_FILE there, I added
this and an equivalent to TDEPFILES to configure.host.  This is in
line with discussion I vaguely remember from last year that the
makefile fragments were not a preferable solution for this sort
of thing.  I do agree that it looks more elegant this way.

-- 
Daniel Jacobowitz
CodeSourcery

2006-02-06  Daniel Jacobowitz  <dan@codesourcery.com>

	* Makefile.in (mingw-hdep.o): New dependencies.
	* configure.ac: Add gdb_host_obs to CONFIG_OBS.  Don't fetch hostfile
	from host_makefile_frag.  Remove obsolete comment.  Rename hostfile
	to gdb_hostfile.
	* configure: Regenerated.
	* configure.host: Document gdb_host_obs and gdb_hostfile.  Add
	an entry for i[34567]86-*-mingw32*.
	* mingw-hdep.c, config/i386/xm-mingw.h: New files.

Index: src/gdb/Makefile.in
===================================================================
--- src.orig/gdb/Makefile.in	2006-02-06 10:58:30.000000000 -0500
+++ src/gdb/Makefile.in	2006-02-06 12:27:15.000000000 -0500
@@ -2280,6 +2280,7 @@ memattr.o: memattr.c $(defs_h) $(command
 	$(target_h) $(value_h) $(language_h) $(gdb_string_h)
 mem-break.o: mem-break.c $(defs_h) $(symtab_h) $(breakpoint_h) $(inferior_h) \
 	$(target_h)
+mingw-hdep.o: mingw-hdep.c $(defs_h) $(gdb_string_h)
 minsyms.o: minsyms.c $(defs_h) $(gdb_string_h) $(symtab_h) $(bfd_h) \
 	$(symfile_h) $(objfiles_h) $(demangle_h) $(value_h) $(cp_abi_h)
 mips64obsd-nat.o: mips64obsd-nat.c $(defs_h) $(inferior_h) $(regcache_h) \
Index: src/gdb/configure.ac
===================================================================
--- src.orig/gdb/configure.ac	2006-02-06 10:58:30.000000000 -0500
+++ src/gdb/configure.ac	2006-02-06 12:06:48.000000000 -0500
@@ -1225,6 +1225,9 @@ case ${host} in
 esac	    
 AC_SUBST(WIN32LIBS)
 
+# Add any host-specific objects to GDB.
+CONFIG_OBS="${CONFIG_OBS} ${gdb_host_obs}"
+
 LIBGUI="../libgui/src/libgui.a"
 GUI_CFLAGS_X="-I${srcdir}/../libgui/src"
 AC_SUBST(LIBGUI)
@@ -1443,10 +1446,6 @@ AC_SUBST_FILE(target_makefile_frag)
 AC_SUBST(frags)
 
 changequote(,)dnl
-hostfile=`sed -n '
-s/XM_FILE[ 	]*=[ 	]*\([^ 	]*\)/\1/p
-' ${host_makefile_frag}`
-
 targetfile=`sed -n '
 s/DEPRECATED_TM_FILE[ 	]*=[ 	]*\([^ 	]*\)/\1/p
 ' ${target_makefile_frag}`
@@ -1494,20 +1493,16 @@ if test "x$build_nlm" = xyes; then
    AC_CONFIG_SUBDIRS(nlm)
 fi
 
-# If hostfile (XM_FILE) and/or targetfile (DEPRECATED_TM_FILE) and/or
-# nativefile (NAT_FILE) is not set in config/*/*.m[ht] files, we link
-# to an empty version.
-
 files=
 links=
 
 rm -f xm.h
 xm_h=""
-if test "${hostfile}" != ""; then
+if test "${gdb_hostfile}" != ""; then
     xm_h=xm.h
-    case "${hostfile}" in
-      xm-*.h ) GDB_XM_FILE="config/${gdb_host_cpu}/${hostfile}" ;;
-      * ) GDB_XM_FILE="${hostfile}"
+    case "${gdb_hostfile}" in
+      xm-*.h ) GDB_XM_FILE="config/${gdb_host_cpu}/${gdb_hostfile}" ;;
+      * ) GDB_XM_FILE="${gdb_hostfile}"
     esac
     files="${files} ${GDB_XM_FILE}"
     links="${links} xm.h"
Index: src/gdb/configure.host
===================================================================
--- src.orig/gdb/configure.host	2005-05-22 15:11:42.000000000 -0400
+++ src/gdb/configure.host	2006-02-06 12:29:41.000000000 -0500
@@ -7,6 +7,8 @@
 #  gdb_host_float_format	host's float floatformat, or 0
 #  gdb_host_double_format	host's double floatformat, or 0
 #  gdb_host_long_double_format	host's long double floatformat, or 0
+#  gdb_host_obs			host-specific .o files to include
+#  gdb_hostfile			host-specific .h file to include
 
 # Map host cpu into the config cpu subdirectory name.
 # The default is $host_cpu.
@@ -64,6 +66,10 @@ i[34567]86-*-netbsdelf* | i[34567]86-*-k
 			gdb_host=nbsdelf ;;
 i[34567]86-*-netbsd*)	gdb_host=nbsdaout ;;
 i[34567]86-*-go32*)	gdb_host=go32 ;;
+i[34567]86-*-mingw32*)	gdb_host=mingw
+			gdb_host_obs=mingw-hdep.o
+			gdb_hostfile=xm-mingw.h
+			;;
 i[34567]86-*-msdosdjgpp*) gdb_host=go32 ;;
 i[34567]86-*-linux*)	gdb_host=linux ;;
 i[34567]86-*-lynxos*)	gdb_host=i386lynx ;;
Index: src/gdb/config/i386/xm-mingw.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ src/gdb/config/i386/xm-mingw.h	2006-02-06 12:28:38.000000000 -0500
@@ -0,0 +1,26 @@
+/* Host support for i386 running under MinGW.
+
+   Copyright (C) 2006
+   Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program 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 of the License, or
+   (at your option) any later version.
+
+   This program 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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* The standard strerror is too unfriendly in some cases; we provide our
+   own.  */
+char *mingw_strerror (int);
+#define strerror mingw_strerror
Index: src/gdb/mingw-hdep.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ src/gdb/mingw-hdep.c	2006-02-06 12:29:23.000000000 -0500
@@ -0,0 +1,62 @@
+/* Host support routines for MinGW, for GDB, the GNU debugger.
+
+   Copyright (C) 2006
+   Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program 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 of the License, or
+   (at your option) any later version.
+
+   This program 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 this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+#include "defs.h"
+#include "gdb_string.h"
+
+#include <windows.h>
+
+/* The Windows runtime implementation of strerror never returns NULL,
+   but does return a useless string for anything above sys_nerr;
+   unfortunately this includes all socket-related error codes.
+   This replacement tries to find a system-provided error message.  */
+
+char *
+mingw_strerror (int errnum)
+{
+  static char *buffer;
+  int len;
+
+  if (errnum >= 0 && errnum < sys_nerr)
+    return strerror (errnum);
+
+  if (buffer)
+    {
+      LocalFree (buffer);
+      buffer = NULL;
+    }
+
+  if (FormatMessage (FORMAT_MESSAGE_ALLOCATE_BUFFER
+		     | FORMAT_MESSAGE_FROM_SYSTEM,
+		     NULL, errnum,
+		     MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
+		     (LPTSTR) &buffer, 0, NULL) == 0)
+    return NULL;
+
+  /* Windows error messages end with a period and a CR-LF; strip them
+     out.  */
+  len = strlen (buffer);
+  if (len > 3 && strcmp (buffer + len - 3, ".\r\n") == 0)
+    buffer[len - 3] = '\0';
+
+  return buffer;
+}