Re: RFA: Support Windows extended error numbers in safe_strerror

Daniel Jacobowitz
2006-02-09T22:37:26Z

On Wed, Feb 08, 2006 at 10:07:59PM +0100, Mark Kettenis wrote:
> My dislike for this stuff is probably there because where I've been
> cleaning out much of the host-specific quirks, this MinGW support
> seems to add back a lot special tweaks, and since Windows is so
> different from Unix-like systems, there's absolutely no hope, things
> can be unified. That, together with the reintroduction of xm.h, seems
> like a giant leap backwards to me. I really don't like that xm.h is
> back now, since it sets a precedent. People have used these files for
> quick hacks in the past, and the new xm.h will make it harder to tell
> people that's not acceptable. I think there is a better approach
> though. How about having the implementation of safe_strerror() and
> gdb_select() in mingw-hdep.c and move the (trivial) existing
> implementations of these functions to a new posix-hdep.c?

I really dislike _this_ precedent: Don't allow the existance of xm.h
because people abused it in the past. That's what review is for,
right?

Anyway, here's a patch updated in every way I can think of to make it
less upsetting. Is this really better? Select to follow in the proper
thread.

--
Daniel Jacobowitz
CodeSourcery

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

* Makefile.in (mingw-hdep.o, posix-hdep.o): New dependencies.
(ALLDEPFILES): Add mingw-hdep.c and posix-hdep.c.
* configure.ac: Add gdb_host_obs to CONFIG_OBS. Set gdb_host_obs
to posix-hdep.o by default.
* configure: Regenerated.
* configure.host: Document gdb_host_obs. Add an entry for
i[34567]86-*-mingw32*.
* mingw-hdep.c, posix-hdep.c: New files.
* utils.c (safe_strerror): Remove, moved to posix-hdep.o.

Index: src/gdb/Makefile.in
===================================================================
--- src.orig/gdb/Makefile.in 2006-02-09 13:28:51.000000000 -0500
+++ src/gdb/Makefile.in 2006-02-09 16:50:17.000000000 -0500
@@ -1422,6 +1422,7 @@ ALLDEPFILES = \
m68kbsd-nat.c m68kbsd-tdep.c \
m68klinux-nat.c m68klinux-tdep.c \
m88k-tdep.c m88kbsd-nat.c \
+ mingw-hdep.c \
mips-linux-nat.c mips-linux-tdep.c \
mips-irix-tdep.c \
mips-tdep.c mipsv4-nat.c \
@@ -1430,6 +1431,7 @@ ALLDEPFILES = \
nbsd-tdep.c obsd-tdep.c \
solib-osf.c \
somread.c solib-som.c $(HPREAD_SOURCE) \
+ posix-hdep.c \
ppc-sysv-tdep.c ppc-linux-nat.c ppc-linux-tdep.c \
ppcnbsd-nat.c ppcnbsd-tdep.c \
ppcobsd-nat.c ppcobsd-tdep.c \
@@ -2280,6 +2282,7 @@ 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) \
@@ -2375,6 +2378,7 @@ p-exp.o: p-exp.c $(defs_h) $(gdb_string_
p-lang.o: p-lang.c $(defs_h) $(gdb_string_h) $(symtab_h) $(gdbtypes_h) \
$(expression_h) $(parser_defs_h) $(language_h) $(p_lang_h) \
$(valprint_h) $(value_h)
+posix-hdep.o: posix-hdep.c $(defs_h)
ppc-bdm.o: ppc-bdm.c $(defs_h) $(gdbcore_h) $(gdb_string_h) $(frame_h) \
$(inferior_h) $(bfd_h) $(symfile_h) $(target_h) $(gdbcmd_h) \
$(objfiles_h) $(gdb_stabs_h) $(serial_h) $(ocd_h) $(ppc_tdep_h) \
Index: src/gdb/configure.ac
===================================================================
--- src.orig/gdb/configure.ac 2006-02-09 13:28:51.000000000 -0500
+++ src/gdb/configure.ac 2006-02-09 16:52:25.000000000 -0500
@@ -112,6 +112,10 @@ AC_DEFINE_DIR(DEBUGDIR, debugdir,

AC_CONFIG_SUBDIRS(doc testsuite)

+# Provide defaults for some variables set by the per-host and per-target
+# configuration.
+gdb_host_obs=posix-hdep.o
+
. $srcdir/configure.host

. $srcdir/configure.tgt
@@ -1225,6 +1229,9 @@ 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)
Index: src/gdb/configure.host
===================================================================
--- src.orig/gdb/configure.host 2006-02-09 13:28:51.000000000 -0500
+++ src/gdb/configure.host 2006-02-09 16:52:12.000000000 -0500
@@ -7,6 +7,7 @@
# 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

# Map host cpu into the config cpu subdirectory name.
# The default is $host_cpu.
@@ -64,6 +65,9 @@ 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
+ ;;
i[34567]86-*-msdosdjgpp*) gdb_host=go32 ;;
i[34567]86-*-linux*) gdb_host=linux ;;
i[34567]86-*-lynxos*) gdb_host=i386lynx ;;
Index: src/gdb/mingw-hdep.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ src/gdb/mingw-hdep.c 2006-02-09 16:49:11.000000000 -0500
@@ -0,0 +1,71 @@
+/* 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 strerror() function can return NULL for errno values that are
+ out of range. Provide a "safe" version that always returns a
+ printable string.
+
+ 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 *
+safe_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)
+ {
+ static char buf[32];
+ xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum);
+ return buf;
+ }
+
+ /* Windows error messages end with a period and a CR-LF; strip that
+ out. */
+ len = strlen (buffer);
+ if (len > 3 && strcmp (buffer + len - 3, ".\r\n") == 0)
+ buffer[len - 3] = '\0';
+
+ return buffer;
+}
Index: src/gdb/posix-hdep.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ src/gdb/posix-hdep.c 2006-02-09 16:47:26.000000000 -0500
@@ -0,0 +1,43 @@
+/* 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"
+
+/* The strerror() function can return NULL for errno values that are
+ out of range. Provide a "safe" version that always returns a
+ printable string. */
+
+char *
+safe_strerror (int errnum)
+{
+ char *msg;
+
+ msg = strerror (errnum);
+ if (msg == NULL)
+ {
+ static char buf[32];
+ xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum);
+ msg = buf;
+ }
+ return (msg);
+}
+
Index: src/gdb/utils.c
===================================================================
--- src.orig/gdb/utils.c 2006-02-07 11:11:34.000000000 -0500
+++ src/gdb/utils.c 2006-02-09 16:47:34.000000000 -0500
@@ -838,25 +838,6 @@ internal_warning (const char *file, int
va_end (ap);
}

-/* The strerror() function can return NULL for errno values that are
- out of range. Provide a "safe" version that always returns a
- printable string. */
-
-char *
-safe_strerror (int errnum)
-{
- char *msg;
-
- msg = strerror (errnum);
- if (msg == NULL)
- {
- static char buf[32];
- xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum);
- msg = buf;
- }
- return (msg);
-}
-
/* Print the system error message for errno, and also mention STRING
as the file name for which the error was encountered.
Then return to command level. */