oslib-win32: only provide localtime_r/gmtime_r if missing
The oslib-win32 file currently provides a localtime_r and
gmtime_r replacement unconditionally. Some versions of
Mingw-w64 would provide crude macros for localtime_r/gmtime_r
which QEMU takes care to disable. Latest versions of Mingw-w64
now provide actual functions for localtime_r/gmtime_r, but
with a twist that you have to include unistd.h or pthread.h
before including time.h. By luck some files in QEMU have
such an include order, resulting in compile errors:
CC util/osdep.o
In file included from include/qemu-common.h:48:0,
from util/osdep.c:48:
include/sysemu/os-win32.h:77:12: error: redundant redeclaration of 'gmtime_r' [-Werror=redundant-decls]
struct tm *gmtime_r(const time_t *timep, struct tm *result);
^
In file included from include/qemu-common.h:35:0,
from util/osdep.c:48:
/usr/i686-w64-mingw32/sys-root/mingw/include/time.h:272:107: note: previous definition of 'gmtime_r' was here
In file included from include/qemu-common.h:48:0,
from util/osdep.c:48:
include/sysemu/os-win32.h:79:12: error: redundant redeclaration of 'localtime_r' [-Werror=redundant-decls]
struct tm *localtime_r(const time_t *timep, struct tm *result);
^
In file included from include/qemu-common.h:35:0,
from util/osdep.c:48:
/usr/i686-w64-mingw32/sys-root/mingw/include/time.h:269:107: note: previous definition of 'localtime_r' was here
This change adds a configure test to see if localtime_r
exits, and only enables the QEMU impl if missing. We also
re-arrange qemu-common.h try attempt to guarantee that all
source files get unistd.h before time.h and thus see the
localtime_r/gmtime_r defs.
[sw: Use "official" spellings for Mingw-w64, MinGW in comments.]
[sw: Terminate sentences with a dot in comments.]
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
diff --git a/configure b/configure
index 29009ee..f14454e 100755
--- a/configure
+++ b/configure
@@ -1737,6 +1737,37 @@
fi
##########################################
+# MinGW / Mingw-w64 localtime_r/gmtime_r check
+
+if test "$mingw32" = "yes"; then
+ # Some versions of MinGW / Mingw-w64 lack localtime_r
+ # and gmtime_r entirely.
+ #
+ # Some versions of Mingw-w64 define a macro for
+ # localtime_r/gmtime_r.
+ #
+ # Some versions of Mingw-w64 will define functions
+ # for localtime_r/gmtime_r, but only if you have
+ # _POSIX_THREAD_SAFE_FUNCTIONS defined. For fun
+ # though, unistd.h and pthread.h both define
+ # that for you.
+ #
+ # So this #undef localtime_r and #include <unistd.h>
+ # are not in fact redundant.
+cat > $TMPC << EOF
+#include <unistd.h>
+#include <time.h>
+#undef localtime_r
+int main(void) { localtime_r(NULL, NULL); return 0; }
+EOF
+ if compile_prog "" "" ; then
+ localtime_r="yes"
+ else
+ localtime_r="no"
+ fi
+fi
+
+##########################################
# pkg-config probe
if ! has "$pkg_config_exe"; then
@@ -5034,6 +5065,9 @@
if test "$zero_malloc" = "yes" ; then
echo "CONFIG_ZERO_MALLOC=y" >> $config_host_mak
fi
+if test "$localtime_r" = "yes" ; then
+ echo "CONFIG_LOCALTIME_R=y" >> $config_host_mak
+fi
if test "$qom_cast_debug" = "yes" ; then
echo "CONFIG_QOM_CAST_DEBUG=y" >> $config_host_mak
fi
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index ab3c876..ef21efb 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -38,10 +38,12 @@
#include <strings.h>
#include <inttypes.h>
#include <limits.h>
+/* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
+ * function availability on recentish Mingw-w64 platforms. */
+#include <unistd.h>
#include <time.h>
#include <ctype.h>
#include <errno.h>
-#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/time.h>
diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h
index 706d85a..13dcef6 100644
--- a/include/sysemu/os-win32.h
+++ b/include/sysemu/os-win32.h
@@ -73,10 +73,12 @@
#define siglongjmp(env, val) longjmp(env, val)
/* Missing POSIX functions. Don't use MinGW-w64 macros. */
+#ifndef CONFIG_LOCALTIME_R
#undef gmtime_r
struct tm *gmtime_r(const time_t *timep, struct tm *result);
#undef localtime_r
struct tm *localtime_r(const time_t *timep, struct tm *result);
+#endif /* CONFIG_LOCALTIME_R */
static inline void os_setup_signal_handling(void) {}
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index 730a670..08f5a9c 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -95,6 +95,7 @@
}
}
+#ifndef CONFIG_LOCALTIME_R
/* FIXME: add proper locking */
struct tm *gmtime_r(const time_t *timep, struct tm *result)
{
@@ -118,6 +119,7 @@
}
return p;
}
+#endif /* CONFIG_LOCALTIME_R */
void qemu_set_block(int fd)
{
