[v8,05/27] win32: Simplify gmtime_r detection direct base on _POSIX_THREAD_SAFE_FUNCTIONS.

Commit Message

Yonggang Luo Sept. 12, 2020, 10:44 p.m. UTC

First, this reduce the size of configure, configure are tending to removal in future,
and this didn't introduce any new feature or remove any exist feature.
Second, the current localtime_r detection are conflict with ncursesw detection in
mingw, when ncursesw detected, it will provide the following compile flags
pkg-config --cflags ncursesw
-D_XOPEN_SOURCE=600 -D_POSIX_C_SOURCE=199506L -IC:/CI-Tools/msys64/mingw64/include/ncursesw
And the compile flag _POSIX_C_SOURCE will always cause _POSIX_THREAD_SAFE_FUNCTIONS to
be defined, in new version of mingw, that's will cause localtime_r to be defined.
But the configure script didn't provide _POSIX_C_SOURCE macro, and that's will result
localtime_r not detected because localtime_r are defined in forceinline manner.

And finally cause conflict between QEMU defined localtime_r
struct tm *localtime_r(const time_t *timep, struct tm *result);
with mingw defined localtime_r

```
#if defined(_POSIX_C_SOURCE) && !defined(_POSIX_THREAD_SAFE_FUNCTIONS)
#define _POSIX_THREAD_SAFE_FUNCTIONS 200112L
#endif

#ifdef _POSIX_THREAD_SAFE_FUNCTIONS
__forceinline struct tm *__CRTDECL localtime_r(const time_t *_Time, struct tm *_Tm) {
  return localtime_s(_Tm, _Time) ? NULL : _Tm;
}
__forceinline struct tm *__CRTDECL gmtime_r(const time_t *_Time, struct tm *_Tm) {
  return gmtime_s(_Tm, _Time) ? NULL : _Tm;
}
__forceinline char *__CRTDECL ctime_r(const time_t *_Time, char *_Str) {
  return ctime_s(_Str, 0x7fffffff, _Time) ? NULL : _Str;
}
__forceinline char *__CRTDECL asctime_r(const struct tm *_Tm, char * _Str) {
  return asctime_s(_Str, 0x7fffffff, _Tm) ? NULL : _Str;
}
#endif
```

So I suggest remove this configure script, and restrict msys2/mingw version to easy to maintain.
And use _POSIX_THREAD_SAFE_FUNCTIONS to guard the localtime_r and counterpart functions

Signed-off-by: Yonggang Luo <[e-mail]>
---
 configure                 | 34 ----------------------------------
 include/sysemu/os-win32.h |  4 ++--
 util/oslib-win32.c        |  2 +-
 3 files changed, 3 insertions(+), 37 deletions(-)

Patch

diff --git a/configure b/configure
index b21843fdb9..af86ba1db3 100755
--- a/configure
+++ b/configure
@@ -2495,37 +2495,6 @@  if test "$vhost_net" = ""; then
   test "$vhost_kernel" = "yes" && vhost_net=yes
 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
 
@@ -7087,9 +7056,6 @@  if [ "$bsd" = "yes" ] ; then
   echo "CONFIG_BSD=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/sysemu/os-win32.h b/include/sysemu/os-win32.h
index d8978e28c0..3ac8a53bac 100644
--- a/include/sysemu/os-win32.h
+++ b/include/sysemu/os-win32.h
@@ -48,12 +48,12 @@ 
 #define siglongjmp(env, val) longjmp(env, val)
 
 /* Missing POSIX functions. Don't use MinGW-w64 macros. */
-#ifndef CONFIG_LOCALTIME_R
+#ifndef _POSIX_THREAD_SAFE_FUNCTIONS
 #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 */
+#endif
 
 static inline void os_setup_signal_handling(void) {}
 static inline void os_daemonize(void) {}
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index c654dafd93..f2fa9a3549 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -106,7 +106,7 @@  void qemu_anon_ram_free(void *ptr, size_t size)
     }
 }
 
-#ifndef CONFIG_LOCALTIME_R
+#ifndef _POSIX_THREAD_SAFE_FUNCTIONS
 /* FIXME: add proper locking */
 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 {