mingw-w64: check if localtime_r exists

- check in cmake if localtime_r exists
- if localtime_r is missing (MSVC, mingw-w64 on linux) redefine it using
  localtime_s

CMakeLists.txt

@@ -386,6 +386,18 @@ elseif (UNIX OR (APPLE AND HAVE_DLADDR))
   set (HAVE_SYMBOLIZE 1)
 endif (WIN32 OR CYGWIN)
 
+check_cxx_source_compiles ("
+#include <cstdlib>
+#include <time.h>
+int main()
+{
+    time_t timep;
+    struct tm result;
+    localtime_r(&timep, &result);
+    return EXIT_SUCCESS;
+}
+" HAVE_LOCALTIME_R)
+
 set (SIZEOF_VOID_P ${CMAKE_SIZEOF_VOID_P})
 
 if (WITH_THREADS AND Threads_FOUND)

src/config.h.cmake.in

@@ -136,6 +136,9 @@
 /* define if symbolize support is available */
 #cmakedefine HAVE_SYMBOLIZE
 
+/* define if localtime_r is available in time.h */
+#cmakedefine HAVE_LOCALTIME_R
+
 /* Define to the sub-directory in which libtool stores uninstalled libraries.
    */
 #cmakedefine LT_OBJDIR

src/windows/port.h

@@ -147,10 +147,12 @@ enum { PTHREAD_ONCE_INIT = 0 };   // important that this be 0! for SpinLock
 #define pthread_equal(pthread_t_1, pthread_t_2)  ((pthread_t_1)==(pthread_t_2))
 #endif // HAVE_PTHREAD
 
+#ifndef HAVE_LOCALTIME_R
 inline struct tm* localtime_r(const time_t* timep, struct tm* result) {
   localtime_s(result, timep);
   return result;
 }
+#endif
 
 inline char* strerror_r(int errnum, char* buf, size_t buflen) {
   strerror_s(buf, buflen, errnum);