build: Remove HAVE_GMTIME_R

configure.ac

@@ -1092,22 +1092,6 @@ if test "$use_thread_local" = "yes" || test "$use_thread_local" = "auto"; then
   LDFLAGS="$TEMP_LDFLAGS"
 fi
 
-dnl check for gmtime_r(), fallback to gmtime_s() if that is unavailable
-dnl fail if neither are available.
-AC_MSG_CHECKING([for gmtime_r])
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <ctime>]],
-  [[ gmtime_r((const time_t *) nullptr, (struct tm *) nullptr); ]])],
-  [ AC_MSG_RESULT([yes]); AC_DEFINE([HAVE_GMTIME_R], [1], [Define this symbol if gmtime_r is available]) ],
-  [ AC_MSG_RESULT([no]);
-    AC_MSG_CHECKING([for gmtime_s]);
-    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <ctime>]],
-       [[ gmtime_s((struct tm *) nullptr, (const time_t *) nullptr); ]])],
-       [ AC_MSG_RESULT([yes])],
-       [ AC_MSG_RESULT([no]); AC_MSG_ERROR([Both gmtime_r and gmtime_s are unavailable]) ]
-    )
-  ]
-)
-
 dnl Check for different ways of gathering OS randomness
 AC_MSG_CHECKING([for Linux getrandom function])
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
@@ -1879,7 +1863,6 @@ AC_SUBST(MINIUPNPC_CPPFLAGS)
 AC_SUBST(MINIUPNPC_LIBS)
 AC_SUBST(NATPMP_CPPFLAGS)
 AC_SUBST(NATPMP_LIBS)
-AC_SUBST(HAVE_GMTIME_R)
 AC_SUBST(HAVE_FDATASYNC)
 AC_SUBST(HAVE_FULLFSYNC)
 AC_SUBST(HAVE_O_CLOEXEC)