configure/genstamp: check for struct tm.tm_gmtoff

[citadel.git] / citadel / acinclude.m4

diff --git a/citadel/acinclude.m4 b/citadel/acinclude.m4
new file mode 100644 (file)
index 0000000..ae541a6
--- /dev/null
+++ b/citadel/acinclude.m4
@@ -0,0 +1,22 @@
+# CIT_STRUCT_TM
+# ------------------
+# Figure out how to get the current GMT offset.  If `struct tm' has a
+# `tm_gmtoff' member, define `HAVE_STRUCT_TM_TM_GMTOFF'.  Otherwise, if the
+# external variable `timezone' is found, define `HAVE_TIMEZONE'.
+AC_DEFUN([CIT_STRUCT_TM],
+[AC_REQUIRE([AC_STRUCT_TM])dnl
+AC_CHECK_MEMBERS([struct tm.tm_gmtoff],,,[#include <sys/types.h>
+#include <$ac_cv_struct_tm>
+])
+if test "$ac_cv_member_struct_tm_tm_gmtoff" != yes; then
+  AC_CACHE_CHECK(for timezone, ac_cv_var_timezone,
+[AC_TRY_LINK(
+[#include <time.h>],
+[printf("%ld", (long)timezone);], ac_cv_var_timezone=yes, ac_cv_var_timezone=no)])
+  if test $ac_cv_var_timezone = yes; then
+    AC_DEFINE(HAVE_TIMEZONE, 1,
+              [Define if you don't have `tm_gmtoff' but do have the external
+               variable `timezone'.])
+  fi
+fi
+])# CIT_STRUCT_TM