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dnl * how large time_t values does gmtime() accept?
AC_DEFUN([DOVECOT_GMTIME_MAX], [
AC_CACHE_CHECK([how large time_t values gmtime() accepts],i_cv_gmtime_max_time_t,[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <stdio.h>
#include <time.h>
int main() {
FILE *f;
int bits;
for (bits = 1; bits < sizeof(time_t)*8; bits++) {
time_t t = ((time_t)1 << bits) - 1;
if (gmtime(&t) == NULL) {
bits--;
break;
}
}
if (bits > 40) {
/* Solaris 9 breaks after 55 bits. Perhaps other systems break earlier.
Let's just do the same as Cyrus folks and limit it to 40 bits. */
bits = 40;
}
f = fopen("conftest.temp", "w");
if (f == NULL) {
perror("fopen()");
return 1;
}
fprintf(f, "%d", bits);
fclose(f);
return 0;
}
]])],[
i_cv_gmtime_max_time_t=`cat conftest.temp`
rm -f conftest.temp
], [
printf "check failed, assuming "
i_cv_gmtime_max_time_t=31
],[])
])
AC_DEFINE_UNQUOTED(TIME_T_MAX_BITS, $i_cv_gmtime_max_time_t, [max. time_t bits gmtime() can handle])
])
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