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/* A helper tool for perl's 2038 support.
* See Porting/README.y2038 for details
*/
#include <sys/types.h>
#include <stdio.h>
#include <time.h>
#include <errno.h>
#include <values.h>
int opt_v = 0;
int i;
struct tm *tmp;
time_t pt, pt_max, pt_min;
static char hexbuf[80];
char *hex (time_t t)
{
if ((long long)t < 0)
sprintf (hexbuf, " -0x%016lx", -t);
else
sprintf (hexbuf, " 0x%016lx", t);
return (hexbuf);
} /* hex */
void gm_check (time_t t, int min_year, int max_year)
{
tmp = gmtime (&t);
if ( tmp == NULL ||
/* Check tm_year overflow */
tmp->tm_year < min_year || tmp->tm_year > max_year) {
if (opt_v)
fprintf (stderr, "gmtime (%ld) failed with errno %d\n", t, errno);
}
else {
if (opt_v)
fprintf (stderr, "%3d:%s: %12ld-%02d-%02d %02d:%02d:%02d\n",
i, hex (t),
tmp->tm_year + 1900, tmp->tm_mon + 1, tmp->tm_mday,
tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
pt = t;
}
} /* gm_check */
int check_gm_max ()
{
tmp = NULL;
pt = 0;
if (tmp == NULL || tmp->tm_year < 0) {
for (i = 63; i >= 0; i--) {
time_t x = pt | ((time_t)1 << i);
if (x < 0 || x < pt) continue;
gm_check (x, 69, 0x7fffffff);
}
}
pt_max = pt;
return (0);
} /* check_gm_max */
int check_gm_min ()
{
tmp = NULL;
pt = 0;
if (tmp == NULL) {
for (i = 36; i >= 0; i--) {
time_t x = pt - ((time_t)1 << i);
if (x > 0) continue;
gm_check (x, -1900, 70);
}
}
pt_min = pt;
return (0);
} /* check_gm_min */
void lt_check (time_t t, int min_year, int max_year)
{
if (sizeof (time_t) > 4 && t > 0x7ffffffffffff000LL)
tmp = NULL;
else
tmp = localtime (&t);
if ( tmp == NULL ||
/* Check tm_year overflow */
tmp->tm_year < min_year || tmp->tm_year > max_year) {
if (opt_v)
fprintf (stderr, "localtime (%ld) failed with errno %d\n", t, errno);
}
else {
if (opt_v)
fprintf (stderr, "%3d:%s: %12ld-%02d-%02d %02d:%02d:%02d\n",
i, hex (t),
tmp->tm_year + 1900, tmp->tm_mon + 1, tmp->tm_mday,
tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
pt = t;
}
} /* lt_check */
int check_lt_max ()
{
tmp = NULL;
pt = 0;
if (tmp == NULL || tmp->tm_year < 0) {
for (i = 63; i >= 0; i--) {
time_t x = pt | ((time_t)1 << i);
if (x < 0 || x < pt) continue;
lt_check (x, 69, 0x7fffffff);
}
}
pt_max = pt;
return (0);
} /* check_lt_max */
int check_lt_min ()
{
tmp = NULL;
pt = 0;
if (tmp == NULL) {
for (i = 36; i >= 0; i--) {
time_t x = pt - ((time_t)1 << i);
if (x > 0) continue;
lt_check (x, -1900, 70);
}
}
pt_min = pt;
return (0);
} /* check_lt_min */
int main (int argc, char *argv[])
{
time_t gm_max, gm_min, lt_max, lt_min;
if (argc > 1 && strcmp (argv[1], "-v") == 0) opt_v++;
check_gm_max (); gm_max = pt_max;
check_gm_min (); gm_min = pt_min;
check_lt_max (); lt_max = pt_max;
check_lt_min (); lt_min = pt_min;
opt_v++;
printf ("======================\n");
printf ("Sizeof time_t = %ld\n", (i = sizeof (time_t)));
printf ("gmtime () boundaries:\n");
gm_check (gm_max, 69, 0x7fffffff);
gm_check (gm_min, -1900, 70);
printf ("localtime () boundaries:\n");
lt_check (lt_max, 69, 0x7fffffff);
lt_check (lt_min, -1900, 70);
printf ("Configure variables:\n");
printf ("sGMTIME_max='%ld'\n", gm_max);
printf ("sGMTIME_min='%ld'\n", gm_min);
printf ("sLOCALTIME_max='%ld'\n", lt_max);
printf ("sLOCALTIME_min='%ld'\n", lt_min);
return (0);
} /* main */
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