X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=m4%2Fmktime.m4;h=6df253b36f8ae4572b3b653dd231b6fd8c5f9e48;hb=66bec62b1852c1389265e9d05ec95101cfcf504b;hp=fef22225626aea3ded8442de4dac1e44c5d27d85;hpb=3b078cb57dc8592b174e6eb3ffee1072ea7227f1;p=gnulib.git

diff --git a/m4/mktime.m4 b/m4/mktime.m4
index fef222256..6df253b36 100644
--- a/m4/mktime.m4
+++ b/m4/mktime.m4
@@ -1,17 +1,18 @@
-#serial 103
-dnl FIXME: when this goes back into automake, reset this to a small number
+#serial 1000
 
-dnl From Jim Meyering.
-dnl FIXME: this should migrate into libit.
+dnl From Paul Eggert
+dnl Check for a working mktime.
+dnl This is a preview of what should appear in the next public autoconf release.
 
-dnl FIXME: when this goes back into automake, remove all jm_ prefixes
+dnl Override any existing definition.
+undefine([AC_FUNC_MKTIME])
 
-AC_DEFUN(jm_AM_FUNC_MKTIME,
+AC_DEFUN(AC_FUNC_MKTIME,
 [AC_REQUIRE([AC_HEADER_TIME])dnl
- AC_CHECK_HEADERS(sys/time.h unistd.h)
- AC_CHECK_FUNCS(alarm)
- AC_CACHE_CHECK([for working mktime], jm_am_cv_func_working_mktime,
-  [AC_TRY_RUN(
+AC_CHECK_HEADERS(sys/time.h unistd.h)
+AC_CHECK_FUNCS(alarm)
+AC_CACHE_CHECK([for working mktime], ac_cv_func_working_mktime,
+[AC_TRY_RUN(
 changequote(<<, >>)dnl
 <</* Test program from Paul Eggert (eggert@twinsun.com)
    and Tony Leneis (tony@plaza.ds.adp.com).  */
@@ -41,11 +42,36 @@ static time_t time_t_max;
 
 /* Values we'll use to set the TZ environment variable.  */
 static const char *const tz_strings[] = {
-  (const char *) 0, "GMT0", "JST-9",
-  "EST+3EDT+2,M10.1.0/00:00:00,M2.3.0/00:00:00"
+  (const char *) 0, "TZ=GMT0", "TZ=JST-9",
+  "TZ=EST+3EDT+2,M10.1.0/00:00:00,M2.3.0/00:00:00"
 };
 #define N_STRINGS (sizeof (tz_strings) / sizeof (tz_strings[0]))
 
+/* Fail if mktime fails to convert a date in the spring-forward gap.
+   Based on a problem report from Andreas Jaeger.  */
+static void
+spring_forward_gap ()
+{
+  /* glibc (up to about 1998-10-07) failed this test) */
+  struct tm tm;
+
+  /* Use the portable POSIX.1 specification "TZ=PST8PDT,M4.1.0,M10.5.0"
+     instead of "TZ=America/Vancouver" in order to detect the bug even
+     on systems that don't support the Olson extension, or don't have the
+     full zoneinfo tables installed.  */
+  putenv ("TZ=PST8PDT,M4.1.0,M10.5.0");
+
+  tm.tm_year = 98;
+  tm.tm_mon = 3;
+  tm.tm_mday = 5;
+  tm.tm_hour = 2;
+  tm.tm_min = 0;
+  tm.tm_sec = 0;
+  tm.tm_isdst = -1;
+  if (mktime (&tm) == (time_t)-1)
+    exit (1);
+}
+
 static void
 mktime_test (now)
      time_t now;
@@ -82,11 +108,7 @@ bigtime_test (j)
   struct tm tm;
   time_t now;
   tm.tm_year = tm.tm_mon = tm.tm_mday = tm.tm_hour = tm.tm_min = tm.tm_sec = j;
-  /* This test makes some buggy mktime implementations loop.
-     Give up after 10 seconds.  */
-  alarm (10);
   now = mktime (&tm);
-  alarm (0);
   if (now != (time_t) -1)
     {
       struct tm *lt = localtime (&now);
@@ -111,6 +133,11 @@ main ()
   time_t t, delta;
   int i, j;
 
+  /* This test makes some buggy mktime implementations loop.
+     Give up after 60 seconds; a mktime slower than that
+     isn't worth using anyway.  */
+  alarm (60);
+
   for (time_t_max = 1; 0 < time_t_max; time_t_max *= 2)
     continue;
   time_t_max--;
@@ -130,15 +157,14 @@ main ()
       bigtime_test (j - 1);
     }
   irix_6_4_bug ();
+  spring_forward_gap ();
   exit (0);
 }
-	      >>,
+>>,
 changequote([, ])dnl
-	     jm_am_cv_func_working_mktime=yes, jm_am_cv_func_working_mktime=no,
-	     dnl When crosscompiling, assume mktime is missing or broken.
-	     jm_am_cv_func_working_mktime=no)
-  ])
-  if test $jm_am_cv_func_working_mktime = no; then
-    LIBOBJS="$LIBOBJS mktime.o"
-  fi
+ac_cv_func_working_mktime=yes, ac_cv_func_working_mktime=no,
+ac_cv_func_working_mktime=no)])
+if test $ac_cv_func_working_mktime = no; then
+  LIBOBJS="$LIBOBJS mktime.${ac_objext}"
+fi
 ])