y2038 preparation for Schwern

p4raw-id: //depot/metaconfig@34104

diff --git a/U/perl/time_size.U b/U/perl/time_size.U
new file mode 100644 (file)
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+++ b/U/perl/time_size.U
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+?RCS: $Id$
+?RCS:
+?RCS: Copyright (c) 2008 H.Merijn Brand
+?RCS:
+?RCS: You may distribute under the terms of either the GNU General Public
+?RCS: License or the Artistic License, as specified in the README file.
+?RCS:
+?MAKE:sGMTIME_max sGMTIME_min: cat rm_try Setvar Compile run
+?MAKE: -pick add $@ %<
+?S:sGMTIME_max:
+?S:    This variable defines the maximum value of the time_t offset that
+?S:    the system function gmtime () accepts
+?S:.
+?S:sGMTIME_min:
+?S:    This variable defines the minimum value of the time_t offset that
+?S:    the system function gmtime () accepts
+?S:.
+?C:GMTIME_MAX:
+?C:    This symbol contains the maximum value for the time_t offset that
+?C:    the system function gmtime () accepts, and defaults to 0
+?C:.
+?C:GMTIME_MIN:
+?C:    This symbol contains the minimum value for the time_t offset that
+?C:    the system function gmtime () accepts, and defaults to 0
+?C:.
+?H:#define GMTIME_MAX  $sGMTIME_max    /**/
+?H:#define GMTIME_MIN  $sGMTIME_min    /**/
+?H:.
+?D:sGMTIME_max=0
+?D:sGMTIME_min=0
+?F:!try
+: Check the max offset that gmtime accepts
+echo "Checking max offset that gmtime () accepts"
+
+$cat >try.c <<'EOCP'
+#include <sys/types.h>
+#include <stdio.h>
+#include <time.h>
+int main () {
+  struct tm *tmp;
+  int i, y = 0;
+  time_t pt = 0;
+
+  for (i = 0; i < 78; i++) {
+    time_t t = (1 << i) - 1;
+    tmp = gmtime (&t);
+    if (tmp == NULL || tmp->tm_year < y) {
+      i--;
+      printf ("%d\n", pt);
+      return (i);
+      }
+
+    y = tmp->tm_year;
+    pt = t;
+    }
+  printf ("%d\n", pt);
+  return (0);
+  }
+EOCP
+set try
+if eval $compile; then
+    sGMTIME_max=`$run ./try`
+else
+    echo "Cannot determine sGMTIME_max"
+    fi
+$rm_try
+
+echo "Checking min offset that gmtime () accepts"
+
+$cat >try.c <<'EOCP'
+#include <sys/types.h>
+#include <stdio.h>
+#include <time.h>
+int main () {
+  struct tm *tmp;
+  int i, y = 70;
+  time_t pt = 0;
+
+  for (i = 0; i < 78; i++) {
+    time_t t = - (1 << i);
+    tmp = gmtime (&t);
+    if (tmp == NULL || tmp->tm_year > y) {
+      i--;
+      printf ("%d\n", pt);
+      return (i);
+      }
+
+    y = tmp->tm_year;
+    pt = t;
+    }
+  printf ("%d\n", pt);
+  return (0);
+  }
+EOCP
+set try
+if eval $compile; then
+    sGMTIME_min=`$run ./try`
+else
+    echo "Cannot determine sGMTIME_min"
+    fi
+$rm_try
+