Sat Apr 20 17:07:17 1996 Ulrich Drepper <drepper@cygnus.com>

[kopensolaris-gnu/glibc.git] / time / tzfile.c

diff --git a/time/tzfile.c b/time/tzfile.c
index 4b1aff4..e78a05e 100644 (file)
--- a/time/tzfile.c
+++ b/time/tzfile.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
+/* Copyright (C) 1991, 1992, 1993, 1995 Free Software Foundation, Inc.

 This file is part of the GNU C Library.
 
 The GNU C Library is free software; you can redistribute it and/or
 This file is part of the GNU C Library.
 
 The GNU C Library is free software; you can redistribute it and/or


@@ -26,12 +26,6 @@ Cambridge, MA 02139, USA.  */
 #define        NOID
 #include <tzfile.h>
 
 #define        NOID
 #include <tzfile.h>
 

-#ifndef        HAVE_GNU_LD
-#define        __tzname        tzname
-#define        __daylight      daylight
-#define        __timezone      timezone
-#endif
-

 int __use_tzfile = 0;
 
 struct ttinfo
 int __use_tzfile = 0;
 
 struct ttinfo


@@ -39,15 +33,18 @@ struct ttinfo
     long int offset;           /* Seconds east of GMT.  */
     unsigned char isdst;       /* Used to set tm_isdst.  */
     unsigned char idx;         /* Index into `zone_names'.  */
     long int offset;           /* Seconds east of GMT.  */
     unsigned char isdst;       /* Used to set tm_isdst.  */
     unsigned char idx;         /* Index into `zone_names'.  */

-    unsigned int isstd:1;      /* Transition times are standard time.  */
+    unsigned char isstd;       /* Transition times are in standard time.  */
+    unsigned char isgmt;       /* Transition times are in GMT.  */

   };
 
 struct leap
   {
   };
 
 struct leap
   {

-    time_t transition;
-    long int change;
+    time_t transition;         /* Time the transition takes effect.  */
+    long int change;           /* Seconds of correction to apply.  */

   };
 
   };
 

+static void compute_tzname_max __P ((size_t));
+

 static size_t num_transitions;
 static time_t *transitions = NULL;
 static unsigned char *type_idxs = NULL;
 static size_t num_transitions;
 static time_t *transitions = NULL;
 static unsigned char *type_idxs = NULL;


@@ -57,15 +54,32 @@ static char *zone_names = NULL;
 static size_t num_leaps;
 static struct leap *leaps = NULL;
 
 static size_t num_leaps;
 static struct leap *leaps = NULL;
 

-#define        uc2ul(x)        _uc2ul((unsigned char *) (x))
-#define        _uc2ul(x)                                                             \
-  ((x)[3] + ((x)[2] << CHAR_BIT) + ((x)[1] << (2 * CHAR_BIT)) +                      \
-   ((x)[0] << (3 * CHAR_BIT)))
+#include <endian.h>
+
+/* Decode the four bytes at PTR as a signed integer in network byte order.  */
+static inline int
+decode (const void *ptr)
+{
+  if ((BYTE_ORDER == BIG_ENDIAN) && sizeof (int) == 4)
+    return *(const int *) ptr;
+  else
+    {
+      const unsigned char *p = ptr;
+      int result = *p & (1 << (CHAR_BIT - 1)) ? ~0 : 0;
+
+      result = (result << 8) | *p++;
+      result = (result << 8) | *p++;
+      result = (result << 8) | *p++;
+      result = (result << 8) | *p++;
+
+      return result;
+    }
+}

 
 void
 DEFUN(__tzfile_read, (file), CONST char *file)
 {
 
 void
 DEFUN(__tzfile_read, (file), CONST char *file)
 {

-  size_t num_isstd;
+  size_t num_isstd, num_isgmt;

   register FILE *f;
   struct tzhead tzhead;
   size_t chars;
   register FILE *f;
   struct tzhead tzhead;
   size_t chars;


@@ -110,11 +124,12 @@ DEFUN(__tzfile_read, (file), CONST char *file)
   if (fread((PTR) &tzhead, sizeof(tzhead), 1, f) != 1)
     goto lose;
 
   if (fread((PTR) &tzhead, sizeof(tzhead), 1, f) != 1)
     goto lose;
 

-  num_transitions = (size_t) uc2ul(tzhead.tzh_timecnt);
-  num_types = (size_t) uc2ul(tzhead.tzh_typecnt);
-  chars = (size_t) uc2ul(tzhead.tzh_charcnt);
-  num_leaps = (size_t) uc2ul(tzhead.tzh_leapcnt);
-  num_isstd = (size_t) uc2ul(tzhead.tzh_ttisstdcnt);
+  num_transitions = (size_t) decode (tzhead.tzh_timecnt);
+  num_types = (size_t) decode (tzhead.tzh_typecnt);
+  chars = (size_t) decode (tzhead.tzh_charcnt);
+  num_leaps = (size_t) decode (tzhead.tzh_leapcnt);
+  num_isstd = (size_t) decode (tzhead.tzh_ttisstdcnt);
+  num_isgmt = (size_t) decode (tzhead.tzh_ttisgmtcnt);

 
   if (num_transitions > 0)
     {
 
   if (num_transitions > 0)
     {


@@ -144,13 +159,23 @@ DEFUN(__tzfile_read, (file), CONST char *file)
        goto lose;
     }
 
        goto lose;
     }
 

-  if (fread((PTR) transitions, sizeof(time_t),
-           num_transitions, f) != num_transitions ||
+  if (sizeof (time_t) < 4)
+      abort ();
+
+  if (fread((PTR) transitions, 4, num_transitions, f) != num_transitions ||

       fread((PTR) type_idxs, 1, num_transitions, f) != num_transitions)
     goto lose;
 
       fread((PTR) type_idxs, 1, num_transitions, f) != num_transitions)
     goto lose;
 

-  for (i = 0; i < num_transitions; ++i)
-    transitions[i] = uc2ul (&transitions[i]);
+  if (BYTE_ORDER != BIG_ENDIAN || sizeof (time_t) != 4)
+    {
+      /* Decode the transition times, stored as 4-byte integers in
+        network (big-endian) byte order.  We work from the end of
+        the array so as not to clobber the next element to be
+        processed when sizeof (time_t) > 4.  */
+      i = num_transitions;
+      while (i-- > 0)
+       transitions[i] = decode ((char *) transitions + i*4);
+    }

 
   for (i = 0; i < num_types; ++i)
     {
 
   for (i = 0; i < num_types; ++i)
     {


@@ -159,7 +184,7 @@ DEFUN(__tzfile_read, (file), CONST char *file)
          fread((PTR) &types[i].isdst, 1, 1, f) != 1 ||
          fread((PTR) &types[i].idx, 1, 1, f) != 1)
        goto lose;
          fread((PTR) &types[i].isdst, 1, 1, f) != 1 ||
          fread((PTR) &types[i].idx, 1, 1, f) != 1)
        goto lose;

-      types[i].offset = (long int) uc2ul(x);
+      types[i].offset = (long int) decode (x);

     }
 
   if (fread((PTR) zone_names, 1, chars, f) != chars)
     }
 
   if (fread((PTR) zone_names, 1, chars, f) != chars)


@@ -170,10 +195,10 @@ DEFUN(__tzfile_read, (file), CONST char *file)
       unsigned char x[4];
       if (fread((PTR) x, 1, sizeof(x), f) != sizeof(x))
        goto lose;
       unsigned char x[4];
       if (fread((PTR) x, 1, sizeof(x), f) != sizeof(x))
        goto lose;

-      leaps[i].transition = (time_t) uc2ul(x);
+      leaps[i].transition = (time_t) decode (x);

       if (fread((PTR) x, 1, sizeof(x), f) != sizeof(x))
        goto lose;
       if (fread((PTR) x, 1, sizeof(x), f) != sizeof(x))
        goto lose;

-      leaps[i].change = (long int) uc2ul(x);
+      leaps[i].change = (long int) decode (x);

     }
 
   for (i = 0; i < num_isstd; ++i)
     }
 
   for (i = 0; i < num_isstd; ++i)


@@ -186,17 +211,126 @@ DEFUN(__tzfile_read, (file), CONST char *file)
   while (i < num_types)
     types[i++].isstd = 0;
 
   while (i < num_types)
     types[i++].isstd = 0;
 

+  for (i = 0; i < num_isgmt; ++i)
+    {
+      char c = getc(f);
+      if (c == EOF)
+       goto lose;
+      types[i].isgmt = c != 0;
+    }
+  while (i < num_types)
+    types[i++].isgmt = 0;
+

   (void) fclose(f);
   (void) fclose(f);

+
+  compute_tzname_max (chars);
+  

   __use_tzfile = 1;
   return;
 
  lose:;
   (void) fclose(f);
 }
   __use_tzfile = 1;
   return;
 
  lose:;
   (void) fclose(f);
 }

+\f
+/* The user specified a hand-made timezone, but not its DST rules.
+   We will use the names and offsets from the user, and the rules
+   from the TZDEFRULES file.  */

 
 

+void
+DEFUN(__tzfile_default, (std, dst, stdoff, dstoff),
+      char *std AND char *dst AND
+      long int stdoff AND long int dstoff)
+{
+  size_t stdlen, dstlen, i;
+  long int rule_offset, rule_stdoff, rule_dstoff;
+  int isdst;
+
+  __tzfile_read (TZDEFRULES);
+  if (!__use_tzfile)
+    return;
+
+  if (num_types < 2)
+    {
+      __use_tzfile = 0;
+      return;
+    }

 
 

+  /* Ignore the zone names read from the file.  */
+  free (zone_names);
+
+  /* Use the names the user specified.  */
+  stdlen = strlen (std) + 1;
+  dstlen = strlen (dst) + 1;
+  zone_names = malloc (stdlen + dstlen);
+  if (zone_names == NULL)
+    {
+      __use_tzfile = 0;
+      return;
+    }
+  memcpy (zone_names, std, stdlen);
+  memcpy (&zone_names[stdlen], dst, dstlen);
+
+  /* Find the standard and daylight time offsets used by the rule file.
+     We choose the offsets in the types of each flavor that are
+     transitioned to earliest in time.  */
+  rule_stdoff = rule_dstoff = 0;
+  for (i = 0; i < num_transitions; ++i)
+    {
+      if (!rule_stdoff && !types[type_idxs[i]].isdst)
+       rule_stdoff = types[type_idxs[i]].offset;
+      if (!rule_dstoff && types[type_idxs[i]].isdst)
+       rule_dstoff = types[type_idxs[i]].offset;
+      if (rule_stdoff && rule_dstoff)
+       break;
+    }
+
+  /* Now correct the transition times for the user-specified standard and
+     daylight offsets from GMT.  */
+  isdst = 0;
+  rule_offset = rule_offset;
+  for (i = 0; i < num_transitions; ++i)
+    {
+      struct ttinfo *trans_type = &types[type_idxs[i]];
+
+      /* We will use only types 0 (standard) and 1 (daylight).
+        Fix up this transition to point to whichever matches
+        the flavor of its original type.  */
+      type_idxs[i] = trans_type->isdst;
+
+      if (trans_type->isgmt)
+       /* The transition time is in GMT.  No correction to apply.  */ ;
+      else if (isdst && !trans_type->isstd)
+       /* The type says this transition is in "local wall clock time", and
+          wall clock time as of the previous transition was DST.  Correct
+          for the difference between the rule's DST offset and the user's
+          DST offset.  */
+       transitions[i] += dstoff - rule_dstoff;
+      else
+       /* This transition is in "local wall clock time", and wall clock
+          time as of this iteration is non-DST.  Correct for the
+          difference between the rule's standard offset and the user's
+          standard offset.  */
+       transitions[i] += stdoff - rule_stdoff;
+
+      /* The DST state of "local wall clock time" for the next iteration is
+        as specified by this transition.  */
+      isdst = trans_type->isdst;
+    }
+
+  /* Reset types 0 and 1 to describe the user's settings.  */
+  types[0].idx = 0;
+  types[0].offset = stdoff;
+  types[0].isdst = 0;
+  types[1].idx = stdlen;
+  types[1].offset = dstoff;
+  types[1].isdst = 1;
+
+  compute_tzname_max (stdlen + dstlen);
+}
+\f

 int
 int

-DEFUN(__tzfile_compute, (timer, tm), time_t timer AND struct tm tm)
+DEFUN(__tzfile_compute, (timer, leap_correct, leap_hit),
+      time_t timer AND long int *leap_correct AND int *leap_hit)

 {
   struct ttinfo *info;
   register size_t i;
 {
   struct ttinfo *info;
   register size_t i;


@@ -214,14 +348,15 @@ DEFUN(__tzfile_compute, (timer, tm), time_t timer AND struct tm tm)
     }
   else
     {
     }
   else
     {

-      /* Find the first transition after TIMER, and then go back one.  */
-      i = 1;
-      while (i < num_transitions && transitions[i] < timer)
-       ++i;
-      --i;
+      /* Find the first transition after TIMER, and
+        then pick the type of the transition before it.  */
+      for (i = 1; i < num_transitions; ++i)
+       if (timer < transitions[i])
+         break;
+      i = type_idxs[i - 1];

     }
 
     }
 

-  info = &types[type_idxs[i]];
+  info = &types[i];

   __daylight = info->isdst;
   __timezone = info->offset;
   for (i = 0; i < num_types && i < sizeof (__tzname) / sizeof (__tzname[0]);
   __daylight = info->isdst;
   __timezone = info->offset;
   for (i = 0; i < num_types && i < sizeof (__tzname) / sizeof (__tzname[0]);


@@ -230,11 +365,50 @@ DEFUN(__tzfile_compute, (timer, tm), time_t timer AND struct tm tm)
   if (info->isdst < sizeof (__tzname) / sizeof (__tzname[0]))
     __tzname[info->isdst] = &zone_names[info->idx];
 
   if (info->isdst < sizeof (__tzname) / sizeof (__tzname[0]))
     __tzname[info->isdst] = &zone_names[info->idx];
 

+  *leap_correct = 0L;
+  *leap_hit = 0;
+
+  /* Find the last leap second correction transition time before TIMER.  */

   i = num_leaps;
   do
     if (i-- == 0)
       return 1;
   while (timer < leaps[i].transition);
   i = num_leaps;
   do
     if (i-- == 0)
       return 1;
   while (timer < leaps[i].transition);

-  __timezone += leaps[i].change;
+
+  /* Apply its correction.  */
+  *leap_correct = leaps[i].change;
+
+  if (timer == leaps[i].transition && /* Exactly at the transition time.  */
+      ((i == 0 && leaps[i].change > 0) ||
+       leaps[i].change > leaps[i - 1].change))
+    {
+      *leap_hit = 1;
+      while (i > 0 &&
+            leaps[i].transition == leaps[i - 1].transition + 1 &&
+            leaps[i].change == leaps[i - 1].change + 1)
+       {
+         ++*leap_hit;
+         --i;
+       }
+    }
+

   return 1;
 }
   return 1;
 }

+\f
+void
+DEFUN(compute_tzname_max, (chars), size_t chars)
+{
+  extern long int __tzname_cur_max; /* Defined in __tzset.c. */
+
+  const char *p;
+
+  p = zone_names;
+  do
+    {
+      const char *start = p;
+      while (*p != '\0')
+       ++p;
+      if (p - start > __tzname_cur_max)
+       __tzname_cur_max = p - start;
+    } while (++p < &zone_names[chars]);
+}