glibc/timezone/zdump.c
Adhemerval Zanella 1b171c942e timezone: sync to TZDB 2024b
Sync tzselect, zdump, zic to TZDB 2024b. This patch incorporates the
following TZDB source code changes:

6903dde3 Release 2024b
812aff32 Improve historical transitions in Mexico 1921-1997
52662566 Adjust to mailing list software change
7748036b Mention Internet RFC 9557
339e81d1 Mention Levine’s proposal to replace leap seconds
b4e6ad2d No leap second on 2024-12-31
7eb5bf88 Asia/Choibalsan is now an alias for Asia/Ulaanbaatar
43450cbf Improve historical data for Portugal and former possessions.
13d7348b Typo and validation fixes.
3c39cde8 Fix typo for “removed” in a comment
03fd9e45 More documentation updates for POSIX.1-2024
eb3bcceb POSIX.1-2014 is now published
913b0410 tzselect: support POSIX.1-2024 offset range
b5318b55 Document POSIX.1-2024 better
837609b7 Fix typo when making .txt man pages
d56ae6ee SUPPORT_C89 now defaults to 1, not 0
b1fe113d Port ! to Solaris make
8f1fd321 Avoid crash in Solaris 10 /usr/xpg4/bin/make
e0fcfdd6 Use ‘export VAR=VAL’ syntax
eba43166 Avoid an awk invocation via $'...'
36479a80 Avoid some subshells in tzselect
7f6cf054 * tzselect.ksh: Assume POSIX.2 awk.
a1cf1daf * tzselect.ksh: Assume POSIX.2 $PWD.
a9b8e536 Assume POSIX.2 command substitution
eaa4ef16 Avoid subshells when possible
9dac9eb7 Prefer $PWD to $(pwd) in Makefile
fada6a4c Prefer $(CMD) to `CMD` in Makefile
3e871b9a Assume POSIX.2 and eschew ‘expr’
c5d67805 difftime isn’t pure either
5857c056 * CONTRIBUTING: Document build assumptions.
6822cc82 ‘make check’ no longer depends on curl+Internet
cc6eb255 Document GCC bug 114833 and workaround
bcbc86bf Scale back on function attribute use
c0789e46 C23 [[reproducible]] and [[unsequenced]] fixups
bbd88154 More updates to GCC_DEBUG_FLAGS for GCC 14
1a35b7c8 Spelling fixes
f71085f2 POSIX.1-2024 removes asctime_r, ctime_r
70856f8e Adjust to refactored location of ctime, ctime_r
aacd151d Update GCC_DEBUG_FLAGS for GCC 14
967dcf3b Sub-second history for Maputo and Zurich
782d0826 Make EET, MET and WET links
a0b09c02 Mark CET, CST6CDT etc. as obsolescent
db7fb40d Document SMPTE timecodes and rolling leaps
97232e18 Don’t be so sure about leap seconds going away
5b6a74fb Update some URLs
a75a6251 * zic.8: Tweak for consistency.
1e75b31f Document what %s means before any rule applies
00c96cbb Conform to RFC 8536 section 3.2 for default type
3e944959 Document problems with stripped-down TZif readers
20fc91cf Shanks is likely wrong about Maputo switch to CAT
d99589b6 * zic.8: Add missing tab character.
94e6b3b0 Switch to %z in main dataform
2cd57b93 Treat W-Eur like Port when reguarding
ad6f6d94 Check that main.zi agrees with sources
a43b030f .gitignore: Add .pdf, .ps, .s. Remove obsolete ‘yearistype’.
253ca020 * theory.html: ‘CLT’ → ‘LTC’ (per Michael H Deckers)
a3dee8c8 * NEWS: ‘how’ → ‘now’ (thanks to Paul Goyette).
ea6341c5 * theory.html: Mention NASA and CLT (per Arthur David Olson).
0dcebe37 America/Scoresbysund matches America/Nuuk from now on
b1e07fb0 Update Vzic link (thanks to Allen Winter)
a4b05030 Fix wday/mday typo in previous patch
732a4803 Document how to detect mktime failure reliably
a64067e9 ziguard.awk: generalize for proposed Portugal patch
59c861fd Line up zdump examples
66c106c9 tzfile.5: srcfix
e5553001 Fix .RS/.RE problem in tzfile.5
d647eb01 Add Doctorow book
59d4a1ba Asia/Almaty matches Asia/Tashkent from now on
d4d3c3ba * asia: Update Philippine URLs (thanks to Guy Harris).
9fc11a27 Port unlikely overflow check to C23
b52a2969 Fix 2023d NEWS typo
e48c5b53 Cite "The NTP Leap Second File"
b1dc2122 Update Israel tz-link
6cf4e912 Extrapolate less from the 2022 CGPM resolution.

It fixes glibc build with gcc master [1].

Checked on x86_64-linux-gnu and on i686-linux-gnu.

[1] https://sourceware.org/pipermail/libc-alpha/2024-September/159571.html
Reviewed-by: Paul Eggert <eggert@cs.ucla.edu>
2024-09-05 20:57:17 +00:00

1268 lines
33 KiB
C

/* Dump time zone data in a textual format. */
/*
** This file is in the public domain, so clarified as of
** 2009-05-17 by Arthur David Olson.
*/
#include "version.h"
#ifndef NETBSD_INSPIRED
# define NETBSD_INSPIRED 1
#endif
#include "private.h"
#include <stdio.h>
#ifndef HAVE_SNPRINTF
# define HAVE_SNPRINTF (!PORT_TO_C89 || 199901 <= __STDC_VERSION__)
#endif
#ifndef HAVE_LOCALTIME_R
# define HAVE_LOCALTIME_R 1
#endif
#ifndef HAVE_LOCALTIME_RZ
# ifdef TM_ZONE
# define HAVE_LOCALTIME_RZ (NETBSD_INSPIRED && USE_LTZ)
# else
# define HAVE_LOCALTIME_RZ 0
# endif
#endif
#ifndef HAVE_TZSET
# define HAVE_TZSET 1
#endif
#ifndef ZDUMP_LO_YEAR
# define ZDUMP_LO_YEAR (-500)
#endif /* !defined ZDUMP_LO_YEAR */
#ifndef ZDUMP_HI_YEAR
# define ZDUMP_HI_YEAR 2500
#endif /* !defined ZDUMP_HI_YEAR */
#define SECSPERNYEAR (SECSPERDAY * DAYSPERNYEAR)
#define SECSPERLYEAR (SECSPERNYEAR + SECSPERDAY)
#define SECSPER400YEARS (SECSPERNYEAR * (intmax_t) (300 + 3) \
+ SECSPERLYEAR * (intmax_t) (100 - 3))
/*
** True if SECSPER400YEARS is known to be representable as an
** intmax_t. It's OK that SECSPER400YEARS_FITS can in theory be false
** even if SECSPER400YEARS is representable, because when that happens
** the code merely runs a bit more slowly, and this slowness doesn't
** occur on any practical platform.
*/
enum { SECSPER400YEARS_FITS = SECSPERLYEAR <= INTMAX_MAX / 400 };
#if HAVE_GETTEXT
# include <locale.h> /* for setlocale */
#endif /* HAVE_GETTEXT */
#if ! HAVE_LOCALTIME_RZ
# undef timezone_t
# define timezone_t char **
#endif
#if !HAVE_POSIX_DECLS
extern int getopt(int argc, char * const argv[],
const char * options);
extern char * optarg;
extern int optind;
#endif
/* The minimum and maximum finite time values. */
enum { atime_shift = CHAR_BIT * sizeof(time_t) - 2 };
static time_t const absolute_min_time =
((time_t) -1 < 0
? (- ((time_t) ~ (time_t) 0 < 0)
- (((time_t) 1 << atime_shift) - 1 + ((time_t) 1 << atime_shift)))
: 0);
static time_t const absolute_max_time =
((time_t) -1 < 0
? (((time_t) 1 << atime_shift) - 1 + ((time_t) 1 << atime_shift))
: -1);
static int longest;
static char const *progname;
static bool warned;
static bool errout;
static char const *abbr(struct tm const *);
static intmax_t delta(struct tm *, struct tm *);
static void dumptime(struct tm const *);
static time_t hunt(timezone_t, time_t, time_t, bool);
static void show(timezone_t, char *, time_t, bool);
static void showextrema(timezone_t, char *, time_t, struct tm *, time_t);
static void showtrans(char const *, struct tm const *, time_t, char const *,
char const *);
static const char *tformat(void);
ATTRIBUTE_PURE_114833 static time_t yeartot(intmax_t);
/* Is C an ASCII digit? */
static bool
is_digit(char c)
{
return '0' <= c && c <= '9';
}
/* Is A an alphabetic character in the C locale? */
static bool
is_alpha(char a)
{
switch (a) {
default:
return false;
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G':
case 'H': case 'I': case 'J': case 'K': case 'L': case 'M': case 'N':
case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T': case 'U':
case 'V': case 'W': case 'X': case 'Y': case 'Z':
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
case 'v': case 'w': case 'x': case 'y': case 'z':
return true;
}
}
ATTRIBUTE_NORETURN static void
size_overflow(void)
{
fprintf(stderr, _("%s: size overflow\n"), progname);
exit(EXIT_FAILURE);
}
/* Return A + B, exiting if the result would overflow either ptrdiff_t
or size_t. A and B are both nonnegative. */
ATTRIBUTE_PURE_114833 static ptrdiff_t
sumsize(ptrdiff_t a, ptrdiff_t b)
{
#ifdef ckd_add
ptrdiff_t sum;
if (!ckd_add(&sum, a, b) && sum <= INDEX_MAX)
return sum;
#else
if (a <= INDEX_MAX && b <= INDEX_MAX - a)
return a + b;
#endif
size_overflow();
}
/* Return the size of of the string STR, including its trailing NUL.
Report an error and exit if this would exceed INDEX_MAX which means
pointer subtraction wouldn't work. */
static ptrdiff_t
xstrsize(char const *str)
{
size_t len = strlen(str);
if (len < INDEX_MAX)
return len + 1;
size_overflow();
}
/* Return a pointer to a newly allocated buffer of size SIZE, exiting
on failure. SIZE should be positive. */
static void *
xmalloc(ptrdiff_t size)
{
void *p = malloc(size);
if (!p) {
fprintf(stderr, _("%s: Memory exhausted\n"), progname);
exit(EXIT_FAILURE);
}
return p;
}
#if ! HAVE_TZSET
# undef tzset
# define tzset zdump_tzset
static void tzset(void) { }
#endif
/* Assume gmtime_r works if localtime_r does.
A replacement localtime_r is defined below if needed. */
#if ! HAVE_LOCALTIME_R
# undef gmtime_r
# define gmtime_r zdump_gmtime_r
static struct tm *
gmtime_r(time_t *tp, struct tm *tmp)
{
struct tm *r = gmtime(tp);
if (r) {
*tmp = *r;
r = tmp;
}
return r;
}
#endif
/* Platforms with TM_ZONE don't need tzname, so they can use the
faster localtime_rz or localtime_r if available. */
#if defined TM_ZONE && HAVE_LOCALTIME_RZ
# define USE_LOCALTIME_RZ true
#else
# define USE_LOCALTIME_RZ false
#endif
#if ! USE_LOCALTIME_RZ
# if !defined TM_ZONE || ! HAVE_LOCALTIME_R || ! HAVE_TZSET
# undef localtime_r
# define localtime_r zdump_localtime_r
static struct tm *
localtime_r(time_t *tp, struct tm *tmp)
{
struct tm *r = localtime(tp);
if (r) {
*tmp = *r;
r = tmp;
}
return r;
}
# endif
# undef localtime_rz
# define localtime_rz zdump_localtime_rz
static struct tm *
localtime_rz(ATTRIBUTE_MAYBE_UNUSED timezone_t rz, time_t *tp, struct tm *tmp)
{
return localtime_r(tp, tmp);
}
# ifdef TYPECHECK
# undef mktime_z
# define mktime_z zdump_mktime_z
static time_t
mktime_z(timezone_t tz, struct tm *tmp)
{
return mktime(tmp);
}
# endif
# undef tzalloc
# undef tzfree
# define tzalloc zdump_tzalloc
# define tzfree zdump_tzfree
static timezone_t
tzalloc(char const *val)
{
# if HAVE_SETENV
if (setenv("TZ", val, 1) != 0) {
char const *e = strerror(errno);
fprintf(stderr, _("%s: setenv: %s\n"), progname, e);
exit(EXIT_FAILURE);
}
tzset();
return &optarg; /* Any valid non-null char ** will do. */
# else
enum { TZeqlen = 3 };
static char const TZeq[TZeqlen] = "TZ=";
static char **fakeenv;
static ptrdiff_t fakeenv0size;
void *freeable = NULL;
char **env = fakeenv, **initial_environ;
ptrdiff_t valsize = xstrsize(val);
if (fakeenv0size < valsize) {
char **e = environ, **to;
ptrdiff_t initial_nenvptrs = 1; /* Counting the trailing NULL pointer. */
while (*e++) {
# ifdef ckd_add
if (ckd_add(&initial_nenvptrs, initial_nenvptrs, 1)
|| INDEX_MAX < initial_nenvptrs)
size_overflow();
# else
if (initial_nenvptrs == INDEX_MAX / sizeof *environ)
size_overflow();
initial_nenvptrs++;
# endif
}
fakeenv0size = sumsize(valsize, valsize);
fakeenv0size = max(fakeenv0size, 64);
freeable = env;
fakeenv = env =
xmalloc(sumsize(sumsize(sizeof *environ,
initial_nenvptrs * sizeof *environ),
sumsize(TZeqlen, fakeenv0size)));
to = env + 1;
for (e = environ; (*to = *e); e++)
to += strncmp(*e, TZeq, TZeqlen) != 0;
env[0] = memcpy(to + 1, TZeq, TZeqlen);
}
memcpy(env[0] + TZeqlen, val, valsize);
initial_environ = environ;
environ = env;
tzset();
free(freeable);
return initial_environ;
# endif
}
static void
tzfree(ATTRIBUTE_MAYBE_UNUSED timezone_t initial_environ)
{
# if !HAVE_SETENV
environ = initial_environ;
tzset();
# endif
}
#endif /* ! USE_LOCALTIME_RZ */
/* A UT time zone, and its initializer. */
static timezone_t gmtz;
static void
gmtzinit(void)
{
if (USE_LOCALTIME_RZ) {
/* Try "GMT" first to find out whether this is one of the rare
platforms where time_t counts leap seconds; this works due to
the "Zone GMT 0 - GMT" line in the "etcetera" file. If "GMT"
fails, fall back on "GMT0" which might be similar due to the
"Link GMT GMT0" line in the "backward" file, and which
should work on all POSIX platforms. The rest of zdump does not
use the "GMT" abbreviation that comes from this setting, so it
is OK to use "GMT" here rather than the modern "UTC" which
would not work on platforms that omit the "backward" file. */
gmtz = tzalloc("GMT");
if (!gmtz) {
static char const gmt0[] = "GMT0";
gmtz = tzalloc(gmt0);
if (!gmtz) {
char const *e = strerror(errno);
fprintf(stderr, _("%s: unknown timezone '%s': %s\n"),
progname, gmt0, e);
exit(EXIT_FAILURE);
}
}
}
}
/* Convert *TP to UT, storing the broken-down time into *TMP.
Return TMP if successful, NULL otherwise. This is like gmtime_r(TP, TMP),
except typically faster if USE_LOCALTIME_RZ. */
static struct tm *
my_gmtime_r(time_t *tp, struct tm *tmp)
{
return USE_LOCALTIME_RZ ? localtime_rz(gmtz, tp, tmp) : gmtime_r(tp, tmp);
}
#ifndef TYPECHECK
# define my_localtime_rz localtime_rz
#else /* !defined TYPECHECK */
static struct tm *
my_localtime_rz(timezone_t tz, time_t *tp, struct tm *tmp)
{
tmp = localtime_rz(tz, tp, tmp);
if (tmp) {
struct tm tm;
register time_t t;
tm = *tmp;
t = mktime_z(tz, &tm);
if (t != *tp) {
fflush(stdout);
fprintf(stderr, "\n%s: ", progname);
fprintf(stderr, tformat(), *tp);
fprintf(stderr, " ->");
fprintf(stderr, " year=%d", tmp->tm_year);
fprintf(stderr, " mon=%d", tmp->tm_mon);
fprintf(stderr, " mday=%d", tmp->tm_mday);
fprintf(stderr, " hour=%d", tmp->tm_hour);
fprintf(stderr, " min=%d", tmp->tm_min);
fprintf(stderr, " sec=%d", tmp->tm_sec);
fprintf(stderr, " isdst=%d", tmp->tm_isdst);
fprintf(stderr, " -> ");
fprintf(stderr, tformat(), t);
fprintf(stderr, "\n");
errout = true;
}
}
return tmp;
}
#endif /* !defined TYPECHECK */
static void
abbrok(const char *const abbrp, const char *const zone)
{
register const char * cp;
register const char * wp;
if (warned)
return;
cp = abbrp;
while (is_alpha(*cp) || is_digit(*cp) || *cp == '-' || *cp == '+')
++cp;
if (*cp)
wp = _("has characters other than ASCII alphanumerics, '-' or '+'");
else if (cp - abbrp < 3)
wp = _("has fewer than 3 characters");
else if (cp - abbrp > 6)
wp = _("has more than 6 characters");
else
return;
fflush(stdout);
fprintf(stderr,
_("%s: warning: zone \"%s\" abbreviation \"%s\" %s\n"),
progname, zone, abbrp, wp);
warned = errout = true;
}
/* Return a time zone abbreviation. If the abbreviation needs to be
saved, use *BUF (of size *BUFALLOC) to save it, and return the
abbreviation in the possibly reallocated *BUF. Otherwise, just
return the abbreviation. Get the abbreviation from TMP.
Exit on memory allocation failure. */
static char const *
saveabbr(char **buf, ptrdiff_t *bufalloc, struct tm const *tmp)
{
char const *ab = abbr(tmp);
if (HAVE_LOCALTIME_RZ)
return ab;
else {
ptrdiff_t absize = xstrsize(ab);
if (*bufalloc < absize) {
free(*buf);
/* Make the new buffer at least twice as long as the old,
to avoid O(N**2) behavior on repeated calls. */
*bufalloc = sumsize(*bufalloc, absize);
*buf = xmalloc(*bufalloc);
}
return strcpy(*buf, ab);
}
}
static void
close_file(FILE *stream)
{
char const *e = (ferror(stream) ? _("I/O error")
: fclose(stream) != 0 ? strerror(errno) : NULL);
if (e) {
fprintf(stderr, "%s: %s\n", progname, e);
exit(EXIT_FAILURE);
}
}
static void
usage(FILE * const stream, const int status)
{
fprintf(stream,
_("%s: usage: %s OPTIONS TIMEZONE ...\n"
"Options include:\n"
" -c [L,]U Start at year L (default -500), end before year U (default 2500)\n"
" -t [L,]U Start at time L, end before time U (in seconds since 1970)\n"
" -i List transitions briefly (format is experimental)\n" \
" -v List transitions verbosely\n"
" -V List transitions a bit less verbosely\n"
" --help Output this help\n"
" --version Output version info\n"
"\n"
"Report bugs to %s.\n"),
progname, progname, REPORT_BUGS_TO);
if (status == EXIT_SUCCESS)
close_file(stream);
exit(status);
}
int
main(int argc, char *argv[])
{
/* These are static so that they're initially zero. */
static char * abbrev;
static ptrdiff_t abbrevsize;
register int i;
register bool vflag;
register bool Vflag;
register char * cutarg;
register char * cuttimes;
register time_t cutlotime;
register time_t cuthitime;
time_t now;
bool iflag = false;
cutlotime = absolute_min_time;
cuthitime = absolute_max_time;
#if HAVE_GETTEXT
setlocale(LC_ALL, "");
# ifdef TZ_DOMAINDIR
bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
# endif /* defined TEXTDOMAINDIR */
textdomain(TZ_DOMAIN);
#endif /* HAVE_GETTEXT */
progname = argv[0] ? argv[0] : "zdump";
for (i = 1; i < argc; ++i)
if (strcmp(argv[i], "--version") == 0) {
printf("zdump %s%s\n", PKGVERSION, TZVERSION);
return EXIT_SUCCESS;
} else if (strcmp(argv[i], "--help") == 0) {
usage(stdout, EXIT_SUCCESS);
}
vflag = Vflag = false;
cutarg = cuttimes = NULL;
for (;;)
switch (getopt(argc, argv, "c:it:vV")) {
case 'c': cutarg = optarg; break;
case 't': cuttimes = optarg; break;
case 'i': iflag = true; break;
case 'v': vflag = true; break;
case 'V': Vflag = true; break;
case -1:
if (! (optind == argc - 1 && strcmp(argv[optind], "=") == 0))
goto arg_processing_done;
ATTRIBUTE_FALLTHROUGH;
default:
usage(stderr, EXIT_FAILURE);
}
arg_processing_done:;
if (iflag | vflag | Vflag) {
intmax_t lo;
intmax_t hi;
char *loend, *hiend;
register intmax_t cutloyear = ZDUMP_LO_YEAR;
register intmax_t cuthiyear = ZDUMP_HI_YEAR;
if (cutarg != NULL) {
lo = strtoimax(cutarg, &loend, 10);
if (cutarg != loend && !*loend) {
hi = lo;
cuthiyear = hi;
} else if (cutarg != loend && *loend == ','
&& (hi = strtoimax(loend + 1, &hiend, 10),
loend + 1 != hiend && !*hiend)) {
cutloyear = lo;
cuthiyear = hi;
} else {
fprintf(stderr, _("%s: wild -c argument %s\n"),
progname, cutarg);
return EXIT_FAILURE;
}
}
if (cutarg != NULL || cuttimes == NULL) {
cutlotime = yeartot(cutloyear);
cuthitime = yeartot(cuthiyear);
}
if (cuttimes != NULL) {
lo = strtoimax(cuttimes, &loend, 10);
if (cuttimes != loend && !*loend) {
hi = lo;
if (hi < cuthitime) {
if (hi < absolute_min_time + 1)
hi = absolute_min_time + 1;
cuthitime = hi;
}
} else if (cuttimes != loend && *loend == ','
&& (hi = strtoimax(loend + 1, &hiend, 10),
loend + 1 != hiend && !*hiend)) {
if (cutlotime < lo) {
if (absolute_max_time < lo)
lo = absolute_max_time;
cutlotime = lo;
}
if (hi < cuthitime) {
if (hi < absolute_min_time + 1)
hi = absolute_min_time + 1;
cuthitime = hi;
}
} else {
fprintf(stderr,
_("%s: wild -t argument %s\n"),
progname, cuttimes);
return EXIT_FAILURE;
}
}
}
gmtzinit();
if (iflag | vflag | Vflag)
now = 0;
else {
now = time(NULL);
now |= !now;
}
longest = 0;
for (i = optind; i < argc; i++) {
size_t arglen = strlen(argv[i]);
if (longest < arglen)
longest = min(arglen, INT_MAX);
}
for (i = optind; i < argc; ++i) {
timezone_t tz = tzalloc(argv[i]);
char const *ab;
time_t t;
struct tm tm, newtm;
bool tm_ok;
if (!tz) {
char const *e = strerror(errno);
fprintf(stderr, _("%s: unknown timezone '%s': %s\n"),
progname, argv[i], e);
return EXIT_FAILURE;
}
if (now) {
show(tz, argv[i], now, false);
tzfree(tz);
continue;
}
warned = false;
t = absolute_min_time;
if (! (iflag | Vflag)) {
show(tz, argv[i], t, true);
if (my_localtime_rz(tz, &t, &tm) == NULL
&& t < cutlotime) {
time_t newt = cutlotime;
if (my_localtime_rz(tz, &newt, &newtm) != NULL)
showextrema(tz, argv[i], t, NULL, newt);
}
}
if (t + 1 < cutlotime)
t = cutlotime - 1;
tm_ok = my_localtime_rz(tz, &t, &tm) != NULL;
if (tm_ok) {
ab = saveabbr(&abbrev, &abbrevsize, &tm);
if (iflag) {
showtrans("\nTZ=%f", &tm, t, ab, argv[i]);
showtrans("-\t-\t%Q", &tm, t, ab, argv[i]);
}
} else
ab = NULL;
while (t < cuthitime - 1) {
time_t newt = ((t < absolute_max_time - SECSPERDAY / 2
&& t + SECSPERDAY / 2 < cuthitime - 1)
? t + SECSPERDAY / 2
: cuthitime - 1);
struct tm *newtmp = localtime_rz(tz, &newt, &newtm);
bool newtm_ok = newtmp != NULL;
if (tm_ok != newtm_ok
|| (ab && (delta(&newtm, &tm) != newt - t
|| newtm.tm_isdst != tm.tm_isdst
|| strcmp(abbr(&newtm), ab) != 0))) {
newt = hunt(tz, t, newt, false);
newtmp = localtime_rz(tz, &newt, &newtm);
newtm_ok = newtmp != NULL;
if (iflag)
showtrans("%Y-%m-%d\t%L\t%Q", newtmp, newt,
newtm_ok ? abbr(&newtm) : NULL, argv[i]);
else {
show(tz, argv[i], newt - 1, true);
show(tz, argv[i], newt, true);
}
}
t = newt;
tm_ok = newtm_ok;
if (newtm_ok) {
ab = saveabbr(&abbrev, &abbrevsize, &newtm);
tm = newtm;
}
}
if (! (iflag | Vflag)) {
time_t newt = absolute_max_time;
t = cuthitime;
if (t < newt) {
struct tm *tmp = my_localtime_rz(tz, &t, &tm);
if (tmp != NULL
&& my_localtime_rz(tz, &newt, &newtm) == NULL)
showextrema(tz, argv[i], t, tmp, newt);
}
show(tz, argv[i], absolute_max_time, true);
}
tzfree(tz);
}
close_file(stdout);
if (errout && (ferror(stderr) || fclose(stderr) != 0))
return EXIT_FAILURE;
return EXIT_SUCCESS;
}
static time_t
yeartot(intmax_t y)
{
register intmax_t myy, seconds, years;
register time_t t;
myy = EPOCH_YEAR;
t = 0;
while (myy < y) {
if (SECSPER400YEARS_FITS && 400 <= y - myy) {
intmax_t diff400 = (y - myy) / 400;
if (INTMAX_MAX / SECSPER400YEARS < diff400)
return absolute_max_time;
seconds = diff400 * SECSPER400YEARS;
years = diff400 * 400;
} else {
seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
years = 1;
}
myy += years;
if (t > absolute_max_time - seconds)
return absolute_max_time;
t += seconds;
}
while (y < myy) {
if (SECSPER400YEARS_FITS && y + 400 <= myy && myy < 0) {
intmax_t diff400 = (myy - y) / 400;
if (INTMAX_MAX / SECSPER400YEARS < diff400)
return absolute_min_time;
seconds = diff400 * SECSPER400YEARS;
years = diff400 * 400;
} else {
seconds = isleap(myy - 1) ? SECSPERLYEAR : SECSPERNYEAR;
years = 1;
}
myy -= years;
if (t < absolute_min_time + seconds)
return absolute_min_time;
t -= seconds;
}
return t;
}
/* Search for a discontinuity in timezone TZ, in the
timestamps ranging from LOT through HIT. LOT and HIT disagree
about some aspect of timezone. If ONLY_OK, search only for
definedness changes, i.e., localtime succeeds on one side of the
transition but fails on the other side. Return the timestamp just
before the transition from LOT's settings. */
static time_t
hunt(timezone_t tz, time_t lot, time_t hit, bool only_ok)
{
static char * loab;
static ptrdiff_t loabsize;
struct tm lotm;
struct tm tm;
/* Convert LOT into a broken-down time here, even though our
caller already did that. On platforms without TM_ZONE,
tzname may have been altered since our caller broke down
LOT, and tzname needs to be changed back. */
bool lotm_ok = my_localtime_rz(tz, &lot, &lotm) != NULL;
bool tm_ok;
char const *ab = lotm_ok ? saveabbr(&loab, &loabsize, &lotm) : NULL;
for ( ; ; ) {
/* T = average of LOT and HIT, rounding down.
Avoid overflow. */
int rem_sum = lot % 2 + hit % 2;
time_t t = (rem_sum == 2) - (rem_sum < 0) + lot / 2 + hit / 2;
if (t == lot)
break;
tm_ok = my_localtime_rz(tz, &t, &tm) != NULL;
if (lotm_ok == tm_ok
&& (only_ok
|| (ab && tm.tm_isdst == lotm.tm_isdst
&& delta(&tm, &lotm) == t - lot
&& strcmp(abbr(&tm), ab) == 0))) {
lot = t;
if (tm_ok)
lotm = tm;
} else hit = t;
}
return hit;
}
/*
** Thanks to Paul Eggert for logic used in delta_nonneg.
*/
static intmax_t
delta_nonneg(struct tm *newp, struct tm *oldp)
{
intmax_t oldy = oldp->tm_year;
int cycles = (newp->tm_year - oldy) / YEARSPERREPEAT;
intmax_t sec = SECSPERREPEAT, result = cycles * sec;
int tmy = oldp->tm_year + cycles * YEARSPERREPEAT;
for ( ; tmy < newp->tm_year; ++tmy)
result += DAYSPERNYEAR + isleap_sum(tmy, TM_YEAR_BASE);
result += newp->tm_yday - oldp->tm_yday;
result *= HOURSPERDAY;
result += newp->tm_hour - oldp->tm_hour;
result *= MINSPERHOUR;
result += newp->tm_min - oldp->tm_min;
result *= SECSPERMIN;
result += newp->tm_sec - oldp->tm_sec;
return result;
}
static intmax_t
delta(struct tm *newp, struct tm *oldp)
{
return (newp->tm_year < oldp->tm_year
? -delta_nonneg(oldp, newp)
: delta_nonneg(newp, oldp));
}
#ifndef TM_GMTOFF
/* Return A->tm_yday, adjusted to compare it fairly to B->tm_yday.
Assume A and B differ by at most one year. */
static int
adjusted_yday(struct tm const *a, struct tm const *b)
{
int yday = a->tm_yday;
if (b->tm_year < a->tm_year)
yday += 365 + isleap_sum(b->tm_year, TM_YEAR_BASE);
return yday;
}
#endif
/* If A is the broken-down local time and B the broken-down UT for
the same instant, return A's UT offset in seconds, where positive
offsets are east of Greenwich. On failure, return LONG_MIN.
If T is nonnull, *T is the timestamp that corresponds to A; call
my_gmtime_r and use its result instead of B. Otherwise, B is the
possibly nonnull result of an earlier call to my_gmtime_r. */
static long
gmtoff(struct tm const *a, ATTRIBUTE_MAYBE_UNUSED time_t *t,
ATTRIBUTE_MAYBE_UNUSED struct tm const *b)
{
#ifdef TM_GMTOFF
return a->TM_GMTOFF;
#else
struct tm tm;
if (t)
b = my_gmtime_r(t, &tm);
if (! b)
return LONG_MIN;
else {
int ayday = adjusted_yday(a, b);
int byday = adjusted_yday(b, a);
int days = ayday - byday;
long hours = a->tm_hour - b->tm_hour + 24 * days;
long minutes = a->tm_min - b->tm_min + 60 * hours;
long seconds = a->tm_sec - b->tm_sec + 60 * minutes;
return seconds;
}
#endif
}
static void
show(timezone_t tz, char *zone, time_t t, bool v)
{
register struct tm * tmp;
register struct tm * gmtmp;
struct tm tm, gmtm;
printf("%-*s ", longest, zone);
if (v) {
gmtmp = my_gmtime_r(&t, &gmtm);
if (gmtmp == NULL) {
printf(tformat(), t);
printf(_(" (gmtime failed)"));
} else {
dumptime(gmtmp);
printf(" UT");
}
printf(" = ");
}
tmp = my_localtime_rz(tz, &t, &tm);
if (tmp == NULL) {
printf(tformat(), t);
printf(_(" (localtime failed)"));
} else {
dumptime(tmp);
if (*abbr(tmp) != '\0')
printf(" %s", abbr(tmp));
if (v) {
long off = gmtoff(tmp, NULL, gmtmp);
printf(" isdst=%d", tmp->tm_isdst);
if (off != LONG_MIN)
printf(" gmtoff=%ld", off);
}
}
printf("\n");
if (tmp != NULL && *abbr(tmp) != '\0')
abbrok(abbr(tmp), zone);
}
/* Show timestamps just before and just after a transition between
defined and undefined (or vice versa) in either localtime or
gmtime. These transitions are for timezone TZ with name ZONE, in
the range from LO (with broken-down time LOTMP if that is nonnull)
through HI. LO and HI disagree on definedness. */
static void
showextrema(timezone_t tz, char *zone, time_t lo, struct tm *lotmp, time_t hi)
{
struct tm localtm[2], gmtm[2];
time_t t, boundary = hunt(tz, lo, hi, true);
bool old = false;
hi = (SECSPERDAY < hi - boundary
? boundary + SECSPERDAY
: hi + (hi < TIME_T_MAX));
if (SECSPERDAY < boundary - lo) {
lo = boundary - SECSPERDAY;
lotmp = my_localtime_rz(tz, &lo, &localtm[old]);
}
if (lotmp)
localtm[old] = *lotmp;
else
localtm[old].tm_sec = -1;
if (! my_gmtime_r(&lo, &gmtm[old]))
gmtm[old].tm_sec = -1;
/* Search sequentially for definedness transitions. Although this
could be sped up by refining 'hunt' to search for either
localtime or gmtime definedness transitions, it hardly seems
worth the trouble. */
for (t = lo + 1; t < hi; t++) {
bool new = !old;
if (! my_localtime_rz(tz, &t, &localtm[new]))
localtm[new].tm_sec = -1;
if (! my_gmtime_r(&t, &gmtm[new]))
gmtm[new].tm_sec = -1;
if (((localtm[old].tm_sec < 0) != (localtm[new].tm_sec < 0))
| ((gmtm[old].tm_sec < 0) != (gmtm[new].tm_sec < 0))) {
show(tz, zone, t - 1, true);
show(tz, zone, t, true);
}
old = new;
}
}
#if HAVE_SNPRINTF
# define my_snprintf snprintf
#else
# include <stdarg.h>
/* A substitute for snprintf that is good enough for zdump. */
static int
my_snprintf(char *s, size_t size, char const *format, ...)
{
int n;
va_list args;
char const *arg;
size_t arglen, slen;
char buf[1024];
va_start(args, format);
if (strcmp(format, "%s") == 0) {
arg = va_arg(args, char const *);
arglen = strlen(arg);
} else {
n = vsprintf(buf, format, args);
if (n < 0) {
va_end(args);
return n;
}
arg = buf;
arglen = n;
}
slen = arglen < size ? arglen : size - 1;
memcpy(s, arg, slen);
s[slen] = '\0';
n = arglen <= INT_MAX ? arglen : -1;
va_end(args);
return n;
}
#endif
/* Store into BUF, of size SIZE, a formatted local time taken from *TM.
Use ISO 8601 format +HH:MM:SS. Omit :SS if SS is zero, and omit
:MM too if MM is also zero.
Return the length of the resulting string. If the string does not
fit, return the length that the string would have been if it had
fit; do not overrun the output buffer. */
static int
format_local_time(char *buf, ptrdiff_t size, struct tm const *tm)
{
int ss = tm->tm_sec, mm = tm->tm_min, hh = tm->tm_hour;
return (ss
? my_snprintf(buf, size, "%02d:%02d:%02d", hh, mm, ss)
: mm
? my_snprintf(buf, size, "%02d:%02d", hh, mm)
: my_snprintf(buf, size, "%02d", hh));
}
/* Store into BUF, of size SIZE, a formatted UT offset for the
localtime *TM corresponding to time T. Use ISO 8601 format
+HHMMSS, or -HHMMSS for timestamps west of Greenwich; use the
format -00 for unknown UT offsets. If the hour needs more than
two digits to represent, extend the length of HH as needed.
Otherwise, omit SS if SS is zero, and omit MM too if MM is also
zero.
Return the length of the resulting string, or -1 if the result is
not representable as a string. If the string does not fit, return
the length that the string would have been if it had fit; do not
overrun the output buffer. */
static int
format_utc_offset(char *buf, ptrdiff_t size, struct tm const *tm, time_t t)
{
long off = gmtoff(tm, &t, NULL);
char sign = ((off < 0
|| (off == 0
&& (*abbr(tm) == '-' || strcmp(abbr(tm), "zzz") == 0)))
? '-' : '+');
long hh;
int mm, ss;
if (off < 0)
{
if (off == LONG_MIN)
return -1;
off = -off;
}
ss = off % 60;
mm = off / 60 % 60;
hh = off / 60 / 60;
return (ss || 100 <= hh
? my_snprintf(buf, size, "%c%02ld%02d%02d", sign, hh, mm, ss)
: mm
? my_snprintf(buf, size, "%c%02ld%02d", sign, hh, mm)
: my_snprintf(buf, size, "%c%02ld", sign, hh));
}
/* Store into BUF (of size SIZE) a quoted string representation of P.
If the representation's length is less than SIZE, return the
length; the representation is not null terminated. Otherwise
return SIZE, to indicate that BUF is too small. */
static ptrdiff_t
format_quoted_string(char *buf, ptrdiff_t size, char const *p)
{
char *b = buf;
ptrdiff_t s = size;
if (!s)
return size;
*b++ = '"', s--;
for (;;) {
char c = *p++;
if (s <= 1)
return size;
switch (c) {
default: *b++ = c, s--; continue;
case '\0': *b++ = '"', s--; return size - s;
case '"': case '\\': break;
case ' ': c = 's'; break;
case '\f': c = 'f'; break;
case '\n': c = 'n'; break;
case '\r': c = 'r'; break;
case '\t': c = 't'; break;
case '\v': c = 'v'; break;
}
*b++ = '\\', *b++ = c, s -= 2;
}
}
/* Store into BUF (of size SIZE) a timestamp formatted by TIME_FMT.
TM is the broken-down time, T the seconds count, AB the time zone
abbreviation, and ZONE_NAME the zone name. Return true if
successful, false if the output would require more than SIZE bytes.
TIME_FMT uses the same format that strftime uses, with these
additions:
%f zone name
%L local time as per format_local_time
%Q like "U\t%Z\tD" where U is the UT offset as for format_utc_offset
and D is the isdst flag; except omit D if it is zero, omit %Z if
it equals U, quote and escape %Z if it contains nonalphabetics,
and omit any trailing tabs. */
static bool
istrftime(char *buf, ptrdiff_t size, char const *time_fmt,
struct tm const *tm, time_t t, char const *ab, char const *zone_name)
{
char *b = buf;
ptrdiff_t s = size;
char const *f = time_fmt, *p;
for (p = f; ; p++)
if (*p == '%' && p[1] == '%')
p++;
else if (!*p
|| (*p == '%'
&& (p[1] == 'f' || p[1] == 'L' || p[1] == 'Q'))) {
ptrdiff_t formatted_len;
ptrdiff_t f_prefix_len = p - f;
ptrdiff_t f_prefix_copy_size = sumsize(f_prefix_len, 2);
char fbuf[100];
bool oversized = sizeof fbuf <= f_prefix_copy_size;
char *f_prefix_copy = oversized ? xmalloc(f_prefix_copy_size) : fbuf;
memcpy(f_prefix_copy, f, f_prefix_len);
strcpy(f_prefix_copy + f_prefix_len, "X");
formatted_len = strftime(b, s, f_prefix_copy, tm);
if (oversized)
free(f_prefix_copy);
if (formatted_len == 0)
return false;
formatted_len--;
b += formatted_len, s -= formatted_len;
if (!*p++)
break;
switch (*p) {
case 'f':
formatted_len = format_quoted_string(b, s, zone_name);
break;
case 'L':
formatted_len = format_local_time(b, s, tm);
break;
case 'Q':
{
bool show_abbr;
int offlen = format_utc_offset(b, s, tm, t);
if (! (0 <= offlen && offlen < s))
return false;
show_abbr = strcmp(b, ab) != 0;
b += offlen, s -= offlen;
if (show_abbr) {
char const *abp;
ptrdiff_t len;
if (s <= 1)
return false;
*b++ = '\t', s--;
for (abp = ab; is_alpha(*abp); abp++)
continue;
len = (!*abp && *ab
? my_snprintf(b, s, "%s", ab)
: format_quoted_string(b, s, ab));
if (s <= len)
return false;
b += len, s -= len;
}
formatted_len
= (tm->tm_isdst
? my_snprintf(b, s, &"\t\t%d"[show_abbr], tm->tm_isdst)
: 0);
}
break;
}
if (s <= formatted_len)
return false;
b += formatted_len, s -= formatted_len;
f = p + 1;
}
*b = '\0';
return true;
}
/* Show a time transition. */
static void
showtrans(char const *time_fmt, struct tm const *tm, time_t t, char const *ab,
char const *zone_name)
{
if (!tm) {
printf(tformat(), t);
putchar('\n');
} else {
char stackbuf[1000];
ptrdiff_t size = sizeof stackbuf;
char *buf = stackbuf;
char *bufalloc = NULL;
while (! istrftime(buf, size, time_fmt, tm, t, ab, zone_name)) {
size = sumsize(size, size);
free(bufalloc);
buf = bufalloc = xmalloc(size);
}
puts(buf);
free(bufalloc);
}
}
static char const *
abbr(struct tm const *tmp)
{
#ifdef TM_ZONE
return tmp->TM_ZONE;
#else
# if HAVE_TZNAME
if (0 <= tmp->tm_isdst && tzname[0 < tmp->tm_isdst])
return tzname[0 < tmp->tm_isdst];
# endif
return "";
#endif
}
/*
** The code below can fail on certain theoretical systems;
** it works on all known real-world systems as of 2022-01-25.
*/
static const char *
tformat(void)
{
#if HAVE__GENERIC
/* C11-style _Generic is more likely to return the correct
format when distinct types have the same size. */
char const *fmt =
_Generic(+ (time_t) 0,
int: "%d", long: "%ld", long long: "%lld",
unsigned: "%u", unsigned long: "%lu",
unsigned long long: "%llu",
default: NULL);
if (fmt)
return fmt;
fmt = _Generic((time_t) 0,
intmax_t: "%"PRIdMAX, uintmax_t: "%"PRIuMAX,
default: NULL);
if (fmt)
return fmt;
#endif
if (0 > (time_t) -1) { /* signed */
if (sizeof(time_t) == sizeof(intmax_t))
return "%"PRIdMAX;
if (sizeof(time_t) > sizeof(long))
return "%lld";
if (sizeof(time_t) > sizeof(int))
return "%ld";
return "%d";
}
#ifdef PRIuMAX
if (sizeof(time_t) == sizeof(uintmax_t))
return "%"PRIuMAX;
#endif
if (sizeof(time_t) > sizeof(unsigned long))
return "%llu";
if (sizeof(time_t) > sizeof(unsigned int))
return "%lu";
return "%u";
}
static void
dumptime(register const struct tm *timeptr)
{
static const char wday_name[][4] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static const char mon_name[][4] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
register int lead;
register int trail;
int DIVISOR = 10;
/*
** The packaged localtime_rz and gmtime_r never put out-of-range
** values in tm_wday or tm_mon, but since this code might be compiled
** with other (perhaps experimental) versions, paranoia is in order.
*/
printf("%s %s%3d %.2d:%.2d:%.2d ",
((0 <= timeptr->tm_wday
&& timeptr->tm_wday < sizeof wday_name / sizeof wday_name[0])
? wday_name[timeptr->tm_wday] : "???"),
((0 <= timeptr->tm_mon
&& timeptr->tm_mon < sizeof mon_name / sizeof mon_name[0])
? mon_name[timeptr->tm_mon] : "???"),
timeptr->tm_mday, timeptr->tm_hour,
timeptr->tm_min, timeptr->tm_sec);
trail = timeptr->tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
lead = timeptr->tm_year / DIVISOR + TM_YEAR_BASE / DIVISOR +
trail / DIVISOR;
trail %= DIVISOR;
if (trail < 0 && lead > 0) {
trail += DIVISOR;
--lead;
} else if (lead < 0 && trail > 0) {
trail -= DIVISOR;
++lead;
}
if (lead == 0)
printf("%d", trail);
else printf("%d%d", lead, ((trail < 0) ? -trail : trail));
}