zic.c

Go to the documentation of this file.

/* Compile .zi time zone data into TZif binary files.  */
 
/*
 * This file is in the public domain, so clarified as of
 * 2006-07-17 by Arthur David Olson.
 *
 * IDENTIFICATION
 *    src/timezone/zic.c
 */
 
#include "postgres_fe.h"
 
#include <fcntl.h>
#include <sys/stat.h>
#include <time.h>
 
#include "pg_getopt.h"
 
#include "private.h"
#include "tzfile.h"
 
#define ZIC_VERSION_PRE_2013 '2'
#define ZIC_VERSION '3'
 
typedef int_fast64_t zic_t;
#define ZIC_MIN INT_FAST64_MIN
#define ZIC_MAX INT_FAST64_MAX
#define PRIdZIC PRIdFAST64
#define SCNdZIC SCNdFAST64
 
#ifndef ZIC_MAX_ABBR_LEN_WO_WARN
#define ZIC_MAX_ABBR_LEN_WO_WARN    6
#endif                          /* !defined ZIC_MAX_ABBR_LEN_WO_WARN */
 
#ifndef WIN32
#ifdef S_IRUSR
#define MKDIR_UMASK (S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
#else
#define MKDIR_UMASK 0755
#endif
#endif
/* Port to native MS-Windows and to ancient UNIX.  */
#if !defined S_ISDIR && defined S_IFDIR && defined S_IFMT
#define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
#endif
 
/* The maximum ptrdiff_t value, for pre-C99 platforms.  */
#ifndef PTRDIFF_MAX
static ptrdiff_t const PTRDIFF_MAX = MAXVAL(ptrdiff_t, TYPE_BIT(ptrdiff_t));
#endif
 
/* The minimum alignment of a type, for pre-C11 platforms.  */
#if __STDC_VERSION__ < 201112
#define _Alignof(type) offsetof(struct { char a; type b; }, b)
#endif
 
/*
 * The type for line numbers.  Use PRIdMAX to format them; formerly
 * there was also "#define PRIdLINENO PRIdMAX" and formats used
 * PRIdLINENO, but xgettext cannot grok that.
 */
typedef intmax_t lineno_t;
 
struct rule
{
    const char *r_filename;
    lineno_t    r_linenum;
    const char *r_name;
 
    zic_t       r_loyear;       /* for example, 1986 */
    zic_t       r_hiyear;       /* for example, 1986 */
    bool        r_lowasnum;
    bool        r_hiwasnum;
 
    int         r_month;        /* 0..11 */
 
    int         r_dycode;       /* see below */
    int         r_dayofmonth;
    int         r_wday;
 
    zic_t       r_tod;          /* time from midnight */
    bool        r_todisstd;     /* is r_tod standard time? */
    bool        r_todisut;      /* is r_tod UT? */
    bool        r_isdst;        /* is this daylight saving time? */
    zic_t       r_save;         /* offset from standard time */
    const char *r_abbrvar;      /* variable part of abbreviation */
 
    bool        r_todo;         /* a rule to do (used in outzone) */
    zic_t       r_temp;         /* used in outzone */
};
 
/*
 *  r_dycode        r_dayofmonth    r_wday
 */
 
#define DC_DOM      0   /* 1..31 */ /* unused */
#define DC_DOWGEQ   1   /* 1..31 */ /* 0..6 (Sun..Sat) */
#define DC_DOWLEQ   2   /* 1..31 */ /* 0..6 (Sun..Sat) */
 
struct zone
{
    const char *z_filename;
    lineno_t    z_linenum;
 
    const char *z_name;
    zic_t       z_stdoff;
    char       *z_rule;
    const char *z_format;
    char        z_format_specifier;
 
    bool        z_isdst;
    zic_t       z_save;
 
    struct rule *z_rules;
    ptrdiff_t   z_nrules;
 
    struct rule z_untilrule;
    zic_t       z_untiltime;
};
 
extern int  link(const char *target, const char *linkname);
#ifndef AT_SYMLINK_FOLLOW
#define linkat(targetdir, target, linknamedir, linkname, flag) \
    (itssymlink(target) ? (errno = ENOTSUP, -1) : link(target, linkname))
#endif
 
static void verror(const char *const string, va_list args) pg_attribute_printf(1, 0);
static void error(const char *const string, ...) pg_attribute_printf(1, 2);
static void warning(const char *const string, ...) pg_attribute_printf(1, 2);
static void addtt(zic_t starttime, int type);
static int  addtype(zic_t utoff, char const *abbr,
                    bool isdst, bool ttisstd, bool ttisut);
static void leapadd(zic_t t, int correction, int rolling);
static void adjleap(void);
static void associate(void);
static void dolink(const char *target, const char *linkname,
                   bool staysymlink);
static char **getfields(char *cp);
static zic_t gethms(const char *string, const char *errstring);
static zic_t getsave(char *field, bool *isdst);
static void inexpires(char **fields, int nfields);
static void infile(const char *name);
static void inleap(char **fields, int nfields);
static void inlink(char **fields, int nfields);
static void inrule(char **fields, int nfields);
static bool inzcont(char **fields, int nfields);
static bool inzone(char **fields, int nfields);
static bool inzsub(char **fields, int nfields, bool iscont);
static bool itsdir(char const *name);
static bool itssymlink(char const *name);
static bool is_alpha(char a);
static char lowerit(char a);
static void mkdirs(char const *argname, bool ancestors);
static void newabbr(const char *string);
static zic_t oadd(zic_t t1, zic_t t2);
static void outzone(const struct zone *zpfirst, ptrdiff_t zonecount);
static zic_t rpytime(const struct rule *rp, zic_t wantedy);
static void rulesub(struct rule *rp,
                    const char *loyearp, const char *hiyearp,
                    const char *typep, const char *monthp,
                    const char *dayp, const char *timep);
static zic_t tadd(zic_t t1, zic_t t2);
 
/* Bound on length of what %z can expand to.  */
enum
{
PERCENT_Z_LEN_BOUND = sizeof "+995959" - 1};
 
/*
 * If true, work around a bug in Qt 5.6.1 and earlier, which mishandles
 * TZif files whose POSIX-TZ-style strings contain '<'; see
 * QTBUG-53071 <https://bugreports.qt.io/browse/QTBUG-53071>.  This
 * workaround will no longer be needed when Qt 5.6.1 and earlier are
 * obsolete, say in the year 2021.
 */
#ifndef WORK_AROUND_QTBUG_53071
enum
{
WORK_AROUND_QTBUG_53071 = true};
#endif
 
static int  charcnt;
static bool errors;
static bool warnings;
static const char *filename;
static int  leapcnt;
static bool leapseen;
static zic_t leapminyear;
static zic_t leapmaxyear;
static lineno_t linenum;
static int  max_abbrvar_len = PERCENT_Z_LEN_BOUND;
static int  max_format_len;
static zic_t max_year;
static zic_t min_year;
static bool noise;
static bool print_abbrevs;
static zic_t print_cutoff;
static const char *rfilename;
static lineno_t rlinenum;
static const char *progname;
static ptrdiff_t timecnt;
static ptrdiff_t timecnt_alloc;
static int  typecnt;
 
/*
 * Line codes.
 */
 
#define LC_RULE     0
#define LC_ZONE     1
#define LC_LINK     2
#define LC_LEAP     3
#define LC_EXPIRES  4
 
/*
 * Which fields are which on a Zone line.
 */
 
#define ZF_NAME     1
#define ZF_STDOFF   2
#define ZF_RULE     3
#define ZF_FORMAT   4
#define ZF_TILYEAR  5
#define ZF_TILMONTH 6
#define ZF_TILDAY   7
#define ZF_TILTIME  8
#define ZONE_MINFIELDS  5
#define ZONE_MAXFIELDS  9
 
/*
 * Which fields are which on a Zone continuation line.
 */
 
#define ZFC_STDOFF  0
#define ZFC_RULE    1
#define ZFC_FORMAT  2
#define ZFC_TILYEAR 3
#define ZFC_TILMONTH    4
#define ZFC_TILDAY  5
#define ZFC_TILTIME 6
#define ZONEC_MINFIELDS 3
#define ZONEC_MAXFIELDS 7
 
/*
 * Which files are which on a Rule line.
 */
 
#define RF_NAME     1
#define RF_LOYEAR   2
#define RF_HIYEAR   3
#define RF_COMMAND  4
#define RF_MONTH    5
#define RF_DAY      6
#define RF_TOD      7
#define RF_SAVE     8
#define RF_ABBRVAR  9
#define RULE_FIELDS 10
 
/*
 * Which fields are which on a Link line.
 */
 
#define LF_TARGET   1
#define LF_LINKNAME 2
#define LINK_FIELDS 3
 
/*
 * Which fields are which on a Leap line.
 */
 
#define LP_YEAR     1
#define LP_MONTH    2
#define LP_DAY      3
#define LP_TIME     4
#define LP_CORR     5
#define LP_ROLL     6
#define LEAP_FIELDS 7
 
/* Expires lines are like Leap lines, except without CORR and ROLL fields.  */
#define EXPIRES_FIELDS  5
 
/*
 * Year synonyms.
 */
 
#define YR_MINIMUM  0
#define YR_MAXIMUM  1
#define YR_ONLY     2
 
static struct rule *rules;
static ptrdiff_t nrules;        /* number of rules */
static ptrdiff_t nrules_alloc;
 
static struct zone *zones;
static ptrdiff_t nzones;        /* number of zones */
static ptrdiff_t nzones_alloc;
 
struct link
{
    const char *l_filename;
    lineno_t    l_linenum;
    const char *l_target;
    const char *l_linkname;
};
 
static struct link *links;
static ptrdiff_t nlinks;
static ptrdiff_t nlinks_alloc;
 
struct lookup
{
    const char *l_word;
    const int   l_value;
};
 
static struct lookup const *byword(const char *word,
                                   const struct lookup *table);
 
static struct lookup const zi_line_codes[] = {
    {"Rule", LC_RULE},
    {"Zone", LC_ZONE},
    {"Link", LC_LINK},
    {NULL, 0}
};
static struct lookup const leap_line_codes[] = {
    {"Leap", LC_LEAP},
    {"Expires", LC_EXPIRES},
    {NULL, 0}
};
 
static struct lookup const mon_names[] = {
    {"January", TM_JANUARY},
    {"February", TM_FEBRUARY},
    {"March", TM_MARCH},
    {"April", TM_APRIL},
    {"May", TM_MAY},
    {"June", TM_JUNE},
    {"July", TM_JULY},
    {"August", TM_AUGUST},
    {"September", TM_SEPTEMBER},
    {"October", TM_OCTOBER},
    {"November", TM_NOVEMBER},
    {"December", TM_DECEMBER},
    {NULL, 0}
};
 
static struct lookup const wday_names[] = {
    {"Sunday", TM_SUNDAY},
    {"Monday", TM_MONDAY},
    {"Tuesday", TM_TUESDAY},
    {"Wednesday", TM_WEDNESDAY},
    {"Thursday", TM_THURSDAY},
    {"Friday", TM_FRIDAY},
    {"Saturday", TM_SATURDAY},
    {NULL, 0}
};
 
static struct lookup const lasts[] = {
    {"last-Sunday", TM_SUNDAY},
    {"last-Monday", TM_MONDAY},
    {"last-Tuesday", TM_TUESDAY},
    {"last-Wednesday", TM_WEDNESDAY},
    {"last-Thursday", TM_THURSDAY},
    {"last-Friday", TM_FRIDAY},
    {"last-Saturday", TM_SATURDAY},
    {NULL, 0}
};
 
static struct lookup const begin_years[] = {
    {"minimum", YR_MINIMUM},
    {"maximum", YR_MAXIMUM},
    {NULL, 0}
};
 
static struct lookup const end_years[] = {
    {"minimum", YR_MINIMUM},
    {"maximum", YR_MAXIMUM},
    {"only", YR_ONLY},
    {NULL, 0}
};
 
static struct lookup const leap_types[] = {
    {"Rolling", true},
    {"Stationary", false},
    {NULL, 0}
};
 
static const int len_months[2][MONSPERYEAR] = {
    {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
    {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
};
 
static const int len_years[2] = {
    DAYSPERNYEAR, DAYSPERLYEAR
};
 
static struct attype
{
    zic_t       at;
    bool        dontmerge;
    unsigned char type;
}          *attypes;
static zic_t utoffs[TZ_MAX_TYPES];
static char isdsts[TZ_MAX_TYPES];
static unsigned char desigidx[TZ_MAX_TYPES];
static bool ttisstds[TZ_MAX_TYPES];
static bool ttisuts[TZ_MAX_TYPES];
static char chars[TZ_MAX_CHARS];
static zic_t trans[TZ_MAX_LEAPS];
static zic_t corr[TZ_MAX_LEAPS];
static char roll[TZ_MAX_LEAPS];
 
/*
 * Memory allocation.
 */
 
static _Noreturn void
memory_exhausted(const char *msg)
{
    fprintf(stderr, _("%s: Memory exhausted: %s\n"), progname, msg);
    exit(EXIT_FAILURE);
}
 
static size_t
size_product(size_t nitems, size_t itemsize)
{
    if (SIZE_MAX / itemsize < nitems)
        memory_exhausted(_("size overflow"));
    return nitems * itemsize;
}
 
static size_t
align_to(size_t size, size_t alignment)
{
    size_t      aligned_size = size + alignment - 1;
 
    aligned_size -= aligned_size % alignment;
    if (aligned_size < size)
        memory_exhausted(_("alignment overflow"));
    return aligned_size;
}
 
static void *
memcheck(void *ptr)
{
    if (ptr == NULL)
        memory_exhausted(strerror(errno));
    return ptr;
}
 
static void *
emalloc(size_t size)
{
    return memcheck(malloc(size));
}
 
static void *
erealloc(void *ptr, size_t size)
{
    return memcheck(realloc(ptr, size));
}
 
static char *
ecpyalloc(char const *str)
{
    return memcheck(strdup(str));
}
 
static void *
growalloc(void *ptr, size_t itemsize, ptrdiff_t nitems, ptrdiff_t *nitems_alloc)
{
    if (nitems < *nitems_alloc)
        return ptr;
    else
    {
        ptrdiff_t   nitems_max = PTRDIFF_MAX - WORK_AROUND_QTBUG_53071;
        ptrdiff_t   amax = nitems_max < SIZE_MAX ? nitems_max : SIZE_MAX;
 
        if ((amax - 1) / 3 * 2 < *nitems_alloc)
            memory_exhausted(_("integer overflow"));
        *nitems_alloc += (*nitems_alloc >> 1) + 1;
        return erealloc(ptr, size_product(*nitems_alloc, itemsize));
    }
}
 
/*
 * Error handling.
 */
 
static void
eats(char const *name, lineno_t num, char const *rname, lineno_t rnum)
{
    filename = name;
    linenum = num;
    rfilename = rname;
    rlinenum = rnum;
}
 
static void
eat(char const *name, lineno_t num)
{
    eats(name, num, NULL, -1);
}
 
static void
verror(const char *const string, va_list args)
{
    /*
     * Match the format of "cc" to allow sh users to zic ... 2>&1 | error -t
     * "*" -v on BSD systems.
     */
    if (filename)
        fprintf(stderr, _("\"%s\", line %" PRIdMAX ": "), filename, linenum);
    vfprintf(stderr, string, args);
    if (rfilename != NULL)
        fprintf(stderr, _(" (rule from \"%s\", line %" PRIdMAX ")"),
                rfilename, rlinenum);
    fprintf(stderr, "\n");
}
 
static void
error(const char *const string, ...)
{
    va_list     args;
 
    va_start(args, string);
    verror(string, args);
    va_end(args);
    errors = true;
}
 
static void
warning(const char *const string, ...)
{
    va_list     args;
 
    fprintf(stderr, _("warning: "));
    va_start(args, string);
    verror(string, args);
    va_end(args);
    warnings = true;
}
 
static void
close_file(FILE *stream, char const *dir, char const *name)
{
    char const *e = (ferror(stream) ? _("I/O error")
                     : fclose(stream) != 0 ? strerror(errno) : NULL);
 
    if (e)
    {
        fprintf(stderr, "%s: %s%s%s%s%s\n", progname,
                dir ? dir : "", dir ? "/" : "",
                name ? name : "", name ? ": " : "",
                e);
        exit(EXIT_FAILURE);
    }
}
 
static _Noreturn void
usage(FILE *stream, int status)
{
    fprintf(stream,
            _("%s: usage is %s [ --version ] [ --help ] [ -v ] [ -P ] \\\n"
              "\t[ -b {slim|fat} ] [ -d directory ] [ -l localtime ]"
              " [ -L leapseconds ] \\\n"
              "\t[ -p posixrules ] [ -r '[@lo][/@hi]' ] [ -t localtime-link ] \\\n"
              "\t[ filename ... ]\n\n"
              "Report bugs to %s.\n"),
            progname, progname, PACKAGE_BUGREPORT);
    if (status == EXIT_SUCCESS)
        close_file(stream, NULL, NULL);
    exit(status);
}
 
/*
 * Change the working directory to DIR, possibly creating DIR and its
 * ancestors.  After this is done, all files are accessed with names
 * relative to DIR.
 */
static void
change_directory(char const *dir)
{
    if (chdir(dir) != 0)
    {
        int         chdir_errno = errno;
 
        if (chdir_errno == ENOENT)
        {
            mkdirs(dir, false);
            chdir_errno = chdir(dir) == 0 ? 0 : errno;
        }
        if (chdir_errno != 0)
        {
            fprintf(stderr, _("%s: Can't chdir to %s: %s\n"),
                    progname, dir, strerror(chdir_errno));
            exit(EXIT_FAILURE);
        }
    }
}
 
#define TIME_T_BITS_IN_FILE 64
 
/* The minimum and maximum values representable in a TZif file.  */
static zic_t const min_time = MINVAL(zic_t, TIME_T_BITS_IN_FILE);
static zic_t const max_time = MAXVAL(zic_t, TIME_T_BITS_IN_FILE);
 
/*
 * The minimum, and one less than the maximum, values specified by
 * the -r option.  These default to MIN_TIME and MAX_TIME.
 */
static zic_t lo_time = MINVAL(zic_t, TIME_T_BITS_IN_FILE);
static zic_t hi_time = MAXVAL(zic_t, TIME_T_BITS_IN_FILE);
 
/* The time specified by an Expires line, or negative if no such line.  */
static zic_t leapexpires = -1;
 
/* The time specified by an #expires comment, or negative if no such line.  */
static zic_t comment_leapexpires = -1;
 
/*
 * Set the time range of the output to TIMERANGE.
 * Return true if successful.
 */
static bool
timerange_option(char *timerange)
{
    intmax_t    lo = min_time,
                hi = max_time;
    char       *lo_end = timerange,
               *hi_end;
 
    if (*timerange == '@')
    {
        errno = 0;
        lo = strtoimax(timerange + 1, &lo_end, 10);
        if (lo_end == timerange + 1 || (lo == INTMAX_MAX && errno == ERANGE))
            return false;
    }
    hi_end = lo_end;
    if (lo_end[0] == '/' && lo_end[1] == '@')
    {
        errno = 0;
        hi = strtoimax(lo_end + 2, &hi_end, 10);
        if (hi_end == lo_end + 2 || hi == INTMAX_MIN)
            return false;
        hi -= !(hi == INTMAX_MAX && errno == ERANGE);
    }
    if (*hi_end || hi < lo || max_time < lo || hi < min_time)
        return false;
    lo_time = lo < min_time ? min_time : lo;
    hi_time = max_time < hi ? max_time : hi;
    return true;
}
 
static const char *psxrules;
static const char *lcltime;
static const char *directory;
static const char *leapsec;
static const char *tzdefault;
 
/*
 * -1 if the TZif output file should be slim, 0 if default, 1 if the
 * output should be fat for backward compatibility.  ZIC_BLOAT_DEFAULT
 * determines the default.
 */
static int  bloat;
 
static bool
want_bloat(void)
{
    return 0 <= bloat;
}
 
#ifndef ZIC_BLOAT_DEFAULT
#define ZIC_BLOAT_DEFAULT "slim"
#endif
 
int
main(int argc, char **argv)
{
    int         c,
                k;
    ptrdiff_t   i,
                j;
    bool        timerange_given = false;
 
#ifndef WIN32
    umask(umask(S_IWGRP | S_IWOTH) | (S_IWGRP | S_IWOTH));
#endif
    progname = argv[0];
    if (TYPE_BIT(zic_t) < 64)
    {
        fprintf(stderr, "%s: %s\n", progname,
                _("wild compilation-time specification of zic_t"));
        return EXIT_FAILURE;
    }
    for (k = 1; k < argc; k++)
        if (strcmp(argv[k], "--version") == 0)
        {
            printf("zic %s\n", PG_VERSION);
            close_file(stdout, NULL, NULL);
            return EXIT_SUCCESS;
        }
        else if (strcmp(argv[k], "--help") == 0)
        {
            usage(stdout, EXIT_SUCCESS);
        }
    while ((c = getopt(argc, argv, "b:d:l:L:p:Pr:st:vy:")) != EOF && c != -1)
        switch (c)
        {
            default:
                usage(stderr, EXIT_FAILURE);
            case 'b':
                if (strcmp(optarg, "slim") == 0)
                {
                    if (0 < bloat)
                        error(_("incompatible -b options"));
                    bloat = -1;
                }
                else if (strcmp(optarg, "fat") == 0)
                {
                    if (bloat < 0)
                        error(_("incompatible -b options"));
                    bloat = 1;
                }
                else
                    error(_("invalid option: -b '%s'"), optarg);
                break;
            case 'd':
                if (directory == NULL)
                    directory = strdup(optarg);
                else
                {
                    fprintf(stderr,
                            _("%s: More than one -d option specified\n"),
                            progname);
                    return EXIT_FAILURE;
                }
                break;
            case 'l':
                if (lcltime == NULL)
                    lcltime = strdup(optarg);
                else
                {
                    fprintf(stderr,
                            _("%s: More than one -l option specified\n"),
                            progname);
                    return EXIT_FAILURE;
                }
                break;
            case 'p':
                if (psxrules == NULL)
                    psxrules = strdup(optarg);
                else
                {
                    fprintf(stderr,
                            _("%s: More than one -p option specified\n"),
                            progname);
                    return EXIT_FAILURE;
                }
                break;
            case 't':
                if (tzdefault != NULL)
                {
                    fprintf(stderr,
                            _("%s: More than one -t option"
                              " specified\n"),
                            progname);
                    return EXIT_FAILURE;
                }
                tzdefault = optarg;
                break;
            case 'y':
                warning(_("-y ignored"));
                break;
            case 'L':
                if (leapsec == NULL)
                    leapsec = strdup(optarg);
                else
                {
                    fprintf(stderr,
                            _("%s: More than one -L option specified\n"),
                            progname);
                    return EXIT_FAILURE;
                }
                break;
            case 'v':
                noise = true;
                break;
            case 'P':
                print_abbrevs = true;
                print_cutoff = time(NULL);
                break;
            case 'r':
                if (timerange_given)
                {
                    fprintf(stderr,
                            _("%s: More than one -r option specified\n"),
                            progname);
                    return EXIT_FAILURE;
                }
                if (!timerange_option(optarg))
                {
                    fprintf(stderr,
                            _("%s: invalid time range: %s\n"),
                            progname, optarg);
                    return EXIT_FAILURE;
                }
                timerange_given = true;
                break;
            case 's':
                warning(_("-s ignored"));
                break;
        }
    if (optind == argc - 1 && strcmp(argv[optind], "=") == 0)
        usage(stderr, EXIT_FAILURE);    /* usage message by request */
    if (bloat == 0)
    {
        static char const bloat_default[] = ZIC_BLOAT_DEFAULT;
 
        if (strcmp(bloat_default, "slim") == 0)
            bloat = -1;
        else if (strcmp(bloat_default, "fat") == 0)
            bloat = 1;
        else
            abort();            /* Configuration error.  */
    }
    if (directory == NULL)
        directory = "data";
    if (tzdefault == NULL)
        tzdefault = TZDEFAULT;
 
    if (optind < argc && leapsec != NULL)
    {
        infile(leapsec);
        adjleap();
    }
 
    for (k = optind; k < argc; k++)
        infile(argv[k]);
    if (errors)
        return EXIT_FAILURE;
    associate();
    change_directory(directory);
    for (i = 0; i < nzones; i = j)
    {
        /*
         * Find the next non-continuation zone entry.
         */
        for (j = i + 1; j < nzones && zones[j].z_name == NULL; ++j)
            continue;
        outzone(&zones[i], j - i);
    }
 
    /*
     * Make links.
     */
    for (i = 0; i < nlinks; ++i)
    {
        eat(links[i].l_filename, links[i].l_linenum);
        dolink(links[i].l_target, links[i].l_linkname, false);
        if (noise)
            for (j = 0; j < nlinks; ++j)
                if (strcmp(links[i].l_linkname,
                           links[j].l_target) == 0)
                    warning(_("link to link"));
    }
    if (lcltime != NULL)
    {
        eat(_("command line"), 1);
        dolink(lcltime, tzdefault, true);
    }
    if (psxrules != NULL)
    {
        eat(_("command line"), 1);
        dolink(psxrules, TZDEFRULES, true);
    }
    if (warnings && (ferror(stderr) || fclose(stderr) != 0))
        return EXIT_FAILURE;
    return errors ? EXIT_FAILURE : EXIT_SUCCESS;
}
 
static bool
componentcheck(char const *name, char const *component,
               char const *component_end)
{
    enum
    {
    component_len_max = 14};
    ptrdiff_t   component_len = component_end - component;
 
    if (component_len == 0)
    {
        if (!*name)
            error(_("empty file name"));
        else
            error(_(component == name
                    ? "file name '%s' begins with '/'"
                    : *component_end
                    ? "file name '%s' contains '//'"
                    : "file name '%s' ends with '/'"),
                  name);
        return false;
    }
    if (0 < component_len && component_len <= 2
        && component[0] == '.' && component_end[-1] == '.')
    {
        int         len = component_len;
 
        error(_("file name '%s' contains '%.*s' component"),
              name, len, component);
        return false;
    }
    if (noise)
    {
        if (0 < component_len && component[0] == '-')
            warning(_("file name '%s' component contains leading '-'"),
                    name);
        if (component_len_max < component_len)
            warning(_("file name '%s' contains overlength component"
                      " '%.*s...'"),
                    name, component_len_max, component);
    }
    return true;
}
 
static bool
namecheck(const char *name)
{
    char const *cp;
 
    /* Benign characters in a portable file name.  */
    static char const benign[] =
        "-/_"
        "abcdefghijklmnopqrstuvwxyz"
        "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 
    /*
     * Non-control chars in the POSIX portable character set, excluding the
     * benign characters.
     */
    static char const printable_and_not_benign[] =
        " !\"#$%&'()*+,.0123456789:;<=>?@[\\]^`{|}~";
 
    char const *component = name;
 
    for (cp = name; *cp; cp++)
    {
        unsigned char c = *cp;
 
        if (noise && !strchr(benign, c))
        {
            warning((strchr(printable_and_not_benign, c)
                     ? _("file name '%s' contains byte '%c'")
                     : _("file name '%s' contains byte '\\%o'")),
                    name, c);
        }
        if (c == '/')
        {
            if (!componentcheck(name, component, cp))
                return false;
            component = cp + 1;
        }
    }
    return componentcheck(name, component, cp);
}
 
/*
 * Create symlink contents suitable for symlinking FROM to TO, as a
 * freshly allocated string.  FROM should be a relative file name, and
 * is relative to the global variable DIRECTORY.  TO can be either
 * relative or absolute.
 */
#ifdef HAVE_SYMLINK
static char *
relname(char const *target, char const *linkname)
{
    size_t      i,
                taillen,
                dotdotetcsize;
    size_t      dir_len = 0,
                dotdots = 0,
                linksize = SIZE_MAX;
    char const *f = target;
    char       *result = NULL;
 
    if (*linkname == '/')
    {
        /* Make F absolute too.  */
        size_t      len = strlen(directory);
        bool        needslash = len && directory[len - 1] != '/';
 
        linksize = len + needslash + strlen(target) + 1;
        f = result = emalloc(linksize);
        strcpy(result, directory);
        result[len] = '/';
        strcpy(result + len + needslash, target);
    }
    for (i = 0; f[i] && f[i] == linkname[i]; i++)
        if (f[i] == '/')
            dir_len = i + 1;
    for (; linkname[i]; i++)
        dotdots += linkname[i] == '/' && linkname[i - 1] != '/';
    taillen = strlen(f + dir_len);
    dotdotetcsize = 3 * dotdots + taillen + 1;
    if (dotdotetcsize <= linksize)
    {
        if (!result)
            result = emalloc(dotdotetcsize);
        for (i = 0; i < dotdots; i++)
            memcpy(result + 3 * i, "../", 3);
        memmove(result + 3 * dotdots, f + dir_len, taillen + 1);
    }
    return result;
}
#endif                          /* HAVE_SYMLINK */
 
/*
 * Hard link FROM to TO, following any symbolic links.
 * Return 0 if successful, an error number otherwise.
 */
static int
hardlinkerr(char const *target, char const *linkname)
{
    int         r = linkat(AT_FDCWD, target, AT_FDCWD, linkname, AT_SYMLINK_FOLLOW);
 
    return r == 0 ? 0 : errno;
}
 
static void
dolink(char const *target, char const *linkname, bool staysymlink)
{
    bool        remove_only = strcmp(target, "-") == 0;
    bool        linkdirs_made = false;
    int         link_errno;
 
    /*
     * We get to be careful here since there's a fair chance of root running
     * us.
     */
    if (!remove_only && itsdir(target))
    {
        fprintf(stderr, _("%s: linking target %s/%s failed: %s\n"),
                progname, directory, target, strerror(EPERM));
        exit(EXIT_FAILURE);
    }
    if (staysymlink)
        staysymlink = itssymlink(linkname);
    if (remove(linkname) == 0)
        linkdirs_made = true;
    else if (errno != ENOENT)
    {
        char const *e = strerror(errno);
 
        fprintf(stderr, _("%s: Can't remove %s/%s: %s\n"),
                progname, directory, linkname, e);
        exit(EXIT_FAILURE);
    }
    if (remove_only)
        return;
    link_errno = staysymlink ? ENOTSUP : hardlinkerr(target, linkname);
    if (link_errno == ENOENT && !linkdirs_made)
    {
        mkdirs(linkname, true);
        linkdirs_made = true;
        link_errno = hardlinkerr(target, linkname);
    }
    if (link_errno != 0)
    {
#ifdef HAVE_SYMLINK
        bool        absolute = *target == '/';
        char       *linkalloc = absolute ? NULL : relname(target, linkname);
        char const *contents = absolute ? target : linkalloc;
        int         symlink_errno = symlink(contents, linkname) == 0 ? 0 : errno;
 
        if (!linkdirs_made
            && (symlink_errno == ENOENT || symlink_errno == ENOTSUP))
        {
            mkdirs(linkname, true);
            if (symlink_errno == ENOENT)
                symlink_errno = symlink(contents, linkname) == 0 ? 0 : errno;
        }
        free(linkalloc);
        if (symlink_errno == 0)
        {
            if (link_errno != ENOTSUP)
                warning(_("symbolic link used because hard link failed: %s"),
                        strerror(link_errno));
        }
        else
#endif                          /* HAVE_SYMLINK */
        {
            FILE       *fp,
                       *tp;
            int         c;
 
            fp = fopen(target, "rb");
            if (!fp)
            {
                char const *e = strerror(errno);
 
                fprintf(stderr, _("%s: Can't read %s/%s: %s\n"),
                        progname, directory, target, e);
                exit(EXIT_FAILURE);
            }
            tp = fopen(linkname, "wb");
            if (!tp)
            {
                char const *e = strerror(errno);
 
                fprintf(stderr, _("%s: Can't create %s/%s: %s\n"),
                        progname, directory, linkname, e);
                exit(EXIT_FAILURE);
            }
            while ((c = getc(fp)) != EOF)
                putc(c, tp);
            close_file(fp, directory, target);
            close_file(tp, directory, linkname);
            if (link_errno != ENOTSUP)
                warning(_("copy used because hard link failed: %s"),
                        strerror(link_errno));
#ifdef HAVE_SYMLINK
            else if (symlink_errno != ENOTSUP)
                warning(_("copy used because symbolic link failed: %s"),
                        strerror(symlink_errno));
#endif
        }
    }
}
 
/* Return true if NAME is a directory.  */
static bool
itsdir(char const *name)
{
    struct stat st;
    int         res = stat(name, &st);
#ifdef S_ISDIR
    if (res == 0)
        return S_ISDIR(st.st_mode) != 0;
#endif
    if (res == 0 || errno == EOVERFLOW)
    {
        size_t      n = strlen(name);
        char       *nameslashdot = emalloc(n + 3);
        bool        dir;
 
        memcpy(nameslashdot, name, n);
        strcpy(&nameslashdot[n], &"/."[!(n && name[n - 1] != '/')]);
        dir = stat(nameslashdot, &st) == 0 || errno == EOVERFLOW;
        free(nameslashdot);
        return dir;
    }
    return false;
}
 
/* Return true if NAME is a symbolic link.  */
static bool
itssymlink(char const *name)
{
#ifdef HAVE_SYMLINK
    char        c;
 
    return 0 <= readlink(name, &c, 1);
#else
    return false;
#endif
}
 
/*
 * Associate sets of rules with zones.
 */
 
/*
 * Sort by rule name.
 */
 
static int
rcomp(const void *cp1, const void *cp2)
{
    return strcmp(((const struct rule *) cp1)->r_name,
                  ((const struct rule *) cp2)->r_name);
}
 
static void
associate(void)
{
    struct zone *zp;
    struct rule *rp;
    ptrdiff_t   i,
                j,
                base,
                out;
 
    if (nrules != 0)
    {
        qsort(rules, nrules, sizeof *rules, rcomp);
        for (i = 0; i < nrules - 1; ++i)
        {
            if (strcmp(rules[i].r_name,
                       rules[i + 1].r_name) != 0)
                continue;
            if (strcmp(rules[i].r_filename,
                       rules[i + 1].r_filename) == 0)
                continue;
            eat(rules[i].r_filename, rules[i].r_linenum);
            warning(_("same rule name in multiple files"));
            eat(rules[i + 1].r_filename, rules[i + 1].r_linenum);
            warning(_("same rule name in multiple files"));
            for (j = i + 2; j < nrules; ++j)
            {
                if (strcmp(rules[i].r_name,
                           rules[j].r_name) != 0)
                    break;
                if (strcmp(rules[i].r_filename,
                           rules[j].r_filename) == 0)
                    continue;
                if (strcmp(rules[i + 1].r_filename,
                           rules[j].r_filename) == 0)
                    continue;
                break;
            }
            i = j - 1;
        }
    }
    for (i = 0; i < nzones; ++i)
    {
        zp = &zones[i];
        zp->z_rules = NULL;
        zp->z_nrules = 0;
    }
    for (base = 0; base < nrules; base = out)
    {
        rp = &rules[base];
        for (out = base + 1; out < nrules; ++out)
            if (strcmp(rp->r_name, rules[out].r_name) != 0)
                break;
        for (i = 0; i < nzones; ++i)
        {
            zp = &zones[i];
            if (strcmp(zp->z_rule, rp->r_name) != 0)
                continue;
            zp->z_rules = rp;
            zp->z_nrules = out - base;
        }
    }
    for (i = 0; i < nzones; ++i)
    {
        zp = &zones[i];
        if (zp->z_nrules == 0)
        {
            /*
             * Maybe we have a local standard time offset.
             */
            eat(zp->z_filename, zp->z_linenum);
            zp->z_save = getsave(zp->z_rule, &zp->z_isdst);
 
            /*
             * Note, though, that if there's no rule, a '%s' in the format is
             * a bad thing.
             */
            if (zp->z_format_specifier == 's')
                error("%s", _("%s in ruleless zone"));
        }
    }
    if (errors)
        exit(EXIT_FAILURE);
}
 
static void
infile(const char *name)
{
    FILE       *fp;
    char      **fields;
    char       *cp;
    const struct lookup *lp;
    int         nfields;
    bool        wantcont;
    lineno_t    num;
    char        buf[BUFSIZ];
 
    if (strcmp(name, "-") == 0)
    {
        name = _("standard input");
        fp = stdin;
    }
    else if ((fp = fopen(name, "r")) == NULL)
    {
        const char *e = strerror(errno);
 
        fprintf(stderr, _("%s: Cannot open %s: %s\n"),
                progname, name, e);
        exit(EXIT_FAILURE);
    }
    wantcont = false;
    for (num = 1;; ++num)
    {
        eat(name, num);
        if (fgets(buf, sizeof buf, fp) != buf)
            break;
        cp = strchr(buf, '\n');
        if (cp == NULL)
        {
            error(_("line too long"));
            exit(EXIT_FAILURE);
        }
        *cp = '\0';
        fields = getfields(buf);
        nfields = 0;
        while (fields[nfields] != NULL)
        {
            static char nada;
 
            if (strcmp(fields[nfields], "-") == 0)
                fields[nfields] = &nada;
            ++nfields;
        }
        if (nfields == 0)
        {
            if (name == leapsec && *buf == '#')
                sscanf(buf, "#expires %" SCNdZIC, &comment_leapexpires);
        }
        else if (wantcont)
        {
            wantcont = inzcont(fields, nfields);
        }
        else
        {
            struct lookup const *line_codes
            = name == leapsec ? leap_line_codes : zi_line_codes;
 
            lp = byword(fields[0], line_codes);
            if (lp == NULL)
                error(_("input line of unknown type"));
            else
                switch (lp->l_value)
                {
                    case LC_RULE:
                        inrule(fields, nfields);
                        wantcont = false;
                        break;
                    case LC_ZONE:
                        wantcont = inzone(fields, nfields);
                        break;
                    case LC_LINK:
                        inlink(fields, nfields);
                        wantcont = false;
                        break;
                    case LC_LEAP:
                        inleap(fields, nfields);
                        wantcont = false;
                        break;
                    case LC_EXPIRES:
                        inexpires(fields, nfields);
                        wantcont = false;
                        break;
                    default:    /* "cannot happen" */
                        fprintf(stderr,
                                _("%s: panic: Invalid l_value %d\n"),
                                progname, lp->l_value);
                        exit(EXIT_FAILURE);
                }
        }
        free(fields);
    }
    close_file(fp, NULL, filename);
    if (wantcont)
        error(_("expected continuation line not found"));
}
 
/*
 * Convert a string of one of the forms
 *  h   -h  hh:mm   -hh:mm  hh:mm:ss    -hh:mm:ss
 * into a number of seconds.
 * A null string maps to zero.
 * Call error with errstring and return zero on errors.
 */
 
static zic_t
gethms(char const *string, char const *errstring)
{
    zic_t       hh;
    int         sign,
                mm = 0,
                ss = 0;
    char        hhx,
                mmx,
                ssx,
                xr = '0',
                xs;
    int         tenths = 0;
    bool        ok = true;
 
    if (string == NULL || *string == '\0')
        return 0;
    if (*string == '-')
    {
        sign = -1;
        ++string;
    }
    else
        sign = 1;
    switch (sscanf(string,
                   "%" SCNdZIC "%c%d%c%d%c%1d%*[0]%c%*[0123456789]%c",
                   &hh, &hhx, &mm, &mmx, &ss, &ssx, &tenths, &xr, &xs))
    {
        default:
            ok = false;
            break;
        case 8:
            ok = '0' <= xr && xr <= '9';
            pg_fallthrough;
        case 7:
            ok &= ssx == '.';
            if (ok && noise)
                warning(_("fractional seconds rejected by"
                          " pre-2018 versions of zic"));
            pg_fallthrough;
        case 5:
            ok &= mmx == ':';
            pg_fallthrough;
        case 3:
            ok &= hhx == ':';
            pg_fallthrough;
        case 1:
            break;
    }
    if (!ok)
    {
        error("%s", errstring);
        return 0;
    }
    if (hh < 0 ||
        mm < 0 || mm >= MINSPERHOUR ||
        ss < 0 || ss > SECSPERMIN)
    {
        error("%s", errstring);
        return 0;
    }
    if (ZIC_MAX / SECSPERHOUR < hh)
    {
        error(_("time overflow"));
        return 0;
    }
    ss += 5 + ((ss ^ 1) & (xr == '0')) <= tenths;   /* Round to even.  */
    if (noise && (hh > HOURSPERDAY ||
                  (hh == HOURSPERDAY && (mm != 0 || ss != 0))))
        warning(_("values over 24 hours not handled by pre-2007 versions of zic"));
    return oadd(sign * hh * SECSPERHOUR,
                sign * (mm * SECSPERMIN + ss));
}
 
static zic_t
getsave(char *field, bool *isdst)
{
    int         dst = -1;
    zic_t       save;
    size_t      fieldlen = strlen(field);
 
    if (fieldlen != 0)
    {
        char       *ep = field + fieldlen - 1;
 
        switch (*ep)
        {
            case 'd':
                dst = 1;
                *ep = '\0';
                break;
            case 's':
                dst = 0;
                *ep = '\0';
                break;
        }
    }
    save = gethms(field, _("invalid saved time"));
    *isdst = dst < 0 ? save != 0 : dst;
    return save;
}
 
static void
inrule(char **fields, int nfields)
{
    static struct rule r;
 
    if (nfields != RULE_FIELDS)
    {
        error(_("wrong number of fields on Rule line"));
        return;
    }
    switch (*fields[RF_NAME])
    {
        case '\0':
        case ' ':
        case '\f':
        case '\n':
        case '\r':
        case '\t':
        case '\v':
        case '+':
        case '-':
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            error(_("Invalid rule name \"%s\""), fields[RF_NAME]);
            return;
    }
    r.r_filename = filename;
    r.r_linenum = linenum;
    r.r_save = getsave(fields[RF_SAVE], &r.r_isdst);
    rulesub(&r, fields[RF_LOYEAR], fields[RF_HIYEAR], fields[RF_COMMAND],
            fields[RF_MONTH], fields[RF_DAY], fields[RF_TOD]);
    r.r_name = ecpyalloc(fields[RF_NAME]);
    r.r_abbrvar = ecpyalloc(fields[RF_ABBRVAR]);
    if (max_abbrvar_len < strlen(r.r_abbrvar))
        max_abbrvar_len = strlen(r.r_abbrvar);
    rules = growalloc(rules, sizeof *rules, nrules, &nrules_alloc);
    rules[nrules++] = r;
}
 
static bool
inzone(char **fields, int nfields)
{
    ptrdiff_t   i;
 
    if (nfields < ZONE_MINFIELDS || nfields > ZONE_MAXFIELDS)
    {
        error(_("wrong number of fields on Zone line"));
        return false;
    }
    if (lcltime != NULL && strcmp(fields[ZF_NAME], tzdefault) == 0)
    {
        error(
              _("\"Zone %s\" line and -l option are mutually exclusive"),
              tzdefault);
        return false;
    }
    if (strcmp(fields[ZF_NAME], TZDEFRULES) == 0 && psxrules != NULL)
    {
        error(
              _("\"Zone %s\" line and -p option are mutually exclusive"),
              TZDEFRULES);
        return false;
    }
    for (i = 0; i < nzones; ++i)
        if (zones[i].z_name != NULL &&
            strcmp(zones[i].z_name, fields[ZF_NAME]) == 0)
        {
            error(_("duplicate zone name %s"
                    " (file \"%s\", line %" PRIdMAX ")"),
                  fields[ZF_NAME],
                  zones[i].z_filename,
                  zones[i].z_linenum);
            return false;
        }
    return inzsub(fields, nfields, false);
}
 
static bool
inzcont(char **fields, int nfields)
{
    if (nfields < ZONEC_MINFIELDS || nfields > ZONEC_MAXFIELDS)
    {
        error(_("wrong number of fields on Zone continuation line"));
        return false;
    }
    return inzsub(fields, nfields, true);
}
 
static bool
inzsub(char **fields, int nfields, bool iscont)
{
    char       *cp;
    char       *cp1;
    static struct zone z;
    int         i_stdoff,
                i_rule,
                i_format;
    int         i_untilyear,
                i_untilmonth;
    int         i_untilday,
                i_untiltime;
    bool        hasuntil;
 
    if (iscont)
    {
        i_stdoff = ZFC_STDOFF;
        i_rule = ZFC_RULE;
        i_format = ZFC_FORMAT;
        i_untilyear = ZFC_TILYEAR;
        i_untilmonth = ZFC_TILMONTH;
        i_untilday = ZFC_TILDAY;
        i_untiltime = ZFC_TILTIME;
        z.z_name = NULL;
    }
    else if (!namecheck(fields[ZF_NAME]))
        return false;
    else
    {
        i_stdoff = ZF_STDOFF;
        i_rule = ZF_RULE;
        i_format = ZF_FORMAT;
        i_untilyear = ZF_TILYEAR;
        i_untilmonth = ZF_TILMONTH;
        i_untilday = ZF_TILDAY;
        i_untiltime = ZF_TILTIME;
        z.z_name = ecpyalloc(fields[ZF_NAME]);
    }
    z.z_filename = filename;
    z.z_linenum = linenum;
    z.z_stdoff = gethms(fields[i_stdoff], _("invalid UT offset"));
    if ((cp = strchr(fields[i_format], '%')) != NULL)
    {
        if ((*++cp != 's' && *cp != 'z') || strchr(cp, '%')
            || strchr(fields[i_format], '/'))
        {
            error(_("invalid abbreviation format"));
            return false;
        }
    }
    z.z_rule = ecpyalloc(fields[i_rule]);
    z.z_format = cp1 = ecpyalloc(fields[i_format]);
    z.z_format_specifier = cp ? *cp : '\0';
    if (z.z_format_specifier == 'z')
    {
        if (noise)
            warning(_("format '%s' not handled by pre-2015 versions of zic"),
                    z.z_format);
        cp1[cp - fields[i_format]] = 's';
    }
    if (max_format_len < strlen(z.z_format))
        max_format_len = strlen(z.z_format);
    hasuntil = nfields > i_untilyear;
    if (hasuntil)
    {
        z.z_untilrule.r_filename = filename;
        z.z_untilrule.r_linenum = linenum;
        rulesub(&z.z_untilrule,
                fields[i_untilyear],
                "only",
                "",
                (nfields > i_untilmonth) ?
                fields[i_untilmonth] : "Jan",
                (nfields > i_untilday) ? fields[i_untilday] : "1",
                (nfields > i_untiltime) ? fields[i_untiltime] : "0");
        z.z_untiltime = rpytime(&z.z_untilrule,
                                z.z_untilrule.r_loyear);
        if (iscont && nzones > 0 &&
            z.z_untiltime > min_time &&
            z.z_untiltime < max_time &&
            zones[nzones - 1].z_untiltime > min_time &&
            zones[nzones - 1].z_untiltime < max_time &&
            zones[nzones - 1].z_untiltime >= z.z_untiltime)
        {
            error(_("Zone continuation line end time is not after end time of previous line"));
            return false;
        }
    }
    zones = growalloc(zones, sizeof *zones, nzones, &nzones_alloc);
    zones[nzones++] = z;
 
    /*
     * If there was an UNTIL field on this line, there's more information
     * about the zone on the next line.
     */
    return hasuntil;
}
 
static zic_t
getleapdatetime(char **fields, int nfields, bool expire_line)
{
    const char *cp;
    const struct lookup *lp;
    zic_t       i,
                j;
    zic_t       year;
    int         month,
                day;
    zic_t       dayoff,
                tod;
    zic_t       t;
    char        xs;
 
    dayoff = 0;
    cp = fields[LP_YEAR];
    if (sscanf(cp, "%" SCNdZIC "%c", &year, &xs) != 1)
    {
        /*
         * Leapin' Lizards!
         */
        error(_("invalid leaping year"));
        return -1;
    }
    if (!expire_line)
    {
        if (!leapseen || leapmaxyear < year)
            leapmaxyear = year;
        if (!leapseen || leapminyear > year)
            leapminyear = year;
        leapseen = true;
    }
    j = EPOCH_YEAR;
    while (j != year)
    {
        if (year > j)
        {
            i = len_years[isleap(j)];
            ++j;
        }
        else
        {
            --j;
            i = -len_years[isleap(j)];
        }
        dayoff = oadd(dayoff, i);
    }
    if ((lp = byword(fields[LP_MONTH], mon_names)) == NULL)
    {
        error(_("invalid month name"));
        return -1;
    }
    month = lp->l_value;
    j = TM_JANUARY;
    while (j != month)
    {
        i = len_months[isleap(year)][j];
        dayoff = oadd(dayoff, i);
        ++j;
    }
    cp = fields[LP_DAY];
    if (sscanf(cp, "%d%c", &day, &xs) != 1 ||
        day <= 0 || day > len_months[isleap(year)][month])
    {
        error(_("invalid day of month"));
        return -1;
    }
    dayoff = oadd(dayoff, day - 1);
    if (dayoff < min_time / SECSPERDAY)
    {
        error(_("time too small"));
        return -1;
    }
    if (dayoff > max_time / SECSPERDAY)
    {
        error(_("time too large"));
        return -1;
    }
    t = dayoff * SECSPERDAY;
    tod = gethms(fields[LP_TIME], _("invalid time of day"));
    t = tadd(t, tod);
    if (t < 0)
        error(_("leap second precedes Epoch"));
    return t;
}
 
static void
inleap(char **fields, int nfields)
{
    if (nfields != LEAP_FIELDS)
        error(_("wrong number of fields on Leap line"));
    else
    {
        zic_t       t = getleapdatetime(fields, nfields, false);
 
        if (0 <= t)
        {
            struct lookup const *lp = byword(fields[LP_ROLL], leap_types);
 
            if (!lp)
                error(_("invalid Rolling/Stationary field on Leap line"));
            else
            {
                int         correction = 0;
 
                if (!fields[LP_CORR][0])    /* infile() turns "-" into "".  */
                    correction = -1;
                else if (strcmp(fields[LP_CORR], "+") == 0)
                    correction = 1;
                else
                    error(_("invalid CORRECTION field on Leap line"));
                if (correction)
                    leapadd(t, correction, lp->l_value);
            }
        }
    }
}
 
static void
inexpires(char **fields, int nfields)
{
    if (nfields != EXPIRES_FIELDS)
        error(_("wrong number of fields on Expires line"));
    else if (0 <= leapexpires)
        error(_("multiple Expires lines"));
    else
        leapexpires = getleapdatetime(fields, nfields, true);
}
 
static void
inlink(char **fields, int nfields)
{
    struct link l;
 
    if (nfields != LINK_FIELDS)
    {
        error(_("wrong number of fields on Link line"));
        return;
    }
    if (*fields[LF_TARGET] == '\0')
    {
        error(_("blank TARGET field on Link line"));
        return;
    }
    if (!namecheck(fields[LF_LINKNAME]))
        return;
    l.l_filename = filename;
    l.l_linenum = linenum;
    l.l_target = ecpyalloc(fields[LF_TARGET]);
    l.l_linkname = ecpyalloc(fields[LF_LINKNAME]);
    links = growalloc(links, sizeof *links, nlinks, &nlinks_alloc);
    links[nlinks++] = l;
}
 
static void
rulesub(struct rule *rp, const char *loyearp, const char *hiyearp,
        const char *typep, const char *monthp, const char *dayp,
        const char *timep)
{
    const struct lookup *lp;
    const char *cp;
    char       *dp;
    char       *ep;
    char        xs;
 
    if ((lp = byword(monthp, mon_names)) == NULL)
    {
        error(_("invalid month name"));
        return;
    }
    rp->r_month = lp->l_value;
    rp->r_todisstd = false;
    rp->r_todisut = false;
    dp = ecpyalloc(timep);
    if (*dp != '\0')
    {
        ep = dp + strlen(dp) - 1;
        switch (lowerit(*ep))
        {
            case 's':           /* Standard */
                rp->r_todisstd = true;
                rp->r_todisut = false;
                *ep = '\0';
                break;
            case 'w':           /* Wall */
                rp->r_todisstd = false;
                rp->r_todisut = false;
                *ep = '\0';
                break;
            case 'g':           /* Greenwich */
            case 'u':           /* Universal */
            case 'z':           /* Zulu */
                rp->r_todisstd = true;
                rp->r_todisut = true;
                *ep = '\0';
                break;
        }
    }
    rp->r_tod = gethms(dp, _("invalid time of day"));
    free(dp);
 
    /*
     * Year work.
     */
    cp = loyearp;
    lp = byword(cp, begin_years);
    rp->r_lowasnum = lp == NULL;
    if (!rp->r_lowasnum)
        switch (lp->l_value)
        {
            case YR_MINIMUM:
                rp->r_loyear = ZIC_MIN;
                break;
            case YR_MAXIMUM:
                rp->r_loyear = ZIC_MAX;
                break;
            default:            /* "cannot happen" */
                fprintf(stderr,
                        _("%s: panic: Invalid l_value %d\n"),
                        progname, lp->l_value);
                exit(EXIT_FAILURE);
        }
    else if (sscanf(cp, "%" SCNdZIC "%c", &rp->r_loyear, &xs) != 1)
    {
        error(_("invalid starting year"));
        return;
    }
    cp = hiyearp;
    lp = byword(cp, end_years);
    rp->r_hiwasnum = lp == NULL;
    if (!rp->r_hiwasnum)
        switch (lp->l_value)
        {
            case YR_MINIMUM:
                rp->r_hiyear = ZIC_MIN;
                break;
            case YR_MAXIMUM:
                rp->r_hiyear = ZIC_MAX;
                break;
            case YR_ONLY:
                rp->r_hiyear = rp->r_loyear;
                break;
            default:            /* "cannot happen" */
                fprintf(stderr,
                        _("%s: panic: Invalid l_value %d\n"),
                        progname, lp->l_value);
                exit(EXIT_FAILURE);
        }
    else if (sscanf(cp, "%" SCNdZIC "%c", &rp->r_hiyear, &xs) != 1)
    {
        error(_("invalid ending year"));
        return;
    }
    if (rp->r_loyear > rp->r_hiyear)
    {
        error(_("starting year greater than ending year"));
        return;
    }
    if (*typep != '\0')
    {
        error(_("year type \"%s\" is unsupported; use \"-\" instead"),
              typep);
        return;
    }
 
    /*
     * Day work. Accept things such as: 1 lastSunday last-Sunday
     * (undocumented; warn about this) Sun<=20 Sun>=7
     */
    dp = ecpyalloc(dayp);
    if ((lp = byword(dp, lasts)) != NULL)
    {
        rp->r_dycode = DC_DOWLEQ;
        rp->r_wday = lp->l_value;
        rp->r_dayofmonth = len_months[1][rp->r_month];
    }
    else
    {
        if ((ep = strchr(dp, '<')) != NULL)
            rp->r_dycode = DC_DOWLEQ;
        else if ((ep = strchr(dp, '>')) != NULL)
            rp->r_dycode = DC_DOWGEQ;
        else
        {
            ep = dp;
            rp->r_dycode = DC_DOM;
        }
        if (rp->r_dycode != DC_DOM)
        {
            *ep++ = 0;
            if (*ep++ != '=')
            {
                error(_("invalid day of month"));
                free(dp);
                return;
            }
            if ((lp = byword(dp, wday_names)) == NULL)
            {
                error(_("invalid weekday name"));
                free(dp);
                return;
            }
            rp->r_wday = lp->l_value;
        }
        if (sscanf(ep, "%d%c", &rp->r_dayofmonth, &xs) != 1 ||
            rp->r_dayofmonth <= 0 ||
            (rp->r_dayofmonth > len_months[1][rp->r_month]))
        {
            error(_("invalid day of month"));
            free(dp);
            return;
        }
    }
    free(dp);
}
 
static void
convert(const int_fast32_t val, char *const buf)
{
    int         i;
    int         shift;
    unsigned char *const b = (unsigned char *) buf;
 
    for (i = 0, shift = 24; i < 4; ++i, shift -= 8)
        b[i] = val >> shift;
}
 
static void
convert64(const zic_t val, char *const buf)
{
    int         i;
    int         shift;
    unsigned char *const b = (unsigned char *) buf;
 
    for (i = 0, shift = 56; i < 8; ++i, shift -= 8)
        b[i] = val >> shift;
}
 
static void
puttzcode(const int_fast32_t val, FILE *const fp)
{
    char        buf[4];
 
    convert(val, buf);
    fwrite(buf, sizeof buf, 1, fp);
}
 
static void
puttzcodepass(zic_t val, FILE *fp, int pass)
{
    if (pass == 1)
        puttzcode(val, fp);
    else
    {
        char        buf[8];
 
        convert64(val, buf);
        fwrite(buf, sizeof buf, 1, fp);
    }
}
 
static int
atcomp(const void *avp, const void *bvp)
{
    const zic_t a = ((const struct attype *) avp)->at;
    const zic_t b = ((const struct attype *) bvp)->at;
 
    return (a < b) ? -1 : (a > b);
}
 
struct timerange
{
    int         defaulttype;
    ptrdiff_t   base,
                count;
    int         leapbase,
                leapcount;
};
 
static struct timerange
limitrange(struct timerange r, zic_t lo, zic_t hi,
           zic_t const *ats, unsigned char const *types)
{
    while (0 < r.count && ats[r.base] < lo)
    {
        r.defaulttype = types[r.base];
        r.count--;
        r.base++;
    }
    while (0 < r.leapcount && trans[r.leapbase] < lo)
    {
        r.leapcount--;
        r.leapbase++;
    }
 
    if (hi < ZIC_MAX)
    {
        while (0 < r.count && hi + 1 < ats[r.base + r.count - 1])
            r.count--;
        while (0 < r.leapcount && hi + 1 < trans[r.leapbase + r.leapcount - 1])
            r.leapcount--;
    }
 
    return r;
}
 
static void
writezone(const char *const name, const char *const string, char version,
          int defaulttype)
{
    FILE       *fp;
    ptrdiff_t   i,
                j;
    int         pass;
    static const struct tzhead tzh0;
    static struct tzhead tzh;
    bool        dir_checked = false;
    zic_t       one = 1;
    zic_t       y2038_boundary = one << 31;
    ptrdiff_t   nats = timecnt + WORK_AROUND_QTBUG_53071;
 
    /*
     * Allocate the ATS and TYPES arrays via a single malloc, as this is a bit
     * faster.
     */
    zic_t      *ats = emalloc(align_to(size_product(nats, sizeof *ats + 1),
                                       _Alignof(zic_t)));
    void       *typesptr = ats + nats;
    unsigned char *types = typesptr;
    struct timerange rangeall,
                range32,
                range64;
 
    /*
     * Sort.
     */
    if (timecnt > 1)
        qsort(attypes, timecnt, sizeof *attypes, atcomp);
 
    /*
     * Optimize.
     */
    {
        ptrdiff_t   fromi,
                    toi;
 
        toi = 0;
        fromi = 0;
        for (; fromi < timecnt; ++fromi)
        {
            if (toi != 0
                && ((attypes[fromi].at
                     + utoffs[attypes[toi - 1].type])
                    <= (attypes[toi - 1].at
                        + utoffs[toi == 1 ? 0
                                 : attypes[toi - 2].type])))
            {
                attypes[toi - 1].type =
                    attypes[fromi].type;
                continue;
            }
            if (toi == 0
                || attypes[fromi].dontmerge
                || (utoffs[attypes[toi - 1].type]
                    != utoffs[attypes[fromi].type])
                || (isdsts[attypes[toi - 1].type]
                    != isdsts[attypes[fromi].type])
                || (desigidx[attypes[toi - 1].type]
                    != desigidx[attypes[fromi].type]))
                attypes[toi++] = attypes[fromi];
        }
        timecnt = toi;
    }
 
    if (noise && timecnt > 1200)
    {
        if (timecnt > TZ_MAX_TIMES)
            warning(_("reference clients mishandle"
                      " more than %d transition times"),
                    TZ_MAX_TIMES);
        else
            warning(_("pre-2014 clients may mishandle"
                      " more than 1200 transition times"));
    }
 
    /*
     * Transfer.
     */
    for (i = 0; i < timecnt; ++i)
    {
        ats[i] = attypes[i].at;
        types[i] = attypes[i].type;
    }
 
    /*
     * Correct for leap seconds.
     */
    for (i = 0; i < timecnt; ++i)
    {
        j = leapcnt;
        while (--j >= 0)
            if (ats[i] > trans[j] - corr[j])
            {
                ats[i] = tadd(ats[i], corr[j]);
                break;
            }
    }
 
    /*
     * Work around QTBUG-53071 for timestamps less than y2038_boundary - 1, by
     * inserting a no-op transition at time y2038_boundary - 1. This works
     * only for timestamps before the boundary, which should be good enough in
     * practice as QTBUG-53071 should be long-dead by 2038.  Do this after
     * correcting for leap seconds, as the idea is to insert a transition just
     * before 32-bit pg_time_t rolls around, and this occurs at a slightly
     * different moment if transitions are leap-second corrected.
     */
    if (WORK_AROUND_QTBUG_53071 && timecnt != 0 && want_bloat()
        && ats[timecnt - 1] < y2038_boundary - 1 && strchr(string, '<'))
    {
        ats[timecnt] = y2038_boundary - 1;
        types[timecnt] = types[timecnt - 1];
        timecnt++;
    }
 
    rangeall.defaulttype = defaulttype;
    rangeall.base = rangeall.leapbase = 0;
    rangeall.count = timecnt;
    rangeall.leapcount = leapcnt;
    range64 = limitrange(rangeall, lo_time, hi_time, ats, types);
    range32 = limitrange(range64, INT32_MIN, INT32_MAX, ats, types);
 
    /*
     * Remove old file, if any, to snap links.
     */
    if (remove(name) == 0)
        dir_checked = true;
    else if (errno != ENOENT)
    {
        const char *e = strerror(errno);
 
        fprintf(stderr, _("%s: Cannot remove %s/%s: %s\n"),
                progname, directory, name, e);
        exit(EXIT_FAILURE);
    }
    fp = fopen(name, "wb");
    if (!fp)
    {
        int         fopen_errno = errno;
 
        if (fopen_errno == ENOENT && !dir_checked)
        {
            mkdirs(name, true);
            fp = fopen(name, "wb");
            fopen_errno = errno;
        }
        if (!fp)
        {
            fprintf(stderr, _("%s: Cannot create %s/%s: %s\n"),
                    progname, directory, name, strerror(fopen_errno));
            exit(EXIT_FAILURE);
        }
    }
    for (pass = 1; pass <= 2; ++pass)
    {
        ptrdiff_t   thistimei,
                    thistimecnt,
                    thistimelim;
        int         thisleapi,
                    thisleapcnt,
                    thisleaplim;
        int         currenttype,
                    thisdefaulttype;
        bool        locut,
                    hicut;
        zic_t       lo;
        int         old0;
        char        omittype[TZ_MAX_TYPES];
        int         typemap[TZ_MAX_TYPES];
        int         thistypecnt,
                    stdcnt,
                    utcnt;
        char        thischars[TZ_MAX_CHARS];
        int         thischarcnt;
        bool        toomanytimes;
        int         indmap[TZ_MAX_CHARS];
 
        if (pass == 1)
        {
            /*
             * Arguably the default time type in the 32-bit data should be
             * range32.defaulttype, which is suited for timestamps just before
             * INT32_MIN.  However, zic traditionally used the time type of
             * the indefinite past instead.  Internet RFC 8532 says readers
             * should ignore 32-bit data, so this discrepancy matters only to
             * obsolete readers where the traditional type might be more
             * appropriate even if it's "wrong".  So, use the historical zic
             * value, unless -r specifies a low cutoff that excludes some
             * 32-bit timestamps.
             */
            thisdefaulttype = (lo_time <= INT32_MIN
                               ? range64.defaulttype
                               : range32.defaulttype);
 
            thistimei = range32.base;
            thistimecnt = range32.count;
            toomanytimes = thistimecnt >> 31 >> 1 != 0;
            thisleapi = range32.leapbase;
            thisleapcnt = range32.leapcount;
            locut = INT32_MIN < lo_time;
            hicut = hi_time < INT32_MAX;
        }
        else
        {
            thisdefaulttype = range64.defaulttype;
            thistimei = range64.base;
            thistimecnt = range64.count;
            toomanytimes = thistimecnt >> 31 >> 31 >> 2 != 0;
            thisleapi = range64.leapbase;
            thisleapcnt = range64.leapcount;
            locut = min_time < lo_time;
            hicut = hi_time < max_time;
        }
        if (toomanytimes)
            error(_("too many transition times"));
 
        /*
         * Keep the last too-low transition if no transition is exactly at LO.
         * The kept transition will be output as a LO "transition"; see
         * "Output a LO_TIME transition" below.  This is needed when the
         * output is truncated at the start, and is also useful when catering
         * to buggy 32-bit clients that do not use time type 0 for timestamps
         * before the first transition.
         */
        if (0 < thistimei && ats[thistimei] != lo_time)
        {
            thistimei--;
            thistimecnt++;
            locut = false;
        }
 
        thistimelim = thistimei + thistimecnt;
        thisleaplim = thisleapi + thisleapcnt;
        if (thistimecnt != 0)
        {
            if (ats[thistimei] == lo_time)
                locut = false;
            if (hi_time < ZIC_MAX && ats[thistimelim - 1] == hi_time + 1)
                hicut = false;
        }
        memset(omittype, true, typecnt);
        omittype[thisdefaulttype] = false;
        for (i = thistimei; i < thistimelim; i++)
            omittype[types[i]] = false;
 
        /*
         * Reorder types to make THISDEFAULTTYPE type 0. Use TYPEMAP to swap
         * OLD0 and THISDEFAULTTYPE so that THISDEFAULTTYPE appears as type 0
         * in the output instead of OLD0.  TYPEMAP also omits unused types.
         */
        old0 = strlen(omittype);
 
#ifndef LEAVE_SOME_PRE_2011_SYSTEMS_IN_THE_LURCH
 
        /*
         * For some pre-2011 systems: if the last-to-be-written standard (or
         * daylight) type has an offset different from the most recently used
         * offset, append an (unused) copy of the most recently used type (to
         * help get global "altzone" and "timezone" variables set correctly).
         */
        if (want_bloat())
        {
            int         mrudst,
                        mrustd,
                        hidst,
                        histd,
                        type;
 
            hidst = histd = mrudst = mrustd = -1;
            for (i = thistimei; i < thistimelim; ++i)
                if (isdsts[types[i]])
                    mrudst = types[i];
                else
                    mrustd = types[i];
            for (i = old0; i < typecnt; i++)
            {
                int         h = (i == old0 ? thisdefaulttype
                                 : i == thisdefaulttype ? old0 : i);
 
                if (!omittype[h])
                {
                    if (isdsts[h])
                        hidst = i;
                    else
                        histd = i;
                }
            }
            if (hidst >= 0 && mrudst >= 0 && hidst != mrudst &&
                utoffs[hidst] != utoffs[mrudst])
            {
                isdsts[mrudst] = -1;
                type = addtype(utoffs[mrudst],
                               &chars[desigidx[mrudst]],
                               true,
                               ttisstds[mrudst],
                               ttisuts[mrudst]);
                isdsts[mrudst] = 1;
                omittype[type] = false;
            }
            if (histd >= 0 && mrustd >= 0 && histd != mrustd &&
                utoffs[histd] != utoffs[mrustd])
            {
                isdsts[mrustd] = -1;
                type = addtype(utoffs[mrustd],
                               &chars[desigidx[mrustd]],
                               false,
                               ttisstds[mrustd],
                               ttisuts[mrustd]);
                isdsts[mrustd] = 0;
                omittype[type] = false;
            }
        }
#endif                          /* !defined
                                 * LEAVE_SOME_PRE_2011_SYSTEMS_IN_THE_LURCH */
        thistypecnt = 0;
        for (i = old0; i < typecnt; i++)
            if (!omittype[i])
                typemap[i == old0 ? thisdefaulttype
                        : i == thisdefaulttype ? old0 : i]
                    = thistypecnt++;
 
        for (i = 0; i < sizeof indmap / sizeof indmap[0]; ++i)
            indmap[i] = -1;
        thischarcnt = stdcnt = utcnt = 0;
        for (i = old0; i < typecnt; i++)
        {
            char       *thisabbr;
 
            if (omittype[i])
                continue;
            if (ttisstds[i])
                stdcnt = thistypecnt;
            if (ttisuts[i])
                utcnt = thistypecnt;
            if (indmap[desigidx[i]] >= 0)
                continue;
            thisabbr = &chars[desigidx[i]];
            for (j = 0; j < thischarcnt; ++j)
                if (strcmp(&thischars[j], thisabbr) == 0)
                    break;
            if (j == thischarcnt)
            {
                strcpy(&thischars[thischarcnt], thisabbr);
                thischarcnt += strlen(thisabbr) + 1;
            }
            indmap[desigidx[i]] = j;
        }
        if (pass == 1 && !want_bloat())
        {
            utcnt = stdcnt = thisleapcnt = 0;
            thistimecnt = -(locut + hicut);
            thistypecnt = thischarcnt = 1;
            thistimelim = thistimei;
        }
#define DO(field)   fwrite(tzh.field, sizeof tzh.field, 1, fp)
        tzh = tzh0;
        memcpy(tzh.tzh_magic, TZ_MAGIC, sizeof tzh.tzh_magic);
        tzh.tzh_version[0] = version;
        convert(utcnt, tzh.tzh_ttisutcnt);
        convert(stdcnt, tzh.tzh_ttisstdcnt);
        convert(thisleapcnt, tzh.tzh_leapcnt);
        convert(locut + thistimecnt + hicut, tzh.tzh_timecnt);
        convert(thistypecnt, tzh.tzh_typecnt);
        convert(thischarcnt, tzh.tzh_charcnt);
        DO(tzh_magic);
        DO(tzh_version);
        DO(tzh_reserved);
        DO(tzh_ttisutcnt);
        DO(tzh_ttisstdcnt);
        DO(tzh_leapcnt);
        DO(tzh_timecnt);
        DO(tzh_typecnt);
        DO(tzh_charcnt);
#undef DO
        if (pass == 1 && !want_bloat())
        {
            /* Output a minimal data block with just one time type.  */
            puttzcode(0, fp);   /* utoff */
            putc(0, fp);        /* dst */
            putc(0, fp);        /* index of abbreviation */
            putc(0, fp);        /* empty-string abbreviation */
            continue;
        }
 
        /* PG: print current timezone abbreviations if requested */
        if (print_abbrevs && pass == 2)
        {
            /* Print "type" data for periods ending after print_cutoff */
            for (i = thistimei; i < thistimelim; ++i)
            {
                if (i == thistimelim - 1 || ats[i + 1] > print_cutoff)
                {
                    unsigned char tm = types[i];
                    char       *thisabbrev = &thischars[indmap[desigidx[tm]]];
 
                    fprintf(stdout, "%s\t%" PRIdFAST64 "%s\n",
                            thisabbrev,
                            utoffs[tm],
                            isdsts[tm] ? "\tD" : "");
                }
            }
            /* Print the default type if we have no transitions at all */
            if (thistimei >= thistimelim)
            {
                unsigned char tm = defaulttype;
                char       *thisabbrev = &thischars[indmap[desigidx[tm]]];
 
                fprintf(stdout, "%s\t%" PRIdFAST64 "%s\n",
                        thisabbrev,
                        utoffs[tm],
                        isdsts[tm] ? "\tD" : "");
            }
        }
 
        /*
         * Output a LO_TIME transition if needed; see limitrange. But do not
         * go below the minimum representable value for this pass.
         */
        lo = pass == 1 && lo_time < INT32_MIN ? INT32_MIN : lo_time;
 
        if (locut)
            puttzcodepass(lo, fp, pass);
        for (i = thistimei; i < thistimelim; ++i)
        {
            zic_t       at = ats[i] < lo ? lo : ats[i];
 
            puttzcodepass(at, fp, pass);
        }
        if (hicut)
            puttzcodepass(hi_time + 1, fp, pass);
        currenttype = 0;
        if (locut)
            putc(currenttype, fp);
        for (i = thistimei; i < thistimelim; ++i)
        {
            currenttype = typemap[types[i]];
            putc(currenttype, fp);
        }
        if (hicut)
            putc(currenttype, fp);
 
        for (i = old0; i < typecnt; i++)
        {
            int         h = (i == old0 ? thisdefaulttype
                             : i == thisdefaulttype ? old0 : i);
 
            if (!omittype[h])
            {
                puttzcode(utoffs[h], fp);
                putc(isdsts[h], fp);
                putc(indmap[desigidx[h]], fp);
            }
        }
        if (thischarcnt != 0)
            fwrite(thischars, sizeof thischars[0],
                   thischarcnt, fp);
        for (i = thisleapi; i < thisleaplim; ++i)
        {
            zic_t       todo;
 
            if (roll[i])
            {
                if (timecnt == 0 || trans[i] < ats[0])
                {
                    j = 0;
                    while (isdsts[j])
                        if (++j >= typecnt)
                        {
                            j = 0;
                            break;
                        }
                }
                else
                {
                    j = 1;
                    while (j < timecnt &&
                           trans[i] >= ats[j])
                        ++j;
                    j = types[j - 1];
                }
                todo = tadd(trans[i], -utoffs[j]);
            }
            else
                todo = trans[i];
            puttzcodepass(todo, fp, pass);
            puttzcode(corr[i], fp);
        }
        if (stdcnt != 0)
            for (i = old0; i < typecnt; i++)
                if (!omittype[i])
                    putc(ttisstds[i], fp);
        if (utcnt != 0)
            for (i = old0; i < typecnt; i++)
                if (!omittype[i])
                    putc(ttisuts[i], fp);
    }
    fprintf(fp, "\n%s\n", string);
    close_file(fp, directory, name);
    free(ats);
}
 
static char const *
abbroffset(char *buf, zic_t offset)
{
    char        sign = '+';
    int         seconds,
                minutes;
 
    if (offset < 0)
    {
        offset = -offset;
        sign = '-';
    }
 
    seconds = offset % SECSPERMIN;
    offset /= SECSPERMIN;
    minutes = offset % MINSPERHOUR;
    offset /= MINSPERHOUR;
    if (100 <= offset)
    {
        error(_("%%z UT offset magnitude exceeds 99:59:59"));
        return "%z";
    }
    else
    {
        char       *p = buf;
 
        *p++ = sign;
        *p++ = '0' + offset / 10;
        *p++ = '0' + offset % 10;
        if (minutes | seconds)
        {
            *p++ = '0' + minutes / 10;
            *p++ = '0' + minutes % 10;
            if (seconds)
            {
                *p++ = '0' + seconds / 10;
                *p++ = '0' + seconds % 10;
            }
        }
        *p = '\0';
        return buf;
    }
}
 
static size_t
doabbr(char *abbr, struct zone const *zp, char const *letters,
       bool isdst, zic_t save, bool doquotes)
{
    char       *cp;
    char const *slashp;
    size_t      len;
    char const *format = zp->z_format;
 
    slashp = strchr(format, '/');
    if (slashp == NULL)
    {
        char        letterbuf[PERCENT_Z_LEN_BOUND + 1];
 
        if (zp->z_format_specifier == 'z')
            letters = abbroffset(letterbuf, zp->z_stdoff + save);
        else if (!letters)
            letters = "%s";
        sprintf(abbr, format, letters);
    }
    else if (isdst)
    {
        strcpy(abbr, slashp + 1);
    }
    else
    {
        memcpy(abbr, format, slashp - format);
        abbr[slashp - format] = '\0';
    }
    len = strlen(abbr);
    if (!doquotes)
        return len;
    for (cp = abbr; is_alpha(*cp); cp++)
        continue;
    if (len > 0 && *cp == '\0')
        return len;
    abbr[len + 2] = '\0';
    abbr[len + 1] = '>';
    memmove(abbr + 1, abbr, len);
    abbr[0] = '<';
    return len + 2;
}
 
static void
updateminmax(const zic_t x)
{
    if (min_year > x)
        min_year = x;
    if (max_year < x)
        max_year = x;
}
 
static int
stringoffset(char *result, zic_t offset)
{
    int         hours;
    int         minutes;
    int         seconds;
    bool        negative = offset < 0;
    int         len = negative;
 
    if (negative)
    {
        offset = -offset;
        result[0] = '-';
    }
    seconds = offset % SECSPERMIN;
    offset /= SECSPERMIN;
    minutes = offset % MINSPERHOUR;
    offset /= MINSPERHOUR;
    hours = offset;
    if (hours >= HOURSPERDAY * DAYSPERWEEK)
    {
        result[0] = '\0';
        return 0;
    }
    len += sprintf(result + len, "%d", hours);
    if (minutes != 0 || seconds != 0)
    {
        len += sprintf(result + len, ":%02d", minutes);
        if (seconds != 0)
            len += sprintf(result + len, ":%02d", seconds);
    }
    return len;
}
 
static int
stringrule(char *result, struct rule *const rp, zic_t save, zic_t stdoff)
{
    zic_t       tod = rp->r_tod;
    int         compat = 0;
 
    if (rp->r_dycode == DC_DOM)
    {
        int         month,
                    total;
 
        if (rp->r_dayofmonth == 29 && rp->r_month == TM_FEBRUARY)
            return -1;
        total = 0;
        for (month = 0; month < rp->r_month; ++month)
            total += len_months[0][month];
        /* Omit the "J" in Jan and Feb, as that's shorter.  */
        if (rp->r_month <= 1)
            result += sprintf(result, "%d", total + rp->r_dayofmonth - 1);
        else
            result += sprintf(result, "J%d", total + rp->r_dayofmonth);
    }
    else
    {
        int         week;
        int         wday = rp->r_wday;
        int         wdayoff;
 
        if (rp->r_dycode == DC_DOWGEQ)
        {
            wdayoff = (rp->r_dayofmonth - 1) % DAYSPERWEEK;
            if (wdayoff)
                compat = 2013;
            wday -= wdayoff;
            tod += wdayoff * SECSPERDAY;
            week = 1 + (rp->r_dayofmonth - 1) / DAYSPERWEEK;
        }
        else if (rp->r_dycode == DC_DOWLEQ)
        {
            if (rp->r_dayofmonth == len_months[1][rp->r_month])
                week = 5;
            else
            {
                wdayoff = rp->r_dayofmonth % DAYSPERWEEK;
                if (wdayoff)
                    compat = 2013;
                wday -= wdayoff;
                tod += wdayoff * SECSPERDAY;
                week = rp->r_dayofmonth / DAYSPERWEEK;
            }
        }
        else
            return -1;          /* "cannot happen" */
        if (wday < 0)
            wday += DAYSPERWEEK;
        result += sprintf(result, "M%d.%d.%d",
                          rp->r_month + 1, week, wday);
    }
    if (rp->r_todisut)
        tod += stdoff;
    if (rp->r_todisstd && !rp->r_isdst)
        tod += save;
    if (tod != 2 * SECSPERMIN * MINSPERHOUR)
    {
        *result++ = '/';
        if (!stringoffset(result, tod))
            return -1;
        if (tod < 0)
        {
            if (compat < 2013)
                compat = 2013;
        }
        else if (SECSPERDAY <= tod)
        {
            if (compat < 1994)
                compat = 1994;
        }
    }
    return compat;
}
 
static int
rule_cmp(struct rule const *a, struct rule const *b)
{
    if (!a)
        return -!!b;
    if (!b)
        return 1;
    if (a->r_hiyear != b->r_hiyear)
        return a->r_hiyear < b->r_hiyear ? -1 : 1;
    if (a->r_month - b->r_month != 0)
        return a->r_month - b->r_month;
    return a->r_dayofmonth - b->r_dayofmonth;
}
 
static int
stringzone(char *result, struct zone const *zpfirst, ptrdiff_t zonecount)
{
    const struct zone *zp;
    struct rule *rp;
    struct rule *stdrp;
    struct rule *dstrp;
    ptrdiff_t   i;
    const char *abbrvar;
    int         compat = 0;
    int         c;
    size_t      len;
    int         offsetlen;
    struct rule stdr,
                dstr;
 
    result[0] = '\0';
 
    /*
     * Internet RFC 8536 section 5.1 says to use an empty TZ string if future
     * timestamps are truncated.
     */
    if (hi_time < max_time)
        return -1;
 
    zp = zpfirst + zonecount - 1;
    stdrp = dstrp = NULL;
    for (i = 0; i < zp->z_nrules; ++i)
    {
        rp = &zp->z_rules[i];
        if (rp->r_hiwasnum || rp->r_hiyear != ZIC_MAX)
            continue;
        if (!rp->r_isdst)
        {
            if (stdrp == NULL)
                stdrp = rp;
            else
                return -1;
        }
        else
        {
            if (dstrp == NULL)
                dstrp = rp;
            else
                return -1;
        }
    }
    if (stdrp == NULL && dstrp == NULL)
    {
        /*
         * There are no rules running through "max". Find the latest std rule
         * in stdabbrrp and latest rule of any type in stdrp.
         */
        struct rule *stdabbrrp = NULL;
 
        for (i = 0; i < zp->z_nrules; ++i)
        {
            rp = &zp->z_rules[i];
            if (!rp->r_isdst && rule_cmp(stdabbrrp, rp) < 0)
                stdabbrrp = rp;
            if (rule_cmp(stdrp, rp) < 0)
                stdrp = rp;
        }
        if (stdrp != NULL && stdrp->r_isdst)
        {
            /* Perpetual DST.  */
            dstr.r_month = TM_JANUARY;
            dstr.r_dycode = DC_DOM;
            dstr.r_dayofmonth = 1;
            dstr.r_tod = 0;
            dstr.r_todisstd = dstr.r_todisut = false;
            dstr.r_isdst = stdrp->r_isdst;
            dstr.r_save = stdrp->r_save;
            dstr.r_abbrvar = stdrp->r_abbrvar;
            stdr.r_month = TM_DECEMBER;
            stdr.r_dycode = DC_DOM;
            stdr.r_dayofmonth = 31;
            stdr.r_tod = SECSPERDAY + stdrp->r_save;
            stdr.r_todisstd = stdr.r_todisut = false;
            stdr.r_isdst = false;
            stdr.r_save = 0;
            stdr.r_abbrvar
                = (stdabbrrp ? stdabbrrp->r_abbrvar : "");
            dstrp = &dstr;
            stdrp = &stdr;
        }
    }
    if (stdrp == NULL && (zp->z_nrules != 0 || zp->z_isdst))
        return -1;
    abbrvar = (stdrp == NULL) ? "" : stdrp->r_abbrvar;
    len = doabbr(result, zp, abbrvar, false, 0, true);
    offsetlen = stringoffset(result + len, -zp->z_stdoff);
    if (!offsetlen)
    {
        result[0] = '\0';
        return -1;
    }
    len += offsetlen;
    if (dstrp == NULL)
        return compat;
    len += doabbr(result + len, zp, dstrp->r_abbrvar,
                  dstrp->r_isdst, dstrp->r_save, true);
    if (dstrp->r_save != SECSPERMIN * MINSPERHOUR)
    {
        offsetlen = stringoffset(result + len,
                                 -(zp->z_stdoff + dstrp->r_save));
        if (!offsetlen)
        {
            result[0] = '\0';
            return -1;
        }
        len += offsetlen;
    }
    result[len++] = ',';
    c = stringrule(result + len, dstrp, dstrp->r_save, zp->z_stdoff);
    if (c < 0)
    {
        result[0] = '\0';
        return -1;
    }
    if (compat < c)
        compat = c;
    len += strlen(result + len);
    result[len++] = ',';
    c = stringrule(result + len, stdrp, dstrp->r_save, zp->z_stdoff);
    if (c < 0)
    {
        result[0] = '\0';
        return -1;
    }
    if (compat < c)
        compat = c;
    return compat;
}
 
static void
outzone(const struct zone *zpfirst, ptrdiff_t zonecount)
{
    const struct zone *zp;
    struct rule *rp;
    ptrdiff_t   i,
                j;
    bool        usestart,
                useuntil;
    zic_t       starttime,
                untiltime;
    zic_t       stdoff;
    zic_t       save;
    zic_t       year;
    zic_t       startoff;
    bool        startttisstd;
    bool        startttisut;
    int         type;
    char       *startbuf;
    char       *ab;
    char       *envvar;
    int         max_abbr_len;
    int         max_envvar_len;
    bool        prodstic;       /* all rules are min to max */
    int         compat;
    bool        do_extend;
    char        version;
    ptrdiff_t   lastatmax = -1;
    zic_t       one = 1;
    zic_t       y2038_boundary = one << 31;
    zic_t       max_year0;
    int         defaulttype = -1;
 
    max_abbr_len = 2 + max_format_len + max_abbrvar_len;
    max_envvar_len = 2 * max_abbr_len + 5 * 9;
    startbuf = emalloc(max_abbr_len + 1);
    ab = emalloc(max_abbr_len + 1);
    envvar = emalloc(max_envvar_len + 1);
    INITIALIZE(untiltime);
    INITIALIZE(starttime);
 
    /*
     * Now. . .finally. . .generate some useful data!
     */
    timecnt = 0;
    typecnt = 0;
    charcnt = 0;
    prodstic = zonecount == 1;
 
    /*
     * Thanks to Earl Chew for noting the need to unconditionally initialize
     * startttisstd.
     */
    startttisstd = false;
    startttisut = false;
    min_year = max_year = EPOCH_YEAR;
    if (leapseen)
    {
        updateminmax(leapminyear);
        updateminmax(leapmaxyear + (leapmaxyear < ZIC_MAX));
    }
    for (i = 0; i < zonecount; ++i)
    {
        zp = &zpfirst[i];
        if (i < zonecount - 1)
            updateminmax(zp->z_untilrule.r_loyear);
        for (j = 0; j < zp->z_nrules; ++j)
        {
            rp = &zp->z_rules[j];
            if (rp->r_lowasnum)
                updateminmax(rp->r_loyear);
            if (rp->r_hiwasnum)
                updateminmax(rp->r_hiyear);
            if (rp->r_lowasnum || rp->r_hiwasnum)
                prodstic = false;
        }
    }
 
    /*
     * Generate lots of data if a rule can't cover all future times.
     */
    compat = stringzone(envvar, zpfirst, zonecount);
    version = compat < 2013 ? ZIC_VERSION_PRE_2013 : ZIC_VERSION;
    do_extend = compat < 0;
    if (noise)
    {
        if (!*envvar)
            warning("%s %s",
                    _("no POSIX environment variable for zone"),
                    zpfirst->z_name);
        else if (compat != 0)
        {
            /*
             * Circa-COMPAT clients, and earlier clients, might not work for
             * this zone when given dates before 1970 or after 2038.
             */
            warning(_("%s: pre-%d clients may mishandle"
                      " distant timestamps"),
                    zpfirst->z_name, compat);
        }
    }
    if (do_extend)
    {
        /*
         * Search through a couple of extra years past the obvious 400, to
         * avoid edge cases.  For example, suppose a non-POSIX rule applies
         * from 2012 onwards and has transitions in March and September, plus
         * some one-off transitions in November 2013.  If zic looked only at
         * the last 400 years, it would set max_year=2413, with the intent
         * that the 400 years 2014 through 2413 will be repeated.  The last
         * transition listed in the tzfile would be in 2413-09, less than 400
         * years after the last one-off transition in 2013-11.  Two years
         * might be overkill, but with the kind of edge cases available we're
         * not sure that one year would suffice.
         */
        enum
        {
        years_of_observations = YEARSPERREPEAT + 2};
 
        if (min_year >= ZIC_MIN + years_of_observations)
            min_year -= years_of_observations;
        else
            min_year = ZIC_MIN;
        if (max_year <= ZIC_MAX - years_of_observations)
            max_year += years_of_observations;
        else
            max_year = ZIC_MAX;
 
        /*
         * Regardless of any of the above, for a "proDSTic" zone which
         * specifies that its rules always have and always will be in effect,
         * we only need one cycle to define the zone.
         */
        if (prodstic)
        {
            min_year = 1900;
            max_year = min_year + years_of_observations;
        }
    }
    max_year0 = max_year;
    if (want_bloat())
    {
        /*
         * For the benefit of older systems, generate data from 1900 through
         * 2038.
         */
        if (min_year > 1900)
            min_year = 1900;
        if (max_year < 2038)
            max_year = 2038;
    }
 
    for (i = 0; i < zonecount; ++i)
    {
        struct rule *prevrp = NULL;
 
        /*
         * A guess that may well be corrected later.
         */
        save = 0;
        zp = &zpfirst[i];
        usestart = i > 0 && (zp - 1)->z_untiltime > min_time;
        useuntil = i < (zonecount - 1);
        if (useuntil && zp->z_untiltime <= min_time)
            continue;
        stdoff = zp->z_stdoff;
        eat(zp->z_filename, zp->z_linenum);
        *startbuf = '\0';
        startoff = zp->z_stdoff;
        if (zp->z_nrules == 0)
        {
            save = zp->z_save;
            doabbr(startbuf, zp, NULL, zp->z_isdst, save, false);
            type = addtype(oadd(zp->z_stdoff, save),
                           startbuf, zp->z_isdst, startttisstd,
                           startttisut);
            if (usestart)
            {
                addtt(starttime, type);
                usestart = false;
            }
            else
                defaulttype = type;
        }
        else
            for (year = min_year; year <= max_year; ++year)
            {
                if (useuntil && year > zp->z_untilrule.r_hiyear)
                    break;
 
                /*
                 * Mark which rules to do in the current year. For those to
                 * do, calculate rpytime(rp, year); The former TYPE field was
                 * also considered here.
                 */
                for (j = 0; j < zp->z_nrules; ++j)
                {
                    rp = &zp->z_rules[j];
                    eats(zp->z_filename, zp->z_linenum,
                         rp->r_filename, rp->r_linenum);
                    rp->r_todo = year >= rp->r_loyear &&
                        year <= rp->r_hiyear;
                    if (rp->r_todo)
                    {
                        rp->r_temp = rpytime(rp, year);
                        rp->r_todo
                            = (rp->r_temp < y2038_boundary
                               || year <= max_year0);
                    }
                }
                for (;;)
                {
                    ptrdiff_t   k;
                    zic_t       jtime,
                                ktime;
                    zic_t       offset;
 
                    INITIALIZE(ktime);
                    if (useuntil)
                    {
                        /*
                         * Turn untiltime into UT assuming the current stdoff
                         * and save values.
                         */
                        untiltime = zp->z_untiltime;
                        if (!zp->z_untilrule.r_todisut)
                            untiltime = tadd(untiltime,
                                             -stdoff);
                        if (!zp->z_untilrule.r_todisstd)
                            untiltime = tadd(untiltime,
                                             -save);
                    }
 
                    /*
                     * Find the rule (of those to do, if any) that takes
                     * effect earliest in the year.
                     */
                    k = -1;
                    for (j = 0; j < zp->z_nrules; ++j)
                    {
                        rp = &zp->z_rules[j];
                        if (!rp->r_todo)
                            continue;
                        eats(zp->z_filename, zp->z_linenum,
                             rp->r_filename, rp->r_linenum);
                        offset = rp->r_todisut ? 0 : stdoff;
                        if (!rp->r_todisstd)
                            offset = oadd(offset, save);
                        jtime = rp->r_temp;
                        if (jtime == min_time ||
                            jtime == max_time)
                            continue;
                        jtime = tadd(jtime, -offset);
                        if (k < 0 || jtime < ktime)
                        {
                            k = j;
                            ktime = jtime;
                        }
                        else if (jtime == ktime)
                        {
                            char const *dup_rules_msg =
                                _("two rules for same instant");
 
                            eats(zp->z_filename, zp->z_linenum,
                                 rp->r_filename, rp->r_linenum);
                            warning("%s", dup_rules_msg);
                            rp = &zp->z_rules[k];
                            eats(zp->z_filename, zp->z_linenum,
                                 rp->r_filename, rp->r_linenum);
                            error("%s", dup_rules_msg);
                        }
                    }
                    if (k < 0)
                        break;  /* go on to next year */
                    rp = &zp->z_rules[k];
                    rp->r_todo = false;
                    if (useuntil && ktime >= untiltime)
                        break;
                    save = rp->r_save;
                    if (usestart && ktime == starttime)
                        usestart = false;
                    if (usestart)
                    {
                        if (ktime < starttime)
                        {
                            startoff = oadd(zp->z_stdoff,
                                            save);
                            doabbr(startbuf, zp,
                                   rp->r_abbrvar,
                                   rp->r_isdst,
                                   rp->r_save,
                                   false);
                            continue;
                        }
                        if (*startbuf == '\0'
                            && startoff == oadd(zp->z_stdoff,
                                                save))
                        {
                            doabbr(startbuf,
                                   zp,
                                   rp->r_abbrvar,
                                   rp->r_isdst,
                                   rp->r_save,
                                   false);
                        }
                    }
                    eats(zp->z_filename, zp->z_linenum,
                         rp->r_filename, rp->r_linenum);
                    doabbr(ab, zp, rp->r_abbrvar,
                           rp->r_isdst, rp->r_save, false);
                    offset = oadd(zp->z_stdoff, rp->r_save);
                    if (!want_bloat() && !useuntil && !do_extend
                        && prevrp
                        && rp->r_hiyear == ZIC_MAX
                        && prevrp->r_hiyear == ZIC_MAX)
                        break;
                    type = addtype(offset, ab, rp->r_isdst,
                                   rp->r_todisstd, rp->r_todisut);
                    if (defaulttype < 0 && !rp->r_isdst)
                        defaulttype = type;
                    if (rp->r_hiyear == ZIC_MAX
                        && !(0 <= lastatmax
                             && ktime < attypes[lastatmax].at))
                        lastatmax = timecnt;
                    addtt(ktime, type);
                    prevrp = rp;
                }
            }
        if (usestart)
        {
            if (*startbuf == '\0' &&
                zp->z_format != NULL &&
                strchr(zp->z_format, '%') == NULL &&
                strchr(zp->z_format, '/') == NULL)
                strcpy(startbuf, zp->z_format);
            eat(zp->z_filename, zp->z_linenum);
            if (*startbuf == '\0')
                error(_("cannot determine time zone abbreviation to use just after until time"));
            else
            {
                bool        isdst = startoff != zp->z_stdoff;
 
                type = addtype(startoff, startbuf, isdst,
                               startttisstd, startttisut);
                if (defaulttype < 0 && !isdst)
                    defaulttype = type;
                addtt(starttime, type);
            }
        }
 
        /*
         * Now we may get to set starttime for the next zone line.
         */
        if (useuntil)
        {
            startttisstd = zp->z_untilrule.r_todisstd;
            startttisut = zp->z_untilrule.r_todisut;
            starttime = zp->z_untiltime;
            if (!startttisstd)
                starttime = tadd(starttime, -save);
            if (!startttisut)
                starttime = tadd(starttime, -stdoff);
        }
    }
    if (defaulttype < 0)
        defaulttype = 0;
    if (0 <= lastatmax)
        attypes[lastatmax].dontmerge = true;
    if (do_extend)
    {
        /*
         * If we're extending the explicitly listed observations for 400 years
         * because we can't fill the POSIX-TZ field, check whether we actually
         * ended up explicitly listing observations through that period.  If
         * there aren't any near the end of the 400-year period, add a
         * redundant one at the end of the final year, to make it clear that
         * we are claiming to have definite knowledge of the lack of
         * transitions up to that point.
         */
        struct rule xr;
        struct attype *lastat;
 
        xr.r_month = TM_JANUARY;
        xr.r_dycode = DC_DOM;
        xr.r_dayofmonth = 1;
        xr.r_tod = 0;
        for (lastat = attypes, i = 1; i < timecnt; i++)
            if (attypes[i].at > lastat->at)
                lastat = &attypes[i];
        if (!lastat || lastat->at < rpytime(&xr, max_year - 1))
        {
            addtt(rpytime(&xr, max_year + 1),
                  lastat ? lastat->type : defaulttype);
            attypes[timecnt - 1].dontmerge = true;
        }
    }
    writezone(zpfirst->z_name, envvar, version, defaulttype);
    free(startbuf);
    free(ab);
    free(envvar);
}
 
static void
addtt(zic_t starttime, int type)
{
    attypes = growalloc(attypes, sizeof *attypes, timecnt, &timecnt_alloc);
    attypes[timecnt].at = starttime;
    attypes[timecnt].dontmerge = false;
    attypes[timecnt].type = type;
    ++timecnt;
}
 
static int
addtype(zic_t utoff, char const *abbr, bool isdst, bool ttisstd, bool ttisut)
{
    int         i,
                j;
 
    if (!(-1L - 2147483647L <= utoff && utoff <= 2147483647L))
    {
        error(_("UT offset out of range"));
        exit(EXIT_FAILURE);
    }
    if (!want_bloat())
        ttisstd = ttisut = false;
 
    for (j = 0; j < charcnt; ++j)
        if (strcmp(&chars[j], abbr) == 0)
            break;
    if (j == charcnt)
        newabbr(abbr);
    else
    {
        /* If there's already an entry, return its index.  */
        for (i = 0; i < typecnt; i++)
            if (utoff == utoffs[i] && isdst == isdsts[i] && j == desigidx[i]
                && ttisstd == ttisstds[i] && ttisut == ttisuts[i])
                return i;
    }
 
    /*
     * There isn't one; add a new one, unless there are already too many.
     */
    if (typecnt >= TZ_MAX_TYPES)
    {
        error(_("too many local time types"));
        exit(EXIT_FAILURE);
    }
    i = typecnt++;
    utoffs[i] = utoff;
    isdsts[i] = isdst;
    ttisstds[i] = ttisstd;
    ttisuts[i] = ttisut;
    desigidx[i] = j;
    return i;
}
 
static void
leapadd(zic_t t, int correction, int rolling)
{
    int         i;
 
    if (TZ_MAX_LEAPS <= leapcnt)
    {
        error(_("too many leap seconds"));
        exit(EXIT_FAILURE);
    }
    for (i = 0; i < leapcnt; ++i)
        if (t <= trans[i])
            break;
    memmove(&trans[i + 1], &trans[i], (leapcnt - i) * sizeof *trans);
    memmove(&corr[i + 1], &corr[i], (leapcnt - i) * sizeof *corr);
    memmove(&roll[i + 1], &roll[i], (leapcnt - i) * sizeof *roll);
    trans[i] = t;
    corr[i] = correction;
    roll[i] = rolling;
    ++leapcnt;
}
 
static void
adjleap(void)
{
    int         i;
    zic_t       last = 0;
    zic_t       prevtrans = 0;
 
    /*
     * propagate leap seconds forward
     */
    for (i = 0; i < leapcnt; ++i)
    {
        if (trans[i] - prevtrans < 28 * SECSPERDAY)
        {
            error(_("Leap seconds too close together"));
            exit(EXIT_FAILURE);
        }
        prevtrans = trans[i];
        trans[i] = tadd(trans[i], last);
        last = corr[i] += last;
    }
 
    if (leapexpires < 0)
    {
        leapexpires = comment_leapexpires;
        if (0 <= leapexpires)
            warning(_("\"#expires\" is obsolescent; use \"Expires\""));
    }
 
    if (0 <= leapexpires)
    {
        leapexpires = oadd(leapexpires, last);
        if (!(leapcnt == 0 || (trans[leapcnt - 1] < leapexpires)))
        {
            error(_("last Leap time does not precede Expires time"));
            exit(EXIT_FAILURE);
        }
        if (leapexpires <= hi_time)
            hi_time = leapexpires - 1;
    }
}
 
/* Is A a space character in the C locale?  */
static bool
is_space(char a)
{
    switch (a)
    {
        default:
            return false;
        case ' ':
        case '\f':
        case '\n':
        case '\r':
        case '\t':
        case '\v':
            return true;
    }
}
 
/* 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;
    }
}
 
/*
 * If A is an uppercase character in the C locale, return its lowercase
 * counterpart.  Otherwise, return A.
 */
static char
lowerit(char a)
{
    switch (a)
    {
        default:
            return a;
        case 'A':
            return 'a';
        case 'B':
            return 'b';
        case 'C':
            return 'c';
        case 'D':
            return 'd';
        case 'E':
            return 'e';
        case 'F':
            return 'f';
        case 'G':
            return 'g';
        case 'H':
            return 'h';
        case 'I':
            return 'i';
        case 'J':
            return 'j';
        case 'K':
            return 'k';
        case 'L':
            return 'l';
        case 'M':
            return 'm';
        case 'N':
            return 'n';
        case 'O':
            return 'o';
        case 'P':
            return 'p';
        case 'Q':
            return 'q';
        case 'R':
            return 'r';
        case 'S':
            return 's';
        case 'T':
            return 't';
        case 'U':
            return 'u';
        case 'V':
            return 'v';
        case 'W':
            return 'w';
        case 'X':
            return 'x';
        case 'Y':
            return 'y';
        case 'Z':
            return 'z';
    }
}
 
/* case-insensitive equality */
static bool
ciequal(const char *ap, const char *bp)
{
    while (lowerit(*ap) == lowerit(*bp++))
        if (*ap++ == '\0')
            return true;
    return false;
}
 
static bool
itsabbr(const char *abbr, const char *word)
{
    if (lowerit(*abbr) != lowerit(*word))
        return false;
    ++word;
    while (*++abbr != '\0')
        do
        {
            if (*word == '\0')
                return false;
        } while (lowerit(*word++) != lowerit(*abbr));
    return true;
}
 
/* Return true if ABBR is an initial prefix of WORD, ignoring ASCII case.  */
 
static bool
ciprefix(char const *abbr, char const *word)
{
    do
        if (!*abbr)
            return true;
    while (lowerit(*abbr++) == lowerit(*word++));
 
    return false;
}
 
static const struct lookup *
byword(const char *word, const struct lookup *table)
{
    const struct lookup *foundlp;
    const struct lookup *lp;
 
    if (word == NULL || table == NULL)
        return NULL;
 
    /*
     * If TABLE is LASTS and the word starts with "last" followed by a
     * non-'-', skip the "last" and look in WDAY_NAMES instead. Warn about any
     * usage of the undocumented prefix "last-".
     */
    if (table == lasts && ciprefix("last", word) && word[4])
    {
        if (word[4] == '-')
            warning(_("\"%s\" is undocumented; use \"last%s\" instead"),
                    word, word + 5);
        else
        {
            word += 4;
            table = wday_names;
        }
    }
 
    /*
     * Look for exact match.
     */
    for (lp = table; lp->l_word != NULL; ++lp)
        if (ciequal(word, lp->l_word))
            return lp;
 
    /*
     * Look for inexact match.
     */
    foundlp = NULL;
    for (lp = table; lp->l_word != NULL; ++lp)
        if (ciprefix(word, lp->l_word))
        {
            if (foundlp == NULL)
                foundlp = lp;
            else
                return NULL;    /* multiple inexact matches */
        }
 
    if (foundlp && noise)
    {
        /* Warn about any backward-compatibility issue with pre-2017c zic.  */
        bool        pre_2017c_match = false;
 
        for (lp = table; lp->l_word; lp++)
            if (itsabbr(word, lp->l_word))
            {
                if (pre_2017c_match)
                {
                    warning(_("\"%s\" is ambiguous in pre-2017c zic"), word);
                    break;
                }
                pre_2017c_match = true;
            }
    }
 
    return foundlp;
}
 
static char **
getfields(char *cp)
{
    char       *dp;
    char      **array;
    int         nsubs;
 
    if (cp == NULL)
        return NULL;
    array = emalloc(size_product(strlen(cp) + 1, sizeof *array));
    nsubs = 0;
    for (;;)
    {
        while (is_space(*cp))
            ++cp;
        if (*cp == '\0' || *cp == '#')
            break;
        array[nsubs++] = dp = cp;
        do
        {
            if ((*dp = *cp++) != '"')
                ++dp;
            else
                while ((*dp = *cp++) != '"')
                    if (*dp != '\0')
                        ++dp;
                    else
                    {
                        error(_("Odd number of quotation marks"));
                        exit(EXIT_FAILURE);
                    }
        } while (*cp && *cp != '#' && !is_space(*cp));
        if (is_space(*cp))
            ++cp;
        *dp = '\0';
    }
    array[nsubs] = NULL;
    return array;
}
 
static _Noreturn void
time_overflow(void)
{
    error(_("time overflow"));
    exit(EXIT_FAILURE);
}
 
static zic_t
oadd(zic_t t1, zic_t t2)
{
    if (t1 < 0 ? t2 < ZIC_MIN - t1 : ZIC_MAX - t1 < t2)
        time_overflow();
    return t1 + t2;
}
 
static zic_t
tadd(zic_t t1, zic_t t2)
{
    if (t1 < 0)
    {
        if (t2 < min_time - t1)
        {
            if (t1 != min_time)
                time_overflow();
            return min_time;
        }
    }
    else
    {
        if (max_time - t1 < t2)
        {
            if (t1 != max_time)
                time_overflow();
            return max_time;
        }
    }
    return t1 + t2;
}
 
/*
 * Given a rule, and a year, compute the date (in seconds since January 1,
 * 1970, 00:00 LOCAL time) in that year that the rule refers to.
 */
 
static zic_t
rpytime(const struct rule *rp, zic_t wantedy)
{
    int         m,
                i;
    zic_t       dayoff;         /* with a nod to Margaret O. */
    zic_t       t,
                y;
 
    if (wantedy == ZIC_MIN)
        return min_time;
    if (wantedy == ZIC_MAX)
        return max_time;
    dayoff = 0;
    m = TM_JANUARY;
    y = EPOCH_YEAR;
    if (y < wantedy)
    {
        wantedy -= y;
        dayoff = (wantedy / YEARSPERREPEAT) * (SECSPERREPEAT / SECSPERDAY);
        wantedy %= YEARSPERREPEAT;
        wantedy += y;
    }
    else if (wantedy < 0)
    {
        dayoff = (wantedy / YEARSPERREPEAT) * (SECSPERREPEAT / SECSPERDAY);
        wantedy %= YEARSPERREPEAT;
    }
    while (wantedy != y)
    {
        if (wantedy > y)
        {
            i = len_years[isleap(y)];
            ++y;
        }
        else
        {
            --y;
            i = -len_years[isleap(y)];
        }
        dayoff = oadd(dayoff, i);
    }
    while (m != rp->r_month)
    {
        i = len_months[isleap(y)][m];
        dayoff = oadd(dayoff, i);
        ++m;
    }
    i = rp->r_dayofmonth;
    if (m == TM_FEBRUARY && i == 29 && !isleap(y))
    {
        if (rp->r_dycode == DC_DOWLEQ)
            --i;
        else
        {
            error(_("use of 2/29 in non leap-year"));
            exit(EXIT_FAILURE);
        }
    }
    --i;
    dayoff = oadd(dayoff, i);
    if (rp->r_dycode == DC_DOWGEQ || rp->r_dycode == DC_DOWLEQ)
    {
        zic_t       wday;
 
#define LDAYSPERWEEK    ((zic_t) DAYSPERWEEK)
        wday = EPOCH_WDAY;
 
        /*
         * Don't trust mod of negative numbers.
         */
        if (dayoff >= 0)
            wday = (wday + dayoff) % LDAYSPERWEEK;
        else
        {
            wday -= ((-dayoff) % LDAYSPERWEEK);
            if (wday < 0)
                wday += LDAYSPERWEEK;
        }
        while (wday != rp->r_wday)
            if (rp->r_dycode == DC_DOWGEQ)
            {
                dayoff = oadd(dayoff, 1);
                if (++wday >= LDAYSPERWEEK)
                    wday = 0;
                ++i;
            }
            else
            {
                dayoff = oadd(dayoff, -1);
                if (--wday < 0)
                    wday = LDAYSPERWEEK - 1;
                --i;
            }
        if (i < 0 || i >= len_months[isleap(y)][m])
        {
            if (noise)
                warning(_("rule goes past start/end of month; \
will not work with pre-2004 versions of zic"));
        }
    }
    if (dayoff < min_time / SECSPERDAY)
        return min_time;
    if (dayoff > max_time / SECSPERDAY)
        return max_time;
    t = (zic_t) dayoff * SECSPERDAY;
    return tadd(t, rp->r_tod);
}
 
static void
newabbr(const char *string)
{
    int         i;
 
    if (strcmp(string, GRANDPARENTED) != 0)
    {
        const char *cp;
        const char *mp;
 
        cp = string;
        mp = NULL;
        while (is_alpha(*cp) || ('0' <= *cp && *cp <= '9')
               || *cp == '-' || *cp == '+')
            ++cp;
        if (noise && cp - string < 3)
            mp = _("time zone abbreviation has fewer than 3 characters");
        if (cp - string > ZIC_MAX_ABBR_LEN_WO_WARN)
            mp = _("time zone abbreviation has too many characters");
        if (*cp != '\0')
            mp = _("time zone abbreviation differs from POSIX standard");
        if (mp != NULL)
            warning("%s (%s)", mp, string);
    }
    i = strlen(string) + 1;
    if (charcnt + i > TZ_MAX_CHARS)
    {
        error(_("too many, or too long, time zone abbreviations"));
        exit(EXIT_FAILURE);
    }
    strcpy(&chars[charcnt], string);
    charcnt += i;
}
 
/*
 * Ensure that the directories of ARGNAME exist, by making any missing
 * ones.  If ANCESTORS, do this only for ARGNAME's ancestors; otherwise,
 * do it for ARGNAME too.  Exit with failure if there is trouble.
 * Do not consider an existing non-directory to be trouble.
 */
static void
mkdirs(char const *argname, bool ancestors)
{
    char       *name;
    char       *cp;
 
    cp = name = ecpyalloc(argname);
 
    /*
     * On MS-Windows systems, do not worry about drive letters or backslashes,
     * as this should suffice in practice.  Time zone names do not use drive
     * letters and backslashes.  If the -d option of zic does not name an
     * already-existing directory, it can use slashes to separate the
     * already-existing ancestor prefix from the to-be-created subdirectories.
     */
 
    /* Do not mkdir a root directory, as it must exist.  */
    while (*cp == '/')
        cp++;
 
    while (cp && ((cp = strchr(cp, '/')) || !ancestors))
    {
        if (cp)
            *cp = '\0';
 
        /*
         * Try to create it.  It's OK if creation fails because the directory
         * already exists, perhaps because some other process just created it.
         * For simplicity do not check first whether it already exists, as
         * that is checked anyway if the mkdir fails.
         */
        if (mkdir(name, MKDIR_UMASK) != 0)
        {
            /*
             * For speed, skip itsdir if errno == EEXIST.  Since mkdirs is
             * called only after open fails with ENOENT on a subfile, EEXIST
             * implies itsdir here.
             */
            int         err = errno;
 
            if (err != EEXIST && !itsdir(name))
            {
                error(_("%s: Cannot create directory %s: %s"),
                      progname, name, strerror(err));
                exit(EXIT_FAILURE);
            }
        }
        if (cp)
            *cp++ = '/';
    }
    free(name);
}
 
 
#ifdef WIN32
/*
 * To run on win32
 */
int
link(const char *oldpath, const char *newpath)
{
    if (!CopyFile(oldpath, newpath, false))
    {
        _dosmaperr(GetLastError());
        return -1;
    }
    return 0;
}
#endif