strftime: import from gnulib

1 files changed, 1468 insertions, 0 deletions

diff --git a/lib/strftime.c b/lib/strftime.c
new file mode 100644
index 00000000000..0a02b507744
--- /dev/null
+++ b/lib/strftime.c
@@ -0,0 +1,1468 @@
+/* Copyright (C) 1991-2001, 2003-2007, 2009-2011 Free Software Foundation, Inc.
+
+   NOTE: The canonical source of this file is maintained with the GNU C Library.
+   Bugs can be reported to bug-glibc@prep.ai.mit.edu.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef _LIBC
+# define HAVE_STRUCT_ERA_ENTRY 1
+# define HAVE_TM_GMTOFF 1
+# define HAVE_TM_ZONE 1
+# define HAVE_TZNAME 1
+# define HAVE_TZSET 1
+# include "../locale/localeinfo.h"
+#else
+# include <config.h>
+# if FPRINTFTIME
+#  include "ignore-value.h"
+#  include "fprintftime.h"
+# else
+#  include "strftime.h"
+# endif
+#endif
+
+#include <ctype.h>
+#include <time.h>
+
+#if HAVE_TZNAME && !HAVE_DECL_TZNAME
+extern char *tzname[];
+#endif
+
+/* Do multibyte processing if multibytes are supported, unless
+   multibyte sequences are safe in formats.  Multibyte sequences are
+   safe if they cannot contain byte sequences that look like format
+   conversion specifications.  The multibyte encodings used by the
+   C library on the various platforms (UTF-8, GB2312, GBK, CP936,
+   GB18030, EUC-TW, BIG5, BIG5-HKSCS, CP950, EUC-JP, EUC-KR, CP949,
+   SHIFT_JIS, CP932, JOHAB) are safe for formats, because the byte '%'
+   cannot occur in a multibyte character except in the first byte.
+
+   The DEC-HANYU encoding used on OSF/1 is not safe for formats, but
+   this encoding has never been seen in real-life use, so we ignore
+   it.  */
+#if !(defined __osf__ && 0)
+# define MULTIBYTE_IS_FORMAT_SAFE 1
+#endif
+#define DO_MULTIBYTE (! MULTIBYTE_IS_FORMAT_SAFE)
+
+#if DO_MULTIBYTE
+# include <wchar.h>
+  static const mbstate_t mbstate_zero;
+#endif
+
+#include <limits.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef COMPILE_WIDE
+# include <endian.h>
+# define CHAR_T wchar_t
+# define UCHAR_T unsigned int
+# define L_(Str) L##Str
+# define NLW(Sym) _NL_W##Sym
+
+# define MEMCPY(d, s, n) __wmemcpy (d, s, n)
+# define STRLEN(s) __wcslen (s)
+
+#else
+# define CHAR_T char
+# define UCHAR_T unsigned char
+# define L_(Str) Str
+# define NLW(Sym) Sym
+
+# define MEMCPY(d, s, n) memcpy (d, s, n)
+# define STRLEN(s) strlen (s)
+
+#endif
+
+/* Shift A right by B bits portably, by dividing A by 2**B and
+   truncating towards minus infinity.  A and B should be free of side
+   effects, and B should be in the range 0 <= B <= INT_BITS - 2, where
+   INT_BITS is the number of useful bits in an int.  GNU code can
+   assume that INT_BITS is at least 32.
+
+   ISO C99 says that A >> B is implementation-defined if A < 0.  Some
+   implementations (e.g., UNICOS 9.0 on a Cray Y-MP EL) don't shift
+   right in the usual way when A < 0, so SHR falls back on division if
+   ordinary A >> B doesn't seem to be the usual signed shift.  */
+#define SHR(a, b)       \
+  (-1 >> 1 == -1        \
+   ? (a) >> (b)         \
+   : (a) / (1 << (b)) - ((a) % (1 << (b)) < 0))
+
+/* Bound on length of the string representing an integer type or expression T.
+   Subtract 1 for the sign bit if t is signed; log10 (2.0) < 146/485;
+   add 1 for integer division truncation; add 1 more for a minus sign
+   if needed.  */
+#define INT_STRLEN_BOUND(t) \
+  ((sizeof (t) * CHAR_BIT - 1) * 146 / 485 + 2)
+
+#define TM_YEAR_BASE 1900
+
+#ifndef __isleap
+/* Nonzero if YEAR is a leap year (every 4 years,
+   except every 100th isn't, and every 400th is).  */
+# define __isleap(year) \
+  ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
+#endif
+
+
+#ifdef _LIBC
+# define tzname __tzname
+# define tzset __tzset
+#endif
+
+#if !HAVE_TM_GMTOFF
+/* Portable standalone applications should supply a "time.h" that
+   declares a POSIX-compliant localtime_r, for the benefit of older
+   implementations that lack localtime_r or have a nonstandard one.
+   See the gnulib time_r module for one way to implement this.  */
+# undef __gmtime_r
+# undef __localtime_r
+# define __gmtime_r gmtime_r
+# define __localtime_r localtime_r
+#endif
+
+
+#ifndef FPRINTFTIME
+# define FPRINTFTIME 0
+#endif
+
+#if FPRINTFTIME
+# define STREAM_OR_CHAR_T FILE
+# define STRFTIME_ARG(x) /* empty */
+#else
+# define STREAM_OR_CHAR_T CHAR_T
+# define STRFTIME_ARG(x) x,
+#endif
+
+#if FPRINTFTIME
+# define memset_byte(P, Len, Byte) \
+  do { size_t _i; for (_i = 0; _i < Len; _i++) fputc (Byte, P); } while (0)
+# define memset_space(P, Len) memset_byte (P, Len, ' ')
+# define memset_zero(P, Len) memset_byte (P, Len, '0')
+#elif defined COMPILE_WIDE
+# define memset_space(P, Len) (wmemset (P, L' ', Len), (P) += (Len))
+# define memset_zero(P, Len) (wmemset (P, L'0', Len), (P) += (Len))
+#else
+# define memset_space(P, Len) (memset (P, ' ', Len), (P) += (Len))
+# define memset_zero(P, Len) (memset (P, '0', Len), (P) += (Len))
+#endif
+
+#if FPRINTFTIME
+# define advance(P, N)
+#else
+# define advance(P, N) ((P) += (N))
+#endif
+
+#define add(n, f)                                                             \
+  do                                                                          \
+    {                                                                         \
+      int _n = (n);                                                           \
+      int _delta = width - _n;                                                \
+      int _incr = _n + (_delta > 0 ? _delta : 0);                             \
+      if ((size_t) _incr >= maxsize - i)                                      \
+        return 0;                                                             \
+      if (p)                                                                  \
+        {                                                                     \
+          if (digits == 0 && _delta > 0)                                      \
+            {                                                                 \
+              if (pad == L_('0'))                                             \
+                memset_zero (p, _delta);                                      \
+              else                                                            \
+                memset_space (p, _delta);                                     \
+            }                                                                 \
+          f;                                                                  \
+          advance (p, _n);                                                    \
+        }                                                                     \
+      i += _incr;                                                             \
+    } while (0)
+
+#if FPRINTFTIME
+# define add1(C) add (1, fputc (C, p))
+#else
+# define add1(C) add (1, *p = C)
+#endif
+
+#if FPRINTFTIME
+# define cpy(n, s) \
+    add ((n),                                                                 \
+     do                                                                       \
+       {                                                                      \
+         if (to_lowcase)                                                      \
+           fwrite_lowcase (p, (s), _n);                                       \
+         else if (to_uppcase)                                                 \
+           fwrite_uppcase (p, (s), _n);                                       \
+         else                                                                 \
+           {                                                                  \
+             /* We are ignoring the value of fwrite here, in spite of the     \
+                fact that technically, that may not be valid: the fwrite      \
+                specification in POSIX 2008 defers to that of fputc, which    \
+                is intended to be consistent with the one from ISO C,         \
+                which permits failure due to ENOMEM *without* setting the     \
+                stream's error indicator.  */                                 \
+             ignore_value (fwrite ((s), _n, 1, p));                           \
+           }                                                                  \
+       }                                                                      \
+     while (0)                                                                \
+    )
+#else
+# define cpy(n, s)                                                            \
+    add ((n),                                                                 \
+         if (to_lowcase)                                                      \
+           memcpy_lowcase (p, (s), _n LOCALE_ARG);                            \
+         else if (to_uppcase)                                                 \
+           memcpy_uppcase (p, (s), _n LOCALE_ARG);                            \
+         else                                                                 \
+           MEMCPY ((void *) p, (void const *) (s), _n))
+#endif
+
+#ifdef COMPILE_WIDE
+# ifndef USE_IN_EXTENDED_LOCALE_MODEL
+#  undef __mbsrtowcs_l
+#  define __mbsrtowcs_l(d, s, l, st, loc) __mbsrtowcs (d, s, l, st)
+# endif
+# define widen(os, ws, l) \
+  {                                                                           \
+    mbstate_t __st;                                                           \
+    const char *__s = os;                                                     \
+    memset (&__st, '\0', sizeof (__st));                                      \
+    l = __mbsrtowcs_l (NULL, &__s, 0, &__st, loc);                            \
+    ws = (wchar_t *) alloca ((l + 1) * sizeof (wchar_t));                     \
+    (void) __mbsrtowcs_l (ws, &__s, l, &__st, loc);                           \
+  }
+#endif
+
+
+#if defined _LIBC && defined USE_IN_EXTENDED_LOCALE_MODEL
+/* We use this code also for the extended locale handling where the
+   function gets as an additional argument the locale which has to be
+   used.  To access the values we have to redefine the _NL_CURRENT
+   macro.  */
+# define strftime               __strftime_l
+# define wcsftime               __wcsftime_l
+# undef _NL_CURRENT
+# define _NL_CURRENT(category, item) \
+  (current->values[_NL_ITEM_INDEX (item)].string)
+# define LOCALE_ARG , loc
+# define LOCALE_PARAM_PROTO , __locale_t loc
+# define HELPER_LOCALE_ARG  , current
+#else
+# define LOCALE_PARAM_PROTO
+# define LOCALE_ARG
+# ifdef _LIBC
+#  define HELPER_LOCALE_ARG , _NL_CURRENT_DATA (LC_TIME)
+# else
+#  define HELPER_LOCALE_ARG
+# endif
+#endif
+
+#ifdef COMPILE_WIDE
+# ifdef USE_IN_EXTENDED_LOCALE_MODEL
+#  define TOUPPER(Ch, L) __towupper_l (Ch, L)
+#  define TOLOWER(Ch, L) __towlower_l (Ch, L)
+# else
+#  define TOUPPER(Ch, L) towupper (Ch)
+#  define TOLOWER(Ch, L) towlower (Ch)
+# endif
+#else
+# ifdef USE_IN_EXTENDED_LOCALE_MODEL
+#  define TOUPPER(Ch, L) __toupper_l (Ch, L)
+#  define TOLOWER(Ch, L) __tolower_l (Ch, L)
+# else
+#  define TOUPPER(Ch, L) toupper (Ch)
+#  define TOLOWER(Ch, L) tolower (Ch)
+# endif
+#endif
+/* We don't use `isdigit' here since the locale dependent
+   interpretation is not what we want here.  We only need to accept
+   the arabic digits in the ASCII range.  One day there is perhaps a
+   more reliable way to accept other sets of digits.  */
+#define ISDIGIT(Ch) ((unsigned int) (Ch) - L_('0') <= 9)
+
+#if FPRINTFTIME
+static void
+fwrite_lowcase (FILE *fp, const CHAR_T *src, size_t len)
+{
+  while (len-- > 0)
+    {
+      fputc (TOLOWER ((UCHAR_T) *src, loc), fp);
+      ++src;
+    }
+}
+
+static void
+fwrite_uppcase (FILE *fp, const CHAR_T *src, size_t len)
+{
+  while (len-- > 0)
+    {
+      fputc (TOUPPER ((UCHAR_T) *src, loc), fp);
+      ++src;
+    }
+}
+#else
+static CHAR_T *
+memcpy_lowcase (CHAR_T *dest, const CHAR_T *src,
+                size_t len LOCALE_PARAM_PROTO)
+{
+  while (len-- > 0)
+    dest[len] = TOLOWER ((UCHAR_T) src[len], loc);
+  return dest;
+}
+
+static CHAR_T *
+memcpy_uppcase (CHAR_T *dest, const CHAR_T *src,
+                size_t len LOCALE_PARAM_PROTO)
+{
+  while (len-- > 0)
+    dest[len] = TOUPPER ((UCHAR_T) src[len], loc);
+  return dest;
+}
+#endif
+
+
+#if ! HAVE_TM_GMTOFF
+/* Yield the difference between *A and *B,
+   measured in seconds, ignoring leap seconds.  */
+# define tm_diff ftime_tm_diff
+static int
+tm_diff (const struct tm *a, const struct tm *b)
+{
+  /* Compute intervening leap days correctly even if year is negative.
+     Take care to avoid int overflow in leap day calculations,
+     but it's OK to assume that A and B are close to each other.  */
+  int a4 = SHR (a->tm_year, 2) + SHR (TM_YEAR_BASE, 2) - ! (a->tm_year & 3);
+  int b4 = SHR (b->tm_year, 2) + SHR (TM_YEAR_BASE, 2) - ! (b->tm_year & 3);
+  int a100 = a4 / 25 - (a4 % 25 < 0);
+  int b100 = b4 / 25 - (b4 % 25 < 0);
+  int a400 = SHR (a100, 2);
+  int b400 = SHR (b100, 2);
+  int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
+  int years = a->tm_year - b->tm_year;
+  int days = (365 * years + intervening_leap_days
+              + (a->tm_yday - b->tm_yday));
+  return (60 * (60 * (24 * days + (a->tm_hour - b->tm_hour))
+                + (a->tm_min - b->tm_min))
+          + (a->tm_sec - b->tm_sec));
+}
+#endif /* ! HAVE_TM_GMTOFF */
+
+
+
+/* The number of days from the first day of the first ISO week of this
+   year to the year day YDAY with week day WDAY.  ISO weeks start on
+   Monday; the first ISO week has the year's first Thursday.  YDAY may
+   be as small as YDAY_MINIMUM.  */
+#define ISO_WEEK_START_WDAY 1 /* Monday */
+#define ISO_WEEK1_WDAY 4 /* Thursday */
+#define YDAY_MINIMUM (-366)
+#ifdef __GNUC__
+__inline__
+#endif
+static int
+iso_week_days (int yday, int wday)
+{
+  /* Add enough to the first operand of % to make it nonnegative.  */
+  int big_enough_multiple_of_7 = (-YDAY_MINIMUM / 7 + 2) * 7;
+  return (yday
+          - (yday - wday + ISO_WEEK1_WDAY + big_enough_multiple_of_7) % 7
+          + ISO_WEEK1_WDAY - ISO_WEEK_START_WDAY);
+}
+
+
+/* When compiling this file, GNU applications can #define my_strftime
+   to a symbol (typically nstrftime) to get an extended strftime with
+   extra arguments UT and NS.  Emacs is a special case for now, but
+   this Emacs-specific code can be removed once Emacs's config.h
+   defines my_strftime.  */
+#if defined emacs && !defined my_strftime
+# define my_strftime nstrftime
+#endif
+
+#if FPRINTFTIME
+# undef my_strftime
+# define my_strftime fprintftime
+#endif
+
+#ifdef my_strftime
+# define extra_args , ut, ns
+# define extra_args_spec , int ut, int ns
+#else
+# if defined COMPILE_WIDE
+#  define my_strftime wcsftime
+#  define nl_get_alt_digit _nl_get_walt_digit
+# else
+#  define my_strftime strftime
+#  define nl_get_alt_digit _nl_get_alt_digit
+# endif
+# define extra_args
+# define extra_args_spec
+/* We don't have this information in general.  */
+# define ut 0
+# define ns 0
+#endif
+
+
+/* Just like my_strftime, below, but with one more parameter, UPCASE,
+   to indicate that the result should be converted to upper case.  */
+static size_t
+strftime_case_ (bool upcase, STREAM_OR_CHAR_T *s,
+                STRFTIME_ARG (size_t maxsize)
+                const CHAR_T *format,
+                const struct tm *tp extra_args_spec LOCALE_PARAM_PROTO)
+{
+#if defined _LIBC && defined USE_IN_EXTENDED_LOCALE_MODEL
+  struct locale_data *const current = loc->__locales[LC_TIME];
+#endif
+#if FPRINTFTIME
+  size_t maxsize = (size_t) -1;
+#endif
+
+  int hour12 = tp->tm_hour;
+#ifdef _NL_CURRENT
+  /* We cannot make the following values variables since we must delay
+     the evaluation of these values until really needed since some
+     expressions might not be valid in every situation.  The `struct tm'
+     might be generated by a strptime() call that initialized
+     only a few elements.  Dereference the pointers only if the format
+     requires this.  Then it is ok to fail if the pointers are invalid.  */
+# define a_wkday \
+  ((const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(ABDAY_1) + tp->tm_wday))
+# define f_wkday \
+  ((const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(DAY_1) + tp->tm_wday))
+# define a_month \
+  ((const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(ABMON_1) + tp->tm_mon))
+# define f_month \
+  ((const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(MON_1) + tp->tm_mon))
+# define ampm \
+  ((const CHAR_T *) _NL_CURRENT (LC_TIME, tp->tm_hour > 11                    \
+                                 ? NLW(PM_STR) : NLW(AM_STR)))
+
+# define aw_len STRLEN (a_wkday)
+# define am_len STRLEN (a_month)
+# define ap_len STRLEN (ampm)
+#endif
+  const char *zone;
+  size_t i = 0;
+  STREAM_OR_CHAR_T *p = s;
+  const CHAR_T *f;
+#if DO_MULTIBYTE && !defined COMPILE_WIDE
+  const char *format_end = NULL;
+#endif
+
+#if ! defined _LIBC && ! HAVE_RUN_TZSET_TEST
+  /* Solaris 2.5.x and 2.6 tzset sometimes modify the storage returned
+     by localtime.  On such systems, we must either use the tzset and
+     localtime wrappers to work around the bug (which sets
+     HAVE_RUN_TZSET_TEST) or make a copy of the structure.  */
+  struct tm copy = *tp;
+  tp = &copy;
+#endif
+
+  zone = NULL;
+#if HAVE_TM_ZONE
+  /* The POSIX test suite assumes that setting
+     the environment variable TZ to a new value before calling strftime()
+     will influence the result (the %Z format) even if the information in
+     TP is computed with a totally different time zone.
+     This is bogus: though POSIX allows bad behavior like this,
+     POSIX does not require it.  Do the right thing instead.  */
+  zone = (const char *) tp->tm_zone;
+#endif
+#if HAVE_TZNAME
+  if (ut)
+    {
+      if (! (zone && *zone))
+        zone = "GMT";
+    }
+  else
+    {
+      /* POSIX.1 requires that local time zone information be used as
+         though strftime called tzset.  */
+# if HAVE_TZSET
+      tzset ();
+# endif
+    }
+#endif
+
+  if (hour12 > 12)
+    hour12 -= 12;
+  else
+    if (hour12 == 0)
+      hour12 = 12;
+
+  for (f = format; *f != '\0'; ++f)
+    {
+      int pad = 0;              /* Padding for number ('-', '_', or 0).  */
+      int modifier;             /* Field modifier ('E', 'O', or 0).  */
+      int digits = 0;           /* Max digits for numeric format.  */
+      int number_value;         /* Numeric value to be printed.  */
+      unsigned int u_number_value; /* (unsigned int) number_value.  */
+      bool negative_number;     /* The number is negative.  */
+      bool always_output_a_sign; /* +/- should always be output.  */
+      int tz_colon_mask;        /* Bitmask of where ':' should appear.  */
+      const CHAR_T *subfmt;
+      CHAR_T sign_char;
+      CHAR_T *bufp;
+      CHAR_T buf[1
+                 + 2 /* for the two colons in a %::z or %:::z time zone */
+                 + (sizeof (int) < sizeof (time_t)
+                    ? INT_STRLEN_BOUND (time_t)
+                    : INT_STRLEN_BOUND (int))];
+      int width = -1;
+      bool to_lowcase = false;
+      bool to_uppcase = upcase;
+      size_t colons;
+      bool change_case = false;
+      int format_char;
+
+#if DO_MULTIBYTE && !defined COMPILE_WIDE
+      switch (*f)
+        {
+        case L_('%'):
+          break;
+
+        case L_('\b'): case L_('\t'): case L_('\n'):
+        case L_('\v'): case L_('\f'): case L_('\r'):
+        case L_(' '): case L_('!'): case L_('"'): case L_('#'): case L_('&'):
+        case L_('\''): case L_('('): case L_(')'): case L_('*'): case L_('+'):
+        case L_(','): case L_('-'): case L_('.'): case L_('/'): case L_('0'):
+        case L_('1'): case L_('2'): case L_('3'): case L_('4'): case L_('5'):
+        case L_('6'): case L_('7'): case L_('8'): case L_('9'): case L_(':'):
+        case L_(';'): case L_('<'): case L_('='): case L_('>'): case L_('?'):
+        case L_('A'): case L_('B'): case L_('C'): case L_('D'): case L_('E'):
+        case L_('F'): case L_('G'): case L_('H'): case L_('I'): case L_('J'):
+        case L_('K'): case L_('L'): case L_('M'): case L_('N'): case L_('O'):
+        case L_('P'): case L_('Q'): case L_('R'): case L_('S'): case L_('T'):
+        case L_('U'): case L_('V'): case L_('W'): case L_('X'): case L_('Y'):
+        case L_('Z'): case L_('['): case L_('\\'): case L_(']'): case L_('^'):
+        case L_('_'): case L_('a'): case L_('b'): case L_('c'): case L_('d'):
+        case L_('e'): case L_('f'): case L_('g'): case L_('h'): case L_('i'):
+        case L_('j'): case L_('k'): case L_('l'): case L_('m'): case L_('n'):
+        case L_('o'): case L_('p'): case L_('q'): case L_('r'): case L_('s'):
+        case L_('t'): case L_('u'): case L_('v'): case L_('w'): case L_('x'):
+        case L_('y'): case L_('z'): case L_('{'): case L_('|'): case L_('}'):
+        case L_('~'):
+          /* The C Standard requires these 98 characters (plus '%') to
+             be in the basic execution character set.  None of these
+             characters can start a multibyte sequence, so they need
+             not be analyzed further.  */
+          add1 (*f);
+          continue;
+
+        default:
+          /* Copy this multibyte sequence until we reach its end, find
+             an error, or come back to the initial shift state.  */
+          {
+            mbstate_t mbstate = mbstate_zero;
+            size_t len = 0;
+            size_t fsize;
+
+            if (! format_end)
+              format_end = f + strlen (f) + 1;
+            fsize = format_end - f;
+
+            do
+              {
+                size_t bytes = mbrlen (f + len, fsize - len, &mbstate);
+
+                if (bytes == 0)
+                  break;
+
+                if (bytes == (size_t) -2)
+                  {
+                    len += strlen (f + len);
+                    break;
+                  }
+
+                if (bytes == (size_t) -1)
+                  {
+                    len++;
+                    break;
+                  }
+
+                len += bytes;
+              }
+            while (! mbsinit (&mbstate));
+
+            cpy (len, f);
+            f += len - 1;
+            continue;
+          }
+        }
+
+#else /* ! DO_MULTIBYTE */
+
+      /* Either multibyte encodings are not supported, they are
+         safe for formats, so any non-'%' byte can be copied through,
+         or this is the wide character version.  */
+      if (*f != L_('%'))
+        {
+          add1 (*f);
+          continue;
+        }
+
+#endif /* ! DO_MULTIBYTE */
+
+      /* Check for flags that can modify a format.  */
+      while (1)
+        {
+          switch (*++f)
+            {
+              /* This influences the number formats.  */
+            case L_('_'):
+            case L_('-'):
+            case L_('0'):
+              pad = *f;
+              continue;
+
+              /* This changes textual output.  */
+            case L_('^'):
+              to_uppcase = true;
+              continue;
+            case L_('#'):
+              change_case = true;
+              continue;
+
+            default:
+              break;
+            }
+          break;
+        }
+
+      /* As a GNU extension we allow to specify the field width.  */
+      if (ISDIGIT (*f))
+        {
+          width = 0;
+          do
+            {
+              if (width > INT_MAX / 10
+                  || (width == INT_MAX / 10 && *f - L_('0') > INT_MAX % 10))
+                /* Avoid overflow.  */
+                width = INT_MAX;
+              else
+                {
+                  width *= 10;
+                  width += *f - L_('0');
+                }
+              ++f;
+            }
+          while (ISDIGIT (*f));
+        }
+
+      /* Check for modifiers.  */
+      switch (*f)
+        {
+        case L_('E'):
+        case L_('O'):
+          modifier = *f++;
+          break;
+
+        default:
+          modifier = 0;
+          break;
+        }
+
+      /* Now do the specified format.  */
+      format_char = *f;
+      switch (format_char)
+        {
+#define DO_NUMBER(d, v) \
+          digits = d;                                                         \
+          number_value = v; goto do_number
+#define DO_SIGNED_NUMBER(d, negative, v) \
+          digits = d;                                                         \
+          negative_number = negative;                                         \
+          u_number_value = v; goto do_signed_number
+
+          /* The mask is not what you might think.
+             When the ordinal i'th bit is set, insert a colon
+             before the i'th digit of the time zone representation.  */
+#define DO_TZ_OFFSET(d, negative, mask, v) \
+          digits = d;                                                         \
+          negative_number = negative;                                         \
+          tz_colon_mask = mask;                                               \
+          u_number_value = v; goto do_tz_offset
+#define DO_NUMBER_SPACEPAD(d, v) \
+          digits = d;                                                         \
+          number_value = v; goto do_number_spacepad
+
+        case L_('%'):
+          if (modifier != 0)
+            goto bad_format;
+          add1 (*f);
+          break;
+
+        case L_('a'):
+          if (modifier != 0)
+            goto bad_format;
+          if (change_case)
+            {
+              to_uppcase = true;
+              to_lowcase = false;
+            }
+#ifdef _NL_CURRENT
+          cpy (aw_len, a_wkday);
+          break;
+#else
+          goto underlying_strftime;
+#endif
+
+        case 'A':
+          if (modifier != 0)
+            goto bad_format;
+          if (change_case)
+            {
+              to_uppcase = true;
+              to_lowcase = false;
+            }
+#ifdef _NL_CURRENT
+          cpy (STRLEN (f_wkday), f_wkday);
+          break;
+#else
+          goto underlying_strftime;
+#endif
+
+        case L_('b'):
+        case L_('h'):
+          if (change_case)
+            {
+              to_uppcase = true;
+              to_lowcase = false;
+            }
+          if (modifier != 0)
+            goto bad_format;
+#ifdef _NL_CURRENT
+          cpy (am_len, a_month);
+          break;
+#else
+          goto underlying_strftime;
+#endif
+
+        case L_('B'):
+          if (modifier != 0)
+            goto bad_format;
+          if (change_case)
+            {
+              to_uppcase = true;
+              to_lowcase = false;
+            }
+#ifdef _NL_CURRENT
+          cpy (STRLEN (f_month), f_month);
+          break;
+#else
+          goto underlying_strftime;
+#endif
+
+        case L_('c'):
+          if (modifier == L_('O'))
+            goto bad_format;
+#ifdef _NL_CURRENT
+          if (! (modifier == 'E'
+                 && (*(subfmt =
+                       (const CHAR_T *) _NL_CURRENT (LC_TIME,
+                                                     NLW(ERA_D_T_FMT)))
+                     != '\0')))
+            subfmt = (const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(D_T_FMT));
+#else
+          goto underlying_strftime;
+#endif
+
+        subformat:
+          {
+            size_t len = strftime_case_ (to_uppcase,
+                                         NULL, STRFTIME_ARG ((size_t) -1)
+                                         subfmt,
+                                         tp extra_args LOCALE_ARG);
+            add (len, strftime_case_ (to_uppcase, p,
+                                      STRFTIME_ARG (maxsize - i)
+                                      subfmt,
+                                      tp extra_args LOCALE_ARG));
+          }
+          break;
+
+#if !(defined _NL_CURRENT && HAVE_STRUCT_ERA_ENTRY)
+        underlying_strftime:
+          {
+            /* The relevant information is available only via the
+               underlying strftime implementation, so use that.  */
+            char ufmt[5];
+            char *u = ufmt;
+            char ubuf[1024]; /* enough for any single format in practice */
+            size_t len;
+            /* Make sure we're calling the actual underlying strftime.
+               In some cases, config.h contains something like
+               "#define strftime rpl_strftime".  */
+# ifdef strftime
+#  undef strftime
+            size_t strftime ();
+# endif
+
+            /* The space helps distinguish strftime failure from empty
+               output.  */
+            *u++ = ' ';
+            *u++ = '%';
+            if (modifier != 0)
+              *u++ = modifier;
+            *u++ = format_char;
+            *u = '\0';
+            len = strftime (ubuf, sizeof ubuf, ufmt, tp);
+            if (len != 0)
+              cpy (len - 1, ubuf + 1);
+          }
+          break;
+#endif
+
+        case L_('C'):
+          if (modifier == L_('O'))
+            goto bad_format;
+          if (modifier == L_('E'))
+            {
+#if HAVE_STRUCT_ERA_ENTRY
+              struct era_entry *era = _nl_get_era_entry (tp HELPER_LOCALE_ARG);
+              if (era)
+                {
+# ifdef COMPILE_WIDE
+                  size_t len = __wcslen (era->era_wname);
+                  cpy (len, era->era_wname);
+# else
+                  size_t len = strlen (era->era_name);
+                  cpy (len, era->era_name);
+# endif
+                  break;
+                }
+#else
+              goto underlying_strftime;
+#endif
+            }
+
+          {
+            int century = tp->tm_year / 100 + TM_YEAR_BASE / 100;
+            century -= tp->tm_year % 100 < 0 && 0 < century;
+            DO_SIGNED_NUMBER (2, tp->tm_year < - TM_YEAR_BASE, century);
+          }
+
+        case L_('x'):
+          if (modifier == L_('O'))
+            goto bad_format;
+#ifdef _NL_CURRENT
+          if (! (modifier == L_('E')
+                 && (*(subfmt =
+                       (const CHAR_T *)_NL_CURRENT (LC_TIME, NLW(ERA_D_FMT)))
+                     != L_('\0'))))
+            subfmt = (const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(D_FMT));
+          goto subformat;
+#else
+          goto underlying_strftime;
+#endif
+        case L_('D'):
+          if (modifier != 0)
+            goto bad_format;
+          subfmt = L_("%m/%d/%y");
+          goto subformat;
+
+        case L_('d'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER (2, tp->tm_mday);
+
+        case L_('e'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER_SPACEPAD (2, tp->tm_mday);
+
+          /* All numeric formats set DIGITS and NUMBER_VALUE (or U_NUMBER_VALUE)
+             and then jump to one of these labels.  */
+
+        do_tz_offset:
+          always_output_a_sign = true;
+          goto do_number_body;
+
+        do_number_spacepad:
+          /* Force `_' flag unless overridden by `0' or `-' flag.  */
+          if (pad != L_('0') && pad != L_('-'))
+            pad = L_('_');
+
+        do_number:
+          /* Format NUMBER_VALUE according to the MODIFIER flag.  */
+          negative_number = number_value < 0;
+          u_number_value = number_value;
+
+        do_signed_number:
+          always_output_a_sign = false;
+          tz_colon_mask = 0;
+
+        do_number_body:
+          /* Format U_NUMBER_VALUE according to the MODIFIER flag.
+             NEGATIVE_NUMBER is nonzero if the original number was
+             negative; in this case it was converted directly to
+             unsigned int (i.e., modulo (UINT_MAX + 1)) without
+             negating it.  */
+          if (modifier == L_('O') && !negative_number)
+            {
+#ifdef _NL_CURRENT
+              /* Get the locale specific alternate representation of
+                 the number.  If none exist NULL is returned.  */
+              const CHAR_T *cp = nl_get_alt_digit (u_number_value
+                                                   HELPER_LOCALE_ARG);
+
+              if (cp != NULL)
+                {
+                  size_t digitlen = STRLEN (cp);
+                  if (digitlen != 0)
+                    {
+                      cpy (digitlen, cp);
+                      break;
+                    }
+                }
+#else
+              goto underlying_strftime;
+#endif
+            }
+
+          bufp = buf + sizeof (buf) / sizeof (buf[0]);
+
+          if (negative_number)
+            u_number_value = - u_number_value;
+
+          do
+            {
+              if (tz_colon_mask & 1)
+                *--bufp = ':';
+              tz_colon_mask >>= 1;
+              *--bufp = u_number_value % 10 + L_('0');
+              u_number_value /= 10;
+            }
+          while (u_number_value != 0 || tz_colon_mask != 0);
+
+        do_number_sign_and_padding:
+          if (digits < width)
+            digits = width;
+
+          sign_char = (negative_number ? L_('-')
+                       : always_output_a_sign ? L_('+')
+                       : 0);
+
+          if (pad == L_('-'))
+            {
+              if (sign_char)
+                add1 (sign_char);
+            }
+          else
+            {
+              int padding = digits - (buf + (sizeof (buf) / sizeof (buf[0]))
+                                      - bufp) - !!sign_char;
+
+              if (padding > 0)
+                {
+                  if (pad == L_('_'))
+                    {
+                      if ((size_t) padding >= maxsize - i)
+                        return 0;
+
+                      if (p)
+                        memset_space (p, padding);
+                      i += padding;
+                      width = width > padding ? width - padding : 0;
+                      if (sign_char)
+                        add1 (sign_char);
+                    }
+                  else
+                    {
+                      if ((size_t) digits >= maxsize - i)
+                        return 0;
+
+                      if (sign_char)
+                        add1 (sign_char);
+
+                      if (p)
+                        memset_zero (p, padding);
+                      i += padding;
+                      width = 0;
+                    }
+                }
+              else
+                {
+                  if (sign_char)
+                    add1 (sign_char);
+                }
+            }
+
+          cpy (buf + sizeof (buf) / sizeof (buf[0]) - bufp, bufp);
+          break;
+
+        case L_('F'):
+          if (modifier != 0)
+            goto bad_format;
+          subfmt = L_("%Y-%m-%d");
+          goto subformat;
+
+        case L_('H'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER (2, tp->tm_hour);
+
+        case L_('I'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER (2, hour12);
+
+        case L_('k'):           /* GNU extension.  */
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER_SPACEPAD (2, tp->tm_hour);
+
+        case L_('l'):           /* GNU extension.  */
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER_SPACEPAD (2, hour12);
+
+        case L_('j'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_SIGNED_NUMBER (3, tp->tm_yday < -1, tp->tm_yday + 1U);
+
+        case L_('M'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER (2, tp->tm_min);
+
+        case L_('m'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_SIGNED_NUMBER (2, tp->tm_mon < -1, tp->tm_mon + 1U);
+
+#ifndef _LIBC
+        case L_('N'):           /* GNU extension.  */
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          number_value = ns;
+          if (width == -1)
+            width = 9;
+          else
+            {
+              /* Take an explicit width less than 9 as a precision.  */
+              int j;
+              for (j = width; j < 9; j++)
+                number_value /= 10;
+            }
+
+          DO_NUMBER (width, number_value);
+#endif
+
+        case L_('n'):
+          add1 (L_('\n'));
+          break;
+
+        case L_('P'):
+          to_lowcase = true;
+#ifndef _NL_CURRENT
+          format_char = L_('p');
+#endif
+          /* FALLTHROUGH */
+
+        case L_('p'):
+          if (change_case)
+            {
+              to_uppcase = false;
+              to_lowcase = true;
+            }
+#ifdef _NL_CURRENT
+          cpy (ap_len, ampm);
+          break;
+#else
+          goto underlying_strftime;
+#endif
+
+        case L_('R'):
+          subfmt = L_("%H:%M");
+          goto subformat;
+
+        case L_('r'):
+#ifdef _NL_CURRENT
+          if (*(subfmt = (const CHAR_T *) _NL_CURRENT (LC_TIME,
+                                                       NLW(T_FMT_AMPM)))
+              == L_('\0'))
+            subfmt = L_("%I:%M:%S %p");
+          goto subformat;
+#else
+          goto underlying_strftime;
+#endif
+
+        case L_('S'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER (2, tp->tm_sec);
+
+        case L_('s'):           /* GNU extension.  */
+          {
+            struct tm ltm;
+            time_t t;
+
+            ltm = *tp;
+            t = mktime (&ltm);
+
+            /* Generate string value for T using time_t arithmetic;
+               this works even if sizeof (long) < sizeof (time_t).  */
+
+            bufp = buf + sizeof (buf) / sizeof (buf[0]);
+            negative_number = t < 0;
+
+            do
+              {
+                int d = t % 10;
+                t /= 10;
+                *--bufp = (negative_number ? -d : d) + L_('0');
+              }
+            while (t != 0);
+
+            digits = 1;
+            always_output_a_sign = false;
+            goto do_number_sign_and_padding;
+          }
+
+        case L_('X'):
+          if (modifier == L_('O'))
+            goto bad_format;
+#ifdef _NL_CURRENT
+          if (! (modifier == L_('E')
+                 && (*(subfmt =
+                       (const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(ERA_T_FMT)))
+                     != L_('\0'))))
+            subfmt = (const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(T_FMT));
+          goto subformat;
+#else
+          goto underlying_strftime;
+#endif
+        case L_('T'):
+          subfmt = L_("%H:%M:%S");
+          goto subformat;
+
+        case L_('t'):
+          add1 (L_('\t'));
+          break;
+
+        case L_('u'):
+          DO_NUMBER (1, (tp->tm_wday - 1 + 7) % 7 + 1);
+
+        case L_('U'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER (2, (tp->tm_yday - tp->tm_wday + 7) / 7);
+
+        case L_('V'):
+        case L_('g'):
+        case L_('G'):
+          if (modifier == L_('E'))
+            goto bad_format;
+          {
+            /* YEAR is a leap year if and only if (tp->tm_year + TM_YEAR_BASE)
+               is a leap year, except that YEAR and YEAR - 1 both work
+               correctly even when (tp->tm_year + TM_YEAR_BASE) would
+               overflow.  */
+            int year = (tp->tm_year
+                        + (tp->tm_year < 0
+                           ? TM_YEAR_BASE % 400
+                           : TM_YEAR_BASE % 400 - 400));
+            int year_adjust = 0;
+            int days = iso_week_days (tp->tm_yday, tp->tm_wday);
+
+            if (days < 0)
+              {
+                /* This ISO week belongs to the previous year.  */
+                year_adjust = -1;
+                days = iso_week_days (tp->tm_yday + (365 + __isleap (year - 1)),
+                                      tp->tm_wday);
+              }
+            else
+              {
+                int d = iso_week_days (tp->tm_yday - (365 + __isleap (year)),
+                                       tp->tm_wday);
+                if (0 <= d)
+                  {
+                    /* This ISO week belongs to the next year.  */
+                    year_adjust = 1;
+                    days = d;
+                  }
+              }
+
+            switch (*f)
+              {
+              case L_('g'):
+                {
+                  int yy = (tp->tm_year % 100 + year_adjust) % 100;
+                  DO_NUMBER (2, (0 <= yy
+                                 ? yy
+                                 : tp->tm_year < -TM_YEAR_BASE - year_adjust
+                                 ? -yy
+                                 : yy + 100));
+                }
+
+              case L_('G'):
+                DO_SIGNED_NUMBER (4, tp->tm_year < -TM_YEAR_BASE - year_adjust,
+                                  (tp->tm_year + (unsigned int) TM_YEAR_BASE
+                                   + year_adjust));
+
+              default:
+                DO_NUMBER (2, days / 7 + 1);
+              }
+          }
+
+        case L_('W'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER (2, (tp->tm_yday - (tp->tm_wday - 1 + 7) % 7 + 7) / 7);
+
+        case L_('w'):
+          if (modifier == L_('E'))
+            goto bad_format;
+
+          DO_NUMBER (1, tp->tm_wday);
+
+        case L_('Y'):
+          if (modifier == 'E')
+            {
+#if HAVE_STRUCT_ERA_ENTRY
+              struct era_entry *era = _nl_get_era_entry (tp HELPER_LOCALE_ARG);
+              if (era)
+                {
+# ifdef COMPILE_WIDE
+                  subfmt = era->era_wformat;
+# else
+                  subfmt = era->era_format;
+# endif
+                  goto subformat;
+                }
+#else
+              goto underlying_strftime;
+#endif
+            }
+          if (modifier == L_('O'))
+            goto bad_format;
+          else
+            DO_SIGNED_NUMBER (4, tp->tm_year < -TM_YEAR_BASE,
+                              tp->tm_year + (unsigned int) TM_YEAR_BASE);
+
+        case L_('y'):
+          if (modifier == L_('E'))
+            {
+#if HAVE_STRUCT_ERA_ENTRY
+              struct era_entry *era = _nl_get_era_entry (tp HELPER_LOCALE_ARG);
+              if (era)
+                {
+                  int delta = tp->tm_year - era->start_date[0];
+                  DO_NUMBER (1, (era->offset
+                                 + delta * era->absolute_direction));
+                }
+#else
+              goto underlying_strftime;
+#endif
+            }
+
+          {
+            int yy = tp->tm_year % 100;
+            if (yy < 0)
+              yy = tp->tm_year < - TM_YEAR_BASE ? -yy : yy + 100;
+            DO_NUMBER (2, yy);
+          }
+
+        case L_('Z'):
+          if (change_case)
+            {
+              to_uppcase = false;
+              to_lowcase = true;
+            }
+
+#if HAVE_TZNAME
+          /* The tzset() call might have changed the value.  */
+          if (!(zone && *zone) && tp->tm_isdst >= 0)
+            zone = tzname[tp->tm_isdst != 0];
+#endif
+          if (! zone)
+            zone = "";
+
+#ifdef COMPILE_WIDE
+          {
+            /* The zone string is always given in multibyte form.  We have
+               to transform it first.  */
+            wchar_t *wczone;
+            size_t len;
+            widen (zone, wczone, len);
+            cpy (len, wczone);
+          }
+#else
+          cpy (strlen (zone), zone);
+#endif
+          break;
+
+        case L_(':'):
+          /* :, ::, and ::: are valid only just before 'z'.
+             :::: etc. are rejected later.  */
+          for (colons = 1; f[colons] == L_(':'); colons++)
+            continue;
+          if (f[colons] != L_('z'))
+            goto bad_format;
+          f += colons;
+          goto do_z_conversion;
+
+        case L_('z'):
+          colons = 0;
+
+        do_z_conversion:
+          if (tp->tm_isdst < 0)
+            break;
+
+          {
+            int diff;
+            int hour_diff;
+            int min_diff;
+            int sec_diff;
+#if HAVE_TM_GMTOFF
+            diff = tp->tm_gmtoff;
+#else
+            if (ut)
+              diff = 0;
+            else
+              {
+                struct tm gtm;
+                struct tm ltm;
+                time_t lt;
+
+                ltm = *tp;
+                lt = mktime (&ltm);
+
+                if (lt == (time_t) -1)
+                  {
+                    /* mktime returns -1 for errors, but -1 is also a
+                       valid time_t value.  Check whether an error really
+                       occurred.  */
+                    struct tm tm;
+
+                    if (! __localtime_r (&lt, &tm)
+                        || ((ltm.tm_sec ^ tm.tm_sec)
+                            | (ltm.tm_min ^ tm.tm_min)
+                            | (ltm.tm_hour ^ tm.tm_hour)
+                            | (ltm.tm_mday ^ tm.tm_mday)
+                            | (ltm.tm_mon ^ tm.tm_mon)
+                            | (ltm.tm_year ^ tm.tm_year)))
+                      break;
+                  }
+
+                if (! __gmtime_r (&lt, &gtm))
+                  break;
+
+                diff = tm_diff (&ltm, &gtm);
+              }
+#endif
+
+            hour_diff = diff / 60 / 60;
+            min_diff = diff / 60 % 60;
+            sec_diff = diff % 60;
+
+            switch (colons)
+              {
+              case 0: /* +hhmm */
+                DO_TZ_OFFSET (5, diff < 0, 0, hour_diff * 100 + min_diff);
+
+              case 1: tz_hh_mm: /* +hh:mm */
+                DO_TZ_OFFSET (6, diff < 0, 04, hour_diff * 100 + min_diff);
+
+              case 2: tz_hh_mm_ss: /* +hh:mm:ss */
+                DO_TZ_OFFSET (9, diff < 0, 024,
+                              hour_diff * 10000 + min_diff * 100 + sec_diff);
+
+              case 3: /* +hh if possible, else +hh:mm, else +hh:mm:ss */
+                if (sec_diff != 0)
+                  goto tz_hh_mm_ss;
+                if (min_diff != 0)
+                  goto tz_hh_mm;
+                DO_TZ_OFFSET (3, diff < 0, 0, hour_diff);
+
+              default:
+                goto bad_format;
+              }
+          }
+
+        case L_('\0'):          /* GNU extension: % at end of format.  */
+            --f;
+            /* Fall through.  */
+        default:
+          /* Unknown format; output the format, including the '%',
+             since this is most likely the right thing to do if a
+             multibyte string has been misparsed.  */
+        bad_format:
+          {
+            int flen;
+            for (flen = 1; f[1 - flen] != L_('%'); flen++)
+              continue;
+            cpy (flen, &f[1 - flen]);
+          }
+          break;
+        }
+    }
+
+#if ! FPRINTFTIME
+  if (p && maxsize != 0)
+    *p = L_('\0');
+#endif
+
+  return i;
+}
+
+/* Write information from TP into S according to the format
+   string FORMAT, writing no more that MAXSIZE characters
+   (including the terminating '\0') and returning number of
+   characters written.  If S is NULL, nothing will be written
+   anywhere, so to determine how many characters would be
+   written, use NULL for S and (size_t) -1 for MAXSIZE.  */
+size_t
+my_strftime (STREAM_OR_CHAR_T *s, STRFTIME_ARG (size_t maxsize)
+             const CHAR_T *format,
+             const struct tm *tp extra_args_spec LOCALE_PARAM_PROTO)
+{
+  return strftime_case_ (false, s, STRFTIME_ARG (maxsize)
+                         format, tp extra_args LOCALE_ARG);
+}
+
+#if defined _LIBC && ! FPRINTFTIME
+libc_hidden_def (my_strftime)
+#endif
+
+
+#if defined emacs && ! FPRINTFTIME
+/* For Emacs we have a separate interface which corresponds to the normal
+   strftime function plus the ut argument, but without the ns argument.  */
+size_t
+emacs_strftimeu (char *s, size_t maxsize, const char *format,
+                 const struct tm *tp, int ut)
+{
+  return my_strftime (s, maxsize, format, tp, ut, 0);
+}
+#endif