Add gnulib files to support higher-resolution time stamps.

Fixes: debbugs:9000

lib/dtotimespec.c

@@ -0,0 +1,69 @@
+/* Convert double to timespec.
+
+   Copyright (C) 2011-2012 Free Software Foundation, Inc.
+
+   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/>.  */
+
+/* written by Paul Eggert */
+
+/* Convert the double value SEC to a struct timespec.  Round toward
+   positive infinity.  On overflow, return an extremal value.  */
+
+#include <config.h>
+
+#include "timespec.h"
+
+#include "intprops.h"
+
+struct timespec
+dtotimespec (double sec)
+{
+  enum { BILLION = 1000 * 1000 * 1000 };
+  double min_representable = TYPE_MINIMUM (time_t);
+  double max_representable =
+    ((TYPE_MAXIMUM (time_t) * (double) BILLION + (BILLION - 1))
+     / BILLION);
+  struct timespec r;
+
+  if (! (min_representable < sec))
+    {
+      r.tv_sec = TYPE_MINIMUM (time_t);
+      r.tv_nsec = 0;
+    }
+  else if (! (sec < max_representable))
+    {
+      r.tv_sec = TYPE_MAXIMUM (time_t);
+      r.tv_nsec = BILLION - 1;
+    }
+  else
+    {
+      time_t s = sec;
+      double frac = BILLION * (sec - s);
+      long ns = frac;
+      ns += ns < frac;
+      s += ns / BILLION;
+      ns %= BILLION;
+
+      if (ns < 0)
+        {
+          s--;
+          ns += BILLION;
+        }
+
+      r.tv_sec = s;
+      r.tv_nsec = ns;
+    }
+
+  return r;
+}

lib/gettime.c

@@ -0,0 +1,48 @@
+/* gettime -- get the system clock
+
+   Copyright (C) 2002, 2004-2007, 2009-2012 Free Software Foundation, Inc.
+
+   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/>.  */
+
+/* Written by Paul Eggert.  */
+
+#include <config.h>
+
+#include "timespec.h"
+
+#include <sys/time.h>
+
+/* Get the system time into *TS.  */
+
+void
+gettime (struct timespec *ts)
+{
+#if HAVE_NANOTIME
+  nanotime (ts);
+#else
+
+# if defined CLOCK_REALTIME && HAVE_CLOCK_GETTIME
+  if (clock_gettime (CLOCK_REALTIME, ts) == 0)
+    return;
+# endif
+
+  {
+    struct timeval tv;
+    gettimeofday (&tv, NULL);
+    ts->tv_sec = tv.tv_sec;
+    ts->tv_nsec = tv.tv_usec * 1000;
+  }
+
+#endif
+}

lib/gettimeofday.c

@@ -0,0 +1,154 @@
+/* Provide gettimeofday for systems that don't have it or for which it's broken.
+
+   Copyright (C) 2001-2003, 2005-2007, 2009-2012 Free Software Foundation, Inc.
+
+   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, 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/>.  */
+
+/* written by Jim Meyering */
+
+#include <config.h>
+
+/* Specification.  */
+#include <sys/time.h>
+
+#include <time.h>
+
+#if HAVE_SYS_TIMEB_H
+# include <sys/timeb.h>
+#endif
+
+#if GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME
+
+/* Work around the bug in some systems whereby gettimeofday clobbers
+   the static buffer that localtime uses for its return value.  The
+   gettimeofday function from Mac OS X 10.0.4 (i.e., Darwin 1.3.7) has
+   this problem.  The tzset replacement is necessary for at least
+   Solaris 2.5, 2.5.1, and 2.6.  */
+
+static struct tm tm_zero_buffer;
+static struct tm *localtime_buffer_addr = &tm_zero_buffer;
+
+# undef localtime
+extern struct tm *localtime (time_t const *);
+
+# undef gmtime
+extern struct tm *gmtime (time_t const *);
+
+/* This is a wrapper for localtime.  It is used only on systems for which
+   gettimeofday clobbers the static buffer used for localtime's result.
+
+   On the first call, record the address of the static buffer that
+   localtime uses for its result.  */
+
+struct tm *
+rpl_localtime (time_t const *timep)
+{
+  struct tm *tm = localtime (timep);
+
+  if (localtime_buffer_addr == &tm_zero_buffer)
+    localtime_buffer_addr = tm;
+
+  return tm;
+}
+
+/* Same as above, since gmtime and localtime use the same buffer.  */
+struct tm *
+rpl_gmtime (time_t const *timep)
+{
+  struct tm *tm = gmtime (timep);
+
+  if (localtime_buffer_addr == &tm_zero_buffer)
+    localtime_buffer_addr = tm;
+
+  return tm;
+}
+
+#endif /* GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME */
+
+#if TZSET_CLOBBERS_LOCALTIME
+
+# undef tzset
+extern void tzset (void);
+
+/* This is a wrapper for tzset, for systems on which tzset may clobber
+   the static buffer used for localtime's result.  */
+void
+rpl_tzset (void)
+{
+  /* Save and restore the contents of the buffer used for localtime's
+     result around the call to tzset.  */
+  struct tm save = *localtime_buffer_addr;
+  tzset ();
+  *localtime_buffer_addr = save;
+}
+#endif
+
+/* This is a wrapper for gettimeofday.  It is used only on systems
+   that lack this function, or whose implementation of this function
+   causes problems.  */
+
+int
+gettimeofday (struct timeval *restrict tv, void *restrict tz)
+{
+#undef gettimeofday
+#if HAVE_GETTIMEOFDAY
+# if GETTIMEOFDAY_CLOBBERS_LOCALTIME
+  /* Save and restore the contents of the buffer used for localtime's
+     result around the call to gettimeofday.  */
+  struct tm save = *localtime_buffer_addr;
+# endif
+
+# if defined timeval /* 'struct timeval' overridden by gnulib?  */
+#  undef timeval
+  struct timeval otv;
+  int result = gettimeofday (&otv, (struct timezone *) tz);
+  if (result == 0)
+    {
+      tv->tv_sec = otv.tv_sec;
+      tv->tv_usec = otv.tv_usec;
+    }
+# else
+  int result = gettimeofday (tv, (struct timezone *) tz);
+# endif
+
+# if GETTIMEOFDAY_CLOBBERS_LOCALTIME
+  *localtime_buffer_addr = save;
+# endif
+
+  return result;
+
+#else
+
+# if HAVE__FTIME
+
+  struct _timeb timebuf;
+  _ftime (&timebuf);
+  tv->tv_sec = timebuf.time;
+  tv->tv_usec = timebuf.millitm * 1000;
+
+# else
+
+#  if !defined OK_TO_USE_1S_CLOCK
+#   error "Only 1-second nominal clock resolution found.  Is that intended?" \
+          "If so, compile with the -DOK_TO_USE_1S_CLOCK option."
+#  endif
+  tv->tv_sec = time (NULL);
+  tv->tv_usec = 0;
+
+# endif
+
+  return 0;
+
+#endif
+}

lib/pselect.c

@@ -0,0 +1,76 @@
+/* pselect - synchronous I/O multiplexing
+
+   Copyright 2011-2012 Free Software Foundation, Inc.
+
+   This file is part of gnulib.
+
+   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, 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/>.  */
+
+/* written by Paul Eggert */
+
+#include <config.h>
+
+#include <sys/select.h>
+
+#include <errno.h>
+#include <signal.h>
+
+/* Examine the size-NFDS file descriptor sets in RFDS, WFDS, and XFDS
+   to see whether some of their descriptors are ready for reading,
+   ready for writing, or have exceptions pending.  Wait for at most
+   TIMEOUT seconds, and use signal mask SIGMASK while waiting.  A null
+   pointer parameter stands for no descriptors, an infinite timeout,
+   or an unaffected signal mask.  */
+
+int
+pselect (int nfds, fd_set *restrict rfds,
+         fd_set *restrict wfds, fd_set *restrict xfds,
+         struct timespec const *restrict timeout,
+         sigset_t const *restrict sigmask)
+{
+  int select_result;
+  sigset_t origmask;
+  struct timeval tv, *tvp;
+
+  if (timeout)
+    {
+      if (! (0 <= timeout->tv_nsec && timeout->tv_nsec < 1000000000))
+        {
+          errno = EINVAL;
+          return -1;
+        }
+
+      tv.tv_sec = timeout->tv_sec;
+      tv.tv_usec = (timeout->tv_nsec + 999) / 1000;
+      tvp = &tv;
+    }
+  else
+    tvp = NULL;
+
+  /* Signal mask munging should be atomic, but this is the best we can
+     do in this emulation.  */
+  if (sigmask)
+    pthread_sigmask (SIG_SETMASK, sigmask, &origmask);
+
+  select_result = select (nfds, rfds, wfds, xfds, tvp);
+
+  if (sigmask)
+    {
+      int select_errno = errno;
+      pthread_sigmask (SIG_SETMASK, &origmask, NULL);
+      errno = select_errno;
+    }
+
+  return select_result;
+}

lib/stat-time.h

@@ -0,0 +1,189 @@
+/* stat-related time functions.
+
+   Copyright (C) 2005, 2007, 2009-2012 Free Software Foundation, Inc.
+
+   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/>.  */
+
+/* Written by Paul Eggert.  */
+
+#ifndef STAT_TIME_H
+#define STAT_TIME_H 1
+
+#include <sys/stat.h>
+#include <time.h>
+
+/* STAT_TIMESPEC (ST, ST_XTIM) is the ST_XTIM member for *ST of type
+   struct timespec, if available.  If not, then STAT_TIMESPEC_NS (ST,
+   ST_XTIM) is the nanosecond component of the ST_XTIM member for *ST,
+   if available.  ST_XTIM can be st_atim, st_ctim, st_mtim, or st_birthtim
+   for access, status change, data modification, or birth (creation)
+   time respectively.
+
+   These macros are private to stat-time.h.  */
+#if defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC
+# ifdef TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC
+#  define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim)
+# else
+#  define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec)
+# endif
+#elif defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC
+# define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim##espec)
+#elif defined HAVE_STRUCT_STAT_ST_ATIMENSEC
+# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim##ensec)
+#elif defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC
+# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.st__tim.tv_nsec)
+#endif
+
+/* Return the nanosecond component of *ST's access time.  */
+static inline long int
+get_stat_atime_ns (struct stat const *st)
+{
+# if defined STAT_TIMESPEC
+  return STAT_TIMESPEC (st, st_atim).tv_nsec;
+# elif defined STAT_TIMESPEC_NS
+  return STAT_TIMESPEC_NS (st, st_atim);
+# else
+  return 0;
+# endif
+}
+
+/* Return the nanosecond component of *ST's status change time.  */
+static inline long int
+get_stat_ctime_ns (struct stat const *st)
+{
+# if defined STAT_TIMESPEC
+  return STAT_TIMESPEC (st, st_ctim).tv_nsec;
+# elif defined STAT_TIMESPEC_NS
+  return STAT_TIMESPEC_NS (st, st_ctim);
+# else
+  return 0;
+# endif
+}
+
+/* Return the nanosecond component of *ST's data modification time.  */
+static inline long int
+get_stat_mtime_ns (struct stat const *st)
+{
+# if defined STAT_TIMESPEC
+  return STAT_TIMESPEC (st, st_mtim).tv_nsec;
+# elif defined STAT_TIMESPEC_NS
+  return STAT_TIMESPEC_NS (st, st_mtim);
+# else
+  return 0;
+# endif
+}
+
+/* Return the nanosecond component of *ST's birth time.  */
+static inline long int
+get_stat_birthtime_ns (struct stat const *st)
+{
+# if defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC
+  return STAT_TIMESPEC (st, st_birthtim).tv_nsec;
+# elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
+  return STAT_TIMESPEC_NS (st, st_birthtim);
+# else
+  /* Avoid a "parameter unused" warning.  */
+  (void) st;
+  return 0;
+# endif
+}
+
+/* Return *ST's access time.  */
+static inline struct timespec
+get_stat_atime (struct stat const *st)
+{
+#ifdef STAT_TIMESPEC
+  return STAT_TIMESPEC (st, st_atim);
+#else
+  struct timespec t;
+  t.tv_sec = st->st_atime;
+  t.tv_nsec = get_stat_atime_ns (st);
+  return t;
+#endif
+}
+
+/* Return *ST's status change time.  */
+static inline struct timespec
+get_stat_ctime (struct stat const *st)
+{
+#ifdef STAT_TIMESPEC
+  return STAT_TIMESPEC (st, st_ctim);
+#else
+  struct timespec t;
+  t.tv_sec = st->st_ctime;
+  t.tv_nsec = get_stat_ctime_ns (st);
+  return t;
+#endif
+}
+
+/* Return *ST's data modification time.  */
+static inline struct timespec
+get_stat_mtime (struct stat const *st)
+{
+#ifdef STAT_TIMESPEC
+  return STAT_TIMESPEC (st, st_mtim);
+#else
+  struct timespec t;
+  t.tv_sec = st->st_mtime;
+  t.tv_nsec = get_stat_mtime_ns (st);
+  return t;
+#endif
+}
+
+/* Return *ST's birth time, if available; otherwise return a value
+   with tv_sec and tv_nsec both equal to -1.  */
+static inline struct timespec
+get_stat_birthtime (struct stat const *st)
+{
+  struct timespec t;
+
+#if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
+     || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC)
+  t = STAT_TIMESPEC (st, st_birthtim);
+#elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
+  t.tv_sec = st->st_birthtime;
+  t.tv_nsec = st->st_birthtimensec;
+#elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  /* Native Windows platforms (but not Cygwin) put the "file creation
+     time" in st_ctime (!).  See
+     <http://msdn2.microsoft.com/de-de/library/14h5k7ff(VS.80).aspx>.  */
+  t.tv_sec = st->st_ctime;
+  t.tv_nsec = 0;
+#else
+  /* Birth time is not supported.  */
+  t.tv_sec = -1;
+  t.tv_nsec = -1;
+  /* Avoid a "parameter unused" warning.  */
+  (void) st;
+#endif
+
+#if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
+     || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC \
+     || defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)
+  /* FreeBSD and NetBSD sometimes signal the absence of knowledge by
+     using zero.  Attempt to work around this problem.  Alas, this can
+     report failure even for valid time stamps.  Also, NetBSD
+     sometimes returns junk in the birth time fields; work around this
+     bug if it is detected.  */
+  if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000))
+    {
+      t.tv_sec = -1;
+      t.tv_nsec = -1;
+    }
+#endif
+
+  return t;
+}
+
+#endif

lib/sys_select.in.h

@@ -0,0 +1,298 @@
+/* Substitute for <sys/select.h>.
+   Copyright (C) 2007-2012 Free Software Foundation, Inc.
+
+   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, 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/>.  */
+
+# if __GNUC__ >= 3
+@PRAGMA_SYSTEM_HEADER@
+# endif
+@PRAGMA_COLUMNS@
+
+/* On OSF/1, <sys/types.h> and <sys/time.h> include <sys/select.h>.
+   Simply delegate to the system's header in this case.  */
+#if @HAVE_SYS_SELECT_H@ && defined __osf__ && (defined _SYS_TYPES_H_ && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H) && defined _OSF_SOURCE
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#elif @HAVE_SYS_SELECT_H@ && defined __osf__ && (defined _SYS_TIME_H_ && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H) && defined _OSF_SOURCE
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+/* On IRIX 6.5, <sys/timespec.h> includes <sys/types.h>, which includes
+   <sys/bsd_types.h>, which includes <sys/select.h>.  At this point we cannot
+   include <signal.h>, because that includes <internal/signal_core.h>, which
+   gives a syntax error because <sys/timespec.h> has not been completely
+   processed.  Simply delegate to the system's header in this case.  */
+#elif @HAVE_SYS_SELECT_H@ && defined __sgi && (defined _SYS_BSD_TYPES_H && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_BSD_TYPES_H)
+
+# define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_BSD_TYPES_H
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+/* On OpenBSD 5.0, <pthread.h> includes <sys/types.h>, which includes
+   <sys/select.h>.  At this point we cannot include <signal.h>, because that
+   includes gnulib's pthread.h override, which gives a syntax error because
+   /usr/include/pthread.h has not been completely processed.  Simply delegate
+   to the system's header in this case.  */
+#elif @HAVE_SYS_SELECT_H@ && defined __OpenBSD__ && (defined _PTHREAD_H_ && !defined PTHREAD_MUTEX_INITIALIZER)
+
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#else
+
+#ifndef _@GUARD_PREFIX@_SYS_SELECT_H
+
+/* On many platforms, <sys/select.h> assumes prior inclusion of
+   <sys/types.h>.  Also, mingw defines sigset_t there, instead of
+   in <signal.h> where it belongs.  */
+#include <sys/types.h>
+
+#if @HAVE_SYS_SELECT_H@
+
+/* On OSF/1 4.0, <sys/select.h> provides only a forward declaration
+   of 'struct timeval', and no definition of this type.
+   Also, Mac OS X, AIX, HP-UX, IRIX, Solaris, Interix declare select()
+   in <sys/time.h>.
+   But avoid namespace pollution on glibc systems.  */
+# ifndef __GLIBC__
+#  include <sys/time.h>
+# endif
+
+/* On AIX 7 and Solaris 10, <sys/select.h> provides an FD_ZERO implementation
+   that relies on memset(), but without including <string.h>.
+   But in any case avoid namespace pollution on glibc systems.  */
+# if (defined __OpenBSD__ || defined _AIX || defined __sun || defined __osf__ || defined __BEOS__) \
+     && ! defined __GLIBC__
+#  include <string.h>
+# endif
+
+/* The include_next requires a split double-inclusion guard.  */
+# @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
+
+#endif
+
+/* Get definition of 'sigset_t'.
+   But avoid namespace pollution on glibc systems.
+   Do this after the include_next (for the sake of OpenBSD 5.0) but before
+   the split double-inclusion guard (for the sake of Solaris).  */
+#if !(defined __GLIBC__ && !defined __UCLIBC__)
+# include <signal.h>
+#endif
+
+#ifndef _@GUARD_PREFIX@_SYS_SELECT_H
+#define _@GUARD_PREFIX@_SYS_SELECT_H
+
+#if !@HAVE_SYS_SELECT_H@
+/* A platform that lacks <sys/select.h>.  */
+/* Get the 'struct timeval' and 'fd_set' types and the FD_* macros
+   on most platforms.  */
+# include <sys/time.h>
+/* On HP-UX 11, <sys/time.h> provides an FD_ZERO implementation
+   that relies on memset(), but without including <string.h>.  */
+# if defined __hpux
+#  include <string.h>
+# endif
+/* On native Windows platforms:
+   Get the 'fd_set' type.
+   Get the close() declaration before we override it.  */
+# if @HAVE_WINSOCK2_H@
+#  if !defined _GL_INCLUDING_WINSOCK2_H
+#   define _GL_INCLUDING_WINSOCK2_H
+#   include <winsock2.h>
+#   undef _GL_INCLUDING_WINSOCK2_H
+#  endif
+#  include <io.h>
+# endif
+#endif
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+
+/* Fix some definitions from <winsock2.h>.  */
+
+#if @HAVE_WINSOCK2_H@
+
+# if !GNULIB_defined_rpl_fd_isset
+
+/* Re-define FD_ISSET to avoid a WSA call while we are not using
+   network sockets.  */
+static inline int
+rpl_fd_isset (SOCKET fd, fd_set * set)
+{
+  u_int i;
+  if (set == NULL)
+    return 0;
+
+  for (i = 0; i < set->fd_count; i++)
+    if (set->fd_array[i] == fd)
+      return 1;
+
+  return 0;
+}
+
+#  define GNULIB_defined_rpl_fd_isset 1
+# endif
+
+# undef FD_ISSET
+# define FD_ISSET(fd, set) rpl_fd_isset(fd, set)
+
+#endif
+
+/* Hide some function declarations from <winsock2.h>.  */
+
+#if @HAVE_WINSOCK2_H@
+# if !defined _@GUARD_PREFIX@_UNISTD_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef close
+#   define close close_used_without_including_unistd_h
+#  else
+    _GL_WARN_ON_USE (close,
+                     "close() used without including <unistd.h>");
+#  endif
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef gethostname
+#   define gethostname gethostname_used_without_including_unistd_h
+#  else
+    _GL_WARN_ON_USE (gethostname,
+                     "gethostname() used without including <unistd.h>");
+#  endif
+# endif
+# if !defined _@GUARD_PREFIX@_SYS_SOCKET_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef socket
+#   define socket              socket_used_without_including_sys_socket_h
+#   undef connect
+#   define connect             connect_used_without_including_sys_socket_h
+#   undef accept
+#   define accept              accept_used_without_including_sys_socket_h
+#   undef bind
+#   define bind                bind_used_without_including_sys_socket_h
+#   undef getpeername
+#   define getpeername         getpeername_used_without_including_sys_socket_h
+#   undef getsockname
+#   define getsockname         getsockname_used_without_including_sys_socket_h
+#   undef getsockopt
+#   define getsockopt          getsockopt_used_without_including_sys_socket_h
+#   undef listen
+#   define listen              listen_used_without_including_sys_socket_h
+#   undef recv
+#   define recv                recv_used_without_including_sys_socket_h
+#   undef send
+#   define send                send_used_without_including_sys_socket_h
+#   undef recvfrom
+#   define recvfrom            recvfrom_used_without_including_sys_socket_h
+#   undef sendto
+#   define sendto              sendto_used_without_including_sys_socket_h
+#   undef setsockopt
+#   define setsockopt          setsockopt_used_without_including_sys_socket_h
+#   undef shutdown
+#   define shutdown            shutdown_used_without_including_sys_socket_h
+#  else
+    _GL_WARN_ON_USE (socket,
+                     "socket() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (connect,
+                     "connect() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (accept,
+                     "accept() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (bind,
+                     "bind() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getpeername,
+                     "getpeername() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getsockname,
+                     "getsockname() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (getsockopt,
+                     "getsockopt() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (listen,
+                     "listen() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (recv,
+                     "recv() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (send,
+                     "send() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (recvfrom,
+                     "recvfrom() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (sendto,
+                     "sendto() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (setsockopt,
+                     "setsockopt() used without including <sys/socket.h>");
+    _GL_WARN_ON_USE (shutdown,
+                     "shutdown() used without including <sys/socket.h>");
+#  endif
+# endif
+#endif
+
+
+#if @GNULIB_PSELECT@
+# if @REPLACE_PSELECT@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef pselect
+#   define pselect rpl_pselect
+#  endif
+_GL_FUNCDECL_RPL (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+_GL_CXXALIAS_RPL (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+# else
+#  if !@HAVE_PSELECT@
+_GL_FUNCDECL_SYS (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+#  endif
+_GL_CXXALIAS_SYS (pselect, int,
+                  (int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
+                   struct timespec const *restrict, const sigset_t *restrict));
+# endif
+_GL_CXXALIASWARN (pselect);
+#elif defined GNULIB_POSIXCHECK
+# undef pselect
+# if HAVE_RAW_DECL_PSELECT
+_GL_WARN_ON_USE (pselect, "pselect is not portable - "
+                 "use gnulib module pselect for portability");
+# endif
+#endif
+
+#if @GNULIB_SELECT@
+# if @REPLACE_SELECT@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef select
+#   define select rpl_select
+#  endif
+_GL_FUNCDECL_RPL (select, int,
+                  (int, fd_set *, fd_set *, fd_set *, struct timeval *));
+_GL_CXXALIAS_RPL (select, int,
+                  (int, fd_set *, fd_set *, fd_set *, struct timeval *));
+# else
+_GL_CXXALIAS_SYS (select, int,
+                  (int, fd_set *, fd_set *, fd_set *, struct timeval *));
+# endif
+_GL_CXXALIASWARN (select);
+#elif @HAVE_WINSOCK2_H@
+# undef select
+# define select select_used_without_requesting_gnulib_module_select
+#elif defined GNULIB_POSIXCHECK
+# undef select
+# if HAVE_RAW_DECL_SELECT
+_GL_WARN_ON_USE (select, "select is not always POSIX compliant - "
+                 "use gnulib module select for portability");
+# endif
+#endif
+
+
+#endif /* _@GUARD_PREFIX@_SYS_SELECT_H */
+#endif /* _@GUARD_PREFIX@_SYS_SELECT_H */
+#endif /* OSF/1 */

lib/sys_time.in.h

@@ -0,0 +1,205 @@
+/* Provide a more complete sys/time.h.
+
+   Copyright (C) 2007-2012 Free Software Foundation, Inc.
+
+   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, 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/>.  */
+
+/* Written by Paul Eggert.  */
+
+#if __GNUC__ >= 3
+@PRAGMA_SYSTEM_HEADER@
+#endif
+@PRAGMA_COLUMNS@
+
+#if defined _@GUARD_PREFIX@_SYS_TIME_H
+
+/* Simply delegate to the system's header, without adding anything.  */
+# if @HAVE_SYS_TIME_H@
+#  @INCLUDE_NEXT@ @NEXT_SYS_TIME_H@
+# endif
+
+#else
+
+# define _@GUARD_PREFIX@_SYS_TIME_H
+
+# if @HAVE_SYS_TIME_H@
+#  @INCLUDE_NEXT@ @NEXT_SYS_TIME_H@
+# else
+#  include <time.h>
+# endif
+
+/* On native Windows with MSVC, get the 'struct timeval' type.
+   Also, on native Windows with a 64-bit time_t, where we are overriding the
+   'struct timeval' type, get all declarations of system functions whose
+   signature contains 'struct timeval'.  */
+# if (defined _MSC_VER || @REPLACE_STRUCT_TIMEVAL@) && @HAVE_WINSOCK2_H@ && !defined _GL_INCLUDING_WINSOCK2_H
+#  define _GL_INCLUDING_WINSOCK2_H
+#  include <winsock2.h>
+#  undef _GL_INCLUDING_WINSOCK2_H
+# endif
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_ARG_NONNULL is copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+# if !@HAVE_STRUCT_TIMEVAL@ || @REPLACE_STRUCT_TIMEVAL@
+
+#  if @REPLACE_STRUCT_TIMEVAL@
+#   define timeval rpl_timeval
+#  endif
+
+#  if !GNULIB_defined_struct_timeval
+struct timeval
+{
+  time_t tv_sec;
+  long int tv_usec;
+};
+#   define GNULIB_defined_struct_timeval 1
+#  endif
+
+# endif
+
+# ifdef __cplusplus
+}
+# endif
+
+# if @GNULIB_GETTIMEOFDAY@
+#  if @REPLACE_GETTIMEOFDAY@
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef gettimeofday
+#    define gettimeofday rpl_gettimeofday
+#   endif
+_GL_FUNCDECL_RPL (gettimeofday, int,
+                  (struct timeval *restrict, void *restrict)
+                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (gettimeofday, int,
+                  (struct timeval *restrict, void *restrict));
+#  else
+#   if !@HAVE_GETTIMEOFDAY@
+_GL_FUNCDECL_SYS (gettimeofday, int,
+                  (struct timeval *restrict, void *restrict)
+                  _GL_ARG_NONNULL ((1)));
+#   endif
+/* Need to cast, because on glibc systems, by default, the second argument is
+                                                  struct timezone *.  */
+_GL_CXXALIAS_SYS_CAST (gettimeofday, int,
+                       (struct timeval *restrict, void *restrict));
+#  endif
+_GL_CXXALIASWARN (gettimeofday);
+# elif defined GNULIB_POSIXCHECK
+#  undef gettimeofday
+#  if HAVE_RAW_DECL_GETTIMEOFDAY
+_GL_WARN_ON_USE (gettimeofday, "gettimeofday is unportable - "
+                 "use gnulib module gettimeofday for portability");
+#  endif
+# endif
+
+/* Hide some function declarations from <winsock2.h>.  */
+
+# if defined _MSC_VER && @HAVE_WINSOCK2_H@
+#  if !defined _@GUARD_PREFIX@_UNISTD_H
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef close
+#    define close close_used_without_including_unistd_h
+#   else
+     _GL_WARN_ON_USE (close,
+                      "close() used without including <unistd.h>");
+#   endif
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef gethostname
+#    define gethostname gethostname_used_without_including_unistd_h
+#   else
+     _GL_WARN_ON_USE (gethostname,
+                      "gethostname() used without including <unistd.h>");
+#   endif
+#  endif
+#  if !defined _@GUARD_PREFIX@_SYS_SOCKET_H
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef socket
+#    define socket              socket_used_without_including_sys_socket_h
+#    undef connect
+#    define connect             connect_used_without_including_sys_socket_h
+#    undef accept
+#    define accept              accept_used_without_including_sys_socket_h
+#    undef bind
+#    define bind                bind_used_without_including_sys_socket_h
+#    undef getpeername
+#    define getpeername         getpeername_used_without_including_sys_socket_h
+#    undef getsockname
+#    define getsockname         getsockname_used_without_including_sys_socket_h
+#    undef getsockopt
+#    define getsockopt          getsockopt_used_without_including_sys_socket_h
+#    undef listen
+#    define listen              listen_used_without_including_sys_socket_h
+#    undef recv
+#    define recv                recv_used_without_including_sys_socket_h
+#    undef send
+#    define send                send_used_without_including_sys_socket_h
+#    undef recvfrom
+#    define recvfrom            recvfrom_used_without_including_sys_socket_h
+#    undef sendto
+#    define sendto              sendto_used_without_including_sys_socket_h
+#    undef setsockopt
+#    define setsockopt          setsockopt_used_without_including_sys_socket_h
+#    undef shutdown
+#    define shutdown            shutdown_used_without_including_sys_socket_h
+#   else
+     _GL_WARN_ON_USE (socket,
+                      "socket() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (connect,
+                      "connect() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (accept,
+                      "accept() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (bind,
+                      "bind() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (getpeername,
+                      "getpeername() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (getsockname,
+                      "getsockname() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (getsockopt,
+                      "getsockopt() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (listen,
+                      "listen() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (recv,
+                      "recv() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (send,
+                      "send() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (recvfrom,
+                      "recvfrom() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (sendto,
+                      "sendto() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (setsockopt,
+                      "setsockopt() used without including <sys/socket.h>");
+     _GL_WARN_ON_USE (shutdown,
+                      "shutdown() used without including <sys/socket.h>");
+#   endif
+#  endif
+#  if !defined _@GUARD_PREFIX@_SYS_SELECT_H
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef select
+#    define select select_used_without_including_sys_select_h
+#   else
+     _GL_WARN_ON_USE (select,
+                      "select() used without including <sys/select.h>");
+#   endif
+#  endif
+# endif
+
+#endif /* _@GUARD_PREFIX@_SYS_TIME_H */

lib/timespec-add.c

@@ -0,0 +1,71 @@
+/* Add two struct timespec values.
+
+   Copyright (C) 2011-2012 Free Software Foundation, Inc.
+
+   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/>.  */
+
+/* Written by Paul Eggert.  */
+
+/* Return the sum of two timespec values A and B.  On overflow, return
+   an extremal value.  This assumes 0 <= tv_nsec <= 999999999.  */
+
+#include <config.h>
+#include "timespec.h"
+
+#include "intprops.h"
+
+struct timespec
+timespec_add (struct timespec a, struct timespec b)
+{
+  struct timespec r;
+  time_t rs = a.tv_sec;
+  time_t bs = b.tv_sec;
+  int ns = a.tv_nsec + b.tv_nsec;
+  int nsd = ns - 1000000000;
+  int rns = ns;
+
+  if (0 <= nsd)
+    {
+      rns = nsd;
+      if (rs == TYPE_MAXIMUM (time_t))
+        {
+          if (0 <= bs)
+            goto high_overflow;
+          bs++;
+        }
+      else
+        rs++;
+    }
+
+  if (INT_ADD_OVERFLOW (rs, bs))
+    {
+      if (rs < 0)
+        {
+          rs = TYPE_MINIMUM (time_t);
+          rns = 0;
+        }
+      else
+        {
+        high_overflow:
+          rs = TYPE_MAXIMUM (time_t);
+          rns = 999999999;
+        }
+    }
+  else
+    rs += bs;
+
+  r.tv_sec = rs;
+  r.tv_nsec = rns;
+  return r;
+}

lib/timespec-sub.c

@@ -0,0 +1,72 @@
+/* Subtract two struct timespec values.
+
+   Copyright (C) 2011-2012 Free Software Foundation, Inc.
+
+   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/>.  */
+
+/* Written by Paul Eggert.  */
+
+/* Return the difference between two timespec values A and B.  On
+   overflow, return an extremal value.  This assumes 0 <= tv_nsec <=
+   999999999.  */
+
+#include <config.h>
+#include <config.h>
+#include "timespec.h"
+
+#include "intprops.h"
+
+struct timespec
+timespec_sub (struct timespec a, struct timespec b)
+{
+  struct timespec r;
+  time_t rs = a.tv_sec;
+  time_t bs = b.tv_sec;
+  int ns = a.tv_nsec - b.tv_nsec;
+  int rns = ns;
+
+  if (ns < 0)
+    {
+      rns = ns + 1000000000;
+      if (rs == TYPE_MINIMUM (time_t))
+        {
+          if (bs <= 0)
+            goto low_overflow;
+          bs--;
+        }
+      else
+        rs--;
+    }
+
+  if (INT_SUBTRACT_OVERFLOW (rs, bs))
+    {
+      if (rs < 0)
+        {
+        low_overflow:
+          rs = TYPE_MINIMUM (time_t);
+          rns = 0;
+        }
+      else
+        {
+          rs = TYPE_MAXIMUM (time_t);
+          rns = 999999999;
+        }
+    }
+  else
+    rs -= bs;
+
+  r.tv_sec = rs;
+  r.tv_nsec = rns;
+  return r;
+}

lib/timespec.h

@@ -0,0 +1,82 @@
+/* timespec -- System time interface
+
+   Copyright (C) 2000, 2002, 2004-2005, 2007, 2009-2012 Free Software
+   Foundation, Inc.
+
+   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/>.  */
+
+#if ! defined TIMESPEC_H
+# define TIMESPEC_H
+
+# include <time.h>
+
+/* Return negative, zero, positive if A < B, A == B, A > B, respectively.
+
+   For each time stamp T, this code assumes that either:
+
+     * T.tv_nsec is in the range 0..999999999; or
+     * T.tv_sec corresponds to a valid leap second on a host that supports
+       leap seconds, and T.tv_nsec is in the range 1000000000..1999999999; or
+     * T.tv_sec is the minimum time_t value and T.tv_nsec is -1; or
+       T.tv_sec is the maximum time_t value and T.tv_nsec is 2000000000.
+       This allows for special struct timespec values that are less or
+       greater than all possible valid time stamps.
+
+   In all these cases, it is safe to subtract two tv_nsec values and
+   convert the result to integer without worrying about overflow on
+   any platform of interest to the GNU project, since all such
+   platforms have 32-bit int or wider.
+
+   Replacing "(int) (a.tv_nsec - b.tv_nsec)" with something like
+   "a.tv_nsec < b.tv_nsec ? -1 : a.tv_nsec > b.tv_nsec" would cause
+   this function to work in some cases where the above assumption is
+   violated, but not in all cases (e.g., a.tv_sec==1, a.tv_nsec==-2,
+   b.tv_sec==0, b.tv_nsec==999999999) and is arguably not worth the
+   extra instructions.  Using a subtraction has the advantage of
+   detecting some invalid cases on platforms that detect integer
+   overflow.
+
+   The (int) cast avoids a gcc -Wconversion warning.  */
+
+static inline int
+timespec_cmp (struct timespec a, struct timespec b)
+{
+  return (a.tv_sec < b.tv_sec ? -1
+          : a.tv_sec > b.tv_sec ? 1
+          : (int) (a.tv_nsec - b.tv_nsec));
+}
+
+/* Return -1, 0, 1, depending on the sign of A.  A.tv_nsec must be
+   nonnegative.  */
+static inline int
+timespec_sign (struct timespec a)
+{
+  return a.tv_sec < 0 ? -1 : a.tv_sec || a.tv_nsec;
+}
+
+struct timespec timespec_add (struct timespec, struct timespec);
+struct timespec timespec_sub (struct timespec, struct timespec);
+struct timespec dtotimespec (double);
+
+/* Return an approximation to A, of type 'double'.  */
+static inline double
+timespectod (struct timespec a)
+{
+  return a.tv_sec + a.tv_nsec / 1e9;
+}
+
+void gettime (struct timespec *);
+int settime (struct timespec const *);
+
+#endif

lib/utimens.c

@@ -0,0 +1,533 @@
+/* Set file access and modification times.
+
+   Copyright (C) 2003-2012 Free Software Foundation, Inc.
+
+   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 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/>.  */
+
+/* Written by Paul Eggert.  */
+
+/* derived from a function in touch.c */
+
+#include <config.h>
+
+#include "utimens.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include "stat-time.h"
+#include "timespec.h"
+
+#if HAVE_UTIME_H
+# include <utime.h>
+#endif
+
+/* Some systems (even some that do have <utime.h>) don't declare this
+   structure anywhere.  */
+#ifndef HAVE_STRUCT_UTIMBUF
+struct utimbuf
+{
+  long actime;
+  long modtime;
+};
+#endif
+
+/* Avoid recursion with rpl_futimens or rpl_utimensat.  */
+#undef futimens
+#undef utimensat
+
+/* Solaris 9 mistakenly succeeds when given a non-directory with a
+   trailing slash.  Force the use of rpl_stat for a fix.  */
+#ifndef REPLACE_FUNC_STAT_FILE
+# define REPLACE_FUNC_STAT_FILE 0
+#endif
+
+#if HAVE_UTIMENSAT || HAVE_FUTIMENS
+/* Cache variables for whether the utimensat syscall works; used to
+   avoid calling the syscall if we know it will just fail with ENOSYS,
+   and to avoid unnecessary work in massaging timestamps if the
+   syscall will work.  Multiple variables are needed, to distinguish
+   between the following scenarios on Linux:
+   utimensat doesn't exist, or is in glibc but kernel 2.6.18 fails with ENOSYS
+   kernel 2.6.22 and earlier rejects AT_SYMLINK_NOFOLLOW
+   kernel 2.6.25 and earlier reject UTIME_NOW/UTIME_OMIT with non-zero tv_sec
+   kernel 2.6.32 used with xfs or ntfs-3g fail to honor UTIME_OMIT
+   utimensat completely works
+   For each cache variable: 0 = unknown, 1 = yes, -1 = no.  */
+static int utimensat_works_really;
+static int lutimensat_works_really;
+#endif /* HAVE_UTIMENSAT || HAVE_FUTIMENS */
+
+/* Validate the requested timestamps.  Return 0 if the resulting
+   timespec can be used for utimensat (after possibly modifying it to
+   work around bugs in utimensat).  Return a positive value if the
+   timespec needs further adjustment based on stat results: 1 if any
+   adjustment is needed for utimes, and 2 if any adjustment is needed
+   for Linux utimensat.  Return -1, with errno set to EINVAL, if
+   timespec is out of range.  */
+static int
+validate_timespec (struct timespec timespec[2])
+{
+  int result = 0;
+  int utime_omit_count = 0;
+  assert (timespec);
+  if ((timespec[0].tv_nsec != UTIME_NOW
+       && timespec[0].tv_nsec != UTIME_OMIT
+       && (timespec[0].tv_nsec < 0 || 1000000000 <= timespec[0].tv_nsec))
+      || (timespec[1].tv_nsec != UTIME_NOW
+          && timespec[1].tv_nsec != UTIME_OMIT
+          && (timespec[1].tv_nsec < 0 || 1000000000 <= timespec[1].tv_nsec)))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  /* Work around Linux kernel 2.6.25 bug, where utimensat fails with
+     EINVAL if tv_sec is not 0 when using the flag values of tv_nsec.
+     Flag a Linux kernel 2.6.32 bug, where an mtime of UTIME_OMIT
+     fails to bump ctime.  */
+  if (timespec[0].tv_nsec == UTIME_NOW
+      || timespec[0].tv_nsec == UTIME_OMIT)
+    {
+      timespec[0].tv_sec = 0;
+      result = 1;
+      if (timespec[0].tv_nsec == UTIME_OMIT)
+        utime_omit_count++;
+    }
+  if (timespec[1].tv_nsec == UTIME_NOW
+      || timespec[1].tv_nsec == UTIME_OMIT)
+    {
+      timespec[1].tv_sec = 0;
+      result = 1;
+      if (timespec[1].tv_nsec == UTIME_OMIT)
+        utime_omit_count++;
+    }
+  return result + (utime_omit_count == 1);
+}
+
+/* Normalize any UTIME_NOW or UTIME_OMIT values in *TS, using stat
+   buffer STATBUF to obtain the current timestamps of the file.  If
+   both times are UTIME_NOW, set *TS to NULL (as this can avoid some
+   permissions issues).  If both times are UTIME_OMIT, return true
+   (nothing further beyond the prior collection of STATBUF is
+   necessary); otherwise return false.  */
+static bool
+update_timespec (struct stat const *statbuf, struct timespec *ts[2])
+{
+  struct timespec *timespec = *ts;
+  if (timespec[0].tv_nsec == UTIME_OMIT
+      && timespec[1].tv_nsec == UTIME_OMIT)
+    return true;
+  if (timespec[0].tv_nsec == UTIME_NOW
+      && timespec[1].tv_nsec == UTIME_NOW)
+    {
+      *ts = NULL;
+      return false;
+    }
+
+  if (timespec[0].tv_nsec == UTIME_OMIT)
+    timespec[0] = get_stat_atime (statbuf);
+  else if (timespec[0].tv_nsec == UTIME_NOW)
+    gettime (&timespec[0]);
+
+  if (timespec[1].tv_nsec == UTIME_OMIT)
+    timespec[1] = get_stat_mtime (statbuf);
+  else if (timespec[1].tv_nsec == UTIME_NOW)
+    gettime (&timespec[1]);
+
+  return false;
+}
+
+/* Set the access and modification time stamps of FD (a.k.a. FILE) to be
+   TIMESPEC[0] and TIMESPEC[1], respectively.
+   FD must be either negative -- in which case it is ignored --
+   or a file descriptor that is open on FILE.
+   If FD is nonnegative, then FILE can be NULL, which means
+   use just futimes (or equivalent) instead of utimes (or equivalent),
+   and fail if on an old system without futimes (or equivalent).
+   If TIMESPEC is null, set the time stamps to the current time.
+   Return 0 on success, -1 (setting errno) on failure.  */
+
+int
+fdutimens (int fd, char const *file, struct timespec const timespec[2])
+{
+  struct timespec adjusted_timespec[2];
+  struct timespec *ts = timespec ? adjusted_timespec : NULL;
+  int adjustment_needed = 0;
+  struct stat st;
+
+  if (ts)
+    {
+      adjusted_timespec[0] = timespec[0];
+      adjusted_timespec[1] = timespec[1];
+      adjustment_needed = validate_timespec (ts);
+    }
+  if (adjustment_needed < 0)
+    return -1;
+
+  /* Require that at least one of FD or FILE are potentially valid, to avoid
+     a Linux bug where futimens (AT_FDCWD, NULL) changes "." rather
+     than failing.  */
+  if (fd < 0 && !file)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  /* Some Linux-based NFS clients are buggy, and mishandle time stamps
+     of files in NFS file systems in some cases.  We have no
+     configure-time test for this, but please see
+     <http://bugs.gentoo.org/show_bug.cgi?id=132673> for references to
+     some of the problems with Linux 2.6.16.  If this affects you,
+     compile with -DHAVE_BUGGY_NFS_TIME_STAMPS; this is reported to
+     help in some cases, albeit at a cost in performance.  But you
+     really should upgrade your kernel to a fixed version, since the
+     problem affects many applications.  */
+
+#if HAVE_BUGGY_NFS_TIME_STAMPS
+  if (fd < 0)
+    sync ();
+  else
+    fsync (fd);
+#endif
+
+  /* POSIX 2008 added two interfaces to set file timestamps with
+     nanosecond resolution; newer Linux implements both functions via
+     a single syscall.  We provide a fallback for ENOSYS (for example,
+     compiling against Linux 2.6.25 kernel headers and glibc 2.7, but
+     running on Linux 2.6.18 kernel).  */
+#if HAVE_UTIMENSAT || HAVE_FUTIMENS
+  if (0 <= utimensat_works_really)
+    {
+      int result;
+# if __linux__
+      /* As recently as Linux kernel 2.6.32 (Dec 2009), several file
+         systems (xfs, ntfs-3g) have bugs with a single UTIME_OMIT,
+         but work if both times are either explicitly specified or
+         UTIME_NOW.  Work around it with a preparatory [f]stat prior
+         to calling futimens/utimensat; fortunately, there is not much
+         timing impact due to the extra syscall even on file systems
+         where UTIME_OMIT would have worked.  FIXME: Simplify this in
+         2012, when file system bugs are no longer common.  */
+      if (adjustment_needed == 2)
+        {
+          if (fd < 0 ? stat (file, &st) : fstat (fd, &st))
+            return -1;
+          if (ts[0].tv_nsec == UTIME_OMIT)
+            ts[0] = get_stat_atime (&st);
+          else if (ts[1].tv_nsec == UTIME_OMIT)
+            ts[1] = get_stat_mtime (&st);
+          /* Note that st is good, in case utimensat gives ENOSYS.  */
+          adjustment_needed++;
+        }
+# endif /* __linux__ */
+# if HAVE_UTIMENSAT
+      if (fd < 0)
+        {
+          result = utimensat (AT_FDCWD, file, ts, 0);
+#  ifdef __linux__
+          /* Work around a kernel bug:
+             http://bugzilla.redhat.com/442352
+             http://bugzilla.redhat.com/449910
+             It appears that utimensat can mistakenly return 280 rather
+             than -1 upon ENOSYS failure.
+             FIXME: remove in 2010 or whenever the offending kernels
+             are no longer in common use.  */
+          if (0 < result)
+            errno = ENOSYS;
+#  endif /* __linux__ */
+          if (result == 0 || errno != ENOSYS)
+            {
+              utimensat_works_really = 1;
+              return result;
+            }
+        }
+# endif /* HAVE_UTIMENSAT */
+# if HAVE_FUTIMENS
+      if (0 <= fd)
+        {
+          result = futimens (fd, ts);
+#  ifdef __linux__
+          /* Work around the same bug as above.  */
+          if (0 < result)
+            errno = ENOSYS;
+#  endif /* __linux__ */
+          if (result == 0 || errno != ENOSYS)
+            {
+              utimensat_works_really = 1;
+              return result;
+            }
+        }
+# endif /* HAVE_FUTIMENS */
+    }
+  utimensat_works_really = -1;
+  lutimensat_works_really = -1;
+#endif /* HAVE_UTIMENSAT || HAVE_FUTIMENS */
+
+  /* The platform lacks an interface to set file timestamps with
+     nanosecond resolution, so do the best we can, discarding any
+     fractional part of the timestamp.  */
+
+  if (adjustment_needed || (REPLACE_FUNC_STAT_FILE && fd < 0))
+    {
+      if (adjustment_needed != 3
+          && (fd < 0 ? stat (file, &st) : fstat (fd, &st)))
+        return -1;
+      if (ts && update_timespec (&st, &ts))
+        return 0;
+    }
+
+  {
+#if HAVE_FUTIMESAT || HAVE_WORKING_UTIMES
+    struct timeval timeval[2];
+    struct timeval *t;
+    if (ts)
+      {
+        timeval[0].tv_sec = ts[0].tv_sec;
+        timeval[0].tv_usec = ts[0].tv_nsec / 1000;
+        timeval[1].tv_sec = ts[1].tv_sec;
+        timeval[1].tv_usec = ts[1].tv_nsec / 1000;
+        t = timeval;
+      }
+    else
+      t = NULL;
+
+    if (fd < 0)
+      {
+# if HAVE_FUTIMESAT
+        return futimesat (AT_FDCWD, file, t);
+# endif
+      }
+    else
+      {
+        /* If futimesat or futimes fails here, don't try to speed things
+           up by returning right away.  glibc can incorrectly fail with
+           errno == ENOENT if /proc isn't mounted.  Also, Mandrake 10.0
+           in high security mode doesn't allow ordinary users to read
+           /proc/self, so glibc incorrectly fails with errno == EACCES.
+           If errno == EIO, EPERM, or EROFS, it's probably safe to fail
+           right away, but these cases are rare enough that they're not
+           worth optimizing, and who knows what other messed-up systems
+           are out there?  So play it safe and fall back on the code
+           below.  */
+
+# if (HAVE_FUTIMESAT && !FUTIMESAT_NULL_BUG) || HAVE_FUTIMES
+#  if HAVE_FUTIMESAT && !FUTIMESAT_NULL_BUG
+#   undef futimes
+#   define futimes(fd, t) futimesat (fd, NULL, t)
+#  endif
+        if (futimes (fd, t) == 0)
+          {
+#  if __linux__ && __GLIBC__
+            /* Work around a longstanding glibc bug, still present as
+               of 2010-12-27.  On older Linux kernels that lack both
+               utimensat and utimes, glibc's futimes rounds instead of
+               truncating when falling back on utime.  The same bug
+               occurs in futimesat with a null 2nd arg.  */
+            if (t)
+              {
+                bool abig = 500000 <= t[0].tv_usec;
+                bool mbig = 500000 <= t[1].tv_usec;
+                if ((abig | mbig) && fstat (fd, &st) == 0)
+                  {
+                    /* If these two subtractions overflow, they'll
+                       track the overflows inside the buggy glibc.  */
+                    time_t adiff = st.st_atime - t[0].tv_sec;
+                    time_t mdiff = st.st_mtime - t[1].tv_sec;
+
+                    struct timeval *tt = NULL;
+                    struct timeval truncated_timeval[2];
+                    truncated_timeval[0] = t[0];
+                    truncated_timeval[1] = t[1];
+                    if (abig && adiff == 1 && get_stat_atime_ns (&st) == 0)
+                      {
+                        tt = truncated_timeval;
+                        tt[0].tv_usec = 0;
+                      }
+                    if (mbig && mdiff == 1 && get_stat_mtime_ns (&st) == 0)
+                      {
+                        tt = truncated_timeval;
+                        tt[1].tv_usec = 0;
+                      }
+                    if (tt)
+                      futimes (fd, tt);
+                  }
+              }
+#  endif
+
+            return 0;
+          }
+# endif
+      }
+#endif /* HAVE_FUTIMESAT || HAVE_WORKING_UTIMES */
+
+    if (!file)
+      {
+#if ! ((HAVE_FUTIMESAT && !FUTIMESAT_NULL_BUG)          \
+        || (HAVE_WORKING_UTIMES && HAVE_FUTIMES))
+        errno = ENOSYS;
+#endif
+        return -1;
+      }
+
+#if HAVE_WORKING_UTIMES
+    return utimes (file, t);
+#else
+    {
+      struct utimbuf utimbuf;
+      struct utimbuf *ut;
+      if (ts)
+        {
+          utimbuf.actime = ts[0].tv_sec;
+          utimbuf.modtime = ts[1].tv_sec;
+          ut = &utimbuf;
+        }
+      else
+        ut = NULL;
+
+      return utime (file, ut);
+    }
+#endif /* !HAVE_WORKING_UTIMES */
+  }
+}
+
+/* Set the access and modification time stamps of FILE to be
+   TIMESPEC[0] and TIMESPEC[1], respectively.  */
+int
+utimens (char const *file, struct timespec const timespec[2])
+{
+  return fdutimens (-1, file, timespec);
+}
+
+/* Set the access and modification time stamps of FILE to be
+   TIMESPEC[0] and TIMESPEC[1], respectively, without dereferencing
+   symlinks.  Fail with ENOSYS if the platform does not support
+   changing symlink timestamps, but FILE was a symlink.  */
+int
+lutimens (char const *file, struct timespec const timespec[2])
+{
+  struct timespec adjusted_timespec[2];
+  struct timespec *ts = timespec ? adjusted_timespec : NULL;
+  int adjustment_needed = 0;
+  struct stat st;
+
+  if (ts)
+    {
+      adjusted_timespec[0] = timespec[0];
+      adjusted_timespec[1] = timespec[1];
+      adjustment_needed = validate_timespec (ts);
+    }
+  if (adjustment_needed < 0)
+    return -1;
+
+  /* The Linux kernel did not support symlink timestamps until
+     utimensat, in version 2.6.22, so we don't need to mimic
+     fdutimens' worry about buggy NFS clients.  But we do have to
+     worry about bogus return values.  */
+
+#if HAVE_UTIMENSAT
+  if (0 <= lutimensat_works_really)
+    {
+      int result;
+# if __linux__
+      /* As recently as Linux kernel 2.6.32 (Dec 2009), several file
+         systems (xfs, ntfs-3g) have bugs with a single UTIME_OMIT,
+         but work if both times are either explicitly specified or
+         UTIME_NOW.  Work around it with a preparatory lstat prior to
+         calling utimensat; fortunately, there is not much timing
+         impact due to the extra syscall even on file systems where
+         UTIME_OMIT would have worked.  FIXME: Simplify this in 2012,
+         when file system bugs are no longer common.  */
+      if (adjustment_needed == 2)
+        {
+          if (lstat (file, &st))
+            return -1;
+          if (ts[0].tv_nsec == UTIME_OMIT)
+            ts[0] = get_stat_atime (&st);
+          else if (ts[1].tv_nsec == UTIME_OMIT)
+            ts[1] = get_stat_mtime (&st);
+          /* Note that st is good, in case utimensat gives ENOSYS.  */
+          adjustment_needed++;
+        }
+# endif /* __linux__ */
+      result = utimensat (AT_FDCWD, file, ts, AT_SYMLINK_NOFOLLOW);
+# ifdef __linux__
+      /* Work around a kernel bug:
+         http://bugzilla.redhat.com/442352
+         http://bugzilla.redhat.com/449910
+         It appears that utimensat can mistakenly return 280 rather
+         than -1 upon ENOSYS failure.
+         FIXME: remove in 2010 or whenever the offending kernels
+         are no longer in common use.  */
+      if (0 < result)
+        errno = ENOSYS;
+# endif
+      if (result == 0 || errno != ENOSYS)
+        {
+          utimensat_works_really = 1;
+          lutimensat_works_really = 1;
+          return result;
+        }
+    }
+  lutimensat_works_really = -1;
+#endif /* HAVE_UTIMENSAT */
+
+  /* The platform lacks an interface to set file timestamps with
+     nanosecond resolution, so do the best we can, discarding any
+     fractional part of the timestamp.  */
+
+  if (adjustment_needed || REPLACE_FUNC_STAT_FILE)
+    {
+      if (adjustment_needed != 3 && lstat (file, &st))
+        return -1;
+      if (ts && update_timespec (&st, &ts))
+        return 0;
+    }
+
+  /* On Linux, lutimes is a thin wrapper around utimensat, so there is
+     no point trying lutimes if utimensat failed with ENOSYS.  */
+#if HAVE_LUTIMES && !HAVE_UTIMENSAT
+  {
+    struct timeval timeval[2];
+    struct timeval *t;
+    int result;
+    if (ts)
+      {
+        timeval[0].tv_sec = ts[0].tv_sec;
+        timeval[0].tv_usec = ts[0].tv_nsec / 1000;
+        timeval[1].tv_sec = ts[1].tv_sec;
+        timeval[1].tv_usec = ts[1].tv_nsec / 1000;
+        t = timeval;
+      }
+    else
+      t = NULL;
+
+    result = lutimes (file, t);
+    if (result == 0 || errno != ENOSYS)
+      return result;
+  }
+#endif /* HAVE_LUTIMES && !HAVE_UTIMENSAT */
+
+  /* Out of luck for symlinks, but we still handle regular files.  */
+  if (!(adjustment_needed || REPLACE_FUNC_STAT_FILE) && lstat (file, &st))
+    return -1;
+  if (!S_ISLNK (st.st_mode))
+    return fdutimens (-1, file, ts);
+  errno = ENOSYS;
+  return -1;
+}

lib/utimens.h

@@ -0,0 +1,19 @@
+#include <time.h>
+int fdutimens (int, char const *, struct timespec const [2]);
+int utimens (char const *, struct timespec const [2]);
+int lutimens (char const *, struct timespec const [2]);
+
+#if GNULIB_FDUTIMENSAT
+# include <fcntl.h>
+# include <sys/stat.h>
+
+int fdutimensat (int fd, int dir, char const *name, struct timespec const [2],
+                 int atflag);
+
+/* Using this function makes application code slightly more readable.  */
+static inline int
+lutimensat (int dir, char const *file, struct timespec const times[2])
+{
+  return utimensat (dir, file, times, AT_SYMLINK_NOFOLLOW);
+}
+#endif

m4/clock_time.m4

@@ -0,0 +1,31 @@
+# clock_time.m4 serial 10
+dnl Copyright (C) 2002-2006, 2009-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Check for clock_gettime and clock_settime, and set LIB_CLOCK_GETTIME.
+# For a program named, say foo, you should add a line like the following
+# in the corresponding Makefile.am file:
+# foo_LDADD = $(LDADD) $(LIB_CLOCK_GETTIME)
+
+AC_DEFUN([gl_CLOCK_TIME],
+[
+  dnl Persuade glibc and Solaris <time.h> to declare these functions.
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  # Solaris 2.5.1 needs -lposix4 to get the clock_gettime function.
+  # Solaris 7 prefers the library name -lrt to the obsolescent name -lposix4.
+
+  # Save and restore LIBS so e.g., -lrt, isn't added to it.  Otherwise, *all*
+  # programs in the package would end up linked with that potentially-shared
+  # library, inducing unnecessary run-time overhead.
+  LIB_CLOCK_GETTIME=
+  AC_SUBST([LIB_CLOCK_GETTIME])
+  gl_saved_libs=$LIBS
+    AC_SEARCH_LIBS([clock_gettime], [rt posix4],
+                   [test "$ac_cv_search_clock_gettime" = "none required" ||
+                    LIB_CLOCK_GETTIME=$ac_cv_search_clock_gettime])
+    AC_CHECK_FUNCS([clock_gettime clock_settime])
+  LIBS=$gl_saved_libs
+])

m4/gettime.m4

@@ -0,0 +1,13 @@
+# gettime.m4 serial 8
+dnl Copyright (C) 2002, 2004-2006, 2009-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_GETTIME],
+[
+  dnl Prerequisites of lib/gettime.c.
+  AC_REQUIRE([gl_CLOCK_TIME])
+  AC_REQUIRE([gl_TIMESPEC])
+  AC_CHECK_FUNCS_ONCE([gettimeofday nanotime])
+])

m4/gettimeofday.m4

@@ -0,0 +1,140 @@
+# serial 20
+
+# Copyright (C) 2001-2003, 2005, 2007, 2009-2012 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl From Jim Meyering.
+
+AC_DEFUN([gl_FUNC_GETTIMEOFDAY],
+[
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([gl_HEADER_SYS_TIME_H])
+  AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([gettimeofday])
+
+  gl_gettimeofday_timezone=void
+  if test $ac_cv_func_gettimeofday != yes; then
+    HAVE_GETTIMEOFDAY=0
+  else
+    gl_FUNC_GETTIMEOFDAY_CLOBBER
+    AC_CACHE_CHECK([for gettimeofday with POSIX signature],
+      [gl_cv_func_gettimeofday_posix_signature],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[#include <sys/time.h>
+              struct timeval c;
+              int gettimeofday (struct timeval *restrict, void *restrict);
+            ]],
+            [[/* glibc uses struct timezone * rather than the POSIX void *
+                 if _GNU_SOURCE is defined.  However, since the only portable
+                 use of gettimeofday uses NULL as the second parameter, and
+                 since the glibc definition is actually more typesafe, it is
+                 not worth wrapping this to get a compliant signature.  */
+              int (*f) (struct timeval *restrict, void *restrict)
+                = gettimeofday;
+              int x = f (&c, 0);
+              return !(x | c.tv_sec | c.tv_usec);
+            ]])],
+          [gl_cv_func_gettimeofday_posix_signature=yes],
+          [AC_COMPILE_IFELSE(
+            [AC_LANG_PROGRAM(
+              [[#include <sys/time.h>
+int gettimeofday (struct timeval *restrict, struct timezone *restrict);
+              ]])],
+            [gl_cv_func_gettimeofday_posix_signature=almost],
+            [gl_cv_func_gettimeofday_posix_signature=no])])])
+    if test $gl_cv_func_gettimeofday_posix_signature = almost; then
+      gl_gettimeofday_timezone='struct timezone'
+    elif test $gl_cv_func_gettimeofday_posix_signature != yes; then
+      REPLACE_GETTIMEOFDAY=1
+    fi
+    dnl If we override 'struct timeval', we also have to override gettimeofday.
+    if test $REPLACE_STRUCT_TIMEVAL = 1; then
+      REPLACE_GETTIMEOFDAY=1
+    fi
+    m4_ifdef([gl_FUNC_TZSET_CLOBBER], [
+      gl_FUNC_TZSET_CLOBBER
+      case "$gl_cv_func_tzset_clobber" in
+        *yes)
+          REPLACE_GETTIMEOFDAY=1
+          gl_GETTIMEOFDAY_REPLACE_LOCALTIME
+          AC_DEFINE([tzset], [rpl_tzset],
+            [Define to rpl_tzset if the wrapper function should be used.])
+          AC_DEFINE([TZSET_CLOBBERS_LOCALTIME], [1],
+            [Define if tzset clobbers localtime's static buffer.])
+          ;;
+      esac
+    ])
+  fi
+  AC_DEFINE_UNQUOTED([GETTIMEOFDAY_TIMEZONE], [$gl_gettimeofday_timezone],
+    [Define this to 'void' or 'struct timezone' to match the system's
+     declaration of the second argument to gettimeofday.])
+])
+
+
+dnl See if gettimeofday clobbers the static buffer that localtime uses
+dnl for its return value.  The gettimeofday function from Mac OS X 10.0.4
+dnl (i.e., Darwin 1.3.7) has this problem.
+dnl
+dnl If it does, then arrange to use gettimeofday and localtime only via
+dnl the wrapper functions that work around the problem.
+
+AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
+[
+ AC_REQUIRE([gl_HEADER_SYS_TIME_H])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+ AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer],
+  [gl_cv_func_gettimeofday_clobber],
+  [AC_RUN_IFELSE(
+     [AC_LANG_PROGRAM(
+        [[#include <string.h>
+          #include <sys/time.h>
+          #include <time.h>
+          #include <stdlib.h>
+        ]],
+        [[
+          time_t t = 0;
+          struct tm *lt;
+          struct tm saved_lt;
+          struct timeval tv;
+          lt = localtime (&t);
+          saved_lt = *lt;
+          gettimeofday (&tv, NULL);
+          return memcmp (lt, &saved_lt, sizeof (struct tm)) != 0;
+        ]])],
+     [gl_cv_func_gettimeofday_clobber=no],
+     [gl_cv_func_gettimeofday_clobber=yes],
+     [# When cross-compiling:
+      case "$host_os" in
+                # Guess all is fine on glibc systems.
+        *-gnu*) gl_cv_func_gettimeofday_clobber="guessing no" ;;
+                # If we don't know, assume the worst.
+        *)      gl_cv_func_gettimeofday_clobber="guessing yes" ;;
+      esac
+     ])])
+
+ case "$gl_cv_func_gettimeofday_clobber" in
+   *yes)
+     REPLACE_GETTIMEOFDAY=1
+     gl_GETTIMEOFDAY_REPLACE_LOCALTIME
+     AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], [1],
+       [Define if gettimeofday clobbers the localtime buffer.])
+     ;;
+ esac
+])
+
+AC_DEFUN([gl_GETTIMEOFDAY_REPLACE_LOCALTIME], [
+  AC_DEFINE([gmtime], [rpl_gmtime],
+    [Define to rpl_gmtime if the replacement function should be used.])
+  AC_DEFINE([localtime], [rpl_localtime],
+    [Define to rpl_localtime if the replacement function should be used.])
+])
+
+# Prerequisites of lib/gettimeofday.c.
+AC_DEFUN([gl_PREREQ_GETTIMEOFDAY], [
+  AC_CHECK_HEADERS([sys/timeb.h])
+  AC_CHECK_FUNCS([_ftime])
+])

m4/pselect.m4

@@ -0,0 +1,31 @@
+# pselect.m4
+dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_PSELECT],
+[
+  AC_REQUIRE([gl_HEADER_SYS_SELECT])
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_CHECK_FUNCS_ONCE([pselect])
+
+  if test $ac_cv_func_pselect = yes; then
+    AC_CACHE_CHECK([whether signature of pselect conforms to POSIX],
+      gl_cv_sig_pselect,
+      [AC_LINK_IFELSE(
+         [AC_LANG_PROGRAM(
+              [[#include <sys/select.h>
+                ]],
+              [[int (*p) (int, fd_set *, fd_set *, fd_set *restrict,
+                          struct timespec const *restrict,
+                          sigset_t const *restrict) = pselect;
+                return !p;]])],
+         [gl_cv_sig_pselect=yes],
+         [gl_cv_sig_pselect=no])])
+  fi
+
+  if test $ac_cv_func_pselect = no || test $gl_cv_sig_pselect = no; then
+    REPLACE_PSELECT=1
+  fi
+])

m4/stat-time.m4

@@ -0,0 +1,85 @@
+# Checks for stat-related time functions.
+
+# Copyright (C) 1998-1999, 2001, 2003, 2005-2007, 2009-2012 Free Software
+# Foundation, Inc.
+
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl From Paul Eggert.
+
+# st_atim.tv_nsec - Linux, Solaris, Cygwin
+# st_atimespec.tv_nsec - FreeBSD, NetBSD, if ! defined _POSIX_SOURCE
+# st_atimensec - FreeBSD, NetBSD, if defined _POSIX_SOURCE
+# st_atim.st__tim.tv_nsec - UnixWare (at least 2.1.2 through 7.1)
+
+# st_birthtimespec - FreeBSD, NetBSD (hidden on OpenBSD 3.9, anyway)
+# st_birthtim - Cygwin 1.7.0+
+
+AC_DEFUN([gl_STAT_TIME],
+[
+  AC_REQUIRE([AC_C_INLINE])
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_HEADERS_ONCE([sys/time.h])
+
+  AC_CHECK_MEMBERS([struct stat.st_atim.tv_nsec],
+    [AC_CACHE_CHECK([whether struct stat.st_atim is of type struct timespec],
+       [ac_cv_typeof_struct_stat_st_atim_is_struct_timespec],
+       [AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+          [[
+            #include <sys/types.h>
+            #include <sys/stat.h>
+            #if HAVE_SYS_TIME_H
+            # include <sys/time.h>
+            #endif
+            #include <time.h>
+            struct timespec ts;
+            struct stat st;
+          ]],
+          [[
+            st.st_atim = ts;
+          ]])],
+          [ac_cv_typeof_struct_stat_st_atim_is_struct_timespec=yes],
+          [ac_cv_typeof_struct_stat_st_atim_is_struct_timespec=no])])
+     if test $ac_cv_typeof_struct_stat_st_atim_is_struct_timespec = yes; then
+       AC_DEFINE([TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC], [1],
+         [Define to 1 if the type of the st_atim member of a struct stat is
+          struct timespec.])
+     fi],
+    [AC_CHECK_MEMBERS([struct stat.st_atimespec.tv_nsec], [],
+       [AC_CHECK_MEMBERS([struct stat.st_atimensec], [],
+          [AC_CHECK_MEMBERS([struct stat.st_atim.st__tim.tv_nsec], [], [],
+             [#include <sys/types.h>
+              #include <sys/stat.h>])],
+          [#include <sys/types.h>
+           #include <sys/stat.h>])],
+       [#include <sys/types.h>
+        #include <sys/stat.h>])],
+    [#include <sys/types.h>
+     #include <sys/stat.h>])
+])
+
+# Check for st_birthtime, a feature from UFS2 (FreeBSD, NetBSD, OpenBSD, etc.)
+# and NTFS (Cygwin).
+# There was a time when this field was named st_createtime (21 June
+# 2002 to 16 July 2002) But that window is very small and applied only
+# to development code, so systems still using that configuration are
+# not supported.  See revisions 1.10 and 1.11 of FreeBSD's
+# src/sys/ufs/ufs/dinode.h.
+#
+AC_DEFUN([gl_STAT_BIRTHTIME],
+[
+  AC_REQUIRE([AC_C_INLINE])
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_HEADERS_ONCE([sys/time.h])
+  AC_CHECK_MEMBERS([struct stat.st_birthtimespec.tv_nsec], [],
+    [AC_CHECK_MEMBERS([struct stat.st_birthtimensec], [],
+      [AC_CHECK_MEMBERS([struct stat.st_birthtim.tv_nsec], [], [],
+         [#include <sys/types.h>
+          #include <sys/stat.h>])],
+       [#include <sys/types.h>
+        #include <sys/stat.h>])],
+    [#include <sys/types.h>
+     #include <sys/stat.h>])
+])

m4/sys_select_h.m4

@@ -0,0 +1,95 @@
+# sys_select_h.m4 serial 20
+dnl Copyright (C) 2006-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_HEADER_SYS_SELECT],
+[
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([gl_SYS_SELECT_H_DEFAULTS])
+  AC_CACHE_CHECK([whether <sys/select.h> is self-contained],
+    [gl_cv_header_sys_select_h_selfcontained],
+    [
+      dnl Test against two bugs:
+      dnl 1. On many platforms, <sys/select.h> assumes prior inclusion of
+      dnl    <sys/types.h>.
+      dnl 2. On OSF/1 4.0, <sys/select.h> provides only a forward declaration
+      dnl    of 'struct timeval', and no definition of this type.
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/select.h>]],
+                                         [[struct timeval b;]])],
+        [gl_cv_header_sys_select_h_selfcontained=yes],
+        [gl_cv_header_sys_select_h_selfcontained=no])
+      dnl Test against another bug:
+      dnl 3. On Solaris 10, <sys/select.h> provides an FD_ZERO implementation
+      dnl    that relies on memset(), but without including <string.h>.
+      if test $gl_cv_header_sys_select_h_selfcontained = yes; then
+        AC_COMPILE_IFELSE(
+          [AC_LANG_PROGRAM([[#include <sys/select.h>]],
+                           [[int memset; int bzero;]])
+          ],
+          [AC_LINK_IFELSE(
+             [AC_LANG_PROGRAM([[#include <sys/select.h>]], [[
+                  #undef memset
+                  #define memset nonexistent_memset
+                  extern
+                  #ifdef __cplusplus
+                  "C"
+                  #endif
+                  void *memset (void *, int, unsigned long);
+                  #undef bzero
+                  #define bzero nonexistent_bzero
+                  extern
+                  #ifdef __cplusplus
+                  "C"
+                  #endif
+                  void bzero (void *, unsigned long);
+                  fd_set fds;
+                  FD_ZERO (&fds);
+                ]])
+             ],
+             [],
+             [gl_cv_header_sys_select_h_selfcontained=no])
+          ])
+      fi
+    ])
+  dnl <sys/select.h> is always overridden, because of GNULIB_POSIXCHECK.
+  gl_CHECK_NEXT_HEADERS([sys/select.h])
+  if test $ac_cv_header_sys_select_h = yes; then
+    HAVE_SYS_SELECT_H=1
+  else
+    HAVE_SYS_SELECT_H=0
+  fi
+  AC_SUBST([HAVE_SYS_SELECT_H])
+  gl_PREREQ_SYS_H_WINSOCK2
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[
+/* Some systems require prerequisite headers.  */
+#include <sys/types.h>
+#if !(defined __GLIBC__ && !defined __UCLIBC__) && HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include <sys/select.h>
+    ]], [pselect select])
+])
+
+AC_DEFUN([gl_SYS_SELECT_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_SYS_SELECT_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_SYS_SELECT_H_DEFAULTS],
+[
+  GNULIB_PSELECT=0; AC_SUBST([GNULIB_PSELECT])
+  GNULIB_SELECT=0; AC_SUBST([GNULIB_SELECT])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_PSELECT=1; AC_SUBST([HAVE_PSELECT])
+  REPLACE_PSELECT=0; AC_SUBST([REPLACE_PSELECT])
+  REPLACE_SELECT=0; AC_SUBST([REPLACE_SELECT])
+])

m4/sys_socket_h.m4

@@ -0,0 +1,177 @@
+# sys_socket_h.m4 serial 22
+dnl Copyright (C) 2005-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Simon Josefsson.
+
+AC_DEFUN([gl_HEADER_SYS_SOCKET],
+[
+  AC_REQUIRE([gl_SYS_SOCKET_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([AC_C_INLINE])
+
+  dnl On OSF/1, the functions recv(), send(), recvfrom(), sendto() have
+  dnl old-style declarations (with return type 'int' instead of 'ssize_t')
+  dnl unless _POSIX_PII_SOCKET is defined.
+  case "$host_os" in
+    osf*)
+      AC_DEFINE([_POSIX_PII_SOCKET], [1],
+        [Define to 1 in order to get the POSIX compatible declarations
+         of socket functions.])
+      ;;
+  esac
+
+  AC_CACHE_CHECK([whether <sys/socket.h> is self-contained],
+    [gl_cv_header_sys_socket_h_selfcontained],
+    [
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/socket.h>]], [[]])],
+        [gl_cv_header_sys_socket_h_selfcontained=yes],
+        [gl_cv_header_sys_socket_h_selfcontained=no])
+    ])
+  if test $gl_cv_header_sys_socket_h_selfcontained = yes; then
+    dnl If the shutdown function exists, <sys/socket.h> should define
+    dnl SHUT_RD, SHUT_WR, SHUT_RDWR.
+    AC_CHECK_FUNCS([shutdown])
+    if test $ac_cv_func_shutdown = yes; then
+      AC_CACHE_CHECK([whether <sys/socket.h> defines the SHUT_* macros],
+        [gl_cv_header_sys_socket_h_shut],
+        [
+          AC_COMPILE_IFELSE(
+            [AC_LANG_PROGRAM([[#include <sys/socket.h>]],
+               [[int a[] = { SHUT_RD, SHUT_WR, SHUT_RDWR };]])],
+            [gl_cv_header_sys_socket_h_shut=yes],
+            [gl_cv_header_sys_socket_h_shut=no])
+        ])
+      if test $gl_cv_header_sys_socket_h_shut = no; then
+        SYS_SOCKET_H='sys/socket.h'
+      fi
+    fi
+  fi
+  # We need to check for ws2tcpip.h now.
+  gl_PREREQ_SYS_H_SOCKET
+  AC_CHECK_TYPES([struct sockaddr_storage, sa_family_t],,,[
+  /* sys/types.h is not needed according to POSIX, but the
+     sys/socket.h in i386-unknown-freebsd4.10 and
+     powerpc-apple-darwin5.5 required it. */
+#include <sys/types.h>
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_WS2TCPIP_H
+#include <ws2tcpip.h>
+#endif
+])
+  if test $ac_cv_type_struct_sockaddr_storage = no; then
+    HAVE_STRUCT_SOCKADDR_STORAGE=0
+  fi
+  if test $ac_cv_type_sa_family_t = no; then
+    HAVE_SA_FAMILY_T=0
+  fi
+  if test $ac_cv_type_struct_sockaddr_storage != no; then
+    AC_CHECK_MEMBERS([struct sockaddr_storage.ss_family],
+      [],
+      [HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY=0],
+      [#include <sys/types.h>
+       #ifdef HAVE_SYS_SOCKET_H
+       #include <sys/socket.h>
+       #endif
+       #ifdef HAVE_WS2TCPIP_H
+       #include <ws2tcpip.h>
+       #endif
+      ])
+  fi
+  if test $HAVE_STRUCT_SOCKADDR_STORAGE = 0 || test $HAVE_SA_FAMILY_T = 0 \
+     || test $HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY = 0; then
+    SYS_SOCKET_H='sys/socket.h'
+  fi
+  gl_PREREQ_SYS_H_WINSOCK2
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[
+/* Some systems require prerequisite headers.  */
+#include <sys/types.h>
+#include <sys/socket.h>
+    ]], [socket connect accept bind getpeername getsockname getsockopt
+    listen recv send recvfrom sendto setsockopt shutdown accept4])
+])
+
+AC_DEFUN([gl_PREREQ_SYS_H_SOCKET],
+[
+  dnl Check prerequisites of the <sys/socket.h> replacement.
+  AC_REQUIRE([gl_CHECK_SOCKET_HEADERS])
+  gl_CHECK_NEXT_HEADERS([sys/socket.h])
+  if test $ac_cv_header_sys_socket_h = yes; then
+    HAVE_SYS_SOCKET_H=1
+    HAVE_WS2TCPIP_H=0
+  else
+    HAVE_SYS_SOCKET_H=0
+    if test $ac_cv_header_ws2tcpip_h = yes; then
+      HAVE_WS2TCPIP_H=1
+    else
+      HAVE_WS2TCPIP_H=0
+    fi
+  fi
+  AC_SUBST([HAVE_SYS_SOCKET_H])
+  AC_SUBST([HAVE_WS2TCPIP_H])
+])
+
+# Common prerequisites of the <sys/socket.h> replacement and of the
+# <sys/select.h> replacement.
+# Sets and substitutes HAVE_WINSOCK2_H.
+AC_DEFUN([gl_PREREQ_SYS_H_WINSOCK2],
+[
+  m4_ifdef([gl_UNISTD_H_DEFAULTS], [AC_REQUIRE([gl_UNISTD_H_DEFAULTS])])
+  m4_ifdef([gl_SYS_IOCTL_H_DEFAULTS], [AC_REQUIRE([gl_SYS_IOCTL_H_DEFAULTS])])
+  AC_CHECK_HEADERS_ONCE([sys/socket.h])
+  if test $ac_cv_header_sys_socket_h != yes; then
+    dnl We cannot use AC_CHECK_HEADERS_ONCE here, because that would make
+    dnl the check for those headers unconditional; yet cygwin reports
+    dnl that the headers are present but cannot be compiled (since on
+    dnl cygwin, all socket information should come from sys/socket.h).
+    AC_CHECK_HEADERS([winsock2.h])
+  fi
+  if test "$ac_cv_header_winsock2_h" = yes; then
+    HAVE_WINSOCK2_H=1
+    UNISTD_H_HAVE_WINSOCK2_H=1
+    SYS_IOCTL_H_HAVE_WINSOCK2_H=1
+  else
+    HAVE_WINSOCK2_H=0
+  fi
+  AC_SUBST([HAVE_WINSOCK2_H])
+])
+
+AC_DEFUN([gl_SYS_SOCKET_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_SYS_SOCKET_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_SYS_SOCKET_H_DEFAULTS],
+[
+  GNULIB_SOCKET=0;      AC_SUBST([GNULIB_SOCKET])
+  GNULIB_CONNECT=0;     AC_SUBST([GNULIB_CONNECT])
+  GNULIB_ACCEPT=0;      AC_SUBST([GNULIB_ACCEPT])
+  GNULIB_BIND=0;        AC_SUBST([GNULIB_BIND])
+  GNULIB_GETPEERNAME=0; AC_SUBST([GNULIB_GETPEERNAME])
+  GNULIB_GETSOCKNAME=0; AC_SUBST([GNULIB_GETSOCKNAME])
+  GNULIB_GETSOCKOPT=0;  AC_SUBST([GNULIB_GETSOCKOPT])
+  GNULIB_LISTEN=0;      AC_SUBST([GNULIB_LISTEN])
+  GNULIB_RECV=0;        AC_SUBST([GNULIB_RECV])
+  GNULIB_SEND=0;        AC_SUBST([GNULIB_SEND])
+  GNULIB_RECVFROM=0;    AC_SUBST([GNULIB_RECVFROM])
+  GNULIB_SENDTO=0;      AC_SUBST([GNULIB_SENDTO])
+  GNULIB_SETSOCKOPT=0;  AC_SUBST([GNULIB_SETSOCKOPT])
+  GNULIB_SHUTDOWN=0;    AC_SUBST([GNULIB_SHUTDOWN])
+  GNULIB_ACCEPT4=0;     AC_SUBST([GNULIB_ACCEPT4])
+  HAVE_STRUCT_SOCKADDR_STORAGE=1; AC_SUBST([HAVE_STRUCT_SOCKADDR_STORAGE])
+  HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY=1;
+                        AC_SUBST([HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY])
+  HAVE_SA_FAMILY_T=1;   AC_SUBST([HAVE_SA_FAMILY_T])
+  HAVE_ACCEPT4=1;       AC_SUBST([HAVE_ACCEPT4])
+])

m4/sys_time_h.m4

@@ -0,0 +1,106 @@
+# Configure a replacement for <sys/time.h>.
+# serial 8
+
+# Copyright (C) 2007, 2009-2012 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# Written by Paul Eggert and Martin Lambers.
+
+AC_DEFUN([gl_HEADER_SYS_TIME_H],
+[
+  dnl Use AC_REQUIRE here, so that the REPLACE_GETTIMEOFDAY=0 statement
+  dnl below is expanded once only, before all REPLACE_GETTIMEOFDAY=1
+  dnl statements that occur in other macros.
+  AC_REQUIRE([gl_HEADER_SYS_TIME_H_BODY])
+])
+
+AC_DEFUN([gl_HEADER_SYS_TIME_H_BODY],
+[
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
+  AC_CHECK_HEADERS_ONCE([sys/time.h])
+  gl_CHECK_NEXT_HEADERS([sys/time.h])
+
+  if test $ac_cv_header_sys_time_h != yes; then
+    HAVE_SYS_TIME_H=0
+  fi
+
+  dnl On native Windows with MSVC, 'struct timeval' is defined in <winsock2.h>
+  dnl only. So include that header in the list.
+  gl_PREREQ_SYS_H_WINSOCK2
+  AC_CACHE_CHECK([for struct timeval], [gl_cv_sys_struct_timeval],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#if HAVE_SYS_TIME_H
+             #include <sys/time.h>
+            #endif
+            #include <time.h>
+            #if HAVE_WINSOCK2_H
+            # include <winsock2.h>
+            #endif
+          ]],
+          [[static struct timeval x; x.tv_sec = x.tv_usec;]])],
+       [gl_cv_sys_struct_timeval=yes],
+       [gl_cv_sys_struct_timeval=no])
+    ])
+  if test $gl_cv_sys_struct_timeval != yes; then
+    HAVE_STRUCT_TIMEVAL=0
+  else
+    dnl On native Windows with a 64-bit 'time_t', 'struct timeval' is defined
+    dnl (in <sys/time.h> and <winsock2.h> for mingw64, in <winsock2.h> only
+    dnl for MSVC) with a tv_sec field of type 'long' (32-bit!), which is
+    dnl smaller than the 'time_t' type mandated by POSIX.
+    AC_CACHE_CHECK([for correct struct timeval.tv_sec member],
+      [gl_cv_sys_struct_timeval_tv_sec],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[#if HAVE_SYS_TIME_H
+               #include <sys/time.h>
+              #endif
+              #include <time.h>
+              #if HAVE_WINSOCK2_H
+              # include <winsock2.h>
+              #endif
+            ]],
+            [[static struct timeval x;
+              typedef int verify_tv_sec_type[sizeof (x.tv_sec) == sizeof (time_t) ? 1 : -1];
+            ]])],
+         [gl_cv_sys_struct_timeval_tv_sec=yes],
+         [gl_cv_sys_struct_timeval_tv_sec=no])
+      ])
+    if test $gl_cv_sys_struct_timeval_tv_sec != yes; then
+      REPLACE_STRUCT_TIMEVAL=1
+    fi
+  fi
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[
+#if HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include <time.h>
+    ]], [gettimeofday])
+])
+
+AC_DEFUN([gl_SYS_TIME_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_HEADER_SYS_TIME_H_DEFAULTS],
+[
+  GNULIB_GETTIMEOFDAY=0;     AC_SUBST([GNULIB_GETTIMEOFDAY])
+  dnl Assume POSIX behavior unless another module says otherwise.
+  HAVE_GETTIMEOFDAY=1;       AC_SUBST([HAVE_GETTIMEOFDAY])
+  HAVE_STRUCT_TIMEVAL=1;     AC_SUBST([HAVE_STRUCT_TIMEVAL])
+  HAVE_SYS_TIME_H=1;         AC_SUBST([HAVE_SYS_TIME_H])
+  REPLACE_GETTIMEOFDAY=0;    AC_SUBST([REPLACE_GETTIMEOFDAY])
+  REPLACE_STRUCT_TIMEVAL=0;  AC_SUBST([REPLACE_STRUCT_TIMEVAL])
+])

m4/timespec.m4

@@ -0,0 +1,15 @@
+#serial 14
+
+# Copyright (C) 2000-2001, 2003-2007, 2009-2012 Free Software Foundation, Inc.
+
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl From Jim Meyering
+
+AC_DEFUN([gl_TIMESPEC],
+[
+  dnl Prerequisites of lib/timespec.h.
+  AC_REQUIRE([AC_C_INLINE])
+])

m4/utimbuf.m4

@@ -0,0 +1,39 @@
+# serial 9
+
+# Copyright (C) 1998-2001, 2003-2004, 2007, 2009-2012 Free Software Foundation,
+# Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl From Jim Meyering
+
+dnl Define HAVE_STRUCT_UTIMBUF if 'struct utimbuf' is declared --
+dnl usually in <utime.h>.
+dnl Some systems have utime.h but don't declare the struct anywhere.
+
+AC_DEFUN([gl_CHECK_TYPE_STRUCT_UTIMBUF],
+[
+  AC_CHECK_HEADERS_ONCE([sys/time.h utime.h])
+  AC_CACHE_CHECK([for struct utimbuf], [gl_cv_sys_struct_utimbuf],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#if HAVE_SYS_TIME_H
+             #include <sys/time.h>
+            #endif
+            #include <time.h>
+            #ifdef HAVE_UTIME_H
+             #include <utime.h>
+            #endif
+          ]],
+          [[static struct utimbuf x; x.actime = x.modtime;]])],
+       [gl_cv_sys_struct_utimbuf=yes],
+       [gl_cv_sys_struct_utimbuf=no])])
+
+  if test $gl_cv_sys_struct_utimbuf = yes; then
+    AC_DEFINE([HAVE_STRUCT_UTIMBUF], [1],
+      [Define if struct utimbuf is declared -- usually in <utime.h>.
+       Some systems have utime.h but don't declare the struct anywhere. ])
+  fi
+])

m4/utimens.m4

@@ -0,0 +1,50 @@
+dnl Copyright (C) 2003-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl serial 7
+
+AC_DEFUN([gl_UTIMENS],
+[
+  dnl Prerequisites of lib/utimens.c.
+  AC_REQUIRE([gl_FUNC_UTIMES])
+  AC_REQUIRE([gl_CHECK_TYPE_STRUCT_TIMESPEC])
+  AC_REQUIRE([gl_CHECK_TYPE_STRUCT_UTIMBUF])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CHECK_FUNCS_ONCE([futimes futimesat futimens utimensat lutimes])
+
+  if test $ac_cv_func_futimens = no && test $ac_cv_func_futimesat = yes; then
+    dnl FreeBSD 8.0-rc2 mishandles futimesat(fd,NULL,time).  It is not
+    dnl standardized, but Solaris implemented it first and uses it as
+    dnl its only means to set fd time.
+    AC_CACHE_CHECK([whether futimesat handles NULL file],
+      [gl_cv_func_futimesat_works],
+      [touch conftest.file
+       AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <stddef.h>
+#include <sys/times.h>
+#include <fcntl.h>
+]], [[    int fd = open ("conftest.file", O_RDWR);
+          if (fd < 0) return 1;
+          if (futimesat (fd, NULL, NULL)) return 2;
+        ]])],
+        [gl_cv_func_futimesat_works=yes],
+        [gl_cv_func_futimesat_works=no],
+        [case "$host_os" in
+                   # Guess yes on glibc systems.
+           *-gnu*) gl_cv_func_futimesat_works="guessing yes" ;;
+                   # If we don't know, assume the worst.
+           *)      gl_cv_func_futimesat_works="guessing no" ;;
+         esac
+        ])
+      rm -f conftest.file])
+    case "$gl_cv_func_futimesat_works" in
+      *yes) ;;
+      *)
+        AC_DEFINE([FUTIMESAT_NULL_BUG], [1],
+          [Define to 1 if futimesat mishandles a NULL file name.])
+        ;;
+    esac
+  fi
+])

m4/utimes.m4

@@ -0,0 +1,136 @@
+# Detect some bugs in glibc's implementation of utimes.
+# serial 3
+
+dnl Copyright (C) 2003-2005, 2009-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# See if we need to work around bugs in glibc's implementation of
+# utimes from 2003-07-12 to 2003-09-17.
+# First, there was a bug that would make utimes set mtime
+# and atime to zero (1970-01-01) unconditionally.
+# Then, there was code to round rather than truncate.
+# Then, there was an implementation (sparc64, Linux-2.4.28, glibc-2.3.3)
+# that didn't honor the NULL-means-set-to-current-time semantics.
+# Finally, there was also a version of utimes that failed on read-only
+# files, while utime worked fine (linux-2.2.20, glibc-2.2.5).
+#
+# From Jim Meyering, with suggestions from Paul Eggert.
+
+AC_DEFUN([gl_FUNC_UTIMES],
+[
+  AC_CACHE_CHECK([whether the utimes function works],
+                 [gl_cv_func_working_utimes],
+  [
+  AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <utime.h>
+
+static int
+inorder (time_t a, time_t b, time_t c)
+{
+  return a <= b && b <= c;
+}
+
+int
+main ()
+{
+  int result = 0;
+  char const *file = "conftest.utimes";
+  static struct timeval timeval[2] = {{9, 10}, {999999, 999999}};
+
+  /* Test whether utimes() essentially works.  */
+  {
+    struct stat sbuf;
+    FILE *f = fopen (file, "w");
+    if (f == NULL)
+      result |= 1;
+    else if (fclose (f) != 0)
+      result |= 1;
+    else if (utimes (file, timeval) != 0)
+      result |= 2;
+    else if (lstat (file, &sbuf) != 0)
+      result |= 1;
+    else if (!(sbuf.st_atime == timeval[0].tv_sec
+               && sbuf.st_mtime == timeval[1].tv_sec))
+      result |= 4;
+    if (unlink (file) != 0)
+      result |= 1;
+  }
+
+  /* Test whether utimes() with a NULL argument sets the file's timestamp
+     to the current time.  Use 'fstat' as well as 'time' to
+     determine the "current" time, to accommodate NFS file systems
+     if there is a time skew between the host and the NFS server.  */
+  {
+    int fd = open (file, O_WRONLY|O_CREAT, 0644);
+    if (fd < 0)
+      result |= 1;
+    else
+      {
+        time_t t0, t2;
+        struct stat st0, st1, st2;
+        if (time (&t0) == (time_t) -1)
+          result |= 1;
+        else if (fstat (fd, &st0) != 0)
+          result |= 1;
+        else if (utimes (file, timeval) != 0)
+          result |= 2;
+        else if (utimes (file, NULL) != 0)
+          result |= 8;
+        else if (fstat (fd, &st1) != 0)
+          result |= 1;
+        else if (write (fd, "\n", 1) != 1)
+          result |= 1;
+        else if (fstat (fd, &st2) != 0)
+          result |= 1;
+        else if (time (&t2) == (time_t) -1)
+          result |= 1;
+        else
+          {
+            int m_ok_POSIX = inorder (t0, st1.st_mtime, t2);
+            int m_ok_NFS = inorder (st0.st_mtime, st1.st_mtime, st2.st_mtime);
+            if (! (st1.st_atime == st1.st_mtime))
+              result |= 16;
+            if (! (m_ok_POSIX || m_ok_NFS))
+              result |= 32;
+          }
+        if (close (fd) != 0)
+          result |= 1;
+      }
+    if (unlink (file) != 0)
+      result |= 1;
+  }
+
+  /* Test whether utimes() with a NULL argument works on read-only files.  */
+  {
+    int fd = open (file, O_WRONLY|O_CREAT, 0444);
+    if (fd < 0)
+      result |= 1;
+    else if (close (fd) != 0)
+      result |= 1;
+    else if (utimes (file, NULL) != 0)
+      result |= 64;
+    if (unlink (file) != 0)
+      result |= 1;
+  }
+
+  return result;
+}
+  ]])],
+       [gl_cv_func_working_utimes=yes],
+       [gl_cv_func_working_utimes=no],
+       [gl_cv_func_working_utimes=no])])
+
+  if test $gl_cv_func_working_utimes = yes; then
+    AC_DEFINE([HAVE_WORKING_UTIMES], [1], [Define if utimes works properly. ])
+  fi
+])