[PATCH 1/3] io: Consolidate fts implementation

Carlos O'Donell carlos@redhat.com
Fri Apr 17 20:09:45 GMT 2026


On 4/17/26 1:31 PM, Adhemerval Zanella Netto wrote:
> This is a mechanical patch and I install if no one opposes it.

Please feel free to push if it is just a mechanical sync from gnulib.

> On 17/04/26 10:24, Adhemerval Zanella wrote:
>> Remove wordsize-64 and arch-specific implementations, for ABIs when
>> off_t is the same as off64_t (__OFF_T_MATCHES_OFF64_T) the fts64.c
>> will create the requires aliases.
>>
>> The fts.c implementation is moved to fts-common.c to simplify
>> the __OFF_T_MATCHES_OFF64_T usage.
>> ---
>>   SHARED-FILES                                  |    2 +-
>>   io/fts-common.c                               | 2208 ++++++++++++++++
>>   io/fts.c                                      | 2217 +----------------
>>   io/fts64-time64.c                             |    2 +-
>>   io/fts64.c                                    |   38 +-
>>   sysdeps/unix/sysv/linux/mips/mips64/n64/fts.c |    1 -
>>   .../unix/sysv/linux/mips/mips64/n64/fts64.c   |    1 -
>>   sysdeps/unix/sysv/linux/x86_64/x32/fts.c      |    1 -
>>   sysdeps/unix/sysv/linux/x86_64/x32/fts64.c    |    1 -
>>   sysdeps/wordsize-64/fts.c                     |   19 -
>>   sysdeps/wordsize-64/fts64.c                   |    1 -
>>   11 files changed, 2258 insertions(+), 2233 deletions(-)
>>   create mode 100644 io/fts-common.c
>>   delete mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/fts.c
>>   delete mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/fts64.c
>>   delete mode 100644 sysdeps/unix/sysv/linux/x86_64/x32/fts.c
>>   delete mode 100644 sysdeps/unix/sysv/linux/x86_64/x32/fts64.c
>>   delete mode 100644 sysdeps/wordsize-64/fts.c
>>   delete mode 100644 sysdeps/wordsize-64/fts64.c
>>
>> diff --git a/SHARED-FILES b/SHARED-FILES
>> index 126aaf096d..645040d7e1 100644
>> --- a/SHARED-FILES
>> +++ b/SHARED-FILES
>> @@ -49,7 +49,7 @@ gnulib:
>>     io/cycle-check.h
>>     io/dev-ino.h
>>     io/fts-cycle.c
>> -  io/fts.c
>> +  io/fts-common.c
>>     io/i-ring.c
>>     io/same-inode.h
>>     locale/programs/3level.h
>> diff --git a/io/fts-common.c b/io/fts-common.c
>> new file mode 100644
>> index 0000000000..3825f0aeb4
>> --- /dev/null
>> +++ b/io/fts-common.c
>> @@ -0,0 +1,2208 @@
>> +/* Traverse a file hierarchy.
>> +
>> +   Copyright (C) 2004-2026 Free Software Foundation, Inc.
>> +
>> +   This file is free software: you can redistribute it and/or modify
>> +   it under the terms of the GNU Lesser General Public License as
>> +   published by the Free Software Foundation; either version 2.1 of the
>> +   License, or (at your option) any later version.
>> +
>> +   This file 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 Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public License
>> +   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
>> +
>> +/*-
>> + * Copyright (c) 1990, 1993, 1994
>> + *      The Regents of the University of California.  All rights reserved.
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + * 1. Redistributions of source code must retain the above copyright
>> + *    notice, this list of conditions and the following disclaimer.
>> + * 2. Redistributions in binary form must reproduce the above copyright
>> + *    notice, this list of conditions and the following disclaimer in the
>> + *    documentation and/or other materials provided with the distribution.
>> + * 4. Neither the name of the University nor the names of its contributors
>> + *    may be used to endorse or promote products derived from this software
>> + *    without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
>> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
>> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
>> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
>> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
>> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
>> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
>> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
>> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
>> + * SUCH DAMAGE.
>> + */
>> +
>> +#include <config.h>
>> +
>> +#if defined LIBC_SCCS && !defined GCC_LINT && !defined lint
>> +static char sccsid[] = "@(#)fts.c       8.6 (Berkeley) 8/14/94";
>> +#endif
>> +
>> +#if _LIBC
>> +# include <fts.h>
>> +#else
>> +# include "fts_.h"
>> +#endif
>> +#if _LIBC || HAVE_SYS_PARAM_H
>> +# include <sys/param.h>
>> +#endif
>> +#include <sys/stat.h>
>> +#include <fcntl.h>
>> +#include <errno.h>
>> +#include <stddef.h>
>> +#include <stdint.h>
>> +#include <stdlib.h>
>> +#include <string.h>
>> +#include <unistd.h>
>> +
>> +/* Support for the LFS API version.  */
>> +#ifndef FTS_OPEN
>> +# define FTS_OPEN fts_open
>> +# define FTS_CLOSE fts_close
>> +# define FTS_READ fts_read
>> +# define FTS_SET fts_set
>> +# define FTS_CHILDREN fts_children
>> +# define FTSOBJ FTS
>> +# define FTSENTRY FTSENT
>> +# define INO_T ino_t
>> +# define STRUCT_STAT stat
>> +# define FSTAT __fstat
>> +# define FSTATAT __fstatat
>> +# define STRUCT_STATFS statfs
>> +# define FSTATFS __fstatfs
>> +#endif
>> +
>> +#if ! _LIBC
>> +# include "attribute.h"
>> +# include "fcntl--.h"
>> +# include "openat.h"
>> +# include "opendirat.h"
>> +# include "same-inode.h"
>> +# define OPENDIRAT opendirat
>> +# define FTSENT_WRAPPER(__p) __p
>> +# define FTS_COMPAR_CAST(__fn) __fn
>> +#else
>> +# include <stdbool.h>
>> +
>> +# define internal_function
>> +# define FALLTHROUGH               ; [[fallthrough]]
>> +# define HAVE_STRUCT_DIRENT_D_TYPE 1
>> +# define GNULIB_FTS_DEBUG          0
>> +# ifdef O_PATH
>> +#  define O_SEARCH                 O_PATH
>> +# else
>> +#  define O_SEARCH                 O_RDONLY
>> +# endif
>> +# define HAVE_SYS_VFS_H            1
>> +# define HAVE_FSTATFS              1
>> +# define HAVE_STRUCT_STATFS_F_TYPE 1
>> +# define HAVE_OPENAT               1
>> +# define HAVE_WORKING_O_NOFOLLOW   1
>> +# define _GL_CMP(a, b)             ((a) < (b) ? -1 : (a) > (b))
>> +# define OPENDIRAT                 __opendirat
>> +
>> +static inline bool openat_needs_fchdir (void)
>> +{
>> +  return false;
>> +}
>> +
>> +static inline bool streq (const char *s1, const char *s2)
>> +{
>> +  return strcmp (s1, s2) == 0;
>> +}
>> +# define reallocarray              __libc_reallocarray
>> +# define fchdir                    __fchdir
>> +# define close                     __close
>> +# define closedir                  __closedir
>> +# define fcntl                     __fcntl
>> +# define readdir                   __readdir
>> +# ifndef dirfd
>> +#  define dirfd                    __dirfd
>> +# endif
>> +# define open                      __open
>> +# define openat                    __openat
>> +
>> +# include "cycle-check.c"
>> +# include "i-ring.c"
>> +
>> +struct FTSENT_wrapper
>> +{
>> +  FTSOBJ *fts_fts;                /* the file hierarchy itself */
>> +  DIR *fts_dirp;                  /* Dir pointer for any directory containing
>> +				     more entries than we read at one time.  */
>> +  struct STRUCT_STAT fts_stat;
>> +
>> +  FTSENTRY ent;
>> +};
>> +
>> +/* glibc historicaly defines the FTS::fts_compar as having 'void *', while the
>> +   fts_open has a function point using 'FTSENT **' as argument.  */
>> +# define FTS_COMPAR_CAST(__fn) ((int (*) (void const *, void const *))__fn)
>> +
>> +# define FTSENT_WRAPPER(p) \
>> +    ((struct FTSENT_wrapper *) ((char *)(p) - offsetof(struct FTSENT_wrapper, ent)))
>> +#endif
>> +#define FTSENT_FTS(p)   (FTSENT_WRAPPER(p)->fts_fts)
>> +#define FTSENT_DIRP(p)  (FTSENT_WRAPPER(p)->fts_dirp)
>> +
>> +#include "flexmember.h"
>> +
>> +#include <dirent.h>
>> +#ifndef _D_EXACT_NAMLEN
>> +# define _D_EXACT_NAMLEN(dirent) strlen ((dirent)->d_name)
>> +#endif
>> +
>> +#if HAVE_STRUCT_DIRENT_D_TYPE
>> +/* True if the type of the directory entry D is known.  */
>> +# define DT_IS_KNOWN(d) ((d)->d_type != DT_UNKNOWN)
>> +/* True if the type of the directory entry D must be T.  */
>> +# define DT_MUST_BE(d, t) ((d)->d_type == (t))
>> +# define D_TYPE(d) ((d)->d_type)
>> +#else
>> +# define DT_IS_KNOWN(d) false
>> +# define DT_MUST_BE(d, t) false
>> +# define D_TYPE(d) DT_UNKNOWN
>> +
>> +# undef DT_UNKNOWN
>> +# define DT_UNKNOWN 0
>> +
>> +/* Any nonzero values will do here, so long as they're distinct.
>> +   Undef any existing macros out of the way.  */
>> +# undef DT_BLK
>> +# undef DT_CHR
>> +# undef DT_DIR
>> +# undef DT_FIFO
>> +# undef DT_LNK
>> +# undef DT_REG
>> +# undef DT_SOCK
>> +# define DT_BLK 1
>> +# define DT_CHR 2
>> +# define DT_DIR 3
>> +# define DT_FIFO 4
>> +# define DT_LNK 5
>> +# define DT_REG 6
>> +# define DT_SOCK 7
>> +#endif
>> +
>> +#ifndef S_IFBLK
>> +# define S_IFBLK 0
>> +#endif
>> +#ifndef S_IFLNK
>> +# define S_IFLNK 0
>> +#endif
>> +#ifndef S_IFSOCK
>> +# define S_IFSOCK 0
>> +#endif
>> +
>> +enum
>> +{
>> +  NOT_AN_INODE_NUMBER = 0
>> +};
>> +
>> +#ifdef D_INO_IN_DIRENT
>> +# define D_INO(dp) (dp)->d_ino
>> +#else
>> +/* Some systems don't have inodes, so fake them to avoid lots of ifdefs.  */
>> +# define D_INO(dp) NOT_AN_INODE_NUMBER
>> +#endif
>> +
>> +/* If possible (see max_entries, below), read no more than this many directory
>> +   entries at a time.  Without this limit (i.e., when using non-NULL
>> +   fts_compar), processing a directory with 4,000,000 entries requires ~1GiB
>> +   of memory, and handling 64M entries would require 16GiB of memory.  */
>> +#ifndef FTS_MAX_READDIR_ENTRIES
>> +# define FTS_MAX_READDIR_ENTRIES 100000
>> +#endif
>> +
>> +/* If there are more than this many entries in a directory,
>> +   and the conditions mentioned below are satisfied, then sort
>> +   the entries on inode number before any further processing.  */
>> +#ifndef FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
>> +# define FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD 10000
>> +#endif
>> +
>> +enum
>> +{
>> +  _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD = FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
>> +};
>> +
>> +enum Fts_stat
>> +{
>> +  FTS_NO_STAT_REQUIRED = 1,
>> +  FTS_STAT_REQUIRED = 2
>> +};
>> +
>> +#ifndef __set_errno
>> +# define __set_errno(Val) errno = (Val)
>> +#endif
>> +
>> +/* If this host provides the openat function, then we can avoid
>> +   attempting to open "." in some initialization code below.  */
>> +#ifdef HAVE_OPENAT
>> +# define HAVE_OPENAT_SUPPORT 1
>> +#else
>> +# define HAVE_OPENAT_SUPPORT 0
>> +#endif
>> +
>> +#ifdef NDEBUG
>> +# define fts_assert(expr) ((void) (0 && (expr)))
>> +#else
>> +# define fts_assert(expr)       \
>> +    do                          \
>> +      {                         \
>> +        if (!(expr))            \
>> +          abort ();             \
>> +      }                         \
>> +    while (false)
>> +#endif
>> +
>> +static FTSENTRY  *fts_alloc (FTSOBJ *, const char *, size_t);
>> +static FTSENTRY  *fts_build (FTSOBJ *, int);
>> +static void      fts_lfree (FTSENTRY *);
>> +static void      fts_load (FTSOBJ *, FTSENTRY *);
>> +static size_t    fts_maxarglen (char * const *);
>> +static void      fts_padjust (FTSOBJ *, FTSENTRY *);
>> +static bool      fts_palloc (FTSOBJ *, size_t);
>> +static FTSENTRY  *fts_sort (FTSOBJ *, FTSENTRY *, size_t);
>> +static unsigned short int fts_stat (FTSOBJ *, FTSENTRY *, bool);
>> +static int      fts_safe_changedir (FTSOBJ *, FTSENTRY *, int, const char *);
>> +
>> +#include "fts-cycle.c"
>> +
>> +#ifndef MAX
>> +# define MAX(a,b) ((a) > (b) ? (a) : (b))
>> +#endif
>> +
>> +#ifndef SIZE_MAX
>> +# define SIZE_MAX ((size_t) -1)
>> +#endif
>> +
>> +#define ISDOT(a)        (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
>> +
>> +#define CLR(opt)        (sp->fts_options &= ~(opt))
>> +#define ISSET(opt)      ((sp->fts_options & (opt)) != 0)
>> +#define SET(opt)        (sp->fts_options |= (opt))
>> +
>> +/* FIXME: FTS_NOCHDIR is now misnamed.
>> +   Call it FTS_USE_FULL_RELATIVE_FILE_NAMES instead. */
>> +#define FCHDIR(sp, fd)                                  \
>> +  (!ISSET(FTS_NOCHDIR) && (ISSET(FTS_CWDFD)             \
>> +                           ? (cwd_advance_fd ((sp), (fd), true), 0) \
>> +                           : fchdir (fd)))
>> +
>> +
>> +/* fts_build flags */
>> +/* FIXME: make this an enum */
>> +#define BCHILD          1               /* fts_children */
>> +#define BNAMES          2               /* fts_children, names only */
>> +#define BREAD           3               /* fts_read */
>> +
>> +#if GNULIB_FTS_DEBUG
>> +# include <inttypes.h>
>> +# include <stdio.h>
>> +bool fts_debug = false;
>> +# define Dprintf(x) do { if (fts_debug) printf x; } while (false)
>> +static void fd_ring_check (FTSOBJ const *);
>> +static void fd_ring_print (FTSOBJ const *, FILE *, char const *);
>> +#else
>> +# define Dprintf(x)
>> +# define fd_ring_check(x)
>> +# define fd_ring_print(a, b, c)
>> +#endif
>> +
>> +#define LEAVE_DIR(Fts, Ent, Tag)                                \
>> +  do                                                            \
>> +    {                                                           \
>> +      Dprintf (("  %s-leaving: %s\n", Tag, (Ent)->fts_path));   \
>> +      leave_dir (Fts, Ent);                                     \
>> +      fd_ring_check (Fts);                                      \
>> +    }                                                           \
>> +  while (false)
>> +
>> +static void
>> +fd_ring_clear (I_ring *fd_ring)
>> +{
>> +  while ( ! i_ring_empty (fd_ring))
>> +    {
>> +      int fd = i_ring_pop (fd_ring);
>> +      if (0 <= fd)
>> +        close (fd);
>> +    }
>> +}
>> +
>> +/* Overload the fts_statp->st_size member (otherwise unused, when
>> +   fts_info is FTS_NSOK) to indicate whether fts_read should stat
>> +   this entry or not.  */
>> +static void
>> +fts_set_stat_required (FTSENTRY *p, bool required)
>> +{
>> +  fts_assert (p->fts_info == FTS_NSOK);
>> +  p->fts_statp->st_size = (required
>> +                           ? FTS_STAT_REQUIRED
>> +                           : FTS_NO_STAT_REQUIRED);
>> +}
>> +
>> +/* Virtual fchdir.  Advance SP's working directory file descriptor,
>> +   SP->fts_cwd_fd, to FD, and push the previous value onto the fd_ring.
>> +   CHDIR_DOWN_ONE is true if FD corresponds to an entry in the directory
>> +   open on sp->fts_cwd_fd; i.e., to move the working directory one level
>> +   down.  */
>> +static void
>> +internal_function
>> +cwd_advance_fd (FTSOBJ *sp, int fd, bool chdir_down_one)
>> +{
>> +  int old = sp->fts_cwd_fd;
>> +  fts_assert (old != fd || old == AT_FDCWD);
>> +
>> +  if (chdir_down_one)
>> +    {
>> +      /* Push "old" onto the ring.
>> +         If the displaced file descriptor is non-negative, close it.  */
>> +      int prev_fd_in_slot = i_ring_push (&sp->fts_fd_ring, old);
>> +      fd_ring_print (sp, stderr, "post-push");
>> +      if (0 <= prev_fd_in_slot)
>> +        close (prev_fd_in_slot); /* ignore any close failure */
>> +    }
>> +  else if ( ! ISSET (FTS_NOCHDIR))
>> +    {
>> +      if (0 <= old)
>> +        close (old); /* ignore any close failure */
>> +    }
>> +
>> +  sp->fts_cwd_fd = fd;
>> +}
>> +
>> +/* Restore the initial, pre-traversal, "working directory".
>> +   In FTS_CWDFD mode, we merely call cwd_advance_fd, otherwise,
>> +   we may actually change the working directory.
>> +   Return 0 upon success. Upon failure, set errno and return nonzero.  */
>> +static int
>> +restore_initial_cwd (FTSOBJ *sp)
>> +{
>> +  int fail = FCHDIR (sp, ISSET (FTS_CWDFD) ? AT_FDCWD : sp->fts_rfd);
>> +  fd_ring_clear (&(sp->fts_fd_ring));
>> +  return fail;
>> +}
>> +
>> +/* Open the directory DIR if possible, and return a file
>> +   descriptor.  Return -1 and set errno on failure.  It doesn't matter
>> +   whether the file descriptor has read or write access.  */
>> +
>> +static int
>> +internal_function
>> +diropen (FTSOBJ const *sp, char const *dir)
>> +{
>> +  int open_flags = (O_SEARCH | O_CLOEXEC | O_DIRECTORY | O_NOCTTY | O_NONBLOCK
>> +                    | (ISSET (FTS_PHYSICAL) ? O_NOFOLLOW : 0));
>> +
>> +  int fd = (ISSET (FTS_CWDFD)
>> +            ? openat (sp->fts_cwd_fd, dir, open_flags)
>> +            : open (dir, open_flags));
>> +  return fd;
>> +}
>> +
>> +FTSOBJ *
>> +FTS_OPEN (char * const *argv,
>> +          register int options,
>> +          int (*compar) (const FTSENTRY **, const FTSENTRY **))
>> +{
>> +        /* Options check: glibc added other flags after FTS_NAMEONLY and
>> +	   FTS_STOP, and they are assumed to be private.  */
>> +        if (options & ~FTS_OPTIONMASK
>> +#if _LIBC
>> +	    || options & (FTS_NAMEONLY | FTS_STOP)
>> +#endif
>> +	    ) {
>> +                __set_errno (EINVAL);
>> +                return (NULL);
>> +        }
>> +        if ((options & FTS_NOCHDIR) && (options & FTS_CWDFD)) {
>> +                __set_errno (EINVAL);
>> +                return (NULL);
>> +        }
>> +#if !_LIBC
>> +        if ( ! (options & (FTS_LOGICAL | FTS_PHYSICAL))) {
>> +                __set_errno (EINVAL);
>> +                return (NULL);
>> +        }
>> +#else
>> +	/* glibc historically falls to FTS_PHYSICAL if no FTS_PHYSICAL or
>> +	   FTS_LOGICAL is specified.  */
>> +        if (! (options & (FTS_PHYSICAL | FTS_LOGICAL)))
>> +	  options |= FTS_PHYSICAL;
>> +#endif
>> +
>> +        /* Allocate/initialize the stream */
>> +        register FTSOBJ *sp = calloc (1, sizeof *sp);
>> +        if (sp == NULL)
>> +                return (NULL);
>> +        sp->fts_compar = FTS_COMPAR_CAST(compar);
>> +        sp->fts_options = options;
>> +
>> +        /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
>> +        if (ISSET(FTS_LOGICAL)) {
>> +                SET(FTS_NOCHDIR);
>> +                CLR(FTS_CWDFD);
>> +        }
>> +
>> +        /* Initialize fts_cwd_fd.  */
>> +        sp->fts_cwd_fd = AT_FDCWD;
>> +        if ( ISSET(FTS_CWDFD) && ! HAVE_OPENAT_SUPPORT)
>> +          {
>> +            /* While it isn't technically necessary to open "." this
>> +               early, doing it here saves us the trouble of ensuring
>> +               later (where it'd be messier) that "." can in fact
>> +               be opened.  If not, revert to FTS_NOCHDIR mode.  */
>> +            int fd = open (".", O_SEARCH | O_CLOEXEC);
>> +            if (fd < 0)
>> +              {
>> +                /* Even if "." is unreadable, don't revert to FTS_NOCHDIR mode
>> +                   on systems like Linux+PROC_FS, where our openat emulation
>> +                   is good enough.  Note: on a system that emulates
>> +                   openat via /proc, this technique can still fail, but
>> +                   only in extreme conditions, e.g., when the working
>> +                   directory cannot be saved (i.e. save_cwd fails) --
>> +                   and that happens on Linux only when "." is unreadable
>> +                   and the CWD would be longer than PATH_MAX.
>> +                   FIXME: once Linux kernel openat support is well established,
>> +                   replace the above open call and this entire if/else block
>> +                   with the body of the if-block below.  */
>> +                if ( openat_needs_fchdir ())
>> +                  {
>> +                    SET(FTS_NOCHDIR);
>> +                    CLR(FTS_CWDFD);
>> +                  }
>> +              }
>> +            else
>> +              {
>> +                close (fd);
>> +              }
>> +          }
>> +
>> +        /*
>> +         * Start out with 1K of file name space, and enough, in any case,
>> +         * to hold the user's file names.
>> +         */
>> +#ifndef MAXPATHLEN
>> +# define MAXPATHLEN 1024
>> +#endif
>> +        {
>> +          size_t maxarglen = fts_maxarglen(argv);
>> +          if (! fts_palloc(sp, MAX(maxarglen, MAXPATHLEN)))
>> +                  goto mem1;
>> +        }
>> +
>> +        /* Allocate/initialize root's parent. */
>> +        FTSENTRY *parent = NULL;
>> +        if (*argv != NULL) {
>> +                if ((parent = fts_alloc(sp, "", 0)) == NULL)
>> +                        goto mem2;
>> +                parent->fts_level = FTS_ROOTPARENTLEVEL;
>> +          }
>> +
>> +        /* The classic fts implementation would call fts_stat with
>> +           a new entry for each iteration of the loop below.
>> +           If the comparison function is not specified or if the
>> +           FTS_DEFER_STAT option is in effect, don't stat any entry
>> +           in this loop.  This is an attempt to minimize the interval
>> +           between the initial stat/lstat/fstatat and the point at which
>> +           a directory argument is first opened.  This matters for any
>> +           directory command line argument that resides on a file system
>> +           without genuine i-nodes.  If you specify FTS_DEFER_STAT along
>> +           with a comparison function, that function must not access any
>> +           data via the fts_statp pointer.  */
>> +        bool defer_stat = (compar == NULL || ISSET(FTS_DEFER_STAT));
>> +
>> +        /* Allocate/initialize root(s). */
>> +        register FTSENTRY *root;
>> +        register size_t nitems;
>> +        FTSENTRY *tmp = NULL;     /* pacify gcc */
>> +        for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
>> +                /* *Do* allow zero-length file names. */
>> +                size_t len = strlen(*argv);
>> +
>> +                if ( ! (options & FTS_VERBATIM))
>> +                  {
>> +                    /* If there are two or more trailing slashes, trim all but one,
>> +                       but don't change "//" to "/", and do map "///" to "/".  */
>> +                    char const *v = *argv;
>> +                    if (2 < len && v[len - 1] == '/')
>> +                      while (1 < len && v[len - 2] == '/')
>> +                        --len;
>> +                  }
>> +
>> +                register FTSENTRY *p = fts_alloc(sp, *argv, len);
>> +                if (p == NULL)
>> +                        goto mem3;
>> +                p->fts_level = FTS_ROOTLEVEL;
>> +                p->fts_parent = parent;
>> +                p->fts_accpath = p->fts_name;
>> +                /* Even when defer_stat is true, be sure to stat the first
>> +                   command line argument, since fts_read (at least with
>> +                   FTS_XDEV) requires that.  */
>> +                if (defer_stat && root != NULL) {
>> +                        p->fts_info = FTS_NSOK;
>> +                        fts_set_stat_required(p, true);
>> +                } else {
>> +                        p->fts_info = fts_stat(sp, p, false);
>> +                }
>> +
>> +                /*
>> +                 * If comparison routine supplied, traverse in sorted
>> +                 * order; otherwise traverse in the order specified.
>> +                 */
>> +                if (compar) {
>> +                        p->fts_link = root;
>> +                        root = p;
>> +                } else {
>> +                        p->fts_link = NULL;
>> +                        if (root == NULL)
>> +                                tmp = root = p;
>> +                        else {
>> +                                tmp->fts_link = p;
>> +                                tmp = p;
>> +                        }
>> +                }
>> +        }
>> +        if (compar && nitems > 1)
>> +                root = fts_sort(sp, root, nitems);
>> +
>> +        /*
>> +         * Allocate a dummy pointer and make fts_read think that we've just
>> +         * finished the node before the root(s); set p->fts_info to FTS_INIT
>> +         * so that everything about the "current" node is ignored.
>> +         */
>> +        if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
>> +                goto mem3;
>> +        sp->fts_cur->fts_link = root;
>> +        sp->fts_cur->fts_info = FTS_INIT;
>> +        sp->fts_cur->fts_level = 1;
>> +        if (! setup_dir (sp))
>> +                goto mem3;
>> +
>> +        /*
>> +         * If using chdir(2), grab a file descriptor pointing to dot to ensure
>> +         * that we can get back here; this could be avoided for some file names,
>> +         * but almost certainly not worth the effort.  Slashes, symbolic links,
>> +         * and ".." are all fairly nasty problems.  Note, if we can't get the
>> +         * descriptor we run anyway, just more slowly.
>> +         */
>> +        if (!ISSET(FTS_NOCHDIR) && !ISSET(FTS_CWDFD)
>> +            && (sp->fts_rfd = diropen (sp, ".")) < 0)
>> +                SET(FTS_NOCHDIR);
>> +
>> +        i_ring_init (&sp->fts_fd_ring, -1);
>> +        return (sp);
>> +
>> +mem3:   fts_lfree(root);
>> +        free(FTSENT_WRAPPER(parent));
>> +mem2:   free(sp->fts_path);
>> +mem1:   free(sp);
>> +        return (NULL);
>> +}
>> +
>> +static void
>> +internal_function
>> +fts_load (FTSOBJ *sp, register FTSENTRY *p)
>> +{
>> +        /*
>> +         * Load the stream structure for the next traversal.  Since we don't
>> +         * actually enter the directory until after the preorder visit, set
>> +         * the fts_accpath field specially so the chdir gets done to the right
>> +         * place and the user can access the first node.  From fts_open it's
>> +         * known that the file name will fit.
>> +         */
>> +        register size_t len = p->fts_pathlen = p->fts_namelen;
>> +        memmove(sp->fts_path, p->fts_name, len + 1);
>> +        register char *cp = strrchr(p->fts_name, '/');
>> +        if (cp && (cp != p->fts_name || cp[1])) {
>> +                len = strlen(++cp);
>> +                memmove(p->fts_name, cp, len + 1);
>> +                p->fts_namelen = len;
>> +        }
>> +        p->fts_accpath = p->fts_path = sp->fts_path;
>> +}
>> +
>> +int
>> +FTS_CLOSE (FTSOBJ *sp)
>> +{
>> +        /*
>> +         * This still works if we haven't read anything -- the dummy structure
>> +         * points to the root list, so we step through to the end of the root
>> +         * list which has a valid parent pointer.
>> +         */
>> +        if (sp->fts_cur) {
>> +                register FTSENTRY *p;
>> +                for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
>> +                        register FTSENTRY *freep = p;
>> +                        p = p->fts_link != NULL ? p->fts_link : p->fts_parent;
>> +                        free(FTSENT_WRAPPER(freep));
>> +                }
>> +                free(FTSENT_WRAPPER(p));
>> +        }
>> +
>> +        /* Free up child linked list, sort array, file name buffer. */
>> +        if (sp->fts_child)
>> +                fts_lfree(sp->fts_child);
>> +        free(sp->fts_array);
>> +        free(sp->fts_path);
>> +
>> +        int saved_errno = 0;
>> +        if (ISSET(FTS_CWDFD))
>> +          {
>> +            if (0 <= sp->fts_cwd_fd)
>> +              if (close (sp->fts_cwd_fd))
>> +                saved_errno = errno;
>> +          }
>> +        else if (!ISSET(FTS_NOCHDIR))
>> +          {
>> +            /* Return to original directory, save errno if necessary. */
>> +            if (fchdir(sp->fts_rfd))
>> +              saved_errno = errno;
>> +
>> +            /* If close fails, record errno only if saved_errno is zero,
>> +               so that we report the probably-more-meaningful fchdir errno.  */
>> +            if (close (sp->fts_rfd))
>> +              if (saved_errno == 0)
>> +                saved_errno = errno;
>> +          }
>> +
>> +        fd_ring_clear (&sp->fts_fd_ring);
>> +
>> +        if (sp->fts_leaf_optimization_works_ht)
>> +          hash_free (sp->fts_leaf_optimization_works_ht);
>> +
>> +        free_dir (sp);
>> +
>> +        /* Free up the stream pointer. */
>> +        free(sp);
>> +
>> +        /* Set errno and return. */
>> +        if (saved_errno) {
>> +                __set_errno (saved_errno);
>> +                return (-1);
>> +        }
>> +
>> +        return (0);
>> +}
>> +
>> +/* Minimum link count of a traditional Unix directory.  When leaf
>> +   optimization is OK and a directory's st_nlink == MIN_DIR_NLINK,
>> +   then the directory has no subdirectories.  */
>> +enum { MIN_DIR_NLINK = 2 };
>> +
>> +/* Whether leaf optimization is OK for a directory.  */
>> +enum leaf_optimization
>> +  {
>> +    /* st_nlink is not reliable for this directory's subdirectories.  */
>> +    NO_LEAF_OPTIMIZATION,
>> +
>> +    /* st_nlink == 2 means the directory lacks subdirectories.  */
>> +    OK_LEAF_OPTIMIZATION
>> +  };
>> +
>> +#if (defined __linux__ || defined __ANDROID__) \
>> +  && HAVE_SYS_VFS_H && HAVE_FSTATFS && HAVE_STRUCT_STATFS_F_TYPE
>> +
>> +# include <sys/vfs.h>
>> +
>> +/* Linux-specific constants from coreutils' src/fs.h */
>> +# define S_MAGIC_AFS 0x5346414F
>> +# define S_MAGIC_CIFS 0xFF534D42
>> +# define S_MAGIC_LUSTRE 0x0BD00BD0
>> +# define S_MAGIC_NFS 0x6969
>> +# define S_MAGIC_PROC 0x9FA0
>> +# define S_MAGIC_TMPFS 0x1021994
>> +
>> +# ifdef HAVE___FSWORD_T
>> +typedef __fsword_t fsword;
>> +# else
>> +typedef long int fsword;
>> +# endif
>> +
>> +/* Map a stat.st_dev number to a file system type number f_ftype.  */
>> +struct dev_type
>> +{
>> +  dev_t st_dev;
>> +  fsword f_type;
>> +};
>> +
>> +/* Use a tiny initial size.  If a traversal encounters more than
>> +   a few devices, the cost of growing/rehashing this table will be
>> +   rendered negligible by the number of inodes processed.  */
>> +enum { DEV_TYPE_HT_INITIAL_SIZE = 13 };
>> +
>> +static size_t
>> +dev_type_hash (void const *x, size_t table_size)
>> +{
>> +  struct dev_type const *ax = x;
>> +  uintmax_t dev = ax->st_dev;
>> +  return dev % table_size;
>> +}
>> +
>> +static bool
>> +dev_type_compare (void const *x, void const *y)
>> +{
>> +  struct dev_type const *ax = x;
>> +  struct dev_type const *ay = y;
>> +  return ax->st_dev == ay->st_dev;
>> +}
>> +
>> +/* Return the file system type of P with file descriptor FD, or 0 if not known.
>> +   If FD is negative, P's file descriptor is unavailable.
>> +   Try to cache known values.  */
>> +
>> +static fsword
>> +filesystem_type (FTSENTRY const *p, int fd)
>> +{
>> +  FTSOBJ *sp = FTSENT_FTS(p);
>> +
>> +  /* If we're not in CWDFD mode, don't bother with this optimization,
>> +     since the caller is not serious about performance.  */
>> +  if (!ISSET (FTS_CWDFD))
>> +    return 0;
>> +
>> +  Hash_table *h = sp->fts_leaf_optimization_works_ht;
>> +  if (! h)
>> +    h = sp->fts_leaf_optimization_works_ht
>> +      = hash_initialize (DEV_TYPE_HT_INITIAL_SIZE, NULL, dev_type_hash,
>> +                         dev_type_compare, free);
>> +
>> +  if (h)
>> +    {
>> +      struct dev_type tmp;
>> +      tmp.st_dev = p->fts_statp->st_dev;
>> +      struct dev_type *ent = hash_lookup (h, &tmp);
>> +      if (ent)
>> +        return ent->f_type;
>> +    }
>> +
>> +  /* Look-up failed.  Query directly and cache the result.  */
>> +  struct STRUCT_STATFS fs_buf;
>> +  if (fd < 0 || FSTATFS (fd, &fs_buf) != 0)
>> +    return 0;
>> +
>> +  if (h)
>> +    {
>> +      struct dev_type *t2 = malloc (sizeof *t2);
>> +      if (t2)
>> +        {
>> +          t2->st_dev = p->fts_statp->st_dev;
>> +          t2->f_type = fs_buf.f_type;
>> +
>> +          struct dev_type *ent = hash_insert (h, t2);
>> +          if (ent)
>> +            fts_assert (ent == t2);
>> +          else
>> +            free (t2);
>> +        }
>> +    }
>> +
>> +  return fs_buf.f_type;
>> +}
>> +
>> +/* Return true if sorting dirents on inode numbers is known to improve
>> +   traversal performance for the directory P with descriptor DIR_FD.
>> +   Return false otherwise.  When in doubt, return true.
>> +   DIR_FD is negative if unavailable.  */
>> +static bool
>> +dirent_inode_sort_may_be_useful (FTSENTRY const *p, int dir_fd)
>> +{
>> +  /* Skip the sort only if we can determine efficiently
>> +     that skipping it is the right thing to do.
>> +     The cost of performing an unnecessary sort is negligible,
>> +     while the cost of *not* performing it can be O(N^2) with
>> +     a very large constant.  */
>> +
>> +  switch (filesystem_type (p, dir_fd))
>> +    {
>> +    case S_MAGIC_LUSTRE:
>> +      /* On Lustre, sorting directory entries interferes with its ability to
>> +         prefetch file metadata (via statahead).  This would make a command
>> +         like 'du' around 9 times slower.  See
>> +         <https://bugs.gnu.org/80106>.  */
>> +    case S_MAGIC_CIFS:
>> +    case S_MAGIC_NFS:
>> +    case S_MAGIC_TMPFS:
>> +      /* On a file system of any of these types, sorting
>> +         is unnecessary, and hence wasteful.  */
>> +      return false;
>> +
>> +    default:
>> +      return true;
>> +    }
>> +}
>> +
>> +/* Given an FTS entry P for a directory with descriptor DIR_FD,
>> +   return whether it is valid to apply leaf optimization.
>> +   The optimization is valid if a directory's st_nlink value equal
>> +   to MIN_DIR_NLINK means the directory has no subdirectories.
>> +   DIR_FD is negative if unavailable.  */
>> +static enum leaf_optimization
>> +leaf_optimization (FTSENTRY const *p, int dir_fd)
>> +{
>> +  switch (filesystem_type (p, dir_fd))
>> +    {
>> +    case 0:
>> +      /* Leaf optimization is unsafe if the file system type is unknown.  */
>> +      FALLTHROUGH;
>> +    case S_MAGIC_AFS:
>> +      /* Although AFS mount points are not counted in st_nlink, they
>> +         act like directories.  See <https://bugs.debian.org/143111>.  */
>> +      FALLTHROUGH;
>> +    case S_MAGIC_CIFS:
>> +      /* Leaf optimization causes 'find' to abort.  See
>> +         <https://lists.gnu.org/r/bug-gnulib/2018-04/msg00015.html>.  */
>> +      FALLTHROUGH;
>> +    case S_MAGIC_NFS:
>> +      /* NFS provides usable dirent.d_type but not necessarily for all entries
>> +         of large directories, so as per <https://bugzilla.redhat.com/1252549>
>> +         NFS should return true.  However st_nlink values are not accurate on
>> +         all implementations as per <https://bugzilla.redhat.com/1299169>.  */
>> +      FALLTHROUGH;
>> +    case S_MAGIC_PROC:
>> +      /* Per <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=143111> /proc
>> +         may have bogus stat.st_nlink values.  */
>> +      return NO_LEAF_OPTIMIZATION;
>> +
>> +    default:
>> +      return OK_LEAF_OPTIMIZATION;
>> +    }
>> +}
>> +
>> +#else
>> +static bool
>> +dirent_inode_sort_may_be_useful (_GL_UNUSED FTSENTRY const *p,
>> +                                 _GL_UNUSED int dir_fd)
>> +{
>> +  return true;
>> +}
>> +static enum leaf_optimization
>> +leaf_optimization (_GL_UNUSED FTSENTRY const *p, _GL_UNUSED int dir_fd)
>> +{
>> +  return NO_LEAF_OPTIMIZATION;
>> +}
>> +#endif
>> +
>> +/*
>> + * Special case of "/" at the end of the file name so that slashes aren't
>> + * appended which would cause file names to be written as "....//foo".
>> + */
>> +#define NAPPEND(p)                                                      \
>> +        (p->fts_path[p->fts_pathlen - 1] == '/'                         \
>> +            ? p->fts_pathlen - 1 : p->fts_pathlen)
>> +
>> +FTSENTRY *
>> +FTS_READ (FTSOBJ *sp)
>> +{
>> +        /* If finished or unrecoverable error, return NULL. */
>> +        if (sp->fts_cur == NULL || ISSET(FTS_STOP))
>> +                return (NULL);
>> +
>> +        /* Set current node pointer. */
>> +        register FTSENTRY *p = sp->fts_cur;
>> +
>> +        /* Save and zero out user instructions. */
>> +        register unsigned short int instr = p->fts_instr;
>> +        p->fts_instr = FTS_NOINSTR;
>> +
>> +        /* Any type of file may be re-visited; re-stat and re-turn. */
>> +        if (instr == FTS_AGAIN) {
>> +                p->fts_info = fts_stat(sp, p, false);
>> +                return (p);
>> +        }
>> +        Dprintf (("fts_read: p=%s\n",
>> +                  p->fts_info == FTS_INIT ? "" : p->fts_path));
>> +
>> +        /*
>> +         * Following a symlink -- SLNONE test allows application to see
>> +         * SLNONE and recover.  If indirecting through a symlink, have
>> +         * keep a pointer to current location.  If unable to get that
>> +         * pointer, follow fails.
>> +         */
>> +        if (instr == FTS_FOLLOW &&
>> +            (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
>> +                p->fts_info = fts_stat(sp, p, true);
>> +                if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
>> +                        if ((p->fts_symfd = diropen (sp, ".")) < 0) {
>> +                                p->fts_errno = errno;
>> +                                p->fts_info = FTS_ERR;
>> +                        } else
>> +                                p->fts_flags |= FTS_SYMFOLLOW;
>> +                }
>> +                goto check_for_dir;
>> +        }
>> +
>> +        /* Directory in pre-order. */
>> +        if (p->fts_info == FTS_D) {
>> +                /* If skipped or crossed mount point, do post-order visit. */
>> +                if (instr == FTS_SKIP ||
>> +                    (ISSET(FTS_XDEV) && p->fts_statp->st_dev != sp->fts_dev)) {
>> +                        if (p->fts_flags & FTS_SYMFOLLOW)
>> +                                (void)close(p->fts_symfd);
>> +                        if (sp->fts_child) {
>> +                                fts_lfree(sp->fts_child);
>> +                                sp->fts_child = NULL;
>> +                        }
>> +                        p->fts_info = FTS_DP;
>> +                        LEAVE_DIR (sp, p, "1");
>> +                        return (p);
>> +                }
>> +
>> +                /* Rebuild if only read the names and now traversing. */
>> +                if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) {
>> +                        CLR(FTS_NAMEONLY);
>> +                        fts_lfree(sp->fts_child);
>> +                        sp->fts_child = NULL;
>> +                }
>> +
>> +                /*
>> +                 * Cd to the subdirectory.
>> +                 *
>> +                 * If have already read and now fail to chdir, whack the list
>> +                 * to make the names come out right, and set the parent errno
>> +                 * so the application will eventually get an error condition.
>> +                 * Set the FTS_DONTCHDIR flag so that when we logically change
>> +                 * directories back to the parent we don't do a chdir.
>> +                 *
>> +                 * If haven't read do so.  If the read fails, fts_build sets
>> +                 * FTS_STOP or the fts_info field of the node.
>> +                 */
>> +                if (sp->fts_child != NULL) {
>> +                        if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
>> +                                p->fts_errno = errno;
>> +                                p->fts_flags |= FTS_DONTCHDIR;
>> +                                for (p = sp->fts_child; p != NULL;
>> +                                     p = p->fts_link)
>> +                                        p->fts_accpath =
>> +                                            p->fts_parent->fts_accpath;
>> +                        }
>> +                } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
>> +                        if (ISSET(FTS_STOP))
>> +                                return (NULL);
>> +                        /* If fts_build's call to fts_safe_changedir failed
>> +                           because it was not able to fchdir into a
>> +                           subdirectory, tell the caller.  */
>> +                        if (p->fts_errno && p->fts_info != FTS_DNR)
>> +                                p->fts_info = FTS_ERR;
>> +                        LEAVE_DIR (sp, p, "2");
>> +                        return (p);
>> +                }
>> +                p = sp->fts_child;
>> +                sp->fts_child = NULL;
>> +                goto name;
>> +        }
>> +
>> +        /* Move to the next node on this level. */
>> +next: ;
>> +        register FTSENTRY *tmp = p;
>> +
>> +        /* If we have so many directory entries that we're reading them
>> +           in batches, and we've reached the end of the current batch,
>> +           read in a new batch.  */
>> +        if (p->fts_link == NULL && FTSENT_DIRP(p->fts_parent))
>> +          {
>> +            p = tmp->fts_parent;
>> +            sp->fts_cur = p;
>> +            sp->fts_path[p->fts_pathlen] = '\0';
>> +
>> +            if ((p = fts_build (sp, BREAD)) == NULL)
>> +              {
>> +                if (ISSET(FTS_STOP))
>> +                  return NULL;
>> +                goto cd_dot_dot;
>> +              }
>> +
>> +            free(FTSENT_WRAPPER(tmp));
>> +            goto name;
>> +          }
>> +
>> +        if ((p = p->fts_link) != NULL) {
>> +                sp->fts_cur = p;
>> +                free(FTSENT_WRAPPER(tmp));
>> +
>> +                /*
>> +                 * If reached the top, return to the original directory (or
>> +                 * the root of the tree), and load the file names for the next
>> +                 * root.
>> +                 */
>> +                if (p->fts_level == FTS_ROOTLEVEL) {
>> +                        if (restore_initial_cwd(sp)) {
>> +                                SET(FTS_STOP);
>> +                                return (NULL);
>> +                        }
>> +                        free_dir(sp);
>> +                        fts_load(sp, p);
>> +                        if (! setup_dir(sp)) {
>> +                                free_dir(sp);
>> +                                return (NULL);
>> +                        }
>> +                        goto check_for_dir;
>> +                }
>> +
>> +                /*
>> +                 * User may have called fts_set on the node.  If skipped,
>> +                 * ignore.  If followed, get a file descriptor so we can
>> +                 * get back if necessary.
>> +                 */
>> +                if (p->fts_instr == FTS_SKIP)
>> +                        goto next;
>> +                if (p->fts_instr == FTS_FOLLOW) {
>> +                        p->fts_info = fts_stat(sp, p, true);
>> +                        if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
>> +                                if ((p->fts_symfd = diropen (sp, ".")) < 0) {
>> +                                        p->fts_errno = errno;
>> +                                        p->fts_info = FTS_ERR;
>> +                                } else
>> +                                        p->fts_flags |= FTS_SYMFOLLOW;
>> +                        }
>> +                        p->fts_instr = FTS_NOINSTR;
>> +                }
>> +
>> +name:           {
>> +                  register char *t = sp->fts_path + NAPPEND(p->fts_parent);
>> +                  *t++ = '/';
>> +                  memmove(t, p->fts_name, p->fts_namelen + 1);
>> +                }
>> +check_for_dir:
>> +                sp->fts_cur = p;
>> +                if (p->fts_info == FTS_NSOK)
>> +                  {
>> +                    if (p->fts_statp->st_size == FTS_STAT_REQUIRED)
>> +                      p->fts_info = fts_stat(sp, p, false);
>> +                    else
>> +                      fts_assert (p->fts_statp->st_size == FTS_NO_STAT_REQUIRED);
>> +                  }
>> +
>> +                /* Skip files with different device numbers when FTS_MOUNT
>> +                   is set.  */
>> +                if (ISSET (FTS_MOUNT) && p->fts_info != FTS_NS &&
>> +                    p->fts_level != FTS_ROOTLEVEL &&
>> +                    p->fts_statp->st_dev != sp->fts_dev)
>> +                      goto next;
>> +
>> +                if (p->fts_info == FTS_D)
>> +                  {
>> +                    /* Now that P->fts_statp is guaranteed to be valid, if
>> +                       this is a command-line directory, record its device
>> +                       number, to be used for FTS_MOUNT and FTS_XDEV.  */
>> +                    if (p->fts_level == FTS_ROOTLEVEL)
>> +                      sp->fts_dev = p->fts_statp->st_dev;
>> +                    Dprintf (("  entering: %s\n", p->fts_path));
>> +                    if (! enter_dir (sp, p))
>> +                      return NULL;
>> +                  }
>> +                return p;
>> +        }
>> +cd_dot_dot:
>> +
>> +        /* Move up to the parent node. */
>> +        p = tmp->fts_parent;
>> +        sp->fts_cur = p;
>> +        free(FTSENT_WRAPPER(tmp));
>> +
>> +        if (p->fts_level == FTS_ROOTPARENTLEVEL) {
>> +                /*
>> +                 * Done; free everything up and set errno to 0 so the user
>> +                 * can distinguish between error and EOF.
>> +                 */
>> +                free(FTSENT_WRAPPER(p));
>> +                __set_errno (0);
>> +                return (sp->fts_cur = NULL);
>> +        }
>> +
>> +        fts_assert (p->fts_info != FTS_NSOK);
>> +
>> +        /* NUL terminate the file name.  */
>> +        sp->fts_path[p->fts_pathlen] = '\0';
>> +
>> +        /*
>> +         * Return to the parent directory.  If at a root node, restore
>> +         * the initial working directory.  If we came through a symlink,
>> +         * go back through the file descriptor.  Otherwise, move up
>> +         * one level, via "..".
>> +         */
>> +        if (p->fts_level == FTS_ROOTLEVEL) {
>> +                if (restore_initial_cwd(sp)) {
>> +                        p->fts_errno = errno;
>> +                        SET(FTS_STOP);
>> +                }
>> +        } else if (p->fts_flags & FTS_SYMFOLLOW) {
>> +                if (FCHDIR(sp, p->fts_symfd)) {
>> +                        p->fts_errno = errno;
>> +                        SET(FTS_STOP);
>> +                }
>> +                (void)close(p->fts_symfd);
>> +        } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
>> +                   fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
>> +                p->fts_errno = errno;
>> +                SET(FTS_STOP);
>> +        }
>> +
>> +        /* If the directory causes a cycle, preserve the FTS_DC flag and keep
>> +           the corresponding dev/ino pair in the hash table.  It is going to be
>> +           removed when leaving the original directory.  */
>> +        if (p->fts_info != FTS_DC) {
>> +                p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
>> +                if (p->fts_errno == 0)
>> +                        LEAVE_DIR (sp, p, "3");
>> +        }
>> +        return ISSET(FTS_STOP) ? NULL : p;
>> +}
>> +
>> +/*
>> + * Fts_set takes the stream as an argument although it's not used in this
>> + * implementation; it would be necessary if anyone wanted to add global
>> + * semantics to fts using fts_set.  An error return is allowed for similar
>> + * reasons.
>> + */
>> +/* ARGSUSED */
>> +int
>> +FTS_SET (_GL_UNUSED FTSOBJ *sp, FTSENTRY *p, int instr)
>> +{
>> +        if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
>> +            instr != FTS_NOINSTR && instr != FTS_SKIP) {
>> +                __set_errno (EINVAL);
>> +                return (1);
>> +        }
>> +        p->fts_instr = instr;
>> +        return (0);
>> +}
>> +
>> +FTSENTRY *
>> +FTS_CHILDREN (FTSOBJ *sp, int instr)
>> +{
>> +        if (instr != 0 && instr != FTS_NAMEONLY) {
>> +                __set_errno (EINVAL);
>> +                return (NULL);
>> +        }
>> +
>> +        /* Set current node pointer. */
>> +        register FTSENTRY *p = sp->fts_cur;
>> +
>> +        /*
>> +         * Errno set to 0 so user can distinguish empty directory from
>> +         * an error.
>> +         */
>> +        __set_errno (0);
>> +
>> +        /* Fatal errors stop here. */
>> +        if (ISSET(FTS_STOP))
>> +                return (NULL);
>> +
>> +        /* Return logical hierarchy of user's arguments. */
>> +        if (p->fts_info == FTS_INIT)
>> +                return (p->fts_link);
>> +
>> +        /*
>> +         * If not a directory being visited in pre-order, stop here.  Could
>> +         * allow FTS_DNR, assuming the user has fixed the problem, but the
>> +         * same effect is available with FTS_AGAIN.
>> +         */
>> +        if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
>> +                return (NULL);
>> +
>> +        /* Free up any previous child list. */
>> +        if (sp->fts_child != NULL)
>> +                fts_lfree(sp->fts_child);
>> +
>> +        if (instr == FTS_NAMEONLY) {
>> +                SET(FTS_NAMEONLY);
>> +                instr = BNAMES;
>> +        } else
>> +                instr = BCHILD;
>> +
>> +        /*
>> +         * If using chdir on a relative file name and called BEFORE fts_read
>> +         * does its chdir to the root of a traversal, we can lose -- we need to
>> +         * chdir into the subdirectory, and we don't know where the current
>> +         * directory is, so we can't get back so that the upcoming chdir by
>> +         * fts_read will work.
>> +         */
>> +        if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
>> +            ISSET(FTS_NOCHDIR))
>> +                return (sp->fts_child = fts_build(sp, instr));
>> +
>> +        int fd = diropen (sp, ".");
>> +        if (fd < 0)
>> +                return (sp->fts_child = NULL);
>> +        sp->fts_child = fts_build(sp, instr);
>> +        if (ISSET(FTS_CWDFD))
>> +          {
>> +            cwd_advance_fd (sp, fd, true);
>> +          }
>> +        else
>> +          {
>> +            if (fchdir(fd))
>> +              {
>> +                int saved_errno = errno;
>> +                close (fd);
>> +                __set_errno (saved_errno);
>> +                return NULL;
>> +              }
>> +            close (fd);
>> +          }
>> +        return (sp->fts_child);
>> +}
>> +
>> +/* A comparison function to sort on increasing inode number.
>> +   For some file system types, sorting either way makes a huge
>> +   performance difference for a directory with very many entries,
>> +   but sorting on increasing values is slightly better than sorting
>> +   on decreasing values.  The difference is in the 5% range.  */
>> +static int
>> +fts_compare_ino (FTSENTRY const **a, FTSENTRY const **b)
>> +{
>> +  return _GL_CMP (a[0]->fts_statp->st_ino, b[0]->fts_statp->st_ino);
>> +}
>> +
>> +/* Map the dirent.d_type value, DTYPE, to the corresponding stat.st_mode
>> +   S_IF* bit and set ST.st_mode, thus clearing all other bits in that field.  */
>> +static void
>> +set_stat_type (struct STRUCT_STAT *st, unsigned int dtype)
>> +{
>> +  mode_t type;
>> +  switch (dtype)
>> +    {
>> +    case DT_BLK:
>> +      type = S_IFBLK;
>> +      break;
>> +    case DT_CHR:
>> +      type = S_IFCHR;
>> +      break;
>> +    case DT_DIR:
>> +      type = S_IFDIR;
>> +      break;
>> +    case DT_FIFO:
>> +      type = S_IFIFO;
>> +      break;
>> +    case DT_LNK:
>> +      type = S_IFLNK;
>> +      break;
>> +    case DT_REG:
>> +      type = S_IFREG;
>> +      break;
>> +    case DT_SOCK:
>> +      type = S_IFSOCK;
>> +      break;
>> +    default:
>> +      type = 0;
>> +    }
>> +  st->st_mode = type;
>> +}
>> +
>> +#define closedir_and_clear(dirp)                \
>> +  do                                            \
>> +    {                                           \
>> +      closedir (dirp);                          \
>> +      dirp = NULL;                              \
>> +    }                                           \
>> +  while (0)
>> +
>> +#define fts_opendir(file, Pdir_fd)                              \
>> +        OPENDIRAT((! ISSET(FTS_NOCHDIR) && ISSET(FTS_CWDFD)     \
>> +                   ? sp->fts_cwd_fd : AT_FDCWD),                \
>> +                  file,                                         \
>> +                  (((ISSET(FTS_PHYSICAL)                        \
>> +                     && ! (ISSET(FTS_COMFOLLOW)                 \
>> +                           && cur->fts_level == FTS_ROOTLEVEL)) \
>> +                    ? O_NOFOLLOW : 0)),                         \
>> +                  Pdir_fd)
>> +
>> +/*
>> + * This is the tricky part -- do not casually change *anything* in here.  The
>> + * idea is to build the linked list of entries that are used by fts_children
>> + * and fts_read.  There are lots of special cases.
>> + *
>> + * The real slowdown in walking the tree is the stat calls.  If FTS_NOSTAT is
>> + * set and it's a physical walk (so that symbolic links can't be directories),
>> + * we can do things quickly.  First, if it's a 4.4BSD file system, the type
>> + * of the file is in the directory entry.  Otherwise, we assume that the number
>> + * of subdirectories in a node is equal to the number of links to the parent.
>> + * The former skips all stat calls.  The latter skips stat calls in any leaf
>> + * directories and for any files after the subdirectories in the directory have
>> + * been found, cutting the stat calls by about 2/3.
>> + */
>> +static FTSENTRY *
>> +internal_function
>> +fts_build (register FTSOBJ *sp, int type)
>> +{
>> +        FTSENTRY *cur = sp->fts_cur;
>> +        bool continue_readdir = !!FTSENT_DIRP(cur);
>> +
>> +        /* When cur->fts_dirp is non-NULL, that means we should
>> +           continue calling readdir on that existing DIR* pointer
>> +           rather than opening a new one.  */
>> +        int dir_fd;
>> +        if (continue_readdir)
>> +          {
>> +            DIR *dp = FTSENT_DIRP(cur);
>> +            dir_fd = dirfd (dp);
>> +            if (dir_fd < 0)
>> +              {
>> +                int dirfd_errno = errno;
>> +                closedir_and_clear (FTSENT_DIRP(cur));
>> +                if (type == BREAD)
>> +                  {
>> +                    cur->fts_info = FTS_DNR;
>> +                    cur->fts_errno = dirfd_errno;
>> +                  }
>> +                return NULL;
>> +              }
>> +          }
>> +        else
>> +          {
>> +            /* Open the directory for reading.  If this fails, we're done.
>> +               If being called from fts_read, set the fts_info field. */
>> +            if ((FTSENT_DIRP (cur) = fts_opendir(cur->fts_accpath, &dir_fd)) == NULL)
>> +              {
>> +                if (type == BREAD)
>> +                  {
>> +                    cur->fts_info = FTS_DNR;
>> +                    cur->fts_errno = errno;
>> +                  }
>> +                return NULL;
>> +              }
>> +            /* Rather than calling fts_stat for each and every entry encountered
>> +               in the readdir loop (below), stat each directory only right after
>> +               opening it.  */
>> +            bool stat_optimization = cur->fts_info == FTS_NSOK;
>> +
>> +            if (stat_optimization
>> +                /* Also read the stat info again after opening a directory to
>> +                   reveal eventual changes caused by a submount triggered by
>> +                   the traversal.  But do it only for utilities which use
>> +                   FTS_TIGHT_CYCLE_CHECK.  Therefore, only find and du
>> +                   benefit/suffer from this feature for now.  */
>> +                || ISSET (FTS_TIGHT_CYCLE_CHECK))
>> +              {
>> +                if (!stat_optimization)
>> +                  LEAVE_DIR (sp, cur, "4");
>> +                if (FSTAT (dir_fd, cur->fts_statp) != 0)
>> +                  {
>> +                    int fstat_errno = errno;
>> +                    closedir_and_clear (FTSENT_DIRP(cur));
>> +                    if (type == BREAD)
>> +                      {
>> +                        cur->fts_errno = fstat_errno;
>> +                        cur->fts_info = FTS_NS;
>> +                      }
>> +                    __set_errno (fstat_errno);
>> +                    return NULL;
>> +                  }
>> +                if (stat_optimization)
>> +                  cur->fts_info = FTS_D;
>> +                else if (! enter_dir (sp, cur))
>> +                  {
>> +                    int saved_errno = errno;
>> +                    closedir_and_clear (FTSENT_DIRP(cur));
>> +                    __set_errno (saved_errno);
>> +                    return NULL;
>> +                  }
>> +              }
>> +          }
>> +
>> +        /* Maximum number of readdir entries to read at one time.  This
>> +           limitation is to avoid reading millions of entries into memory
>> +           at once.  When an fts_compar function is specified, we have no
>> +           choice: we must read all entries into memory before calling that
>> +           function.  But when no such function is specified, we can read
>> +           entries in batches that are large enough to help us with inode-
>> +           sorting, yet not so large that we risk exhausting memory.  */
>> +        size_t max_entries = sp->fts_compar ? SIZE_MAX : FTS_MAX_READDIR_ENTRIES;
>> +
>> +        /*
>> +         * If we're going to need to stat anything or we want to descend
>> +         * and stay in the directory, chdir.  If this fails we keep going,
>> +         * but set a flag so we don't chdir after the post-order visit.
>> +         * We won't be able to stat anything, but we can still return the
>> +         * names themselves.  Note, that since fts_read won't be able to
>> +         * chdir into the directory, it will have to return different file
>> +         * names than before, i.e. "a/b" instead of "b".  Since the node
>> +         * has already been visited in pre-order, have to wait until the
>> +         * post-order visit to return the error.  There is a special case
>> +         * here, if there was nothing to stat then it's not an error to
>> +         * not be able to stat.  This is all fairly nasty.  If a program
>> +         * needed sorted entries or stat information, they had better be
>> +         * checking FTS_NS on the returned nodes.
>> +         */
>> +        bool descend;
>> +        if (continue_readdir)
>> +          {
>> +            /* When resuming a short readdir run, we already have
>> +               the required dirp and dir_fd.  */
>> +            descend = true;
>> +          }
>> +        else
>> +          {
>> +            /* Try to descend unless it is a names-only fts_children,
>> +               or the directory is known to lack subdirectories.  */
>> +            descend = (type != BNAMES
>> +                       && ! (ISSET (FTS_NOSTAT) && ISSET (FTS_PHYSICAL)
>> +                             && ! ISSET (FTS_SEEDOT)
>> +                             && cur->fts_statp->st_nlink == MIN_DIR_NLINK
>> +                             && (leaf_optimization (cur, dir_fd)
>> +                                 != NO_LEAF_OPTIMIZATION)));
>> +            if (descend || type == BREAD)
>> +              {
>> +                if (ISSET(FTS_CWDFD))
>> +                  dir_fd = fcntl (dir_fd, F_DUPFD_CLOEXEC, STDERR_FILENO + 1);
>> +                if (dir_fd < 0 || fts_safe_changedir(sp, cur, dir_fd, NULL)) {
>> +                        if (descend && type == BREAD)
>> +                                cur->fts_errno = errno;
>> +                        cur->fts_flags |= FTS_DONTCHDIR;
>> +                        descend = false;
>> +                        closedir_and_clear(FTSENT_DIRP(cur));
>> +                        if (ISSET(FTS_CWDFD) && 0 <= dir_fd)
>> +                                close (dir_fd);
>> +                        FTSENT_DIRP(cur) = NULL;
>> +                } else
>> +                        descend = true;
>> +              }
>> +          }
>> +
>> +        /*
>> +         * Figure out the max file name length that can be stored in the
>> +         * current buffer -- the inner loop allocates more space as necessary.
>> +         * We really wouldn't have to do the maxlen calculations here, we
>> +         * could do them in fts_read before returning the name, but it's a
>> +         * lot easier here since the length is part of the dirent structure.
>> +         *
>> +         * If not changing directories set a pointer so that can just append
>> +         * each new component into the file name.
>> +         */
>> +        size_t len = NAPPEND(cur);
>> +        char *cp;
>> +        if (ISSET(FTS_NOCHDIR)) {
>> +                cp = sp->fts_path + len;
>> +                *cp++ = '/';
>> +        } else {
>> +                /* GCC, you're too verbose. */
>> +                cp = NULL;
>> +        }
>> +        len++;
>> +        size_t maxlen = sp->fts_pathlen - len;
>> +
>> +        ptrdiff_t level = cur->fts_level + 1;
>> +
>> +        /* Read the directory, attaching each entry to the "link" pointer. */
>> +        bool doadjust = false;
>> +        register FTSENTRY *head = NULL;
>> +        FTSENTRY *tail = NULL;
>> +        register size_t nitems = 0;
>> +        bool sort_by_inode = false;
>> +        while (FTSENT_DIRP(cur)) {
>> +                __set_errno (0);
>> +                struct dirent *dp = readdir(FTSENT_DIRP(cur));
>> +                if (dp == NULL) {
>> +                        /* Some readdir()s do not absorb ENOENT (dir
>> +                           deleted but open).  This bug was fixed in
>> +                           glibc 2.3 (2002).  */
>> +#if ! (2 < __GLIBC__ + (3 <= __GLIBC_MINOR__))
>> +                        if (errno == ENOENT)
>> +                          errno = 0;
>> +#endif
>> +                        if (errno) {
>> +                                cur->fts_errno = errno;
>> +                                /* If we've not read any items yet, treat
>> +                                   the error as if we can't access the dir.  */
>> +                                cur->fts_info = (continue_readdir || nitems)
>> +                                                ? FTS_ERR : FTS_DNR;
>> +                        }
>> +                        closedir_and_clear(FTSENT_DIRP(cur));
>> +                        break;
>> +                }
>> +                if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
>> +                        continue;
>> +
>> +                size_t d_namelen = _D_EXACT_NAMLEN (dp);
>> +                register FTSENTRY *p = fts_alloc (sp, dp->d_name, d_namelen);
>> +                if (!p)
>> +                        goto mem1;
>> +                if (d_namelen >= maxlen) {
>> +                        /* include space for NUL */
>> +                        uintptr_t oldaddr = (uintptr_t) sp->fts_path;
>> +                        if (! fts_palloc(sp, d_namelen + len + 1)) {
>> +                                /*
>> +                                 * No more memory.  Save
>> +                                 * errno, free up the current structure and the
>> +                                 * structures already allocated.
>> +                                 */
>> +mem1: ;
>> +                                int saved_errno = errno;
>> +                                free(FTSENT_WRAPPER(p));
>> +                                fts_lfree(head);
>> +                                closedir_and_clear(FTSENT_DIRP(cur));
>> +                                cur->fts_info = FTS_ERR;
>> +                                SET(FTS_STOP);
>> +                                __set_errno (saved_errno);
>> +                                return (NULL);
>> +                        }
>> +                        /* Did realloc() change the pointer? */
>> +                        if (oldaddr != (uintptr_t) sp->fts_path) {
>> +                                doadjust = true;
>> +                                if (ISSET(FTS_NOCHDIR))
>> +                                        cp = sp->fts_path + len;
>> +                        }
>> +                        maxlen = sp->fts_pathlen - len;
>> +                }
>> +
>> +                size_t new_len = len + d_namelen;
>> +                if (new_len < len) {
>> +                        /*
>> +                         * In the unlikely event that we would end up
>> +                         * with a file name longer than SIZE_MAX, free up
>> +                         * the current structure and the structures already
>> +                         * allocated, then error out with ENAMETOOLONG.
>> +                         */
>> +                        free(FTSENT_WRAPPER(p));
>> +                        fts_lfree(head);
>> +                        closedir_and_clear(FTSENT_DIRP(cur));
>> +                        cur->fts_info = FTS_ERR;
>> +                        SET(FTS_STOP);
>> +                        __set_errno (ENAMETOOLONG);
>> +                        return (NULL);
>> +                }
>> +                p->fts_level = level;
>> +                p->fts_parent = sp->fts_cur;
>> +                p->fts_pathlen = new_len;
>> +
>> +                /* Store dirent.d_ino, in case we need to sort
>> +                   entries before processing them.  */
>> +                p->fts_statp->st_ino = D_INO (dp);
>> +
>> +                /* Build a file name for fts_stat to stat. */
>> +                if (ISSET(FTS_NOCHDIR)) {
>> +                        p->fts_accpath = p->fts_path;
>> +                        memmove(cp, p->fts_name, p->fts_namelen + 1);
>> +                } else
>> +                        p->fts_accpath = p->fts_name;
>> +
>> +                if (sp->fts_compar == NULL || ISSET(FTS_DEFER_STAT)) {
>> +                        /* Record what fts_read will have to do with this
>> +                           entry. In many cases, it will simply fts_stat it,
>> +                           but we can take advantage of any d_type information
>> +                           to optimize away the unnecessary stat calls.  I.e.,
>> +                           if FTS_NOSTAT is in effect, we don't need device
>> +                           numbers unconditionally (FTS_MOUNT) and we're not
>> +                           following symlinks (FTS_PHYSICAL) and d_type
>> +                           indicates this is *not* a directory, then we won't
>> +                           have to stat it  at all.  If it *is* a directory,
>> +                           then (currently) we stat it regardless, in order to
>> +                           get device and inode numbers.  Some day we might
>> +                           optimize that away, too, for directories where
>> +                           d_ino is known to be valid.  */
>> +                        bool skip_stat = (ISSET(FTS_NOSTAT)
>> +                                          && DT_IS_KNOWN(dp)
>> +                                          && ! DT_MUST_BE(dp, DT_DIR)
>> +                                          && (ISSET(FTS_PHYSICAL)
>> +                                              || ! DT_MUST_BE(dp, DT_LNK))
>> +                                          && ! ISSET(FTS_MOUNT));
>> +                        p->fts_info = FTS_NSOK;
>> +                        /* Propagate dirent.d_type information back
>> +                           to caller, when possible.  */
>> +                        set_stat_type (p->fts_statp, D_TYPE (dp));
>> +                        fts_set_stat_required(p, !skip_stat);
>> +                } else {
>> +                        p->fts_info = fts_stat(sp, p, false);
>> +                }
>> +
>> +                /* We walk in directory order so "ls -f" doesn't get upset. */
>> +                p->fts_link = NULL;
>> +                if (head == NULL)
>> +                        head = tail = p;
>> +                else {
>> +                        tail->fts_link = p;
>> +                        tail = p;
>> +                }
>> +
>> +                /* If there are many entries, no sorting function has been
>> +                   specified, and this file system is of a type that may be
>> +                   slow with a large number of entries, arrange to sort the
>> +                   directory entries on increasing inode numbers.
>> +
>> +                   The NITEMS comparison uses ==, not >, because the test
>> +                   needs to be tried at most once once, and NITEMS will exceed
>> +                   the threshold after it is incremented below.  */
>> +                if (nitems == _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
>> +                    && !sp->fts_compar)
>> +                  sort_by_inode = dirent_inode_sort_may_be_useful (cur, dir_fd);
>> +
>> +                ++nitems;
>> +                if (max_entries <= nitems) {
>> +                        /* When there are too many dir entries, leave
>> +                           fts_dirp open, so that a subsequent fts_read
>> +                           can take up where we leave off.  */
>> +                        break;
>> +                }
>> +        }
>> +
>> +        /*
>> +         * If realloc() changed the address of the file name, adjust the
>> +         * addresses for the rest of the tree and the dir list.
>> +         */
>> +        if (doadjust)
>> +                fts_padjust(sp, head);
>> +
>> +        /*
>> +         * If not changing directories, reset the file name back to original
>> +         * state.
>> +         */
>> +        if (ISSET(FTS_NOCHDIR)) {
>> +                if (len == sp->fts_pathlen || nitems == 0)
>> +                        --cp;
>> +                *cp = '\0';
>> +        }
>> +
>> +        /*
>> +         * If descended after called from fts_children or after called from
>> +         * fts_read and nothing found, get back.  At the root level we use
>> +         * the saved fd; if one of fts_open()'s arguments is a relative name
>> +         * to an empty directory, we wind up here with no other way back.  If
>> +         * can't get back, we're done.
>> +         */
>> +        if (!continue_readdir && descend && (type == BCHILD || !nitems) &&
>> +            (cur->fts_level == FTS_ROOTLEVEL
>> +             ? restore_initial_cwd(sp)
>> +             : fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
>> +                cur->fts_info = FTS_ERR;
>> +                SET(FTS_STOP);
>> +                fts_lfree(head);
>> +                return (NULL);
>> +        }
>> +
>> +        /* If didn't find anything, return NULL. */
>> +        if (!nitems) {
>> +                if (type == BREAD
>> +                    && cur->fts_info != FTS_DNR && cur->fts_info != FTS_ERR)
>> +                        cur->fts_info = FTS_DP;
>> +                fts_lfree(head);
>> +                return (NULL);
>> +        }
>> +
>> +        if (sort_by_inode) {
>> +                sp->fts_compar = FTS_COMPAR_CAST (fts_compare_ino);
>> +                head = fts_sort (sp, head, nitems);
>> +                sp->fts_compar = NULL;
>> +        }
>> +
>> +        /* Sort the entries. */
>> +        if (sp->fts_compar && nitems > 1)
>> +                head = fts_sort(sp, head, nitems);
>> +        return (head);
>> +}
>> +
>> +#if GNULIB_FTS_DEBUG
>> +
>> +struct devino {
>> +  intmax_t dev, ino;
>> +};
>> +#define PRINT_DEVINO "(%jd,%jd)"
>> +
>> +static struct devino
>> +getdevino (int fd)
>> +{
>> +  struct STRUCT_STAT st;
>> +  return (fd == AT_FDCWD
>> +          ? (struct devino) { -1, 0 }
>> +          : FSTAT (fd, &st) == 0
>> +          ? (struct devino) { st.st_dev, st.st_ino }
>> +          : (struct devino) { -1, errno });
>> +}
>> +
>> +/* Walk ->fts_parent links starting at E_CURR, until the root of the
>> +   current hierarchy.  There should be a directory with dev/inode
>> +   matching those of AD.  If not, print a lot of diagnostics.  */
>> +static void
>> +find_matching_ancestor (FTSENTRY const *e_curr, struct Active_dir const *ad)
>> +{
>> +  for (FTSENTRY const *ent = e_curr;
>> +       ent->fts_level >= FTS_ROOTLEVEL;
>> +       ent = ent->fts_parent)
>> +    {
>> +      if (ad->ino == ent->fts_statp->st_ino
>> +          && ad->dev == ent->fts_statp->st_dev)
>> +        return;
>> +    }
>> +  printf ("ERROR: tree dir, %s, not active\n", ad->fts_ent->fts_accpath);
>> +  printf ("active dirs:\n");
>> +  for (FTSENTRY const *ent = e_curr;
>> +       ent->fts_level >= FTS_ROOTLEVEL;
>> +       ent = ent->fts_parent)
>> +    printf ("  %s(%"PRIuMAX"/%"PRIuMAX") to %s(%"PRIuMAX"/%"PRIuMAX")...\n",
>> +            ad->fts_ent->fts_accpath,
>> +            (uintmax_t) ad->dev,
>> +            (uintmax_t) ad->ino,
>> +            ent->fts_accpath,
>> +            (uintmax_t) ent->fts_statp->st_dev,
>> +            (uintmax_t) ent->fts_statp->st_ino);
>> +}
>> +
>> +void
>> +fts_cross_check (FTSOBJ const *sp)
>> +{
>> +  if ( ! ISSET (FTS_TIGHT_CYCLE_CHECK))
>> +    return;
>> +
>> +  FTSENTRY const *ent = sp->fts_cur;
>> +
>> +  Dprintf (("fts-cross-check cur=%s\n", ent->fts_path));
>> +  /* Make sure every parent dir is in the tree.  */
>> +  for (FTSENTRY const *t = ent->fts_parent;
>> +       t->fts_level >= FTS_ROOTLEVEL;
>> +       t = t->fts_parent)
>> +    {
>> +      struct Active_dir ad;
>> +      ad.ino = t->fts_statp->st_ino;
>> +      ad.dev = t->fts_statp->st_dev;
>> +      if ( ! hash_lookup (sp->fts_cycle.ht, &ad))
>> +        printf ("ERROR: active dir, %s, not in tree\n", t->fts_path);
>> +    }
>> +
>> +  /* Make sure every dir in the tree is an active dir.
>> +     But ENT is not necessarily a directory.  If so, just skip this part. */
>> +  if (ent->fts_parent->fts_level >= FTS_ROOTLEVEL
>> +      && (ent->fts_info == FTS_DP
>> +          || ent->fts_info == FTS_D))
>> +    for (struct Active_dir *ad = hash_get_first (sp->fts_cycle.ht);
>> +         ad != NULL;
>> +         ad = hash_get_next (sp->fts_cycle.ht, ad))
>> +      {
>> +        find_matching_ancestor (ent, ad);
>> +      }
>> +}
>> +
>> +static bool
>> +same_fd (int fd1, int fd2)
>> +{
>> +  struct STRUCT_STAT sb1, sb2;
>> +  return (FSTAT (fd1, &sb1) == 0
>> +          && FSTAT (fd2, &sb2) == 0
>> +          && psame_inode (&sb1, &sb2));
>> +}
>> +
>> +static void
>> +fd_ring_print (FTSOBJ const *sp, FILE *stream, char const *msg)
>> +{
>> +  if (!fts_debug)
>> +    return;
>> +  I_ring const *fd_ring = &sp->fts_fd_ring;
>> +  struct devino cwd = getdevino (sp->fts_cwd_fd);
>> +  fprintf (stream, "=== %s ========== "PRINT_DEVINO"\n", msg, cwd.dev, cwd.ino);
>> +  if (i_ring_empty (fd_ring))
>> +    return;
>> +
>> +  unsigned int i = fd_ring->ir_front;
>> +  while (true)
>> +    {
>> +      int fd = fd_ring->ir_data[i];
>> +      if (fd < 0)
>> +        fprintf (stream, "%u: %d:\n", i, fd);
>> +      else
>> +        {
>> +          struct devino wd = getdevino (fd);
>> +          fprintf (stream, "%u: %d: "PRINT_DEVINO"\n", i, fd, wd.dev, wd.ino);
>> +        }
>> +      if (i == fd_ring->ir_back)
>> +        break;
>> +      i = (i + I_RING_SIZE - 1) % I_RING_SIZE;
>> +    }
>> +}
>> +
>> +/* Ensure that each file descriptor on the fd_ring matches a
>> +   parent, grandparent, etc. of the current working directory.  */
>> +static void
>> +fd_ring_check (FTSOBJ const *sp)
>> +{
>> +  if (!fts_debug)
>> +    return;
>> +
>> +  /* Make a writable copy.  */
>> +  I_ring fd_w = sp->fts_fd_ring;
>> +
>> +  int cwd_fd = sp->fts_cwd_fd;
>> +  cwd_fd = fcntl (cwd_fd, F_DUPFD_CLOEXEC, STDERR_FILENO + 1);
>> +  struct devino dot = getdevino (cwd_fd);
>> +  fprintf (stderr, "===== check ===== cwd: "PRINT_DEVINO"\n",
>> +           dot.dev, dot.ino);
>> +  while ( ! i_ring_empty (&fd_w))
>> +    {
>> +      int fd = i_ring_pop (&fd_w);
>> +      if (0 <= fd)
>> +        {
>> +          int open_flags = O_SEARCH | O_CLOEXEC;
>> +          int parent_fd = openat (cwd_fd, "..", open_flags);
>> +          if (parent_fd < 0)
>> +            {
>> +              // Warn?
>> +              break;
>> +            }
>> +          if (!same_fd (fd, parent_fd))
>> +            {
>> +              struct devino cwd = getdevino (fd);
>> +              fprintf (stderr, "ring  : "PRINT_DEVINO"\n", cwd.dev, cwd.ino);
>> +              struct devino c2 = getdevino (parent_fd);
>> +              fprintf (stderr, "parent: "PRINT_DEVINO"\n", c2.dev, c2.ino);
>> +              fts_assert (0);
>> +            }
>> +          close (cwd_fd);
>> +          cwd_fd = parent_fd;
>> +        }
>> +    }
>> +  close (cwd_fd);
>> +}
>> +#endif
>> +
>> +static unsigned short int
>> +internal_function
>> +fts_stat(FTSOBJ *sp, register FTSENTRY *p, bool follow)
>> +{
>> +        if (ISSET (FTS_LOGICAL)
>> +            || (ISSET (FTS_COMFOLLOW) && p->fts_level == FTS_ROOTLEVEL))
>> +                follow = true;
>> +
>> +        struct STRUCT_STAT *sbp = p->fts_statp;
>> +
>> +        /*
>> +         * If doing a logical walk, or application requested FTS_FOLLOW, do
>> +         * a stat(2).  If that fails, check for a nonexistent symlink.  If
>> +         * fail, set the errno from the stat call.
>> +         */
>> +        int flags = follow ? 0 : AT_SYMLINK_NOFOLLOW;
>> +        if (FSTATAT (sp->fts_cwd_fd, p->fts_accpath, sbp, flags) < 0)
>> +          {
>> +            if (follow && errno == ENOENT
>> +                && 0 <= FSTATAT (sp->fts_cwd_fd, p->fts_accpath, sbp,
>> +                                 AT_SYMLINK_NOFOLLOW))
>> +              {
>> +                __set_errno (0);
>> +                return FTS_SLNONE;
>> +              }
>> +
>> +            p->fts_errno = errno;
>> +           memset (sbp, 0, sizeof *sbp);
>> +            return FTS_NS;
>> +          }
>> +
>> +        if (S_ISDIR(sbp->st_mode)) {
>> +                if (ISDOT(p->fts_name)) {
>> +                        /* Command-line "." and ".." are real directories. */
>> +                        return (p->fts_level == FTS_ROOTLEVEL ? FTS_D : FTS_DOT);
>> +                }
>> +
>> +                return (FTS_D);
>> +        }
>> +        if (S_ISLNK(sbp->st_mode))
>> +                return (FTS_SL);
>> +        if (S_ISREG(sbp->st_mode))
>> +                return (FTS_F);
>> +        return (FTS_DEFAULT);
>> +}
>> +
>> +static int
>> +fts_compar (void const *a, void const *b)
>> +{
>> +  /* Convert A and B to the correct types, to pacify the compiler, and
>> +     for portability to bizarre hosts where "void const *" and "FTSENT
>> +     const **" differ in runtime representation.  The comparison
>> +     function cannot modify *a and *b, but there is no compile-time
>> +     check for this.  */
>> +  FTSENTRY const **pa = (FTSENTRY const **) a;
>> +  FTSENTRY const **pb = (FTSENTRY const **) b;
>> +  return FTSENT_FTS(pa[0])->fts_compar (pa, pb);
>> +}
>> +
>> +static FTSENTRY *
>> +internal_function
>> +fts_sort (FTSOBJ *sp, FTSENTRY *head, register size_t nitems)
>> +{
>> +        register FTSENTRY **ap, *p;
>> +
>> +        /* On most modern hosts, void * and FTSENT ** have the same
>> +           run-time representation, and one can convert sp->fts_compar to
>> +           the type qsort expects without problem.  Use the heuristic that
>> +           this is OK if the two pointer types are the same size, and if
>> +           converting FTSENT ** to uintptr_t is the same as converting
>> +           FTSENT ** to void * and then to uintptr_t.  This heuristic isn't
>> +           valid in general but we don't know of any counterexamples.  */
>> +        FTSENTRY *dummy;
>> +        int (*compare) (void const *, void const *) =
>> +          ((sizeof &dummy == sizeof (void *)
>> +            && (uintptr_t) &dummy == (uintptr_t) (void *) &dummy)
>> +           ? (int (*) (void const *, void const *)) sp->fts_compar
>> +           : fts_compar);
>> +
>> +        /*
>> +         * Construct an array of pointers to the structures and call qsort(3).
>> +         * Reassemble the array in the order returned by qsort.  If unable to
>> +         * sort for memory reasons, return the directory entries in their
>> +         * current order.  Allocate enough space for the current needs plus
>> +         * 40 so don't realloc one entry at a time.
>> +         */
>> +        if (nitems > sp->fts_nitems) {
>> +                sp->fts_nitems = nitems + 40;
>> +                FTSENTRY **a;
>> +                if (! (a = reallocarray (sp->fts_array,
>> +                                         sp->fts_nitems, sizeof *a))) {
>> +                        free(sp->fts_array);
>> +                        sp->fts_array = NULL;
>> +                        sp->fts_nitems = 0;
>> +                        return (head);
>> +                }
>> +                sp->fts_array = a;
>> +        }
>> +        for (ap = sp->fts_array, p = head; p; p = p->fts_link)
>> +                *ap++ = p;
>> +        qsort((void *)sp->fts_array, nitems, sizeof(FTSENTRY *), compare);
>> +        for (head = *(ap = sp->fts_array); --nitems; ++ap)
>> +                ap[0]->fts_link = ap[1];
>> +        ap[0]->fts_link = NULL;
>> +        return (head);
>> +}
>> +
>> +static FTSENTRY *
>> +internal_function
>> +fts_alloc (FTSOBJ *sp, const char *name, register size_t namelen)
>> +{
>> +        /*
>> +         * The file name is a variable length array.  Allocate the FTSENT
>> +         * structure and the file name in one chunk.
>> +         */
>> +        size_t len = FLEXSIZEOF(FTSENT, fts_name, namelen + 1);
>> +	register FTSENTRY *p;
>> +#if !_LIBC
>> +        p = malloc(len);
>> +        if (p == NULL)
>> +                return (NULL);
>> +#else
>> +	/*
>> +	 * For glibc, we use a wrapper struct to provide the extra required
>> +	 * fields without changing the FSENT layout.
>> +	 */
>> +	len += sizeof (struct FTSENT_wrapper);
>> +	struct FTSENT_wrapper *wrapper = malloc(len);
>> +	if (wrapper == NULL)
>> +		return (NULL);
>> +	p = &wrapper->ent;
>> +        p->fts_statp = &wrapper->fts_stat;
>> +#endif
>> +
>> +        /* Copy the name and guarantee NUL termination. */
>> +        memcpy(p->fts_name, name, namelen);
>> +        p->fts_name[namelen] = '\0';
>> +
>> +        p->fts_namelen = namelen;
>> +        FTSENT_FTS(p)= sp;
>> +        p->fts_path = sp->fts_path;
>> +        p->fts_errno = 0;
>> +        FTSENT_DIRP(p) = NULL;
>> +        p->fts_flags = 0;
>> +        p->fts_instr = FTS_NOINSTR;
>> +        p->fts_number = 0;
>> +        p->fts_pointer = NULL;
>> +        return (p);
>> +}
>> +
>> +static void
>> +internal_function
>> +fts_lfree (register FTSENTRY *head)
>> +{
>> +        int saved_errno = errno;
>> +
>> +        /* Free a linked list of structures. */
>> +        register FTSENTRY *p;
>> +        while ((p = head)) {
>> +                head = head->fts_link;
>> +                if (FTSENT_DIRP(p))
>> +                        closedir (FTSENT_DIRP(p));
>> +                free(FTSENT_WRAPPER(p));
>> +        }
>> +
>> +        __set_errno (saved_errno);
>> +}
>> +
>> +/*
>> + * Allow essentially unlimited file name lengths; find, rm, ls should
>> + * all work on any tree.  Most systems will allow creation of file
>> + * names much longer than MAXPATHLEN, even though the kernel won't
>> + * resolve them.  Add the size (not just what's needed) plus 256 bytes
>> + * so don't realloc the file name 2 bytes at a time.
>> + */
>> +static bool
>> +internal_function
>> +fts_palloc (FTSOBJ *sp, size_t more)
>> +{
>> +        size_t new_len = sp->fts_pathlen + more + 256;
>> +
>> +        /*
>> +         * See if fts_pathlen would overflow.
>> +         */
>> +        if (new_len < sp->fts_pathlen) {
>> +                free(sp->fts_path);
>> +                sp->fts_path = NULL;
>> +                __set_errno (ENAMETOOLONG);
>> +                return false;
>> +        }
>> +        sp->fts_pathlen = new_len;
>> +        char *p = realloc(sp->fts_path, sp->fts_pathlen);
>> +        if (p == NULL) {
>> +                free(sp->fts_path);
>> +                sp->fts_path = NULL;
>> +                return false;
>> +        }
>> +        sp->fts_path = p;
>> +        return true;
>> +}
>> +
>> +/*
>> + * When the file name is realloc'd, have to fix all of the pointers in
>> + *  structures already returned.
>> + */
>> +static void
>> +internal_function
>> +fts_padjust (FTSOBJ *sp, FTSENTRY *head)
>> +{
>> +        char *addr = sp->fts_path;
>> +
>> +        /* This code looks at bit-patterns of freed pointers to
>> +           relocate them, so it relies on undefined behavior.  If this
>> +           trick does not work on your platform, please report a bug.  */
>> +
>> +#define ADJUST(p) do {                                                  \
>> +        uintptr_t old_accpath = (uintptr_t) (p)->fts_accpath;           \
>> +        if (old_accpath != (uintptr_t) (p)->fts_name) {                 \
>> +                (p)->fts_accpath =                                      \
>> +                  addr + (old_accpath - (uintptr_t) (p)->fts_path);     \
>> +        }                                                               \
>> +        (p)->fts_path = addr;                                           \
>> +} while (0)
>> +        /* Adjust the current set of children. */
>> +        for (FTSENTRY *p = sp->fts_child; p; p = p->fts_link)
>> +                ADJUST(p);
>> +
>> +        /* Adjust the rest of the tree, including the current level. */
>> +        for (FTSENTRY *p = head; p->fts_level >= FTS_ROOTLEVEL;) {
>> +                ADJUST(p);
>> +                p = p->fts_link ? p->fts_link : p->fts_parent;
>> +        }
>> +}
>> +
>> +static size_t
>> +internal_function _GL_ATTRIBUTE_PURE
>> +fts_maxarglen (char * const *argv)
>> +{
>> +        size_t max;
>> +
>> +        for (max = 0; *argv; ++argv) {
>> +                size_t len = strlen(*argv);
>> +                if (len > max)
>> +                        max = len;
>> +        }
>> +        return (max + 1);
>> +}
>> +
>> +/*
>> + * Change to dir specified by fd or file name without getting
>> + * tricked by someone changing the world out from underneath us.
>> + * Assumes p->fts_statp->st_dev and p->fts_statp->st_ino are filled in.
>> + * If FD is non-negative, expect it to be used after this function returns,
>> + * and to be closed eventually.  So don't pass e.g., 'dirfd(dirp)' and then
>> + * do closedir(dirp), because that would invalidate the saved FD.
>> + * Upon failure, close FD immediately and return nonzero.
>> + */
>> +static int
>> +internal_function
>> +fts_safe_changedir (FTSOBJ *sp, FTSENTRY *p, int fd, char const *dir)
>> +{
>> +        fts_assert (0 <= fd || dir != NULL);
>> +        bool is_dotdot = dir && streq (dir, "..");
>> +
>> +        /* This clause handles the unusual case in which FTS_NOCHDIR
>> +           is specified, along with FTS_CWDFD.  In that case, there is
>> +           no need to change even the virtual cwd file descriptor.
>> +           However, if FD is non-negative, we do close it here.  */
>> +        if (ISSET (FTS_NOCHDIR))
>> +          {
>> +            if (ISSET (FTS_CWDFD) && 0 <= fd)
>> +              close (fd);
>> +            return 0;
>> +          }
>> +
>> +        if (fd < 0 && is_dotdot && ISSET (FTS_CWDFD))
>> +          {
>> +            /* When possible, skip the diropen and subsequent fstat+dev/ino
>> +               comparison.  I.e., when changing to parent directory
>> +               (chdir ("..")), use a file descriptor from the ring and
>> +               save the overhead of diropen+fstat, as well as avoiding
>> +               failure when we lack "x" access to the virtual cwd.  */
>> +            if ( ! i_ring_empty (&sp->fts_fd_ring))
>> +              {
>> +                int parent_fd;
>> +                fd_ring_print (sp, stderr, "pre-pop");
>> +                parent_fd = i_ring_pop (&sp->fts_fd_ring);
>> +                if (0 <= parent_fd)
>> +                  {
>> +                    fd = parent_fd;
>> +                    dir = NULL;
>> +                  }
>> +              }
>> +          }
>> +
>> +        int newfd = fd;
>> +        if (fd < 0 && (newfd = diropen (sp, dir)) < 0)
>> +          return -1;
>> +
>> +        /* The following dev/inode check is necessary if we're doing a
>> +           "logical" traversal (through symlinks, a la chown -L), if the
>> +           system lacks O_NOFOLLOW support, or if we're changing to ".."
>> +           (but not via a popped file descriptor).  When changing to the
>> +           name "..", O_NOFOLLOW can't help.  In general, when the target is
>> +           not "..", diropen's use of O_NOFOLLOW ensures we don't mistakenly
>> +           follow a symlink, so we can avoid the expense of this fstat.  */
>> +        int ret;
>> +        if (ISSET(FTS_LOGICAL) || ! HAVE_WORKING_O_NOFOLLOW
>> +            || (dir && streq (dir, "..")))
>> +          {
>> +            struct STRUCT_STAT sb;
>> +            if (FSTAT (newfd, &sb))
>> +              {
>> +                ret = -1;
>> +                goto bail;
>> +              }
>> +            if (p->fts_statp->st_dev != sb.st_dev
>> +                || p->fts_statp->st_ino != sb.st_ino)
>> +              {
>> +                __set_errno (ENOENT);           /* disinformation */
>> +                ret = -1;
>> +                goto bail;
>> +              }
>> +          }
>> +
>> +        if (ISSET(FTS_CWDFD))
>> +          {
>> +            cwd_advance_fd (sp, newfd, ! is_dotdot);
>> +            return 0;
>> +          }
>> +
>> +        ret = fchdir(newfd);
>> +bail:
>> +        if (fd < 0)
>> +          {
>> +            int oerrno = errno;
>> +            (void)close(newfd);
>> +            __set_errno (oerrno);
>> +          }
>> +        return ret;
>> +}
>> diff --git a/io/fts.c b/io/fts.c
>> index 3825f0aeb4..d3b8e5a100 100644
>> --- a/io/fts.c
>> +++ b/io/fts.c
>> @@ -1,2208 +1,23 @@
>> -/* Traverse a file hierarchy.
>> +/* File tree traversal functions LFS version.
>> +   Copyright (C) 2026 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>>   
>> -   Copyright (C) 2004-2026 Free Software Foundation, Inc.
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>>   
>> -   This file is free software: you can redistribute it and/or modify
>> -   it under the terms of the GNU Lesser General Public License as
>> -   published by the Free Software Foundation; either version 2.1 of the
>> -   License, or (at your option) any later version.
>> -
>> -   This file is distributed in the hope that it will be useful,
>> +   The GNU C Library 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 Lesser General Public License for more details.
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>>   
>> -   You should have received a copy of the GNU Lesser General Public License
>> -   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <https://www.gnu.org/licenses/>.  */
>>   
>> -/*-
>> - * Copyright (c) 1990, 1993, 1994
>> - *      The Regents of the University of California.  All rights reserved.
>> - *
>> - * Redistribution and use in source and binary forms, with or without
>> - * modification, are permitted provided that the following conditions
>> - * are met:
>> - * 1. Redistributions of source code must retain the above copyright
>> - *    notice, this list of conditions and the following disclaimer.
>> - * 2. Redistributions in binary form must reproduce the above copyright
>> - *    notice, this list of conditions and the following disclaimer in the
>> - *    documentation and/or other materials provided with the distribution.
>> - * 4. Neither the name of the University nor the names of its contributors
>> - *    may be used to endorse or promote products derived from this software
>> - *    without specific prior written permission.
>> - *
>> - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
>> - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
>> - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
>> - * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
>> - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
>> - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
>> - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
>> - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
>> - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
>> - * SUCH DAMAGE.
>> - */
>> +#include <sys/types.h>
>>   
>> -#include <config.h>
>> -
>> -#if defined LIBC_SCCS && !defined GCC_LINT && !defined lint
>> -static char sccsid[] = "@(#)fts.c       8.6 (Berkeley) 8/14/94";
>> +#ifndef __OFF_T_MATCHES_OFF64_T
>> +# include "io/fts-common.c"
>>   #endif
>> -
>> -#if _LIBC
>> -# include <fts.h>
>> -#else
>> -# include "fts_.h"
>> -#endif
>> -#if _LIBC || HAVE_SYS_PARAM_H
>> -# include <sys/param.h>
>> -#endif
>> -#include <sys/stat.h>
>> -#include <fcntl.h>
>> -#include <errno.h>
>> -#include <stddef.h>
>> -#include <stdint.h>
>> -#include <stdlib.h>
>> -#include <string.h>
>> -#include <unistd.h>
>> -
>> -/* Support for the LFS API version.  */
>> -#ifndef FTS_OPEN
>> -# define FTS_OPEN fts_open
>> -# define FTS_CLOSE fts_close
>> -# define FTS_READ fts_read
>> -# define FTS_SET fts_set
>> -# define FTS_CHILDREN fts_children
>> -# define FTSOBJ FTS
>> -# define FTSENTRY FTSENT
>> -# define INO_T ino_t
>> -# define STRUCT_STAT stat
>> -# define FSTAT __fstat
>> -# define FSTATAT __fstatat
>> -# define STRUCT_STATFS statfs
>> -# define FSTATFS __fstatfs
>> -#endif
>> -
>> -#if ! _LIBC
>> -# include "attribute.h"
>> -# include "fcntl--.h"
>> -# include "openat.h"
>> -# include "opendirat.h"
>> -# include "same-inode.h"
>> -# define OPENDIRAT opendirat
>> -# define FTSENT_WRAPPER(__p) __p
>> -# define FTS_COMPAR_CAST(__fn) __fn
>> -#else
>> -# include <stdbool.h>
>> -
>> -# define internal_function
>> -# define FALLTHROUGH               ; [[fallthrough]]
>> -# define HAVE_STRUCT_DIRENT_D_TYPE 1
>> -# define GNULIB_FTS_DEBUG          0
>> -# ifdef O_PATH
>> -#  define O_SEARCH                 O_PATH
>> -# else
>> -#  define O_SEARCH                 O_RDONLY
>> -# endif
>> -# define HAVE_SYS_VFS_H            1
>> -# define HAVE_FSTATFS              1
>> -# define HAVE_STRUCT_STATFS_F_TYPE 1
>> -# define HAVE_OPENAT               1
>> -# define HAVE_WORKING_O_NOFOLLOW   1
>> -# define _GL_CMP(a, b)             ((a) < (b) ? -1 : (a) > (b))
>> -# define OPENDIRAT                 __opendirat
>> -
>> -static inline bool openat_needs_fchdir (void)
>> -{
>> -  return false;
>> -}
>> -
>> -static inline bool streq (const char *s1, const char *s2)
>> -{
>> -  return strcmp (s1, s2) == 0;
>> -}
>> -# define reallocarray              __libc_reallocarray
>> -# define fchdir                    __fchdir
>> -# define close                     __close
>> -# define closedir                  __closedir
>> -# define fcntl                     __fcntl
>> -# define readdir                   __readdir
>> -# ifndef dirfd
>> -#  define dirfd                    __dirfd
>> -# endif
>> -# define open                      __open
>> -# define openat                    __openat
>> -
>> -# include "cycle-check.c"
>> -# include "i-ring.c"
>> -
>> -struct FTSENT_wrapper
>> -{
>> -  FTSOBJ *fts_fts;                /* the file hierarchy itself */
>> -  DIR *fts_dirp;                  /* Dir pointer for any directory containing
>> -				     more entries than we read at one time.  */
>> -  struct STRUCT_STAT fts_stat;
>> -
>> -  FTSENTRY ent;
>> -};
>> -
>> -/* glibc historicaly defines the FTS::fts_compar as having 'void *', while the
>> -   fts_open has a function point using 'FTSENT **' as argument.  */
>> -# define FTS_COMPAR_CAST(__fn) ((int (*) (void const *, void const *))__fn)
>> -
>> -# define FTSENT_WRAPPER(p) \
>> -    ((struct FTSENT_wrapper *) ((char *)(p) - offsetof(struct FTSENT_wrapper, ent)))
>> -#endif
>> -#define FTSENT_FTS(p)   (FTSENT_WRAPPER(p)->fts_fts)
>> -#define FTSENT_DIRP(p)  (FTSENT_WRAPPER(p)->fts_dirp)
>> -
>> -#include "flexmember.h"
>> -
>> -#include <dirent.h>
>> -#ifndef _D_EXACT_NAMLEN
>> -# define _D_EXACT_NAMLEN(dirent) strlen ((dirent)->d_name)
>> -#endif
>> -
>> -#if HAVE_STRUCT_DIRENT_D_TYPE
>> -/* True if the type of the directory entry D is known.  */
>> -# define DT_IS_KNOWN(d) ((d)->d_type != DT_UNKNOWN)
>> -/* True if the type of the directory entry D must be T.  */
>> -# define DT_MUST_BE(d, t) ((d)->d_type == (t))
>> -# define D_TYPE(d) ((d)->d_type)
>> -#else
>> -# define DT_IS_KNOWN(d) false
>> -# define DT_MUST_BE(d, t) false
>> -# define D_TYPE(d) DT_UNKNOWN
>> -
>> -# undef DT_UNKNOWN
>> -# define DT_UNKNOWN 0
>> -
>> -/* Any nonzero values will do here, so long as they're distinct.
>> -   Undef any existing macros out of the way.  */
>> -# undef DT_BLK
>> -# undef DT_CHR
>> -# undef DT_DIR
>> -# undef DT_FIFO
>> -# undef DT_LNK
>> -# undef DT_REG
>> -# undef DT_SOCK
>> -# define DT_BLK 1
>> -# define DT_CHR 2
>> -# define DT_DIR 3
>> -# define DT_FIFO 4
>> -# define DT_LNK 5
>> -# define DT_REG 6
>> -# define DT_SOCK 7
>> -#endif
>> -
>> -#ifndef S_IFBLK
>> -# define S_IFBLK 0
>> -#endif
>> -#ifndef S_IFLNK
>> -# define S_IFLNK 0
>> -#endif
>> -#ifndef S_IFSOCK
>> -# define S_IFSOCK 0
>> -#endif
>> -
>> -enum
>> -{
>> -  NOT_AN_INODE_NUMBER = 0
>> -};
>> -
>> -#ifdef D_INO_IN_DIRENT
>> -# define D_INO(dp) (dp)->d_ino
>> -#else
>> -/* Some systems don't have inodes, so fake them to avoid lots of ifdefs.  */
>> -# define D_INO(dp) NOT_AN_INODE_NUMBER
>> -#endif
>> -
>> -/* If possible (see max_entries, below), read no more than this many directory
>> -   entries at a time.  Without this limit (i.e., when using non-NULL
>> -   fts_compar), processing a directory with 4,000,000 entries requires ~1GiB
>> -   of memory, and handling 64M entries would require 16GiB of memory.  */
>> -#ifndef FTS_MAX_READDIR_ENTRIES
>> -# define FTS_MAX_READDIR_ENTRIES 100000
>> -#endif
>> -
>> -/* If there are more than this many entries in a directory,
>> -   and the conditions mentioned below are satisfied, then sort
>> -   the entries on inode number before any further processing.  */
>> -#ifndef FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
>> -# define FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD 10000
>> -#endif
>> -
>> -enum
>> -{
>> -  _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD = FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
>> -};
>> -
>> -enum Fts_stat
>> -{
>> -  FTS_NO_STAT_REQUIRED = 1,
>> -  FTS_STAT_REQUIRED = 2
>> -};
>> -
>> -#ifndef __set_errno
>> -# define __set_errno(Val) errno = (Val)
>> -#endif
>> -
>> -/* If this host provides the openat function, then we can avoid
>> -   attempting to open "." in some initialization code below.  */
>> -#ifdef HAVE_OPENAT
>> -# define HAVE_OPENAT_SUPPORT 1
>> -#else
>> -# define HAVE_OPENAT_SUPPORT 0
>> -#endif
>> -
>> -#ifdef NDEBUG
>> -# define fts_assert(expr) ((void) (0 && (expr)))
>> -#else
>> -# define fts_assert(expr)       \
>> -    do                          \
>> -      {                         \
>> -        if (!(expr))            \
>> -          abort ();             \
>> -      }                         \
>> -    while (false)
>> -#endif
>> -
>> -static FTSENTRY  *fts_alloc (FTSOBJ *, const char *, size_t);
>> -static FTSENTRY  *fts_build (FTSOBJ *, int);
>> -static void      fts_lfree (FTSENTRY *);
>> -static void      fts_load (FTSOBJ *, FTSENTRY *);
>> -static size_t    fts_maxarglen (char * const *);
>> -static void      fts_padjust (FTSOBJ *, FTSENTRY *);
>> -static bool      fts_palloc (FTSOBJ *, size_t);
>> -static FTSENTRY  *fts_sort (FTSOBJ *, FTSENTRY *, size_t);
>> -static unsigned short int fts_stat (FTSOBJ *, FTSENTRY *, bool);
>> -static int      fts_safe_changedir (FTSOBJ *, FTSENTRY *, int, const char *);
>> -
>> -#include "fts-cycle.c"
>> -
>> -#ifndef MAX
>> -# define MAX(a,b) ((a) > (b) ? (a) : (b))
>> -#endif
>> -
>> -#ifndef SIZE_MAX
>> -# define SIZE_MAX ((size_t) -1)
>> -#endif
>> -
>> -#define ISDOT(a)        (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
>> -
>> -#define CLR(opt)        (sp->fts_options &= ~(opt))
>> -#define ISSET(opt)      ((sp->fts_options & (opt)) != 0)
>> -#define SET(opt)        (sp->fts_options |= (opt))
>> -
>> -/* FIXME: FTS_NOCHDIR is now misnamed.
>> -   Call it FTS_USE_FULL_RELATIVE_FILE_NAMES instead. */
>> -#define FCHDIR(sp, fd)                                  \
>> -  (!ISSET(FTS_NOCHDIR) && (ISSET(FTS_CWDFD)             \
>> -                           ? (cwd_advance_fd ((sp), (fd), true), 0) \
>> -                           : fchdir (fd)))
>> -
>> -
>> -/* fts_build flags */
>> -/* FIXME: make this an enum */
>> -#define BCHILD          1               /* fts_children */
>> -#define BNAMES          2               /* fts_children, names only */
>> -#define BREAD           3               /* fts_read */
>> -
>> -#if GNULIB_FTS_DEBUG
>> -# include <inttypes.h>
>> -# include <stdio.h>
>> -bool fts_debug = false;
>> -# define Dprintf(x) do { if (fts_debug) printf x; } while (false)
>> -static void fd_ring_check (FTSOBJ const *);
>> -static void fd_ring_print (FTSOBJ const *, FILE *, char const *);
>> -#else
>> -# define Dprintf(x)
>> -# define fd_ring_check(x)
>> -# define fd_ring_print(a, b, c)
>> -#endif
>> -
>> -#define LEAVE_DIR(Fts, Ent, Tag)                                \
>> -  do                                                            \
>> -    {                                                           \
>> -      Dprintf (("  %s-leaving: %s\n", Tag, (Ent)->fts_path));   \
>> -      leave_dir (Fts, Ent);                                     \
>> -      fd_ring_check (Fts);                                      \
>> -    }                                                           \
>> -  while (false)
>> -
>> -static void
>> -fd_ring_clear (I_ring *fd_ring)
>> -{
>> -  while ( ! i_ring_empty (fd_ring))
>> -    {
>> -      int fd = i_ring_pop (fd_ring);
>> -      if (0 <= fd)
>> -        close (fd);
>> -    }
>> -}
>> -
>> -/* Overload the fts_statp->st_size member (otherwise unused, when
>> -   fts_info is FTS_NSOK) to indicate whether fts_read should stat
>> -   this entry or not.  */
>> -static void
>> -fts_set_stat_required (FTSENTRY *p, bool required)
>> -{
>> -  fts_assert (p->fts_info == FTS_NSOK);
>> -  p->fts_statp->st_size = (required
>> -                           ? FTS_STAT_REQUIRED
>> -                           : FTS_NO_STAT_REQUIRED);
>> -}
>> -
>> -/* Virtual fchdir.  Advance SP's working directory file descriptor,
>> -   SP->fts_cwd_fd, to FD, and push the previous value onto the fd_ring.
>> -   CHDIR_DOWN_ONE is true if FD corresponds to an entry in the directory
>> -   open on sp->fts_cwd_fd; i.e., to move the working directory one level
>> -   down.  */
>> -static void
>> -internal_function
>> -cwd_advance_fd (FTSOBJ *sp, int fd, bool chdir_down_one)
>> -{
>> -  int old = sp->fts_cwd_fd;
>> -  fts_assert (old != fd || old == AT_FDCWD);
>> -
>> -  if (chdir_down_one)
>> -    {
>> -      /* Push "old" onto the ring.
>> -         If the displaced file descriptor is non-negative, close it.  */
>> -      int prev_fd_in_slot = i_ring_push (&sp->fts_fd_ring, old);
>> -      fd_ring_print (sp, stderr, "post-push");
>> -      if (0 <= prev_fd_in_slot)
>> -        close (prev_fd_in_slot); /* ignore any close failure */
>> -    }
>> -  else if ( ! ISSET (FTS_NOCHDIR))
>> -    {
>> -      if (0 <= old)
>> -        close (old); /* ignore any close failure */
>> -    }
>> -
>> -  sp->fts_cwd_fd = fd;
>> -}
>> -
>> -/* Restore the initial, pre-traversal, "working directory".
>> -   In FTS_CWDFD mode, we merely call cwd_advance_fd, otherwise,
>> -   we may actually change the working directory.
>> -   Return 0 upon success. Upon failure, set errno and return nonzero.  */
>> -static int
>> -restore_initial_cwd (FTSOBJ *sp)
>> -{
>> -  int fail = FCHDIR (sp, ISSET (FTS_CWDFD) ? AT_FDCWD : sp->fts_rfd);
>> -  fd_ring_clear (&(sp->fts_fd_ring));
>> -  return fail;
>> -}
>> -
>> -/* Open the directory DIR if possible, and return a file
>> -   descriptor.  Return -1 and set errno on failure.  It doesn't matter
>> -   whether the file descriptor has read or write access.  */
>> -
>> -static int
>> -internal_function
>> -diropen (FTSOBJ const *sp, char const *dir)
>> -{
>> -  int open_flags = (O_SEARCH | O_CLOEXEC | O_DIRECTORY | O_NOCTTY | O_NONBLOCK
>> -                    | (ISSET (FTS_PHYSICAL) ? O_NOFOLLOW : 0));
>> -
>> -  int fd = (ISSET (FTS_CWDFD)
>> -            ? openat (sp->fts_cwd_fd, dir, open_flags)
>> -            : open (dir, open_flags));
>> -  return fd;
>> -}
>> -
>> -FTSOBJ *
>> -FTS_OPEN (char * const *argv,
>> -          register int options,
>> -          int (*compar) (const FTSENTRY **, const FTSENTRY **))
>> -{
>> -        /* Options check: glibc added other flags after FTS_NAMEONLY and
>> -	   FTS_STOP, and they are assumed to be private.  */
>> -        if (options & ~FTS_OPTIONMASK
>> -#if _LIBC
>> -	    || options & (FTS_NAMEONLY | FTS_STOP)
>> -#endif
>> -	    ) {
>> -                __set_errno (EINVAL);
>> -                return (NULL);
>> -        }
>> -        if ((options & FTS_NOCHDIR) && (options & FTS_CWDFD)) {
>> -                __set_errno (EINVAL);
>> -                return (NULL);
>> -        }
>> -#if !_LIBC
>> -        if ( ! (options & (FTS_LOGICAL | FTS_PHYSICAL))) {
>> -                __set_errno (EINVAL);
>> -                return (NULL);
>> -        }
>> -#else
>> -	/* glibc historically falls to FTS_PHYSICAL if no FTS_PHYSICAL or
>> -	   FTS_LOGICAL is specified.  */
>> -        if (! (options & (FTS_PHYSICAL | FTS_LOGICAL)))
>> -	  options |= FTS_PHYSICAL;
>> -#endif
>> -
>> -        /* Allocate/initialize the stream */
>> -        register FTSOBJ *sp = calloc (1, sizeof *sp);
>> -        if (sp == NULL)
>> -                return (NULL);
>> -        sp->fts_compar = FTS_COMPAR_CAST(compar);
>> -        sp->fts_options = options;
>> -
>> -        /* Logical walks turn on NOCHDIR; symbolic links are too hard. */
>> -        if (ISSET(FTS_LOGICAL)) {
>> -                SET(FTS_NOCHDIR);
>> -                CLR(FTS_CWDFD);
>> -        }
>> -
>> -        /* Initialize fts_cwd_fd.  */
>> -        sp->fts_cwd_fd = AT_FDCWD;
>> -        if ( ISSET(FTS_CWDFD) && ! HAVE_OPENAT_SUPPORT)
>> -          {
>> -            /* While it isn't technically necessary to open "." this
>> -               early, doing it here saves us the trouble of ensuring
>> -               later (where it'd be messier) that "." can in fact
>> -               be opened.  If not, revert to FTS_NOCHDIR mode.  */
>> -            int fd = open (".", O_SEARCH | O_CLOEXEC);
>> -            if (fd < 0)
>> -              {
>> -                /* Even if "." is unreadable, don't revert to FTS_NOCHDIR mode
>> -                   on systems like Linux+PROC_FS, where our openat emulation
>> -                   is good enough.  Note: on a system that emulates
>> -                   openat via /proc, this technique can still fail, but
>> -                   only in extreme conditions, e.g., when the working
>> -                   directory cannot be saved (i.e. save_cwd fails) --
>> -                   and that happens on Linux only when "." is unreadable
>> -                   and the CWD would be longer than PATH_MAX.
>> -                   FIXME: once Linux kernel openat support is well established,
>> -                   replace the above open call and this entire if/else block
>> -                   with the body of the if-block below.  */
>> -                if ( openat_needs_fchdir ())
>> -                  {
>> -                    SET(FTS_NOCHDIR);
>> -                    CLR(FTS_CWDFD);
>> -                  }
>> -              }
>> -            else
>> -              {
>> -                close (fd);
>> -              }
>> -          }
>> -
>> -        /*
>> -         * Start out with 1K of file name space, and enough, in any case,
>> -         * to hold the user's file names.
>> -         */
>> -#ifndef MAXPATHLEN
>> -# define MAXPATHLEN 1024
>> -#endif
>> -        {
>> -          size_t maxarglen = fts_maxarglen(argv);
>> -          if (! fts_palloc(sp, MAX(maxarglen, MAXPATHLEN)))
>> -                  goto mem1;
>> -        }
>> -
>> -        /* Allocate/initialize root's parent. */
>> -        FTSENTRY *parent = NULL;
>> -        if (*argv != NULL) {
>> -                if ((parent = fts_alloc(sp, "", 0)) == NULL)
>> -                        goto mem2;
>> -                parent->fts_level = FTS_ROOTPARENTLEVEL;
>> -          }
>> -
>> -        /* The classic fts implementation would call fts_stat with
>> -           a new entry for each iteration of the loop below.
>> -           If the comparison function is not specified or if the
>> -           FTS_DEFER_STAT option is in effect, don't stat any entry
>> -           in this loop.  This is an attempt to minimize the interval
>> -           between the initial stat/lstat/fstatat and the point at which
>> -           a directory argument is first opened.  This matters for any
>> -           directory command line argument that resides on a file system
>> -           without genuine i-nodes.  If you specify FTS_DEFER_STAT along
>> -           with a comparison function, that function must not access any
>> -           data via the fts_statp pointer.  */
>> -        bool defer_stat = (compar == NULL || ISSET(FTS_DEFER_STAT));
>> -
>> -        /* Allocate/initialize root(s). */
>> -        register FTSENTRY *root;
>> -        register size_t nitems;
>> -        FTSENTRY *tmp = NULL;     /* pacify gcc */
>> -        for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) {
>> -                /* *Do* allow zero-length file names. */
>> -                size_t len = strlen(*argv);
>> -
>> -                if ( ! (options & FTS_VERBATIM))
>> -                  {
>> -                    /* If there are two or more trailing slashes, trim all but one,
>> -                       but don't change "//" to "/", and do map "///" to "/".  */
>> -                    char const *v = *argv;
>> -                    if (2 < len && v[len - 1] == '/')
>> -                      while (1 < len && v[len - 2] == '/')
>> -                        --len;
>> -                  }
>> -
>> -                register FTSENTRY *p = fts_alloc(sp, *argv, len);
>> -                if (p == NULL)
>> -                        goto mem3;
>> -                p->fts_level = FTS_ROOTLEVEL;
>> -                p->fts_parent = parent;
>> -                p->fts_accpath = p->fts_name;
>> -                /* Even when defer_stat is true, be sure to stat the first
>> -                   command line argument, since fts_read (at least with
>> -                   FTS_XDEV) requires that.  */
>> -                if (defer_stat && root != NULL) {
>> -                        p->fts_info = FTS_NSOK;
>> -                        fts_set_stat_required(p, true);
>> -                } else {
>> -                        p->fts_info = fts_stat(sp, p, false);
>> -                }
>> -
>> -                /*
>> -                 * If comparison routine supplied, traverse in sorted
>> -                 * order; otherwise traverse in the order specified.
>> -                 */
>> -                if (compar) {
>> -                        p->fts_link = root;
>> -                        root = p;
>> -                } else {
>> -                        p->fts_link = NULL;
>> -                        if (root == NULL)
>> -                                tmp = root = p;
>> -                        else {
>> -                                tmp->fts_link = p;
>> -                                tmp = p;
>> -                        }
>> -                }
>> -        }
>> -        if (compar && nitems > 1)
>> -                root = fts_sort(sp, root, nitems);
>> -
>> -        /*
>> -         * Allocate a dummy pointer and make fts_read think that we've just
>> -         * finished the node before the root(s); set p->fts_info to FTS_INIT
>> -         * so that everything about the "current" node is ignored.
>> -         */
>> -        if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
>> -                goto mem3;
>> -        sp->fts_cur->fts_link = root;
>> -        sp->fts_cur->fts_info = FTS_INIT;
>> -        sp->fts_cur->fts_level = 1;
>> -        if (! setup_dir (sp))
>> -                goto mem3;
>> -
>> -        /*
>> -         * If using chdir(2), grab a file descriptor pointing to dot to ensure
>> -         * that we can get back here; this could be avoided for some file names,
>> -         * but almost certainly not worth the effort.  Slashes, symbolic links,
>> -         * and ".." are all fairly nasty problems.  Note, if we can't get the
>> -         * descriptor we run anyway, just more slowly.
>> -         */
>> -        if (!ISSET(FTS_NOCHDIR) && !ISSET(FTS_CWDFD)
>> -            && (sp->fts_rfd = diropen (sp, ".")) < 0)
>> -                SET(FTS_NOCHDIR);
>> -
>> -        i_ring_init (&sp->fts_fd_ring, -1);
>> -        return (sp);
>> -
>> -mem3:   fts_lfree(root);
>> -        free(FTSENT_WRAPPER(parent));
>> -mem2:   free(sp->fts_path);
>> -mem1:   free(sp);
>> -        return (NULL);
>> -}
>> -
>> -static void
>> -internal_function
>> -fts_load (FTSOBJ *sp, register FTSENTRY *p)
>> -{
>> -        /*
>> -         * Load the stream structure for the next traversal.  Since we don't
>> -         * actually enter the directory until after the preorder visit, set
>> -         * the fts_accpath field specially so the chdir gets done to the right
>> -         * place and the user can access the first node.  From fts_open it's
>> -         * known that the file name will fit.
>> -         */
>> -        register size_t len = p->fts_pathlen = p->fts_namelen;
>> -        memmove(sp->fts_path, p->fts_name, len + 1);
>> -        register char *cp = strrchr(p->fts_name, '/');
>> -        if (cp && (cp != p->fts_name || cp[1])) {
>> -                len = strlen(++cp);
>> -                memmove(p->fts_name, cp, len + 1);
>> -                p->fts_namelen = len;
>> -        }
>> -        p->fts_accpath = p->fts_path = sp->fts_path;
>> -}
>> -
>> -int
>> -FTS_CLOSE (FTSOBJ *sp)
>> -{
>> -        /*
>> -         * This still works if we haven't read anything -- the dummy structure
>> -         * points to the root list, so we step through to the end of the root
>> -         * list which has a valid parent pointer.
>> -         */
>> -        if (sp->fts_cur) {
>> -                register FTSENTRY *p;
>> -                for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
>> -                        register FTSENTRY *freep = p;
>> -                        p = p->fts_link != NULL ? p->fts_link : p->fts_parent;
>> -                        free(FTSENT_WRAPPER(freep));
>> -                }
>> -                free(FTSENT_WRAPPER(p));
>> -        }
>> -
>> -        /* Free up child linked list, sort array, file name buffer. */
>> -        if (sp->fts_child)
>> -                fts_lfree(sp->fts_child);
>> -        free(sp->fts_array);
>> -        free(sp->fts_path);
>> -
>> -        int saved_errno = 0;
>> -        if (ISSET(FTS_CWDFD))
>> -          {
>> -            if (0 <= sp->fts_cwd_fd)
>> -              if (close (sp->fts_cwd_fd))
>> -                saved_errno = errno;
>> -          }
>> -        else if (!ISSET(FTS_NOCHDIR))
>> -          {
>> -            /* Return to original directory, save errno if necessary. */
>> -            if (fchdir(sp->fts_rfd))
>> -              saved_errno = errno;
>> -
>> -            /* If close fails, record errno only if saved_errno is zero,
>> -               so that we report the probably-more-meaningful fchdir errno.  */
>> -            if (close (sp->fts_rfd))
>> -              if (saved_errno == 0)
>> -                saved_errno = errno;
>> -          }
>> -
>> -        fd_ring_clear (&sp->fts_fd_ring);
>> -
>> -        if (sp->fts_leaf_optimization_works_ht)
>> -          hash_free (sp->fts_leaf_optimization_works_ht);
>> -
>> -        free_dir (sp);
>> -
>> -        /* Free up the stream pointer. */
>> -        free(sp);
>> -
>> -        /* Set errno and return. */
>> -        if (saved_errno) {
>> -                __set_errno (saved_errno);
>> -                return (-1);
>> -        }
>> -
>> -        return (0);
>> -}
>> -
>> -/* Minimum link count of a traditional Unix directory.  When leaf
>> -   optimization is OK and a directory's st_nlink == MIN_DIR_NLINK,
>> -   then the directory has no subdirectories.  */
>> -enum { MIN_DIR_NLINK = 2 };
>> -
>> -/* Whether leaf optimization is OK for a directory.  */
>> -enum leaf_optimization
>> -  {
>> -    /* st_nlink is not reliable for this directory's subdirectories.  */
>> -    NO_LEAF_OPTIMIZATION,
>> -
>> -    /* st_nlink == 2 means the directory lacks subdirectories.  */
>> -    OK_LEAF_OPTIMIZATION
>> -  };
>> -
>> -#if (defined __linux__ || defined __ANDROID__) \
>> -  && HAVE_SYS_VFS_H && HAVE_FSTATFS && HAVE_STRUCT_STATFS_F_TYPE
>> -
>> -# include <sys/vfs.h>
>> -
>> -/* Linux-specific constants from coreutils' src/fs.h */
>> -# define S_MAGIC_AFS 0x5346414F
>> -# define S_MAGIC_CIFS 0xFF534D42
>> -# define S_MAGIC_LUSTRE 0x0BD00BD0
>> -# define S_MAGIC_NFS 0x6969
>> -# define S_MAGIC_PROC 0x9FA0
>> -# define S_MAGIC_TMPFS 0x1021994
>> -
>> -# ifdef HAVE___FSWORD_T
>> -typedef __fsword_t fsword;
>> -# else
>> -typedef long int fsword;
>> -# endif
>> -
>> -/* Map a stat.st_dev number to a file system type number f_ftype.  */
>> -struct dev_type
>> -{
>> -  dev_t st_dev;
>> -  fsword f_type;
>> -};
>> -
>> -/* Use a tiny initial size.  If a traversal encounters more than
>> -   a few devices, the cost of growing/rehashing this table will be
>> -   rendered negligible by the number of inodes processed.  */
>> -enum { DEV_TYPE_HT_INITIAL_SIZE = 13 };
>> -
>> -static size_t
>> -dev_type_hash (void const *x, size_t table_size)
>> -{
>> -  struct dev_type const *ax = x;
>> -  uintmax_t dev = ax->st_dev;
>> -  return dev % table_size;
>> -}
>> -
>> -static bool
>> -dev_type_compare (void const *x, void const *y)
>> -{
>> -  struct dev_type const *ax = x;
>> -  struct dev_type const *ay = y;
>> -  return ax->st_dev == ay->st_dev;
>> -}
>> -
>> -/* Return the file system type of P with file descriptor FD, or 0 if not known.
>> -   If FD is negative, P's file descriptor is unavailable.
>> -   Try to cache known values.  */
>> -
>> -static fsword
>> -filesystem_type (FTSENTRY const *p, int fd)
>> -{
>> -  FTSOBJ *sp = FTSENT_FTS(p);
>> -
>> -  /* If we're not in CWDFD mode, don't bother with this optimization,
>> -     since the caller is not serious about performance.  */
>> -  if (!ISSET (FTS_CWDFD))
>> -    return 0;
>> -
>> -  Hash_table *h = sp->fts_leaf_optimization_works_ht;
>> -  if (! h)
>> -    h = sp->fts_leaf_optimization_works_ht
>> -      = hash_initialize (DEV_TYPE_HT_INITIAL_SIZE, NULL, dev_type_hash,
>> -                         dev_type_compare, free);
>> -
>> -  if (h)
>> -    {
>> -      struct dev_type tmp;
>> -      tmp.st_dev = p->fts_statp->st_dev;
>> -      struct dev_type *ent = hash_lookup (h, &tmp);
>> -      if (ent)
>> -        return ent->f_type;
>> -    }
>> -
>> -  /* Look-up failed.  Query directly and cache the result.  */
>> -  struct STRUCT_STATFS fs_buf;
>> -  if (fd < 0 || FSTATFS (fd, &fs_buf) != 0)
>> -    return 0;
>> -
>> -  if (h)
>> -    {
>> -      struct dev_type *t2 = malloc (sizeof *t2);
>> -      if (t2)
>> -        {
>> -          t2->st_dev = p->fts_statp->st_dev;
>> -          t2->f_type = fs_buf.f_type;
>> -
>> -          struct dev_type *ent = hash_insert (h, t2);
>> -          if (ent)
>> -            fts_assert (ent == t2);
>> -          else
>> -            free (t2);
>> -        }
>> -    }
>> -
>> -  return fs_buf.f_type;
>> -}
>> -
>> -/* Return true if sorting dirents on inode numbers is known to improve
>> -   traversal performance for the directory P with descriptor DIR_FD.
>> -   Return false otherwise.  When in doubt, return true.
>> -   DIR_FD is negative if unavailable.  */
>> -static bool
>> -dirent_inode_sort_may_be_useful (FTSENTRY const *p, int dir_fd)
>> -{
>> -  /* Skip the sort only if we can determine efficiently
>> -     that skipping it is the right thing to do.
>> -     The cost of performing an unnecessary sort is negligible,
>> -     while the cost of *not* performing it can be O(N^2) with
>> -     a very large constant.  */
>> -
>> -  switch (filesystem_type (p, dir_fd))
>> -    {
>> -    case S_MAGIC_LUSTRE:
>> -      /* On Lustre, sorting directory entries interferes with its ability to
>> -         prefetch file metadata (via statahead).  This would make a command
>> -         like 'du' around 9 times slower.  See
>> -         <https://bugs.gnu.org/80106>.  */
>> -    case S_MAGIC_CIFS:
>> -    case S_MAGIC_NFS:
>> -    case S_MAGIC_TMPFS:
>> -      /* On a file system of any of these types, sorting
>> -         is unnecessary, and hence wasteful.  */
>> -      return false;
>> -
>> -    default:
>> -      return true;
>> -    }
>> -}
>> -
>> -/* Given an FTS entry P for a directory with descriptor DIR_FD,
>> -   return whether it is valid to apply leaf optimization.
>> -   The optimization is valid if a directory's st_nlink value equal
>> -   to MIN_DIR_NLINK means the directory has no subdirectories.
>> -   DIR_FD is negative if unavailable.  */
>> -static enum leaf_optimization
>> -leaf_optimization (FTSENTRY const *p, int dir_fd)
>> -{
>> -  switch (filesystem_type (p, dir_fd))
>> -    {
>> -    case 0:
>> -      /* Leaf optimization is unsafe if the file system type is unknown.  */
>> -      FALLTHROUGH;
>> -    case S_MAGIC_AFS:
>> -      /* Although AFS mount points are not counted in st_nlink, they
>> -         act like directories.  See <https://bugs.debian.org/143111>.  */
>> -      FALLTHROUGH;
>> -    case S_MAGIC_CIFS:
>> -      /* Leaf optimization causes 'find' to abort.  See
>> -         <https://lists.gnu.org/r/bug-gnulib/2018-04/msg00015.html>.  */
>> -      FALLTHROUGH;
>> -    case S_MAGIC_NFS:
>> -      /* NFS provides usable dirent.d_type but not necessarily for all entries
>> -         of large directories, so as per <https://bugzilla.redhat.com/1252549>
>> -         NFS should return true.  However st_nlink values are not accurate on
>> -         all implementations as per <https://bugzilla.redhat.com/1299169>.  */
>> -      FALLTHROUGH;
>> -    case S_MAGIC_PROC:
>> -      /* Per <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=143111> /proc
>> -         may have bogus stat.st_nlink values.  */
>> -      return NO_LEAF_OPTIMIZATION;
>> -
>> -    default:
>> -      return OK_LEAF_OPTIMIZATION;
>> -    }
>> -}
>> -
>> -#else
>> -static bool
>> -dirent_inode_sort_may_be_useful (_GL_UNUSED FTSENTRY const *p,
>> -                                 _GL_UNUSED int dir_fd)
>> -{
>> -  return true;
>> -}
>> -static enum leaf_optimization
>> -leaf_optimization (_GL_UNUSED FTSENTRY const *p, _GL_UNUSED int dir_fd)
>> -{
>> -  return NO_LEAF_OPTIMIZATION;
>> -}
>> -#endif
>> -
>> -/*
>> - * Special case of "/" at the end of the file name so that slashes aren't
>> - * appended which would cause file names to be written as "....//foo".
>> - */
>> -#define NAPPEND(p)                                                      \
>> -        (p->fts_path[p->fts_pathlen - 1] == '/'                         \
>> -            ? p->fts_pathlen - 1 : p->fts_pathlen)
>> -
>> -FTSENTRY *
>> -FTS_READ (FTSOBJ *sp)
>> -{
>> -        /* If finished or unrecoverable error, return NULL. */
>> -        if (sp->fts_cur == NULL || ISSET(FTS_STOP))
>> -                return (NULL);
>> -
>> -        /* Set current node pointer. */
>> -        register FTSENTRY *p = sp->fts_cur;
>> -
>> -        /* Save and zero out user instructions. */
>> -        register unsigned short int instr = p->fts_instr;
>> -        p->fts_instr = FTS_NOINSTR;
>> -
>> -        /* Any type of file may be re-visited; re-stat and re-turn. */
>> -        if (instr == FTS_AGAIN) {
>> -                p->fts_info = fts_stat(sp, p, false);
>> -                return (p);
>> -        }
>> -        Dprintf (("fts_read: p=%s\n",
>> -                  p->fts_info == FTS_INIT ? "" : p->fts_path));
>> -
>> -        /*
>> -         * Following a symlink -- SLNONE test allows application to see
>> -         * SLNONE and recover.  If indirecting through a symlink, have
>> -         * keep a pointer to current location.  If unable to get that
>> -         * pointer, follow fails.
>> -         */
>> -        if (instr == FTS_FOLLOW &&
>> -            (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) {
>> -                p->fts_info = fts_stat(sp, p, true);
>> -                if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
>> -                        if ((p->fts_symfd = diropen (sp, ".")) < 0) {
>> -                                p->fts_errno = errno;
>> -                                p->fts_info = FTS_ERR;
>> -                        } else
>> -                                p->fts_flags |= FTS_SYMFOLLOW;
>> -                }
>> -                goto check_for_dir;
>> -        }
>> -
>> -        /* Directory in pre-order. */
>> -        if (p->fts_info == FTS_D) {
>> -                /* If skipped or crossed mount point, do post-order visit. */
>> -                if (instr == FTS_SKIP ||
>> -                    (ISSET(FTS_XDEV) && p->fts_statp->st_dev != sp->fts_dev)) {
>> -                        if (p->fts_flags & FTS_SYMFOLLOW)
>> -                                (void)close(p->fts_symfd);
>> -                        if (sp->fts_child) {
>> -                                fts_lfree(sp->fts_child);
>> -                                sp->fts_child = NULL;
>> -                        }
>> -                        p->fts_info = FTS_DP;
>> -                        LEAVE_DIR (sp, p, "1");
>> -                        return (p);
>> -                }
>> -
>> -                /* Rebuild if only read the names and now traversing. */
>> -                if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) {
>> -                        CLR(FTS_NAMEONLY);
>> -                        fts_lfree(sp->fts_child);
>> -                        sp->fts_child = NULL;
>> -                }
>> -
>> -                /*
>> -                 * Cd to the subdirectory.
>> -                 *
>> -                 * If have already read and now fail to chdir, whack the list
>> -                 * to make the names come out right, and set the parent errno
>> -                 * so the application will eventually get an error condition.
>> -                 * Set the FTS_DONTCHDIR flag so that when we logically change
>> -                 * directories back to the parent we don't do a chdir.
>> -                 *
>> -                 * If haven't read do so.  If the read fails, fts_build sets
>> -                 * FTS_STOP or the fts_info field of the node.
>> -                 */
>> -                if (sp->fts_child != NULL) {
>> -                        if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) {
>> -                                p->fts_errno = errno;
>> -                                p->fts_flags |= FTS_DONTCHDIR;
>> -                                for (p = sp->fts_child; p != NULL;
>> -                                     p = p->fts_link)
>> -                                        p->fts_accpath =
>> -                                            p->fts_parent->fts_accpath;
>> -                        }
>> -                } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) {
>> -                        if (ISSET(FTS_STOP))
>> -                                return (NULL);
>> -                        /* If fts_build's call to fts_safe_changedir failed
>> -                           because it was not able to fchdir into a
>> -                           subdirectory, tell the caller.  */
>> -                        if (p->fts_errno && p->fts_info != FTS_DNR)
>> -                                p->fts_info = FTS_ERR;
>> -                        LEAVE_DIR (sp, p, "2");
>> -                        return (p);
>> -                }
>> -                p = sp->fts_child;
>> -                sp->fts_child = NULL;
>> -                goto name;
>> -        }
>> -
>> -        /* Move to the next node on this level. */
>> -next: ;
>> -        register FTSENTRY *tmp = p;
>> -
>> -        /* If we have so many directory entries that we're reading them
>> -           in batches, and we've reached the end of the current batch,
>> -           read in a new batch.  */
>> -        if (p->fts_link == NULL && FTSENT_DIRP(p->fts_parent))
>> -          {
>> -            p = tmp->fts_parent;
>> -            sp->fts_cur = p;
>> -            sp->fts_path[p->fts_pathlen] = '\0';
>> -
>> -            if ((p = fts_build (sp, BREAD)) == NULL)
>> -              {
>> -                if (ISSET(FTS_STOP))
>> -                  return NULL;
>> -                goto cd_dot_dot;
>> -              }
>> -
>> -            free(FTSENT_WRAPPER(tmp));
>> -            goto name;
>> -          }
>> -
>> -        if ((p = p->fts_link) != NULL) {
>> -                sp->fts_cur = p;
>> -                free(FTSENT_WRAPPER(tmp));
>> -
>> -                /*
>> -                 * If reached the top, return to the original directory (or
>> -                 * the root of the tree), and load the file names for the next
>> -                 * root.
>> -                 */
>> -                if (p->fts_level == FTS_ROOTLEVEL) {
>> -                        if (restore_initial_cwd(sp)) {
>> -                                SET(FTS_STOP);
>> -                                return (NULL);
>> -                        }
>> -                        free_dir(sp);
>> -                        fts_load(sp, p);
>> -                        if (! setup_dir(sp)) {
>> -                                free_dir(sp);
>> -                                return (NULL);
>> -                        }
>> -                        goto check_for_dir;
>> -                }
>> -
>> -                /*
>> -                 * User may have called fts_set on the node.  If skipped,
>> -                 * ignore.  If followed, get a file descriptor so we can
>> -                 * get back if necessary.
>> -                 */
>> -                if (p->fts_instr == FTS_SKIP)
>> -                        goto next;
>> -                if (p->fts_instr == FTS_FOLLOW) {
>> -                        p->fts_info = fts_stat(sp, p, true);
>> -                        if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) {
>> -                                if ((p->fts_symfd = diropen (sp, ".")) < 0) {
>> -                                        p->fts_errno = errno;
>> -                                        p->fts_info = FTS_ERR;
>> -                                } else
>> -                                        p->fts_flags |= FTS_SYMFOLLOW;
>> -                        }
>> -                        p->fts_instr = FTS_NOINSTR;
>> -                }
>> -
>> -name:           {
>> -                  register char *t = sp->fts_path + NAPPEND(p->fts_parent);
>> -                  *t++ = '/';
>> -                  memmove(t, p->fts_name, p->fts_namelen + 1);
>> -                }
>> -check_for_dir:
>> -                sp->fts_cur = p;
>> -                if (p->fts_info == FTS_NSOK)
>> -                  {
>> -                    if (p->fts_statp->st_size == FTS_STAT_REQUIRED)
>> -                      p->fts_info = fts_stat(sp, p, false);
>> -                    else
>> -                      fts_assert (p->fts_statp->st_size == FTS_NO_STAT_REQUIRED);
>> -                  }
>> -
>> -                /* Skip files with different device numbers when FTS_MOUNT
>> -                   is set.  */
>> -                if (ISSET (FTS_MOUNT) && p->fts_info != FTS_NS &&
>> -                    p->fts_level != FTS_ROOTLEVEL &&
>> -                    p->fts_statp->st_dev != sp->fts_dev)
>> -                      goto next;
>> -
>> -                if (p->fts_info == FTS_D)
>> -                  {
>> -                    /* Now that P->fts_statp is guaranteed to be valid, if
>> -                       this is a command-line directory, record its device
>> -                       number, to be used for FTS_MOUNT and FTS_XDEV.  */
>> -                    if (p->fts_level == FTS_ROOTLEVEL)
>> -                      sp->fts_dev = p->fts_statp->st_dev;
>> -                    Dprintf (("  entering: %s\n", p->fts_path));
>> -                    if (! enter_dir (sp, p))
>> -                      return NULL;
>> -                  }
>> -                return p;
>> -        }
>> -cd_dot_dot:
>> -
>> -        /* Move up to the parent node. */
>> -        p = tmp->fts_parent;
>> -        sp->fts_cur = p;
>> -        free(FTSENT_WRAPPER(tmp));
>> -
>> -        if (p->fts_level == FTS_ROOTPARENTLEVEL) {
>> -                /*
>> -                 * Done; free everything up and set errno to 0 so the user
>> -                 * can distinguish between error and EOF.
>> -                 */
>> -                free(FTSENT_WRAPPER(p));
>> -                __set_errno (0);
>> -                return (sp->fts_cur = NULL);
>> -        }
>> -
>> -        fts_assert (p->fts_info != FTS_NSOK);
>> -
>> -        /* NUL terminate the file name.  */
>> -        sp->fts_path[p->fts_pathlen] = '\0';
>> -
>> -        /*
>> -         * Return to the parent directory.  If at a root node, restore
>> -         * the initial working directory.  If we came through a symlink,
>> -         * go back through the file descriptor.  Otherwise, move up
>> -         * one level, via "..".
>> -         */
>> -        if (p->fts_level == FTS_ROOTLEVEL) {
>> -                if (restore_initial_cwd(sp)) {
>> -                        p->fts_errno = errno;
>> -                        SET(FTS_STOP);
>> -                }
>> -        } else if (p->fts_flags & FTS_SYMFOLLOW) {
>> -                if (FCHDIR(sp, p->fts_symfd)) {
>> -                        p->fts_errno = errno;
>> -                        SET(FTS_STOP);
>> -                }
>> -                (void)close(p->fts_symfd);
>> -        } else if (!(p->fts_flags & FTS_DONTCHDIR) &&
>> -                   fts_safe_changedir(sp, p->fts_parent, -1, "..")) {
>> -                p->fts_errno = errno;
>> -                SET(FTS_STOP);
>> -        }
>> -
>> -        /* If the directory causes a cycle, preserve the FTS_DC flag and keep
>> -           the corresponding dev/ino pair in the hash table.  It is going to be
>> -           removed when leaving the original directory.  */
>> -        if (p->fts_info != FTS_DC) {
>> -                p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
>> -                if (p->fts_errno == 0)
>> -                        LEAVE_DIR (sp, p, "3");
>> -        }
>> -        return ISSET(FTS_STOP) ? NULL : p;
>> -}
>> -
>> -/*
>> - * Fts_set takes the stream as an argument although it's not used in this
>> - * implementation; it would be necessary if anyone wanted to add global
>> - * semantics to fts using fts_set.  An error return is allowed for similar
>> - * reasons.
>> - */
>> -/* ARGSUSED */
>> -int
>> -FTS_SET (_GL_UNUSED FTSOBJ *sp, FTSENTRY *p, int instr)
>> -{
>> -        if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW &&
>> -            instr != FTS_NOINSTR && instr != FTS_SKIP) {
>> -                __set_errno (EINVAL);
>> -                return (1);
>> -        }
>> -        p->fts_instr = instr;
>> -        return (0);
>> -}
>> -
>> -FTSENTRY *
>> -FTS_CHILDREN (FTSOBJ *sp, int instr)
>> -{
>> -        if (instr != 0 && instr != FTS_NAMEONLY) {
>> -                __set_errno (EINVAL);
>> -                return (NULL);
>> -        }
>> -
>> -        /* Set current node pointer. */
>> -        register FTSENTRY *p = sp->fts_cur;
>> -
>> -        /*
>> -         * Errno set to 0 so user can distinguish empty directory from
>> -         * an error.
>> -         */
>> -        __set_errno (0);
>> -
>> -        /* Fatal errors stop here. */
>> -        if (ISSET(FTS_STOP))
>> -                return (NULL);
>> -
>> -        /* Return logical hierarchy of user's arguments. */
>> -        if (p->fts_info == FTS_INIT)
>> -                return (p->fts_link);
>> -
>> -        /*
>> -         * If not a directory being visited in pre-order, stop here.  Could
>> -         * allow FTS_DNR, assuming the user has fixed the problem, but the
>> -         * same effect is available with FTS_AGAIN.
>> -         */
>> -        if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */)
>> -                return (NULL);
>> -
>> -        /* Free up any previous child list. */
>> -        if (sp->fts_child != NULL)
>> -                fts_lfree(sp->fts_child);
>> -
>> -        if (instr == FTS_NAMEONLY) {
>> -                SET(FTS_NAMEONLY);
>> -                instr = BNAMES;
>> -        } else
>> -                instr = BCHILD;
>> -
>> -        /*
>> -         * If using chdir on a relative file name and called BEFORE fts_read
>> -         * does its chdir to the root of a traversal, we can lose -- we need to
>> -         * chdir into the subdirectory, and we don't know where the current
>> -         * directory is, so we can't get back so that the upcoming chdir by
>> -         * fts_read will work.
>> -         */
>> -        if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' ||
>> -            ISSET(FTS_NOCHDIR))
>> -                return (sp->fts_child = fts_build(sp, instr));
>> -
>> -        int fd = diropen (sp, ".");
>> -        if (fd < 0)
>> -                return (sp->fts_child = NULL);
>> -        sp->fts_child = fts_build(sp, instr);
>> -        if (ISSET(FTS_CWDFD))
>> -          {
>> -            cwd_advance_fd (sp, fd, true);
>> -          }
>> -        else
>> -          {
>> -            if (fchdir(fd))
>> -              {
>> -                int saved_errno = errno;
>> -                close (fd);
>> -                __set_errno (saved_errno);
>> -                return NULL;
>> -              }
>> -            close (fd);
>> -          }
>> -        return (sp->fts_child);
>> -}
>> -
>> -/* A comparison function to sort on increasing inode number.
>> -   For some file system types, sorting either way makes a huge
>> -   performance difference for a directory with very many entries,
>> -   but sorting on increasing values is slightly better than sorting
>> -   on decreasing values.  The difference is in the 5% range.  */
>> -static int
>> -fts_compare_ino (FTSENTRY const **a, FTSENTRY const **b)
>> -{
>> -  return _GL_CMP (a[0]->fts_statp->st_ino, b[0]->fts_statp->st_ino);
>> -}
>> -
>> -/* Map the dirent.d_type value, DTYPE, to the corresponding stat.st_mode
>> -   S_IF* bit and set ST.st_mode, thus clearing all other bits in that field.  */
>> -static void
>> -set_stat_type (struct STRUCT_STAT *st, unsigned int dtype)
>> -{
>> -  mode_t type;
>> -  switch (dtype)
>> -    {
>> -    case DT_BLK:
>> -      type = S_IFBLK;
>> -      break;
>> -    case DT_CHR:
>> -      type = S_IFCHR;
>> -      break;
>> -    case DT_DIR:
>> -      type = S_IFDIR;
>> -      break;
>> -    case DT_FIFO:
>> -      type = S_IFIFO;
>> -      break;
>> -    case DT_LNK:
>> -      type = S_IFLNK;
>> -      break;
>> -    case DT_REG:
>> -      type = S_IFREG;
>> -      break;
>> -    case DT_SOCK:
>> -      type = S_IFSOCK;
>> -      break;
>> -    default:
>> -      type = 0;
>> -    }
>> -  st->st_mode = type;
>> -}
>> -
>> -#define closedir_and_clear(dirp)                \
>> -  do                                            \
>> -    {                                           \
>> -      closedir (dirp);                          \
>> -      dirp = NULL;                              \
>> -    }                                           \
>> -  while (0)
>> -
>> -#define fts_opendir(file, Pdir_fd)                              \
>> -        OPENDIRAT((! ISSET(FTS_NOCHDIR) && ISSET(FTS_CWDFD)     \
>> -                   ? sp->fts_cwd_fd : AT_FDCWD),                \
>> -                  file,                                         \
>> -                  (((ISSET(FTS_PHYSICAL)                        \
>> -                     && ! (ISSET(FTS_COMFOLLOW)                 \
>> -                           && cur->fts_level == FTS_ROOTLEVEL)) \
>> -                    ? O_NOFOLLOW : 0)),                         \
>> -                  Pdir_fd)
>> -
>> -/*
>> - * This is the tricky part -- do not casually change *anything* in here.  The
>> - * idea is to build the linked list of entries that are used by fts_children
>> - * and fts_read.  There are lots of special cases.
>> - *
>> - * The real slowdown in walking the tree is the stat calls.  If FTS_NOSTAT is
>> - * set and it's a physical walk (so that symbolic links can't be directories),
>> - * we can do things quickly.  First, if it's a 4.4BSD file system, the type
>> - * of the file is in the directory entry.  Otherwise, we assume that the number
>> - * of subdirectories in a node is equal to the number of links to the parent.
>> - * The former skips all stat calls.  The latter skips stat calls in any leaf
>> - * directories and for any files after the subdirectories in the directory have
>> - * been found, cutting the stat calls by about 2/3.
>> - */
>> -static FTSENTRY *
>> -internal_function
>> -fts_build (register FTSOBJ *sp, int type)
>> -{
>> -        FTSENTRY *cur = sp->fts_cur;
>> -        bool continue_readdir = !!FTSENT_DIRP(cur);
>> -
>> -        /* When cur->fts_dirp is non-NULL, that means we should
>> -           continue calling readdir on that existing DIR* pointer
>> -           rather than opening a new one.  */
>> -        int dir_fd;
>> -        if (continue_readdir)
>> -          {
>> -            DIR *dp = FTSENT_DIRP(cur);
>> -            dir_fd = dirfd (dp);
>> -            if (dir_fd < 0)
>> -              {
>> -                int dirfd_errno = errno;
>> -                closedir_and_clear (FTSENT_DIRP(cur));
>> -                if (type == BREAD)
>> -                  {
>> -                    cur->fts_info = FTS_DNR;
>> -                    cur->fts_errno = dirfd_errno;
>> -                  }
>> -                return NULL;
>> -              }
>> -          }
>> -        else
>> -          {
>> -            /* Open the directory for reading.  If this fails, we're done.
>> -               If being called from fts_read, set the fts_info field. */
>> -            if ((FTSENT_DIRP (cur) = fts_opendir(cur->fts_accpath, &dir_fd)) == NULL)
>> -              {
>> -                if (type == BREAD)
>> -                  {
>> -                    cur->fts_info = FTS_DNR;
>> -                    cur->fts_errno = errno;
>> -                  }
>> -                return NULL;
>> -              }
>> -            /* Rather than calling fts_stat for each and every entry encountered
>> -               in the readdir loop (below), stat each directory only right after
>> -               opening it.  */
>> -            bool stat_optimization = cur->fts_info == FTS_NSOK;
>> -
>> -            if (stat_optimization
>> -                /* Also read the stat info again after opening a directory to
>> -                   reveal eventual changes caused by a submount triggered by
>> -                   the traversal.  But do it only for utilities which use
>> -                   FTS_TIGHT_CYCLE_CHECK.  Therefore, only find and du
>> -                   benefit/suffer from this feature for now.  */
>> -                || ISSET (FTS_TIGHT_CYCLE_CHECK))
>> -              {
>> -                if (!stat_optimization)
>> -                  LEAVE_DIR (sp, cur, "4");
>> -                if (FSTAT (dir_fd, cur->fts_statp) != 0)
>> -                  {
>> -                    int fstat_errno = errno;
>> -                    closedir_and_clear (FTSENT_DIRP(cur));
>> -                    if (type == BREAD)
>> -                      {
>> -                        cur->fts_errno = fstat_errno;
>> -                        cur->fts_info = FTS_NS;
>> -                      }
>> -                    __set_errno (fstat_errno);
>> -                    return NULL;
>> -                  }
>> -                if (stat_optimization)
>> -                  cur->fts_info = FTS_D;
>> -                else if (! enter_dir (sp, cur))
>> -                  {
>> -                    int saved_errno = errno;
>> -                    closedir_and_clear (FTSENT_DIRP(cur));
>> -                    __set_errno (saved_errno);
>> -                    return NULL;
>> -                  }
>> -              }
>> -          }
>> -
>> -        /* Maximum number of readdir entries to read at one time.  This
>> -           limitation is to avoid reading millions of entries into memory
>> -           at once.  When an fts_compar function is specified, we have no
>> -           choice: we must read all entries into memory before calling that
>> -           function.  But when no such function is specified, we can read
>> -           entries in batches that are large enough to help us with inode-
>> -           sorting, yet not so large that we risk exhausting memory.  */
>> -        size_t max_entries = sp->fts_compar ? SIZE_MAX : FTS_MAX_READDIR_ENTRIES;
>> -
>> -        /*
>> -         * If we're going to need to stat anything or we want to descend
>> -         * and stay in the directory, chdir.  If this fails we keep going,
>> -         * but set a flag so we don't chdir after the post-order visit.
>> -         * We won't be able to stat anything, but we can still return the
>> -         * names themselves.  Note, that since fts_read won't be able to
>> -         * chdir into the directory, it will have to return different file
>> -         * names than before, i.e. "a/b" instead of "b".  Since the node
>> -         * has already been visited in pre-order, have to wait until the
>> -         * post-order visit to return the error.  There is a special case
>> -         * here, if there was nothing to stat then it's not an error to
>> -         * not be able to stat.  This is all fairly nasty.  If a program
>> -         * needed sorted entries or stat information, they had better be
>> -         * checking FTS_NS on the returned nodes.
>> -         */
>> -        bool descend;
>> -        if (continue_readdir)
>> -          {
>> -            /* When resuming a short readdir run, we already have
>> -               the required dirp and dir_fd.  */
>> -            descend = true;
>> -          }
>> -        else
>> -          {
>> -            /* Try to descend unless it is a names-only fts_children,
>> -               or the directory is known to lack subdirectories.  */
>> -            descend = (type != BNAMES
>> -                       && ! (ISSET (FTS_NOSTAT) && ISSET (FTS_PHYSICAL)
>> -                             && ! ISSET (FTS_SEEDOT)
>> -                             && cur->fts_statp->st_nlink == MIN_DIR_NLINK
>> -                             && (leaf_optimization (cur, dir_fd)
>> -                                 != NO_LEAF_OPTIMIZATION)));
>> -            if (descend || type == BREAD)
>> -              {
>> -                if (ISSET(FTS_CWDFD))
>> -                  dir_fd = fcntl (dir_fd, F_DUPFD_CLOEXEC, STDERR_FILENO + 1);
>> -                if (dir_fd < 0 || fts_safe_changedir(sp, cur, dir_fd, NULL)) {
>> -                        if (descend && type == BREAD)
>> -                                cur->fts_errno = errno;
>> -                        cur->fts_flags |= FTS_DONTCHDIR;
>> -                        descend = false;
>> -                        closedir_and_clear(FTSENT_DIRP(cur));
>> -                        if (ISSET(FTS_CWDFD) && 0 <= dir_fd)
>> -                                close (dir_fd);
>> -                        FTSENT_DIRP(cur) = NULL;
>> -                } else
>> -                        descend = true;
>> -              }
>> -          }
>> -
>> -        /*
>> -         * Figure out the max file name length that can be stored in the
>> -         * current buffer -- the inner loop allocates more space as necessary.
>> -         * We really wouldn't have to do the maxlen calculations here, we
>> -         * could do them in fts_read before returning the name, but it's a
>> -         * lot easier here since the length is part of the dirent structure.
>> -         *
>> -         * If not changing directories set a pointer so that can just append
>> -         * each new component into the file name.
>> -         */
>> -        size_t len = NAPPEND(cur);
>> -        char *cp;
>> -        if (ISSET(FTS_NOCHDIR)) {
>> -                cp = sp->fts_path + len;
>> -                *cp++ = '/';
>> -        } else {
>> -                /* GCC, you're too verbose. */
>> -                cp = NULL;
>> -        }
>> -        len++;
>> -        size_t maxlen = sp->fts_pathlen - len;
>> -
>> -        ptrdiff_t level = cur->fts_level + 1;
>> -
>> -        /* Read the directory, attaching each entry to the "link" pointer. */
>> -        bool doadjust = false;
>> -        register FTSENTRY *head = NULL;
>> -        FTSENTRY *tail = NULL;
>> -        register size_t nitems = 0;
>> -        bool sort_by_inode = false;
>> -        while (FTSENT_DIRP(cur)) {
>> -                __set_errno (0);
>> -                struct dirent *dp = readdir(FTSENT_DIRP(cur));
>> -                if (dp == NULL) {
>> -                        /* Some readdir()s do not absorb ENOENT (dir
>> -                           deleted but open).  This bug was fixed in
>> -                           glibc 2.3 (2002).  */
>> -#if ! (2 < __GLIBC__ + (3 <= __GLIBC_MINOR__))
>> -                        if (errno == ENOENT)
>> -                          errno = 0;
>> -#endif
>> -                        if (errno) {
>> -                                cur->fts_errno = errno;
>> -                                /* If we've not read any items yet, treat
>> -                                   the error as if we can't access the dir.  */
>> -                                cur->fts_info = (continue_readdir || nitems)
>> -                                                ? FTS_ERR : FTS_DNR;
>> -                        }
>> -                        closedir_and_clear(FTSENT_DIRP(cur));
>> -                        break;
>> -                }
>> -                if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name))
>> -                        continue;
>> -
>> -                size_t d_namelen = _D_EXACT_NAMLEN (dp);
>> -                register FTSENTRY *p = fts_alloc (sp, dp->d_name, d_namelen);
>> -                if (!p)
>> -                        goto mem1;
>> -                if (d_namelen >= maxlen) {
>> -                        /* include space for NUL */
>> -                        uintptr_t oldaddr = (uintptr_t) sp->fts_path;
>> -                        if (! fts_palloc(sp, d_namelen + len + 1)) {
>> -                                /*
>> -                                 * No more memory.  Save
>> -                                 * errno, free up the current structure and the
>> -                                 * structures already allocated.
>> -                                 */
>> -mem1: ;
>> -                                int saved_errno = errno;
>> -                                free(FTSENT_WRAPPER(p));
>> -                                fts_lfree(head);
>> -                                closedir_and_clear(FTSENT_DIRP(cur));
>> -                                cur->fts_info = FTS_ERR;
>> -                                SET(FTS_STOP);
>> -                                __set_errno (saved_errno);
>> -                                return (NULL);
>> -                        }
>> -                        /* Did realloc() change the pointer? */
>> -                        if (oldaddr != (uintptr_t) sp->fts_path) {
>> -                                doadjust = true;
>> -                                if (ISSET(FTS_NOCHDIR))
>> -                                        cp = sp->fts_path + len;
>> -                        }
>> -                        maxlen = sp->fts_pathlen - len;
>> -                }
>> -
>> -                size_t new_len = len + d_namelen;
>> -                if (new_len < len) {
>> -                        /*
>> -                         * In the unlikely event that we would end up
>> -                         * with a file name longer than SIZE_MAX, free up
>> -                         * the current structure and the structures already
>> -                         * allocated, then error out with ENAMETOOLONG.
>> -                         */
>> -                        free(FTSENT_WRAPPER(p));
>> -                        fts_lfree(head);
>> -                        closedir_and_clear(FTSENT_DIRP(cur));
>> -                        cur->fts_info = FTS_ERR;
>> -                        SET(FTS_STOP);
>> -                        __set_errno (ENAMETOOLONG);
>> -                        return (NULL);
>> -                }
>> -                p->fts_level = level;
>> -                p->fts_parent = sp->fts_cur;
>> -                p->fts_pathlen = new_len;
>> -
>> -                /* Store dirent.d_ino, in case we need to sort
>> -                   entries before processing them.  */
>> -                p->fts_statp->st_ino = D_INO (dp);
>> -
>> -                /* Build a file name for fts_stat to stat. */
>> -                if (ISSET(FTS_NOCHDIR)) {
>> -                        p->fts_accpath = p->fts_path;
>> -                        memmove(cp, p->fts_name, p->fts_namelen + 1);
>> -                } else
>> -                        p->fts_accpath = p->fts_name;
>> -
>> -                if (sp->fts_compar == NULL || ISSET(FTS_DEFER_STAT)) {
>> -                        /* Record what fts_read will have to do with this
>> -                           entry. In many cases, it will simply fts_stat it,
>> -                           but we can take advantage of any d_type information
>> -                           to optimize away the unnecessary stat calls.  I.e.,
>> -                           if FTS_NOSTAT is in effect, we don't need device
>> -                           numbers unconditionally (FTS_MOUNT) and we're not
>> -                           following symlinks (FTS_PHYSICAL) and d_type
>> -                           indicates this is *not* a directory, then we won't
>> -                           have to stat it  at all.  If it *is* a directory,
>> -                           then (currently) we stat it regardless, in order to
>> -                           get device and inode numbers.  Some day we might
>> -                           optimize that away, too, for directories where
>> -                           d_ino is known to be valid.  */
>> -                        bool skip_stat = (ISSET(FTS_NOSTAT)
>> -                                          && DT_IS_KNOWN(dp)
>> -                                          && ! DT_MUST_BE(dp, DT_DIR)
>> -                                          && (ISSET(FTS_PHYSICAL)
>> -                                              || ! DT_MUST_BE(dp, DT_LNK))
>> -                                          && ! ISSET(FTS_MOUNT));
>> -                        p->fts_info = FTS_NSOK;
>> -                        /* Propagate dirent.d_type information back
>> -                           to caller, when possible.  */
>> -                        set_stat_type (p->fts_statp, D_TYPE (dp));
>> -                        fts_set_stat_required(p, !skip_stat);
>> -                } else {
>> -                        p->fts_info = fts_stat(sp, p, false);
>> -                }
>> -
>> -                /* We walk in directory order so "ls -f" doesn't get upset. */
>> -                p->fts_link = NULL;
>> -                if (head == NULL)
>> -                        head = tail = p;
>> -                else {
>> -                        tail->fts_link = p;
>> -                        tail = p;
>> -                }
>> -
>> -                /* If there are many entries, no sorting function has been
>> -                   specified, and this file system is of a type that may be
>> -                   slow with a large number of entries, arrange to sort the
>> -                   directory entries on increasing inode numbers.
>> -
>> -                   The NITEMS comparison uses ==, not >, because the test
>> -                   needs to be tried at most once once, and NITEMS will exceed
>> -                   the threshold after it is incremented below.  */
>> -                if (nitems == _FTS_INODE_SORT_DIR_ENTRIES_THRESHOLD
>> -                    && !sp->fts_compar)
>> -                  sort_by_inode = dirent_inode_sort_may_be_useful (cur, dir_fd);
>> -
>> -                ++nitems;
>> -                if (max_entries <= nitems) {
>> -                        /* When there are too many dir entries, leave
>> -                           fts_dirp open, so that a subsequent fts_read
>> -                           can take up where we leave off.  */
>> -                        break;
>> -                }
>> -        }
>> -
>> -        /*
>> -         * If realloc() changed the address of the file name, adjust the
>> -         * addresses for the rest of the tree and the dir list.
>> -         */
>> -        if (doadjust)
>> -                fts_padjust(sp, head);
>> -
>> -        /*
>> -         * If not changing directories, reset the file name back to original
>> -         * state.
>> -         */
>> -        if (ISSET(FTS_NOCHDIR)) {
>> -                if (len == sp->fts_pathlen || nitems == 0)
>> -                        --cp;
>> -                *cp = '\0';
>> -        }
>> -
>> -        /*
>> -         * If descended after called from fts_children or after called from
>> -         * fts_read and nothing found, get back.  At the root level we use
>> -         * the saved fd; if one of fts_open()'s arguments is a relative name
>> -         * to an empty directory, we wind up here with no other way back.  If
>> -         * can't get back, we're done.
>> -         */
>> -        if (!continue_readdir && descend && (type == BCHILD || !nitems) &&
>> -            (cur->fts_level == FTS_ROOTLEVEL
>> -             ? restore_initial_cwd(sp)
>> -             : fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) {
>> -                cur->fts_info = FTS_ERR;
>> -                SET(FTS_STOP);
>> -                fts_lfree(head);
>> -                return (NULL);
>> -        }
>> -
>> -        /* If didn't find anything, return NULL. */
>> -        if (!nitems) {
>> -                if (type == BREAD
>> -                    && cur->fts_info != FTS_DNR && cur->fts_info != FTS_ERR)
>> -                        cur->fts_info = FTS_DP;
>> -                fts_lfree(head);
>> -                return (NULL);
>> -        }
>> -
>> -        if (sort_by_inode) {
>> -                sp->fts_compar = FTS_COMPAR_CAST (fts_compare_ino);
>> -                head = fts_sort (sp, head, nitems);
>> -                sp->fts_compar = NULL;
>> -        }
>> -
>> -        /* Sort the entries. */
>> -        if (sp->fts_compar && nitems > 1)
>> -                head = fts_sort(sp, head, nitems);
>> -        return (head);
>> -}
>> -
>> -#if GNULIB_FTS_DEBUG
>> -
>> -struct devino {
>> -  intmax_t dev, ino;
>> -};
>> -#define PRINT_DEVINO "(%jd,%jd)"
>> -
>> -static struct devino
>> -getdevino (int fd)
>> -{
>> -  struct STRUCT_STAT st;
>> -  return (fd == AT_FDCWD
>> -          ? (struct devino) { -1, 0 }
>> -          : FSTAT (fd, &st) == 0
>> -          ? (struct devino) { st.st_dev, st.st_ino }
>> -          : (struct devino) { -1, errno });
>> -}
>> -
>> -/* Walk ->fts_parent links starting at E_CURR, until the root of the
>> -   current hierarchy.  There should be a directory with dev/inode
>> -   matching those of AD.  If not, print a lot of diagnostics.  */
>> -static void
>> -find_matching_ancestor (FTSENTRY const *e_curr, struct Active_dir const *ad)
>> -{
>> -  for (FTSENTRY const *ent = e_curr;
>> -       ent->fts_level >= FTS_ROOTLEVEL;
>> -       ent = ent->fts_parent)
>> -    {
>> -      if (ad->ino == ent->fts_statp->st_ino
>> -          && ad->dev == ent->fts_statp->st_dev)
>> -        return;
>> -    }
>> -  printf ("ERROR: tree dir, %s, not active\n", ad->fts_ent->fts_accpath);
>> -  printf ("active dirs:\n");
>> -  for (FTSENTRY const *ent = e_curr;
>> -       ent->fts_level >= FTS_ROOTLEVEL;
>> -       ent = ent->fts_parent)
>> -    printf ("  %s(%"PRIuMAX"/%"PRIuMAX") to %s(%"PRIuMAX"/%"PRIuMAX")...\n",
>> -            ad->fts_ent->fts_accpath,
>> -            (uintmax_t) ad->dev,
>> -            (uintmax_t) ad->ino,
>> -            ent->fts_accpath,
>> -            (uintmax_t) ent->fts_statp->st_dev,
>> -            (uintmax_t) ent->fts_statp->st_ino);
>> -}
>> -
>> -void
>> -fts_cross_check (FTSOBJ const *sp)
>> -{
>> -  if ( ! ISSET (FTS_TIGHT_CYCLE_CHECK))
>> -    return;
>> -
>> -  FTSENTRY const *ent = sp->fts_cur;
>> -
>> -  Dprintf (("fts-cross-check cur=%s\n", ent->fts_path));
>> -  /* Make sure every parent dir is in the tree.  */
>> -  for (FTSENTRY const *t = ent->fts_parent;
>> -       t->fts_level >= FTS_ROOTLEVEL;
>> -       t = t->fts_parent)
>> -    {
>> -      struct Active_dir ad;
>> -      ad.ino = t->fts_statp->st_ino;
>> -      ad.dev = t->fts_statp->st_dev;
>> -      if ( ! hash_lookup (sp->fts_cycle.ht, &ad))
>> -        printf ("ERROR: active dir, %s, not in tree\n", t->fts_path);
>> -    }
>> -
>> -  /* Make sure every dir in the tree is an active dir.
>> -     But ENT is not necessarily a directory.  If so, just skip this part. */
>> -  if (ent->fts_parent->fts_level >= FTS_ROOTLEVEL
>> -      && (ent->fts_info == FTS_DP
>> -          || ent->fts_info == FTS_D))
>> -    for (struct Active_dir *ad = hash_get_first (sp->fts_cycle.ht);
>> -         ad != NULL;
>> -         ad = hash_get_next (sp->fts_cycle.ht, ad))
>> -      {
>> -        find_matching_ancestor (ent, ad);
>> -      }
>> -}
>> -
>> -static bool
>> -same_fd (int fd1, int fd2)
>> -{
>> -  struct STRUCT_STAT sb1, sb2;
>> -  return (FSTAT (fd1, &sb1) == 0
>> -          && FSTAT (fd2, &sb2) == 0
>> -          && psame_inode (&sb1, &sb2));
>> -}
>> -
>> -static void
>> -fd_ring_print (FTSOBJ const *sp, FILE *stream, char const *msg)
>> -{
>> -  if (!fts_debug)
>> -    return;
>> -  I_ring const *fd_ring = &sp->fts_fd_ring;
>> -  struct devino cwd = getdevino (sp->fts_cwd_fd);
>> -  fprintf (stream, "=== %s ========== "PRINT_DEVINO"\n", msg, cwd.dev, cwd.ino);
>> -  if (i_ring_empty (fd_ring))
>> -    return;
>> -
>> -  unsigned int i = fd_ring->ir_front;
>> -  while (true)
>> -    {
>> -      int fd = fd_ring->ir_data[i];
>> -      if (fd < 0)
>> -        fprintf (stream, "%u: %d:\n", i, fd);
>> -      else
>> -        {
>> -          struct devino wd = getdevino (fd);
>> -          fprintf (stream, "%u: %d: "PRINT_DEVINO"\n", i, fd, wd.dev, wd.ino);
>> -        }
>> -      if (i == fd_ring->ir_back)
>> -        break;
>> -      i = (i + I_RING_SIZE - 1) % I_RING_SIZE;
>> -    }
>> -}
>> -
>> -/* Ensure that each file descriptor on the fd_ring matches a
>> -   parent, grandparent, etc. of the current working directory.  */
>> -static void
>> -fd_ring_check (FTSOBJ const *sp)
>> -{
>> -  if (!fts_debug)
>> -    return;
>> -
>> -  /* Make a writable copy.  */
>> -  I_ring fd_w = sp->fts_fd_ring;
>> -
>> -  int cwd_fd = sp->fts_cwd_fd;
>> -  cwd_fd = fcntl (cwd_fd, F_DUPFD_CLOEXEC, STDERR_FILENO + 1);
>> -  struct devino dot = getdevino (cwd_fd);
>> -  fprintf (stderr, "===== check ===== cwd: "PRINT_DEVINO"\n",
>> -           dot.dev, dot.ino);
>> -  while ( ! i_ring_empty (&fd_w))
>> -    {
>> -      int fd = i_ring_pop (&fd_w);
>> -      if (0 <= fd)
>> -        {
>> -          int open_flags = O_SEARCH | O_CLOEXEC;
>> -          int parent_fd = openat (cwd_fd, "..", open_flags);
>> -          if (parent_fd < 0)
>> -            {
>> -              // Warn?
>> -              break;
>> -            }
>> -          if (!same_fd (fd, parent_fd))
>> -            {
>> -              struct devino cwd = getdevino (fd);
>> -              fprintf (stderr, "ring  : "PRINT_DEVINO"\n", cwd.dev, cwd.ino);
>> -              struct devino c2 = getdevino (parent_fd);
>> -              fprintf (stderr, "parent: "PRINT_DEVINO"\n", c2.dev, c2.ino);
>> -              fts_assert (0);
>> -            }
>> -          close (cwd_fd);
>> -          cwd_fd = parent_fd;
>> -        }
>> -    }
>> -  close (cwd_fd);
>> -}
>> -#endif
>> -
>> -static unsigned short int
>> -internal_function
>> -fts_stat(FTSOBJ *sp, register FTSENTRY *p, bool follow)
>> -{
>> -        if (ISSET (FTS_LOGICAL)
>> -            || (ISSET (FTS_COMFOLLOW) && p->fts_level == FTS_ROOTLEVEL))
>> -                follow = true;
>> -
>> -        struct STRUCT_STAT *sbp = p->fts_statp;
>> -
>> -        /*
>> -         * If doing a logical walk, or application requested FTS_FOLLOW, do
>> -         * a stat(2).  If that fails, check for a nonexistent symlink.  If
>> -         * fail, set the errno from the stat call.
>> -         */
>> -        int flags = follow ? 0 : AT_SYMLINK_NOFOLLOW;
>> -        if (FSTATAT (sp->fts_cwd_fd, p->fts_accpath, sbp, flags) < 0)
>> -          {
>> -            if (follow && errno == ENOENT
>> -                && 0 <= FSTATAT (sp->fts_cwd_fd, p->fts_accpath, sbp,
>> -                                 AT_SYMLINK_NOFOLLOW))
>> -              {
>> -                __set_errno (0);
>> -                return FTS_SLNONE;
>> -              }
>> -
>> -            p->fts_errno = errno;
>> -           memset (sbp, 0, sizeof *sbp);
>> -            return FTS_NS;
>> -          }
>> -
>> -        if (S_ISDIR(sbp->st_mode)) {
>> -                if (ISDOT(p->fts_name)) {
>> -                        /* Command-line "." and ".." are real directories. */
>> -                        return (p->fts_level == FTS_ROOTLEVEL ? FTS_D : FTS_DOT);
>> -                }
>> -
>> -                return (FTS_D);
>> -        }
>> -        if (S_ISLNK(sbp->st_mode))
>> -                return (FTS_SL);
>> -        if (S_ISREG(sbp->st_mode))
>> -                return (FTS_F);
>> -        return (FTS_DEFAULT);
>> -}
>> -
>> -static int
>> -fts_compar (void const *a, void const *b)
>> -{
>> -  /* Convert A and B to the correct types, to pacify the compiler, and
>> -     for portability to bizarre hosts where "void const *" and "FTSENT
>> -     const **" differ in runtime representation.  The comparison
>> -     function cannot modify *a and *b, but there is no compile-time
>> -     check for this.  */
>> -  FTSENTRY const **pa = (FTSENTRY const **) a;
>> -  FTSENTRY const **pb = (FTSENTRY const **) b;
>> -  return FTSENT_FTS(pa[0])->fts_compar (pa, pb);
>> -}
>> -
>> -static FTSENTRY *
>> -internal_function
>> -fts_sort (FTSOBJ *sp, FTSENTRY *head, register size_t nitems)
>> -{
>> -        register FTSENTRY **ap, *p;
>> -
>> -        /* On most modern hosts, void * and FTSENT ** have the same
>> -           run-time representation, and one can convert sp->fts_compar to
>> -           the type qsort expects without problem.  Use the heuristic that
>> -           this is OK if the two pointer types are the same size, and if
>> -           converting FTSENT ** to uintptr_t is the same as converting
>> -           FTSENT ** to void * and then to uintptr_t.  This heuristic isn't
>> -           valid in general but we don't know of any counterexamples.  */
>> -        FTSENTRY *dummy;
>> -        int (*compare) (void const *, void const *) =
>> -          ((sizeof &dummy == sizeof (void *)
>> -            && (uintptr_t) &dummy == (uintptr_t) (void *) &dummy)
>> -           ? (int (*) (void const *, void const *)) sp->fts_compar
>> -           : fts_compar);
>> -
>> -        /*
>> -         * Construct an array of pointers to the structures and call qsort(3).
>> -         * Reassemble the array in the order returned by qsort.  If unable to
>> -         * sort for memory reasons, return the directory entries in their
>> -         * current order.  Allocate enough space for the current needs plus
>> -         * 40 so don't realloc one entry at a time.
>> -         */
>> -        if (nitems > sp->fts_nitems) {
>> -                sp->fts_nitems = nitems + 40;
>> -                FTSENTRY **a;
>> -                if (! (a = reallocarray (sp->fts_array,
>> -                                         sp->fts_nitems, sizeof *a))) {
>> -                        free(sp->fts_array);
>> -                        sp->fts_array = NULL;
>> -                        sp->fts_nitems = 0;
>> -                        return (head);
>> -                }
>> -                sp->fts_array = a;
>> -        }
>> -        for (ap = sp->fts_array, p = head; p; p = p->fts_link)
>> -                *ap++ = p;
>> -        qsort((void *)sp->fts_array, nitems, sizeof(FTSENTRY *), compare);
>> -        for (head = *(ap = sp->fts_array); --nitems; ++ap)
>> -                ap[0]->fts_link = ap[1];
>> -        ap[0]->fts_link = NULL;
>> -        return (head);
>> -}
>> -
>> -static FTSENTRY *
>> -internal_function
>> -fts_alloc (FTSOBJ *sp, const char *name, register size_t namelen)
>> -{
>> -        /*
>> -         * The file name is a variable length array.  Allocate the FTSENT
>> -         * structure and the file name in one chunk.
>> -         */
>> -        size_t len = FLEXSIZEOF(FTSENT, fts_name, namelen + 1);
>> -	register FTSENTRY *p;
>> -#if !_LIBC
>> -        p = malloc(len);
>> -        if (p == NULL)
>> -                return (NULL);
>> -#else
>> -	/*
>> -	 * For glibc, we use a wrapper struct to provide the extra required
>> -	 * fields without changing the FSENT layout.
>> -	 */
>> -	len += sizeof (struct FTSENT_wrapper);
>> -	struct FTSENT_wrapper *wrapper = malloc(len);
>> -	if (wrapper == NULL)
>> -		return (NULL);
>> -	p = &wrapper->ent;
>> -        p->fts_statp = &wrapper->fts_stat;
>> -#endif
>> -
>> -        /* Copy the name and guarantee NUL termination. */
>> -        memcpy(p->fts_name, name, namelen);
>> -        p->fts_name[namelen] = '\0';
>> -
>> -        p->fts_namelen = namelen;
>> -        FTSENT_FTS(p)= sp;
>> -        p->fts_path = sp->fts_path;
>> -        p->fts_errno = 0;
>> -        FTSENT_DIRP(p) = NULL;
>> -        p->fts_flags = 0;
>> -        p->fts_instr = FTS_NOINSTR;
>> -        p->fts_number = 0;
>> -        p->fts_pointer = NULL;
>> -        return (p);
>> -}
>> -
>> -static void
>> -internal_function
>> -fts_lfree (register FTSENTRY *head)
>> -{
>> -        int saved_errno = errno;
>> -
>> -        /* Free a linked list of structures. */
>> -        register FTSENTRY *p;
>> -        while ((p = head)) {
>> -                head = head->fts_link;
>> -                if (FTSENT_DIRP(p))
>> -                        closedir (FTSENT_DIRP(p));
>> -                free(FTSENT_WRAPPER(p));
>> -        }
>> -
>> -        __set_errno (saved_errno);
>> -}
>> -
>> -/*
>> - * Allow essentially unlimited file name lengths; find, rm, ls should
>> - * all work on any tree.  Most systems will allow creation of file
>> - * names much longer than MAXPATHLEN, even though the kernel won't
>> - * resolve them.  Add the size (not just what's needed) plus 256 bytes
>> - * so don't realloc the file name 2 bytes at a time.
>> - */
>> -static bool
>> -internal_function
>> -fts_palloc (FTSOBJ *sp, size_t more)
>> -{
>> -        size_t new_len = sp->fts_pathlen + more + 256;
>> -
>> -        /*
>> -         * See if fts_pathlen would overflow.
>> -         */
>> -        if (new_len < sp->fts_pathlen) {
>> -                free(sp->fts_path);
>> -                sp->fts_path = NULL;
>> -                __set_errno (ENAMETOOLONG);
>> -                return false;
>> -        }
>> -        sp->fts_pathlen = new_len;
>> -        char *p = realloc(sp->fts_path, sp->fts_pathlen);
>> -        if (p == NULL) {
>> -                free(sp->fts_path);
>> -                sp->fts_path = NULL;
>> -                return false;
>> -        }
>> -        sp->fts_path = p;
>> -        return true;
>> -}
>> -
>> -/*
>> - * When the file name is realloc'd, have to fix all of the pointers in
>> - *  structures already returned.
>> - */
>> -static void
>> -internal_function
>> -fts_padjust (FTSOBJ *sp, FTSENTRY *head)
>> -{
>> -        char *addr = sp->fts_path;
>> -
>> -        /* This code looks at bit-patterns of freed pointers to
>> -           relocate them, so it relies on undefined behavior.  If this
>> -           trick does not work on your platform, please report a bug.  */
>> -
>> -#define ADJUST(p) do {                                                  \
>> -        uintptr_t old_accpath = (uintptr_t) (p)->fts_accpath;           \
>> -        if (old_accpath != (uintptr_t) (p)->fts_name) {                 \
>> -                (p)->fts_accpath =                                      \
>> -                  addr + (old_accpath - (uintptr_t) (p)->fts_path);     \
>> -        }                                                               \
>> -        (p)->fts_path = addr;                                           \
>> -} while (0)
>> -        /* Adjust the current set of children. */
>> -        for (FTSENTRY *p = sp->fts_child; p; p = p->fts_link)
>> -                ADJUST(p);
>> -
>> -        /* Adjust the rest of the tree, including the current level. */
>> -        for (FTSENTRY *p = head; p->fts_level >= FTS_ROOTLEVEL;) {
>> -                ADJUST(p);
>> -                p = p->fts_link ? p->fts_link : p->fts_parent;
>> -        }
>> -}
>> -
>> -static size_t
>> -internal_function _GL_ATTRIBUTE_PURE
>> -fts_maxarglen (char * const *argv)
>> -{
>> -        size_t max;
>> -
>> -        for (max = 0; *argv; ++argv) {
>> -                size_t len = strlen(*argv);
>> -                if (len > max)
>> -                        max = len;
>> -        }
>> -        return (max + 1);
>> -}
>> -
>> -/*
>> - * Change to dir specified by fd or file name without getting
>> - * tricked by someone changing the world out from underneath us.
>> - * Assumes p->fts_statp->st_dev and p->fts_statp->st_ino are filled in.
>> - * If FD is non-negative, expect it to be used after this function returns,
>> - * and to be closed eventually.  So don't pass e.g., 'dirfd(dirp)' and then
>> - * do closedir(dirp), because that would invalidate the saved FD.
>> - * Upon failure, close FD immediately and return nonzero.
>> - */
>> -static int
>> -internal_function
>> -fts_safe_changedir (FTSOBJ *sp, FTSENTRY *p, int fd, char const *dir)
>> -{
>> -        fts_assert (0 <= fd || dir != NULL);
>> -        bool is_dotdot = dir && streq (dir, "..");
>> -
>> -        /* This clause handles the unusual case in which FTS_NOCHDIR
>> -           is specified, along with FTS_CWDFD.  In that case, there is
>> -           no need to change even the virtual cwd file descriptor.
>> -           However, if FD is non-negative, we do close it here.  */
>> -        if (ISSET (FTS_NOCHDIR))
>> -          {
>> -            if (ISSET (FTS_CWDFD) && 0 <= fd)
>> -              close (fd);
>> -            return 0;
>> -          }
>> -
>> -        if (fd < 0 && is_dotdot && ISSET (FTS_CWDFD))
>> -          {
>> -            /* When possible, skip the diropen and subsequent fstat+dev/ino
>> -               comparison.  I.e., when changing to parent directory
>> -               (chdir ("..")), use a file descriptor from the ring and
>> -               save the overhead of diropen+fstat, as well as avoiding
>> -               failure when we lack "x" access to the virtual cwd.  */
>> -            if ( ! i_ring_empty (&sp->fts_fd_ring))
>> -              {
>> -                int parent_fd;
>> -                fd_ring_print (sp, stderr, "pre-pop");
>> -                parent_fd = i_ring_pop (&sp->fts_fd_ring);
>> -                if (0 <= parent_fd)
>> -                  {
>> -                    fd = parent_fd;
>> -                    dir = NULL;
>> -                  }
>> -              }
>> -          }
>> -
>> -        int newfd = fd;
>> -        if (fd < 0 && (newfd = diropen (sp, dir)) < 0)
>> -          return -1;
>> -
>> -        /* The following dev/inode check is necessary if we're doing a
>> -           "logical" traversal (through symlinks, a la chown -L), if the
>> -           system lacks O_NOFOLLOW support, or if we're changing to ".."
>> -           (but not via a popped file descriptor).  When changing to the
>> -           name "..", O_NOFOLLOW can't help.  In general, when the target is
>> -           not "..", diropen's use of O_NOFOLLOW ensures we don't mistakenly
>> -           follow a symlink, so we can avoid the expense of this fstat.  */
>> -        int ret;
>> -        if (ISSET(FTS_LOGICAL) || ! HAVE_WORKING_O_NOFOLLOW
>> -            || (dir && streq (dir, "..")))
>> -          {
>> -            struct STRUCT_STAT sb;
>> -            if (FSTAT (newfd, &sb))
>> -              {
>> -                ret = -1;
>> -                goto bail;
>> -              }
>> -            if (p->fts_statp->st_dev != sb.st_dev
>> -                || p->fts_statp->st_ino != sb.st_ino)
>> -              {
>> -                __set_errno (ENOENT);           /* disinformation */
>> -                ret = -1;
>> -                goto bail;
>> -              }
>> -          }
>> -
>> -        if (ISSET(FTS_CWDFD))
>> -          {
>> -            cwd_advance_fd (sp, newfd, ! is_dotdot);
>> -            return 0;
>> -          }
>> -
>> -        ret = fchdir(newfd);
>> -bail:
>> -        if (fd < 0)
>> -          {
>> -            int oerrno = errno;
>> -            (void)close(newfd);
>> -            __set_errno (oerrno);
>> -          }
>> -        return ret;
>> -}
>> diff --git a/io/fts64-time64.c b/io/fts64-time64.c
>> index 6a1053194e..29f2dbc28c 100644
>> --- a/io/fts64-time64.c
>> +++ b/io/fts64-time64.c
>> @@ -33,5 +33,5 @@
>>   # define STRUCT_STATFS      statfs64
>>   # define FSTATFS            __fstatfs64
>>   
>> -# include "fts.c"
>> +# include "fts-common.c"
>>   #endif
>> diff --git a/io/fts64.c b/io/fts64.c
>> index a6f607a873..1efa06ab3b 100644
>> --- a/io/fts64.c
>> +++ b/io/fts64.c
>> @@ -16,11 +16,11 @@
>>      License along with the GNU C Library; if not, see
>>      <https://www.gnu.org/licenses/>.  */
>>   
>> -#define FTS_OPEN fts64_open
>> -#define FTS_CLOSE fts64_close
>> -#define FTS_READ fts64_read
>> -#define FTS_SET fts64_set
>> -#define FTS_CHILDREN fts64_children
>> +#define FTS_OPEN __fts64_open
>> +#define FTS_CLOSE __fts64_close
>> +#define FTS_READ __fts64_read
>> +#define FTS_SET __fts64_set
>> +#define FTS_CHILDREN __fts64_children
>>   #define FTSOBJ FTS64
>>   #define FTSENTRY FTSENT64
>>   #define INO_T ino64_t
>> @@ -30,4 +30,30 @@
>>   #define STRUCT_STATFS statfs64
>>   #define FSTATFS __fstatfs64
>>   
>> -#include "fts.c"
>> +#define fts_open __rename_fts_open
>> +#define fts_close __rename_fts_close
>> +#define fts_read __rename_fts_read
>> +#define fts_set __rename_fts_set
>> +#define fts_children __rename_fts_children
>> +
>> +#include "fts-common.c"
>> +
>> +#undef fts_open
>> +#undef fts_close
>> +#undef fts_read
>> +#undef fts_set
>> +#undef fts_children
>> +
>> +weak_alias (__fts64_open, fts64_open)
>> +weak_alias (__fts64_close, fts64_close)
>> +weak_alias (__fts64_read, fts64_read)
>> +weak_alias (__fts64_set, fts64_set)
>> +weak_alias (__fts64_children, fts64_children)
>> +
>> +#ifdef __OFF_T_MATCHES_OFF64_T
>> +weak_alias (__fts64_open, fts_open)
>> +weak_alias (__fts64_close, fts_close)
>> +weak_alias (__fts64_read, fts_read)
>> +weak_alias (__fts64_set, fts_set)
>> +weak_alias (__fts64_children, fts_children)
>> +#endif
>> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/fts.c b/sysdeps/unix/sysv/linux/mips/mips64/n64/fts.c
>> deleted file mode 100644
>> index d0c62e6195..0000000000
>> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/fts.c
>> +++ /dev/null
>> @@ -1 +0,0 @@
>> -#include <io/fts.c>
>> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/fts64.c b/sysdeps/unix/sysv/linux/mips/mips64/n64/fts64.c
>> deleted file mode 100644
>> index 2472f8bf75..0000000000
>> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/fts64.c
>> +++ /dev/null
>> @@ -1 +0,0 @@
>> -#include <io/fts64.c>
>> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/fts.c b/sysdeps/unix/sysv/linux/x86_64/x32/fts.c
>> deleted file mode 100644
>> index 980573ed68..0000000000
>> --- a/sysdeps/unix/sysv/linux/x86_64/x32/fts.c
>> +++ /dev/null
>> @@ -1 +0,0 @@
>> -#include <sysdeps/wordsize-64/fts.c>
>> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/fts64.c b/sysdeps/unix/sysv/linux/x86_64/x32/fts64.c
>> deleted file mode 100644
>> index 221d1b5608..0000000000
>> --- a/sysdeps/unix/sysv/linux/x86_64/x32/fts64.c
>> +++ /dev/null
>> @@ -1 +0,0 @@
>> -#include <sysdeps/wordsize-64/fts64.c>
>> diff --git a/sysdeps/wordsize-64/fts.c b/sysdeps/wordsize-64/fts.c
>> deleted file mode 100644
>> index 159dc1febe..0000000000
>> --- a/sysdeps/wordsize-64/fts.c
>> +++ /dev/null
>> @@ -1,19 +0,0 @@
>> -#define fts64_open __rename_fts64_open
>> -#define fts64_close __rename_fts64_close
>> -#define fts64_read __rename_fts64_read
>> -#define fts64_set __rename_fts64_set
>> -#define fts64_children __rename_fts64_children
>> -
>> -#include "../../io/fts.c"
>> -
>> -#undef fts64_open
>> -#undef fts64_close
>> -#undef fts64_read
>> -#undef fts64_set
>> -#undef fts64_children
>> -
>> -weak_alias (fts_open, fts64_open)
>> -weak_alias (fts_close, fts64_close)
>> -weak_alias (fts_read, fts64_read)
>> -weak_alias (fts_set, fts64_set)
>> -weak_alias (fts_children, fts64_children)
>> diff --git a/sysdeps/wordsize-64/fts64.c b/sysdeps/wordsize-64/fts64.c
>> deleted file mode 100644
>> index f2848fc3e4..0000000000
>> --- a/sysdeps/wordsize-64/fts64.c
>> +++ /dev/null
>> @@ -1 +0,0 @@
>> -/* Defined in fts.c.  */
> 


-- 
Cheers,
Carlos.



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