/* rename.c -- rename a file, preserving symlinks.

   Copyright (C) 1999-2023 Free Software Foundation, Inc.

   This file is part of GNU Binutils.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, write to the Free Software

   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA

   02110-1301, USA.  */

#include "sysdep.h"

#include "bfd.h"

#include "bucomm.h"

#if defined HAVE_UTIMES

#include <sys/time.h>

#elif defined HAVE_GOOD_UTIME_H

#include <utime.h>

#endif

/* The number of bytes to copy at once.  */

#define COPY_BUF 8192

/* Copy file FROMFD to file TO, performing no translations.

   Return 0 if ok, -1 if error.  */

static int

simple_copy (int fromfd, const char *to,

       struct stat *target_stat ATTRIBUTE_UNUSED)

{

  int tofd, nread;

  int saved;

  char buf[COPY_BUF];

  if (fromfd < 0

      || lseek (fromfd, 0, SEEK_SET) != 0)

    return -1;

  tofd = open (to, O_WRONLY | O_TRUNC | O_BINARY);

  if (tofd < 0)

    {

      saved = errno;

      close (fromfd);

      errno = saved;

      return -1;

    }

  while ((nread = read (fromfd, buf, sizeof buf)) > 0)

    {

      if (write (tofd, buf, nread) != nread)

  {

    saved = errno;

    close (fromfd);

    close (tofd);

    errno = saved;

    return -1;

  }

    }

  saved = errno;

#if !defined (_WIN32) || defined (__CYGWIN32__)

  /* Writing to a setuid/setgid file may clear S_ISUID and S_ISGID.

     Try to restore them, ignoring failure.  */

  if (target_stat != NULL)

    fchmod (tofd, target_stat->st_mode);

#endif

  close (fromfd);

  close (tofd);

  if (nread < 0)

    {

      errno = saved;

      return -1;

    }

  return 0;

}

/* The following defines and inline functions are copied from gnulib.

   FIXME: Use a gnulib import and stat-time.h instead.  */

#if defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC

# if defined TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC

#  define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim)

# else

#  define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec)

# endif

#elif defined HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC

# define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim##espec)

#elif defined HAVE_STRUCT_STAT_ST_ATIMENSEC

# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim##ensec)

#elif defined HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC

# define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.st__tim.tv_nsec)

#endif

static inline long int get_stat_atime_ns (struct stat const *) ATTRIBUTE_UNUSED;

static inline long int get_stat_mtime_ns (struct stat const *) ATTRIBUTE_UNUSED;

/* Return the nanosecond component of *ST's access time.  */

static inline long int

get_stat_atime_ns (struct stat const *st ATTRIBUTE_UNUSED)

{

# if defined STAT_TIMESPEC

  return STAT_TIMESPEC (st, st_atim).tv_nsec;

# elif defined STAT_TIMESPEC_NS

  return STAT_TIMESPEC_NS (st, st_atim);

# else

  return 0;

# endif

}

/* Return the nanosecond component of *ST's data modification time.  */

static inline long int

get_stat_mtime_ns (struct stat const *st ATTRIBUTE_UNUSED)

{

# if defined STAT_TIMESPEC

  return STAT_TIMESPEC (st, st_mtim).tv_nsec;

# elif defined STAT_TIMESPEC_NS

  return STAT_TIMESPEC_NS (st, st_mtim);

# else

  return 0;

# endif

}

#if defined HAVE_UTIMENSAT

/* Return *ST's access time.  */

static inline struct timespec

get_stat_atime (struct stat const *st)

{

#ifdef STAT_TIMESPEC

  return STAT_TIMESPEC (st, st_atim);

#else

  struct timespec t;

  t.tv_sec = st->st_atime;

  t.tv_nsec = get_stat_atime_ns (st);

  return t;

#endif

}

/* Return *ST's data modification time.  */

static inline struct timespec

get_stat_mtime (struct stat const *st)

{

#ifdef STAT_TIMESPEC

  return STAT_TIMESPEC (st, st_mtim);

#else

  struct timespec t;

  t.tv_sec = st->st_mtime;

  t.tv_nsec = get_stat_mtime_ns (st);

  return t;

#endif

}

#endif

/* End FIXME.  */

/* Set the times of the file DESTINATION to be the same as those in

   STATBUF.  */

void

set_times (const char *destination, const struct stat *statbuf)

{

  int result;

#if defined HAVE_UTIMENSAT

  struct timespec times[2];

  times[0] = get_stat_atime (statbuf);

  times[1] = get_stat_mtime (statbuf);

  result = utimensat (AT_FDCWD, destination, times, 0);

#elif defined HAVE_UTIMES

  struct timeval tv[2];

  tv[0].tv_sec = statbuf->st_atime;

  tv[0].tv_usec = get_stat_atime_ns (statbuf) / 1000;

  tv[1].tv_sec = statbuf->st_mtime;

  tv[1].tv_usec = get_stat_mtime_ns (statbuf) / 1000;

  result = utimes (destination, tv);

#elif defined HAVE_GOOD_UTIME_H

  struct utimbuf tb;

  tb.actime = statbuf->st_atime;

  tb.modtime = statbuf->st_mtime;

  result = utime (destination, &tb);

#else

  long tb[2];

  tb[0] = statbuf->st_atime;

  tb[1] = statbuf->st_mtime;

  result = utime (destination, tb);

#endif

  if (result != 0)

    non_fatal (_("%s: cannot set time: %s"), destination, strerror (errno));

}

/* Copy FROM to TO.  TARGET_STAT has the file status that, if non-NULL,

   is used to fix up timestamps.  Return 0 if ok, -1 if error.

   At one time this function renamed files, but file permissions are

   tricky to update given the number of different schemes used by

   various systems.  So now we just copy.  */

int

smart_rename (const char *from, const char *to, int fromfd,

        struct stat *target_stat, bool preserve_dates)

{

  int ret = 0;

  if (to != from)

    {

      ret = simple_copy (fromfd, to, target_stat);

      if (ret != 0)

  non_fatal (_("unable to copy file '%s'; reason: %s"),

       to, strerror (errno));

      unlink (from);

    }

  if (preserve_dates)

    set_times (to, target_stat);

  return ret;

}