C++ __mempcpy函数代码示例

static char *
getttyname (int fd, dev_t mydev, ino_t myino, int save, int *dostat)
{
  static const char dev[] = "/dev";
  static size_t namelen;
  struct stat st;
  DIR *dirstream;
  struct dirent *d;

  dirstream = __opendir (dev);
  if (dirstream == NULL)
    {
      *dostat = -1;
      return NULL;
    }

  while ((d = __readdir (dirstream)) != NULL)
    if (((ino_t) d->d_fileno == myino || *dostat)
	&& strcmp (d->d_name, "stdin")
	&& strcmp (d->d_name, "stdout")
	&& strcmp (d->d_name, "stderr"))
      {
	size_t dlen = _D_ALLOC_NAMLEN (d);
	if (sizeof (dev) + dlen > namelen)
	  {
	    free (getttyname_name);
	    namelen = 2 * (sizeof (dev) + dlen); /* Big enough.  */
	    getttyname_name = malloc (namelen);
	    if (! getttyname_name)
	      {
		*dostat = -1;
		/* Perhaps it helps to free the directory stream buffer.  */
		(void) __closedir (dirstream);
		return NULL;
	      }
	    *((char *) __mempcpy (getttyname_name, dev, sizeof (dev) - 1))
	      = '/';
	  }
	(void) __mempcpy (&getttyname_name[sizeof (dev)], d->d_name, dlen);
	if (stat (getttyname_name, &st) == 0
#ifdef _STATBUF_ST_RDEV
	    && S_ISCHR (st.st_mode) && st.st_rdev == mydev
#else
	    && (ino_t) d->d_fileno == myino && st.st_dev == mydev
#endif
	   )
	  {
	    (void) __closedir (dirstream);
	    __ttyname = getttyname_name;
	    __set_errno (save);
	    return getttyname_name;
	  }
      }

  (void) __closedir (dirstream);
  __set_errno (save);
  return NULL;
}

static void
msort_with_tmp (void *b, size_t n, size_t s, __compar_fn_t cmp,
		char *t)
{
  char *tmp;
  char *b1, *b2;
  size_t n1, n2;

  if (n <= 1)
    return;

  n1 = n / 2;
  n2 = n - n1;
  b1 = b;
  b2 = (char *) b + (n1 * s);

  msort_with_tmp (b1, n1, s, cmp, t);
  msort_with_tmp (b2, n2, s, cmp, t);

  tmp = t;

  if (s == OPSIZ && (b1 - (char *) 0) % OPSIZ == 0)
    /* We are operating on aligned words.  Use direct word stores.  */
    while (n1 > 0 && n2 > 0)
      {
	if ((*cmp) (b1, b2) <= 0)
	  {
	    --n1;
	    *((op_t *) tmp)++ = *((op_t *) b1)++;
	  }
	else
	  {
	    --n2;
	    *((op_t *) tmp)++ = *((op_t *) b2)++;
	  }
      }
  else
    while (n1 > 0 && n2 > 0)
      {
	if ((*cmp) (b1, b2) <= 0)
	  {
	    tmp = (char *) __mempcpy (tmp, b1, s);
	    b1 += s;
	    --n1;
	  }
	else
	  {
	    tmp = (char *) __mempcpy (tmp, b2, s);
	    b2 += s;
	    --n2;
	  }
      }
  if (n1 > 0)
    memcpy (tmp, b1, n1 * s);
  memcpy (b, t, (n - n2) * s);
}

static _IO_size_t
_IO_file_xsgetn_mmap (_IO_FILE *fp, void *data, _IO_size_t n)
{
  _IO_size_t have;
  char *read_ptr = fp->_IO_read_ptr;
  char *s = (char *) data;

  have = fp->_IO_read_end - fp->_IO_read_ptr;

  if (have < n)
    {
      if (__glibc_unlikely (_IO_in_backup (fp)))
	{
#ifdef _LIBC
	  s = __mempcpy (s, read_ptr, have);
#else
	  memcpy (s, read_ptr, have);
	  s += have;
#endif
	  n -= have;
	  _IO_switch_to_main_get_area (fp);
	  read_ptr = fp->_IO_read_ptr;
	  have = fp->_IO_read_end - fp->_IO_read_ptr;
	}

      if (have < n)
	{
	  /* Check that we are mapping all of the file, in case it grew.  */
	  if (__glibc_unlikely (mmap_remap_check (fp)))
	    /* We punted mmap, so complete with the vanilla code.  */
	    return s - (char *) data + _IO_XSGETN (fp, data, n);

	  read_ptr = fp->_IO_read_ptr;
	  have = fp->_IO_read_end - read_ptr;
	}
    }

  if (have < n)
    fp->_flags |= _IO_EOF_SEEN;

  if (have != 0)
    {
      have = MIN (have, n);
#ifdef _LIBC
      s = __mempcpy (s, read_ptr, have);
#else
      memcpy (s, read_ptr, have);
      s += have;
#endif
      fp->_IO_read_ptr = read_ptr + have;
    }

  return s - (char *) data;
}

/* Open shared memory object.  This implementation assumes the shmfs
   implementation introduced in the late 2.3.x kernel series to be
   available.  Normally the filesystem will be mounted at /dev/shm but
   we fall back on searching for the actual mount point should opening
   such a file fail.  */
int
shm_open (const char *name, int oflag, mode_t mode)
{
  size_t namelen;
  char *fname;
  int fd;

  /* Determine where the shmfs is mounted.  */
  __libc_once (once, where_is_shmfs);

  /* If we don't know the mount points there is nothing we can do.  Ever.  */
  if (mountpoint.dir == NULL)
    {
      __set_errno (ENOSYS);
      return -1;
    }

  /* Construct the filename.  */
  while (name[0] == '/')
    ++name;

  namelen = strlen (name);

  /* Validate the filename.  */
  if (name[0] == '\0' || namelen > NAME_MAX || strchr (name, '/') != NULL)
    {
      __set_errno (EINVAL);
      return -1;
    }

  fname = (char *) alloca (mountpoint.dirlen + namelen + 1);
  __mempcpy (__mempcpy (fname, mountpoint.dir, mountpoint.dirlen),
	     name, namelen + 1);

  /* And get the file descriptor.
     XXX Maybe we should test each descriptor whether it really is for a
     file on the shmfs.  If this is what should be done the whole function
     should be revamped since we can determine whether shmfs is available
     while trying to open the file, all in one turn.  */
  fd = open (fname, oflag | O_CLOEXEC | O_NOFOLLOW, mode);
  if (fd == -1 && __glibc_unlikely (errno == EISDIR))
    /* It might be better to fold this error with EINVAL since
       directory names are just another example for unsuitable shared
       object names and the standard does not mention EISDIR.  */
    __set_errno (EINVAL);

  return fd;
}

nis_name
nis_leaf_of_r (const_nis_name name, char *buffer, size_t buflen)
{
  size_t i = 0;

  buffer[0] = '\0';

  while (name[i] != '.' && name[i] != '\0')
    i++;

  if (i > buflen - 1)
    {
      __set_errno (ERANGE);
      return NULL;
    }

  if (i > 0)
    {
      if ((size_t)i >= buflen)
	{
	  __set_errno (ERANGE);
	  return NULL;
	}

      *((char *) __mempcpy (buffer, name, i)) = '\0';
    }

  return buffer;
}

nis_name
nis_name_of_r (const_nis_name name, char *buffer, size_t buflen)
{
  char *local_domain;
  int diff;

  local_domain = nis_local_directory ();

  diff = strlen (name) - strlen (local_domain);
  if (diff <= 0)
    return NULL;

  if (strcmp (&name[diff], local_domain) != 0)
    return NULL;

  if ((size_t) diff >= buflen)
    {
      __set_errno (ERANGE);
      return NULL;
    }

  *((char *) __mempcpy (buffer, name, diff - 1)) = '\0';

  if (diff - 1 == 0)
    return NULL;

  return buffer;
}

static _IO_size_t
_IO_obstack_xsputn (_IO_FILE *fp, const void *data, _IO_size_t n)
{
  struct obstack *obstack = ((struct _IO_obstack_file *) fp)->obstack;

  if (fp->_IO_write_ptr + n > fp->_IO_write_end)
    {
      int size;

      /* We need some more memory.  First shrink the buffer to the
	 space we really currently need.  */
      obstack_blank_fast (obstack, fp->_IO_write_ptr - fp->_IO_write_end);

      /* Now grow for N bytes, and put the data there.  */
      obstack_grow (obstack, data, n);

      /* Setup the buffer pointers again.  */
      fp->_IO_write_base = obstack_base (obstack);
      fp->_IO_write_ptr = obstack_next_free (obstack);
      size = obstack_room (obstack);
      fp->_IO_write_end = fp->_IO_write_ptr + size;
      /* Now allocate the rest of the current chunk.  */
      obstack_blank_fast (obstack, size);
    }
  else
    fp->_IO_write_ptr = __mempcpy (fp->_IO_write_ptr, data, n);

  return n;
}

static int
internal_function
find_module (const char *directory, const char *filename,
	     struct __gconv_step *result)
{
  size_t dirlen = strlen (directory);
  size_t fnamelen = strlen (filename) + 1;
  char fullname[dirlen + fnamelen];
  int status = __GCONV_NOCONV;

  memcpy (__mempcpy (fullname, directory, dirlen), filename, fnamelen);

  result->__shlib_handle = __gconv_find_shlib (fullname);
  if (result->__shlib_handle != NULL)
    {
      status = __GCONV_OK;

      result->__modname = NULL;
      result->__fct = result->__shlib_handle->fct;
      result->__init_fct = result->__shlib_handle->init_fct;
      result->__end_fct = result->__shlib_handle->end_fct;

      /* These settings can be overridden by the init function.  */
      result->__btowc_fct = NULL;
      result->__data = NULL;

      /* Call the init function.  */
      if (result->__init_fct != NULL)
	status = DL_CALL_FCT (result->__init_fct, (result));
    }

  return status;
}

/* Open a master pseudo terminal and return its file descriptor.  */
int
__getpt (void)
{
  char buf[sizeof (_PATH_PTY) + 2];
  const char *p, *q;
  char *s;

  s = __mempcpy (buf, _PATH_PTY, sizeof (_PATH_PTY) - 1);
  /* s[0] and s[1] will be filled in the loop.  */
  s[2] = '\0';

  for (p = __libc_ptyname1; *p != '\0'; ++p)
    {
      s[0] = *p;

      for (q = __libc_ptyname2; *q != '\0'; ++q)
	{
	  int fd;

	  s[1] = *q;

	  fd = __open (buf, O_RDWR);
	  if (fd != -1)
	    return fd;

	  if (errno == ENOENT)
	    return -1;
	}
    }

  __set_errno (ENOENT);
  return -1;
}

const char *
_dl_get_origin (void)
{
  char linkval[PATH_MAX];
  char *result;
  int len;
  INTERNAL_SYSCALL_DECL (err);

  len = INTERNAL_SYSCALL (readlinkat, err, 4, AT_FDCWD, "/proc/self/exe",
                          linkval, sizeof (linkval));
  if (! INTERNAL_SYSCALL_ERROR_P (len, err) && len > 0 && linkval[0] != '[')
    {
      /* We can use this value.  */
      assert (linkval[0] == '/');
      while (len > 1 && linkval[len - 1] != '/')
	--len;
      result = (char *) malloc (len + 1);
      if (result == NULL)
	result = (char *) -1;
      else if (len == 1)
	memcpy (result, "/", 2);
      else
	*((char *) __mempcpy (result, linkval, len - 1)) = '\0';
    }
  else
    {
      result = (char *) -1;
      /* We use the environment variable LD_ORIGIN_PATH.  If it is set make
	 a copy and strip out trailing slashes.  */
      if (GLRO(dl_origin_path) != NULL)
	{
	  size_t len = strlen (GLRO(dl_origin_path));
	  result = (char *) malloc (len + 1);
	  if (result == NULL)
	    result = (char *) -1;
	  else
	    {
	      char *cp = __mempcpy (result, GLRO(dl_origin_path), len);
	      while (cp > result + 1 && cp[-1] == '/')
		--cp;
	      *cp = '\0';
	    }
	}
    }

  return result;
}

internal_function attribute_compat_text_section
getttyname (const char *dev, dev_t mydev, ino64_t myino, int save, int *dostat)
{
  static size_t namelen;
  struct stat64 st;
  DIR *dirstream;
  struct dirent64 *d;
  size_t devlen = strlen (dev) + 1;

  dirstream = __opendir (dev);
  if (dirstream == NULL)
    {
      *dostat = -1;
      return NULL;
    }

  while ((d = __readdir64 (dirstream)) != NULL)
    if ((d->d_fileno == myino || *dostat)
	&& strcmp (d->d_name, "stdin")
	&& strcmp (d->d_name, "stdout")
	&& strcmp (d->d_name, "stderr"))
      {
	size_t dlen = _D_ALLOC_NAMLEN (d);
	if (devlen + dlen > namelen)
	  {
	    free (getttyname_name);
	    namelen = 2 * (devlen + dlen); /* Big enough.  */
	    getttyname_name = malloc (namelen);
	    if (! getttyname_name)
	      {
		*dostat = -1;
		/* Perhaps it helps to free the directory stream buffer.  */
		(void) __closedir (dirstream);
		return NULL;
	      }
	    *((char *) __mempcpy (getttyname_name, dev, devlen - 1)) = '/';
	  }
	memcpy (&getttyname_name[devlen], d->d_name, dlen);
	if (__xstat64 (_STAT_VER, getttyname_name, &st) == 0
#ifdef _STATBUF_ST_RDEV
	    && S_ISCHR (st.st_mode) && st.st_rdev == mydev
#else
	    && d->d_fileno == myino && st.st_dev == mydev
#endif
	   )
	  {
	    (void) __closedir (dirstream);
#if 0
	    __ttyname = getttyname_name;
#endif
	    __set_errno (save);
	    return getttyname_name;
	  }
      }

  (void) __closedir (dirstream);
  __set_errno (save);
  return NULL;
}

void *
__mempcpy_chk (void *dstpp, const void *srcpp, size_t len, size_t dstlen)
{
  if (__glibc_unlikely (dstlen < len))
    __chk_fail ();

  return __mempcpy (dstpp, srcpp, len);
}

wchar_t *
__wmempcpy_chk (wchar_t *s1, const wchar_t *s2, size_t n, size_t ns1)
{
  if (__glibc_unlikely (ns1 < n))
    __chk_fail ();
  return (wchar_t *) __mempcpy ((char *) s1, (char *) s2,
				n * sizeof (wchar_t));
}

internal_function
getttyname (const char *dev, dev_t mydev, ino64_t myino, int save)
{
  static size_t namelen;
  struct stat64 st;
  DIR *dirstream;
  struct dirent *d;
  size_t devlen = strlen (dev) + 1;

  dirstream = __opendir (dev);
  if (dirstream == NULL)
    {
      return NULL;
    }

  while ((d = __readdir (dirstream)) != NULL)
    if (d->d_fileno == myino)
      {
	size_t dlen = _D_ALLOC_NAMLEN (d);
	if (devlen + dlen > namelen)
	  {
	    free (getttyname_name);
	    namelen = 2 * (devlen + dlen); /* Big enough.  */
	    getttyname_name = malloc (namelen);
	    if (! getttyname_name)
	      {
		/* Perhaps it helps to free the directory stream buffer.  */
		(void) __closedir (dirstream);
		return NULL;
	      }
	  }
	/* Always recopy dev since it may be master or slave.  */
	*((char *) __mempcpy (getttyname_name, dev, devlen - 1)) = '/';

	memcpy (&getttyname_name[devlen], d->d_name, dlen);
	if (__xstat64 (_STAT_VER, getttyname_name, &st) == 0
#ifdef _STATBUF_ST_RDEV
	    && S_ISCHR (st.st_mode) && st.st_rdev == mydev
#else
	    && d->d_fileno == myino && st.st_dev == mydev
#endif
	   )
	  {
	    (void) __closedir (dirstream);
#if 0
	    __ttyname = getttyname_name;
#endif
	    __set_errno (save);
	    return getttyname_name;
	  }
      }

  (void) __closedir (dirstream);
  __set_errno (save);
  return NULL;
}

error_t
_hurd_xattr_list (io_t port, void *buffer, size_t *size)
{
  size_t total = 0;
  char *bufp = buffer;
  inline void add (const char *name, size_t len)
    {
      total += len;
      if (bufp != NULL && total <= *size)
	bufp = __mempcpy (bufp, name, len);
    }