/* ftell{,o} implementation. The only time we modify the state of the stream
is when we have unflushed writes. In that case we seek to the end and
record that offset in the stream object. */
static _IO_off64_t
do_ftell (_IO_FILE *fp)
{
_IO_off64_t result, offset = 0;
/* No point looking at unflushed data if we haven't allocated buffers
yet. */
if (fp->_IO_buf_base != NULL)
{
bool unflushed_writes = fp->_IO_write_ptr > fp->_IO_write_base;
bool append_mode = (fp->_flags & _IO_IS_APPENDING) == _IO_IS_APPENDING;
/* When we have unflushed writes in append mode, seek to the end of the
file and record that offset. This is the only time we change the file
stream state and it is safe since the file handle is active. */
if (unflushed_writes && append_mode)
{
result = _IO_SYSSEEK (fp, 0, _IO_seek_end);
if (result == _IO_pos_BAD)
return EOF;
else
fp->_offset = result;
}
/* Adjust for unflushed data. */
if (!unflushed_writes)
offset -= fp->_IO_read_end - fp->_IO_read_ptr;
/* We don't trust _IO_read_end to represent the current file offset when
writing in append mode because the value would have to be shifted to
the end of the file during a flush. Use the write base instead, along
with the new offset we got above when we did a seek to the end of the
file. */
else if (append_mode)
offset += fp->_IO_write_ptr - fp->_IO_write_base;
/* For all other modes, _IO_read_end represents the file offset. */
else
offset += fp->_IO_write_ptr - fp->_IO_read_end;
}
if (fp->_offset != _IO_pos_BAD)
result = fp->_offset;
else
result = _IO_SYSSEEK (fp, 0, _IO_seek_cur);
if (result == EOF)
return result;
result += offset;
if (result < 0)
{
__set_errno (EINVAL);
return EOF;
}
return result;
}
int
attribute_compat_text_section
_IO_old_file_sync (_IO_FILE *fp)
{
_IO_ssize_t delta;
int retval = 0;
/* char* ptr = cur_ptr(); */
if (fp->_IO_write_ptr > fp->_IO_write_base)
if (_IO_old_do_flush(fp)) return EOF;
delta = fp->_IO_read_ptr - fp->_IO_read_end;
if (delta != 0)
{
#ifdef TODO
if (_IO_in_backup (fp))
delta -= eGptr () - Gbase ();
#endif
_IO_off_t new_pos = _IO_SYSSEEK (fp, delta, 1);
if (new_pos != (_IO_off_t) EOF)
fp->_IO_read_end = fp->_IO_read_ptr;
#ifdef ESPIPE
else if (errno == ESPIPE)
; /* Ignore error from unseekable devices. */
#endif
else
retval = EOF;
}
if (retval != EOF)
fp->_old_offset = _IO_pos_BAD;
/* FIXME: Cleanup - can this be shared? */
/* setg(base(), ptr, ptr); */
return retval;
}
static int
attribute_compat_text_section
old_do_write (_IO_FILE *fp, const char *data, _IO_size_t to_do)
{
_IO_size_t count;
if (fp->_flags & _IO_IS_APPENDING)
/* On a system without a proper O_APPEND implementation,
you would need to sys_seek(0, SEEK_END) here, but is
not needed nor desirable for Unix- or Posix-like systems.
Instead, just indicate that offset (before and after) is
unpredictable. */
fp->_old_offset = _IO_pos_BAD;
else if (fp->_IO_read_end != fp->_IO_write_base)
{
_IO_off_t new_pos
= _IO_SYSSEEK (fp, fp->_IO_write_base - fp->_IO_read_end, 1);
if (new_pos == _IO_pos_BAD)
return 0;
fp->_old_offset = new_pos;
}
count = _IO_SYSWRITE (fp, data, to_do);
if (fp->_cur_column && count)
fp->_cur_column = _IO_adjust_column (fp->_cur_column - 1, data, count) + 1;
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_buf_base;
fp->_IO_write_end = ((fp->_flags & (_IO_LINE_BUF | _IO_UNBUFFERED))
? fp->_IO_buf_base : fp->_IO_buf_end);
return count;
}
_IO_FILE *
_IO_file_open (_IO_FILE *fp, const char *filename, int posix_mode, int prot,
int read_write, int is32not64)
{
int fdesc;
#ifdef _LIBC
if (__glibc_unlikely (fp->_flags2 & _IO_FLAGS2_NOTCANCEL))
fdesc = open_not_cancel (filename,
posix_mode | (is32not64 ? 0 : O_LARGEFILE), prot);
else
fdesc = open (filename, posix_mode | (is32not64 ? 0 : O_LARGEFILE), prot);
#else
fdesc = open (filename, posix_mode, prot);
#endif
if (fdesc < 0)
return NULL;
fp->_fileno = fdesc;
_IO_mask_flags (fp, read_write,_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
/* For append mode, send the file offset to the end of the file. Don't
update the offset cache though, since the file handle is not active. */
if ((read_write & (_IO_IS_APPENDING | _IO_NO_READS))
== (_IO_IS_APPENDING | _IO_NO_READS))
{
_IO_off64_t new_pos = _IO_SYSSEEK (fp, 0, _IO_seek_end);
if (new_pos == _IO_pos_BAD && errno != ESPIPE)
{
close_not_cancel (fdesc);
return NULL;
}
}
_IO_link_in ((struct _IO_FILE_plus *) fp);
return fp;
}
wint_t
_IO_wfile_sync (_IO_FILE *fp)
{
_IO_ssize_t delta;
wint_t retval = 0;
/* char* ptr = cur_ptr(); */
if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_write_base)
if (_IO_do_flush (fp))
return WEOF;
delta = fp->_wide_data->_IO_read_ptr - fp->_wide_data->_IO_read_end;
if (delta != 0)
{
/* We have to find out how many bytes we have to go back in the
external buffer. */
struct _IO_codecvt *cv = fp->_codecvt;
_IO_off64_t new_pos;
int clen = (*cv->__codecvt_do_encoding) (cv);
if (clen > 0)
/* It is easy, a fixed number of input bytes are used for each
wide character. */
delta *= clen;
else
{
/* We have to find out the hard way how much to back off.
To do this we determine how much input we needed to
generate the wide characters up to the current reading
position. */
int nread;
fp->_wide_data->_IO_state = fp->_wide_data->_IO_last_state;
nread = (*cv->__codecvt_do_length) (cv, &fp->_wide_data->_IO_state,
fp->_IO_read_base,
fp->_IO_read_end, delta);
fp->_IO_read_ptr = fp->_IO_read_base + nread;
delta = -(fp->_IO_read_end - fp->_IO_read_base - nread);
}
new_pos = _IO_SYSSEEK (fp, delta, 1);
if (new_pos != (_IO_off64_t) EOF)
{
fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_read_ptr;
fp->_IO_read_end = fp->_IO_read_ptr;
}
#ifdef ESPIPE
else if (errno == ESPIPE)
; /* Ignore error from unseekable devices. */
#endif
else
retval = WEOF;
}
if (retval != WEOF)
fp->_offset = _IO_pos_BAD;
/* FIXME: Cleanup - can this be shared? */
/* setg(base(), ptr, ptr); */
return retval;
}
_IO_off64_t
_IO_file_seekoff_mmap (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
{
_IO_off64_t result;
/* If we are only interested in the current position, calculate it and
return right now. This calculation does the right thing when we are
using a pushback buffer, but in the usual case has the same value as
(fp->_IO_read_ptr - fp->_IO_buf_base). */
if (mode == 0)
return fp->_offset - (fp->_IO_read_end - fp->_IO_read_ptr);
switch (dir)
{
case _IO_seek_cur:
/* Adjust for read-ahead (bytes is buffer). */
offset += fp->_IO_read_ptr - fp->_IO_read_base;
break;
case _IO_seek_set:
break;
case _IO_seek_end:
offset += fp->_IO_buf_end - fp->_IO_buf_base;
break;
}
/* At this point, dir==_IO_seek_set. */
if (offset < 0)
{
/* No negative offsets are valid. */
__set_errno (EINVAL);
return EOF;
}
result = _IO_SYSSEEK (fp, offset, 0);
if (result < 0)
return EOF;
if (offset > fp->_IO_buf_end - fp->_IO_buf_base)
/* One can fseek arbitrarily past the end of the file
and it is meaningless until one attempts to read.
Leave the buffer pointers in EOF state until underflow. */
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_end, fp->_IO_buf_end);
else
/* Adjust the read pointers to match the file position,
but so the next read attempt will call underflow. */
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + offset,
fp->_IO_buf_base + offset);
fp->_offset = result;
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
return offset;
}
static _IO_off64_t
_IO_file_seekoff_maybe_mmap (_IO_FILE *fp, _IO_off64_t offset, int dir,
int mode)
{
/* We only get here when we haven't tried to read anything yet.
So there is nothing more useful for us to do here than just
the underlying lseek call. */
_IO_off64_t result = _IO_SYSSEEK (fp, offset, dir);
if (result < 0)
return EOF;
fp->_offset = result;
return result;
}
_IO_off64_t
attribute_compat_text_section
_IO_old_file_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
{
_IO_off_t result;
_IO_off64_t delta, new_offset;
long count;
/* POSIX.1 8.2.3.7 says that after a call the fflush() the file
offset of the underlying file must be exact. */
int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end
&& fp->_IO_write_base == fp->_IO_write_ptr);
if (mode == 0)
dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */
/* Flush unwritten characters.
(This may do an unneeded write if we seek within the buffer.
But to be able to switch to reading, we would need to set
egptr to pptr. That can't be done in the current design,
which assumes file_ptr() is eGptr. Anyway, since we probably
end up flushing when we close(), it doesn't make much difference.)
FIXME: simulate mem-mapped files. */
if (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp))
if (_IO_switch_to_get_mode (fp))
return EOF;
if (fp->_IO_buf_base == NULL)
{
/* It could be that we already have a pushback buffer. */
if (fp->_IO_read_base != NULL)
{
free (fp->_IO_read_base);
fp->_flags &= ~_IO_IN_BACKUP;
}
_IO_doallocbuf (fp);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
}
switch (dir)
{
case _IO_seek_cur:
/* Adjust for read-ahead (bytes is buffer). */
offset -= fp->_IO_read_end - fp->_IO_read_ptr;
if (fp->_old_offset == _IO_pos_BAD)
goto dumb;
/* Make offset absolute, assuming current pointer is file_ptr(). */
offset += fp->_old_offset;
dir = _IO_seek_set;
break;
case _IO_seek_set:
break;
case _IO_seek_end:
{
struct stat64 st;
if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode))
{
offset += st.st_size;
dir = _IO_seek_set;
}
else
goto dumb;
}
}
/* At this point, dir==_IO_seek_set. */
/* If we are only interested in the current position we've found it now. */
if (mode == 0)
return offset;
/* If destination is within current buffer, optimize: */
if (fp->_old_offset != _IO_pos_BAD && fp->_IO_read_base != NULL
&& !_IO_in_backup (fp))
{
/* Offset relative to start of main get area. */
_IO_off_t rel_offset = (offset - fp->_old_offset
+ (fp->_IO_read_end - fp->_IO_read_base));
if (rel_offset >= 0)
{
#if 0
if (_IO_in_backup (fp))
_IO_switch_to_main_get_area (fp);
#endif
if (rel_offset <= fp->_IO_read_end - fp->_IO_read_base)
{
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + rel_offset,
fp->_IO_read_end);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
{
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
goto resync;
}
}
#ifdef TODO
/* If we have streammarkers, seek forward by reading ahead. */
if (_IO_have_markers (fp))
{
int to_skip = rel_offset
- (fp->_IO_read_ptr - fp->_IO_read_base);
if (ignore (to_skip) != to_skip)
goto dumb;
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
goto resync;
}
#endif
}
#ifdef TODO
if (rel_offset < 0 && rel_offset >= Bbase () - Bptr ())
{
if (!_IO_in_backup (fp))
_IO_switch_to_backup_area (fp);
gbump (fp->_IO_read_end + rel_offset - fp->_IO_read_ptr);
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
goto resync;
}
#endif
}
#ifdef TODO
_IO_unsave_markers (fp);
#endif
if (fp->_flags & _IO_NO_READS)
goto dumb;
/* Try to seek to a block boundary, to improve kernel page management. */
new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1);
delta = offset - new_offset;
if (delta > fp->_IO_buf_end - fp->_IO_buf_base)
{
new_offset = offset;
delta = 0;
}
result = _IO_SYSSEEK (fp, new_offset, 0);
if (result < 0)
return EOF;
if (delta == 0)
count = 0;
else
{
count = _IO_SYSREAD (fp, fp->_IO_buf_base,
(must_be_exact
? delta : fp->_IO_buf_end - fp->_IO_buf_base));
if (count < delta)
{
/* We weren't allowed to read, but try to seek the remainder. */
offset = count == EOF ? delta : delta-count;
dir = _IO_seek_cur;
goto dumb;
}
}
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta,
fp->_IO_buf_base + count);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
fp->_old_offset = result + count;
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
return offset;
dumb:
_IO_unsave_markers (fp);
result = _IO_SYSSEEK (fp, offset, dir);
if (result != EOF)
{
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
fp->_old_offset = result;
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
}
return result;
resync:
/* We need to do it since it is possible that the file offset in
the kernel may be changed behind our back. It may happen when
we fopen a file and then do a fork. One process may access the
file and the kernel file offset will be changed. */
if (fp->_old_offset >= 0)
_IO_SYSSEEK (fp, fp->_old_offset, 0);
return offset;
}
_IO_off64_t
_IO_new_file_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
{
_IO_off64_t result;
_IO_off64_t delta, new_offset;
long count;
/* Short-circuit into a separate function. We don't want to mix any
functionality and we don't want to touch anything inside the FILE
object. */
if (mode == 0)
return do_ftell (fp);
/* POSIX.1 8.2.3.7 says that after a call the fflush() the file
offset of the underlying file must be exact. */
int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end
&& fp->_IO_write_base == fp->_IO_write_ptr);
bool was_writing = (fp->_IO_write_ptr > fp->_IO_write_base
|| _IO_in_put_mode (fp));
/* Flush unwritten characters.
(This may do an unneeded write if we seek within the buffer.
But to be able to switch to reading, we would need to set
egptr to pptr. That can't be done in the current design,
which assumes file_ptr() is eGptr. Anyway, since we probably
end up flushing when we close(), it doesn't make much difference.)
FIXME: simulate mem-mapped files. */
if (was_writing && _IO_switch_to_get_mode (fp))
return EOF;
if (fp->_IO_buf_base == NULL)
{
/* It could be that we already have a pushback buffer. */
if (fp->_IO_read_base != NULL)
{
free (fp->_IO_read_base);
fp->_flags &= ~_IO_IN_BACKUP;
}
_IO_doallocbuf (fp);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
}
switch (dir)
{
case _IO_seek_cur:
/* Adjust for read-ahead (bytes is buffer). */
offset -= fp->_IO_read_end - fp->_IO_read_ptr;
if (fp->_offset == _IO_pos_BAD)
goto dumb;
/* Make offset absolute, assuming current pointer is file_ptr(). */
offset += fp->_offset;
if (offset < 0)
{
__set_errno (EINVAL);
return EOF;
}
dir = _IO_seek_set;
break;
case _IO_seek_set:
break;
case _IO_seek_end:
{
struct stat64 st;
if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode))
{
offset += st.st_size;
dir = _IO_seek_set;
}
else
goto dumb;
}
}
/* At this point, dir==_IO_seek_set. */
/* If destination is within current buffer, optimize: */
if (fp->_offset != _IO_pos_BAD && fp->_IO_read_base != NULL
&& !_IO_in_backup (fp))
{
_IO_off64_t start_offset = (fp->_offset
- (fp->_IO_read_end - fp->_IO_buf_base));
if (offset >= start_offset && offset < fp->_offset)
{
_IO_setg (fp, fp->_IO_buf_base,
fp->_IO_buf_base + (offset - start_offset),
fp->_IO_read_end);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
goto resync;
}
}
if (fp->_flags & _IO_NO_READS)
goto dumb;
/* Try to seek to a block boundary, to improve kernel page management. */
new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1);
delta = offset - new_offset;
if (delta > fp->_IO_buf_end - fp->_IO_buf_base)
{
new_offset = offset;
delta = 0;
}
result = _IO_SYSSEEK (fp, new_offset, 0);
if (result < 0)
return EOF;
if (delta == 0)
count = 0;
else
{
count = _IO_SYSREAD (fp, fp->_IO_buf_base,
(must_be_exact
? delta : fp->_IO_buf_end - fp->_IO_buf_base));
if (count < delta)
{
/* We weren't allowed to read, but try to seek the remainder. */
offset = count == EOF ? delta : delta-count;
dir = _IO_seek_cur;
goto dumb;
}
}
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta,
fp->_IO_buf_base + count);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
fp->_offset = result + count;
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
return offset;
dumb:
_IO_unsave_markers (fp);
result = _IO_SYSSEEK (fp, offset, dir);
if (result != EOF)
{
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
fp->_offset = result;
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
}
return result;
resync:
/* We need to do it since it is possible that the file offset in
the kernel may be changed behind our back. It may happen when
we fopen a file and then do a fork. One process may access the
file and the kernel file offset will be changed. */
if (fp->_offset >= 0)
_IO_SYSSEEK (fp, fp->_offset, 0);
return offset;
}
_IO_FILE *
_IO_new_fdopen (int fd, const char *mode)
{
int read_write;
struct locked_FILE
{
struct _IO_FILE_plus fp;
#ifdef _IO_MTSAFE_IO
_IO_lock_t lock;
#endif
struct _IO_wide_data wd;
} *new_f;
int i;
int use_mmap = 0;
/* Decide whether we modify the offset of the file we attach to and seek to
the end of file. We only do this if the mode is 'a' and if the file
descriptor did not have O_APPEND in its flags already. */
bool do_seek = false;
switch (*mode)
{
case 'r':
read_write = _IO_NO_WRITES;
break;
case 'w':
read_write = _IO_NO_READS;
break;
case 'a':
read_write = _IO_NO_READS|_IO_IS_APPENDING;
break;
default:
MAYBE_SET_EINVAL;
return NULL;
}
for (i = 1; i < 5; ++i)
{
switch (*++mode)
{
case '\0':
break;
case '+':
read_write &= _IO_IS_APPENDING;
break;
case 'm':
use_mmap = 1;
continue;
case 'x':
case 'b':
default:
/* Ignore */
continue;
}
break;
}
#ifdef F_GETFL
int fd_flags = _IO_fcntl (fd, F_GETFL);
#ifndef O_ACCMODE
#define O_ACCMODE (O_RDONLY|O_WRONLY|O_RDWR)
#endif
if (fd_flags == -1)
return NULL;
if (((fd_flags & O_ACCMODE) == O_RDONLY && !(read_write & _IO_NO_WRITES))
|| ((fd_flags & O_ACCMODE) == O_WRONLY && !(read_write & _IO_NO_READS)))
{
MAYBE_SET_EINVAL;
return NULL;
}
/* The May 93 draft of P1003.4/D14.1 (redesignated as 1003.1b)
[System Application Program Interface (API) Amendment 1:
Realtime Extensions], Rationale B.8.3.3
Open a Stream on a File Descriptor says:
Although not explicitly required by POSIX.1, a good
implementation of append ("a") mode would cause the
O_APPEND flag to be set.
(Historical implementations [such as Solaris2] do a one-time
seek in fdopen.)
However, we do not turn O_APPEND off if the mode is "w" (even
though that would seem consistent) because that would be more
likely to break historical programs.
*/
if ((read_write & _IO_IS_APPENDING) && !(fd_flags & O_APPEND))
{
do_seek = true;
#ifdef F_SETFL
if (_IO_fcntl (fd, F_SETFL, fd_flags | O_APPEND) == -1)
#endif
return NULL;
}
#endif
new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
if (new_f == NULL)
return NULL;
#ifdef _IO_MTSAFE_IO
new_f->fp.file._lock = &new_f->lock;
#endif
_IO_no_init (&new_f->fp.file, 0, 0, &new_f->wd,
#ifdef _G_HAVE_MMAP
(use_mmap && (read_write & _IO_NO_WRITES))
? &_IO_wfile_jumps_maybe_mmap :
#endif
&_IO_wfile_jumps);
_IO_JUMPS (&new_f->fp) =
#ifdef _G_HAVE_MMAP
(use_mmap && (read_write & _IO_NO_WRITES)) ? &_IO_file_jumps_maybe_mmap :
#endif
&_IO_file_jumps;
_IO_new_file_init_internal (&new_f->fp);
#if !_IO_UNIFIED_JUMPTABLES
new_f->fp.vtable = NULL;
#endif
/* We only need to record the fd because _IO_file_init_internal will
have unset the offset. It is important to unset the cached
offset because the real offset in the file could change between
now and when the handle is activated and we would then mislead
ftell into believing that we have a valid offset. */
new_f->fp.file._fileno = fd;
new_f->fp.file._flags &= ~_IO_DELETE_DONT_CLOSE;
_IO_mask_flags (&new_f->fp.file, read_write,
_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
/* For append mode, set the file offset to the end of the file if we added
O_APPEND to the file descriptor flags. Don't update the offset cache
though, since the file handle is not active. */
if (do_seek && ((read_write & (_IO_IS_APPENDING | _IO_NO_READS))
== (_IO_IS_APPENDING | _IO_NO_READS)))
{
_IO_off64_t new_pos = _IO_SYSSEEK (&new_f->fp.file, 0, _IO_seek_end);
if (new_pos == _IO_pos_BAD && errno != ESPIPE)
return NULL;
}
return &new_f->fp.file;
}
/* ftell{,o} implementation for wide mode. Don't modify any state of the file
pointer while we try to get the current state of the stream except in one
case, which is when we have unflushed writes in append mode. */
static _IO_off64_t
do_ftell_wide (_IO_FILE *fp)
{
_IO_off64_t result, offset = 0;
/* No point looking for offsets in the buffer if it hasn't even been
allocated. */
if (fp->_wide_data->_IO_buf_base != NULL)
{
const wchar_t *wide_read_base;
const wchar_t *wide_read_ptr;
const wchar_t *wide_read_end;
bool unflushed_writes = (fp->_wide_data->_IO_write_ptr
> fp->_wide_data->_IO_write_base);
bool append_mode = (fp->_flags & _IO_IS_APPENDING) == _IO_IS_APPENDING;
/* When we have unflushed writes in append mode, seek to the end of the
file and record that offset. This is the only time we change the file
stream state and it is safe since the file handle is active. */
if (unflushed_writes && append_mode)
{
result = _IO_SYSSEEK (fp, 0, _IO_seek_end);
if (result == _IO_pos_BAD)
return EOF;
else
fp->_offset = result;
}
/* XXX For wide stream with backup store it is not very
reasonable to determine the offset. The pushed-back
character might require a state change and we need not be
able to compute the initial state by reverse transformation
since there is no guarantee of symmetry. So we don't even
try and return an error. */
if (_IO_in_backup (fp))
{
if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
{
__set_errno (EINVAL);
return -1;
}
/* Nothing in the backup store, so note the backed up pointers
without changing the state. */
wide_read_base = fp->_wide_data->_IO_save_base;
wide_read_ptr = wide_read_base;
wide_read_end = fp->_wide_data->_IO_save_end;
}
else
{
wide_read_base = fp->_wide_data->_IO_read_base;
wide_read_ptr = fp->_wide_data->_IO_read_ptr;
wide_read_end = fp->_wide_data->_IO_read_end;
}
struct _IO_codecvt *cv = fp->_codecvt;
int clen = (*cv->__codecvt_do_encoding) (cv);
if (!unflushed_writes)
{
if (clen > 0)
{
offset -= (wide_read_end - wide_read_ptr) * clen;
offset -= fp->_IO_read_end - fp->_IO_read_ptr;
}
else
{
int nread;
size_t delta = wide_read_ptr - wide_read_base;
__mbstate_t state = fp->_wide_data->_IO_last_state;
nread = (*cv->__codecvt_do_length) (cv, &state,
fp->_IO_read_base,
fp->_IO_read_end, delta);
offset -= fp->_IO_read_end - fp->_IO_read_base - nread;
}
}
else
{
if (clen > 0)
offset += (fp->_wide_data->_IO_write_ptr
- fp->_wide_data->_IO_write_base) * clen;
else
{
size_t delta = (fp->_wide_data->_IO_write_ptr
- fp->_wide_data->_IO_write_base);
/* Allocate enough space for the conversion. */
size_t outsize = delta * sizeof (wchar_t);
char *out = malloc (outsize);
char *outstop = out;
const wchar_t *in = fp->_wide_data->_IO_write_base;
enum __codecvt_result status;
__mbstate_t state = fp->_wide_data->_IO_last_state;
status = (*cv->__codecvt_do_out) (cv, &state,
in, in + delta, &in,
out, out + outsize, &outstop);
/* We don't check for __codecvt_partial because it can be
returned on one of two conditions: either the output
buffer is full or the input sequence is incomplete. We
take care to allocate enough buffer and our input
sequences must be complete since they are accepted as
wchar_t; if not, then that is an error. */
if (__glibc_unlikely (status != __codecvt_ok))
{
free (out);
return WEOF;
}
offset += outstop - out;
free (out);
}
/* We don't trust _IO_read_end to represent the current file offset
when writing in append mode because the value would have to be
shifted to the end of the file during a flush. Use the write base
instead, along with the new offset we got above when we did a seek
to the end of the file. */
if (append_mode)
offset += fp->_IO_write_ptr - fp->_IO_write_base;
/* For all other modes, _IO_read_end represents the file offset. */
else
offset += fp->_IO_write_ptr - fp->_IO_read_end;
}
}
if (fp->_offset != _IO_pos_BAD)
result = fp->_offset;
else
result = _IO_SYSSEEK (fp, 0, _IO_seek_cur);
if (result == EOF)
return result;
result += offset;
if (result < 0)
{
__set_errno (EINVAL);
return EOF;
}
return result;
}
