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/* Copyright (C) 2004 Manuel Novoa III <mjn3@codepoet.org>
*
* GNU Library General Public License (LGPL) version 2 or later.
*
* Dedicated to Toni. See uClibc/DEDICATION.mjn3 for details.
*/
#include "_stdio.h"
/* Function to handle transition to reading.
* Initialize or verify the stream's orientation (even if writeonly).
* Check that the stream is readable.
* If currently reading, check that we can transition to writing.
* C99 requires that we not be reading, but attempting to
* auto-transition by commiting the write buffer is a configurable
* option.
* Returns 0 on success and EOF otherwise.
*
* Notes:
* There are two function signatures, depending on wchar support,
* since with no wchar support the orientation is narrow by default.
*/
#ifdef __UCLIBC_HAS_WCHAR__
int __stdio_trans2r_o(FILE * __restrict stream, int oflag)
#else
int __stdio_trans2r(FILE * __restrict stream)
#endif
{
__STDIO_STREAM_VALIDATE(stream);
assert(!__STDIO_STREAM_IS_READING(stream));
#ifdef __UCLIBC_HAS_WCHAR__
if (!(stream->__modeflags & oflag)) {
if (stream->__modeflags & (__FLAG_NARROW|__FLAG_WIDE)) {
__UNDEFINED_OR_NONPORTABLE;
goto DO_EBADF;
}
stream->__modeflags |= oflag;
}
#endif
if (stream->__modeflags & __FLAG_WRITEONLY) {
#if defined(__UCLIBC_HAS_WCHAR__) || !defined(__UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION__)
DO_EBADF:
#endif
__set_errno(EBADF);
#ifdef __UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION__
ERROR:
#endif
__STDIO_STREAM_SET_ERROR(stream);
__STDIO_STREAM_VALIDATE(stream);
return EOF;
}
if (__STDIO_STREAM_IS_WRITING(stream)) {
#ifdef __UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION__
if (__STDIO_COMMIT_WRITE_BUFFER(stream)) { /* commit failed! */
goto ERROR;
}
assert(!__STDIO_STREAM_BUFFER_WUSED(stream));
__STDIO_STREAM_DISABLE_PUTC(stream);
__STDIO_STREAM_CLEAR_WRITING(stream);
#else
/* C99: Output shall not be directly followed by input without an
intervening call to the fflush function or to a file positioning
function (fseek, fsetpos, or rewind). */
__UNDEFINED_OR_NONPORTABLE;
goto DO_EBADF;
#endif
}
__STDIO_STREAM_SET_READING(stream);
/* getc macro is enabled when data is read into buffer. */
__STDIO_STREAM_VALIDATE(stream);
return 0;
}
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