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freebsd/lib/libc/stdio/fgetwc.c
David Schultz d7af8cf14b Previously, vfscanf()'s wide character processing functions were
reading wide characters manually.  With this change, they now use
fgetwc().  To make this work, we use an internal version of fgetwc()
with a few extensions: it takes an mbstate * because non-wide streams
don't have a built-in mbstate, and it indicates the number of bytes
read.

vfscanf() now resembles vfwscanf() more closely.  Minor functional
improvements include working xlocale support in vfscanf(), setting the
stream error indicator on encoding errors, and proper handling of
shift-based encodings.  (Actually, making shift-based encodings work
with non-wide streams is hopeless, but the implementation now matches
the broken specification.)
2012-04-29 16:28:39 +00:00

116 lines
3.0 KiB
C

/*-
* Copyright (c) 2002-2004 Tim J. Robbins.
* All rights reserved.
*
* Copyright (c) 2011 The FreeBSD Foundation
* All rights reserved.
* Portions of this software were developed by David Chisnall
* under sponsorship from the FreeBSD Foundation.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <wchar.h>
#include "un-namespace.h"
#include "libc_private.h"
#include "local.h"
#include "mblocal.h"
#include "xlocale_private.h"
/*
* MT-safe version.
*/
wint_t
fgetwc_l(FILE *fp, locale_t locale)
{
wint_t r;
FIX_LOCALE(locale);
FLOCKFILE(fp);
ORIENT(fp, 1);
r = __fgetwc(fp, locale);
FUNLOCKFILE(fp);
return (r);
}
wint_t
fgetwc(FILE *fp)
{
return fgetwc_l(fp, __get_locale());
}
/*
* Internal (non-MPSAFE) version of fgetwc(). This version takes an
* mbstate_t argument specifying the initial conversion state. For
* wide streams, this should always be fp->_mbstate. On return, *nread
* is set to the number of bytes read.
*/
wint_t
__fgetwc_mbs(FILE *fp, mbstate_t *mbs, int *nread, locale_t locale)
{
wchar_t wc;
size_t nconv;
struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
if (fp->_r <= 0 && __srefill(fp)) {
*nread = 0;
return (WEOF);
}
if (MB_CUR_MAX == 1) {
/* Fast path for single-byte encodings. */
wc = *fp->_p++;
fp->_r--;
*nread = 1;
return (wc);
}
*nread = 0;
do {
nconv = l->__mbrtowc(&wc, fp->_p, fp->_r, mbs);
if (nconv == (size_t)-1)
break;
else if (nconv == (size_t)-2)
continue;
else if (nconv == 0) {
fp->_p++;
fp->_r--;
(*nread)++;
return (L'\0');
} else {
fp->_p += nconv;
fp->_r -= nconv;
*nread += nconv;
return (wc);
}
} while (__srefill(fp) == 0);
fp->_flags |= __SERR;
errno = EILSEQ;
return (WEOF);
}