glibc/wcsmbs/mbrtowc.c

115 lines
3.3 KiB
C

/* Copyright (C) 1996, 1997, 1998, 1999, 2000, 2002, 2004
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <dlfcn.h>
#include <errno.h>
#include <gconv.h>
#include <wchar.h>
#include <wcsmbsload.h>
#include <assert.h>
#ifndef EILSEQ
# define EILSEQ EINVAL
#endif
/* This is the private state used if PS is NULL. */
static mbstate_t state;
size_t
__mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
{
wchar_t buf[1];
struct __gconv_step_data data;
int status;
size_t result;
size_t dummy;
const unsigned char *inbuf, *endbuf;
char *outbuf = (char *) (pwc ?: buf);
const struct gconv_fcts *fcts;
/* Set information for this step. */
data.__invocation_counter = 0;
data.__internal_use = 1;
data.__flags = __GCONV_IS_LAST;
data.__statep = ps ?: &state;
data.__trans = NULL;
/* A first special case is if S is NULL. This means put PS in the
initial state. */
if (s == NULL)
{
outbuf = (char *) buf;
s = "";
n = 1;
}
/* Tell where we want the result. */
data.__outbuf = outbuf;
data.__outbufend = outbuf + sizeof (wchar_t);
/* Get the conversion functions. */
fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
/* Do a normal conversion. */
inbuf = (const unsigned char *) s;
endbuf = inbuf + n;
if (__builtin_expect (endbuf < inbuf, 0))
endbuf = (const unsigned char *) ~(uintptr_t) 0;
status = DL_CALL_FCT (fcts->towc->__fct,
(fcts->towc, &data, &inbuf, endbuf,
NULL, &dummy, 0, 1));
/* There must not be any problems with the conversion but illegal input
characters. The output buffer must be large enough, otherwise the
definition of MB_CUR_MAX is not correct. All the other possible
errors also must not happen. */
assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
|| status == __GCONV_ILLEGAL_INPUT
|| status == __GCONV_INCOMPLETE_INPUT
|| status == __GCONV_FULL_OUTPUT);
if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
|| status == __GCONV_FULL_OUTPUT)
{
if (data.__outbuf != (unsigned char *) outbuf
&& *(wchar_t *) outbuf == L'\0')
{
/* The converted character is the NUL character. */
assert (__mbsinit (data.__statep));
result = 0;
}
else
result = inbuf - (const unsigned char *) s;
}
else if (status == __GCONV_INCOMPLETE_INPUT)
result = (size_t) -2;
else
{
result = (size_t) -1;
__set_errno (EILSEQ);
}
return result;
}
libc_hidden_def (__mbrtowc)
weak_alias (__mbrtowc, mbrtowc)
libc_hidden_weak (mbrtowc)