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[glibc.git] / wcsmbs / mbrtowc.c
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1 /* Copyright (C) 1996,1997,1998,1999,2000,2002 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <dlfcn.h>
21 #include <errno.h>
22 #include <gconv.h>
23 #include <wchar.h>
24 #include <wcsmbsload.h>
26 #include <assert.h>
28 #ifndef EILSEQ
29 # define EILSEQ EINVAL
30 #endif
32 /* This is the private state used if PS is NULL. */
33 static mbstate_t state;
35 size_t
36 __mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
38 wchar_t buf[1];
39 struct __gconv_step_data data;
40 int status;
41 size_t result;
42 size_t dummy;
43 const unsigned char *inbuf;
44 char *outbuf = (char *) (pwc ?: buf);
45 const struct gconv_fcts *fcts;
47 /* Set information for this step. */
48 data.__invocation_counter = 0;
49 data.__internal_use = 1;
50 data.__flags = __GCONV_IS_LAST;
51 data.__statep = ps ?: &state;
52 data.__trans = NULL;
54 /* A first special case is if S is NULL. This means put PS in the
55 initial state. */
56 if (s == NULL)
58 outbuf = (char *) buf;
59 s = "";
60 n = 1;
63 /* Tell where we want the result. */
64 data.__outbuf = outbuf;
65 data.__outbufend = outbuf + sizeof (wchar_t);
67 /* Get the conversion functions. */
68 fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
70 /* Do a normal conversion. */
71 inbuf = (const unsigned char *) s;
72 status = DL_CALL_FCT (fcts->towc->__fct,
73 (fcts->towc, &data, &inbuf, inbuf + n,
74 NULL, &dummy, 0, 1));
76 /* There must not be any problems with the conversion but illegal input
77 characters. The output buffer must be large enough, otherwise the
78 definition of MB_CUR_MAX is not correct. All the other possible
79 errors also must not happen. */
80 assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
81 || status == __GCONV_ILLEGAL_INPUT
82 || status == __GCONV_INCOMPLETE_INPUT
83 || status == __GCONV_FULL_OUTPUT);
85 if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
86 || status == __GCONV_FULL_OUTPUT)
88 if (data.__outbuf != (unsigned char *) outbuf
89 && *(wchar_t *) outbuf == L'\0')
91 /* The converted character is the NUL character. */
92 assert (__mbsinit (data.__statep));
93 result = 0;
95 else
96 result = inbuf - (const unsigned char *) s;
98 else if (status == __GCONV_INCOMPLETE_INPUT)
99 result = (size_t) -2;
100 else
102 result = (size_t) -1;
103 __set_errno (EILSEQ);
106 return result;
108 libc_hidden_def (__mbrtowc)
109 weak_alias (__mbrtowc, mbrtowc)
110 libc_hidden_weak (mbrtowc)