1/* Copyright (C) 1996-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
4
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.
9
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.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <assert.h>
20#include <dlfcn.h>
21#include <errno.h>
22#include <gconv.h>
23#include <wchar.h>
24#include <wcsmbsload.h>
25
26#include <sysdep.h>
27
28#ifndef EILSEQ
29# define EILSEQ EINVAL
30#endif
31
32/* This is the private state used if PS is NULL. */
33static mbstate_t state;
34
35size_t
36__mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
37{
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, *endbuf;
44 unsigned char *outbuf = (unsigned char *) (pwc ?: buf);
45 const struct gconv_fcts *fcts;
46
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
53 /* A first special case is if S is NULL. This means put PS in the
54 initial state. */
55 if (s == NULL)
56 {
57 outbuf = (unsigned char *) buf;
58 s = "";
59 n = 1;
60 }
61
62 if (n == 0)
63 return (size_t) -2;
64
65 /* Tell where we want the result. */
66 data.__outbuf = outbuf;
67 data.__outbufend = outbuf + sizeof (wchar_t);
68
69 /* Get the conversion functions. */
70 fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
71
72 /* Do a normal conversion. */
73 inbuf = (const unsigned char *) s;
74 endbuf = inbuf + n;
75 if (__glibc_unlikely (endbuf < inbuf))
76 {
77 endbuf = (const unsigned char *) ~(uintptr_t) 0;
78 if (endbuf == inbuf)
79 goto ilseq;
80 }
81 __gconv_fct fct = fcts->towc->__fct;
82#ifdef PTR_DEMANGLE
83 if (fcts->towc->__shlib_handle != NULL)
84 PTR_DEMANGLE (fct);
85#endif
86 status = DL_CALL_FCT (fct, (fcts->towc, &data, &inbuf, endbuf,
87 NULL, &dummy, 0, 1));
88
89 /* There must not be any problems with the conversion but illegal input
90 characters. The output buffer must be large enough, otherwise the
91 definition of MB_CUR_MAX is not correct. All the other possible
92 errors also must not happen. */
93 assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
94 || status == __GCONV_ILLEGAL_INPUT
95 || status == __GCONV_INCOMPLETE_INPUT
96 || status == __GCONV_FULL_OUTPUT);
97
98 if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
99 || status == __GCONV_FULL_OUTPUT)
100 {
101 if (data.__outbuf != (unsigned char *) outbuf
102 && *(wchar_t *) outbuf == L'\0')
103 {
104 /* The converted character is the NUL character. */
105 assert (__mbsinit (data.__statep));
106 result = 0;
107 }
108 else
109 result = inbuf - (const unsigned char *) s;
110 }
111 else if (status == __GCONV_INCOMPLETE_INPUT)
112 result = (size_t) -2;
113 else
114 {
115 ilseq:
116 result = (size_t) -1;
117 __set_errno (EILSEQ);
118 }
119
120 return result;
121}
122libc_hidden_def (__mbrtowc)
123weak_alias (__mbrtowc, mbrtowc)
124libc_hidden_weak (mbrtowc)
125