1/* Copyright (C) 2011-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
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 <uchar.h>
24#include <wcsmbsload.h>
25
26#include <sysdep.h>
27
28#ifndef EILSEQ
29# define EILSEQ EINVAL
30#endif
31
32
33/* This is the private state used if PS is NULL. */
34static mbstate_t state;
35
36size_t
37mbrtoc16 (char16_t *pc16, const char *s, size_t n, mbstate_t *ps)
38{
39 if (ps == NULL)
40 ps = &state;
41
42 /* The standard text does not say that S being NULL means the state
43 is reset even if the second half of a surrogate still have to be
44 returned. In fact, the error code description indicates
45 otherwise. Therefore always first try to return a second
46 half. */
47 if (ps->__count & 0x80000000)
48 {
49 /* We have to return the second word for a surrogate. */
50 ps->__count &= 0x7fffffff;
51 *pc16 = ps->__value.__wch;
52 ps->__value.__wch = L'\0';
53 return (size_t) -3;
54 }
55
56 wchar_t wc;
57 struct __gconv_step_data data;
58 int status;
59 size_t result;
60 size_t dummy;
61 const unsigned char *inbuf, *endbuf;
62 unsigned char *outbuf = (unsigned char *) &wc;
63 const struct gconv_fcts *fcts;
64
65 /* Set information for this step. */
66 data.__invocation_counter = 0;
67 data.__internal_use = 1;
68 data.__flags = __GCONV_IS_LAST;
69 data.__statep = ps;
70
71 /* A first special case is if S is NULL. This means put PS in the
72 initial state. */
73 if (s == NULL)
74 {
75 pc16 = NULL;
76 s = "";
77 n = 1;
78 }
79
80 if (n == 0)
81 return (size_t) -2;
82
83 /* Tell where we want the result. */
84 data.__outbuf = outbuf;
85 data.__outbufend = outbuf + sizeof (wchar_t);
86
87 /* Get the conversion functions. */
88 fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
89
90 /* Do a normal conversion. */
91 inbuf = (const unsigned char *) s;
92 endbuf = inbuf + n;
93 if (__glibc_unlikely (endbuf < inbuf))
94 {
95 endbuf = (const unsigned char *) ~(uintptr_t) 0;
96 if (endbuf == inbuf)
97 goto ilseq;
98 }
99 __gconv_fct fct = fcts->towc->__fct;
100#ifdef PTR_DEMANGLE
101 if (fcts->towc->__shlib_handle != NULL)
102 PTR_DEMANGLE (fct);
103#endif
104
105 status = DL_CALL_FCT (fct, (fcts->towc, &data, &inbuf, endbuf,
106 NULL, &dummy, 0, 1));
107
108 /* There must not be any problems with the conversion but illegal input
109 characters. The output buffer must be large enough, otherwise the
110 definition of MB_CUR_MAX is not correct. All the other possible
111 errors also must not happen. */
112 assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
113 || status == __GCONV_ILLEGAL_INPUT
114 || status == __GCONV_INCOMPLETE_INPUT
115 || status == __GCONV_FULL_OUTPUT);
116
117 if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
118 || status == __GCONV_FULL_OUTPUT)
119 {
120 result = inbuf - (const unsigned char *) s;
121
122 if (wc < 0x10000)
123 {
124 if (pc16 != NULL)
125 *pc16 = wc;
126
127 if (data.__outbuf != outbuf && wc == L'\0')
128 {
129 /* The converted character is the NUL character. */
130 assert (__mbsinit (data.__statep));
131 result = 0;
132 }
133 }
134 else
135 {
136 /* This is a surrogate. */
137 if (pc16 != NULL)
138 *pc16 = 0xd7c0 + (wc >> 10);
139
140 ps->__count |= 0x80000000;
141 ps->__value.__wch = 0xdc00 + (wc & 0x3ff);
142 }
143 }
144 else if (status == __GCONV_INCOMPLETE_INPUT)
145 result = (size_t) -2;
146 else
147 {
148 ilseq:
149 result = (size_t) -1;
150 __set_errno (EILSEQ);
151 }
152
153 return result;
154}
155