1/* Convert characters in input buffer using conversion descriptor to
2 output buffer.
3 Copyright (C) 1997-2022 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <stddef.h> /* for NULL */
21#include <errno.h>
22#include <iconv.h>
23
24#include <gconv_int.h>
25
26#include <assert.h>
27
28
29size_t
30iconv (iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf,
31 size_t *outbytesleft)
32{
33 __gconv_t gcd = (__gconv_t) cd;
34 char *outstart = outbuf ? *outbuf : NULL;
35 size_t irreversible;
36 int result;
37
38 if (__glibc_unlikely (inbuf == NULL || *inbuf == NULL))
39 {
40 if (outbuf == NULL || *outbuf == NULL)
41 result = __gconv (cd: gcd, NULL, NULL, NULL, NULL, irreversible: &irreversible);
42 else
43 result = __gconv (cd: gcd, NULL, NULL, outbuf: (unsigned char **) outbuf,
44 outbufend: (unsigned char *) (outstart + *outbytesleft),
45 irreversible: &irreversible);
46 }
47 else
48 {
49 const char *instart = *inbuf;
50
51 result = __gconv (cd: gcd, inbuf: (const unsigned char **) inbuf,
52 inbufend: (const unsigned char *) (*inbuf + *inbytesleft),
53 outbuf: (unsigned char **) outbuf,
54 outbufend: (unsigned char *) (*outbuf + *outbytesleft),
55 irreversible: &irreversible);
56
57 *inbytesleft -= *inbuf - instart;
58 }
59 if (outstart != NULL)
60 *outbytesleft -= *outbuf - outstart;
61
62 switch (__builtin_expect (result, __GCONV_OK))
63 {
64 case __GCONV_ILLEGAL_DESCRIPTOR:
65 __set_errno (EBADF);
66 irreversible = (size_t) -1L;
67 break;
68
69 case __GCONV_ILLEGAL_INPUT:
70 __set_errno (EILSEQ);
71 irreversible = (size_t) -1L;
72 break;
73
74 case __GCONV_FULL_OUTPUT:
75 __set_errno (E2BIG);
76 irreversible = (size_t) -1L;
77 break;
78
79 case __GCONV_INCOMPLETE_INPUT:
80 __set_errno (EINVAL);
81 irreversible = (size_t) -1L;
82 break;
83
84 case __GCONV_EMPTY_INPUT:
85 case __GCONV_OK:
86 /* Nothing. */
87 break;
88
89 default:
90 assert (!"Nothing like this should happen");
91 }
92
93 return irreversible;
94}
95

source code of glibc/iconv/iconv.c