1/*
2 * Copyright (C) 1999-2001, 2005 Free Software Foundation, Inc.
3 * This file is part of the GNU LIBICONV Library.
4 *
5 * The GNU LIBICONV Library is free software; you can redistribute it
6 * and/or modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * The GNU LIBICONV Library is distributed in the hope that it will be
11 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public
16 * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
17 * If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
18 * Fifth Floor, Boston, MA 02110-1301, USA.
19 */
20
21/*
22 * GBK
23 */
24
25/*
26 * GBK, as described in Ken Lunde's book, is an extension of GB 2312-1980
27 * (shifted by adding 0x8080 to the range 0xA1A1..0xFEFE, as used in EUC-CN).
28 * It adds the following ranges:
29 *
30 * (part of GBK/1)  0xA2A1-0xA2AA  Small Roman numerals
31 * GBK/3   0x{81-A0}{40-7E,80-FE}  6080 new characters, all in Unicode
32 * GBK/4   0x{AA-FE}{40-7E,80-A0}  8160 new characters, 8080 in Unicode
33 * GBK/5   0x{A8-A9}{40-7E,80-A0}  166 new characters, 153 in Unicode
34 *
35 * Furthermore, all four tables I have looked at
36 *   - the CP936 table by Microsoft, found on ftp.unicode.org in 1999,
37 *   - the GBK table by Sun, investigated on a Solaris 2.7 machine,
38 *   - the GBK tables by CWEX, found in the Big5+ package,
39 *   - the GB18030 standard (second printing),
40 * agree in the following extensions. (Ken Lunde must have overlooked these
41 * differences between GB2312 and GBK. Also, the CWEX tables have additional
42 * differences.)
43 *
44 * 1. Some characters in the GB2312 range are defined differently:
45 *
46 *     code    GB2312                         GBK
47 *    0xA1A4   0x30FB # KATAKANA MIDDLE DOT   0x00B7 # MIDDLE DOT
48 *    0xA1AA   0x2015 # HORIZONTAL BAR        0x2014 # EM DASH
49 *
50 * 2. 19 characters added in the range 0xA6E0-0xA6F5.
51 *
52 * 3. 4 characters added in the range 0xA8BB-0xA8C0.
53 *
54 * CP936 as of 1999 was identical to GBK. However, since 1999, Microsoft has
55 * added new mappings to CP936...
56 */
57
58#include "gbkext1.h"
59#include "gbkext2.h"
60#include "gbkext_inv.h"
61#include "cp936ext.h"
62
63static int
64gbk_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
65{
66  unsigned char c = *s;
67
68  if (c >= 0x81 && c < 0xff) {
69    if (n < 2)
70      return RET_TOOFEW(0);
71    if (c >= 0xa1 && c <= 0xf7) {
72      unsigned char c2 = s[1];
73      if (c == 0xa1) {
74        if (c2 == 0xa4) {
75          *pwc = 0x00b7;
76          return 2;
77        }
78        if (c2 == 0xaa) {
79          *pwc = 0x2014;
80          return 2;
81        }
82      }
83      if (c2 >= 0xa1 && c2 < 0xff) {
84        unsigned char buf[2];
85        int ret;
86        buf[0] = c-0x80; buf[1] = c2-0x80;
87        ret = gb2312_mbtowc(conv,pwc,buf,2);
88        if (ret != RET_ILSEQ)
89          return ret;
90        buf[0] = c; buf[1] = c2;
91        ret = cp936ext_mbtowc(conv,pwc,buf,2);
92        if (ret != RET_ILSEQ)
93          return ret;
94      }
95    }
96    if (c >= 0x81 && c <= 0xa0)
97      return gbkext1_mbtowc(conv,pwc,s,2);
98    if (c >= 0xa8 && c <= 0xfe)
99      return gbkext2_mbtowc(conv,pwc,s,2);
100    if (c == 0xa2) {
101      unsigned char c2 = s[1];
102      if (c2 >= 0xa1 && c2 <= 0xaa) {
103        *pwc = 0x2170+(c2-0xa1);
104        return 2;
105      }
106    }
107  }
108  return RET_ILSEQ;
109}
110
111static int
112gbk_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
113{
114  unsigned char buf[2];
115  int ret;
116
117  if (wc != 0x30fb && wc != 0x2015) {
118    ret = gb2312_wctomb(conv,buf,wc,2);
119    if (ret != RET_ILUNI) {
120      if (ret != 2) abort();
121      if (n < 2)
122        return RET_TOOSMALL;
123      r[0] = buf[0]+0x80;
124      r[1] = buf[1]+0x80;
125      return 2;
126    }
127  }
128  ret = gbkext_inv_wctomb(conv,buf,wc,2);
129  if (ret != RET_ILUNI) {
130    if (ret != 2) abort();
131    if (n < 2)
132      return RET_TOOSMALL;
133    r[0] = buf[0];
134    r[1] = buf[1];
135    return 2;
136  }
137  if (wc >= 0x2170 && wc <= 0x2179) {
138    r[0] = 0xa2;
139    r[1] = 0xa1 + (wc-0x2170);
140    return 2;
141  }
142  ret = cp936ext_wctomb(conv,buf,wc,2);
143  if (ret != RET_ILUNI) {
144    if (ret != 2) abort();
145    if (n < 2)
146      return RET_TOOSMALL;
147    r[0] = buf[0];
148    r[1] = buf[1];
149    return 2;
150  }
151  if (wc == 0x00b7) {
152    if (n < 2)
153      return RET_TOOSMALL;
154    r[0] = 0xa1;
155    r[1] = 0xa4;
156    return 2;
157  }
158  if (wc == 0x2014) {
159    if (n < 2)
160      return RET_TOOSMALL;
161    r[0] = 0xa1;
162    r[1] = 0xaa;
163    return 2;
164  }
165
166  return RET_ILUNI;
167}
168