1/*
2 * Copyright (C) 1999-2001 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., 59 Temple Place -
18 * Suite 330, Boston, MA 02111-1307, 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
36/*
37 * CP936 is nearly identical to GBK. It differs as follows:
38 *
39 * 1. Some characters in the GB2312 range are defined differently:
40 *
41 *     code    GB2312                         CP936.TXT
42 *    0xA1A4   0x30FB # KATAKANA MIDDLE DOT   0x00B7 # MIDDLE DOT
43 *    0xA1AA   0x2015 # HORIZONTAL BAR        0x2014 # EM DASH
44 *
45 * 2. 19 characters added in the range 0xA6E0-0xA6F5.
46 *
47 * 3. 4 characters added in the range 0xA8BB-0xA8C0.
48 */
49
50/*
51 * Since all three tables I have looked at
52 *   - the CP936 table by Microsoft, found on ftp.unicode.org,
53 *   - the GBK table by Sun, investigated on a Solaris 2.7 machine,
54 *   - the GBK tables by CWEX, found in the Big5+ package,
55 * all include these CP936 extensions (the CWEX tables have additional
56 * differences), I conclude that either Ken Lunde has overlooked some of
57 * the differences between GB2312 and GBK, or he is right but the major
58 * vendors don't care about it. In either case, CP936 is the de facto
59 * standard under the name "GBK", and we should better support it.
60 *
61 * So in what follows, when we write "GBK" we always mean "CP936".
62 */
63
64#include "gbkext1.h"
65#include "gbkext2.h"
66#include "gbkext_inv.h"
67#include "cp936ext.h"
68
69static int
70gbk_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
71{
72  unsigned char c = *s;
73
74  if (c >= 0x81 && c < 0xff) {
75    if (n < 2)
76      return RET_TOOFEW(0);
77    if (c >= 0xa1 && c <= 0xf7) {
78      unsigned char c2 = s[1];
79      if (c == 0xa1) {
80        if (c2 == 0xa4) {
81          *pwc = 0x00b7;
82          return 2;
83        }
84        if (c2 == 0xaa) {
85          *pwc = 0x2014;
86          return 2;
87        }
88      }
89      if (c2 >= 0xa1 && c2 < 0xff) {
90        unsigned char buf[2];
91        int ret;
92        buf[0] = c-0x80; buf[1] = c2-0x80;
93        ret = gb2312_mbtowc(conv,pwc,buf,2);
94        if (ret != RET_ILSEQ)
95          return ret;
96        buf[0] = c; buf[1] = c2;
97        ret = cp936ext_mbtowc(conv,pwc,buf,2);
98        if (ret != RET_ILSEQ)
99          return ret;
100      }
101    }
102    if (c >= 0x81 && c <= 0xa0)
103      return gbkext1_mbtowc(conv,pwc,s,2);
104    if (c >= 0xa8 && c <= 0xfe)
105      return gbkext2_mbtowc(conv,pwc,s,2);
106    if (c == 0xa2) {
107      unsigned char c2 = s[1];
108      if (c2 >= 0xa1 && c2 <= 0xaa) {
109        *pwc = 0x2170+(c2-0xa1);
110        return 2;
111      }
112    }
113  }
114  return RET_ILSEQ;
115}
116
117static int
118gbk_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
119{
120  unsigned char buf[2];
121  int ret;
122
123  if (wc != 0x30fb && wc != 0x2015) {
124    ret = gb2312_wctomb(conv,buf,wc,2);
125    if (ret != RET_ILUNI) {
126      if (ret != 2) abort();
127      if (n < 2)
128        return RET_TOOSMALL;
129      r[0] = buf[0]+0x80;
130      r[1] = buf[1]+0x80;
131      return 2;
132    }
133  }
134  ret = gbkext_inv_wctomb(conv,buf,wc,2);
135  if (ret != RET_ILUNI) {
136    if (ret != 2) abort();
137    if (n < 2)
138      return RET_TOOSMALL;
139    r[0] = buf[0];
140    r[1] = buf[1];
141    return 2;
142  }
143  if (wc >= 0x2170 && wc <= 0x2179) {
144    r[0] = 0xa2;
145    r[1] = 0xa1 + (wc-0x2170);
146    return 2;
147  }
148  ret = cp936ext_wctomb(conv,buf,wc,2);
149  if (ret != RET_ILUNI) {
150    if (ret != 2) abort();
151    if (n < 2)
152      return RET_TOOSMALL;
153    r[0] = buf[0];
154    r[1] = buf[1];
155    return 2;
156  }
157  if (wc == 0x00b7) {
158    if (n < 2)
159      return RET_TOOSMALL;
160    r[0] = 0xa1;
161    r[1] = 0xa4;
162    return 2;
163  }
164  if (wc == 0x2014) {
165    if (n < 2)
166      return RET_TOOSMALL;
167    r[0] = 0xa1;
168    r[1] = 0xaa;
169    return 2;
170  }
171
172  return RET_ILUNI;
173}
174