1/* Conversion from and to IBM937.
2 Copyright (C) 2000-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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/* IBM937 is designed for the representation of Traditional Chinese
20 using a stateful EBCDIC encoding scheme. It is also known as
21 CCSID 937 or CP937. See:
22 https://www-01.ibm.com/software/globalization/ccsid/ccsid937.html */
23
24#include <dlfcn.h>
25#include <stdint.h>
26#include <wchar.h>
27#include <byteswap.h>
28#include "ibm937.h"
29
30/* The shift sequences for this charset (it does not use ESC). */
31#define SI 0x0F /* Shift In, host code to turn DBCS off. */
32#define SO 0x0E /* Shift Out, host code to turn DBCS on. */
33
34/* Definitions used in the body of the `gconv' function. */
35#define CHARSET_NAME "IBM937//"
36#define FROM_LOOP from_ibm937
37#define TO_LOOP to_ibm937
38#define ONE_DIRECTION 0
39#define FROM_LOOP_MIN_NEEDED_FROM 1
40#define FROM_LOOP_MAX_NEEDED_FROM 2
41#define FROM_LOOP_MIN_NEEDED_TO 4
42#define FROM_LOOP_MAX_NEEDED_TO 4
43#define TO_LOOP_MIN_NEEDED_FROM 4
44#define TO_LOOP_MAX_NEEDED_FROM 4
45#define TO_LOOP_MIN_NEEDED_TO 1
46#define TO_LOOP_MAX_NEEDED_TO 3
47#define PREPARE_LOOP \
48 int save_curcs; \
49 int *curcsp = &data->__statep->__count;
50#define EXTRA_LOOP_ARGS , curcsp
51
52/* Definitions of initialization and destructor function. */
53#define DEFINE_INIT 1
54#define DEFINE_FINI 1
55
56
57/* Since this is a stateful encoding we have to provide code which resets
58 the output state to the initial state. This has to be done during the
59 flushing. */
60#define EMIT_SHIFT_TO_INIT \
61 if ((data->__statep->__count & ~7) != sb) \
62 { \
63 if (FROM_DIRECTION) \
64 data->__statep->__count &= 7; \
65 else \
66 { \
67 /* We are not in the initial state. To switch back we have \
68 to emit `SI'. */ \
69 if (__glibc_unlikely (outbuf >= outend)) \
70 /* We don't have enough room in the output buffer. */ \
71 status = __GCONV_FULL_OUTPUT; \
72 else \
73 { \
74 /* Write out the shift sequence. */ \
75 *outbuf++ = SI; \
76 data->__statep->__count &= 7; \
77 } \
78 } \
79 }
80
81
82/* Since we might have to reset input pointer we must be able to save
83 and retore the state. */
84#define SAVE_RESET_STATE(Save) \
85 if (Save) \
86 save_curcs = *curcsp; \
87 else \
88 *curcsp = save_curcs
89
90
91/* Current codeset type. */
92enum
93{
94 sb = 0,
95 db = 64
96};
97
98/* First, define the conversion function from IBM-937 to UCS4. */
99#define MIN_NEEDED_INPUT FROM_LOOP_MIN_NEEDED_FROM
100#define MAX_NEEDED_INPUT FROM_LOOP_MAX_NEEDED_FROM
101#define MIN_NEEDED_OUTPUT FROM_LOOP_MIN_NEEDED_TO
102#define MAX_NEEDED_OUTPUT FROM_LOOP_MAX_NEEDED_TO
103#define LOOPFCT FROM_LOOP
104#define BODY \
105 { \
106 uint32_t ch = *inptr; \
107 uint32_t res; \
108 \
109 if (__builtin_expect (ch, 0) == SO) \
110 { \
111 /* Shift OUT, change to DBCS converter (redundant escape okay). */ \
112 curcs = db; \
113 ++inptr; \
114 continue; \
115 } \
116 else if (__builtin_expect (ch, 0) == SI) \
117 { \
118 /* Shift IN, change to SBCS converter (redundant escape okay). */ \
119 curcs = sb; \
120 ++inptr; \
121 continue; \
122 } \
123 \
124 if (curcs == sb) \
125 { \
126 /* Use the IBM937 table for single byte. */ \
127 res = __ibm937sb_to_ucs4[ch]; \
128 if (__builtin_expect (res, L'\1') == L'\0' && ch != '\0') \
129 { \
130 /* This is an illegal character. */ \
131 STANDARD_FROM_LOOP_ERR_HANDLER (1); \
132 } \
133 else \
134 { \
135 put32 (outptr, res); \
136 outptr += 4; \
137 } \
138 ++inptr; \
139 } \
140 else \
141 { \
142 const struct gap *rp2 = __ibm937db_to_ucs4_idx; \
143 \
144 assert (curcs == db); \
145 \
146 /* Use the IBM937 table for double byte. */ \
147 if (__glibc_unlikely (inptr + 1 >= inend)) \
148 { \
149 /* The second character is not available. \
150 Store the intermediate result. */ \
151 result = __GCONV_INCOMPLETE_INPUT; \
152 break; \
153 } \
154 \
155 ch = (ch * 0x100) + inptr[1]; \
156 while (ch > rp2->end) \
157 ++rp2; \
158 \
159 if (__builtin_expect (rp2->start == 0xffff, 0) \
160 || __builtin_expect (ch < rp2->start, 0) \
161 || (res = __ibm937db_to_ucs4[ch + rp2->idx], \
162 __builtin_expect (res, L'\1') == L'\0' && ch != '\0')) \
163 { \
164 /* This is an illegal character. */ \
165 STANDARD_FROM_LOOP_ERR_HANDLER (2); \
166 } \
167 else \
168 { \
169 put32 (outptr, res); \
170 outptr += 4; \
171 } \
172 inptr += 2; \
173 } \
174 }
175#define LOOP_NEED_FLAGS
176#define EXTRA_LOOP_DECLS , int *curcsp
177#define INIT_PARAMS int curcs = *curcsp & ~7
178#define UPDATE_PARAMS *curcsp = curcs
179#include <iconv/loop.c>
180
181/* Next, define the other direction. */
182#define MIN_NEEDED_INPUT TO_LOOP_MIN_NEEDED_FROM
183#define MAX_NEEDED_INPUT TO_LOOP_MAX_NEEDED_FROM
184#define MIN_NEEDED_OUTPUT TO_LOOP_MIN_NEEDED_TO
185#define MAX_NEEDED_OUTPUT TO_LOOP_MAX_NEEDED_TO
186#define LOOPFCT TO_LOOP
187#define BODY \
188 { \
189 uint32_t ch = get32 (inptr); \
190 const struct gap *rp1 = __ucs4_to_ibm937sb_idx; \
191 const struct gap *rp2 = __ucs4_to_ibm937db_idx; \
192 const char *cp; \
193 \
194 if (__glibc_unlikely (ch >= 0xffff)) \
195 { \
196 UNICODE_TAG_HANDLER (ch, 4); \
197 \
198 STANDARD_TO_LOOP_ERR_HANDLER (4); \
199 } \
200 \
201 while (ch > rp1->end) \
202 ++rp1; \
203 \
204 /* Use the UCS4 table for single byte. */ \
205 if (__builtin_expect (ch < rp1->start, 0) \
206 || (cp = __ucs4_to_ibm937sb[ch + rp1->idx], \
207 __builtin_expect (cp[0], L'\1') == L'\0' && ch != '\0')) \
208 { \
209 /* Use the UCS4 table for double byte. */ \
210 while (ch > rp2->end) \
211 ++rp2; \
212 \
213 if (__builtin_expect (ch < rp2->start, 0) \
214 || (cp = __ucs4_to_ibm937db[ch + rp2->idx], \
215 __builtin_expect (cp[0], L'\1')==L'\0' && ch != '\0')) \
216 { \
217 /* This is an illegal character. */ \
218 STANDARD_TO_LOOP_ERR_HANDLER (4); \
219 } \
220 else \
221 { \
222 if (curcs == sb) \
223 { \
224 if (__glibc_unlikely (outptr + 1 > outend)) \
225 { \
226 result = __GCONV_FULL_OUTPUT; \
227 break; \
228 } \
229 *outptr++ = SO; \
230 curcs = db; \
231 } \
232 \
233 if (__glibc_unlikely (outptr + 2 > outend)) \
234 { \
235 result = __GCONV_FULL_OUTPUT; \
236 break; \
237 } \
238 *outptr++ = cp[0]; \
239 *outptr++ = cp[1]; \
240 } \
241 } \
242 else \
243 { \
244 if (curcs == db) \
245 { \
246 if (__glibc_unlikely (outptr + 1 > outend)) \
247 { \
248 result = __GCONV_FULL_OUTPUT; \
249 break; \
250 } \
251 *outptr++ = SI; \
252 curcs = sb; \
253 } \
254 \
255 if (__glibc_unlikely (outptr + 1 > outend)) \
256 { \
257 result = __GCONV_FULL_OUTPUT; \
258 break; \
259 } \
260 *outptr++ = cp[0]; \
261 } \
262 \
263 /* Now that we wrote the output increment the input pointer. */ \
264 inptr += 4; \
265 }
266#define LOOP_NEED_FLAGS
267#define EXTRA_LOOP_DECLS , int *curcsp
268#define INIT_PARAMS int curcs = *curcsp & ~7
269#define REINIT_PARAMS curcs = *curcsp & ~7
270#define UPDATE_PARAMS *curcsp = curcs
271#include <iconv/loop.c>
272
273/* Now define the toplevel functions. */
274#include <iconv/skeleton.c>
275