about summary refs log tree commit diff
path: root/iconvdata/iso-2022-cn.c
blob: 5ffbfa565e0ab0a9ef66625f02828fc72c0ab2ac (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
/* Conversion module for ISO-2022-CN.
   Copyright (C) 1999, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <gconv.h>
#include <stdint.h>
#include <string.h>
#include "gb2312.h"
#include "cns11643l1.h"
#include "cns11643l2.h"

#include <assert.h>

/* This makes obvious what everybody knows: 0x1b is the Esc character.  */
#define ESC	0x1b

/* We have single-byte shift-in and shift-out sequences, and the single
   shift sequence SS2 which replaces the SS2 designation for the next
   two bytes.  */
#define SI	0x0f
#define SO	0x0e
#define SS2_0	ESC
#define SS2_1	0x4e

/* Definitions used in the body of the `gconv' function.  */
#define CHARSET_NAME		"ISO-2022-CN//"
#define DEFINE_INIT		1
#define DEFINE_FINI		1
#define FROM_LOOP		from_iso2022cn_loop
#define TO_LOOP			to_iso2022cn_loop
#define MIN_NEEDED_FROM		1
#define MAX_NEEDED_FROM		4
#define MIN_NEEDED_TO		4
#define MAX_NEEDED_TO		4
#define PREPARE_LOOP \
  int save_set;								      \
  int *setp = &data->__statep->__count;
#define EXTRA_LOOP_ARGS		, setp


/* The COUNT element of the state keeps track of the currently selected
   character set.  The possible values are:  */
enum
{
  ASCII_set = 0,
  GB2312_set = 8,
  CNS11643_1_set = 16,
  CNS11643_2_set = 24,
  CURRENT_SEL_MASK = 24,
  GB2312_ann = 32,
  CNS11643_1_ann = 64,
  CNS11643_2_ann = 128,
  CURRENT_ANN_MASK = 224
};


/* Since this is a stateful encoding we have to provide code which resets
   the output state to the initial state.  This has to be done during the
   flushing.  */
#define EMIT_SHIFT_TO_INIT \
  if (data->__statep->__count != ASCII_set)				      \
    {									      \
      if (FROM_DIRECTION)						      \
	/* It's easy, we don't have to emit anything, we just reset the	      \
	   state for the input.  */					      \
	data->__statep->__count = ASCII_set;				      \
      else								      \
	{								      \
	  unsigned char *outbuf = data->__outbuf;			      \
	  								      \
	  /* We are not in the initial state.  To switch back we have	      \
	     to emit `SI'.  */						      \
	  if (outbuf == data->__outbufend)				      \
	    /* We don't have enough room in the output buffer.  */	      \
	    status = __GCONV_FULL_OUTPUT;				      \
	  else								      \
	    {								      \
	      /* Write out the shift sequence.  */			      \
	      *outbuf++ = SI;						      \
	      if (data->__is_last)					      \
		*written += 1;						      \
	      data->__outbuf = outbuf;					      \
	      data->__statep->__count = ASCII_set;			      \
	    }								      \
	}								      \
    }


/* Since we might have to reset input pointer we must be able to save
   and retore the state.  */
#define SAVE_RESET_STATE(Save) \
  if (Save)								      \
    save_set = *setp;							      \
  else									      \
    *setp = save_set


/* First define the conversion function from ISO-2022-CN to UCS4.  */
#define MIN_NEEDED_INPUT	MIN_NEEDED_FROM
#define MAX_NEEDED_INPUT	MAX_NEEDED_FROM
#define MIN_NEEDED_OUTPUT	MIN_NEEDED_TO
#define LOOPFCT			FROM_LOOP
#define BODY \
  {									      \
    uint32_t ch = *inptr;						      \
									      \
    /* This is a 7bit character set, disallow all 8bit characters.  */	      \
    if (ch > 0x7f)							      \
      {									      \
	result = __GCONV_ILLEGAL_INPUT;					      \
	break;								      \
      }									      \
									      \
    /* Recognize escape sequences.  */					      \
    if (ch == ESC)							      \
      {									      \
	/* There are two kinds of escape sequences we have to handle:	      \
	   - those announcing the use of GB and CNS characters on the	      \
	     line; we can simply ignore them				      \
	   - the initial byte of the SS2 sequence.			      \
	*/								      \
	if (NEED_LENGTH_TEST						      \
	    && (inptr + 1 > inend					      \
		|| (inptr[1] == '$'					      \
		    && (inptr + 2 > inend				      \
			|| (inptr[2] == ')' && inptr + 3 > inend)	      \
			|| (inptr[2] == '*' && inptr + 3 > inend)))	      \
		|| (inptr[1] == SS2_1 && inptr + 3 > inend)))		      \
	  {								      \
	    result = __GCONV_EMPTY_INPUT;				      \
	    break;							      \
	  }								      \
	if (inptr[1] == '$'						      \
	    && ((inptr[2] == ')' && (inptr[3] == 'A' || inptr[3] == 'G'))     \
		|| (inptr[2] == '*' && inptr[3] == 'H')))		      \
	  {								      \
	    /* OK, we accept those character sets.  */			      \
	    if (inptr[3] == 'A')					      \
	      ann = GB2312_ann;						      \
	    else if (inptr[3] == 'G')					      \
	      ann = CNS11643_1_ann;					      \
	    inptr += 4;							      \
	    continue;							      \
	  }								      \
      }									      \
    else if (ch == SO)							      \
      {									      \
	/* Switch to use GB2312 or CNS 11643 plane 1, depending on which      \
	   S0 designation came last.  The only problem is what to do with     \
	   faulty input files where no designator came.			      \
	   XXX For now I'll default to use GB2312.  If this is not the	      \
	   best behaviour (e.g., we should flag an error) let me know.  */    \
	++inptr;							      \
	set = ann == CNS11643_1_ann ? CNS11643_1_set : GB2312_set;	      \
	continue;							      \
      }									      \
    else if (ch == SI)							      \
      {									      \
	/* Switch to use ASCII.  */					      \
	++inptr;							      \
	set = ASCII_set;						      \
	continue;							      \
      }									      \
									      \
    if (ch == ESC && inptr[1] == SS2_1)					      \
      {									      \
	/* This is a character from CNS 11643 plane 2.			      \
	   XXX We could test here whether the use of this character	      \
	   set was announced.  */					      \
	inptr += 2;							      \
	ch = cns11643l2_to_ucs4 (&inptr, 2, 0);				      \
	if (ch == __UNKNOWN_10646_CHAR)					      \
	  {								      \
	    inptr -= 2;							      \
	    result = __GCONV_ILLEGAL_INPUT;				      \
	    break;							      \
	  }								      \
      }									      \
    else if (set == ASCII_set)						      \
      {									      \
	/* Almost done, just advance the input pointer.  */		      \
	++inptr;							      \
      }									      \
    else								      \
      {									      \
	/* That's pretty easy, we have a dedicated functions for this.  */    \
	if (set == GB2312_set)						      \
	  ch = gb2312_to_ucs4 (&inptr,					      \
			       NEED_LENGTH_TEST ? inend - inptr : 2, 0);      \
	else								      \
	  {								      \
	    assert (set == CNS11643_1_set);				      \
	    ch = cns11643l1_to_ucs4 (&inptr,				      \
				     NEED_LENGTH_TEST ? inend - inptr : 2, 0);\
	  }								      \
									      \
	if (NEED_LENGTH_TEST && ch == 0)				      \
	  {								      \
	    result = __GCONV_EMPTY_INPUT;				      \
	    break;							      \
	  }								      \
	else if (ch == __UNKNOWN_10646_CHAR)				      \
	  {								      \
	    result = __GCONV_ILLEGAL_INPUT;				      \
	    break;							      \
	  }								      \
      }									      \
									      \
    put32 (outptr, ch);							      \
    outptr += 4;							      \
  }
#define EXTRA_LOOP_DECLS	, int *setp
#define INIT_PARAMS		int set = *setp & CURRENT_SEL_MASK; \
				int ann = *setp & CURRENT_ANN_MASK
#define UPDATE_PARAMS		*setp = set | ann
#include <iconv/loop.c>


/* Next, define the other direction.  */
#define MIN_NEEDED_INPUT	MIN_NEEDED_TO
#define MIN_NEEDED_OUTPUT	MIN_NEEDED_FROM
#define MAX_NEEDED_OUTPUT	MAX_NEEDED_FROM
#define LOOPFCT			TO_LOOP
#define BODY \
  {									      \
    uint32_t ch;							      \
    size_t written = 0;							      \
									      \
    ch = get32 (inptr);							      \
									      \
    /* First see whether we can write the character using the currently	      \
       selected character set.  */					      \
    if (ch < 0x80)							      \
      {									      \
	if (set != ASCII_set)						      \
	  {								      \
	    *outptr++ = SI;						      \
	    set = ASCII_set;						      \
	    if (NEED_LENGTH_TEST && outptr == outend)			      \
	      {								      \
		result = __GCONV_FULL_OUTPUT;				      \
		break;							      \
	      }								      \
	  }								      \
									      \
	*outptr++ = ch;							      \
	written = 1;							      \
									      \
	/* At the end of the line we have to clear the `ann' flags since      \
	   every line must contain this information again.  */		      \
	if (ch == L'\n')						      \
	  ann = 0;							      \
      }									      \
    else								      \
      {									      \
	char buf[2];							      \
	int used;							      \
									      \
	if (set == GB2312_set || (ann & CNS11643_1_ann) == 0)		      \
	  {								      \
	    written = ucs4_to_gb2312 (ch, buf, 2);			      \
	    used = GB2312_set;						      \
	  }								      \
	else								      \
	  {								      \
	    written = ucs4_to_cns11643l1 (ch, buf, 2);			      \
	    used = CNS11643_1_set;					      \
	  }								      \
									      \
	if (written == __UNKNOWN_10646_CHAR)				      \
	  {								      \
	    /* Cannot convert it using the currently selected SO set.	      \
	       Next try the SS2 set.  */				      \
	    written = ucs4_to_cns11643l2 (ch, buf, 2);			      \
	    if (written != __UNKNOWN_10646_CHAR)			      \
	      /* Yep, that worked.  */					      \
	      used = CNS11643_2_set;					      \
	    else							      \
	      {								      \
		/* Well, see whether we have to change the SO set.  */	      \
		if (set == GB2312_set)					      \
		  written = ucs4_to_cns11643l1 (ch, buf, 2);		      \
		else							      \
		  written = ucs4_to_gb2312 (ch, buf, 2);		      \
									      \
		if (written != __UNKNOWN_10646_CHAR)			      \
		  /* Oh well, then switch SO.  */			      \
		  used = GB2312_set + CNS11643_1_set - set;		      \
		else							      \
		  {							      \
		    /* Even this does not work.  Error.  */		      \
		    result = __GCONV_ILLEGAL_INPUT;			      \
		    break;						      \
		  }							      \
	      }								      \
	  }								      \
	assert (written == 2);						      \
									      \
	/* See whether we have to emit an escape sequence.  */		      \
	if (set != used)						      \
	  {								      \
	    /* First see whether we announced that we use this		      \
	       character set.  */					      \
	    if ((ann & (2 << used)) == 0)				      \
	      {								      \
		const char *escseq;					      \
									      \
		if (NEED_LENGTH_TEST && outptr + 4 > outend)		      \
		  {							      \
		    result = __GCONV_FULL_OUTPUT;			      \
		    break;						      \
		  }							      \
									      \
		assert (used >= 1 && used <= 3);			      \
		escseq = "\e$)A\e$)G\e$*H" + (used - 1) * 4;		      \
		*outptr++ = *escseq++;					      \
		*outptr++ = *escseq++;					      \
		*outptr++ = *escseq++;					      \
		*outptr++ = *escseq++;					      \
									      \
		if (used == GB2312_set)					      \
		  ann = (ann & CNS11643_2_ann) | GB2312_ann;		      \
		else if (used == CNS11643_1_set)			      \
		  ann = (ann & CNS11643_2_ann) | CNS11643_1_ann;	      \
		else							      \
		  ann |= CNS11643_2_ann;				      \
	      }								      \
									      \
	    if (used == CNS11643_2_set)					      \
	      {								      \
		if (outptr + 2 > outend)				      \
		  {							      \
		    result = __GCONV_FULL_OUTPUT;			      \
		    break;						      \
		  }							      \
		*outptr++ = SS2_0;					      \
		*outptr++ = SS2_1;					      \
	      }								      \
	    else							      \
	      {								      \
		/* We only have to emit something is currently ASCII is	      \
		   selected.  Otherwise we are switching within the	      \
		   SO charset.  */					      \
		if (set == ASCII_set)					      \
		  {							      \
		    if (outptr + 1 > outend)				      \
		      {							      \
			result = __GCONV_FULL_OUTPUT;			      \
			break;						      \
		      }							      \
		    *outptr++ = SO;					      \
		  }							      \
	      }								      \
									      \
	    /* Always test the length here since we have used up all the      \
	       guaranteed output buffer slots.  */			      \
	    if (outptr + 2 > outend)					      \
	      {								      \
		result = __GCONV_FULL_OUTPUT;				      \
		break;							      \
	      }								      \
	  }								      \
	else if (NEED_LENGTH_TEST && outptr + 2 > outend)		      \
	  {								      \
	    result = __GCONV_FULL_OUTPUT;				      \
	    break;							      \
	  }								      \
									      \
	*outptr++ = buf[0];						      \
	*outptr++ = buf[1];						      \
      }									      \
									      \
    /* Now that we wrote the output increment the input pointer.  */	      \
    inptr += 4;								      \
  }
#define EXTRA_LOOP_DECLS	, int *setp
#define INIT_PARAMS		int set = *setp & CURRENT_SEL_MASK; \
				int ann = *setp & CURRENT_ANN_MASK
#define UPDATE_PARAMS		*setp = set | ann
#include <iconv/loop.c>


/* Now define the toplevel functions.  */
#include <iconv/skeleton.c>