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1 /* Conversion loop frame work.
2 Copyright (C) 1998-2002, 2003 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
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, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
20
21 /* This file provides a frame for the reader loop in all conversion modules.
22 The actual code must (of course) be provided in the actual module source
23 code but certain actions can be written down generically, with some
24 customization options which are these:
25
26 MIN_NEEDED_INPUT minimal number of input bytes needed for the next
27 conversion.
28 MIN_NEEDED_OUTPUT minimal number of bytes produced by the next round
29 of conversion.
30
31 MAX_NEEDED_INPUT you guess it, this is the maximal number of input
32 bytes needed. It defaults to MIN_NEEDED_INPUT
33 MAX_NEEDED_OUTPUT likewise for output bytes.
34
35 LOOPFCT name of the function created. If not specified
36 the name is `loop' but this prevents the use
37 of multiple functions in the same file.
38
39 BODY this is supposed to expand to the body of the loop.
40 The user must provide this.
41
42 EXTRA_LOOP_DECLS extra arguments passed from converion loop call.
43
44 INIT_PARAMS code to define and initialize variables from params.
45 UPDATE_PARAMS code to store result in params.
46
47 ONEBYTE_BODY body of the specialized conversion function for a
48 single byte from the current character set to INTERNAL.
49 */
50
51 #include <assert.h>
52 #include <endian.h>
53 #include <gconv.h>
54 #include <stdint.h>
55 #include <string.h>
56 #include <wchar.h>
57 #include <sys/param.h> /* For MIN. */
58 #define __need_size_t
59 #include <stddef.h>
60
61
62 /* We have to provide support for machines which are not able to handled
63 unaligned memory accesses. Some of the character encodings have
64 representations with a fixed width of 2 or 4 bytes. But if we cannot
65 access unaligned memory we still have to read byte-wise. */
66 #undef FCTNAME2
67 #if defined _STRING_ARCH_unaligned || !defined DEFINE_UNALIGNED
68 /* We can handle unaligned memory access. */
69 # define get16(addr) *((__const uint16_t *) (addr))
70 # define get32(addr) *((__const uint32_t *) (addr))
71
72 /* We need no special support for writing values either. */
73 # define put16(addr, val) *((uint16_t *) (addr)) = (val)
74 # define put32(addr, val) *((uint32_t *) (addr)) = (val)
75
76 # define FCTNAME2(name) name
77 #else
78 /* Distinguish between big endian and little endian. */
79 # if __BYTE_ORDER == __LITTLE_ENDIAN
80 # define get16(addr) \
81 (((__const unsigned char *) (addr))[1] << 8 \
82 | ((__const unsigned char *) (addr))[0])
83 # define get32(addr) \
84 (((((__const unsigned char *) (addr))[3] << 8 \
85 | ((__const unsigned char *) (addr))[2]) << 8 \
86 | ((__const unsigned char *) (addr))[1]) << 8 \
87 | ((__const unsigned char *) (addr))[0])
88
89 # define put16(addr, val) \
90 ({ uint16_t __val = (val); \
91 ((unsigned char *) (addr))[0] = __val; \
92 ((unsigned char *) (addr))[1] = __val >> 8; \
93 (void) 0; })
94 # define put32(addr, val) \
95 ({ uint32_t __val = (val); \
96 ((unsigned char *) (addr))[0] = __val; \
97 __val >>= 8; \
98 ((unsigned char *) (addr))[1] = __val; \
99 __val >>= 8; \
100 ((unsigned char *) (addr))[2] = __val; \
101 __val >>= 8; \
102 ((unsigned char *) (addr))[3] = __val; \
103 (void) 0; })
104 # else
105 # define get16(addr) \
106 (((__const unsigned char *) (addr))[0] << 8 \
107 | ((__const unsigned char *) (addr))[1])
108 # define get32(addr) \
109 (((((__const unsigned char *) (addr))[0] << 8 \
110 | ((__const unsigned char *) (addr))[1]) << 8 \
111 | ((__const unsigned char *) (addr))[2]) << 8 \
112 | ((__const unsigned char *) (addr))[3])
113
114 # define put16(addr, val) \
115 ({ uint16_t __val = (val); \
116 ((unsigned char *) (addr))[1] = __val; \
117 ((unsigned char *) (addr))[0] = __val >> 8; \
118 (void) 0; })
119 # define put32(addr, val) \
120 ({ uint32_t __val = (val); \
121 ((unsigned char *) (addr))[3] = __val; \
122 __val >>= 8; \
123 ((unsigned char *) (addr))[2] = __val; \
124 __val >>= 8; \
125 ((unsigned char *) (addr))[1] = __val; \
126 __val >>= 8; \
127 ((unsigned char *) (addr))[0] = __val; \
128 (void) 0; })
129 # endif
130
131 # define FCTNAME2(name) name##_unaligned
132 #endif
133 #define FCTNAME(name) FCTNAME2(name)
134
135
136 /* We need at least one byte for the next round. */
137 #ifndef MIN_NEEDED_INPUT
138 # error "MIN_NEEDED_INPUT definition missing"
139 #elif MIN_NEEDED_INPUT < 1
140 # error "MIN_NEEDED_INPUT must be >= 1"
141 #endif
142
143 /* Let's see how many bytes we produce. */
144 #ifndef MAX_NEEDED_INPUT
145 # define MAX_NEEDED_INPUT MIN_NEEDED_INPUT
146 #endif
147
148 /* We produce at least one byte in the next round. */
149 #ifndef MIN_NEEDED_OUTPUT
150 # error "MIN_NEEDED_OUTPUT definition missing"
151 #elif MIN_NEEDED_OUTPUT < 1
152 # error "MIN_NEEDED_OUTPUT must be >= 1"
153 #endif
154
155 /* Let's see how many bytes we produce. */
156 #ifndef MAX_NEEDED_OUTPUT
157 # define MAX_NEEDED_OUTPUT MIN_NEEDED_OUTPUT
158 #endif
159
160 /* Default name for the function. */
161 #ifndef LOOPFCT
162 # define LOOPFCT loop
163 #endif
164
165 /* Make sure we have a loop body. */
166 #ifndef BODY
167 # error "Definition of BODY missing for function" LOOPFCT
168 #endif
169
170
171 /* If no arguments have to passed to the loop function define the macro
172 as empty. */
173 #ifndef EXTRA_LOOP_DECLS
174 # define EXTRA_LOOP_DECLS
175 #endif
176
177
178 /* To make it easier for the writers of the modules, we define a macro
179 to test whether we have to ignore errors. */
180 #define ignore_errors_p() \
181 (irreversible != NULL && (flags & __GCONV_IGNORE_ERRORS))
182
183
184 /* Error handling for the FROM_LOOP direction, with ignoring of errors.
185 Note that we cannot use the do while (0) trick since `break' and
186 `continue' must reach certain points. */
187 #define STANDARD_FROM_LOOP_ERR_HANDLER(Incr) \
188 { \
189 result = __GCONV_ILLEGAL_INPUT; \
190 \
191 if (! ignore_errors_p ()) \
192 break; \
193 \
194 /* We ignore the invalid input byte sequence. */ \
195 inptr += (Incr); \
196 ++*irreversible; \
197 /* But we keep result == __GCONV_ILLEGAL_INPUT, because of the constraint \
198 that "iconv -c" must give the same exitcode as "iconv". */ \
199 continue; \
200 }
201
202 /* Error handling for the TO_LOOP direction, with use of transliteration/
203 transcription functions and ignoring of errors. Note that we cannot use
204 the do while (0) trick since `break' and `continue' must reach certain
205 points. */
206 #define STANDARD_TO_LOOP_ERR_HANDLER(Incr) \
207 { \
208 struct __gconv_trans_data *trans; \
209 \
210 result = __GCONV_ILLEGAL_INPUT; \
211 \
212 if (irreversible == NULL) \
213 /* This means we are in call from __gconv_transliterate. In this \
214 case we are not doing any error recovery outself. */ \
215 break; \
216 \
217 /* First try the transliteration methods. */ \
218 for (trans = step_data->__trans; trans != NULL; trans = trans->__next) \
219 { \
220 result = DL_CALL_FCT (trans->__trans_fct, \
221 (step, step_data, trans->__data, *inptrp, \
222 &inptr, inend, &outptr, irreversible)); \
223 if (result != __GCONV_ILLEGAL_INPUT) \
224 break; \
225 } \
226 /* If any of them recognized the input continue with the loop. */ \
227 if (result != __GCONV_ILLEGAL_INPUT) \
228 continue; \
229 \
230 /* Next see whether we have to ignore the error. If not, stop. */ \
231 if (! ignore_errors_p ()) \
232 break; \
233 \
234 /* When we come here it means we ignore the character. */ \
235 ++*irreversible; \
236 inptr += Incr; \
237 /* But we keep result == __GCONV_ILLEGAL_INPUT, because of the constraint \
238 that "iconv -c" must give the same exitcode as "iconv". */ \
239 continue; \
240 }
241
242
243 /* Handling of Unicode 3.1 TAG characters. Unicode recommends
244 "If language codes are not relevant to the particular processing
245 operation, then they should be ignored." This macro is usually
246 called right before STANDARD_TO_LOOP_ERR_HANDLER (Incr). */
247 #define UNICODE_TAG_HANDLER(Character, Incr) \
248 { \
249 /* TAG characters are those in the range U+E0000..U+E007F. */ \
250 if (((Character) >> 7) == (0xe0000 >> 7)) \
251 { \
252 inptr += Incr; \
253 continue; \
254 } \
255 }
256
257
258 /* The function returns the status, as defined in gconv.h. */
259 static inline int
260 __attribute ((always_inline))
261 FCTNAME (LOOPFCT) (struct __gconv_step *step,
262 struct __gconv_step_data *step_data,
263 const unsigned char **inptrp, const unsigned char *inend,
264 unsigned char **outptrp, const unsigned char *outend,
265 size_t *irreversible EXTRA_LOOP_DECLS)
266 {
267 #ifdef LOOP_NEED_STATE
268 mbstate_t *state = step_data->__statep;
269 #endif
270 #ifdef LOOP_NEED_FLAGS
271 int flags = step_data->__flags;
272 #endif
273 #ifdef LOOP_NEED_DATA
274 void *data = step->__data;
275 #endif
276 int result = __GCONV_EMPTY_INPUT;
277 const unsigned char *inptr = *inptrp;
278 unsigned char *outptr = *outptrp;
279
280 #ifdef INIT_PARAMS
281 INIT_PARAMS;
282 #endif
283
284 while (inptr != inend)
285 {
286 /* `if' cases for MIN_NEEDED_OUTPUT ==/!= 1 is made to help the
287 compiler generating better code. They will be optimized away
288 since MIN_NEEDED_OUTPUT is always a constant. */
289 if (MIN_NEEDED_INPUT > 1
290 && __builtin_expect (inptr + MIN_NEEDED_INPUT > inend, 0))
291 {
292 /* We don't have enough input for another complete input
293 character. */
294 result = __GCONV_INCOMPLETE_INPUT;
295 break;
296 }
297 if ((MIN_NEEDED_OUTPUT != 1
298 && __builtin_expect (outptr + MIN_NEEDED_OUTPUT > outend, 0))
299 || (MIN_NEEDED_OUTPUT == 1
300 && __builtin_expect (outptr >= outend, 0)))
301 {
302 /* Overflow in the output buffer. */
303 result = __GCONV_FULL_OUTPUT;
304 break;
305 }
306
307 /* Here comes the body the user provides. It can stop with
308 RESULT set to GCONV_INCOMPLETE_INPUT (if the size of the
309 input characters vary in size), GCONV_ILLEGAL_INPUT, or
310 GCONV_FULL_OUTPUT (if the output characters vary in size). */
311 BODY
312 }
313
314 /* Update the pointers pointed to by the parameters. */
315 *inptrp = inptr;
316 *outptrp = outptr;
317 #ifdef UPDATE_PARAMS
318 UPDATE_PARAMS;
319 #endif
320
321 return result;
322 }
323
324
325 /* Include the file a second time to define the function to handle
326 unaligned access. */
327 #if !defined DEFINE_UNALIGNED && !defined _STRING_ARCH_unaligned \
328 && MIN_NEEDED_INPUT != 1 && MAX_NEEDED_INPUT % MIN_NEEDED_INPUT == 0 \
329 && MIN_NEEDED_OUTPUT != 1 && MAX_NEEDED_OUTPUT % MIN_NEEDED_OUTPUT == 0
330 # undef get16
331 # undef get32
332 # undef put16
333 # undef put32
334 # undef unaligned
335
336 # define DEFINE_UNALIGNED
337 # include "loop.c"
338 # undef DEFINE_UNALIGNED
339 #endif
340
341
342 #if MAX_NEEDED_INPUT > 1
343 # define SINGLE(fct) SINGLE2 (fct)
344 # define SINGLE2(fct) fct##_single
345 static inline int
346 __attribute ((always_inline))
347 SINGLE(LOOPFCT) (struct __gconv_step *step,
348 struct __gconv_step_data *step_data,
349 const unsigned char **inptrp, const unsigned char *inend,
350 unsigned char **outptrp, unsigned char *outend,
351 size_t *irreversible EXTRA_LOOP_DECLS)
352 {
353 mbstate_t *state = step_data->__statep;
354 #ifdef LOOP_NEED_FLAGS
355 int flags = step_data->__flags;
356 #endif
357 #ifdef LOOP_NEED_DATA
358 void *data = step->__data;
359 #endif
360 int result = __GCONV_OK;
361 unsigned char bytebuf[MAX_NEEDED_INPUT];
362 const unsigned char *inptr = *inptrp;
363 unsigned char *outptr = *outptrp;
364 size_t inlen;
365
366 #ifdef INIT_PARAMS
367 INIT_PARAMS;
368 #endif
369
370 #ifdef UNPACK_BYTES
371 UNPACK_BYTES
372 #else
373 /* Add the bytes from the state to the input buffer. */
374 for (inlen = 0; inlen < (size_t) (state->__count & 7); ++inlen)
375 bytebuf[inlen] = state->__value.__wchb[inlen];
376 #endif
377
378 /* Are there enough bytes in the input buffer? */
379 if (__builtin_expect (inptr + (MIN_NEEDED_INPUT - inlen) > inend, 0))
380 {
381 *inptrp = inend;
382 #ifdef STORE_REST
383 inptr = bytebuf;
384 inptrp = &inptr;
385 inend = &bytebuf[inlen];
386
387 STORE_REST
388 #else
389 /* We don't have enough input for another complete input
390 character. */
391 while (inptr < inend)
392 state->__value.__wchb[inlen++] = *inptr++;
393 #endif
394
395 return __GCONV_INCOMPLETE_INPUT;
396 }
397
398 /* Enough space in output buffer. */
399 if ((MIN_NEEDED_OUTPUT != 1 && outptr + MIN_NEEDED_OUTPUT > outend)
400 || (MIN_NEEDED_OUTPUT == 1 && outptr >= outend))
401 /* Overflow in the output buffer. */
402 return __GCONV_FULL_OUTPUT;
403
404 /* Now add characters from the normal input buffer. */
405 do
406 bytebuf[inlen++] = *inptr++;
407 while (inlen < MAX_NEEDED_INPUT && inptr < inend);
408
409 inptr = bytebuf;
410 inend = &bytebuf[inlen];
411
412 do
413 {
414 BODY
415 }
416 while (0);
417
418 /* Now we either have produced an output character and consumed all the
419 bytes from the state and at least one more, or the character is still
420 incomplete, or we have some other error (like illegal input character,
421 no space in output buffer). */
422 if (__builtin_expect (inptr != bytebuf, 1))
423 {
424 /* We found a new character. */
425 assert (inptr - bytebuf > (state->__count & 7));
426
427 *inptrp += inptr - bytebuf - (state->__count & 7);
428 *outptrp = outptr;
429
430 result = __GCONV_OK;
431
432 /* Clear the state buffer. */
433 #ifdef CLEAR_STATE
434 CLEAR_STATE;
435 #else
436 state->__count &= ~7;
437 #endif
438 }
439 else if (result == __GCONV_INCOMPLETE_INPUT)
440 {
441 /* This can only happen if we have less than MAX_NEEDED_INPUT bytes
442 available. */
443 assert (inend != &bytebuf[MAX_NEEDED_INPUT]);
444
445 *inptrp += inend - bytebuf - (state->__count & 7);
446 #ifdef STORE_REST
447 inptrp = &inptr;
448
449 STORE_REST
450 #else
451 /* We don't have enough input for another complete input
452 character. */
453 while (inptr < inend)
454 state->__value.__wchb[inlen++] = *inptr++;
455 #endif
456 }
457
458 return result;
459 }
460 # undef SINGLE
461 # undef SINGLE2
462 #endif
463
464
465 #ifdef ONEBYTE_BODY
466 /* Define the shortcut function for btowc. */
467 static wint_t
468 gconv_btowc (struct __gconv_step *step, unsigned char c)
469 ONEBYTE_BODY
470 # define FROM_ONEBYTE gconv_btowc
471 #endif
472
473
474 /* We remove the macro definitions so that we can include this file again
475 for the definition of another function. */
476 #undef MIN_NEEDED_INPUT
477 #undef MAX_NEEDED_INPUT
478 #undef MIN_NEEDED_OUTPUT
479 #undef MAX_NEEDED_OUTPUT
480 #undef LOOPFCT
481 #undef BODY
482 #undef LOOPFCT
483 #undef EXTRA_LOOP_DECLS
484 #undef INIT_PARAMS
485 #undef UPDATE_PARAMS
486 #undef ONEBYTE_BODY
487 #undef UNPACK_BYTES
488 #undef CLEAR_STATE
489 #undef LOOP_NEED_STATE
490 #undef LOOP_NEED_FLAGS
491 #undef LOOP_NEED_DATA
492 #undef get16
493 #undef get32
494 #undef put16
495 #undef put32
496 #undef unaligned