1/* Conversion loop frame work.
2 Copyright (C) 1998-2016 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, see
18 <http://www.gnu.org/licenses/>. */
19
20/* This file provides a frame for the reader loop in all conversion modules.
21 The actual code must (of course) be provided in the actual module source
22 code but certain actions can be written down generically, with some
23 customization options which are these:
24
25 MIN_NEEDED_INPUT minimal number of input bytes needed for the next
26 conversion.
27 MIN_NEEDED_OUTPUT minimal number of bytes produced by the next round
28 of conversion.
29
30 MAX_NEEDED_INPUT you guess it, this is the maximal number of input
31 bytes needed. It defaults to MIN_NEEDED_INPUT
32 MAX_NEEDED_OUTPUT likewise for output bytes.
33
34 LOOPFCT name of the function created. If not specified
35 the name is `loop' but this prevents the use
36 of multiple functions in the same file.
37
38 BODY this is supposed to expand to the body of the loop.
39 The user must provide this.
40
41 EXTRA_LOOP_DECLS extra arguments passed from conversion loop call.
42
43 INIT_PARAMS code to define and initialize variables from params.
44 UPDATE_PARAMS code to store result in params.
45
46 ONEBYTE_BODY body of the specialized conversion function for a
47 single byte from the current character set to INTERNAL.
48*/
49
50#include <assert.h>
51#include <endian.h>
52#include <gconv.h>
53#include <stdint.h>
54#include <string.h>
55#include <wchar.h>
56#include <sys/param.h> /* For MIN. */
57#define __need_size_t
58#include <stddef.h>
59#include <libc-internal.h>
60
61/* We have to provide support for machines which are not able to handled
62 unaligned memory accesses. Some of the character encodings have
63 representations with a fixed width of 2 or 4 bytes. But if we cannot
64 access unaligned memory we still have to read byte-wise. */
65#undef FCTNAME2
66#if _STRING_ARCH_unaligned || !defined DEFINE_UNALIGNED
67/* We can handle unaligned memory access. */
68# define get16(addr) *((const uint16_t *) (addr))
69# define get32(addr) *((const uint32_t *) (addr))
70
71/* We need no special support for writing values either. */
72# define put16(addr, val) *((uint16_t *) (addr)) = (val)
73# define put32(addr, val) *((uint32_t *) (addr)) = (val)
74
75# define FCTNAME2(name) name
76#else
77/* Distinguish between big endian and little endian. */
78# if __BYTE_ORDER == __LITTLE_ENDIAN
79# define get16(addr) \
80 (((const unsigned char *) (addr))[1] << 8 \
81 | ((const unsigned char *) (addr))[0])
82# define get32(addr) \
83 (((((const unsigned char *) (addr))[3] << 8 \
84 | ((const unsigned char *) (addr))[2]) << 8 \
85 | ((const unsigned char *) (addr))[1]) << 8 \
86 | ((const unsigned char *) (addr))[0])
87
88# define put16(addr, val) \
89 ({ uint16_t __val = (val); \
90 ((unsigned char *) (addr))[0] = __val; \
91 ((unsigned char *) (addr))[1] = __val >> 8; \
92 (void) 0; })
93# define put32(addr, val) \
94 ({ uint32_t __val = (val); \
95 ((unsigned char *) (addr))[0] = __val; \
96 __val >>= 8; \
97 ((unsigned char *) (addr))[1] = __val; \
98 __val >>= 8; \
99 ((unsigned char *) (addr))[2] = __val; \
100 __val >>= 8; \
101 ((unsigned char *) (addr))[3] = __val; \
102 (void) 0; })
103# else
104# define get16(addr) \
105 (((const unsigned char *) (addr))[0] << 8 \
106 | ((const unsigned char *) (addr))[1])
107# define get32(addr) \
108 (((((const unsigned char *) (addr))[0] << 8 \
109 | ((const unsigned char *) (addr))[1]) << 8 \
110 | ((const unsigned char *) (addr))[2]) << 8 \
111 | ((const unsigned char *) (addr))[3])
112
113# define put16(addr, val) \
114 ({ uint16_t __val = (val); \
115 ((unsigned char *) (addr))[1] = __val; \
116 ((unsigned char *) (addr))[0] = __val >> 8; \
117 (void) 0; })
118# define put32(addr, val) \
119 ({ uint32_t __val = (val); \
120 ((unsigned char *) (addr))[3] = __val; \
121 __val >>= 8; \
122 ((unsigned char *) (addr))[2] = __val; \
123 __val >>= 8; \
124 ((unsigned char *) (addr))[1] = __val; \
125 __val >>= 8; \
126 ((unsigned char *) (addr))[0] = __val; \
127 (void) 0; })
128# endif
129
130# define FCTNAME2(name) name##_unaligned
131#endif
132#define FCTNAME(name) FCTNAME2(name)
133
134
135/* We need at least one byte for the next round. */
136#ifndef MIN_NEEDED_INPUT
137# error "MIN_NEEDED_INPUT definition missing"
138#elif MIN_NEEDED_INPUT < 1
139# error "MIN_NEEDED_INPUT must be >= 1"
140#endif
141
142/* Let's see how many bytes we produce. */
143#ifndef MAX_NEEDED_INPUT
144# define MAX_NEEDED_INPUT MIN_NEEDED_INPUT
145#endif
146
147/* We produce at least one byte in the next round. */
148#ifndef MIN_NEEDED_OUTPUT
149# error "MIN_NEEDED_OUTPUT definition missing"
150#elif MIN_NEEDED_OUTPUT < 1
151# error "MIN_NEEDED_OUTPUT must be >= 1"
152#endif
153
154/* Let's see how many bytes we produce. */
155#ifndef MAX_NEEDED_OUTPUT
156# define MAX_NEEDED_OUTPUT MIN_NEEDED_OUTPUT
157#endif
158
159/* Default name for the function. */
160#ifndef LOOPFCT
161# define LOOPFCT loop
162#endif
163
164/* Make sure we have a loop body. */
165#ifndef BODY
166# error "Definition of BODY missing for function" LOOPFCT
167#endif
168
169
170/* If no arguments have to passed to the loop function define the macro
171 as empty. */
172#ifndef EXTRA_LOOP_DECLS
173# define EXTRA_LOOP_DECLS
174#endif
175
176/* Allow using UPDATE_PARAMS in macros where #ifdef UPDATE_PARAMS test
177 isn't possible. */
178#ifndef UPDATE_PARAMS
179# define UPDATE_PARAMS do { } while (0)
180#endif
181#ifndef REINIT_PARAMS
182# define REINIT_PARAMS do { } while (0)
183#endif
184
185
186/* To make it easier for the writers of the modules, we define a macro
187 to test whether we have to ignore errors. */
188#define ignore_errors_p() \
189 (irreversible != NULL && (flags & __GCONV_IGNORE_ERRORS))
190
191
192/* Error handling for the FROM_LOOP direction, with ignoring of errors.
193 Note that we cannot use the do while (0) trick since `break' and
194 `continue' must reach certain points. */
195#define STANDARD_FROM_LOOP_ERR_HANDLER(Incr) \
196 { \
197 result = __GCONV_ILLEGAL_INPUT; \
198 \
199 if (! ignore_errors_p ()) \
200 break; \
201 \
202 /* We ignore the invalid input byte sequence. */ \
203 inptr += (Incr); \
204 ++*irreversible; \
205 /* But we keep result == __GCONV_ILLEGAL_INPUT, because of the constraint \
206 that "iconv -c" must give the same exitcode as "iconv". */ \
207 continue; \
208 }
209
210/* Error handling for the TO_LOOP direction, with use of transliteration/
211 transcription functions and ignoring of errors. Note that we cannot use
212 the do while (0) trick since `break' and `continue' must reach certain
213 points. */
214#define STANDARD_TO_LOOP_ERR_HANDLER(Incr) \
215 { \
216 result = __GCONV_ILLEGAL_INPUT; \
217 \
218 if (irreversible == NULL) \
219 /* This means we are in call from __gconv_transliterate. In this \
220 case we are not doing any error recovery outself. */ \
221 break; \
222 \
223 /* If needed, flush any conversion state, so that __gconv_transliterate \
224 starts with current shift state. */ \
225 UPDATE_PARAMS; \
226 \
227 /* First try the transliteration methods. */ \
228 if ((step_data->__flags & __GCONV_TRANSLIT) != 0) \
229 result = __gconv_transliterate \
230 (step, step_data, *inptrp, \
231 &inptr, inend, &outptr, irreversible); \
232 \
233 REINIT_PARAMS; \
234 \
235 /* If any of them recognized the input continue with the loop. */ \
236 if (result != __GCONV_ILLEGAL_INPUT) \
237 { \
238 if (__glibc_unlikely (result == __GCONV_FULL_OUTPUT)) \
239 break; \
240 \
241 continue; \
242 } \
243 \
244 /* Next see whether we have to ignore the error. If not, stop. */ \
245 if (! ignore_errors_p ()) \
246 break; \
247 \
248 /* When we come here it means we ignore the character. */ \
249 ++*irreversible; \
250 inptr += Incr; \
251 /* But we keep result == __GCONV_ILLEGAL_INPUT, because of the constraint \
252 that "iconv -c" must give the same exitcode as "iconv". */ \
253 continue; \
254 }
255
256
257/* Handling of Unicode 3.1 TAG characters. Unicode recommends
258 "If language codes are not relevant to the particular processing
259 operation, then they should be ignored." This macro is usually
260 called right before STANDARD_TO_LOOP_ERR_HANDLER (Incr). */
261#define UNICODE_TAG_HANDLER(Character, Incr) \
262 { \
263 /* TAG characters are those in the range U+E0000..U+E007F. */ \
264 if (((Character) >> 7) == (0xe0000 >> 7)) \
265 { \
266 inptr += Incr; \
267 continue; \
268 } \
269 }
270
271
272/* The function returns the status, as defined in gconv.h. */
273static inline int
274__attribute ((always_inline))
275FCTNAME (LOOPFCT) (struct __gconv_step *step,
276 struct __gconv_step_data *step_data,
277 const unsigned char **inptrp, const unsigned char *inend,
278 unsigned char **outptrp, const unsigned char *outend,
279 size_t *irreversible EXTRA_LOOP_DECLS)
280{
281#ifdef LOOP_NEED_STATE
282 mbstate_t *state = step_data->__statep;
283#endif
284#ifdef LOOP_NEED_FLAGS
285 int flags = step_data->__flags;
286#endif
287#ifdef LOOP_NEED_DATA
288 void *data = step->__data;
289#endif
290 int result = __GCONV_EMPTY_INPUT;
291 const unsigned char *inptr = *inptrp;
292 unsigned char *outptr = *outptrp;
293
294#ifdef INIT_PARAMS
295 INIT_PARAMS;
296#endif
297
298 while (inptr != inend)
299 {
300 /* `if' cases for MIN_NEEDED_OUTPUT ==/!= 1 is made to help the
301 compiler generating better code. They will be optimized away
302 since MIN_NEEDED_OUTPUT is always a constant. */
303 if (MIN_NEEDED_INPUT > 1
304 && __builtin_expect (inptr + MIN_NEEDED_INPUT > inend, 0))
305 {
306 /* We don't have enough input for another complete input
307 character. */
308 result = __GCONV_INCOMPLETE_INPUT;
309 break;
310 }
311 if ((MIN_NEEDED_OUTPUT != 1
312 && __builtin_expect (outptr + MIN_NEEDED_OUTPUT > outend, 0))
313 || (MIN_NEEDED_OUTPUT == 1
314 && __builtin_expect (outptr >= outend, 0)))
315 {
316 /* Overflow in the output buffer. */
317 result = __GCONV_FULL_OUTPUT;
318 break;
319 }
320
321 /* Here comes the body the user provides. It can stop with
322 RESULT set to GCONV_INCOMPLETE_INPUT (if the size of the
323 input characters vary in size), GCONV_ILLEGAL_INPUT, or
324 GCONV_FULL_OUTPUT (if the output characters vary in size). */
325 BODY
326 }
327
328 /* Update the pointers pointed to by the parameters. */
329 *inptrp = inptr;
330 *outptrp = outptr;
331 UPDATE_PARAMS;
332
333 return result;
334}
335
336
337/* Include the file a second time to define the function to handle
338 unaligned access. */
339#if !defined DEFINE_UNALIGNED && !_STRING_ARCH_unaligned \
340 && MIN_NEEDED_INPUT != 1 && MAX_NEEDED_INPUT % MIN_NEEDED_INPUT == 0 \
341 && MIN_NEEDED_OUTPUT != 1 && MAX_NEEDED_OUTPUT % MIN_NEEDED_OUTPUT == 0
342# undef get16
343# undef get32
344# undef put16
345# undef put32
346# undef unaligned
347
348# define DEFINE_UNALIGNED
349# include "loop.c"
350# undef DEFINE_UNALIGNED
351#else
352# if MAX_NEEDED_INPUT > 1
353# define SINGLE(fct) SINGLE2 (fct)
354# define SINGLE2(fct) fct##_single
355static inline int
356__attribute ((always_inline))
357SINGLE(LOOPFCT) (struct __gconv_step *step,
358 struct __gconv_step_data *step_data,
359 const unsigned char **inptrp, const unsigned char *inend,
360 unsigned char **outptrp, unsigned char *outend,
361 size_t *irreversible EXTRA_LOOP_DECLS)
362{
363 mbstate_t *state = step_data->__statep;
364# ifdef LOOP_NEED_FLAGS
365 int flags = step_data->__flags;
366# endif
367# ifdef LOOP_NEED_DATA
368 void *data = step->__data;
369# endif
370 int result = __GCONV_OK;
371 unsigned char bytebuf[MAX_NEEDED_INPUT];
372 const unsigned char *inptr = *inptrp;
373 unsigned char *outptr = *outptrp;
374 size_t inlen;
375
376# ifdef INIT_PARAMS
377 INIT_PARAMS;
378# endif
379
380# ifdef UNPACK_BYTES
381 UNPACK_BYTES
382# else
383 /* Add the bytes from the state to the input buffer. */
384 assert ((state->__count & 7) <= sizeof (state->__value));
385 for (inlen = 0; inlen < (size_t) (state->__count & 7); ++inlen)
386 bytebuf[inlen] = state->__value.__wchb[inlen];
387# endif
388
389 /* Are there enough bytes in the input buffer? */
390 if (MIN_NEEDED_INPUT > 1
391 && __builtin_expect (inptr + (MIN_NEEDED_INPUT - inlen) > inend, 0))
392 {
393 *inptrp = inend;
394# ifdef STORE_REST
395
396 /* Building with -O3 GCC emits a `array subscript is above array
397 bounds' warning. GCC BZ #64739 has been opened for this. */
398 DIAG_PUSH_NEEDS_COMMENT;
399 DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Warray-bounds");
400 while (inptr < inend)
401 bytebuf[inlen++] = *inptr++;
402 DIAG_POP_NEEDS_COMMENT;
403
404 inptr = bytebuf;
405 inptrp = &inptr;
406 inend = &bytebuf[inlen];
407
408 STORE_REST
409# else
410 /* We don't have enough input for another complete input
411 character. */
412 while (inptr < inend)
413 state->__value.__wchb[inlen++] = *inptr++;
414# endif
415
416 return __GCONV_INCOMPLETE_INPUT;
417 }
418
419 /* Enough space in output buffer. */
420 if ((MIN_NEEDED_OUTPUT != 1 && outptr + MIN_NEEDED_OUTPUT > outend)
421 || (MIN_NEEDED_OUTPUT == 1 && outptr >= outend))
422 /* Overflow in the output buffer. */
423 return __GCONV_FULL_OUTPUT;
424
425 /* Now add characters from the normal input buffer. */
426 do
427 bytebuf[inlen++] = *inptr++;
428 while (inlen < MAX_NEEDED_INPUT && inptr < inend);
429
430 inptr = bytebuf;
431 inend = &bytebuf[inlen];
432
433 do
434 {
435 BODY
436 }
437 while (0);
438
439 /* Now we either have produced an output character and consumed all the
440 bytes from the state and at least one more, or the character is still
441 incomplete, or we have some other error (like illegal input character,
442 no space in output buffer). */
443 if (__glibc_likely (inptr != bytebuf))
444 {
445 /* We found a new character. */
446 assert (inptr - bytebuf > (state->__count & 7));
447
448 *inptrp += inptr - bytebuf - (state->__count & 7);
449 *outptrp = outptr;
450
451 result = __GCONV_OK;
452
453 /* Clear the state buffer. */
454# ifdef CLEAR_STATE
455 CLEAR_STATE;
456# else
457 state->__count &= ~7;
458# endif
459 }
460 else if (result == __GCONV_INCOMPLETE_INPUT)
461 {
462 /* This can only happen if we have less than MAX_NEEDED_INPUT bytes
463 available. */
464 assert (inend != &bytebuf[MAX_NEEDED_INPUT]);
465
466 *inptrp += inend - bytebuf - (state->__count & 7);
467# ifdef STORE_REST
468 inptrp = &inptr;
469
470 STORE_REST
471# else
472 /* We don't have enough input for another complete input
473 character. */
474 assert (inend - inptr > (state->__count & ~7));
475 assert (inend - inptr <= sizeof (state->__value));
476 state->__count = (state->__count & ~7) | (inend - inptr);
477 inlen = 0;
478 while (inptr < inend)
479 state->__value.__wchb[inlen++] = *inptr++;
480# endif
481 }
482
483 return result;
484}
485# undef SINGLE
486# undef SINGLE2
487# endif
488
489
490# ifdef ONEBYTE_BODY
491/* Define the shortcut function for btowc. */
492static wint_t
493gconv_btowc (struct __gconv_step *step, unsigned char c)
494 ONEBYTE_BODY
495# define FROM_ONEBYTE gconv_btowc
496# endif
497
498#endif
499
500/* We remove the macro definitions so that we can include this file again
501 for the definition of another function. */
502#undef MIN_NEEDED_INPUT
503#undef MAX_NEEDED_INPUT
504#undef MIN_NEEDED_OUTPUT
505#undef MAX_NEEDED_OUTPUT
506#undef LOOPFCT
507#undef BODY
508#undef LOOPFCT
509#undef EXTRA_LOOP_DECLS
510#undef INIT_PARAMS
511#undef UPDATE_PARAMS
512#undef REINIT_PARAMS
513#undef ONEBYTE_BODY
514#undef UNPACK_BYTES
515#undef CLEAR_STATE
516#undef LOOP_NEED_STATE
517#undef LOOP_NEED_FLAGS
518#undef LOOP_NEED_DATA
519#undef get16
520#undef get32
521#undef put16
522#undef put32
523#undef unaligned
524