b54e787bd4cc10a5b671146dbad7661b5e9101bc
[wimlib] / src / encoding.c
1 /*
2  * encoding.c
3  */
4
5 /*
6  * Copyright (C) 2012, 2013 Eric Biggers
7  *
8  * This file is free software; you can redistribute it and/or modify it under
9  * the terms of the GNU Lesser General Public License as published by the Free
10  * Software Foundation; either version 3 of the License, or (at your option) any
11  * later version.
12  *
13  * This file is distributed in the hope that it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
15  * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
16  * details.
17  *
18  * You should have received a copy of the GNU Lesser General Public License
19  * along with this file; if not, see http://www.gnu.org/licenses/.
20  */
21
22 #ifdef HAVE_CONFIG_H
23 #  include "config.h"
24 #endif
25
26 #include "wimlib.h"
27 #include "wimlib/assert.h"
28 #include "wimlib/encoding.h"
29 #include "wimlib/endianness.h"
30 #include "wimlib/error.h"
31 #include "wimlib/list.h"
32 #include "wimlib/util.h"
33
34 #include <errno.h>
35 #include <iconv.h>
36 #include <pthread.h>
37 #include <stdlib.h>
38 #include <string.h>
39
40 #ifdef HAVE_ALLOCA_H
41 #  include <alloca.h>
42 #endif
43
44 bool wimlib_mbs_is_utf8 = !TCHAR_IS_UTF16LE;
45
46 /* List of iconv_t conversion descriptors for a specific character conversion.
47  * The idea is that it is not thread-safe to have just one conversion
48  * descriptor, but it also is inefficient to open a new conversion descriptor to
49  * convert every string.  Both these problems can be solved by maintaining a
50  * list of conversion descriptors; then, a thread can use an existing conversion
51  * descriptor if available. */
52 struct iconv_list_head {
53         const char *from_encoding;
54         const char *to_encoding;
55         struct list_head list;
56         pthread_mutex_t mutex;
57 };
58
59 struct iconv_node {
60         iconv_t cd;
61         struct list_head list;
62         struct iconv_list_head *head;
63 };
64
65 #define ICONV_LIST(name, from, to)                      \
66 struct iconv_list_head name = {                         \
67         .from_encoding = from,                          \
68         .to_encoding = to,                              \
69 }
70
71 static iconv_t *
72 get_iconv(struct iconv_list_head *head)
73 {
74         iconv_t cd;
75         iconv_t *cd_p;
76         struct iconv_node *i;
77
78         pthread_mutex_lock(&head->mutex);
79         if (list_empty(&head->list)) {
80                 cd = iconv_open(head->to_encoding, head->from_encoding);
81                 if (cd == (iconv_t)-1) {
82                         ERROR_WITH_ERRNO("Failed to open iconv from %s to %s",
83                                          head->from_encoding, head->to_encoding);
84                         cd_p = NULL;
85                 } else {
86                         i = MALLOC(sizeof(struct iconv_node));
87                         if (i) {
88                                 i->head = head;
89                                 i->cd = cd;
90                                 cd_p = &i->cd;
91                         } else {
92                                 iconv_close(cd);
93                                 cd_p = NULL;
94                         }
95                 }
96         } else {
97                 i = container_of(head->list.next, struct iconv_node, list);
98                 list_del(head->list.next);
99                 cd_p = &i->cd;
100         }
101         pthread_mutex_unlock(&head->mutex);
102         return cd_p;
103 }
104
105 static void
106 put_iconv(iconv_t *cd)
107 {
108         int errno_save = errno;
109         struct iconv_node *i = container_of(cd, struct iconv_node, cd);
110         struct iconv_list_head *head = i->head;
111
112         pthread_mutex_lock(&head->mutex);
113         list_add(&i->list, &head->list);
114         pthread_mutex_unlock(&head->mutex);
115         errno = errno_save;
116 }
117
118 #define DEFINE_CHAR_CONVERSION_FUNCTIONS(varname1, longname1, chartype1,\
119                                          varname2, longname2, chartype2,\
120                                          earlyreturn_on_utf8_locale,    \
121                                          earlyreturn_expr,              \
122                                          worst_case_len_expr,           \
123                                          err_return,                    \
124                                          err_msg,                       \
125                                          modifier)                      \
126 static ICONV_LIST(iconv_##varname1##_to_##varname2,                     \
127                   longname1, longname2);                                \
128                                                                         \
129 modifier int                                                            \
130 varname1##_to_##varname2##_nbytes(const chartype1 *in, size_t in_nbytes,\
131                                   size_t *out_nbytes_ret)               \
132 {                                                                       \
133         iconv_t *cd = get_iconv(&iconv_##varname1##_to_##varname2);     \
134         if (cd == NULL)                                                 \
135                 return WIMLIB_ERR_ICONV_NOT_AVAILABLE;                  \
136                                                                         \
137         chartype2 *buf;                                                 \
138         size_t bufsize;                                                 \
139         bool buf_onheap;                                                \
140         bufsize = (worst_case_len_expr) * sizeof(chartype2);            \
141         /* Worst case length */                                         \
142         if (bufsize <= STACK_MAX) {                                     \
143                 buf = alloca(bufsize);                                  \
144                 buf_onheap = false;                                     \
145         } else {                                                        \
146                 buf = MALLOC(bufsize);                                  \
147                 if (!buf)                                               \
148                         return WIMLIB_ERR_NOMEM;                        \
149                 buf_onheap = true;                                      \
150         }                                                               \
151                                                                         \
152         char *inbuf = (char*)in;                                        \
153         size_t inbytesleft = in_nbytes;                                 \
154         char *outbuf = (char*)buf;                                      \
155         size_t outbytesleft = bufsize;                                  \
156         size_t len;                                                     \
157         int ret;                                                        \
158                                                                         \
159         len = iconv(*cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft); \
160         if (len == (size_t)-1) {                                        \
161                 err_msg;                                                \
162                 ret = err_return;                                       \
163         } else {                                                        \
164                 *out_nbytes_ret = bufsize - outbytesleft;               \
165                 ret = 0;                                                \
166         }                                                               \
167         put_iconv(cd);                                                  \
168         if (buf_onheap)                                                 \
169                 FREE(buf);                                              \
170         return ret;                                                     \
171 }                                                                       \
172                                                                         \
173 modifier int                                                            \
174 varname1##_to_##varname2##_buf(const chartype1 *in, size_t in_nbytes,   \
175                                chartype2 *out)                          \
176 {                                                                       \
177         iconv_t *cd = get_iconv(&iconv_##varname1##_to_##varname2);     \
178         if (cd == NULL)                                                 \
179                 return WIMLIB_ERR_ICONV_NOT_AVAILABLE;                  \
180                                                                         \
181         char *inbuf = (char*)in;                                        \
182         size_t inbytesleft = in_nbytes;                                 \
183         char *outbuf = (char*)out;                                      \
184         const size_t LARGE_NUMBER = 1000000000;                         \
185         size_t outbytesleft = LARGE_NUMBER;                             \
186         size_t len;                                                     \
187         int ret;                                                        \
188                                                                         \
189         len = iconv(*cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft); \
190         if (len == (size_t)-1) {                                        \
191                 err_msg;                                                \
192                 ret = err_return;                                       \
193         } else {                                                        \
194                 out[(LARGE_NUMBER-outbytesleft)/sizeof(chartype2)] = 0; \
195                 ret = 0;                                                \
196         }                                                               \
197         put_iconv(cd);                                                  \
198         return ret;                                                     \
199 }                                                                       \
200                                                                         \
201 modifier int                                                            \
202 varname1##_to_##varname2(const chartype1 *in, size_t in_nbytes,         \
203                          chartype2 **out_ret,                           \
204                          size_t *out_nbytes_ret)                        \
205 {                                                                       \
206         int ret;                                                        \
207         chartype2 *out;                                                 \
208         size_t out_nbytes;                                              \
209                                                                         \
210         if (earlyreturn_on_utf8_locale && wimlib_mbs_is_utf8) {         \
211                 earlyreturn_expr;                                       \
212                 /* Out same as in */                                    \
213                 out = MALLOC(in_nbytes + sizeof(chartype2));            \
214                 if (!out)                                               \
215                         return WIMLIB_ERR_NOMEM;                        \
216                 memcpy(out, in, in_nbytes);                             \
217                 out[in_nbytes / sizeof(chartype2)] = 0;                 \
218                 *out_ret = out;                                         \
219                 *out_nbytes_ret = in_nbytes;                            \
220                 return 0;                                               \
221         }                                                               \
222                                                                         \
223         ret = varname1##_to_##varname2##_nbytes(in, in_nbytes,          \
224                                                 &out_nbytes);           \
225         if (ret)                                                        \
226                 return ret;                                             \
227                                                                         \
228         out = MALLOC(out_nbytes + sizeof(chartype2));                   \
229         if (!out)                                                       \
230                 return WIMLIB_ERR_NOMEM;                                \
231                                                                         \
232         ret = varname1##_to_##varname2##_buf(in, in_nbytes, out);       \
233         if (ret) {                                                      \
234                 FREE(out);                                              \
235         } else {                                                        \
236                 *out_ret = out;                                         \
237                 *out_nbytes_ret = out_nbytes;                           \
238         }                                                               \
239         return ret;                                                     \
240 }
241
242 #if !TCHAR_IS_UTF16LE
243
244 /* UNIX */
245
246 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", tchar,
247                                  utf16le, "UTF-16LE", utf16lechar,
248                                  false,
249                                  ,
250                                  in_nbytes * 2,
251                                  WIMLIB_ERR_INVALID_UTF8_STRING,
252                                  ERROR_WITH_ERRNO("Failed to convert UTF-8 string "
253                                                   "to UTF-16LE string!"),
254                                  static)
255
256 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf16le, "UTF-16LE", utf16lechar,
257                                  utf8, "UTF-8", tchar,
258                                  false,
259                                  ,
260                                  in_nbytes * 2,
261                                  WIMLIB_ERR_INVALID_UTF16_STRING,
262                                  ERROR_WITH_ERRNO("Failed to convert UTF-16LE string "
263                                                   "to UTF-8 string!"),
264                                  static)
265
266 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "", tchar,
267                                  utf16le, "UTF-16LE", utf16lechar,
268                                  true,
269                                  return utf8_to_utf16le(in, in_nbytes, out_ret, out_nbytes_ret),
270                                  in_nbytes * 2,
271                                  WIMLIB_ERR_INVALID_MULTIBYTE_STRING,
272                                  ERROR_WITH_ERRNO("Failed to convert multibyte "
273                                                   "string \"%"TS"\" to UTF-16LE string!", in);
274                                  ERROR("If the data you provided was UTF-8, please make sure "
275                                        "the character encoding\n"
276                                        "        of your current locale is UTF-8."),
277                                  )
278
279 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf16le, "UTF-16LE", utf16lechar,
280                                  tstr, "", tchar,
281                                  true,
282                                  return utf16le_to_utf8(in, in_nbytes, out_ret, out_nbytes_ret),
283                                  in_nbytes * 2,
284                                  WIMLIB_ERR_UNICODE_STRING_NOT_REPRESENTABLE,
285                                  ERROR("Failed to convert UTF-16LE string to "
286                                        "multibyte string!");
287                                  ERROR("This may be because the UTF-16LE string "
288                                        "could not be represented\n"
289                                        "        in your locale's character encoding."),
290                                  )
291 #endif
292
293 /* tchar to UTF-8 and back */
294 #if TCHAR_IS_UTF16LE
295
296 /* Windows */
297 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "UTF-16LE", tchar,
298                                  utf8, "UTF-8", char,
299                                  false,
300                                  ,
301                                  in_nbytes * 2,
302                                  WIMLIB_ERR_INVALID_UTF16_STRING,
303                                  ERROR_WITH_ERRNO("Failed to convert UTF-16LE "
304                                                   "string \"%"TS"\" to UTF-8 string!", in),
305                                  )
306
307 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", char,
308                                  tstr, "UTF-16LE", tchar,
309                                  false,
310                                  ,
311                                  in_nbytes * 2,
312                                  WIMLIB_ERR_INVALID_UTF8_STRING,
313                                  ERROR_WITH_ERRNO("Failed to convert UTF-8 string "
314                                                   "to UTF-16LE string!"),
315                                  )
316 #else
317
318 /* UNIX */
319
320 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "", tchar,
321                                  utf8, "UTF-8", char,
322                                  true,
323                                  ,
324                                  in_nbytes * 4,
325                                  WIMLIB_ERR_INVALID_MULTIBYTE_STRING,
326                                  ERROR_WITH_ERRNO("Failed to convert multibyte "
327                                                   "string \"%"TS"\" to UTF-8 string!", in);
328                                  ERROR("If the data you provided was UTF-8, please make sure "
329                                        "the character\n"
330                                        "        encoding of your current locale is UTF-8."),
331                                  )
332
333 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", char,
334                                  tstr, "", tchar,
335                                  true,
336                                  ,
337                                  in_nbytes * 4,
338                                  WIMLIB_ERR_UNICODE_STRING_NOT_REPRESENTABLE,
339                                  ERROR("Failed to convert UTF-8 string to "
340                                        "multibyte string!");
341                                  ERROR("This may be because the UTF-8 data "
342                                        "could not be represented\n"
343                                        "        in your locale's character encoding."),
344                                  )
345 #endif
346
347 int
348 tstr_to_utf8_simple(const tchar *tstr, char **out)
349 {
350         size_t out_nbytes;
351         return tstr_to_utf8(tstr, tstrlen(tstr) * sizeof(tchar),
352                             out, &out_nbytes);
353 }
354
355 int
356 utf8_to_tstr_simple(const char *utf8str, tchar **out)
357 {
358         size_t out_nbytes;
359         return utf8_to_tstr(utf8str, strlen(utf8str), out, &out_nbytes);
360 }
361
362 static void
363 iconv_init(struct iconv_list_head *head)
364 {
365         pthread_mutex_init(&head->mutex, NULL);
366         INIT_LIST_HEAD(&head->list);
367 }
368
369 static void
370 iconv_cleanup(struct iconv_list_head *head)
371 {
372         pthread_mutex_destroy(&head->mutex);
373         while (!list_empty(&head->list)) {
374                 struct iconv_node *i;
375
376                 i = container_of(head->list.next, struct iconv_node, list);
377                 list_del(&i->list);
378                 iconv_close(i->cd);
379                 FREE(i);
380         }
381 }
382
383 void
384 iconv_global_init(void)
385 {
386         iconv_init(&iconv_utf8_to_tstr);
387         iconv_init(&iconv_tstr_to_utf8);
388 #if !TCHAR_IS_UTF16LE
389         iconv_init(&iconv_utf16le_to_tstr);
390         iconv_init(&iconv_tstr_to_utf16le);
391         iconv_init(&iconv_utf16le_to_utf8);
392         iconv_init(&iconv_utf8_to_utf16le);
393 #endif
394 }
395
396 void
397 iconv_global_cleanup(void)
398 {
399         iconv_cleanup(&iconv_utf8_to_tstr);
400         iconv_cleanup(&iconv_tstr_to_utf8);
401 #if !TCHAR_IS_UTF16LE
402         iconv_cleanup(&iconv_utf16le_to_tstr);
403         iconv_cleanup(&iconv_tstr_to_utf16le);
404         iconv_cleanup(&iconv_utf16le_to_utf8);
405         iconv_cleanup(&iconv_utf8_to_utf16le);
406 #endif
407 }
408
409 /* A table that maps from UCS-2 characters to their upper case equivalents.
410  * Index and array values are both CPU endian.
411  * Note: this is only an *approximation* of real UTF-16 case folding.
412  */
413 static u16 upcase[65536];
414
415 /*
416  * Initialize the 'upcase' table.
417  *
418  * Code modified from NTFS-3g, original copyright notices below:
419  *
420  * Copyright (c) 2000-2004 Anton Altaparmakov
421  * Copyright (c) 2002-2009 Szabolcs Szakacsits
422  * Copyright (c) 2008-2011 Jean-Pierre Andre
423  * Copyright (c) 2008      Bernhard Kaindl
424  *
425  * License GPLv2 or later.
426  *
427  * The expanded table itself is the same as that used by Windows Vista for
428  * NTFS case insensitivity.
429  */
430 void
431 init_upcase(void)
432 {
433         /*
434          *      This is the table as defined by Vista
435          */
436         /*
437          * "Start" is inclusive and "End" is exclusive, every value has the
438          * value of "Add" added to it.
439          */
440         static const u16 uc_run_table[][3] = { /* Start, End, Add */
441         {0x0061, 0x007b,   -32}, {0x00e0, 0x00f7,  -32}, {0x00f8, 0x00ff, -32},
442         {0x0256, 0x0258,  -205}, {0x028a, 0x028c, -217}, {0x037b, 0x037e, 130},
443         {0x03ac, 0x03ad,   -38}, {0x03ad, 0x03b0,  -37}, {0x03b1, 0x03c2, -32},
444         {0x03c2, 0x03c3,   -31}, {0x03c3, 0x03cc,  -32}, {0x03cc, 0x03cd, -64},
445         {0x03cd, 0x03cf,   -63}, {0x0430, 0x0450,  -32}, {0x0450, 0x0460, -80},
446         {0x0561, 0x0587,   -48}, {0x1f00, 0x1f08,    8}, {0x1f10, 0x1f16,   8},
447         {0x1f20, 0x1f28,     8}, {0x1f30, 0x1f38,    8}, {0x1f40, 0x1f46,   8},
448         {0x1f51, 0x1f52,     8}, {0x1f53, 0x1f54,    8}, {0x1f55, 0x1f56,   8},
449         {0x1f57, 0x1f58,     8}, {0x1f60, 0x1f68,    8}, {0x1f70, 0x1f72,  74},
450         {0x1f72, 0x1f76,    86}, {0x1f76, 0x1f78,  100}, {0x1f78, 0x1f7a, 128},
451         {0x1f7a, 0x1f7c,   112}, {0x1f7c, 0x1f7e,  126}, {0x1f80, 0x1f88,   8},
452         {0x1f90, 0x1f98,     8}, {0x1fa0, 0x1fa8,    8}, {0x1fb0, 0x1fb2,   8},
453         {0x1fb3, 0x1fb4,     9}, {0x1fcc, 0x1fcd,   -9}, {0x1fd0, 0x1fd2,   8},
454         {0x1fe0, 0x1fe2,     8}, {0x1fe5, 0x1fe6,    7}, {0x1ffc, 0x1ffd,  -9},
455         {0x2170, 0x2180,   -16}, {0x24d0, 0x24ea,  -26}, {0x2c30, 0x2c5f, -48},
456         {0x2d00, 0x2d26, -7264}, {0xff41, 0xff5b,  -32},
457         };
458         /*
459          * "Start" is exclusive and "End" is inclusive, every second value is
460          * decremented by one.
461          */
462         static const u16 uc_dup_table[][2] = { /* Start, End */
463         {0x0100, 0x012f}, {0x0132, 0x0137}, {0x0139, 0x0149}, {0x014a, 0x0178},
464         {0x0179, 0x017e}, {0x01a0, 0x01a6}, {0x01b3, 0x01b7}, {0x01cd, 0x01dd},
465         {0x01de, 0x01ef}, {0x01f4, 0x01f5}, {0x01f8, 0x01f9}, {0x01fa, 0x0220},
466         {0x0222, 0x0234}, {0x023b, 0x023c}, {0x0241, 0x0242}, {0x0246, 0x024f},
467         {0x03d8, 0x03ef}, {0x03f7, 0x03f8}, {0x03fa, 0x03fb}, {0x0460, 0x0481},
468         {0x048a, 0x04bf}, {0x04c1, 0x04c4}, {0x04c5, 0x04c8}, {0x04c9, 0x04ce},
469         {0x04ec, 0x04ed}, {0x04d0, 0x04eb}, {0x04ee, 0x04f5}, {0x04f6, 0x0513},
470         {0x1e00, 0x1e95}, {0x1ea0, 0x1ef9}, {0x2183, 0x2184}, {0x2c60, 0x2c61},
471         {0x2c67, 0x2c6c}, {0x2c75, 0x2c76}, {0x2c80, 0x2ce3},
472         };
473         /*
474          * Set the Unicode character at offset "Offset" to "Value".  Note,
475          * "Value" is host endian.
476          */
477         static const u16 uc_byte_table[][2] = { /* Offset, Value */
478         {0x00ff, 0x0178}, {0x0180, 0x0243}, {0x0183, 0x0182}, {0x0185, 0x0184},
479         {0x0188, 0x0187}, {0x018c, 0x018b}, {0x0192, 0x0191}, {0x0195, 0x01f6},
480         {0x0199, 0x0198}, {0x019a, 0x023d}, {0x019e, 0x0220}, {0x01a8, 0x01a7},
481         {0x01ad, 0x01ac}, {0x01b0, 0x01af}, {0x01b9, 0x01b8}, {0x01bd, 0x01bc},
482         {0x01bf, 0x01f7}, {0x01c6, 0x01c4}, {0x01c9, 0x01c7}, {0x01cc, 0x01ca},
483         {0x01dd, 0x018e}, {0x01f3, 0x01f1}, {0x023a, 0x2c65}, {0x023e, 0x2c66},
484         {0x0253, 0x0181}, {0x0254, 0x0186}, {0x0259, 0x018f}, {0x025b, 0x0190},
485         {0x0260, 0x0193}, {0x0263, 0x0194}, {0x0268, 0x0197}, {0x0269, 0x0196},
486         {0x026b, 0x2c62}, {0x026f, 0x019c}, {0x0272, 0x019d}, {0x0275, 0x019f},
487         {0x027d, 0x2c64}, {0x0280, 0x01a6}, {0x0283, 0x01a9}, {0x0288, 0x01ae},
488         {0x0289, 0x0244}, {0x028c, 0x0245}, {0x0292, 0x01b7}, {0x03f2, 0x03f9},
489         {0x04cf, 0x04c0}, {0x1d7d, 0x2c63}, {0x214e, 0x2132},
490         };
491
492         for (u32 i = 0; i < 65536; i++)
493                 upcase[i] = i;
494
495         for (u32 r = 0; r < ARRAY_LEN(uc_run_table); r++)
496                 for (u32 i = uc_run_table[r][0]; i < uc_run_table[r][1]; i++)
497                         upcase[i] = i + uc_run_table[r][2];
498
499         for (u32 r = 0; r < ARRAY_LEN(uc_dup_table); r++)
500                 for (u32 i = uc_dup_table[r][0]; i < uc_dup_table[r][1]; i += 2)
501                         upcase[i + 1] = i;
502
503         for (u32 r = 0; r < ARRAY_LEN(uc_byte_table); r++)
504                 upcase[uc_byte_table[r][0]] = uc_byte_table[r][1];
505
506 #if 0
507         /* Sanity checks  */
508         wimlib_assert(upcase['a'] == 'A');
509         wimlib_assert(upcase['A'] == 'A');
510         wimlib_assert(upcase['z'] == 'Z');
511         wimlib_assert(upcase['Z'] == 'Z');
512         wimlib_assert(upcase['1'] == '1');
513         wimlib_assert(upcase[0x00e9] == 0x00c9); /* Latin letter e, with acute accent  */
514         wimlib_assert(upcase[0x00c9] == 0x00c9);
515         wimlib_assert(upcase[0x03c1] == 0x03a1); /* Greek letter rho  */
516         wimlib_assert(upcase[0x03a1] == 0x03a1);
517         wimlib_assert(upcase[0x0436] == 0x0416); /* Cyrillic letter zhe  */
518         wimlib_assert(upcase[0x0416] == 0x0416);
519         wimlib_assert(upcase[0x0567] == 0x0537); /* Armenian letter eh  */
520         wimlib_assert(upcase[0x0537] == 0x0537);
521         wimlib_assert(upcase[0x24d0] == 0x24b6); /* Circled Latin letter A
522                                                     (is that a real character???)  */
523         wimlib_assert(upcase[0x24b6] == 0x24b6);
524         wimlib_assert(upcase[0x2603] == 0x2603); /* Note to self: Upper case
525                                                     snowman symbol does not
526                                                     exist.  */
527 #endif
528 }
529
530 /* Compare UTF-16LE strings case-sensitively (%ignore_case == false) or
531  * case-insensitively (%ignore_case == true).
532  *
533  * This is implemented using the default upper-case table used by NTFS.  It does
534  * not handle all possible cases allowed by UTF-16LE.  For example, different
535  * normalizations of the same sequence of "characters" are not considered equal.
536  * It hopefully does the right thing most of the time though.  */
537 int
538 cmp_utf16le_strings(const utf16lechar *s1, size_t n1,
539                     const utf16lechar *s2, size_t n2,
540                     bool ignore_case)
541 {
542         size_t n = min(n1, n2);
543
544         if (ignore_case) {
545                 for (size_t i = 0; i < n; i++) {
546                         u16 c1 = upcase[le16_to_cpu(s1[i])];
547                         u16 c2 = upcase[le16_to_cpu(s2[i])];
548                         if (c1 != c2)
549                                 return (c1 < c2) ? -1 : 1;
550                 }
551         } else {
552                 for (size_t i = 0; i < n; i++) {
553                         u16 c1 = le16_to_cpu(s1[i]);
554                         u16 c2 = le16_to_cpu(s2[i]);
555                         if (c1 != c2)
556                                 return (c1 < c2) ? -1 : 1;
557                 }
558         }
559         if (n1 == n2)
560                 return 0;
561         return (n1 < n2) ? -1 : 1;
562 }
563
564 /* Duplicate a UTF16-LE string which may not be null-terminated.  */
565 utf16lechar *
566 utf16le_dupz(const utf16lechar *ustr, size_t usize)
567 {
568         utf16lechar *dup = MALLOC(usize + sizeof(utf16lechar));
569         if (dup) {
570                 memcpy(dup, ustr, usize);
571                 dup[usize / sizeof(utf16lechar)] = 0;
572         }
573         return dup;
574 }