Allow multiple wimlib_global_init/cleanup per app
[wimlib] / src / encoding.c
1 /*
2  * encoding.c
3  */
4
5 /*
6  * Copyright (C) 2012, 2013 Eric Biggers
7  *
8  * This file is part of wimlib, a library for working with WIM files.
9  *
10  * wimlib is free software; you can redistribute it and/or modify it under the
11  * terms of the GNU General Public License as published by the Free
12  * Software Foundation; either version 3 of the License, or (at your option)
13  * any later version.
14  *
15  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
16  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
17  * A PARTICULAR PURPOSE. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with wimlib; if not, see http://www.gnu.org/licenses/.
22  */
23
24 #ifdef HAVE_CONFIG_H
25 #  include "config.h"
26 #endif
27
28 #include "wimlib.h"
29 #include "wimlib/assert.h"
30 #include "wimlib/encoding.h"
31 #include "wimlib/endianness.h"
32 #include "wimlib/error.h"
33 #include "wimlib/list.h"
34 #include "wimlib/util.h"
35
36 #include <errno.h>
37 #include <iconv.h>
38 #include <pthread.h>
39 #include <stdlib.h>
40 #include <string.h>
41
42 #ifdef HAVE_ALLOCA_H
43 #  include <alloca.h>
44 #endif
45
46 bool wimlib_mbs_is_utf8 = !TCHAR_IS_UTF16LE;
47
48 /* List of iconv_t conversion descriptors for a specific character conversion.
49  * The idea is that it is not thread-safe to have just one conversion
50  * descriptor, but it also is inefficient to open a new conversion descriptor to
51  * convert every string.  Both these problems can be solved by maintaining a
52  * list of conversion descriptors; then, a thread can use an existing conversion
53  * descriptor if available. */
54 struct iconv_list_head {
55         const char *from_encoding;
56         const char *to_encoding;
57         struct list_head list;
58         pthread_mutex_t mutex;
59 };
60
61 struct iconv_node {
62         iconv_t cd;
63         struct list_head list;
64         struct iconv_list_head *head;
65 };
66
67 #define ICONV_LIST(name, from, to)                      \
68 struct iconv_list_head name = {                         \
69         .from_encoding = from,                          \
70         .to_encoding = to,                              \
71 }
72
73 static iconv_t *
74 get_iconv(struct iconv_list_head *head)
75 {
76         iconv_t cd;
77         iconv_t *cd_p;
78         struct iconv_node *i;
79
80         pthread_mutex_lock(&head->mutex);
81         if (list_empty(&head->list)) {
82                 cd = iconv_open(head->to_encoding, head->from_encoding);
83                 if (cd == (iconv_t)-1) {
84                         ERROR_WITH_ERRNO("Failed to open iconv from %s to %s",
85                                          head->from_encoding, head->to_encoding);
86                         cd_p = NULL;
87                 } else {
88                         i = MALLOC(sizeof(struct iconv_node));
89                         if (i) {
90                                 i->head = head;
91                                 i->cd = cd;
92                                 cd_p = &i->cd;
93                         } else {
94                                 iconv_close(cd);
95                                 cd_p = NULL;
96                         }
97                 }
98         } else {
99                 i = container_of(head->list.next, struct iconv_node, list);
100                 list_del(head->list.next);
101                 cd_p = &i->cd;
102         }
103         pthread_mutex_unlock(&head->mutex);
104         return cd_p;
105 }
106
107 static void
108 put_iconv(iconv_t *cd)
109 {
110         int errno_save = errno;
111         struct iconv_node *i = container_of(cd, struct iconv_node, cd);
112         struct iconv_list_head *head = i->head;
113
114         pthread_mutex_lock(&head->mutex);
115         list_add(&i->list, &head->list);
116         pthread_mutex_unlock(&head->mutex);
117         errno = errno_save;
118 }
119
120 #define DEFINE_CHAR_CONVERSION_FUNCTIONS(varname1, longname1, chartype1,\
121                                          varname2, longname2, chartype2,\
122                                          earlyreturn_on_utf8_locale,    \
123                                          earlyreturn_expr,              \
124                                          worst_case_len_expr,           \
125                                          err_return,                    \
126                                          err_msg,                       \
127                                          modifier)                      \
128 static ICONV_LIST(iconv_##varname1##_to_##varname2,                     \
129                   longname1, longname2);                                \
130                                                                         \
131 modifier int                                                            \
132 varname1##_to_##varname2##_nbytes(const chartype1 *in, size_t in_nbytes,\
133                                   size_t *out_nbytes_ret)               \
134 {                                                                       \
135         iconv_t *cd = get_iconv(&iconv_##varname1##_to_##varname2);     \
136         if (cd == NULL)                                                 \
137                 return WIMLIB_ERR_ICONV_NOT_AVAILABLE;                  \
138                                                                         \
139         chartype2 *buf;                                                 \
140         size_t bufsize;                                                 \
141         bool buf_onheap;                                                \
142         bufsize = (worst_case_len_expr) * sizeof(chartype2);            \
143         /* Worst case length */                                         \
144         if (bufsize <= STACK_MAX) {                                     \
145                 buf = alloca(bufsize);                                  \
146                 buf_onheap = false;                                     \
147         } else {                                                        \
148                 buf = MALLOC(bufsize);                                  \
149                 if (!buf)                                               \
150                         return WIMLIB_ERR_NOMEM;                        \
151                 buf_onheap = true;                                      \
152         }                                                               \
153                                                                         \
154         char *inbuf = (char*)in;                                        \
155         size_t inbytesleft = in_nbytes;                                 \
156         char *outbuf = (char*)buf;                                      \
157         size_t outbytesleft = bufsize;                                  \
158         size_t len;                                                     \
159         int ret;                                                        \
160                                                                         \
161         len = iconv(*cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft); \
162         if (len == (size_t)-1) {                                        \
163                 err_msg;                                                \
164                 ret = err_return;                                       \
165         } else {                                                        \
166                 *out_nbytes_ret = bufsize - outbytesleft;               \
167                 ret = 0;                                                \
168         }                                                               \
169         put_iconv(cd);                                                  \
170         if (buf_onheap)                                                 \
171                 FREE(buf);                                              \
172         return ret;                                                     \
173 }                                                                       \
174                                                                         \
175 modifier int                                                            \
176 varname1##_to_##varname2##_buf(const chartype1 *in, size_t in_nbytes,   \
177                                chartype2 *out)                          \
178 {                                                                       \
179         iconv_t *cd = get_iconv(&iconv_##varname1##_to_##varname2);     \
180         if (cd == NULL)                                                 \
181                 return WIMLIB_ERR_ICONV_NOT_AVAILABLE;                  \
182                                                                         \
183         char *inbuf = (char*)in;                                        \
184         size_t inbytesleft = in_nbytes;                                 \
185         char *outbuf = (char*)out;                                      \
186         const size_t LARGE_NUMBER = 1000000000;                         \
187         size_t outbytesleft = LARGE_NUMBER;                             \
188         size_t len;                                                     \
189         int ret;                                                        \
190                                                                         \
191         len = iconv(*cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft); \
192         if (len == (size_t)-1) {                                        \
193                 err_msg;                                                \
194                 ret = err_return;                                       \
195         } else {                                                        \
196                 out[(LARGE_NUMBER-outbytesleft)/sizeof(chartype2)] = 0; \
197                 ret = 0;                                                \
198         }                                                               \
199         put_iconv(cd);                                                  \
200         return ret;                                                     \
201 }                                                                       \
202                                                                         \
203 modifier int                                                            \
204 varname1##_to_##varname2(const chartype1 *in, size_t in_nbytes,         \
205                          chartype2 **out_ret,                           \
206                          size_t *out_nbytes_ret)                        \
207 {                                                                       \
208         int ret;                                                        \
209         chartype2 *out;                                                 \
210         size_t out_nbytes;                                              \
211                                                                         \
212         if (earlyreturn_on_utf8_locale && wimlib_mbs_is_utf8) {         \
213                 earlyreturn_expr;                                       \
214                 /* Out same as in */                                    \
215                 out = MALLOC(in_nbytes + sizeof(chartype2));            \
216                 if (!out)                                               \
217                         return WIMLIB_ERR_NOMEM;                        \
218                 memcpy(out, in, in_nbytes);                             \
219                 out[in_nbytes / sizeof(chartype2)] = 0;                 \
220                 *out_ret = out;                                         \
221                 *out_nbytes_ret = in_nbytes;                            \
222                 return 0;                                               \
223         }                                                               \
224                                                                         \
225         ret = varname1##_to_##varname2##_nbytes(in, in_nbytes,          \
226                                                 &out_nbytes);           \
227         if (ret)                                                        \
228                 return ret;                                             \
229                                                                         \
230         out = MALLOC(out_nbytes + sizeof(chartype2));                   \
231         if (!out)                                                       \
232                 return WIMLIB_ERR_NOMEM;                                \
233                                                                         \
234         ret = varname1##_to_##varname2##_buf(in, in_nbytes, out);       \
235         if (ret) {                                                      \
236                 FREE(out);                                              \
237         } else {                                                        \
238                 *out_ret = out;                                         \
239                 *out_nbytes_ret = out_nbytes;                           \
240         }                                                               \
241         return ret;                                                     \
242 }
243
244 #if !TCHAR_IS_UTF16LE
245
246 /* UNIX */
247
248 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", tchar,
249                                  utf16le, "UTF-16LE", utf16lechar,
250                                  false,
251                                  ,
252                                  in_nbytes * 2,
253                                  WIMLIB_ERR_INVALID_UTF8_STRING,
254                                  ERROR_WITH_ERRNO("Failed to convert UTF-8 string "
255                                                   "to UTF-16LE string!"),
256                                  static)
257
258 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf16le, "UTF-16LE", utf16lechar,
259                                  utf8, "UTF-8", tchar,
260                                  false,
261                                  ,
262                                  in_nbytes * 2,
263                                  WIMLIB_ERR_INVALID_UTF16_STRING,
264                                  ERROR_WITH_ERRNO("Failed to convert UTF-16LE string "
265                                                   "to UTF-8 string!"),
266                                  static)
267
268 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "", tchar,
269                                  utf16le, "UTF-16LE", utf16lechar,
270                                  true,
271                                  return utf8_to_utf16le(in, in_nbytes, out_ret, out_nbytes_ret),
272                                  in_nbytes * 2,
273                                  WIMLIB_ERR_INVALID_MULTIBYTE_STRING,
274                                  ERROR_WITH_ERRNO("Failed to convert multibyte "
275                                                   "string \"%"TS"\" to UTF-16LE string!", in);
276                                  ERROR("If the data you provided was UTF-8, please make sure "
277                                        "the character encoding\n"
278                                        "        of your current locale is UTF-8."),
279                                  )
280
281 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf16le, "UTF-16LE", utf16lechar,
282                                  tstr, "", tchar,
283                                  true,
284                                  return utf16le_to_utf8(in, in_nbytes, out_ret, out_nbytes_ret),
285                                  in_nbytes * 2,
286                                  WIMLIB_ERR_UNICODE_STRING_NOT_REPRESENTABLE,
287                                  ERROR("Failed to convert UTF-16LE string to "
288                                        "multibyte string!");
289                                  ERROR("This may be because the UTF-16LE string "
290                                        "could not be represented\n"
291                                        "        in your locale's character encoding."),
292                                  )
293 #endif
294
295 /* tchar to UTF-8 and back */
296 #if TCHAR_IS_UTF16LE
297
298 /* Windows */
299 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "UTF-16LE", tchar,
300                                  utf8, "UTF-8", char,
301                                  false,
302                                  ,
303                                  in_nbytes * 2,
304                                  WIMLIB_ERR_INVALID_UTF16_STRING,
305                                  ERROR_WITH_ERRNO("Failed to convert UTF-16LE "
306                                                   "string \"%"TS"\" to UTF-8 string!", in),
307                                  )
308
309 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", char,
310                                  tstr, "UTF-16LE", tchar,
311                                  false,
312                                  ,
313                                  in_nbytes * 2,
314                                  WIMLIB_ERR_INVALID_UTF8_STRING,
315                                  ERROR_WITH_ERRNO("Failed to convert UTF-8 string "
316                                                   "to UTF-16LE string!"),
317                                  )
318 #else
319
320 /* UNIX */
321
322 DEFINE_CHAR_CONVERSION_FUNCTIONS(tstr, "", tchar,
323                                  utf8, "UTF-8", char,
324                                  true,
325                                  ,
326                                  in_nbytes * 4,
327                                  WIMLIB_ERR_INVALID_MULTIBYTE_STRING,
328                                  ERROR_WITH_ERRNO("Failed to convert multibyte "
329                                                   "string \"%"TS"\" to UTF-8 string!", in);
330                                  ERROR("If the data you provided was UTF-8, please make sure "
331                                        "the character\n"
332                                        "        encoding of your current locale is UTF-8."),
333                                  )
334
335 DEFINE_CHAR_CONVERSION_FUNCTIONS(utf8, "UTF-8", char,
336                                  tstr, "", tchar,
337                                  true,
338                                  ,
339                                  in_nbytes * 4,
340                                  WIMLIB_ERR_UNICODE_STRING_NOT_REPRESENTABLE,
341                                  ERROR("Failed to convert UTF-8 string to "
342                                        "multibyte string!");
343                                  ERROR("This may be because the UTF-8 data "
344                                        "could not be represented\n"
345                                        "        in your locale's character encoding."),
346                                  )
347 #endif
348
349 int
350 tstr_to_utf8_simple(const tchar *tstr, char **out)
351 {
352         size_t out_nbytes;
353         return tstr_to_utf8(tstr, tstrlen(tstr) * sizeof(tchar),
354                             out, &out_nbytes);
355 }
356
357 int
358 utf8_to_tstr_simple(const char *utf8str, tchar **out)
359 {
360         size_t out_nbytes;
361         return utf8_to_tstr(utf8str, strlen(utf8str), out, &out_nbytes);
362 }
363
364 static void
365 iconv_init(struct iconv_list_head *head)
366 {
367         pthread_mutex_init(&head->mutex, NULL);
368         INIT_LIST_HEAD(&head->list);
369 }
370
371 static void
372 iconv_cleanup(struct iconv_list_head *head)
373 {
374         pthread_mutex_destroy(&head->mutex);
375         while (!list_empty(&head->list)) {
376                 struct iconv_node *i;
377
378                 i = container_of(head->list.next, struct iconv_node, list);
379                 list_del(&i->list);
380                 iconv_close(i->cd);
381                 FREE(i);
382         }
383 }
384
385 void
386 iconv_global_init(void)
387 {
388         iconv_init(&iconv_utf8_to_tstr);
389         iconv_init(&iconv_tstr_to_utf8);
390 #if !TCHAR_IS_UTF16LE
391         iconv_init(&iconv_utf16le_to_tstr);
392         iconv_init(&iconv_tstr_to_utf16le);
393         iconv_init(&iconv_utf16le_to_utf8);
394         iconv_init(&iconv_utf8_to_utf16le);
395 #endif
396 }
397
398 void
399 iconv_global_cleanup(void)
400 {
401         iconv_cleanup(&iconv_utf8_to_tstr);
402         iconv_cleanup(&iconv_tstr_to_utf8);
403 #if !TCHAR_IS_UTF16LE
404         iconv_cleanup(&iconv_utf16le_to_tstr);
405         iconv_cleanup(&iconv_tstr_to_utf16le);
406         iconv_cleanup(&iconv_utf16le_to_utf8);
407         iconv_cleanup(&iconv_utf8_to_utf16le);
408 #endif
409 }
410
411 /* A table that maps from UCS-2 characters to their upper case equivalents.
412  * Index and array values are both CPU endian.
413  * Note: this is only an *approximation* of real UTF-16 case folding.
414  */
415 static u16 upcase[65536];
416
417 /*
418  * Initialize the 'upcase' table.
419  *
420  * Code modified from NTFS-3g, original copyright notices below:
421  *
422  * Copyright (c) 2000-2004 Anton Altaparmakov
423  * Copyright (c) 2002-2009 Szabolcs Szakacsits
424  * Copyright (c) 2008-2011 Jean-Pierre Andre
425  * Copyright (c) 2008      Bernhard Kaindl
426  *
427  * License GPLv2 or later.
428  *
429  * The expanded table itself is the same as that used by Windows Vista for
430  * NTFS case insensitivity.
431  */
432 void
433 init_upcase(void)
434 {
435         /*
436          *      This is the table as defined by Vista
437          */
438         /*
439          * "Start" is inclusive and "End" is exclusive, every value has the
440          * value of "Add" added to it.
441          */
442         static const u16 uc_run_table[][3] = { /* Start, End, Add */
443         {0x0061, 0x007b,   -32}, {0x00e0, 0x00f7,  -32}, {0x00f8, 0x00ff, -32},
444         {0x0256, 0x0258,  -205}, {0x028a, 0x028c, -217}, {0x037b, 0x037e, 130},
445         {0x03ac, 0x03ad,   -38}, {0x03ad, 0x03b0,  -37}, {0x03b1, 0x03c2, -32},
446         {0x03c2, 0x03c3,   -31}, {0x03c3, 0x03cc,  -32}, {0x03cc, 0x03cd, -64},
447         {0x03cd, 0x03cf,   -63}, {0x0430, 0x0450,  -32}, {0x0450, 0x0460, -80},
448         {0x0561, 0x0587,   -48}, {0x1f00, 0x1f08,    8}, {0x1f10, 0x1f16,   8},
449         {0x1f20, 0x1f28,     8}, {0x1f30, 0x1f38,    8}, {0x1f40, 0x1f46,   8},
450         {0x1f51, 0x1f52,     8}, {0x1f53, 0x1f54,    8}, {0x1f55, 0x1f56,   8},
451         {0x1f57, 0x1f58,     8}, {0x1f60, 0x1f68,    8}, {0x1f70, 0x1f72,  74},
452         {0x1f72, 0x1f76,    86}, {0x1f76, 0x1f78,  100}, {0x1f78, 0x1f7a, 128},
453         {0x1f7a, 0x1f7c,   112}, {0x1f7c, 0x1f7e,  126}, {0x1f80, 0x1f88,   8},
454         {0x1f90, 0x1f98,     8}, {0x1fa0, 0x1fa8,    8}, {0x1fb0, 0x1fb2,   8},
455         {0x1fb3, 0x1fb4,     9}, {0x1fcc, 0x1fcd,   -9}, {0x1fd0, 0x1fd2,   8},
456         {0x1fe0, 0x1fe2,     8}, {0x1fe5, 0x1fe6,    7}, {0x1ffc, 0x1ffd,  -9},
457         {0x2170, 0x2180,   -16}, {0x24d0, 0x24ea,  -26}, {0x2c30, 0x2c5f, -48},
458         {0x2d00, 0x2d26, -7264}, {0xff41, 0xff5b,  -32},
459         };
460         /*
461          * "Start" is exclusive and "End" is inclusive, every second value is
462          * decremented by one.
463          */
464         static const u16 uc_dup_table[][2] = { /* Start, End */
465         {0x0100, 0x012f}, {0x0132, 0x0137}, {0x0139, 0x0149}, {0x014a, 0x0178},
466         {0x0179, 0x017e}, {0x01a0, 0x01a6}, {0x01b3, 0x01b7}, {0x01cd, 0x01dd},
467         {0x01de, 0x01ef}, {0x01f4, 0x01f5}, {0x01f8, 0x01f9}, {0x01fa, 0x0220},
468         {0x0222, 0x0234}, {0x023b, 0x023c}, {0x0241, 0x0242}, {0x0246, 0x024f},
469         {0x03d8, 0x03ef}, {0x03f7, 0x03f8}, {0x03fa, 0x03fb}, {0x0460, 0x0481},
470         {0x048a, 0x04bf}, {0x04c1, 0x04c4}, {0x04c5, 0x04c8}, {0x04c9, 0x04ce},
471         {0x04ec, 0x04ed}, {0x04d0, 0x04eb}, {0x04ee, 0x04f5}, {0x04f6, 0x0513},
472         {0x1e00, 0x1e95}, {0x1ea0, 0x1ef9}, {0x2183, 0x2184}, {0x2c60, 0x2c61},
473         {0x2c67, 0x2c6c}, {0x2c75, 0x2c76}, {0x2c80, 0x2ce3},
474         };
475         /*
476          * Set the Unicode character at offset "Offset" to "Value".  Note,
477          * "Value" is host endian.
478          */
479         static const u16 uc_byte_table[][2] = { /* Offset, Value */
480         {0x00ff, 0x0178}, {0x0180, 0x0243}, {0x0183, 0x0182}, {0x0185, 0x0184},
481         {0x0188, 0x0187}, {0x018c, 0x018b}, {0x0192, 0x0191}, {0x0195, 0x01f6},
482         {0x0199, 0x0198}, {0x019a, 0x023d}, {0x019e, 0x0220}, {0x01a8, 0x01a7},
483         {0x01ad, 0x01ac}, {0x01b0, 0x01af}, {0x01b9, 0x01b8}, {0x01bd, 0x01bc},
484         {0x01bf, 0x01f7}, {0x01c6, 0x01c4}, {0x01c9, 0x01c7}, {0x01cc, 0x01ca},
485         {0x01dd, 0x018e}, {0x01f3, 0x01f1}, {0x023a, 0x2c65}, {0x023e, 0x2c66},
486         {0x0253, 0x0181}, {0x0254, 0x0186}, {0x0259, 0x018f}, {0x025b, 0x0190},
487         {0x0260, 0x0193}, {0x0263, 0x0194}, {0x0268, 0x0197}, {0x0269, 0x0196},
488         {0x026b, 0x2c62}, {0x026f, 0x019c}, {0x0272, 0x019d}, {0x0275, 0x019f},
489         {0x027d, 0x2c64}, {0x0280, 0x01a6}, {0x0283, 0x01a9}, {0x0288, 0x01ae},
490         {0x0289, 0x0244}, {0x028c, 0x0245}, {0x0292, 0x01b7}, {0x03f2, 0x03f9},
491         {0x04cf, 0x04c0}, {0x1d7d, 0x2c63}, {0x214e, 0x2132},
492         };
493
494         for (u32 i = 0; i < 65536; i++)
495                 upcase[i] = i;
496
497         for (u32 r = 0; r < ARRAY_LEN(uc_run_table); r++)
498                 for (u32 i = uc_run_table[r][0]; i < uc_run_table[r][1]; i++)
499                         upcase[i] = i + uc_run_table[r][2];
500
501         for (u32 r = 0; r < ARRAY_LEN(uc_dup_table); r++)
502                 for (u32 i = uc_dup_table[r][0]; i < uc_dup_table[r][1]; i += 2)
503                         upcase[i + 1] = i;
504
505         for (u32 r = 0; r < ARRAY_LEN(uc_byte_table); r++)
506                 upcase[uc_byte_table[r][0]] = uc_byte_table[r][1];
507
508 #if 0
509         /* Sanity checks  */
510         wimlib_assert(upcase['a'] == 'A');
511         wimlib_assert(upcase['A'] == 'A');
512         wimlib_assert(upcase['z'] == 'Z');
513         wimlib_assert(upcase['Z'] == 'Z');
514         wimlib_assert(upcase['1'] == '1');
515         wimlib_assert(upcase[0x00e9] == 0x00c9); /* Latin letter e, with acute accent  */
516         wimlib_assert(upcase[0x00c9] == 0x00c9);
517         wimlib_assert(upcase[0x03c1] == 0x03a1); /* Greek letter rho  */
518         wimlib_assert(upcase[0x03a1] == 0x03a1);
519         wimlib_assert(upcase[0x0436] == 0x0416); /* Cyrillic letter zhe  */
520         wimlib_assert(upcase[0x0416] == 0x0416);
521         wimlib_assert(upcase[0x0567] == 0x0537); /* Armenian letter eh  */
522         wimlib_assert(upcase[0x0537] == 0x0537);
523         wimlib_assert(upcase[0x24d0] == 0x24b6); /* Circled Latin letter A
524                                                     (is that a real character???)  */
525         wimlib_assert(upcase[0x24b6] == 0x24b6);
526         wimlib_assert(upcase[0x2603] == 0x2603); /* Note to self: Upper case
527                                                     snowman symbol does not
528                                                     exist.  */
529 #endif
530 }
531
532 /* Compare UTF-16LE strings case-sensitively (%ignore_case == false) or
533  * case-insensitively (%ignore_case == true).
534  *
535  * This is implemented using the default upper-case table used by NTFS.  It does
536  * not handle all possible cases allowed by UTF-16LE.  For example, different
537  * normalizations of the same sequence of "characters" are not considered equal.
538  * It hopefully does the right thing most of the time though.  */
539 int
540 cmp_utf16le_strings(const utf16lechar *s1, size_t n1,
541                     const utf16lechar *s2, size_t n2,
542                     bool ignore_case)
543 {
544         size_t n = min(n1, n2);
545
546         if (ignore_case) {
547                 for (size_t i = 0; i < n; i++) {
548                         u16 c1 = upcase[le16_to_cpu(s1[i])];
549                         u16 c2 = upcase[le16_to_cpu(s2[i])];
550                         if (c1 != c2)
551                                 return (c1 < c2) ? -1 : 1;
552                 }
553         } else {
554                 for (size_t i = 0; i < n; i++) {
555                         u16 c1 = le16_to_cpu(s1[i]);
556                         u16 c2 = le16_to_cpu(s2[i]);
557                         if (c1 != c2)
558                                 return (c1 < c2) ? -1 : 1;
559                 }
560         }
561         if (n1 == n2)
562                 return 0;
563         return (n1 < n2) ? -1 : 1;
564 }
565
566 /* Duplicate a UTF16-LE string which may not be null-terminated.  */
567 utf16lechar *
568 utf16le_dupz(const utf16lechar *ustr, size_t usize)
569 {
570         utf16lechar *dup = MALLOC(usize + sizeof(utf16lechar));
571         if (dup) {
572                 memcpy(dup, ustr, usize);
573                 dup[usize / sizeof(utf16lechar)] = 0;
574         }
575         return dup;
576 }