1/*
2** 2004 April 13
3**
4** The author disclaims copyright to this source code.  In place of
5** a legal notice, here is a blessing:
6**
7**    May you do good and not evil.
8**    May you find forgiveness for yourself and forgive others.
9**    May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This file contains routines used to translate between UTF-8,
13** UTF-16, UTF-16BE, and UTF-16LE.
14**
15** Notes on UTF-8:
16**
17**   Byte-0    Byte-1    Byte-2    Byte-3    Value
18**  0xxxxxxx                                 00000000 00000000 0xxxxxxx
19**  110yyyyy  10xxxxxx                       00000000 00000yyy yyxxxxxx
20**  1110zzzz  10yyyyyy  10xxxxxx             00000000 zzzzyyyy yyxxxxxx
21**  11110uuu  10uuzzzz  10yyyyyy  10xxxxxx   000uuuuu zzzzyyyy yyxxxxxx
22**
23**
24** Notes on UTF-16:  (with wwww+1==uuuuu)
25**
26**      Word-0               Word-1          Value
27**  110110ww wwzzzzyy   110111yy yyxxxxxx    000uuuuu zzzzyyyy yyxxxxxx
28**  zzzzyyyy yyxxxxxx                        00000000 zzzzyyyy yyxxxxxx
29**
30**
31** BOM or Byte Order Mark:
32**     0xff 0xfe   little-endian utf-16 follows
33**     0xfe 0xff   big-endian utf-16 follows
34**
35*/
36#include "sqliteInt.h"
37#include <assert.h>
38#include "vdbeInt.h"
39
40#ifndef SQLITE_AMALGAMATION
41/*
42** The following constant value is used by the SQLITE_BIGENDIAN and
43** SQLITE_LITTLEENDIAN macros.
44*/
45const int sqlite3one = 1;
46#endif /* SQLITE_AMALGAMATION */
47
48/*
49** This lookup table is used to help decode the first byte of
50** a multi-byte UTF8 character.
51*/
52static const unsigned char sqlite3Utf8Trans1[] = {
53  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
54  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
55  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
56  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
57  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
58  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
59  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
60  0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
61};
62
63
64#define WRITE_UTF8(zOut, c) {                          \
65  if( c<0x00080 ){                                     \
66    *zOut++ = (u8)(c&0xFF);                            \
67  }                                                    \
68  else if( c<0x00800 ){                                \
69    *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);                \
70    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
71  }                                                    \
72  else if( c<0x10000 ){                                \
73    *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);               \
74    *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \
75    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
76  }else{                                               \
77    *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);             \
78    *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);             \
79    *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \
80    *zOut++ = 0x80 + (u8)(c & 0x3F);                   \
81  }                                                    \
82}
83
84#define WRITE_UTF16LE(zOut, c) {                                    \
85  if( c<=0xFFFF ){                                                  \
86    *zOut++ = (u8)(c&0x00FF);                                       \
87    *zOut++ = (u8)((c>>8)&0x00FF);                                  \
88  }else{                                                            \
89    *zOut++ = (u8)(((c>>10)&0x003F) + (((c-0x10000)>>10)&0x00C0));  \
90    *zOut++ = (u8)(0x00D8 + (((c-0x10000)>>18)&0x03));              \
91    *zOut++ = (u8)(c&0x00FF);                                       \
92    *zOut++ = (u8)(0x00DC + ((c>>8)&0x03));                         \
93  }                                                                 \
94}
95
96#define WRITE_UTF16BE(zOut, c) {                                    \
97  if( c<=0xFFFF ){                                                  \
98    *zOut++ = (u8)((c>>8)&0x00FF);                                  \
99    *zOut++ = (u8)(c&0x00FF);                                       \
100  }else{                                                            \
101    *zOut++ = (u8)(0x00D8 + (((c-0x10000)>>18)&0x03));              \
102    *zOut++ = (u8)(((c>>10)&0x003F) + (((c-0x10000)>>10)&0x00C0));  \
103    *zOut++ = (u8)(0x00DC + ((c>>8)&0x03));                         \
104    *zOut++ = (u8)(c&0x00FF);                                       \
105  }                                                                 \
106}
107
108#define READ_UTF16LE(zIn, TERM, c){                                   \
109  c = (*zIn++);                                                       \
110  c += ((*zIn++)<<8);                                                 \
111  if( c>=0xD800 && c<0xE000 && TERM ){                                \
112    int c2 = (*zIn++);                                                \
113    c2 += ((*zIn++)<<8);                                              \
114    c = (c2&0x03FF) + ((c&0x003F)<<10) + (((c&0x03C0)+0x0040)<<10);   \
115  }                                                                   \
116}
117
118#define READ_UTF16BE(zIn, TERM, c){                                   \
119  c = ((*zIn++)<<8);                                                  \
120  c += (*zIn++);                                                      \
121  if( c>=0xD800 && c<0xE000 && TERM ){                                \
122    int c2 = ((*zIn++)<<8);                                           \
123    c2 += (*zIn++);                                                   \
124    c = (c2&0x03FF) + ((c&0x003F)<<10) + (((c&0x03C0)+0x0040)<<10);   \
125  }                                                                   \
126}
127
128/*
129** Translate a single UTF-8 character.  Return the unicode value.
130**
131** During translation, assume that the byte that zTerm points
132** is a 0x00.
133**
134** Write a pointer to the next unread byte back into *pzNext.
135**
136** Notes On Invalid UTF-8:
137**
138**  *  This routine never allows a 7-bit character (0x00 through 0x7f) to
139**     be encoded as a multi-byte character.  Any multi-byte character that
140**     attempts to encode a value between 0x00 and 0x7f is rendered as 0xfffd.
141**
142**  *  This routine never allows a UTF16 surrogate value to be encoded.
143**     If a multi-byte character attempts to encode a value between
144**     0xd800 and 0xe000 then it is rendered as 0xfffd.
145**
146**  *  Bytes in the range of 0x80 through 0xbf which occur as the first
147**     byte of a character are interpreted as single-byte characters
148**     and rendered as themselves even though they are technically
149**     invalid characters.
150**
151**  *  This routine accepts an infinite number of different UTF8 encodings
152**     for unicode values 0x80 and greater.  It do not change over-length
153**     encodings to 0xfffd as some systems recommend.
154*/
155#define READ_UTF8(zIn, zTerm, c)                           \
156  c = *(zIn++);                                            \
157  if( c>=0xc0 ){                                           \
158    c = sqlite3Utf8Trans1[c-0xc0];                         \
159    while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){            \
160      c = (c<<6) + (0x3f & *(zIn++));                      \
161    }                                                      \
162    if( c<0x80                                             \
163        || (c&0xFFFFF800)==0xD800                          \
164        || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \
165  }
166int sqlite3Utf8Read(
167  const unsigned char *zIn,       /* First byte of UTF-8 character */
168  const unsigned char **pzNext    /* Write first byte past UTF-8 char here */
169){
170  unsigned int c;
171
172  /* Same as READ_UTF8() above but without the zTerm parameter.
173  ** For this routine, we assume the UTF8 string is always zero-terminated.
174  */
175  c = *(zIn++);
176  if( c>=0xc0 ){
177    c = sqlite3Utf8Trans1[c-0xc0];
178    while( (*zIn & 0xc0)==0x80 ){
179      c = (c<<6) + (0x3f & *(zIn++));
180    }
181    if( c<0x80
182        || (c&0xFFFFF800)==0xD800
183        || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }
184  }
185  *pzNext = zIn;
186  return c;
187}
188
189
190
191
192/*
193** If the TRANSLATE_TRACE macro is defined, the value of each Mem is
194** printed on stderr on the way into and out of sqlite3VdbeMemTranslate().
195*/
196/* #define TRANSLATE_TRACE 1 */
197
198#ifndef SQLITE_OMIT_UTF16
199/*
200** This routine transforms the internal text encoding used by pMem to
201** desiredEnc. It is an error if the string is already of the desired
202** encoding, or if *pMem does not contain a string value.
203*/
204int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
205  int len;                    /* Maximum length of output string in bytes */
206  unsigned char *zOut;                  /* Output buffer */
207  unsigned char *zIn;                   /* Input iterator */
208  unsigned char *zTerm;                 /* End of input */
209  unsigned char *z;                     /* Output iterator */
210  unsigned int c;
211
212  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
213  assert( pMem->flags&MEM_Str );
214  assert( pMem->enc!=desiredEnc );
215  assert( pMem->enc!=0 );
216  assert( pMem->n>=0 );
217
218#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
219  {
220    char zBuf[100];
221    sqlite3VdbeMemPrettyPrint(pMem, zBuf);
222    fprintf(stderr, "INPUT:  %s\n", zBuf);
223  }
224#endif
225
226  /* If the translation is between UTF-16 little and big endian, then
227  ** all that is required is to swap the byte order. This case is handled
228  ** differently from the others.
229  */
230  if( pMem->enc!=SQLITE_UTF8 && desiredEnc!=SQLITE_UTF8 ){
231    u8 temp;
232    int rc;
233    rc = sqlite3VdbeMemMakeWriteable(pMem);
234    if( rc!=SQLITE_OK ){
235      assert( rc==SQLITE_NOMEM );
236      return SQLITE_NOMEM;
237    }
238    zIn = (u8*)pMem->z;
239    zTerm = &zIn[pMem->n&~1];
240    while( zIn<zTerm ){
241      temp = *zIn;
242      *zIn = *(zIn+1);
243      zIn++;
244      *zIn++ = temp;
245    }
246    pMem->enc = desiredEnc;
247    goto translate_out;
248  }
249
250  /* Set len to the maximum number of bytes required in the output buffer. */
251  if( desiredEnc==SQLITE_UTF8 ){
252    /* When converting from UTF-16, the maximum growth results from
253    ** translating a 2-byte character to a 4-byte UTF-8 character.
254    ** A single byte is required for the output string
255    ** nul-terminator.
256    */
257    pMem->n &= ~1;
258    len = pMem->n * 2 + 1;
259  }else{
260    /* When converting from UTF-8 to UTF-16 the maximum growth is caused
261    ** when a 1-byte UTF-8 character is translated into a 2-byte UTF-16
262    ** character. Two bytes are required in the output buffer for the
263    ** nul-terminator.
264    */
265    len = pMem->n * 2 + 2;
266  }
267
268  /* Set zIn to point at the start of the input buffer and zTerm to point 1
269  ** byte past the end.
270  **
271  ** Variable zOut is set to point at the output buffer, space obtained
272  ** from sqlite3_malloc().
273  */
274  zIn = (u8*)pMem->z;
275  zTerm = &zIn[pMem->n];
276  zOut = sqlite3DbMallocRaw(pMem->db, len);
277  if( !zOut ){
278    return SQLITE_NOMEM;
279  }
280  z = zOut;
281
282  if( pMem->enc==SQLITE_UTF8 ){
283    if( desiredEnc==SQLITE_UTF16LE ){
284      /* UTF-8 -> UTF-16 Little-endian */
285      while( zIn<zTerm ){
286        /* c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn); */
287        READ_UTF8(zIn, zTerm, c);
288        WRITE_UTF16LE(z, c);
289      }
290    }else{
291      assert( desiredEnc==SQLITE_UTF16BE );
292      /* UTF-8 -> UTF-16 Big-endian */
293      while( zIn<zTerm ){
294        /* c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn); */
295        READ_UTF8(zIn, zTerm, c);
296        WRITE_UTF16BE(z, c);
297      }
298    }
299    pMem->n = (int)(z - zOut);
300    *z++ = 0;
301  }else{
302    assert( desiredEnc==SQLITE_UTF8 );
303    if( pMem->enc==SQLITE_UTF16LE ){
304      /* UTF-16 Little-endian -> UTF-8 */
305      while( zIn<zTerm ){
306        READ_UTF16LE(zIn, zIn<zTerm, c);
307        WRITE_UTF8(z, c);
308      }
309    }else{
310      /* UTF-16 Big-endian -> UTF-8 */
311      while( zIn<zTerm ){
312        READ_UTF16BE(zIn, zIn<zTerm, c);
313        WRITE_UTF8(z, c);
314      }
315    }
316    pMem->n = (int)(z - zOut);
317  }
318  *z = 0;
319  assert( (pMem->n+(desiredEnc==SQLITE_UTF8?1:2))<=len );
320
321  sqlite3VdbeMemRelease(pMem);
322  pMem->flags &= ~(MEM_Static|MEM_Dyn|MEM_Ephem);
323  pMem->enc = desiredEnc;
324  pMem->flags |= (MEM_Term|MEM_Dyn);
325  pMem->z = (char*)zOut;
326  pMem->zMalloc = pMem->z;
327
328translate_out:
329#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
330  {
331    char zBuf[100];
332    sqlite3VdbeMemPrettyPrint(pMem, zBuf);
333    fprintf(stderr, "OUTPUT: %s\n", zBuf);
334  }
335#endif
336  return SQLITE_OK;
337}
338
339/*
340** This routine checks for a byte-order mark at the beginning of the
341** UTF-16 string stored in *pMem. If one is present, it is removed and
342** the encoding of the Mem adjusted. This routine does not do any
343** byte-swapping, it just sets Mem.enc appropriately.
344**
345** The allocation (static, dynamic etc.) and encoding of the Mem may be
346** changed by this function.
347*/
348int sqlite3VdbeMemHandleBom(Mem *pMem){
349  int rc = SQLITE_OK;
350  u8 bom = 0;
351
352  assert( pMem->n>=0 );
353  if( pMem->n>1 ){
354    u8 b1 = *(u8 *)pMem->z;
355    u8 b2 = *(((u8 *)pMem->z) + 1);
356    if( b1==0xFE && b2==0xFF ){
357      bom = SQLITE_UTF16BE;
358    }
359    if( b1==0xFF && b2==0xFE ){
360      bom = SQLITE_UTF16LE;
361    }
362  }
363
364  if( bom ){
365    rc = sqlite3VdbeMemMakeWriteable(pMem);
366    if( rc==SQLITE_OK ){
367      pMem->n -= 2;
368      memmove(pMem->z, &pMem->z[2], pMem->n);
369      pMem->z[pMem->n] = '\0';
370      pMem->z[pMem->n+1] = '\0';
371      pMem->flags |= MEM_Term;
372      pMem->enc = bom;
373    }
374  }
375  return rc;
376}
377#endif /* SQLITE_OMIT_UTF16 */
378
379/*
380** pZ is a UTF-8 encoded unicode string. If nByte is less than zero,
381** return the number of unicode characters in pZ up to (but not including)
382** the first 0x00 byte. If nByte is not less than zero, return the
383** number of unicode characters in the first nByte of pZ (or up to
384** the first 0x00, whichever comes first).
385*/
386int sqlite3Utf8CharLen(const char *zIn, int nByte){
387  int r = 0;
388  const u8 *z = (const u8*)zIn;
389  const u8 *zTerm;
390  if( nByte>=0 ){
391    zTerm = &z[nByte];
392  }else{
393    zTerm = (const u8*)(-1);
394  }
395  assert( z<=zTerm );
396  while( *z!=0 && z<zTerm ){
397    SQLITE_SKIP_UTF8(z);
398    r++;
399  }
400  return r;
401}
402
403/* This test function is not currently used by the automated test-suite.
404** Hence it is only available in debug builds.
405*/
406#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
407/*
408** Translate UTF-8 to UTF-8.
409**
410** This has the effect of making sure that the string is well-formed
411** UTF-8.  Miscoded characters are removed.
412**
413** The translation is done in-place and aborted if the output
414** overruns the input.
415*/
416int sqlite3Utf8To8(unsigned char *zIn){
417  unsigned char *zOut = zIn;
418  unsigned char *zStart = zIn;
419  u32 c;
420
421  while( zIn[0] && zOut<=zIn ){
422    c = sqlite3Utf8Read(zIn, (const u8**)&zIn);
423    if( c!=0xfffd ){
424      WRITE_UTF8(zOut, c);
425    }
426  }
427  *zOut = 0;
428  return (int)(zOut - zStart);
429}
430#endif
431
432#ifndef SQLITE_OMIT_UTF16
433/*
434** Convert a UTF-16 string in the native encoding into a UTF-8 string.
435** Memory to hold the UTF-8 string is obtained from sqlite3_malloc and must
436** be freed by the calling function.
437**
438** NULL is returned if there is an allocation error.
439*/
440char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte, u8 enc){
441  Mem m;
442  memset(&m, 0, sizeof(m));
443  m.db = db;
444  sqlite3VdbeMemSetStr(&m, z, nByte, enc, SQLITE_STATIC);
445  sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);
446  if( db->mallocFailed ){
447    sqlite3VdbeMemRelease(&m);
448    m.z = 0;
449  }
450  assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
451  assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
452  assert( (m.flags & MEM_Dyn)!=0 || db->mallocFailed );
453  assert( m.z || db->mallocFailed );
454  return m.z;
455}
456
457/*
458** Convert a UTF-8 string to the UTF-16 encoding specified by parameter
459** enc. A pointer to the new string is returned, and the value of *pnOut
460** is set to the length of the returned string in bytes. The call should
461** arrange to call sqlite3DbFree() on the returned pointer when it is
462** no longer required.
463**
464** If a malloc failure occurs, NULL is returned and the db.mallocFailed
465** flag set.
466*/
467#ifdef SQLITE_ENABLE_STAT2
468char *sqlite3Utf8to16(sqlite3 *db, u8 enc, char *z, int n, int *pnOut){
469  Mem m;
470  memset(&m, 0, sizeof(m));
471  m.db = db;
472  sqlite3VdbeMemSetStr(&m, z, n, SQLITE_UTF8, SQLITE_STATIC);
473  if( sqlite3VdbeMemTranslate(&m, enc) ){
474    assert( db->mallocFailed );
475    return 0;
476  }
477  assert( m.z==m.zMalloc );
478  *pnOut = m.n;
479  return m.z;
480}
481#endif
482
483/*
484** zIn is a UTF-16 encoded unicode string at least nChar characters long.
485** Return the number of bytes in the first nChar unicode characters
486** in pZ.  nChar must be non-negative.
487*/
488int sqlite3Utf16ByteLen(const void *zIn, int nChar){
489  int c;
490  unsigned char const *z = zIn;
491  int n = 0;
492
493  if( SQLITE_UTF16NATIVE==SQLITE_UTF16BE ){
494    while( n<nChar ){
495      READ_UTF16BE(z, 1, c);
496      n++;
497    }
498  }else{
499    while( n<nChar ){
500      READ_UTF16LE(z, 1, c);
501      n++;
502    }
503  }
504  return (int)(z-(unsigned char const *)zIn);
505}
506
507#if defined(SQLITE_TEST)
508/*
509** This routine is called from the TCL test function "translate_selftest".
510** It checks that the primitives for serializing and deserializing
511** characters in each encoding are inverses of each other.
512*/
513void sqlite3UtfSelfTest(void){
514  unsigned int i, t;
515  unsigned char zBuf[20];
516  unsigned char *z;
517  int n;
518  unsigned int c;
519
520  for(i=0; i<0x00110000; i++){
521    z = zBuf;
522    WRITE_UTF8(z, i);
523    n = (int)(z-zBuf);
524    assert( n>0 && n<=4 );
525    z[0] = 0;
526    z = zBuf;
527    c = sqlite3Utf8Read(z, (const u8**)&z);
528    t = i;
529    if( i>=0xD800 && i<=0xDFFF ) t = 0xFFFD;
530    if( (i&0xFFFFFFFE)==0xFFFE ) t = 0xFFFD;
531    assert( c==t );
532    assert( (z-zBuf)==n );
533  }
534  for(i=0; i<0x00110000; i++){
535    if( i>=0xD800 && i<0xE000 ) continue;
536    z = zBuf;
537    WRITE_UTF16LE(z, i);
538    n = (int)(z-zBuf);
539    assert( n>0 && n<=4 );
540    z[0] = 0;
541    z = zBuf;
542    READ_UTF16LE(z, 1, c);
543    assert( c==i );
544    assert( (z-zBuf)==n );
545  }
546  for(i=0; i<0x00110000; i++){
547    if( i>=0xD800 && i<0xE000 ) continue;
548    z = zBuf;
549    WRITE_UTF16BE(z, i);
550    n = (int)(z-zBuf);
551    assert( n>0 && n<=4 );
552    z[0] = 0;
553    z = zBuf;
554    READ_UTF16BE(z, 1, c);
555    assert( c==i );
556    assert( (z-zBuf)==n );
557  }
558}
559#endif /* SQLITE_TEST */
560#endif /* SQLITE_OMIT_UTF16 */
561