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1 /*===--- ConvertUTF.c - Universal Character Names conversions ---------------===
3 * The LLVM Compiler Infrastructure
5 * This file is distributed under the University of Illinois Open Source
6 * License. See LICENSE.TXT for details.
8 *===------------------------------------------------------------------------=*/
10 * Copyright 2001-2004 Unicode, Inc.
14 * This source code is provided as is by Unicode, Inc. No claims are
15 * made as to fitness for any particular purpose. No warranties of any
16 * kind are expressed or implied. The recipient agrees to determine
17 * applicability of information provided. If this file has been
18 * purchased on magnetic or optical media from Unicode, Inc., the
19 * sole remedy for any claim will be exchange of defective media
20 * within 90 days of receipt.
22 * Limitations on Rights to Redistribute This Code
24 * Unicode, Inc. hereby grants the right to freely use the information
25 * supplied in this file in the creation of products supporting the
26 * Unicode Standard, and to make copies of this file in any form
27 * for internal or external distribution as long as this notice
31 /* ---------------------------------------------------------------------
33 Conversions between UTF32, UTF-16, and UTF-8. Source code file.
34 Author: Mark E. Davis, 1994.
35 Rev History: Rick McGowan, fixes & updates May 2001.
36 Sept 2001: fixed const & error conditions per
37 mods suggested by S. Parent & A. Lillich.
38 June 2002: Tim Dodd added detection and handling of incomplete
39 source sequences, enhanced error detection, added casts
40 to eliminate compiler warnings.
41 July 2003: slight mods to back out aggressive FFFE detection.
42 Jan 2004: updated switches in from-UTF8 conversions.
43 Oct 2004: updated to use UNI_MAX_LEGAL_UTF32 in UTF-32 conversions.
45 See the header file "ConvertUTF.h" for complete documentation.
47 ------------------------------------------------------------------------ */
50 #include "llvm/Support/ConvertUTF.h"
56 static const int halfShift
= 10; /* used for shifting by 10 bits */
58 static const UTF32 halfBase
= 0x0010000UL
;
59 static const UTF32 halfMask
= 0x3FFUL
;
61 #define UNI_SUR_HIGH_START (UTF32)0xD800
62 #define UNI_SUR_HIGH_END (UTF32)0xDBFF
63 #define UNI_SUR_LOW_START (UTF32)0xDC00
64 #define UNI_SUR_LOW_END (UTF32)0xDFFF
68 /* --------------------------------------------------------------------- */
71 * Index into the table below with the first byte of a UTF-8 sequence to
72 * get the number of trailing bytes that are supposed to follow it.
73 * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is
74 * left as-is for anyone who may want to do such conversion, which was
75 * allowed in earlier algorithms.
77 static const char trailingBytesForUTF8
[256] = {
78 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
79 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
80 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
81 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
82 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
83 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
84 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
85 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5
89 * Magic values subtracted from a buffer value during UTF8 conversion.
90 * This table contains as many values as there might be trailing bytes
91 * in a UTF-8 sequence.
93 static const UTF32 offsetsFromUTF8
[6] = { 0x00000000UL
, 0x00003080UL
, 0x000E2080UL
,
94 0x03C82080UL
, 0xFA082080UL
, 0x82082080UL
};
97 * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed
98 * into the first byte, depending on how many bytes follow. There are
99 * as many entries in this table as there are UTF-8 sequence types.
100 * (I.e., one byte sequence, two byte... etc.). Remember that sequencs
101 * for *legal* UTF-8 will be 4 or fewer bytes total.
103 static const UTF8 firstByteMark
[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
105 /* --------------------------------------------------------------------- */
107 /* The interface converts a whole buffer to avoid function-call overhead.
108 * Constants have been gathered. Loops & conditionals have been removed as
109 * much as possible for efficiency, in favor of drop-through switches.
110 * (See "Note A" at the bottom of the file for equivalent code.)
111 * If your compiler supports it, the "isLegalUTF8" call can be turned
112 * into an inline function.
116 /* --------------------------------------------------------------------- */
118 ConversionResult
ConvertUTF32toUTF16 (
119 const UTF32
** sourceStart
, const UTF32
* sourceEnd
,
120 UTF16
** targetStart
, UTF16
* targetEnd
, ConversionFlags flags
) {
121 ConversionResult result
= conversionOK
;
122 const UTF32
* source
= *sourceStart
;
123 UTF16
* target
= *targetStart
;
124 while (source
< sourceEnd
) {
126 if (target
>= targetEnd
) {
127 result
= targetExhausted
; break;
130 if (ch
<= UNI_MAX_BMP
) { /* Target is a character <= 0xFFFF */
131 /* UTF-16 surrogate values are illegal in UTF-32; 0xffff or 0xfffe are both reserved values */
132 if (ch
>= UNI_SUR_HIGH_START
&& ch
<= UNI_SUR_LOW_END
) {
133 if (flags
== strictConversion
) {
134 --source
; /* return to the illegal value itself */
135 result
= sourceIllegal
;
138 *target
++ = UNI_REPLACEMENT_CHAR
;
141 *target
++ = (UTF16
)ch
; /* normal case */
143 } else if (ch
> UNI_MAX_LEGAL_UTF32
) {
144 if (flags
== strictConversion
) {
145 result
= sourceIllegal
;
147 *target
++ = UNI_REPLACEMENT_CHAR
;
150 /* target is a character in range 0xFFFF - 0x10FFFF. */
151 if (target
+ 1 >= targetEnd
) {
152 --source
; /* Back up source pointer! */
153 result
= targetExhausted
; break;
156 *target
++ = (UTF16
)((ch
>> halfShift
) + UNI_SUR_HIGH_START
);
157 *target
++ = (UTF16
)((ch
& halfMask
) + UNI_SUR_LOW_START
);
160 *sourceStart
= source
;
161 *targetStart
= target
;
165 /* --------------------------------------------------------------------- */
167 ConversionResult
ConvertUTF16toUTF32 (
168 const UTF16
** sourceStart
, const UTF16
* sourceEnd
,
169 UTF32
** targetStart
, UTF32
* targetEnd
, ConversionFlags flags
) {
170 ConversionResult result
= conversionOK
;
171 const UTF16
* source
= *sourceStart
;
172 UTF32
* target
= *targetStart
;
174 while (source
< sourceEnd
) {
175 const UTF16
* oldSource
= source
; /* In case we have to back up because of target overflow. */
177 /* If we have a surrogate pair, convert to UTF32 first. */
178 if (ch
>= UNI_SUR_HIGH_START
&& ch
<= UNI_SUR_HIGH_END
) {
179 /* If the 16 bits following the high surrogate are in the source buffer... */
180 if (source
< sourceEnd
) {
182 /* If it's a low surrogate, convert to UTF32. */
183 if (ch2
>= UNI_SUR_LOW_START
&& ch2
<= UNI_SUR_LOW_END
) {
184 ch
= ((ch
- UNI_SUR_HIGH_START
) << halfShift
)
185 + (ch2
- UNI_SUR_LOW_START
) + halfBase
;
187 } else if (flags
== strictConversion
) { /* it's an unpaired high surrogate */
188 --source
; /* return to the illegal value itself */
189 result
= sourceIllegal
;
192 } else { /* We don't have the 16 bits following the high surrogate. */
193 --source
; /* return to the high surrogate */
194 result
= sourceExhausted
;
197 } else if (flags
== strictConversion
) {
198 /* UTF-16 surrogate values are illegal in UTF-32 */
199 if (ch
>= UNI_SUR_LOW_START
&& ch
<= UNI_SUR_LOW_END
) {
200 --source
; /* return to the illegal value itself */
201 result
= sourceIllegal
;
205 if (target
>= targetEnd
) {
206 source
= oldSource
; /* Back up source pointer! */
207 result
= targetExhausted
; break;
211 *sourceStart
= source
;
212 *targetStart
= target
;
214 if (result
== sourceIllegal
) {
215 fprintf(stderr
, "ConvertUTF16toUTF32 illegal seq 0x%04x,%04x\n", ch
, ch2
);
221 ConversionResult
ConvertUTF16toUTF8 (
222 const UTF16
** sourceStart
, const UTF16
* sourceEnd
,
223 UTF8
** targetStart
, UTF8
* targetEnd
, ConversionFlags flags
) {
224 ConversionResult result
= conversionOK
;
225 const UTF16
* source
= *sourceStart
;
226 UTF8
* target
= *targetStart
;
227 while (source
< sourceEnd
) {
229 unsigned short bytesToWrite
= 0;
230 const UTF32 byteMask
= 0xBF;
231 const UTF32 byteMark
= 0x80;
232 const UTF16
* oldSource
= source
; /* In case we have to back up because of target overflow. */
234 /* If we have a surrogate pair, convert to UTF32 first. */
235 if (ch
>= UNI_SUR_HIGH_START
&& ch
<= UNI_SUR_HIGH_END
) {
236 /* If the 16 bits following the high surrogate are in the source buffer... */
237 if (source
< sourceEnd
) {
239 /* If it's a low surrogate, convert to UTF32. */
240 if (ch2
>= UNI_SUR_LOW_START
&& ch2
<= UNI_SUR_LOW_END
) {
241 ch
= ((ch
- UNI_SUR_HIGH_START
) << halfShift
)
242 + (ch2
- UNI_SUR_LOW_START
) + halfBase
;
244 } else if (flags
== strictConversion
) { /* it's an unpaired high surrogate */
245 --source
; /* return to the illegal value itself */
246 result
= sourceIllegal
;
249 } else { /* We don't have the 16 bits following the high surrogate. */
250 --source
; /* return to the high surrogate */
251 result
= sourceExhausted
;
254 } else if (flags
== strictConversion
) {
255 /* UTF-16 surrogate values are illegal in UTF-32 */
256 if (ch
>= UNI_SUR_LOW_START
&& ch
<= UNI_SUR_LOW_END
) {
257 --source
; /* return to the illegal value itself */
258 result
= sourceIllegal
;
262 /* Figure out how many bytes the result will require */
263 if (ch
< (UTF32
)0x80) { bytesToWrite
= 1;
264 } else if (ch
< (UTF32
)0x800) { bytesToWrite
= 2;
265 } else if (ch
< (UTF32
)0x10000) { bytesToWrite
= 3;
266 } else if (ch
< (UTF32
)0x110000) { bytesToWrite
= 4;
267 } else { bytesToWrite
= 3;
268 ch
= UNI_REPLACEMENT_CHAR
;
271 target
+= bytesToWrite
;
272 if (target
> targetEnd
) {
273 source
= oldSource
; /* Back up source pointer! */
274 target
-= bytesToWrite
; result
= targetExhausted
; break;
276 switch (bytesToWrite
) { /* note: everything falls through. */
277 case 4: *--target
= (UTF8
)((ch
| byteMark
) & byteMask
); ch
>>= 6;
278 case 3: *--target
= (UTF8
)((ch
| byteMark
) & byteMask
); ch
>>= 6;
279 case 2: *--target
= (UTF8
)((ch
| byteMark
) & byteMask
); ch
>>= 6;
280 case 1: *--target
= (UTF8
)(ch
| firstByteMark
[bytesToWrite
]);
282 target
+= bytesToWrite
;
284 *sourceStart
= source
;
285 *targetStart
= target
;
289 /* --------------------------------------------------------------------- */
291 ConversionResult
ConvertUTF32toUTF8 (
292 const UTF32
** sourceStart
, const UTF32
* sourceEnd
,
293 UTF8
** targetStart
, UTF8
* targetEnd
, ConversionFlags flags
) {
294 ConversionResult result
= conversionOK
;
295 const UTF32
* source
= *sourceStart
;
296 UTF8
* target
= *targetStart
;
297 while (source
< sourceEnd
) {
299 unsigned short bytesToWrite
= 0;
300 const UTF32 byteMask
= 0xBF;
301 const UTF32 byteMark
= 0x80;
303 if (flags
== strictConversion
) {
304 /* UTF-16 surrogate values are illegal in UTF-32 */
305 if (ch
>= UNI_SUR_HIGH_START
&& ch
<= UNI_SUR_LOW_END
) {
306 --source
; /* return to the illegal value itself */
307 result
= sourceIllegal
;
312 * Figure out how many bytes the result will require. Turn any
313 * illegally large UTF32 things (> Plane 17) into replacement chars.
315 if (ch
< (UTF32
)0x80) { bytesToWrite
= 1;
316 } else if (ch
< (UTF32
)0x800) { bytesToWrite
= 2;
317 } else if (ch
< (UTF32
)0x10000) { bytesToWrite
= 3;
318 } else if (ch
<= UNI_MAX_LEGAL_UTF32
) { bytesToWrite
= 4;
319 } else { bytesToWrite
= 3;
320 ch
= UNI_REPLACEMENT_CHAR
;
321 result
= sourceIllegal
;
324 target
+= bytesToWrite
;
325 if (target
> targetEnd
) {
326 --source
; /* Back up source pointer! */
327 target
-= bytesToWrite
; result
= targetExhausted
; break;
329 switch (bytesToWrite
) { /* note: everything falls through. */
330 case 4: *--target
= (UTF8
)((ch
| byteMark
) & byteMask
); ch
>>= 6;
331 case 3: *--target
= (UTF8
)((ch
| byteMark
) & byteMask
); ch
>>= 6;
332 case 2: *--target
= (UTF8
)((ch
| byteMark
) & byteMask
); ch
>>= 6;
333 case 1: *--target
= (UTF8
) (ch
| firstByteMark
[bytesToWrite
]);
335 target
+= bytesToWrite
;
337 *sourceStart
= source
;
338 *targetStart
= target
;
342 /* --------------------------------------------------------------------- */
345 * Utility routine to tell whether a sequence of bytes is legal UTF-8.
346 * This must be called with the length pre-determined by the first byte.
347 * If not calling this from ConvertUTF8to*, then the length can be set by:
348 * length = trailingBytesForUTF8[*source]+1;
349 * and the sequence is illegal right away if there aren't that many bytes
351 * If presented with a length > 4, this returns false. The Unicode
352 * definition of UTF-8 goes up to 4-byte sequences.
355 static Boolean
isLegalUTF8(const UTF8
*source
, int length
) {
357 const UTF8
*srcptr
= source
+length
;
359 default: return false;
360 /* Everything else falls through when "true"... */
361 case 4: if ((a
= (*--srcptr
)) < 0x80 || a
> 0xBF) return false;
362 case 3: if ((a
= (*--srcptr
)) < 0x80 || a
> 0xBF) return false;
363 case 2: if ((a
= (*--srcptr
)) < 0x80 || a
> 0xBF) return false;
366 /* no fall-through in this inner switch */
367 case 0xE0: if (a
< 0xA0) return false; break;
368 case 0xED: if (a
> 0x9F) return false; break;
369 case 0xF0: if (a
< 0x90) return false; break;
370 case 0xF4: if (a
> 0x8F) return false; break;
371 default: if (a
< 0x80) return false;
374 case 1: if (*source
>= 0x80 && *source
< 0xC2) return false;
376 if (*source
> 0xF4) return false;
380 /* --------------------------------------------------------------------- */
383 * Exported function to return whether a UTF-8 sequence is legal or not.
384 * This is not used here; it's just exported.
386 Boolean
isLegalUTF8Sequence(const UTF8
*source
, const UTF8
*sourceEnd
) {
387 int length
= trailingBytesForUTF8
[*source
]+1;
388 if (length
> sourceEnd
- source
) {
391 return isLegalUTF8(source
, length
);
394 /* --------------------------------------------------------------------- */
397 findMaximalSubpartOfIllFormedUTF8Sequence(const UTF8
*source
,
398 const UTF8
*sourceEnd
) {
401 assert(!isLegalUTF8Sequence(source
, sourceEnd
));
404 * Unicode 6.3.0, D93b:
406 * Maximal subpart of an ill-formed subsequence: The longest code unit
407 * subsequence starting at an unconvertible offset that is either:
408 * a. the initial subsequence of a well-formed code unit sequence, or
409 * b. a subsequence of length one.
412 if (source
== sourceEnd
)
416 * Perform case analysis. See Unicode 6.3.0, Table 3-7. Well-Formed UTF-8
422 if (b1
>= 0xC2 && b1
<= 0xDF) {
424 * First byte is valid, but we know that this code unit sequence is
425 * invalid, so the maximal subpart has to end after the first byte.
430 if (source
== sourceEnd
)
437 return (b2
>= 0xA0 && b2
<= 0xBF) ? 2 : 1;
439 if (b1
>= 0xE1 && b1
<= 0xEC) {
440 return (b2
>= 0x80 && b2
<= 0xBF) ? 2 : 1;
443 return (b2
>= 0x80 && b2
<= 0x9F) ? 2 : 1;
445 if (b1
>= 0xEE && b1
<= 0xEF) {
446 return (b2
>= 0x80 && b2
<= 0xBF) ? 2 : 1;
449 if (b2
>= 0x90 && b2
<= 0xBF) {
450 if (source
== sourceEnd
)
454 return (b3
>= 0x80 && b3
<= 0xBF) ? 3 : 2;
458 if (b1
>= 0xF1 && b1
<= 0xF3) {
459 if (b2
>= 0x80 && b2
<= 0xBF) {
460 if (source
== sourceEnd
)
464 return (b3
>= 0x80 && b3
<= 0xBF) ? 3 : 2;
469 if (b2
>= 0x80 && b2
<= 0x8F) {
470 if (source
== sourceEnd
)
474 return (b3
>= 0x80 && b3
<= 0xBF) ? 3 : 2;
479 assert((b1
>= 0x80 && b1
<= 0xC1) || b1
>= 0xF5);
481 * There are no valid sequences that start with these bytes. Maximal subpart
482 * is defined to have length 1 in these cases.
487 /* --------------------------------------------------------------------- */
490 * Exported function to return the total number of bytes in a codepoint
491 * represented in UTF-8, given the value of the first byte.
493 unsigned getNumBytesForUTF8(UTF8 first
) {
494 return trailingBytesForUTF8
[first
] + 1;
497 /* --------------------------------------------------------------------- */
500 * Exported function to return whether a UTF-8 string is legal or not.
501 * This is not used here; it's just exported.
503 Boolean
isLegalUTF8String(const UTF8
**source
, const UTF8
*sourceEnd
) {
504 while (*source
!= sourceEnd
) {
505 int length
= trailingBytesForUTF8
[**source
] + 1;
506 if (length
> sourceEnd
- *source
|| !isLegalUTF8(*source
, length
))
513 /* --------------------------------------------------------------------- */
515 ConversionResult
ConvertUTF8toUTF16 (
516 const UTF8
** sourceStart
, const UTF8
* sourceEnd
,
517 UTF16
** targetStart
, UTF16
* targetEnd
, ConversionFlags flags
) {
518 ConversionResult result
= conversionOK
;
519 const UTF8
* source
= *sourceStart
;
520 UTF16
* target
= *targetStart
;
521 while (source
< sourceEnd
) {
523 unsigned short extraBytesToRead
= trailingBytesForUTF8
[*source
];
524 if (extraBytesToRead
>= sourceEnd
- source
) {
525 result
= sourceExhausted
; break;
527 /* Do this check whether lenient or strict */
528 if (!isLegalUTF8(source
, extraBytesToRead
+1)) {
529 result
= sourceIllegal
;
533 * The cases all fall through. See "Note A" below.
535 switch (extraBytesToRead
) {
536 case 5: ch
+= *source
++; ch
<<= 6; /* remember, illegal UTF-8 */
537 case 4: ch
+= *source
++; ch
<<= 6; /* remember, illegal UTF-8 */
538 case 3: ch
+= *source
++; ch
<<= 6;
539 case 2: ch
+= *source
++; ch
<<= 6;
540 case 1: ch
+= *source
++; ch
<<= 6;
541 case 0: ch
+= *source
++;
543 ch
-= offsetsFromUTF8
[extraBytesToRead
];
545 if (target
>= targetEnd
) {
546 source
-= (extraBytesToRead
+1); /* Back up source pointer! */
547 result
= targetExhausted
; break;
549 if (ch
<= UNI_MAX_BMP
) { /* Target is a character <= 0xFFFF */
550 /* UTF-16 surrogate values are illegal in UTF-32 */
551 if (ch
>= UNI_SUR_HIGH_START
&& ch
<= UNI_SUR_LOW_END
) {
552 if (flags
== strictConversion
) {
553 source
-= (extraBytesToRead
+1); /* return to the illegal value itself */
554 result
= sourceIllegal
;
557 *target
++ = UNI_REPLACEMENT_CHAR
;
560 *target
++ = (UTF16
)ch
; /* normal case */
562 } else if (ch
> UNI_MAX_UTF16
) {
563 if (flags
== strictConversion
) {
564 result
= sourceIllegal
;
565 source
-= (extraBytesToRead
+1); /* return to the start */
566 break; /* Bail out; shouldn't continue */
568 *target
++ = UNI_REPLACEMENT_CHAR
;
571 /* target is a character in range 0xFFFF - 0x10FFFF. */
572 if (target
+ 1 >= targetEnd
) {
573 source
-= (extraBytesToRead
+1); /* Back up source pointer! */
574 result
= targetExhausted
; break;
577 *target
++ = (UTF16
)((ch
>> halfShift
) + UNI_SUR_HIGH_START
);
578 *target
++ = (UTF16
)((ch
& halfMask
) + UNI_SUR_LOW_START
);
581 *sourceStart
= source
;
582 *targetStart
= target
;
586 /* --------------------------------------------------------------------- */
588 static ConversionResult
ConvertUTF8toUTF32Impl(
589 const UTF8
** sourceStart
, const UTF8
* sourceEnd
,
590 UTF32
** targetStart
, UTF32
* targetEnd
, ConversionFlags flags
,
591 Boolean InputIsPartial
) {
592 ConversionResult result
= conversionOK
;
593 const UTF8
* source
= *sourceStart
;
594 UTF32
* target
= *targetStart
;
595 while (source
< sourceEnd
) {
597 unsigned short extraBytesToRead
= trailingBytesForUTF8
[*source
];
598 if (extraBytesToRead
>= sourceEnd
- source
) {
599 if (flags
== strictConversion
|| InputIsPartial
) {
600 result
= sourceExhausted
;
603 result
= sourceIllegal
;
606 * Replace the maximal subpart of ill-formed sequence with
607 * replacement character.
609 source
+= findMaximalSubpartOfIllFormedUTF8Sequence(source
,
611 *target
++ = UNI_REPLACEMENT_CHAR
;
615 if (target
>= targetEnd
) {
616 result
= targetExhausted
; break;
619 /* Do this check whether lenient or strict */
620 if (!isLegalUTF8(source
, extraBytesToRead
+1)) {
621 result
= sourceIllegal
;
622 if (flags
== strictConversion
) {
623 /* Abort conversion. */
627 * Replace the maximal subpart of ill-formed sequence with
628 * replacement character.
630 source
+= findMaximalSubpartOfIllFormedUTF8Sequence(source
,
632 *target
++ = UNI_REPLACEMENT_CHAR
;
637 * The cases all fall through. See "Note A" below.
639 switch (extraBytesToRead
) {
640 case 5: ch
+= *source
++; ch
<<= 6;
641 case 4: ch
+= *source
++; ch
<<= 6;
642 case 3: ch
+= *source
++; ch
<<= 6;
643 case 2: ch
+= *source
++; ch
<<= 6;
644 case 1: ch
+= *source
++; ch
<<= 6;
645 case 0: ch
+= *source
++;
647 ch
-= offsetsFromUTF8
[extraBytesToRead
];
649 if (ch
<= UNI_MAX_LEGAL_UTF32
) {
651 * UTF-16 surrogate values are illegal in UTF-32, and anything
652 * over Plane 17 (> 0x10FFFF) is illegal.
654 if (ch
>= UNI_SUR_HIGH_START
&& ch
<= UNI_SUR_LOW_END
) {
655 if (flags
== strictConversion
) {
656 source
-= (extraBytesToRead
+1); /* return to the illegal value itself */
657 result
= sourceIllegal
;
660 *target
++ = UNI_REPLACEMENT_CHAR
;
665 } else { /* i.e., ch > UNI_MAX_LEGAL_UTF32 */
666 result
= sourceIllegal
;
667 *target
++ = UNI_REPLACEMENT_CHAR
;
670 *sourceStart
= source
;
671 *targetStart
= target
;
675 ConversionResult
ConvertUTF8toUTF32Partial(const UTF8
**sourceStart
,
676 const UTF8
*sourceEnd
,
679 ConversionFlags flags
) {
680 return ConvertUTF8toUTF32Impl(sourceStart
, sourceEnd
, targetStart
, targetEnd
,
681 flags
, /*InputIsPartial=*/true);
684 ConversionResult
ConvertUTF8toUTF32(const UTF8
**sourceStart
,
685 const UTF8
*sourceEnd
, UTF32
**targetStart
,
686 UTF32
*targetEnd
, ConversionFlags flags
) {
687 return ConvertUTF8toUTF32Impl(sourceStart
, sourceEnd
, targetStart
, targetEnd
,
688 flags
, /*InputIsPartial=*/false);
691 /* ---------------------------------------------------------------------
694 The fall-through switches in UTF-8 reading code save a
695 temp variable, some decrements & conditionals. The switches
696 are equivalent to the following loop:
698 int tmpBytesToRead = extraBytesToRead+1;
702 if (tmpBytesToRead) ch <<= 6;
703 } while (tmpBytesToRead > 0);
705 In UTF-8 writing code, the switches on "bytesToWrite" are
706 similarly unrolled loops.
708 --------------------------------------------------------------------- */