/*
*******************************************************************************
*
-* Copyright (C) 2003, International Business Machines
+* Copyright (C) 2003-2006, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* but it is sufficient for a UCharIterator that returns only UChars anyway.
*
* The code is copied and modified from utf_impl.c and utf8.h.
- * The "strict" argument in the implementation functions is completely removed,
- * using the "<0" branch from the original code.
- * Checks for surrogate code points are removed for the leniency
- * described above.
+ *
+ * Change 2006feb08: Much of the implementation code is replaced by calling
+ * the utf_impl.c functions which accept a new "strict" parameter value
+ * of -2 implementing exactly this leniency.
*/
-static const UChar32
-lenient8_minLegal[4]={ 0, 0x80, 0x800, 0x10000 };
-
-static UChar32
-lenient8_nextCharSafeBody(const uint8_t *s, int32_t *pi, int32_t length, UChar32 c) {
- int32_t i=*pi;
- uint8_t count=U8_COUNT_TRAIL_BYTES(c);
- if((i)+count<=(length)) {
- uint8_t trail, illegal=0;
-
- U8_MASK_LEAD_BYTE((c), count);
- /* count==0 for illegally leading trail bytes and the illegal bytes 0xfe and 0xff */
- switch(count) {
- /* each branch falls through to the next one */
- case 5:
- case 4:
- /* count>=4 is always illegal: no more than 3 trail bytes in Unicode's UTF-8 */
- illegal=1;
- break;
- case 3:
- trail=s[(i)++];
- (c)=((c)<<6)|(trail&0x3f);
- if(c<0x110) {
- illegal|=(trail&0xc0)^0x80;
- } else {
- /* code point>0x10ffff, outside Unicode */
- illegal=1;
- break;
- }
- case 2:
- trail=s[(i)++];
- (c)=((c)<<6)|(trail&0x3f);
- illegal|=(trail&0xc0)^0x80;
- case 1:
- trail=s[(i)++];
- (c)=((c)<<6)|(trail&0x3f);
- illegal|=(trail&0xc0)^0x80;
- break;
- case 0:
- return U_SENTINEL;
- /* no default branch to optimize switch() - all values are covered */
- }
-
- /* correct sequence - all trail bytes have (b7..b6)==(10)? */
- /* illegal is also set if count>=4 */
- if(illegal || (c)<lenient8_minLegal[count]) {
- /* error handling */
- uint8_t errorCount=count;
- /* don't go beyond this sequence */
- i=*pi;
- while(count>0 && U8_IS_TRAIL(s[i])) {
- ++(i);
- --count;
- }
- c=U_SENTINEL;
- }
- } else /* too few bytes left */ {
- /* error handling */
- int32_t i0=i;
- /* don't just set (i)=(length) in case there is an illegal sequence */
- while((i)<(length) && U8_IS_TRAIL(s[i])) {
- ++(i);
- }
- c=U_SENTINEL;
- }
- *pi=i;
- return c;
-}
-
-static UChar32
-lenient8_prevCharSafeBody(const uint8_t *s, int32_t start, int32_t *pi, UChar32 c) {
- int32_t i=*pi;
- uint8_t b, count=1, shift=6;
-
- /* extract value bits from the last trail byte */
- c&=0x3f;
-
- for(;;) {
- if(i<=start) {
- /* no lead byte at all */
- return U_SENTINEL;
- }
-
- /* read another previous byte */
- b=s[--i];
- if((uint8_t)(b-0x80)<0x7e) { /* 0x80<=b<0xfe */
- if(b&0x40) {
- /* lead byte, this will always end the loop */
- uint8_t shouldCount=U8_COUNT_TRAIL_BYTES(b);
-
- if(count==shouldCount) {
- /* set the new position */
- *pi=i;
- U8_MASK_LEAD_BYTE(b, count);
- c|=(UChar32)b<<shift;
- if(count>=4 || c>0x10ffff || c<lenient8_minLegal[count]) {
- /* illegal sequence */
- if(count>=4) {
- count=3;
- }
- c=U_SENTINEL;
- } else {
- /* exit with correct c */
- }
- } else {
- /* the lead byte does not match the number of trail bytes */
- /* only set the position to the lead byte if it would
- include the trail byte that we started with */
- if(count<shouldCount) {
- *pi=i;
- }
- c=U_SENTINEL;
- }
- break;
- } else if(count<5) {
- /* trail byte */
- c|=(UChar32)(b&0x3f)<<shift;
- ++count;
- shift+=6;
- } else {
- /* more than 5 trail bytes is illegal */
- c=U_SENTINEL;
- break;
- }
- } else {
- /* single-byte character precedes trailing bytes */
- c=U_SENTINEL;
- break;
- }
- }
- return c;
-}
-
#define L8_NEXT(s, i, length, c) { \
- (c)=(s)[(i)++]; \
+ (c)=(uint8_t)(s)[(i)++]; \
if((c)>=0x80) { \
if(U8_IS_LEAD(c)) { \
- (c)=lenient8_nextCharSafeBody(s, &(i), (int32_t)(length), c); \
+ (c)=utf8_nextCharSafeBody((const uint8_t *)s, &(i), (int32_t)(length), c, -2); \
} else { \
(c)=U_SENTINEL; \
} \
}
#define L8_PREV(s, start, i, c) { \
- (c)=(s)[--(i)]; \
+ (c)=(uint8_t)(s)[--(i)]; \
if((c)>=0x80) { \
if((c)<=0xbf) { \
- (c)=lenient8_prevCharSafeBody(s, start, &(i), c); \
+ (c)=utf8_prevCharSafeBody((const uint8_t *)s, start, &(i), c, -2); \
} else { \
(c)=U_SENTINEL; \
} \
projects / apple / icu.git / blobdiff