+++ /dev/null
-/*
-******************************************************************************
-*
-* Copyright (C) 1999-2012, International Business Machines
-* Corporation and others. All Rights Reserved.
-*
-******************************************************************************
-* file name: utf_impl.c
-* encoding: US-ASCII
-* tab size: 8 (not used)
-* indentation:4
-*
-* created on: 1999sep13
-* created by: Markus W. Scherer
-*
-* This file provides implementation functions for macros in the utfXX.h
-* that would otherwise be too long as macros.
-*/
-
-/* set import/export definitions */
-#ifndef U_UTF8_IMPL
-# define U_UTF8_IMPL
-#endif
-
-#include "unicode/utypes.h"
-#include "unicode/utf.h"
-#include "unicode/utf8.h"
-#include "unicode/utf_old.h"
-#include "uassert.h"
-
-/*
- * This table could be replaced on many machines by
- * a few lines of assembler code using an
- * "index of first 0-bit from msb" instruction and
- * one or two more integer instructions.
- *
- * For example, on an i386, do something like
- * - MOV AL, leadByte
- * - NOT AL (8-bit, leave b15..b8==0..0, reverse only b7..b0)
- * - MOV AH, 0
- * - BSR BX, AX (16-bit)
- * - MOV AX, 6 (result)
- * - JZ finish (ZF==1 if leadByte==0xff)
- * - SUB AX, BX (result)
- * -finish:
- * (BSR: Bit Scan Reverse, scans for a 1-bit, starting from the MSB)
- *
- * In Unicode, all UTF-8 byte sequences with more than 4 bytes are illegal;
- * lead bytes above 0xf4 are illegal.
- * We keep them in this table for skipping long ISO 10646-UTF-8 sequences.
- */
-U_EXPORT const uint8_t
-utf8_countTrailBytes[256]={
- 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,
- 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,
-
- 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,
- 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,
-
- 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,
- 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,
-
- 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,
-
- 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
- 3, 3, 3, 3, 3,
- 3, 3, 3, /* illegal in Unicode */
- 4, 4, 4, 4, /* illegal in Unicode */
- 5, 5, /* illegal in Unicode */
- 0, 0 /* illegal bytes 0xfe and 0xff */
-};
-
-static const UChar32
-utf8_minLegal[4]={ 0, 0x80, 0x800, 0x10000 };
-
-static const UChar32
-utf8_errorValue[6]={
- UTF8_ERROR_VALUE_1, UTF8_ERROR_VALUE_2, UTF_ERROR_VALUE, 0x10ffff,
- 0x3ffffff, 0x7fffffff
-};
-
-static UChar32
-errorValue(int32_t count, int8_t strict) {
- if(strict>=0) {
- return utf8_errorValue[count];
- } else if(strict==-3) {
- return 0xfffd;
- } else {
- return U_SENTINEL;
- }
-}
-
-/*
- * Handle the non-inline part of the U8_NEXT() and U8_NEXT_FFFD() macros
- * and their obsolete sibling UTF8_NEXT_CHAR_SAFE().
- *
- * U8_NEXT() supports NUL-terminated strings indicated via length<0.
- *
- * The "strict" parameter controls the error behavior:
- * <0 "Safe" behavior of U8_NEXT():
- * -1: All illegal byte sequences yield U_SENTINEL=-1.
- * -2: Same as -1, except for lenient treatment of surrogate code points as legal.
- * Some implementations use this for roundtripping of
- * Unicode 16-bit strings that are not well-formed UTF-16, that is, they
- * contain unpaired surrogates.
- * -3: All illegal byte sequences yield U+FFFD.
- * 0 Obsolete "safe" behavior of UTF8_NEXT_CHAR_SAFE(..., FALSE):
- * All illegal byte sequences yield a positive code point such that this
- * result code point would be encoded with the same number of bytes as
- * the illegal sequence.
- * >0 Obsolete "strict" behavior of UTF8_NEXT_CHAR_SAFE(..., TRUE):
- * Same as the obsolete "safe" behavior, but non-characters are also treated
- * like illegal sequences.
- *
- * Note that a UBool is the same as an int8_t.
- */
-U_CAPI UChar32 U_EXPORT2
-utf8_nextCharSafeBody(const uint8_t *s, int32_t *pi, int32_t length, UChar32 c, UBool strict) {
- int32_t i=*pi;
- uint8_t count=U8_COUNT_TRAIL_BYTES(c);
- U_ASSERT(count <= 5); /* U8_COUNT_TRAIL_BYTES returns value 0...5 */
- if(i+count<=length || length<0) {
- uint8_t trail;
-
- U8_MASK_LEAD_BYTE(c, count);
- /* support NUL-terminated strings: do not read beyond the first non-trail byte */
- switch(count) {
- /* each branch falls through to the next one */
- case 0:
- /* count==0 for illegally leading trail bytes and the illegal bytes 0xfe and 0xff */
- case 5:
- case 4:
- /* count>=4 is always illegal: no more than 3 trail bytes in Unicode's UTF-8 */
- break;
- case 3:
- trail=s[i++]-0x80;
- c=(c<<6)|trail;
- /* c>=0x110 would result in code point>0x10ffff, outside Unicode */
- if(c>=0x110 || trail>0x3f) { break; }
- case 2:
- trail=s[i++]-0x80;
- c=(c<<6)|trail;
- /*
- * test for a surrogate d800..dfff unless we are lenient:
- * before the last (c<<6), a surrogate is c=360..37f
- */
- if(((c&0xffe0)==0x360 && strict!=-2) || trail>0x3f) { break; }
- case 1:
- trail=s[i++]-0x80;
- c=(c<<6)|trail;
- if(trail>0x3f) { break; }
- /* correct sequence - all trail bytes have (b7..b6)==(10) */
- if(c>=utf8_minLegal[count] &&
- /* strict: forbid non-characters like U+fffe */
- (strict<=0 || !U_IS_UNICODE_NONCHAR(c))) {
- *pi=i;
- return c;
- }
- /* no default branch to optimize switch() - all values are covered */
- }
- } else {
- /* too few bytes left */
- count=length-i;
- }
-
- /* error handling */
- i=*pi;
- while(count>0 && U8_IS_TRAIL(s[i])) {
- ++i;
- --count;
- }
- c=errorValue(i-*pi, strict);
- *pi=i;
- return c;
-}
-
-U_CAPI int32_t U_EXPORT2
-utf8_appendCharSafeBody(uint8_t *s, int32_t i, int32_t length, UChar32 c, UBool *pIsError) {
- if((uint32_t)(c)<=0x7ff) {
- if((i)+1<(length)) {
- (s)[(i)++]=(uint8_t)(((c)>>6)|0xc0);
- (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80);
- return i;
- }
- } else if((uint32_t)(c)<=0xffff) {
- /* Starting with Unicode 3.2, surrogate code points must not be encoded in UTF-8. */
- if((i)+2<(length) && !U_IS_SURROGATE(c)) {
- (s)[(i)++]=(uint8_t)(((c)>>12)|0xe0);
- (s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80);
- (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80);
- return i;
- }
- } else if((uint32_t)(c)<=0x10ffff) {
- if((i)+3<(length)) {
- (s)[(i)++]=(uint8_t)(((c)>>18)|0xf0);
- (s)[(i)++]=(uint8_t)((((c)>>12)&0x3f)|0x80);
- (s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80);
- (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80);
- return i;
- }
- }
- /* c>0x10ffff or not enough space, write an error value */
- if(pIsError!=NULL) {
- *pIsError=TRUE;
- } else {
- length-=i;
- if(length>0) {
- int32_t offset;
- if(length>3) {
- length=3;
- }
- s+=i;
- offset=0;
- c=utf8_errorValue[length-1];
- UTF8_APPEND_CHAR_UNSAFE(s, offset, c);
- i=i+offset;
- }
- }
- return i;
-}
-
-U_CAPI UChar32 U_EXPORT2
-utf8_prevCharSafeBody(const uint8_t *s, int32_t start, int32_t *pi, UChar32 c, UBool strict) {
- int32_t i=*pi;
- uint8_t b, count=1, shift=6;
-
- if(!U8_IS_TRAIL(c)) { return errorValue(0, strict); }
-
- /* extract value bits from the last trail byte */
- c&=0x3f;
-
- for(;;) {
- if(i<=start) {
- /* no lead byte at all */
- return errorValue(0, strict);
- }
-
- /* 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<utf8_minLegal[count] || (U_IS_SURROGATE(c) && strict!=-2) || (strict>0 && U_IS_UNICODE_NONCHAR(c))) {
- /* illegal sequence or (strict and non-character) */
- if(count>=4) {
- count=3;
- }
- c=errorValue(count, strict);
- } 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=errorValue(count, strict);
- } else {
- c=errorValue(0, strict);
- }
- }
- break;
- } else if(count<5) {
- /* trail byte */
- c|=(UChar32)(b&0x3f)<<shift;
- ++count;
- shift+=6;
- } else {
- /* more than 5 trail bytes is illegal */
- c=errorValue(0, strict);
- break;
- }
- } else {
- /* single-byte character precedes trailing bytes */
- c=errorValue(0, strict);
- break;
- }
- }
- return c;
-}
-
-U_CAPI int32_t U_EXPORT2
-utf8_back1SafeBody(const uint8_t *s, int32_t start, int32_t i) {
- /* i had been decremented once before the function call */
- int32_t I=i, Z;
- uint8_t b;
-
- /* read at most the 6 bytes s[Z] to s[i], inclusively */
- if(I-5>start) {
- Z=I-5;
- } else {
- Z=start;
- }
-
- /* return I if the sequence starting there is long enough to include i */
- do {
- b=s[I];
- if((uint8_t)(b-0x80)>=0x7e) { /* not 0x80<=b<0xfe */
- break;
- } else if(b>=0xc0) {
- if(U8_COUNT_TRAIL_BYTES(b)>=(i-I)) {
- return I;
- } else {
- break;
- }
- }
- } while(Z<=--I);
-
- /* return i itself to be consistent with the FWD_1 macro */
- return i;
-}
projects / apple / icu.git / blobdiff