| Index: base/third_party/icu/icu_utf.cc
|
| ===================================================================
|
| --- base/third_party/icu/icu_utf.cc (revision 0)
|
| +++ base/third_party/icu/icu_utf.cc (revision 0)
|
| @@ -0,0 +1,228 @@
|
| +/*
|
| +******************************************************************************
|
| +*
|
| +* Copyright (C) 1999-2006, 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.
|
| +*/
|
| +
|
| +#include "base/third_party/icu/icu_utf.h"
|
| +
|
| +namespace base_icu {
|
| +
|
| +/**
|
| + * UTF8_ERROR_VALUE_1 and UTF8_ERROR_VALUE_2 are special error values for UTF-8,
|
| + * which need 1 or 2 bytes in UTF-8:
|
| + * \code
|
| + * U+0015 = NAK = Negative Acknowledge, C0 control character
|
| + * U+009f = highest C1 control character
|
| + * \endcode
|
| + *
|
| + * These are used by UTF8_..._SAFE macros so that they can return an error value
|
| + * that needs the same number of code units (bytes) as were seen by
|
| + * a macro. They should be tested with UTF_IS_ERROR() or UTF_IS_VALID().
|
| + *
|
| + * @deprecated ICU 2.4. Obsolete, see utf_old.h.
|
| + */
|
| +#define CBUTF8_ERROR_VALUE_1 0x15
|
| +
|
| +/**
|
| + * See documentation on UTF8_ERROR_VALUE_1 for details.
|
| + *
|
| + * @deprecated ICU 2.4. Obsolete, see utf_old.h.
|
| + */
|
| +#define CBUTF8_ERROR_VALUE_2 0x9f
|
| +
|
| +
|
| +/**
|
| + * Error value for all UTFs. This code point value will be set by macros with e>
|
| + * checking if an error is detected.
|
| + *
|
| + * @deprecated ICU 2.4. Obsolete, see utf_old.h.
|
| + */
|
| +#define CBUTF_ERROR_VALUE 0xffff
|
| +
|
| +/*
|
| + * 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.
|
| + */
|
| +const uint8
|
| +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]={
|
| + CBUTF8_ERROR_VALUE_1, CBUTF8_ERROR_VALUE_2, CBUTF_ERROR_VALUE, 0x10ffff,
|
| + 0x3ffffff, 0x7fffffff
|
| +};
|
| +
|
| +/*
|
| + * Handle the non-inline part of the U8_NEXT() macro and its obsolete sibling
|
| + * UTF8_NEXT_CHAR_SAFE().
|
| + *
|
| + * The "strict" parameter controls the error behavior:
|
| + * <0 "Safe" behavior of U8_NEXT(): All illegal byte sequences yield a negative
|
| + * code point result.
|
| + * 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.
|
| + *
|
| + * The special negative (<0) value -2 is used 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.
|
| + *
|
| + * Note that a UBool is the same as an int8_t.
|
| + */
|
| +UChar32
|
| +utf8_nextCharSafeBody(const uint8 *s, int32 *pi, int32 length, UChar32 c, UBool strict) {
|
| + int32 i=*pi;
|
| + uint8 count=CBU8_COUNT_TRAIL_BYTES(c);
|
| + if((i)+count<=(length)) {
|
| + uint8 trail, illegal=0;
|
| +
|
| + CBU8_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:
|
| + if(strict>=0) {
|
| + return CBUTF8_ERROR_VALUE_1;
|
| + } else {
|
| + return CBU_SENTINEL;
|
| + }
|
| + /* no default branch to optimize switch() - all values are covered */
|
| + }
|
| +
|
| + /*
|
| + * All the error handling should return a value
|
| + * that needs count bytes so that UTF8_GET_CHAR_SAFE() works right.
|
| + *
|
| + * Starting with Unicode 3.0.1, non-shortest forms are illegal.
|
| + * Starting with Unicode 3.2, surrogate code points must not be
|
| + * encoded in UTF-8, and there are no irregular sequences any more.
|
| + *
|
| + * U8_ macros (new in ICU 2.4) return negative values for error conditions.
|
| + */
|
| +
|
| + /* correct sequence - all trail bytes have (b7..b6)==(10)? */
|
| + /* illegal is also set if count>=4 */
|
| + if(illegal || (c)<utf8_minLegal[count] || (CBU_IS_SURROGATE(c) && strict!=-2)) {
|
| + /* error handling */
|
| + uint8 errorCount=count;
|
| + /* don't go beyond this sequence */
|
| + i=*pi;
|
| + while(count>0 && CBU8_IS_TRAIL(s[i])) {
|
| + ++(i);
|
| + --count;
|
| + }
|
| + if(strict>=0) {
|
| + c=utf8_errorValue[errorCount-count];
|
| + } else {
|
| + c=CBU_SENTINEL;
|
| + }
|
| + } else if((strict)>0 && CBU_IS_UNICODE_NONCHAR(c)) {
|
| + /* strict: forbid non-characters like U+fffe */
|
| + c=utf8_errorValue[count];
|
| + }
|
| + } else /* too few bytes left */ {
|
| + /* error handling */
|
| + int32 i0=i;
|
| + /* don't just set (i)=(length) in case there is an illegal sequence */
|
| + while((i)<(length) && CBU8_IS_TRAIL(s[i])) {
|
| + ++(i);
|
| + }
|
| + if(strict>=0) {
|
| + c=utf8_errorValue[i-i0];
|
| + } else {
|
| + c=CBU_SENTINEL;
|
| + }
|
| + }
|
| + *pi=i;
|
| + return c;
|
| +}
|
| +
|
| +} // namespace base_icu
|
|
|