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/*
* Copyright (C) 2007 Apple Inc. All rights reserved.
* Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "UTF8.h"
#include "ASCIICType.h"
#include <wtf/StringHasher.h>
#include <wtf/unicode/CharacterNames.h>
namespace WTF {
namespace Unicode {
inline int inlineUTF8SequenceLengthNonASCII(char b0)
{
if ((b0 & 0xC0) != 0xC0)
return 0;
if ((b0 & 0xE0) == 0xC0)
return 2;
if ((b0 & 0xF0) == 0xE0)
return 3;
if ((b0 & 0xF8) == 0xF0)
return 4;
return 0;
}
inline int inlineUTF8SequenceLength(char b0)
{
return isASCII(b0) ? 1 : inlineUTF8SequenceLengthNonASCII(b0);
}
int UTF8SequenceLength(char b0)
{
return isASCII(b0) ? 1 : inlineUTF8SequenceLengthNonASCII(b0);
}
int decodeUTF8Sequence(const char* sequence)
{
// Handle 0-byte sequences (never valid).
const unsigned char b0 = sequence[0];
const int length = inlineUTF8SequenceLength(b0);
if (length == 0)
return -1;
// Handle 1-byte sequences (plain ASCII).
const unsigned char b1 = sequence[1];
if (length == 1) {
if (b1)
return -1;
return b0;
}
// Handle 2-byte sequences.
if ((b1 & 0xC0) != 0x80)
return -1;
const unsigned char b2 = sequence[2];
if (length == 2) {
if (b2)
return -1;
const int c = ((b0 & 0x1F) << 6) | (b1 & 0x3F);
if (c < 0x80)
return -1;
return c;
}
// Handle 3-byte sequences.
if ((b2 & 0xC0) != 0x80)
return -1;
const unsigned char b3 = sequence[3];
if (length == 3) {
if (b3)
return -1;
const int c = ((b0 & 0xF) << 12) | ((b1 & 0x3F) << 6) | (b2 & 0x3F);
if (c < 0x800)
return -1;
// UTF-16 surrogates should never appear in UTF-8 data.
if (c >= 0xD800 && c <= 0xDFFF)
return -1;
return c;
}
// Handle 4-byte sequences.
if ((b3 & 0xC0) != 0x80)
return -1;
const unsigned char b4 = sequence[4];
if (length == 4) {
if (b4)
return -1;
const int c = ((b0 & 0x7) << 18) | ((b1 & 0x3F) << 12) | ((b2 & 0x3F) << 6) | (b3 & 0x3F);
if (c < 0x10000 || c > 0x10FFFF)
return -1;
return c;
}
return -1;
}
// Once the bits are split out into bytes of UTF-8, this is a mask OR-ed
// into the first byte, depending on how many bytes follow. There are
// as many entries in this table as there are UTF-8 sequence types.
// (I.e., one byte sequence, two byte... etc.). Remember that sequencs
// for *legal* UTF-8 will be 4 or fewer bytes total.
static const unsigned char firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
ConversionResult convertLatin1ToUTF8(
const LChar** sourceStart, const LChar* sourceEnd,
char** targetStart, char* targetEnd)
{
ConversionResult result = conversionOK;
const LChar* source = *sourceStart;
char* target = *targetStart;
while (source < sourceEnd) {
UChar32 ch;
unsigned short bytesToWrite = 0;
const UChar32 byteMask = 0xBF;
const UChar32 byteMark = 0x80;
const LChar* oldSource = source; // In case we have to back up because of target overflow.
ch = static_cast<unsigned short>(*source++);
// Figure out how many bytes the result will require
if (ch < (UChar32)0x80)
bytesToWrite = 1;
else
bytesToWrite = 2;
target += bytesToWrite;
if (target > targetEnd) {
source = oldSource; // Back up source pointer!
target -= bytesToWrite;
result = targetExhausted;
break;
}
switch (bytesToWrite) { // note: everything falls through.
case 2:
*--target = (char)((ch | byteMark) & byteMask);
ch >>= 6;
case 1:
*--target = (char)(ch | firstByteMark[bytesToWrite]);
}
target += bytesToWrite;
}
*sourceStart = source;
*targetStart = target;
return result;
}
ConversionResult convertUTF16ToUTF8(
const UChar** sourceStart, const UChar* sourceEnd,
char** targetStart, char* targetEnd, bool strict)
{
ConversionResult result = conversionOK;
const UChar* source = *sourceStart;
char* target = *targetStart;
while (source < sourceEnd) {
UChar32 ch;
unsigned short bytesToWrite = 0;
const UChar32 byteMask = 0xBF;
const UChar32 byteMark = 0x80;
const UChar* oldSource = source; // In case we have to back up because of target overflow.
ch = static_cast<unsigned short>(*source++);
// If we have a surrogate pair, convert to UChar32 first.
if (ch >= 0xD800 && ch <= 0xDBFF) {
// If the 16 bits following the high surrogate are in the source buffer...
if (source < sourceEnd) {
UChar32 ch2 = static_cast<unsigned short>(*source);
// If it's a low surrogate, convert to UChar32.
if (ch2 >= 0xDC00 && ch2 <= 0xDFFF) {
ch = ((ch - 0xD800) << 10) + (ch2 - 0xDC00) + 0x0010000;
++source;
} else if (strict) { // it's an unpaired high surrogate
--source; // return to the illegal value itself
result = sourceIllegal;
break;
}
} else { // We don't have the 16 bits following the high surrogate.
--source; // return to the high surrogate
result = sourceExhausted;
break;
}
} else if (strict) {
// UTF-16 surrogate values are illegal in UTF-32
if (ch >= 0xDC00 && ch <= 0xDFFF) {
--source; // return to the illegal value itself
result = sourceIllegal;
break;
}
}
// Figure out how many bytes the result will require
if (ch < (UChar32)0x80) {
bytesToWrite = 1;
} else if (ch < (UChar32)0x800) {
bytesToWrite = 2;
} else if (ch < (UChar32)0x10000) {
bytesToWrite = 3;
} else if (ch < (UChar32)0x110000) {
bytesToWrite = 4;
} else {
bytesToWrite = 3;
ch = replacementCharacter;
}
target += bytesToWrite;
if (target > targetEnd) {
source = oldSource; // Back up source pointer!
target -= bytesToWrite;
result = targetExhausted;
break;
}
switch (bytesToWrite) { // note: everything falls through.
case 4: *--target = (char)((ch | byteMark) & byteMask); ch >>= 6;
case 3: *--target = (char)((ch | byteMark) & byteMask); ch >>= 6;
case 2: *--target = (char)((ch | byteMark) & byteMask); ch >>= 6;
case 1: *--target = (char)(ch | firstByteMark[bytesToWrite]);
}
target += bytesToWrite;
}
*sourceStart = source;
*targetStart = target;
return result;
}
// This must be called with the length pre-determined by the first byte.
// If presented with a length > 4, this returns false. The Unicode
// definition of UTF-8 goes up to 4-byte sequences.
static bool isLegalUTF8(const unsigned char* source, int length)
{
unsigned char a;
const unsigned char* srcptr = source + length;
switch (length) {
default: return false;
// Everything else falls through when "true"...
case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
case 2: if ((a = (*--srcptr)) > 0xBF) return false;
switch (*source) {
// no fall-through in this inner switch
case 0xE0: if (a < 0xA0) return false; break;
case 0xED: if (a > 0x9F) return false; break;
case 0xF0: if (a < 0x90) return false; break;
case 0xF4: if (a > 0x8F) return false; break;
default: if (a < 0x80) return false;
}
case 1: if (*source >= 0x80 && *source < 0xC2) return false;
}
if (*source > 0xF4)
return false;
return true;
}
// Magic values subtracted from a buffer value during UTF8 conversion.
// This table contains as many values as there might be trailing bytes
// in a UTF-8 sequence.
static const UChar32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL, 0x03C82080UL, static_cast<UChar32>(0xFA082080UL), static_cast<UChar32>(0x82082080UL) };
static inline UChar32 readUTF8Sequence(const char*& sequence, unsigned length)
{
UChar32 character = 0;
// The cases all fall through.
switch (length) {
case 6: character += static_cast<unsigned char>(*sequence++); character <<= 6;
case 5: character += static_cast<unsigned char>(*sequence++); character <<= 6;
case 4: character += static_cast<unsigned char>(*sequence++); character <<= 6;
case 3: character += static_cast<unsigned char>(*sequence++); character <<= 6;
case 2: character += static_cast<unsigned char>(*sequence++); character <<= 6;
case 1: character += static_cast<unsigned char>(*sequence++);
}
return character - offsetsFromUTF8[length - 1];
}
ConversionResult convertUTF8ToUTF16(
const char** sourceStart, const char* sourceEnd,
UChar** targetStart, UChar* targetEnd, bool* sourceAllASCII, bool strict)
{
ConversionResult result = conversionOK;
const char* source = *sourceStart;
UChar* target = *targetStart;
UChar orAllData = 0;
while (source < sourceEnd) {
int utf8SequenceLength = inlineUTF8SequenceLength(*source);
if (sourceEnd - source < utf8SequenceLength) {
result = sourceExhausted;
break;
}
// Do this check whether lenient or strict
if (!isLegalUTF8(reinterpret_cast<const unsigned char*>(source), utf8SequenceLength)) {
result = sourceIllegal;
break;
}
UChar32 character = readUTF8Sequence(source, utf8SequenceLength);
if (target >= targetEnd) {
source -= utf8SequenceLength; // Back up source pointer!
result = targetExhausted;
break;
}
if (U_IS_BMP(character)) {
// UTF-16 surrogate values are illegal in UTF-32
if (U_IS_SURROGATE(character)) {
if (strict) {
source -= utf8SequenceLength; // return to the illegal value itself
result = sourceIllegal;
break;
} else {
*target++ = replacementCharacter;
orAllData |= replacementCharacter;
}
} else {
*target++ = character; // normal case
orAllData |= character;
}
} else if (U_IS_SUPPLEMENTARY(character)) {
// target is a character in range 0xFFFF - 0x10FFFF
if (target + 1 >= targetEnd) {
source -= utf8SequenceLength; // Back up source pointer!
result = targetExhausted;
break;
}
*target++ = U16_LEAD(character);
*target++ = U16_TRAIL(character);
orAllData = 0xffff;
} else {
if (strict) {
source -= utf8SequenceLength; // return to the start
result = sourceIllegal;
break; // Bail out; shouldn't continue
} else {
*target++ = replacementCharacter;
orAllData |= replacementCharacter;
}
}
}
*sourceStart = source;
*targetStart = target;
if (sourceAllASCII)
*sourceAllASCII = !(orAllData & ~0x7f);
return result;
}
unsigned calculateStringHashAndLengthFromUTF8MaskingTop8Bits(const char* data, const char* dataEnd, unsigned& dataLength, unsigned& utf16Length)
{
if (!data)
return 0;
StringHasher stringHasher;
dataLength = 0;
utf16Length = 0;
while (data < dataEnd || (!dataEnd && *data)) {
if (isASCII(*data)) {
stringHasher.addCharacter(*data++);
dataLength++;
utf16Length++;
continue;
}
int utf8SequenceLength = inlineUTF8SequenceLengthNonASCII(*data);
dataLength += utf8SequenceLength;
if (!dataEnd) {
for (int i = 1; i < utf8SequenceLength; ++i) {
if (!data[i])
return 0;
}
} else if (dataEnd - data < utf8SequenceLength)
return 0;
if (!isLegalUTF8(reinterpret_cast<const unsigned char*>(data), utf8SequenceLength))
return 0;
UChar32 character = readUTF8Sequence(data, utf8SequenceLength);
ASSERT(!isASCII(character));
if (U_IS_BMP(character)) {
// UTF-16 surrogate values are illegal in UTF-32
if (U_IS_SURROGATE(character))
return 0;
stringHasher.addCharacter(static_cast<UChar>(character)); // normal case
utf16Length++;
} else if (U_IS_SUPPLEMENTARY(character)) {
stringHasher.addCharacters(static_cast<UChar>(U16_LEAD(character)),
static_cast<UChar>(U16_TRAIL(character)));
utf16Length += 2;
} else
return 0;
}
return stringHasher.hashWithTop8BitsMasked();
}
bool equalUTF16WithUTF8(const UChar* a, const UChar* aEnd, const char* b, const char* bEnd)
{
while (b < bEnd) {
if (isASCII(*b)) {
if (*a++ != *b++)
return false;
continue;
}
int utf8SequenceLength = inlineUTF8SequenceLengthNonASCII(*b);
if (bEnd - b < utf8SequenceLength)
return false;
if (!isLegalUTF8(reinterpret_cast<const unsigned char*>(b), utf8SequenceLength))
return 0;
UChar32 character = readUTF8Sequence(b, utf8SequenceLength);
ASSERT(!isASCII(character));
if (U_IS_BMP(character)) {
// UTF-16 surrogate values are illegal in UTF-32
if (U_IS_SURROGATE(character))
return false;
if (*a++ != character)
return false;
} else if (U_IS_SUPPLEMENTARY(character)) {
if (*a++ != U16_LEAD(character))
return false;
if (*a++ != U16_TRAIL(character))
return false;
} else
return false;
}
return a == aEnd;
}
} // namespace Unicode
} // namespace WTF