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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_LIBDEXFILE_DEX_UTF_INL_H_
#define ART_LIBDEXFILE_DEX_UTF_INL_H_
#include "utf.h"
namespace art {
inline uint16_t GetTrailingUtf16Char(uint32_t maybe_pair) {
return static_cast<uint16_t>(maybe_pair >> 16);
}
inline uint16_t GetLeadingUtf16Char(uint32_t maybe_pair) {
return static_cast<uint16_t>(maybe_pair & 0x0000FFFF);
}
inline uint32_t GetUtf16FromUtf8(const char** utf8_data_in) {
const uint8_t one = *(*utf8_data_in)++;
if ((one & 0x80) == 0) {
// one-byte encoding
return one;
}
const uint8_t two = *(*utf8_data_in)++;
if ((one & 0x20) == 0) {
// two-byte encoding
return ((one & 0x1f) << 6) | (two & 0x3f);
}
const uint8_t three = *(*utf8_data_in)++;
if ((one & 0x10) == 0) {
return ((one & 0x0f) << 12) | ((two & 0x3f) << 6) | (three & 0x3f);
}
// Four byte encodings need special handling. We'll have
// to convert them into a surrogate pair.
const uint8_t four = *(*utf8_data_in)++;
// Since this is a 4 byte UTF-8 sequence, it will lie between
// U+10000 and U+1FFFFF.
//
// TODO: What do we do about values in (U+10FFFF, U+1FFFFF) ? The
// spec says they're invalid but nobody appears to check for them.
const uint32_t code_point = ((one & 0x0f) << 18) | ((two & 0x3f) << 12)
| ((three & 0x3f) << 6) | (four & 0x3f);
uint32_t surrogate_pair = 0;
// Step two: Write out the high (leading) surrogate to the bottom 16 bits
// of the of the 32 bit type.
surrogate_pair |= ((code_point >> 10) + 0xd7c0) & 0xffff;
// Step three : Write out the low (trailing) surrogate to the top 16 bits.
surrogate_pair |= ((code_point & 0x03ff) + 0xdc00) << 16;
return surrogate_pair;
}
inline int CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(const char* utf8_1,
const char* utf8_2) {
uint32_t c1, c2;
do {
c1 = *utf8_1;
c2 = *utf8_2;
// Did we reach a terminating character?
if (c1 == 0) {
return (c2 == 0) ? 0 : -1;
} else if (c2 == 0) {
return 1;
}
c1 = GetUtf16FromUtf8(&utf8_1);
c2 = GetUtf16FromUtf8(&utf8_2);
} while (c1 == c2);
const uint32_t leading_surrogate_diff = GetLeadingUtf16Char(c1) - GetLeadingUtf16Char(c2);
if (leading_surrogate_diff != 0) {
return static_cast<int>(leading_surrogate_diff);
}
return GetTrailingUtf16Char(c1) - GetTrailingUtf16Char(c2);
}
} // namespace art
#endif // ART_LIBDEXFILE_DEX_UTF_INL_H_