1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_LIBDEXFILE_DEX_UTF_INL_H_ 18 #define ART_LIBDEXFILE_DEX_UTF_INL_H_ 19 20 #include "utf.h" 21 22 namespace art { 23 24 inline uint16_t GetTrailingUtf16Char(uint32_t maybe_pair) { 25 return static_cast<uint16_t>(maybe_pair >> 16); 26 } 27 28 inline uint16_t GetLeadingUtf16Char(uint32_t maybe_pair) { 29 return static_cast<uint16_t>(maybe_pair & 0x0000FFFF); 30 } 31 32 inline uint32_t GetUtf16FromUtf8(const char** utf8_data_in) { 33 const uint8_t one = *(*utf8_data_in)++; 34 if ((one & 0x80) == 0) { 35 // one-byte encoding 36 return one; 37 } 38 39 const uint8_t two = *(*utf8_data_in)++; 40 if ((one & 0x20) == 0) { 41 // two-byte encoding 42 return ((one & 0x1f) << 6) | (two & 0x3f); 43 } 44 45 const uint8_t three = *(*utf8_data_in)++; 46 if ((one & 0x10) == 0) { 47 return ((one & 0x0f) << 12) | ((two & 0x3f) << 6) | (three & 0x3f); 48 } 49 50 // Four byte encodings need special handling. We'll have 51 // to convert them into a surrogate pair. 52 const uint8_t four = *(*utf8_data_in)++; 53 54 // Since this is a 4 byte UTF-8 sequence, it will lie between 55 // U+10000 and U+1FFFFF. 56 // 57 // TODO: What do we do about values in (U+10FFFF, U+1FFFFF) ? The 58 // spec says they're invalid but nobody appears to check for them. 59 const uint32_t code_point = ((one & 0x0f) << 18) | ((two & 0x3f) << 12) 60 | ((three & 0x3f) << 6) | (four & 0x3f); 61 62 uint32_t surrogate_pair = 0; 63 // Step two: Write out the high (leading) surrogate to the bottom 16 bits 64 // of the of the 32 bit type. 65 surrogate_pair |= ((code_point >> 10) + 0xd7c0) & 0xffff; 66 // Step three : Write out the low (trailing) surrogate to the top 16 bits. 67 surrogate_pair |= ((code_point & 0x03ff) + 0xdc00) << 16; 68 69 return surrogate_pair; 70 } 71 72 inline int CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(const char* utf8_1, 73 const char* utf8_2) { 74 uint32_t c1, c2; 75 do { 76 c1 = *utf8_1; 77 c2 = *utf8_2; 78 // Did we reach a terminating character? 79 if (c1 == 0) { 80 return (c2 == 0) ? 0 : -1; 81 } else if (c2 == 0) { 82 return 1; 83 } 84 85 c1 = GetUtf16FromUtf8(&utf8_1); 86 c2 = GetUtf16FromUtf8(&utf8_2); 87 } while (c1 == c2); 88 89 const uint32_t leading_surrogate_diff = GetLeadingUtf16Char(c1) - GetLeadingUtf16Char(c2); 90 if (leading_surrogate_diff != 0) { 91 return static_cast<int>(leading_surrogate_diff); 92 } 93 94 return GetTrailingUtf16Char(c1) - GetTrailingUtf16Char(c2); 95 } 96 97 } // namespace art 98 99 #endif // ART_LIBDEXFILE_DEX_UTF_INL_H_ 100
