| /* |
| * 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. |
| */ |
| |
| #include "utf.h" |
| |
| #include <android-base/logging.h> |
| #include <android-base/stringprintf.h> |
| #include <android-base/strings.h> |
| |
| #include "base/casts.h" |
| #include "utf-inl.h" |
| |
| namespace art { |
| |
| using android::base::StringAppendF; |
| |
| // This is used only from debugger and test code. |
| size_t CountModifiedUtf8Chars(const char* utf8) { |
| return CountModifiedUtf8Chars(utf8, strlen(utf8)); |
| } |
| |
| /* |
| * This does not validate UTF8 rules (nor did older code). But it gets the right answer |
| * for valid UTF-8 and that's fine because it's used only to size a buffer for later |
| * conversion. |
| * |
| * Modified UTF-8 consists of a series of bytes up to 21 bit Unicode code points as follows: |
| * U+0001 - U+007F 0xxxxxxx |
| * U+0080 - U+07FF 110xxxxx 10xxxxxx |
| * U+0800 - U+FFFF 1110xxxx 10xxxxxx 10xxxxxx |
| * U+10000 - U+1FFFFF 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx |
| * |
| * U+0000 is encoded using the 2nd form to avoid nulls inside strings (this differs from |
| * standard UTF-8). |
| * The four byte encoding converts to two utf16 characters. |
| */ |
| size_t CountModifiedUtf8Chars(const char* utf8, size_t byte_count) { |
| DCHECK_LE(byte_count, strlen(utf8)); |
| size_t len = 0; |
| const char* end = utf8 + byte_count; |
| for (; utf8 < end; ++utf8) { |
| int ic = *utf8; |
| len++; |
| if (LIKELY((ic & 0x80) == 0)) { |
| // One-byte encoding. |
| continue; |
| } |
| // Two- or three-byte encoding. |
| utf8++; |
| if ((ic & 0x20) == 0) { |
| // Two-byte encoding. |
| continue; |
| } |
| utf8++; |
| if ((ic & 0x10) == 0) { |
| // Three-byte encoding. |
| continue; |
| } |
| |
| // Four-byte encoding: needs to be converted into a surrogate |
| // pair. |
| utf8++; |
| len++; |
| } |
| return len; |
| } |
| |
| // This is used only from debugger and test code. |
| void ConvertModifiedUtf8ToUtf16(uint16_t* utf16_data_out, const char* utf8_data_in) { |
| while (*utf8_data_in != '\0') { |
| const uint32_t ch = GetUtf16FromUtf8(&utf8_data_in); |
| const uint16_t leading = GetLeadingUtf16Char(ch); |
| const uint16_t trailing = GetTrailingUtf16Char(ch); |
| |
| *utf16_data_out++ = leading; |
| if (trailing != 0) { |
| *utf16_data_out++ = trailing; |
| } |
| } |
| } |
| |
| void ConvertModifiedUtf8ToUtf16(uint16_t* utf16_data_out, size_t out_chars, |
| const char* utf8_data_in, size_t in_bytes) { |
| const char *in_start = utf8_data_in; |
| const char *in_end = utf8_data_in + in_bytes; |
| uint16_t *out_p = utf16_data_out; |
| |
| if (LIKELY(out_chars == in_bytes)) { |
| // Common case where all characters are ASCII. |
| for (const char *p = in_start; p < in_end;) { |
| // Safe even if char is signed because ASCII characters always have |
| // the high bit cleared. |
| *out_p++ = dchecked_integral_cast<uint16_t>(*p++); |
| } |
| return; |
| } |
| |
| // String contains non-ASCII characters. |
| for (const char *p = in_start; p < in_end;) { |
| const uint32_t ch = GetUtf16FromUtf8(&p); |
| const uint16_t leading = GetLeadingUtf16Char(ch); |
| const uint16_t trailing = GetTrailingUtf16Char(ch); |
| |
| *out_p++ = leading; |
| if (trailing != 0) { |
| *out_p++ = trailing; |
| } |
| } |
| } |
| |
| void ConvertUtf16ToModifiedUtf8(char* utf8_out, size_t byte_count, |
| const uint16_t* utf16_in, size_t char_count) { |
| if (LIKELY(byte_count == char_count)) { |
| // Common case where all characters are ASCII. |
| const uint16_t *utf16_end = utf16_in + char_count; |
| for (const uint16_t *p = utf16_in; p < utf16_end;) { |
| *utf8_out++ = dchecked_integral_cast<char>(*p++); |
| } |
| return; |
| } |
| |
| // String contains non-ASCII characters. |
| while (char_count--) { |
| const uint16_t ch = *utf16_in++; |
| if (ch > 0 && ch <= 0x7f) { |
| *utf8_out++ = ch; |
| } else { |
| // Char_count == 0 here implies we've encountered an unpaired |
| // surrogate and we have no choice but to encode it as 3-byte UTF |
| // sequence. Note that unpaired surrogates can occur as a part of |
| // "normal" operation. |
| if ((ch >= 0xd800 && ch <= 0xdbff) && (char_count > 0)) { |
| const uint16_t ch2 = *utf16_in; |
| |
| // Check if the other half of the pair is within the expected |
| // range. If it isn't, we will have to emit both "halves" as |
| // separate 3 byte sequences. |
| if (ch2 >= 0xdc00 && ch2 <= 0xdfff) { |
| utf16_in++; |
| char_count--; |
| const uint32_t code_point = (ch << 10) + ch2 - 0x035fdc00; |
| *utf8_out++ = (code_point >> 18) | 0xf0; |
| *utf8_out++ = ((code_point >> 12) & 0x3f) | 0x80; |
| *utf8_out++ = ((code_point >> 6) & 0x3f) | 0x80; |
| *utf8_out++ = (code_point & 0x3f) | 0x80; |
| continue; |
| } |
| } |
| |
| if (ch > 0x07ff) { |
| // Three byte encoding. |
| *utf8_out++ = (ch >> 12) | 0xe0; |
| *utf8_out++ = ((ch >> 6) & 0x3f) | 0x80; |
| *utf8_out++ = (ch & 0x3f) | 0x80; |
| } else /*(ch > 0x7f || ch == 0)*/ { |
| // Two byte encoding. |
| *utf8_out++ = (ch >> 6) | 0xc0; |
| *utf8_out++ = (ch & 0x3f) | 0x80; |
| } |
| } |
| } |
| } |
| |
| int32_t ComputeUtf16HashFromModifiedUtf8(const char* utf8, size_t utf16_length) { |
| uint32_t hash = 0; |
| while (utf16_length != 0u) { |
| const uint32_t pair = GetUtf16FromUtf8(&utf8); |
| const uint16_t first = GetLeadingUtf16Char(pair); |
| hash = hash * 31 + first; |
| --utf16_length; |
| const uint16_t second = GetTrailingUtf16Char(pair); |
| if (second != 0) { |
| hash = hash * 31 + second; |
| DCHECK_NE(utf16_length, 0u); |
| --utf16_length; |
| } |
| } |
| return static_cast<int32_t>(hash); |
| } |
| |
| uint32_t ComputeModifiedUtf8Hash(const char* chars) { |
| uint32_t hash = 0; |
| while (*chars != '\0') { |
| hash = hash * 31 + static_cast<uint8_t>(*chars); |
| ++chars; |
| } |
| return hash; |
| } |
| |
| int CompareModifiedUtf8ToUtf16AsCodePointValues(const char* utf8, const uint16_t* utf16, |
| size_t utf16_length) { |
| for (;;) { |
| if (*utf8 == '\0') { |
| return (utf16_length == 0) ? 0 : -1; |
| } else if (utf16_length == 0) { |
| return 1; |
| } |
| |
| const uint32_t pair = GetUtf16FromUtf8(&utf8); |
| |
| // First compare the leading utf16 char. |
| const uint16_t lhs = GetLeadingUtf16Char(pair); |
| const uint16_t rhs = *utf16++; |
| --utf16_length; |
| if (lhs != rhs) { |
| return lhs > rhs ? 1 : -1; |
| } |
| |
| // Then compare the trailing utf16 char. First check if there |
| // are any characters left to consume. |
| const uint16_t lhs2 = GetTrailingUtf16Char(pair); |
| if (lhs2 != 0) { |
| if (utf16_length == 0) { |
| return 1; |
| } |
| |
| const uint16_t rhs2 = *utf16++; |
| --utf16_length; |
| if (lhs2 != rhs2) { |
| return lhs2 > rhs2 ? 1 : -1; |
| } |
| } |
| } |
| } |
| |
| size_t CountUtf8Bytes(const uint16_t* chars, size_t char_count) { |
| size_t result = 0; |
| const uint16_t *end = chars + char_count; |
| while (chars < end) { |
| const uint16_t ch = *chars++; |
| if (LIKELY(ch != 0 && ch < 0x80)) { |
| result++; |
| continue; |
| } |
| if (ch < 0x800) { |
| result += 2; |
| continue; |
| } |
| if (ch >= 0xd800 && ch < 0xdc00) { |
| if (chars < end) { |
| const uint16_t ch2 = *chars; |
| // If we find a properly paired surrogate, we emit it as a 4 byte |
| // UTF sequence. If we find an unpaired leading or trailing surrogate, |
| // we emit it as a 3 byte sequence like would have done earlier. |
| if (ch2 >= 0xdc00 && ch2 < 0xe000) { |
| chars++; |
| result += 4; |
| continue; |
| } |
| } |
| } |
| result += 3; |
| } |
| return result; |
| } |
| |
| static inline constexpr bool NeedsEscaping(uint16_t ch) { |
| return (ch < ' ' || ch > '~'); |
| } |
| |
| std::string PrintableChar(uint16_t ch) { |
| std::string result; |
| result += '\''; |
| if (NeedsEscaping(ch)) { |
| StringAppendF(&result, "\\u%04x", ch); |
| } else { |
| result += static_cast<std::string::value_type>(ch); |
| } |
| result += '\''; |
| return result; |
| } |
| |
| std::string PrintableString(const char* utf) { |
| std::string result; |
| result += '"'; |
| const char* p = utf; |
| size_t char_count = CountModifiedUtf8Chars(p); |
| for (size_t i = 0; i < char_count; ++i) { |
| uint32_t ch = GetUtf16FromUtf8(&p); |
| if (ch == '\\') { |
| result += "\\\\"; |
| } else if (ch == '\n') { |
| result += "\\n"; |
| } else if (ch == '\r') { |
| result += "\\r"; |
| } else if (ch == '\t') { |
| result += "\\t"; |
| } else { |
| const uint16_t leading = GetLeadingUtf16Char(ch); |
| |
| if (NeedsEscaping(leading)) { |
| StringAppendF(&result, "\\u%04x", leading); |
| } else { |
| result += static_cast<std::string::value_type>(leading); |
| } |
| |
| const uint32_t trailing = GetTrailingUtf16Char(ch); |
| if (trailing != 0) { |
| // All high surrogates will need escaping. |
| StringAppendF(&result, "\\u%04x", trailing); |
| } |
| } |
| } |
| result += '"'; |
| return result; |
| } |
| |
| } // namespace art |