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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.
+ */
+
+#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;
+using android::base::StringPrintf;
+
+// 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 + *chars++;
+ }
+ return static_cast<int32_t>(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
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