AAPT2: Convert from Modified UTF-8 ResStringPool
Since ResStringPools are encoded using Modified UTF-8, retrieving
strings from the string pool convert the strings to UTF-8 before
returning.
Bug: 114734350
Test: m aapt2_tests
Change-Id: Ib459018186f4c5b40f3f3786425a335ecfb9ed02
diff --git a/tools/aapt2/util/Util.cpp b/tools/aapt2/util/Util.cpp
index 9bef54e5..59b7fff 100644
--- a/tools/aapt2/util/Util.cpp
+++ b/tools/aapt2/util/Util.cpp
@@ -322,11 +322,11 @@
output.reserve(modified_size);
for (size_t i = 0; i < size; i++) {
if (((uint8_t) utf8[i] >> 4) == 0xF) {
- auto codepoint = (char32_t) utf32_from_utf8_at(utf8.data(), size, i, nullptr);
+ int32_t codepoint = utf32_from_utf8_at(utf8.data(), size, i, nullptr);
// Calculate the high and low surrogates as UTF-16 would
- char32_t high = ((codepoint - 0x10000) / 0x400) + 0xD800;
- char32_t low = ((codepoint - 0x10000) % 0x400) + 0xDC00;
+ int32_t high = ((codepoint - 0x10000) / 0x400) + 0xD800;
+ int32_t low = ((codepoint - 0x10000) % 0x400) + 0xDC00;
// Encode each surrogate in UTF-8
output.push_back((char) (0xE4 | ((high >> 12) & 0xF)));
@@ -344,6 +344,60 @@
return output;
}
+std::string ModifiedUtf8ToUtf8(const std::string& modified_utf8) {
+ // The UTF-8 representation will have a byte length less than or equal to the Modified UTF-8
+ // representation.
+ std::string output;
+ output.reserve(modified_utf8.size());
+
+ size_t index = 0;
+ const size_t modified_size = modified_utf8.size();
+ while (index < modified_size) {
+ size_t next_index;
+ int32_t high_surrogate = utf32_from_utf8_at(modified_utf8.data(), modified_size, index,
+ &next_index);
+ if (high_surrogate < 0) {
+ return {};
+ }
+
+ // Check that the first codepoint is within the high surrogate range
+ if (high_surrogate >= 0xD800 && high_surrogate <= 0xDB7F) {
+ int32_t low_surrogate = utf32_from_utf8_at(modified_utf8.data(), modified_size, next_index,
+ &next_index);
+ if (low_surrogate < 0) {
+ return {};
+ }
+
+ // Check that the second codepoint is within the low surrogate range
+ if (low_surrogate >= 0xDC00 && low_surrogate <= 0xDFFF) {
+ const char32_t codepoint = (char32_t) (((high_surrogate - 0xD800) * 0x400)
+ + (low_surrogate - 0xDC00) + 0x10000);
+
+ // The decoded codepoint should represent a 4 byte, UTF-8 character
+ const size_t utf8_length = (size_t) utf32_to_utf8_length(&codepoint, 1);
+ if (utf8_length != 4) {
+ return {};
+ }
+
+ // Encode the UTF-8 representation of the codepoint into the string
+ char* start = &output[output.size()];
+ output.resize(output.size() + utf8_length);
+ utf32_to_utf8((char32_t*) &codepoint, 1, start, utf8_length + 1);
+
+ index = next_index;
+ continue;
+ }
+ }
+
+ // Append non-surrogate pairs to the output string
+ for (size_t i = index; i < next_index; i++) {
+ output.push_back(modified_utf8[i]);
+ }
+ index = next_index;
+ }
+ return output;
+}
+
std::u16string Utf8ToUtf16(const StringPiece& utf8) {
ssize_t utf16_length = utf8_to_utf16_length(
reinterpret_cast<const uint8_t*>(utf8.data()), utf8.length());
@@ -469,7 +523,7 @@
size_t len;
const char* str = pool.string8At(idx, &len);
if (str != nullptr) {
- return std::string(str, len);
+ return ModifiedUtf8ToUtf8(std::string(str, len));
}
return Utf16ToUtf8(GetString16(pool, idx));
}