- else if (m_current == 'x') {
- shift();
- if (!isASCIIHexDigit(m_current) || !isASCIIHexDigit(peek(1))) {
- m_lexErrorMessage = "\\x can only be followed by a hex character sequence";
- return false;
- }
- T prev = m_current;
- shift();
- if (shouldBuildStrings)
- record16(convertHex(prev, m_current));
- shift();
- } else if (m_current == 'u') {
- shift();
- int character = parseFourDigitUnicodeHex();
- if (character != -1) {
- if (shouldBuildStrings)
- record16(character);
- } else if (m_current == stringQuoteCharacter) {
- if (shouldBuildStrings)
- record16('u');
- } else {
- m_lexErrorMessage = "\\u can only be followed by a Unicode character sequence";
- return false;
- }
- } else if (strictMode && isASCIIDigit(m_current)) {
- // The only valid numeric escape in strict mode is '\0', and this must not be followed by a decimal digit.
- int character1 = m_current;
- shift();
- if (character1 != '0' || isASCIIDigit(m_current)) {
- m_lexErrorMessage = "The only valid numeric escape in strict mode is '\\0'";
- return false;
- }
+ else {
+ StringParseResult result = parseComplexEscape<shouldBuildStrings>(EscapeParseMode::String, strictMode, stringQuoteCharacter);
+ if (result != StringParsedSuccessfully)
+ return result;
+ }
+
+ stringStart = currentSourcePtr();
+ continue;
+ }
+ // Fast check for characters that require special handling.
+ // Catches 0, \n, \r, 0x2028, and 0x2029 as efficiently
+ // as possible, and lets through all common ASCII characters.
+ if (UNLIKELY(((static_cast<unsigned>(m_current) - 0xE) & 0x2000))) {
+ // New-line or end of input is not allowed
+ if (atEnd() || isLineTerminator(m_current)) {
+ m_lexErrorMessage = ASCIILiteral("Unexpected EOF");
+ return atEnd() ? StringUnterminated : StringCannotBeParsed;
+ }
+ // Anything else is just a normal character
+ }
+ shift();
+ }
+
+ if (currentSourcePtr() != stringStart && shouldBuildStrings)
+ append16(stringStart, currentSourcePtr() - stringStart);
+ if (shouldBuildStrings)
+ tokenData->ident = makeIdentifier(m_buffer16.data(), m_buffer16.size());
+ else
+ tokenData->ident = 0;
+
+ m_buffer16.shrink(0);
+ return StringParsedSuccessfully;
+}
+
+#if ENABLE(ES6_TEMPLATE_LITERAL_SYNTAX)
+// While the lexer accepts <LF><CR> (not <CR><LF>) sequence
+// as one line terminator and increments one line number,
+// TemplateLiteral considers it as two line terminators <LF> and <CR>.
+//
+// TemplateLiteral normalizes line terminators as follows.
+//
+// <LF> => <LF>
+// <CR> => <LF>
+// <CR><LF> => <LF>
+// <\u2028> => <\u2028>
+// <\u2029> => <\u2029>
+//
+// So, <LF><CR> should be normalized to <LF><LF>.
+// However, the lexer should increment the line number only once for <LF><CR>.
+//
+// To achieve this, LineNumberAdder holds the current status of line terminator sequence.
+// When TemplateLiteral lexer encounters a line terminator, it notifies to LineNumberAdder.
+// LineNumberAdder maintains the status and increments the line number when it's necessary.
+// For example, LineNumberAdder increments the line number only once for <LF><CR> and <CR><LF>.
+template<typename CharacterType>
+class LineNumberAdder {
+public:
+ LineNumberAdder(int& lineNumber)
+ : m_lineNumber(lineNumber)
+ {
+ }
+
+ void clear()
+ {
+ m_previous = 0;
+ }
+
+ void add(CharacterType character)
+ {
+ ASSERT(Lexer<CharacterType>::isLineTerminator(character));
+ if ((character + m_previous) == ('\n' + '\r'))
+ m_previous = 0;
+ else {
+ ++m_lineNumber;
+ m_previous = character;
+ }
+ }
+
+private:
+ int& m_lineNumber;
+ CharacterType m_previous { 0 };
+};
+
+template <typename T>
+template <bool shouldBuildStrings> typename Lexer<T>::StringParseResult Lexer<T>::parseTemplateLiteral(JSTokenData* tokenData, RawStringsBuildMode rawStringsBuildMode)
+{
+ const T* stringStart = currentSourcePtr();
+ const T* rawStringStart = currentSourcePtr();
+
+ LineNumberAdder<T> lineNumberAdder(m_lineNumber);
+
+ while (m_current != '`') {
+ if (UNLIKELY(m_current == '\\')) {
+ lineNumberAdder.clear();
+ if (stringStart != currentSourcePtr() && shouldBuildStrings)
+ append16(stringStart, currentSourcePtr() - stringStart);
+ shift();
+
+ LChar escape = singleEscape(m_current);
+
+ // Most common escape sequences first.
+ if (escape) {
projects / apple / javascriptcore.git / blobdiff