| // Copyright 2010 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| // Features shared by parsing and pre-parsing scanners. |
| |
| #include "../include/v8stdint.h" |
| #include "scanner-base.h" |
| #include "char-predicates-inl.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // ---------------------------------------------------------------------------- |
| // Character predicates |
| |
| unibrow::Predicate<IdentifierStart, 128> ScannerConstants::kIsIdentifierStart; |
| unibrow::Predicate<IdentifierPart, 128> ScannerConstants::kIsIdentifierPart; |
| unibrow::Predicate<unibrow::WhiteSpace, 128> ScannerConstants::kIsWhiteSpace; |
| unibrow::Predicate<unibrow::LineTerminator, 128> |
| ScannerConstants::kIsLineTerminator; |
| |
| StaticResource<ScannerConstants::Utf8Decoder> ScannerConstants::utf8_decoder_; |
| |
| // Compound predicates. |
| |
| bool ScannerConstants::IsIdentifier(unibrow::CharacterStream* buffer) { |
| // Checks whether the buffer contains an identifier (no escape). |
| if (!buffer->has_more()) return false; |
| if (!kIsIdentifierStart.get(buffer->GetNext())) { |
| return false; |
| } |
| while (buffer->has_more()) { |
| if (!kIsIdentifierPart.get(buffer->GetNext())) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| // ---------------------------------------------------------------------------- |
| // Scanner |
| |
| Scanner::Scanner() |
| : octal_pos_(kNoOctalLocation) { } |
| |
| |
| uc32 Scanner::ScanHexEscape(uc32 c, int length) { |
| ASSERT(length <= 4); // prevent overflow |
| |
| uc32 digits[4]; |
| uc32 x = 0; |
| for (int i = 0; i < length; i++) { |
| digits[i] = c0_; |
| int d = HexValue(c0_); |
| if (d < 0) { |
| // According to ECMA-262, 3rd, 7.8.4, page 18, these hex escapes |
| // should be illegal, but other JS VMs just return the |
| // non-escaped version of the original character. |
| |
| // Push back digits read, except the last one (in c0_). |
| for (int j = i-1; j >= 0; j--) { |
| PushBack(digits[j]); |
| } |
| // Notice: No handling of error - treat it as "\u"->"u". |
| return c; |
| } |
| x = x * 16 + d; |
| Advance(); |
| } |
| |
| return x; |
| } |
| |
| |
| // Octal escapes of the forms '\0xx' and '\xxx' are not a part of |
| // ECMA-262. Other JS VMs support them. |
| uc32 Scanner::ScanOctalEscape(uc32 c, int length) { |
| uc32 x = c - '0'; |
| int i = 0; |
| for (; i < length; i++) { |
| int d = c0_ - '0'; |
| if (d < 0 || d > 7) break; |
| int nx = x * 8 + d; |
| if (nx >= 256) break; |
| x = nx; |
| Advance(); |
| } |
| // Anything excelt '\0' is an octal escape sequence, illegal in strict mode. |
| // Remember the position of octal escape sequences so that better error |
| // can be reported later (in strict mode). |
| if (c != '0' || i > 0) { |
| octal_pos_ = source_pos() - i - 1; // Already advanced |
| } |
| return x; |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // JavaScriptScanner |
| |
| JavaScriptScanner::JavaScriptScanner() : Scanner() {} |
| |
| |
| Token::Value JavaScriptScanner::Next() { |
| current_ = next_; |
| has_line_terminator_before_next_ = false; |
| Scan(); |
| return current_.token; |
| } |
| |
| |
| static inline bool IsByteOrderMark(uc32 c) { |
| // The Unicode value U+FFFE is guaranteed never to be assigned as a |
| // Unicode character; this implies that in a Unicode context the |
| // 0xFF, 0xFE byte pattern can only be interpreted as the U+FEFF |
| // character expressed in little-endian byte order (since it could |
| // not be a U+FFFE character expressed in big-endian byte |
| // order). Nevertheless, we check for it to be compatible with |
| // Spidermonkey. |
| return c == 0xFEFF || c == 0xFFFE; |
| } |
| |
| |
| bool JavaScriptScanner::SkipWhiteSpace() { |
| int start_position = source_pos(); |
| |
| while (true) { |
| // We treat byte-order marks (BOMs) as whitespace for better |
| // compatibility with Spidermonkey and other JavaScript engines. |
| while (ScannerConstants::kIsWhiteSpace.get(c0_) || IsByteOrderMark(c0_)) { |
| // IsWhiteSpace() includes line terminators! |
| if (ScannerConstants::kIsLineTerminator.get(c0_)) { |
| // Ignore line terminators, but remember them. This is necessary |
| // for automatic semicolon insertion. |
| has_line_terminator_before_next_ = true; |
| } |
| Advance(); |
| } |
| |
| // If there is an HTML comment end '-->' at the beginning of a |
| // line (with only whitespace in front of it), we treat the rest |
| // of the line as a comment. This is in line with the way |
| // SpiderMonkey handles it. |
| if (c0_ == '-' && has_line_terminator_before_next_) { |
| Advance(); |
| if (c0_ == '-') { |
| Advance(); |
| if (c0_ == '>') { |
| // Treat the rest of the line as a comment. |
| SkipSingleLineComment(); |
| // Continue skipping white space after the comment. |
| continue; |
| } |
| PushBack('-'); // undo Advance() |
| } |
| PushBack('-'); // undo Advance() |
| } |
| // Return whether or not we skipped any characters. |
| return source_pos() != start_position; |
| } |
| } |
| |
| |
| Token::Value JavaScriptScanner::SkipSingleLineComment() { |
| Advance(); |
| |
| // The line terminator at the end of the line is not considered |
| // to be part of the single-line comment; it is recognized |
| // separately by the lexical grammar and becomes part of the |
| // stream of input elements for the syntactic grammar (see |
| // ECMA-262, section 7.4, page 12). |
| while (c0_ >= 0 && !ScannerConstants::kIsLineTerminator.get(c0_)) { |
| Advance(); |
| } |
| |
| return Token::WHITESPACE; |
| } |
| |
| |
| Token::Value JavaScriptScanner::SkipMultiLineComment() { |
| ASSERT(c0_ == '*'); |
| Advance(); |
| |
| while (c0_ >= 0) { |
| char ch = c0_; |
| Advance(); |
| // If we have reached the end of the multi-line comment, we |
| // consume the '/' and insert a whitespace. This way all |
| // multi-line comments are treated as whitespace - even the ones |
| // containing line terminators. This contradicts ECMA-262, section |
| // 7.4, page 12, that says that multi-line comments containing |
| // line terminators should be treated as a line terminator, but it |
| // matches the behaviour of SpiderMonkey and KJS. |
| if (ch == '*' && c0_ == '/') { |
| c0_ = ' '; |
| return Token::WHITESPACE; |
| } |
| } |
| |
| // Unterminated multi-line comment. |
| return Token::ILLEGAL; |
| } |
| |
| |
| Token::Value JavaScriptScanner::ScanHtmlComment() { |
| // Check for <!-- comments. |
| ASSERT(c0_ == '!'); |
| Advance(); |
| if (c0_ == '-') { |
| Advance(); |
| if (c0_ == '-') return SkipSingleLineComment(); |
| PushBack('-'); // undo Advance() |
| } |
| PushBack('!'); // undo Advance() |
| ASSERT(c0_ == '!'); |
| return Token::LT; |
| } |
| |
| |
| void JavaScriptScanner::Scan() { |
| next_.literal_chars = NULL; |
| Token::Value token; |
| do { |
| // Remember the position of the next token |
| next_.location.beg_pos = source_pos(); |
| |
| switch (c0_) { |
| case ' ': |
| case '\t': |
| Advance(); |
| token = Token::WHITESPACE; |
| break; |
| |
| case '\n': |
| Advance(); |
| has_line_terminator_before_next_ = true; |
| token = Token::WHITESPACE; |
| break; |
| |
| case '"': case '\'': |
| token = ScanString(); |
| break; |
| |
| case '<': |
| // < <= << <<= <!-- |
| Advance(); |
| if (c0_ == '=') { |
| token = Select(Token::LTE); |
| } else if (c0_ == '<') { |
| token = Select('=', Token::ASSIGN_SHL, Token::SHL); |
| } else if (c0_ == '!') { |
| token = ScanHtmlComment(); |
| } else { |
| token = Token::LT; |
| } |
| break; |
| |
| case '>': |
| // > >= >> >>= >>> >>>= |
| Advance(); |
| if (c0_ == '=') { |
| token = Select(Token::GTE); |
| } else if (c0_ == '>') { |
| // >> >>= >>> >>>= |
| Advance(); |
| if (c0_ == '=') { |
| token = Select(Token::ASSIGN_SAR); |
| } else if (c0_ == '>') { |
| token = Select('=', Token::ASSIGN_SHR, Token::SHR); |
| } else { |
| token = Token::SAR; |
| } |
| } else { |
| token = Token::GT; |
| } |
| break; |
| |
| case '=': |
| // = == === |
| Advance(); |
| if (c0_ == '=') { |
| token = Select('=', Token::EQ_STRICT, Token::EQ); |
| } else { |
| token = Token::ASSIGN; |
| } |
| break; |
| |
| case '!': |
| // ! != !== |
| Advance(); |
| if (c0_ == '=') { |
| token = Select('=', Token::NE_STRICT, Token::NE); |
| } else { |
| token = Token::NOT; |
| } |
| break; |
| |
| case '+': |
| // + ++ += |
| Advance(); |
| if (c0_ == '+') { |
| token = Select(Token::INC); |
| } else if (c0_ == '=') { |
| token = Select(Token::ASSIGN_ADD); |
| } else { |
| token = Token::ADD; |
| } |
| break; |
| |
| case '-': |
| // - -- --> -= |
| Advance(); |
| if (c0_ == '-') { |
| Advance(); |
| if (c0_ == '>' && has_line_terminator_before_next_) { |
| // For compatibility with SpiderMonkey, we skip lines that |
| // start with an HTML comment end '-->'. |
| token = SkipSingleLineComment(); |
| } else { |
| token = Token::DEC; |
| } |
| } else if (c0_ == '=') { |
| token = Select(Token::ASSIGN_SUB); |
| } else { |
| token = Token::SUB; |
| } |
| break; |
| |
| case '*': |
| // * *= |
| token = Select('=', Token::ASSIGN_MUL, Token::MUL); |
| break; |
| |
| case '%': |
| // % %= |
| token = Select('=', Token::ASSIGN_MOD, Token::MOD); |
| break; |
| |
| case '/': |
| // / // /* /= |
| Advance(); |
| if (c0_ == '/') { |
| token = SkipSingleLineComment(); |
| } else if (c0_ == '*') { |
| token = SkipMultiLineComment(); |
| } else if (c0_ == '=') { |
| token = Select(Token::ASSIGN_DIV); |
| } else { |
| token = Token::DIV; |
| } |
| break; |
| |
| case '&': |
| // & && &= |
| Advance(); |
| if (c0_ == '&') { |
| token = Select(Token::AND); |
| } else if (c0_ == '=') { |
| token = Select(Token::ASSIGN_BIT_AND); |
| } else { |
| token = Token::BIT_AND; |
| } |
| break; |
| |
| case '|': |
| // | || |= |
| Advance(); |
| if (c0_ == '|') { |
| token = Select(Token::OR); |
| } else if (c0_ == '=') { |
| token = Select(Token::ASSIGN_BIT_OR); |
| } else { |
| token = Token::BIT_OR; |
| } |
| break; |
| |
| case '^': |
| // ^ ^= |
| token = Select('=', Token::ASSIGN_BIT_XOR, Token::BIT_XOR); |
| break; |
| |
| case '.': |
| // . Number |
| Advance(); |
| if (IsDecimalDigit(c0_)) { |
| token = ScanNumber(true); |
| } else { |
| token = Token::PERIOD; |
| } |
| break; |
| |
| case ':': |
| token = Select(Token::COLON); |
| break; |
| |
| case ';': |
| token = Select(Token::SEMICOLON); |
| break; |
| |
| case ',': |
| token = Select(Token::COMMA); |
| break; |
| |
| case '(': |
| token = Select(Token::LPAREN); |
| break; |
| |
| case ')': |
| token = Select(Token::RPAREN); |
| break; |
| |
| case '[': |
| token = Select(Token::LBRACK); |
| break; |
| |
| case ']': |
| token = Select(Token::RBRACK); |
| break; |
| |
| case '{': |
| token = Select(Token::LBRACE); |
| break; |
| |
| case '}': |
| token = Select(Token::RBRACE); |
| break; |
| |
| case '?': |
| token = Select(Token::CONDITIONAL); |
| break; |
| |
| case '~': |
| token = Select(Token::BIT_NOT); |
| break; |
| |
| default: |
| if (ScannerConstants::kIsIdentifierStart.get(c0_)) { |
| token = ScanIdentifierOrKeyword(); |
| } else if (IsDecimalDigit(c0_)) { |
| token = ScanNumber(false); |
| } else if (SkipWhiteSpace()) { |
| token = Token::WHITESPACE; |
| } else if (c0_ < 0) { |
| token = Token::EOS; |
| } else { |
| token = Select(Token::ILLEGAL); |
| } |
| break; |
| } |
| |
| // Continue scanning for tokens as long as we're just skipping |
| // whitespace. |
| } while (token == Token::WHITESPACE); |
| |
| next_.location.end_pos = source_pos(); |
| next_.token = token; |
| } |
| |
| |
| void JavaScriptScanner::SeekForward(int pos) { |
| // After this call, we will have the token at the given position as |
| // the "next" token. The "current" token will be invalid. |
| if (pos == next_.location.beg_pos) return; |
| int current_pos = source_pos(); |
| ASSERT_EQ(next_.location.end_pos, current_pos); |
| // Positions inside the lookahead token aren't supported. |
| ASSERT(pos >= current_pos); |
| if (pos != current_pos) { |
| source_->SeekForward(pos - source_->pos()); |
| Advance(); |
| // This function is only called to seek to the location |
| // of the end of a function (at the "}" token). It doesn't matter |
| // whether there was a line terminator in the part we skip. |
| has_line_terminator_before_next_ = false; |
| } |
| Scan(); |
| } |
| |
| |
| void JavaScriptScanner::ScanEscape() { |
| uc32 c = c0_; |
| Advance(); |
| |
| // Skip escaped newlines. |
| if (ScannerConstants::kIsLineTerminator.get(c)) { |
| // Allow CR+LF newlines in multiline string literals. |
| if (IsCarriageReturn(c) && IsLineFeed(c0_)) Advance(); |
| // Allow LF+CR newlines in multiline string literals. |
| if (IsLineFeed(c) && IsCarriageReturn(c0_)) Advance(); |
| return; |
| } |
| |
| switch (c) { |
| case '\'': // fall through |
| case '"' : // fall through |
| case '\\': break; |
| case 'b' : c = '\b'; break; |
| case 'f' : c = '\f'; break; |
| case 'n' : c = '\n'; break; |
| case 'r' : c = '\r'; break; |
| case 't' : c = '\t'; break; |
| case 'u' : c = ScanHexEscape(c, 4); break; |
| case 'v' : c = '\v'; break; |
| case 'x' : c = ScanHexEscape(c, 2); break; |
| case '0' : // fall through |
| case '1' : // fall through |
| case '2' : // fall through |
| case '3' : // fall through |
| case '4' : // fall through |
| case '5' : // fall through |
| case '6' : // fall through |
| case '7' : c = ScanOctalEscape(c, 2); break; |
| } |
| |
| // According to ECMA-262, 3rd, 7.8.4 (p 18ff) these |
| // should be illegal, but they are commonly handled |
| // as non-escaped characters by JS VMs. |
| AddLiteralChar(c); |
| } |
| |
| |
| Token::Value JavaScriptScanner::ScanString() { |
| uc32 quote = c0_; |
| Advance(); // consume quote |
| |
| LiteralScope literal(this); |
| while (c0_ != quote && c0_ >= 0 |
| && !ScannerConstants::kIsLineTerminator.get(c0_)) { |
| uc32 c = c0_; |
| Advance(); |
| if (c == '\\') { |
| if (c0_ < 0) return Token::ILLEGAL; |
| ScanEscape(); |
| } else { |
| AddLiteralChar(c); |
| } |
| } |
| if (c0_ != quote) return Token::ILLEGAL; |
| literal.Complete(); |
| |
| Advance(); // consume quote |
| return Token::STRING; |
| } |
| |
| |
| void JavaScriptScanner::ScanDecimalDigits() { |
| while (IsDecimalDigit(c0_)) |
| AddLiteralCharAdvance(); |
| } |
| |
| |
| Token::Value JavaScriptScanner::ScanNumber(bool seen_period) { |
| ASSERT(IsDecimalDigit(c0_)); // the first digit of the number or the fraction |
| |
| enum { DECIMAL, HEX, OCTAL } kind = DECIMAL; |
| |
| LiteralScope literal(this); |
| if (seen_period) { |
| // we have already seen a decimal point of the float |
| AddLiteralChar('.'); |
| ScanDecimalDigits(); // we know we have at least one digit |
| |
| } else { |
| // if the first character is '0' we must check for octals and hex |
| if (c0_ == '0') { |
| AddLiteralCharAdvance(); |
| |
| // either 0, 0exxx, 0Exxx, 0.xxx, an octal number, or a hex number |
| if (c0_ == 'x' || c0_ == 'X') { |
| // hex number |
| kind = HEX; |
| AddLiteralCharAdvance(); |
| if (!IsHexDigit(c0_)) { |
| // we must have at least one hex digit after 'x'/'X' |
| return Token::ILLEGAL; |
| } |
| while (IsHexDigit(c0_)) { |
| AddLiteralCharAdvance(); |
| } |
| } else if ('0' <= c0_ && c0_ <= '7') { |
| // (possible) octal number |
| kind = OCTAL; |
| while (true) { |
| if (c0_ == '8' || c0_ == '9') { |
| kind = DECIMAL; |
| break; |
| } |
| if (c0_ < '0' || '7' < c0_) { |
| // Octal literal finished. |
| octal_pos_ = next_.location.beg_pos; |
| break; |
| } |
| AddLiteralCharAdvance(); |
| } |
| } |
| } |
| |
| // Parse decimal digits and allow trailing fractional part. |
| if (kind == DECIMAL) { |
| ScanDecimalDigits(); // optional |
| if (c0_ == '.') { |
| AddLiteralCharAdvance(); |
| ScanDecimalDigits(); // optional |
| } |
| } |
| } |
| |
| // scan exponent, if any |
| if (c0_ == 'e' || c0_ == 'E') { |
| ASSERT(kind != HEX); // 'e'/'E' must be scanned as part of the hex number |
| if (kind == OCTAL) return Token::ILLEGAL; // no exponent for octals allowed |
| // scan exponent |
| AddLiteralCharAdvance(); |
| if (c0_ == '+' || c0_ == '-') |
| AddLiteralCharAdvance(); |
| if (!IsDecimalDigit(c0_)) { |
| // we must have at least one decimal digit after 'e'/'E' |
| return Token::ILLEGAL; |
| } |
| ScanDecimalDigits(); |
| } |
| |
| // The source character immediately following a numeric literal must |
| // not be an identifier start or a decimal digit; see ECMA-262 |
| // section 7.8.3, page 17 (note that we read only one decimal digit |
| // if the value is 0). |
| if (IsDecimalDigit(c0_) || ScannerConstants::kIsIdentifierStart.get(c0_)) |
| return Token::ILLEGAL; |
| |
| literal.Complete(); |
| |
| return Token::NUMBER; |
| } |
| |
| |
| uc32 JavaScriptScanner::ScanIdentifierUnicodeEscape() { |
| Advance(); |
| if (c0_ != 'u') return unibrow::Utf8::kBadChar; |
| Advance(); |
| uc32 c = ScanHexEscape('u', 4); |
| // We do not allow a unicode escape sequence to start another |
| // unicode escape sequence. |
| if (c == '\\') return unibrow::Utf8::kBadChar; |
| return c; |
| } |
| |
| |
| Token::Value JavaScriptScanner::ScanIdentifierOrKeyword() { |
| ASSERT(ScannerConstants::kIsIdentifierStart.get(c0_)); |
| LiteralScope literal(this); |
| KeywordMatcher keyword_match; |
| // Scan identifier start character. |
| if (c0_ == '\\') { |
| uc32 c = ScanIdentifierUnicodeEscape(); |
| // Only allow legal identifier start characters. |
| if (!ScannerConstants::kIsIdentifierStart.get(c)) return Token::ILLEGAL; |
| AddLiteralChar(c); |
| return ScanIdentifierSuffix(&literal); |
| } |
| |
| uc32 first_char = c0_; |
| Advance(); |
| AddLiteralChar(first_char); |
| if (!keyword_match.AddChar(first_char)) { |
| return ScanIdentifierSuffix(&literal); |
| } |
| |
| // Scan the rest of the identifier characters. |
| while (ScannerConstants::kIsIdentifierPart.get(c0_)) { |
| if (c0_ != '\\') { |
| uc32 next_char = c0_; |
| Advance(); |
| AddLiteralChar(next_char); |
| if (keyword_match.AddChar(next_char)) continue; |
| } |
| // Fallthrough if no loner able to complete keyword. |
| return ScanIdentifierSuffix(&literal); |
| } |
| literal.Complete(); |
| |
| return keyword_match.token(); |
| } |
| |
| |
| Token::Value JavaScriptScanner::ScanIdentifierSuffix(LiteralScope* literal) { |
| // Scan the rest of the identifier characters. |
| while (ScannerConstants::kIsIdentifierPart.get(c0_)) { |
| if (c0_ == '\\') { |
| uc32 c = ScanIdentifierUnicodeEscape(); |
| // Only allow legal identifier part characters. |
| if (!ScannerConstants::kIsIdentifierPart.get(c)) return Token::ILLEGAL; |
| AddLiteralChar(c); |
| } else { |
| AddLiteralChar(c0_); |
| Advance(); |
| } |
| } |
| literal->Complete(); |
| |
| return Token::IDENTIFIER; |
| } |
| |
| |
| bool JavaScriptScanner::ScanRegExpPattern(bool seen_equal) { |
| // Scan: ('/' | '/=') RegularExpressionBody '/' RegularExpressionFlags |
| bool in_character_class = false; |
| |
| // Previous token is either '/' or '/=', in the second case, the |
| // pattern starts at =. |
| next_.location.beg_pos = source_pos() - (seen_equal ? 2 : 1); |
| next_.location.end_pos = source_pos() - (seen_equal ? 1 : 0); |
| |
| // Scan regular expression body: According to ECMA-262, 3rd, 7.8.5, |
| // the scanner should pass uninterpreted bodies to the RegExp |
| // constructor. |
| LiteralScope literal(this); |
| if (seen_equal) |
| AddLiteralChar('='); |
| |
| while (c0_ != '/' || in_character_class) { |
| if (ScannerConstants::kIsLineTerminator.get(c0_) || c0_ < 0) return false; |
| if (c0_ == '\\') { // Escape sequence. |
| AddLiteralCharAdvance(); |
| if (ScannerConstants::kIsLineTerminator.get(c0_) || c0_ < 0) return false; |
| AddLiteralCharAdvance(); |
| // If the escape allows more characters, i.e., \x??, \u????, or \c?, |
| // only "safe" characters are allowed (letters, digits, underscore), |
| // otherwise the escape isn't valid and the invalid character has |
| // its normal meaning. I.e., we can just continue scanning without |
| // worrying whether the following characters are part of the escape |
| // or not, since any '/', '\\' or '[' is guaranteed to not be part |
| // of the escape sequence. |
| } else { // Unescaped character. |
| if (c0_ == '[') in_character_class = true; |
| if (c0_ == ']') in_character_class = false; |
| AddLiteralCharAdvance(); |
| } |
| } |
| Advance(); // consume '/' |
| |
| literal.Complete(); |
| |
| return true; |
| } |
| |
| |
| bool JavaScriptScanner::ScanRegExpFlags() { |
| // Scan regular expression flags. |
| LiteralScope literal(this); |
| while (ScannerConstants::kIsIdentifierPart.get(c0_)) { |
| if (c0_ == '\\') { |
| uc32 c = ScanIdentifierUnicodeEscape(); |
| if (c != static_cast<uc32>(unibrow::Utf8::kBadChar)) { |
| // We allow any escaped character, unlike the restriction on |
| // IdentifierPart when it is used to build an IdentifierName. |
| AddLiteralChar(c); |
| continue; |
| } |
| } |
| AddLiteralCharAdvance(); |
| } |
| literal.Complete(); |
| |
| next_.location.end_pos = source_pos() - 1; |
| return true; |
| } |
| |
| // ---------------------------------------------------------------------------- |
| // Keyword Matcher |
| |
| KeywordMatcher::FirstState KeywordMatcher::first_states_[] = { |
| { "break", KEYWORD_PREFIX, Token::BREAK }, |
| { NULL, C, Token::ILLEGAL }, |
| { NULL, D, Token::ILLEGAL }, |
| { NULL, E, Token::ILLEGAL }, |
| { NULL, F, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, I, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { "let", KEYWORD_PREFIX, Token::FUTURE_RESERVED_WORD }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, N, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, P, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { "return", KEYWORD_PREFIX, Token::RETURN }, |
| { NULL, S, Token::ILLEGAL }, |
| { NULL, T, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, V, Token::ILLEGAL }, |
| { NULL, W, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { "yield", KEYWORD_PREFIX, Token::FUTURE_RESERVED_WORD } |
| }; |
| |
| |
| void KeywordMatcher::Step(unibrow::uchar input) { |
| switch (state_) { |
| case INITIAL: { |
| // matching the first character is the only state with significant fanout. |
| // Match only lower-case letters in range 'b'..'y'. |
| unsigned int offset = input - kFirstCharRangeMin; |
| if (offset < kFirstCharRangeLength) { |
| state_ = first_states_[offset].state; |
| if (state_ == KEYWORD_PREFIX) { |
| keyword_ = first_states_[offset].keyword; |
| counter_ = 1; |
| keyword_token_ = first_states_[offset].token; |
| } |
| return; |
| } |
| break; |
| } |
| case KEYWORD_PREFIX: |
| if (static_cast<unibrow::uchar>(keyword_[counter_]) == input) { |
| counter_++; |
| if (keyword_[counter_] == '\0') { |
| state_ = KEYWORD_MATCHED; |
| token_ = keyword_token_; |
| } |
| return; |
| } |
| break; |
| case KEYWORD_MATCHED: |
| token_ = Token::IDENTIFIER; |
| break; |
| case C: |
| if (MatchState(input, 'a', CA)) return; |
| if (MatchKeywordStart(input, "class", 1, |
| Token::FUTURE_RESERVED_WORD)) return; |
| if (MatchState(input, 'o', CO)) return; |
| break; |
| case CA: |
| if (MatchKeywordStart(input, "case", 2, Token::CASE)) return; |
| if (MatchKeywordStart(input, "catch", 2, Token::CATCH)) return; |
| break; |
| case CO: |
| if (MatchState(input, 'n', CON)) return; |
| break; |
| case CON: |
| if (MatchKeywordStart(input, "const", 3, Token::CONST)) return; |
| if (MatchKeywordStart(input, "continue", 3, Token::CONTINUE)) return; |
| break; |
| case D: |
| if (MatchState(input, 'e', DE)) return; |
| if (MatchKeyword(input, 'o', KEYWORD_MATCHED, Token::DO)) return; |
| break; |
| case DE: |
| if (MatchKeywordStart(input, "debugger", 2, Token::DEBUGGER)) return; |
| if (MatchKeywordStart(input, "default", 2, Token::DEFAULT)) return; |
| if (MatchKeywordStart(input, "delete", 2, Token::DELETE)) return; |
| break; |
| case E: |
| if (MatchKeywordStart(input, "else", 1, Token::ELSE)) return; |
| if (MatchKeywordStart(input, "enum", 1, |
| Token::FUTURE_RESERVED_WORD)) return; |
| if (MatchState(input, 'x', EX)) return; |
| break; |
| case EX: |
| if (MatchKeywordStart(input, "export", 2, |
| Token::FUTURE_RESERVED_WORD)) return; |
| if (MatchKeywordStart(input, "extends", 2, |
| Token::FUTURE_RESERVED_WORD)) return; |
| break; |
| case F: |
| if (MatchKeywordStart(input, "false", 1, Token::FALSE_LITERAL)) return; |
| if (MatchKeywordStart(input, "finally", 1, Token::FINALLY)) return; |
| if (MatchKeywordStart(input, "for", 1, Token::FOR)) return; |
| if (MatchKeywordStart(input, "function", 1, Token::FUNCTION)) return; |
| break; |
| case I: |
| if (MatchKeyword(input, 'f', KEYWORD_MATCHED, Token::IF)) return; |
| if (MatchState(input, 'm', IM)) return; |
| if (MatchKeyword(input, 'n', IN, Token::IN)) return; |
| break; |
| case IM: |
| if (MatchState(input, 'p', IMP)) return; |
| break; |
| case IMP: |
| if (MatchKeywordStart(input, "implements", 3, |
| Token::FUTURE_RESERVED_WORD )) return; |
| if (MatchKeywordStart(input, "import", 3, |
| Token::FUTURE_RESERVED_WORD)) return; |
| break; |
| case IN: |
| token_ = Token::IDENTIFIER; |
| if (MatchKeywordStart(input, "interface", 2, |
| Token::FUTURE_RESERVED_WORD)) return; |
| if (MatchKeywordStart(input, "instanceof", 2, Token::INSTANCEOF)) return; |
| break; |
| case N: |
| if (MatchKeywordStart(input, "native", 1, Token::NATIVE)) return; |
| if (MatchKeywordStart(input, "new", 1, Token::NEW)) return; |
| if (MatchKeywordStart(input, "null", 1, Token::NULL_LITERAL)) return; |
| break; |
| case P: |
| if (MatchKeywordStart(input, "package", 1, |
| Token::FUTURE_RESERVED_WORD)) return; |
| if (MatchState(input, 'r', PR)) return; |
| if (MatchKeywordStart(input, "public", 1, |
| Token::FUTURE_RESERVED_WORD)) return; |
| break; |
| case PR: |
| if (MatchKeywordStart(input, "private", 2, |
| Token::FUTURE_RESERVED_WORD)) return; |
| if (MatchKeywordStart(input, "protected", 2, |
| Token::FUTURE_RESERVED_WORD)) return; |
| break; |
| case S: |
| if (MatchKeywordStart(input, "static", 1, |
| Token::FUTURE_RESERVED_WORD)) return; |
| if (MatchKeywordStart(input, "super", 1, |
| Token::FUTURE_RESERVED_WORD)) return; |
| if (MatchKeywordStart(input, "switch", 1, |
| Token::SWITCH)) return; |
| break; |
| case T: |
| if (MatchState(input, 'h', TH)) return; |
| if (MatchState(input, 'r', TR)) return; |
| if (MatchKeywordStart(input, "typeof", 1, Token::TYPEOF)) return; |
| break; |
| case TH: |
| if (MatchKeywordStart(input, "this", 2, Token::THIS)) return; |
| if (MatchKeywordStart(input, "throw", 2, Token::THROW)) return; |
| break; |
| case TR: |
| if (MatchKeywordStart(input, "true", 2, Token::TRUE_LITERAL)) return; |
| if (MatchKeyword(input, 'y', KEYWORD_MATCHED, Token::TRY)) return; |
| break; |
| case V: |
| if (MatchKeywordStart(input, "var", 1, Token::VAR)) return; |
| if (MatchKeywordStart(input, "void", 1, Token::VOID)) return; |
| break; |
| case W: |
| if (MatchKeywordStart(input, "while", 1, Token::WHILE)) return; |
| if (MatchKeywordStart(input, "with", 1, Token::WITH)) return; |
| break; |
| case UNMATCHABLE: |
| break; |
| } |
| // On fallthrough, it's a failure. |
| state_ = UNMATCHABLE; |
| } |
| |
| } } // namespace v8::internal |