| // Copyright 2011 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 "scanner.h" |
| |
| #include "../include/v8stdint.h" |
| #include "char-predicates-inl.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // ---------------------------------------------------------------------------- |
| // Scanner |
| |
| Scanner::Scanner(UnicodeCache* unicode_cache) |
| : unicode_cache_(unicode_cache), |
| octal_pos_(Location::invalid()), |
| harmony_scoping_(false), |
| harmony_modules_(false) { } |
| |
| |
| void Scanner::Initialize(Utf16CharacterStream* source) { |
| source_ = source; |
| // Need to capture identifiers in order to recognize "get" and "set" |
| // in object literals. |
| Init(); |
| // Skip initial whitespace allowing HTML comment ends just like |
| // after a newline and scan first token. |
| has_line_terminator_before_next_ = true; |
| SkipWhiteSpace(); |
| Scan(); |
| } |
| |
| |
| uc32 Scanner::ScanHexNumber(int expected_length) { |
| ASSERT(expected_length <= 4); // prevent overflow |
| |
| uc32 digits[4] = { 0, 0, 0, 0 }; |
| uc32 x = 0; |
| for (int i = 0; i < expected_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 that we have advanced past. |
| for (int j = i-1; j >= 0; j--) { |
| PushBack(digits[j]); |
| } |
| return -1; |
| } |
| x = x * 16 + d; |
| Advance(); |
| } |
| |
| return x; |
| } |
| |
| |
| // Ensure that tokens can be stored in a byte. |
| STATIC_ASSERT(Token::NUM_TOKENS <= 0x100); |
| |
| // Table of one-character tokens, by character (0x00..0x7f only). |
| static const byte one_char_tokens[] = { |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::LPAREN, // 0x28 |
| Token::RPAREN, // 0x29 |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::COMMA, // 0x2c |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::COLON, // 0x3a |
| Token::SEMICOLON, // 0x3b |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::CONDITIONAL, // 0x3f |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::LBRACK, // 0x5b |
| Token::ILLEGAL, |
| Token::RBRACK, // 0x5d |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::ILLEGAL, |
| Token::LBRACE, // 0x7b |
| Token::ILLEGAL, |
| Token::RBRACE, // 0x7d |
| Token::BIT_NOT, // 0x7e |
| Token::ILLEGAL |
| }; |
| |
| |
| Token::Value Scanner::Next() { |
| current_ = next_; |
| has_line_terminator_before_next_ = false; |
| has_multiline_comment_before_next_ = false; |
| if (static_cast<unsigned>(c0_) <= 0x7f) { |
| Token::Value token = static_cast<Token::Value>(one_char_tokens[c0_]); |
| if (token != Token::ILLEGAL) { |
| int pos = source_pos(); |
| next_.token = token; |
| next_.location.beg_pos = pos; |
| next_.location.end_pos = pos + 1; |
| Advance(); |
| return current_.token; |
| } |
| } |
| 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 Scanner::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 (unicode_cache_->IsWhiteSpace(c0_) || IsByteOrderMark(c0_)) { |
| // IsWhiteSpace() includes line terminators! |
| if (unicode_cache_->IsLineTerminator(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 Scanner::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). |
| while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) { |
| Advance(); |
| } |
| |
| return Token::WHITESPACE; |
| } |
| |
| |
| Token::Value Scanner::SkipMultiLineComment() { |
| ASSERT(c0_ == '*'); |
| Advance(); |
| |
| while (c0_ >= 0) { |
| uc32 ch = c0_; |
| Advance(); |
| if (unicode_cache_->IsLineTerminator(ch)) { |
| // Following ECMA-262, section 7.4, a comment containing |
| // a newline will make the comment count as a line-terminator. |
| has_multiline_comment_before_next_ = true; |
| } |
| // 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. |
| if (ch == '*' && c0_ == '/') { |
| c0_ = ' '; |
| return Token::WHITESPACE; |
| } |
| } |
| |
| // Unterminated multi-line comment. |
| return Token::ILLEGAL; |
| } |
| |
| |
| Token::Value Scanner::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 Scanner::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 (unicode_cache_->IsIdentifierStart(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 Scanner::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; |
| has_multiline_comment_before_next_ = false; |
| } |
| Scan(); |
| } |
| |
| |
| void Scanner::ScanEscape() { |
| uc32 c = c0_; |
| Advance(); |
| |
| // Skip escaped newlines. |
| if (unicode_cache_->IsLineTerminator(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 = ScanHexNumber(4); |
| if (c < 0) c = 'u'; |
| break; |
| } |
| case 'v' : c = '\v'; break; |
| case 'x' : { |
| c = ScanHexNumber(2); |
| if (c < 0) c = 'x'; |
| 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); |
| } |
| |
| |
| // 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 except '\0' is an octal escape sequence, illegal in strict mode. |
| // Remember the position of octal escape sequences so that an error |
| // can be reported later (in strict mode). |
| // We don't report the error immediately, because the octal escape can |
| // occur before the "use strict" directive. |
| if (c != '0' || i > 0) { |
| octal_pos_ = Location(source_pos() - i - 1, source_pos() - 1); |
| } |
| return x; |
| } |
| |
| |
| Token::Value Scanner::ScanString() { |
| uc32 quote = c0_; |
| Advance(); // consume quote |
| |
| LiteralScope literal(this); |
| while (c0_ != quote && c0_ >= 0 |
| && !unicode_cache_->IsLineTerminator(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 Scanner::ScanDecimalDigits() { |
| while (IsDecimalDigit(c0_)) |
| AddLiteralCharAdvance(); |
| } |
| |
| |
| Token::Value Scanner::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') { |
| int start_pos = source_pos(); // For reporting octal positions. |
| 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_ = Location(start_pos, source_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_) || unicode_cache_->IsIdentifierStart(c0_)) |
| return Token::ILLEGAL; |
| |
| literal.Complete(); |
| |
| return Token::NUMBER; |
| } |
| |
| |
| uc32 Scanner::ScanIdentifierUnicodeEscape() { |
| Advance(); |
| if (c0_ != 'u') return -1; |
| Advance(); |
| uc32 result = ScanHexNumber(4); |
| if (result < 0) PushBack('u'); |
| return result; |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Keyword Matcher |
| |
| #define KEYWORDS(KEYWORD_GROUP, KEYWORD) \ |
| KEYWORD_GROUP('b') \ |
| KEYWORD("break", Token::BREAK) \ |
| KEYWORD_GROUP('c') \ |
| KEYWORD("case", Token::CASE) \ |
| KEYWORD("catch", Token::CATCH) \ |
| KEYWORD("class", Token::FUTURE_RESERVED_WORD) \ |
| KEYWORD("const", Token::CONST) \ |
| KEYWORD("continue", Token::CONTINUE) \ |
| KEYWORD_GROUP('d') \ |
| KEYWORD("debugger", Token::DEBUGGER) \ |
| KEYWORD("default", Token::DEFAULT) \ |
| KEYWORD("delete", Token::DELETE) \ |
| KEYWORD("do", Token::DO) \ |
| KEYWORD_GROUP('e') \ |
| KEYWORD("else", Token::ELSE) \ |
| KEYWORD("enum", Token::FUTURE_RESERVED_WORD) \ |
| KEYWORD("export", harmony_modules \ |
| ? Token::EXPORT : Token::FUTURE_RESERVED_WORD) \ |
| KEYWORD("extends", Token::FUTURE_RESERVED_WORD) \ |
| KEYWORD_GROUP('f') \ |
| KEYWORD("false", Token::FALSE_LITERAL) \ |
| KEYWORD("finally", Token::FINALLY) \ |
| KEYWORD("for", Token::FOR) \ |
| KEYWORD("function", Token::FUNCTION) \ |
| KEYWORD_GROUP('i') \ |
| KEYWORD("if", Token::IF) \ |
| KEYWORD("implements", Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD("import", harmony_modules \ |
| ? Token::IMPORT : Token::FUTURE_RESERVED_WORD) \ |
| KEYWORD("in", Token::IN) \ |
| KEYWORD("instanceof", Token::INSTANCEOF) \ |
| KEYWORD("interface", Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD_GROUP('l') \ |
| KEYWORD("let", harmony_scoping \ |
| ? Token::LET : Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD_GROUP('n') \ |
| KEYWORD("new", Token::NEW) \ |
| KEYWORD("null", Token::NULL_LITERAL) \ |
| KEYWORD_GROUP('p') \ |
| KEYWORD("package", Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD("private", Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD("protected", Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD("public", Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD_GROUP('r') \ |
| KEYWORD("return", Token::RETURN) \ |
| KEYWORD_GROUP('s') \ |
| KEYWORD("static", Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD("super", Token::FUTURE_RESERVED_WORD) \ |
| KEYWORD("switch", Token::SWITCH) \ |
| KEYWORD_GROUP('t') \ |
| KEYWORD("this", Token::THIS) \ |
| KEYWORD("throw", Token::THROW) \ |
| KEYWORD("true", Token::TRUE_LITERAL) \ |
| KEYWORD("try", Token::TRY) \ |
| KEYWORD("typeof", Token::TYPEOF) \ |
| KEYWORD_GROUP('v') \ |
| KEYWORD("var", Token::VAR) \ |
| KEYWORD("void", Token::VOID) \ |
| KEYWORD_GROUP('w') \ |
| KEYWORD("while", Token::WHILE) \ |
| KEYWORD("with", Token::WITH) \ |
| KEYWORD_GROUP('y') \ |
| KEYWORD("yield", Token::FUTURE_STRICT_RESERVED_WORD) |
| |
| |
| static Token::Value KeywordOrIdentifierToken(const char* input, |
| int input_length, |
| bool harmony_scoping, |
| bool harmony_modules) { |
| ASSERT(input_length >= 1); |
| const int kMinLength = 2; |
| const int kMaxLength = 10; |
| if (input_length < kMinLength || input_length > kMaxLength) { |
| return Token::IDENTIFIER; |
| } |
| switch (input[0]) { |
| default: |
| #define KEYWORD_GROUP_CASE(ch) \ |
| break; \ |
| case ch: |
| #define KEYWORD(keyword, token) \ |
| { \ |
| /* 'keyword' is a char array, so sizeof(keyword) is */ \ |
| /* strlen(keyword) plus 1 for the NUL char. */ \ |
| const int keyword_length = sizeof(keyword) - 1; \ |
| STATIC_ASSERT(keyword_length >= kMinLength); \ |
| STATIC_ASSERT(keyword_length <= kMaxLength); \ |
| if (input_length == keyword_length && \ |
| input[1] == keyword[1] && \ |
| (keyword_length <= 2 || input[2] == keyword[2]) && \ |
| (keyword_length <= 3 || input[3] == keyword[3]) && \ |
| (keyword_length <= 4 || input[4] == keyword[4]) && \ |
| (keyword_length <= 5 || input[5] == keyword[5]) && \ |
| (keyword_length <= 6 || input[6] == keyword[6]) && \ |
| (keyword_length <= 7 || input[7] == keyword[7]) && \ |
| (keyword_length <= 8 || input[8] == keyword[8]) && \ |
| (keyword_length <= 9 || input[9] == keyword[9])) { \ |
| return token; \ |
| } \ |
| } |
| KEYWORDS(KEYWORD_GROUP_CASE, KEYWORD) |
| } |
| return Token::IDENTIFIER; |
| } |
| |
| |
| Token::Value Scanner::ScanIdentifierOrKeyword() { |
| ASSERT(unicode_cache_->IsIdentifierStart(c0_)); |
| LiteralScope literal(this); |
| // Scan identifier start character. |
| if (c0_ == '\\') { |
| uc32 c = ScanIdentifierUnicodeEscape(); |
| // Only allow legal identifier start characters. |
| if (c < 0 || |
| c == '\\' || // No recursive escapes. |
| !unicode_cache_->IsIdentifierStart(c)) { |
| return Token::ILLEGAL; |
| } |
| AddLiteralChar(c); |
| return ScanIdentifierSuffix(&literal); |
| } |
| |
| uc32 first_char = c0_; |
| Advance(); |
| AddLiteralChar(first_char); |
| |
| // Scan the rest of the identifier characters. |
| while (unicode_cache_->IsIdentifierPart(c0_)) { |
| if (c0_ != '\\') { |
| uc32 next_char = c0_; |
| Advance(); |
| AddLiteralChar(next_char); |
| continue; |
| } |
| // Fallthrough if no longer able to complete keyword. |
| return ScanIdentifierSuffix(&literal); |
| } |
| |
| literal.Complete(); |
| |
| if (next_.literal_chars->is_ascii()) { |
| Vector<const char> chars = next_.literal_chars->ascii_literal(); |
| return KeywordOrIdentifierToken(chars.start(), |
| chars.length(), |
| harmony_scoping_, |
| harmony_modules_); |
| } |
| |
| return Token::IDENTIFIER; |
| } |
| |
| |
| Token::Value Scanner::ScanIdentifierSuffix(LiteralScope* literal) { |
| // Scan the rest of the identifier characters. |
| while (unicode_cache_->IsIdentifierPart(c0_)) { |
| if (c0_ == '\\') { |
| uc32 c = ScanIdentifierUnicodeEscape(); |
| // Only allow legal identifier part characters. |
| if (c < 0 || |
| c == '\\' || |
| !unicode_cache_->IsIdentifierPart(c)) { |
| return Token::ILLEGAL; |
| } |
| AddLiteralChar(c); |
| } else { |
| AddLiteralChar(c0_); |
| Advance(); |
| } |
| } |
| literal->Complete(); |
| |
| return Token::IDENTIFIER; |
| } |
| |
| |
| bool Scanner::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 (unicode_cache_->IsLineTerminator(c0_) || c0_ < 0) return false; |
| if (c0_ == '\\') { // Escape sequence. |
| AddLiteralCharAdvance(); |
| if (unicode_cache_->IsLineTerminator(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. |
| |
| // TODO(896): At some point, parse RegExps more throughly to capture |
| // octal esacpes in strict mode. |
| } else { // Unescaped character. |
| if (c0_ == '[') in_character_class = true; |
| if (c0_ == ']') in_character_class = false; |
| AddLiteralCharAdvance(); |
| } |
| } |
| Advance(); // consume '/' |
| |
| literal.Complete(); |
| |
| return true; |
| } |
| |
| |
| bool Scanner::ScanLiteralUnicodeEscape() { |
| ASSERT(c0_ == '\\'); |
| uc32 chars_read[6] = {'\\', 'u', 0, 0, 0, 0}; |
| Advance(); |
| int i = 1; |
| if (c0_ == 'u') { |
| i++; |
| while (i < 6) { |
| Advance(); |
| if (!IsHexDigit(c0_)) break; |
| chars_read[i] = c0_; |
| i++; |
| } |
| } |
| if (i < 6) { |
| // Incomplete escape. Undo all advances and return false. |
| while (i > 0) { |
| i--; |
| PushBack(chars_read[i]); |
| } |
| return false; |
| } |
| // Complete escape. Add all chars to current literal buffer. |
| for (int i = 0; i < 6; i++) { |
| AddLiteralChar(chars_read[i]); |
| } |
| return true; |
| } |
| |
| |
| bool Scanner::ScanRegExpFlags() { |
| // Scan regular expression flags. |
| LiteralScope literal(this); |
| while (unicode_cache_->IsIdentifierPart(c0_)) { |
| if (c0_ != '\\') { |
| AddLiteralCharAdvance(); |
| } else { |
| if (!ScanLiteralUnicodeEscape()) { |
| break; |
| } |
| } |
| } |
| literal.Complete(); |
| |
| next_.location.end_pos = source_pos() - 1; |
| return true; |
| } |
| |
| } } // namespace v8::internal |
