| // Copyright 2006-2008 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. |
| |
| #include "v8.h" |
| |
| #include "ast.h" |
| #include "handles.h" |
| #include "scanner.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // ---------------------------------------------------------------------------- |
| // Character predicates |
| |
| |
| unibrow::Predicate<IdentifierStart, 128> Scanner::kIsIdentifierStart; |
| unibrow::Predicate<IdentifierPart, 128> Scanner::kIsIdentifierPart; |
| unibrow::Predicate<unibrow::LineTerminator, 128> Scanner::kIsLineTerminator; |
| unibrow::Predicate<unibrow::WhiteSpace, 128> Scanner::kIsWhiteSpace; |
| |
| |
| StaticResource<Scanner::Utf8Decoder> Scanner::utf8_decoder_; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // UTF8Buffer |
| |
| UTF8Buffer::UTF8Buffer() : data_(NULL), limit_(NULL) { } |
| |
| |
| UTF8Buffer::~UTF8Buffer() { |
| if (data_ != NULL) DeleteArray(data_); |
| } |
| |
| |
| void UTF8Buffer::AddCharSlow(uc32 c) { |
| static const int kCapacityGrowthLimit = 1 * MB; |
| if (cursor_ > limit_) { |
| int old_capacity = Capacity(); |
| int old_position = pos(); |
| int new_capacity = |
| Min(old_capacity * 3, old_capacity + kCapacityGrowthLimit); |
| char* new_data = NewArray<char>(new_capacity); |
| memcpy(new_data, data_, old_position); |
| DeleteArray(data_); |
| data_ = new_data; |
| cursor_ = new_data + old_position; |
| limit_ = ComputeLimit(new_data, new_capacity); |
| ASSERT(Capacity() == new_capacity && pos() == old_position); |
| } |
| if (static_cast<unsigned>(c) <= unibrow::Utf8::kMaxOneByteChar) { |
| *cursor_++ = c; // Common case: 7-bit ASCII. |
| } else { |
| cursor_ += unibrow::Utf8::Encode(cursor_, c); |
| } |
| ASSERT(pos() <= Capacity()); |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // UTF16Buffer |
| |
| |
| UTF16Buffer::UTF16Buffer() |
| : pos_(0), end_(Scanner::kNoEndPosition) { } |
| |
| |
| // CharacterStreamUTF16Buffer |
| CharacterStreamUTF16Buffer::CharacterStreamUTF16Buffer() |
| : pushback_buffer_(0), last_(0), stream_(NULL) { } |
| |
| |
| void CharacterStreamUTF16Buffer::Initialize(Handle<String> data, |
| unibrow::CharacterStream* input, |
| int start_position, |
| int end_position) { |
| stream_ = input; |
| if (start_position > 0) { |
| SeekForward(start_position); |
| } |
| end_ = end_position != Scanner::kNoEndPosition ? end_position : kMaxInt; |
| } |
| |
| |
| void CharacterStreamUTF16Buffer::PushBack(uc32 ch) { |
| pushback_buffer()->Add(last_); |
| last_ = ch; |
| pos_--; |
| } |
| |
| |
| uc32 CharacterStreamUTF16Buffer::Advance() { |
| ASSERT(end_ != Scanner::kNoEndPosition); |
| ASSERT(end_ >= 0); |
| // NOTE: It is of importance to Persian / Farsi resources that we do |
| // *not* strip format control characters in the scanner; see |
| // |
| // https://bugzilla.mozilla.org/show_bug.cgi?id=274152 |
| // |
| // So, even though ECMA-262, section 7.1, page 11, dictates that we |
| // must remove Unicode format-control characters, we do not. This is |
| // in line with how IE and SpiderMonkey handles it. |
| if (!pushback_buffer()->is_empty()) { |
| pos_++; |
| return last_ = pushback_buffer()->RemoveLast(); |
| } else if (stream_->has_more() && pos_ < end_) { |
| pos_++; |
| uc32 next = stream_->GetNext(); |
| return last_ = next; |
| } else { |
| // Note: currently the following increment is necessary to avoid a |
| // test-parser problem! |
| pos_++; |
| return last_ = static_cast<uc32>(-1); |
| } |
| } |
| |
| |
| void CharacterStreamUTF16Buffer::SeekForward(int pos) { |
| pos_ = pos; |
| ASSERT(pushback_buffer()->is_empty()); |
| stream_->Seek(pos); |
| } |
| |
| |
| // ExternalStringUTF16Buffer |
| template <typename StringType, typename CharType> |
| ExternalStringUTF16Buffer<StringType, CharType>::ExternalStringUTF16Buffer() |
| : raw_data_(NULL) { } |
| |
| |
| template <typename StringType, typename CharType> |
| void ExternalStringUTF16Buffer<StringType, CharType>::Initialize( |
| Handle<StringType> data, |
| int start_position, |
| int end_position) { |
| ASSERT(!data.is_null()); |
| raw_data_ = data->resource()->data(); |
| |
| ASSERT(end_position <= data->length()); |
| if (start_position > 0) { |
| SeekForward(start_position); |
| } |
| end_ = |
| end_position != Scanner::kNoEndPosition ? end_position : data->length(); |
| } |
| |
| |
| template <typename StringType, typename CharType> |
| uc32 ExternalStringUTF16Buffer<StringType, CharType>::Advance() { |
| if (pos_ < end_) { |
| return raw_data_[pos_++]; |
| } else { |
| // note: currently the following increment is necessary to avoid a |
| // test-parser problem! |
| pos_++; |
| return static_cast<uc32>(-1); |
| } |
| } |
| |
| |
| template <typename StringType, typename CharType> |
| void ExternalStringUTF16Buffer<StringType, CharType>::PushBack(uc32 ch) { |
| pos_--; |
| ASSERT(pos_ >= Scanner::kCharacterLookaheadBufferSize); |
| ASSERT(raw_data_[pos_ - Scanner::kCharacterLookaheadBufferSize] == ch); |
| } |
| |
| |
| template <typename StringType, typename CharType> |
| void ExternalStringUTF16Buffer<StringType, CharType>::SeekForward(int pos) { |
| pos_ = pos; |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Keyword Matcher |
| |
| KeywordMatcher::FirstState KeywordMatcher::first_states_[] = { |
| { "break", KEYWORD_PREFIX, Token::BREAK }, |
| { NULL, C, Token::ILLEGAL }, |
| { NULL, D, Token::ILLEGAL }, |
| { "else", KEYWORD_PREFIX, Token::ELSE }, |
| { NULL, F, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, I, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, N, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { "return", KEYWORD_PREFIX, Token::RETURN }, |
| { "switch", KEYWORD_PREFIX, Token::SWITCH }, |
| { NULL, T, Token::ILLEGAL }, |
| { NULL, UNMATCHABLE, Token::ILLEGAL }, |
| { NULL, V, Token::ILLEGAL }, |
| { NULL, W, Token::ILLEGAL } |
| }; |
| |
| |
| void KeywordMatcher::Step(uc32 input) { |
| switch (state_) { |
| case INITIAL: { |
| // matching the first character is the only state with significant fanout. |
| // Match only lower-case letters in range 'b'..'w'. |
| 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 (keyword_[counter_] == input) { |
| ASSERT_NE(input, '\0'); |
| 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 (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 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 (MatchKeyword(input, 'n', IN, Token::IN)) return; |
| break; |
| case IN: |
| token_ = Token::IDENTIFIER; |
| 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 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; |
| default: |
| UNREACHABLE(); |
| } |
| // On fallthrough, it's a failure. |
| state_ = UNMATCHABLE; |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Scanner |
| |
| Scanner::Scanner(ParserMode pre) |
| : is_pre_parsing_(pre == PREPARSE), stack_overflow_(false) { } |
| |
| |
| void Scanner::Initialize(Handle<String> source, |
| ParserLanguage language) { |
| safe_string_input_buffer_.Reset(source.location()); |
| Init(source, &safe_string_input_buffer_, 0, source->length(), language); |
| } |
| |
| |
| void Scanner::Initialize(Handle<String> source, |
| unibrow::CharacterStream* stream, |
| ParserLanguage language) { |
| Init(source, stream, 0, kNoEndPosition, language); |
| } |
| |
| |
| void Scanner::Initialize(Handle<String> source, |
| int start_position, |
| int end_position, |
| ParserLanguage language) { |
| safe_string_input_buffer_.Reset(source.location()); |
| Init(source, &safe_string_input_buffer_, |
| start_position, end_position, language); |
| } |
| |
| |
| void Scanner::Init(Handle<String> source, |
| unibrow::CharacterStream* stream, |
| int start_position, |
| int end_position, |
| ParserLanguage language) { |
| // Initialize the source buffer. |
| if (!source.is_null() && StringShape(*source).IsExternalTwoByte()) { |
| two_byte_string_buffer_.Initialize( |
| Handle<ExternalTwoByteString>::cast(source), |
| start_position, |
| end_position); |
| source_ = &two_byte_string_buffer_; |
| } else if (!source.is_null() && StringShape(*source).IsExternalAscii()) { |
| ascii_string_buffer_.Initialize( |
| Handle<ExternalAsciiString>::cast(source), |
| start_position, |
| end_position); |
| source_ = &ascii_string_buffer_; |
| } else { |
| char_stream_buffer_.Initialize(source, |
| stream, |
| start_position, |
| end_position); |
| source_ = &char_stream_buffer_; |
| } |
| |
| is_parsing_json_ = (language == JSON); |
| |
| // Set c0_ (one character ahead) |
| ASSERT(kCharacterLookaheadBufferSize == 1); |
| Advance(); |
| // Initializer current_ to not refer to a literal buffer. |
| current_.literal_buffer = NULL; |
| |
| // Skip initial whitespace allowing HTML comment ends just like |
| // after a newline and scan first token. |
| has_line_terminator_before_next_ = true; |
| SkipWhiteSpace(); |
| Scan(); |
| } |
| |
| |
| Token::Value Scanner::Next() { |
| // BUG 1215673: Find a thread safe way to set a stack limit in |
| // pre-parse mode. Otherwise, we cannot safely pre-parse from other |
| // threads. |
| current_ = next_; |
| // Check for stack-overflow before returning any tokens. |
| StackLimitCheck check; |
| if (check.HasOverflowed()) { |
| stack_overflow_ = true; |
| next_.token = Token::ILLEGAL; |
| } else { |
| Scan(); |
| } |
| return current_.token; |
| } |
| |
| |
| void Scanner::StartLiteral() { |
| // Use the first buffer unless it's currently in use by the current_ token. |
| // In most cases we won't have two literals/identifiers in a row, so |
| // the second buffer won't be used very often and is unlikely to grow much. |
| UTF8Buffer* free_buffer = |
| (current_.literal_buffer != &literal_buffer_1_) ? &literal_buffer_1_ |
| : &literal_buffer_2_; |
| next_.literal_buffer = free_buffer; |
| free_buffer->Reset(); |
| } |
| |
| |
| void Scanner::AddChar(uc32 c) { |
| next_.literal_buffer->AddChar(c); |
| } |
| |
| |
| void Scanner::TerminateLiteral() { |
| AddChar(0); |
| } |
| |
| |
| void Scanner::AddCharAdvance() { |
| AddChar(c0_); |
| Advance(); |
| } |
| |
| |
| 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::SkipJsonWhiteSpace() { |
| int start_position = source_pos(); |
| // JSON WhiteSpace is tab, carrige-return, newline and space. |
| while (c0_ == ' ' || c0_ == '\n' || c0_ == '\r' || c0_ == '\t') { |
| Advance(); |
| } |
| return source_pos() != start_position; |
| } |
| |
| |
| bool Scanner::SkipJavaScriptWhiteSpace() { |
| 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 (kIsWhiteSpace.get(c0_) || IsByteOrderMark(c0_)) { |
| // IsWhiteSpace() includes line terminators! |
| if (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 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, page 12). |
| while (c0_ >= 0 && !kIsLineTerminator.get(c0_)) { |
| Advance(); |
| } |
| |
| return Token::WHITESPACE; |
| } |
| |
| |
| Token::Value Scanner::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 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::ScanJson() { |
| next_.literal_buffer = NULL; |
| Token::Value token; |
| has_line_terminator_before_next_ = false; |
| do { |
| // Remember the position of the next token |
| next_.location.beg_pos = source_pos(); |
| switch (c0_) { |
| case '\t': |
| case '\r': |
| case '\n': |
| case ' ': |
| Advance(); |
| token = Token::WHITESPACE; |
| break; |
| case '{': |
| Advance(); |
| token = Token::LBRACE; |
| break; |
| case '}': |
| Advance(); |
| token = Token::RBRACE; |
| break; |
| case '[': |
| Advance(); |
| token = Token::LBRACK; |
| break; |
| case ']': |
| Advance(); |
| token = Token::RBRACK; |
| break; |
| case ':': |
| Advance(); |
| token = Token::COLON; |
| break; |
| case ',': |
| Advance(); |
| token = Token::COMMA; |
| break; |
| case '"': |
| token = ScanJsonString(); |
| break; |
| case '-': |
| case '0': |
| case '1': |
| case '2': |
| case '3': |
| case '4': |
| case '5': |
| case '6': |
| case '7': |
| case '8': |
| case '9': |
| token = ScanJsonNumber(); |
| break; |
| case 't': |
| token = ScanJsonIdentifier("true", Token::TRUE_LITERAL); |
| break; |
| case 'f': |
| token = ScanJsonIdentifier("false", Token::FALSE_LITERAL); |
| break; |
| case 'n': |
| token = ScanJsonIdentifier("null", Token::NULL_LITERAL); |
| break; |
| default: |
| if (c0_ < 0) { |
| Advance(); |
| token = Token::EOS; |
| } else { |
| Advance(); |
| token = Select(Token::ILLEGAL); |
| } |
| } |
| } while (token == Token::WHITESPACE); |
| |
| next_.location.end_pos = source_pos(); |
| next_.token = token; |
| } |
| |
| |
| Token::Value Scanner::ScanJsonString() { |
| ASSERT_EQ('"', c0_); |
| Advance(); |
| StartLiteral(); |
| while (c0_ != '"' && c0_ > 0) { |
| // Check for control character (0x00-0x1f) or unterminated string (<0). |
| if (c0_ < 0x20) return Token::ILLEGAL; |
| if (c0_ != '\\') { |
| AddCharAdvance(); |
| } else { |
| Advance(); |
| switch (c0_) { |
| case '"': |
| case '\\': |
| case '/': |
| AddChar(c0_); |
| break; |
| case 'b': |
| AddChar('\x08'); |
| break; |
| case 'f': |
| AddChar('\x0c'); |
| break; |
| case 'n': |
| AddChar('\x0a'); |
| break; |
| case 'r': |
| AddChar('\x0d'); |
| break; |
| case 't': |
| AddChar('\x09'); |
| break; |
| case 'u': { |
| uc32 value = 0; |
| for (int i = 0; i < 4; i++) { |
| Advance(); |
| int digit = HexValue(c0_); |
| if (digit < 0) return Token::ILLEGAL; |
| value = value * 16 + digit; |
| } |
| AddChar(value); |
| break; |
| } |
| default: |
| return Token::ILLEGAL; |
| } |
| Advance(); |
| } |
| } |
| if (c0_ != '"') { |
| return Token::ILLEGAL; |
| } |
| TerminateLiteral(); |
| Advance(); |
| return Token::STRING; |
| } |
| |
| |
| Token::Value Scanner::ScanJsonNumber() { |
| StartLiteral(); |
| if (c0_ == '-') AddCharAdvance(); |
| if (c0_ == '0') { |
| AddCharAdvance(); |
| // Prefix zero is only allowed if it's the only digit before |
| // a decimal point or exponent. |
| if ('0' <= c0_ && c0_ <= '9') return Token::ILLEGAL; |
| } else { |
| if (c0_ < '1' || c0_ > '9') return Token::ILLEGAL; |
| do { |
| AddCharAdvance(); |
| } while (c0_ >= '0' && c0_ <= '9'); |
| } |
| if (c0_ == '.') { |
| AddCharAdvance(); |
| if (c0_ < '0' || c0_ > '9') return Token::ILLEGAL; |
| do { |
| AddCharAdvance(); |
| } while (c0_ >= '0' && c0_ <= '9'); |
| } |
| if ((c0_ | 0x20) == 'e') { |
| AddCharAdvance(); |
| if (c0_ == '-' || c0_ == '+') AddCharAdvance(); |
| if (c0_ < '0' || c0_ > '9') return Token::ILLEGAL; |
| do { |
| AddCharAdvance(); |
| } while (c0_ >= '0' && c0_ <= '9'); |
| } |
| TerminateLiteral(); |
| return Token::NUMBER; |
| } |
| |
| |
| Token::Value Scanner::ScanJsonIdentifier(const char* text, |
| Token::Value token) { |
| StartLiteral(); |
| while (*text != '\0') { |
| if (c0_ != *text) return Token::ILLEGAL; |
| Advance(); |
| text++; |
| } |
| if (kIsIdentifierPart.get(c0_)) return Token::ILLEGAL; |
| TerminateLiteral(); |
| return token; |
| } |
| |
| |
| void Scanner::ScanJavaScript() { |
| next_.literal_buffer = NULL; |
| Token::Value token; |
| has_line_terminator_before_next_ = false; |
| 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 (kIsIdentifierStart.get(c0_)) { |
| token = ScanIdentifier(); |
| } 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) { |
| source_->SeekForward(pos - 1); |
| Advance(); |
| Scan(); |
| } |
| |
| |
| 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'; |
| for (int i = 0; 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(); |
| } |
| return x; |
| } |
| |
| |
| void Scanner::ScanEscape() { |
| uc32 c = c0_; |
| Advance(); |
| |
| // Skip escaped newlines. |
| if (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. |
| AddChar(c); |
| } |
| |
| |
| Token::Value Scanner::ScanString() { |
| uc32 quote = c0_; |
| Advance(); // consume quote |
| |
| StartLiteral(); |
| while (c0_ != quote && c0_ >= 0 && !kIsLineTerminator.get(c0_)) { |
| uc32 c = c0_; |
| Advance(); |
| if (c == '\\') { |
| if (c0_ < 0) return Token::ILLEGAL; |
| ScanEscape(); |
| } else { |
| AddChar(c); |
| } |
| } |
| if (c0_ != quote) { |
| return Token::ILLEGAL; |
| } |
| TerminateLiteral(); |
| |
| Advance(); // consume quote |
| return Token::STRING; |
| } |
| |
| |
| Token::Value Scanner::Select(Token::Value tok) { |
| Advance(); |
| return tok; |
| } |
| |
| |
| Token::Value Scanner::Select(uc32 next, Token::Value then, Token::Value else_) { |
| Advance(); |
| if (c0_ == next) { |
| Advance(); |
| return then; |
| } else { |
| return else_; |
| } |
| } |
| |
| |
| // Returns true if any decimal digits were scanned, returns false otherwise. |
| void Scanner::ScanDecimalDigits() { |
| while (IsDecimalDigit(c0_)) |
| AddCharAdvance(); |
| } |
| |
| |
| 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; |
| |
| StartLiteral(); |
| if (seen_period) { |
| // we have already seen a decimal point of the float |
| AddChar('.'); |
| 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') { |
| AddCharAdvance(); |
| |
| // either 0, 0exxx, 0Exxx, 0.xxx, an octal number, or a hex number |
| if (c0_ == 'x' || c0_ == 'X') { |
| // hex number |
| kind = HEX; |
| AddCharAdvance(); |
| if (!IsHexDigit(c0_)) |
| // we must have at least one hex digit after 'x'/'X' |
| return Token::ILLEGAL; |
| while (IsHexDigit(c0_)) |
| AddCharAdvance(); |
| |
| } 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_) break; |
| AddCharAdvance(); |
| } |
| } |
| } |
| |
| // Parse decimal digits and allow trailing fractional part. |
| if (kind == DECIMAL) { |
| ScanDecimalDigits(); // optional |
| if (c0_ == '.') { |
| AddCharAdvance(); |
| 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 |
| AddCharAdvance(); |
| if (c0_ == '+' || c0_ == '-') |
| AddCharAdvance(); |
| if (!IsDecimalDigit(c0_)) |
| // we must have at least one decimal digit after 'e'/'E' |
| return Token::ILLEGAL; |
| ScanDecimalDigits(); |
| } |
| TerminateLiteral(); |
| |
| // 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_) || kIsIdentifierStart.get(c0_)) |
| return Token::ILLEGAL; |
| |
| return Token::NUMBER; |
| } |
| |
| |
| uc32 Scanner::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 Scanner::ScanIdentifier() { |
| ASSERT(kIsIdentifierStart.get(c0_)); |
| |
| StartLiteral(); |
| KeywordMatcher keyword_match; |
| |
| // Scan identifier start character. |
| if (c0_ == '\\') { |
| uc32 c = ScanIdentifierUnicodeEscape(); |
| // Only allow legal identifier start characters. |
| if (!kIsIdentifierStart.get(c)) return Token::ILLEGAL; |
| AddChar(c); |
| keyword_match.Fail(); |
| } else { |
| AddChar(c0_); |
| keyword_match.AddChar(c0_); |
| Advance(); |
| } |
| |
| // Scan the rest of the identifier characters. |
| while (kIsIdentifierPart.get(c0_)) { |
| if (c0_ == '\\') { |
| uc32 c = ScanIdentifierUnicodeEscape(); |
| // Only allow legal identifier part characters. |
| if (!kIsIdentifierPart.get(c)) return Token::ILLEGAL; |
| AddChar(c); |
| keyword_match.Fail(); |
| } else { |
| AddChar(c0_); |
| keyword_match.AddChar(c0_); |
| Advance(); |
| } |
| } |
| TerminateLiteral(); |
| |
| return keyword_match.token(); |
| } |
| |
| |
| |
| bool Scanner::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; |
| } |
| |
| |
| 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. |
| StartLiteral(); |
| if (seen_equal) |
| AddChar('='); |
| |
| while (c0_ != '/' || in_character_class) { |
| if (kIsLineTerminator.get(c0_) || c0_ < 0) |
| return false; |
| if (c0_ == '\\') { // escaped character |
| AddCharAdvance(); |
| if (kIsLineTerminator.get(c0_) || c0_ < 0) |
| return false; |
| AddCharAdvance(); |
| } else { // unescaped character |
| if (c0_ == '[') |
| in_character_class = true; |
| if (c0_ == ']') |
| in_character_class = false; |
| AddCharAdvance(); |
| } |
| } |
| Advance(); // consume '/' |
| |
| TerminateLiteral(); |
| |
| return true; |
| } |
| |
| bool Scanner::ScanRegExpFlags() { |
| // Scan regular expression flags. |
| StartLiteral(); |
| while (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. |
| AddChar(c); |
| continue; |
| } |
| } |
| AddCharAdvance(); |
| } |
| TerminateLiteral(); |
| |
| next_.location.end_pos = source_pos() - 1; |
| return true; |
| } |
| |
| } } // namespace v8::internal |
