| // Copyright 2011 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Features shared by parsing and pre-parsing scanners. |
| |
| #include "src/scanner.h" |
| |
| #include <stdint.h> |
| |
| #include <cmath> |
| |
| #include "src/ast-value-factory.h" |
| #include "src/char-predicates-inl.h" |
| #include "src/conversions-inl.h" |
| #include "src/list-inl.h" |
| #include "src/parser.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| Handle<String> LiteralBuffer::Internalize(Isolate* isolate) const { |
| if (is_one_byte()) { |
| return isolate->factory()->InternalizeOneByteString(one_byte_literal()); |
| } |
| return isolate->factory()->InternalizeTwoByteString(two_byte_literal()); |
| } |
| |
| |
| // Default implementation for streams that do not support bookmarks. |
| bool Utf16CharacterStream::SetBookmark() { return false; } |
| void Utf16CharacterStream::ResetToBookmark() { UNREACHABLE(); } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Scanner |
| |
| Scanner::Scanner(UnicodeCache* unicode_cache) |
| : unicode_cache_(unicode_cache), |
| bookmark_c0_(kNoBookmark), |
| octal_pos_(Location::invalid()) { |
| bookmark_current_.literal_chars = &bookmark_current_literal_; |
| bookmark_current_.raw_literal_chars = &bookmark_current_raw_literal_; |
| bookmark_next_.literal_chars = &bookmark_next_literal_; |
| bookmark_next_.raw_literal_chars = &bookmark_next_raw_literal_; |
| } |
| |
| |
| 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(); |
| } |
| |
| |
| template <bool capture_raw> |
| uc32 Scanner::ScanHexNumber(int expected_length) { |
| DCHECK(expected_length <= 4); // prevent overflow |
| |
| uc32 x = 0; |
| for (int i = 0; i < expected_length; i++) { |
| int d = HexValue(c0_); |
| if (d < 0) { |
| return -1; |
| } |
| x = x * 16 + d; |
| Advance<capture_raw>(); |
| } |
| |
| return x; |
| } |
| |
| |
| template <bool capture_raw> |
| uc32 Scanner::ScanUnlimitedLengthHexNumber(int max_value) { |
| uc32 x = 0; |
| int d = HexValue(c0_); |
| if (d < 0) { |
| return -1; |
| } |
| while (d >= 0) { |
| x = x * 16 + d; |
| if (x > max_value) return -1; |
| Advance<capture_raw>(); |
| d = HexValue(c0_); |
| } |
| 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() { |
| if (next_.token == Token::EOS) { |
| next_.location.beg_pos = current_.location.beg_pos; |
| next_.location.end_pos = current_.location.end_pos; |
| } |
| current_ = next_; |
| if (V8_UNLIKELY(next_next_.token != Token::UNINITIALIZED)) { |
| next_ = next_next_; |
| next_next_.token = Token::UNINITIALIZED; |
| return current_.token; |
| } |
| 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; |
| } |
| |
| |
| Token::Value Scanner::PeekAhead() { |
| if (next_next_.token != Token::UNINITIALIZED) { |
| return next_next_.token; |
| } |
| TokenDesc prev = current_; |
| Next(); |
| Token::Value ret = next_.token; |
| next_next_ = next_; |
| next_ = current_; |
| current_ = prev; |
| return ret; |
| } |
| |
| |
| // TODO(yangguo): check whether this is actually necessary. |
| static inline bool IsLittleEndianByteOrderMark(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 == 0xFFFE; |
| } |
| |
| |
| bool Scanner::SkipWhiteSpace() { |
| int start_position = source_pos(); |
| |
| while (true) { |
| while (true) { |
| // The unicode cache accepts unsigned inputs. |
| if (c0_ < 0) break; |
| // Advance as long as character is a WhiteSpace or LineTerminator. |
| // Remember if the latter is the case. |
| if (unicode_cache_->IsLineTerminator(c0_)) { |
| has_line_terminator_before_next_ = true; |
| } else if (!unicode_cache_->IsWhiteSpace(c0_) && |
| !IsLittleEndianByteOrderMark(c0_)) { |
| break; |
| } |
| 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::SkipSourceURLComment() { |
| TryToParseSourceURLComment(); |
| while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) { |
| Advance(); |
| } |
| |
| return Token::WHITESPACE; |
| } |
| |
| |
| void Scanner::TryToParseSourceURLComment() { |
| // Magic comments are of the form: //[#@]\s<name>=\s*<value>\s*.* and this |
| // function will just return if it cannot parse a magic comment. |
| if (c0_ < 0 || !unicode_cache_->IsWhiteSpace(c0_)) return; |
| Advance(); |
| LiteralBuffer name; |
| while (c0_ >= 0 && !unicode_cache_->IsWhiteSpaceOrLineTerminator(c0_) && |
| c0_ != '=') { |
| name.AddChar(c0_); |
| Advance(); |
| } |
| if (!name.is_one_byte()) return; |
| Vector<const uint8_t> name_literal = name.one_byte_literal(); |
| LiteralBuffer* value; |
| if (name_literal == STATIC_CHAR_VECTOR("sourceURL")) { |
| value = &source_url_; |
| } else if (name_literal == STATIC_CHAR_VECTOR("sourceMappingURL")) { |
| value = &source_mapping_url_; |
| } else { |
| return; |
| } |
| if (c0_ != '=') |
| return; |
| Advance(); |
| value->Reset(); |
| while (c0_ >= 0 && unicode_cache_->IsWhiteSpace(c0_)) { |
| Advance(); |
| } |
| while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) { |
| // Disallowed characters. |
| if (c0_ == '"' || c0_ == '\'') { |
| value->Reset(); |
| return; |
| } |
| if (unicode_cache_->IsWhiteSpace(c0_)) { |
| break; |
| } |
| value->AddChar(c0_); |
| Advance(); |
| } |
| // Allow whitespace at the end. |
| while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) { |
| if (!unicode_cache_->IsWhiteSpace(c0_)) { |
| value->Reset(); |
| break; |
| } |
| Advance(); |
| } |
| } |
| |
| |
| Token::Value Scanner::SkipMultiLineComment() { |
| DCHECK(c0_ == '*'); |
| Advance(); |
| |
| while (c0_ >= 0) { |
| uc32 ch = c0_; |
| Advance(); |
| if (c0_ >= 0 && 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. |
| DCHECK(c0_ == '!'); |
| Advance(); |
| if (c0_ == '-') { |
| Advance(); |
| if (c0_ == '-') return SkipSingleLineComment(); |
| PushBack('-'); // undo Advance() |
| } |
| PushBack('!'); // undo Advance() |
| DCHECK(c0_ == '!'); |
| return Token::LT; |
| } |
| |
| |
| void Scanner::Scan() { |
| next_.literal_chars = NULL; |
| next_.raw_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 if (c0_ == '>') { |
| token = Select(Token::ARROW); |
| } 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_ == '/') { |
| Advance(); |
| if (c0_ == '@' || c0_ == '#') { |
| Advance(); |
| token = SkipSourceURLComment(); |
| } else { |
| PushBack(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; |
| if (c0_ == '.') { |
| Advance(); |
| if (c0_ == '.') { |
| Advance(); |
| token = Token::ELLIPSIS; |
| } else { |
| PushBack('.'); |
| } |
| } |
| } |
| 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; |
| |
| case '`': |
| token = ScanTemplateStart(); |
| break; |
| |
| default: |
| if (c0_ < 0) { |
| token = Token::EOS; |
| } else if (unicode_cache_->IsIdentifierStart(c0_)) { |
| token = ScanIdentifierOrKeyword(); |
| } else if (IsDecimalDigit(c0_)) { |
| token = ScanNumber(false); |
| } else if (SkipWhiteSpace()) { |
| token = Token::WHITESPACE; |
| } 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(); |
| DCHECK_EQ(next_.location.end_pos, current_pos); |
| // Positions inside the lookahead token aren't supported. |
| DCHECK(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(); |
| } |
| |
| |
| template <bool capture_raw, bool in_template_literal> |
| bool Scanner::ScanEscape() { |
| uc32 c = c0_; |
| Advance<capture_raw>(); |
| |
| // Skip escaped newlines. |
| if (!in_template_literal && c0_ >= 0 && unicode_cache_->IsLineTerminator(c)) { |
| // Allow CR+LF newlines in multiline string literals. |
| if (IsCarriageReturn(c) && IsLineFeed(c0_)) Advance<capture_raw>(); |
| // Allow LF+CR newlines in multiline string literals. |
| if (IsLineFeed(c) && IsCarriageReturn(c0_)) Advance<capture_raw>(); |
| return true; |
| } |
| |
| 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 = ScanUnicodeEscape<capture_raw>(); |
| if (c < 0) return false; |
| break; |
| } |
| case 'v': |
| c = '\v'; |
| break; |
| case 'x': { |
| c = ScanHexNumber<capture_raw>(2); |
| if (c < 0) return false; |
| 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<capture_raw>(c, 2); |
| break; |
| } |
| |
| // According to ECMA-262, section 7.8.4, characters not covered by the |
| // above cases should be illegal, but they are commonly handled as |
| // non-escaped characters by JS VMs. |
| AddLiteralChar(c); |
| return true; |
| } |
| |
| |
| // Octal escapes of the forms '\0xx' and '\xxx' are not a part of |
| // ECMA-262. Other JS VMs support them. |
| template <bool capture_raw> |
| 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<capture_raw>(); |
| } |
| // 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; |
| } |
| |
| |
| const int kMaxAscii = 127; |
| |
| |
| Token::Value Scanner::ScanString() { |
| uc32 quote = c0_; |
| Advance<false, false>(); // consume quote |
| |
| LiteralScope literal(this); |
| while (true) { |
| if (c0_ > kMaxAscii) { |
| HandleLeadSurrogate(); |
| break; |
| } |
| if (c0_ < 0 || c0_ == '\n' || c0_ == '\r') return Token::ILLEGAL; |
| if (c0_ == quote) { |
| literal.Complete(); |
| Advance<false, false>(); |
| return Token::STRING; |
| } |
| uc32 c = c0_; |
| if (c == '\\') break; |
| Advance<false, false>(); |
| AddLiteralChar(c); |
| } |
| |
| while (c0_ != quote && c0_ >= 0 |
| && !unicode_cache_->IsLineTerminator(c0_)) { |
| uc32 c = c0_; |
| Advance(); |
| if (c == '\\') { |
| if (c0_ < 0 || !ScanEscape<false, false>()) return Token::ILLEGAL; |
| } else { |
| AddLiteralChar(c); |
| } |
| } |
| if (c0_ != quote) return Token::ILLEGAL; |
| literal.Complete(); |
| |
| Advance(); // consume quote |
| return Token::STRING; |
| } |
| |
| |
| Token::Value Scanner::ScanTemplateSpan() { |
| // When scanning a TemplateSpan, we are looking for the following construct: |
| // TEMPLATE_SPAN :: |
| // ` LiteralChars* ${ |
| // | } LiteralChars* ${ |
| // |
| // TEMPLATE_TAIL :: |
| // ` LiteralChars* ` |
| // | } LiteralChar* ` |
| // |
| // A TEMPLATE_SPAN should always be followed by an Expression, while a |
| // TEMPLATE_TAIL terminates a TemplateLiteral and does not need to be |
| // followed by an Expression. |
| |
| Token::Value result = Token::TEMPLATE_SPAN; |
| LiteralScope literal(this); |
| StartRawLiteral(); |
| const bool capture_raw = true; |
| const bool in_template_literal = true; |
| |
| while (true) { |
| uc32 c = c0_; |
| Advance<capture_raw>(); |
| if (c == '`') { |
| result = Token::TEMPLATE_TAIL; |
| ReduceRawLiteralLength(1); |
| break; |
| } else if (c == '$' && c0_ == '{') { |
| Advance<capture_raw>(); // Consume '{' |
| ReduceRawLiteralLength(2); |
| break; |
| } else if (c == '\\') { |
| if (c0_ > 0 && unicode_cache_->IsLineTerminator(c0_)) { |
| // The TV of LineContinuation :: \ LineTerminatorSequence is the empty |
| // code unit sequence. |
| uc32 lastChar = c0_; |
| Advance<capture_raw>(); |
| if (lastChar == '\r') { |
| ReduceRawLiteralLength(1); // Remove \r |
| if (c0_ == '\n') { |
| Advance<capture_raw>(); // Adds \n |
| } else { |
| AddRawLiteralChar('\n'); |
| } |
| } |
| } else if (!ScanEscape<capture_raw, in_template_literal>()) { |
| return Token::ILLEGAL; |
| } |
| } else if (c < 0) { |
| // Unterminated template literal |
| PushBack(c); |
| break; |
| } else { |
| // The TRV of LineTerminatorSequence :: <CR> is the CV 0x000A. |
| // The TRV of LineTerminatorSequence :: <CR><LF> is the sequence |
| // consisting of the CV 0x000A. |
| if (c == '\r') { |
| ReduceRawLiteralLength(1); // Remove \r |
| if (c0_ == '\n') { |
| Advance<capture_raw>(); // Adds \n |
| } else { |
| AddRawLiteralChar('\n'); |
| } |
| c = '\n'; |
| } |
| AddLiteralChar(c); |
| } |
| } |
| literal.Complete(); |
| next_.location.end_pos = source_pos(); |
| next_.token = result; |
| return result; |
| } |
| |
| |
| Token::Value Scanner::ScanTemplateStart() { |
| DCHECK(c0_ == '`'); |
| next_.location.beg_pos = source_pos(); |
| Advance(); // Consume ` |
| return ScanTemplateSpan(); |
| } |
| |
| |
| Token::Value Scanner::ScanTemplateContinuation() { |
| DCHECK_EQ(next_.token, Token::RBRACE); |
| next_.location.beg_pos = source_pos() - 1; // We already consumed } |
| return ScanTemplateSpan(); |
| } |
| |
| |
| void Scanner::ScanDecimalDigits() { |
| while (IsDecimalDigit(c0_)) |
| AddLiteralCharAdvance(); |
| } |
| |
| |
| Token::Value Scanner::ScanNumber(bool seen_period) { |
| DCHECK(IsDecimalDigit(c0_)); // the first digit of the number or the fraction |
| |
| enum { DECIMAL, HEX, OCTAL, IMPLICIT_OCTAL, BINARY } kind = DECIMAL; |
| |
| LiteralScope literal(this); |
| bool at_start = !seen_period; |
| 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, a hex number, a binary number or |
| // an octal 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 (c0_ == 'o' || c0_ == 'O') { |
| kind = OCTAL; |
| AddLiteralCharAdvance(); |
| if (!IsOctalDigit(c0_)) { |
| // we must have at least one octal digit after 'o'/'O' |
| return Token::ILLEGAL; |
| } |
| while (IsOctalDigit(c0_)) { |
| AddLiteralCharAdvance(); |
| } |
| } else if (c0_ == 'b' || c0_ == 'B') { |
| kind = BINARY; |
| AddLiteralCharAdvance(); |
| if (!IsBinaryDigit(c0_)) { |
| // we must have at least one binary digit after 'b'/'B' |
| return Token::ILLEGAL; |
| } |
| while (IsBinaryDigit(c0_)) { |
| AddLiteralCharAdvance(); |
| } |
| } else if ('0' <= c0_ && c0_ <= '7') { |
| // (possible) octal number |
| kind = IMPLICIT_OCTAL; |
| while (true) { |
| if (c0_ == '8' || c0_ == '9') { |
| at_start = false; |
| 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) { |
| if (at_start) { |
| uint64_t value = 0; |
| while (IsDecimalDigit(c0_)) { |
| value = 10 * value + (c0_ - '0'); |
| |
| uc32 first_char = c0_; |
| Advance<false, false>(); |
| AddLiteralChar(first_char); |
| } |
| |
| if (next_.literal_chars->one_byte_literal().length() <= 10 && |
| value <= Smi::kMaxValue && c0_ != '.' && c0_ != 'e' && c0_ != 'E') { |
| next_.smi_value_ = static_cast<int>(value); |
| literal.Complete(); |
| HandleLeadSurrogate(); |
| |
| return Token::SMI; |
| } |
| HandleLeadSurrogate(); |
| } |
| |
| ScanDecimalDigits(); // optional |
| if (c0_ == '.') { |
| AddLiteralCharAdvance(); |
| ScanDecimalDigits(); // optional |
| } |
| } |
| } |
| |
| // scan exponent, if any |
| if (c0_ == 'e' || c0_ == 'E') { |
| DCHECK(kind != HEX); // 'e'/'E' must be scanned as part of the hex number |
| if (kind != DECIMAL) return Token::ILLEGAL; |
| // 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_) || |
| (c0_ >= 0 && unicode_cache_->IsIdentifierStart(c0_))) |
| return Token::ILLEGAL; |
| |
| literal.Complete(); |
| |
| return Token::NUMBER; |
| } |
| |
| |
| uc32 Scanner::ScanIdentifierUnicodeEscape() { |
| Advance(); |
| if (c0_ != 'u') return -1; |
| Advance(); |
| return ScanUnicodeEscape<false>(); |
| } |
| |
| |
| template <bool capture_raw> |
| uc32 Scanner::ScanUnicodeEscape() { |
| // Accept both \uxxxx and \u{xxxxxx}. In the latter case, the number of |
| // hex digits between { } is arbitrary. \ and u have already been read. |
| if (c0_ == '{') { |
| Advance<capture_raw>(); |
| uc32 cp = ScanUnlimitedLengthHexNumber<capture_raw>(0x10ffff); |
| if (cp < 0) { |
| return -1; |
| } |
| if (c0_ != '}') { |
| return -1; |
| } |
| Advance<capture_raw>(); |
| return cp; |
| } |
| return ScanHexNumber<capture_raw>(4); |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // 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::CLASS) \ |
| 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", Token::EXPORT) \ |
| KEYWORD("extends", Token::EXTENDS) \ |
| 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", Token::IMPORT) \ |
| KEYWORD("in", Token::IN) \ |
| KEYWORD("instanceof", Token::INSTANCEOF) \ |
| KEYWORD("interface", Token::FUTURE_STRICT_RESERVED_WORD) \ |
| KEYWORD_GROUP('l') \ |
| KEYWORD("let", Token::LET) \ |
| 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::STATIC) \ |
| KEYWORD("super", Token::SUPER) \ |
| 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::YIELD) |
| |
| |
| static Token::Value KeywordOrIdentifierToken(const uint8_t* input, |
| int input_length, bool escaped) { |
| DCHECK(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])) { \ |
| if (escaped) { \ |
| return token == Token::FUTURE_STRICT_RESERVED_WORD \ |
| ? Token::ESCAPED_STRICT_RESERVED_WORD \ |
| : Token::ESCAPED_KEYWORD; \ |
| } \ |
| return token; \ |
| } \ |
| } |
| KEYWORDS(KEYWORD_GROUP_CASE, KEYWORD) |
| } |
| return Token::IDENTIFIER; |
| } |
| |
| |
| bool Scanner::IdentifierIsFutureStrictReserved( |
| const AstRawString* string) const { |
| // Keywords are always 1-byte strings. |
| if (!string->is_one_byte()) return false; |
| if (string->IsOneByteEqualTo("let") || string->IsOneByteEqualTo("static") || |
| string->IsOneByteEqualTo("yield")) { |
| return true; |
| } |
| return Token::FUTURE_STRICT_RESERVED_WORD == |
| KeywordOrIdentifierToken(string->raw_data(), string->length(), false); |
| } |
| |
| |
| Token::Value Scanner::ScanIdentifierOrKeyword() { |
| DCHECK(unicode_cache_->IsIdentifierStart(c0_)); |
| LiteralScope literal(this); |
| if (IsInRange(c0_, 'a', 'z')) { |
| do { |
| uc32 first_char = c0_; |
| Advance<false, false>(); |
| AddLiteralChar(first_char); |
| } while (IsInRange(c0_, 'a', 'z')); |
| |
| if (IsDecimalDigit(c0_) || IsInRange(c0_, 'A', 'Z') || c0_ == '_' || |
| c0_ == '$') { |
| // Identifier starting with lowercase. |
| uc32 first_char = c0_; |
| Advance<false, false>(); |
| AddLiteralChar(first_char); |
| while (IsAsciiIdentifier(c0_)) { |
| uc32 first_char = c0_; |
| Advance<false, false>(); |
| AddLiteralChar(first_char); |
| } |
| if (c0_ <= kMaxAscii && c0_ != '\\') { |
| literal.Complete(); |
| return Token::IDENTIFIER; |
| } |
| } else if (c0_ <= kMaxAscii && c0_ != '\\') { |
| // Only a-z+: could be a keyword or identifier. |
| literal.Complete(); |
| Vector<const uint8_t> chars = next_.literal_chars->one_byte_literal(); |
| return KeywordOrIdentifierToken(chars.start(), chars.length(), false); |
| } |
| |
| HandleLeadSurrogate(); |
| } else if (IsInRange(c0_, 'A', 'Z') || c0_ == '_' || c0_ == '$') { |
| do { |
| uc32 first_char = c0_; |
| Advance<false, false>(); |
| AddLiteralChar(first_char); |
| } while (IsAsciiIdentifier(c0_)); |
| |
| if (c0_ <= kMaxAscii && c0_ != '\\') { |
| literal.Complete(); |
| return Token::IDENTIFIER; |
| } |
| |
| HandleLeadSurrogate(); |
| } else if (c0_ == '\\') { |
| // Scan identifier start character. |
| 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, true); |
| } else { |
| uc32 first_char = c0_; |
| Advance(); |
| AddLiteralChar(first_char); |
| } |
| |
| // Scan the rest of the identifier characters. |
| while (c0_ >= 0 && 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, false); |
| } |
| |
| literal.Complete(); |
| |
| if (next_.literal_chars->is_one_byte()) { |
| Vector<const uint8_t> chars = next_.literal_chars->one_byte_literal(); |
| return KeywordOrIdentifierToken(chars.start(), chars.length(), false); |
| } |
| return Token::IDENTIFIER; |
| } |
| |
| |
| Token::Value Scanner::ScanIdentifierSuffix(LiteralScope* literal, |
| bool escaped) { |
| // Scan the rest of the identifier characters. |
| while (c0_ >= 0 && unicode_cache_->IsIdentifierPart(c0_)) { |
| if (c0_ == '\\') { |
| uc32 c = ScanIdentifierUnicodeEscape(); |
| escaped = true; |
| // 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(); |
| |
| if (escaped && next_.literal_chars->is_one_byte()) { |
| Vector<const uint8_t> chars = next_.literal_chars->one_byte_literal(); |
| return KeywordOrIdentifierToken(chars.start(), chars.length(), true); |
| } |
| 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 (c0_ < 0 || unicode_cache_->IsLineTerminator(c0_)) return false; |
| if (c0_ == '\\') { // Escape sequence. |
| AddLiteralCharAdvance(); |
| if (c0_ < 0 || unicode_cache_->IsLineTerminator(c0_)) 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::ScanRegExpFlags() { |
| // Scan regular expression flags. |
| LiteralScope literal(this); |
| while (c0_ >= 0 && unicode_cache_->IsIdentifierPart(c0_)) { |
| if (c0_ != '\\') { |
| AddLiteralCharAdvance(); |
| } else { |
| return false; |
| } |
| } |
| literal.Complete(); |
| |
| next_.location.end_pos = source_pos(); |
| return true; |
| } |
| |
| |
| const AstRawString* Scanner::CurrentSymbol(AstValueFactory* ast_value_factory) { |
| if (is_literal_one_byte()) { |
| return ast_value_factory->GetOneByteString(literal_one_byte_string()); |
| } |
| return ast_value_factory->GetTwoByteString(literal_two_byte_string()); |
| } |
| |
| |
| const AstRawString* Scanner::NextSymbol(AstValueFactory* ast_value_factory) { |
| if (is_next_literal_one_byte()) { |
| return ast_value_factory->GetOneByteString(next_literal_one_byte_string()); |
| } |
| return ast_value_factory->GetTwoByteString(next_literal_two_byte_string()); |
| } |
| |
| |
| const AstRawString* Scanner::CurrentRawSymbol( |
| AstValueFactory* ast_value_factory) { |
| if (is_raw_literal_one_byte()) { |
| return ast_value_factory->GetOneByteString(raw_literal_one_byte_string()); |
| } |
| return ast_value_factory->GetTwoByteString(raw_literal_two_byte_string()); |
| } |
| |
| |
| double Scanner::DoubleValue() { |
| DCHECK(is_literal_one_byte()); |
| return StringToDouble( |
| unicode_cache_, |
| literal_one_byte_string(), |
| ALLOW_HEX | ALLOW_OCTAL | ALLOW_IMPLICIT_OCTAL | ALLOW_BINARY); |
| } |
| |
| |
| bool Scanner::ContainsDot() { |
| DCHECK(is_literal_one_byte()); |
| Vector<const uint8_t> str = literal_one_byte_string(); |
| return std::find(str.begin(), str.end(), '.') != str.end(); |
| } |
| |
| |
| int Scanner::FindSymbol(DuplicateFinder* finder, int value) { |
| if (is_literal_one_byte()) { |
| return finder->AddOneByteSymbol(literal_one_byte_string(), value); |
| } |
| return finder->AddTwoByteSymbol(literal_two_byte_string(), value); |
| } |
| |
| |
| bool Scanner::SetBookmark() { |
| if (c0_ != kNoBookmark && bookmark_c0_ == kNoBookmark && |
| next_next_.token == Token::UNINITIALIZED && source_->SetBookmark()) { |
| bookmark_c0_ = c0_; |
| CopyTokenDesc(&bookmark_current_, ¤t_); |
| CopyTokenDesc(&bookmark_next_, &next_); |
| return true; |
| } |
| return false; |
| } |
| |
| |
| void Scanner::ResetToBookmark() { |
| DCHECK(BookmarkHasBeenSet()); // Caller hasn't called SetBookmark. |
| |
| source_->ResetToBookmark(); |
| c0_ = bookmark_c0_; |
| StartLiteral(); |
| StartRawLiteral(); |
| CopyTokenDesc(&next_, &bookmark_current_); |
| current_ = next_; |
| StartLiteral(); |
| StartRawLiteral(); |
| CopyTokenDesc(&next_, &bookmark_next_); |
| |
| bookmark_c0_ = kBookmarkWasApplied; |
| } |
| |
| |
| bool Scanner::BookmarkHasBeenSet() { return bookmark_c0_ >= 0; } |
| |
| |
| bool Scanner::BookmarkHasBeenReset() { |
| return bookmark_c0_ == kBookmarkWasApplied; |
| } |
| |
| |
| void Scanner::DropBookmark() { bookmark_c0_ = kNoBookmark; } |
| |
| |
| void Scanner::CopyTokenDesc(TokenDesc* to, TokenDesc* from) { |
| DCHECK_NOT_NULL(to); |
| DCHECK_NOT_NULL(from); |
| to->token = from->token; |
| to->location = from->location; |
| to->literal_chars->CopyFrom(from->literal_chars); |
| to->raw_literal_chars->CopyFrom(from->raw_literal_chars); |
| } |
| |
| |
| int DuplicateFinder::AddOneByteSymbol(Vector<const uint8_t> key, int value) { |
| return AddSymbol(key, true, value); |
| } |
| |
| |
| int DuplicateFinder::AddTwoByteSymbol(Vector<const uint16_t> key, int value) { |
| return AddSymbol(Vector<const uint8_t>::cast(key), false, value); |
| } |
| |
| |
| int DuplicateFinder::AddSymbol(Vector<const uint8_t> key, |
| bool is_one_byte, |
| int value) { |
| uint32_t hash = Hash(key, is_one_byte); |
| byte* encoding = BackupKey(key, is_one_byte); |
| HashMap::Entry* entry = map_.LookupOrInsert(encoding, hash); |
| int old_value = static_cast<int>(reinterpret_cast<intptr_t>(entry->value)); |
| entry->value = |
| reinterpret_cast<void*>(static_cast<intptr_t>(value | old_value)); |
| return old_value; |
| } |
| |
| |
| int DuplicateFinder::AddNumber(Vector<const uint8_t> key, int value) { |
| DCHECK(key.length() > 0); |
| // Quick check for already being in canonical form. |
| if (IsNumberCanonical(key)) { |
| return AddOneByteSymbol(key, value); |
| } |
| |
| int flags = ALLOW_HEX | ALLOW_OCTAL | ALLOW_IMPLICIT_OCTAL | ALLOW_BINARY; |
| double double_value = StringToDouble( |
| unicode_constants_, key, flags, 0.0); |
| int length; |
| const char* string; |
| if (!std::isfinite(double_value)) { |
| string = "Infinity"; |
| length = 8; // strlen("Infinity"); |
| } else { |
| string = DoubleToCString(double_value, |
| Vector<char>(number_buffer_, kBufferSize)); |
| length = StrLength(string); |
| } |
| return AddSymbol(Vector<const byte>(reinterpret_cast<const byte*>(string), |
| length), true, value); |
| } |
| |
| |
| bool DuplicateFinder::IsNumberCanonical(Vector<const uint8_t> number) { |
| // Test for a safe approximation of number literals that are already |
| // in canonical form: max 15 digits, no leading zeroes, except an |
| // integer part that is a single zero, and no trailing zeros below |
| // the decimal point. |
| int pos = 0; |
| int length = number.length(); |
| if (number.length() > 15) return false; |
| if (number[pos] == '0') { |
| pos++; |
| } else { |
| while (pos < length && |
| static_cast<unsigned>(number[pos] - '0') <= ('9' - '0')) pos++; |
| } |
| if (length == pos) return true; |
| if (number[pos] != '.') return false; |
| pos++; |
| bool invalid_last_digit = true; |
| while (pos < length) { |
| uint8_t digit = number[pos] - '0'; |
| if (digit > '9' - '0') return false; |
| invalid_last_digit = (digit == 0); |
| pos++; |
| } |
| return !invalid_last_digit; |
| } |
| |
| |
| uint32_t DuplicateFinder::Hash(Vector<const uint8_t> key, bool is_one_byte) { |
| // Primitive hash function, almost identical to the one used |
| // for strings (except that it's seeded by the length and representation). |
| int length = key.length(); |
| uint32_t hash = (length << 1) | (is_one_byte ? 1 : 0); |
| for (int i = 0; i < length; i++) { |
| uint32_t c = key[i]; |
| hash = (hash + c) * 1025; |
| hash ^= (hash >> 6); |
| } |
| return hash; |
| } |
| |
| |
| bool DuplicateFinder::Match(void* first, void* second) { |
| // Decode lengths. |
| // Length + representation is encoded as base 128, most significant heptet |
| // first, with a 8th bit being non-zero while there are more heptets. |
| // The value encodes the number of bytes following, and whether the original |
| // was Latin1. |
| byte* s1 = reinterpret_cast<byte*>(first); |
| byte* s2 = reinterpret_cast<byte*>(second); |
| uint32_t length_one_byte_field = 0; |
| byte c1; |
| do { |
| c1 = *s1; |
| if (c1 != *s2) return false; |
| length_one_byte_field = (length_one_byte_field << 7) | (c1 & 0x7f); |
| s1++; |
| s2++; |
| } while ((c1 & 0x80) != 0); |
| int length = static_cast<int>(length_one_byte_field >> 1); |
| return memcmp(s1, s2, length) == 0; |
| } |
| |
| |
| byte* DuplicateFinder::BackupKey(Vector<const uint8_t> bytes, |
| bool is_one_byte) { |
| uint32_t one_byte_length = (bytes.length() << 1) | (is_one_byte ? 1 : 0); |
| backing_store_.StartSequence(); |
| // Emit one_byte_length as base-128 encoded number, with the 7th bit set |
| // on the byte of every heptet except the last, least significant, one. |
| if (one_byte_length >= (1 << 7)) { |
| if (one_byte_length >= (1 << 14)) { |
| if (one_byte_length >= (1 << 21)) { |
| if (one_byte_length >= (1 << 28)) { |
| backing_store_.Add( |
| static_cast<uint8_t>((one_byte_length >> 28) | 0x80)); |
| } |
| backing_store_.Add( |
| static_cast<uint8_t>((one_byte_length >> 21) | 0x80u)); |
| } |
| backing_store_.Add( |
| static_cast<uint8_t>((one_byte_length >> 14) | 0x80u)); |
| } |
| backing_store_.Add(static_cast<uint8_t>((one_byte_length >> 7) | 0x80u)); |
| } |
| backing_store_.Add(static_cast<uint8_t>(one_byte_length & 0x7f)); |
| |
| backing_store_.AddBlock(bytes); |
| return backing_store_.EndSequence().start(); |
| } |
| |
| } // namespace internal |
| } // namespace v8 |
