| // 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. |
| |
| #ifndef V8_PARSING_SCANNER_H_ |
| #define V8_PARSING_SCANNER_H_ |
| |
| #include "src/allocation.h" |
| #include "src/base/logging.h" |
| #include "src/char-predicates.h" |
| #include "src/globals.h" |
| #include "src/hashmap.h" |
| #include "src/list.h" |
| #include "src/parsing/token.h" |
| #include "src/unicode.h" |
| #include "src/unicode-decoder.h" |
| #include "src/utils.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| class AstRawString; |
| class AstValueFactory; |
| class ParserRecorder; |
| class UnicodeCache; |
| |
| |
| // --------------------------------------------------------------------- |
| // Buffered stream of UTF-16 code units, using an internal UTF-16 buffer. |
| // A code unit is a 16 bit value representing either a 16 bit code point |
| // or one part of a surrogate pair that make a single 21 bit code point. |
| |
| class Utf16CharacterStream { |
| public: |
| Utf16CharacterStream() : pos_(0) { } |
| virtual ~Utf16CharacterStream() { } |
| |
| // Returns and advances past the next UTF-16 code unit in the input |
| // stream. If there are no more code units, it returns a negative |
| // value. |
| inline uc32 Advance() { |
| if (buffer_cursor_ < buffer_end_ || ReadBlock()) { |
| pos_++; |
| return static_cast<uc32>(*(buffer_cursor_++)); |
| } |
| // Note: currently the following increment is necessary to avoid a |
| // parser problem! The scanner treats the final kEndOfInput as |
| // a code unit with a position, and does math relative to that |
| // position. |
| pos_++; |
| |
| return kEndOfInput; |
| } |
| |
| // Return the current position in the code unit stream. |
| // Starts at zero. |
| inline size_t pos() const { return pos_; } |
| |
| // Skips forward past the next code_unit_count UTF-16 code units |
| // in the input, or until the end of input if that comes sooner. |
| // Returns the number of code units actually skipped. If less |
| // than code_unit_count, |
| inline size_t SeekForward(size_t code_unit_count) { |
| size_t buffered_chars = buffer_end_ - buffer_cursor_; |
| if (code_unit_count <= buffered_chars) { |
| buffer_cursor_ += code_unit_count; |
| pos_ += code_unit_count; |
| return code_unit_count; |
| } |
| return SlowSeekForward(code_unit_count); |
| } |
| |
| // Pushes back the most recently read UTF-16 code unit (or negative |
| // value if at end of input), i.e., the value returned by the most recent |
| // call to Advance. |
| // Must not be used right after calling SeekForward. |
| virtual void PushBack(int32_t code_unit) = 0; |
| |
| virtual bool SetBookmark(); |
| virtual void ResetToBookmark(); |
| |
| protected: |
| static const uc32 kEndOfInput = -1; |
| |
| // Ensures that the buffer_cursor_ points to the code_unit at |
| // position pos_ of the input, if possible. If the position |
| // is at or after the end of the input, return false. If there |
| // are more code_units available, return true. |
| virtual bool ReadBlock() = 0; |
| virtual size_t SlowSeekForward(size_t code_unit_count) = 0; |
| |
| const uint16_t* buffer_cursor_; |
| const uint16_t* buffer_end_; |
| size_t pos_; |
| }; |
| |
| |
| // --------------------------------------------------------------------- |
| // DuplicateFinder discovers duplicate symbols. |
| |
| class DuplicateFinder { |
| public: |
| explicit DuplicateFinder(UnicodeCache* constants) |
| : unicode_constants_(constants), |
| backing_store_(16), |
| map_(&Match) { } |
| |
| int AddOneByteSymbol(Vector<const uint8_t> key, int value); |
| int AddTwoByteSymbol(Vector<const uint16_t> key, int value); |
| // Add a a number literal by converting it (if necessary) |
| // to the string that ToString(ToNumber(literal)) would generate. |
| // and then adding that string with AddOneByteSymbol. |
| // This string is the actual value used as key in an object literal, |
| // and the one that must be different from the other keys. |
| int AddNumber(Vector<const uint8_t> key, int value); |
| |
| private: |
| int AddSymbol(Vector<const uint8_t> key, bool is_one_byte, int value); |
| // Backs up the key and its length in the backing store. |
| // The backup is stored with a base 127 encoding of the |
| // length (plus a bit saying whether the string is one byte), |
| // followed by the bytes of the key. |
| uint8_t* BackupKey(Vector<const uint8_t> key, bool is_one_byte); |
| |
| // Compare two encoded keys (both pointing into the backing store) |
| // for having the same base-127 encoded lengths and representation. |
| // and then having the same 'length' bytes following. |
| static bool Match(void* first, void* second); |
| // Creates a hash from a sequence of bytes. |
| static uint32_t Hash(Vector<const uint8_t> key, bool is_one_byte); |
| // Checks whether a string containing a JS number is its canonical |
| // form. |
| static bool IsNumberCanonical(Vector<const uint8_t> key); |
| |
| // Size of buffer. Sufficient for using it to call DoubleToCString in |
| // from conversions.h. |
| static const int kBufferSize = 100; |
| |
| UnicodeCache* unicode_constants_; |
| // Backing store used to store strings used as hashmap keys. |
| SequenceCollector<unsigned char> backing_store_; |
| HashMap map_; |
| // Buffer used for string->number->canonical string conversions. |
| char number_buffer_[kBufferSize]; |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // LiteralBuffer - Collector of chars of literals. |
| |
| class LiteralBuffer { |
| public: |
| LiteralBuffer() : is_one_byte_(true), position_(0), backing_store_() { } |
| |
| ~LiteralBuffer() { backing_store_.Dispose(); } |
| |
| INLINE(void AddChar(uint32_t code_unit)) { |
| if (position_ >= backing_store_.length()) ExpandBuffer(); |
| if (is_one_byte_) { |
| if (code_unit <= unibrow::Latin1::kMaxChar) { |
| backing_store_[position_] = static_cast<byte>(code_unit); |
| position_ += kOneByteSize; |
| return; |
| } |
| ConvertToTwoByte(); |
| } |
| if (code_unit <= unibrow::Utf16::kMaxNonSurrogateCharCode) { |
| *reinterpret_cast<uint16_t*>(&backing_store_[position_]) = code_unit; |
| position_ += kUC16Size; |
| } else { |
| *reinterpret_cast<uint16_t*>(&backing_store_[position_]) = |
| unibrow::Utf16::LeadSurrogate(code_unit); |
| position_ += kUC16Size; |
| if (position_ >= backing_store_.length()) ExpandBuffer(); |
| *reinterpret_cast<uint16_t*>(&backing_store_[position_]) = |
| unibrow::Utf16::TrailSurrogate(code_unit); |
| position_ += kUC16Size; |
| } |
| } |
| |
| bool is_one_byte() const { return is_one_byte_; } |
| |
| bool is_contextual_keyword(Vector<const char> keyword) const { |
| return is_one_byte() && keyword.length() == position_ && |
| (memcmp(keyword.start(), backing_store_.start(), position_) == 0); |
| } |
| |
| Vector<const uint16_t> two_byte_literal() const { |
| DCHECK(!is_one_byte_); |
| DCHECK((position_ & 0x1) == 0); |
| return Vector<const uint16_t>( |
| reinterpret_cast<const uint16_t*>(backing_store_.start()), |
| position_ >> 1); |
| } |
| |
| Vector<const uint8_t> one_byte_literal() const { |
| DCHECK(is_one_byte_); |
| return Vector<const uint8_t>( |
| reinterpret_cast<const uint8_t*>(backing_store_.start()), |
| position_); |
| } |
| |
| int length() const { |
| return is_one_byte_ ? position_ : (position_ >> 1); |
| } |
| |
| void ReduceLength(int delta) { |
| position_ -= delta * (is_one_byte_ ? kOneByteSize : kUC16Size); |
| } |
| |
| void Reset() { |
| position_ = 0; |
| is_one_byte_ = true; |
| } |
| |
| Handle<String> Internalize(Isolate* isolate) const; |
| |
| void CopyFrom(const LiteralBuffer* other) { |
| if (other == nullptr) { |
| Reset(); |
| } else { |
| is_one_byte_ = other->is_one_byte_; |
| position_ = other->position_; |
| backing_store_.Dispose(); |
| backing_store_ = other->backing_store_.Clone(); |
| } |
| } |
| |
| private: |
| static const int kInitialCapacity = 16; |
| static const int kGrowthFactory = 4; |
| static const int kMinConversionSlack = 256; |
| static const int kMaxGrowth = 1 * MB; |
| inline int NewCapacity(int min_capacity) { |
| int capacity = Max(min_capacity, backing_store_.length()); |
| int new_capacity = Min(capacity * kGrowthFactory, capacity + kMaxGrowth); |
| return new_capacity; |
| } |
| |
| void ExpandBuffer() { |
| Vector<byte> new_store = Vector<byte>::New(NewCapacity(kInitialCapacity)); |
| MemCopy(new_store.start(), backing_store_.start(), position_); |
| backing_store_.Dispose(); |
| backing_store_ = new_store; |
| } |
| |
| void ConvertToTwoByte() { |
| DCHECK(is_one_byte_); |
| Vector<byte> new_store; |
| int new_content_size = position_ * kUC16Size; |
| if (new_content_size >= backing_store_.length()) { |
| // Ensure room for all currently read code units as UC16 as well |
| // as the code unit about to be stored. |
| new_store = Vector<byte>::New(NewCapacity(new_content_size)); |
| } else { |
| new_store = backing_store_; |
| } |
| uint8_t* src = backing_store_.start(); |
| uint16_t* dst = reinterpret_cast<uint16_t*>(new_store.start()); |
| for (int i = position_ - 1; i >= 0; i--) { |
| dst[i] = src[i]; |
| } |
| if (new_store.start() != backing_store_.start()) { |
| backing_store_.Dispose(); |
| backing_store_ = new_store; |
| } |
| position_ = new_content_size; |
| is_one_byte_ = false; |
| } |
| |
| bool is_one_byte_; |
| int position_; |
| Vector<byte> backing_store_; |
| |
| DISALLOW_COPY_AND_ASSIGN(LiteralBuffer); |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // JavaScript Scanner. |
| |
| class Scanner { |
| public: |
| // Scoped helper for literal recording. Automatically drops the literal |
| // if aborting the scanning before it's complete. |
| class LiteralScope { |
| public: |
| explicit LiteralScope(Scanner* self) : scanner_(self), complete_(false) { |
| scanner_->StartLiteral(); |
| } |
| ~LiteralScope() { |
| if (!complete_) scanner_->DropLiteral(); |
| } |
| void Complete() { |
| complete_ = true; |
| } |
| |
| private: |
| Scanner* scanner_; |
| bool complete_; |
| }; |
| |
| // Scoped helper for a re-settable bookmark. |
| class BookmarkScope { |
| public: |
| explicit BookmarkScope(Scanner* scanner) : scanner_(scanner) { |
| DCHECK_NOT_NULL(scanner_); |
| } |
| ~BookmarkScope() { scanner_->DropBookmark(); } |
| |
| bool Set() { return scanner_->SetBookmark(); } |
| void Reset() { scanner_->ResetToBookmark(); } |
| bool HasBeenSet() { return scanner_->BookmarkHasBeenSet(); } |
| bool HasBeenReset() { return scanner_->BookmarkHasBeenReset(); } |
| |
| private: |
| Scanner* scanner_; |
| |
| DISALLOW_COPY_AND_ASSIGN(BookmarkScope); |
| }; |
| |
| // Representation of an interval of source positions. |
| struct Location { |
| Location(int b, int e) : beg_pos(b), end_pos(e) { } |
| Location() : beg_pos(0), end_pos(0) { } |
| |
| bool IsValid() const { |
| return beg_pos >= 0 && end_pos >= beg_pos; |
| } |
| |
| static Location invalid() { return Location(-1, -1); } |
| |
| int beg_pos; |
| int end_pos; |
| }; |
| |
| // -1 is outside of the range of any real source code. |
| static const int kNoOctalLocation = -1; |
| |
| explicit Scanner(UnicodeCache* scanner_contants); |
| |
| void Initialize(Utf16CharacterStream* source); |
| |
| // Returns the next token and advances input. |
| Token::Value Next(); |
| // Returns the token following peek() |
| Token::Value PeekAhead(); |
| // Returns the current token again. |
| Token::Value current_token() { return current_.token; } |
| // Returns the location information for the current token |
| // (the token last returned by Next()). |
| Location location() const { return current_.location; } |
| |
| // Similar functions for the upcoming token. |
| |
| // One token look-ahead (past the token returned by Next()). |
| Token::Value peek() const { return next_.token; } |
| |
| Location peek_location() const { return next_.location; } |
| |
| bool literal_contains_escapes() const { |
| return LiteralContainsEscapes(current_); |
| } |
| bool next_literal_contains_escapes() const { |
| return LiteralContainsEscapes(next_); |
| } |
| bool is_literal_contextual_keyword(Vector<const char> keyword) { |
| DCHECK_NOT_NULL(current_.literal_chars); |
| return current_.literal_chars->is_contextual_keyword(keyword); |
| } |
| bool is_next_contextual_keyword(Vector<const char> keyword) { |
| DCHECK_NOT_NULL(next_.literal_chars); |
| return next_.literal_chars->is_contextual_keyword(keyword); |
| } |
| |
| const AstRawString* CurrentSymbol(AstValueFactory* ast_value_factory); |
| const AstRawString* NextSymbol(AstValueFactory* ast_value_factory); |
| const AstRawString* CurrentRawSymbol(AstValueFactory* ast_value_factory); |
| |
| double DoubleValue(); |
| bool ContainsDot(); |
| bool LiteralMatches(const char* data, int length, bool allow_escapes = true) { |
| if (is_literal_one_byte() && |
| literal_length() == length && |
| (allow_escapes || !literal_contains_escapes())) { |
| const char* token = |
| reinterpret_cast<const char*>(literal_one_byte_string().start()); |
| return !strncmp(token, data, length); |
| } |
| return false; |
| } |
| inline bool UnescapedLiteralMatches(const char* data, int length) { |
| return LiteralMatches(data, length, false); |
| } |
| |
| void IsGetOrSet(bool* is_get, bool* is_set) { |
| if (is_literal_one_byte() && |
| literal_length() == 3 && |
| !literal_contains_escapes()) { |
| const char* token = |
| reinterpret_cast<const char*>(literal_one_byte_string().start()); |
| *is_get = strncmp(token, "get", 3) == 0; |
| *is_set = !*is_get && strncmp(token, "set", 3) == 0; |
| } |
| } |
| |
| int FindSymbol(DuplicateFinder* finder, int value); |
| |
| UnicodeCache* unicode_cache() { return unicode_cache_; } |
| |
| // Returns the location of the last seen octal literal. |
| Location octal_position() const { return octal_pos_; } |
| void clear_octal_position() { octal_pos_ = Location::invalid(); } |
| |
| // Returns the value of the last smi that was scanned. |
| int smi_value() const { return current_.smi_value_; } |
| |
| // Seek forward to the given position. This operation does not |
| // work in general, for instance when there are pushed back |
| // characters, but works for seeking forward until simple delimiter |
| // tokens, which is what it is used for. |
| void SeekForward(int pos); |
| |
| // Returns true if there was a line terminator before the peek'ed token, |
| // possibly inside a multi-line comment. |
| bool HasAnyLineTerminatorBeforeNext() const { |
| return has_line_terminator_before_next_ || |
| has_multiline_comment_before_next_; |
| } |
| |
| // Scans the input as a regular expression pattern, previous |
| // character(s) must be /(=). Returns true if a pattern is scanned. |
| bool ScanRegExpPattern(bool seen_equal); |
| // Scans the input as regular expression flags. Returns the flags on success. |
| Maybe<RegExp::Flags> ScanRegExpFlags(); |
| |
| // Scans the input as a template literal |
| Token::Value ScanTemplateStart(); |
| Token::Value ScanTemplateContinuation(); |
| |
| const LiteralBuffer* source_url() const { return &source_url_; } |
| const LiteralBuffer* source_mapping_url() const { |
| return &source_mapping_url_; |
| } |
| |
| bool IdentifierIsFutureStrictReserved(const AstRawString* string) const; |
| |
| private: |
| // The current and look-ahead token. |
| struct TokenDesc { |
| Token::Value token; |
| Location location; |
| LiteralBuffer* literal_chars; |
| LiteralBuffer* raw_literal_chars; |
| int smi_value_; |
| }; |
| |
| static const int kCharacterLookaheadBufferSize = 1; |
| |
| // Scans octal escape sequence. Also accepts "\0" decimal escape sequence. |
| template <bool capture_raw> |
| uc32 ScanOctalEscape(uc32 c, int length); |
| |
| // Call this after setting source_ to the input. |
| void Init() { |
| // Set c0_ (one character ahead) |
| STATIC_ASSERT(kCharacterLookaheadBufferSize == 1); |
| Advance(); |
| // Initialize current_ to not refer to a literal. |
| current_.literal_chars = NULL; |
| current_.raw_literal_chars = NULL; |
| next_next_.token = Token::UNINITIALIZED; |
| } |
| |
| // Support BookmarkScope functionality. |
| bool SetBookmark(); |
| void ResetToBookmark(); |
| bool BookmarkHasBeenSet(); |
| bool BookmarkHasBeenReset(); |
| void DropBookmark(); |
| static void CopyTokenDesc(TokenDesc* to, TokenDesc* from); |
| |
| // Literal buffer support |
| inline void StartLiteral() { |
| LiteralBuffer* free_buffer = |
| (current_.literal_chars == &literal_buffer0_) |
| ? &literal_buffer1_ |
| : (current_.literal_chars == &literal_buffer1_) ? &literal_buffer2_ |
| : &literal_buffer0_; |
| free_buffer->Reset(); |
| next_.literal_chars = free_buffer; |
| } |
| |
| inline void StartRawLiteral() { |
| LiteralBuffer* free_buffer = |
| (current_.raw_literal_chars == &raw_literal_buffer0_) |
| ? &raw_literal_buffer1_ |
| : (current_.raw_literal_chars == &raw_literal_buffer1_) |
| ? &raw_literal_buffer2_ |
| : &raw_literal_buffer0_; |
| free_buffer->Reset(); |
| next_.raw_literal_chars = free_buffer; |
| } |
| |
| INLINE(void AddLiteralChar(uc32 c)) { |
| DCHECK_NOT_NULL(next_.literal_chars); |
| next_.literal_chars->AddChar(c); |
| } |
| |
| INLINE(void AddRawLiteralChar(uc32 c)) { |
| DCHECK_NOT_NULL(next_.raw_literal_chars); |
| next_.raw_literal_chars->AddChar(c); |
| } |
| |
| INLINE(void ReduceRawLiteralLength(int delta)) { |
| DCHECK_NOT_NULL(next_.raw_literal_chars); |
| next_.raw_literal_chars->ReduceLength(delta); |
| } |
| |
| // Stops scanning of a literal and drop the collected characters, |
| // e.g., due to an encountered error. |
| inline void DropLiteral() { |
| next_.literal_chars = NULL; |
| next_.raw_literal_chars = NULL; |
| } |
| |
| inline void AddLiteralCharAdvance() { |
| AddLiteralChar(c0_); |
| Advance(); |
| } |
| |
| // Low-level scanning support. |
| template <bool capture_raw = false, bool check_surrogate = true> |
| void Advance() { |
| if (capture_raw) { |
| AddRawLiteralChar(c0_); |
| } |
| c0_ = source_->Advance(); |
| if (check_surrogate) HandleLeadSurrogate(); |
| } |
| |
| void HandleLeadSurrogate() { |
| if (unibrow::Utf16::IsLeadSurrogate(c0_)) { |
| uc32 c1 = source_->Advance(); |
| if (!unibrow::Utf16::IsTrailSurrogate(c1)) { |
| source_->PushBack(c1); |
| } else { |
| c0_ = unibrow::Utf16::CombineSurrogatePair(c0_, c1); |
| } |
| } |
| } |
| |
| void PushBack(uc32 ch) { |
| if (ch > static_cast<uc32>(unibrow::Utf16::kMaxNonSurrogateCharCode)) { |
| source_->PushBack(unibrow::Utf16::TrailSurrogate(c0_)); |
| source_->PushBack(unibrow::Utf16::LeadSurrogate(c0_)); |
| } else { |
| source_->PushBack(c0_); |
| } |
| c0_ = ch; |
| } |
| |
| inline Token::Value Select(Token::Value tok) { |
| Advance(); |
| return tok; |
| } |
| |
| inline Token::Value Select(uc32 next, Token::Value then, Token::Value else_) { |
| Advance(); |
| if (c0_ == next) { |
| Advance(); |
| return then; |
| } else { |
| return else_; |
| } |
| } |
| |
| // Returns the literal string, if any, for the current token (the |
| // token last returned by Next()). The string is 0-terminated. |
| // Literal strings are collected for identifiers, strings, numbers as well |
| // as for template literals. For template literals we also collect the raw |
| // form. |
| // These functions only give the correct result if the literal was scanned |
| // when a LiteralScope object is alive. |
| Vector<const uint8_t> literal_one_byte_string() { |
| DCHECK_NOT_NULL(current_.literal_chars); |
| return current_.literal_chars->one_byte_literal(); |
| } |
| Vector<const uint16_t> literal_two_byte_string() { |
| DCHECK_NOT_NULL(current_.literal_chars); |
| return current_.literal_chars->two_byte_literal(); |
| } |
| bool is_literal_one_byte() { |
| DCHECK_NOT_NULL(current_.literal_chars); |
| return current_.literal_chars->is_one_byte(); |
| } |
| int literal_length() const { |
| DCHECK_NOT_NULL(current_.literal_chars); |
| return current_.literal_chars->length(); |
| } |
| // Returns the literal string for the next token (the token that |
| // would be returned if Next() were called). |
| Vector<const uint8_t> next_literal_one_byte_string() { |
| DCHECK_NOT_NULL(next_.literal_chars); |
| return next_.literal_chars->one_byte_literal(); |
| } |
| Vector<const uint16_t> next_literal_two_byte_string() { |
| DCHECK_NOT_NULL(next_.literal_chars); |
| return next_.literal_chars->two_byte_literal(); |
| } |
| bool is_next_literal_one_byte() { |
| DCHECK_NOT_NULL(next_.literal_chars); |
| return next_.literal_chars->is_one_byte(); |
| } |
| Vector<const uint8_t> raw_literal_one_byte_string() { |
| DCHECK_NOT_NULL(current_.raw_literal_chars); |
| return current_.raw_literal_chars->one_byte_literal(); |
| } |
| Vector<const uint16_t> raw_literal_two_byte_string() { |
| DCHECK_NOT_NULL(current_.raw_literal_chars); |
| return current_.raw_literal_chars->two_byte_literal(); |
| } |
| bool is_raw_literal_one_byte() { |
| DCHECK_NOT_NULL(current_.raw_literal_chars); |
| return current_.raw_literal_chars->is_one_byte(); |
| } |
| |
| template <bool capture_raw> |
| uc32 ScanHexNumber(int expected_length); |
| // Scan a number of any length but not bigger than max_value. For example, the |
| // number can be 000000001, so it's very long in characters but its value is |
| // small. |
| template <bool capture_raw> |
| uc32 ScanUnlimitedLengthHexNumber(int max_value); |
| |
| // Scans a single JavaScript token. |
| void Scan(); |
| |
| bool SkipWhiteSpace(); |
| Token::Value SkipSingleLineComment(); |
| Token::Value SkipSourceURLComment(); |
| void TryToParseSourceURLComment(); |
| Token::Value SkipMultiLineComment(); |
| // Scans a possible HTML comment -- begins with '<!'. |
| Token::Value ScanHtmlComment(); |
| |
| void ScanDecimalDigits(); |
| Token::Value ScanNumber(bool seen_period); |
| Token::Value ScanIdentifierOrKeyword(); |
| Token::Value ScanIdentifierSuffix(LiteralScope* literal, bool escaped); |
| |
| Token::Value ScanString(); |
| |
| // Scans an escape-sequence which is part of a string and adds the |
| // decoded character to the current literal. Returns true if a pattern |
| // is scanned. |
| template <bool capture_raw, bool in_template_literal> |
| bool ScanEscape(); |
| |
| // Decodes a Unicode escape-sequence which is part of an identifier. |
| // If the escape sequence cannot be decoded the result is kBadChar. |
| uc32 ScanIdentifierUnicodeEscape(); |
| // Helper for the above functions. |
| template <bool capture_raw> |
| uc32 ScanUnicodeEscape(); |
| |
| Token::Value ScanTemplateSpan(); |
| |
| // Return the current source position. |
| int source_pos() { |
| return static_cast<int>(source_->pos()) - kCharacterLookaheadBufferSize; |
| } |
| |
| static bool LiteralContainsEscapes(const TokenDesc& token) { |
| Location location = token.location; |
| int source_length = (location.end_pos - location.beg_pos); |
| if (token.token == Token::STRING) { |
| // Subtract delimiters. |
| source_length -= 2; |
| } |
| return token.literal_chars->length() != source_length; |
| } |
| |
| UnicodeCache* unicode_cache_; |
| |
| // Buffers collecting literal strings, numbers, etc. |
| LiteralBuffer literal_buffer0_; |
| LiteralBuffer literal_buffer1_; |
| LiteralBuffer literal_buffer2_; |
| |
| // Values parsed from magic comments. |
| LiteralBuffer source_url_; |
| LiteralBuffer source_mapping_url_; |
| |
| // Buffer to store raw string values |
| LiteralBuffer raw_literal_buffer0_; |
| LiteralBuffer raw_literal_buffer1_; |
| LiteralBuffer raw_literal_buffer2_; |
| |
| TokenDesc current_; // desc for current token (as returned by Next()) |
| TokenDesc next_; // desc for next token (one token look-ahead) |
| TokenDesc next_next_; // desc for the token after next (after PeakAhead()) |
| |
| // Variables for Scanner::BookmarkScope and the *Bookmark implementation. |
| // These variables contain the scanner state when a bookmark is set. |
| // |
| // We will use bookmark_c0_ as a 'control' variable, where: |
| // - bookmark_c0_ >= 0: A bookmark has been set and this contains c0_. |
| // - bookmark_c0_ == -1: No bookmark has been set. |
| // - bookmark_c0_ == -2: The bookmark has been applied (ResetToBookmark). |
| // |
| // Which state is being bookmarked? The parser state is distributed over |
| // several variables, roughly like this: |
| // ... 1234 + 5678 ..... [character stream] |
| // [current_] [next_] c0_ | [scanner state] |
| // So when the scanner is logically at the beginning of an expression |
| // like "1234 + 4567", then: |
| // - current_ contains "1234" |
| // - next_ contains "+" |
| // - c0_ contains ' ' (the space between "+" and "5678", |
| // - the source_ character stream points to the beginning of "5678". |
| // To be able to restore this state, we will keep copies of current_, next_, |
| // and c0_; we'll ask the stream to bookmark itself, and we'll copy the |
| // contents of current_'s and next_'s literal buffers to bookmark_*_literal_. |
| static const uc32 kNoBookmark = -1; |
| static const uc32 kBookmarkWasApplied = -2; |
| uc32 bookmark_c0_; |
| TokenDesc bookmark_current_; |
| TokenDesc bookmark_next_; |
| LiteralBuffer bookmark_current_literal_; |
| LiteralBuffer bookmark_current_raw_literal_; |
| LiteralBuffer bookmark_next_literal_; |
| LiteralBuffer bookmark_next_raw_literal_; |
| |
| // Input stream. Must be initialized to an Utf16CharacterStream. |
| Utf16CharacterStream* source_; |
| |
| |
| // Start position of the octal literal last scanned. |
| Location octal_pos_; |
| |
| // One Unicode character look-ahead; c0_ < 0 at the end of the input. |
| uc32 c0_; |
| |
| // Whether there is a line terminator whitespace character after |
| // the current token, and before the next. Does not count newlines |
| // inside multiline comments. |
| bool has_line_terminator_before_next_; |
| // Whether there is a multi-line comment that contains a |
| // line-terminator after the current token, and before the next. |
| bool has_multiline_comment_before_next_; |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_PARSING_SCANNER_H_ |