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// 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 <algorithm>
#include "src/allocation.h"
#include "src/base/logging.h"
#include "src/char-predicates.h"
#include "src/globals.h"
#include "src/messages.h"
#include "src/parsing/token.h"
#include "src/unicode-decoder.h"
#include "src/unicode.h"
namespace v8 {
namespace internal {
class AstRawString;
class AstValueFactory;
class DuplicateFinder;
class ExternalOneByteString;
class ExternalTwoByteString;
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:
static const uc32 kEndOfInput = -1;
virtual ~Utf16CharacterStream() {}
inline uc32 Peek() {
if (V8_LIKELY(buffer_cursor_ < buffer_end_)) {
return static_cast<uc32>(*buffer_cursor_);
} else if (ReadBlockChecked()) {
return static_cast<uc32>(*buffer_cursor_);
} else {
return kEndOfInput;
}
}
// Returns and advances past the next UTF-16 code unit in the input
// stream. If there are no more code units it returns kEndOfInput.
inline uc32 Advance() {
uc32 result = Peek();
buffer_cursor_++;
return result;
}
// Returns and advances past the next UTF-16 code unit in the input stream
// that meets the checks requirement. If there are no more code units it
// returns kEndOfInput.
template <typename FunctionType>
V8_INLINE uc32 AdvanceUntil(FunctionType check) {
while (true) {
auto next_cursor_pos =
std::find_if(buffer_cursor_, buffer_end_, [&check](uint16_t raw_c0_) {
uc32 c0_ = static_cast<uc32>(raw_c0_);
return check(c0_);
});
if (next_cursor_pos == buffer_end_) {
buffer_cursor_ = buffer_end_;
if (!ReadBlockChecked()) {
buffer_cursor_++;
return kEndOfInput;
}
} else {
buffer_cursor_ = next_cursor_pos + 1;
return static_cast<uc32>(*next_cursor_pos);
}
}
}
// Go back one by one character in the input stream.
// This undoes the most recent Advance().
inline void Back() {
// The common case - if the previous character is within
// buffer_start_ .. buffer_end_ will be handles locally.
// Otherwise, a new block is requested.
if (V8_LIKELY(buffer_cursor_ > buffer_start_)) {
buffer_cursor_--;
} else {
ReadBlockAt(pos() - 1);
}
}
inline size_t pos() const {
return buffer_pos_ + (buffer_cursor_ - buffer_start_);
}
inline void Seek(size_t pos) {
if (V8_LIKELY(pos >= buffer_pos_ &&
pos < (buffer_pos_ + (buffer_end_ - buffer_start_)))) {
buffer_cursor_ = buffer_start_ + (pos - buffer_pos_);
} else {
ReadBlockAt(pos);
}
}
// Returns true if the stream could access the V8 heap after construction.
virtual bool can_access_heap() = 0;
protected:
Utf16CharacterStream(const uint16_t* buffer_start,
const uint16_t* buffer_cursor,
const uint16_t* buffer_end, size_t buffer_pos)
: buffer_start_(buffer_start),
buffer_cursor_(buffer_cursor),
buffer_end_(buffer_end),
buffer_pos_(buffer_pos) {}
Utf16CharacterStream() : Utf16CharacterStream(nullptr, nullptr, nullptr, 0) {}
bool ReadBlockChecked() {
size_t position = pos();
USE(position);
bool success = ReadBlock();
// Post-conditions: 1, We should always be at the right position.
// 2, Cursor should be inside the buffer.
// 3, We should have more characters available iff success.
DCHECK_EQ(pos(), position);
DCHECK_LE(buffer_cursor_, buffer_end_);
DCHECK_LE(buffer_start_, buffer_cursor_);
DCHECK_EQ(success, buffer_cursor_ < buffer_end_);
return success;
}
void ReadBlockAt(size_t new_pos) {
// The callers of this method (Back/Back2/Seek) should handle the easy
// case (seeking within the current buffer), and we should only get here
// if we actually require new data.
// (This is really an efficiency check, not a correctness invariant.)
DCHECK(new_pos < buffer_pos_ ||
new_pos >= buffer_pos_ + (buffer_end_ - buffer_start_));
// Change pos() to point to new_pos.
buffer_pos_ = new_pos;
buffer_cursor_ = buffer_start_;
DCHECK_EQ(pos(), new_pos);
ReadBlockChecked();
}
// Read more data, and update buffer_*_ to point to it.
// Returns true if more data was available.
//
// ReadBlock() may modify any of the buffer_*_ members, but must sure that
// the result of pos() remains unaffected.
//
// Examples:
// - a stream could either fill a separate buffer. Then buffer_start_ and
// buffer_cursor_ would point to the beginning of the buffer, and
// buffer_pos would be the old pos().
// - a stream with existing buffer chunks would set buffer_start_ and
// buffer_end_ to cover the full chunk, and then buffer_cursor_ would
// point into the middle of the buffer, while buffer_pos_ would describe
// the start of the buffer.
virtual bool ReadBlock() = 0;
const uint16_t* buffer_start_;
const uint16_t* buffer_cursor_;
const uint16_t* buffer_end_;
size_t buffer_pos_;
};
// ----------------------------------------------------------------------------
// JavaScript Scanner.
class Scanner {
public:
// Scoped helper for a re-settable bookmark.
class BookmarkScope {
public:
explicit BookmarkScope(Scanner* scanner)
: scanner_(scanner), bookmark_(kNoBookmark) {
DCHECK_NOT_NULL(scanner_);
}
~BookmarkScope() {}
void Set();
void Apply();
bool HasBeenSet();
bool HasBeenApplied();
private:
static const size_t kNoBookmark;
static const size_t kBookmarkWasApplied;
static const size_t kBookmarkAtFirstPos;
Scanner* scanner_;
size_t bookmark_;
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;
static const uc32 kEndOfInput = Utf16CharacterStream::kEndOfInput;
explicit Scanner(UnicodeCache* scanner_contants, Utf16CharacterStream* source,
bool is_module);
void Initialize();
// 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; }
Token::Value current_contextual_token() { return current().contextual_token; }
Token::Value next_contextual_token() { return next().contextual_token; }
// Returns the location information for the current token
// (the token last returned by Next()).
Location location() const { return current().location; }
// This error is specifically an invalid hex or unicode escape sequence.
bool has_error() const { return scanner_error_ != MessageTemplate::kNone; }
MessageTemplate::Template error() const { return scanner_error_; }
Location error_location() const { return scanner_error_location_; }
bool has_invalid_template_escape() const {
return current().invalid_template_escape_message != MessageTemplate::kNone;
}
MessageTemplate::Template invalid_template_escape_message() const {
DCHECK(has_invalid_template_escape());
return current().invalid_template_escape_message;
}
Location invalid_template_escape_location() const {
DCHECK(has_invalid_template_escape());
return current().invalid_template_escape_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());
}
const AstRawString* CurrentSymbol(AstValueFactory* ast_value_factory) const;
const AstRawString* NextSymbol(AstValueFactory* ast_value_factory) const;
const AstRawString* CurrentRawSymbol(
AstValueFactory* ast_value_factory) const;
double DoubleValue();
const char* CurrentLiteralAsCString(Zone* zone) const;
inline bool CurrentMatches(Token::Value token) const {
DCHECK(Token::IsKeyword(token));
return current().token == token;
}
inline bool CurrentMatchesContextual(Token::Value token) const {
DCHECK(Token::IsContextualKeyword(token));
return current().contextual_token == token;
}
// Match the token against the contextual keyword or literal buffer.
inline bool CurrentMatchesContextualEscaped(Token::Value token) const {
DCHECK(Token::IsContextualKeyword(token) || token == Token::LET);
// Escaped keywords are not matched as tokens. So if we require escape
// and/or string processing we need to look at the literal content
// (which was escape-processed already).
// Conveniently, !current().literal_chars.is_used() for all proper
// keywords, so this second condition should exit early in common cases.
return (current().contextual_token == token) ||
(current().literal_chars.is_used() &&
current().literal_chars.Equals(Vector<const char>(
Token::String(token), Token::StringLength(token))));
}
bool IsUseStrict() const {
return current().token == Token::STRING &&
current().literal_chars.Equals(
Vector<const char>("use strict", strlen("use strict")));
}
bool IsGetOrSet(bool* is_get, bool* is_set) const {
*is_get = CurrentMatchesContextual(Token::GET);
*is_set = CurrentMatchesContextual(Token::SET);
return *is_get || *is_set;
}
bool IsLet() const {
return CurrentMatches(Token::LET) ||
CurrentMatchesContextualEscaped(Token::LET);
}
// Check whether the CurrentSymbol() has already been seen.
// The DuplicateFinder holds the data, so different instances can be used
// for different sets of duplicates to check for.
bool IsDuplicateSymbol(DuplicateFinder* duplicate_finder,
AstValueFactory* ast_value_factory) const;
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();
octal_message_ = MessageTemplate::kNone;
}
MessageTemplate::Template octal_message() const { return octal_message_; }
// Returns the value of the last smi that was scanned.
uint32_t 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 HasLineTerminatorBeforeNext() const {
return next().after_line_terminator;
}
bool HasLineTerminatorAfterNext() {
Token::Value ensure_next_next = PeekAhead();
USE(ensure_next_next);
return next_next().after_line_terminator;
}
// Scans the input as a regular expression pattern, next token must be /(=).
// Returns true if a pattern is scanned.
bool ScanRegExpPattern();
// 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() {
DCHECK_EQ(next().token, Token::RBRACE);
next().location.beg_pos = source_pos() - 1; // We already consumed }
return ScanTemplateSpan();
}
Handle<String> SourceUrl(Isolate* isolate) const;
Handle<String> SourceMappingUrl(Isolate* isolate) const;
bool FoundHtmlComment() const { return found_html_comment_; }
bool allow_harmony_bigint() const { return allow_harmony_bigint_; }
void set_allow_harmony_bigint(bool allow) { allow_harmony_bigint_ = allow; }
bool allow_harmony_private_fields() const {
return allow_harmony_private_fields_;
}
void set_allow_harmony_private_fields(bool allow) {
allow_harmony_private_fields_ = allow;
}
bool allow_harmony_numeric_separator() const {
return allow_harmony_numeric_separator_;
}
void set_allow_harmony_numeric_separator(bool allow) {
allow_harmony_numeric_separator_ = allow;
}
private:
// Scoped helper for saving & restoring scanner error state.
// This is used for tagged template literals, in which normally forbidden
// escape sequences are allowed.
class ErrorState;
// 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_;
};
// LiteralBuffer - Collector of chars of literals.
class LiteralBuffer {
public:
LiteralBuffer()
: position_(0), is_one_byte_(true), is_used_(false), backing_store_() {}
~LiteralBuffer() { backing_store_.Dispose(); }
V8_INLINE void AddChar(char code_unit) {
DCHECK(is_used_);
DCHECK(IsValidAscii(code_unit));
AddOneByteChar(static_cast<byte>(code_unit));
}
V8_INLINE void AddChar(uc32 code_unit) {
DCHECK(is_used_);
if (is_one_byte_) {
if (code_unit <= static_cast<uc32>(unibrow::Latin1::kMaxChar)) {
AddOneByteChar(static_cast<byte>(code_unit));
return;
}
ConvertToTwoByte();
}
AddTwoByteChar(code_unit);
}
bool is_one_byte() const { return is_one_byte_; }
bool Equals(Vector<const char> keyword) const {
DCHECK(is_used_);
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(is_used_);
DCHECK_EQ(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_);
DCHECK(is_used_);
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 Start() {
DCHECK(!is_used_);
DCHECK_EQ(0, position_);
is_used_ = true;
}
bool is_used() const { return is_used_; }
void Drop() {
is_used_ = false;
position_ = 0;
is_one_byte_ = true;
}
Handle<String> Internalize(Isolate* isolate) const;
private:
static const int kInitialCapacity = 16;
static const int kGrowthFactory = 4;
static const int kMinConversionSlack = 256;
static const int kMaxGrowth = 1 * MB;
inline bool IsValidAscii(char code_unit) {
// Control characters and printable characters span the range of
// valid ASCII characters (0-127). Chars are unsigned on some
// platforms which causes compiler warnings if the validity check
// tests the lower bound >= 0 as it's always true.
return iscntrl(code_unit) || isprint(code_unit);
}
V8_INLINE void AddOneByteChar(byte one_byte_char) {
DCHECK(is_one_byte_);
if (position_ >= backing_store_.length()) ExpandBuffer();
backing_store_[position_] = one_byte_char;
position_ += kOneByteSize;
}
void AddTwoByteChar(uc32 code_unit);
int NewCapacity(int min_capacity);
void ExpandBuffer();
void ConvertToTwoByte();
int position_;
bool is_one_byte_;
bool is_used_;
Vector<byte> backing_store_;
DISALLOW_COPY_AND_ASSIGN(LiteralBuffer);
};
// The current and look-ahead token.
struct TokenDesc {
Location location = {0, 0};
LiteralBuffer literal_chars;
LiteralBuffer raw_literal_chars;
Token::Value token = Token::UNINITIALIZED;
MessageTemplate::Template invalid_template_escape_message =
MessageTemplate::kNone;
Location invalid_template_escape_location;
Token::Value contextual_token = Token::UNINITIALIZED;
uint32_t smi_value_ = 0;
bool after_line_terminator = false;
};
enum NumberKind {
BINARY,
OCTAL,
IMPLICIT_OCTAL,
HEX,
DECIMAL,
DECIMAL_WITH_LEADING_ZERO
};
static const int kCharacterLookaheadBufferSize = 1;
const int kMaxAscii = 127;
// 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();
current_ = &token_storage_[0];
next_ = &token_storage_[1];
next_next_ = &token_storage_[2];
found_html_comment_ = false;
scanner_error_ = MessageTemplate::kNone;
}
void ReportScannerError(const Location& location,
MessageTemplate::Template error) {
if (has_error()) return;
scanner_error_ = error;
scanner_error_location_ = location;
}
void ReportScannerError(int pos, MessageTemplate::Template error) {
if (has_error()) return;
scanner_error_ = error;
scanner_error_location_ = Location(pos, pos + 1);
}
// Seek to the next_ token at the given position.
void SeekNext(size_t position);
// Literal buffer support
inline void StartLiteral() { next().literal_chars.Start(); }
inline void StartRawLiteral() { next().raw_literal_chars.Start(); }
V8_INLINE void AddLiteralChar(uc32 c) { next().literal_chars.AddChar(c); }
V8_INLINE void AddLiteralChar(char c) { next().literal_chars.AddChar(c); }
V8_INLINE void AddRawLiteralChar(uc32 c) {
next().raw_literal_chars.AddChar(c);
}
// Stops scanning of a literal and drop the collected characters,
// e.g., due to an encountered error.
inline void DropLiteral() {
next().literal_chars.Drop();
next().raw_literal_chars.Drop();
}
inline void AddLiteralCharAdvance() {
AddLiteralChar(c0_);
Advance();
}
// Low-level scanning support.
template <bool capture_raw = false>
void Advance() {
if (capture_raw) {
AddRawLiteralChar(c0_);
}
c0_ = source_->Advance();
}
template <typename FunctionType>
V8_INLINE void AdvanceUntil(FunctionType check) {
c0_ = source_->AdvanceUntil(check);
}
bool CombineSurrogatePair() {
DCHECK(!unibrow::Utf16::IsLeadSurrogate(kEndOfInput));
if (unibrow::Utf16::IsLeadSurrogate(c0_)) {
uc32 c1 = source_->Advance();
DCHECK(!unibrow::Utf16::IsTrailSurrogate(kEndOfInput));
if (unibrow::Utf16::IsTrailSurrogate(c1)) {
c0_ = unibrow::Utf16::CombineSurrogatePair(c0_, c1);
return true;
}
source_->Back();
}
return false;
}
void PushBack(uc32 ch) {
DCHECK_LE(c0_, static_cast<uc32>(unibrow::Utf16::kMaxNonSurrogateCharCode));
source_->Back();
c0_ = ch;
}
uc32 Peek() const { return source_->Peek(); }
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.
//
// Current usage of these functions is unfortunately a little undisciplined,
// and is_literal_one_byte() + is_literal_one_byte_string() is also
// requested for tokens that do not have a literal. Hence, we treat any
// token as a one-byte literal. E.g. Token::FUNCTION pretends to have a
// literal "function".
Vector<const uint8_t> literal_one_byte_string() const {
if (current().literal_chars.is_used())
return current().literal_chars.one_byte_literal();
const char* str = Token::String(current().token);
const uint8_t* str_as_uint8 = reinterpret_cast<const uint8_t*>(str);
return Vector<const uint8_t>(str_as_uint8,
Token::StringLength(current().token));
}
Vector<const uint16_t> literal_two_byte_string() const {
DCHECK(current().literal_chars.is_used());
return current().literal_chars.two_byte_literal();
}
bool is_literal_one_byte() const {
return !current().literal_chars.is_used() ||
current().literal_chars.is_one_byte();
}
// 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() const {
DCHECK(next().literal_chars.is_used());
return next().literal_chars.one_byte_literal();
}
Vector<const uint16_t> next_literal_two_byte_string() const {
DCHECK(next().literal_chars.is_used());
return next().literal_chars.two_byte_literal();
}
bool is_next_literal_one_byte() const {
DCHECK(next().literal_chars.is_used());
return next().literal_chars.is_one_byte();
}
Vector<const uint8_t> raw_literal_one_byte_string() const {
DCHECK(current().raw_literal_chars.is_used());
return current().raw_literal_chars.one_byte_literal();
}
Vector<const uint16_t> raw_literal_two_byte_string() const {
DCHECK(current().raw_literal_chars.is_used());
return current().raw_literal_chars.two_byte_literal();
}
bool is_raw_literal_one_byte() const {
DCHECK(current().raw_literal_chars.is_used());
return current().raw_literal_chars.is_one_byte();
}
template <bool capture_raw, bool unicode = false>
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, int beg_pos);
// Scans a single JavaScript token.
void Scan();
V8_INLINE Token::Value SkipWhiteSpace();
Token::Value SkipSingleHTMLComment();
Token::Value SkipSingleLineComment();
Token::Value SkipSourceURLComment();
void TryToParseSourceURLComment();
Token::Value SkipMultiLineComment();
// Scans a possible HTML comment -- begins with '<!'.
Token::Value ScanHtmlComment();
bool ScanDigitsWithNumericSeparators(bool (*predicate)(uc32 ch),
bool is_check_first_digit);
bool ScanDecimalDigits();
// Optimized function to scan decimal number as Smi.
bool ScanDecimalAsSmi(uint64_t* value);
bool ScanDecimalAsSmiWithNumericSeparators(uint64_t* value);
bool ScanHexDigits();
bool ScanBinaryDigits();
bool ScanSignedInteger();
bool ScanOctalDigits();
bool ScanImplicitOctalDigits(int start_pos, NumberKind* kind);
Token::Value ScanNumber(bool seen_period);
Token::Value ScanIdentifierOrKeyword();
Token::Value ScanIdentifierOrKeywordInner(LiteralScope* literal);
Token::Value ScanString();
Token::Value ScanPrivateName();
// 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 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.is_used() &&
(token.literal_chars.length() != source_length);
}
#ifdef DEBUG
void SanityCheckTokenDesc(const TokenDesc&) const;
#endif
UnicodeCache* unicode_cache_;
// Values parsed from magic comments.
LiteralBuffer source_url_;
LiteralBuffer source_mapping_url_;
TokenDesc token_storage_[3];
TokenDesc& next() { return *next_; }
const TokenDesc& current() const { return *current_; }
const TokenDesc& next() const { return *next_; }
const TokenDesc& next_next() const { return *next_next_; }
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())
// Input stream. Must be initialized to an Utf16CharacterStream.
Utf16CharacterStream* const source_;
// Last-seen positions of potentially problematic tokens.
Location octal_pos_;
MessageTemplate::Template octal_message_;
// One Unicode character look-ahead; c0_ < 0 at the end of the input.
uc32 c0_;
// Whether this scanner encountered an HTML comment.
bool found_html_comment_;
// Harmony flags to allow ESNext features.
bool allow_harmony_bigint_;
bool allow_harmony_private_fields_;
bool allow_harmony_numeric_separator_;
const bool is_module_;
MessageTemplate::Template scanner_error_;
Location scanner_error_location_;
};
} // namespace internal
} // namespace v8
#endif // V8_PARSING_SCANNER_H_
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