// 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/parsing/scanner.h"
#include <stdint.h>
#include <cmath>
#include "src/ast/ast-value-factory.h"
#include "src/char-predicates-inl.h"
#include "src/conversions-inl.h"
#include "src/list-inl.h"
#include "src/parsing/duplicate-finder.h" // For Scanner::FindSymbol
namespace v8 {
namespace internal {
// 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 {
public:
ErrorState(MessageTemplate::Template* message_stack,
Scanner::Location* location_stack)
: message_stack_(message_stack),
old_message_(*message_stack),
location_stack_(location_stack),
old_location_(*location_stack) {
*message_stack_ = MessageTemplate::kNone;
*location_stack_ = Scanner::Location::invalid();
}
~ErrorState() {
*message_stack_ = old_message_;
*location_stack_ = old_location_;
}
void MoveErrorTo(MessageTemplate::Template* message_dest,
Scanner::Location* location_dest) {
if (*message_stack_ == MessageTemplate::kNone) {
return;
}
if (*message_dest == MessageTemplate::kNone) {
*message_dest = *message_stack_;
*location_dest = *location_stack_;
}
*message_stack_ = MessageTemplate::kNone;
*location_stack_ = Scanner::Location::invalid();
}
private:
MessageTemplate::Template* const message_stack_;
MessageTemplate::Template const old_message_;
Scanner::Location* const location_stack_;
Scanner::Location const old_location_;
};
Handle<String> Scanner::LiteralBuffer::Internalize(Isolate* isolate) const {
if (is_one_byte()) {
return isolate->factory()->InternalizeOneByteString(one_byte_literal());
}
return isolate->factory()->InternalizeTwoByteString(two_byte_literal());
}
int Scanner::LiteralBuffer::NewCapacity(int min_capacity) {
int capacity = Max(min_capacity, backing_store_.length());
int new_capacity = Min(capacity * kGrowthFactory, capacity + kMaxGrowth);
return new_capacity;
}
void Scanner::LiteralBuffer::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 Scanner::LiteralBuffer::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;
}
void Scanner::LiteralBuffer::AddCharSlow(uc32 code_unit) {
if (position_ >= backing_store_.length()) ExpandBuffer();
if (is_one_byte_) {
if (code_unit <= static_cast<uc32>(unibrow::Latin1::kMaxChar)) {
backing_store_[position_] = static_cast<byte>(code_unit);
position_ += kOneByteSize;
return;
}
ConvertToTwoByte();
}
if (code_unit <=
static_cast<uc32>(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;
}
}
// ----------------------------------------------------------------------------
// Scanner::BookmarkScope
const size_t Scanner::BookmarkScope::kBookmarkAtFirstPos =
std::numeric_limits<size_t>::max() - 2;
const size_t Scanner::BookmarkScope::kNoBookmark =
std::numeric_limits<size_t>::max() - 1;
const size_t Scanner::BookmarkScope::kBookmarkWasApplied =
std::numeric_limits<size_t>::max();
void Scanner::BookmarkScope::Set() {
DCHECK_EQ(bookmark_, kNoBookmark);
DCHECK_EQ(scanner_->next_next_.token, Token::UNINITIALIZED);
// The first token is a bit special, since current_ will still be
// uninitialized. In this case, store kBookmarkAtFirstPos and special-case it
// when
// applying the bookmark.
DCHECK_IMPLIES(
scanner_->current_.token == Token::UNINITIALIZED,
scanner_->current_.location.beg_pos == scanner_->next_.location.beg_pos);
bookmark_ = (scanner_->current_.token == Token::UNINITIALIZED)
? kBookmarkAtFirstPos
: scanner_->location().beg_pos;
}
void Scanner::BookmarkScope::Apply() {
DCHECK(HasBeenSet()); // Caller hasn't called SetBookmark.
if (bookmark_ == kBookmarkAtFirstPos) {
scanner_->SeekNext(0);
} else {
scanner_->SeekNext(bookmark_);
scanner_->Next();
DCHECK_EQ(scanner_->location().beg_pos, static_cast<int>(bookmark_));
}
bookmark_ = kBookmarkWasApplied;
}
bool Scanner::BookmarkScope::HasBeenSet() {
return bookmark_ != kNoBookmark && bookmark_ != kBookmarkWasApplied;
}
bool Scanner::BookmarkScope::HasBeenApplied() {
return bookmark_ == kBookmarkWasApplied;
}
// ----------------------------------------------------------------------------
// Scanner
Scanner::Scanner(UnicodeCache* unicode_cache)
: unicode_cache_(unicode_cache),
octal_pos_(Location::invalid()),
octal_message_(MessageTemplate::kNone),
found_html_comment_(false) {}
void Scanner::Initialize(Utf16CharacterStream* source) {
source_ = source;
// Need to capture identifiers in order to recognize "get" and "set"
// in object literals.
Init();
// Skip initial whitespace allowing HTML comment ends just like
// after a newline and scan first token.
has_line_terminator_before_next_ = true;
SkipWhiteSpace();
Scan();
}
template <bool capture_raw, bool unicode>
uc32 Scanner::ScanHexNumber(int expected_length) {
DCHECK(expected_length <= 4); // prevent overflow
int begin = source_pos() - 2;
uc32 x = 0;
for (int i = 0; i < expected_length; i++) {
int d = HexValue(c0_);
if (d < 0) {
ReportScannerError(Location(begin, begin + expected_length + 2),
unicode
? MessageTemplate::kInvalidUnicodeEscapeSequence
: MessageTemplate::kInvalidHexEscapeSequence);
return -1;
}
x = x * 16 + d;
Advance<capture_raw>();
}
return x;
}
template <bool capture_raw>
uc32 Scanner::ScanUnlimitedLengthHexNumber(int max_value, int beg_pos) {
uc32 x = 0;
int d = HexValue(c0_);
if (d < 0) return -1;
while (d >= 0) {
x = x * 16 + d;
if (x > max_value) {
ReportScannerError(Location(beg_pos, source_pos() + 1),
MessageTemplate::kUndefinedUnicodeCodePoint);
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;
has_line_terminator_before_next_ = has_line_terminator_after_next_;
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;
next_.literal_chars = nullptr;
next_.raw_literal_chars = nullptr;
Advance();
return current_.token;
}
}
Scan();
return current_.token;
}
Token::Value Scanner::PeekAhead() {
DCHECK(next_.token != Token::DIV);
DCHECK(next_.token != Token::ASSIGN_DIV);
if (next_next_.token != Token::UNINITIALIZED) {
return next_next_.token;
}
TokenDesc prev = current_;
bool has_line_terminator_before_next =
has_line_terminator_before_next_ || has_multiline_comment_before_next_;
Next();
has_line_terminator_after_next_ =
has_line_terminator_before_next_ || has_multiline_comment_before_next_;
has_line_terminator_before_next_ = has_line_terminator_before_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) {
// Don't skip behind the end of input.
if (c0_ == kEndOfInput) 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_) break;
Advance();
if (c0_ != '-') {
PushBack('-'); // undo Advance()
break;
}
Advance();
if (c0_ != '>') {
PushBack2('-', '-'); // undo 2x Advance();
break;
}
// Treat the rest of the line as a comment.
SkipSingleLineComment();
}
// 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_ != kEndOfInput && !unicode_cache_->IsLineTerminator(c0_)) {
Advance();
}
return Token::WHITESPACE;
}
Token::Value Scanner::SkipSourceURLComment() {
TryToParseSourceURLComment();
while (c0_ != kEndOfInput && !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_ == kEndOfInput || !unicode_cache_->IsWhiteSpace(c0_)) return;
Advance();
LiteralBuffer name;
while (c0_ != kEndOfInput &&
!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_ != kEndOfInput && unicode_cache_->IsWhiteSpace(c0_)) {
Advance();
}
while (c0_ != kEndOfInput && !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_ != kEndOfInput && !unicode_cache_->IsLineTerminator(c0_)) {
if (!unicode_cache_->IsWhiteSpace(c0_)) {
value->Reset();
break;
}
Advance();
}
}
Token::Value Scanner::SkipMultiLineComment() {
DCHECK(c0_ == '*');
Advance();
while (c0_ != kEndOfInput) {
uc32 ch = c0_;
Advance();
if (c0_ != kEndOfInput && 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_ != '-') {
PushBack('!'); // undo Advance()
return Token::LT;
}
Advance();
if (c0_ != '-') {
PushBack2('-', '!'); // undo 2x Advance()
return Token::LT;
}
found_html_comment_ = true;
return SkipSingleLineComment();
}
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_ == '>' && HasAnyLineTerminatorBeforeNext()) {
// 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 '*':
// * *=
Advance();
if (c0_ == '*') {
token = Select('=', Token::ASSIGN_EXP, Token::EXP);
} else if (c0_ == '=') {
token = Select(Token::ASSIGN_MUL);
} else {
token = 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_ == kEndOfInput) {
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;
#ifdef DEBUG
SanityCheckTokenDesc(current_);
SanityCheckTokenDesc(next_);
SanityCheckTokenDesc(next_next_);
#endif
}
#ifdef DEBUG
void Scanner::SanityCheckTokenDesc(const TokenDesc& token) const {
// Most tokens should not have literal_chars or even raw_literal chars.
// The rules are:
// - UNINITIALIZED: we don't care.
// - TEMPLATE_*: need both literal + raw literal chars.
// - IDENTIFIERS, STRINGS, etc.: need a literal, but no raw literal.
// - all others: should have neither.
switch (token.token) {
case Token::UNINITIALIZED:
// token.literal_chars & other members might be garbage. That's ok.
break;
case Token::TEMPLATE_SPAN:
case Token::TEMPLATE_TAIL:
DCHECK_NOT_NULL(token.raw_literal_chars);
DCHECK_NOT_NULL(token.literal_chars);
break;
case Token::ESCAPED_KEYWORD:
case Token::ESCAPED_STRICT_RESERVED_WORD:
case Token::FUTURE_STRICT_RESERVED_WORD:
case Token::IDENTIFIER:
case Token::NUMBER:
case Token::REGEXP_LITERAL:
case Token::SMI:
case Token::STRING:
DCHECK_NOT_NULL(token.literal_chars);
DCHECK_NULL(token.raw_literal_chars);
break;
default:
DCHECK_NULL(token.literal_chars);
DCHECK_NULL(token.raw_literal_chars);
break;
}
}
#endif // DEBUG
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_->Seek(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_ != kEndOfInput &&
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;
}
// Other escaped characters are interpreted as their non-escaped version.
AddLiteralChar(c);
return true;
}
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);
octal_message_ = MessageTemplate::kStrictOctalEscape;
}
return x;
}
Token::Value Scanner::ScanString() {
uc32 quote = c0_;
Advance<false, false>(); // consume quote
LiteralScope literal(this);
while (true) {
if (c0_ > kMaxAscii) {
HandleLeadSurrogate();
break;
}
if (c0_ == kEndOfInput || c0_ == '\n' || c0_ == '\r') return Token::ILLEGAL;
if (c0_ == quote) {
literal.Complete();
Advance<false, false>();
return Token::STRING;
}
char c = static_cast<char>(c0_);
if (c == '\\') break;
Advance<false, false>();
AddLiteralChar(c);
}
while (c0_ != quote && c0_ != kEndOfInput &&
!unicode_cache_->IsLineTerminator(c0_)) {
uc32 c = c0_;
Advance();
if (c == '\\') {
if (c0_ == kEndOfInput || !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* ${
//
// TEMPLATE_TAIL ::
// ` LiteralChars* `
// | } LiteralChar* `
//
// A TEMPLATE_SPAN should always be followed by an Expression, while a
// TEMPLATE_TAIL terminates a TemplateLiteral and does not need to be
// followed by an Expression.
// These scoped helpers save and restore the original error state, so that we
// can specially treat invalid escape sequences in templates (which are
// handled by the parser).
ErrorState scanner_error_state(&scanner_error_, &scanner_error_location_);
ErrorState octal_error_state(&octal_message_, &octal_pos_);
Token::Value result = Token::TEMPLATE_SPAN;
LiteralScope literal(this);
StartRawLiteral();
const bool capture_raw = true;
const bool in_template_literal = true;
while (true) {
uc32 c = c0_;
Advance<capture_raw>();
if (c == '`') {
result = Token::TEMPLATE_TAIL;
ReduceRawLiteralLength(1);
break;
} else if (c == '$' && c0_ == '{') {
Advance<capture_raw>(); // Consume '{'
ReduceRawLiteralLength(2);
break;
} else if (c == '\\') {
if (c0_ != kEndOfInput && 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 {
bool success = ScanEscape<capture_raw, in_template_literal>();
USE(success);
DCHECK_EQ(!success, has_error());
// For templates, invalid escape sequence checking is handled in the
// parser.
scanner_error_state.MoveErrorTo(&invalid_template_escape_message_,
&invalid_template_escape_location_);
octal_error_state.MoveErrorTo(&invalid_template_escape_message_,
&invalid_template_escape_location_);
}
} 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(next_next_.token == Token::UNINITIALIZED);
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,
DECIMAL_WITH_LEADING_ZERO,
HEX,
OCTAL,
IMPLICIT_OCTAL,
BINARY
} kind = DECIMAL;
LiteralScope literal(this);
bool at_start = !seen_period;
int start_pos = source_pos(); // For reporting octal positions.
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') {
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_WITH_LEADING_ZERO;
break;
}
if (c0_ < '0' || '7' < c0_) {
// Octal literal finished.
octal_pos_ = Location(start_pos, source_pos());
octal_message_ = MessageTemplate::kStrictOctalLiteral;
break;
}
AddLiteralCharAdvance();
}
} else if (c0_ == '8' || c0_ == '9') {
kind = DECIMAL_WITH_LEADING_ZERO;
}
}
// Parse decimal digits and allow trailing fractional part.
if (kind == DECIMAL || kind == DECIMAL_WITH_LEADING_ZERO) {
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_ == kEndOfInput || !unicode_cache_->IsIdentifierStart(c0_))) {
next_.smi_value_ = static_cast<uint32_t>(value);
literal.Complete();
HandleLeadSurrogate();
if (kind == DECIMAL_WITH_LEADING_ZERO) {
octal_pos_ = Location(start_pos, source_pos());
octal_message_ = MessageTemplate::kStrictDecimalWithLeadingZero;
}
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 || kind == DECIMAL_WITH_LEADING_ZERO))
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_ != kEndOfInput && unicode_cache_->IsIdentifierStart(c0_)))
return Token::ILLEGAL;
literal.Complete();
if (kind == DECIMAL_WITH_LEADING_ZERO) {
octal_pos_ = Location(start_pos, source_pos());
octal_message_ = MessageTemplate::kStrictDecimalWithLeadingZero;
}
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_ == '{') {
int begin = source_pos() - 2;
Advance<capture_raw>();
uc32 cp = ScanUnlimitedLengthHexNumber<capture_raw>(0x10ffff, begin);
if (cp < 0 || c0_ != '}') {
ReportScannerError(source_pos(),
MessageTemplate::kInvalidUnicodeEscapeSequence);
return -1;
}
Advance<capture_raw>();
return cp;
}
const bool unicode = true;
return ScanHexNumber<capture_raw, unicode>(4);
}
// ----------------------------------------------------------------------------
// Keyword Matcher
#define KEYWORDS(KEYWORD_GROUP, KEYWORD) \
KEYWORD_GROUP('a') \
KEYWORD("async", Token::ASYNC) \
KEYWORD("await", Token::AWAIT) \
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::ENUM) \
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) {
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])) { \
return token; \
} \
}
KEYWORDS(KEYWORD_GROUP_CASE, KEYWORD)
}
return Token::IDENTIFIER;
}
Token::Value Scanner::ScanIdentifierOrKeyword() {
DCHECK(unicode_cache_->IsIdentifierStart(c0_));
LiteralScope literal(this);
if (IsInRange(c0_, 'a', 'z')) {
do {
char first_char = static_cast<char>(c0_);
Advance<false, false>();
AddLiteralChar(first_char);
} while (IsInRange(c0_, 'a', 'z'));
if (IsDecimalDigit(c0_) || IsInRange(c0_, 'A', 'Z') || c0_ == '_' ||
c0_ == '$') {
// Identifier starting with lowercase.
char first_char = static_cast<char>(c0_);
Advance<false, false>();
AddLiteralChar(first_char);
while (IsAsciiIdentifier(c0_)) {
char first_char = static_cast<char>(c0_);
Advance<false, false>();
AddLiteralChar(first_char);
}
if (c0_ <= kMaxAscii && c0_ != '\\') {
literal.Complete();
return Token::IDENTIFIER;
}
} else if (c0_ <= kMaxAscii && c0_ != '\\') {
// Only a-z+: could be a keyword or identifier.
Vector<const uint8_t> chars = next_.literal_chars->one_byte_literal();
Token::Value token =
KeywordOrIdentifierToken(chars.start(), chars.length());
if (token == Token::IDENTIFIER ||
token == Token::FUTURE_STRICT_RESERVED_WORD)
literal.Complete();
return token;
}
HandleLeadSurrogate();
} else if (IsInRange(c0_, 'A', 'Z') || c0_ == '_' || c0_ == '$') {
do {
char first_char = static_cast<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_ != kEndOfInput && 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);
}
if (next_.literal_chars->is_one_byte()) {
Vector<const uint8_t> chars = next_.literal_chars->one_byte_literal();
Token::Value token =
KeywordOrIdentifierToken(chars.start(), chars.length());
if (token == Token::IDENTIFIER ||
token == Token::FUTURE_STRICT_RESERVED_WORD)
literal.Complete();
return token;
}
literal.Complete();
return Token::IDENTIFIER;
}
Token::Value Scanner::ScanIdentifierSuffix(LiteralScope* literal,
bool escaped) {
// Scan the rest of the identifier characters.
while (c0_ != kEndOfInput && 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();
Token::Value token =
KeywordOrIdentifierToken(chars.start(), chars.length());
/* TODO(adamk): YIELD should be handled specially. */
if (token == Token::IDENTIFIER) {
return Token::IDENTIFIER;
} else if (token == Token::FUTURE_STRICT_RESERVED_WORD ||
token == Token::LET || token == Token::STATIC) {
return Token::ESCAPED_STRICT_RESERVED_WORD;
} else {
return Token::ESCAPED_KEYWORD;
}
}
return Token::IDENTIFIER;
}
bool Scanner::ScanRegExpPattern() {
DCHECK(next_next_.token == Token::UNINITIALIZED);
DCHECK(next_.token == Token::DIV || next_.token == Token::ASSIGN_DIV);
// Scan: ('/' | '/=') RegularExpressionBody '/' RegularExpressionFlags
bool in_character_class = false;
bool seen_equal = (next_.token == Token::ASSIGN_DIV);
// 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_ == kEndOfInput || unicode_cache_->IsLineTerminator(c0_))
return false;
if (c0_ == '\\') { // Escape sequence.
AddLiteralCharAdvance();
if (c0_ == kEndOfInput || 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();
next_.token = Token::REGEXP_LITERAL;
return true;
}
Maybe<RegExp::Flags> Scanner::ScanRegExpFlags() {
DCHECK(next_.token == Token::REGEXP_LITERAL);
// Scan regular expression flags.
int flags = 0;
while (c0_ != kEndOfInput && unicode_cache_->IsIdentifierPart(c0_)) {
RegExp::Flags flag = RegExp::kNone;
switch (c0_) {
case 'g':
flag = RegExp::kGlobal;
break;
case 'i':
flag = RegExp::kIgnoreCase;
break;
case 'm':
flag = RegExp::kMultiline;
break;
case 'u':
flag = RegExp::kUnicode;
break;
case 'y':
flag = RegExp::kSticky;
break;
default:
return Nothing<RegExp::Flags>();
}
if (flags & flag) {
return Nothing<RegExp::Flags>();
}
Advance();
flags |= flag;
}
next_.location.end_pos = source_pos();
return Just(RegExp::Flags(flags));
}
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();
}
bool Scanner::FindSymbol(DuplicateFinder* finder) {
// TODO(vogelheim): Move this logic into the calling class; this can be fully
// implemented using the public interface.
if (is_literal_one_byte()) {
return finder->AddOneByteSymbol(literal_one_byte_string());
}
return finder->AddTwoByteSymbol(literal_two_byte_string());
}
void Scanner::SeekNext(size_t position) {
// Use with care: This cleanly resets most, but not all scanner state.
// TODO(vogelheim): Fix this, or at least DCHECK the relevant conditions.
// To re-scan from a given character position, we need to:
// 1, Reset the current_, next_ and next_next_ tokens
// (next_ + next_next_ will be overwrittem by Next(),
// current_ will remain unchanged, so overwrite it fully.)
current_ = {{0, 0}, nullptr, nullptr, 0, Token::UNINITIALIZED};
next_.token = Token::UNINITIALIZED;
next_next_.token = Token::UNINITIALIZED;
// 2, reset the source to the desired position,
source_->Seek(position);
// 3, re-scan, by scanning the look-ahead char + 1 token (next_).
c0_ = source_->Advance();
Next();
DCHECK_EQ(next_.location.beg_pos, static_cast<int>(position));
}
} // namespace internal
} // namespace v8