blob: faec88b8a4bfb5ff37bf8dad58fefc32cd8ff03f [file] [log] [blame]
// 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/parser.h"
namespace v8 {
namespace internal {
Handle<String> LiteralBuffer::Internalize(Isolate* isolate) const {
if (is_one_byte()) {
return isolate->factory()->InternalizeOneByteString(one_byte_literal());
}
return isolate->factory()->InternalizeTwoByteString(two_byte_literal());
}
// Default implementation for streams that do not support bookmarks.
bool Utf16CharacterStream::SetBookmark() { return false; }
void Utf16CharacterStream::ResetToBookmark() { UNREACHABLE(); }
// ----------------------------------------------------------------------------
// Scanner
Scanner::Scanner(UnicodeCache* unicode_cache)
: unicode_cache_(unicode_cache),
bookmark_c0_(kNoBookmark),
octal_pos_(Location::invalid()),
found_html_comment_(false),
allow_harmony_exponentiation_operator_(false) {
bookmark_current_.literal_chars = &bookmark_current_literal_;
bookmark_current_.raw_literal_chars = &bookmark_current_raw_literal_;
bookmark_next_.literal_chars = &bookmark_next_literal_;
bookmark_next_.raw_literal_chars = &bookmark_next_raw_literal_;
}
void Scanner::Initialize(Utf16CharacterStream* source) {
source_ = source;
// Need to capture identifiers in order to recognize "get" and "set"
// in object literals.
Init();
// Skip initial whitespace allowing HTML comment ends just like
// after a newline and scan first token.
has_line_terminator_before_next_ = true;
SkipWhiteSpace();
Scan();
}
template <bool capture_raw, 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;
return current_.token;
}
has_line_terminator_before_next_ = false;
has_multiline_comment_before_next_ = false;
if (static_cast<unsigned>(c0_) <= 0x7f) {
Token::Value token = static_cast<Token::Value>(one_char_tokens[c0_]);
if (token != Token::ILLEGAL) {
int pos = source_pos();
next_.token = token;
next_.location.beg_pos = pos;
next_.location.end_pos = pos + 1;
Advance();
return current_.token;
}
}
Scan();
return current_.token;
}
Token::Value Scanner::PeekAhead() {
if (next_next_.token != Token::UNINITIALIZED) {
return next_next_.token;
}
TokenDesc prev = current_;
Next();
Token::Value ret = next_.token;
next_next_ = next_;
next_ = current_;
current_ = prev;
return ret;
}
// TODO(yangguo): check whether this is actually necessary.
static inline bool IsLittleEndianByteOrderMark(uc32 c) {
// The Unicode value U+FFFE is guaranteed never to be assigned as a
// Unicode character; this implies that in a Unicode context the
// 0xFF, 0xFE byte pattern can only be interpreted as the U+FEFF
// character expressed in little-endian byte order (since it could
// not be a U+FFFE character expressed in big-endian byte
// order). Nevertheless, we check for it to be compatible with
// Spidermonkey.
return c == 0xFFFE;
}
bool Scanner::SkipWhiteSpace() {
int start_position = source_pos();
while (true) {
while (true) {
// The unicode cache accepts unsigned inputs.
if (c0_ < 0) break;
// Advance as long as character is a WhiteSpace or LineTerminator.
// Remember if the latter is the case.
if (unicode_cache_->IsLineTerminator(c0_)) {
has_line_terminator_before_next_ = true;
} else if (!unicode_cache_->IsWhiteSpace(c0_) &&
!IsLittleEndianByteOrderMark(c0_)) {
break;
}
Advance();
}
// If there is an HTML comment end '-->' at the beginning of a
// line (with only whitespace in front of it), we treat the rest
// of the line as a comment. This is in line with the way
// SpiderMonkey handles it.
if (c0_ == '-' && has_line_terminator_before_next_) {
Advance();
if (c0_ == '-') {
Advance();
if (c0_ == '>') {
// Treat the rest of the line as a comment.
SkipSingleLineComment();
// Continue skipping white space after the comment.
continue;
}
PushBack('-'); // undo Advance()
}
PushBack('-'); // undo Advance()
}
// Return whether or not we skipped any characters.
return source_pos() != start_position;
}
}
Token::Value Scanner::SkipSingleLineComment() {
Advance();
// The line terminator at the end of the line is not considered
// to be part of the single-line comment; it is recognized
// separately by the lexical grammar and becomes part of the
// stream of input elements for the syntactic grammar (see
// ECMA-262, section 7.4).
while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
Advance();
}
return Token::WHITESPACE;
}
Token::Value Scanner::SkipSourceURLComment() {
TryToParseSourceURLComment();
while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
Advance();
}
return Token::WHITESPACE;
}
void Scanner::TryToParseSourceURLComment() {
// Magic comments are of the form: //[#@]\s<name>=\s*<value>\s*.* and this
// function will just return if it cannot parse a magic comment.
if (c0_ < 0 || !unicode_cache_->IsWhiteSpace(c0_)) return;
Advance();
LiteralBuffer name;
while (c0_ >= 0 && !unicode_cache_->IsWhiteSpaceOrLineTerminator(c0_) &&
c0_ != '=') {
name.AddChar(c0_);
Advance();
}
if (!name.is_one_byte()) return;
Vector<const uint8_t> name_literal = name.one_byte_literal();
LiteralBuffer* value;
if (name_literal == STATIC_CHAR_VECTOR("sourceURL")) {
value = &source_url_;
} else if (name_literal == STATIC_CHAR_VECTOR("sourceMappingURL")) {
value = &source_mapping_url_;
} else {
return;
}
if (c0_ != '=')
return;
Advance();
value->Reset();
while (c0_ >= 0 && unicode_cache_->IsWhiteSpace(c0_)) {
Advance();
}
while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
// Disallowed characters.
if (c0_ == '"' || c0_ == '\'') {
value->Reset();
return;
}
if (unicode_cache_->IsWhiteSpace(c0_)) {
break;
}
value->AddChar(c0_);
Advance();
}
// Allow whitespace at the end.
while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
if (!unicode_cache_->IsWhiteSpace(c0_)) {
value->Reset();
break;
}
Advance();
}
}
Token::Value Scanner::SkipMultiLineComment() {
DCHECK(c0_ == '*');
Advance();
while (c0_ >= 0) {
uc32 ch = c0_;
Advance();
if (c0_ >= 0 && unicode_cache_->IsLineTerminator(ch)) {
// Following ECMA-262, section 7.4, a comment containing
// a newline will make the comment count as a line-terminator.
has_multiline_comment_before_next_ = true;
}
// If we have reached the end of the multi-line comment, we
// consume the '/' and insert a whitespace. This way all
// multi-line comments are treated as whitespace.
if (ch == '*' && c0_ == '/') {
c0_ = ' ';
return Token::WHITESPACE;
}
}
// Unterminated multi-line comment.
return Token::ILLEGAL;
}
Token::Value Scanner::ScanHtmlComment() {
// Check for <!-- comments.
DCHECK(c0_ == '!');
Advance();
if (c0_ == '-') {
Advance();
if (c0_ == '-') {
found_html_comment_ = true;
return SkipSingleLineComment();
}
PushBack('-'); // undo Advance()
}
PushBack('!'); // undo Advance()
DCHECK(c0_ == '!');
return Token::LT;
}
void Scanner::Scan() {
next_.literal_chars = NULL;
next_.raw_literal_chars = NULL;
Token::Value token;
do {
// Remember the position of the next token
next_.location.beg_pos = source_pos();
switch (c0_) {
case ' ':
case '\t':
Advance();
token = Token::WHITESPACE;
break;
case '\n':
Advance();
has_line_terminator_before_next_ = true;
token = Token::WHITESPACE;
break;
case '"': case '\'':
token = ScanString();
break;
case '<':
// < <= << <<= <!--
Advance();
if (c0_ == '=') {
token = Select(Token::LTE);
} else if (c0_ == '<') {
token = Select('=', Token::ASSIGN_SHL, Token::SHL);
} else if (c0_ == '!') {
token = ScanHtmlComment();
} else {
token = Token::LT;
}
break;
case '>':
// > >= >> >>= >>> >>>=
Advance();
if (c0_ == '=') {
token = Select(Token::GTE);
} else if (c0_ == '>') {
// >> >>= >>> >>>=
Advance();
if (c0_ == '=') {
token = Select(Token::ASSIGN_SAR);
} else if (c0_ == '>') {
token = Select('=', Token::ASSIGN_SHR, Token::SHR);
} else {
token = Token::SAR;
}
} else {
token = Token::GT;
}
break;
case '=':
// = == === =>
Advance();
if (c0_ == '=') {
token = Select('=', Token::EQ_STRICT, Token::EQ);
} else if (c0_ == '>') {
token = Select(Token::ARROW);
} else {
token = Token::ASSIGN;
}
break;
case '!':
// ! != !==
Advance();
if (c0_ == '=') {
token = Select('=', Token::NE_STRICT, Token::NE);
} else {
token = Token::NOT;
}
break;
case '+':
// + ++ +=
Advance();
if (c0_ == '+') {
token = Select(Token::INC);
} else if (c0_ == '=') {
token = Select(Token::ASSIGN_ADD);
} else {
token = Token::ADD;
}
break;
case '-':
// - -- --> -=
Advance();
if (c0_ == '-') {
Advance();
if (c0_ == '>' && has_line_terminator_before_next_) {
// For compatibility with SpiderMonkey, we skip lines that
// start with an HTML comment end '-->'.
token = SkipSingleLineComment();
} else {
token = Token::DEC;
}
} else if (c0_ == '=') {
token = Select(Token::ASSIGN_SUB);
} else {
token = Token::SUB;
}
break;
case '*':
// * *=
Advance();
if (c0_ == '*' && allow_harmony_exponentiation_operator()) {
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_ < 0) {
token = Token::EOS;
} else if (unicode_cache_->IsIdentifierStart(c0_)) {
token = ScanIdentifierOrKeyword();
} else if (IsDecimalDigit(c0_)) {
token = ScanNumber(false);
} else if (SkipWhiteSpace()) {
token = Token::WHITESPACE;
} else {
token = Select(Token::ILLEGAL);
}
break;
}
// Continue scanning for tokens as long as we're just skipping
// whitespace.
} while (token == Token::WHITESPACE);
next_.location.end_pos = source_pos();
next_.token = token;
}
void Scanner::SeekForward(int pos) {
// After this call, we will have the token at the given position as
// the "next" token. The "current" token will be invalid.
if (pos == next_.location.beg_pos) return;
int current_pos = source_pos();
DCHECK_EQ(next_.location.end_pos, current_pos);
// Positions inside the lookahead token aren't supported.
DCHECK(pos >= current_pos);
if (pos != current_pos) {
source_->SeekForward(pos - source_->pos());
Advance();
// This function is only called to seek to the location
// of the end of a function (at the "}" token). It doesn't matter
// whether there was a line terminator in the part we skip.
has_line_terminator_before_next_ = false;
has_multiline_comment_before_next_ = false;
}
Scan();
}
template <bool capture_raw, bool in_template_literal>
bool Scanner::ScanEscape() {
uc32 c = c0_;
Advance<capture_raw>();
// Skip escaped newlines.
if (!in_template_literal && c0_ >= 0 && unicode_cache_->IsLineTerminator(c)) {
// Allow CR+LF newlines in multiline string literals.
if (IsCarriageReturn(c) && IsLineFeed(c0_)) Advance<capture_raw>();
// Allow LF+CR newlines in multiline string literals.
if (IsLineFeed(c) && IsCarriageReturn(c0_)) Advance<capture_raw>();
return true;
}
switch (c) {
case '\'': // fall through
case '"' : // fall through
case '\\': break;
case 'b' : c = '\b'; break;
case 'f' : c = '\f'; break;
case 'n' : c = '\n'; break;
case 'r' : c = '\r'; break;
case 't' : c = '\t'; break;
case 'u' : {
c = ScanUnicodeEscape<capture_raw>();
if (c < 0) return false;
break;
}
case 'v':
c = '\v';
break;
case 'x': {
c = ScanHexNumber<capture_raw>(2);
if (c < 0) return false;
break;
}
case '0': // Fall through.
case '1': // fall through
case '2': // fall through
case '3': // fall through
case '4': // fall through
case '5': // fall through
case '6': // fall through
case '7':
c = ScanOctalEscape<capture_raw>(c, 2);
break;
}
// According to ECMA-262, section 7.8.4, characters not covered by the
// above cases should be illegal, but they are commonly handled as
// non-escaped characters by JS VMs.
AddLiteralChar(c);
return true;
}
// Octal escapes of the forms '\0xx' and '\xxx' are not a part of
// ECMA-262. Other JS VMs support them.
template <bool capture_raw>
uc32 Scanner::ScanOctalEscape(uc32 c, int length) {
uc32 x = c - '0';
int i = 0;
for (; i < length; i++) {
int d = c0_ - '0';
if (d < 0 || d > 7) break;
int nx = x * 8 + d;
if (nx >= 256) break;
x = nx;
Advance<capture_raw>();
}
// Anything except '\0' is an octal escape sequence, illegal in strict mode.
// Remember the position of octal escape sequences so that an error
// can be reported later (in strict mode).
// We don't report the error immediately, because the octal escape can
// occur before the "use strict" directive.
if (c != '0' || i > 0) {
octal_pos_ = Location(source_pos() - i - 1, source_pos() - 1);
}
return x;
}
const int kMaxAscii = 127;
Token::Value Scanner::ScanString() {
uc32 quote = c0_;
Advance<false, false>(); // consume quote
LiteralScope literal(this);
while (true) {
if (c0_ > kMaxAscii) {
HandleLeadSurrogate();
break;
}
if (c0_ < 0 || c0_ == '\n' || c0_ == '\r') return Token::ILLEGAL;
if (c0_ == quote) {
literal.Complete();
Advance<false, false>();
return Token::STRING;
}
uc32 c = c0_;
if (c == '\\') break;
Advance<false, false>();
AddLiteralChar(c);
}
while (c0_ != quote && c0_ >= 0
&& !unicode_cache_->IsLineTerminator(c0_)) {
uc32 c = c0_;
Advance();
if (c == '\\') {
if (c0_ < 0 || !ScanEscape<false, false>()) {
return Token::ILLEGAL;
}
} else {
AddLiteralChar(c);
}
}
if (c0_ != quote) return Token::ILLEGAL;
literal.Complete();
Advance(); // consume quote
return Token::STRING;
}
Token::Value Scanner::ScanTemplateSpan() {
// When scanning a TemplateSpan, we are looking for the following construct:
// TEMPLATE_SPAN ::
// ` LiteralChars* ${
// | } LiteralChars* ${
//
// TEMPLATE_TAIL ::
// ` LiteralChars* `
// | } LiteralChar* `
//
// A TEMPLATE_SPAN should always be followed by an Expression, while a
// TEMPLATE_TAIL terminates a TemplateLiteral and does not need to be
// followed by an Expression.
Token::Value result = Token::TEMPLATE_SPAN;
LiteralScope literal(this);
StartRawLiteral();
const bool capture_raw = true;
const bool in_template_literal = true;
while (true) {
uc32 c = c0_;
Advance<capture_raw>();
if (c == '`') {
result = Token::TEMPLATE_TAIL;
ReduceRawLiteralLength(1);
break;
} else if (c == '$' && c0_ == '{') {
Advance<capture_raw>(); // Consume '{'
ReduceRawLiteralLength(2);
break;
} else if (c == '\\') {
if (c0_ > 0 && unicode_cache_->IsLineTerminator(c0_)) {
// The TV of LineContinuation :: \ LineTerminatorSequence is the empty
// code unit sequence.
uc32 lastChar = c0_;
Advance<capture_raw>();
if (lastChar == '\r') {
ReduceRawLiteralLength(1); // Remove \r
if (c0_ == '\n') {
Advance<capture_raw>(); // Adds \n
} else {
AddRawLiteralChar('\n');
}
}
} else if (!ScanEscape<capture_raw, in_template_literal>()) {
return Token::ILLEGAL;
}
} else if (c < 0) {
// Unterminated template literal
PushBack(c);
break;
} else {
// The TRV of LineTerminatorSequence :: <CR> is the CV 0x000A.
// The TRV of LineTerminatorSequence :: <CR><LF> is the sequence
// consisting of the CV 0x000A.
if (c == '\r') {
ReduceRawLiteralLength(1); // Remove \r
if (c0_ == '\n') {
Advance<capture_raw>(); // Adds \n
} else {
AddRawLiteralChar('\n');
}
c = '\n';
}
AddLiteralChar(c);
}
}
literal.Complete();
next_.location.end_pos = source_pos();
next_.token = result;
return result;
}
Token::Value Scanner::ScanTemplateStart() {
DCHECK(c0_ == '`');
next_.location.beg_pos = source_pos();
Advance(); // Consume `
return ScanTemplateSpan();
}
Token::Value Scanner::ScanTemplateContinuation() {
DCHECK_EQ(next_.token, Token::RBRACE);
next_.location.beg_pos = source_pos() - 1; // We already consumed }
return ScanTemplateSpan();
}
void Scanner::ScanDecimalDigits() {
while (IsDecimalDigit(c0_))
AddLiteralCharAdvance();
}
Token::Value Scanner::ScanNumber(bool seen_period) {
DCHECK(IsDecimalDigit(c0_)); // the first digit of the number or the fraction
enum { DECIMAL, HEX, OCTAL, IMPLICIT_OCTAL, BINARY } kind = DECIMAL;
LiteralScope literal(this);
bool at_start = !seen_period;
if (seen_period) {
// we have already seen a decimal point of the float
AddLiteralChar('.');
ScanDecimalDigits(); // we know we have at least one digit
} else {
// if the first character is '0' we must check for octals and hex
if (c0_ == '0') {
int start_pos = source_pos(); // For reporting octal positions.
AddLiteralCharAdvance();
// either 0, 0exxx, 0Exxx, 0.xxx, a hex number, a binary number or
// an octal number.
if (c0_ == 'x' || c0_ == 'X') {
// hex number
kind = HEX;
AddLiteralCharAdvance();
if (!IsHexDigit(c0_)) {
// we must have at least one hex digit after 'x'/'X'
return Token::ILLEGAL;
}
while (IsHexDigit(c0_)) {
AddLiteralCharAdvance();
}
} else if (c0_ == 'o' || c0_ == 'O') {
kind = OCTAL;
AddLiteralCharAdvance();
if (!IsOctalDigit(c0_)) {
// we must have at least one octal digit after 'o'/'O'
return Token::ILLEGAL;
}
while (IsOctalDigit(c0_)) {
AddLiteralCharAdvance();
}
} else if (c0_ == 'b' || c0_ == 'B') {
kind = BINARY;
AddLiteralCharAdvance();
if (!IsBinaryDigit(c0_)) {
// we must have at least one binary digit after 'b'/'B'
return Token::ILLEGAL;
}
while (IsBinaryDigit(c0_)) {
AddLiteralCharAdvance();
}
} else if ('0' <= c0_ && c0_ <= '7') {
// (possible) octal number
kind = IMPLICIT_OCTAL;
while (true) {
if (c0_ == '8' || c0_ == '9') {
at_start = false;
kind = DECIMAL;
break;
}
if (c0_ < '0' || '7' < c0_) {
// Octal literal finished.
octal_pos_ = Location(start_pos, source_pos());
break;
}
AddLiteralCharAdvance();
}
}
}
// Parse decimal digits and allow trailing fractional part.
if (kind == DECIMAL) {
if (at_start) {
uint64_t value = 0;
while (IsDecimalDigit(c0_)) {
value = 10 * value + (c0_ - '0');
uc32 first_char = c0_;
Advance<false, false>();
AddLiteralChar(first_char);
}
if (next_.literal_chars->one_byte_literal().length() <= 10 &&
value <= Smi::kMaxValue && c0_ != '.' && c0_ != 'e' && c0_ != 'E') {
next_.smi_value_ = static_cast<int>(value);
literal.Complete();
HandleLeadSurrogate();
return Token::SMI;
}
HandleLeadSurrogate();
}
ScanDecimalDigits(); // optional
if (c0_ == '.') {
AddLiteralCharAdvance();
ScanDecimalDigits(); // optional
}
}
}
// scan exponent, if any
if (c0_ == 'e' || c0_ == 'E') {
DCHECK(kind != HEX); // 'e'/'E' must be scanned as part of the hex number
if (kind != DECIMAL) return Token::ILLEGAL;
// scan exponent
AddLiteralCharAdvance();
if (c0_ == '+' || c0_ == '-')
AddLiteralCharAdvance();
if (!IsDecimalDigit(c0_)) {
// we must have at least one decimal digit after 'e'/'E'
return Token::ILLEGAL;
}
ScanDecimalDigits();
}
// The source character immediately following a numeric literal must
// not be an identifier start or a decimal digit; see ECMA-262
// section 7.8.3, page 17 (note that we read only one decimal digit
// if the value is 0).
if (IsDecimalDigit(c0_) ||
(c0_ >= 0 && unicode_cache_->IsIdentifierStart(c0_)))
return Token::ILLEGAL;
literal.Complete();
return Token::NUMBER;
}
uc32 Scanner::ScanIdentifierUnicodeEscape() {
Advance();
if (c0_ != 'u') return -1;
Advance();
return ScanUnicodeEscape<false>();
}
template <bool capture_raw>
uc32 Scanner::ScanUnicodeEscape() {
// Accept both \uxxxx and \u{xxxxxx}. In the latter case, the number of
// hex digits between { } is arbitrary. \ and u have already been read.
if (c0_ == '{') {
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("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, bool escaped) {
DCHECK(input_length >= 1);
const int kMinLength = 2;
const int kMaxLength = 10;
if (input_length < kMinLength || input_length > kMaxLength) {
return Token::IDENTIFIER;
}
switch (input[0]) {
default:
#define KEYWORD_GROUP_CASE(ch) \
break; \
case ch:
#define KEYWORD(keyword, token) \
{ \
/* 'keyword' is a char array, so sizeof(keyword) is */ \
/* strlen(keyword) plus 1 for the NUL char. */ \
const int keyword_length = sizeof(keyword) - 1; \
STATIC_ASSERT(keyword_length >= kMinLength); \
STATIC_ASSERT(keyword_length <= kMaxLength); \
if (input_length == keyword_length && input[1] == keyword[1] && \
(keyword_length <= 2 || input[2] == keyword[2]) && \
(keyword_length <= 3 || input[3] == keyword[3]) && \
(keyword_length <= 4 || input[4] == keyword[4]) && \
(keyword_length <= 5 || input[5] == keyword[5]) && \
(keyword_length <= 6 || input[6] == keyword[6]) && \
(keyword_length <= 7 || input[7] == keyword[7]) && \
(keyword_length <= 8 || input[8] == keyword[8]) && \
(keyword_length <= 9 || input[9] == keyword[9])) { \
if (escaped) { \
/* TODO(adamk): YIELD should be handled specially. */ \
return (token == Token::FUTURE_STRICT_RESERVED_WORD || \
token == Token::LET || token == Token::STATIC) \
? Token::ESCAPED_STRICT_RESERVED_WORD \
: Token::ESCAPED_KEYWORD; \
} \
return token; \
} \
}
KEYWORDS(KEYWORD_GROUP_CASE, KEYWORD)
}
return Token::IDENTIFIER;
}
bool Scanner::IdentifierIsFutureStrictReserved(
const AstRawString* string) const {
// Keywords are always 1-byte strings.
if (!string->is_one_byte()) return false;
if (string->IsOneByteEqualTo("let") || string->IsOneByteEqualTo("static") ||
string->IsOneByteEqualTo("yield")) {
return true;
}
return Token::FUTURE_STRICT_RESERVED_WORD ==
KeywordOrIdentifierToken(string->raw_data(), string->length(), false);
}
Token::Value Scanner::ScanIdentifierOrKeyword() {
DCHECK(unicode_cache_->IsIdentifierStart(c0_));
LiteralScope literal(this);
if (IsInRange(c0_, 'a', 'z')) {
do {
uc32 first_char = c0_;
Advance<false, false>();
AddLiteralChar(first_char);
} while (IsInRange(c0_, 'a', 'z'));
if (IsDecimalDigit(c0_) || IsInRange(c0_, 'A', 'Z') || c0_ == '_' ||
c0_ == '$') {
// Identifier starting with lowercase.
uc32 first_char = c0_;
Advance<false, false>();
AddLiteralChar(first_char);
while (IsAsciiIdentifier(c0_)) {
uc32 first_char = c0_;
Advance<false, false>();
AddLiteralChar(first_char);
}
if (c0_ <= kMaxAscii && c0_ != '\\') {
literal.Complete();
return Token::IDENTIFIER;
}
} else if (c0_ <= kMaxAscii && c0_ != '\\') {
// Only a-z+: could be a keyword or identifier.
literal.Complete();
Vector<const uint8_t> chars = next_.literal_chars->one_byte_literal();
return KeywordOrIdentifierToken(chars.start(), chars.length(), false);
}
HandleLeadSurrogate();
} else if (IsInRange(c0_, 'A', 'Z') || c0_ == '_' || c0_ == '$') {
do {
uc32 first_char = c0_;
Advance<false, false>();
AddLiteralChar(first_char);
} while (IsAsciiIdentifier(c0_));
if (c0_ <= kMaxAscii && c0_ != '\\') {
literal.Complete();
return Token::IDENTIFIER;
}
HandleLeadSurrogate();
} else if (c0_ == '\\') {
// Scan identifier start character.
uc32 c = ScanIdentifierUnicodeEscape();
// Only allow legal identifier start characters.
if (c < 0 ||
c == '\\' || // No recursive escapes.
!unicode_cache_->IsIdentifierStart(c)) {
return Token::ILLEGAL;
}
AddLiteralChar(c);
return ScanIdentifierSuffix(&literal, true);
} else {
uc32 first_char = c0_;
Advance();
AddLiteralChar(first_char);
}
// Scan the rest of the identifier characters.
while (c0_ >= 0 && unicode_cache_->IsIdentifierPart(c0_)) {
if (c0_ != '\\') {
uc32 next_char = c0_;
Advance();
AddLiteralChar(next_char);
continue;
}
// Fallthrough if no longer able to complete keyword.
return ScanIdentifierSuffix(&literal, false);
}
literal.Complete();
if (next_.literal_chars->is_one_byte()) {
Vector<const uint8_t> chars = next_.literal_chars->one_byte_literal();
return KeywordOrIdentifierToken(chars.start(), chars.length(), false);
}
return Token::IDENTIFIER;
}
Token::Value Scanner::ScanIdentifierSuffix(LiteralScope* literal,
bool escaped) {
// Scan the rest of the identifier characters.
while (c0_ >= 0 && unicode_cache_->IsIdentifierPart(c0_)) {
if (c0_ == '\\') {
uc32 c = ScanIdentifierUnicodeEscape();
escaped = true;
// Only allow legal identifier part characters.
if (c < 0 ||
c == '\\' ||
!unicode_cache_->IsIdentifierPart(c)) {
return Token::ILLEGAL;
}
AddLiteralChar(c);
} else {
AddLiteralChar(c0_);
Advance();
}
}
literal->Complete();
if (escaped && next_.literal_chars->is_one_byte()) {
Vector<const uint8_t> chars = next_.literal_chars->one_byte_literal();
return KeywordOrIdentifierToken(chars.start(), chars.length(), true);
}
return Token::IDENTIFIER;
}
bool Scanner::ScanRegExpPattern(bool seen_equal) {
// Scan: ('/' | '/=') RegularExpressionBody '/' RegularExpressionFlags
bool in_character_class = false;
// Previous token is either '/' or '/=', in the second case, the
// pattern starts at =.
next_.location.beg_pos = source_pos() - (seen_equal ? 2 : 1);
next_.location.end_pos = source_pos() - (seen_equal ? 1 : 0);
// Scan regular expression body: According to ECMA-262, 3rd, 7.8.5,
// the scanner should pass uninterpreted bodies to the RegExp
// constructor.
LiteralScope literal(this);
if (seen_equal) {
AddLiteralChar('=');
}
while (c0_ != '/' || in_character_class) {
if (c0_ < 0 || unicode_cache_->IsLineTerminator(c0_)) return false;
if (c0_ == '\\') { // Escape sequence.
AddLiteralCharAdvance();
if (c0_ < 0 || unicode_cache_->IsLineTerminator(c0_)) return false;
AddLiteralCharAdvance();
// If the escape allows more characters, i.e., \x??, \u????, or \c?,
// only "safe" characters are allowed (letters, digits, underscore),
// otherwise the escape isn't valid and the invalid character has
// its normal meaning. I.e., we can just continue scanning without
// worrying whether the following characters are part of the escape
// or not, since any '/', '\\' or '[' is guaranteed to not be part
// of the escape sequence.
// TODO(896): At some point, parse RegExps more throughly to capture
// octal esacpes in strict mode.
} else { // Unescaped character.
if (c0_ == '[') in_character_class = true;
if (c0_ == ']') in_character_class = false;
AddLiteralCharAdvance();
}
}
Advance(); // consume '/'
literal.Complete();
return true;
}
Maybe<RegExp::Flags> Scanner::ScanRegExpFlags() {
// Scan regular expression flags.
LiteralScope literal(this);
int flags = 0;
while (c0_ >= 0 && 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':
if (!FLAG_harmony_unicode_regexps) return Nothing<RegExp::Flags>();
flag = RegExp::kUnicode;
break;
case 'y':
flag = RegExp::kSticky;
break;
default:
return Nothing<RegExp::Flags>();
}
if (flags & flag) return Nothing<RegExp::Flags>();
AddLiteralCharAdvance();
flags |= flag;
}
literal.Complete();
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();
}
int Scanner::FindSymbol(DuplicateFinder* finder, int value) {
if (is_literal_one_byte()) {
return finder->AddOneByteSymbol(literal_one_byte_string(), value);
}
return finder->AddTwoByteSymbol(literal_two_byte_string(), value);
}
bool Scanner::SetBookmark() {
if (c0_ != kNoBookmark && bookmark_c0_ == kNoBookmark &&
next_next_.token == Token::UNINITIALIZED && source_->SetBookmark()) {
bookmark_c0_ = c0_;
CopyTokenDesc(&bookmark_current_, &current_);
CopyTokenDesc(&bookmark_next_, &next_);
return true;
}
return false;
}
void Scanner::ResetToBookmark() {
DCHECK(BookmarkHasBeenSet()); // Caller hasn't called SetBookmark.
source_->ResetToBookmark();
c0_ = bookmark_c0_;
StartLiteral();
StartRawLiteral();
CopyTokenDesc(&next_, &bookmark_current_);
current_ = next_;
StartLiteral();
StartRawLiteral();
CopyTokenDesc(&next_, &bookmark_next_);
bookmark_c0_ = kBookmarkWasApplied;
}
bool Scanner::BookmarkHasBeenSet() { return bookmark_c0_ >= 0; }
bool Scanner::BookmarkHasBeenReset() {
return bookmark_c0_ == kBookmarkWasApplied;
}
void Scanner::DropBookmark() { bookmark_c0_ = kNoBookmark; }
void Scanner::CopyTokenDesc(TokenDesc* to, TokenDesc* from) {
DCHECK_NOT_NULL(to);
DCHECK_NOT_NULL(from);
to->token = from->token;
to->location = from->location;
to->literal_chars->CopyFrom(from->literal_chars);
to->raw_literal_chars->CopyFrom(from->raw_literal_chars);
}
int DuplicateFinder::AddOneByteSymbol(Vector<const uint8_t> key, int value) {
return AddSymbol(key, true, value);
}
int DuplicateFinder::AddTwoByteSymbol(Vector<const uint16_t> key, int value) {
return AddSymbol(Vector<const uint8_t>::cast(key), false, value);
}
int DuplicateFinder::AddSymbol(Vector<const uint8_t> key,
bool is_one_byte,
int value) {
uint32_t hash = Hash(key, is_one_byte);
byte* encoding = BackupKey(key, is_one_byte);
HashMap::Entry* entry = map_.LookupOrInsert(encoding, hash);
int old_value = static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
entry->value =
reinterpret_cast<void*>(static_cast<intptr_t>(value | old_value));
return old_value;
}
int DuplicateFinder::AddNumber(Vector<const uint8_t> key, int value) {
DCHECK(key.length() > 0);
// Quick check for already being in canonical form.
if (IsNumberCanonical(key)) {
return AddOneByteSymbol(key, value);
}
int flags = ALLOW_HEX | ALLOW_OCTAL | ALLOW_IMPLICIT_OCTAL | ALLOW_BINARY;
double double_value = StringToDouble(
unicode_constants_, key, flags, 0.0);
int length;
const char* string;
if (!std::isfinite(double_value)) {
string = "Infinity";
length = 8; // strlen("Infinity");
} else {
string = DoubleToCString(double_value,
Vector<char>(number_buffer_, kBufferSize));
length = StrLength(string);
}
return AddSymbol(Vector<const byte>(reinterpret_cast<const byte*>(string),
length), true, value);
}
bool DuplicateFinder::IsNumberCanonical(Vector<const uint8_t> number) {
// Test for a safe approximation of number literals that are already
// in canonical form: max 15 digits, no leading zeroes, except an
// integer part that is a single zero, and no trailing zeros below
// the decimal point.
int pos = 0;
int length = number.length();
if (number.length() > 15) return false;
if (number[pos] == '0') {
pos++;
} else {
while (pos < length &&
static_cast<unsigned>(number[pos] - '0') <= ('9' - '0')) pos++;
}
if (length == pos) return true;
if (number[pos] != '.') return false;
pos++;
bool invalid_last_digit = true;
while (pos < length) {
uint8_t digit = number[pos] - '0';
if (digit > '9' - '0') return false;
invalid_last_digit = (digit == 0);
pos++;
}
return !invalid_last_digit;
}
uint32_t DuplicateFinder::Hash(Vector<const uint8_t> key, bool is_one_byte) {
// Primitive hash function, almost identical to the one used
// for strings (except that it's seeded by the length and representation).
int length = key.length();
uint32_t hash = (length << 1) | (is_one_byte ? 1 : 0);
for (int i = 0; i < length; i++) {
uint32_t c = key[i];
hash = (hash + c) * 1025;
hash ^= (hash >> 6);
}
return hash;
}
bool DuplicateFinder::Match(void* first, void* second) {
// Decode lengths.
// Length + representation is encoded as base 128, most significant heptet
// first, with a 8th bit being non-zero while there are more heptets.
// The value encodes the number of bytes following, and whether the original
// was Latin1.
byte* s1 = reinterpret_cast<byte*>(first);
byte* s2 = reinterpret_cast<byte*>(second);
uint32_t length_one_byte_field = 0;
byte c1;
do {
c1 = *s1;
if (c1 != *s2) return false;
length_one_byte_field = (length_one_byte_field << 7) | (c1 & 0x7f);
s1++;
s2++;
} while ((c1 & 0x80) != 0);
int length = static_cast<int>(length_one_byte_field >> 1);
return memcmp(s1, s2, length) == 0;
}
byte* DuplicateFinder::BackupKey(Vector<const uint8_t> bytes,
bool is_one_byte) {
uint32_t one_byte_length = (bytes.length() << 1) | (is_one_byte ? 1 : 0);
backing_store_.StartSequence();
// Emit one_byte_length as base-128 encoded number, with the 7th bit set
// on the byte of every heptet except the last, least significant, one.
if (one_byte_length >= (1 << 7)) {
if (one_byte_length >= (1 << 14)) {
if (one_byte_length >= (1 << 21)) {
if (one_byte_length >= (1 << 28)) {
backing_store_.Add(
static_cast<uint8_t>((one_byte_length >> 28) | 0x80));
}
backing_store_.Add(
static_cast<uint8_t>((one_byte_length >> 21) | 0x80u));
}
backing_store_.Add(
static_cast<uint8_t>((one_byte_length >> 14) | 0x80u));
}
backing_store_.Add(static_cast<uint8_t>((one_byte_length >> 7) | 0x80u));
}
backing_store_.Add(static_cast<uint8_t>(one_byte_length & 0x7f));
backing_store_.AddBlock(bytes);
return backing_store_.EndSequence().start();
}
} // namespace internal
} // namespace v8