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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.
#include "src/parsing/scanner.h"
#include <stdint.h>
#include <cmath>
#include "src/ast/ast-value-factory.h"
#include "src/conversions-inl.h"
#include "src/objects/bigint.h"
#include "src/parsing/scanner-inl.h"
#include "src/zone/zone.h"
namespace v8 {
namespace internal {
class Scanner::ErrorState {
public:
ErrorState(MessageTemplate* 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_ = Location::invalid();
}
~ErrorState() {
*message_stack_ = old_message_;
*location_stack_ = old_location_;
}
void MoveErrorTo(TokenDesc* dest) {
if (*message_stack_ == MessageTemplate::kNone) {
return;
}
if (dest->invalid_template_escape_message == MessageTemplate::kNone) {
dest->invalid_template_escape_message = *message_stack_;
dest->invalid_template_escape_location = *location_stack_;
}
*message_stack_ = MessageTemplate::kNone;
*location_stack_ = Location::invalid();
}
private:
MessageTemplate* const message_stack_;
MessageTemplate const old_message_;
Scanner::Location* const location_stack_;
Scanner::Location const old_location_;
};
// ----------------------------------------------------------------------------
// Scanner::BookmarkScope
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(size_t position) {
DCHECK_EQ(bookmark_, kNoBookmark);
bookmark_ = position;
}
void Scanner::BookmarkScope::Apply() {
DCHECK(HasBeenSet()); // Caller hasn't called SetBookmark.
if (had_parser_error_) {
scanner_->set_parser_error();
} else {
scanner_->reset_parser_error_flag();
scanner_->SeekNext(bookmark_);
}
bookmark_ = kBookmarkWasApplied;
}
bool Scanner::BookmarkScope::HasBeenSet() const {
return bookmark_ != kNoBookmark && bookmark_ != kBookmarkWasApplied;
}
bool Scanner::BookmarkScope::HasBeenApplied() const {
return bookmark_ == kBookmarkWasApplied;
}
// ----------------------------------------------------------------------------
// Scanner
Scanner::Scanner(Utf16CharacterStream* source, bool is_module)
: source_(source),
found_html_comment_(false),
allow_harmony_numeric_separator_(false),
is_module_(is_module),
octal_pos_(Location::invalid()),
octal_message_(MessageTemplate::kNone) {
DCHECK_NOT_NULL(source);
}
void Scanner::Initialize() {
// Need to capture identifiers in order to recognize "get" and "set"
// in object literals.
Init();
next().after_line_terminator = true;
Scan();
}
template <bool capture_raw, bool unicode>
uc32 Scanner::ScanHexNumber(int expected_length) {
DCHECK_LE(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;
}
Token::Value Scanner::Next() {
// Rotate through tokens.
TokenDesc* previous = current_;
current_ = next_;
// Either we already have the next token lined up, in which case next_next_
// simply becomes next_. In that case we use current_ as new next_next_ and
// clear its token to indicate that it wasn't scanned yet. Otherwise we use
// current_ as next_ and scan into it, leaving next_next_ uninitialized.
if (V8_LIKELY(next_next().token == Token::UNINITIALIZED)) {
next_ = previous;
// User 'previous' instead of 'next_' because for some reason the compiler
// thinks 'next_' could be modified before the entry into Scan.
previous->after_line_terminator = false;
Scan(previous);
} else {
next_ = next_next_;
next_next_ = previous;
previous->token = Token::UNINITIALIZED;
DCHECK_NE(Token::UNINITIALIZED, current().token);
}
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* temp = next_;
next_ = next_next_;
next().after_line_terminator = false;
Scan();
next_next_ = next_;
next_ = temp;
return next_next().token;
}
Token::Value Scanner::SkipSingleHTMLComment() {
if (is_module_) {
ReportScannerError(source_pos(), MessageTemplate::kHtmlCommentInModule);
return Token::ILLEGAL;
}
return SkipSingleLineComment();
}
Token::Value Scanner::SkipSingleLineComment() {
// 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).
AdvanceUntil([](uc32 c0_) { return unibrow::IsLineTerminator(c0_); });
return Token::WHITESPACE;
}
Token::Value Scanner::SkipSourceURLComment() {
TryToParseSourceURLComment();
if (unibrow::IsLineTerminator(c0_) || c0_ == kEndOfInput) {
return Token::WHITESPACE;
}
return SkipSingleLineComment();
}
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.
DCHECK(!IsWhiteSpaceOrLineTerminator(kEndOfInput));
if (!IsWhiteSpace(c0_)) return;
Advance();
LiteralBuffer name;
name.Start();
while (c0_ != kEndOfInput && !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 == StaticCharVector("sourceURL")) {
value = &source_url_;
} else if (name_literal == StaticCharVector("sourceMappingURL")) {
value = &source_mapping_url_;
} else {
return;
}
if (c0_ != '=')
return;
value->Start();
Advance();
while (IsWhiteSpace(c0_)) {
Advance();
}
while (c0_ != kEndOfInput && !unibrow::IsLineTerminator(c0_)) {
// Disallowed characters.
if (c0_ == '"' || c0_ == '\'') {
value->Start();
return;
}
if (IsWhiteSpace(c0_)) {
break;
}
value->AddChar(c0_);
Advance();
}
// Allow whitespace at the end.
while (c0_ != kEndOfInput && !unibrow::IsLineTerminator(c0_)) {
if (!IsWhiteSpace(c0_)) {
value->Start();
break;
}
Advance();
}
}
Token::Value Scanner::SkipMultiLineComment() {
DCHECK_EQ(c0_, '*');
// Until we see the first newline, check for * and newline characters.
if (!next().after_line_terminator) {
do {
AdvanceUntil([](uc32 c0) {
if (V8_UNLIKELY(static_cast<uint32_t>(c0) > kMaxAscii)) {
return unibrow::IsLineTerminator(c0);
}
uint8_t char_flags = character_scan_flags[c0];
return MultilineCommentCharacterNeedsSlowPath(char_flags);
});
while (c0_ == '*') {
Advance();
if (c0_ == '/') {
Advance();
return Token::WHITESPACE;
}
}
if (unibrow::IsLineTerminator(c0_)) {
next().after_line_terminator = true;
break;
}
} while (c0_ != kEndOfInput);
}
// After we've seen newline, simply try to find '*/'.
while (c0_ != kEndOfInput) {
AdvanceUntil([](uc32 c0) { return c0 == '*'; });
while (c0_ == '*') {
Advance();
if (c0_ == '/') {
Advance();
return Token::WHITESPACE;
}
}
}
return Token::ILLEGAL;
}
void Scanner::SkipHashBang() {
if (c0_ == '#' && Peek() == '!' && source_pos() == 0) {
SkipSingleLineComment();
Scan();
}
}
Token::Value Scanner::ScanHtmlComment() {
// Check for <!-- comments.
DCHECK_EQ(c0_, '!');
Advance();
if (c0_ != '-' || Peek() != '-') {
PushBack('!'); // undo Advance()
return Token::LT;
}
Advance();
found_html_comment_ = true;
return SkipSingleHTMLComment();
}
#ifdef DEBUG
void Scanner::SanityCheckTokenDesc(const TokenDesc& token) const {
// Only TEMPLATE_* tokens can have a invalid_template_escape_message.
// ILLEGAL and UNINITIALIZED can have garbage for the field.
switch (token.token) {
case Token::UNINITIALIZED:
case Token::ILLEGAL:
// token.literal_chars & other members might be garbage. That's ok.
case Token::TEMPLATE_SPAN:
case Token::TEMPLATE_TAIL:
break;
default:
DCHECK_EQ(token.invalid_template_escape_message, MessageTemplate::kNone);
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.
next().after_line_terminator = false;
}
Scan();
}
template <bool capture_raw>
bool Scanner::ScanEscape() {
uc32 c = c0_;
Advance<capture_raw>();
// Skip escaped newlines.
DCHECK(!unibrow::IsLineTerminator(kEndOfInput));
if (!capture_raw && unibrow::IsLineTerminator(c)) {
// Allow escaped CR+LF newlines in multiline string literals.
if (IsCarriageReturn(c) && IsLineFeed(c0_)) Advance();
return true;
}
switch (c) {
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 || IsNonOctalDecimalDigit(c0_)) {
octal_pos_ = Location(source_pos() - i - 1, source_pos() - 1);
octal_message_ = capture_raw ? MessageTemplate::kTemplateOctalLiteral
: MessageTemplate::kStrictOctalEscape;
}
return x;
}
Token::Value Scanner::ScanString() {
uc32 quote = c0_;
next().literal_chars.Start();
while (true) {
AdvanceUntil([this](uc32 c0) {
if (V8_UNLIKELY(static_cast<uint32_t>(c0) > kMaxAscii)) {
if (V8_UNLIKELY(unibrow::IsStringLiteralLineTerminator(c0))) {
return true;
}
AddLiteralChar(c0);
return false;
}
uint8_t char_flags = character_scan_flags[c0];
if (MayTerminateString(char_flags)) return true;
AddLiteralChar(c0);
return false;
});
while (c0_ == '\\') {
Advance();
// TODO(verwaest): Check whether we can remove the additional check.
if (V8_UNLIKELY(c0_ == kEndOfInput || !ScanEscape<false>())) {
return Token::ILLEGAL;
}
}
if (c0_ == quote) {
Advance();
return Token::STRING;
}
if (V8_UNLIKELY(c0_ == kEndOfInput ||
unibrow::IsStringLiteralLineTerminator(c0_))) {
return Token::ILLEGAL;
}
AddLiteralChar(c0_);
}
}
Token::Value Scanner::ScanPrivateName() {
next().literal_chars.Start();
DCHECK_EQ(c0_, '#');
DCHECK(!IsIdentifierStart(kEndOfInput));
if (!IsIdentifierStart(Peek())) {
ReportScannerError(source_pos(),
MessageTemplate::kInvalidOrUnexpectedToken);
return Token::ILLEGAL;
}
AddLiteralCharAdvance();
Token::Value token = ScanIdentifierOrKeywordInner();
return token == Token::ILLEGAL ? Token::ILLEGAL : Token::PRIVATE_NAME;
}
Token::Value Scanner::ScanTemplateSpan() {
// When scanning a TemplateSpan, we are looking for the following construct:
// TEMPLATE_SPAN ::
// ` LiteralChars* ${
// | } LiteralChars* ${
//
// TEMPLATE_TAIL ::
// ` LiteralChars* `
// | } LiteralChar* `
//
// A TEMPLATE_SPAN should always be followed by an Expression, while a
// TEMPLATE_TAIL terminates a TemplateLiteral and does not need to be
// followed by an Expression.
// These scoped helpers save and restore the original error state, so that we
// can specially treat invalid escape sequences in templates (which are
// handled by the parser).
ErrorState scanner_error_state(&scanner_error_, &scanner_error_location_);
ErrorState octal_error_state(&octal_message_, &octal_pos_);
Token::Value result = Token::TEMPLATE_SPAN;
next().literal_chars.Start();
next().raw_literal_chars.Start();
const bool capture_raw = true;
while (true) {
uc32 c = c0_;
if (c == '`') {
Advance(); // Consume '`'
result = Token::TEMPLATE_TAIL;
break;
} else if (c == '$' && Peek() == '{') {
Advance(); // Consume '$'
Advance(); // Consume '{'
break;
} else if (c == '\\') {
Advance(); // Consume '\\'
DCHECK(!unibrow::IsLineTerminator(kEndOfInput));
if (capture_raw) AddRawLiteralChar('\\');
if (unibrow::IsLineTerminator(c0_)) {
// The TV of LineContinuation :: \ LineTerminatorSequence is the empty
// code unit sequence.
uc32 lastChar = c0_;
Advance();
if (lastChar == '\r') {
// Also skip \n.
if (c0_ == '\n') Advance();
lastChar = '\n';
}
if (capture_raw) AddRawLiteralChar(lastChar);
} else {
bool success = ScanEscape<capture_raw>();
USE(success);
DCHECK_EQ(!success, has_error());
// For templates, invalid escape sequence checking is handled in the
// parser.
scanner_error_state.MoveErrorTo(next_);
octal_error_state.MoveErrorTo(next_);
}
} else if (c < 0) {
// Unterminated template literal
break;
} else {
Advance(); // Consume c.
// 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') {
if (c0_ == '\n') Advance(); // Consume '\n'
c = '\n';
}
if (capture_raw) AddRawLiteralChar(c);
AddLiteralChar(c);
}
}
next().location.end_pos = source_pos();
next().token = result;
return result;
}
Handle<String> Scanner::SourceUrl(Isolate* isolate) const {
Handle<String> tmp;
if (source_url_.length() > 0) {
tmp = source_url_.Internalize(isolate);
}
return tmp;
}
Handle<String> Scanner::SourceMappingUrl(Isolate* isolate) const {
Handle<String> tmp;
if (source_mapping_url_.length() > 0) {
tmp = source_mapping_url_.Internalize(isolate);
}
return tmp;
}
bool Scanner::ScanDigitsWithNumericSeparators(bool (*predicate)(uc32 ch),
bool is_check_first_digit) {
// we must have at least one digit after 'x'/'b'/'o'
if (is_check_first_digit && !predicate(c0_)) return false;
bool separator_seen = false;
while (predicate(c0_) || c0_ == '_') {
if (c0_ == '_') {
Advance();
if (c0_ == '_') {
ReportScannerError(Location(source_pos(), source_pos() + 1),
MessageTemplate::kContinuousNumericSeparator);
return false;
}
separator_seen = true;
continue;
}
separator_seen = false;
AddLiteralCharAdvance();
}
if (separator_seen) {
ReportScannerError(Location(source_pos(), source_pos() + 1),
MessageTemplate::kTrailingNumericSeparator);
return false;
}
return true;
}
bool Scanner::ScanDecimalDigits() {
if (allow_harmony_numeric_separator()) {
return ScanDigitsWithNumericSeparators(&IsDecimalDigit, false);
}
while (IsDecimalDigit(c0_)) {
AddLiteralCharAdvance();
}
return true;
}
bool Scanner::ScanDecimalAsSmiWithNumericSeparators(uint64_t* value) {
bool separator_seen = false;
while (IsDecimalDigit(c0_) || c0_ == '_') {
if (c0_ == '_') {
Advance();
if (c0_ == '_') {
ReportScannerError(Location(source_pos(), source_pos() + 1),
MessageTemplate::kContinuousNumericSeparator);
return false;
}
separator_seen = true;
continue;
}
separator_seen = false;
*value = 10 * *value + (c0_ - '0');
uc32 first_char = c0_;
Advance();
AddLiteralChar(first_char);
}
if (separator_seen) {
ReportScannerError(Location(source_pos(), source_pos() + 1),
MessageTemplate::kTrailingNumericSeparator);
return false;
}
return true;
}
bool Scanner::ScanDecimalAsSmi(uint64_t* value) {
if (allow_harmony_numeric_separator()) {
return ScanDecimalAsSmiWithNumericSeparators(value);
}
while (IsDecimalDigit(c0_)) {
*value = 10 * *value + (c0_ - '0');
uc32 first_char = c0_;
Advance();
AddLiteralChar(first_char);
}
return true;
}
bool Scanner::ScanBinaryDigits() {
if (allow_harmony_numeric_separator()) {
return ScanDigitsWithNumericSeparators(&IsBinaryDigit, true);
}
// we must have at least one binary digit after 'b'/'B'
if (!IsBinaryDigit(c0_)) {
return false;
}
while (IsBinaryDigit(c0_)) {
AddLiteralCharAdvance();
}
return true;
}
bool Scanner::ScanOctalDigits() {
if (allow_harmony_numeric_separator()) {
return ScanDigitsWithNumericSeparators(&IsOctalDigit, true);
}
// we must have at least one octal digit after 'o'/'O'
if (!IsOctalDigit(c0_)) {
return false;
}
while (IsOctalDigit(c0_)) {
AddLiteralCharAdvance();
}
return true;
}
bool Scanner::ScanImplicitOctalDigits(int start_pos,
Scanner::NumberKind* kind) {
*kind = IMPLICIT_OCTAL;
while (true) {
// (possible) octal number
if (IsNonOctalDecimalDigit(c0_)) {
*kind = DECIMAL_WITH_LEADING_ZERO;
return true;
}
if (!IsOctalDigit(c0_)) {
// Octal literal finished.
octal_pos_ = Location(start_pos, source_pos());
octal_message_ = MessageTemplate::kStrictOctalLiteral;
return true;
}
AddLiteralCharAdvance();
}
}
bool Scanner::ScanHexDigits() {
if (allow_harmony_numeric_separator()) {
return ScanDigitsWithNumericSeparators(&IsHexDigit, true);
}
// we must have at least one hex digit after 'x'/'X'
if (!IsHexDigit(c0_)) {
return false;
}
while (IsHexDigit(c0_)) {
AddLiteralCharAdvance();
}
return true;
}
bool Scanner::ScanSignedInteger() {
if (c0_ == '+' || c0_ == '-') AddLiteralCharAdvance();
// we must have at least one decimal digit after 'e'/'E'
if (!IsDecimalDigit(c0_)) return false;
return ScanDecimalDigits();
}
Token::Value Scanner::ScanNumber(bool seen_period) {
DCHECK(IsDecimalDigit(c0_)); // the first digit of the number or the fraction
NumberKind kind = DECIMAL;
next().literal_chars.Start();
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('.');
if (allow_harmony_numeric_separator() && c0_ == '_') {
return Token::ILLEGAL;
}
// we know we have at least one digit
if (!ScanDecimalDigits()) return Token::ILLEGAL;
} 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 (AsciiAlphaToLower(c0_) == 'x') {
AddLiteralCharAdvance();
kind = HEX;
if (!ScanHexDigits()) return Token::ILLEGAL;
} else if (AsciiAlphaToLower(c0_) == 'o') {
AddLiteralCharAdvance();
kind = OCTAL;
if (!ScanOctalDigits()) return Token::ILLEGAL;
} else if (AsciiAlphaToLower(c0_) == 'b') {
AddLiteralCharAdvance();
kind = BINARY;
if (!ScanBinaryDigits()) return Token::ILLEGAL;
} else if (IsOctalDigit(c0_)) {
kind = IMPLICIT_OCTAL;
if (!ScanImplicitOctalDigits(start_pos, &kind)) {
return Token::ILLEGAL;
}
if (kind == DECIMAL_WITH_LEADING_ZERO) {
at_start = false;
}
} else if (IsNonOctalDecimalDigit(c0_)) {
kind = DECIMAL_WITH_LEADING_ZERO;
} else if (allow_harmony_numeric_separator() && c0_ == '_') {
ReportScannerError(Location(source_pos(), source_pos() + 1),
MessageTemplate::kZeroDigitNumericSeparator);
return Token::ILLEGAL;
}
}
// Parse decimal digits and allow trailing fractional part.
if (IsDecimalNumberKind(kind)) {
// This is an optimization for parsing Decimal numbers as Smi's.
if (at_start) {
uint64_t value = 0;
// scan subsequent decimal digits
if (!ScanDecimalAsSmi(&value)) return Token::ILLEGAL;
if (next().literal_chars.one_byte_literal().length() <= 10 &&
value <= Smi::kMaxValue && c0_ != '.' && !IsIdentifierStart(c0_)) {
next().smi_value_ = static_cast<uint32_t>(value);
if (kind == DECIMAL_WITH_LEADING_ZERO) {
octal_pos_ = Location(start_pos, source_pos());
octal_message_ = MessageTemplate::kStrictDecimalWithLeadingZero;
}
return Token::SMI;
}
}
if (!ScanDecimalDigits()) return Token::ILLEGAL;
if (c0_ == '.') {
seen_period = true;
AddLiteralCharAdvance();
if (allow_harmony_numeric_separator() && c0_ == '_') {
return Token::ILLEGAL;
}
if (!ScanDecimalDigits()) return Token::ILLEGAL;
}
}
}
bool is_bigint = false;
if (c0_ == 'n' && !seen_period && IsValidBigIntKind(kind)) {
// Check that the literal is within our limits for BigInt length.
// For simplicity, use 4 bits per character to calculate the maximum
// allowed literal length.
static const int kMaxBigIntCharacters = BigInt::kMaxLengthBits / 4;
int length = source_pos() - start_pos - (kind != DECIMAL ? 2 : 0);
if (length > kMaxBigIntCharacters) {
ReportScannerError(Location(start_pos, source_pos()),
MessageTemplate::kBigIntTooBig);
return Token::ILLEGAL;
}
is_bigint = true;
Advance();
} else if (AsciiAlphaToLower(c0_) == 'e') {
// scan exponent, if any
DCHECK(kind != HEX); // 'e'/'E' must be scanned as part of the hex number
if (!IsDecimalNumberKind(kind)) return Token::ILLEGAL;
// scan exponent
AddLiteralCharAdvance();
if (!ScanSignedInteger()) return Token::ILLEGAL;
}
// 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_) || IsIdentifierStart(c0_)) {
return Token::ILLEGAL;
}
if (kind == DECIMAL_WITH_LEADING_ZERO) {
octal_pos_ = Location(start_pos, source_pos());
octal_message_ = MessageTemplate::kStrictDecimalWithLeadingZero;
}
return is_bigint ? Token::BIGINT : 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);
}
Token::Value Scanner::ScanIdentifierOrKeywordInnerSlow(bool escaped,
bool can_be_keyword) {
while (true) {
if (c0_ == '\\') {
escaped = true;
uc32 c = ScanIdentifierUnicodeEscape();
// Only allow legal identifier part characters.
// TODO(verwaest): Make this true.
// DCHECK(!IsIdentifierPart('\'));
DCHECK(!IsIdentifierPart(-1));
if (c == '\\' || !IsIdentifierPart(c)) {
return Token::ILLEGAL;
}
can_be_keyword = can_be_keyword && CharCanBeKeyword(c);
AddLiteralChar(c);
} else if (IsIdentifierPart(c0_) ||
(CombineSurrogatePair() && IsIdentifierPart(c0_))) {
can_be_keyword = can_be_keyword && CharCanBeKeyword(c0_);
AddLiteralCharAdvance();
} else {
break;
}
}
if (can_be_keyword && next().literal_chars.is_one_byte()) {
Vector<const uint8_t> chars = next().literal_chars.one_byte_literal();
Token::Value token =
KeywordOrIdentifierToken(chars.begin(), chars.length());
if (IsInRange(token, Token::IDENTIFIER, Token::YIELD)) return token;
if (token == Token::FUTURE_STRICT_RESERVED_WORD) {
if (escaped) return Token::ESCAPED_STRICT_RESERVED_WORD;
return token;
}
if (!escaped) return token;
STATIC_ASSERT(Token::LET + 1 == Token::STATIC);
if (IsInRange(token, Token::LET, Token::STATIC)) {
return Token::ESCAPED_STRICT_RESERVED_WORD;
}
return Token::ESCAPED_KEYWORD;
}
return Token::IDENTIFIER;
}
bool Scanner::ScanRegExpPattern() {
DCHECK_EQ(Token::UNINITIALIZED, next_next().token);
DCHECK(next().token == Token::DIV || next().token == Token::ASSIGN_DIV);
// Scan: ('/' | '/=') RegularExpressionBody '/' RegularExpressionFlags
bool in_character_class = false;
// Scan regular expression body: According to ECMA-262, 3rd, 7.8.5,
// the scanner should pass uninterpreted bodies to the RegExp
// constructor.
next().literal_chars.Start();
if (next().token == Token::ASSIGN_DIV) {
AddLiteralChar('=');
}
while (c0_ != '/' || in_character_class) {
if (c0_ == kEndOfInput || unibrow::IsLineTerminator(c0_)) {
return false;
}
if (c0_ == '\\') { // Escape sequence.
AddLiteralCharAdvance();
if (c0_ == kEndOfInput || unibrow::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 thoroughly 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 '/'
next().token = Token::REGEXP_LITERAL;
return true;
}
Maybe<RegExp::Flags> Scanner::ScanRegExpFlags() {
DCHECK_EQ(Token::REGEXP_LITERAL, next().token);
// Scan regular expression flags.
int flags = 0;
while (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 's':
flag = RegExp::kDotAll;
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) const {
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) const {
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) const {
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(
literal_one_byte_string(),
ALLOW_HEX | ALLOW_OCTAL | ALLOW_IMPLICIT_OCTAL | ALLOW_BINARY);
}
const char* Scanner::CurrentLiteralAsCString(Zone* zone) const {
DCHECK(is_literal_one_byte());
Vector<const uint8_t> vector = literal_one_byte_string();
int length = vector.length();
char* buffer = zone->NewArray<char>(length + 1);
memcpy(buffer, vector.begin(), length);
buffer[length] = '\0';
return buffer;
}
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.)
for (TokenDesc& token : token_storage_) {
token.token = Token::UNINITIALIZED;
token.invalid_template_escape_message = MessageTemplate::kNone;
}
// 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().after_line_terminator = false;
Scan();
DCHECK_EQ(next().location.beg_pos, static_cast<int>(position));
}
} // namespace internal
} // namespace v8