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Commit cf0d7455 authored by lrn@chromium.org's avatar lrn@chromium.org
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Remove unnecessary buffer doubling and content copying. 

Review URL: http://codereview.chromium.org/377006


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3246 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
parent be8e9c0b
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Showing with 235 additions and 198 deletions
src/scanner.cc
View file @ cf0d7455
......@@ -42,35 +42,27 @@ unibrow::Predicate<IdentifierPart, 128> Scanner::kIsIdentifierPart;
unibrow::Predicate<unibrow::LineTerminator, 128> Scanner::kIsLineTerminator;
unibrow::Predicate<unibrow::WhiteSpace, 128> Scanner::kIsWhiteSpace;
StaticResource<Scanner::Utf8Decoder> Scanner::utf8_decoder_;
// ----------------------------------------------------------------------------
// UTF8Buffer
UTF8Buffer::UTF8Buffer() {
static const int kInitialCapacity = 1 * KB;
data_ = NewArray<char>(kInitialCapacity);
limit_ = ComputeLimit(data_, kInitialCapacity);
Reset();
ASSERT(Capacity() == kInitialCapacity && pos() == 0);
UTF8Buffer::UTF8Buffer() :
data_(NULL), limit_(NULL) {
}
UTF8Buffer::~UTF8Buffer() {
DeleteArray(data_);
}
void UTF8Buffer::AddCharSlow(uc32 c) {
static const int kCapacityGrowthLimit = 1 * MB;
if (cursor_ > limit_) {
int old_capacity = Capacity();
int old_position = pos();
int new_capacity =
Min(old_capacity * 2, old_capacity + kCapacityGrowthLimit);
char* new_data = NewArray<char>(new_capacity);
int new_capacity = Min(old_capacity * 3, old_capacity
+ kCapacityGrowthLimit);
char* new_data = NewArray<char> (new_capacity);
memcpy(new_data, data_, old_position);
DeleteArray(data_);
data_ = new_data;
......@@ -78,32 +70,30 @@ void UTF8Buffer::AddCharSlow(uc32 c) {
limit_ = ComputeLimit(new_data, new_capacity);
ASSERT(Capacity() == new_capacity && pos() == old_position);
}
if (static_cast<unsigned>(c) <= unibrow::Utf8::kMaxOneByteChar) {
*cursor_++ = c; // Common case: 7-bit ASCII.
if (static_cast<unsigned> (c) <= unibrow::Utf8::kMaxOneByteChar) {
*cursor_++ = c; // Common case: 7-bit ASCII.
} else {
cursor_ += unibrow::Utf8::Encode(cursor_, c);
}
ASSERT(pos() <= Capacity());
}
// ----------------------------------------------------------------------------
// UTF16Buffer
UTF16Buffer::UTF16Buffer()
: pos_(0), size_(0) { }
UTF16Buffer::UTF16Buffer() :
pos_(0), size_(0) {
}
Handle<String> UTF16Buffer::SubString(int start, int end) {
return internal::SubString(data_, start, end);
}
// CharacterStreamUTF16Buffer
CharacterStreamUTF16Buffer::CharacterStreamUTF16Buffer()
: pushback_buffer_(0), last_(0), stream_(NULL) { }
CharacterStreamUTF16Buffer::CharacterStreamUTF16Buffer() :
pushback_buffer_(0), last_(0), stream_(NULL) {
}
void CharacterStreamUTF16Buffer::Initialize(Handle<String> data,
unibrow::CharacterStream* input) {
......@@ -112,14 +102,12 @@ void CharacterStreamUTF16Buffer::Initialize(Handle<String> data,
stream_ = input;
}
void CharacterStreamUTF16Buffer::PushBack(uc32 ch) {
pushback_buffer()->Add(last_);
last_ = ch;
pos_--;
}
uc32 CharacterStreamUTF16Buffer::Advance() {
// NOTE: It is of importance to Persian / Farsi resources that we do
// *not* strip format control characters in the scanner; see
......@@ -140,25 +128,22 @@ uc32 CharacterStreamUTF16Buffer::Advance() {
// Note: currently the following increment is necessary to avoid a
// test-parser problem!
pos_++;
return last_ = static_cast<uc32>(-1);
return last_ = static_cast<uc32> (-1);
}
}
void CharacterStreamUTF16Buffer::SeekForward(int pos) {
pos_ = pos;
ASSERT(pushback_buffer()->is_empty());
stream_->Seek(pos);
}
// TwoByteStringUTF16Buffer
TwoByteStringUTF16Buffer::TwoByteStringUTF16Buffer()
: raw_data_(NULL) { }
TwoByteStringUTF16Buffer::TwoByteStringUTF16Buffer() :
raw_data_(NULL) {
}
void TwoByteStringUTF16Buffer::Initialize(
Handle<ExternalTwoByteString> data) {
void TwoByteStringUTF16Buffer::Initialize(Handle<ExternalTwoByteString> data) {
ASSERT(!data.is_null());
data_ = data;
......@@ -168,7 +153,6 @@ void TwoByteStringUTF16Buffer::Initialize(
size_ = data->length();
}
uc32 TwoByteStringUTF16Buffer::Advance() {
if (pos_ < size_) {
return raw_data_[pos_++];
......@@ -176,50 +160,35 @@ uc32 TwoByteStringUTF16Buffer::Advance() {
// note: currently the following increment is necessary to avoid a
// test-parser problem!
pos_++;
return static_cast<uc32>(-1);
return static_cast<uc32> (-1);
}
}
void TwoByteStringUTF16Buffer::PushBack(uc32 ch) {
pos_--;
ASSERT(pos_ >= Scanner::kCharacterLookaheadBufferSize);
ASSERT(raw_data_[pos_ - Scanner::kCharacterLookaheadBufferSize] == ch);
}
void TwoByteStringUTF16Buffer::SeekForward(int pos) {
pos_ = pos;
}
// ----------------------------------------------------------------------------
// Keyword Matcher
KeywordMatcher::FirstState KeywordMatcher::first_states_[] = {
{ "break", KEYWORD_PREFIX, Token::BREAK },
{ NULL, C, Token::ILLEGAL },
{ NULL, D, Token::ILLEGAL },
{ "else", KEYWORD_PREFIX, Token::ELSE },
{ NULL, F, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, I, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, N, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ "return", KEYWORD_PREFIX, Token::RETURN },
{ "switch", KEYWORD_PREFIX, Token::SWITCH },
{ NULL, T, Token::ILLEGAL },
{ NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, V, Token::ILLEGAL },
{ NULL, W, Token::ILLEGAL }
};
KeywordMatcher::FirstState KeywordMatcher::first_states_[] = { { "break",
KEYWORD_PREFIX, Token::BREAK }, { NULL, C, Token::ILLEGAL }, { NULL, D,
Token::ILLEGAL }, { "else", KEYWORD_PREFIX, Token::ELSE }, { NULL, F,
Token::ILLEGAL }, { NULL, UNMATCHABLE, Token::ILLEGAL }, { NULL,
UNMATCHABLE, Token::ILLEGAL }, { NULL, I, Token::ILLEGAL }, { NULL,
UNMATCHABLE, Token::ILLEGAL }, { NULL, UNMATCHABLE, Token::ILLEGAL }, {
NULL, UNMATCHABLE, Token::ILLEGAL }, { NULL, UNMATCHABLE, Token::ILLEGAL },
{ NULL, N, Token::ILLEGAL }, { NULL, UNMATCHABLE, Token::ILLEGAL }, { NULL,
UNMATCHABLE, Token::ILLEGAL }, { NULL, UNMATCHABLE, Token::ILLEGAL }, {
"return", KEYWORD_PREFIX, Token::RETURN }, { "switch", KEYWORD_PREFIX,
Token::SWITCH }, { NULL, T, Token::ILLEGAL }, { NULL, UNMATCHABLE,
Token::ILLEGAL }, { NULL, V, Token::ILLEGAL }, { NULL, W,
Token::ILLEGAL } };
void KeywordMatcher::Step(uc32 input) {
switch (state_) {
......@@ -253,38 +222,56 @@ void KeywordMatcher::Step(uc32 input) {
token_ = Token::IDENTIFIER;
break;
case C:
if (MatchState(input, 'a', CA)) return;
if (MatchState(input, 'o', CO)) return;
if (MatchState(input, 'a', CA))
return;
if (MatchState(input, 'o', CO))
return;
break;
case CA:
if (MatchKeywordStart(input, "case", 2, Token::CASE)) return;
if (MatchKeywordStart(input, "catch", 2, Token::CATCH)) return;
if (MatchKeywordStart(input, "case", 2, Token::CASE))
return;
if (MatchKeywordStart(input, "catch", 2, Token::CATCH))
return;
break;
case CO:
if (MatchState(input, 'n', CON)) return;
if (MatchState(input, 'n', CON))
return;
break;
case CON:
if (MatchKeywordStart(input, "const", 3, Token::CONST)) return;
if (MatchKeywordStart(input, "continue", 3, Token::CONTINUE)) return;
if (MatchKeywordStart(input, "const", 3, Token::CONST))
return;
if (MatchKeywordStart(input, "continue", 3, Token::CONTINUE))
return;
break;
case D:
if (MatchState(input, 'e', DE)) return;
if (MatchKeyword(input, 'o', KEYWORD_MATCHED, Token::DO)) return;
if (MatchState(input, 'e', DE))
return;
if (MatchKeyword(input, 'o', KEYWORD_MATCHED, Token::DO))
return;
break;
case DE:
if (MatchKeywordStart(input, "debugger", 2, Token::DEBUGGER)) return;
if (MatchKeywordStart(input, "default", 2, Token::DEFAULT)) return;
if (MatchKeywordStart(input, "delete", 2, Token::DELETE)) return;
if (MatchKeywordStart(input, "debugger", 2, Token::DEBUGGER))
return;
if (MatchKeywordStart(input, "default", 2, Token::DEFAULT))
return;
if (MatchKeywordStart(input, "delete", 2, Token::DELETE))
return;
break;
case F:
if (MatchKeywordStart(input, "false", 1, Token::FALSE_LITERAL)) return;
if (MatchKeywordStart(input, "finally", 1, Token::FINALLY)) return;
if (MatchKeywordStart(input, "for", 1, Token::FOR)) return;
if (MatchKeywordStart(input, "function", 1, Token::FUNCTION)) return;
if (MatchKeywordStart(input, "false", 1, Token::FALSE_LITERAL))
return;
if (MatchKeywordStart(input, "finally", 1, Token::FINALLY))
return;
if (MatchKeywordStart(input, "for", 1, Token::FOR))
return;
if (MatchKeywordStart(input, "function", 1, Token::FUNCTION))
return;
break;
case I:
if (MatchKeyword(input, 'f', KEYWORD_MATCHED, Token::IF)) return;
if (MatchKeyword(input, 'n', IN, Token::IN)) return;
if (MatchKeyword(input, 'f', KEYWORD_MATCHED, Token::IF))
return;
if (MatchKeyword(input, 'n', IN, Token::IN))
return;
break;
case IN:
token_ = Token::IDENTIFIER;
......@@ -293,30 +280,44 @@ void KeywordMatcher::Step(uc32 input) {
}
break;
case N:
if (MatchKeywordStart(input, "native", 1, Token::NATIVE)) return;
if (MatchKeywordStart(input, "new", 1, Token::NEW)) return;
if (MatchKeywordStart(input, "null", 1, Token::NULL_LITERAL)) return;
if (MatchKeywordStart(input, "native", 1, Token::NATIVE))
return;
if (MatchKeywordStart(input, "new", 1, Token::NEW))
return;
if (MatchKeywordStart(input, "null", 1, Token::NULL_LITERAL))
return;
break;
case T:
if (MatchState(input, 'h', TH)) return;
if (MatchState(input, 'r', TR)) return;
if (MatchKeywordStart(input, "typeof", 1, Token::TYPEOF)) return;
if (MatchState(input, 'h', TH))
return;
if (MatchState(input, 'r', TR))
return;
if (MatchKeywordStart(input, "typeof", 1, Token::TYPEOF))
return;
break;
case TH:
if (MatchKeywordStart(input, "this", 2, Token::THIS)) return;
if (MatchKeywordStart(input, "throw", 2, Token::THROW)) return;
if (MatchKeywordStart(input, "this", 2, Token::THIS))
return;
if (MatchKeywordStart(input, "throw", 2, Token::THROW))
return;
break;
case TR:
if (MatchKeywordStart(input, "true", 2, Token::TRUE_LITERAL)) return;
if (MatchKeyword(input, 'y', KEYWORD_MATCHED, Token::TRY)) return;
if (MatchKeywordStart(input, "true", 2, Token::TRUE_LITERAL))
return;
if (MatchKeyword(input, 'y', KEYWORD_MATCHED, Token::TRY))
return;
break;
case V:
if (MatchKeywordStart(input, "var", 1, Token::VAR)) return;
if (MatchKeywordStart(input, "void", 1, Token::VOID)) return;
if (MatchKeywordStart(input, "var", 1, Token::VAR))
return;
if (MatchKeywordStart(input, "void", 1, Token::VOID))
return;
break;
case W:
if (MatchKeywordStart(input, "while", 1, Token::WHILE)) return;
if (MatchKeywordStart(input, "with", 1, Token::WITH)) return;
if (MatchKeywordStart(input, "while", 1, Token::WHILE))
return;
if (MatchKeywordStart(input, "with", 1, Token::WITH))
return;
break;
default:
UNREACHABLE();
......@@ -325,19 +326,20 @@ void KeywordMatcher::Step(uc32 input) {
state_ = UNMATCHABLE;
}
// ----------------------------------------------------------------------------
// Scanner
Scanner::Scanner(bool pre) : stack_overflow_(false), is_pre_parsing_(pre) { }
Scanner::Scanner(bool pre) :
stack_overflow_(false), is_pre_parsing_(pre) {
}
void Scanner::Init(Handle<String> source, unibrow::CharacterStream* stream,
int position) {
int position) {
// Initialize the source buffer.
if (!source.is_null() && StringShape(*source).IsExternalTwoByte()) {
two_byte_string_buffer_.Initialize(
Handle<ExternalTwoByteString>::cast(source));
Handle<ExternalTwoByteString>::cast(
source));
source_ = &two_byte_string_buffer_;
} else {
char_stream_buffer_.Initialize(source, stream);
......@@ -346,9 +348,6 @@ void Scanner::Init(Handle<String> source, unibrow::CharacterStream* stream,
position_ = position;
// Reset literals buffer
literals_.Reset();
// Set c0_ (one character ahead)
ASSERT(kCharacterLookaheadBufferSize == 1);
Advance();
......@@ -360,12 +359,10 @@ void Scanner::Init(Handle<String> source, unibrow::CharacterStream* stream,
Scan();
}
Handle<String> Scanner::SubString(int start, int end) {
return source_->SubString(start - position_, end - position_);
}
Token::Value Scanner::Next() {
// BUG 1215673: Find a thread safe way to set a stack limit in
// pre-parse mode. Otherwise, we cannot safely pre-parse from other
......@@ -376,35 +373,37 @@ Token::Value Scanner::Next() {
if (check.HasOverflowed()) {
stack_overflow_ = true;
next_.token = Token::ILLEGAL;
next_.literal_buffer = NULL;
} else {
Scan();
}
return current_.token;
}
void Scanner::StartLiteral() {
next_.literal_pos = literals_.pos();
// Use the first buffer unless it's currently in use by the current_ token.
// In most cases we won't have two literals/identifiers in a row, so
// the second buffer won't be used very often and is unlikely to grow much.
UTF8Buffer* free_buffer =
(current_.literal_buffer != &literal_buffer_1_) ? &literal_buffer_1_
: &literal_buffer_2_;
next_.literal_buffer = free_buffer;
free_buffer->Reset();
}
void Scanner::AddChar(uc32 c) {
literals_.AddChar(c);
next_.literal_buffer->AddChar(c);
}
void Scanner::TerminateLiteral() {
next_.literal_end = literals_.pos();
AddChar(0);
}
void Scanner::AddCharAdvance() {
AddChar(c0_);
Advance();
}
static inline bool IsByteOrderMark(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
......@@ -416,7 +415,6 @@ static inline bool IsByteOrderMark(uc32 c) {
return c == 0xFEFF || c == 0xFFFE;
}
bool Scanner::SkipWhiteSpace() {
int start_position = source_pos();
......@@ -447,16 +445,15 @@ bool Scanner::SkipWhiteSpace() {
// Continue skipping white space after the comment.
continue;
}
PushBack('-'); // undo Advance()
PushBack('-'); // undo Advance()
}
PushBack('-'); // undo Advance()
PushBack('-'); // undo Advance()
}
// Return whether or not we skipped any characters.
return source_pos() != start_position;
}
}
Token::Value Scanner::SkipSingleLineComment() {
Advance();
......@@ -472,7 +469,6 @@ Token::Value Scanner::SkipSingleLineComment() {
return Token::WHITESPACE;
}
Token::Value Scanner::SkipMultiLineComment() {
ASSERT(c0_ == '*');
Advance();
......@@ -497,22 +493,21 @@ Token::Value Scanner::SkipMultiLineComment() {
return Token::ILLEGAL;
}
Token::Value Scanner::ScanHtmlComment() {
// Check for <!-- comments.
ASSERT(c0_ == '!');
Advance();
if (c0_ == '-') {
Advance();
if (c0_ == '-') return SkipSingleLineComment();
PushBack('-'); // undo Advance()
if (c0_ == '-')
return SkipSingleLineComment();
PushBack('-'); // undo Advance()
}
PushBack('!'); // undo Advance()
PushBack('!'); // undo Advance()
ASSERT(c0_ == '!');
return Token::LT;
}
void Scanner::Scan() {
Token::Value token;
has_line_terminator_before_next_ = false;
......@@ -533,7 +528,8 @@ void Scanner::Scan() {
token = Token::WHITESPACE;
break;
case '"': case '\'':
case '"':
case '\'':
token = ScanString();
break;
......@@ -752,16 +748,14 @@ void Scanner::Scan() {
next_.token = token;
}
void Scanner::SeekForward(int pos) {
source_->SeekForward(pos - 1);
Advance();
Scan();
}
uc32 Scanner::ScanHexEscape(uc32 c, int length) {
ASSERT(length <= 4); // prevent overflow
ASSERT(length <= 4); // prevent overflow
uc32 digits[4];
uc32 x = 0;
......@@ -774,7 +768,7 @@ uc32 Scanner::ScanHexEscape(uc32 c, int length) {
// non-escaped version of the original character.
// Push back digits read, except the last one (in c0_).
for (int j = i-1; j >= 0; j--) {
for (int j = i - 1; j >= 0; j--) {
PushBack(digits[j]);
}
// Notice: No handling of error - treat it as "\u"->"u".
......@@ -787,23 +781,23 @@ uc32 Scanner::ScanHexEscape(uc32 c, int length) {
return x;
}
// Octal escapes of the forms '\0xx' and '\xxx' are not a part of
// ECMA-262. Other JS VMs support them.
uc32 Scanner::ScanOctalEscape(uc32 c, int length) {
uc32 x = c - '0';
for (int i = 0; i < length; i++) {
int d = c0_ - '0';
if (d < 0 || d > 7) break;
if (d < 0 || d > 7)
break;
int nx = x * 8 + d;
if (nx >= 256) break;
if (nx >= 256)
break;
x = nx;
Advance();
}
return x;
}
void Scanner::ScanEscape() {
uc32 c = c0_;
Advance();
......@@ -811,32 +805,53 @@ void Scanner::ScanEscape() {
// Skip escaped newlines.
if (kIsLineTerminator.get(c)) {
// Allow CR+LF newlines in multiline string literals.
if (IsCarriageReturn(c) && IsLineFeed(c0_)) Advance();
if (IsCarriageReturn(c) && IsLineFeed(c0_))
Advance();
// Allow LF+CR newlines in multiline string literals.
if (IsLineFeed(c) && IsCarriageReturn(c0_)) Advance();
if (IsLineFeed(c) && IsCarriageReturn(c0_))
Advance();
return;
}
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 = ScanHexEscape(c, 4); break;
case 'v' : c = '\v'; break;
case 'x' : c = ScanHexEscape(c, 2); 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(c, 2); break;
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 = ScanHexEscape(c, 4);
break;
case 'v':
c = '\v';
break;
case 'x':
c = ScanHexEscape(c, 2);
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(c, 2);
break;
}
// According to ECMA-262, 3rd, 7.8.4 (p 18ff) these
......@@ -845,17 +860,17 @@ void Scanner::ScanEscape() {
AddChar(c);
}
Token::Value Scanner::ScanString() {
uc32 quote = c0_;
Advance(); // consume quote
Advance(); // consume quote
StartLiteral();
while (c0_ != quote && c0_ >= 0 && !kIsLineTerminator.get(c0_)) {
uc32 c = c0_;
Advance();
if (c == '\\') {
if (c0_ < 0) return Token::ILLEGAL;
if (c0_ < 0)
return Token::ILLEGAL;
ScanEscape();
} else {
AddChar(c);
......@@ -866,17 +881,15 @@ Token::Value Scanner::ScanString() {
}
TerminateLiteral();
Advance(); // consume quote
Advance(); // consume quote
return Token::STRING;
}
Token::Value Scanner::Select(Token::Value tok) {
Advance();
return tok;
}
Token::Value Scanner::Select(uc32 next, Token::Value then, Token::Value else_) {
Advance();
if (c0_ == next) {
......@@ -887,24 +900,24 @@ Token::Value Scanner::Select(uc32 next, Token::Value then, Token::Value else_) {
}
}
// Returns true if any decimal digits were scanned, returns false otherwise.
void Scanner::ScanDecimalDigits() {
while (IsDecimalDigit(c0_))
AddCharAdvance();
}
Token::Value Scanner::ScanNumber(bool seen_period) {
ASSERT(IsDecimalDigit(c0_)); // the first digit of the number or the fraction
ASSERT(IsDecimalDigit(c0_)); // the first digit of the number or the fraction
enum { DECIMAL, HEX, OCTAL } kind = DECIMAL;
enum {
DECIMAL, HEX, OCTAL
} kind = DECIMAL;
StartLiteral();
if (seen_period) {
// we have already seen a decimal point of the float
AddChar('.');
ScanDecimalDigits(); // we know we have at least one digit
ScanDecimalDigits(); // we know we have at least one digit
} else {
// if the first character is '0' we must check for octals and hex
......@@ -930,7 +943,8 @@ Token::Value Scanner::ScanNumber(bool seen_period) {
kind = DECIMAL;
break;
}
if (c0_ < '0' || '7' < c0_) break;
if (c0_ < '0' || '7' < c0_)
break;
AddCharAdvance();
}
}
......@@ -938,18 +952,19 @@ Token::Value Scanner::ScanNumber(bool seen_period) {
// Parse decimal digits and allow trailing fractional part.
if (kind == DECIMAL) {
ScanDecimalDigits(); // optional
ScanDecimalDigits(); // optional
if (c0_ == '.') {
AddCharAdvance();
ScanDecimalDigits(); // optional
ScanDecimalDigits(); // optional
}
}
}
// scan exponent, if any
if (c0_ == 'e' || c0_ == 'E') {
ASSERT(kind != HEX); // 'e'/'E' must be scanned as part of the hex number
if (kind == OCTAL) return Token::ILLEGAL; // no exponent for octals allowed
ASSERT(kind != HEX); // 'e'/'E' must be scanned as part of the hex number
if (kind == OCTAL)
return Token::ILLEGAL; // no exponent for octals allowed
// scan exponent
AddCharAdvance();
if (c0_ == '+' || c0_ == '-')
......@@ -971,19 +986,19 @@ Token::Value Scanner::ScanNumber(bool seen_period) {
return Token::NUMBER;
}
uc32 Scanner::ScanIdentifierUnicodeEscape() {
Advance();
if (c0_ != 'u') return unibrow::Utf8::kBadChar;
if (c0_ != 'u')
return unibrow::Utf8::kBadChar;
Advance();
uc32 c = ScanHexEscape('u', 4);
// We do not allow a unicode escape sequence to start another
// unicode escape sequence.
if (c == '\\') return unibrow::Utf8::kBadChar;
if (c == '\\')
return unibrow::Utf8::kBadChar;
return c;
}
Token::Value Scanner::ScanIdentifier() {
ASSERT(kIsIdentifierStart.get(c0_));
......@@ -994,7 +1009,8 @@ Token::Value Scanner::ScanIdentifier() {
if (c0_ == '\\') {
uc32 c = ScanIdentifierUnicodeEscape();
// Only allow legal identifier start characters.
if (!kIsIdentifierStart.get(c)) return Token::ILLEGAL;
if (!kIsIdentifierStart.get(c))
return Token::ILLEGAL;
AddChar(c);
keyword_match.Fail();
} else {
......@@ -1008,7 +1024,8 @@ Token::Value Scanner::ScanIdentifier() {
if (c0_ == '\\') {
uc32 c = ScanIdentifierUnicodeEscape();
// Only allow legal identifier part characters.
if (!kIsIdentifierPart.get(c)) return Token::ILLEGAL;
if (!kIsIdentifierPart.get(c))
return Token::ILLEGAL;
AddChar(c);
keyword_match.Fail();
} else {
......@@ -1022,19 +1039,19 @@ Token::Value Scanner::ScanIdentifier() {
return keyword_match.token();
}
bool Scanner::IsIdentifier(unibrow::CharacterStream* buffer) {
// Checks whether the buffer contains an identifier (no escape).
if (!buffer->has_more()) return false;
if (!kIsIdentifierStart.get(buffer->GetNext())) return false;
if (!buffer->has_more())
return false;
if (!kIsIdentifierStart.get(buffer->GetNext()))
return false;
while (buffer->has_more()) {
if (!kIsIdentifierPart.get(buffer->GetNext())) return false;
if (!kIsIdentifierPart.get(buffer->GetNext()))
return false;
}
return true;
}
bool Scanner::ScanRegExpPattern(bool seen_equal) {
// Scan: ('/' | '/=') RegularExpressionBody '/' RegularExpressionFlags
bool in_character_class = false;
......@@ -1054,12 +1071,12 @@ bool Scanner::ScanRegExpPattern(bool seen_equal) {
while (c0_ != '/' || in_character_class) {
if (kIsLineTerminator.get(c0_) || c0_ < 0)
return false;
if (c0_ == '\\') { // escaped character
if (c0_ == '\\') { // escaped character
AddCharAdvance();
if (kIsLineTerminator.get(c0_) || c0_ < 0)
return false;
AddCharAdvance();
} else { // unescaped character
} else { // unescaped character
if (c0_ == '[')
in_character_class = true;
if (c0_ == ']')
......@@ -1067,7 +1084,7 @@ bool Scanner::ScanRegExpPattern(bool seen_equal) {
AddCharAdvance();
}
}
Advance(); // consume '/'
Advance(); // consume '/'
TerminateLiteral();
......@@ -1080,7 +1097,7 @@ bool Scanner::ScanRegExpFlags() {
while (kIsIdentifierPart.get(c0_)) {
if (c0_ == '\\') {
uc32 c = ScanIdentifierUnicodeEscape();
if (c != static_cast<uc32>(unibrow::Utf8::kBadChar)) {
if (c != static_cast<uc32> (unibrow::Utf8::kBadChar)) {
// We allow any escaped character, unlike the restriction on
// IdentifierPart when it is used to build an IdentifierName.
AddChar(c);
......@@ -1095,4 +1112,5 @@ bool Scanner::ScanRegExpFlags() {
return true;
}
} } // namespace v8::internal
}
} // namespace v8::internal
src/scanner.h
View file @ cf0d7455
......@@ -41,6 +41,7 @@ class UTF8Buffer {
~UTF8Buffer();
void AddChar(uc32 c) {
ASSERT_NOT_NULL(data_);
if (cursor_ <= limit_ &&
static_cast<unsigned>(c) <= unibrow::Utf8::kMaxOneByteChar) {
*cursor_++ = static_cast<char>(c);
......@@ -49,16 +50,29 @@ class UTF8Buffer {
}
}
void Reset() { cursor_ = data_; }
int pos() const { return cursor_ - data_; }
void Reset() {
if (data_ == NULL) {
data_ = NewArray<char>(kInitialCapacity);
limit_ = ComputeLimit(data_, kInitialCapacity);
}
cursor_ = data_;
}
int pos() const {
ASSERT_NOT_NULL(data_);
return cursor_ - data_;
}
char* data() const { return data_; }
private:
static const int kInitialCapacity = 256;
char* data_;
char* cursor_;
char* limit_;
int Capacity() const {
ASSERT_NOT_NULL(data_);
return (limit_ - data_) + unibrow::Utf8::kMaxEncodedSize;
}
......@@ -278,26 +292,30 @@ class Scanner {
// token returned by Next()). The string is 0-terminated and in
// UTF-8 format; they may contain 0-characters. Literal strings are
// collected for identifiers, strings, and numbers.
// These functions only give the correct result if the literal
// was scanned between calls to StartLiteral() and TerminateLiteral().
const char* literal_string() const {
return &literals_.data()[current_.literal_pos];
return current_.literal_buffer->data();
}
int literal_length() const {
return current_.literal_end - current_.literal_pos;
}
Vector<const char> next_literal() const {
return Vector<const char>(next_literal_string(), next_literal_length());
// Excluding terminal '\0' added by TerminateLiteral().
return current_.literal_buffer->pos() - 1;
}
// Returns the literal string for the next token (the token that
// would be returned if Next() were called).
const char* next_literal_string() const {
return &literals_.data()[next_.literal_pos];
return next_.literal_buffer->data();
}
// Returns the length of the next token (that would be returned if
// Next() were called).
int next_literal_length() const {
return next_.literal_end - next_.literal_pos;
return next_.literal_buffer->pos() - 1;
}
Vector<const char> next_literal() const {
return Vector<const char>(next_literal_string(),
next_literal_length());
}
// Scans the input as a regular expression pattern, previous
......@@ -339,7 +357,8 @@ class Scanner {
// Buffer to hold literal values (identifiers, strings, numbers)
// using 0-terminated UTF-8 encoding.
UTF8Buffer literals_;
UTF8Buffer literal_buffer_1_;
UTF8Buffer literal_buffer_2_;
bool stack_overflow_;
static StaticResource<Utf8Decoder> utf8_decoder_;
......@@ -351,7 +370,7 @@ class Scanner {
struct TokenDesc {
Token::Value token;
Location location;
int literal_pos, literal_end;
UTF8Buffer* literal_buffer;
};
TokenDesc current_; // desc for current token (as returned by Next())
......
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