ladybird/Userland/Libraries/LibRegex/RegexParser.cpp
Andreas Kling dc65f54c06 AK: Rename Vector::append(Vector) => Vector::extend(Vector)
Let's make it a bit more clear when we're appending the elements from
one vector to the end of another vector.
2021-06-12 13:24:45 +02:00

1763 lines
61 KiB
C++

/*
* Copyright (c) 2020, Emanuel Sprung <emanuel.sprung@gmail.com>
* Copyright (c) 2020-2021, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "RegexParser.h"
#include "RegexDebug.h"
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/StringUtils.h>
namespace regex {
ALWAYS_INLINE bool Parser::set_error(Error error)
{
if (m_parser_state.error == Error::NoError) {
m_parser_state.error = error;
m_parser_state.error_token = m_parser_state.current_token;
}
return false; // always return false, that eases the API usage (return set_error(...)) :^)
}
ALWAYS_INLINE bool Parser::done() const
{
return match(TokenType::Eof);
}
ALWAYS_INLINE bool Parser::match(TokenType type) const
{
return m_parser_state.current_token.type() == type;
}
ALWAYS_INLINE bool Parser::match(char ch) const
{
return m_parser_state.current_token.type() == TokenType::Char && m_parser_state.current_token.value().length() == 1 && m_parser_state.current_token.value()[0] == ch;
}
ALWAYS_INLINE Token Parser::consume()
{
auto old_token = m_parser_state.current_token;
m_parser_state.current_token = m_parser_state.lexer.next();
return old_token;
}
ALWAYS_INLINE Token Parser::consume(TokenType type, Error error)
{
if (m_parser_state.current_token.type() != type) {
set_error(error);
dbgln_if(REGEX_DEBUG, "[PARSER] Error: Unexpected token {}. Expected: {}", m_parser_state.current_token.name(), Token::name(type));
}
return consume();
}
ALWAYS_INLINE bool Parser::consume(const String& str)
{
size_t potentially_go_back { 1 };
for (auto ch : str) {
if (match(TokenType::Char)) {
if (m_parser_state.current_token.value()[0] != ch) {
m_parser_state.lexer.back(potentially_go_back);
m_parser_state.current_token = m_parser_state.lexer.next();
return false;
}
} else {
m_parser_state.lexer.back(potentially_go_back);
m_parser_state.current_token = m_parser_state.lexer.next();
return false;
}
consume(TokenType::Char, Error::NoError);
++potentially_go_back;
}
return true;
}
ALWAYS_INLINE bool Parser::try_skip(StringView str)
{
if (str.starts_with(m_parser_state.current_token.value()))
str = str.substring_view(m_parser_state.current_token.value().length(), str.length() - m_parser_state.current_token.value().length());
else
return false;
size_t potentially_go_back { 0 };
for (auto ch : str) {
if (!m_parser_state.lexer.try_skip(ch)) {
m_parser_state.lexer.back(potentially_go_back);
return false;
}
++potentially_go_back;
}
m_parser_state.current_token = m_parser_state.lexer.next();
return true;
}
ALWAYS_INLINE bool Parser::lookahead_any(StringView str)
{
for (auto ch : str) {
if (match(ch))
return true;
}
return false;
}
ALWAYS_INLINE char Parser::skip()
{
char ch;
if (m_parser_state.current_token.value().length() == 1) {
ch = m_parser_state.current_token.value()[0];
} else {
m_parser_state.lexer.back(m_parser_state.current_token.value().length());
ch = m_parser_state.lexer.skip();
}
m_parser_state.current_token = m_parser_state.lexer.next();
return ch;
}
ALWAYS_INLINE void Parser::back(size_t count)
{
m_parser_state.lexer.back(count);
m_parser_state.current_token = m_parser_state.lexer.next();
}
ALWAYS_INLINE void Parser::reset()
{
m_parser_state.bytecode.clear();
m_parser_state.lexer.reset();
m_parser_state.current_token = m_parser_state.lexer.next();
m_parser_state.error = Error::NoError;
m_parser_state.error_token = { TokenType::Eof, 0, StringView(nullptr) };
m_parser_state.capture_group_minimum_lengths.clear();
m_parser_state.capture_groups_count = 0;
m_parser_state.named_capture_groups_count = 0;
m_parser_state.named_capture_group_minimum_lengths.clear();
m_parser_state.named_capture_groups.clear();
}
Parser::Result Parser::parse(Optional<AllOptions> regex_options)
{
reset();
if (regex_options.has_value())
m_parser_state.regex_options = regex_options.value();
if (parse_internal(m_parser_state.bytecode, m_parser_state.match_length_minimum))
consume(TokenType::Eof, Error::InvalidPattern);
else
set_error(Error::InvalidPattern);
dbgln_if(REGEX_DEBUG, "[PARSER] Produced bytecode with {} entries (opcodes + arguments)", m_parser_state.bytecode.size());
return {
move(m_parser_state.bytecode),
move(m_parser_state.capture_groups_count),
move(m_parser_state.named_capture_groups_count),
move(m_parser_state.match_length_minimum),
move(m_parser_state.error),
move(m_parser_state.error_token)
};
}
ALWAYS_INLINE bool Parser::match_ordinary_characters()
{
// NOTE: This method must not be called during bracket and repetition parsing!
// FIXME: Add assertion for that?
auto type = m_parser_state.current_token.type();
return (type == TokenType::Char
|| type == TokenType::Comma
|| type == TokenType::Slash
|| type == TokenType::EqualSign
|| type == TokenType::HyphenMinus
|| type == TokenType::Colon);
}
// =============================
// PosixExtended Parser
// =============================
bool PosixExtendedParser::parse_internal(ByteCode& stack, size_t& match_length_minimum)
{
return parse_root(stack, match_length_minimum);
}
ALWAYS_INLINE bool PosixExtendedParser::match_repetition_symbol()
{
auto type = m_parser_state.current_token.type();
return (type == TokenType::Asterisk
|| type == TokenType::Plus
|| type == TokenType::Questionmark
|| type == TokenType::LeftCurly);
}
ALWAYS_INLINE bool PosixExtendedParser::parse_repetition_symbol(ByteCode& bytecode_to_repeat, size_t& match_length_minimum)
{
if (match(TokenType::LeftCurly)) {
consume();
StringBuilder number_builder;
while (match(TokenType::Char)) {
number_builder.append(consume().value());
}
auto maybe_minimum = number_builder.build().to_uint();
if (!maybe_minimum.has_value())
return set_error(Error::InvalidBraceContent);
auto minimum = maybe_minimum.value();
match_length_minimum *= minimum;
if (match(TokenType::Comma)) {
consume();
} else {
ByteCode bytecode;
bytecode.insert_bytecode_repetition_n(bytecode_to_repeat, minimum);
bytecode_to_repeat = move(bytecode);
consume(TokenType::RightCurly, Error::MismatchingBrace);
return !has_error();
}
Optional<size_t> maybe_maximum {};
number_builder.clear();
while (match(TokenType::Char)) {
number_builder.append(consume().value());
}
if (!number_builder.is_empty()) {
auto value = number_builder.build().to_uint();
if (!value.has_value() || minimum > value.value())
return set_error(Error::InvalidBraceContent);
maybe_maximum = value.value();
}
bytecode_to_repeat.insert_bytecode_repetition_min_max(bytecode_to_repeat, minimum, maybe_maximum);
consume(TokenType::RightCurly, Error::MismatchingBrace);
return !has_error();
} else if (match(TokenType::Plus)) {
consume();
bool nongreedy = match(TokenType::Questionmark);
if (nongreedy)
consume();
// Note: don't touch match_length_minimum, it's already correct
bytecode_to_repeat.insert_bytecode_repetition_min_one(bytecode_to_repeat, !nongreedy);
return !has_error();
} else if (match(TokenType::Asterisk)) {
consume();
match_length_minimum = 0;
bool nongreedy = match(TokenType::Questionmark);
if (nongreedy)
consume();
bytecode_to_repeat.insert_bytecode_repetition_any(bytecode_to_repeat, !nongreedy);
return !has_error();
} else if (match(TokenType::Questionmark)) {
consume();
match_length_minimum = 0;
bool nongreedy = match(TokenType::Questionmark);
if (nongreedy)
consume();
bytecode_to_repeat.insert_bytecode_repetition_zero_or_one(bytecode_to_repeat, !nongreedy);
return !has_error();
}
return false;
}
ALWAYS_INLINE bool PosixExtendedParser::parse_bracket_expression(ByteCode& stack, size_t& match_length_minimum)
{
Vector<CompareTypeAndValuePair> values;
for (;;) {
if (match(TokenType::HyphenMinus)) {
consume();
if (values.is_empty() || (values.size() == 1 && values.last().type == CharacterCompareType::Inverse)) {
// first in the bracket expression
values.append({ CharacterCompareType::Char, (ByteCodeValueType)'-' });
} else if (match(TokenType::RightBracket)) {
// Last in the bracket expression
values.append({ CharacterCompareType::Char, (ByteCodeValueType)'-' });
} else if (values.last().type == CharacterCompareType::Char) {
values.append({ CharacterCompareType::RangeExpressionDummy, 0 });
if (match(TokenType::HyphenMinus)) {
consume();
// Valid range, add ordinary character
values.append({ CharacterCompareType::Char, (ByteCodeValueType)'-' });
}
} else {
return set_error(Error::InvalidRange);
}
} else if (match(TokenType::Circumflex)) {
auto t = consume();
if (values.is_empty())
values.append({ CharacterCompareType::Inverse, 0 });
else
values.append({ CharacterCompareType::Char, (ByteCodeValueType)*t.value().characters_without_null_termination() });
} else if (match(TokenType::LeftBracket)) {
consume();
if (match(TokenType::Period)) {
consume();
// FIXME: Parse collating element, this is needed when we have locale support
// This could have impact on length parameter, I guess.
VERIFY_NOT_REACHED();
consume(TokenType::Period, Error::InvalidCollationElement);
consume(TokenType::RightBracket, Error::MismatchingBracket);
} else if (match(TokenType::EqualSign)) {
consume();
// FIXME: Parse collating element, this is needed when we have locale support
// This could have impact on length parameter, I guess.
VERIFY_NOT_REACHED();
consume(TokenType::EqualSign, Error::InvalidCollationElement);
consume(TokenType::RightBracket, Error::MismatchingBracket);
} else if (match(TokenType::Colon)) {
consume();
CharClass ch_class;
// parse character class
if (match(TokenType::Char)) {
if (consume("alnum"))
ch_class = CharClass::Alnum;
else if (consume("alpha"))
ch_class = CharClass::Alpha;
else if (consume("blank"))
ch_class = CharClass::Blank;
else if (consume("cntrl"))
ch_class = CharClass::Cntrl;
else if (consume("digit"))
ch_class = CharClass::Digit;
else if (consume("graph"))
ch_class = CharClass::Graph;
else if (consume("lower"))
ch_class = CharClass::Lower;
else if (consume("print"))
ch_class = CharClass::Print;
else if (consume("punct"))
ch_class = CharClass::Punct;
else if (consume("space"))
ch_class = CharClass::Space;
else if (consume("upper"))
ch_class = CharClass::Upper;
else if (consume("xdigit"))
ch_class = CharClass::Xdigit;
else
return set_error(Error::InvalidCharacterClass);
values.append({ CharacterCompareType::CharClass, (ByteCodeValueType)ch_class });
} else
return set_error(Error::InvalidCharacterClass);
// FIXME: we do not support locale specific character classes until locales are implemented
consume(TokenType::Colon, Error::InvalidCharacterClass);
consume(TokenType::RightBracket, Error::MismatchingBracket);
} else {
return set_error(Error::MismatchingBracket);
}
} else if (match(TokenType::RightBracket)) {
if (values.is_empty() || (values.size() == 1 && values.last().type == CharacterCompareType::Inverse)) {
// handle bracket as ordinary character
values.append({ CharacterCompareType::Char, (ByteCodeValueType)*consume().value().characters_without_null_termination() });
} else {
// closing bracket expression
break;
}
} else {
values.append({ CharacterCompareType::Char, (ByteCodeValueType)skip() });
}
// check if range expression has to be completed...
if (values.size() >= 3 && values.at(values.size() - 2).type == CharacterCompareType::RangeExpressionDummy) {
if (values.last().type != CharacterCompareType::Char)
return set_error(Error::InvalidRange);
auto value2 = values.take_last();
values.take_last(); // RangeExpressionDummy
auto value1 = values.take_last();
values.append({ CharacterCompareType::CharRange, static_cast<ByteCodeValueType>(CharRange { (u32)value1.value, (u32)value2.value }) });
}
}
if (values.size())
match_length_minimum = 1;
if (values.first().type == CharacterCompareType::Inverse)
match_length_minimum = 0;
stack.insert_bytecode_compare_values(move(values));
return !has_error();
}
ALWAYS_INLINE bool PosixExtendedParser::parse_sub_expression(ByteCode& stack, size_t& match_length_minimum)
{
ByteCode bytecode;
size_t length = 0;
bool should_parse_repetition_symbol { false };
for (;;) {
if (match_ordinary_characters()) {
Token start_token = m_parser_state.current_token;
Token last_token = m_parser_state.current_token;
for (;;) {
if (!match_ordinary_characters())
break;
++length;
last_token = consume();
}
if (length > 1) {
// last character is inserted into 'bytecode' for duplication symbol handling
auto new_length = length - ((match_repetition_symbol() && length > 1) ? 1 : 0);
stack.insert_bytecode_compare_string({ start_token.value().characters_without_null_termination(), new_length });
}
if ((match_repetition_symbol() && length > 1) || length == 1) // Create own compare opcode for last character before duplication symbol
bytecode.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)last_token.value().characters_without_null_termination()[0] } });
should_parse_repetition_symbol = true;
break;
}
if (match_repetition_symbol())
return set_error(Error::InvalidRepetitionMarker);
if (match(TokenType::Period)) {
length = 1;
consume();
bytecode.insert_bytecode_compare_values({ { CharacterCompareType::AnyChar, 0 } });
should_parse_repetition_symbol = true;
break;
}
if (match(TokenType::EscapeSequence)) {
length = 1;
Token t = consume();
dbgln_if(REGEX_DEBUG, "[PARSER] EscapeSequence with substring {}", t.value());
bytecode.insert_bytecode_compare_values({ { CharacterCompareType::Char, (u32)t.value().characters_without_null_termination()[1] } });
should_parse_repetition_symbol = true;
break;
}
if (match(TokenType::LeftBracket)) {
consume();
ByteCode sub_ops;
if (!parse_bracket_expression(sub_ops, length) || !sub_ops.size())
return set_error(Error::InvalidBracketContent);
bytecode.extend(move(sub_ops));
consume(TokenType::RightBracket, Error::MismatchingBracket);
should_parse_repetition_symbol = true;
break;
}
if (match(TokenType::RightBracket)) {
return set_error(Error::MismatchingBracket);
}
if (match(TokenType::RightCurly)) {
return set_error(Error::MismatchingBrace);
}
if (match(TokenType::Circumflex)) {
consume();
bytecode.empend((ByteCodeValueType)OpCodeId::CheckBegin);
break;
}
if (match(TokenType::Dollar)) {
consume();
bytecode.empend((ByteCodeValueType)OpCodeId::CheckEnd);
break;
}
if (match(TokenType::RightParen))
return false;
if (match(TokenType::LeftParen)) {
consume();
Optional<StringView> capture_group_name;
bool prevent_capture_group = false;
if (match(TokenType::Questionmark)) {
consume();
if (match(TokenType::Colon)) {
consume();
prevent_capture_group = true;
} else if (consume("<")) { // named capturing group
Token start_token = m_parser_state.current_token;
Token last_token = m_parser_state.current_token;
size_t capture_group_name_length = 0;
for (;;) {
if (!match_ordinary_characters())
return set_error(Error::InvalidNameForCaptureGroup);
if (match(TokenType::Char) && m_parser_state.current_token.value()[0] == '>') {
consume();
break;
}
++capture_group_name_length;
last_token = consume();
}
capture_group_name = StringView(start_token.value().characters_without_null_termination(), capture_group_name_length);
} else if (match(TokenType::EqualSign)) { // positive lookahead
consume();
VERIFY_NOT_REACHED();
} else if (consume("!")) { // negative lookahead
VERIFY_NOT_REACHED();
} else if (consume("<")) {
if (match(TokenType::EqualSign)) { // positive lookbehind
consume();
VERIFY_NOT_REACHED();
}
if (consume("!")) // negative lookbehind
VERIFY_NOT_REACHED();
} else {
return set_error(Error::InvalidRepetitionMarker);
}
}
if (!(m_parser_state.regex_options & AllFlags::SkipSubExprResults || prevent_capture_group)) {
if (capture_group_name.has_value())
bytecode.insert_bytecode_group_capture_left(capture_group_name.value());
else
bytecode.insert_bytecode_group_capture_left(m_parser_state.capture_groups_count);
}
ByteCode capture_group_bytecode;
if (!parse_root(capture_group_bytecode, length))
return set_error(Error::InvalidPattern);
bytecode.extend(move(capture_group_bytecode));
consume(TokenType::RightParen, Error::MismatchingParen);
if (!(m_parser_state.regex_options & AllFlags::SkipSubExprResults || prevent_capture_group)) {
if (capture_group_name.has_value()) {
bytecode.insert_bytecode_group_capture_right(capture_group_name.value());
++m_parser_state.named_capture_groups_count;
} else {
bytecode.insert_bytecode_group_capture_right(m_parser_state.capture_groups_count);
++m_parser_state.capture_groups_count;
}
}
should_parse_repetition_symbol = true;
break;
}
return false;
}
if (match_repetition_symbol()) {
if (should_parse_repetition_symbol)
parse_repetition_symbol(bytecode, length);
else
return set_error(Error::InvalidRepetitionMarker);
}
stack.extend(move(bytecode));
match_length_minimum += length;
return true;
}
bool PosixExtendedParser::parse_root(ByteCode& stack, size_t& match_length_minimum)
{
ByteCode bytecode_left;
size_t match_length_minimum_left { 0 };
if (match_repetition_symbol())
return set_error(Error::InvalidRepetitionMarker);
for (;;) {
if (!parse_sub_expression(bytecode_left, match_length_minimum_left))
break;
if (match(TokenType::Pipe)) {
consume();
ByteCode bytecode_right;
size_t match_length_minimum_right { 0 };
if (!parse_root(bytecode_right, match_length_minimum_right) || bytecode_right.is_empty())
return set_error(Error::InvalidPattern);
ByteCode new_bytecode;
new_bytecode.insert_bytecode_alternation(move(bytecode_left), move(bytecode_right));
bytecode_left = move(new_bytecode);
match_length_minimum_left = min(match_length_minimum_right, match_length_minimum_left);
}
}
if (bytecode_left.is_empty())
set_error(Error::EmptySubExpression);
stack.extend(move(bytecode_left));
match_length_minimum = match_length_minimum_left;
return !has_error();
}
// =============================
// ECMA262 Parser
// =============================
bool ECMA262Parser::parse_internal(ByteCode& stack, size_t& match_length_minimum)
{
if (m_parser_state.regex_options.has_flag_set(AllFlags::Unicode)) {
return parse_pattern(stack, match_length_minimum, true, true);
} else {
ByteCode new_stack;
size_t new_match_length = 0;
auto res = parse_pattern(new_stack, new_match_length, false, false);
if (m_parser_state.named_capture_groups_count > 0) {
reset();
return parse_pattern(stack, match_length_minimum, false, true);
}
if (!res)
return false;
stack.extend(new_stack);
match_length_minimum = new_match_length;
return res;
}
}
bool ECMA262Parser::parse_pattern(ByteCode& stack, size_t& match_length_minimum, bool unicode, bool named)
{
return parse_disjunction(stack, match_length_minimum, unicode, named);
}
bool ECMA262Parser::parse_disjunction(ByteCode& stack, size_t& match_length_minimum, bool unicode, bool named)
{
ByteCode left_alternative_stack;
size_t left_alternative_min_length = 0;
auto alt_ok = parse_alternative(left_alternative_stack, left_alternative_min_length, unicode, named);
if (!alt_ok)
return false;
if (!match(TokenType::Pipe)) {
stack.extend(left_alternative_stack);
match_length_minimum = left_alternative_min_length;
return alt_ok;
}
consume();
ByteCode right_alternative_stack;
size_t right_alternative_min_length = 0;
auto continuation_ok = parse_disjunction(right_alternative_stack, right_alternative_min_length, unicode, named);
if (!continuation_ok)
return false;
stack.insert_bytecode_alternation(move(left_alternative_stack), move(right_alternative_stack));
match_length_minimum = min(left_alternative_min_length, right_alternative_min_length);
return continuation_ok;
}
bool ECMA262Parser::parse_alternative(ByteCode& stack, size_t& match_length_minimum, bool unicode, bool named)
{
for (;;) {
if (match(TokenType::Eof))
return true;
if (parse_term(stack, match_length_minimum, unicode, named))
continue;
return !has_error();
}
}
bool ECMA262Parser::parse_term(ByteCode& stack, size_t& match_length_minimum, bool unicode, bool named)
{
if (parse_assertion(stack, match_length_minimum, unicode, named))
return true;
ByteCode atom_stack;
size_t minimum_atom_length = 0;
auto parse_with_quantifier = [&] {
bool did_parse_one = false;
if (m_should_use_browser_extended_grammar)
did_parse_one = parse_extended_atom(atom_stack, minimum_atom_length, named);
if (!did_parse_one)
did_parse_one = parse_atom(atom_stack, minimum_atom_length, unicode, named);
if (!did_parse_one)
return false;
VERIFY(did_parse_one);
if (!parse_quantifier(atom_stack, minimum_atom_length, unicode, named))
return false;
return true;
};
if (!parse_with_quantifier())
return false;
stack.extend(move(atom_stack));
match_length_minimum += minimum_atom_length;
return true;
}
bool ECMA262Parser::parse_assertion(ByteCode& stack, [[maybe_unused]] size_t& match_length_minimum, bool unicode, bool named)
{
if (match(TokenType::Circumflex)) {
consume();
stack.empend((ByteCodeValueType)OpCodeId::CheckBegin);
return true;
}
if (match(TokenType::Dollar)) {
consume();
stack.empend((ByteCodeValueType)OpCodeId::CheckEnd);
return true;
}
if (try_skip("\\b")) {
stack.insert_bytecode_check_boundary(BoundaryCheckType::Word);
return true;
}
if (try_skip("\\B")) {
stack.insert_bytecode_check_boundary(BoundaryCheckType::NonWord);
return true;
}
if (match(TokenType::LeftParen)) {
if (!try_skip("(?"))
return false;
if (done()) {
set_error(Error::InvalidCaptureGroup);
return false;
}
ByteCode assertion_stack;
size_t length_dummy = 0;
bool should_parse_forward_assertion = m_should_use_browser_extended_grammar ? unicode : true;
if (should_parse_forward_assertion && try_skip("=")) {
if (!parse_inner_disjunction(assertion_stack, length_dummy, unicode, named))
return false;
stack.insert_bytecode_lookaround(move(assertion_stack), ByteCode::LookAroundType::LookAhead);
return true;
}
if (should_parse_forward_assertion && try_skip("!")) {
if (!parse_inner_disjunction(assertion_stack, length_dummy, unicode, named))
return false;
stack.insert_bytecode_lookaround(move(assertion_stack), ByteCode::LookAroundType::NegatedLookAhead);
return true;
}
if (m_should_use_browser_extended_grammar) {
if (!unicode) {
if (parse_quantifiable_assertion(assertion_stack, match_length_minimum, named)) {
stack.extend(move(assertion_stack));
return true;
}
}
}
if (try_skip("<=")) {
if (!parse_inner_disjunction(assertion_stack, length_dummy, unicode, named))
return false;
// FIXME: Somehow ensure that this assertion regexp has a fixed length.
stack.insert_bytecode_lookaround(move(assertion_stack), ByteCode::LookAroundType::LookBehind, length_dummy);
return true;
}
if (try_skip("<!")) {
if (!parse_inner_disjunction(assertion_stack, length_dummy, unicode, named))
return false;
stack.insert_bytecode_lookaround(move(assertion_stack), ByteCode::LookAroundType::NegatedLookBehind, length_dummy);
return true;
}
// If none of these matched, put the '(?' back.
m_parser_state.lexer.back(3);
m_parser_state.current_token = m_parser_state.lexer.next();
return false;
}
return false;
}
bool ECMA262Parser::parse_inner_disjunction(ByteCode& bytecode_stack, size_t& length, bool unicode, bool named)
{
auto disjunction_ok = parse_disjunction(bytecode_stack, length, unicode, named);
if (!disjunction_ok)
return false;
consume(TokenType::RightParen, Error::MismatchingParen);
return true;
}
bool ECMA262Parser::parse_quantifiable_assertion(ByteCode& stack, size_t&, bool named)
{
VERIFY(m_should_use_browser_extended_grammar);
ByteCode assertion_stack;
size_t match_length_minimum = 0;
if (try_skip("=")) {
if (!parse_inner_disjunction(assertion_stack, match_length_minimum, false, named))
return false;
stack.insert_bytecode_lookaround(move(assertion_stack), ByteCode::LookAroundType::LookAhead);
return true;
}
if (try_skip("!")) {
if (!parse_inner_disjunction(assertion_stack, match_length_minimum, false, named))
return false;
stack.insert_bytecode_lookaround(move(assertion_stack), ByteCode::LookAroundType::NegatedLookAhead);
return true;
}
return false;
}
StringView ECMA262Parser::read_digits_as_string(ReadDigitsInitialZeroState initial_zero, bool hex, int max_count)
{
if (!match(TokenType::Char))
return {};
if (initial_zero == ReadDigitsInitialZeroState::Disallow && m_parser_state.current_token.value() == "0")
return {};
int count = 0;
size_t offset = 0;
auto start_token = m_parser_state.current_token;
while (match(TokenType::Char)) {
auto& c = m_parser_state.current_token.value();
if (max_count > 0 && count >= max_count)
break;
if (hex && !AK::StringUtils::convert_to_uint_from_hex(c).has_value())
break;
if (!hex && !c.to_uint().has_value())
break;
offset += consume().value().length();
++count;
}
return StringView { start_token.value().characters_without_null_termination(), offset };
}
Optional<unsigned> ECMA262Parser::read_digits(ECMA262Parser::ReadDigitsInitialZeroState initial_zero, bool hex, int max_count)
{
auto str = read_digits_as_string(initial_zero, hex, max_count);
if (str.is_empty())
return {};
if (hex)
return AK::StringUtils::convert_to_uint_from_hex(str);
return str.to_uint();
}
bool ECMA262Parser::parse_quantifier(ByteCode& stack, size_t& match_length_minimum, bool, bool)
{
enum class Repetition {
OneOrMore,
ZeroOrMore,
Optional,
Explicit,
None,
} repetition_mark { Repetition::None };
bool ungreedy = false;
Optional<size_t> repeat_min, repeat_max;
if (match(TokenType::Asterisk)) {
consume();
repetition_mark = Repetition::ZeroOrMore;
} else if (match(TokenType::Plus)) {
consume();
repetition_mark = Repetition::OneOrMore;
} else if (match(TokenType::Questionmark)) {
consume();
repetition_mark = Repetition::Optional;
} else if (match(TokenType::LeftCurly)) {
consume();
auto chars_consumed = 1;
repetition_mark = Repetition::Explicit;
auto low_bound_string = read_digits_as_string();
chars_consumed += low_bound_string.length();
auto low_bound = low_bound_string.to_uint();
if (!low_bound.has_value()) {
back(chars_consumed + 1);
return true;
}
repeat_min = low_bound.value();
if (match(TokenType::Comma)) {
consume();
++chars_consumed;
auto high_bound_string = read_digits_as_string();
auto high_bound = high_bound_string.to_uint();
if (high_bound.has_value()) {
repeat_max = high_bound.value();
chars_consumed += high_bound_string.length();
}
} else {
repeat_max = repeat_min;
}
if (!match(TokenType::RightCurly)) {
back(chars_consumed + 1);
return true;
}
consume();
++chars_consumed;
if (repeat_max.has_value()) {
if (repeat_min.value() > repeat_max.value())
set_error(Error::InvalidBraceContent);
}
} else {
return true;
}
if (match(TokenType::Questionmark)) {
consume();
ungreedy = true;
}
ByteCode new_bytecode;
switch (repetition_mark) {
case Repetition::OneOrMore:
new_bytecode.insert_bytecode_repetition_min_one(stack, !ungreedy);
break;
case Repetition::ZeroOrMore:
new_bytecode.insert_bytecode_repetition_any(stack, !ungreedy);
match_length_minimum = 0;
break;
case Repetition::Optional:
new_bytecode.insert_bytecode_repetition_zero_or_one(stack, !ungreedy);
match_length_minimum = 0;
break;
case Repetition::Explicit:
new_bytecode.insert_bytecode_repetition_min_max(stack, repeat_min.value(), repeat_max, !ungreedy);
match_length_minimum *= repeat_min.value();
break;
case Repetition::None:
VERIFY_NOT_REACHED();
}
return true;
}
bool ECMA262Parser::parse_atom(ByteCode& stack, size_t& match_length_minimum, bool unicode, bool named)
{
if (match(TokenType::EscapeSequence)) {
// Also part of AtomEscape.
auto token = consume();
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)token.value()[1] } });
return true;
}
if (try_skip("\\")) {
// AtomEscape.
return parse_atom_escape(stack, match_length_minimum, unicode, named);
}
if (match(TokenType::LeftBracket)) {
// Character class.
return parse_character_class(stack, match_length_minimum, unicode && !m_should_use_browser_extended_grammar, named);
}
if (match(TokenType::LeftParen)) {
// Non-capturing group, or a capture group.
return parse_capture_group(stack, match_length_minimum, unicode && !m_should_use_browser_extended_grammar, named);
}
if (match(TokenType::Period)) {
consume();
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::AnyChar, 0 } });
return true;
}
if (match(TokenType::Circumflex) || match(TokenType::Dollar) || match(TokenType::RightParen)
|| match(TokenType::Pipe) || match(TokenType::Plus) || match(TokenType::Asterisk)
|| match(TokenType::Questionmark)) {
return false;
}
if (match(TokenType::RightBracket) || match(TokenType::RightCurly) || match(TokenType::LeftCurly)) {
if (m_should_use_browser_extended_grammar) {
auto token = consume();
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)token.value()[0] } });
return true;
} else {
return false;
}
}
if (match_ordinary_characters()) {
auto token = consume().value();
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)token[0] } });
return true;
}
set_error(Error::InvalidPattern);
return false;
}
bool ECMA262Parser::parse_extended_atom(ByteCode&, size_t&, bool)
{
// Note: This includes only rules *not* present in parse_atom()
VERIFY(m_should_use_browser_extended_grammar);
if (parse_invalid_braced_quantifier())
return true; // FAIL FAIL FAIL
return false;
}
bool ECMA262Parser::parse_invalid_braced_quantifier()
{
if (!match(TokenType::LeftCurly))
return false;
consume();
size_t chars_consumed = 1;
auto low_bound = read_digits_as_string();
StringView high_bound;
if (low_bound.is_empty()) {
back(chars_consumed + 1);
return false;
}
chars_consumed += low_bound.length();
if (match(TokenType::Comma)) {
consume();
++chars_consumed;
high_bound = read_digits_as_string();
chars_consumed += high_bound.length();
}
if (!match(TokenType::RightCurly)) {
back(chars_consumed + 1);
return false;
}
consume();
set_error(Error::InvalidPattern);
return true;
}
bool ECMA262Parser::parse_atom_escape(ByteCode& stack, size_t& match_length_minimum, bool unicode, bool named)
{
if (auto escape_str = read_digits_as_string(ReadDigitsInitialZeroState::Disallow); !escape_str.is_empty()) {
if (auto escape = escape_str.to_uint(); escape.has_value()) {
// See if this is a "back"-reference (we've already parsed the group it refers to)
auto maybe_length = m_parser_state.capture_group_minimum_lengths.get(escape.value());
if (maybe_length.has_value()) {
match_length_minimum += maybe_length.value();
stack.insert_bytecode_compare_values({ { CharacterCompareType::Reference, (ByteCodeValueType)escape.value() } });
return true;
}
// It's not a pattern seen before, so we have to see if it's a valid reference to a future group.
if (escape.value() <= ensure_total_number_of_capturing_parenthesis()) {
// This refers to a future group, and it will _always_ be matching an empty string
// So just match nothing and move on.
return true;
}
if (!m_should_use_browser_extended_grammar) {
set_error(Error::InvalidNumber);
return false;
}
}
// If not, put the characters back.
back(escape_str.length());
}
// CharacterEscape > ControlEscape
if (try_skip("f")) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'\f' } });
return true;
}
if (try_skip("n")) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'\n' } });
return true;
}
if (try_skip("r")) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'\r' } });
return true;
}
if (try_skip("t")) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'\t' } });
return true;
}
if (try_skip("v")) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'\v' } });
return true;
}
// CharacterEscape > ControlLetter
if (try_skip("c")) {
for (auto c = 'A'; c <= 'z'; ++c) {
if (try_skip({ &c, 1 })) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)(c % 32) } });
return true;
}
}
if (m_should_use_browser_extended_grammar) {
back(2);
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'\\' } });
match_length_minimum += 1;
return true;
}
if (unicode) {
set_error(Error::InvalidPattern);
return false;
}
// Allow '\c' in non-unicode mode, just matches 'c'.
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'c' } });
return true;
}
// LegacyOctalEscapeSequence
if (m_should_use_browser_extended_grammar) {
if (!unicode) {
if (auto escape = parse_legacy_octal_escape(); escape.has_value()) {
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)escape.value() } });
match_length_minimum += 1;
return true;
}
}
}
// '\0'
if (try_skip("0")) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)0 } });
return true;
}
// HexEscape
if (try_skip("x")) {
if (auto hex_escape = read_digits(ReadDigitsInitialZeroState::Allow, true, 2); hex_escape.has_value()) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)hex_escape.value() } });
return true;
} else if (!unicode) {
// '\x' is allowed in non-unicode mode, just matches 'x'.
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'x' } });
return true;
} else {
set_error(Error::InvalidPattern);
return false;
}
}
if (try_skip("u")) {
if (auto code_point = read_digits(ReadDigitsInitialZeroState::Allow, true, 4); code_point.has_value()) {
// FIXME: The minimum length depends on the mode - should be utf8-length in u8 mode.
match_length_minimum += 1;
StringBuilder builder;
builder.append_code_point(code_point.value());
// FIXME: This isn't actually correct for ECMAScript.
auto u8_encoded = builder.string_view();
stack.insert_bytecode_compare_string(u8_encoded);
return true;
} else if (!unicode) {
// '\u' is allowed in non-unicode mode, just matches 'u'.
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'u' } });
return true;
} else {
set_error(Error::InvalidPattern);
return false;
}
}
// IdentityEscape
auto source_characters = m_should_use_browser_extended_grammar ? "^$\\.*+?()[|"sv : "^$\\.*+?()[]{}|"sv;
for (auto ch : source_characters) {
if (try_skip({ &ch, 1 })) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)ch } });
return true;
}
}
if (unicode) {
if (try_skip("/")) {
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)'/' } });
return true;
}
}
if (named && try_skip("k")) {
auto name = read_capture_group_specifier(true);
if (name.is_empty()) {
set_error(Error::InvalidNameForCaptureGroup);
return false;
}
auto maybe_length = m_parser_state.named_capture_group_minimum_lengths.get(name);
if (!maybe_length.has_value()) {
set_error(Error::InvalidNameForCaptureGroup);
return false;
}
match_length_minimum += maybe_length.value();
stack.insert_bytecode_compare_named_reference(name);
return true;
}
if (unicode) {
if (try_skip("p{")) {
// FIXME: Implement this path, Unicode property match.
TODO();
}
if (try_skip("P{")) {
// FIXME: Implement this path, Unicode property match.
TODO();
}
}
if (done())
return set_error(Error::InvalidTrailingEscape);
bool negate = false;
auto ch = parse_character_class_escape(negate);
if (!ch.has_value()) {
if (!unicode) {
// Allow all SourceCharacter's as escapes here.
auto token = consume();
match_length_minimum += 1;
stack.insert_bytecode_compare_values({ { CharacterCompareType::Char, (ByteCodeValueType)token.value()[0] } });
return true;
}
set_error(Error::InvalidCharacterClass);
return false;
}
Vector<CompareTypeAndValuePair> compares;
if (negate)
compares.empend(CompareTypeAndValuePair { CharacterCompareType::Inverse, 0 });
compares.empend(CompareTypeAndValuePair { CharacterCompareType::CharClass, (ByteCodeValueType)ch.value() });
match_length_minimum += 1;
stack.insert_bytecode_compare_values(move(compares));
return true;
}
Optional<u8> ECMA262Parser::parse_legacy_octal_escape()
{
constexpr auto all_octal_digits = "01234567";
auto read_octal_digit = [&](auto start, auto end, bool should_ensure_no_following_octal_digit) -> Optional<u8> {
for (char c = '0' + start; c <= '0' + end; ++c) {
if (try_skip({ &c, 1 })) {
if (!should_ensure_no_following_octal_digit || !lookahead_any(all_octal_digits))
return c - '0';
back(2);
return {};
}
}
return {};
};
// OctalDigit(1)
if (auto digit = read_octal_digit(0, 7, true); digit.has_value()) {
return digit.value();
}
// OctalDigit(2)
if (auto left_digit = read_octal_digit(0, 3, false); left_digit.has_value()) {
if (auto right_digit = read_octal_digit(0, 7, true); right_digit.has_value()) {
return left_digit.value() * 8 + right_digit.value();
}
back(2);
}
// OctalDigit(2)
if (auto left_digit = read_octal_digit(4, 7, false); left_digit.has_value()) {
if (auto right_digit = read_octal_digit(0, 7, false); right_digit.has_value()) {
return left_digit.value() * 8 + right_digit.value();
}
back(2);
}
// OctalDigit(3)
if (auto left_digit = read_octal_digit(0, 3, false); left_digit.has_value()) {
size_t chars_consumed = 1;
if (auto mid_digit = read_octal_digit(0, 7, false); mid_digit.has_value()) {
++chars_consumed;
if (auto right_digit = read_octal_digit(0, 7, false); right_digit.has_value()) {
return left_digit.value() * 64 + mid_digit.value() * 8 + right_digit.value();
}
}
back(chars_consumed);
}
return {};
}
Optional<CharClass> ECMA262Parser::parse_character_class_escape(bool& negate, bool expect_backslash)
{
if (expect_backslash && !try_skip("\\"))
return {};
// CharacterClassEscape
CharClass ch_class;
if (try_skip("d")) {
ch_class = CharClass::Digit;
} else if (try_skip("D")) {
ch_class = CharClass::Digit;
negate = true;
} else if (try_skip("s")) {
ch_class = CharClass::Space;
} else if (try_skip("S")) {
ch_class = CharClass::Space;
negate = true;
} else if (try_skip("w")) {
ch_class = CharClass::Word;
} else if (try_skip("W")) {
ch_class = CharClass::Word;
negate = true;
} else {
return {};
}
return ch_class;
}
bool ECMA262Parser::parse_character_class(ByteCode& stack, size_t& match_length_minimum, bool unicode, bool)
{
consume(TokenType::LeftBracket, Error::InvalidPattern);
Vector<CompareTypeAndValuePair> compares;
if (match(TokenType::Circumflex)) {
// Negated charclass
consume();
compares.empend(CompareTypeAndValuePair { CharacterCompareType::Inverse, 0 });
}
if (match(TokenType::RightBracket)) {
consume();
// Should only have at most an 'Inverse'
VERIFY(compares.size() <= 1);
stack.insert_bytecode_compare_values(move(compares));
return true;
}
if (!parse_nonempty_class_ranges(compares, unicode))
return false;
match_length_minimum += 1;
stack.insert_bytecode_compare_values(move(compares));
return true;
}
struct CharClassRangeElement {
union {
CharClass character_class;
u32 code_point { 0 };
};
bool is_negated { false };
bool is_character_class { false };
};
bool ECMA262Parser::parse_nonempty_class_ranges(Vector<CompareTypeAndValuePair>& ranges, bool unicode)
{
auto read_class_atom_no_dash = [&]() -> Optional<CharClassRangeElement> {
if (match(TokenType::EscapeSequence)) {
auto token = consume().value();
return { CharClassRangeElement { .code_point = (u32)token[1], .is_character_class = false } };
}
if (try_skip("\\")) {
if (done()) {
set_error(Error::InvalidTrailingEscape);
return {};
}
if (try_skip("f"))
return { CharClassRangeElement { .code_point = '\f', .is_character_class = false } };
if (try_skip("n"))
return { CharClassRangeElement { .code_point = '\n', .is_character_class = false } };
if (try_skip("r"))
return { CharClassRangeElement { .code_point = '\r', .is_character_class = false } };
if (try_skip("t"))
return { CharClassRangeElement { .code_point = '\t', .is_character_class = false } };
if (try_skip("v"))
return { CharClassRangeElement { .code_point = '\v', .is_character_class = false } };
if (try_skip("b"))
return { CharClassRangeElement { .code_point = '\b', .is_character_class = false } };
if (try_skip("/"))
return { CharClassRangeElement { .code_point = '/', .is_character_class = false } };
// CharacterEscape > ControlLetter
if (try_skip("c")) {
for (auto c = 'A'; c <= 'z'; ++c) {
if (try_skip({ &c, 1 }))
return { CharClassRangeElement { .code_point = (u32)(c % 32), .is_character_class = false } };
}
if (m_should_use_browser_extended_grammar) {
for (auto c = '0'; c <= '9'; ++c) {
if (try_skip({ &c, 1 }))
return { CharClassRangeElement { .code_point = (u32)(c % 32), .is_character_class = false } };
}
if (try_skip("_"))
return { CharClassRangeElement { .code_point = (u32)('_' % 32), .is_character_class = false } };
back(2);
return { CharClassRangeElement { .code_point = '\\', .is_character_class = false } };
}
}
// '\0'
if (try_skip("0"))
return { CharClassRangeElement { .code_point = 0, .is_character_class = false } };
// HexEscape
if (try_skip("x")) {
if (auto hex_escape = read_digits(ReadDigitsInitialZeroState::Allow, true, 2); hex_escape.has_value()) {
return { CharClassRangeElement { .code_point = hex_escape.value(), .is_character_class = false } };
} else if (!unicode) {
// '\x' is allowed in non-unicode mode, just matches 'x'.
return { CharClassRangeElement { .code_point = 'x', .is_character_class = false } };
} else {
set_error(Error::InvalidPattern);
return {};
}
}
if (try_skip("u")) {
if (auto code_point = read_digits(ReadDigitsInitialZeroState::Allow, true, 4); code_point.has_value()) {
// FIXME: While code point ranges are supported, code point matches as "Char" are not!
return { CharClassRangeElement { .code_point = code_point.value(), .is_character_class = false } };
} else if (!unicode) {
// '\u' is allowed in non-unicode mode, just matches 'u'.
return { CharClassRangeElement { .code_point = 'u', .is_character_class = false } };
} else {
set_error(Error::InvalidPattern);
return {};
}
}
if (unicode) {
if (try_skip("-"))
return { CharClassRangeElement { .code_point = '-', .is_character_class = false } };
}
if (try_skip("p{") || try_skip("P{")) {
// FIXME: Implement these; unicode properties.
TODO();
}
if (try_skip("d"))
return { CharClassRangeElement { .character_class = CharClass::Digit, .is_character_class = true } };
if (try_skip("s"))
return { CharClassRangeElement { .character_class = CharClass::Space, .is_character_class = true } };
if (try_skip("w"))
return { CharClassRangeElement { .character_class = CharClass::Word, .is_character_class = true } };
if (try_skip("D"))
return { CharClassRangeElement { .character_class = CharClass::Digit, .is_negated = true, .is_character_class = true } };
if (try_skip("S"))
return { CharClassRangeElement { .character_class = CharClass::Space, .is_negated = true, .is_character_class = true } };
if (try_skip("W"))
return { CharClassRangeElement { .character_class = CharClass::Word, .is_negated = true, .is_character_class = true } };
if (!unicode) {
// Any unrecognised escape is allowed in non-unicode mode.
return { CharClassRangeElement { .code_point = (u32)skip(), .is_character_class = false } };
}
}
if (match(TokenType::RightBracket) || match(TokenType::HyphenMinus))
return {};
// Allow any (other) SourceCharacter.
return { CharClassRangeElement { .code_point = (u32)skip(), .is_character_class = false } };
};
auto read_class_atom = [&]() -> Optional<CharClassRangeElement> {
if (match(TokenType::HyphenMinus)) {
consume();
return { CharClassRangeElement { .code_point = '-', .is_character_class = false } };
}
return read_class_atom_no_dash();
};
while (!match(TokenType::RightBracket)) {
if (match(TokenType::Eof)) {
set_error(Error::MismatchingBracket);
return false;
}
auto first_atom = read_class_atom();
if (!first_atom.has_value())
return false;
if (match(TokenType::HyphenMinus)) {
consume();
if (match(TokenType::RightBracket)) {
// Allow '-' as the last element in a charclass, even after an atom.
m_parser_state.lexer.back(2); // -]
m_parser_state.current_token = m_parser_state.lexer.next();
goto read_as_single_atom;
}
auto second_atom = read_class_atom();
if (!second_atom.has_value())
return false;
if (first_atom.value().is_character_class || second_atom.value().is_character_class) {
if (m_should_use_browser_extended_grammar) {
if (unicode) {
set_error(Error::InvalidRange);
return false;
}
// CharacterRangeOrUnion > !Unicode > CharClass
if (first_atom->is_character_class)
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::CharClass, (ByteCodeValueType)first_atom->character_class });
else
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::Char, (ByteCodeValueType)first_atom->code_point });
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::Char, (ByteCodeValueType)'-' });
if (second_atom->is_character_class)
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::CharClass, (ByteCodeValueType)second_atom->character_class });
else
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::Char, (ByteCodeValueType)second_atom->code_point });
continue;
} else {
set_error(Error::InvalidRange);
return false;
}
}
if (first_atom.value().code_point > second_atom.value().code_point) {
set_error(Error::InvalidRange);
return false;
}
VERIFY(!first_atom.value().is_negated);
VERIFY(!second_atom.value().is_negated);
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::CharRange, CharRange { first_atom.value().code_point, second_atom.value().code_point } });
continue;
}
read_as_single_atom:;
auto atom = first_atom.value();
if (atom.is_character_class) {
if (atom.is_negated)
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::TemporaryInverse, 0 });
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::CharClass, (ByteCodeValueType)first_atom.value().character_class });
} else {
VERIFY(!atom.is_negated);
ranges.empend(CompareTypeAndValuePair { CharacterCompareType::Char, first_atom.value().code_point });
}
}
consume(TokenType::RightBracket, Error::MismatchingBracket);
return true;
}
StringView ECMA262Parser::read_capture_group_specifier(bool take_starting_angle_bracket)
{
if (take_starting_angle_bracket && !consume("<"))
return {};
auto start_token = m_parser_state.current_token;
size_t offset = 0;
while (match(TokenType::Char)) {
auto c = m_parser_state.current_token.value();
if (c == ">")
break;
offset += consume().value().length();
}
StringView name { start_token.value().characters_without_null_termination(), offset };
if (!consume(">") || name.is_empty())
set_error(Error::InvalidNameForCaptureGroup);
return name;
}
bool ECMA262Parser::parse_capture_group(ByteCode& stack, size_t& match_length_minimum, bool unicode, bool named)
{
consume(TokenType::LeftParen, Error::InvalidPattern);
if (match(TokenType::Questionmark)) {
// Non-capturing group or group with specifier.
consume();
if (match(TokenType::Colon)) {
consume();
ByteCode noncapture_group_bytecode;
size_t length = 0;
if (!parse_disjunction(noncapture_group_bytecode, length, unicode, named))
return set_error(Error::InvalidPattern);
consume(TokenType::RightParen, Error::MismatchingParen);
stack.extend(move(noncapture_group_bytecode));
match_length_minimum += length;
return true;
}
if (consume("<")) {
++m_parser_state.named_capture_groups_count;
auto group_index = ++m_parser_state.capture_groups_count; // Named capture groups count as normal capture groups too.
auto name = read_capture_group_specifier();
if (name.is_empty()) {
set_error(Error::InvalidNameForCaptureGroup);
return false;
}
ByteCode capture_group_bytecode;
size_t length = 0;
if (!parse_disjunction(capture_group_bytecode, length, unicode, named))
return set_error(Error::InvalidPattern);
consume(TokenType::RightParen, Error::MismatchingParen);
stack.insert_bytecode_group_capture_left(name);
stack.insert_bytecode_group_capture_left(group_index);
stack.extend(move(capture_group_bytecode));
stack.insert_bytecode_group_capture_right(name);
stack.insert_bytecode_group_capture_right(group_index);
match_length_minimum += length;
m_parser_state.named_capture_group_minimum_lengths.set(name, length);
m_parser_state.capture_group_minimum_lengths.set(group_index, length);
return true;
}
set_error(Error::InvalidCaptureGroup);
return false;
}
auto group_index = ++m_parser_state.capture_groups_count;
stack.insert_bytecode_group_capture_left(group_index);
ByteCode capture_group_bytecode;
size_t length = 0;
if (!parse_disjunction(capture_group_bytecode, length, unicode, named))
return set_error(Error::InvalidPattern);
stack.extend(move(capture_group_bytecode));
m_parser_state.capture_group_minimum_lengths.set(group_index, length);
consume(TokenType::RightParen, Error::MismatchingParen);
stack.insert_bytecode_group_capture_right(group_index);
match_length_minimum += length;
return true;
}
size_t ECMA262Parser::ensure_total_number_of_capturing_parenthesis()
{
if (m_total_number_of_capturing_parenthesis.has_value())
return m_total_number_of_capturing_parenthesis.value();
GenericLexer lexer { m_parser_state.lexer.source() };
size_t count = 0;
while (!lexer.is_eof()) {
switch (lexer.peek()) {
case '\\':
lexer.consume(2);
continue;
case '[':
while (!lexer.is_eof()) {
if (lexer.consume_specific('\\'))
lexer.consume();
else if (lexer.consume_specific(']'))
break;
lexer.consume();
}
break;
case '(':
if (lexer.consume_specific('?')) {
// non-capturing group '(?:', lookaround '(?<='/'(?<!', or named capture '(?<'
if (!lexer.consume_specific('<'))
break;
if (lexer.next_is(is_any_of("=!")))
break;
++count;
} else {
++count;
}
break;
}
lexer.consume();
}
m_total_number_of_capturing_parenthesis = count;
return count;
}
}