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LibJS: Fix some small remaining issues with parsing unicode escapes

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Added a test to ensure the behavior stays the same.
We now throw on a direct usage of an escaped keywords with a specific
error to make it more clear to the user.
This commit is contained in:
davidot 2021-08-21 11:27:20 +02:00 • committed by Linus Groh
parent b012170d69
commit 7bcffd1b6a
6 changed files with 125 additions and 9 deletions
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34
Userland/Libraries/LibJS/Parser.cpp
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@ -404,6 +404,11 @@ NonnullRefPtr<Statement> Parser::parse_statement(AllowLabelledFunction allow_lab
m_state.current_token = m_state.lexer.force_slash_as_regex();
[[fallthrough]];
default:
if (m_state.current_token.type() == TokenType::EscapedKeyword
&& (m_state.strict_mode
|| (m_state.current_token.value() != "yield"sv && m_state.current_token.value() != "let"sv)))
syntax_error("Keyword must not contain escaped characters");
if (match_identifier_name()) {
auto result = try_parse_labelled_statement(allow_labelled_function);
if (!result.is_null())
@ -545,7 +550,7 @@ RefPtr<Statement> Parser::try_parse_labelled_statement(AllowLabelledFunction all
load_state();
};
if (match(TokenType::Yield) && (m_state.strict_mode || m_state.in_generator_function_context)) {
if (m_state.current_token.value() == "yield"sv && (m_state.strict_mode || m_state.in_generator_function_context)) {
syntax_error("'yield' label not allowed in this context");
return {};
}
@ -604,7 +609,8 @@ RefPtr<MetaProperty> Parser::try_parse_new_target_expression()
consume();
if (!match(TokenType::Identifier))
return {};
if (consume().value() != "target")
// The string 'target' cannot have escapes so we check original value.
if (consume().original_value() != "target"sv)
return {};
state_rollback_guard.disarm();
@ -847,6 +853,9 @@ Parser::PrimaryExpressionParseResult Parser::parse_primary_expression()
if (!m_state.allow_super_property_lookup)
syntax_error("'super' keyword unexpected here");
return { create_ast_node<SuperExpression>({ m_state.current_token.filename(), rule_start.position(), position() }) };
case TokenType::EscapedKeyword:
syntax_error("Keyword must not contain escaped characters");
[[fallthrough]];
case TokenType::Identifier: {
read_as_identifier:;
if (!try_parse_arrow_function_expression_failed_at_position(position())) {
@ -2800,6 +2809,14 @@ bool Parser::match_variable_declaration()
bool Parser::match_identifier() const
{
if (m_state.current_token.type() == TokenType::EscapedKeyword) {
if (m_state.current_token.value() == "let"sv)
return !m_state.strict_mode;
if (m_state.current_token.value() == "yield"sv)
return !m_state.strict_mode && !m_state.in_generator_function_context;
return true;
}
return m_state.current_token.type() == TokenType::Identifier
|| (m_state.current_token.type() == TokenType::Let && !m_state.strict_mode)
|| (m_state.current_token.type() == TokenType::Yield && !m_state.in_generator_function_context && !m_state.strict_mode); // See note in Parser::parse_identifier().
@ -2859,6 +2876,9 @@ Token Parser::consume_identifier()
if (match(TokenType::Identifier))
return consume(TokenType::Identifier);
if (match(TokenType::EscapedKeyword))
return consume(TokenType::EscapedKeyword);
// Note that 'let' is not a reserved keyword, but our lexer considers it such
// As it's pretty nice to have that (for syntax highlighting and such), we'll
// special-case it here instead.
@ -2884,6 +2904,16 @@ Token Parser::consume_identifier_reference()
if (match(TokenType::Identifier))
return consume(TokenType::Identifier);
if (match(TokenType::EscapedKeyword)) {
auto name = m_state.current_token.value();
if (name == "await"sv)
syntax_error("Identifier reference may not be 'await'");
else if (m_state.strict_mode && (name == "let"sv || name == "yield"sv))
syntax_error(String::formatted("'{}' is not allowed as an identifier in strict mode", name));
return consume();
}
// See note in Parser::parse_identifier().
if (match(TokenType::Let)) {
if (m_state.strict_mode)