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LibJS: Handle non-decimal integer literals in Value::to_number

Implements support for parsing binary and octal literals, and fixes
instances where a hex literal is parsed in ways the spec doesn't
allow.
This commit is contained in:
Slappy826 2022-08-26 11:14:04 -05:00 committed by Linus Groh
parent 583c0dc782
commit f4b3bb519f
2 changed files with 172 additions and 19 deletions

View file

@ -471,6 +471,92 @@ FLATTEN ThrowCompletionOr<Value> Value::to_numeric(VM& vm) const
return primitive.to_number(vm);
}
constexpr bool is_ascii_number(u32 code_point)
{
return is_ascii_digit(code_point) || code_point == '.' || (code_point == 'e' || code_point == 'E') || code_point == '+' || code_point == '-';
}
struct NumberParseResult {
StringView literal;
u8 base;
};
static Optional<NumberParseResult> parse_number_text(StringView text)
{
NumberParseResult result {};
auto check_prefix = [&](auto lower_prefix, auto upper_prefix) {
if (text.length() <= 2)
return false;
if (!text.starts_with(lower_prefix) && !text.starts_with(upper_prefix))
return false;
return true;
};
// https://tc39.es/ecma262/#sec-tonumber-applied-to-the-string-type
if (check_prefix("0b"sv, "0B"sv)) {
if (!all_of(text.substring_view(2), is_ascii_binary_digit))
return {};
result.literal = text.substring_view(2);
result.base = 2;
} else if (check_prefix("0o"sv, "0O"sv)) {
if (!all_of(text.substring_view(2), is_ascii_octal_digit))
return {};
result.literal = text.substring_view(2);
result.base = 8;
} else if (check_prefix("0x"sv, "0X"sv)) {
if (!all_of(text.substring_view(2), is_ascii_hex_digit))
return {};
result.literal = text.substring_view(2);
result.base = 16;
} else {
if (!all_of(text, is_ascii_number))
return {};
result.literal = text;
result.base = 10;
}
return result;
}
// 7.1.4.1.1 StringToNumber ( str ), https://tc39.es/ecma262/#sec-stringtonumber
static Optional<Value> string_to_number(StringView string)
{
// 1. Let text be StringToCodePoints(str).
String text = string.trim_whitespace();
// 2. Let literal be ParseText(text, StringNumericLiteral).
if (text.is_empty())
return Value(0);
if (text == "Infinity" || text == "+Infinity")
return js_infinity();
if (text == "-Infinity")
return js_negative_infinity();
auto result = parse_number_text(text);
// 3. If literal is a List of errors, return NaN.
if (!result.has_value())
return js_nan();
// 4. Return StringNumericValue of literal.
if (result->base != 10) {
auto bigint = Crypto::UnsignedBigInteger::from_base(result->base, result->literal);
return Value(bigint.to_double());
}
char* endptr;
auto parsed_double = strtod(text.characters(), &endptr);
if (*endptr)
return js_nan();
return Value(parsed_double);
}
// 7.1.4 ToNumber ( argument ), https://tc39.es/ecma262/#sec-tonumber
ThrowCompletionOr<Value> Value::to_number(VM& vm) const
{
@ -485,25 +571,8 @@ ThrowCompletionOr<Value> Value::to_number(VM& vm) const
return Value(0);
case BOOLEAN_TAG:
return Value(as_bool() ? 1 : 0);
case STRING_TAG: {
String string = Utf8View(as_string().string()).trim(whitespace_characters, AK::TrimMode::Both).as_string();
if (string.is_empty())
return Value(0);
if (string == "Infinity" || string == "+Infinity")
return js_infinity();
if (string == "-Infinity")
return js_negative_infinity();
char* endptr;
auto parsed_double = strtod(string.characters(), &endptr);
if (*endptr)
return js_nan();
// NOTE: Per the spec only exactly [+-]Infinity should result in infinity
// but strtod gives infinity for any case-insensitive 'infinity' or 'inf' string.
if (isinf(parsed_double) && string.contains('i', AK::CaseSensitivity::CaseInsensitive))
return js_nan();
return Value(parsed_double);
}
case STRING_TAG:
return string_to_number(as_string().string().view());
case SYMBOL_TAG:
return vm.throw_completion<TypeError>(ErrorType::Convert, "symbol", "number");
case BIGINT_TAG: