Add overflow check

This commit is contained in:
Victor Zverovich 2024-01-01 09:17:10 -08:00
parent 1a95e5d1b4
commit ce3161887a
2 changed files with 9 additions and 5 deletions

View File

@ -63,6 +63,9 @@ TEST(scan_test, read_hex) {
unsigned n = 0;
fmt::scan("2a", "{:x}", n);
EXPECT_EQ(n, 42);
auto num_digits = std::numeric_limits<unsigned>::digits / 4;
EXPECT_THROW_MSG(fmt::scan(fmt::format("1{:0{}}", 0, num_digits), "{:x}", n),
fmt::format_error, "number is too big");
}
TEST(scan_test, read_string) {

View File

@ -499,18 +499,19 @@ auto read_hex(scan_iterator it, T& value)
if (digit < 0) break;
} while (it != scan_sentinel());
// TODO: Check overflow.
(void)num_digits;
// Check overflow.
if (num_digits <= (std::numeric_limits<T>::digits >> 2))
value = n;
else
throw_format_error("number is too big");
return it;
}
template <typename T, FMT_ENABLE_IF(std::is_unsigned<T>::value)>
auto read(scan_iterator it, T& value, const format_specs<>& specs)
-> scan_iterator {
if (specs.type == presentation_type::hex_lower) {
if (specs.type == presentation_type::hex_lower)
return read_hex(it, value);
}
return read(it, value);
}