string to int signedness casting GO-E1006
Bug risk
Critical
6 months ago
—
2 years old
string to int signedness cast "int32(t)", might result in lost or misinterpreted data
51 zap.Error(err),
52 )
53 } else {
54 return int32(t) 55 }
56 }
57 if now32 == 0 || cacheConfig.ShortTimeoutSec == 0 || cacheConfig.ShortDuration == 0 {
Description
It is possible for integer casting, if not appropriately done to lose the signedness of the integer and might cause overflow as well.
For example:
- int64 must not be casted to: "uint8", "uint16", "uint32", "uint64", "int8", "int16", "int32"
int64 can lose signedness if converted to unsigned integer and if converted to
a signed integer but a type other than int64, then overflow might occur.
uint64must not be casted to: "uint8", "uint16", "uint32", "int8", "int16", "int32", "int64"uint64would lose signedness if converted to a signed integer and might overflow. If converted to an unsigned integer, i.e., a type other thanuint64, overflow might occur.
Bad practice
n, err := strconv.Atoi("42")
if err != nil {
panic(err)
}
// `n` is of type `int`, so it is either `int64` or `int32` depending on the platform.
// Casting it to `uint8` might result in loss of signedness of the integer and might
// not give expected results.
_ = uint8(n)