Re:Adam Langley's Pond: Secure Async Messaging
by packetslave on Saturday July 13, 2013 @11:09PM
(#6039769)
From the Go language spec:
"For signed integers, the operations +, -, *, and << may legally overflow and the resulting value exists and is deterministically defined by the signed integer representation, the operation, and its operands. No exception is raised as a result of overflow. A compiler may not optimize code under the assumption that overflow does not occur. For instance, it may not assume that x < x + 1 is always true."
func main() {
var foo int8 = 127
fmt.Println(foo + 1)
}
That's checking for integer overflow - an often-overlooked source of many security vulnerabilities.
That's a signed integer though, and I don't know if signed integer overflow has defined behavior in Go. In C that would be undefined behavior, allowing the compiler to do potentially nutty things, so you would want to do the overflow check before the increment. (Edit: considering who the author of this code is, I would assume that Go has sane defined behavior on signed integer overflow ;-)