exit status really is only 8 bits
Mon, 9 Jul 2001 10:18:47 -0700
> The fact that OS.Process.exit takes an integer argument is completely insane.
> I know that the basis documentation explicitly says that on Posix systems it
> does, but this is looney. Even worse, SML/NJ (and sadly MLton) don't detect
> the `overflow'. The exit status of a process holds some bits indicating what
> signal the process died as a result of receiving, and, if it did not die from
> a signal but used the exit system call, 8 bits of status passed to exit.
> Note, ONLY 8 bits.
> I would say that because of this the right thing to use is Word8.word, or a
> more abstract type, not int. If int is used, then an exception should be
> raised if it is not in [0, 256).
> I know that departing from the int that the basis spec kind-of requires may
> be painful, but could we at least raise some kind of exception in the case
> that it isn't in this range?
I hadn't noticed the comment in the basis library specs that says
On Posix-based systems, status will be be int.
I had always thought of status as an abstract type. That is stupid. I agree.
I'll put in a raise Fail in the MLton code.