Re: [PATCH] Smackv10: Smack rules grammar + their stateful parser(2)

From: Jakob Oestergaard
Date: Sat Nov 10 2007 - 12:31:20 EST


...
> I've double-checked the code for any possible off-by-one/overflow
> errors.
...

Two things caught my eye.

...
> + case bol:
> + case subject:
> + if (*label_len >= SMK_MAXLEN)
> + goto out;
> + subjectstr[(*label_len)++] = data[i];

Why is the '>' necessary? Could it happen that you had incremented past the
point of equality?

If that could not happen, then in my oppinion '>=' is very misleading when '=='
is really what is needed.

...
> + case object:
> + if (*prevstate == blank) {
> + subjectstr[*label_len] = '\0';
> + *label_len = 0;
> + }

I wonder why it is valid to uncritically use the already incremented label_len
here, without checking its value (like is done above).

It seems strangely asymmetrical. I'm not saying it's wrong, because there may
be a subtle reason as to why it's not, but if that's the case then I think that
subtle reason should be documented with a comment.

...
> + case access:
> + if (*prevstate == blank) {
> + objectstr[*label_len] = '\0';
> + *label_len = 0;
> + }

Same applies here.


--

/ jakob

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