On Thu, Aug 02, 2018 at 11:00:32AM -0600, Martin Sebor wrote:
> As an alternate approach I have been thinking about, if
> there is a strong feeling that allowing strlen to iterate
> past the subobject boundary is necessary (I don't believe
> it is.)
>
> Rather than indiscriminately expanding the provenance of
> the subobject regardless of what members follow it in
> the enclosing structure, only consider doing that if
> the next member is an array of the same type. E.g.,
>
> struct S { char a[4], b[3], c[2], d; };
> extern struct S *p;
>
> strlen (p->a); // consider p->a's bounds to be char[9]
See the mail with testcases where the middle-end doesn't distinguish
between p->a and (char *) p, unless you want to warn or optimize
in the FEs or extremely early in the lowering passes, that isn't going to
work.
Jakub
