Re: [PATCH] fold more string comparison with known result (PR 90879)

[Jakub Jelinek <jakub at redhat dot com>]

On Fri, Aug 09, 2019 at 10:51:09AM -0600, Martin Sebor wrote:
> That said, we should change this code one way or the other.
> There is even less of a guarantee that other compilers support
> writing past the end of arrays that have non-zero size than
> that they recognize the documented zero-length extension.

We use that everywhere forever, so no.
See e.g. rtx u.fld and u.hwint arrays, tree_exp operands array,
gimple_statement_with_ops op array just to name a few that are
everywhere.  Coverity is indeed unhappy about
that, but it would be with [0] certainly too.  Another option is
to use maximum possible size where we know it (which is the case of
rtxes and most tree expressions and gimple stmts, but not e.g.
CALL_EXPR or GIMPLE_CALL where there is no easy upper bound.

	Jakub