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From: Richard Biener <richard.guenther@gmail.com>
Date: Wed, 5 May 2021 09:26:50 +0200
Message-ID: <CAFiYyc038ZDGA+q6qkhvFMCGXD3qUQVNt0qwz806BAb=7h3FiQ@mail.gmail.com>
Subject: Re: [PATCH] run early sprintf warning after SSA (PR 100325)
To: Martin Sebor <msebor@gmail.com>
Cc: gcc-patches <gcc-patches@gcc.gnu.org>, Aldy Hernandez <aldyh@redhat.com>
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On Wed, May 5, 2021 at 1:32 AM Martin Sebor via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> With no optimization, -Wformat-overflow and -Wformat-truncation
> runs early to detect a subset of simple bugs.  But as it turns out,
> the pass runs just a tad too early, before SSA.  That causes it to
> miss a class of problems that can easily be detected once code is
> in SSA form, and I would expect might also cause false positives.
>
> The attached change moves the sprintf pass just after pass_build_ssa,
> similar to other early flow-sensitive warnings (-Wnonnull-compare and
> -Wuninitialized).

Makes sense.  I suppose walloca might also benefit from SSA - it seems
to do range queries which won't work quite well w/o SSA?

Thus OK.

Thanks,
Richard.

> Martin