From: Joseph Myers <joseph@codesourcery.com>
To: Martin Sebor <msebor@gmail.com>
Cc: Jason Merrill <jason@redhat.com>,
Gcc Patch List <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] detect attribute mismatches in alias declarations (PR 81824)
Date: Wed, 24 Oct 2018 13:04:00 -0000 [thread overview]
Message-ID: <alpine.DEB.2.21.1810241223110.21465@digraph.polyomino.org.uk> (raw)
In-Reply-To: <21833fc0-d4ca-d239-7194-49fe90a2f6d4@gmail.com>
On Wed, 24 Oct 2018, Martin Sebor wrote:
> /* The compiler will optimize based on the knowledge the parameter is
> not NULL. This will omit tests. A robust implementation cannot allow
> this so when compiling glibc itself we ignore this attribute. */
> # undef __nonnull
> # define __nonnull(params)
>
> I don't think this is actually true for recent versions of GCC.
> The nonnull optimization is controlled by
> -fisolate-erroneous-paths-attribute and according to the manual
> and common.opt the option is disabled by default.
I think -fisolate-erroneous-paths-attribute controls something different
(generating tests and traps rather than simply optimizing on the basis of
a parameter not being NULL).
--
Joseph S. Myers
joseph@codesourcery.com
next prev parent reply other threads:[~2018-10-24 12:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-01 21:01 Martin Sebor
2018-10-01 23:47 ` Joseph Myers
2018-10-23 7:29 ` Martin Sebor
2018-10-23 22:55 ` Joseph Myers
2018-10-24 9:06 ` Martin Sebor
2018-10-24 12:50 ` Joseph Myers
2018-10-24 17:00 ` Martin Sebor
2018-10-24 19:00 ` Joseph Myers
2018-10-24 21:29 ` Martin Sebor
2018-10-31 16:35 ` Martin Sebor
2018-10-24 13:04 ` Joseph Myers [this message]
2018-10-24 18:33 ` Martin Sebor
2018-11-07 21:59 ` Jeff Law
2018-11-09 17:33 ` Martin Sebor
2018-11-12 18:29 ` Matthew Malcomson
2018-11-12 18:38 ` Martin Sebor
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