From: "Uecker, Martin" <Martin.Uecker@med.uni-goettingen.de>
To: "Peter.Sewell@cl.cam.ac.uk" <Peter.Sewell@cl.cam.ac.uk>
Cc: "gcc@gcc.gnu.org" <gcc@gcc.gnu.org>,
"law@redhat.com" <law@redhat.com>,
"richard.guenther@gmail.com" <richard.guenther@gmail.com>,
"cl-c-memory-object-model@lists.cam.ac.uk"
<cl-c-memory-object-model@lists.cam.ac.uk>
Subject: Re: C provenance semantics proposal
Date: Thu, 18 Apr 2019 15:09:00 -0000 [thread overview]
Message-ID: <1555600162.29723.1.camel@med.uni-goettingen.de> (raw)
In-Reply-To: <CAHWkzRTGBTVQSPT125dF92se51OPpta5XBpkf4AWCAX3ARbrXA@mail.gmail.com>
Am Donnerstag, den 18.04.2019, 15:49 +0100 schrieb Peter Sewell:
> On Thu, 18 Apr 2019 at 14:54, Uecker, Martin
> <Martin.Uecker@med.uni-goettingen.de> wrote:
> >
> > Am Donnerstag, den 18.04.2019, 07:42 -0600 schrieb Jeff Law:
> > > On 4/18/19 6:20 AM, Uecker, Martin wrote:
> > > > Am Donnerstag, den 18.04.2019, 11:45 +0100 schrieb Peter Sewell:
> > > > > On Thu, 18 Apr 2019 at 10:32, Richard Biener <richard.guenther@gmail.com> wrote:
> >
> > ...
> > > > 4.) Compilers make sure that exposed objects never
> > > > are allocated next to each other (as Jens proposed).
> > >
> > > Ugh. Not sure how you enforce that. Consider that the compiler may
> > > ultimately have no control over layout of data in static storage.
> >
> > One maybe only where it matters? I assume the biggest benefit
> > is for local variables and there the compiler has full control.
> >
> > For arbitrary pointer coming from somewhere, one has no provenance
> > information anyway.
>
> that's not quite true - one does know that it can't have the same provenance
> as anything created more recently than the incoming pointer
Good point. But then the objects can not be next to each other anyway.
Best,
Martin
next prev parent reply other threads:[~2019-04-18 15:09 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-02 8:11 Peter Sewell
2019-04-12 14:51 ` Jeff Law
2019-04-12 15:31 ` Peter Sewell
2019-04-17 9:06 ` Richard Biener
2019-04-17 9:15 ` Peter Sewell
2019-04-17 9:41 ` Richard Biener
2019-04-17 11:53 ` Uecker, Martin
2019-04-17 12:41 ` Richard Biener
2019-04-17 12:56 ` Uecker, Martin
2019-04-17 13:35 ` Richard Biener
2019-04-17 14:12 ` Uecker, Martin
2019-04-17 17:31 ` Peter Sewell
2019-04-18 9:32 ` Richard Biener
2019-04-18 9:56 ` Richard Biener
2019-04-18 10:48 ` Peter Sewell
2019-04-18 11:57 ` Uecker, Martin
2019-04-18 12:31 ` Richard Biener
2019-04-18 13:25 ` Uecker, Martin
2019-04-18 10:45 ` Peter Sewell
2019-04-18 12:20 ` Uecker, Martin
2019-04-18 12:42 ` Richard Biener
2019-04-18 12:47 ` Jakub Jelinek
2019-04-18 12:51 ` Jakub Jelinek
2019-04-18 13:29 ` Jeff Law
2019-04-24 10:12 ` Richard Biener
2019-04-18 13:49 ` Uecker, Martin
2019-04-19 8:19 ` Jens Gustedt
2019-04-19 8:49 ` Jakub Jelinek
2019-04-19 9:09 ` Jens Gustedt
2019-04-19 9:34 ` Jakub Jelinek
2019-04-21 8:15 ` Jens Gustedt
2019-04-24 10:24 ` Richard Biener
2019-04-24 18:43 ` Jeff Law
2019-04-24 19:21 ` Jens Gustedt
2019-04-19 9:11 ` Peter Sewell
2019-04-19 9:15 ` Jens Gustedt
2019-04-19 9:35 ` Peter Sewell
2019-04-19 10:35 ` Uecker, Martin
2019-04-19 10:01 ` Uecker, Martin
2019-04-18 13:42 ` Jeff Law
2019-04-18 13:54 ` Uecker, Martin
2019-04-18 14:49 ` Peter Sewell
2019-04-18 15:09 ` Uecker, Martin [this message]
2019-04-24 10:19 ` Richard Biener
2019-04-24 18:41 ` Jeff Law
2019-04-24 19:30 ` Philipp Klaus Krause
2019-04-24 19:55 ` Uecker, Martin
2019-04-24 19:33 ` Jakub Jelinek
2019-04-24 21:19 ` Peter Sewell
2019-04-25 12:42 ` Richard Biener
2019-04-25 13:03 ` Peter Sewell
2019-04-25 13:13 ` Richard Biener
2019-04-25 13:20 ` Peter Sewell
2019-04-29 14:31 ` Joseph Myers
2019-04-25 12:39 ` Richard Biener
2019-05-09 11:26 ` Ralf Jung
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