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Re: [PATCH][4.3] Deprecate -ftrapv
- From: Richard Guenther <rguenther at suse dot de>
- To: "Joseph S. Myers" <joseph at codesourcery dot com>
- Cc: gcc-patches at gcc dot gnu dot org, gcc at gcc dot gnu dot org, Mark Mitchell <mark at codesourcery dot com>
- Date: Sat, 1 Mar 2008 01:22:53 +0100 (CET)
- Subject: Re: [PATCH][4.3] Deprecate -ftrapv
- References: <Pine.LNX.4.64.0803010041110.4133@zhemvz.fhfr.qr> <Pine.LNX.4.64.0803010010050.21300@digraph.polyomino.org.uk>
On Sat, 1 Mar 2008, Joseph S. Myers wrote:
> On Sat, 1 Mar 2008, Richard Guenther wrote:
>
> > This is a request to depcrecate -ftrapv which has numerous problems
> > making it not work as expected since a long time. As nobody seems
> > to have the energy to ensure it is working I propose to deprecate it
> > for GCC 4.3 to make it possible to remove it during 4.4 (and not
> > block removing libcall notes by it).
> >
> > Ok for 4.3? I'll prepare an entry for the changes.html as well.
>
> If this does need to be deprecated (and it's a feature for which I hope
> someone will step forward to fix or reimplement it, since we know people
> have used it to find integer overflow bugs in their code, despite its
> known limitations), it should give a deprecation warning on all
> compilations using the option, not just be deprecated in documentation.
I seriously doubt anyone has used it for anything useful since at least
the advent of tree-ssa. I see we for example warn for -fforce-mem
in 4.2, but that is a no-op there. Do we have an option to disable
such warnings? After all it would break -Werror.
Richard.