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From: Jonathan Wakely <jwakely.gcc@gmail.com>
Date: Thu, 30 Apr 2020 22:57:49 +0100
Message-ID: <CAH6eHdRXFzFn17CVdpz6S0sWqJixzLboxTm+othc2GksVWnBgw@mail.gmail.com>
Subject: Re: -fsanitize=undefined behavior
To: Tom N <nospam@codesniffer.com>
Cc: gcc-help <gcc-help@gcc.gnu.org>
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On Thu, 30 Apr 2020 at 22:27, Tom N <nospam@codesniffer.com> wrote:
>
> The man page for -fsanitize=3Dundefined lists a bunch of sub-options (eg.=
 -fsanitize=3Dshift, -fsanitize=3Dshift-exponent, etc).  If I include -fsan=
itize=3Dundefined does it enable all of the sub-options, or none, or someth=
ing in between?  If it doesn't enable all sub-options, is there an easy way=
 to do that short of specifying all of them?

The man page says:

"Unlike other similar options, -fsanitize=3Dfloat-divide-by-zero is not
enabled by -fsanitize=3Dundefined" and "Unlike other similar options,
-fsanitize=3Dfloat-cast-overflow is not enabled by -fsanitize=3Dundefined"

So it seems reasonable to assume that all the other suboptions are
enabled by -fsanitize=3Dundefined, and if you want *all* of them then
use -fsanitize=3Dundefined -fsanitize=3Dfloat-divide-by-zero
-fsanitize=3Dfloat-cast-overflow