RFR: 8065648: Remove the flag -fsanitize=undefined for GCC 4.9 and later

[Erik Joelsson]

I think it's a reasonable change to remove the flag as it has most 
likely not seen much use (if any) yet. I'm not sure what it does, but I 
assume it's something to improve exploit protection the source code. But 
if it doesn't work, we can't use it.

We could also consider disabling the flag for the specific file where we 
have the problem, if we think it's useful to keep the flag.

/Erik

On 2014-11-21 15:57, Erik Helin wrote:
> Hi all,
>
> this patch removes the usage of the flag -fsanitize=undefined introduced
> in GCC 4.9. The reason for not using this flag is that the implementation
> in GCC still seem to have some bugs [0] (which I have encountered). The
> flag is currently only enabled for slowdebug builds.
>
> My suggestion is that we remove the flag for now, since the only supported
> GCC version is 4.8.2 [1]. Then we can revisit this decisision when we upgrade
> the supported compiler to GCC 4.9.x, since hopefully the bugs in GCC have
> been fixed by then.
>
> What do you think?
>
> Webrev:
> http://cr.openjdk.java.net/~ehelin/8065648/webrev.00/
>
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8065648
>
> Testing:
> - Verified that generated-configure.sh no longer tries to enable the flag.
>
> Thanks,
> Erik
>
> [0]: https://bugzilla.redhat.com/show_bug.cgi?id=1166173
> [1]: http://mail.openjdk.java.net/pipermail/jdk9-dev/2014-October/001489.html