<span style=" font-size:10pt;font-family:sans-serif"> Re: [OpenJDK
2D-Dev] RFR: Bug Pending: Build fails to compile jchuff.cErik Joelsson
to: Adam Farley8 01/02/2018 17:06</span>
<br><span style=" font-size:10pt;font-family:sans-serif">Cc: build-dev,
David Holmes, John Paul Adrian Glaubitz, Magnus Ihse Bursie</span>
<br><span style=" font-size:10pt;font-family:sans-serif">From: Erik Joelsson
<erik.joelsson@oracle.com></span>
<br><span style=" font-size:10pt;font-family:sans-serif">To: Adam Farley8
<adam.farley@uk.ibm.com></span>
<br><span style=" font-size:10pt;font-family:sans-serif">Cc: build-dev
<build-dev@openjdk.java.net>, David Holmes <david.holmes@oracle.com>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>, Magnus
Ihse Bursie <magnus.ihse.bursie@oracle.com></span>
<br><span style=" font-size:10pt;font-family:sans-serif"> </span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">> Am I understanding
this correctly that it's really not tied to a gcc version</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> but a cpu
architecture, so it's only really affecting s390x? </span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">I'm saying it
is tied to a combination of CPU architecture and gcc version.</span>
<br><span style=" font-size:10pt;font-family:sans-serif">Any combination
of the affected gcc versions (4.8.5, 5.4.0) and affected</span>
<br><span style=" font-size:10pt;font-family:sans-serif">platforms (zLinux,
ppcle Linux) see this error.</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">x86 Linux is not
affected, not are gcc versions equal to (or, I assume, later </span>
<br><span style=" font-size:10pt;font-family:sans-serif">than) 7.2.1.</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">> Are you also
saying that gcc 7.2.1 is also affected but with a different </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> message?
I'm fine with disabling this warning conditional on s390x, no need </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> for specific
gcc versions.</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">I was unclear.
7.2.1 fails my unit test with a different warning, but a build </span>
<br><span style=" font-size:10pt;font-family:sans-serif">I ran proves that
this warning doesn't fail the build.</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">That being said,
the addition of this option to a 7.2.1 test didn't seem to </span>
<br><span style=" font-size:10pt;font-family:sans-serif">break anything,
so we should be fine to just stick </span>
<br><span style=" font-size:10pt;font-family:sans-serif">"DISABLED_WARNINGS_gcc
:= clobbered array-bounds" into Awt2dLibraries.gmk. </span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">> This discussion
has already taken more time than it really warrants. :)</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">Agreed. :)</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">> Regarding
warning chasing. I agree that we it's not feasible to chase down every
</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> warning in
every version of GCC, or any other toolchain, but I also think that </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> for platforms/configurations
where people are actively developing changes for </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> OpenJDK,
it makes sense to try to keep it clean. This helps prevent new code from
</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> introducing
warnings. For the configurations Oracle use, we keep a strict -Werror </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> policy because
we want the code to be clean. I'm fine with other users trying to </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> keep the
same standards on their configurations, but knowing that it will be their
</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> responsibility
to keep up to date. I also think we need to be reasonably fine grained
</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> in when we
disable warnings. Specifying every affected version of a toolchain is too
</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> much, but
if there are specific well defined limits to where the disabling relevant,
</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> then I think
we should use them, within reason. This also helps with keeping track </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> of why a
particular warning is disabled in a future attempt to fix them.</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">I agree with all
of this. Well put. :)</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">> On the other
hand, if you are just building OpenJDK to produce binaries, without </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> producing
and up streaming new code changes, there really isn't much need for </span>
<br><span style=" font-size:10pt;font-family:sans-serif">> making the
effort of trying to keep things clean, and trying to do so will likely
</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> just end
up being more work than it's worth.</span>
<br><span style=" font-size:10pt;font-family:sans-serif">> /Erik</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">I'm building OpenJDK
to test fixes and new features, which I will eventually contribute</span>
<br><span style=" font-size:10pt;font-family:sans-serif">to OpenJDK. I
consider this to be one of those fixes. One fix at a time. :)</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">Given all of this,
I ask for a volunteer to raise a bug so we can integrate this change </span>
<br><span style=" font-size:10pt;font-family:sans-serif">into JDK8 (as
it's still very popular), and JDK. </span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">10 would be great
too, though I understand it's locked against all but the worst bugs.</span>
<br><span style=" font-size:10pt;font-family:sans-serif">9 is optional,
as it's soon to be replaced by 10.</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">Best Regards</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">Adam Farley</span>
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