RFR : 8202322: AIX: symbol visibility flags not support on xlc 12.1

Fri Apr 27 07:20:38 UTC 2018

Hi Christoph

On Fri, Apr 27, 2018 at 8:07 AM, Langer, Christoph
<christoph.langer at sap.com> wrote:
> Hi Thomas,
>
> Look at this blog: https://www.ibm.com/developerworks/aix/library/au-aix-symbol-visibility-part2/index.html
>
> if I understand it correctly, the xlc 12 default behavior should be like what we'd expect from -qvisibility=hidden.
>

Where in this article do you read this?

..Thomas

> Best regards
> Christoph
>
>> -----Original Message-----
>> From: build-dev [mailto:build-dev-bounces at openjdk.java.net] On Behalf Of
>> Thomas Stüfe
>> Sent: Freitag, 27. April 2018 06:55
>> To: Volker Simonis <volker.simonis at gmail.com>; Baesken, Matthias
>> <matthias.baesken at sap.com>
>> Cc: Simonis, Volker <volker.simonis at sap.com>; ppc-aix-port-
>> dev at openjdk.java.net; core-libs-dev at openjdk.java.net; build-
>> dev at openjdk.java.net
>> Subject: Re: RFR : 8202322: AIX: symbol visibility flags not support on xlc 12.1
>>
>> Hi,
>>
>> This was added by "8200178: Remove mapfiles for JDK native libraries".
>> But if the flag is not accepted, what is the default behavior? Do we
>> now export everything?
>>
>> I'd like to understand this first before removing the flag to get rid
>> of the warnings.
>>
>> Best Regards, Thomas
>>
>> On Thu, Apr 26, 2018 at 5:16 PM, Volker Simonis
>> <volker.simonis at gmail.com> wrote:
>> > Hi Matthias,
>> >
>> > after Bhaktavatsal Reddy's report about the problems with
>> > "-qvisibility" with xlC 13 and taking into account that we can't test
>> > this anyway because we don't currently have xlC 13
>> >  on our machines I think it would be best to completely remove this
>> > option for now on AIX. Once we get xlC 13 we can revisit the issue.
>> >
>> > Thanks,
>> > Volker
>> >
>> >
>> > On Thu, Apr 26, 2018 at 4:59 PM, Bhaktavatsal R Maram
>> > <bhamaram at in.ibm.com> wrote:
>> >> Hi Matthias,
>> >>
>> >> At this point, I think we can remove the flag as you found that it is not
>> supported in XLC < 13. And with XLC 13, it require more work to use this flag.
>> >>
>> >> Thanks,
>> >> Bhaktavatsal Reddy
>> >>
>> >>
>> >>
>> >> -----"Baesken, Matthias" <matthias.baesken at sap.com> wrote: -----
>> >> To: "Langer, Christoph" <christoph.langer at sap.com>, "'build-
>> dev at openjdk.java.net'" <build-dev at openjdk.java.net>, "ppc-aix-port-
>> dev at openjdk.java.net" <ppc-aix-port-dev at openjdk.java.net>, "core-libs-
>> dev at openjdk.java.net" <core-libs-dev at openjdk.java.net>
>> >> From: "Baesken, Matthias" <matthias.baesken at sap.com>
>> >> Date: 04/26/2018 08:23PM
>> >> Cc: "Simonis, Volker" <volker.simonis at sap.com>, Bhaktavatsal R Maram
>> <bhamaram at in.ibm.com>
>> >> Subject: RE: RFR : 8202322: AIX: symbol visibility flags not support on xlc
>> 12.1
>> >>
>> >>
>> >>  Hello Christoph,   I think  all XLC versions  < 12.1   are unsupported  (and
>> probably not working anyway)  for the OpenJDK  build .
>> >>  I am only aware   of  XLC  versions  12.1  and 13.1    which  work / in case of
>> 13.1  “might” work   for OpenJDK compilation .
>> >>  And for 12.1  I want to remove the flags  .
>> >>
>> >>  ( waiting for the feedback  of   Bhaktavatsal Reddy ,  in case he  prefers it
>> I remove them for all xlC versions including 13.1 )
>> >>
>> >>  Best regards, Matthias
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>  From: Langer, Christoph
>> >>  Sent: Donnerstag, 26. April 2018 16:38
>> >>  To: Baesken, Matthias <matthias.baesken at sap.com>; 'build-
>> dev at openjdk.java.net' <build-dev at openjdk.java.net>; ppc-aix-port-
>> dev at openjdk.java.net; core-libs-dev at openjdk.java.net
>> >>  Cc: Simonis, Volker <volker.simonis at sap.com>
>> >>  Subject: RE: RFR : 8202322: AIX: symbol visibility flags not support on xlc
>> 12.1
>> >>
>> >>  Hi Matthias,
>> >>
>> >>  to me the change in principal looks good.
>> >>
>> >>  I’m wondering if it is possible to do a comparison like xlc < 13 (e.g. extract
>> major number before the first dot, then compare numerically) – but maybe it
>> is too complicated and the current single version compare suits  our needs ?
>> >>
>> >>  Best regards
>> >>  Christoph
>> >>
>> >>
>> >>
>> >>
>> >>  From: Baesken, Matthias
>> >>  Sent: Donnerstag, 26. April 2018 16:14
>> >>  To: 'build-dev at openjdk.java.net' <build-dev at openjdk.java.net>; ppc-
>> aix-port-dev at openjdk.java.net; core-libs-dev at openjdk.java.net
>> >>  Cc: Langer, Christoph <christoph.langer at sap.com>; Simonis, Volker
>> <volker.simonis at sap.com>
>> >>  Subject: RFR : 8202322: AIX: symbol visibility flags not support on xlc 12.1
>> >>
>> >>  Hello  ,  could you please review this small adjustment to  the symbol
>> visibility compilation settings on AIX ?
>> >>  Currently  we use  XLC 12.1  to compile  JDK on AIX .
>> >>
>> >>  However XLC 12.1   does not support  the “-qvisibility=hidden”  setting
>> currently set on AIX.
>> >>  It was introduced with  XLC 13.1 . Christoph found some info about it here
>> :
>> >>
>> >>  https://www.ibm.com/developerworks/aix/library/au-aix-symbol-
>> visibility-part2/index.html
>> >>
>> >>  Setting it  only generates  hundreds  of warnings  in the build log ,
>> warnings look like this :
>> >>  XlC12.1
>> >>
>> >>  bash-4.4$ xlC -qversion
>> >>  IBM XL C/C++ for AIX, V12.1 (5765-J02, 5725-C72)
>> >>  Version: 12.01.0000.0019
>> >>
>> >>  bash-4.4$ xlC -qvisibility=hidden sizeof.c -o sizeof_aixxlc
>> >>  1506-173 (W) Option visibility=hidden is not valid. Enter xlC for list of valid
>> options.
>> >>
>> >>  Compare to XLC13.1
>> >>
>> >>  bash-3.00$ xlC -qversion
>> >>  IBM XL C/C++ for AIX, V13.1 (5725-C72, 5765-J07)
>> >>  Version: 13.01.0000.0008
>> >>  bash-3.00$ xlC -qvisibility=default sizeof.c -o sizeof_aixxlc
>> >>  bash-3.00$ xlC -qvisibility=hidden sizeof.c -o sizeof_aixxlc
>> >>
>> >>
>> >>  So it is better to avoid  setting these flags when using xlc12.1   .
>> >>  Please review :
>> >>
>> >>  Bug :
>> >>
>> >>  https://bugs.openjdk.java.net/browse/JDK-8202322
>> >>
>> >>  Change :
>> >>
>> >>  http://cr.openjdk.java.net/~mbaesken/webrevs/8202322/
>> >>
>> >>
>> >>  Best regards, Matthias
>> >>
>> >>
>> >>
>> >>