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

Fri Apr 27 06:07:26 UTC 2018

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.

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
> >>
> >>
> >>
> >>