RFR(XS): 8214063: [AIX] Disable symbol visibility flags

[Baesken, Matthias]

> Change "8202322: AIX: symbol visibility flags not support on xlc 12.1"
> [1] blindly introduced these flags for all xlC compiler versions >

Hello,  probably you did not look correctly at  my  change 8202322  .

It   did NOT "blindly"  introduce  visibility flags  for   all xlC  compilers, but Instead it   ***removed***   the flags  in cases  where   xlc 12.1 was used 
(because they generated  a TON of warnings with xlc 12.1 ,  which  messed up the build log  and made  build  operations/analysis a pain).

See the description : 
https://bugs.openjdk.java.net/browse/JDK-8202322

"For a while the OpenJDK build on AIX attempts to set symbol visibility related flags; however they are not supported on our standard xlc version 12.1 so they generate a lot of warnings."


Please see : 

http://hg.openjdk.java.net/jdk/jdk/rev/98f57dff16f3


> Now  that people are starting to really use xlC 13 it turns out that there
> is more to do than just enabling the flags

It was pretty  clear from the  beginning  that  with  higher xlc versions  than 12.1   the chance  that it works "out of the box"  is low .

Regards, Matthias



> -----Original Message-----
> From: ppc-aix-port-dev <ppc-aix-port-dev-bounces at openjdk.java.net> On
> Behalf Of Volker Simonis
> Sent: Dienstag, 27. November 2018 16:34
> To: build-dev <build-dev at openjdk.java.net>; ppc-aix-port-
> dev at openjdk.java.net
> Cc: adam.farley at uk.ibm.com
> Subject: RFR(XS): 8214063: [AIX] Disable symbol visibility flags
> 
> Hi,
> 
> can I please have a review for the following trivial change which
> simply disables the symbol visibility flags on AIX:
> 
> http://cr.openjdk.java.net/~simonis/webrevs/2018/8214063/
> https://bugs.openjdk.java.net/browse/JDK-8214063
> 
> Change "8202322: AIX: symbol visibility flags not support on xlc 12.1"
> [1] blindly introduced these flags for all xlC compiler versions >
> 12.1 without ever testing it (which should not have happened). Now
> that people are starting to really use xlC 13 it turns out that there
> is more to do than just enabling the flags. This future work is
> covered by "8204541: Correctly support AIX xlC 13.1 symbol visibility
> flags".
> 
> Thank you and best regards,
> Volker
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8202322
> [2] https://bugs.openjdk.java.net/browse/JDK-8204541