RFR: 8236714: enable link-time section-gc for linux to remove unused code

[Baesken, Matthias]

Hi Erik, thanks for the comments, new webrev :

http://cr.openjdk.java.net/~mbaesken/webrevs/8236714.7/

Best regards, Matthias



> Hello,
> 
> That's better, but there are still some issues.
> 
> flags-cflags.m4
> 
> Code is repeated in both if and else block.
> 
> jdk-options.m4
> 
> The default is now true for all platforms. I would suggest moving the
> s390x conditional down into an elif after the elif for "no".
> 
> LibCommon.gmk
> 
> Please revert whole file.
> 
> /Erik
> 
> On 2020-01-23 05:15, Baesken, Matthias wrote:
> > Hi Erik,  new webrev :
> >
> > http://cr.openjdk.java.net/~mbaesken/webrevs/8236714.6/
> >
> > I moved the settings back into the  m4 files .
> >
> > Best regards, Matthias
> >
> >> Hello Matthias,
> >>
> >> You can keep the setting up of all the flags in flags-cflags.m4 and
> >> flags-ldflags.m4 based on the value of ENABLE_LINKTIME_GC. You can
> also
> >> default the value of this new parameter to true for s390x to keep the
> >> current behavior for that platform. As it is in this patch, the JVM
> >> flags for s390x are setup in configure while the JDK flags are in make,
> >> which gets confusing I think.
> >>
> >> /Erik
> >>
> >>
> >> On 2020-01-22 05:33, Baesken, Matthias wrote:
> >>> Hi Magnus / David,  here is a new webrev :
> >>>
> >>>
> >>> http://cr.openjdk.java.net/~mbaesken/webrevs/8236714.4/
> >>>
> >>>
> >>> it supports now a  configure switch  --enable-linktime-gc=yes  that needs
> to
> >> be set  to enable the link time section gc  .
> >>> Exception is linuxs390x  where we already have the  feature enabled
> (and
> >> keep it enabled always for LIB_JVM).
> >>> Best regards, Matthias
> >>>
> >>>
> >>>
> >>> From: Baesken, Matthias
> >>> Sent: Freitag, 17. Januar 2020 12:44
> >>> To: Magnus Ihse Bursie <magnus.ihse.bursie at oracle.com>; David
> Holmes
> >> <david.holmes at oracle.com>; 'build-dev at openjdk.java.net' <build-
> >> dev at openjdk.java.net>; 'hotspot-dev at openjdk.java.net' <hotspot-
> >> dev at openjdk.java.net>
> >>> Subject: RE: RFR: 8236714: enable link-time section-gc for linux to
> remove
> >> unused code
> >>>
> >>>
> >>>     *   Matthias: Have a look at some recently added option to get an
> >> indication of the best practice in adding new options. There are some
> ways to
> >> easily make this incorrect
> >>> Hi Magnus, do you have a good/”best practice”  example  (not that I
> catch a
> >> bad one 😉 )  ?
> >>> Best regards, Matthias
> >>>