RFR: [8u] 8141570: Fix Zero interpreter build for --disable-precompiled-headers

[Andrew Hughes]

On Thu, 22 Aug 2019 at 09:52, Severin Gehwolf <sgehwolf at redhat.com> wrote:
>
> Hi Andrew,
>
> On Wed, 2019-08-21 at 20:33 +0100, Andrew John Hughes wrote:
> > This is the first of a series of four changes to support -Wreturn-type
> > in OpenJDK 8u. The -Wreturn-type warning catches instances where control
> > flow exits a non-void function without returning a value. This can
> > combine with compiler optimisations in some cases to cause runtime
> > crashes. The warning is turned on by default in GCC 8 [0], causing the
> > build to fail if it is not explicitly disabled.
> >
> > The subsequent changes are JDK-8062808 to apply the warning and fix
> > issues in the default build, JDK-8143245 to fix issues in the Zero build
> > and JDK-8197981 to fix one remaining Zero issue on 32-bit platforms only.
> >
> > This change ensures the Zero build is not broken by 8062808 by disabling
> > -Wreturn-type in the Zero makefile.
> >
> > Changes in the backport process:
> >
> > * The G1 changes are dropped as 8u does not contain JDK-8073013, which
> > introduces g1EvacStats.*
> > * I've changed the ifeq ($(USE_CLANG), true) to ifeq
> > ($(JVM_VARIANT_ZEROSHARK), true). There seems to have been a mistake in
> > the original patch which equated LLVM with clang. What is actually
> > referred to by "some version of llvm do not like -Wundef" is the LLVM
> > headers that Shark is built against, not the clang compiler which also
> > uses LLVM. This made its way through to the new HotSpot build in OpenJDK
> > 9 & 10, but is gone as of JDK-8198724 in OpenJDK 11 and later.
> >
> > This backport has been in IcedTea since 3.8.0 (2018-05-29) [1] and our
> > RHEL RPMs since 2018-06-16 without issue. Builds of current 8u-dev on
> > x86_64 with Zero release and Zero slowdebug succeeded.
> >
> > [0] https://gcc.gnu.org/gcc-8/changes.html
> > [1] https://icedtea.classpath.org/bugzilla/show_bug.cgi?id=3548
>
> I don't see any webrev. Did you forget to link to it?
>
> Thanks,
> Severin
>

Ha, got so caught up in explaining all the other stuff, I forgot the
meat of the matter.

Here it is: https://cr.openjdk.java.net/~andrew/openjdk8/8141570/
-- 
Andrew :)

Senior Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

Web Site: http://fuseyism.com
Twitter: https://twitter.com/gnu_andrew_java
PGP Key: ed25519/0xCFDA0F9B35964222 (hkp://keys.gnupg.net)
Fingerprint = 5132 579D D154 0ED2 3E04  C5A0 CFDA 0F9B 3596 4222