RFR: 8227397: Add --with-extra-asflags configure option

[Severin Gehwolf]

Hi Martin,

On Mon, 2019-07-08 at 10:42 -0700, Martin Buchholz wrote:
> (not really a review ...)
> 
> I'm confused because the assembler is invoked when compiling any sort of source file - C, C++, or .s/.S.
> Wouldn't we want assembler flags passed uniformly, no matter when the assembler is invoked?

Good point. I guess that's debatable. The intention is to only affect
assembling of, well, assembly files (.s/.S). Right now, --with-extra-
cflags would work, but that's more an accident I'd think:

http://hg.openjdk.java.net/jdk/jdk/file/377e49b3014c/make/autoconf/flags-other.m4#l119

In JDK 8 this is a real issue. See:
https://bugs.openjdk.java.net/browse/JDK-8219772

During review this suggestion (with-extra-asflags) came up:
http://mail.openjdk.java.net/pipermail/jdk8u-dev/2019-March/008861.html

> It looks like this patch only affects compilation of .s/.S files in hotspot?

Yes. I've only found assemly files in hotspot. Happy to add it for core
libs, too, but not sure where.

Thanks,
Severin

> On Mon, Jul 8, 2019 at 8:57 AM Severin Gehwolf <sgehwolf at redhat.com> wrote:
> > Hi,
> > 
> > Could I please get a review for this patch which adds a new configure
> > option --with-extra-asflags? The issue at hand is that we, Red Hat,
> > need to pass certain extra flags to the assembler when OpenJDK is being
> > compiled. -Wa,--generate-missing-build-notes=yes in our case. That's
> > currently not possible and extra C/C++ flags would need to be used,
> > which seems not nice.
> > 
> > Bug: https://bugs.openjdk.java.net/browse/JDK-8227397
> > webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8227397/01/webrev/
> > 
> > After this patch extra assembler flags get added to *.s/.S files for
> > libjvm.so:
> > 
> > $ grep -n generate-missing-build-notes=yes build/linux-x86_64-server-release/build.log 
> > 1049: [18] ASFLAGS := -m64 -Wa,--generate-missing-build-notes=yes  
> > 15005:( /usr/bin/rm -f /disk/openjdk/upstream-sources/openjdk-head/build/linux-x86_64-server-release/hotspot/variant-server/libjvm/objs/linux_x86_64.o.log && /usr/bin/gcc -c -m64 -Wa,--generate-missing-build-notes=yes -g -o /disk/openjdk/upstream-sources/openjdk-head/build/linux-x86_64-server-release/hotspot/variant-server/libjvm/objs/linux_x86_64.o /disk/openjdk/upstream-sources/openjdk-head/src/hotspot/os_cpu/linux_x86/linux_x86_64.s > >(/usr/bin/tee -a /disk/openjdk/upstream-sources/openjdk-head/build/linux-x86_64-server-release/hotspot/variant-server/libjvm/objs/linux_x86_64.o.log) 2> >(/usr/bin/tee -a /disk/openjdk/upstream-sources/openjdk-head/build/linux-x86_64-server-release/hotspot/variant-server/libjvm/objs/linux_x86_64.o.log >&2) || ( exitcode=$? && /usr/bin/cp /disk/openjdk/upstream-sources/openjdk-head/build/linux-x86_64-server-release/hotspot/variant-server/libjvm/objs/linux_x86_64.o.log /disk/openjdk/upstream-sources/openjdk-head/build/linux-x86_64-server-release/make-support/failure-logs/hotspot_variant-server_libjvm_objs_linux_x86_64.o.log && /usr/bin/cp /disk/openjdk/upstream-sources/openjdk-head/build/linux-x86_64-server-release/hotspot/variant-server/libjvm/objs/linux_x86_64.o.cmdline /disk/openjdk/upstream-sources/openjdk-head/build/linux-x86_64-server-release/make-support/failure-logs/hotspot_variant-server_libjvm_objs_linux_x86_64.o.cmdline && exit $exitcode ) )
> > 
> > I'll run this through jdk/submit before I push.
> > 
> > Thoughts?
> > 
> > Thanks,
> > Severin
> >