minimal backport of 8182299 build on OSX 10 + Xcode 8

[Hohensee, Paul]

There are quite a few JBS issues that fix gcc 7 and 8 compilation problems. Possibly backporting these will fix most/all of clang's complaints as well.

Paul

On 7/3/19, 1:33 PM, "jdk8u-dev on behalf of Simon Tooke" <jdk8u-dev-bounces at openjdk.java.net on behalf of stooke at redhat.com> wrote:

    
    On 7/3/2019 4:03 PM, Andrew John Hughes wrote:
    >
    > On 03/07/2019 19:30, Ben Evans wrote:
    >> Hi,
    >>
    >> As this appears to have been Warnock'd (
    >> https://en.wikipedia.org/wiki/Warnock%27s_dilemma), allow me to give it
    >> another kick.
    >>
    >> My personal take (for the little that it's worth) is: Given current
    >> adoption rates and trends, JDK 8 is going to be with us for a long time.
    >> Restricting the potential community size of developers working on OpenJDK 8
    >> by:
    >>
    >> 1.) Requiring that people who develop on Macs jump through virtualisation
    >> hoops and
    >> 2.) Making the building of binaries a byzantine process requiring the
    >> maintenance of obsolete Macs
    >>
    >> is bad, and we should stop doing it.
    >>
    >> Thanks,
    >>
    >> Ben
    >>
    >> On Fri, Jun 28, 2019 at 4:09 PM Simon Tooke <stooke at redhat.com> wrote:
    >>
    >>> Hello everyone,
    >>>
    >>> I would like to make a somewhat controversial proposal: to backport the
    >>> minimal changes required to enable jdk8u to compile and run when built
    >>> with the latest macOS developer tools.
    >>>
    >>> I realize this falls outside of aph's guidelines of "bug fixes only,
    >>> (for now)" and in many ways is only a developer convenience, since I am
    >>> not advocating (at this time) for this build to become the default
    >>> supported for macOS [1].
    >>>
    >>> There changes do not affect the current mac build, which requires an old
    >>> version of Xcode which doesn't run on modern releases of macOS, but they
    >>> make it much easier for macOS hackers to work with jdk8.
    >>>
    >>> At this point, testing has been confined to bootstrapping the build with
    >>> a jdk8 built using this patch, and to using this build to build a
    >>> working Graal substrateVM.
    >>>
    >>> My version of the backport limits the scope of the 8182299 patches to
    >>> the subset required to get the JDK up and running.  I don't propose
    >>> backporting any changes to remove Clang warnings, etc.  Because of that,
    >>> my changes are confined in scope.
    >>>
    >>> Potential long term benefits (if this build does seem healthy enough for
    >>> production) are simplified macOS build platforms, a more modern compiler
    >>> and perhaps higher performance.
    >>>
    >>> Bug: https://bugs.openjdk.java.net/browse/JDK-8182656
    >>>
    >>> Webrev: http://cr.openjdk.java.net/~stooke/webrevs/xcodemacos.webrev/
    >>>
    >>> Thanks for your time,
    >>>
    >>> -Simon
    >>>
    >>> [1] first, potentially removes support for macOS 10.8, second, needs
    >>> more testing.
    >>>
    >>>
    >>>
    > I saw it, but there's a CPU on right now. I'll have a look properly once
    > that's out of the way.
    Yes, I know this is very much on the back burner for now. 
    > My initial thought is what is the subset you refer to? The problem with
    > backporting bits of a change is that it then looks like that change is
    > backported, but some parts of it are actually missing.
    
    We could avoid referring to the initial patch altogether; a large part
    of it (which I avoided) was simply getting rid of clang warning
    messages.  I just went for the bits that stop the crash, and skipped the
    rest.