[OpenJDK 2D-Dev] RFR(XS): 8213944: Fix AIX build after the removal of Xrandr.h and add a configure check for it

[Thomas Stüfe]

FWIW I am very much in favor of (1) and if aesthetics are a problem in
awt_GraphicsEnv.c, a "HAVE_XRANDR" define would make things a bit
prettier...

just my 2c.

On Mon, Nov 19, 2018 at 6:58 PM Volker Simonis <volker.simonis at gmail.com> wrote:
>
> Hi Phil,
>
> I'd like to kindly ask you to suggest how we can proceed with this issue.
>
> As I wrote before, Xrandr is not officially supported on AIX and there
> are no official packages available for it. There are some OpenSource
> sites for AIX which provide Xrandr, but they are all not compatible
> with the default native libraries (e.g. the open source Xrandr package
> depends on another open source package of Xrender.so.1 but the system
> only provides Xrender.so.0 natively). We can't compile the whole JDK
> (i.e. libawt_xawt.so) against some open source package of Xrender.so.1
> because that simply won't be available on the majority of systems.
>
> Remember that forcing people to install these open-source packages
> even as a build dependency is like expecting Linux users to install
> some non-official packages just to be able to build. Especially in
> corporate environments that's not easy. Moreover the benefit would be
> really minimal, because the Xrandr functionality won't be available at
> runtime anyway.
>
> So to cut a long story short, I see two options:
>
> 1. Go with my current patch (ugly but efficient)
>
> 2. Check-in in an AIX specific version of XRander.h/randr.h under
> src/java.desktop/aix (OK for me, but that would actually negate the
> initial purpose of "8210863: Remove Xrandr include files")
>
> Do you have a better proposal?
>
> Thank you and best regards,
> Volker
>
> On Fri, Nov 16, 2018 at 11:22 AM Volker Simonis
> <volker.simonis at gmail.com> wrote:
> >
> > On Thu, Nov 15, 2018 at 6:01 PM Philip Race <philip.race at oracle.com> wrote:
> > >
> > > PS I am not sure why xrandr headers would not be available for AIX.
> > > They are a standard part of the xdistribution.
> > >
> >
> > I'm not an X11 guru, but as far as I understand, xrandr is an
> > extension and as such it doesn't have to be supported by every
> > implementation. To the best of my knowledge (I've just started another
> > poll among some experts) AIX doesn't support Xrandr and does not have
> > the corresponding headers.
> >
> > > If true, think what you are going to have to do is add a
> > > --with-xrandr-include option
> > > and provide it that way.
> > >
> >
> > What if there are no standard Xrandr headers on a platform? Do you
> > really want to force users to get them from some dubious sources just
> > for building the OpenJDK? Sorry, but I don't think that's a good
> > solution. Than I'd rather prefer the ugly ifdefs (or I check the
> > headers back in again in an AIX-specific directory :)
> >
> > Thank you and best regards,
> > Volker
> >
> > > -phil.
> > >
> > > On 11/15/18, 8:55 AM, Philip Race wrote:
> > > > Hmm. I don't like the ifdefs.
> > > >
> > > > Xrandr is a requirement for the build. If its not there at runtime
> > > > that's OK.
> > > >
> > > > -phil.
> > > >
> > > > On 11/15/18, 8:06 AM, Volker Simonis wrote:
> > > >> Hi,
> > > >>
> > > >> can I please have a review for the following small change:
> > > >>
> > > >> http://cr.openjdk.java.net/~simonis/webrevs/2018/8213944/
> > > >> https://bugs.openjdk.java.net/browse/JDK-8213944
> > > >>
> > > >> Change JDK-8210863 removed the Xrandr.h/randr.h headers from the
> > > >> OpenJDK sources but forgot to add a configure check for the Xrandr
> > > >> extension which is now a build dependency.
> > > >>
> > > >> The change also broke the AIX build. AIX never supported Xrandr, but
> > > >> that was only detected at runtime, when the JDK was unable to
> > > >> dynamically load libXrand.so. Now, without Xrandr.h/randr.h in the
> > > >> source tree any more, we have to conditionally compile some parts of
> > > >> src/java.desktop/unix/native/libawt_xawt/awt/awt_GraphicsEnv.c such
> > > >> that it doesn't require the definitions and declarations from
> > > >> Xrandr.h/randr.h any more.
> > > >>
> > > >> Thank you and best regards,
> > > >> Volker