Hello,
New webrev: http://cr.openjdk.java.net/~erikj/8163102/webrev.02
The difference is in libraries.m4, where there was still a reference to
SUPPORT_HEADFUL. I tried building a headless configuration without X11
configured, but it unfortunately failed. libawt.so still requires X11
headers to compile. I suppose we could differentiate between headers and
libs being available, but I will leave that for another time.
On 2016-08-03 22:37, David Holmes wrote:
Hi Erik,
The confusion around that variable due to its legacy always makes me
worried that something is misunderstood. It was originally to deal
with a build platform that had no headful support (no X11 libs and
headers etc) and so could not build headful no matter what. The flag
but not the functionality was carried into the new build system. What
you have now is a different beast entirely.
Right, but unfortunately it still requires X11 headers as said above,
and tracing through history, this must always have been true for a long
time.
In this patch I'm replacing the configure option with
--enable-headless-only. Default is disabled, where both headless and GUI
support is built. When enabled, only headless support is built. These
are the two variants we are ever interested in.
On the makefile side, I redefined the variable as
ENABLE_HEADLESS_ONLY=true/false.
This all seems reasonable. Though of course you have to ensure that a
headless build can still execute all the necessary functionality. Even
for headless some of the AWT API's still have to be available
(printing support for one IIRC).
As far as I can see, this should be fine, but perhaps someone from
2d/awt should comment. This is what --enable-headless-only removes:
* policytool - a gui application which does not seem to have any
functionality without a gui
* appletviewer - seems pointless without a gui
* libsplashscreen - seems pointless without a gui
* libawt_xawt - the X11 specific parts of awt that links to libX11
* A placeholder libjawt is built which just doesn't do anything
These are also exactly the libraries and executables that link to X11.
Regardless of if we can use this option at Oracle, I believe it's a good
fix for OpenJDK.
I also needed to change jawt.c to get a headless only build to actually
work. The requirement that -DJAVASE_EMBEDDED is set seems unnecessary
and unrelated to me.
The JAVASE_EMBEDDED stuff has now all been removed, but that change
hasn't reached dev yet.
Right, and that change conflicts with mine since it also removed the
possibility of building a "headless" libjawt. This means I should hold
on this change until hs gets into dev.
/Erik
