[Buildroot] [PATCH v3 0/5] OpenJDK: new package and tests

[aduskett at gmail.com <aduskett@gmail.com>]

From: Adam Duskett <Aduskett@gmail.com>

This patch series adds OpenJDK and an updated testing framework to BuildRoot.

A previous patch series for OpenJDK8 used the JDK Muricle page to download a
tarball. Instead, what I have chosen to do is use the AdoptOpenJDK GitHub
repository. This repository allows us to use the GitHub macro instead of trying
to provide a nasty workaround when grabbing the source code.

With this patch series, there are some quirks that I would like to detail:

- The openjdk-bin package:
From http://hg.openjdk.java.net/jdk10/jdk10/raw-file/tip/common/doc/building.html#boot-jdk-requirements
"Paradoxically, building OpenJDK requires a pre-existing JDK. This is called
the "boot JDK." The boot JDK does not have to be OpenJDK, though. If you are
porting OpenJDK to a new platform, the chances are that there already exists
another JDK for that platform that is usable as boot JDK.

The rule of thumb is that the boot JDK for building JDK major version N should
be a JDK of major version N-1, so for building JDK 9, a JDK 8 would be suitable
as boot JDK."

This paradox causes an issue because every distribution I have used comes with
JDK8 by default. So there are two solutions that I could come up with:
1) Require the host-system to have JDK N-1
2) Grab the convenient and easy to install binaries from the AdoptOpenJDK
   repository, and use those binaries as the boot-jdk.

- JDK >= 10 requires X11, even if building a headless version.
  It's unfortunate, but there isn't anything I cared to do about it.

- Running "make install" installs the entire JDK to the target directory,
  which is why INSTALL_TARGET is manual. 

- The OpenJDK package:

- Depending on !BR2_SOFT_FLOAT
From http://hg.openjdk.java.net/jdk10/jdk10/raw-file/tip/common/doc/building.html#building-for-armaarch64
"Note that soft-float ABIs are no longer properly supported on OpenJDK."
Yes, it compiles as of right now, but I don't want to have to help people with
possible ASM java bugs because they wanted to use a processor without an FPU.

- Requiring GLIBC
OpenJDK could probably build against uClibc with a few patches, but I decided
against going through the effort of doing so. My reasoning is that uClibc
advertises itself as a small C library, however, at this time, OpenJDK comes in
at over 100MB for a minimal install. So the few megabytes saved by using uClibc
probably isn't going to be a concern for anybody wanting to use Java on their
embedded environment.

- Other thoughts:
It is possible to use fine-grained make targets when building OpenJDK, check out
http://hg.openjdk.java.net/jdk10/jdk10/raw-file/tip/common/doc/building.html#using-fine-grained-make-targets.
Perhaps in the future, BuildRoot could have Java setup just like PHP or Python,
with a large selection of modules to build? This fine-grained build could
potentially save a massive amount of space.

Perhaps in the future, a patch set that removes the X11/Alsa/cups dependencies
can be added.

In addition to the OpenJDK patches, Matt Webber, Daniel Leach and
Ricardo Martincoski extended the testing framework to allow for a more
flexible and comprehensive testing environment. The first of which is to test
OpenJDK by running a simple "Hello world" application.


Comments and critiques are always welcome!

Adam

Daniel J. Leach (1):
  support/testing: openjdk hello world

Ricardo Martincoski (2):
  testing/infra/builder: build with target and environment
  testing/infra/basetest: support br2-external

Adam Duskett (5):
  openjdk-bin: new package
  openjdk: new package

 .gitlab-ci.yml                                |   1 +
 DEVELOPERS                                    |   3 +
 package/Config.in                             |   1 +
 package/Config.in.host                        |   1 +
 package/openjdk-bin/Config.in.host            |  12 ++
 package/openjdk-bin/openjdk-bin.hash          |   6 +
 package/openjdk-bin/openjdk-bin.mk            |  20 +++
 package/openjdk/Config.in                     |  55 +++++++
 package/openjdk/openjdk.hash                  |   3 +
 package/openjdk/openjdk.mk                    | 141 ++++++++++++++++++
 support/testing/infra/basetest.py             |   3 +-
 support/testing/infra/builder.py              |  36 ++++-
 .../package/br2-external/openjdk/Config.in    |   1 +
 .../br2-external/openjdk/external.desc        |   1 +
 .../package/br2-external/openjdk/external.mk  |   1 +
 .../package/openjdk-hello-world/Config.in     |  26 ++++
 .../openjdk-hello-world/HelloWorld.java       |   8 +
 .../openjdk-hello-world.mk                    |  19 +++
 support/testing/tests/package/test_openjdk.py |  42 ++++++
 19 files changed, 375 insertions(+), 5 deletions(-)
 create mode 100644 package/openjdk-bin/Config.in.host
 create mode 100644 package/openjdk-bin/openjdk-bin.hash
 create mode 100644 package/openjdk-bin/openjdk-bin.mk
 create mode 100644 package/openjdk/Config.in
 create mode 100644 package/openjdk/openjdk.hash
 create mode 100644 package/openjdk/openjdk.mk
 create mode 100644 support/testing/tests/package/br2-external/openjdk/Config.in
 create mode 100644 support/testing/tests/package/br2-external/openjdk/external.desc
 create mode 100644 support/testing/tests/package/br2-external/openjdk/external.mk
 create mode 100644 support/testing/tests/package/br2-external/openjdk/package/openjdk-hello-world/Config.in
 create mode 100644 support/testing/tests/package/br2-external/openjdk/package/openjdk-hello-world/HelloWorld.java
 create mode 100644 support/testing/tests/package/br2-external/openjdk/package/openjdk-hello-world/openjdk-hello-world.mk
 create mode 100644 support/testing/tests/package/test_openjdk.py

-- 
2.20.1