[RFC] Fix Zero and Shark builds

[Erik Joelsson]

On 2013-02-13 18:21, Roman Kennke wrote:
> First of all, let me tell you how great the new build machinery is: IT
> ROCKS! Thanks for doing this!
>
Thanks!
> These changes introduce the necessary configure- and make-foo to make
> Zero and Shark builds work with the build-infra machinery. With this,
> Zero and Shark builds are as easy as:
>
> bash configure --with-jvm-variants=zero[shark]
> make
>
> it will check for existence of libffi and llvm, and use pkg-config and
> llvm-config to figure out all required variables. This is basically
> adopted from jdk/make/jdk_generic_profile.sh, and now integrated into
> the build.
>
A couple of comments:

ARCH_DATA_MODEL is considered a legacy variable outside of hotspot. If 
you look in hotspot-spec.gmk.in, we set it there specifically for the 
hotspot build. The source for this value is in 
common/autoconf/platform.m4 and it seems to me that several of the 
values you are calculating should rather be set there (endian, libarch 
etc). Do any of these need special treatment because of the ZERO[SHARK] 
compiler? If not, I would like to have as many of them as possible just 
translated from existing variables in hotspot-spec.gmk and if possible 
handle the special cases in platform.m4.

The library checks look good to me.
> This only contains the source files, not the regenerated configure
> scripts:
>
> http://cr.openjdk.java.net/~rkennke/zero-build-infra/webrev.00/
>
> Which brings up an interesting question (not sure if that has been
> discussed before). Who is responsible to regenerating the configure
> scripts after a change in the sources? Variances between versions of
> autotools will like create a mess in the diffs and probably unforeseen
> hiccups.
So far, the committer reruns autoconf, but we don't necessarily include 
the generated file in the code review. We have still to lock down on a 
specific version and have noted the extra diffs created by this. So far, 
it hasn't been a big problem, but it's sure something we need to address.
> Also, a small change was required to be able to build images:
>
> http://cr.openjdk.java.net/~rkennke/zero-build-infra-jdk/webrev.01/
>
Where is INCLUDE_SA supposed to be set? I know it was handled in 
Defs-[os].gmk files in the old build, but in the new I would assume 
configure should be setting it.

/Erik