Find the right runtime class path for a J9 boot jdk

[Dave Pointon]

Hiya Volker ,

On Thu, 2013-11-14 at 17:38 +0100, Volker Simonis wrote:
> Hi Dave,
> 
> thanks for looking into this issue. However I must say I don't really
> understand your approach. The 'with-jdk-variant' option is documented
> and it says:
> 
>   --with-jdk-variant      JDK variant to build (normal) [normal]
> 

By undocumented, I meant that it isn't present in the README-builds.html
- which I've been taking as gospel thus far into my first foray into
Java internals.

> So this is clearly an output option which can be used to configure
> what kind of JDK to build. As the comments explain, this may be used
> by the Oracle-internal build to specify addition modules for
> compilation into the JDK. I don't think it is suitable to configure
> the bootstrap JDK.
> 

Given my context i.e. attempting to convert the IBM Java build from make
to configure && make, I interpreted the type of JDK as being an IBM JDK
- since, as you've pointed out elsewhere, it is a JDK specific to IBM -
I guess that was an incorrect inference on my part.

> Moreover, you don't address the fact that IBM J9 has different version
> of 'vm.jar', depending on which configuaration you are running with
> (i.e. compressed pointers or not ->
> jre/lib/ppc64/compressedrefs/jclSC170/vm.jar vs.
> jre/lib/ppc64/default/jclSC170/vm.jar). I also don't understand the
> way how you reference the jar file from two directory levels beneath
> the boot JDK root path. I don't think this will work with a standard
> JDK image.
> 

Hmmm, I think that I need to think longer before accepting current ways
of working ad-verbatim - I did think it odd when I implemented it.

> Nevertheless, I think I found a better and more general solution for
> the problem by simply setting BOOT_RTJAR to the value of the
> 'sun.boot.class.path' property. (It works equally well with the Oracle
> and the IBM JDKs - see my mail:
> http://mail.openjdk.java.net/pipermail/build-dev/2013-November/011098.html)
> 
> What do you think, would you be happy with this new solution?

Yeah, I've just seen and read your submission - awesome piece of work
that appears to completely address the specific problem I was attempting
to solve ... and thank you for the pointer as to how to present a
posited change.

I take it you'd have no objection to my taking, using and testing your
proposed change?

> 
> Regards,
> Volker
> 
<snip>

Rgds ,
-- 
Dave Pointon FIAP MBCS

Now I saw, tho' too late, the folly of beginning a work before we count
the cost and before we we judge rightly of our strength to go thro' with
it - Robinson Crusoe