MacOS build tool selections for JDK8

[Tim Bell]

All-

The question of what toolchain to use on MacOS when building JDK8 is in 
play.

This is important because the decisions we make in the next few weeks 
will be in place for the lifetime of JDK8, including all future JDK8 
update releases.

I have a few different pieces of feedback at this point, and (due to my 
own ignorance of the developer environment choices on MacOS), I'd like 
to throw the discussion out to a larger audience of MacOS developers.

1) Use gcc as the build does today.

2) Use Clang.

3) Support both (since they should both compile the same source) but 
identify Clang as the official tool.

4) Use Xcode (er - wait - isn't Clang a part of Xcode?  Please correct 
me if I am mistaken here....)


As part of the build-infrastructure team, my #1 concern is getting 
solid, repeatable builds from the toolchain, every time, that that's 
what I mean by 'official'.

If developers feel adventurous and want to run out ahead using bleeding 
edge tools, good for them - have fun.

What we would like to define here is a solid baseline of what we use to 
run the official from-scratch JDK8 builds.  That said, I'd like to nail 
down the tools used, and the specific version of the tools.

Thanks in advance for any feedback.

Tim Bell
Java Platform Group Infrastructure