[llvmlinux] Choosing which clang to use

[Behan Webster]

I've just pushed updates which allow you to choose which clang you want 
to use.

You can choose your clang by setting the CLANG_TOOLCHAIN variable.
   CLANG_TOOLCHAIN=prebuilt     Download and use llvm.org clang
   CLANG_TOOLCHAIN=native       Use distro installed clang
   CLANG_TOOLCHAIN=from-source  Download and build from source (Default)

As an example, you would use it as follows

$ cd targets/x86_64
$ make CLANG_TOOLCHAIN=prebuilt kernel-build

You can also specify it in your config file if you wish (which extends 
to checkpoints from now on as well). Note that this obviously won't work 
with checkpoints in the past (since the code was only just added to the 
build system).

$ cd targets/x86_64
$ echo "CLANG_TOOLCHAIN=prebuilt" >> config.mk
$ make CONFIG=config.mk kernel-build

I hope this works for everyone. I'm the only one who has tested it so 
far, so doubtless there are still bugs...

Behan

-- 
Behan Webster
behanw at converseincode.com