[LLVMdev] Ideal way to build llvm and friends?

[shea at shealevy.com]

Hi all,

I'm a maintainer for the llvm ecosystem for nixpkgs[1]. Currently only 
clang and llvm are up-to-date, but I'd like to move to building all of 
the packages listed on the release page for the latest version (and in 
particular, have libc++ and compiler RT integrated in with llvm/clang). 
Right now we're using the CMake build, with llvm and clang being built 
as separate packages. Due to a quirk in our package manager that's no 
longer an issue, having them be built together was previously not a good 
option.

I'd like to revamp this to do this the "official" way, but I'm not 
really sure what that is. CMake or autotools? Is it best to build 
everything as a single big build (putting clang, lld, lldb and polly in 
the "tools" subdir and everything else in projects)? Or should I build 
them all separately? I see libc++ is purposefully excluded from 
projects/CMakeLists.txt and compiler-rt is built differently from all 
other projects, why is that? Where does libc++abi fit in with all of 
this (it's not on the release page)? In general it seems like there are 
a lot of options and the documentation is not up-to-date everywhere, so 
I'm a bit lost.

Note that while building from SVN is an option if it's really 
important, ideally we only want released packages, optionally with small 
patches where needed.

Thanks,
Shea

[1]: http://nixos.org/nixpkgs/