Dear libcxx community,

I would like to compile the latest libcxx on Ubuntu 16.04.
Regarding the use of compiler-rt instead of libgcc and given there seems to be a dependency on libunwind i have the following questions:

  • Should i use the system libunwind or the llvm one?
  • Can i use libunwind.a instead of
  • Should i set -D_GNU_SOURCE for the compile (there is at least one cmake test which fails without this if the system libunwind is used)?
  • There once was an activity (or at least a proposal) to combine compiler-rt with libunwind, is this still on target?

Thanks in advance for answers


(Sort of) repost.
Things would be significantly easier if the llvm libunwind would be renamed avoiding the name clash with the “standard” libunwind.
I think someone proposed this recently (or complained about this renaming not being done).