[cfe-dev] Undefined "__Unwind_Resme" when building libc++

[John McCall]

On May 29, 2011, at 8:23 PM, Michael Price wrote:
> I'm trying to build libc++ with top-of-tree clang (which was built on the same system).
> 
> I'm running Mac OS X 10.5.8 on an Intel Core 2 Duo.
> 
> When I run ./buildit from the libcxx/lib directory, I get the following error:
> 
> Undefined symbols for architecture i386:
>   "__Unwind_Resume", referenced from:
> 
> followed by lots of mangled symbols.
> 
> Anyone know what might be going wrong?

It's not linking against libUnwind.  Basically, the libcxx build system
doesn't appear to expect to run on anything earlier than 10.6.  Patches
welcome, I think;  you'll need to figure out what framework/dylib
provides libUnwind on Leopard and make sure you both link against
it and re-export its symbols.

John.