[cfe-dev] [LLVMdev] [3.5 Release] Release Candidate 4 Now Available

[Ben Pope]

On Monday, September 15, 2014 02:08 AM, Larry Evans wrote:
> On 09/14/2014 12:05 PM, Dan Albert wrote:
>> libc++abi can only be compiled by clang. __sync_swap() is a clang builtin.
>
> I tried to get cmake to use clang and clang++ by setting the environment
> variables CC anc CXX; however, I got same error (see attached).
> Is there some other way to cause libc++abi to be compiled by clang?
>
>> I believe the conclusion of the discussion about replacing those calls with
>> std::atomic ended with deciding we couldn't do it, though I don't remember
>> why.
>>
>> Looking at the source, I think the warning about uncaught exception
>> congress from libc++ not being able to find the libc++abi headers.
>
> OK.  So to make lib++ using libc++abi *and* avoid the warnings,
> libc++abi has to be *installed* first?

I seem to recall a small bootstrap issue.  I think you can compile 
libc++ with gcc (and, err, libsupc++ or something), and then build 
libc++abi with clang and libc++, and then recompile libc++ against 
libc++abi.

This may be resolved with the cmake build system, but possibly only on 
trunk.  I may also be making that up, or making it too complicated, my 
memory fails me.

Ben