[cfe-dev] Porting libcxxabi / Unwind to Windows / MingW 32 bit

[David Chisnall]

On 2 Nov 2013, at 12:27, Yaron Keren <yaron.keren at gmail.com> wrote:

> Hi David,
> 
> It's a good idea to have compiler-rt + unwind project in one project as a libgcc replacement. We can name the project "libclang".

THe libclang name is already taken, but so is libcompiler_rt for this purpose...

> While at it, the rest of libcxxabi (the _cxa functions) may be merged into libcxx as a complete replacement for libstdc++.

We already ship the combination of libc++ and libcxxrt on FreeBSD as a complete replacement for libstdc++.

> This project structure matches the gcc library organization and thus will be easier for people (and toolchains) to use them.

Actually, the gcc structure has libstdc++ and libsupc++ as separate libraries.  On FreeBSD, we shipped them as separate dynamic libraries in 9.x so that you can stick libcxxrt under libstdc++ and mix code that uses libc++ and libstdc++.  OS X did something similar.  This setup allows people to use a newer libstdc++ (which we don't ship in the base system, but which you can get from ports) in a library used by an application that uses libc++, without causing errors (unless STL symbols are used on library interfaces).

Merging libc++ and libc++abi would require anyone downstream who cared about interoperability to go and unmerge them again.

David