Re: Clang/LLVM migration roadmap

[Richard Frith-Macdonald]

> On 6 Feb 2022, at 09:35, Andreas Fink <afink@list.fink.org> wrote:
> 
> So to summarize up, we need to get libobjc2 properly working under MSYS2 and 
> we can continue with clang.
> What are the isuses with libobjc2 not working under MSYS2? From what I know 
> libobj2 should not have many dependencies on the operating system itself 
> (well memory management and multithreading but not much more I believe) but 
> more on the architecture. But thats a birds eye view...

I think general portability is an issue, not just MSYS.

Yes, there's the issue of architecture specific code in the runtime,  but 
additionally I have seen two problem areas:

1. building libobjc2
a. dependency on cmake and ninja ... easy to find packages for most systems, 
but definitely an annoyance
b. has failed to build with some compiler versions etc in the past, so we need 
to work out reliable toolchains for all platforms

2. runtime errors
I have had problems with getting things to run, the current one I am aware of 
is related to linker ... the runtime will fail with executable produced by 
common linkers under some conditions.  There also seems to be problems with C++ 
integration for exceptions and compiler bugs.

I do use clang/libobjc2 on a daily basis on gnu/linux amd64 with no problems at 
all, but it took a long time to get the right toolchain in place. We need this 
to be less fragile, so people can update parts of their toolchain without 
breakign things.