Re: Building 64-bit on Windows

[David Chisnall]

On 29/10/2018 14:59, Riccardo Mottola wrote:
> It is based on an older mingw environment and I am having big 
> difficulties upgrading it, still in the realm of remaining on mingw 
> 32bit and gcc (no libobjc2)

For anyone interested in the libobjc2 status:

libobjc2 with the new ABI does not yet handle DLLs on Windows properly. 
Windows DLLs provide some cleaner abstractions than *NIX shared objects, 
but this means a global variable in one DLL cannot be initialised to 
point to globals in another.  We have been working on some solutions to 
this, and I think it's now sensible, but we haven't yet upstreamed the 
changes to clang.  Once this is done, we should be able to ship a 
libobjc.dll as a pure Windows DLL, useable by both WinObjC and GNUstep 
with either Cygwin or MinGW.  The new ABI uses Windows-compatible 
exception handling, so it's safe to mix Visual Studio-compiled C++ code 
with Objective-C and throw exceptions between languages.

I hope to get this all done, tested, and upstreamed before the LLVM 8.0 
release.

David