Re: GNUstep on Windows using Clang + MSVC ABI

[David Chisnall]

Thanks,

I’m taking next week off for Easter - hopefully I’ll have some time to look at 
both of these then.  I don’t think either is much work to fix, if I can easily 
set up the test environment.

David

> On 22 Mar 2021, at 16:53, Frederik Seiffert <frederik@algoriddim.com> wrote:
> 
> Hi David,
> 
>> Am 02.02.2021 um 12:29 schrieb David Chisnall <gnustep@theravensnest.org>:
>> 
>>>>> lld-link: error: relocation against symbol in discarded section: 
>>>>> __start_.objcrt$SEL
>>>>> >>> referenced by C:\msys64\tmp\conftest-78a937.o:(.objc_init)
>>>>> This is reproducible when building a file that calls ObjC runtime 
>>>>> functions but doesn’t actually contain any ObjC code. Not sure if that’s 
>>>>> expected behavior or bug.
>>>> 
>>>> I think this is a bug, probably a clang bug (and probably my fault)
>>> Should I open an LLVM issue for this?
>> 
>> Yes please.  There was an identical bug on ELF platforms, I may have failed 
>> to fix it for Windows.
> 
> Here you go, please let me know if you need any other info:
> https://bugs.llvm.org/show_bug.cgi?id=49681
> 
>>>> Awesome work, and it makes me much happier than trying to support MinGW.
>>> Thank you, glad you like it! This is also exciting to us because it should 
>>> e.g. allow us to use recent Windows technologies like the C++/WinRT 
>>> language projection from ObjC++ which are not compatible with MinGW.
>>> That being said, I would still very much like to get libobjc2 working with 
>>> MinGW as well, as it would allow people currently using GNUstep with GCC in 
>>> a MinGW environment to switch to Clang/libobjc2, should result in a more 
>>> streamlined setup experience with all dependencies being available via 
>>> MinGW packages and everything being built in one shell, and allow for 
>>> existing MinGW-based software to be used.
>>> I’ll try to get you those instructions for building LLVM with the MinGW 
>>> patches in the next couple weeks.
>> 
>> I'll try to find some time to work on it.
> 
> I’ve finally found steps to reproduce the issues with MinGW using a "normal" 
> (non-MinGW) LLDB build using a CMake toolchain file:
> https://github.com/gnustep/libobjc2/pull/190#issuecomment-792676170
> 
> Hopefully that will be sufficient to look into these at some point.
> 
> Thanks!
> Frederik
>