Guys, Since we are talking about building on Windows 10 using clang and msys2 I would like someone to write up a comprehensive guide on how. From A to Z, please. I realize I'm likely to be roasted for this request by multiple people, but at this point it needs to be done and I am quite used to being roasted. :/
Yours, GC On Fri, Mar 6, 2020 at 11:51 AM David Chisnall <gnus...@theravensnest.org> wrote: > On 05/03/2020 00:43, Frederik Seiffert wrote: > > Thanks David. I made some progress with this setup, although it does > > feel like we’re a bit off the beaten track here (again)... > > > > To get libobjc linking with the MinGW clang toolchain using LLD I had to > > create an import library (.dll.a) as outlined on the MinGW website: > > http://www.mingw.org/wiki/CreateImportLibraries > <https://mailtrack.io/trace/link/8cc07744b427f35bd1a4025f72cae182cd829de2?url=http%3A%2F%2Fwww.mingw.org%2Fwiki%2FCreateImportLibraries&userId=2790543&signature=deb25f8156854567> > > > > Basically I ran "dumpbin /exports objc.dll" to get the list of symbols, > > used that to manually create a objc.def file, and then ran "dlltool -d > > objc.def -l objc.dll.a". One thing I noticed is that this doesn’t seem > > to include global variables (e.g. _objc_unexpected_exception), so these > > won’t be picked up by GNUstep configure and thus native exception > > support won’t work. > > > > In the end however I switched to using the llvm-mingw toolchain > > (https://github.com/mstorsjo/llvm-mingw > <https://mailtrack.io/trace/link/d8e147767d4be7e10c18e4f33fd14e1ec080746b?url=https%3A%2F%2Fgithub.com%2Fmstorsjo%2Fllvm-mingw&userId=2790543&signature=8eb6bdcd72edd048>), > which defaults to LLD and > > directly picks up the objc.lib without the need for the import library > > (but also doesn’t seem allow linking global variables). > > > > I also had to remove "OBJ_MERGE_CMD_FLAG" in config.make, as LLD doesn’t > > support the -r flag for incremental linking. > > Hmm, that probably means that -base Additions won't build. > > > > > With this and a couple more configure flags I got Base to start > > compiling, but I’m now stuck at the Additions subproject failing to link > > because it seems to be missing all the necessary linker flags: > > > >> clang -nostdlib -o ./obj/subproject.o > >> obj/Additions.obj/GSTypeEncoding.c.o ... > >> lld-link: error: <root>: undefined symbol: _mainCRTStartup > >> lld-link: error: undefined symbol: _malloc > >> lld-link: error: undefined symbol: __declspec(dllimport) > _object_getClass > >> ... > > > > Does anyone with better knowledge of GNUstep make have an idea of why > > this might happen or how to debug this further? > > If you're not using -r, then I don't know what this .o will be. The > subproject thing is a source of constant pain because almost nothing > other than GNUstep uses -r, so it tends to be horribly buggy. It's > supposed to take a load of .o files and generate a .o file that can be > linked as if it were the original list of .o files. Modern build > systems just pass the list of .o files around. > > > > > > >> There is a bug somewhere in the SEH support that I need to look for. > >> I suspect it is in clang - EH seems to fail with ARC and I think that > >> it may be to do with the ARC calls not being correctly emitted in the > >> funclet. Dustin is planning on looking at some of the Clang funclet > >> issues. > > > > That’s good to know, thanks. > > > > By the way, is libcxxrt needed on Windows for ObjC++ EH on Windows? > > Seems like WinObjC is not using it. > > > No, libcxxrt implements the Itanium C++ ABI. On Windows, libobjc2 > supports the Visual Studio C++ ABI, so exceptions should interop with > C++ libraries compiled with clang or MSVC. > > David > > -- Gregory Casamento GNUstep Lead Developer / OLC, Principal Consultant http://www.gnustep.org <https://mailtrack.io/trace/link/d59b94cadd998bad6d1744bcac4e1d9031586167?url=http%3A%2F%2Fwww.gnustep.org&userId=2790543&signature=c8db5d79a90ce8fe> - http://heronsperch.blogspot.com <https://mailtrack.io/trace/link/5e459c621996e4d8057fc6dc30444a7795ae3377?url=http%3A%2F%2Fheronsperch.blogspot.com&userId=2790543&signature=83071376cf73316a> http://ind.ie/phoenix/ <https://mailtrack.io/trace/link/f0ecd7b9c33c67f677714479a90281a94bb7eb7d?url=http%3A%2F%2Find.ie%2Fphoenix%2F&userId=2790543&signature=6b017efb1aaafbbe>
