Hi David,
Sorry it took me a while to give this a try.
> Am 27.10.2021 um 14:36 schrieb David Chisnall <gnus...@theravensnest.org>:
>
> Since all of them end with a close brace, I suspect that there's something in
> the field names that isn't a valid PE/COFF symbol name (at least for
> dllexported things, not sure if the restrictions are different here). The
> second one was the easiest to find, since only one class in GNUstep looks
> like it implements this (note: *something* is wrong in your build environment
> because I don't think we should be seeing that version when targeting an
> ARC-enabled runtime and the one fourth from the button looks as if it's
> trying to use the old NeXT-style exceptions rather than SEH, but it helps
> find the bug so let's leave it for now).
Good catch. However it looks like autorelease_array_list is always referenced
in _reallyDealloc even with ARC_RUNTIME being set. I’ll have to look into the
SETJMP one in more detail.
> The generated variable should be:
>
> __objc_ivar_offset_NSAutoreleasePool._release.^{autorelease_array_list=^{autorelease_array_list}II[0\01]}
>
> So it looks as if it's being truncated at the first equals sign? I wonder if
> equals is not permitted in dllexported symbols? This doesn't seem to cause
> problems for DLL-local symbols on Windows.
>
> In clang/lib/CodeGen/CGObjCGNU.cpp, you'll see this line:
>
> // Prevent the @ from being interpreted as a symbol version.
> std::replace(TypeEncoding.begin(), TypeEncoding.end(),
> '@', '\1');
>
> Underneath it, can you add this:
>
> std::replace(TypeEncoding.begin(), TypeEncoding.end(),
> '=', '\2');
Yes that works!
> Let me know if that fixes things. If so, it's an ABI break on Windows, so it
> probably needs to be guarded on whether the symbol is dllexported and may
> need an explicit opt-in flag.
I guess the only project using this setup so far is WinObjC, which seems like
it won’t get a compiler update anytime soon, so if it’s an option to break the
ABI without these flags that would seem ok to me too.
Thanks!
Frederik
