Re: Errors compiling Libobjc2

[Riccardo Mottola]

Hi,

On 2019-06-21 16:13:58 +0000 David Chisnall 
<address@hidden> wrote:

> On 21/06/2019 16:08, Riccardo Mottola wrote:
> > ld: error: undefined symbol: _Unwind_Resume
>
> It looks as if your toolchain doesn't automatically link anything 
> that 
> provides the exception ABI.  On most *NIX systems this comes from 
> something 
> called libgcc_s.so (which, on FreeBSD, is actually LLVM's compiler-rt 
> - on 
> some platforms it's installed as such).  What happens when you 
> compile a C 
> program that uses -fexceptions and __attribute__((cleanup)) on 
> OpenBSD?  Does 
> it link something that provides these symbols?

I did some research and found that Unwind_Resume is in libc++, however 
to get all Unwind symbols, libc++abi is needed.

Thus, if I build libobjc2 with:

cmake ..  -DCMAKE_EXE_LINKER_FLAGS=-lc++abi

it will build and link. Why it is needed, I don't know, but other 
projects have the same recent on recent OpenBSD since the clang 
switch.

However, I get then the same error when linking tools and apps,
THus I tried to pass -lc++abi also for base, but then I get

 Compiling file Unicode.m ...
 Linking subproject Additions ...
clang: warning: argument unused during compilation: '-pthread' 
[-Wunused-command-line-argument]
ld: error: attempted static link of dynamic object 
/usr/bin/../lib/libc++abi.so.0.1
clang: error: linker command failed with exit code 1 (use -v to see 
invocation)
gmake[4]: *** [/System/Library/Makefiles/Instance/subproject.make:61: 
obj/subproject.o] Error 1
gmake[3]: *** [/System/Library/Makefiles/Instance/subproject.make:45: 
internal-subproject-all_] Error 2


so, perhaps this is the right track, but I couldn't figure out the 
complete solution.

Riccardo