[llvm-dev] ld.lld on MacOS question

[Lang Hames via llvm-dev]

LLD work on Darwin is stalled out at the moment. Patches are welcome (and
I'll try to find time to review them), but I'd recommend ld64 for any
real-world linking.

- Lang.


On Thu, Apr 27, 2017 at 11:06 AM, Rui Ueyama <ruiu at google.com> wrote:

> Cc'ing people who are working on macOS.
>
> On Thu, Apr 27, 2017 at 9:05 AM, Peter Kriens via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Hopefully the right list … otherwise pointers appreciated (I’ve spent
>> days trying to find a solution but could not find sufficient documentation,
>> could not find a proper list of -flavor darwin commands)
>>
>> I am setting up an environment for cross compiling shared libraries using
>> LLVM. Overall this works perfectly for many unix like environments but
>> MacOS is a pain in the ass despite that I am running on MacOS. (I’ve not
>> tried windows yet.)
>>
>> I seem to be able to compile with clang a proper mach object file for a
>> hello function. However, when I link this function into a shared library I
>> (surprisingly for a shared lib?) get undefined symbols like _printf, stub
>> runtime: dyld_stub_binder, _main, etc. Using the flag
>>
>> -undefined dynamic_lookup
>>
>> I get no errors or warnings but then when I try to link the shared
>> library to a main program I get the error:
>>
>> ld: malformed dylib has MH_NO_REEXPORTED_DYLIBS flag
>> but no LC_REEXPORT_DYLIB load commands: ./libhello.dylib file
>> './libhello.dylib'
>>
>> I’ve included the shell file that makes the hello shared lib and the
>> command that I use to link the file.
>>
>> Thanks for any help, this looks like an amazing solution if it can get to
>> work on all supported platforms.
>>
>> Kind regards,
>>
>> Peter Kriens
>>
>> $ /usr/local/Cellar/llvm/4.0.0_1/bin/clang \
>> -target x86_64-apple-darwin16.5.0 \
>> -Ienvs/x86_64/apple/macos/darwin/16.5.0/include  \
>> -v \
>> -nostdinc \
>> -fPIC \
>> -c \
>> -Wno-nullability-completeness \
>> hello.c x.c
>>
>> $ file hello.o
>> hello.o: Mach-O 64-bit object x86_64
>>
>> $ /usr/local/Cellar/llvm/4.0.0_1/bin/ld.lld \
>> -flavor darwin \
>> -v \
>> -sdk_version 10.5.0 \
>> -demangle \
>> -arch x86_64 \
>> -undefined dynamic_lookup \
>> -dylib \
>> -dynamic \
>> -o libhello.dylib \
>> hello.o
>>
>> $ file libhello.dylib
>> libhello.dylib: Mach-O 64-bit dynamically linked shared library x86_64
>>
>> $ gcc x.c -L. -lhello
>> ld: malformed dylib has MH_NO_REEXPORTED_DYLIBS flag but no
>> LC_REEXPORT_DYLIB load commands: ./libhello.dylib file ‘./libhello.dylib'
>>
>>
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20170506/60c9c4b8/attachment.html>