[llvm-dev] ld.lld on MacOS question

[Lang Hames via llvm-dev]

Hi Guys,

As I left it, lld on Darwin could compile Clang / LLVM and the nightly test
suite, so we were definitely making progress. There were still plenty of
bug fixes to get through though. If anyone's interested in contributing to
MachO support in lld I'm happy to translate some of the radars into llvm.org
bugs.

Cheers,
Lang.


On Thu, May 11, 2017 at 11:34 PM, Peter Kriens <peter.kriens at aqute.biz>
wrote:

> Sounds like a fantastic goal, and enticingly close …
>
> Kind regards,
>
> Peter Kriens
>
> On 11 May 2017, at 20:53, Andrew Kelley <superjoe30 at gmail.com> wrote:
>
> Zig author here in the same boat. Looks like I'm going to have to disable
> cross compiling for MacOS and when compiling native for MacOS add a
> dependency on the system linker. Really looking forward to Mach-O support
> in LLD, because at that point my users will be able to cross compile for
> any OS out of the box.
>
> On Thu, May 11, 2017 at 1:37 PM, Peter Kriens via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Thanks for the answer. However, this means I need a different linker for
>> MacOS as for Windows/Linux?
>>
>> I guess it is a not a major thing but I was hoping to set up a cross
>> compile env. where only the header files and shared libraries differed :-(
>> I guess we’re not there yet … :-)
>>
>> Kind regards,
>>
>> Peter Kriens
>>
>> On 6 May 2017, at 19:57, Lang Hames <lhames at gmail.com> wrote:
>>
>> 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
>>>>
>>>>
>>>
>>
>>
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>>
>
>
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