llvm dev - Sep 2016 - lld: add build-time control for including ELF / COFF / Mach-O linkers?

We're in the process of importing lld into FreeBSD (along with our
Clang 3.9 update project). For now I've removed all but the ELF
linker[1]. We have no need for COFF and Mach-O, and we have a bespoke
build system for all of our contrib code. I didn't bother adding build
support for the source files for non-ELF linkers.

Is this something that'd be reasonable / desirable to have extended
and implemented upstream, in the CMake build and perhaps a bit of an
#ifdef mess in tools/lld/lld.cpp::main()?

[1] https://svnweb.freebsd.org/changeset/base/305070

What's the motivation to not build COFF and Mach-O parts? If you don't
need
it, you could just leave it. Are you trying to reduce the executable size?

On Mon, Sep 12, 2016 at 1:19 PM, Ed Maste via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> We're in the process of importing lld into FreeBSD (along with our
> Clang 3.9 update project). For now I've removed all but the ELF
> linker[1]. We have no need for COFF and Mach-O, and we have a bespoke
> build system for all of our contrib code. I didn't bother adding build
> support for the source files for non-ELF linkers.
>
> Is this something that'd be reasonable / desirable to have extended
> and implemented upstream, in the CMake build and perhaps a bit of an
> #ifdef mess in tools/lld/lld.cpp::main()?
>
> [1] https://svnweb.freebsd.org/changeset/base/305070
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
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On 12 September 2016 at 16:23, Rui Ueyama <ruiu at google.com>
wrote:
> What's the motivation to not build COFF and Mach-O parts? If you
don't need
> it, you could just leave it. Are you trying to reduce the executable size?
It was just easier to remove coff::link() and mach_o::link() from
lld.cpp than to add them to our own build infrastructure
https://svnweb.freebsd.org/base/projects/clang390-import/usr.bin/clang/lld/Makefile?view=markup

We get a slightly faster build and a slightly smaller binary, but I
was motivated more by laziness than those factors. That is, it would
have taken more work to include features that would be unused.