Re: [musl] Newbie cross compiling with LLVM

[Jeffrey Walton <noloader@gmail.com>]

On Sun, Oct 10, 2021 at 7:22 PM Matt Andrews <mattandrews@gmail.com> wrote:
>
> > Have try with setting passing AR=clang-ar?
>
> I actually set
>
>     AR=/usr/lib/llvm-13/bin/llvm-ar
>
> Then I set
>
>     RANLIB=/usr/lib/llvm-13/bin/llvm-ranlib
>
> That got me a little further down the road, but now I'm getting this error
>
>     /usr/bin/ld: unrecognised emulation mode: armelf_linux_eabi
>     Supported emulations: elf_x86_64 elf32_x86_64 elf_i386 elf_iamcu elf_l1om elf_k1om i386pep i386pe
>     clang: error: linker command failed with exit code 1 (use -v to see invocation)
>
> I added this to CFLAGS
>
>     -B/usr/lib/llvm-13/bin
>
> But it still uses the system linker.

That's a linker flag. It should be added to LDFLAGS, not CFLAGS.

> How do I specify which linker to use?

LD. Also see https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html.

Typically, during a cross-compile of a C/C++ program, you set the
following variables:

* CC
* CXX
* CPP (C preprocessor)
* CPPFLAGS (this is where you put --isysroot)
* CFLAGS
* CXXFLAGS
* LD
* LDFLAGS (this is where you put --sysroot)

--isysroot tells the build system where to find the target's header
files. --sysroot tells the build system where to find the target's
libraries.

Set all the variables. Do not leave anything to chance.

If you set your variables properly and the build fails, then the
makefile or Autotool's configure.ac is broken. That happens a lot.

Jeff