[Buildroot] [PATCH] package/llvm: remove $ORIGIN/../lib from RPATH

[Thomas Petazzoni <thomas.petazzoni@bootlin.com>]

Hello Valentin,

On Wed, 11 Apr 2018 17:30:22 +0200, Valentin Korenblit wrote:
> AddLLVM.cmake adds $ORIGIN/../lib to the RPATH of llvm binaries.
> This causes a problem when llvm-config from host installed in
> STAGING_DIR is executed under the following conditions:
> 
> *Target architecture same as host architecture (normally x86_64)
> *Target's libc different from host's libc (normally glibc)
> 
> llvm-config will try to link with the target's libc, resulting in:
> 
> ./llvm-config: error while loading shared libraries: libc.so.0:
> cannot open shared object file: No such file or directory.
> 
> Link to autobuild error:
> http://autobuild.buildroot.net/results/b81c12d529c66a028e2297ea5ce1d6930324fa69/
> 
> To avoid this, remove the code from llvm_setup_rpath in AddLLVM.cmake
> 
> Link to discussion:
> http://lists.busybox.net/pipermail/buildroot/2018-April/218627.html
> 
> Signed-off-by: Valentin Korenblit <valentin.korenblit@smile.fr>

Thanks for this work. However, while this is going to work for the
Buildroot build (thanks to the hardcoded absolute RPATH encoded into
the binaries), I believe it will fail once "make sdk" is executed,
because "make sdk" will change the RPATH of binaries in STAGING_DIR to
be relative RPATHs.

Could you try after applying your patch:

$ make [.... do the normal build ...]
$ ./output/staging/usr/bin/llvm-config --the-flags-that-are-important
$ readelf -d output/staging/usr/bin/llvm-config
$ make sdk
$ ./output/staging/usr/bin/llvm-config --the-flags-that-are-important
$ readelf -d output/staging/usr/bin/llvm-config

Is there any difference before/after the "make sdk" ?

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com