clang --target=bpf missing on f23 was: Re: [PATCH 1/2] perf test: Add libbpf relocation checker

From: Arnaldo Carvalho de Melo
Date: Fri Jan 22 2016 - 12:22:33 EST


Em Fri, Jan 22, 2016 at 09:07:50AM -0800, Alexei Starovoitov escreveu:
> On Fri, Jan 22, 2016 at 12:40:50PM -0300, Arnaldo Carvalho de Melo wrote:
> > [root@jouet ~]# llc --version
> > LLVM (http://llvm.org/):
> > LLVM version 3.7.0
> > Optimized build.
> > Built Dec 4 2015 (15:49:18).
> > Default target: x86_64-redhat-linux-gnu
> > Host CPU: broadwell
> >
> > Registered Targets:
> > aarch64 - AArch64 (little endian)
> > aarch64_be - AArch64 (big endian)
> > amdgcn - AMD GCN GPUs
> > arm - ARM
> > arm64 - ARM64 (little endian)
> > armeb - ARM (big endian)
> > cpp - C++ backend
> > nvptx - NVIDIA PTX 32-bit
> > nvptx64 - NVIDIA PTX 64-bit
> > ppc32 - PowerPC 32
> > ppc64 - PowerPC 64
> > ppc64le - PowerPC 64 LE
> > r600 - AMD GPUs HD2XXX-HD6XXX
> > systemz - SystemZ
> > thumb - Thumb
> > thumbeb - Thumb (big endian)
> > x86 - 32-bit X86: Pentium-Pro and above
> > x86-64 - 64-bit X86: EM64T and AMD64
> > [root@jouet ~]#
>
> ouch, so fedora enabled all sorts of backends, but disabled BPF?!
> Can somebody talk to redhat packaging folks?
> clang/llvm enables BPF backend by default.

Adding Adam Jackson and Dave Airlie, that last updated llvm.

Hi Adam, Dave,

the 'bpf' target for clang is being used together with perf to
build scriptlets into object code that then gets uploaded to the kernel
via sys_bpf(), was the decision not to include 'bpf' just an accident?

BTW, this is on a recently installed Fedora 23 machine.

- Arnaldo

[acme@jouet linux]$ rpm -q --changelog llvm-libs | grep -v ^$ | head -20
* Thu Dec 03 2015 Stephan Bergmann <sbergman@xxxxxxxxxx> 3.7.0-3
- Resolves: rhbz#1282645 add GCC abi_tag support
* Thu Oct 29 2015 Adam Jackson <ajax@xxxxxxxxxx> 3.7.0-2
- Drop -fno-devirtualize
- Link with -static-libstdc++ to work around bundled libstdc++ in Steam
* Wed Sep 16 2015 Dave Airlie <airlied@xxxxxxxxxx> 3.7.0-1
- llvm 3.7.0
* Wed Jul 22 2015 Adam Jackson <ajax@xxxxxxxxxx> 3.6.2-1
- llvm 3.6.2
* Wed Jun 17 2015 Dave Airlie <airlied@xxxxxxxxxx> 3.6.1-1
- llvm 3.6.1
* Fri May 29 2015 Zbigniew JÄdrzejewski-Szmek <zbyszek@xxxxxxxxx> - 3.6.0-2
- Also require gcc-c++ at runtime (#1021645)
* Thu Apr 09 2015 Adam Jackson <ajax@xxxxxxxxxx> 3.6.0-1
- llvm 3.6.0
* Wed Feb 18 2015 Jonathan Wakely <jwakely@xxxxxxxxxx> - 3.5.0-11
- Add patch for http://llvm.org/bugs/show_bug.cgi?id=22625
* Wed Feb 18 2015 Richard W.M. Jones <rjones@xxxxxxxxxx> - 3.5.0-10
- Bump release and rebuild.
* Tue Feb 17 2015 Peter Robinson <pbrobinson@xxxxxxxxxxxxxxxxx> 3.5.0-9
[acme@jouet linux]$