svn commit: r364325 - head

[John Baldwin]

On 8/17/20 1:11 PM, John Baldwin wrote:
> Author: jhb
> Date: Mon Aug 17 20:11:43 2020
> New Revision: 364325
> URL: https://svnweb.freebsd.org/changeset/base/364325
> 
> Log:
>   Add a USE_GCC_TOOLCHAINS knob to make universe.
>   
>   This uses GCC toolchains instead of LLVM on architectures supported by
>   GCC.  Currently this uses GCC 6 on aarch64, amd64, i386, and mips.
>   
>   Although this does also try to use GCC 6 on powerpc, it is always
>   skipped for now since a powerpc-gcc6 package is not available and the
>   structure of make universe makes it hard to skip a subset of arches
>   for a target.  This should be short-lived as freebsd-gcc9 does include
>   a powerpc-gcc9 package so powerpc should work once this switches to
>   GCC 9.

The goal of this change is to make it easier to do a tinderbox run with
GCC rather than clang for things like warning coverage, etc.

I'm currently working on a branch to move this to GCC 9 which adds the
powerpc and riscv leaving only 32-bit arm as the arch without a GCC
external toolchain (which I might rectify at some point).

However, with GCC 9 I currently am working through a few issues:

- For i386, gcc wants some __atomic functions for 64-bit when linking lldb
  even though I've changed it to default to -march=i686 like clang which
  should let it use cmpxchg8b instead AFAIK.

- powerpc64 generates an ICE trying to build CSU bits.

- powerpc is running into issues with secureplt though I have fixes
  for that that I'm testing.

- riscv wants to use some __atomic functions which seems odd.

-- 
John Baldwin