Re: [PATCH] travis-ci: Use clang-10 for the [s390x] Clang (disable-tcg) job

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 5/12/21 5:22 PM, Philippe Mathieu-Daudé wrote:
> On Ubuntu Bionic 18.04 LTS clang binary points to the 6.0 version:
> 
>   $ clang --version
>   clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
> 
> However we can install clang-10 from the bionic-updates stream [*]
> and use it, to silent the following warnings:
> 
>      CC      pc-bios/s390-ccw/main.o
>   clang: warning: optimization flag '-fno-delete-null-pointer-checks' is not supported [-Wignored-optimization-argument]
>   clang: warning: argument unused during compilation: '-msoft-float' [-Wunused-command-line-argument]
>   /home/travis/build/qemu/qemu/pc-bios/s390-ccw/main.c:284:5: warning: no previous prototype for function 'main' [-Wmissing-prototypes]
>   int main(void)
>       ^
>   1 warning generated.
>   clang: warning: optimization flag '-fno-delete-null-pointer-checks' is not supported [-Wignored-optimization-argument]
> 
> [*] https://packages.ubuntu.com/bionic-updates/clang-10
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> However this doesn't resolve:
> 
>     /home/travis/build/philmd/qemu/pc-bios/s390-ccw/jump2ipl.c:67:18: error: invalid operand for instruction
>         asm volatile("lghi 1,1\n\t"
>                      ^
>     <inline asm>:1:7: note: instantiated into assembly here
>             lghi 1,1
>                  ^
>     /home/travis/build/philmd/qemu/pc-bios/s390-ccw/jump2ipl.c:67:29: error: invalid operand for instruction
>         asm volatile("lghi 1,1\n\t"
>                                 ^
>     <inline asm>:2:7: note: instantiated into assembly here
>             diag 1,1,0x308
>                  ^
>     2 errors generated.
>     Makefile:20: recipe for target 'jump2ipl.o' failed
>     make[1]: *** [jump2ipl.o] Error 1
> 
> (see https://travis-ci.org/github/philmd/qemu/jobs/770920106#L1803,
> https://travis-ci.org/github/philmd/qemu/jobs/770920522#L1818 for
> more errors).
> ---
>  .travis.yml | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/.travis.yml b/.travis.yml
> index 4609240b5aa..9c0deea9a06 100644
> --- a/.travis.yml
> +++ b/.travis.yml
> @@ -278,6 +278,7 @@ jobs:
>        compiler: clang
>        addons:
>          apt_packages:
> +          - clang-10
>            - libaio-dev
>            - libattr1-dev
>            - libbrlapi-dev
> @@ -303,7 +304,7 @@ jobs:
>        env:
>          - TEST_CMD="make check-unit"
>          - CONFIG="--disable-containers --disable-tcg --enable-kvm
> -                  --disable-tools --host-cc=clang --cxx=clang++"
> +                  --disable-tools --host-cc=clang-10 --cc=clang-10 --cxx=clang++-10"

I forgot to mention we were missing the --cc= flag, so s390-ccw
was built with an inconsistent $CC. I might respin this part
separately.

>          - UNRELIABLE=true
>  
>      # Release builds
>