[PATCH 01/11] kselftest/arm64: mte: Fix compilation with native compiler

[Nick Desaulniers]

On Fri, Mar 19, 2021 at 9:53 AM Andre Przywara <andre.przywara at arm.com> wrote:
>
> The mte selftest Makefile contains a check for GCC, to add the memtag
> -march flag to the compiler options. This check fails if the compiler
> is not explicitly specified, so reverts to the standard "cc", in which
> case --version doesn't mention the "gcc" string we match against:
> $ cc --version | head -n 1
> cc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0
>
> This will not add the -march switch to the command line, so compilation
> fails:
> mte_helper.S: Assembler messages:
> mte_helper.S:25: Error: selected processor does not support `irg x0,x0,xzr'
> mte_helper.S:38: Error: selected processor does not support `gmi x1,x0,xzr'
> ...
>
> Actually clang accepts the same -march option as well, so we can just
> drop this check and add this unconditionally to the command line, to avoid
> any future issues with this check altogether (gcc actually prints
> basename(argv[0]) when called with --version).
>
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>

Reviewed-by: Nick Desaulniers <ndesaulniers at google.com>

> ---
>  tools/testing/selftests/arm64/mte/Makefile | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/tools/testing/selftests/arm64/mte/Makefile b/tools/testing/selftests/arm64/mte/Makefile
> index 0b3af552632a..df15d44aeb8d 100644
> --- a/tools/testing/selftests/arm64/mte/Makefile
> +++ b/tools/testing/selftests/arm64/mte/Makefile
> @@ -6,9 +6,7 @@ SRCS := $(filter-out mte_common_util.c,$(wildcard *.c))
>  PROGS := $(patsubst %.c,%,$(SRCS))
>
>  #Add mte compiler option
> -ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep gcc),)
>  CFLAGS += -march=armv8.5-a+memtag
> -endif
>
>  #check if the compiler works well
>  mte_cc_support := $(shell if ($(CC) $(CFLAGS) -E -x c /dev/null -o /dev/null 2>&1) then echo "1"; fi)
> --
> 2.17.5
>


-- 
Thanks,
~Nick Desaulniers