Re: [PATCH] selftests/nolibc: explicitly disable position independent executables

[Willy Tarreau <w@1wt.eu>]

Hi Thomas,

On Sun, Oct 18, 2026 at 12:02:18AM +0200, Thomas Weißschuh wrote:
> nolibc does not support position independent executables (PIE).
> However a toolchain might generate these by default depending on various
> circumstances. Recently clang started to do so for hexagon. See LLVM
> commit ab43cb8520c0 ("[Hexagon] Pass -pie to linker when PIE is the
> toolchain default (#189723)").
> 
> As clang can also be configured to create PIE for other architectures by
> default disable it globally. While we are at it also pass the argument
> for GCC to be on the safe side.
> 
> If PIE is disabled already, clang will generate
> -Wunused-command-line-argument warnings. Inhibit those.

Interesting, I didn't know about these options.

> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---
> I ran into this when testing the upcoming PR to Linus.
> The referenced LLVM commit was released between when I wrote the hexagon
> support and today. My plan is to fold this patch into the PR.

Sounds good.

Reviewed-by: Willy Tarreau <w@1wt.eu>

Willy

> ---
>  tools/testing/selftests/nolibc/Makefile.include | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/tools/testing/selftests/nolibc/Makefile.include b/tools/testing/selftests/nolibc/Makefile.include
> index ea520eac64a6..14e51c821d8a 100644
> --- a/tools/testing/selftests/nolibc/Makefile.include
> +++ b/tools/testing/selftests/nolibc/Makefile.include
> @@ -8,6 +8,7 @@ _CFLAGS_SANITIZER ?= $(call cc-option,-fsanitize=undefined -fsanitize-trap=all)
>  CFLAGS_NOLIBC_TEST  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 -ggdb \
>  		-W -Wall -Wextra -Wundef -Wwrite-strings \
>  		$(call cc-option,-fno-stack-protector) $(call cc-option,-Wmissing-prototypes) \
> +	        $(call cc-option,--start-no-unused-arguments) -no-pie $(call cc-option,--end-no-unused-arguments) \
>  		$(_CFLAGS_STACKPROTECTOR) $(_CFLAGS_SANITIZER)
>  
>  NOLIBC_TEST_SOURCES := nolibc-test.c nolibc-test-linkage.c nolibc-test-ignore-errno.c
> 
> ---
> base-commit: f9532b372e415e8198287ce010efa22f337857b5
> change-id: 20261017-nolibc-unused-arguments-b504fc061c46
> 
> Best regards,
> --  
> Thomas Weißschuh <linux@weissschuh.net>