[PATCH] kbuild: dummy-tools, fix inverted tests for gcc

[PATCH] kbuild: dummy-tools, fix inverted tests for gcc

[Jiri Slaby]

There is a test in Kconfig which takes inverted value of a compiler
check:
* config CC_HAS_INT128
        def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0)

This results in CC_HAS_INT128 not being in super-config generated by
dummy-tools. So take this into account in the gcc script.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/dummy-tools/gcc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/scripts/dummy-tools/gcc b/scripts/dummy-tools/gcc
index 5c113cad5601..0d0589cf8184 100755
--- a/scripts/dummy-tools/gcc
+++ b/scripts/dummy-tools/gcc
@@ -85,3 +85,8 @@ if arg_contain -print-file-name=plugin "$@"; then
 	echo $plugin_dir
 	exit 0
 fi
+
+# inverted return value
+if arg_contain -D__SIZEOF_INT128__=0 "$@"; then
+	exit 1
+fi
-- 
2.30.1

Re: [PATCH] kbuild: dummy-tools, fix inverted tests for gcc

[Masahiro Yamada]

On Wed, Mar 3, 2021 at 7:43 PM Jiri Slaby <jslaby@suse.cz> wrote:
>
> There is a test in Kconfig which takes inverted value of a compiler
> check:
> * config CC_HAS_INT128
>         def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0)
>
> This results in CC_HAS_INT128 not being in super-config generated by
> dummy-tools. So take this into account in the gcc script.
>
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> ---


Applied to linux-kbuild/fixes.
Thanks.


We could fix init/Kconfig to use the positive logic as follows,
but I guess (hope) this conditional will go away
when we raise the GCC min version next time.
So, I am fine with fixing this in dummy-tools.




diff --git a/init/Kconfig b/init/Kconfig
index 22946fe5ded9..502594a78282 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -849,7 +849,7 @@ config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
        bool

 config CC_HAS_INT128
-       def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
+       def_bool $(success,echo '__int128 x;' | $(CC) $(CLANG_FLAGS)
-x c - -c -o /dev/null) && 64BIT

 #
 # For architectures that know their GCC __int128 support is sound





-- 
Best Regards
Masahiro Yamada