On Thu, Jan 23, 2020 at 7:52 PM Vincenzo Frascino <vincenzo.frascino@xxxxxxx> wrote: > > On 23/01/2020 10:30, Ard Biesheuvel wrote: > > On Thu, 23 Jan 2020 at 11:22, Amit Daniel Kachhap <amit.kachhap@xxxxxxx> wrote: > >> > >> From: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> > >> > >> Currently kconfig does not have a feature that allows to detect if the > >> used assembler supports a specific compilation option. > >> > >> Introduce 'as-option' to serve this purpose in the context of Kconfig: > >> > >> config X > >> def_bool $(as-option,...) > >> > >> Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> > >> Cc: linux-kbuild@xxxxxxxxxxxxxxx > >> Acked-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> > >> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> > >> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx> > >> --- > >> Changes since v3: > >> *) Changed the assembler option to -c instead of earlier -E. > >> *) Added Masahiro Acked-by. > >> > >> scripts/Kconfig.include | 4 ++++ > >> 1 file changed, 4 insertions(+) > >> > >> diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include > >> index d4adfbe..c4b4424 100644 > >> --- a/scripts/Kconfig.include > >> +++ b/scripts/Kconfig.include > >> @@ -31,6 +31,10 @@ cc-option = $(success,$(CC) -Werror $(CLANG_FLAGS) $(1) -E -x c /dev/null -o /de > >> # Return y if the linker supports <flag>, n otherwise > >> ld-option = $(success,$(LD) -v $(1)) > >> > >> +# $(as-option,<flag>) > >> +# Return y if the assembler supports <flag>, n otherwise > >> +as-option = $(success, $(CC) $(CLANG_FLAGS) $(1) -c -x assembler /dev/null -o /dev/zero) > > > > Did you mean '-o /dev/null' here? > > > > No /dev/zero because otherwise I get a warning that says that I am trying to > compile an object into the same file. > > If I invert /dev/zero and /dev/null this trashes the compilation. It took me a > while to get the right combination. What compiler produces such a warning? GCC? Clang? -- Best Regards Masahiro Yamada
