On Tue, Mar 27, 2018 at 7:29 AM, Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> wrote: > 'cc-option' will be the most frequently used macro. It evaluates to 'y' > if the given argument is supported by the compiler, or 'n' otherwise. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> > --- > > Changes in v2: > - Implement 'success' as a macro > > init/Kconfig | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/init/Kconfig b/init/Kconfig > index 0d6fe20..c456030 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -8,6 +8,12 @@ config DEFCONFIG_LIST > default ARCH_DEFCONFIG > default "arch/$ARCH/defconfig" > > +# expanded to y if the command exits with 0, n otherwise > +macro success $(shell ($(1) && echo y) || echo n) > + > +# expanded to y if the given compiler flag is supported, n otherwise > +macro cc-option $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null) > + > config CONSTRUCTORS > bool > depends on !UML > -- > 2.7.4 > Reviewed-by: Ulf Magnusson <ulfalizer@xxxxxxxxx> Some other tests (e.g. scripts/*-stack-protector.sh) also pass -S and -O0 and stuff to speed things up. Feels like that could lead to gotchas though. -S does help a bit at least: $ time gcc -c -x c /dev/null -o /dev/null real 0m0.020s user 0m0.013s sys 0m0.007s $ time gcc -S -x c /dev/null -o /dev/null real 0m0.012s user 0m0.009s sys 0m0.003s -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html