On Sun, 25 Aug 2019 18:28:32 +0100,
Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> wrote:
>
> Kbuild provides per-file compiler flag addition/removal:
>
> CFLAGS_<basetarget>.o
> CFLAGS_REMOVE_<basetarget>.o
> AFLAGS_<basetarget>.o
> AFLAGS_REMOVE_<basetarget>.o
> CPPFLAGS_<basetarget>
> HOSTCFLAGS_<basetarget>.o
> HOSTCXXFLAGS_<basetarget>.o
>
> The <basetarget> is the filename of the target without its suffix.
>
> This syntax comes into a trouble when two files with the same name
> appear in one Makefile, for example:
>
> obj-y += foo.o
> obj-y += dir/foo.o
> CFLAGS_foo.o := <some-flags>
>
> Here, the <some-flags> applies to both foo.o and dir/foo.o
>
> The real world problem is:
>
> scripts/kconfig/util.c
> scripts/kconfig/lxdialog/util.c
>
> Both files are compiled into scripts/kconfig/mconf, but only the
> latter should be given with additional flags for ncurses.
>
> It is more sensible to use the relative path to the Makefile, like this:
>
> obj-y += foo.o
> CFLAGS_foo.o := <some-flags>
> obj-y += dir/foo.o
> CFLAGS_dir/foo.o := <other-flags>
>
> The $* variable is replaced with the stem ('%') part in a pattern rule.
> In other words, this only works for pattern rules.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> ---
>
> arch/arm/kvm/Makefile | 5 +++--
> arch/x86/entry/vdso/Makefile | 3 ++-
> scripts/Makefile.host | 30 +++++++++++++++---------------
> scripts/Makefile.lib | 10 +++++-----
> scripts/kconfig/Makefile | 8 ++++----
> 5 files changed, 29 insertions(+), 27 deletions(-)
For the KVM/arm part:
Acked-by: Marc Zyngier <maz@xxxxxxxxxx>
Thanks,
M.
--
Jazz is not dead, it just smells funny.
