Re: [PULL 28/53] Makefile: simplify MINIKCONF rules

[Peter Maydell]

On Fri, 17 Jul 2020 at 12:20, Paolo Bonzini <pbonzini@redhat.com> wrote:
> Il ven 17 lug 2020, 13:03 Peter Maydell <peter.maydell@linaro.org> ha scritto:
>> There doesn't seem to be any machinery for creating .d
>> files for make to include to tell it that Kconfig has a
>> dependency on hw/Kconfig which has a dependency on hw/i2c/Kconfig etc.
>> How is this intended to work ?
>
>
> I cannot look at a build tree right now, but shouldn't that be in the .d file 
> produced by minikconf.py Those are passed to minikconf.py as the second 
> argument and included with "include $(SUBDIR_DEVICES_MAK_DEP)".

When you do a "make clean" those .d files get deleted
(but the config-devices.mak files do not). There is no rule
for rebuilding a config-devices.mak.d:

$ make -C build/x86 -n arm-softmmu/config-devices.mak.d
make: Entering directory '/home/petmay01/linaro/qemu-from-laptop/qemu/build/x86'
make[1]: Entering directory '/home/petmay01/linaro/qemu-from-laptop/qemu/slirp'
make[1]: Nothing to be done for 'all'.
make[1]: Leaving directory '/home/petmay01/linaro/qemu-from-laptop/qemu/slirp'
make: *** No rule to make target 'arm-softmmu/config-devices.mak.d'. Stop.
make: Leaving directory '/home/petmay01/linaro/qemu-from-laptop/qemu/build/x86'

and we include them with "-include", so Make silently
proceeds without the dependency information.

My guess is that we need to tell make that this rule:
$(SUBDIR_DEVICES_MAK): %/config-devices.mak: default-configs/%.mak
$(SRC_PATH)/Kconfig $(BUILD_DIR)/config-host.mak

also produces the .mak.d file somehow.

thanks
-- PMM