[PATCH v4 07/11] kbuild: use 'include' directive to load auto.conf from top Makefile

Masahiro Yamada
2018-07-20T07:49:04Z

When you build targets that require the kernel configuration, dot-config
is set to 1, then the top-level Makefile includes auto.conf. However,
Make considers its inclusion is optional because the '-include' directive
is used here.

If a necessary configuration file is missing for the external module
building, the following error message is displayed:

ERROR: Kernel configuration is invalid.
include/generated/autoconf.h or include/config/auto.conf are missing.
Run 'make oldconfig && make prepare' on kernel src to fix it.

However, Make still continues building; /bin/false let the creation of
'include/config/auto.config' fail, but Make can ignore the error since
it is included by the '-include' directive.

I guess the reason of using '-include' directive was to suppress
the warning when you build the kernel from a pristine source tree:

Makefile:605: include/config/auto.conf: No such file or directory

The previous commit made sure include/config/auto.conf exists after
the 'make *config' stage. Now, we can use the 'include' directive
without showing the warning.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v4: None

Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 5c8e9a3..2fa9830 100644
--- a/Makefile
+++ b/Makefile
@@ -585,7 +585,7 @@ virt-y := virt/
endif # KBUILD_EXTMOD

ifeq ($(dot-config),1)
--include include/config/auto.conf
+include include/config/auto.conf
endif

# The all: target is the default when no target is given on the
--
2.7.4