Re: [PATCH 3/3] kbuild: handle C=... and M=... after entering into build directory

[Michal Marek <mmarek@suse.cz>]

Dne 9.9.2014 13:02, Masahiro Yamada napsal(a):
>  sub-make: FORCE
>  	$(Q)$(MAKE) -C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR) \
> -	KBUILD_EXTMOD="$(KBUILD_EXTMOD)" -f $(CURDIR)/Makefile \
> -	$(filter-out _all sub-make,$(MAKECMDGOALS))
> +	-f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
>  
>  # Leave processing to above invocation of make
>  skip-makefile := 1
> @@ -188,6 +158,34 @@ ifeq ($(skip-makefile),)
>  # so that IDEs/editors are able to understand relative filenames.
>  MAKEFLAGS += --no-print-directory
>  
> +# Call a source code checker (by default, "sparse") as part of the
> +# C compilation.
> +#
> +# Use 'make C=1' to enable checking of only re-compiled files.
> +# Use 'make C=2' to enable checking of *all* source files, regardless
> +# of whether they are re-compiled or not.
> +#
> +# See the file "Documentation/sparse.txt" for more details, including
> +# where to get the "sparse" utility.
> +
> +ifeq ("$(origin C)", "command line")

I thought that the origin check would not work in the sub-make, because
the variables are part of the environment. But the sub-makes learn about
commandline variables from the MAKEFLAGS variable, so it works as
expected. Nice cleanup!

Michal