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| author | Masahiro Yamada <masahiroy@kernel.org> | 2021-02-22 01:53:06 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-02-24 15:12:06 +0900 |
| commit | bcf637f54f6d2515d4c9c81808faf01848916152 (patch) | |
| tree | 97121bb2cfbdad70e9eaea63441211231dd37509 /Makefile | |
| parent | 30cef68d2d19e48c5832b126d3f4a7aeae5a64d6 (diff) | |
| download | lwn-bcf637f54f6d2515d4c9c81808faf01848916152.tar.gz lwn-bcf637f54f6d2515d4c9c81808faf01848916152.zip | |
kbuild: parse C= and M= before changing the working directory
If Kbuild recurses to the top Makefile (for example, 'make deb-pkg'),
C= and M= are parsed over again, needlessly.
Parse them before changing the working directory. After that,
sub_make_done is set to 1, so they are parsed just once.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 61 |
1 files changed, 31 insertions, 30 deletions
@@ -100,6 +100,36 @@ endif export quiet Q KBUILD_VERBOSE +# 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/dev-tools/sparse.rst" for more details, +# including where to get the "sparse" utility. + +ifeq ("$(origin C)", "command line") + KBUILD_CHECKSRC = $(C) +endif +ifndef KBUILD_CHECKSRC + KBUILD_CHECKSRC = 0 +endif + +export KBUILD_CHECKSRC + +# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the +# directory of external module to build. Setting M= takes precedence. +ifeq ("$(origin M)", "command line") + KBUILD_EXTMOD := $(M) +endif + +$(if $(word 2, $(KBUILD_EXTMOD)), \ + $(error building multiple external modules is not supported)) + +export KBUILD_EXTMOD + # Kbuild will save output files in the current working directory. # This does not need to match to the root of the kernel source tree. # @@ -194,36 +224,6 @@ ifeq ($(need-sub-make),) # 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/dev-tools/sparse.rst" for more details, -# including where to get the "sparse" utility. - -ifeq ("$(origin C)", "command line") - KBUILD_CHECKSRC = $(C) -endif -ifndef KBUILD_CHECKSRC - KBUILD_CHECKSRC = 0 -endif - -# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the -# directory of external module to build. Setting M= takes precedence. -ifeq ("$(origin M)", "command line") - KBUILD_EXTMOD := $(M) -endif - -$(if $(word 2, $(KBUILD_EXTMOD)), \ - $(error building multiple external modules is not supported)) - -export KBUILD_CHECKSRC KBUILD_EXTMOD - -extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) - ifeq ($(abs_srctree),$(abs_objtree)) # building in the source tree srctree := . @@ -1093,6 +1093,7 @@ endif # CONFIG_BPF PHONY += prepare0 +extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) export MODORDER := $(extmod-prefix)modules.order export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps |