kbuild: check for wrong use of CFLAGS (0c53c8e6) · Commits · 戴 / test

External modules have in a few cases modifed gcc option by modifying CFLAGS. This has never been documented and was a bad practice. With the check to use KBUILD_CFLAGS it will no longer work so we better error out and tell what was wrong as a service to the external module users. This check can be overruled if KBUILD_NOPEDANTIC is set to something. Addid this possibility may allow older external module to build without any code modifications but potentially only loosing some un-important gcc options. Signed-off-by:

Sam Ravnborg <sam@ravnborg.org>

scripts/Makefile.build

+12 −2

Original line number	Diff line number	Diff line
		@@ -28,10 +28,20 @@ EXTRA_LDFLAGS :=

		include scripts/Kbuild.include

		# For backward compatibility check that these variables does not change
		save-cflags := $(CFLAGS)

		# The filename Kbuild has precedence over Makefile
		kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
		include $(if $(wildcard $(kbuild-dir)/Kbuild), $(kbuild-dir)/Kbuild, $(kbuild-dir)/Makefile)
		kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
		include $(kbuild-file)

		# If the save-* variables changed error out
		ifeq ($(KBUILD_NOPEDANTIC),)
		ifneq ("$(save-cflags)","$(CFLAGS)")
		$(error CFLAGS was changed in "$(kbuild-file)". Fix it to use EXTRA_CFLAGS)
		endif
		endif
		include scripts/Makefile.lib

		ifdef host-progs

Admin message