Commit 1d3730f0 authored Nov 10, 2024 by Masahiro Yamada

kbuild: support -fmacro-prefix-map for external modules



This commit makes -fmacro-prefix-map work for external modules built in
a separate output directory. It improves the reproducibility of external
modules and provides the benefits described in commit a73619a8
("kbuild: use -fmacro-prefix-map to make __FILE__ a relative path").

When building_out_of_srctree is not defined (e.g., when the kernel or
external module is built in the source directory), this option is
unnecessary.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

parent 11b3d517

Makefile

+4 −2

Original line number	Diff line number	Diff line
		@@ -1041,8 +1041,10 @@ ifdef CONFIG_CC_IS_GCC
		KBUILD_CFLAGS += -fconserve-stack
		endif

		# change __FILE__ to the relative path from the srctree
		KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
		# change __FILE__ to the relative path to the source directory
		ifdef building_out_of_srctree
		KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srcroot)/=)
		endif

		# include additional Makefiles when needed
		include-y := scripts/Makefile.extrawarn