From b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 27 Apr 2024 23:55:02 +0900 Subject: kbuild: use $(src) instead of $(srctree)/$(src) for source directory Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier --- Makefile | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 12e1a792b8de..c97c8d96061c 100644 --- a/Makefile +++ b/Makefile @@ -263,7 +263,14 @@ srctree := $(abs_srctree) endif objtree := . + +VPATH := + +ifeq ($(KBUILD_EXTMOD),) +ifdef building_out_of_srctree VPATH := $(srctree) +endif +endif export building_out_of_srctree srctree objtree VPATH -- cgit v1.2.3