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| author | Masahiro Yamada <masahiroy@kernel.org> | 2024-04-27 23:55:02 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2024-05-10 04:34:52 +0900 |
| commit | b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0 (patch) | |
| tree | 60cc6428700d3582666b62d1d9dd741656efe1ee /scripts/dtc | |
| parent | 9a0ebe5011f49e932bb0a2cea2034fd65e6e567e (diff) | |
| download | lwn-b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0.tar.gz lwn-b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0.zip | |
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 <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Diffstat (limited to 'scripts/dtc')
| -rw-r--r-- | scripts/dtc/Makefile | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile index 4d32b9497da9..a18657072541 100644 --- a/scripts/dtc/Makefile +++ b/scripts/dtc/Makefile @@ -16,12 +16,12 @@ libfdt = $(addprefix libfdt/,$(libfdt-objs)) fdtoverlay-objs := $(libfdt) fdtoverlay.o util.o # Source files need to get at the userspace version of libfdt_env.h to compile -HOST_EXTRACFLAGS += -I $(srctree)/$(src)/libfdt +HOST_EXTRACFLAGS += -I $(src)/libfdt HOST_EXTRACFLAGS += -DNO_YAML # Generated files need one more search path to include headers in source tree -HOSTCFLAGS_dtc-lexer.lex.o := -I $(srctree)/$(src) -HOSTCFLAGS_dtc-parser.tab.o := -I $(srctree)/$(src) +HOSTCFLAGS_dtc-lexer.lex.o := -I $(src) +HOSTCFLAGS_dtc-parser.tab.o := -I $(src) # dependencies on generated files need to be listed explicitly $(obj)/dtc-lexer.lex.o: $(obj)/dtc-parser.tab.h |