@@ -52,6 +52,12 @@ ifndef obj
$(warning kbuild: Makefile.build is included improperly)
endif
+ifeq ($(need-builtin),)
+ifneq ($(real-obj-y),)
+$(warning '$(real-obj-y)' will not be linked to vmlinux even though obj-y is specified.)
+endif
+endif
+
ifeq ($(need-modorder),)
ifneq ($(obj-m),)
$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
@@ -216,7 +216,7 @@ else
fi;
# final build of init/
-${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
+${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1
#link vmlinux.o
info LD vmlinux.o
obj-y specifies objects linked into vmlinux, but they are actually linked if and only if that sub-directory is visited by the chain of obj-y. If you have an orphan obj-y object, it is a bug, but may not easy to notice. This commit provides build-time warning. I tested allmodconfig based on v5.3-rc4, and I saw one warning: scripts/Makefile.build:57: 'sound/soc/sprd/sprd-mcdt.o' will not be linked to vmlinux even though obj-y is specified. This is a proper warning. sound/soc/sprd/sprd-mcdt.o is compiled as built-in since CONFIG_SND_SOC_SPRD_MCDT is boolean. However, CONFIG_SND and CONFIG_SND_SOC are tristate, and set to m by allmodconfig. So, Kbuild descends into sound/soc/, then sound/soc/sprd/ by obj-m. sound/soc/sprd/sprd-mcdt.o is not linked to vmlinux. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- scripts/Makefile.build | 6 ++++++ scripts/link-vmlinux.sh | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) -- 2.17.1