kbuild: create object directories simpler and faster

CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)

VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1

# This makes sure the $(obj) subdirectory exists even though vdso32/

# is not a kbuild sub-make subdirectory.

override obj-dirs = $(dir $(obj)) $(obj)/vdso32/

targets += vdso32/vdso32.lds

targets += vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o

targets += vdso32/vclock_gettime.o

include scripts/Makefile.host

endif

ifneq ($(KBUILD_SRC),)

# Create output directory if not already present

_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))

# Create directories for object files if directory does not exist

# Needed when obj-y := dir/file.o syntax is used

_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))

endif

ifndef obj

$(warning kbuild: Makefile.build is included improperly)

endif

  include $(cmd_files)

endif

ifneq ($(KBUILD_SRC),)

# Create directories for object files if they do not exist

obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))

$(shell mkdir -p $(obj-dirs))

endif

# Declare the contents of the .PHONY variable as phony.  We keep that

# information in a variable se we can use it in if_changed and friends.

host-cshobjs	:= $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs))))

host-cxxshobjs	:= $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs))))

# output directory for programs/.o files

# hostprogs-y := tools/build may have been specified.

# Retrieve also directory of .o files from prog-objs or prog-cxxobjs notation

host-objdirs := $(dir $(__hostprogs) $(host-cobjs) $(host-cxxobjs))

host-objdirs := $(strip $(sort $(filter-out ./,$(host-objdirs))))

__hostprogs     := $(addprefix $(obj)/,$(__hostprogs))

host-csingle	:= $(addprefix $(obj)/,$(host-csingle))

host-cmulti	:= $(addprefix $(obj)/,$(host-cmulti))

host-cobjs	:= $(addprefix $(obj)/,$(host-cobjs))

host-cxxshlib	:= $(addprefix $(obj)/,$(host-cxxshlib))

host-cshobjs	:= $(addprefix $(obj)/,$(host-cshobjs))

host-cxxshobjs	:= $(addprefix $(obj)/,$(host-cxxshobjs))

host-objdirs    := $(addprefix $(obj)/,$(host-objdirs))

obj-dirs += $(host-objdirs)

#####

# Handle options to gcc. Support building with separate output directory

# objects depend on those (obviously)

multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y)))

multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y)))

multi-objs   := $(multi-objs-y) $(multi-objs-m)

# $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to

# tell kbuild to descend

subdir-obj-y := $(filter %/built-in.o, $(obj-y))

# $(obj-dirs) is a list of directories that contain object files

obj-dirs := $(dir $(multi-objs) $(obj-y))

# Replace multi-part objects by their individual parts, look at local dir only

real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) $(extra-y)

real-objs-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m)))

multi-objs-y	:= $(addprefix $(obj)/,$(multi-objs-y))

multi-objs-m	:= $(addprefix $(obj)/,$(multi-objs-m))

subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))

obj-dirs	:= $(addprefix $(obj)/,$(obj-dirs))

# These flags are needed for modversions and compiling, so we define them here

# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will