# ==========================================================================
  # Building binaries on the host system
  # Binaries are used during the compilation of the kernel, for example
  # to preprocess a data file.
  #
  # Both C and C++ are supported, but preferred language is C for such utilities.
  #
  # Sample syntax (see Documentation/kbuild/makefiles.txt for reference)
  # hostprogs-y := bin2hex
  # Will compile bin2hex.c and create an executable named bin2hex
  #
  # hostprogs-y    := lxdialog
  # lxdialog-objs := checklist.o lxdialog.o
  # Will compile lxdialog.c and checklist.c, and then link the executable
  # lxdialog, based on checklist.o and lxdialog.o
  #
  # hostprogs-y      := qconf
  # qconf-cxxobjs   := qconf.o
  # qconf-objs      := menu.o
  # Will compile qconf as a C++ program, and menu as a C program.
  # They are linked as C++ code to the executable qconf
  
  # hostprogs-y := conf
  # conf-objs  := conf.o libkconfig.so
  # libkconfig-objs := expr.o type.o
  # Will create a shared library named libkconfig.so that consists of
  # expr.o and type.o (they are both compiled as C code and the object files
  # are made as position independent code).
  # conf.c is compiled as a C program, and conf.o is linked together with
  # libkconfig.so as the executable conf.
  # Note: Shared libraries consisting of C++ files are not supported
  
  __hostprogs := $(sort $(hostprogs-y) $(hostprogs-m))
  
  # C code
  # Executables compiled from a single .c file
  host-csingle	:= $(foreach m,$(__hostprogs),$(if $($(m)-objs),,$(m)))
  
  # C executables linked based on several .o files
  host-cmulti	:= $(foreach m,$(__hostprogs),\
  		   $(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m))))
  
  # Object (.o) files compiled from .c files
  host-cobjs	:= $(sort $(foreach m,$(__hostprogs),$($(m)-objs)))
  
  # C++ code
  # C++ executables compiled from at least on .cc file
  # and zero or more .c files
  host-cxxmulti	:= $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m)))
  
  # C++ Object (.o) files compiled from .cc files
  host-cxxobjs	:= $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))
  
  # Shared libaries (only .c supported)
  # Shared libraries (.so) - all .so files referenced in "xxx-objs"
  host-cshlib	:= $(sort $(filter %.so, $(host-cobjs)))
  # Remove .so files from "xxx-objs"
  host-cobjs	:= $(filter-out %.so,$(host-cobjs))
  
  #Object (.o) files used by the shared libaries
  host-cshobjs	:= $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs))))
  
  # output directory for programs/.o files
  # hostprogs-y := tools/build may have been specified. Retrieve directory
  host-objdirs := $(foreach f,$(__hostprogs), $(if $(dir $(f)),$(dir $(f))))
  # directory of .o files from prog-objs notation
  host-objdirs += $(foreach f,$(host-cmulti),                  \
                      $(foreach m,$($(f)-objs),                \
                          $(if $(dir $(m)),$(dir $(m)))))
  # directory of .o files from prog-cxxobjs notation
  host-objdirs += $(foreach f,$(host-cxxmulti),                  \
                      $(foreach m,$($(f)-cxxobjs),                \
                          $(if $(dir $(m)),$(dir $(m)))))
  
  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-cxxmulti	:= $(addprefix $(obj)/,$(host-cxxmulti))
  host-cxxobjs	:= $(addprefix $(obj)/,$(host-cxxobjs))
  host-cshlib	:= $(addprefix $(obj)/,$(host-cshlib))
  host-cshobjs	:= $(addprefix $(obj)/,$(host-cshobjs))
  host-objdirs    := $(addprefix $(obj)/,$(host-objdirs))
  
  obj-dirs += $(host-objdirs)
  
  #####
  # Handle options to gcc. Support building with separate output directory
  
  _hostc_flags   = $(HOSTCFLAGS)   $(HOST_EXTRACFLAGS)   \
                   $(HOSTCFLAGS_$(basetarget).o)
  _hostcxx_flags = $(HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
                   $(HOSTCXXFLAGS_$(basetarget).o)
  
  ifeq ($(KBUILD_SRC),)
  __hostc_flags	= $(_hostc_flags)
  __hostcxx_flags	= $(_hostcxx_flags)
  else
  __hostc_flags	= -I$(obj) $(call flags,_hostc_flags)
  __hostcxx_flags	= -I$(obj) $(call flags,_hostcxx_flags)
  endif
  
  hostc_flags    = -Wp,-MD,$(depfile) $(__hostc_flags)
  hostcxx_flags  = -Wp,-MD,$(depfile) $(__hostcxx_flags)
  
  #####
  # Compile programs on the host
  
  # Create executable from a single .c file
  # host-csingle -> Executable
  quiet_cmd_host-csingle 	= HOSTCC  $@
        cmd_host-csingle	= $(HOSTCC) $(hostc_flags) -o $@ $< \
  	  	$(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
  $(host-csingle): $(obj)/%: $(src)/%.c FORCE
  	$(call if_changed_dep,host-csingle)
  
  # Link an executable based on list of .o files, all plain c
  # host-cmulti -> executable
  quiet_cmd_host-cmulti	= HOSTLD  $@
        cmd_host-cmulti	= $(HOSTCC) $(HOSTLDFLAGS) -o $@ \
  			  $(addprefix $(obj)/,$($(@F)-objs)) \
  			  $(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
  $(host-cmulti): $(obj)/%: $(host-cobjs) $(host-cshlib) FORCE
  	$(call if_changed,host-cmulti)
  
  # Create .o file from a single .c file
  # host-cobjs -> .o
  quiet_cmd_host-cobjs	= HOSTCC  $@
        cmd_host-cobjs	= $(HOSTCC) $(hostc_flags) -c -o $@ $<
  $(host-cobjs): $(obj)/%.o: $(src)/%.c FORCE
  	$(call if_changed_dep,host-cobjs)
  
  # Link an executable based on list of .o files, a mixture of .c and .cc
  # host-cxxmulti -> executable
  quiet_cmd_host-cxxmulti	= HOSTLD  $@
        cmd_host-cxxmulti	= $(HOSTCXX) $(HOSTLDFLAGS) -o $@ \
  			  $(foreach o,objs cxxobjs,\
  			  $(addprefix $(obj)/,$($(@F)-$(o)))) \
  			  $(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
  $(host-cxxmulti): $(obj)/%: $(host-cobjs) $(host-cxxobjs) $(host-cshlib) FORCE
  	$(call if_changed,host-cxxmulti)
  
  # Create .o file from a single .cc (C++) file
  quiet_cmd_host-cxxobjs	= HOSTCXX $@
        cmd_host-cxxobjs	= $(HOSTCXX) $(hostcxx_flags) -c -o $@ $<
  $(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE
  	$(call if_changed_dep,host-cxxobjs)
  
  # Compile .c file, create position independent .o file
  # host-cshobjs -> .o
  quiet_cmd_host-cshobjs	= HOSTCC  -fPIC $@
        cmd_host-cshobjs	= $(HOSTCC) $(hostc_flags) -fPIC -c -o $@ $<
  $(host-cshobjs): $(obj)/%.o: $(src)/%.c FORCE
  	$(call if_changed_dep,host-cshobjs)
  
  # Link a shared library, based on position independent .o files
  # *.o -> .so shared library (host-cshlib)
  quiet_cmd_host-cshlib	= HOSTLLD -shared $@
        cmd_host-cshlib	= $(HOSTCC) $(HOSTLDFLAGS) -shared -o $@ \
  			  $(addprefix $(obj)/,$($(@F:.so=-objs))) \
  			  $(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
  $(host-cshlib): $(obj)/%: $(host-cshobjs) FORCE
  	$(call if_changed,host-cshlib)
  
  targets += $(host-csingle)  $(host-cmulti) $(host-cobjs)\
  	   $(host-cxxmulti) $(host-cxxobjs) $(host-cshlib) $(host-cshobjs)