scripts/Makefile.host

# SPDX-License-Identifier: GPL-2.0
# ==========================================================================
# 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.rst 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 := $(sort $(hostprogs-y) $(hostprogs-m))
host-cshlib := $(sort $(hostlibs-y) $(hostlibs-m))
host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m))

# C code
# Executables compiled from a single .c file
host-csingle	:= $(foreach m,$(__hostprogs), \
			$(if $($(m)-objs)$($(m)-cxxobjs),,$(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 one .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)))

# Object (.o) files used by the shared libaries
host-cshobjs	:= $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs))))
host-cxxshobjs	:= $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs))))

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

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

_hostc_flags   = $(KBUILD_HOSTCFLAGS)   $(HOST_EXTRACFLAGS)   \
                 $(HOSTCFLAGS_$(basetarget).o)
_hostcxx_flags = $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
                 $(HOSTCXXFLAGS_$(basetarget).o)

# $(objtree)/$(obj) for including generated headers from checkin source files
ifeq ($(KBUILD_EXTMOD),)
ifneq ($(srctree),.)
_hostc_flags   += -I $(objtree)/$(obj)
_hostcxx_flags += -I $(objtree)/$(obj)
endif
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) $(KBUILD_HOSTLDFLAGS) -o $@ $< \
		$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@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) $(KBUILD_HOSTLDFLAGS) -o $@ \
			  $(addprefix $(obj)/,$($(@F)-objs)) \
			  $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F))
$(host-cmulti): FORCE
	$(call if_changed,host-cmulti)
$(call multi_depend, $(host-cmulti), , -objs)

# 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) $(KBUILD_HOSTLDFLAGS) -o $@ \
			  $(foreach o,objs cxxobjs,\
			  $(addprefix $(obj)/,$($(@F)-$(o)))) \
			  $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F))
$(host-cxxmulti): FORCE
	$(call if_changed,host-cxxmulti)
$(call multi_depend, $(host-cxxmulti), , -objs -cxxobjs)

# 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)

# Compile .c file, create position independent .o file
# Note that plugin capable gcc versions can be either C or C++ based
# therefore plugin source files have to be compilable in both C and C++ mode.
# This is why a C++ compiler is invoked on a .c file.
# host-cxxshobjs -> .o
quiet_cmd_host-cxxshobjs	= HOSTCXX -fPIC $@
      cmd_host-cxxshobjs	= $(HOSTCXX) $(hostcxx_flags) -fPIC -c -o $@ $<
$(host-cxxshobjs): $(obj)/%.o: $(src)/%.c FORCE
	$(call if_changed_dep,host-cxxshobjs)

# 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) $(KBUILD_HOSTLDFLAGS) -shared -o $@ \
			  $(addprefix $(obj)/,$($(@F:.so=-objs))) \
			  $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F))
$(host-cshlib): FORCE
	$(call if_changed,host-cshlib)
$(call multi_depend, $(host-cshlib), .so, -objs)

# Link a shared library, based on position independent .o files
# *.o -> .so shared library (host-cxxshlib)
quiet_cmd_host-cxxshlib	= HOSTLLD -shared $@
      cmd_host-cxxshlib	= $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -shared -o $@ \
			  $(addprefix $(obj)/,$($(@F:.so=-objs))) \
			  $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F))
$(host-cxxshlib): FORCE
	$(call if_changed,host-cxxshlib)
$(call multi_depend, $(host-cxxshlib), .so, -objs)

targets += $(host-csingle)  $(host-cmulti) $(host-cobjs)\
	   $(host-cxxmulti) $(host-cxxobjs) $(host-cshlib) $(host-cshobjs) $(host-cxxshlib) $(host-cxxshobjs)