1# SPDX-License-Identifier: GPL-2.0 2# ========================================================================== 3# Building binaries on the host system 4# Binaries are used during the compilation of the kernel, for example 5# to preprocess a data file. 6# 7# Both C and C++ are supported, but preferred language is C for such utilities. 8# 9# Sample syntax (see Documentation/kbuild/makefiles.rst for reference) 10# hostprogs-y := bin2hex 11# Will compile bin2hex.c and create an executable named bin2hex 12# 13# hostprogs-y := lxdialog 14# lxdialog-objs := checklist.o lxdialog.o 15# Will compile lxdialog.c and checklist.c, and then link the executable 16# lxdialog, based on checklist.o and lxdialog.o 17# 18# hostprogs-y := qconf 19# qconf-cxxobjs := qconf.o 20# qconf-objs := menu.o 21# Will compile qconf as a C++ program, and menu as a C program. 22# They are linked as C++ code to the executable qconf 23 24__hostprogs := $(sort $(hostprogs-y) $(hostprogs-m)) 25host-cshlib := $(sort $(hostlibs-y) $(hostlibs-m)) 26host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m)) 27 28# C code 29# Executables compiled from a single .c file 30host-csingle := $(foreach m,$(__hostprogs), \ 31 $(if $($(m)-objs)$($(m)-cxxobjs),,$(m))) 32 33# C executables linked based on several .o files 34host-cmulti := $(foreach m,$(__hostprogs),\ 35 $(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m)))) 36 37# Object (.o) files compiled from .c files 38host-cobjs := $(sort $(foreach m,$(__hostprogs),$($(m)-objs))) 39 40# C++ code 41# C++ executables compiled from at least one .cc file 42# and zero or more .c files 43host-cxxmulti := $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m))) 44 45# C++ Object (.o) files compiled from .cc files 46host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs))) 47 48# Object (.o) files used by the shared libaries 49host-cshobjs := $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs)))) 50host-cxxshobjs := $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs)))) 51 52host-csingle := $(addprefix $(obj)/,$(host-csingle)) 53host-cmulti := $(addprefix $(obj)/,$(host-cmulti)) 54host-cobjs := $(addprefix $(obj)/,$(host-cobjs)) 55host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti)) 56host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs)) 57host-cshlib := $(addprefix $(obj)/,$(host-cshlib)) 58host-cxxshlib := $(addprefix $(obj)/,$(host-cxxshlib)) 59host-cshobjs := $(addprefix $(obj)/,$(host-cshobjs)) 60host-cxxshobjs := $(addprefix $(obj)/,$(host-cxxshobjs)) 61 62##### 63# Handle options to gcc. Support building with separate output directory 64 65_hostc_flags = $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) \ 66 $(HOSTCFLAGS_$(basetarget).o) 67_hostcxx_flags = $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \ 68 $(HOSTCXXFLAGS_$(basetarget).o) 69 70# $(objtree)/$(obj) for including generated headers from checkin source files 71ifeq ($(KBUILD_EXTMOD),) 72ifneq ($(srctree),.) 73_hostc_flags += -I $(objtree)/$(obj) 74_hostcxx_flags += -I $(objtree)/$(obj) 75endif 76endif 77 78hostc_flags = -Wp,-MD,$(depfile) $(_hostc_flags) 79hostcxx_flags = -Wp,-MD,$(depfile) $(_hostcxx_flags) 80 81##### 82# Compile programs on the host 83 84# Create executable from a single .c file 85# host-csingle -> Executable 86quiet_cmd_host-csingle = HOSTCC $@ 87 cmd_host-csingle = $(HOSTCC) $(hostc_flags) $(KBUILD_HOSTLDFLAGS) -o $@ $< \ 88 $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F)) 89$(host-csingle): $(obj)/%: $(src)/%.c FORCE 90 $(call if_changed_dep,host-csingle) 91 92# Link an executable based on list of .o files, all plain c 93# host-cmulti -> executable 94quiet_cmd_host-cmulti = HOSTLD $@ 95 cmd_host-cmulti = $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -o $@ \ 96 $(addprefix $(obj)/,$($(@F)-objs)) \ 97 $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F)) 98$(host-cmulti): FORCE 99 $(call if_changed,host-cmulti) 100$(call multi_depend, $(host-cmulti), , -objs) 101 102# Create .o file from a single .c file 103# host-cobjs -> .o 104quiet_cmd_host-cobjs = HOSTCC $@ 105 cmd_host-cobjs = $(HOSTCC) $(hostc_flags) -c -o $@ $< 106$(host-cobjs): $(obj)/%.o: $(src)/%.c FORCE 107 $(call if_changed_dep,host-cobjs) 108 109# Link an executable based on list of .o files, a mixture of .c and .cc 110# host-cxxmulti -> executable 111quiet_cmd_host-cxxmulti = HOSTLD $@ 112 cmd_host-cxxmulti = $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -o $@ \ 113 $(foreach o,objs cxxobjs,\ 114 $(addprefix $(obj)/,$($(@F)-$(o)))) \ 115 $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F)) 116$(host-cxxmulti): FORCE 117 $(call if_changed,host-cxxmulti) 118$(call multi_depend, $(host-cxxmulti), , -objs -cxxobjs) 119 120# Create .o file from a single .cc (C++) file 121quiet_cmd_host-cxxobjs = HOSTCXX $@ 122 cmd_host-cxxobjs = $(HOSTCXX) $(hostcxx_flags) -c -o $@ $< 123$(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE 124 $(call if_changed_dep,host-cxxobjs) 125 126# Compile .c file, create position independent .o file 127# host-cshobjs -> .o 128quiet_cmd_host-cshobjs = HOSTCC -fPIC $@ 129 cmd_host-cshobjs = $(HOSTCC) $(hostc_flags) -fPIC -c -o $@ $< 130$(host-cshobjs): $(obj)/%.o: $(src)/%.c FORCE 131 $(call if_changed_dep,host-cshobjs) 132 133# Compile .c file, create position independent .o file 134# Note that plugin capable gcc versions can be either C or C++ based 135# therefore plugin source files have to be compilable in both C and C++ mode. 136# This is why a C++ compiler is invoked on a .c file. 137# host-cxxshobjs -> .o 138quiet_cmd_host-cxxshobjs = HOSTCXX -fPIC $@ 139 cmd_host-cxxshobjs = $(HOSTCXX) $(hostcxx_flags) -fPIC -c -o $@ $< 140$(host-cxxshobjs): $(obj)/%.o: $(src)/%.c FORCE 141 $(call if_changed_dep,host-cxxshobjs) 142 143# Link a shared library, based on position independent .o files 144# *.o -> .so shared library (host-cshlib) 145quiet_cmd_host-cshlib = HOSTLLD -shared $@ 146 cmd_host-cshlib = $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -shared -o $@ \ 147 $(addprefix $(obj)/,$($(@F:.so=-objs))) \ 148 $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F)) 149$(host-cshlib): FORCE 150 $(call if_changed,host-cshlib) 151$(call multi_depend, $(host-cshlib), .so, -objs) 152 153# Link a shared library, based on position independent .o files 154# *.o -> .so shared library (host-cxxshlib) 155quiet_cmd_host-cxxshlib = HOSTLLD -shared $@ 156 cmd_host-cxxshlib = $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -shared -o $@ \ 157 $(addprefix $(obj)/,$($(@F:.so=-objs))) \ 158 $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(@F)) 159$(host-cxxshlib): FORCE 160 $(call if_changed,host-cxxshlib) 161$(call multi_depend, $(host-cxxshlib), .so, -objs) 162 163targets += $(host-csingle) $(host-cmulti) $(host-cobjs)\ 164 $(host-cxxmulti) $(host-cxxobjs) $(host-cshlib) $(host-cshobjs) $(host-cxxshlib) $(host-cxxshobjs) 165