linux/tools/build/Makefile.build
Wang Nan f61bdc3304 tools build: Support compiling C++ source file
Add new rule to compile .cpp file to .o use g++. C++ support is required
for built-in clang and LLVM support.

Linker side support will be introduced by following commits.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1474874832-134786-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-10-05 19:58:51 -03:00

158 lines
3.8 KiB
Makefile

###
# Main build makefile.
#
# Lots of this code have been borrowed or heavily inspired from parts
# of kbuild code, which is not credited, but mostly developed by:
#
# Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015
# Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015
#
PHONY := __build
__build:
ifeq ($(V),1)
quiet =
Q =
else
quiet=quiet_
Q=@
endif
build-dir := $(srctree)/tools/build
# Define $(fixdep) for dep-cmd function
ifeq ($(OUTPUT),)
fixdep := $(build-dir)/fixdep
else
fixdep := $(OUTPUT)/fixdep
endif
# Generic definitions
include $(build-dir)/Build.include
# do not force detected configuration
-include $(OUTPUT).config-detected
# Init all relevant variables used in build files so
# 1) they have correct type
# 2) they do not inherit any value from the environment
subdir-y :=
obj-y :=
subdir-y :=
subdir-obj-y :=
# Build definitions
build-file := $(dir)/Build
-include $(build-file)
quiet_cmd_flex = FLEX $@
quiet_cmd_bison = BISON $@
# Create directory unless it exists
quiet_cmd_mkdir = MKDIR $(dir $@)
cmd_mkdir = mkdir -p $(dir $@)
rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir))
# Compile command
quiet_cmd_cc_o_c = CC $@
cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
quiet_cmd_host_cc_o_c = HOSTCC $@
cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $<
quiet_cmd_cxx_o_c = CXX $@
cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $<
quiet_cmd_cpp_i_c = CPP $@
cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $<
quiet_cmd_cc_s_c = AS $@
cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $<
quiet_cmd_gen = GEN $@
# Link agregate command
# If there's nothing to link, create empty $@ object.
quiet_cmd_ld_multi = LD $@
cmd_ld_multi = $(if $(strip $(obj-y)),\
$(LD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@)
quiet_cmd_host_ld_multi = HOSTLD $@
cmd_host_ld_multi = $(if $(strip $(obj-y)),\
$(HOSTLD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@)
ifneq ($(filter $(obj),$(hostprogs)),)
host = host_
endif
# Build rules
$(OUTPUT)%.o: %.c FORCE
$(call rule_mkdir)
$(call if_changed_dep,$(host)cc_o_c)
$(OUTPUT)%.o: %.cpp FORCE
$(call rule_mkdir)
$(call if_changed_dep,cxx_o_c)
$(OUTPUT)%.o: %.S FORCE
$(call rule_mkdir)
$(call if_changed_dep,$(host)cc_o_c)
$(OUTPUT)%.i: %.c FORCE
$(call rule_mkdir)
$(call if_changed_dep,cpp_i_c)
$(OUTPUT)%.s: %.S FORCE
$(call rule_mkdir)
$(call if_changed_dep,cpp_i_c)
$(OUTPUT)%.s: %.c FORCE
$(call rule_mkdir)
$(call if_changed_dep,cc_s_c)
# Gather build data:
# obj-y - list of build objects
# subdir-y - list of directories to nest
# subdir-obj-y - list of directories objects 'dir/$(obj)-in.o'
obj-y := $($(obj)-y)
subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
obj-y := $(patsubst %/, %/$(obj)-in.o, $(obj-y))
subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y))
# '$(OUTPUT)/dir' prefix to all objects
objprefix := $(subst ./,,$(OUTPUT)$(dir)/)
obj-y := $(addprefix $(objprefix),$(obj-y))
subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y))
# Final '$(obj)-in.o' object
in-target := $(objprefix)$(obj)-in.o
PHONY += $(subdir-y)
$(subdir-y):
$(Q)$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj)
$(sort $(subdir-obj-y)): $(subdir-y) ;
$(in-target): $(obj-y) FORCE
$(call rule_mkdir)
$(call if_changed,$(host)ld_multi)
__build: $(in-target)
@:
PHONY += FORCE
FORCE:
# Include all cmd files to get all the dependency rules
# for all objects included
targets := $(wildcard $(sort $(obj-y) $(in-target) $(MAKECMDGOALS)))
cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
ifneq ($(cmd_files),)
include $(cmd_files)
endif
.PHONY: $(PHONY)