可build任意目录结构的C/C++代码,此处在linux下以llvm+clang工具链为例
make程序在读取makefile阶段时通过$(shell)间接使用shell脚本递归扫描所有的源码目录,在输出/build目录下生成与源码目录结构一一对应的目录结构,并且在每个目录下生成subdir.mk文件,该文件是子makefile文件,其中描述了对应目录下要编译的资源。生成所有的子subdir.mk后,把这些子subdir.mk再include到主makefile中
################################################################################ ################################################################################ RM := rm -rf *.txt *.a *.hex *.tmp *.dat BH := build ##build home,指定编译或输出目录 APP_NAME := $(APP_NAME) OBJS := ##记录所有要输出的obj文件列表 SUBMKS := ##所有subdir.mk文件列表 C_INCS := ##记录所有inc目录,把所有存放源码文件的目录都当做头文件搜索目录 C_DEPS := ##记录源码文件的依赖文件,主要用于.h被修改后的增量编译 TOOLCHAIN := $(TOOLCHAIN) ##工具链 ifeq ($(strip $(TOOLCHAIN)),) TOOLCHAIN := /home/user/desktop/toolchain endif CFLAGS := $(CFLAGS) AFLAGS := $(AFLAGS) debug := $(debug) ifeq ($(strip $(debug)),1) CFLAGS += -O0 -g AFLAGS += -g else CFLAGS += -O2 endif -include ./Makefile.def define gen_submkf $(shell \ SRC_DIR="$(1)";\ BUD_DIR="$(2)";\ SUBMKF="$$BUD_DIR/subdir.mk";\ OBJS=;\ C_DEPS=;\ SPC_C=;\ SPU_ASM=;\ MPU_ASM=;\ TMP_OBJ=;\ TMP_BUD=;\ for file in `ls $(1)`;\ do \ if [ -d '$$file' ]; \ then \ echo '';\ else \ if [ $${file#*.} = "s.c" ];\ then \ TMP_OBJ="$$BUD_DIR/$${file%%.*}.s.o";\ OBJS="$$OBJS $$TMP_OBJ";\ C_DEPS="$$C_DEPS $$BUD_DIR/$${file%%.*}.s.d";\ fi;\ if [ $${file#*.} = "s.asm" ];\ then \ TMP_OBJ="$$BUD_DIR/$${file%.*}.o";\ TMP_BUD="$$TMP_OBJ: $$SRC_DIR/$$file\n\t\$$(TOOLCHAIN)/bin/llvm-mc -arch=ucps $(AFLAGS) -filetype=obj -o \"\$$@\" \"\$$<\"\n\t@echo ' '";\ OBJS="$$OBJS $$TMP_OBJ";\ SPU_ASM="$$SPU_ASM \n\n$$TMP_BUD";\ fi;\ if [ $${file#*.} == "m0.asm" ] || [ $${file#*.} == "m1.asm" ];\ then \ TMP_OBJ="$$BUD_DIR/$${file%.*}.o";\ TMP_BUD="$$TMP_OBJ: $$SRC_DIR/$$file\n\t\$$(TOOLCHAIN)/bin/llvm-mc -arch=ucpm $(AFLAGS) -filetype=obj -o \"\$$@\" \"\$$<\"\n\t@echo ' '";\ OBJS="$$OBJS $$TMP_OBJ";\ MPU_ASM="$$MPU_ASM \n\n$$TMP_BUD";\ fi;\ fi; \ done;\ SPU_C="$$BUD_DIR/%.s.o: $$SRC_DIR/%.s.c\n\t\$$(TOOLCHAIN)/bin/clang --target=ucps \$$(C_INCS) $(CFLAGS) -MMD -MP -o \"\$$@\" -c \"\$$<\"\n\t@echo ' '";\ echo -e "#generate automatically\n" > $$SUBMKF;\ echo "C_INCS += -I$$SRC_DIR" >> $$SUBMKF;\ echo "C_DEPS += $$C_DEPS" >> $$SUBMKF;\ echo "OBJS += $$OBJS" >> $$SUBMKF;\ echo -e "\n" >> $$SUBMKF;\ echo -e $$SPU_C >> $$SUBMKF;\ echo -e $$SPU_ASM >> $$SUBMKF;\ echo -e $$MPU_ASM >> $$SUBMKF;\ ) endef define gen_submk $(if $(subst $(realpath $(1)),,$(realpath $(BH))),\ $(shell mkdir -p $(2);rm -f $(2)/subdir.mk $(2)/*.o $(2)/*.d;touch $(2)/subdir.mk)$(2)/subdir.mk\ $(call gen_submkf,$(1),$(2)) $(foreach item,$(shell ls $(1)),$(if $(shell if [ -d '$(1)/$(item)' ];then echo 'isDir';fi;),\ $(call gen_submk,$(1)/$(item),$(2)/$(item)),\ )),\ ) endef $(shell mkdir -p $(BH)) SUB_MKS := $(strip $(call gen_submk,.,$(BH))) # All of the sources participating in the build are defined here ifneq ($(strip $(SUB_MKS)),) -include $(SUB_MKS) endif ifneq ($(MAKECMDGOALS),clean) ifneq ($(strip $(C_DEPS)),) -include $(C_DEPS) endif endif OBJS := $(strip $(OBJS)) C_DEPS := $(strip $(C_DEPS)) # Add inputs and outputs from these tool invocations to the build variables # All Target APP: $(BH)/$(APP_NAME).out LIB: $(BH)/$(APP_NAME).a # Tool invocations $(BH)/$(APP_NAME).out: $(OBJS) @echo 'Building target: $@' @echo 'Invoking: lld linker' $(MaPU_TC_HOME)/bin/ld.lld -o "$(BH)/$(APP_NAME).out" $(USER_OBJS) $(OBJS) $(LIBS) -L$(MaPU_TC_HOME)/lib/ucp/release -T$(MaPU_TC_HOME)/include/ucp/c.ld @echo 'Finished building target: $@' @echo ' ' $(BH)/$(APP_NAME).a: $(OBJS) @echo 'Building target: $@' @echo 'Invoking: GNU archiver' ar rcs $@ $(OBJS) @echo 'Finished building target: $@' @echo ' ' # Other Targets clean: -$(RM) $(EXECUTABLES) $(OBJS) $(C_DEPS) $(BH)/$(APP_NAME).out $(BH)/* -@echo ' ' .PHONY: all clean dependents
makefile.def文件,用于自定义一些编译参数、环境变量等,如CFLAGS等