Linux Makefile多目录的编写

手头一个项目，需要编写项目的makefile

多目录结构：

csource/

├── common
│   └── sqlite3
├── inc
│   ├── curl
│   ├── lua
│   └── Protection
├── lib
│   ├── arm
│   └── linux
├── obj
├── out
│   ├── arm
│   └── linux
├── src

源码目录src，输出目录out，include目录inc，输入链接库目录lib，常用静态函数和sqlite3目录common

makefile如下：

 PLAT= none
 CC=
 CXX=
 CFLAGS=
 LDFLAGS=
 MKDIR_P=mkdir -p

 PLATS= linux arm

 root= libroot.so
 root_a= libroot.a

 INC_DIR= ./inc
 COM_DIR= ./common
 SQL_DIR= ./common/sqlite3
 LUA_DIR= ./inc/lua
 PRO_DIR= ./inc/Protection
 INCLUDE= -I$(LUA_DIR) -I$(INC_DIR) -I$(COM_DIR) -I$(SQL_DIR) -I$(PRO_DIR)
 DIR_SRC= ./src

 SRC = $(wildcard ${DIR_SRC}/*.cpp)
 OBJ = $(patsubst %.cpp,${DIR_OBJ}/%.o,$(notdir ${SRC})) $(DIR_OBJ)/sqlite3.o

 SO_TARGET = ${DIR_BIN}/${root}
 LIB_TARGET= ${DIR_BIN}/${root_a}

 # Targets start here.
 default: $(PLAT)

 none:
     @echo "Please do 'make PLATFORM' where PLATFORM is one of these:"
     @echo "  $(PLATS)"

 ${SO_TARGET}:${OBJ}
     $(CXX) $(OBJ) -o $@ $(LDFLAGS)
     cp ${DIR_BIN}/${root} ./test/ -f

 ${LIB_TARGET}:${OBJ}
     $(AR) $@ ${OBJ}
     $(RANLIB) $@

 dir:
     $(MKDIR_P) $(DIR_OBJ) $(DIR_BIN);

 all:$(SO_TARGET) $(LIB_TARGET)

 ALL = dir all

 linux:
     $(MAKE) $(ALL) DIR_OBJ="./obj_linux/" DIR_BIN="./out/linux" \
     CC="gcc" CXX="g++" AR="ar rcu" RANLIB="ranlib" \
     CFLAGS="-Wno-write-strings -m32 -O2 -D_DEBUG -D_LINUX -fPIC" \
     LDFLAGS="-O2 -shared -m32 -ldl -pthread -lrt -L./lib/linux -llua -lProtection -lz -lcurl"

 arm:
     $(MAKE) $(ALL) DIR_OBJ="./obj_arm/" DIR_BIN="./out/arm" \
     CC="arm-linux-gnueabihf-gcc" CXX="arm-linux-gnueabihf-g++" \
     AR="arm-linux-gnueabihf-ar rcu" RANLIB="arm-linux-gnueabihf-ranlib" \
     CFLAGS="-Wno-write-strings -O2 -D_ARM -D__LINUX -fPIC" \
     LDFLAGS="-O2 -shared -ldl -pthread -lrt -L./lib/arm -llua -lProtection -lz -lcurl"

 # list targets that do not create files (but not all makes understand .PHONY)
 .PHONY: all $(PLATS) default clean none

 ${DIR_OBJ}/%.o:${DIR_SRC}/%.cpp
     $(CXX) $(CFLAGS) $(INCLUDE) -c $< -o $@

 ${DIR_OBJ}/sqlite3.o:${DIR_SRC}/sqlite3.c
     $(CC) $(CFLAGS) $(INCLUDE) -c $< -o $@

 .PHONY:clean
 clean:
     -find ${DIR_OBJ} -name *.o -exec rm -rf {} \;