遞歸編譯的Makefile的實現

最近寫了一個遞歸Makefile，目的是既可以實現子模塊的單獨編譯，也可以不做任何修改就和整個程序的整體進行無縫銜接的編譯。具體的思路是借助第三方文件，將子模塊編譯好的.o文件的路徑自動寫到config.mk文件中，在總控Makfile中只需要include這個config.mk就可以。單個模塊的編譯只需要cd到相應目錄就可以進行本模塊的單獨編譯，整個程序的編譯也只需要cd到頂層目錄，分別執行make config,make,make install就可以進行編譯和安裝。下面這個就是頂層Makefile

CROSS_COMPILE=                                                                                            
#CC=/opt/arm-cross-compile/arm-2010.09/bin/arm-none-linux-gnueabi-gcc
#CC=gcc
CC=arm-linux-gnueabi-gcc
D=-DDEBUG
CFLAGS= -g -O3 $(D)

export CC CFLAGS 

INCLUDE_DIR = $(shell cd ./common/include/; pwd)
SUB_DIR= ./entry/   \
         ./sqlite/  \

NFS_DIR:=~/nfs
CORE_NAME = core
$(shell touch config.mk)
include ./config.mk 

all:$(OBJS)
    $(CC) $(CFLAGS) $^ -lpthread -L/home/jiang/nfs/usr/lib/ -lsqlite3 -o $(CORE_NAME)

config:
    @echo "OBJS+=\\" > config.mk    
    @for dir in $(SUB_DIR);         \
    do                              \
        echo "\n";          \
        $(MAKE) -C $$dir ;      \
        echo "\n";              \
    done

clean:
    $(RM) ./config.mk       
    @for dir in $(SUB_DIR);         \
    do                              \
        echo "\n";              \
        $(MAKE) -C $$dir clean; \
        echo "\n";              \
        done
install:
    cp $(CORE_NAME) $(NFS_DIR)

下面這個就是每一個子模塊的Makfile，會把編譯成功的.o文件路徑添加到config.mk中

CUR_DIR=$(shell pwd)
OBJ_DIR:=$(CUR_DIR)/obj
INCLUDE_DIR= -I ./include -I ../common/include
SRC=$(wildcard ./src/*.c)

all:$(SRC)
    $(CC) $(CFLAGS) $(INCLUDE_DIR) -c $^ 
    mv ./*.o $(OBJ_DIR)
    echo "${OBJ_DIR}/*.o \\" >> ../config.mk 
    echo "\033[44;37m $(notdir $(CUR_DIR)) done \033[0m"
clean:
    $(RM) $(OBJ_DIR)/* 

下面就是config.mk的內容，會在頂層目錄中執行make config之後自動生成

OBJS+=\
/home/jiang/Documents/Documents/IntellStorage/A9_main/A9_core/entry/obj/*.o \
/home/jiang/Documents/Documents/IntellStorage/A9_main/A9_core/sqlite/obj/*.o \

為了使一個頭文件的實例在整個工程中只有一份，對於接口文件，約定一律以inter_開頭進行命名並且放置在自己的include目錄中，下面這個腳本的作用就是掃描指定的子模塊的include目錄，將其中的inter_*頭文件在entry模塊的include中自動生成同名符號鏈接文件。

#|/bin/bash
#掃描指定include的文件，符合inter_*.h的文件會自動在entry/include中創建其符號鏈接

SHELL_DIR=$(cd $(dirname ${0});pwd)
cd ${SHELL_DIR}
SUB_INCLUDES="../camera/include ../buzzer/include ../gsm/include ../led/include ../sqlite/include ../zigbee/include"
for A_SUB_INCLUDE in ${SUB_INCLUDES}
do
    echo ${A_SUB_INCLUDE}
    (
    cd ${A_SUB_INCLUDE}
    HEADERS=$(ls ./inter*)
    for A_HEADER in ${HEADERS}
    do
        ln -s ../${A_SUB_INCLUDE}/${A_HEADER} ../../entry/include/${A_HEADER}
    done
    )
done