嵌套Makefile问题解决一例

先看一下目录结构

 

总控Makefile如下：

CFLAGS=-Wall
CC=gcc


SUBDIRS=server client

export CFLAGS CC



all:$(SUBDIRS)

$(SUBDIRS):
    make -C $@


clean:
    $(RM) server/*.o  server/server
    $(RM) client/*.o client/client
.PHONY:clean

 

另外两个Makefile分别如下：

server:server.o
    $(CC) $(CFLAGS) $^ -o $@

server.o:server.c
    $(CC) $(CFLAGS) -c $^ -o $@

client:client.o
    $(CC) $(CFLAGS) $^ -o $@

client.o:client.c
    $(CC) $(CFLAGS) -c $^ -o $@

 

当执行总控Makefile时，出现如下现象：

 

无法实现程序的编译。

 

解决方法：

方法一、将总控Makefile中的$(SUBDIRS)中的两个路径都声明为 伪目标。

 

CFLAGS=-Wall
CC=gcc


SUBDIRS=server client

export CFLAGS CC



all:$(SUBDIRS)

$(SUBDIRS):
    make -C $@


clean:
    $(RM) server/*.o  server/server
    $(RM) client/*.o client/client
.PHONY:clean server client

 

再次指向make

方法二、将总控Makefile作如下修改

 

CFLAGS=-Wall
CC=gcc


SUBDIRS=server client

export CFLAGS CC



all:$(SUBDIRS)

$(SUBDIRS):pp
    make -C $@
pp:

clean:
    $(RM) server/*.o  server/server
    $(RM) client/*.o client/client
.PHONY:clean