Makefile 规则

1.make 后面不带参数 默认执行的是第一个目标，而不是default,如下：

$ make
=== test ===
$ cat Makefile 
test:
    @echo "=== test ==="
default:
    @echo "=== default ==="
deploy:
    @echo "=== deploy ==="
clean:
    @echo "=== clean ==="

2.目标：前置条件 规律如下：

#这里满足规则1，deploy在最前面，所以make = make deploy
$ make
=== clean ===
=== deploy ===

#前置条件先跑
$ cat Makefile 
deploy:clean

test:
    @echo "=== test ==="
default:
    @echo "=== default ==="
deploy:
    @echo "=== deploy ==="
clean:
    @echo "=== clean ==="

3.目标：前置条件 多条件规律如下：

#前置的前置都需要先行
$ make
=== test ===
=== clean ===
=== deploy ===

$ cat Makefile 

deploy:clean
clean:test

test:
    @echo "=== test ==="
default:
    @echo "=== default ==="
deploy:
    @echo "=== deploy ==="
clean:
    @echo "=== clean ==="

$ make clean
=== test ===
=== clean ===