直接用指令编译也可以
g++ foo1.cpp foo1.h foo2.cpp foo2.h main.cpp -o version1all: version1
version1: main.cpp foo1.cpp foo2.cpp foo1.h foo2.h
g++ main.cpp foo1.cpp foo2.cpp -o version1
clean:
rm -rf version1缺点:
- 任何文件只要做了修改项目都要完整的重新编译
all: version2
version2: main.o foo1.o foo2.o
g++ main.o foo1.o foo2.o -o version2
main.o: main.cpp foo1.h foo2.h
g++ -c main.cpp -o main.o
foo1.o: foo1.cpp foo1.h
g++ -c foo1.cpp -o foo1.o
foo2.o: foo2.cpp foo2.h
g++ -c foo2.cpp -o foo2.o
clean:
rm -rf version2 *.o优点:
- 不需要整个项目重新编译, 比如修改了foo1.cpp, 只需要重新构建foo1.o即可
缺点:
- 内容重复
- x.cpp => x.o 重复
- x.cpp 依赖的头文件 => x.o 重复
all: version3
obj = main.o foo1.o foo2.o
target = version3
CXX = g++
# $< xxx.c
# $@ xxx.o
$(target): $(obj)
$(CXX) $(obj) -o $(target)
%.o: %.c
$(CXX) -c $< -o $@
clean:
rm -rf version3 *.o优点:
- x.cpp => x.o 重复 的问题解决了
缺点:
- x.cpp 依赖的头文件变化
all: version4
SRCS = main.cpp foo1.cpp foo2.cpp
OBJS = ${SRCS:.cpp=.o}
target = version4
CXX = g++
$(target): $(OBJS)
$(CXX) $(OBJS) -o $(target)
# $< xxx.cpp
# $@ xxx.d
#sed -i '1s/^/$@ /' $@
%.d: %.cpp
$(CXX) -MM $< > $@
%.o: %.cpp
$(CXX) -c $< -o $@
clean:
rm -rf version4 *.o *.d
-include ${SRCS:.cpp=.d}优点:
- x.cpp 依赖的头文件变换,相应.o会重新编译
解释:
foo1.o: foo1.cpp foo1.h
foo2.o: foo2.cpp foo2.h
main.o: main.cpp foo1.h foo2.h- .cpp => .d依赖 => 补充(xxx.o 依赖 于 xxx.cpp xxx.h) => xxx.o => xxx
- https://i.stack.imgur.com/kuFHy.gif (依赖图)
- https://www.gitignore.io/api/c++ (忽视文件)
- https://www.gitignore.io/api/autotools (忽视文件)
autoscan .
mv configure.scan configure.ac
# AM_INIT_AUTOMAKE 增加这个
aclocal
autoconf
autoheader
automake --add-missing
./configure
make
sudo make install等于:
autoreconf --install
./configure
make
sudo make installMakefile.am
AUTOMAKE_OPTIONS = foreign
bin_PROGRAMS = version5
version5_SOURCES = foo1.cpp foo2.cpp main.cpp优点:
- 上述的依赖推导自动完成,不需要自己实现.d
- 跨平台
静态库:
AUTOMAKE_OPTIONS = foreign
noinst_LIBRARIES = libfoo.a
libfoo_a_SOURCES = foo1.cpp foo2.cpp动态库:
AUTOMAKE_OPTIONS = foreign
SUBDIRS = libfoo
bin_PROGRAMS = version6
version6_SOURCES = main.cpp
version6_LDADD = ./libfoo/libfoo.a
version6_CXXFLAGS = -I./libfoo