(base) ci@cidi-NUC9i9QNX:~/Documents/doxygen-demo/build$ make
[ 7%] Building CXX object src/CMakeFiles/circle.dir/circle.cpp.o
[ 14%] Linking CXX static library libcircle.a
[ 14%] Built target circle
[ 21%] Building CXX object src/CMakeFiles/point.dir/point.cpp.o
[ 28%] Linking CXX static library libpoint.a
[ 28%] Built target point
[ 35%] Building CXX object src/CMakeFiles/rectangle.dir/rectangle.cpp.o
[ 42%] Linking CXX static library librectangle.a
[ 42%] Built target rectangle
[ 50%] Building CXX object src/CMakeFiles/shape.dir/shape.cpp.o
[ 57%] Linking CXX static library libshape.a
[ 57%] Built target shape
[ 64%] Building CXX object src/CMakeFiles/shapefactory.dir/shapefactory.cpp.o
[ 71%] Linking CXX static library libshapefactory.a
[ 71%] Built target shapefactory
[ 78%] Building CXX object src/CMakeFiles/triangle.dir/triangle.cpp.o
[ 85%] Linking CXX static library libtriangle.a
[ 85%] Built target triangle
[ 92%] Building CXX object src/CMakeFiles/shape_demo.dir/main.cpp.o
[100%] Linking CXX executable shape_demo
/usr/bin/ld: libshapefactory.a(shapefactory.cpp.o): in function `RandomSizeShapeFactory::createShape(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)':
shapefactory.cpp:(.text+0x124): undefined reference to `Circle::Circle(int, int, int)'
/usr/bin/ld: shapefactory.cpp:(.text+0x173): undefined reference to `Rectangle::Rectangle(int, int, int, int)'
/usr/bin/ld: libtriangle.a(triangle.cpp.o): in function `Triangle::Triangle(int, int, int, int)':
triangle.cpp:(.text+0x2d): undefined reference to `Shape::Shape(int, int)'
/usr/bin/ld: libtriangle.a(triangle.cpp.o): in function `Triangle::Triangle(int, int, Point)':
triangle.cpp:(.text+0x7f): undefined reference to `Shape::Shape(Point)'
collect2: error: ld returned 1 exit status
make[2]: *** [src/CMakeFiles/shape_demo.dir/build.make:103：src/shape_demo] 错误 1
make[1]: *** [CMakeFiles/Makefile2:271：src/CMakeFiles/shape_demo.dir/all] 错误 2
make: *** [Makefile:91：all] 错误 2
