如何设置这个makefile

Question

I have makefile with two source files namely main.cpp and game.cpp . Once I add game.cpp , I'm getting the following warning

clang++ -framework SDL2 main.o -o game
Undefined symbols for architecture x86_64:

And this is the makefile

CXX      = clang++
SDL      = -framework SDL2
CXXFLAGS = -Wall -c -std-c++11
LDFLAGS  = $(SDL)
TARGET   = game

all: $(TARGET)

$(TARGET): main.o game.o
    $(CXX) $(LDFLAGS) $< -o $@

main.o: main.cpp
    $(CXX) $(CXXFLAGS) $< -o $@

game.o: game.cpp
    $(CXX) $(CXXFLAGS) $< -o $@

clean:
    rm *.o && rm $(TARGET)

I'm using Mac.

Answer 1

You are missing game.o in the build command, this is because $< is only the first dependency (see the first line in your warning). Hence the functions in game.o are undefined.

For more info please refer to gnu.org

EDIT: Updated the link as suggested