无法识别g ++文件格式； 将Object.o视为链接描述文件

Question

Object.hpp

#ifndef OBJECT_HPP
#define OBJECT_HPP

#include <SFML/Graphics.hpp>

using namespace std;

class Object {
  private:
    sf::Image image;

  public:
    float x;
    float y;
    int width;
    int height;
    sf::Sprite sprite;

    virtual void update();
};

#endif

Object.cpp

void Object::update() {

}

Here's my Makefile:

LIBS=-lsfml-graphics -lsfml-window -lsfml-system

all:
    @echo "** Building mahgame"

State.o : State.cpp
    g++ -c State.cpp

PlayState.o : PlayState.cpp
    g++ -c PlayState.cpp

Game.o : Game.cpp
    g++ -c Game.cpp

Object.o : Object.cpp
    g++ -c Object.cpp

Player.o : Player.cpp
    g++ -c Player.cpp

mahgame : Game.o State.o PlayState.o Object.o Player.o
    g++ -o mahgame Game.o State.o PlayState.o Object.o Player.o $(LIBS)

    #g++ -c "State.cpp" -o State.o
    #g++ -c "PlayState.cpp" -o PlayState.o
    #g++ -c "Game.cpp" -o Game.o
    #g++ -c "Object.hpp" -o Object.o
    #g++ -c "Player.hpp" -o Player.o
    #g++ -o mahgame Game.o State.o PlayState.o Object.o Player.o $(LIBS)

clean:
    @echo "** Removing object files and executable..."
    rm -f mahgame

install:
    @echo '** Installing...'
    cp mahgame /usr/bin

uninstall:
    @echo '** Uninstalling...'
    rm mahgame

Here's the error I get when building (after building, it's a linker error):

/usr/bin/ld:Object.o: file format not recognized; treating as linker script
/usr/bin/ld:Object.o:1: syntax error
collect2: error: ld returned 1 exit status
make: *** [all] Error 1

Any idea of what's going on? Thanks in advance.

Answer 1

Were you, by any chance, using ccache? I just had a very similar problem to yours and omitting ccache in the compilation solved it.

Answer 2

makefiles are of the form:

xxx.o : xxx.cpp
   g++ -c xxx.cpp

Yours doesn't look anything like that. So, change yours to be:

LIBS=.....

[EDIT]
all : mahgame rmerr

rmerr :
   rm -f err
[/EDIT]

State.o : State.cpp
   g++ -c State.cpp 2>>err

PlayState.o : PlayState.cpp
   g++ -c PlayState.cpp 2>>err

.....

mahgame : Game.o State.o .....
   g++ -o mahgame Game.o State.o PlayState.o Object.o Player.o $(LIBS) 2>>err

Note that these are your first steps, there are far better ways of writing makefiles that do not include every detail of your source files/object files/etc.

Answer 3

Your Makefile looks perfect, if a little verbose, and missing the header dependencies. I assume the shell commands have a leading tab character. I assume your build command is make mahgame .

As you said, you have a linker error. Object.o does not appear to be a valid .o . Get the compiler to re-generate it.

$ rm Object.o
$ make mahgame
g++ -c Object.cpp
g++ -o mahgame Game.o State.o PlayState.o Object.o Player.o...