c ++缺少vtable错误

Question

我得到一个非常奇怪的错误,与给定的类构造函数和析构函数缺少vtable有关.请帮我解决这个问题.

架构i386的未定义符号:

  "vtable for A", referenced from:
      A::A() in A.o
      A::~MissionController() in A.o
  NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

代码段;

.h文件:

class A: public B

  public:
     A();
    ~A();

};

.cpp文件..

 A::A()   
{


}

A::~A()
{


}

Answer 1

啊! 考虑到这一点,我想我得到了正在发生的事情.我打赌这CCNode是属于别人的代码.

您继承的任何虚函数在派生类中也是虚拟的......通常的做法是将析构函数设置为虚拟...您可能没有意识到析构函数是虚拟的.

此外,如果您使用其他人的头文件,但忘记链接到他们的目标文件,它可能会导致此错误,因为链接器将缺少析构函数CCNode.

Answer 2

找到它,尝试样品,这里是一个例子.

class Shape{

public:
virtual int areas();
virtual void display();

virtual ~Shape(){};
};

编译器抱怨道

Undefined symbols for architecture x86_64:
"typeinfo for Shape", referenced from:
  typeinfo for trian in main_file.o
 "vtable for Shape", referenced from:
  Shape::Shape() in main_file.o
  NOTE: a missing vtable usually means the first non-inline virtual member      function has no definition.
   ld: symbol(s) not found for architecture x86_64
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  make: *** [cpp_tries] Error 1enter code here

修改为空或虚拟函数旁边的{}内的任何内联内容

class Shape{

public:
    virtual int areas(){};
    virtual void display(){};

    virtual ~Shape(){};
};

基本上,它没有找到非内联虚函数的函数定义.

Answer 3

尝试将虚拟析构函数添加到您的类中。CCNode 可能包含一些虚拟方法，而您的编译器无法处理它。

    class MissionController: public CCNode
    {

      public:
         MissionController();
        virtual ~MissionController();
    };

是一些公共框架吗，我们在哪里可以看到CCNode类的定义？请参阅从编译错误 xcode 引用的 vtable或http://www.parashift.com/c++-faq-lite/link-errs-missing-vtable.html以获得更多帮助。