c++ - MSVC 的虚方法崩溃

Question

我想我在 MSVC 的编译器(MSVC Ultimate 2012 版本 11.0.61030.00 更新 4)中发现了一个错误。

#include "stdafx.h"

class Base
{
public:
    Base()
    {
    }

    void print()
    {
        printf("Base::print()\n");
    }
};

class Derived : public Base
{
public:
    Derived() : Base()
    {
    }

    virtual void print()
    {
        printf("Derived::print()\n");
    }
};

class DerivedSquared : public Derived
{
public:
    DerivedSquared() : Derived()
    {
    }

    void print()
    {
        printf("DerivedSquared::print()\n");
    }
};

int main(int argc, char *argv[])
{
    Base *obj1 = new Base();
    Base *obj2 = new Derived();
    Base *obj3 = new DerivedSquared();

    obj1->print();
    obj2->print();
    obj3->print();

    // Memory leaks are ALWAYS nasty :P
    delete obj1;

    // CRASH!!!
    // File: f:\dd\vctools\crt_bld\self_x86\crt\src\dbgdel.cpp
    //  _BLOCK_TYPE_IS_VALID(pHead->nBlockUse)
    delete obj2;
    delete obj3;

    return 0;
}

该代码的特殊性在于 Base 的 printf() 方法不是虚拟的，而 Derived 的是。GCC 不会发生这种情况(我已经用 codepad 测试过)。我想知道这是否是一个真正的编译器错误，或者我遗漏了一些明显的东西。

想法？

Answer 1

5.3.5/3 In the first alternative (delete object), if the static type of the object to be deleted is different from its dynamic type, the static type shall be a base class of the dynamic type of the object to be deleted and the static type shall have a virtual destructor or the behavior is undefined.

强调我的。崩溃是未定义行为的一种可能表现。 “似乎没有什么不好的事情发生”是另一回事。