此GCC 12.1常量是错误还是功能？ “尝试使用const对象调用非const函数”

Question

我们看到的C ++代码在GCC 11.3和Visual Studio 2022中成功编译，并在GCC 12.1上存在问题。该代码在 Compiler Explorer ： https://godbolt.org/z/6pyecsd1h （感谢@nathanpierson对此进行简化

。即使可以使用const超载，也可以在const函数中进行基类功能。这似乎是某种编译器错误，但这可能是我不理解的一些新的C ++规则。这代表编译器错误吗？

struct BaseClass
{
    // Commenting this non-const function out will also fix the compilation.
    int* baseDevice() { return nullptr; }
    const int* baseDevice() const { return nullptr; }
};

template <class ObjectClass>
struct DerivedClass : BaseClass
{

};

template <class ObjectClass>
struct TopClass : DerivedClass<ObjectClass>
{
  public:
    virtual int failsToCompile() const
    {
      // This should choose to call the const function, but it tries to call the non-const version.
      if (BaseClass::baseDevice())
         return 4;

      return 1;
    }
};

int main()
{
    TopClass<int> x;
}

<source>: In instantiation of 'int TopClass<ObjectClass>::failsToCompile() const [with ObjectClass = ConcreteObject]':
<source>:27:17:   required from here
<source>:30:32: error: passing 'const TopClass<ConcreteObject>' as 'this' argument discards qualifiers [-fpermissive]
   30 |       if (BaseClass::baseDevice())
      |           ~~~~~~~~~~~~~~~~~~~~~^~
<source>:14:15: note:   in call to 'MyDevice* BaseClass::baseDevice()'
   14 |     MyDevice* baseDevice() { return nullptr; }
      |               ^~~~~~~~~~
ASM generation compiler returned: 1

Answer 1

是这个GCC 12.1常量问题一个错误或功能

这是一个错误。我提交了a bug Report a href =“ https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git; h = 2decd2cabe5a4f“ rel =“ noreferrer”>此提交。

该票已经被分配了，该分辨率具有第12.2版的针对性里程碑 - 因此我们希望快速修复。