BUG: Internal Compiler Error Creating a Copy of a Temporary Object

• Microsoft Visual C++, 32-bit Editions, version 6.0

SYMPTOMS

When creating an object that is a copy of a virtual function return value (a temporary object) using the compiler-supplied copy constructor, you may get the following error:

test.cpp(22) : fatal error C1001: INTERNAL COMPILER ERROR
   (compiler file 'msc1.cpp', line 1794)
   Please choose the Technical Support command on the Visual C++
   Help menu, or open the Technical Support help file for more information

RESOLUTION

There are four ways to get around the problem:

1. Explicitly Define a Copy Constructor. (See Workaround #1 in sample code below).



2. Remove the virtual keyword from the function which returns the value. (See Workaround #2 in sample code below).



3. Introduce a temporary variable to store the return value. (See Workaround #3 in the sample code below).



4. Remove compiler support for synchronous (C++) exception handling. This is accomplished by removing /GX (the Visual Studio default) from your compile options. (See Workaround #4 in sample code below).

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

////////////////////////////////////////////////////////////////////// 
// cl /c /GX test.cpp
// test.cpp(22) : fatal error C1001: INTERNAL COMPILER ERROR
//  (compiler file 'msc1.cpp', line 1794) 
//  Please choose the Technical Support command on the Visual C++ 
//  Help menu, or open the Technical Support help file for more information
////////////////////////////////////////////////////////////////////// 
class A
{
  public:
    /* workaround #1, add an explicit copy constructor to class A */ 
    // A(A& a) {};
    ~A() {}; 
};
class B
{
  public:
 /* workaround #2, remove virtual keyword from B::GetA */ 
    virtual A& GetA(void);
    void Func (void);
};
void B::Func (void)
{
  A *att;
  att=new A(GetA());
  /* workaround #3, substitute the above line with the following two lines */ 
  //A tmp = GetA();
  //att=new A(tmp);
}
/* workaround #4, remove /GX compiler option */  

Additional query words: Internal Compiler Error ICE C1001

Keywords          : kbCompiler kbVC600bug 
Version           : winnt:6.0
Platform          : winnt 
Issue type        : kbbug 

Last Reviewed: June 1, 1999