BUG: Internal Compiler Error C1001 When You Call __assume() (259244)

The information in this article applies to:

Microsoft C/C++ Compiler (CL.EXE)
Microsoft Visual C++, 32-bit Enterprise Edition 6.0
Microsoft Visual C++, 32-bit Professional Edition 6.0
Microsoft Visual C++, 32-bit Learning Edition 6.0

This article was previously published under Q259244

SYMPTOMS

When a function that expects STL::string as a reference is passed as an input argument to the __assume function, you may get the following error message:

repro.cpp(18): fatal error C1001: INTERNAL COMPILER ERROR

(compiler file 'E:\8447\vc98\p2\src\P2\main.c', line 494)

Please choose the Technical Support command on the Visual C++ Help menu, or open the Technical Support help file for more information.

Please refer to the "More Information" section for the sample code that reproduces the problem.

RESOLUTION

Use one of the following two methods to work around this problem:

Construct a temporary STL::string object and pass this object as a reference to the function (see workaround 1 in the sample code).
Introduce a temporary variable to store the return value of the function, which expects STL::string as reference (see workaround 2 in the sample code).

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

Steps to Reproduce Behavior

The following sample code, when compiled, reproduces the problem. Uncomment the #define statements depending upon which workaround you choose:

// repro.cpp
// cl /Gx /c repro.cpp
#include <string>

//#define WORK_AROUND_1
//#define WORK_AROUND_2

using namespace std;

int MyFunc(string &m_str)
{
	return 1;
}

int main()
{
	string	str ;
	int	temp;
	
	__assume(MyFunc(string())); // This line generates C1001 error.
	
	// Workaround 1: Call the function with a temporary STL string object.
	#ifdef WORK_AROUND_1 
	   __assume(MyFunc(str));
	#endif
    
	// Workaround 2: Store the return value of function in a temporary variable
	#ifdef WORK_AROUND_2
	   temp = MyFunc(string());
	   __assume(temp);
	#endif
	return 1;
}

Modification Type:	Minor	Last Reviewed:	7/5/2005
Keywords:	kbBug kbnofix KB259244