KB122541 - BUG: Goto() Within Try-Except Block Causes C2705 Error

Article ID: 122541

Article Last Modified on 7/5/2005

Microsoft Visual C++ 1.0 Professional Edition
Microsoft Visual C++ 2.0 Professional Edition
Microsoft Visual C++ 4.0 Standard Edition
Microsoft Visual C++ 4.1 Subscription
Microsoft Visual C++ 4.2 Enterprise Edition
Microsoft Visual C++ 5.0 Enterprise Edition
Microsoft Visual C++ 6.0 Enterprise Edition
Microsoft Visual C++ 4.2 Professional Edition
Microsoft Visual C++ 5.0 Professional Edition
Microsoft Visual C++ 6.0 Professional Edition
Microsoft Visual C++ 6.0 Standard Edition

This article was previously published under Q122541

SYMPTOMS

A Goto statement within a try-except block causes the following incorrect error if the destination of the Goto is within the same try-except block:

error C2705: '<label>' : illegal jump into __try scope

RESOLUTION

One workaround demonstrated in the example in the More Information section of this article is to remove the extra braces around the block containing the Goto. This places the goto() at the same nesting level as the destination.

Another workaround is to use the __leave keyword to jump to the end of the try-except block. If you do this, execution resumes after the end of the exception handler. One difference between __leave and Goto is that the __leave statement does not cause stack unwinding, so it is more efficient than goto().

STATUS

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

MORE INFORMATION

The following sample code can be used to demonstrate both the problem and the workaround:

Sample Code

/* Compile options needed: none
*/ 
class TestClass {
      public:
        TestClass() {}
       ~TestClass() {}
};
void main (void) {
    __try
    {
       {
       TestClass test;
       if (1) {
          goto bail;
//         __leave;    // Use this instead of the goto
       }
    }
    bail:  ;
    }
    __except(0) { }
}

Additional query words: 8.00 9.00 10.00 10.10 10.20

Keywords: kbbug kbcode kbcompiler KB122541