FIX: Cannot Set Breakpoint with Boolean Type

ID: Q116312

1.00 1.50 1.51 WINDOWS kbtool kbfixlist kbbuglist

The information in this article applies to:

The Visual Workbench Integrated Debugger included with:

    - Microsoft Visual C++ for Windows, versions 1.0, 1.5, and 1.51

SYMPTOMS

When setting a breakpoint in the Visual Workbench or CodeView for Windows, using the breakpoint type "Break at Location If Expression has Changed" and specifying the expression as a BOOL (int) value causes the breakpoint not to be hit.

STATUS

Microsoft has confirmed this to be a bug in the products listed at the beginning of this article. This problem was corrected in Visual C++ 1.52.

MORE INFORMATION

To reproduce this problem, use the FONTEST sample program and perform the following steps:

1. Start the debugger.

2. Load the file PRINT.C from the FONTEST project.

3. In the function InitPrinting, shown below, break on the line "bUserAbort

   = FALSE:".

      BOOL bUserAbort = TRUE;

      BOOL PASCAL InitPrinting(HDC hdc, HWND hWnd, LPSTR msg)
      {
           HANDLE hInst = GetWindowWord(hWnd, GWW_HINSTANCE);

           bError = FALSE;
           bUserAbort = FALSE;     /* Set breakpoint here. */ 
      }

4. To set a breakpoint, choose the Breakpoints option from the Data menu in

   CodeView for Windows or from the Debug menu in the Visual Workbench.
   Set the breakpoint with the following attributes:

      Type:       Break At Location If Expression has Changed
      Where:      At line 75 in print.c
      Expression: {InitPrinting}bUserAbort
      Length:     1

5. Choose Add from the dialog box, and then select Close to save the

   breakpoints.

6. Return to the main menu. Choose Go from the Run menu in CodeView for

   Windows (or from the Debug menu in the Visual Workbench) to start the
   application.

The debugger never stops at the breakpoint, although it should because the value of bUserAbort changes from TRUE to FALSE at that location.

Additional reference words: 1.00 1.50 Boolean KBCategory: kbtool kbfixlist kbbuglist KBSubcategory: WBDebug

Keywords          : kb16bitonly kbDebug kbide kbbuglist kbfixlist
Version           : 1.00 1.50 1.51
Platform          : WINDOWS
Solution Type     : kbfix

Last Reviewed: September 22, 1997