CodeView Does Not Detect M61xx Math Errors

MS-DOS                                  | OS/2

The information in this article applies to:

• Microsoft CodeView for MS-DOS, versions 2.2, 3.0, 3.11, 3.14, 4.0, 4.01, 4.05, and 4.1
• Microsoft CodeView for OS/2, versions 2.2, 3.0, 3.11, 3.12, and 3.5

An attempt to use CodeView to determine which source code statement causes a "M61xx" math error fails because CodeView is not designed to detect the C run-time library called an application's error-handling function. CodeView does not differentiate an error-handling function from others in the application.

If you run the program in the CodeView debugger, the "M61xx" error may occur, but CodeView does not halt execution at that point. Instead, CodeView displays either the "Program terminated normally" or "Thread terminated normally" message, changes the display to assembly language mode, and displays the C run-time library termination code. The Calls menu does not provide any indication of where the error occurred. CodeView for Windows displays an "Application Error" message and does not display any source code.

Because the error-handling function calls the operating system to terminate the process, CodeView detects a normal application termination and acts accordingly: displaying a termination message and displaying the C run-time library termination code in assembly language mode.

To debug math errors with CodeView, set breakpoints at strategic locations before you run the application or animate the program at key points to see each line before it executes.

Unlike CodeView, the QuickC integrated debugger places the cursor on the line that causes the math error if you select Animate from the Run menu.