BUG: INT3 Encountered When Debugging a P-Code DLL

The information in this article applies to:

• Microsoft CodeView for Windows, versions 4.0, 4.01, and 4.1

SYMPTOMS

An attempt to use CodeView versions 4.0 or 4.01 for Windows to debug a dynamic-link library (DLL) that contains p-code may cause CodeView to display the following error message in the command window:

   Break caused by INT3 in code

CAUSE

Tracing into a Windows DLL that contains p-code with Native mode turned on causes CodeView to display the error message given above.

RESOLUTION

Native mode must be turned off to debug a DLL that contains p-code. To turn off Native mode, choose Native from the Options menu. When Native mode is turned on, a bullet appears to the left of the command on the menu.

STATUS

Microsoft has confirmed this to be a problem in CodeView for Windows versions 4.0, 4.01, and 4.1. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

With Native mode turned on, CodeView displays native machine instructions in the Source and Mixed display modes. The Register window and the Register command show the native CPU registers. With Native mode turned off, CodeView displays native machine instructions in those parts of a program that contain native code, and displays p-code instructions in those parts of a program that contain p-code. Also, the Register window and the Register command display the native CPU registers when debugging a native routine, and display the p-code interpreter's registers when debugging a p-code routine.

Typically, Native mode should be turned off when debugging p-code. Turning Native mode on when debugging p-code causes CodeView to display the native machine code of the p-code interpreter.