PRB: Can't Find Symbols in Modules When Exe's Have Same Basename

ID: Q170116

The information in this article applies to:

Microsoft Win32 Device Driver Kit (DDK) for Windows NT, versions 3.5, 3.51, 4.0
on the following platforms: Alpha, MIPS, PowerPC, winnt, x86

SYMPTOMS

WinDbg or KD can't locate symbols in modules when multiple executable files have matching basenames differing on extension only.

Debugger can't locate symbols between loaded driver modules with same base name. For example, "S3" derived from S3.Sys and S3.Dll.

CAUSE

The dot operator is already used by Windbg and MSDev and cannot be overloaded unambiguously. This cannot be fixed. So, specifying the extension doesn't work. For example, "x s3.dll!*".

RESOLUTION

When you build software components, do not use the same file name with different extensions. Change the basename so that it is different. For exmaple, with a video drivers you could name them "S3mini.sys and S3Disp.dll" instead of S3.SYS and S3.DLL.

MORE INFORMATION

Developers keep inquiring why the debuggers cannot distinguish between Foo.sys and Foo.dll. This arises most often with video driver developers.

For example, in WinDBG the only way to do it currently is to unload the one you don't want and make sure the one you do want is the only one loaded:


   kd> !reload /u S3
   kd> !reload /u S3
   kd> !reload S3.dll
   kd> lm

Best solution is not to use the same basename in a single namespace.


Keywords          : kbdisplay kbprg kbtool NTDDKDebug NTDDKDisplay ntddkvideo 
Version           : 3.5 3.51 4.0
Platform          : NT WINDOWS 
Issue type        : kbprb

Last Reviewed: March 4, 1999