Mike-Ward.Net

Visual Studio 2005 Debugging Tips

A fellow developer at work posted this on our “tips” blog. Good stuff…

Just in case you’ve never tried, it - the next time you’re looking at a call stack while stopped at a break point in visual studio 2005, try right clicking in the call stack window and investigating some of the context menu options.

Here’s some that stand out.

Discovering the first one just gave me a some good insight into why .NET control events were being fired without my, or our users, instigation. It is especially useful in combo with Reflector. .NET (http://www.aisto.com/roeder/dotnet/)

Show External Code

Changes those single line, obstuse call stack phrases “[External Code]” into illuminating exposés of internal .NET assembly method call stacks, complete with cracked message and parameter info.

Include Calls To / From Other Threads

Can provide deeper insight into how your breakpoint was reached in a multithreading scenario

The Load Symbols Menu

This section of the menu provides runtime access to the debug symbol configuration. This is specifically useful in mixed mode apps like ours. You should download the Debugging Tools For Windows from MS (http://www.microsoft.com/whdc/devtools/debugging/default.mspx) and follow the installation instructions.

Basically, you want to configure VS to download and cache the .PDB files which provide the symbols for the OS DLLs we leverage under our products - this capability provides much more accurate and useful stack traces and debug step execution.

You should generally update to the most current version of the 32 bit Debugging Tools for Windows - the current version is 6.6.7.5, July 18, 2006.

VS Config

In VS, go to Tools / Options / Debugging / Symbols and add the following to the ‘Symbol file (.pdb) locations” (note, this is also accessible from the Call Stack window context menu) “http://msdl.microsoft.com/download/symbols” (no quotes tho). Specify a local directory to store the cached .pdb files. My symbol cache consumes approx 260mb, just for references. You may also want to checkmark the option “Load symbols using the update settings when this dialog is closed”.

After debugging our app a few times, I returned to this dialog and disabled the [x] next to the symbol path in the “Symbol file (.pdb) locations” list - the constant checking for newer symbols slows things down a bit, and after a few common sessions you’ve probably downloaded the symbols for the system DLLs we most commonly interact with anyway. YMMV, depending on how scattered your debugging needs are.