How do you enable "Enable .NET Framework source stepping"?

Question 1

How do you enable "Enable .NET Framework source stepping"?

.net visual-studio-2010 visual-studio

Ian Boyd · Nov 15, 2011 · Viewed 31.1k times · Source

Answer

Answer

The PDBs for stepping through the source code are only posted for RTM and Service Packs. As such, when security update comes out and it modifies the dll you are trying to debug, it will cause source stepping to not work (that is, you'll get the "No source Available" with a greyed out "Browse to find Source").

However, once you've made all the appropriate settings, you can use the following workaround. The workaround is essentially to find the security updates that caused the dll to change, and then remove them. This has the obvious downside of having those security updates removed on your machine.

Workaround

Identify which dll you want to debug into (e.g. System.Windows.Forms.dll)
While debugging, open the Modules window in Visual studio, find the Version column. If the version is not the RTM or Service pack version, then you'll need to do the workflow. Typically the RTM dll will say "built by: RTMRel". While a dll that was part of a security update will say "built by: RTMGDR". Note the version number (for example 4.0.30319.269 built by: RTMGDR)
Now, we want to find the update that created this version. Do this by searching for the dll and version number at support.microsoft.com/kb/ For example, I did the following google search: site:support.microsoft.com/kb System.Windows.Forms.dll 4.0.30319.269
The search should turn up information about an update. Note the KB number in the address bar. In my example the address was http://support.microsoft.com/kb/2604121, so KB2604121, is what we're interested in.
Go to Control Panel->Programs and Features, and click "View Installed Updates"
Find an update which lists the KB number (you can use the search in the upper right box).
Uninstall that update.
Repeat this process for this same dll until the dll is back to its RTMRel version or SP version. For example, for System.Windows.Forms.dll, I had to remove KB2686827, KB2604121, KB2518870 before it was back to the RTMRel version.

You'll need to do this for each dll within the .NET framework that you care about debugging into.

Once that's done, set a breakpoint within the .net source (for example, go to the Breakpoints tab, say New->Break at Function, and enter System.Windows.Forms.Form.Form) or step into one of the .net methods in that dll.

Question 2

Update 22nd Feb 2013: The Microsoft Connect entry has note from Alok Shriram (Program Manager, Base Class Libraries, .NET Framework) that the issue should now be resolved. The Connect entry is marked as Resolved (Fixed):

This issue should now be fixed. We published an update to reference sources. Please let us know in case your issue is still not fixed.

Year and a half.

Bonus Links

Original Question

How do I enable .NET framework source stepping in Visual Studio 2010?

Note: This question is one piece of a larger whole:

.NET 2.0 WinForm: Supporting DPI and Default Font Changes

WinForms controls do not scale during ScaleControl

VS2010: How to enable "Enable .NET Framework source stepping"?

Visual Studio 2010 Professional: How to access Modules window?

Visual Studio 2010: Properties.Settings broken after retargetting project to .NET Framework 3.5

Visual Studio 2010 comes with a new feature:

Tools, Options, Debugging, General, Enable .NET Framework source stepping

Screenshot of options menu

Following the instructions on the MSDN page How to: Debug .NET Framework Source:

To enable .NET Framework source debugging

On the Tools menu, click Options.

In the Options dialog box, click the Debugging category.

In the General box, select the following check boxes:

Enable .NET Framework source stepping

Enable source server support

I do this:

Screenshot of options menu, highlighting the relevant options selected

Note: You will note, as the MSDN page notes, and as I noticed, that checking Enable .NET Framework source stepping will automatically uncheck **Enable Just My Code (Managed only). I also enabled the diagnostic messages of source server support.

Enabling those options automatically set a symbol cache download location for me:

Screenshot of options menu, showing cache directory (highlighted)

Note: The Microsoft Symbol Server entry is already present (and cannot be removed).

The MSDN page says to load the symbols:

To load Framework symbols using the Modules window

In the Modules window, right-click a module for which symbols are not loaded. You can tell if symbols are loaded or not by looking at the Symbols Status column.

Point to Load Symbols From and click Microsoft Symbol Servers to download symbols from the Microsoft public symbols server or Symbol Path to load from a directory where you have previously stored symbols.

I try this:

and then all the symbols are loaded:

Screenshot of modules window, as described above

I’ve been sitting on a breakpoint, which is about to call into .NET framework code:

Screenshot of code, transcribed below

protected override void ScaleControl(SizeF factor, BoundsSpecified specified)
{
    base.ScaleControl(factor, specified);

Pushing F11 causes the debugger to simply skip to the next line:

Screenshot of code, transcribed below

protected override void ScaleControl(SizeF factor, BoundsSpecified specified)
{
    base.ScaleControl(factor, specified);

    //Record the running scale factor used
    this.scaleFactor = new SizeF(
            this.scaleFactor.Width * factor.Width,
            this.scaleFactor.Height * factor.Height);