C# Interface Debug Information not linked to sources

Question

I'm trying to re-jig the layout of a very large solution which has become impossibly hard (and s l o w) to work with. My plan is to create a number of solutions containing related projects, and then use binary references where necessary to link to libraries produced by the other solutions.

The thing we rely on to make this usable is Resharper's Navigate to External Sources functionality, so we can easily browse the source of the projects we are referencing from other solutions. Quite why VS can't do this out of the box is beyond me.

This is all working very nicely for classes with implementation. However, for C# interfaces and classes containing only auto-implemented properties, Resharper isn't able to browse to the sources, and falls back to cruddy metadata viewer.

I used srctool.exe, which comes with the Symbol Server tools in MS Debugging Tools For Windows, to browse the sources listed in the .pdb file, and it's clear that the sources for these interfaces and empty(ish) classes are not referenced in the pdb file. If I switch the auto-implemented properties to those with backing fields, then the source link appears in the pdb.

I'm guessing the sources are excluded because there are no places you could set breakpoints on interfaces and auto-implemented properties.

I'm wondering, though, if there is some exotic compiler option or workaround we can employ to force the PDB file to include references to the source of C# interfaces.

Thanks, Mark

Answer 1

The question doesn't have enough detail. Shooting off the hip, I'd guess that you tackled the problems with the slow massive solution by converting project references to assembly references. And used the Release build of those projects as the reference.

And yes, that stumps any tool that tries to find source code files from the PDB. The release build of a .NET project uses a stripped version of the PDB, all the source code file and line number info has been removed from it. That's a pretty normal thing to do with real release builds. Release built code normally is optimized. That causes code to be re-ordered, no longer matching the logical position of the code in the source file. Any info you get from the source+line PDB info now tends to get between harmful and useless, you start looking in the wrong place for a problem.

That is however not a concern for IDE tooling or while debugging your app. The optimizer is automatically disabled in a case like this. Actually a configuration item in VS: Tools + Options, Debugging, General, "Suppress JIT optimization on module load" option. Turned on by default.

Clearly any tooling that uses the PDB is going to catatonic when they don't have a chance to find source files. The fix is to go back to the original project, select the Release configuration again and change a setting: Project + Properties, Build tab, scroll down, Advanced button. Change the "Debug info" combo from "pdb-only" to "full". Rebuild the project.

Should fix your problem. Also revives the debugger, you can step into the source code again.

Don't move files around too much btw, you might stump the chumps again. At least keep the PDB with the DLL in the same directory. If the source code is no longer present in the same directory but you checked it out again in another one then you have to tell the IDE about it. Right-click the solution, Properties, Debug Source Files setting.