PDB files do not include all .net source information

Question

This may come down to my misunderstanding of PDB files and the build process, rather than any particular problem but I've struggled to find a good answer elsewhere.

We have recently been good little developers and started indexing and storing our pdb files on a central symbol server (all part of TFS). The problem is that our PDB files do not appear to include all the source information.

When trying to navigate to sources in Visual Studio, the pdb files of our assemblies are found, as shown by the output window:

PdbNavigator: Downloader: file://server/Symbols/my.assembly.pdb/1DB3F79EA3094EAAADFC6CDE6515FC871/my.assembly.pdb -> ok, 251 KB
PdbNavigator: No debugging information found on symbol servers for my.assembly, Version=1.0.1.1206, Culture=neutral, PublicKeyToken=4cd79aeab39b919b

But at the same time it says it found no sources. If I use some of the tools from the windows SDK I can see that the PDB file does not contain the information on about 30% of the source files in the project.

I think I read somewhere that PDB files only include the source for classes actually used within the project, but surely that creates a massive problem for any API type assemblies where multiple classes may have no function within the assembly, only when used from some other part of your project?

If anyone can shed light on this, please let me know.

Thanks.

Answer 1

A PDB (normally) doesn't store source code - it contains a list of "documents", which are the source code file names, and "method information", which maps source lines to offsets in the assembly or binary. A PDB matches when the signature and build date of the assembly matches the same in the PDB file. Chances are, the MyAssembly.pdb has the correct version, but the signature and/or build date don't match.

The signature is not exposed as far as I know, but you may find some code on the Internet that says how to read a PE signature and a PDB signature so you can do a comparison.