Downloading symbols for .dmp files

We have an automated system for processing .dmp files received from the field, either our own collection or Microsoft's crash report system. We use cdb (the command line version of WinDbg) to automatically create a text file that contains the stack dump.

The batch file looks like this:

@set _NT_SYMBOL_PATH=SRV*c:\cache*http://msdl.microsoft.com/download/symbols
Cdb -lines -c "!analyze -v;q" -z %1

(Thanks to John Robbins for showing me how to use cdb in this manner.)

In theory, setting _NT_SYMBOL_PATH should provide cdb with enough information to automatically download symbols as needed. However, I wasn't seeing that happening. Without symbols, the debugger can't properly processes callstacks using FPO (Frame Pointer Omission), which means that the callstacks were often missing a lot of information.

Today I found a workaround. The symchk utility will examine a dmp file and verify that all of the required pdb and dbg files have been downloaded. Here is an example:

symchk /id Demo_000000.dmp /s SRV*c:\cache*http://msdl.microsoft.com/download/symbols