Symbols (pdb) for native dll not loading due to post build phase

Question

I have a native version of the dll that is built with characters. There is a post build step that modifies the dll. The post build step does some compression and probably adds some data. The pdb file is still valid, however, neither WinDbg nor Visual Studio 2008 download characters for the dll after the post build phase. What bits in the pdb or dll file do we need to change to force WinDbg or Visual Studio to load characters when loading the dump that our version of dll release refers to?

Is this the size of the file that matters? Checksum or hash? Timestamp?

Change dump? or change pdb? change dll before sending?

(We know that pdb is valid because we can use it to manually obtain character names for addresses in dump descriptors that reference the released DLL. It's just a complete pain in * ss to do this manually for each address in a column in all threads. )

Answer 1

This post led me to chkmatch . On the processed dll, chkmatch displays this information:

 Executable:
 TimeDateStamp: 4a086937
 Debug info: 2 (CodeView)
 TimeStamp: 4a086937 Characteristics: 0 MajorVer: 0 MinorVer: 0
 Size: 123 RVA: 00380460 FileOffset: 00380460
 CodeView signature: sUar

 Debug information file:
 Format: PDB 7.00
 Result: unmatched (reason: incompatible debug information formats)

With the same pdb against a preprocessed dll, it reports this:

 Executable:
 TimeDateStamp: 4a086937
 Debug info: 2 (CodeView)
 TimeStamp: 4a086937 Characteristics: 0 MajorVer: 0 MinorVer: 0
 Size: 123 RVA: 00380460 FileOffset: 00380460
 CodeView format: RSDS
 Signature: (my guid) Age: 19
 PdbFile: (my path)

 Debug information file:
 Format: PDB 7.00
 Signature: (my matching guid) Age: 19

I opened both versions of the dll and switched to offset 00380460. In the original version, I see the name pdb quite clearly, but in the post-processed version there is no pdb data at this offset. I searched the pdb path and found the same block - only with a different offset. Then I searched in bytes "38 00 60 04" in the original dll. If you look at the same offset in the processed dll, I found the same bytes. Therefore, I adjusted the RVA and offset (located by matching bytes). Bingo! Now chkmatch reports the same results for the processed dll as the original (except for RVA and FileOffset, which I changed).

Edit : confirmed, now Visual Studio loads symbols for dumps that reference the processed DLL.

Answer 2

in Windbg try using . symopt +40 , this will force pdb to load.