Question

I’m evaluating some underdocumented software. When I build a sample project, I’m getting a linker error that looks like:

error LNK2019: unresolved external symbol

There aren’t a whole lot of lib files with this app, so I can solve this problem with trial and error, but I know there’s a more elegant way is to solve this problem.

In the java world, I would grep FOO *.jar to find the jar and I’m looking for the C++ analog. I’m working with C++ code in Visual Studio 2005.

I suspect the lib.exe utility with the /LIST option can get the information, but I’ve been unsuccessful so far. It just prints this:

 Microsoft (R) Library Manager Version 8.00.50727.762 Copyright (C) Microsoft Corporation.  All rights reserved.  granite50.dll granite50.dll granite50.dll granite50.dll ... 

Any suggestions?

Answer 1

First of all you need to know which type of library you are looking at. Some libraries simply contain linkages for a DLL (i.e., import libraries) and others are code objects that become part of the executable image (i.e., static libraries). From the looks of that output, you were looking at a DLL import library.

Next you want to use the right tool. Lib.exe is used to extract object files from libraries and what-not. This is pretty much the same as the jar utility for Java. Microsoft provides dumpbin.exe which will dump information from the library. I see that LarryF already mentioned this.

For import libraries, run dumpbin.exe -headers foo.lib and redirect it to an output file. The output will contain snippets for each symbol that the related DLL exports. Search for lines starting with ' Symbol name :'. Note that there are two spaces before and after ‘Symbol name’ if you want an exact match. You can also run the output through findstr to generate a list of symbols and redirect that to a text file if you want something a little nicer to look at:

dumpbin.exe -headers foo.lib | findstr /c:'  Symbol name  :' > foo-exports.txt 

The other option is to open the related DLL with depends.exe.