Embedding DLL File Version Information with mingw32/cygwin

If you look at the properties window for a DLL file in Windows, you'll see a few bits about the file version and copyright info. I couldn't find any information on the web about how to embed that information into a DLL. Not terribly surprising, since it's probably something MSVC inserts automatically, so why would any one need to know how it's done?

Well, I'm building a DLL with cygwin/mingw32, so I do need to know how it's done. Fortunately, Mumit Khan, author of mingw32, wrote a utility called "windres", which compiles w32 resources for use in an executable or DLL. It'll compile directly to object format, which you can simply add to your final link.

For example:

% windres -i version.rc -o version.o
So the only thing I needed to figure out was the version resource format (I really didn't want to go grok the resource spec and write it from scratch). Luckily, Java's main DLL (java.dll, what else) has version information in it, and windres can also conveniently dump an exe or dll back into text format.

The java.dll resource info looks like this:

% windres -i java.dll -O rc

// Type: version
// Name: 1
LANGUAGE 0, 0
1 VERSIONINFO
 FILEVERSION 6, 0, 30, 5
 PRODUCTVERSION 6, 0, 30, 5
 FILEFLAGSMASK 0x3f
 FILEOS 0x4
 FILETYPE 0x2
BEGIN
  BLOCK "StringFileInfo"
  BEGIN
    BLOCK "000004b0"
    BEGIN
      VALUE "CompanyName", "Sun Microsystems, Inc."
      VALUE "FileDescription", "Java(TM) Platform SE binary"
      VALUE "FileVersion", "6.0.30.5"
      VALUE "Full Version", "1.6.0_03-b05"
      VALUE "InternalName", "java"
      VALUE "LegalCopyright", "Copyright \251 2004"
      VALUE "OriginalFilename", "java.dll"
      VALUE "ProductName", "Java(TM) Platform SE 6 U3"
      VALUE "ProductVersion", "6.0.30.5" 
  END 
END

With just a few tweaks to do a regexp replace on the new template and include the new obj in my build, my released dll now has visible version information (and in this case I'm perfectly happy having absolutely no clue what any of the resource file text actually means :).