I am writing generically here. https://bugs.php.net/bug.php?id=3386. Do a grep on the folder with the library included .lib/.a/.o/.obj/etc, or do a start-search-files, inside files, inside subfolders, (plus you probably need some registry editing to add (I did) those file extensions to windows search, see http://support.microsoft.com/kb/309173). You are going to have to find where ifx_checkAPI lives. Some googling leaks to this, http://publib.boulder.ibm.com/infocenter/idshelp/v111/index.jsp?topic=/com.ibm.esqlc.doc/sii-13-10773.htm. The other more experimental choice is get ifx_checkAPI out of your XS module, I dont know why it needs to be exported from the XS module (and I dont know your XS module either). http://msdn.microsoft.com/en-us/library/756as972.aspx Dumpbin is a very useful tool. It works on .obj/.o and .a/lib and on .exe/.dll files. Not all the files have all classes of info, a .obj/.o exports and imports nothing for example, but it does have plenty of symbols which some people say are "exported" since they are public and not static/private symbols and you can link with them from oter compliands. Another tool to try is StudPE. It works on exe and dlls, not sure if it will open a .obj/.lib.