> Are the contents of x86_64-w64-mingw32/lib/*.a documented?
This is not the mailing list for the mingw-w64 project. But as such
your question is not specific to mingw-w64.
(Anyway, your question is a bit backward. Surely if you have used some
Windows API in your code, your would want to know in what import
library is that API found. Not the other way, what some random ones of
the import libraries are.)
> For example, libcomctl.a? libgdi32.a?
Unless you have a good reason to suspect otherwise, you can assume
that each .a file in the "lib" subdirectory of a MinGW installation is
the import library for the corresponding DLL that is part of the
Windows OS, or from some optional add-on to Windows.
(Exceptions would be libraries that obviously are MinGW-specific, like
libmingw32.a. And yeah, with hindsight it might be a good idea to
separate these sets into different directories.)
The Windows API is documented on MSDN
(http://msdn.microsoft.com/en-us/library ), and for each function they
say in what library to use. For instance, when the documentation for
CreateCompatibleBitmap says "Library: Gdi32.lib", that means you
should use -lgdi32 when compiling with MinGW. Note that MinGW does not
contain complete import libraries (or headers) for all Microsoft APIs,
especially more "modern" ones.