Building both static and shared library?

[Grinnz]

I see from the changelog that the cmake BUILD_SHARED_LIBS flag is now used to determine whether a static .a or shared .so is built. But previously, both would be built by default, and I don't see how to do this with BUILD_SHARED_LIBS, as when I define the option only the shared .so is built. I need to build both for my Perl extension so that it can be statically linked to XS code as well as dynamically used in FFI code.

[Grinnz]

Additionally if both CMARK_STATIC and CMARK_SHARED options are set it only builds the static library as it does by default.

[jgm]

Changelog says:

• Remove the CMARK_STATIC and CMARK_SHARED options as one of the two
  must be enabled always as the cmark executable depends on the library.
  Instead of having a custom flag to discern between the
  library type, use the native CMake option BUILD_SHARED_LIBS,
  allowing the user to control which library to build. This matches
  CMake recommendations to only build a single copy of the library.

So I guess this was a deliberate decision to conform to recommendations to build only a single copy at a time. I don't really know the motivation for this. @nwellnhof may remember more.