Here we have a set of replacement C and C++ rules using ThinLTO to perform fast incremental link-time optimisation.

Note that you must have sufficiently recent versions of Clang and Gold for this to work. The examples here use Clang 6 although you can almost certainly use older versions as well.

There's a small set of extremely contrived code to illustrate and lightly test it.

This is still extremely experimental and is known not to work entirely correctly yet.