In JDK-8037238 we hit another problem with CacheFind. Hopefully that was the last bug, but I find it unlikely. One reason CacheFind errors are rarely discovered is that it's only enabled on Windows, which is not used much in the build group. I would like to enable it on all platforms, simply to give it more usage and hardening. There is a very slight performance improvement on my Linux workstation, so it's not without benefits. ("time make images" with no changes reports 6.5 secs down from 7.5)

I would also like to make the FillCacheFind macro a little smarter so that it handles being called multiple times with same or similar arguments without incurring a performance overhead. Only execute find if it's really needed. With this check, adding a call to FillCacheFind in SetupJavaCompilation is very cheap and ensures reuse of finds in compilation macros.

I will also reexamine CacheFind usage in the whole build and make sure we aren't missing the cache multiple times for the same directories.