I have mixed feelings about this portable interpreter work at the moment. On the one hand it’s going great: every day feels like I’m progressing faster and faster, partly because I’ve written tools to do the awkward bits and partly because now when I get build errors I have a much better idea of where to fix them. But on the other hand it’s a little daunting, because it’s becoming clear that some big things have changed since it was last used and the lack of revision history means I can’t just go back and see how they were changed in the JITs. So I don’t know what to think.

One cool thing is that before I started trying to build the portable interpreter I toyed with the idea of implementing the JVM interface in a free VM and using it as a replacement for libjvm.so — and it turns out twisti is doing just that! So my “maybe this would work” fallback has turned into a “this will work” without me lifting a finger!