On Sun, 2020-12-20 at 14:19 -0900, Britton Kerin wrote: > A while back there was talk about making Make a bit smarter about > understanding implicit dependencies make-sphere stuff: > > http://gnu-make.2324884.n4.nabble.com/Idea-Add-COMMANDCHANGE-and-CACHE-td19133.html > > I've come to like the idea and am curious if anything ever happened > on this?
No, no one ever pushed that further as far as I know. As a concept it's not bad: similar to some things I've been thinking of although I was thinking of using symlinks to avoid file reads... I'm not a fan of using directories because some filesystems have limits on the number of subdirectories. I'm also not sure about using SHA for this; do we really need the expense of a cryptographic hash here? Don't we really mostly care about uniqueness? But these are just implementation details. The main thing is that once you create a concept of a "make durable state" then there are a lot of things that you might like to have there. That proposal discusses the SHA of a command line, to detect when compiler options change for example. But, there have been other things people have wanted durable state for: for example basing out-of-date detection on things like file content or other attributes besides mod time. And there are probably other things that will come up. It seems like a not-great idea to have multiple ways of storing durable state, so the question is can we come up with a method flexible enough that we won't be banging our heads against it in a year.
