Why are compile-time dependencies between modules transitive?

[hst337]

@japhib

Of course, it’s much harder with compile-time dependencies … If A defines a macro and B uses that to generate code, than probably B should be recompiled after any change to A. I guess that would extend to any other compile-time function calls aside from macros, e.g. module attributes.

Well, that’s a tricky part. I am working on a compiler where compile-time dependencies are traceable per-function (not per-module as vanilla elixir compiler works right now). But this leads to incompatibility in some very weird edge cases (like someone expects module to be recompiled and inserts like @attr Date.utc_today(), but it is not getting recompiled).

That’s why I brought a proposal of compiler specification. If you’re interested, you can leave your opinion about this situation there

@japhib

While I’m sure there’s room for optimizing the compilation time of these individual files, what would be most helpful is if those files didn’t have to be recompiled so often.

Yeah, that’s another problem caused by dependency granularity in tracing mechanism.