3727: Introduce ra_proc_macro r=matklad a=edwin0cheng
This PR implemented:
1. Reading dylib path of proc-macro crate from cargo check , similar to how `OUTDIR` is obtained.
2. Added a new crate `ra_proc_macro` and implement the foot-work for reading result from external proc-macro expander.
3. Added a struct `ProcMacroClient` , which will be responsible to the client side communication to the External process.
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
It improves compile time in `--release` mode quite a bit, it doesn't
really slow things down and, conceptually, it seems closer to what we
want the physical architecture to look like (we don't want to
monomorphise EVERYTHING in a single leaf crate).
3513: Completion in macros r=matklad a=flodiebold
I experimented a bit with completion in macros. It's kind of working, but there are a lot of rough edges.
- I'm trying to expand the macro call with the inserted fake token. This requires some hacky additions on the HIR level to be able to do "hypothetical" expansions. There should probably be a nicer API for this, if we want to do it this way. I'm not sure whether it's worth it, because we still can't do a lot if the original macro call didn't expand in nearly the same way. E.g. if we have something like `println!("", x<|>)` the expansions will look the same and everything is fine; but in that case we could maybe have achieved the same result in a simpler way. If we have something like `m!(<|>)` where `m!()` doesn't even expand or expands to something very different, we don't really know what to do anyway.
- Relatedly, there are a lot of cases where this doesn't work because either the original call or the hypothetical call doesn't expand. E.g. if we have `m!(x.<|>)` the original token tree doesn't parse as an expression; if we have `m!(match x { <|> })` the hypothetical token tree doesn't parse. It would be nice if we could have better error recovery in these cases.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
