Racer searches for crate sources recursively in all package dependencies

[RReverser]

It seems that Racer tries to find crate source somewhat too hard, traversing not only dependencies from current Cargo.toml or Cargo.lock (which are the only accessible to current Rust code), but also dependencies of these dependencies and so on recursively. Additionally, it looks in global overrides, again, returning any match, no matter whether it's actually defined and so accessible in current crate's Cargo.toml or not.

[kngwyu]

Thanks for reporting, but, I think racer doesn't.
Could you tell me why you think so?

[RReverser]

Well I found this while trying to implement #830 and trying to figure out why I'm getting overly extensive list of crates.

Turns out, when looking for crate by name, cargo::get_crate_file will look at global overrides (

racer/src/racer/cargo.rs

Lines 696 to 698 in cff609a

	if let Some(src) = get_crate_file_from_overrides(kratename, from_path) {
	return Some(src);
	}

) and then Cargo.lock without checking Cargo.toml whether this crate is a direct dependency at all (as both global overrides and Cargo.lock contain many more packages then current Rust code can actually access by name).

Then, even if it didn't find in either of those and when it does look at Cargo.toml, it recursively opens another Cargo.toml of each dependency and starts looking there -

racer/src/racer/cargo.rs

Lines 380 to 388 in cff609a

	if let Some(tomlfile) = find_cargo_tomlfile(package_source.clone()) {
	let package_name = get_package_name(tomlfile.as_path());
	debug!("find_src_via_tomlfile package_name: {}", package_name);
	if package_name == kratename {
	return find_src_via_tomlfile(kratename, &tomlfile)
	}
	}

[kngwyu]

Thanks, I understand.
I'm sorry I had misunderstanding that you're pointing out completion problem.

Racer searches Cargo.lock file to complete items in re-exported crates(see #812).
It's surely waste of time, but I'm not sure this should be fixed, because making data structure such as crate_skip_list also takes time.

For second problem(recursive search for Cargo.toml), hmm, this code seems to be for the cases where local path chains, like
Cargo.toml in work directory contains

[dependencies.crate-a]
path = "../../crate-a"

and Cargo.toml in ../../crate-a contains

[dependencies.crate-b]
path = "../../crate-b"

If crate-b isn't visible it's surely waste of time, too. However, I'm not sure this should be fixed, too.

Edited(2018/04/25):
My comment was incorrect.
Recursive search is completely useless here because actually we find outer crates step-by-step

[kristate]

This seems related to #757 -- lots of recursion problems in racer.

[kngwyu]

Hmm...
OK.
I'll try to rewrite racer's file cache to check reexporting and circuit, though not now(I have 4 PRs not yet merged:fearful:).

[kristate]

@kngwyu

I'll try to rewrite racer's file cache to check reexporting and circuit, though not now(I have 4 PRs not yet merged😨).

Thank-you!

[kngwyu]

Fixed in my branch.

[kngwyu]

Closed via #855