rust/xtask
bors[bot] 95e8766db6
Merge #4178
4178: Validate the location of `crate` in paths r=matklad a=djrenren

**This solution does not fully handle `use` statements. See below**

This pull requests implements simple validation of usages of the `crate` keyword in `Path`s. Specifically it validates that:

- If a `PathSegment` is starts with the `crate` keyword, it is also the first segment of the `Path`
- All other usages of `crate` in `Path`s are considered errors.

This aligns with `rustc`'s rules. Unlike rustc this implementation does not issue a special error message in the case of `::crate` but it does catch the error.

Furthermore, this change does not cover all error cases. Specifically the following is not caught:

```rust
use foo::{crate}
```

This is because this check is context sensitive. From an AST perspective, `crate` is the root of the `Path`. Only by inspecting the full `UseItem` do we see that it is not in fact the root. This problem becomes worse because `UseTree`s are allowed to be arbitrarily nested:

```rust
use {crate, {{crate, foo::{crate}}}
```

So this is a hard problem to solve without essentially a breadth-first search. In a traditional compiler, I'd say this error is most easily found during the AST -> HIR conversion pass but within rust-analyzer I'm not sure where it belongs.  

Under the implementation in this PR, such errors are ignored so we're *more correct* just not *entirely correct*. 

Co-authored-by: John Renner <john@jrenner.net>
2020-04-30 10:17:40 +00:00
..
src Merge #4178 2020-04-30 10:17:40 +00:00
tests/tidy-tests tests: add more info about what failed in tidy tests 2020-04-17 10:32:12 +02:00
Cargo.toml Update versions 2020-02-18 16:12:40 +02:00