resolve: Simplify collection of traits in scope
"Traits in scope" for a given location are collected by walking all scopes in type namespace, collecting traits in them and pruning traits that don't have an associated item with the given name and namespace.
Previously we tried to prune traits using some kind of hygienic resolution for associated items, but that was complex and likely incorrect, e.g. in #80762 correction to visibilites of trait items caused some traits to not be in scope anymore.
I previously had some comments and concerns about this in https://github.com/rust-lang/rust/pull/65351.
In this PR we are doing some much simpler pruning based on `Symbol` and `Namespace` comparisons, it should be enough to throw away 99.9% of unnecessary traits.
It is not necessary for pruning to be precise because for trait aliases, for example, we don't do any pruning at all, and precise hygienic resolution for associated items needs to be done in typeck anyway.
The somewhat unexpected effect is that trait imports introduced by macros 2.0 now bring traits into scope due to the removed hygienic check on associated item names.
I'm not sure whether it is desirable or not, but I think it's acceptable for now.
The old check was certainly incorrect because macros 2.0 did bring trait aliases into scope.
If doing this is not desirable, then we should come up with some other way to avoid bringing traits from macros 2.0 into scope, that would accommodate for trait aliases as well.
---
The PR also contains a couple of pure refactorings
- Scope walk is done by using `visit_scopes` instead of a hand-rolled version.
- Code is restructured to accomodate for rustdoc that also wants to query traits in scope, but doesn't want to filter them by associated items at all.
r? ```@matthewjasper```
doctest: Reset errors before dropping the parse session
The first parse is to collect whether the code contains macros, has
`main`, and uses other crates. In that pass we ignore errors as those
will be reported when the test file is actually built.
For that we need to reset errors in the `Diagnostic` otherwise when
dropping it unhandled errors will be reported as compiler bugs.
Fixes#80992
The first parse is to collect whether the code contains macros, has
`main`, and uses other crates. In that pass we ignore errors as those
will be reported when the test file is actually built.
For that we need to reset errors in the `Diagnostic` otherwise when
dropping it unhandled errors will be reported as compiler bugs.
Fixes#80992
Improve JS performance by storing length before comparing to it in loops
Since https://github.com/rust-lang/rust/pull/79052 is quite complicated to review, I suggested to split into smaller parts. This first part is mostly about saving the array length into a variable (I tried to not change anything else as much as possible 😃 ).
r? `@jyn514`
Box Item::Attributes
This reduces the size of Item from 128 to 40 bytes. I think this is as small as it needs to get 🎉
Builds on https://github.com/rust-lang/rust/pull/80339 and should not be merged before.
r? `@GuillaumeGomez`
Rework diagnostics for wrong number of generic args (fixes#66228 and #71924)
This PR reworks the `wrong number of {} arguments` message, so that it provides more details and contextual hints.
Stabilize split_inclusive
### Contents of this MR
This stabilises:
* `slice::split_inclusive`
* `slice::split_inclusive_mut`
* `str::split_inclusive`
Closes#72360.
### A possible concern
The proliferation of `split_*` methods is not particularly pretty. The existence of `split_inclusive` seems to invite the addition of `rsplit_inclusive`, `splitn_inclusive`, etc. We could instead have a more general API, along these kinds of lines maybe:
```
pub fn split_generic('a,P,H>(&'a self, pat: P, how: H) -> ...
where P: Pattern
where H: SplitHow;
pub fn split_generic_mut('a,P,H>(&'a mut self, pat: P, how: H) -> ...
where P: Pattern
where H: SplitHow;
trait SplitHow {
fn reverse(&self) -> bool;
fn inclusive -> bool;
fn limit(&self) -> Option<usize>;
}
pub struct SplitFwd;
...
pub struct SplitRevInclN(pub usize);
```
But maybe that is worse.
### Let us defer that? ###
This seems like a can of worms. I think we can defer opening it now; if and when we have something more general, these two methods can become convenience aliases. But I thought I would mention it so the lang API team can consider it and have an opinion.
Separate out a `hir::Impl` struct
This makes it possible to pass the `Impl` directly to functions, instead
of having to pass each of the many fields one at a time. It also
simplifies matches in many cases.
See `rustc_save_analysis::dump_visitor::process_impl` or `rustdoc::clean::clean_impl` for a good example of how this makes `impl`s easier to work with.
r? `@petrochenkov` maybe?
This makes it possible to pass the `Impl` directly to functions, instead
of having to pass each of the many fields one at a time. It also
simplifies matches in many cases.
rustdoc: Resolve `&str` as `str`
People almost always are referring to `&str`, not `str`, so this will
save a manual link resolve in many cases.
Note that we already accept `&` (resolves to `reference`) in intra-doc
links, so this shouldn't cause breakage.
r? `@jyn514`
rustdoc: Remove `*` intra-doc alias for `pointer`
It's not valid Rust code and it can easily be confused with a wildcard
glob pattern or something else. People can always use `pointer` instead,
so it's just removing an alias.
It hasn't hit stable yet (I think it's still on nightly), so it's okay
to remove it. (We can always add it back later if we change our mind
too.)
r? `@jyn514`
cc https://github.com/rust-lang/rust/pull/80885#discussion_r554622737
It's not valid Rust code and it can easily be confused with a wildcard
glob pattern or something else. People can always use `pointer` instead,
so it's just removing an alias.
It hasn't hit stable yet (I think it's still on nightly), so it's okay
to remove it. (We can always add it back later if we change our mind
too.)
People almost always are referring to `&str`, not `str`, so this will
save a manual link resolve in many cases.
Note that we already accept `&` (resolves to `reference`) in intra-doc
links, so this shouldn't cause breakage.
Remove under-used ImplPolarity enum
It doesn't make much sense to have an enum with only two possible values and to store it inside an `Option` in my opinion when you can do all the same with a simple boolean. I don't expect any chances, performance or RSS usage wise.
r? ``@jyn514``
Rustdoc: Fix macros 2.0 and built-in derives being shown at the wrong path
Fixes#74355
- ~~waiting on author + draft PR since my code ought to be cleaned up _w.r.t._ the way I avoid the `.unwrap()`s:~~
- ~~dummy items may avoid the first `?`,~~
- ~~but within the module traversal some tests did fail (hence the second `?`), meaning the crate did not possess the exact path of the containing module (`extern` / `impl` blocks maybe? I'll look into that).~~
r? `@jyn514`
This adjusts the `rustdoc` trait impl collection path to preserve `Deref` impls
from other crates. This adds a first pass to map all of the `Deref` type to
target edges and then recursively preserves all targets.
Don't panic when an external crate can't be resolved
This isn't actually a bug, it can occur when rustdoc tries to resolve a
crate that isn't used in the main code.
Fixes#72381.
r? `@kinnison` if you have time, otherwise `@Manishearth`
