Nameres related types, like `PerNs<Resolution>`, can represent
unreasonable situations, like a local in a type namespace. We should
clean this up, by requiring that call-site specifies the kind of
resolution it expects.
1795: Make macro scope a real name scope and fix some details r=matklad a=uHOOCCOOHu
This PR make macro's module scope a real name scope in `PerNs`, instead of handling `Either<PerNs, MacroDef>` everywhere.
In `rustc`, the macro scope behave exactly the same as type and value scope.
It is valid that macros, types and values having exact the same name, and a `use` statement will import all of them. This happened to module `alloc::vec` and macro `alloc::vec!`.
So `Either` is not suitable here.
There is a trap that not only does `#[macro_use]` import all `#[macro_export] macro_rules`, but also imports all macros `use`d in the crate root.
In other words, it just _imports all macros in the module scope of crate root_. (Visibility of `use` doesn't matter.)
And it also happened to `libstd` which has `use alloc_crate::vec;` in crate root to re-export `alloc::vec`, which it both a module and a macro.
The current implementation of `#[macro_use] extern crate` doesn't work here, so that is why only macros directly from `libstd` like `dbg!` work, while `vec!` from `liballoc` doesn't.
This PR fixes this.
Another point is that, after some tests, I figure out that _`macro_rules` does NOT define macro in current module scope at all_.
It defines itself in legacy textual scope. And if `#[macro_export]` is given, it also is defined ONLY in module scope of crate root. (Then being `macro_use`d, as mentioned above)
(Well, the nightly [Declarative Macro 2.0](https://github.com/rust-lang/rust/issues/39412) simply always define in current module scope only, just like normal items do. But it is not yet supported by us)
After this PR, in my test, all non-builtin macros are resolved now. (Hover text for documentation is available) So it fixes#1688 . Since compiler builtin macros are marked as `#[rustc_doc_only_macro]` instead of `#[macro_export]`, we can simply tweak the condition to let it resolved, but it may cause expansion error.
Some critical notes are also given in doc-comments.
<img width="447" alt="Screenshot_20190909_223859" src="https://user-images.githubusercontent.com/14816024/64540366-ac1ef600-d352-11e9-804f-566ba7559206.png">
Co-authored-by: uHOOCCOOHu <hooccooh1896@gmail.com>
Some method resolution tests now yield `{unknown}` where they did not
before.
Other tests now succeed, likely because this is helping the solver
steer its efforts.
It's a bit complicated because we basically have to 'undo' the desugaring, and
the result is very dependent on the specifics of the desugaring and will
probably produce weird results otherwise.
When we have one of these, the `Trait` doesn't need to be in scope to call its
methods. So we need to consider this when looking for method
candidates. (Actually I think the same is true when we have a bound `T:
some::Trait`, but we don't handle that yet).
At the same time, since Chalk doesn't handle these types yet, add a small hack
to skip Chalk in method resolution and just consider `impl Trait: Trait` always
true. This is enough to e.g. get completions for `impl Trait`, but since we
don't do any unification we won't infer the return type of e.g. `impl
Into<i64>::into()`.
- refactor bounds handling in the AST a bit
- add HIR for bounds
- add `Ty::Dyn` and `Ty::Opaque` variants and lower `dyn Trait` / `impl Trait`
syntax to them
This adds three different representations, copied from the Chalk model:
- `Ty::Projection` is an associated type projection written somewhere in the
code, like `<Foo as Trait>::Bar`.
- `Ty::UnselectedProjection` is similar, but we don't know the trait
yet (`Foo::Bar`).
- The above representations are normalized to their actual types during type
inference. When that isn't possible, for example for `T::Item` inside an `fn
foo<T: Iterator>`, the type is normalized to an application type with
`TypeCtor::AssociatedType`.
1562: Continue support for .await r=matklad a=unrealhoang
- add await expr to ast and HIR Expr
- infer type for `.await`
Co-authored-by: Unreal Hoang <unrealhoang@gmail.com>
1515: Trait environment r=matklad a=flodiebold
This adds the environment, i.e. the set of `where` clauses in scope, when solving trait goals. That means that e.g. in
```rust
fn foo<T: SomeTrait>(t: T) {}
```
, we are able to complete methods of `SomeTrait` on the `t`. This affects the trait APIs quite a bit (since every method that needs to be able to solve for some trait needs to get this environment somehow), so I thought I'd do it rather sooner than later ;)
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
1499: processing attribute #[path] of module r=matklad a=andreevlex
support two cases
- simple name file `foo.rs`
- declaration in mod.rs
#1211
Co-authored-by: Alexander Andreev <andreevlex.as@gmail.com>
1491: More clippy r=matklad a=kjeremy
A few more clippy changes.
I'm a little unsure of the second commit. It's the trivially_copy_pass_by_ref lint and there are a number of places in the code we could use it if it makes sense.
Co-authored-by: Jeremy Kolb <kjeremy@gmail.com>
This wasn't a right decision in the first place, the feature flag was
broken in the last rustfmt release, and syntax highlighting of imports
is more important anyway
This gives a significant speedup, because chalk will call these
functions several times even withing a single revision. The only
significant one here is `impl_data`, but I figured it might be good to
cache others just for consistency.
The results I get are:
Before:
from scratch: 16.081457952s
no change: 15.846493ms
trivial change: 352.95592ms
comment change: 361.998408ms
const change: 457.629212ms
After:
from scratch: 14.910610278s
no change: 14.934647ms
trivial change: 85.633023ms
comment change: 96.433023ms
const change: 171.543296ms
Seems like a nice win!
Note that we can't just remove CheckCanceled trait altogether:
sometimes it's useful to check for cancellation while the query is
running! We do this, for example, in the name resolution fixed-point
loop.
We use panics for cancellation, so we could trigger panic while
holding the solver. std::sync::Mutex will be poisoned as a result,
which and all further attempts to use solver (from other threads) will
panic as well.
This commit switches to parking_lot::Mutex which just unlocks on panic.
Reducing it to 2 was just a failed attempt to see whether that would help fix
some slow cases; in fact, it can create new slow cases by replacing concrete
types by variables.
For Send/Sync/Sized, we don't handle auto traits correctly yet and because they
have a lot of impls, they can easily lead to slowdowns. In the case of
Fn/FnMut/FnOnce, we don't parse the special Fn notation correctly yet and don't
handle closures yet, so we are very unlikely to find an impl.
This is slightly hacky, but maybe more elegant than alternative solutions: We
just use a hardcoded Chalk trait ID which we special-case to have no impls.
This fixes the order in which candidates are chosen a bit (not completely
though, as the ignored test demonstrates), and makes autoderef work with trait
methods. As a side effect, this also makes completion of trait methods work :)
- make it possible to get parent trait from method
- add 'obligation' machinery for checking that a type implements a
trait (and inferring facts about type variables from that)
- handle type parameters of traits (to a certain degree)
- improve the hacky implements check to cover enough cases to exercise the
handling of traits with type parameters
- basic canonicalization (will probably also be done by Chalk)
