Rename rustc_errors dependency in rust 2018 crates
I think this is a better solution than `use rustc_errors as errors` in `lib.rs` and `use crate::errors` in modules.
Related: rust-lang/cargo#5653
cc #58099
r? @Centril
Cosmetic improvements to doc comments
This has been factored out from https://github.com/rust-lang/rust/pull/58036 to only include changes to documentation comments (throughout the rustc codebase).
r? @steveklabnik
Once you're happy with this, maybe we could get it through with r=1, so it doesn't constantly get invalidated? (I'm not sure this will be an issue, but just in case...) Anyway, thanks for your advice so far!
while we could make this change (it's all unstable after all), there are crates.io crates that use the feature and that the compiler depends upon. We can instead roll out this feature while still supporting the old way.
Error on duplicate matcher bindings
fix #57593
This should not be merged without a crater run and maybe an FCP. Discussion is ongoing at #57593.
TODO:
- [x] write tests
- [x] crater run
- [x] ~maybe need edition gating?~ not for 1 regression /centril
r? @petrochenkov
This commit changes `syntax::fold::Folder` from a functional style
(where most methods take a `T` and produce a new `T`) to a more
imperative style (where most methods take and modify a `&mut T`), and
renames it `syntax::mut_visit::MutVisitor`.
The first benefit is speed. The functional style does not require any
reallocations, due to the use of `P::map` and
`MoveMap::move_{,flat_}map`. However, every field in the AST must be
overwritten; even those fields that are unchanged are overwritten with
the same value. This causes a lot of unnecessary memory writes. The
imperative style reduces instruction counts by 1--3% across a wide range
of workloads, particularly incremental workloads.
The second benefit is conciseness; the imperative style is usually more
concise. E.g. compare the old functional style:
```
fn fold_abc(&mut self, abc: ABC) {
ABC {
a: fold_a(abc.a),
b: fold_b(abc.b),
c: abc.c,
}
}
```
with the imperative style:
```
fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) {
visit_a(a);
visit_b(b);
}
```
(The reductions get larger in more complex examples.)
Overall, the patch removes over 200 lines of code -- even though the new
code has more comments -- and a lot of the remaining lines have fewer
characters.
Some notes:
- The old style used methods called `fold_*`. The new style mostly uses
methods called `visit_*`, but there are a few methods that map a `T`
to something other than a `T`, which are called `flat_map_*` (`T` maps
to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s).
- `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed
`map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to
reflect their slightly changed signatures.
- Although this commit renames the `fold` module as `mut_visit`, it
keeps it in the `fold.rs` file, so as not to confuse git. The next
commit will rename the file.
Simplify `TokenStream` some more
These commits simplify `TokenStream`, remove `ThinTokenStream`, and avoid some clones. The end result is simpler code and a slight perf win on some benchmarks.
r? @petrochenkov
Implement basic input validation for built-in attributes
Correct top-level shape (`#[attr]` vs `#[attr(...)]` vs `#[attr = ...]`) is enforced for built-in attributes, built-in attributes must also fit into the "meta-item" syntax (aka the "classic attribute syntax").
For some subset of attributes (found by crater run), errors are lowered to deprecation warnings.
NOTE: This PR previously included https://github.com/rust-lang/rust/pull/57367 as well.
Make `TokenStream` less recursive.
`TokenStream` is currently recursive in *two* ways:
- the `TokenTree` variant contains a `ThinTokenStream`, which can
contain a `TokenStream`;
- the `TokenStream` variant contains a `Vec<TokenStream>`.
The latter is not necessary and causes significant complexity. This
commit replaces it with the simpler `Vec<(TokenTree, IsJoint)>`.
This reduces complexity significantly. In particular, `StreamCursor` is
eliminated, and `Cursor` becomes much simpler, consisting now of just a
`TokenStream` and an index.
The commit also removes the `Extend` impl for `TokenStream`, because it
is only used in tests. (The commit also removes those tests.)
Overall, the commit reduces the number of lines of code by almost 200.
`TokenStream` is currently recursive in *two* ways:
- the `TokenTree` variant contains a `ThinTokenStream`, which can
contain a `TokenStream`;
- the `TokenStream` variant contains a `Vec<TokenStream>`.
The latter is not necessary and causes significant complexity. This
commit replaces it with the simpler `Vec<(TokenTree, IsJoint)>`.
This reduces complexity significantly. In particular, `StreamCursor` is
eliminated, and `Cursor` becomes much simpler, consisting now of just a
`TokenStream` and an index.
The commit also removes the `Extend` impl for `TokenStream`, because it
is only used in tests. (The commit also removes those tests.)
Overall, the commit reduces the number of lines of code by almost 200.
Resolve `$crate`s for pretty-printing at more appropriate time
Doing it in `BuildReducedGraphVisitor` wasn't a good idea, identifiers wasn't actually visited half of the time.
As a result some `$crate`s weren't resolved and were therefore pretty-printed as `$crate` literally, which turns into two tokens during re-parsing of the pretty-printed text.
Now we are visiting and resolving `$crate` identifiers in an item right before sending that item to a proc macro attribute or derive.
Fixes https://github.com/rust-lang/rust/issues/57089
overhaul external doc attribute diagnostics
This PR improves the error handling and spans for the external doc attribute. Many cases that silently failed before now emit errors, spans are tightened, and the errors have help and suggestions.
I tried to address all the cases that users ran into in the tracking issue.
cc #44732
r? @QuietMisdreavus
Mazdak Farrokhzad