More robust fallback for `use` suggestion
Our old way to suggest where to add `use`s would first look for pre-existing `use`s in the relevant crate/module, and if there are *no* uses, it would fallback on trying to use another item as the basis for the suggestion.
But this was fragile, as illustrated in issue #87613
This PR instead identifies span of the first token after any inner attributes, and uses *that* as the fallback for the `use` suggestion.
Fix#87613
then we just suggest the first legal position where you could inject a use.
To do this, I added `inject_use_span` field to `ModSpans`, and populate it in
parser (it is the span of the first token found after inner attributes, if any).
Then I rewrote the use-suggestion code to utilize it, and threw out some stuff
that is now unnecessary with this in place. (I think the result is easier to
understand.)
Then I added a test of issue 87613.
* Recover from invalid `'label: ` before block.
* Make suggestion to enclose statements in a block multipart.
* Point at `match`, `while`, `loop` and `unsafe` keywords when failing
to parse their expression.
* Do not suggest `{ ; }`.
* Do not suggest `|` when very unlikely to be what was wanted (in `let`
statements).
Adopt let else in more places
Continuation of #89933, #91018, #91481, #93046, #93590, #94011.
I have extended my clippy lint to also recognize tuple passing and match statements. The diff caused by fixing it is way above 1 thousand lines. Thus, I split it up into multiple pull requests to make reviewing easier. This is the biggest of these PRs and handles the changes outside of rustdoc, rustc_typeck, rustc_const_eval, rustc_trait_selection, which were handled in PRs #94139, #94142, #94143, #94144.
i'd guess about 70% of "bad escape" cases occur when someone meant to
use a raw string literal because they're passing it directly to
Regex::new(). this emits an advisory (Applicability::MaybeIncorrect)
help: suggestion to the user that they use an r"" string,
on top of the normal notes about looking at the
string literal documentation/spec.
fix ICE when parsing lifetime as function argument
I don't really like this, but we basically need to emit an error instead of just delaying an bug, because there are too many places in the AST that aren't covered by my previous PRs...
cc: https://github.com/rust-lang/rust/issues/93282#issuecomment-1028052945
If an integer is entered with an upper-case base prefix (0Xbeef, 0O755, 0B1010), suggest to make it lowercase
The current error for this case isn't really great, it just complains about the whole thing past the `0` being an invalid suffix.
Incorporate distance limit from `find_best_match_for_name` directly into
Levenshtein distance computation.
Use the string size difference as a lower bound on the distance and exit
early when it exceeds the specified limit.
After finding a candidate within a limit, lower the limit further to
restrict the search space.
Let qpath contain NtTy: `<$:ty as $:ty>::…`
Example:
```rust
macro_rules! m {
(<$type:ty as $trait:ty>::$name:ident) => {
<$type as $trait>::$name
};
}
fn main() {
let _: m!(<str as ToOwned>::Owned);
}
```
Previous behavior:
```console
error: expected identifier, found `ToOwned`
--> src/main.rs:3:19
|
3 | <$type as $trait>::$name
| ^^^^^^ expected identifier
...
8 | let _: m!(<str as ToOwned>::Owned);
| ---------------------------
| |
| this macro call doesn't expand to a type
| in this macro invocation
```
The <code>expected identifier, found \`ToOwned\`</code> error is particularly silly. I think it should be fine to accept this code as long as $trait is of the form `TyKind::Path(None, path)`; if it is any other kind of `NtTy`, we'll keep the same behavior as before.
