Fix wording for out-of-crate macro error
This fixes the wording of the note for out-of-crate macro errors to fix https://github.com/rust-lang/rust/issues/36469
The previous wording came from older logic in the PR that was replaced without updating the note.
When a type parameter shadows a primitive type, the error message
was non obvious. For example, given the file `file.rs`:
```rust
trait Parser<T> {
fn parse(text: &str) -> Option<T>;
}
impl<bool> Parser<bool> for bool {
fn parse(text: &str) -> Option<bool> {
Some(true)
}
}
fn main() {
println!("{}", bool::parse("ok").unwrap_or(false));
}
```
The output was:
```bash
% rustc file.rs
error[E0308]: mismatched types
--> file.rs:7:14
|
7 | Some(true)
| ^^^^ expected type parameter, found bool
|
= note: expected type `bool`
= note: found type `bool`
error: aborting due to previous error
```
We now show extra information about the type:
```bash
% rustc file.rs
error[E0308]: mismatched types
--> file.rs:7:14
|
7 | Some(true)
| ^^^^ expected type parameter, found bool
|
= note: expected type `bool` (type parameter)
= note: found type `bool` (bool)
error: aborting due to previous error
```
Fixes#35030
Updated e0493 to new format (+ bonus).
Part of #35233.
Fixes#35999.
r? @jonathandturner
I'm not satisfied with the bonus part, there has to be an easier way to reach into the `Drop`'s span implementation. I'm all ears. :)
Update lifetime errors to specifically note temporaries
This PR updates the error message we give in the case of a temporary value not living long enough.
Before:
<img width="497" alt="screen shot 2016-08-31 at 10 02 47 am" src="https://cloud.githubusercontent.com/assets/547158/18138551/27a06794-6f62-11e6-9ee2-bdf8bed75ca7.png">
Now:
<img width="488" alt="screen shot 2016-08-31 at 10 03 01 am" src="https://cloud.githubusercontent.com/assets/547158/18138557/2e5cf322-6f62-11e6-9047-4a78abf3d78c.png">
Specifically, it makes the following changes:
* Detects if a temporary is being used. If so, it changes the labels to mention that a temporary value specifically is in question
* Simplifies wording of the existing labels to focus on lifetimes rather than values being valid
* Changes the help to a note, since the help+span wasn't as helpful (and sometimes more confusing) than just a note.
r? @nikomatsakis
Move 'doesn't live long enough' errors to labels
This patch moves the "doesn't live long enough" region-style errors to instead use labels.
An example follows.
Before:
```
error: `x` does not live long enough
--> src/test/compile-fail/send-is-not-static-ensures-scoping.rs:26:18
|
26 | let y = &x;
| ^
|
note: reference must be valid for the block at 23:10...
--> src/test/compile-fail/send-is-not-static-ensures-scoping.rs:23:11
|
23 | fn main() {
| ^
note: ...but borrowed value is only valid for the block suffix following statement 0 at 25:18
--> src/test/compile-fail/send-is-not-static-ensures-scoping.rs:25:19
|
25 | let x = 1;
| ^
```
After:
```
error: `x` does not live long enough
--> src/test/compile-fail/send-is-not-static-ensures-scoping.rs:26:18
|
26 | let y = &x;
| ^ does not live long enough
...
32 | };
| - borrowed value only valid until here
...
35 | }
| - borrowed value must be valid until here
```
r? @nikomatsakis
