There are three kinds of "byte" literals: byte literals, byte string
literals, and raw byte string literals. None are allowed to have
non-ASCII chars in them.
Two `EscapeError` variants exist for when that constraint is violated.
- `NonAsciiCharInByte`: used for byte literals and byte string literals.
- `NonAsciiCharInByteString`: used for raw byte string literals.
As a result, the messages for raw byte string literals use different
wording, without good reason. Also, byte string literals are incorrectly
described as "byte constants" in some error messages.
This commit eliminates `NonAsciiCharInByteString` so the three cases are
handled similarly, and described correctly. The `mode` is enough to
distinguish them.
Note: Some existing error messages mention "byte constants" and some
mention "byte literals". I went with the latter here, because it's a
more correct name, as used by the Reference.
Suggest calling method if fn does not exist
I tried to split this up into two commits, the first where we stash the resolution error until typeck (which causes a bunch of diagnostics changes because the ordering of error messages change), then the second commit is the actual logic that actually implements the suggestion.
I am not in love with the presentation of the suggestion, so I could use some advice for how to format the actual messaging.
r? diagnostics
Fixes#102518
Move lint level source explanation to the bottom
So, uhhhhh
r? `@estebank`
## User-facing change
"note: `#[warn(...)]` on by default" and such are moved to the bottom of the diagnostic:
```diff
- = note: `#[warn(unsupported_calling_conventions)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #87678 <https://github.com/rust-lang/rust/issues/87678>
+ = note: `#[warn(unsupported_calling_conventions)]` on by default
```
Why warning is enabled is the least important thing, so it shouldn't be the first note the user reads, IMO.
## Developer-facing change
`struct_span_lint` and similar methods have a different signature.
Before: `..., impl for<'a> FnOnce(LintDiagnosticBuilder<'a, ()>)`
After: `..., impl Into<DiagnosticMessage>, impl for<'a, 'b> FnOnce(&'b mut DiagnosticBuilder<'a, ()>) -> &'b mut DiagnosticBuilder<'a, ()>`
The reason for this is that `struct_span_lint` needs to edit the diagnostic _after_ `decorate` closure is called. This also makes lint code a little bit nicer in my opinion.
Another option is to use `impl for<'a> FnOnce(LintDiagnosticBuilder<'a, ()>) -> DiagnosticBuilder<'a, ()>` altough I don't _really_ see reasons to do `let lint = lint.build(message)` everywhere.
## Subtle problem
By moving the message outside of the closure (that may not be called if the lint is disabled) `format!(...)` is executed earlier, possibly formatting `Ty` which may call a query that trims paths that crashes the compiler if there were no warnings...
I don't think it's that big of a deal, considering that we move from `format!(...)` to `fluent` (which is lazy by-default) anyway, however this required adding a workaround which is unfortunate.
## P.S.
I'm sorry, I do not how to make this PR smaller/easier to review. Changes to the lint API affect SO MUCH 😢
Improve errors for incomplete functions in struct definitions
Given the following code:
```rust
fn main() {}
struct Foo {
fn
}
```
[playground](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=29139f870511f6918324be5ddc26c345)
The current output is:
```
Compiling playground v0.0.1 (/playground)
error: functions are not allowed in struct definitions
--> src/main.rs:4:5
|
4 | fn
| ^^
|
= help: unlike in C++, Java, and C#, functions are declared in `impl` blocks
= help: see https://doc.rust-lang.org/book/ch05-03-method-syntax.html for more information
error: could not compile `playground` due to previous error
```
In this case, rustc should suggest escaping `fn` to use it as an identifier.
Migrate more of rustc_parse to SessionDiagnostic
Still far from complete, but I thought I'd add a checkpoint here because rebasing was starting to get annoying.
Rollup of 8 pull requests
Successful merges:
- #100734 (Split out async_fn_in_trait into a separate feature)
- #101664 (Note if mismatched types have a similar name)
- #101815 (Migrated the rustc_passes annotation without effect diagnostic infrastructure)
- #102042 (Distribute rust-docs-json via rustup.)
- #102066 (rustdoc: remove unnecessary `max-width` on headers)
- #102095 (Deduplicate two functions that would soon have been three)
- #102104 (Set 'exec-env:RUST_BACKTRACE=0' in const-eval-select tests)
- #102112 (Allow full relro on powerpc64-unknown-linux-gnu)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
PR #101224 added support for async fn in trait desuraging behind the
return_position_impl_trait_in_trait feature.
Split this out so that it's behind its own feature gate, since async fn
in trait doesn't need to follow the same stabilization schedule.
