remove StructuralEq trait
The documentation given for the trait is outdated: *all* function pointers implement `PartialEq` and `Eq` these days. So the `StructuralEq` trait doesn't really seem to have any reason to exist any more.
One side-effect of this PR is that we allow matching on some consts that do not implement `Eq`. However, we already allowed matching on floats and consts containing floats, so this is not new, it is just allowed in more cases now. IMO it makes no sense at all to allow float matching but also sometimes require an `Eq` instance. If we want to require `Eq` we should adjust https://github.com/rust-lang/rust/pull/115893 to check for `Eq`, and rule out float matching for good.
Fixes https://github.com/rust-lang/rust/issues/115881
Remove `track_errors` entirely
follow up to https://github.com/rust-lang/rust/pull/119869
r? `@matthewjasper`
There are some diagnostic changes adding new diagnostics or not emitting some anymore. We can improve upon that in follow-up work imo.
Change the implicit `Sized` `Obligation` `Span` for call expressions to
include the whole expression. This aids the existing deduplication
machinery to reduce the number of errors caused by a single unsized
expression.
When we encounter a `dyn Trait` that isn't object safe, look for its
implementors. If there's one, mention using it directly If there are
less than 9, mention the possibility of creating a new enum and using
that instead.
Account for object unsafe `impl Trait on dyn Trait {}`. Make a
distinction between public and sealed traits.
Fix#80194.
Return multiple object-safety violation errors and code improvements to the object-safety check
See individual commits for more information. Split off of #114260, since it turned out that the main intent of that PR was wrong.
r? oli-obk
Rollup of 7 pull requests
Successful merges:
- #117111 (Remove support for alias `-Z instrument-coverage`)
- #117141 (Require target features to match exactly during inlining)
- #117152 (Fix unwrap suggestion for async fn)
- #117154 (implement C ABI lowering for CSKY)
- #117159 (Work around the fact that `check_mod_type_wf` may spuriously return `ErrorGuaranteed`)
- #117163 (compiletest: Display compilation errors in mir-opt tests)
- #117173 (Make `Iterator` a lang item)
r? `@ghost`
`@rustbot` modify labels: rollup
Format all the let-chains in compiler crates
Since rust-lang/rustfmt#5910 has landed, soon we will have support for formatting let-chains (as soon as rustfmt syncs and beta gets bumped).
This PR applies the changes [from master rustfmt to rust-lang/rust eagerly](https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/out.20formatting.20of.20prs/near/374997516), so that the next beta bump does not have to deal with a 200+ file diff and can remain concerned with other things like `cfg(bootstrap)` -- #113637 was a pain to land, for example, because of let-else.
I will also add this commit to the ignore list after it has landed.
The commands that were run -- I'm not great at bash-foo, but this applies rustfmt to every compiler crate, and then reverts the two crates that should probably be formatted out-of-tree.
```
~/rustfmt $ ls -1d ~/rust/compiler/* | xargs -I@ cargo run --bin rustfmt -- `@/src/lib.rs` --config-path ~/rust --edition=2021 # format all of the compiler crates
~/rust $ git checkout HEAD -- compiler/rustc_codegen_{gcc,cranelift} # revert changes to cg-gcc and cg-clif
```
cc `@rust-lang/rustfmt`
r? `@WaffleLapkin` or `@Nilstrieb` who said they may be able to review this purely mechanical PR :>
cc `@Mark-Simulacrum` and `@petrochenkov,` who had some thoughts on the order of operations with big formatting changes in https://github.com/rust-lang/rust/pull/95262#issue-1178993801. I think the situation has changed since then, given that let-chains support exists on master rustfmt now, and I'm fairly confident that this formatting PR should land even if *bootstrap* rustfmt doesn't yet format let-chains in order to lessen the burden of the next beta bump.
Show more information when multiple `impl`s apply
- When there are `impl`s without type params, show only those (to avoid showing overly generic `impl`s).
```
error[E0283]: type annotations needed
--> $DIR/multiple-impl-apply.rs:34:9
|
LL | let y = x.into();
| ^ ---- type must be known at this point
|
note: multiple `impl`s satisfying `_: From<Baz>` found
--> $DIR/multiple-impl-apply.rs:14:1
|
LL | impl From<Baz> for Bar {
| ^^^^^^^^^^^^^^^^^^^^^^
...
LL | impl From<Baz> for Foo {
| ^^^^^^^^^^^^^^^^^^^^^^
= note: required for `Baz` to implement `Into<_>`
help: consider giving `y` an explicit type
|
LL | let y: /* Type */ = x.into();
| ++++++++++++
```
- Lower the importance of `T: Sized`, `T: WellFormed` and coercion errors, to prioritize more relevant errors. The pre-existing deduplication logic deals with hiding redundant errors better that way, and we show errors with more metadata that is useful to the user.
- Show `<SelfTy as Trait>::assoc_fn` suggestion in more cases.
```
error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type
--> $DIR/cross-return-site-inference.rs:38:16
|
LL | return Err(From::from("foo"));
| ^^^^^^^^^^ cannot call associated function of trait
|
help: use a fully-qualified path to a specific available implementation
|
LL | return Err(</* self type */ as From>::from("foo"));
| +++++++++++++++++++ +
```
Fix#88284.
In `report_fullfillment_errors` push back `T: Sized`, `T: WellFormed`
and coercion errors to the end of the list. The pre-existing
deduplication logic eliminates redundant errors better that way, keeping
the resulting output with fewer errors than before, while also having
more detail.
Correctly deny late-bound lifetimes from parent in anon consts and TAITs
Reuse the `AnonConstBoundary` scope (introduced in #108553, renamed in this PR to `LateBoundary`) to deny late-bound vars of *all* kinds (ty/const/lifetime) in anon consts and TAITs.
Side-note, but I would like to consolidate this with the error reporting for RPITs (E0657):
c4f25777a0/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs (L733-L754) but the semantics about what we're allowed to capture there are slightly different, so I'm leaving that untouched.
Fixes#115474
