Implement `for<>` lifetime binder for closures
This PR implements RFC 3216 ([TI](https://github.com/rust-lang/rust/issues/97362)) and allows code like the following:
```rust
let _f = for<'a, 'b> |a: &'a A, b: &'b B| -> &'b C { b.c(a) };
// ^^^^^^^^^^^--- new!
```
cc ``@Aaron1011`` ``@cjgillot``
Fix drop-tracking ICE when a struct containing a field with a significant drop is used across an await
Previously, drop-tracking would incorrectly assume the struct would be dropped immediately, which was not true.
Fixes#98476. Also fixes https://github.com/rust-lang/rust/issues/98477, I think because the parent HIR node for type variables is the whole function instead of the expression where the variable is used.
r? `@eholk`
Keep unstable target features for asm feature checking
Inline assembly uses the target features to determine which registers
are available on the current target. However it needs to be able to
access unstable target features for this.
Fixes#99071
Lower let-else in MIR
This MR will switch to lower let-else statements in MIR building instead.
To lower let-else in MIR, we build a mini-switch two branches. One branch leads to the matching case, and the other leads to the `else` block. This arrangement will allow temporary lifetime analysis running as-is so that the temporaries are properly extended according to the same rule applied to regular `let` statements.
cc https://github.com/rust-lang/rust/issues/87335Fix#98672
Do not error during method probe on `Sized` predicates for types that aren't the method receiver
Fixes#61525
This is safe even though we're skipping an error because we end up confirming the method, which means we're still checking the `Sized` predicate in the end. It just means that we don't emit an erroneous message as below:
```
error: the `query` method cannot be invoked on a trait object
--> src/lib.rs:14:11
|
14 | 1.query::<dyn ToString>("")
| ^^^^^
|
= note: another candidate was found in the following trait, perhaps add a `use` for it:
`use crate::Example;`
```
Also fixes erroneously suggesting the same trait over again, as seen in the `issue-35976.rs` UI test.
Inline assembly uses the target features to determine which registers
are available on the current target. However it needs to be able to
access unstable target features for this.
Fixes#99071
Mention similarly named associated type even if it's not clearly in supertrait
Due to query cycle avoidance, we sometimes restrict the candidates in `complain_about_assoc_type_not_found` too much so that we can't detect typo replacements from just supertraits.
This creates a more general note of the existence of a similarly named associated type from _all_ visible traits when possible.
Fixes#55673
Implement `SourceMap::is_span_accessible`
This patch adds `SourceMap::is_span_accessible` and replaces `span_to_snippet(span).is_ok()` and `span_to_snippet(span).is_err()` with it. This removes a `&str` to `String` conversion.
Previously, drop-tracking would incorrectly assume the struct would be dropped immediately, which
was not true: when the field had a type with a manual `Drop` impl, the drop becomes observable and
has to be dropped after the await instead.
For reasons I don't understand, this also fixes another error crater popped up related to type parameters.
#98476
Track implicit `Sized` obligations in type params
When we evaluate `ty::GenericPredicates` we introduce the implicit
`Sized` predicate of type params, but we do so with only the `Predicate`
its `Span` as context, we don't have an `Obligation` or
`ObligationCauseCode` we could influence. To try and carry this
information through, we add a new field to `ty::GenericPredicates` that
tracks both which predicates come from a type param and whether that
param has any bounds already (to use in suggestions).
We also suggest adding a `?Sized` bound if appropriate on E0599.
Address part of #98539.
Add a `-Zdump-drop-tracking-cfg` debugging flag
This is useful for debugging drop-tracking; previously, you had to recompile
rustc from source and manually add a call to `write_graph_to_file`. This
makes the option more discoverable and configurable at runtime.
I also took the liberty of making the labels for the CFG nodes much easier to read:
previously, they looked like `id(2), local_id: 48`, now they look like
```
expr from_config (hir_id=HirId { owner: DefId(0:10 ~ default_struct_update[79f9]::foo), local_id: 2})
```
r? ``@eholk``
