- Add a `HandleCycleError` enum to rustc_query_system, along with a `handle_cycle_error` function
- Move `Value` to rustc_query_system, so `handle_cycle_error` can use it
- Move the `Value` impls from rustc_query_impl to rustc_middle. This is necessary due to orphan rules.
There are several indications that we should not ZST as a ScalarInt:
- We had two ways to have ZST valtrees, either an empty `Branch` or a `Leaf` with a ZST in it.
`ValTree::zst()` used the former, but the latter could possibly arise as well.
- Likewise, the interpreter had `Immediate::Uninit` and `Immediate::Scalar(Scalar::ZST)`.
- LLVM codegen already had to special-case ZST ScalarInt.
So instead add new ZST variants to those types that did not have other variants
which could be used for this purpose.
It looks like the last time had left some remaining cfg's -- which made me think
that the stage0 bump was actually successful. This brings us to a released 1.62
beta though.
Stabilize `derive_default_enum`
This stabilizes `#![feature(derive_default_enum)]`, as proposed in [RFC 3107](https://github.com/rust-lang/rfcs/pull/3107) and tracked in #87517. In short, it permits you to `#[derive(Default)]` on `enum`s, indicating what the default should be by placing a `#[default]` attribute on the desired variant (which must be a unit variant in the interest of forward compatibility).
```````@rustbot``````` label +S-waiting-on-review +T-lang
Add `rustc_middle::ty::suggest_constraining_type_params` that suggests
adding multiple constraints.
`suggest_constraining_type_param` now just forwards params to this new
function.
See #91867
This was mostly straightforward. In several places, I take advantage
of the fact that lifetimes are non-hygenic: a macro declares the
'tcx' lifetime, which is then used in types passed in as macro
arguments.
This commit is intended to follow the stabilization disposition of the
FCP that has now finished in #84223. This stabilizes the ability to flag
thread local initializers as `const` expressions which enables the macro
to generate more efficient code for accessing it, notably removing
runtime checks for initialization.
More information can also be found in #84223 as well as the tests where
the feature usage was removed in this PR.
Closes#84223
This performs a substitution of code following the pattern:
let <id> = if let <pat> = ... { identity } else { ... : ! };
To simplify it to:
let <pat> = ... { identity } else { ... : ! };
By adopting the let_else feature.
Hide allocator details from TryReserveError
I think there's [no need for TryReserveError to carry detailed information](https://github.com/rust-lang/rust/issues/48043#issuecomment-825139280), but I wouldn't want that issue to delay stabilization of the `try_reserve` feature.
So I'm proposing to stabilize `try_reserve` with a `TryReserveError` as an opaque structure, and if needed, expose error details later.
This PR moves the `enum` to an unstable inner `TryReserveErrorKind` that lives under a separate feature flag. `TryReserveErrorKind` could possibly be left as an implementation detail forever, and the `TryReserveError` get methods such as `allocation_size() -> Option<usize>` or `layout() -> Option<Layout>` instead, or the details could be dropped completely to make try-reserve errors just a unit struct, and thus smaller and cheaper.
