Retire the `unnamed_fields` feature for now
`#![feature(unnamed_fields)]` was implemented in part in #115131 and #115367, however work on that feature has (afaict) stalled and in the mean time there have been some concerns raised (e.g.[^1][^2]) about whether `unnamed_fields` is worthwhile to have in the language, especially in its current desugaring. Because it represents a compiler implementation burden including a new kind of anonymous ADT and additional complication to field selection, and is quite prone to bugs today, I'm choosing to remove the feature.
However, since I'm not one to really write a bunch of words, I'm specifically *not* going to de-RFC this feature. This PR essentially *rolls back* the state of this feature to "RFC accepted but not yet implemented"; however if anyone wants to formally unapprove the RFC from the t-lang side, then please be my guest. I'm just not totally willing to summarize the various language-facing reasons for why this feature is or is not worthwhile, since I'm coming from the compiler side mostly.
Fixes#117942Fixes#121161Fixes#121263Fixes#121299Fixes#121722Fixes#121799Fixes#126969Fixes#131041
Tracking:
* https://github.com/rust-lang/rust/issues/49804
[^1]: https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Unnamed.20struct.2Funion.20fields
[^2]: https://github.com/rust-lang/rust/issues/49804#issuecomment-1972619108
- fix for divergence
- fix error message
- fix another cranelift test
- fix some cranelift things
- don't set the NORETURN option for naked asm
- fix use of naked_asm! in doc comment
- fix use of naked_asm! in run-make test
- use `span_bug` in unreachable branch
Make opaque types regular HIR nodes
Having opaque types as HIR owner introduces all sorts of complications. This PR proposes to make them regular HIR nodes instead.
I haven't gone through all the test changes yet, so there may be a few surprises.
Many thanks to `@camelid` for the first draft.
Fixes https://github.com/rust-lang/rust/issues/129023Fixes#129099Fixes#125843Fixes#119716Fixes#121422
Add support for reborrowing pinned method receivers
This builds on #130526 to add pinned reborrowing for method receivers. This enables the folllowing examples to work:
```rust
#![feature(pin_ergonomics)]
#![allow(incomplete_features)]
use std::pin::Pin;
pub struct Foo;
impl Foo {
fn foo(self: Pin<&mut Self>) {
}
fn baz(self: Pin<&Self>) {
}
}
pub fn bar(x: Pin<&mut Foo>) {
x.foo();
x.foo();
x.baz(); // Pin<&mut Foo> is downgraded to Pin<&Foo>
}
pub fn baaz(x: Pin<&Foo>) {
x.baz();
x.baz();
}
```
This PR includes the original one, which is currently in the commit queue, but the only code changes are in the latest commit (d3c53aaa5c6fcb1018c58d229bc5d92202fa6880).
#130494
r? `@compiler-errors`
Refactoring to `OpaqueTyOrigin`
Pulled out of a larger PR that uses these changes to do cross-crate encoding of opaque origin, so we can use them for edition 2024 migrations. These changes should be self-explanatory on their own, tho 😄
add caching to most type folders, rm region uniquification
Fixes the new minimization of the hang in nalgebra and nalgebra itself :3
this is a bit iffy, especially the cache in `TypeRelating`. I believe all the caches are correct, but it definitely adds some non-local complexity in places. The first commit removes region uniquification, reintroducing the ICE from https://github.com/rust-lang/trait-system-refactor-initiative/issues/27. This does not affect coherence and I would like to fix this by introducing OR-region constraints
r? `@compiler-errors`
panic when an interpreter error gets unintentionally discarded
One important invariant of Miri is that when an interpreter error is raised (*in particular* a UB error), those must not be discarded: it's not okay to just check `foo().is_err()` and then continue executing.
This seems to catch new contributors by surprise fairly regularly, so this PR tries to make it so that *if* this ever happens, we get a panic rather than a silent missed UB bug. The interpreter error type now contains a "guard" that panics on drop, and that is explicitly passed to `mem::forget` when an error is deliberately discarded.
Fixes https://github.com/rust-lang/miri/issues/3855
properly elaborate effects implied bounds for super traits
Summary: This PR makes it so that we elaborate `<T as Tr>::Fx: EffectsCompat<somebool>` into `<T as SuperTr>::Fx: EffectsCompat<somebool>` when we know that `trait Tr: ~const SuperTr`.
Some discussion at https://github.com/rust-lang/project-const-traits/issues/2.
r? project-const-traits
`@rust-lang/project-const-traits:` how do we feel about this approach?
