Remove the `NodeId` of `ast::ExprKind::Async`
This is a followup to https://github.com/rust-lang/rust/pull/104833#pullrequestreview-1314537416.
In my original attempt, I was using `LoweringContext::expr`, which was not correct as it creates a fresh `DefId`.
It now uses the correct `DefId` for the wrapping `Expr`, and also makes forwarding `#[track_caller]` attributes more explicit.
Avoid materializing bits in the InitMask bitset when a single value
would be enough: when the mask represents a fully initialized or fully
uninitialized const allocation.
Refactor: Separate `LocalRef` variant for not-evaluated-yet operands
As I was reading through this, I noticed that almost every place that was using this needed to distinguish between Some vs None in the match arm anyway, so thought that separating the cases at the variant level might be clearer instead.
I like how it ended up; let me know what you think!
Rollup of 8 pull requests
Successful merges:
- #97506 (Stabilize `nonnull_slice_from_raw_parts`)
- #98651 (Follow C-RW-VALUE in std::io::Cursor example)
- #102742 (Remove unnecessary raw pointer in __rust_start_panic arg)
- #109587 (Use an IndexVec to debug fingerprints.)
- #109613 (fix type suggestions in match arms)
- #109633 (Fix "Directly go to item in search if there is only one result" setting)
- #109635 (debuginfo: Get pointer size/align from tcx.data_layout instead of layout_of)
- #109641 (Don't elaborate non-obligations into obligations)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Don't elaborate non-obligations into obligations
It's suspicious to elaborate a `PolyTraitRef` or `Predicate` into an `Obligation`, since the former does not have a param-env associated with it, but the latter does. This is a footgun that, while not being misused *currently* in the compiler, easily could be misused by someone less familiar with the elaborator's inner workings.
This PR just changes the API -- ideally, the elaborator wouldn't even have to deal with obligations if we're not elaborating obligations, but that would require a bit more abstraction than I could be bothered with today.
debuginfo: Get pointer size/align from tcx.data_layout instead of layout_of
This avoids some type interning and a query execution. It also just makes the code simpler.
Cleanup `codegen_fn_attrs`
The `match` control flow construct has been stable since 1.0, we should use it here.
Sorry for the hard to review diff, I did try to at least split it into two commits. But looking at before-after side-by-side (instead of whatever github is doing) is probably the easiest way to make sure that I didn't forget about anything.
On top of #109088, you can wait for that
Refactor: `VariantIdx::from_u32(0)` -> `FIRST_VARIANT`
Since structs are always `VariantIdx(0)`, there's a bunch of files where the only reason they had `VariantIdx` or `vec::Idx` imported at all was to get the first variant.
So this uses a constant for that, and adds some doc-comments to `VariantIdx` while I'm there, since [it doesn't have any today](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_target/abi/struct.VariantIdx.html).
Still-further-specializable projections are ambiguous in new solver
Fixes https://github.com/rust-lang/rust/pull/108896/files#r1148450781
r? ``@BoxyUwU`` (though feel free to re-roll)
---
This can be used to create an unsound transmute function with the new solver:
```rust
#![feature(specialization)]
trait Default {
type Id;
fn intu(&self) -> &Self::Id;
}
impl<T> Default for T {
default type Id = T;
fn intu(&self) -> &Self::Id {
self
}
}
fn transmute<T: Default<Id = U>, U: Copy>(t: T) -> U {
*t.intu()
}
use std::num::NonZeroU8;
fn main() {
let s = transmute::<u8, Option<NonZeroU8>>(0);
assert_eq!(s, None);
}
```
Permit the MIR inliner to inline diverging functions
This heuristic prevents inlining of `hint::unreachable_unchecked`, which in turn makes `Option/Result::unwrap_unchecked` a bad inlining candidate. I looked through the changes to `core`, `alloc`, `std`, and `hashbrown` by hand and they all seem reasonable. Let's see how this looks in perf...
---
Based on rustc-perf it looks like this regresses ctfe-stress, and the cachegrind diff indicates that this regression is in `InterpCx::statement`. I don't know how to do any deeper analysis because that function is _enormous_ in the try toolchain, which has no debuginfo in it. And a local build produces significantly different codegen for that function, even with LTO.
Since structs are always `VariantIdx(0)`, there's a bunch of files where the only reason they had `VariantIdx` or `vec::Idx` imported at all was to get the first variant.
So this uses a constant for that, and adds some doc-comments to `VariantIdx` while I'm there, since it doesn't have any today.
Refactor `try_execute_query`
This merges `JobOwner::try_start` into `try_execute_query`, removing `TryGetJob` in the processes. 3 new functions are extracted from `try_execute_query`: `execute_job`, `cycle_error` and `wait_for_query`. This makes the control flow a bit clearer and improves performance.
Based on https://github.com/rust-lang/rust/pull/109046.
<table><tr><td rowspan="2">Benchmark</td><td colspan="1"><b>Before</b></th><td colspan="2"><b>After</b></th></tr><tr><td align="right">Time</td><td align="right">Time</td><td align="right">%</th></tr><tr><td>🟣 <b>clap</b>:check</td><td align="right">1.7134s</td><td align="right">1.7061s</td><td align="right"> -0.43%</td></tr><tr><td>🟣 <b>hyper</b>:check</td><td align="right">0.2519s</td><td align="right">0.2510s</td><td align="right"> -0.35%</td></tr><tr><td>🟣 <b>regex</b>:check</td><td align="right">0.9517s</td><td align="right">0.9481s</td><td align="right"> -0.38%</td></tr><tr><td>🟣 <b>syn</b>:check</td><td align="right">1.5389s</td><td align="right">1.5338s</td><td align="right"> -0.33%</td></tr><tr><td>🟣 <b>syntex_syntax</b>:check</td><td align="right">5.9488s</td><td align="right">5.9258s</td><td align="right"> -0.39%</td></tr><tr><td>Total</td><td align="right">10.4048s</td><td align="right">10.3647s</td><td align="right"> -0.38%</td></tr><tr><td>Summary</td><td align="right">1.0000s</td><td align="right">0.9962s</td><td align="right"> -0.38%</td></tr></table>
r? `@cjgillot`
