Revert #107376 to fix potential `bincode` breakage and `rustc-perf` benchmark.
#107376 caused `rustc-perf`'s `webrender` benchmark to break, by regressing on the `bincode-1.3.3` crate.
~~This PR is a draft revert in case we can't land a fix soon enough, and we'd like to land the revert instead~~
(Though I myself think it'd be safer to do the revert, and run crater when relanding #107376.)
cc `@aliemjay`
Ensure `ptr::read` gets all the same LLVM `load` metadata that dereferencing does
I was looking into `array::IntoIter` optimization, and noticed that it wasn't annotating the loads with `noundef` for simple things like `array::IntoIter<i32, N>`. Trying to narrow it down, it seems that was because `MaybeUninit::assume_init_read` isn't marking the load as initialized (<https://rust.godbolt.org/z/Mxd8TPTnv>), which is unfortunate since that's basically its reason to exist.
The root cause is that `ptr::read` is currently implemented via the *untyped* `copy_nonoverlapping`, and thus the `load` doesn't get any type-aware metadata: no `noundef`, no `!range`. This PR solves that by lowering `ptr::read(p)` to `copy *p` in MIR, for which the backends already do the right thing.
Fortuitiously, this also improves the IR we give to LLVM for things like `mem::replace`, and fixes a couple of long-standing bugs where `ptr::read` on `Copy` types was worse than `*`ing them.
Zulip conversation: <https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Move.20array.3A.3AIntoIter.20to.20ManuallyDrop/near/341189936>
cc `@erikdesjardins` `@JakobDegen` `@workingjubilee` `@the8472`
Fixes#106369Fixes#73258
Simplify message paths
This makes it easier to open the messages file. Right now I have to first click on the `locales` dir to open it, and then on the `en-US.ftl` file. `Cargo.toml` and `build.rs` files are also in the top level, and I think there should not be more than one file, so a directory isn't really needed. The [chosen strategy for pontoon adoption](https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/pontoon.20and.20next.20steps) is out of tree. Even if this descision is changed in the future, the `messages.ftl` approach is also compatible with non-english translations living in-tree, as long as the non-english translations don't live in the `compiler/rustc_foo/` directories but in different ones. That would also be helpful for grepability purposes.
The commit was the result of automated changes:
```
for p in compiler/rustc_*; do mv $p/locales/en-US.ftl $p/messages.ftl; rmdir $p/locales; done
for p in compiler/rustc_*; do sed -i "s#\.\./locales/en-US.ftl#../messages.ftl#" $p/src/lib.rs; done
```
r? `@davidtwco`
I was looking into `array::IntoIter` optimization, and noticed that it wasn't annotating the loads with `noundef` for simple things like `array::IntoIter<i32, N>`.
Turned out to be a more general problem as `MaybeUninit::assume_init_read` isn't marking the load as initialized (<https://rust.godbolt.org/z/Mxd8TPTnv>), which is unfortunate since that's basically its reason to exist.
This PR lowers `ptr::read(p)` to `copy *p` in MIR, which fortuitiously also improves the IR we give to LLVM for things like `mem::replace`.
This makes it easier to open the messages file while developing on features.
The commit was the result of automatted changes:
for p in compiler/rustc_*; do mv $p/locales/en-US.ftl $p/messages.ftl; rmdir $p/locales; done
for p in compiler/rustc_*; do sed -i "s#\.\./locales/en-US.ftl#../messages.ftl#" $p/src/lib.rs; done
feat: implement better error for manual impl of `Fn*` traits
Fixes#39259
cc `@estebank` (you gave me some advice in the linked issue, would you like to review?)
Rollup of 8 pull requests
Successful merges:
- #108754 (Retry `pred_known_to_hold_modulo_regions` with fulfillment if ambiguous)
- #108759 (1.41.1 supported 32-bit Apple targets)
- #108839 (Canonicalize root var when making response from new solver)
- #108856 (Remove DropAndReplace terminator)
- #108882 (Tweak E0740)
- #108898 (Set `LIBC_CHECK_CFG=1` when building Rust code in bootstrap)
- #108911 (Improve rustdoc-gui/tester.js code a bit)
- #108916 (Remove an unused return value in `rustc_hir_typeck`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Do not implement HashStable for HashSet (MCP 533)
This PR removes all occurrences of `HashSet` in query results, replacing it either with `FxIndexSet` or with `UnordSet`, and then removes the `HashStable` implementation of `HashSet`. This is part of implementing [MCP 533](https://github.com/rust-lang/compiler-team/issues/533), that is, removing the `HashStable` implementations of all collection types with unstable iteration order.
The changes are mostly mechanical. The only place where additional sorting is happening is in Miri's override implementation of the `exported_symbols` query.
Add `round_ties_even` to `f32` and `f64`
Tracking issue: #96710
Redux of #82273. See also #55107
Adds a new method, `round_ties_even`, to `f32` and `f64`, that rounds the float to the nearest integer , rounding halfway cases to the number with an even least significant bit. Uses the `roundeven` LLVM intrinsic to do this.
Of the five IEEE 754 rounding modes, this is the only one that doesn't already have a round-to-integer function exposed by Rust (others are `round`, `floor`, `ceil`, and `trunc`). Ties-to-even is also the rounding mode used for int-to-float and float-to-float `as` casts, as well as float arithmentic operations. So not having an explicit rounding method for it seems like an oversight.
Bikeshed: this PR currently uses `round_ties_even` for the name of the method. But maybe `round_ties_to_even` is better, or `round_even`, or `round_to_even`?
rustc_middle: Remove trait `DefIdTree`
This trait was a way to generalize over both `TyCtxt` and `Resolver`, but now `Resolver` has access to `TyCtxt`, so this trait is no longer necessary.
Deny capturing late-bound non-lifetime param in anon const
Introduce a new AnonConstBoundary so we can detect when we capture a late-bound non-lifetime param with `non_lifetime_binders` enabled.
In the future, we could technically do something like introduce an early-bound parameter on the anon const, and stick the late-bound param in its substs (kinda like how we turn late-bound lifetimes in opaques into early-bound ones). But for now, just deny it so we don't ICE.
Fixes#108191
