Rollup of 10 pull requests
Successful merges:
- #117740 (Add some links and minor explanatory comments to `std::fmt`)
- #118307 (Remove an unneeded helper from the tuple library code)
- #119242 (Suggest less bug-prone construction of Duration in docs)
- #119449 (Fix `clippy::correctness` in the library)
- #120307 (core: add Duration constructors)
- #120459 (Document various I/O descriptor/handle conversions)
- #120729 (Update mdbook to 0.4.37)
- #120763 (Suggest pattern tests when modifying exhaustiveness)
- #120906 (Remove myself from some review rotations)
- #120916 (Subtree update of ` rust-analyzer`)
r? `@ghost`
`@rustbot` modify labels: rollup
Downgrade xcode
This is a temporary fix for the CI issues that have been plaguing the macOS builders. GitHub updated the default Xcode to 15 in the [2024-02-04](https://github.com/actions/runner-images/releases/tag/macos-13%2F20240204.1) update. This caused two issues to start appearing in CI:
* cmake fails to verify that clang can build a simple test program.
* An `invalid r_symbolnum` linking error when trying to build one of cranelift's tests.
I believe I have a solution for the first problem, but not the second. In the meantime, to help with the CI problems, this PR should temporarily resolve the issue until we have a solution.
Suggest pattern tests when modifying exhaustiveness
The vast majority of exhaustiveness tests are in `tests/ui/pattern`, this is what I've been using for years. This PR is me telling `x suggest` about that.
cc `@Ezrashaw`
Update mdbook to 0.4.37
This updates mdbook to 0.4.37.
Changelog: https://github.com/rust-lang/mdBook/blob/master/CHANGELOG.md#mdbook-0437
The primary change is the update to pulldown-cmark which has a large number of markdown parsing changes. There shouldn't be any significant changes to the rendering of any of the books (I have posted some PRs to fix some minor issues to the ones that were affected).
core: add Duration constructors
Add more `Duration` constructors.
Tracking issue: #120301.
These match similar convenience constructors available on both `chrono::Duration` and `time::Duration`.
What's the best ordering for these with respect to the existing constructors?
Suggest less bug-prone construction of Duration in docs
std::time::Duration has a well-known quirk: Duration::as_nanos() returns u128 [1], but Duration::from_nanos() takes u64 [2]. So these methods cannot easily roundtrip [3]. It is not possible to simply accept u128 in from_nanos [4], because it requires breaking other API [5].
It seems to me that callers have basically only two options:
1. `Duration::from_nanos(d.as_nanos() as u64)`, which is the "obvious" and buggy approach.
2. `Duration::new(d.as_secs(), d.subsecs_nanos())`, which only becomes apparent after reading and digesting the entire Duration struct documentation.
I suggest that the documentation of `from_nanos` is changed to make option 2 more easily discoverable.
There are two major usecases for this:
- "Weird math" operations that should not be supported directly by `Duration`, like squaring.
- "Disconnected roundtrips", where the u128 value is passed through various other stack frames, and perhaps reconstructed into a Duration on a different machine.
In both cases, it seems like a good idea to not tempt people into thinking "Eh, u64 is good enough, what could possibly go wrong!". That's why I want to add a note that points out the similarly-easy and *safe* way to reconstruct a Duration.
[1] https://doc.rust-lang.org/stable/std/time/struct.Duration.html#method.as_nanos
[2] https://doc.rust-lang.org/stable/std/time/struct.Duration.html#method.from_nanos
[3] https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=fa6bab2b6b72f20c14b5243610ea1dde
[4] https://github.com/rust-lang/rust/issues/103332
[5] https://github.com/rust-lang/rust/issues/51107#issuecomment-392353166
Remove an unneeded helper from the tuple library code
Thanks to https://github.com/rust-lang/rust/pull/107022, this is just what `==` does, so we don't need the helper here anymore.
Add some links and minor explanatory comments to `std::fmt`
I thought the documentation for the `#` flag could do with a link to the explanation of the `?xXbo` flags, because at that point they haven't been explained yet and it's a bit confusing.
I also added that the `0` flag overrides the fill character and alignment flag, here's a [Rust Playgrond](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=0d580b7b78b8a2d8c08a2fc7a936ef17) that shows what I mean.
Allowing the Xcode version to "float" based on whatever default GitHub
selects creates an unreliable environment. When GitHub changes the
default, we can have multiple jobs in the same run using different
versions as it rolls out across machines. It can also cause oscillation
between runs as different machines are used. It also causes
unpredictable timing when the updates happen.
This change helps ensure that the version that is used is pinned. The
downside is that it requires manually bumping the version, and the risk
that if we take too long, older Xcodes will be removed and that will
break the build.
This seems to fix two sporadic errors that have been appearing in CI.
One is an issue with cmake being unable to verify that cmake is able to
build a simple test program. The other is a `invalid r_symbolnum`
linking error when trying to build one of cranelift's tests.
This is intended as a temporary fix until we can figure out how to
resolve those issues.
Fold pointer operations in GVN
This PR proposes 2 combinations of cast operations in MIR GVN:
- a chain of `PtrToPtr` or `MutToConstPointer` casts can be folded together into a single `PtrToPtr` cast;
- we attempt to evaluate more ptr ops when there is no provenance.
In particular, this allows to read from static slices.
This is not yet sufficient to see through slice operations that use `PtrComponents` (because that's a union), but still a step forward.
r? `@ghost`
Add support for custom JSON targets when using build-std.
Currently, when building with `build-std`, some library build scripts check properties of the target by inspecting the target triple at `env::TARGET`, which is simply set to the filename of the JSON file when using JSON target files.
This patch alters these build scripts to use `env::CARGO_CFG_*` to fetch target information instead, allowing JSON target files describing platforms without `restricted_std` to build correctly when using `-Z build-std`. There are some weak assertions here (for example, `nintendo && newlib`), however this seems at least a marginal improvement on the existing solution.
Fixes https://github.com/rust-lang/wg-cargo-std-aware/issues/60.
Print kind of coroutine closure
Make sure that we print "async closure" when we have an async closure, rather than calling it generically a ["coroutine-closure"](https://github.com/rust-lang/rust/pull/120361).
Fixes#120886
r? oli-obk
Adapt `llvm-has-rust-patches` validation to take `llvm-config` into account.
This adapts an assertion that was added in #119556.
The current assertion does not take the `llvm-config` setting into accounts, which does not match the `llvm-has-rust-patches` documentation, which states:
> This would be used in conjunction with either an llvm-config or build.submodules = false.
(It also breaks my workflow: I build LLVM separately, but do have the rust patches applied).
---
**edit:** Originally this PR just removed the assertion, but it now implements the alternative mentioned here:
An alternative fix would be to take `llvm-config` into account in the assertion, but to me the assertion seems to provide little value, thus the simpler fix of just removing it.
cc `@onur-ozkan,` in case I'm missing a reason to keep the assertion.
large_assignments: Allow moves into functions
Moves into functions are typically implemented with pointer passing
rather than memcpy's at the llvm-ir level, so allow moves into
functions.
Part of the "Differentiate between Operand::Move and Operand::Copy" step of https://github.com/rust-lang/rust/issues/83518.
r? `@oli-obk` (who I think is still E-mentor?)
Suppress suggestions in derive macro
close#118809
I suppress warnings inside derive macros.
For example, the compiler emits following error by a program described in https://github.com/rust-lang/rust/issues/118809#issuecomment-1852256687 with a suggestion that indicates invalid syntax.
```
error[E0308]: `?` operator has incompatible types
--> src/main.rs:3:17
|
3 | #[derive(Debug, Deserialize)]
| ^^^^^^^^^^^ expected `u32`, found `u64`
|
= note: `?` operator cannot convert from `u64` to `u32`
= note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
help: you can convert a `u64` to a `u32` and panic if the converted value doesn't fit
|
3 | #[derive(Debug, Deserialize.try_into().unwrap())]
| ++++++++++++++++++++
For more information about this error, try `rustc --explain E0308`.
error: could not compile `serde_test` (bin "serde_test") due to 2 previous errors
```
In this PR, suggestions to cast are suppressed.
```
error[E0308]: `?` operator has incompatible types
--> src/main.rs:3:17
|
3 | #[derive(Debug, Deserialize)]
| ^^^^^^^^^^^ expected `u32`, found `u64`
|
= note: `?` operator cannot convert from `u64` to `u32`
= note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
For more information about this error, try `rustc --explain E0308`.
error: could not compile `serde_test` (bin "serde_test") due to 2 previous errors
```
unstably allow constants to refer to statics and read from immutable statics
I am not aware of any fundamental reason why we cannot allow constants to mention statics. What we really need is that constants do not *read from* statics that can change their value:
- This would break the principle that "constants behave as-if their expression was inlined everywhere and executed at runtime". This is enforced by halting const-eval interpretation when a read from a mutable global occurs.
- When building a valtree we want to be sure that the constant and everything it refers to is truly immutable. This is enforced by aborting valtree construction when a read from a mutable global occurs.
r? `@oli-obk` -- if you are okay with experimenting with this feature, I will create a tracking issue.
Based on and blocked on https://github.com/rust-lang/rust/pull/119044; only the last commit is new.
