Fix SmallCStr conversion from CStr
The conversion from CStr to SmallCStr was not including the null byte. SmallCStr requires a trailing null. This caused `as_c_str` to either panic if std is built with debug assertions, or to have some corrupt memory behavior.
Continue compilation after check_mod_type_wf errors
The ICEs fixed here were probably reachable through const eval gymnastics before, but now they are easily reachable without that, too.
The new errors are often bugfixes, where useful errors were missing, because they were reported after the early abort. In other cases sometimes they are just duplication of already emitted errors, which won't be user-visible due to deduplication.
fixes https://github.com/rust-lang/rust/issues/120860
Rollup of 6 pull requests
Successful merges:
- #120893 (Move some tests)
- #120966 (Remove importing suggestions when there is a shadowed typo candidate)
- #121035 (Format `async` trait bounds in rustfmt)
- #121075 (Fix false positive with if let and ranges)
- #121083 (Extend documentation for `Ty::to_opt_closure_kind` method)
- #121084 (Make sure `tcx.create_def` also depends on the forever red node, instead of just `tcx.at(span).create_def`)
r? `@ghost`
`@rustbot` modify labels: rollup
Make sure `tcx.create_def` also depends on the forever red node, instead of just `tcx.at(span).create_def`
oversight from https://github.com/rust-lang/rust/pull/119136
Not actually an issue, because all uses of `tcx.create_def` were in the resolver, which is `eval_always`, but still good to harden against future uses of `create_def`
cc `@petrochenkov` `@WaffleLapkin`
Extend documentation for `Ty::to_opt_closure_kind` method
This API was... surprising to use. With a little extra documentation, the weirdness can be reduced quite a lot. :)
r? `@compiler-errors`
Format `async` trait bounds in rustfmt
r? `@ytmimi` or `@calebcartwright`
This PR opts to do formatting in the rust-lang/rust tree because otherwise we'd have to wait until a full sync, and rustfmt is currently totally removing the `async` keyword.
cc https://github.com/rust-lang/rustfmt/issues/6070
Rollup of 13 pull requests
Successful merges:
- #116387 (Additional doc links and explanation of `Wake`.)
- #118738 (Netbsd10 update)
- #118890 (Clarify the lifetimes of allocations returned by the `Allocator` trait)
- #120498 (Uplift `TypeVisitableExt` into `rustc_type_ir`)
- #120530 (Be less confident when `dyn` suggestion is not checked for object safety)
- #120915 (Fix suggestion span for `?Sized` when param type has default)
- #121015 (Optimize `delayed_bug` handling.)
- #121024 (implement `Default` for `AsciiChar`)
- #121039 (Correctly compute adjustment casts in GVN)
- #121045 (Fix two UI tests with incorrect directive / invalid revision)
- #121049 (Do not point at `#[allow(_)]` as the reason for compat lint triggering)
- #121071 (Use fewer delayed bugs.)
- #121073 (Fix typos in `OneLock` doc)
r? `@ghost`
`@rustbot` modify labels: rollup
Use fewer delayed bugs.
For some cases where it's clear that an error has already occurred, e.g.:
- there's a comment stating exactly that, or
- things like HIR lowering, where we are lowering an error kind
The commit also tweaks some comments around delayed bug sites.
r? `@oli-obk`
Fix two UI tests with incorrect directive / invalid revision
- `tests/ui/borrowck/copy-suggestion-region-vid.rs` had a `ui_test`-style directive on compiletest: `//`@run-rustfix`.`
- `tests/ui/asm/inline-syntax.rs` has directives for a undeclared revision `[x86_64_allowed]` which seems to have the same directives as declared revision `[x86_64]`.
implement `Default` for `AsciiChar`
This implements `Default` for `AsciiChar` in order to match `char`'s implementation.
From all the different possible ways to do this I think the clearest one is to have both `char` and `AsciiChar` impls together.
I've also updated the doc-comment of the default variant since rustdoc doesn't seem to indicate it otherwise. Probably the text could be improved, though. I couldn't find any similar examples in the codebase and suggestions are welcomed.
r? `@scottmcm`
Optimize `delayed_bug` handling.
Once we have emitted at least one error, delayed bugs won't be used. So we can (a) we can (a) discard any existing delayed bugs, and (b) stop recording any new delayed bugs.
This eliminates a longstanding `FIXME` comment. There should be no soundness issues because it's not possible to un-emit an error.
r? `@oli-obk`
Fix suggestion span for `?Sized` when param type has default
Fixes#120878
Diagnostic suggests adding `: ?Sized` in an incorrect place if a type parameter default is present
r? `@fmease`
Be less confident when `dyn` suggestion is not checked for object safety
#120275 no longer checks bare traits for object safety when making a `dyn` suggestion on Rust < 2021. In this case, qualify the suggestion with a note that the trait must be object safe, to prevent user confusion as seen in #116434
r? ```@fmease```
Uplift `TypeVisitableExt` into `rustc_type_ir`
This uplifts `TypeVisitableExt` into `rustc_type_ir` so it can be used in an interner-agnostic way. It also moves some `TypeSuperVisitable` bounds onto `Interner` since we don't expect to support libraries that have types which aren't foldable by default.
This restores a couple of asserts in the canonicalizer code we uplifted, and also makes it so that we can use type-flags-based helpers in the solver code, which I'm interested in uplifting.
r? lcnr
Clarify the lifetimes of allocations returned by the `Allocator` trait
The previous definition (accidentally) disallowed the implementation of stack-based allocators whose memory would become invalid once the lifetime of the allocator type ended.
This also ensures the validity of the following blanket implementation:
```rust
impl<A: Allocator> Allocator for &'_ A {}
```
Additional doc links and explanation of `Wake`.
This is intended to clarify:
* That `Wake` exists and can be used instead of `RawWaker`.
* How to construct a `Waker` when you are looking at `Wake` (which was previously only documented in the example).
Optimize away poison guards when std is built with panic=abort
> **Note**: To take advantage of this PR, you will have to use `-Zbuild-std` or build your own toolchain. rustup toolchains always link to a libstd that was compiled with `panic=unwind`, since it's compatible with `panic=abort` code.
When std is compiled with `panic=abort` we can remove a lot of the poison machinery from the locks. This changes the `Flag` and `Guard` types to be ZSTs. It also adds an uninhabited member to `PoisonError` so the compiler knows it can optimize away the `Result::Err` paths, and make `LockResult<T>` layout-equivalent to `T`.
### Is this a breaking change?
`PoisonError::new` now panics if invoked from a libstd built with `panic="abort"` (or any non-`unwind` strategy). It is unclear to me whether to consider this a breaking change.
In order to encounter this behavior, **both of the following must be true**:
#### Using a libstd with `panic="abort"`
This is pretty uncommon. We don't build libstd with that in rustup, except in (Tier 2-3) platforms that do not support unwinding, **most notably wasm**.
Most people who do this are using cargo's `-Z build-std` feature, which is unstable.
`panic="abort"` is not a supported option in Rust's build system. It is possible to configure it using `CARGO_TARGET_xxx_RUSTFLAGS`, but I believe this only works on **non-host** platforms.
#### Creating `PoisonError` manually
This is also unlikely. The only common use case I can think of is in tests, and you can't run tests with `panic="abort"` without the unstable `-Z panic_abort_tests` flag.
It's possible that someone is implementing their own locks using std's `PoisonError` **and** defining "thread failure" to mean something other than "panic". If this is the case then we would break their code if it was used with a `panic="abort"` libstd. The locking crates I know of don't replicate std's poison API, but I haven't done much research into this yet.
I've touched on a fair number of considerations here. Which ones do people consider relevant?
For some cases where it's clear that an error has already occurred,
e.g.:
- there's a comment stating exactly that, or
- things like HIR lowering, where we are lowering an error kind
The commit also tweaks some comments around delayed bug sites.
Fully stop using the HIR in trait impl checks
At least I hope I found all happy path usages. I'll need to check if I can figure out a way to make queries declare that they don't access the HIR except in error paths
`cargo update`
Run `cargo update`, with some pinning and fixes necessitated by that. This *should* unblock #112865
There's a couple of places where I only pinned a dependency in one location - this seems like a bit of a hack, but better than duplicating the FIXME across all `Cargo.toml` where a dependency is introduced.
cc `@Nilstrieb`
Ignore own item bounds in parent alias types in `for_each_item_bound`
Fixes#120912
I want to get a vibe check on this approach, which is very obviously a hack, but I believe something that is forwards-compatible with a more thorough solution and "good enough for now".
The problem here is that for a really deep rigid associated type, we are now repeatedly considering unrelated item bounds from the parent alias types, meaning we're doing a *lot* of extra work in the MIR inliner for deeply substituted rigid projections.
This feels intimately related to #107614. In that PR, we split *supertrait* bounds (bound which share the same `Self` type as the predicate which is being elaborated) and *implied* bounds (anything that is implied by elaborating the predicate).
The problem here is related to the fact that we don't maintain the split between these two for `item_bounds`. If we did, then when recursing into a parent alias type, we'd want to consider only the bounds that are given by [`PredicateFilter::All`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir_analysis/astconv/enum.PredicateFilter.html#variant.SelfOnly) **except** those given by [`PredicateFilter::SelfOnly`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir_analysis/astconv/enum.PredicateFilter.html#variant.SelfOnly).
Do not assemble candidates for default impls
There is no reason (as far as I can tell?) that we should assemble an impl candidate for a default impl. This candidate itself does not prove that the impl holds, and any time that it *does* hold, there will be a more specializing non-default impl that also is assembled.
This is because `default impl<T> Foo for T {}` actually expands to `impl<T> Foo for T where T: Foo {}`. The only way to satisfy that where clause (without coinduction) is via *another* implementation that does hold -- precisely an impl that specializes it.
This should fix the specialization related regressions for #116494. That should lead to one root crate regression that doesn't have to do with specialization, which I think we can regress.
r? lcnr cc ``@rust-lang/types``
cc #31844
Fix incorrect use of `compile_fail`
`compile_fail` should only be used when the code is meant to show what *not* to do. In other words, there should be a fundamental flaw in the code. However, in this case, the example is just incomplete, so we should use `ignore` to avoid confusing readers.
rustdoc: replace `clean::InstantiationParam` with `clean::GenericArg`
Probably better known as `SubstParam` (until #120958 which should've probably renamed it to `InstantiatedParam` but anyways).
It doesn't make any sense to me why it should exist as a separate type. `GenericArg` is exactly what we want here anyways from a semantic perspective. Both have the same size btw.
I also took the liberty of doing some drive-by cleanups.
Check normalized call signature for WF in mir typeck
Unfortunately we don't check that the built-in implementations for `Fn*` traits are actually well-formed in the same way that we do for user-provided impls.
Essentially, when checking a call terminator, we end up with a signature that references an unnormalized `<[closure] as FnOnce<...>>::Output` in its output. That output type, due to the built-in impl, doesn't follow the expected rule that `WF(ty)` implies `WF(normalized(ty))`. We fix this by also checking the normalized signature here.
**See** boxy's detailed and useful explanation comment which explains this in more detail: https://github.com/rust-lang/rust/issues/114936#issuecomment-1710388741Fixes#114936Fixes#118876
r? types
cc ``@BoxyUwU`` ``@lcnr``
Once we have emitted at least one error, delayed bugs won't be used. So
we can (a) we can (a) discard any existing delayed bugs, and (b) stop
recording any new delayed bugs.
This eliminates a longstanding `FIXME` comment. There should be no
soundness issues because it's not possible to un-emit an error.
