Closures always implement `FnOnce` in new solver
We should process `[closure]: FnOnce(Tys...) -> Ty` obligations *before* fallback and closure analysis. We can do this by taking advantage of the fact that `FnOnce` is always implemented by closures, even before we definitely know the closure kind.
Fixescompiler-errors/next-solver-hir-issues#15
r? ``@oli-obk`` (trying to spread the reviewer load for new trait solver prs, and this one is pretty self-contained, though feel free to reassign 😸)
Don't ICE on placeholder consts in deep reject
Since we canonicalize const params into placeholder consts, we need to be able to handle them during deep reject.
r? `@lcnr` (though maybe `@oli-obk` can look at this one too, if he wants 😸)
Fixescompiler-errors/next-solver-hir-issues#10
Rollup of 7 pull requests
Successful merges:
- #106985 (Enhanced doucmentation of binary search methods for `slice` and `VecDeque` for unsorted instances)
- #109509 (compiletest: Don't allow tests with overlapping prefix names)
- #109719 (RELEASES: Add "Only support Android NDK 25 or newer" to 1.68.0)
- #109748 (Don't ICE on `DiscriminantKind` projection in new solver)
- #109749 (Canonicalize float var as float in new solver)
- #109761 (Drop binutils on powerpc-unknown-freebsd)
- #109766 (Fix title for openharmony.md)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Canonicalize float var as float in new solver
Typo in new canonicalizer -- we should be canonicalizing float vars as `CanonicalTyVarKind::Float`, not `CanonicalTyVarKind::Int`.
Fixescompiler-errors/next-solver-hir-issues#9
Don't ICE on `DiscriminantKind` projection in new solver
As title says, since we now actually call `Ty::discriminant_kind` on placeholder types 😃
Also drive-by simplify `Pointee::Metadata` projection logic, and fix the UI test because the `<T as Pointee>::Metadata` tests weren't actually exercising the new projection logic, since we still eagerly normalize (which hits `project.rs` in the old solver) in HIR typeck.
r? `@lcnr` tho feel free to re-roll, this pr is very low-priority and not super specific to the new trait solver.
Fixescompiler-errors/next-solver-hir-issues#14
compiletest: Don't allow tests with overlapping prefix names
Some tests will delete their output directory before starting. The output directory is based on the test names. If one test is the prefix of another test, then when that test starts, it could try to delete the output directory of the other test with the longer path, or otherwise clash with it while the two tests are trying to create/delete/modify the same directory.
In practice, this manifested as a random error on macOS where two tests were trying to create/delete/create `rustdoc/primitive` and `rustdoc/primitive/no_std`, which resulted in an EINVAL (InvalidInput) error.
This renames some of the offending tests, adds `compiletest-ignore-dir` to prevent compiletest from processing some files, and adds a check to prevent this from happening in the future.
Fixes#109397
Partial stabilization of `once_cell`
This PR aims to stabilize a portion of the `once_cell` feature:
- `core::cell::OnceCell`
- `std::cell::OnceCell` (re-export of the above)
- `std::sync::OnceLock`
This will leave `LazyCell` and `LazyLock` unstabilized, which have been moved to the `lazy_cell` feature flag.
Tracking issue: https://github.com/rust-lang/rust/issues/74465 (does not fully close, but it may make sense to move to a new issue)
Future steps for separate PRs:
- ~~Add `#[inline]` to many methods~~ #105651
- Update cranelift usage of the `once_cell` crate
- Update rust-analyzer usage of the `once_cell` crate
- Update error messages discussing once_cell
## To be stabilized API summary
```rust
// core::cell (in core/cell/once.rs)
pub struct OnceCell<T> { .. }
impl<T> OnceCell<T> {
pub const fn new() -> OnceCell<T>;
pub fn get(&self) -> Option<&T>;
pub fn get_mut(&mut self) -> Option<&mut T>;
pub fn set(&self, value: T) -> Result<(), T>;
pub fn get_or_init<F>(&self, f: F) -> &T where F: FnOnce() -> T;
pub fn into_inner(self) -> Option<T>;
pub fn take(&mut self) -> Option<T>;
}
impl<T: Clone> Clone for OnceCell<T>;
impl<T: Debug> Debug for OnceCell<T>
impl<T> Default for OnceCell<T>;
impl<T> From<T> for OnceCell<T>;
impl<T: PartialEq> PartialEq for OnceCell<T>;
impl<T: Eq> Eq for OnceCell<T>;
```
```rust
// std::sync (in std/sync/once_lock.rs)
impl<T> OnceLock<T> {
pub const fn new() -> OnceLock<T>;
pub fn get(&self) -> Option<&T>;
pub fn get_mut(&mut self) -> Option<&mut T>;
pub fn set(&self, value: T) -> Result<(), T>;
pub fn get_or_init<F>(&self, f: F) -> &T where F: FnOnce() -> T;
pub fn into_inner(self) -> Option<T>;
pub fn take(&mut self) -> Option<T>;
}
impl<T: Clone> Clone for OnceLock<T>;
impl<T: Debug> Debug for OnceLock<T>;
impl<T> Default for OnceLock<T>;
impl<#[may_dangle] T> Drop for OnceLock<T>;
impl<T> From<T> for OnceLock<T>;
impl<T: PartialEq> PartialEq for OnceLock<T>
impl<T: Eq> Eq for OnceLock<T>;
impl<T: RefUnwindSafe + UnwindSafe> RefUnwindSafe for OnceLock<T>;
unsafe impl<T: Send> Send for OnceLock<T>;
unsafe impl<T: Sync + Send> Sync for OnceLock<T>;
impl<T: UnwindSafe> UnwindSafe for OnceLock<T>;
```
No longer planned as part of this PR, and moved to the `rust_cell_try` feature gate:
```rust
impl<T> OnceCell<T> {
pub fn get_or_try_init<F, E>(&self, f: F) -> Result<&T, E> where F: FnOnce() -> Result<T, E>;
}
impl<T> OnceLock<T> {
pub fn get_or_try_init<F, E>(&self, f: F) -> Result<&T, E> where F: FnOnce() -> Result<T, E>;
}
```
I am new to this process so would appreciate mentorship wherever needed.
Give return-position impl traits in trait a (synthetic) name to avoid name collisions with new lowering strategy
The only needed commit from this PR is the last one.
r? `@compiler-errors`
Needs #109455.
Do not consider elaborated projection predicates for objects in new solver
Object types have projection bounds which are elaborated during astconv. There's no need to do it again for projection goals, since that'll give us duplicate projection candidatesd that are distinct up to regions due to the fact that we canonicalize every region to a separate variable. See quick example below the break for a better explanation.
Discussed this with lcnr, and adding a stop-gap until we get something like intersection region constraints (or modify canonicalization to canonicalize identical regions to the same canonical regions) -- after which, this will hopefully not matter and may be removed.
r? `@lcnr`
---
See `tests/ui/traits/new-solver/more-object-bound.rs`:
Consider a goal: `<dyn Iter<'a, ()> as Iterator>::Item = &'a ()`.
After canonicalization: `<dyn Iter<'!0r, (), Item = '!1r ()> as Iterator>::Item == &!'2r ()`
* First object candidate comes from the item bound in the dyn's bounds itself, giving us `<dyn Iter<'!0r, (), Item = '?!r ()> as Iterator>::Item == &!'1r ()`. This gives us one region constraint: `!'1r == !'2r`.
* Second object candidate comes from elaborating the principal trait ref, gives us `<dyn Iter<'!0r, (), Item = '!1r ()> as Iterator>::Item == &!'0r ()`. This gives us one region constraint: `!'0r == !'2r`.
* Oops! Ambiguity!
Support TLS access into dylibs on Windows
This allows access to `#[thread_local]` in upstream dylibs on Windows by introducing a MIR shim to return the address of the thread local. Accesses that go into an upstream dylib will call the MIR shim to get the address of it.
`convert_tls_rvalues` is introduced in `rustc_codegen_ssa` which rewrites MIR TLS accesses to dummy calls which are replaced with calls to the MIR shims when the dummy calls are lowered to backend calls.
A new `dll_tls_export` target option enables this behavior with a `false` value which is set for Windows platforms.
This fixes https://github.com/rust-lang/rust/issues/84933.
Check for overflow in `assemble_candidates_after_normalizing_self_ty`
Prevents a stack overflow (⚠️❗) in the new solver when we have param-env candidates that look like: `T: Trait<Assoc = <T as Trait>::Assoc>`
The current error message looks bad, but that's because we don't distinguish overflow and other ambiguity errors. I'll break that out into a separate PR since the fix may be controversial.
r? `@lcnr`
Use span of placeholders in format_args!() expansion.
`format_args!("{}", x)` expands to something that contains `Argument::new_display(&x)`. That entire expression was generated with the span of `x`.
After this PR, `&x` uses the span of `x`, but the `new_display` call uses the span of the `{}` placeholder within the format string. If an implicitly captured argument was used like in `format_args!("{x}")`, both use the span of the `{x}` placeholder.
This fixes https://github.com/rust-lang/rust/issues/109576, and also allows for more improvements to similar diagnostics in the future, since the usage of `x` can now be traced to the exact `{}` placeholder that required it to be `Display` (or `Debug` etc.)
Specialization involving RPITITs is broken so ignore the diagnostic differences
Just bless the corresponding test for `-Zlower-impl-trait-in-trait-to-assoc-ty`
r? `@compiler-errors`
Improve error message when writer is forgotten in write and writeln macro
Modified write! macro error message when writer is forgotten as in issue #108713Fixes#108713
r? ``@WaffleLapkin``
Rollup of 8 pull requests
Successful merges:
- #91793 (socket ancillary data implementation for FreeBSD (from 13 and above).)
- #92284 (Change advance(_back)_by to return the remainder instead of the number of processed elements)
- #102472 (stop special-casing `'static` in evaluation)
- #108480 (Use Rayon's TLV directly)
- #109321 (Erase impl regions when checking for impossible to eagerly monomorphize items)
- #109470 (Correctly substitute GAT's type used in `normalize_param_env` in `check_type_bounds`)
- #109562 (Update ar_archive_writer to 0.1.3)
- #109629 (remove obsolete `givens` from regionck)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add a builtin `FnPtr` trait that is implemented for all function pointers
r? `@ghost`
Rebased version of https://github.com/rust-lang/rust/pull/99531 (plus adjustments mentioned in the PR).
If perf is happy with this version, I would like to land it, even if the diagnostics fix in 9df8e1befb5031a5bf9d8dfe25170620642d3c59 only works for `FnPtr` specifically, and does not generally improve blanket impls.
Correctly substitute GAT's type used in `normalize_param_env` in `check_type_bounds`
Given:
```rust
trait Foo {
type Assoc<T>: PartialEq<Self::Assoc<i32>>;
}
impl Foo for () {
type Assoc<T> = Wrapper<T>;
}
struct Wrapper<T>(T);
impl<T> PartialEq<Wrapper<i32>> for Wrapper<T> { }
```
We add an additional predicate in the `normalize_param_env` in `check_type_bounds` that is used to normalize the GAT's bounds to check them in the impl. Problematically, though, that predicate is constructed to be `for<^0> <() as Foo>::Assoc<^0> => Wrapper<T>`, instead of `for<^0> <() as Foo>::Assoc<^0> => Wrapper<^0>`.
That means `Self::Assoc<i32>` in the bounds that we're checking normalizes to `Wrapper<T>`, instead of `Wrapper<i32>`, and so the bound `Self::Assoc<T>: PartialEq<Self::Assoc<i32>>` normalizes to `Wrapper<T>: PartialEq<Wrapper<T>>`, which does not hold.
Fixes this by properly substituting the RHS of that normalizes predicate that we add to the `normalize_param_env`. That means the bound is properly normalized to `Wrapper<T>: PartialEq<Wrapper<i32>>`, which *does* hold.
---
The second commit in this PR just cleans up some substs stuff and some naming.
r? `@jackh726` cc #87900
Erase impl regions when checking for impossible to eagerly monomorphize items
We were inserting `ReErased` for method substs, but not for impl substs, leading to the call for `subst_and_check_impossible_predicates` being a bit weaker than it should be (since it ignores predicates that need substitution -- incl early-bound regions).
Fixes#109297
stop special-casing `'static` in evaluation
fixes#102360
I have no idea whether this actually removed all places where `'static` matters. Without canonicalization it's very easy to accidentally rely on `'static` again. Blocked on changing the `order_dependent_trait_objects` future-compat lint to a hard error
r? `@nikomatsakis`
