Rollup of 7 pull requests
Successful merges:
- #109395 (Fix issue when there are multiple candidates for edit_distance_with_substrings)
- #109755 (Implement support for `GeneratorWitnessMIR` in new solver)
- #109782 (Don't leave a comma at the start of argument list when removing arguments)
- #109977 (rustdoc: avoid including line numbers in Google SERP snippets)
- #109980 (Derive String's PartialEq implementation)
- #109984 (Remove f32 & f64 from MemDecoder/MemEncoder)
- #110004 (add `dont_check_failure_status` option in the compiler test)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove f32 & f64 from MemDecoder/MemEncoder
r? ```@Nilstrieb```
since they said (maybe joked) on discord that it's a bug if the compiler uses f32 anywhere 🙃
Check pattern refutability on THIR
The current `check_match` query is based on HIR, but partially re-lowers HIR into THIR.
This PR proposed to use the results of the `thir_body` query to check matches, instead of re-building THIR.
Most of the diagnostic changes are spans getting shorter, or commas/semicolons not getting removed.
This PR degrades the diagnostic for confusing constants in patterns (`let A = foo()` where `A` resolves to a `const A` somewhere): it does not point ot the definition of `const A` any more.
Tweak debug outputs to make debugging new solver easier
1. Move the fields that are "most important" (I know this is subjective) to the beginning of the structs.
For goals, I typically care more about the predicate than the param-env (which is significantly longer in debug output).
For canonicalized things, I typically care more about what is *being* canonicalized.
For a canonical response, I typically care about the response -- or at least, it's typically useful to put it first since it's short and affects the whether the solver recurses or not...
2. Add some more debug and instrument calls to functions to add more structure to tracing lines.
r? `@oli-obk` or `@BoxyUwU` (since I think `@lcnr` is on holiday)
Avoid a few locks
We can use atomics or datastructures tuned for specific access patterns instead of locks. This may be an improvement for parallel rustc, but it's mostly a cleanup making various datastructures only usable in the way they are used right now (append data, never mutate), instead of having a general purpose lock.
Move a const-prop-lint specific hack from mir interpret to const-prop-lint and make it fallible
fixes#109743
This hack didn't need to live in the mir interpreter. For const-prop-lint it is entirely correct to avoid doing any const prop if normalization fails at this stage. Most likely we couldn't const propagate anything anyway, and if revealing was needed (so opaque types were involved), we wouldn't want to be too smart and leak the hidden type anyway.
Use `&IndexSlice` instead of `&IndexVec` where possible
All the same reasons as for `[T]`: more general, less pointer chasing, and `&mut IndexSlice` emphasizes that it doesn't change *length*.
r? `@ghost`
Insert alignment checks for pointer dereferences when debug assertions are enabled
Closes https://github.com/rust-lang/rust/issues/54915
- [x] Jake tells me this sounds like a place to use `MirPatch`, but I can't figure out how to insert a new basic block with a new terminator in the middle of an existing basic block, using `MirPatch`. (if nobody else backs up this point I'm checking this as "not actually a good idea" because the code looks pretty clean to me after rearranging it a bit)
- [x] Using `CastKind::PointerExposeAddress` is definitely wrong, we don't want to expose. Calling a function to get the pointer address seems quite excessive. ~I'll see if I can add a new `CastKind`.~ `CastKind::Transmute` to the rescue!
- [x] Implement a more helpful panic message like slice bounds checking.
r? `@oli-obk`
Update `ty::VariantDef` to use `IndexVec<FieldIdx, FieldDef>`
And while doing the updates for that, also uses `FieldIdx` in `ProjectionKind::Field` and `TypeckResults::field_indices`.
There's more places that could use it (like `rustc_const_eval` and `LayoutS`), but I tried to keep this PR from exploding to *even more* places.
Part 2/? of https://github.com/rust-lang/compiler-team/issues/606
numeric vars can only be unified with numerical types in deep reject
Don't consider numeric vars (int and float vars) to unify with non-numeric types during deep reject. This helps us reject incompatible impls sooner.
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
And while doing the updates for that, also uses `FieldIdx` in `ProjectionKind::Field` and `TypeckResults::field_indices`.
There's more places that could use it (like `rustc_const_eval` and `LayoutS`), but I tried to keep this PR from exploding to *even more* places.
Part 2/? of https://github.com/rust-lang/compiler-team/issues/606
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.
Move `mir::Field` → `abi::FieldIdx`
The first PR for https://github.com/rust-lang/compiler-team/issues/606
This is just the move-and-rename, because it's plenty big already. Future PRs will start using `FieldIdx` more broadly, and concomitantly removing `FieldIdx::new`s.
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.
Make init mask lazy for fully initialized/uninitialized const allocations
There are a few optimization opportunities in the `InitMask` and related const `Allocation`s (e.g. by taking advantage of the fact that it's a bitset that represents initialization, which is often entirely initialized or uninitialized in a single call, or gradually built up, etc).
There's a few overwrites to the same state, multiple writes in a row to the same indices, the RLE scheme for `memcpy` doesn't always compress, etc.
Here, we start with:
- avoiding materializing the bitset's blocks if the allocation is fully initialized/uninitialized
- dealloc blocks when fully overwriting, including when participating in `memcpy`s
- take care of the fixme about allocating blocks of 0s before overwriting them to the expected value
- expanding unit test coverage of the init mask
This should be most visible on benchmarks and crates where const allocations dominate the runtime (like `ctfe-stress-5` of course), but I was especially looking at the worst cases from #93215.
This first change allows the majority of `set_range` calls to stay with a lazy init mask when bootstrapping rustc (not that the init mask is a big part of the process in cpu time or memory usage).
r? `@oli-obk`
I have another in-progress branch where I'll switch the singular initialized/uninitialized value to a watermark, recording the point after which everything is uninitialized. That will take care of cases where full initialization is monotonic and done in multiple steps (e.g. an array of a type without padding), which should then allow the vast majority of const allocations' init masks to stay lazy during bootstrapping (though interestingly I've seen such gradual initialization in both left-to-right and right-to-left directions, and I don't think a single watermark can handle both).
The first PR for https://github.com/rust-lang/compiler-team/issues/606
This is just the move-and-rename, because it's plenty big-and-bitrotty already. Future PRs will start using `FieldIdx` more broadly, and concomitantly removing `FieldIdx::new`s.
