Various refactorings of the TAIT infrastructure
Before this PR we used to store the opaque type knowledge outside the `InferCtxt`, so it got recomputed on every opaque type instantiation.
I also removed a feature gate check that makes no sense in the planned lazy TAIT resolution scheme
Each commit passes all tests, so this PR is best reviewed commit by commit.
r? `@spastorino`
typeck: don't suggest inaccessible fields in struct literals and suggest ignoring inaccessible fields in struct patterns
Fixes#87872.
This PR adjusts the missing field diagnostic logic in typeck so that when any of the missing fields in a struct literal or pattern is inaccessible then the error is less confusing, even if some of the missing fields are accessible.
See also #76524.
correctly handle enum variants in `opt_const_param_of`
Fixes#87542
`opt_const_param_of` was returning `None` for args on an enum variant `Enum::Variant::<10>` because we called `generics_of` on the enum variant which has no generics.
r? `@oli-obk`
Simplify typeck/primary_body_of, fix comment to match return signature
Hi, new contributor here! I'm carefully reading through the various modules just to learn. I noticed this function, `primary_body_of`, which has gone through a couple of refactors over time, adding new `Option`s to its returned tuple. Observations:
1. the `fn`'s documentation was not all up to date with the the current return signature.
2. `FnHeader` and `FnDecl` are always both `Some` or `None`. So I figured it might just return a reference to the full `hir::FnSig`, for simplicity and more precise typing. It's a pure refactor.
I'm learning better by working with code than just reading it, so here goes! If you want to avoid pure refactor PRs that don't really fix anything, I can revert the code change to only update the comment instead.
This allows opaque type inference to check for defining uses without having to pass down that def id via function arguments to every method that could possibly cause an opaque type to be compared with a concrete type
Previously each opaque type instantiation would create new inference vars, even for the same opaque type/substs combination. Now there is a global map in InferCtxt that gets filled whenever we encounter an opaque type.
Rollup of 9 pull requests
Successful merges:
- #87561 (thread set_name haiku implementation.)
- #87715 (Add long error explanation for E0625)
- #87727 (explicit_generic_args_with_impl_trait: fix min expected number of generics)
- #87742 (Validate FFI-safety warnings on naked functions)
- #87756 (Add back -Zno-profiler-runtime)
- #87759 (Re-use std::sealed::Sealed in os/linux/process.)
- #87760 (Promote `aarch64-apple-ios-sim` to Tier 2)
- #87770 (permit drop impls with generic constants in where clauses)
- #87780 (alloc: Use intra doc links for the reserve function)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
permit drop impls with generic constants in where clauses
Fixes#79248
`==` is not sufficient to check for equality between unevaluated consts which causes the above issue because the const in `[(); N - 1]:` on the impl and the const in `[(); N - 1]:` on the struct def are not seen as equal. Any predicate that can contain an unevaluated const cant use `==` here as it will cause us to incorrectly emit an error.
I dont know much about chalk but it seems like we ought to be relating the `TypeWellFormedFromEnv` instead of `==` as it contains a `Ty` so I added that too...
r? ``````@lcnr``````
explicit_generic_args_with_impl_trait: fix min expected number of generics
Fixes#87718
The problem was that `synth_type_param_count` was already subtracted from `named_type_param_count`, so this ended up being subtracted again. This caused `expected_min` to overflow, and ultimately resulting in weird and wrong behaviour.
I've also added another test not present in the original issue but caused by the same bug.
rustc: Fill out remaining parts of C-unwind ABI
This commit intends to fill out some of the remaining pieces of the
C-unwind ABI. This has a number of other changes with it though to move
this design space forward a bit. Notably contained within here is:
* On `panic=unwind`, the `extern "C"` ABI is now considered as "may
unwind". This fixes a longstanding soundness issue where if you
`panic!()` in an `extern "C"` function defined in Rust that's actually
UB because the LLVM representation for the function has the `nounwind`
attribute, but then you unwind.
* Whether or not a function unwinds now mainly considers the ABI of the
function instead of first checking the panic strategy. This fixes a
miscompile of `extern "C-unwind"` with `panic=abort` because that ABI
can still unwind.
* The aborting stub for non-unwinding ABIs with `panic=unwind` has been
reimplemented. Previously this was done as a small tweak during MIR
generation, but this has been moved to a separate and dedicated MIR
pass. This new pass will, for appropriate functions and function
calls, insert a `cleanup` landing pad for any function call that may
unwind within a function that is itself not allowed to unwind. Note
that this subtly changes some behavior from before where previously on
an unwind which was caught-to-abort it would run active destructors in
the function, and now it simply immediately aborts the process.
* The `#[unwind]` attribute has been removed and all users in tests and
such are now using `C-unwind` and `#![feature(c_unwind)]`.
I think this is largely the last piece of the RFC to implement.
Unfortunately I believe this is still not stabilizable as-is because
activating the feature gate changes the behavior of the existing `extern
"C"` ABI in a way that has no replacement. My thinking for how to enable
this is that we add support for the `C-unwind` ABI on stable Rust first,
and then after it hits stable we change the behavior of the `C` ABI.
That way anyone straddling stable/beta/nightly can switch to `C-unwind`
safely.
This commit intends to fill out some of the remaining pieces of the
C-unwind ABI. This has a number of other changes with it though to move
this design space forward a bit. Notably contained within here is:
* On `panic=unwind`, the `extern "C"` ABI is now considered as "may
unwind". This fixes a longstanding soundness issue where if you
`panic!()` in an `extern "C"` function defined in Rust that's actually
UB because the LLVM representation for the function has the `nounwind`
attribute, but then you unwind.
* Whether or not a function unwinds now mainly considers the ABI of the
function instead of first checking the panic strategy. This fixes a
miscompile of `extern "C-unwind"` with `panic=abort` because that ABI
can still unwind.
* The aborting stub for non-unwinding ABIs with `panic=unwind` has been
reimplemented. Previously this was done as a small tweak during MIR
generation, but this has been moved to a separate and dedicated MIR
pass. This new pass will, for appropriate functions and function
calls, insert a `cleanup` landing pad for any function call that may
unwind within a function that is itself not allowed to unwind. Note
that this subtly changes some behavior from before where previously on
an unwind which was caught-to-abort it would run active destructors in
the function, and now it simply immediately aborts the process.
* The `#[unwind]` attribute has been removed and all users in tests and
such are now using `C-unwind` and `#![feature(c_unwind)]`.
I think this is largely the last piece of the RFC to implement.
Unfortunately I believe this is still not stabilizable as-is because
activating the feature gate changes the behavior of the existing `extern
"C"` ABI in a way that has no replacement. My thinking for how to enable
this is that we add support for the `C-unwind` ABI on stable Rust first,
and then after it hits stable we change the behavior of the `C` ABI.
That way anyone straddling stable/beta/nightly can switch to `C-unwind`
safely.
Rollup of 8 pull requests
Successful merges:
- #87645 (Properly find owner of closure in THIR unsafeck)
- #87646 (Fix a parser ICE on invalid `fn` body)
- #87652 (Validate that naked functions are never inlined)
- #87685 (Write docs for SyncOnceCell From and Default impl)
- #87693 (Add `aarch64-apple-ios-sim` as a possible target to the manifest)
- #87708 (Add convenience method for handling ipv4-mapped addresses by canonicalizing them)
- #87711 (Correct typo)
- #87716 (Allow generic SIMD array element type)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Implement a `explicit_generic_args_with_impl_trait` feature gate
Implements #83701
When this gate is enabled, explicit generic arguments can be specified even if `impl Trait` is used in argument position. Generic arguments can only be specified for explicit generic parameters but not for the synthetic type parameters from `impl Trait`
So code like this will be accepted:
```rust
#![feature(explicit_generic_args_with_impl_trait)]
fn foo<T: ?Sized>(_f: impl AsRef<T>) {}
fn main() {
foo::<str>("".to_string());
}
```
rfc3052 followup: Remove authors field from Cargo manifests
Since RFC 3052 soft deprecated the authors field, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information for contributors, we may as well
remove it from crates in this repo.
When this gate is enabled, explicit generic arguments can be specified even
if `impl Trait` is used in argument position. Generic arguments can only be
specified for explicit generic parameters but not for the synthetic type
parameters from `impl Trait`
Trait upcasting coercion (part1)
This revives the first part of earlier PR #60900 .
It's not very clear to me which parts of that pr was design decisions, so i decide to cut it into pieces and land them incrementally. This allows more eyes on the details.
This is the first part, it adds feature gates, adds feature gates tests, and implemented the unsize conversion part.
(I hope i have dealt with the `ExistentialTraitRef` values correctly...)
The next part will be implementing the pointer casting.
Rollup of 9 pull requests
Successful merges:
- #86072 (Cross compiling rustc_llvm on Darwin requires zlib.)
- #87385 (Make `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` warn by default)
- #87547 (Add missing examples for NonNull)
- #87557 (Fix issue with autofix for ambiguous associated function from Rust 2021 prelude when struct is generic)
- #87559 (Tweak borrowing suggestion in `for` loop)
- #87596 (Add warning when whitespace is not skipped after an escaped newline)
- #87606 (Add some TAIT-related regression tests)
- #87609 (Add docs about performance and `Iterator::map` to `[T; N]::map`)
- #87616 (Fix missing word in rustdoc book)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix issue with autofix for ambiguous associated function from Rust 2021 prelude when struct is generic
Fixes#86940
The test cases and associated issue should make it clear what specifically this is meant to fix. The fix is slightly hacky in that we check against the literal source code of the call site for the presence of `<` in order to determine if the user has included the generics for the struct (meaning we don't need to include them for them).
r? ``@nikomatsakis``
Use more precise span for E0282 in cast expressions
This pull request fixes#85586. The example code given there:
```rust
fn main() {
let a = [1, 2, 3].iter().sum();
let b = (a + 1) as usize;
}
```
currently produces
```
error[E0282]: type annotations needed
--> issue-85586.rs:3:13
|
3 | let b = (a + 1) as usize;
| ^^^^^^^^^^^^^^^^ cannot infer type
|
= note: type must be known at this point
error: aborting due to previous error
```
even though the type of the entire cast expression quite clearly should be `usize`. The error is in the cast's left-hand side, which is made explicit by the changes in this PR:
```
error[E0282]: type annotations needed
--> issue-85586.rs:3:13
|
3 | let b = (a + 1) as usize;
| ^^^^^^^ cannot infer type
|
= note: type must be known at this point
error: aborting due to previous error
```
2229: Discr should be read when PatKind is Range
This PR fixes an issue related to pattern matching in closures when Edition 2021 is enabled.
- If any of the patterns the discr is being matched on is `PatKind::Range` then the discr should be read
r? ```@nikomatsakis```
Closes https://github.com/rust-lang/rust/issues/87426
Since RFC 3052 soft deprecated the authors field anyway, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information, we should remove it from
crates in this repo.
