const_eval: allow function pointer signatures containing &mut T in const contexts
potentially fixes#114994
We utilize a `TypeVisitor` here in order to more easily handle control flow.
- In the event the typekind the Visitor sees is a function pointer, we skip over it
- However, otherwise we do one of two things:
- If we find a mutable reference, check it, then continue visiting types
- If we find any other type, continue visiting types
This means we will check if the function pointer _itself_ is mutable, but not if any of the types _within_ are.
const-eval: make misalignment a hard error
It's been a future-incompat error (showing up in cargo's reports) since https://github.com/rust-lang/rust/pull/104616, Rust 1.68, released in March. That should be long enough.
The question for the lang team is simply -- should we move ahead with this, making const-eval alignment failures a hard error? (It turns out some of them accidentally already were hard errors since #104616. But not all so this is still a breaking change. Crater found no regression.)
improve the suggestion of `generic_bound_failure`
- Fixes#115375
- suggest the bound in the correct scope: trait or impl header vs assoc item. See `tests/ui/suggestions/lifetimes/type-param-bound-scope.rs`
- don't suggest a lifetime name that conflicts with the other late-bound regions of the function:
```rust
type Inv<'a> = *mut &'a ();
fn check_bound<'a, T: 'a>(_: T, _: Inv<'a>) {}
fn test<'a, T>(_: &'a str, t: T, lt: Inv<'_>) { // suggests a new name `'a`
check_bound(t, lt); //~ ERROR
}
```
Add a note to duplicate diagnostics
Helps explain why there may be a difference between manual testing and the test suite output and highlights them as something to potentially look into
For existing duplicate diagnostics I just blessed them other than a few files that had other `NOTE` annotations in
Correctly deny late-bound lifetimes from parent in anon consts and TAITs
Reuse the `AnonConstBoundary` scope (introduced in #108553, renamed in this PR to `LateBoundary`) to deny late-bound vars of *all* kinds (ty/const/lifetime) in anon consts and TAITs.
Side-note, but I would like to consolidate this with the error reporting for RPITs (E0657):
c4f25777a0/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs (L733-L754) but the semantics about what we're allowed to capture there are slightly different, so I'm leaving that untouched.
Fixes#115474
Don't require `Drop` for `[PhantomData<T>; N]` where `N` and `T` are generic, if `T` requires `Drop`
fixes https://github.com/rust-lang/rust/issues/115403
fixes https://github.com/rust-lang/rust/issues/115410
This was accidentally regressed in https://github.com/rust-lang/rust/pull/114134, because it was accidentally stabilized in #102204 (cc `@rust-lang/lang,` seems like an innocent stabilization, considering this PR is more of a bugfix than a feature).
While we have a whole month to beta backport this change before the regression hits stable, I'd still prefer not to go through an FCP on this PR (which fixes a regression), if T-lang wants an FCP, I can can open an issue about the change itself.
remove some unnecessary ignore-debug clauses
ignore-debug is only needed when the debug assertions *in the standard library* somehow affect the test. This can happen with inlining but otherwise should be rare. ignore-debug is problematic since PR CI is only run with debug assertions.
r? `@cjgillot` since it looks like you added most of these
As of commit 7767cbb3b0,
the tests/ui/consts/const-eval/ub-int-array.rs test is
failing on big-endian platforms (in particular s390x),
as the stderr output contains a hex dump that depends
on endianness.
Since this point intentionally verifies the hex dump to
check the uninitialized byte markers, I think we should
not simply standardize away the hex dump as is done with
some of the other tests in this directory.
However, most of the test is already endian-independent.
The only exception is one line of hex dump, which can
also be made endian-independent by choosing appropriate
constants in the source code.
Since the 32bit and 64bit stderr outputs were already
(and remain) identical, I've merged them and removed
the stderr-per-bitwidth marker.
Fixes (again) https://github.com/rust-lang/rust/issues/105383.
Warn on elided lifetimes in associated constants (`ELIDED_LIFETIMES_IN_ASSOCIATED_CONSTANT`)
Elided lifetimes in associated constants (in impls) erroneously resolve to fresh lifetime parameters on the impl since #97313. This is not correct behavior (see #38831).
I originally opened #114716 to fix this, but given the time that has passed, the crater results seem pretty bad: https://github.com/rust-lang/rust/pull/114716#issuecomment-1682091952
This PR alternatively implements a lint against this behavior, and I'm hoping to bump this to deny in a few versions.
Improve spans for indexing expressions
fixes#114388
Indexing is similar to method calls in having an arbitrary left-hand-side and then something on the right, which is the main part of the expression. Method calls already have a span for that right part, but indexing does not. This means that long method chains that use indexing have really bad spans, especially when the indexing panics and that span in coverted into a panic location.
This does the same thing as method calls for the AST and HIR, storing an extra span which is then put into the `fn_span` field in THIR.
r? compiler-errors
