Instantiate higher-ranked transmute goal w/ placeholders before emitting sub-obligations
This avoids an ICE where we weren't keeping track of bound variables correctly in the `Freeze` obligations we emit for transmute goals. We could use `rebind` instead on that goal, but I think it's better just to instantiate the binder.
Fixes#139538
r? `@lcnr` or reassign
Improve presentation of closure signature mismatch from `Fn` trait goal
Flip the order of "expected" and "found" since that wasn't correct.
Don't present the arguments as a tuple, since it leaves a trailing comma. Instead, just use `fn(arg, arg)`.
Finally, be better with binders since we were just skipping binders.
r? oli-obk or reassign
Invert the order that we pass the arguments to the
`contract_check_ensures` function to avoid the warning when the tail
of the function is unreachable.
Note that the call itself is also unreachable, but we have already
handled that case by ignoring unreachable call for contract calls.
Fix stack overflow in exhaustiveness due to recursive HIR opaque hidden types
This fixes several spicy non-trivial recursive opaque definitions inferred from HIR typeck, ensuring that they don't cause stack overflows in exhaustiveness code, which currently reveals opaques manually in a way that is not overflow aware (as opposed to something like the normalizer folders).
These should eventually be outright rejected, but today (some) non-trivial recursive opaque definitions are accepted, and changing that requires an FCP, so for now just make sure we don't stack overflow :^)
Fixes https://github.com/rust-lang/rust/issues/139402
r? lcnr
borrowck typeck children together with their root
This introduces new cycle errors, even with `feature(inline_const_pat)` removed, see the `non-structural-match-types-cycle-err.rs` test.
The new cycle error happens as the layout of `async`-blocks relies on their `optimized_mir`. As that now depends on `mir_borrowck` of its typeck parent, computing the layout of an `async`-block during MIR building, e.g. when evaluating a named `const` pattern. I think there's currently no way to have a named const pattern whose type references an async block while being allowed? cc `@oli-obk` `@RalfJung`
I cannot think of other cases where we currently rely on the MIR of a typeck children while borrowchecking their parent. The crater run came back without any breakage. My work here will prevent any future features which rely on this as we'll get locked into borrowchecking them together as I continue to work on https://github.com/rust-lang/types-team/issues/129, cc `@rust-lang/types.`
r? compiler-errors
Fix trait upcasting to dyn type with no principal when there are projections
#126660 (which I had originally authored, lol) had a subtle bug that is the moral equivalent of #114036, which is that when upcasting from `dyn Principal<Projection = Ty> + AutoTrait` to `dyn AutoTrait`, we were dropping the trait ref for `Principal` but not its projections (if there were any).
With debug assertions enabled, this triggers the assertion I luckily added in a2a0cfe825, but even without debug assertions this is a logical bug since we had a dyn type with just a projection bound but no principal, so it caused a type mismatch.
This does not need an FCP because this should've been covered by the FCP in #126660, but we just weren't testing a case when casting from a `dyn` type with projections 😸Fixes#139418
r? ````@oli-obk```` (or anyone)
compiler: report error when trait object type param reference self
Fixes#139082.
Emits an error when `Self` is found in the projection bounds of a trait
object. In type aliases, `Self` has no meaning, so `type A = &'static
dyn B` where `trait B = Fn() -> Self` will expands to `type A = &'static
Fn() -> Self` which is illegal, causing the region solver to bail out
when hitting the uninferred Self.
r? ````@compiler-errors```` ````@fee1-dead````
Tell LLVM about impossible niche tags
I was trying to find a better way of emitting discriminant calculations, but sadly had no luck.
So here's a fairly small PR with the bits that did seem worth bothering:
1. As the [`TagEncoding::Niche` docs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_abi/enum.TagEncoding.html#variant.Niche) describe, it's possible to end up with a dead value in the input that's not already communicated via the range parameter attribute nor the range load metadata attribute. So this adds an `llvm.assume` in non-debug mode to tell LLVM about that. (That way it can tell that the sides of the `select` have disjoint possible values.)
2. I'd written a bunch more tests, or at least made them parameterized, in the process of trying things out, so this checks in those tests to hopefully help future people not trip on the same weird edge cases, like when the tag type is `i8` but yet there's still a variant index and discriminant of `258` which doesn't fit in that tag type because the enum is really weird.
Make error message for missing fields with `..` and without `..` more consistent
When `..` is not present, we say "missing field `bar` in initializer", but when it is present we say "missing mandatory field `bar`". I don't see why the primary error message should change, b/c the root cause is the same.
Let's harmonize these error messages and instead use a label to explain that `..` is required b/c it's not defaulted.
r? estebank
Fixes#139445.
The additional errors aren't great but the first one is still good and
it's the most important, and imperfect errors are better than ICEing.
This can happen when invalid syntax is passed to a declarative macro. We
shouldn't be too strict about the token stream position once the parser
has rejected the invalid syntax.
Fixes#139248.
Do not visit whole crate to compute `lints_that_dont_need_to_run`.
This allows to reuse the computed lint levels instead of re-visiting the whole crate.
Use `const_eval_select!()` macro to enable contract checking only at
runtime. The existing contract logic relies on closures,
which are not supported in constant functions.
This commit also removes one level of indirection for ensures clauses,
however, it currently has a spurious warning message when the bottom
of the function is unreachable.
