Give preference to projections from where-clauses over those from trait definitions. This makes #28871 work again, though I think there's more to fix in this general area.
r? @arielb1
cc @brson (fixes regression)
Fixes#29184
This adds an error message for the use of the reserved `typeof` keyword, instead of reporting an ICE.
Also adds a `compile-fail` test.
I chose to add a `span_err` instead of removing to parser code, as to preserve the reservation of `typeof`.
trait definitions, and give prefence to the former. This is consistent
with what we do for selection. It also works around a limitation
that was leading to #28871.
This is a WIP PR for my implementation of drain over the VecDeque data structure supporting ranges. It brings the VecDeque drain implementation in line with Vec's.
Tests haven't been written for the new function yet.
Remove leading newlines; replace lines containing only whitespace with empty lines; replace multiple trailing newlines with a single newline; remove trailing whitespace in lines
This PR turns statically known erroneous code (e.g. numeric overflow) into a warning and continues normal code-generation to emit the same code that would have been generated without `check_const` detecting that the result can be computed at compile-time.
<del>It's not done yet, as I don't know how to properly emit a lint from trans. I can't seem to extract the real lint level of the item the erroneous expression is in.</del> It's an unconditional warning now.
r? @pnkfelix
cc @nikomatsakis
* [RFC 1229 text](https://github.com/rust-lang/rfcs/blob/master/text/1229-compile-time-asserts.md)
* RFC PR: rust-lang/rfcs#1229
* tracking issue: https://github.com/rust-lang/rust/issues/28238
This change has two consequences:
1. It makes `Arc<T>` and `Rc<T>` covariant in `T`.
2. It causes the compiler to reject code that was unsound with respect
to dropck. See compile-fail/issue-29106.rs for an example of code that
no longer compiles. Because of this, this is a [breaking-change].
Fixes#29037.
Fixes#29106.
Stricter checking of stability attributes + enforcement of their invariants at compile time
(+ removed dead file librustc_front/attr.rs)
I intended to enforce use of `reason` for unstable items as well (it normally presents for new items), but it turned out too intrusive, many older unstable items don't have `reason`s.
r? @aturon
I'm studying how stability works and do some refactoring along the way, so it's probably not the last PR.
Fixes#28676.
There doesn't seem to be a good way to add a test for this, but I tested the repro in #28676 and confirmed it now yields the correct result.
This is needed as item types are allowed to be unnormalized.
Fixes an ICE that occurs when foreign function signatures contained
an associated type.
Fixes#28983
This rather crucial requirement was not checked. In most cases, that
didn't cause any trouble because the argument types are required to
outlive the call and are subtypes of a subformula of the callee type.
However, binary ops are taken by ref only indirectly, without it being
marked in the argument types, which led to the argument types not being
constrained anywhere causing spurious errors (as these are basically
unconstrainable, I don't think this change can break code). Of course,
the old way was also incorrent with contravariance, but that is still
unsound for other reasons.
This also improves rustc::front to get RUST_LOG to *somewhat* work.
Fixes#28999. That issue is one of the several regression introduced by #28669.
r? @pnkfelix
