do not overwrite child def-id in place but rather remove/insert
When inserting a node N into the tree of impls, we sometimes find than an existing node C should be replaced with N. We used to overwrite C in place with the new def-id N -- but since the lists of def-ids are separated by simplified type, that could lead to N being inserted in the wrong place. This meant we might miss conflicts. We are now not trying to be so smart -- we remove C and then add N later.
Fixes#52050
r? @aturon -- do you still remember this code at all? :)
Rollup of 11 pull requests
Successful merges:
- #52702 (Suggest fix when encountering different mutability from impl to trait)
- #52703 (Improve a few vectors - calculate capacity or build from iterators)
- #52740 (Suggest underscore when using dashes in crate namet push fork)
- #52759 (Impl Send & Sync for JoinHandle)
- #52760 (rustc_metadata: test loading atoi instead of cos)
- #52763 (Omit the vendor component in Fuchsia triple)
- #52765 (Remove unused "-Zenable_nonzeroing_move_hints" flag)
- #52769 (Incorporate a stray test)
- #52777 (Fix doc comment for 'ptr::copy_to' method)
- #52779 (revert accidental atty downgrade)
- #52781 (Use a slice where a vector is not necessary)
Failed merges:
r? @ghost
Incorporate a stray test
`liballoc/repeat-generic-slice.rs` doesn't seem to be tested (I think it was intended to be placed in `run-pass`). This PR incorporates the test into `liballoc/tests`.
Omit the vendor component in Fuchsia triple
Previously, using unknown as the vendor value would lead to the same
result, but with the multiarch runtimes support in Clang, the target is
now used to locate the runtime libraries and so the format is important.
The denormalized format with omitted vendor component is the format we
use with Clang and should be using for Rust as well.
rustc_metadata: test loading atoi instead of cos
Some platforms don't actually have `libm` already linked in the test
infrastructure, and then `dynamic_lib::tests::test_loading_cosine` would
fail to find the "cos" symbol. Every platform running this test should
have `libc` and "atoi" though, so try to use that symbol instead.
Fixes#45410.
Impl Send & Sync for JoinHandle
This is just a cosmetic change - it slightly relaxes and clarifies the public API without effectively promising any new guarantees.
Currently we have [these auto trait implementations](https://doc.rust-lang.org/nightly/std/thread/struct.JoinHandle.html#synthetic-implementations):
```rust
impl<T: Send> Send for JoinHandle<T> {}
impl<T: Sync> Sync for JoinHandle<T> {}
```
Bound `T: Send` doesn't make much sense because `JoinHandle<T>` can be created only when `T: Send`. Note that [`JoinHandle::<T>::join`](https://doc.rust-lang.org/nightly/std/thread/struct.JoinHandle.html#method.join) doesn't require `T: Send` so why should the `Send` impl?
And the `Sync` impl doesn't need `T: Sync` because `JoinHandle<T>` cannot even share `T` - it can only send it to the thread that calls `join`.
Improve a few vectors - calculate capacity or build from iterators
Collecting from iterators improves readability and tailoring vector capacities should be beneficial in terms of performance.
[NLL] Use better spans in some errors
* Use the span of the discriminant and patterns for "fake" statements created to properly check matches. I plan to special case these soon, but this felt like a good first step
* Use the span of the statement, rather than the initialization, when reporting move errors for `let x = ...`, which avoids giving an unhelpful suggestion to use `&{ }`.
r? @nikomatsakis cc @pnkfelix
Rollup of bare_trait_objects PRs
All deny attributes were moved into bootstrap so they can be disabled with a line of config.
Warnings for external tools are allowed and it's up to the tool's maintainer to keep it warnings free.
r? @Mark-Simulacrum
cc @ljedrz @kennytm
Bump bootstrap compiler
This PR bumps the bootstrap compiler to the latest beta, `beta-2017-07-27`. That should be the latest beta with relevant changes (the only nominated PR at the moment is a docs change).
r? @Mark-Simulacrum
[NLL] make temp for each candidate in `match` arm
In NLL, `ref mut` patterns leverage the two-phase borrow infrastructure to allow the shared borrows within a guard before the "activation" of the mutable borrow when we begin execution of the match arm's body. (There is further discussion of this on PR #50783.)
To accommodate the restrictions we impose on two-phase borrows (namely that there is a one-to-one mapping between each activation and the original initialization), this PR is making separate temps for each candidate pattern. So in an arm like this:
```rust
PatA(_, ref mut ident) |
PatB(ref mut ident) |
PatC(_, _, ref mut ident) |
PatD(ref mut ident) if guard_stuff(ident) => ...
```
instead of 3 temps (two for the guard and one for the arm body), we now have 4 + 2 temps associated with `ident`: one for each candidate plus the actual temp that the guard uses directly, and then the sixth is the temp used in the arm body.
Fix#51348
