BTreeMap: expose new_internal function and sanitize from_new_internal
`new_internal` is the functional core of the imperative `push_internal_level`, and `from_new_internal` can easily do a proper job instead of returning a half-baked node.
r? `@Mark-Simulacrum`
Add `as_rchunks` (and friends) to slices
`@est31` mentioned (https://github.com/rust-lang/rust/issues/76354#issuecomment-717027175) that, for completeness, there needed to be an `as_chunks`-like method that chunks from the end (with the remainder at the beginning) like `rchunks` does.
So here's a PR for `as_rchunks: &[T] -> (&[T], &[[T; N]])` and `as_rchunks_mut: &mut [T] -> (&mut [T], &mut [[T; N]])`.
But as I was doing this and copy-pasting `from_raw_parts` calls, I thought that I should extract that into an unsafe method. It started out a private helper, but it seemed like `as_chunks_unchecked` could be reasonable as a "real" method, so I added docs and made it public. Let me know if you think it doesn't pull its weight.
Move some tests to more reasonable directories - 2
All tests with a score equal or greater than 1.0 were moved to their respective directories by issuing
```bash
cat FILE | tr -s " " | tr -d '():' | sort -k3 | awk '$3 >= 1' | cut -d " " -f1-2 | sed 's;\\;/;g' | xargs -n2 git mv
```
**Observation**: The first column values is the only column with results greater zero
To attest the confidentiality of the model, some manual revision of at least of tests is needed and this process will be tracked in the following list:
* `src/test/ui/abi/issue-28676.rs` OK #28676
* `src/test/ui/array-slice-vec/issue-15730.rs` OK
* `src/test/ui/associated-types/issue-24338.rs` OK #54823
* `src/test/ui/associated-types/issue-48551.rs` Looks OK #48551
* `src/test/ui/associated-types/issue-50301.rs` Looks OK #63577
...
cc #73494
r? `@petrochenkov`
Currently they are declared as `mut`, get initialized to a default value, and
then possibly overwritten.
By initializing to the final value directly, they don't need to be `mut` and
it's clear that they don't get mutated elsewhere later on.
This fixed things the last time I had a problem like this. And plausibly will here too -- the check it's failing on is for the high bit being set in the length of the slice, which is a check that's only in a debug_assert.
Rollup of 17 pull requests
Successful merges:
- #78455 (Introduce {Ref, RefMut}::try_map for optional projections in RefCell)
- #80144 (Remove giant badge in README)
- #80614 (Explain why borrows can't be held across yield point in async blocks)
- #80670 (TrustedRandomAaccess specialization composes incorrectly for nested iter::Zips)
- #80681 (Clarify what the effects of a 'logic error' are)
- #80764 (Re-stabilize Weak::as_ptr and friends for unsized T)
- #80901 (Make `x.py --color always` apply to logging too)
- #80902 (Add a regression test for #76281)
- #80941 (Do not suggest invalid code in pattern with loop)
- #80968 (Stabilize the poll_map feature)
- #80971 (Put all feature gate tests under `feature-gates/`)
- #81021 (Remove doctree::Import)
- #81040 (doctest: Reset errors before dropping the parse session)
- #81060 (Add a regression test for #50041)
- #81065 (codegen_cranelift: Fix redundant semicolon warn)
- #81069 (Add sample code for Rc::new_cyclic)
- #81081 (Add test for #34792)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
This copies the unknown_lints code clippy uses for its
unknown_clippy_lints lint to rustc. The unknown_clippy_lints code is
more advanced, because it doesn't suggest renamed or removed lints and
correctly suggest lower casing lints.
doctest: Reset errors before dropping the parse session
The first parse is to collect whether the code contains macros, has
`main`, and uses other crates. In that pass we ignore errors as those
will be reported when the test file is actually built.
For that we need to reset errors in the `Diagnostic` otherwise when
dropping it unhandled errors will be reported as compiler bugs.
Fixes#80992
Put all feature gate tests under `feature-gates/`
There was one directory that had only a single test and there was also a
test in the top-level directory. This moves both of them to
`feature-gates/`.
Add a regression test for #76281
This has been fixed between 1.47.0-nightly (663d2f5cd 2020-08-22) and 1.47.0-nightly (5180f3da5 2020-08-23). Maybe fixed by #73526?
Created `wasm` dir, it currently has only one test but I'll move some wasm-related tests there as a follow-up.
Closes#76281
Re-stabilize Weak::as_ptr and friends for unsized T
As per [T-lang consensus](https://hackmd.io/7r3_is6uTz-163fsOV8Vfg), this uses a branch to handle the dangling case. The discussed optimization of only doing the branch in the T: ?Sized case is left for a followup patch, as doing so is not trivial (as it requires specialization) and not _obviously_ better (as it requires using `wrapping_offset` rather than `offset` more).
<details><summary>Basically said optimization</summary>
Specialize on `T: Sized`:
```rust
fn as_ptr(&self) -> *const T {
if [ T is Sized ] || !is_dangling(ptr) {
(ptr as *mut T).set_ptr_value( (ptr as *mut u8).wrapping_offset(data_offset) )
} else {
ptr::null()
}
}
fn from_raw(*const T) -> Self {
if [ T is Sized ] || !ptr.is_null() {
let ptr = (ptr as *mut RcBox).set_ptr_value( (ptr as *mut u8).wrapping_offset(-data_offset) );
Weak { ptr }
} else {
Weak::new()
}
}
```
(but with more `set_ptr_value` to avoid `Sized` restrictions and maintain metadata.)
Written in this fashion, this is not a correctness-critical specialization (i.e. so long as `[ T is Sized ]` is false for unsized `T`, it can be `rand()` for sized `T` without breaking correctness), but it's still touchy, so I'd rather do it in another PR with separate review.
---
</details>
This effectively reverts #80422 and re-establishes #74160. T-libs [previously signed off](https://github.com/rust-lang/rust/pull/74160#issuecomment-660539373) on this stable API change in #74160.
Clarify what the effects of a 'logic error' are
This clarifies what a 'logic error' is (which is a term used to describe what happens if you put things in a hash table or btree and then use something like a refcell to break the internal ordering). This tries to be as vague as possible, as we don't really want to promise what happens, except "bad things, but not UB". This was discussed in #80657
TrustedRandomAaccess specialization composes incorrectly for nested iter::Zips
I found this while working on improvements for TRA.
After partially consuming a Zip adapter and then wrapping it into another Zip where the adapters use their `TrustedRandomAccess` specializations leads to the outer adapter returning elements which should have already been consumed.
If the optimizer gets tripped up by the addition this might affect performance for chained `zip()` iterators even when the inner one is not partially advanced but it would require more extensive fixes to `TrustedRandomAccess` to communicate those offsets earlier.
Included test fails on nightly, [playground link](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=24fa1edf8a104ff31f5a24830593b01f)
