Reexport tests without polluting namespaces
This should fix issue #52557.
Basically now we gensym a new name for the test function and reexport that.
That way the test function's reexport name can't conflict because it was impossible for the test author to write it down.
We then use a `use` statement to expose the original name using the original visibility.
slices: fix ZST slice iterators making up pointers; debug_assert alignment in from_raw_parts
This fixes the problem that we are fabricating pointers out of thin air. I also managed to share more code between the mutable and shared iterators, while reducing the amount of macros.
I am not sure how useful it really is to add a `debug_assert!` in libcore. Everybody gets a release version of that anyway, right? Is there at least a CI job that runs the test suite with a debug version?
Fixes#42789
Rollup of 15 pull requests
Successful merges:
- #52793 (Add test for NLL: unexpected "free region `` does not outlive" error )
- #52799 (Use BitVector for global sets of AttrId)
- #52809 (Add test for unexpected region for local data ReStatic)
- #52834 ([NLL] Allow conflicting borrows of promoted length zero arrays)
- #52835 (Fix Alias intra doc ICE)
- #52854 (fix memrchr in miri)
- #52899 (tests/ui: Add missing mips{64} ignores)
- #52908 (Use SetLenOnDrop in Vec::truncate())
- #52915 (Don't count MIR locals as borrowed after StorageDead when finding locals live across a yield terminator)
- #52926 (rustc: Trim down the `rust_2018_idioms` lint group)
- #52930 (rustc_resolve: record single-segment extern crate import resolutions.)
- #52939 (Make io::Read::read_to_end consider io::Take::limit)
- #52942 (Another SmallVec.extend optimization)
- #52947 (1.27 actually added the `armv5te-unknown-linux-musleabi` target)
- #52954 (async can begin expressions)
Failed merges:
r? @ghost
1.27 actually added the `armv5te-unknown-linux-musleabi` target
The PR title says `armv5te-unknown-linux-musl`, but it looks like the final code merge renamed the target to `armv5te-unknown-linux-musleabi`. `rustup` reports this as correct as well.
The [Rust Platform Support](https://forge.rust-lang.org/platform-support.html) page needs this added as well, but I'm not certain what codebase that is generated from.
Make io::Read::read_to_end consider io::Take::limit
Add a custom implementation of `io::Read::read_to_end` for `io::Take` that doesn't reserve the default 32 bytes but rather `Take::limit` if `Take::limit < 32`.
It's a conservative adjustment that preserves the default behavior for `Take::limit >= 32`.
Fixes#51746.
rustc_resolve: record single-segment extern crate import resolutions.
Fixes#52489 by recording special-cased single-segment imports for later (e.g. stability) checks.
cc @alexcrichton @Mark-Simulacrum @petrochenkov
Does this need to be backported?
rustc: Trim down the `rust_2018_idioms` lint group
These migration lints aren't all up to par in terms of a good migration
experience. Some, like `unreachable_pub`, hit bugs like #52665 and unprepared
macros to be handled enough of the time. Others like linting against
`#[macro_use]` are swimming upstream in an ecosystem that's not quite ready (and
slightly buggy pending a few current PRs).
The general idea is that we will continue to recommend the `rust_2018_idioms`
lint group as part of the transition guide (as an optional step) but we'll be
much more selective about which lints make it into this group. Only those with a
strong track record of not causing too much churn will make the cut.
cc #52679
fix memrchr in miri
The previous PR https://github.com/rust-lang/rust/pull/52744 was not enough because it assumed that the split between the `mid` and `end` parts returned by `align_to` was aligned. But really the only guarantee we have is that the `mid` part is aligned, so make use of that.
[NLL] Allow conflicting borrows of promoted length zero arrays
This is currently overkill as there's no way to create two conflicting borrows of any promoted.
It is possible that the following code might not fail due to const eval in the future (@oli-obk?). In which case either the array marked needs to not be promoted, or to be checked for conflicts
```rust
static mut A: () = {
let mut y = None;
let z;
let mut done_y = false;
loop {
let x = &mut [1]; // < this array
if done_y {
z = x;
break;
}
y = Some(x);
done_y = true;
}
some_const_fn(y, z); // some_const_fn expects that y to not alias z.
};
```
r? @pnkfelix @nikomatsakis
closes#52671
cc #51823
The PR title says `armv5te-unknown-linux-musl`, but it looks like the final code merge renamed the target to `armv5te-unknown-linux-musleabi`. `rustup` reports this as correct as well.
The [Rust Platform Support](https://forge.rust-lang.org/platform-support.html) page needs this added as well, but I'm not certain what codebase that is generated from.
These migration lints aren't all up to par in terms of a good migration
experience. Some, like `unreachable_pub`, hit bugs like #52665 and unprepared
macros to be handled enough of the time. Others like linting against
`#[macro_use]` are swimming upstream in an ecosystem that's not quite ready (and
slightly buggy pending a few current PRs).
The general idea is that we will continue to recommend the `rust_2018_idioms`
lint group as part of the transition guide (as an optional step) but we'll be
much more selective about which lints make it into this group. Only those with a
strong track record of not causing too much churn will make the cut.
cc #52679
