Make `ThinBox<T>` covariant in `T`
Just like `Box<T>`, we want `ThinBox<T>` to be covariant in `T`, but the
projection in `WithHeader<<T as Pointee>::Metadata>` was making it
invariant. This is now hidden as `WithOpaqueHeader`, which we type-cast
whenever the real `WithHeader<H>` type is needed.
Fixes the problem noted in <https://github.com/rust-lang/rust/issues/92791#issuecomment-1104636249>.
Suggest blanket impl to the local traits
This PR will add additional suggestion regarding the blanket implementation when it is possible, by generation a new help message + suggestion.
Closes https://github.com/rust-lang/rust/issues/96076
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Add a `--build-dir` flag to rustbuild
This adds an optional `--build-dir <path>` flag to rustbuild (to both the python and rust code in src/bootstrap). If provided, it overrides build directory from the config file (if any was provided).
My reason for wanting this is that I often will make a change, save, and then go run `x.py check` or `x.py test` (or something). Because I've saved, vscode will start doing its thing in the background, but this will take the file lock, preventing `x.py` from running until vscode finishes whatever it's doing (since the manually invoked x.py won't be able to acquire said file lock). This is annoying, because I'd rather the command I explicitly invoke *not* wait for r-a to complete, as r-a's check is conceptually a background task (and one which can take quite some time to complete).
Anyway, while there are likely other ways this could be handled, if you have the disk space an easy way is to just have vscode be configured to use a different build directory, and then they never have to block each-other.
This can currently be arranged without this patch, by maintaining two `config.toml`s, one of which has a different build dir, and just exists to be passed into the overridden check command in vscode.
Unfortunately, this has the downside of requiring I maintain two `config.toml`s and keep them (at least somewhat) in sync, aside from the build dir. I dislike for several reasons, not the least of which because I know myself well enough to know that these will inevitably get out of sync and confuse me in the future (perhaps this case would be different since I've thought about it enough to write this patch? Who knows, I'd rather not find out).
Either way, it would be much easier for me to have a way for *only* the build directory to differ, which this patch provides by way of a new flag. I suggested this to `@jyn514` who indicated it sounded reasonable so long as it didn't add too much complexity, which I think I've achieved, but he can be the judge.
Anyway, with this patch I can just use something like `["python3", "x.py", "check", "--build-dir", "build-vscode", "--json-output"]` as the overridden check command to rust-analyzer, and do not need to futz with any additional `config.toml`s. Which is very nice!
I've tested this manually, and can confirm that it works. I'm not sure if it needs automated tests, or where I should add them if so.
r? `@jyn514` (who has had to put up with my complaints about this... many times. <3)
Update RELEASES.md
Clarify that flow sensitive checks now understand that *visibly*
uninhabited call expressions never return.
The change influences checks of reachable and unreachable code alike,
not just dead code like previous wording would imply.
cc ``@Kixunil``
Let rust-analyzer ship on stable, non-preview
The consensus on rust-lang/rust-analyzer#12432 seems to be that we are ready for `rust-analyzer` to ship as a rustup component on the beta and stable channels. This won't always be the preferred distribution method, e.g. the VS Code extension will probably still independently update to its weekly releases, but it's still useful to have a component that follows the release train with the rest of the Rust toolchain. So this removes the nightly-only gating on the bundled component, and removes the "-preview" suffix as well by the usual renaming mechanism.
cc ``@rust-lang/wg-rls-2`` ``@rust-lang/release``
get rid of tidy 'unnecessarily ignored' warnings
I think these warnings are quite pointless: when I say `allow(foo)` in my code, that doesn't necessarily mean that I expect `foo` to happen -- it just means that I am okay with `foo` happening.
For example, having to add and remove `ignore-tidy-linelength` as the longest line in the file keeps growing and shrinking is just annoying and doesn't benefit anyone, IMO. This usually incurs *two* CI roundtrips: first CI tells you that line lengths in your test file are ignored unnecessarily, so you go and remove that attribute; then CI tells you that now your line numbers changed, so you re-bless your tests (often takes >5min if parts of rustc need rebuilding because `./x.py fmt` changed something somewhere). That's just a lot of wasted effort and time and patience.
Remove unneeded methods declaration for old web browsers
All these methods were not defined for IE mostly. But since we don't support it anymore, no need to keep them around.
cc ```@jsha```
r? ```@notriddle```
interpret: add From<&MplaceTy> for PlaceTy
We have a similar instance for `&MPlaceTy` to `OpTy`. Also add the same for `&mut`.
This avoids having to write `&(*place).into()`, which we have a few times here and at least twice in Miri (and it comes up again in my current patch).
r? ```@oli-obk```
For diagnostic information of Boolean, remind it as use the type: 'bool'
Fixes#98492.
It helps programmers coming from other languages
modified: compiler/rustc_resolve/src/late/diagnostics.rs
fix data race in thread::scope
Puts the `ScopeData` into an `Arc` so it sticks around as long as we need it.
This means one extra `Arc::clone` per spawned scoped thread, which I hope is fine.
Fixes https://github.com/rust-lang/rust/issues/98498
r? `````@m-ou-se`````
[core] add `Exclusive` to sync
(discussed here: https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Adding.20.60SyncWrapper.60.20to.20std)
`Exclusive` is a wrapper that exclusively allows mutable access to the inner value if you have exclusive access to the wrapper. It acts like a compile time mutex, and hold an unconditional `Sync` implementation.
## Justification for inclusion into std
- This wrapper unblocks actual problems:
- The example that I hit was a vector of `futures::future::BoxFuture`'s causing a central struct in a script to be non-`Sync`. To work around it, you either write really difficult code, or wrap the futures in a needless mutex.
- Easy to maintain: this struct is as simple as a wrapper can get, and its `Sync` implementation has very clear reasoning
- Fills a gap: `&/&mut` are to `RwLock` as `Exclusive` is to `Mutex`
## Public Api
```rust
// core::sync
#[derive(Default)]
struct Exclusive<T: ?Sized> { ... }
impl<T: ?Sized> Sync for Exclusive {}
impl<T> Exclusive<T> {
pub const fn new(t: T) -> Self;
pub const fn into_inner(self) -> T;
}
impl<T: ?Sized> Exclusive<T> {
pub const fn get_mut(&mut self) -> &mut T;
pub const fn get_pin_mut(Pin<&mut self>) -> Pin<&mut T>;
pub const fn from_mut(&mut T) -> &mut Exclusive<T>;
pub const fn from_pin_mut(Pin<&mut T>) -> Pin<&mut Exclusive<T>>;
}
impl<T: Future> Future for Exclusive { ... }
impl<T> From<T> for Exclusive<T> { ... }
impl<T: ?Sized> Debug for Exclusive { ... }
```
## Naming
This is a big bikeshed, but I felt that `Exclusive` captured its general purpose quite well.
## Stability and location
As this is so simple, it can be in `core`. I feel that it can be stabilized quite soon after it is merged, if the libs teams feels its reasonable to add. Also, I don't really know how unstable feature work in std/core's codebases, so I might need help fixing them
## Tips for review
The docs probably are the thing that needs to be reviewed! I tried my best, but I'm sure people have more experience than me writing docs for `Core`
### Implementation:
The API is mostly pulled from https://docs.rs/sync_wrapper/latest/sync_wrapper/struct.SyncWrapper.html (which is apache 2.0 licenesed), and the implementation is trivial:
- its an unsafe justification for pinning
- its an unsafe justification for the `Sync` impl (mostly reasoned about by ````@danielhenrymantilla```` here: https://github.com/Actyx/sync_wrapper/pull/2)
- and forwarding impls, starting with derivable ones and `Future`
Added llvm lifetime annotations to function call argument temporaries.
The goal of this change is to ensure that llvm will do stack slot
optimization on these temporaries. This ensures that in code like:
```rust
const A: [u8; 1024] = [0; 1024];
fn copy_const() {
f(A);
f(A);
}
```
we only use 1024 bytes of stack space, instead of 2048 bytes.
I am new to developing for the rust compiler, and as such not entirely sure, but I believe this should be sufficient to close#98156.
Also, this does not contain a test case to ensure this keeps working, primarily because I am not sure how to go about testing this. I would love some suggestions as to how that could be approached.
