Usage of `Pin::new_unchecked(&mut …)` is dangerous with `poll_fn`, even
though the `!Unpin`-infectiousness has made things smoother.
Nonetheless, there are easy ways to avoid the need for any `unsafe`
altogether, be it through `Box::pin`ning, or the `pin!` macro. Since the
latter only works within an `async` context, showing an example
artifically introducing one ought to help people navigate this subtlety
with safety and confidence.
std: only depend on dlmalloc for wasm*-unknown
It was already filtered out for emscripten, but wasi doesn't need dlmalloc
either since it reuses `unix/alloc.rs`.
io: soften ‘at most one write attempt’ requirement in io::Write::write
At the moment, documentation of std::io::Write::write indicates that
call to it ‘represents at most one attempt to write to any wrapped
object’. It seems that such wording was put there to contrast it with
pre-1.0 interface which attempted to write all the data (it has since
been changed in [RFC 517]).
However, the requirement puts unnecessary constraints and may
complicate adaptors which perform non-trivial transformations on the
data. For example, they may maintain an internal buffer which needs
to be written out before the write method accepts more data. It might
be natural to code the method such that it flushes the buffer and then
grabs another chunk of user data. With the current wording in the
documentation, the adaptor would be forced to return Ok(0).
This commit softens the wording such that implementations can choose
code structure which makes most sense for their particular use case.
While at it, elaborate on the meaning of `Ok(0)` return pointing out
that the write_all methods interprets it as an error.
[RFC 517]: https://rust-lang.github.io/rfcs/0517-io-os-reform.html
Launch a non-unwinding panic for misaligned pointer deref
This panic already never unwinds, but that's only because it always hits the unwind guard that's created by our `UnwindAction::Terminate`. Hitting the unwind guard generates a huge double-panic backtrace. Now we generate a normal-looking panic message when this check is hit.
r? `@thomcc`
fix: get the l4re target working again
This is based on work from https://github.com/rust-lang/rust/pull/103966, addressing the review comment by `@m-ou-se` at the time and "fixing" the (probably newly) missing read_buf.
Remove `box_free` lang item
This PR removes the `box_free` lang item, replacing it with `Box`'s `Drop` impl. Box dropping is still slightly magic because the contained value is still dropped by the compiler.
Rollup of 6 pull requests
Successful merges:
- #112352 (Fix documentation build on FreeBSD)
- #112644 (Correct types in method descriptions of `NonZero*` types)
- #112683 (fix ICE on specific malformed asm clobber_abi)
- #112707 ([rustdoc] Fix invalid handling of "going back in history" when "go to only search result" setting is enabled)
- #112719 (Replace fvdl with ffx, allow test without install)
- #112728 (Add `<meta charset="utf-8">` to `-Zdump-mir-spanview` output)
r? `@ghost`
`@rustbot` modify labels: rollup
Correct types in method descriptions of `NonZero*` types
- `$Int`: e.g. i32, usize
- `$Ty`: e.g. NonZeroI32, NonZeroUsize
|method|current description|after my changes|
|-|-|-|
|`saturating_add`|...Return `$Int`::MAX on overflow.|...Return `$Ty`::MAX on overflow.|
|`checked_abs`|...returns None if self == `$Int`::MIN.|...returns None if self == `$Ty`::MIN.|
|`checked_neg`|...returning None if self == i32::MIN.|...returning None if self == `$Ty`::MIN.|
|`saturating_neg`|...returning MAX if self == i32::MIN...|...returning `$Ty`::MAX if self == `$Ty`::MIN...|
|`saturating_mul`|...Return `$Int`::MAX...|...Return `$Ty`::MAX...|
|`saturating_pow`|...Return `$Int`::MIN or `$Int`::MAX...|...Return `$Ty`::MIN or `$Ty`::MAX...|
---
For example:
```rust
pub const fn saturating_neg(self) -> NonZeroI128
```
- current
- Saturating negation. Computes `-self`, returning `MAX` if `self == i32::MIN` instead of overflowing.
- after my changes
- Saturating negation. Computes `-self`, returning `NonZeroI128::MAX` if `self == NonZeroI128::MIN` instead of overflowing.
Fix documentation build on FreeBSD
After the socket ancillary data implementation was introduced, the documentation build was broken on FreeBSD hosts, add the same workaround as for the existing implementations.
Fixes the doc build after #91793
previously it was only able to use BufWriter. This was due to a limitation in the
BufReader generics that prevented specialization. This change works around the issue
by using `where Self: Read` instead of `where I: Read`. This limits our options, e.g.
we can't access BufRead methods, but it happens to work out if we rely on some
implementation details.
There's no need for the `const_eval_select` dance here. And while I originally wrote the `.try_into().unwrap_unchecked()` implementation here, it's kinda a mess in MIR -- this new one is substantially simpler, as shown by the old one being above the inlining threshold but the new one being below it.
`#[lang_item]` for `core::ptr::Unique`
Tree Borrows is about to introduce experimental special handling of `core::ptr::Unique` in Miri to give it a semantics.
As of now there does not seem to be a clean way (i.e. other than `&format!("{adt:?}") == "std::ptr::Unique"`) to check if an `AdtDef` represents a `Unique`.
r? `@RalfJung`
Draft: making a lang item
Fix building libstd documentation on FreeBSD.
It fixes the following error:
```
error[E0412]: cannot find type `sockcred2` in module `libc`
--> library/std/src/os/unix/net/ancillary.rs:211:29
|
211 | pub struct SocketCred(libc::sockcred2);
| ^^^^^^^^^ not found in `libc`
```
Extend `unused_must_use` to cover block exprs
Given code like
```rust
#[must_use]
fn foo() -> i32 {
42
}
fn warns() {
{
foo();
}
}
fn does_not_warn() {
{
foo()
};
}
fn main() {
warns();
does_not_warn();
}
```
### Before This PR
```
warning: unused return value of `foo` that must be used
--> test.rs:8:9
|
8 | foo();
| ^^^^^
|
= note: `#[warn(unused_must_use)]` on by default
help: use `let _ = ...` to ignore the resulting value
|
8 | let _ = foo();
| +++++++
warning: 1 warning emitted
```
### After This PR
```
warning: unused return value of `foo` that must be used
--> test.rs:8:9
|
8 | foo();
| ^^^^^
|
= note: `#[warn(unused_must_use)]` on by default
help: use `let _ = ...` to ignore the resulting value
|
8 | let _ = foo();
| +++++++
warning: unused return value of `foo` that must be used
--> test.rs:14:9
|
14 | foo()
| ^^^^^
|
help: use `let _ = ...` to ignore the resulting value
|
14 | let _ = foo();
| +++++++ +
warning: 2 warnings emitted
```
Fixes#104253.
This commit reverts a change made in #111425.
It was believed that this change was necessary for implementing type privacy lints, but #111801 showed that it was not necessary.
Quite opposite, the revert fixes some issues.
Mention `env!` in `option_env!`'s docs
`env!` mentions that there is an alternative that returns an `Option<...>` instead of emitting a compile error.
Now `option_env!` also mentions that there is an alternative that emits a compile error instead of returning an `Option<...>`.
Update runtime guarantee for `select_nth_unstable`
#106933 changed the runtime guarantee for `select_nth_unstable` from O(n) to O(n log n), since the old guarantee wasn't actually met by the implementation at the time. Now with #107522, `select_nth_unstable` should be truly linear in runtime, so we can revert its runtime guarantee to O(n). Since #106933 was considered a bug fix, this will probably need an FCP because it counts as a new API guarantee.
r? `@Amanieu`
Stabilize String::leak
Stabilizes the following API:
```Rust
impl String {
pub fn leak(self) -> &'static mut str;
}
```
closes#102929
blocked by having an FCP for stabilization.
Implement `TryFrom<&OsStr>` for `&str`
Recently when trying to work with `&OsStr` I was surprised to find this `impl` missing.
Since the `to_str` method already existed the actual implementation is fairly non-controversial, except for maybe the choice of the error type. I chose an opaque error here instead of something like `std::str::Utf8Error`, since that would already make a number of assumption about the underlying implementation of `OsStr`.
As this is a trait implementation, it is insta-stable, if I'm not mistaken?
Either way this will need an FCP.
I chose "1.64.0" as the version, since this is unlikely to land before the beta cut-off.
`@rustbot` modify labels: +T-libs-api
API Change Proposal: rust-lang/rust#99031 (accepted)
