Make `render_example_with_highlighting` return an `impl fmt::Display`
Removes some more usages of `write_str`. Shouldn't affect runtime, but makes the codebase a bit more consistent.
Each commit can be reviewed separately
Add doc for `NonZero*` const creation
I ran into trouble using `NonZero*` values because I didn’t see any clear way to create them at compile time. At first I ended up using `NonZero*::new_unchecked` a lot, until I realized that `Option::unwrap` and `Option::expect` are `const` and can be used in a `const` context. With that, you can create non-zero values at compile time safely, without touching `unsafe`. This wasn’t obvious to me and my peers who’ve been using Rust for a while, so I thought adding a note to the docs would make it easier for others to discover.
If this should be worded differently or placed in another location, we can do that. I just want to make this more obvious.
BTreeMap: Don't leak allocators when initializing nodes
Memory was allocated via `Box::leak` and thence intended to be tracked and deallocated manually, but the allocator was also leaked, not tracked, and never dropped. Now it is dropped immediately.
According to my reading of the `Allocator` trait, if a copy of the allocator remains live, then its allocations must remain live. Since the B-tree has a copy of the allocator that will only be dropped after the nodes, it's safe to not store the allocator in each node (which would be a much more intrusive change).
Fixes: rust-lang/rust#106203
avoid violating `slice::from_raw_parts` safety contract in `Vec::extract_if`
The implementation of the `Vec::extract_if` iterator violates the safety contract adverized by `slice::from_raw_parts` by always constructing a mutable slice for the entire length of the vector even though that span of memory can contain holes from items already drained. The safety contract of `slice::from_raw_parts` requires that all elements must be properly
initialized.
As an example we can look at the following code:
```rust
let mut v = vec![Box::new(0u64), Box::new(1u64)];
for item in v.extract_if(.., |x| **x == 0) {
drop(item);
}
```
In the second iteration a `&mut [Box<u64>]` slice of length 2 will be constructed. The first slot of the slice contains the bitpattern of an already deallocated box, which is invalid.
This fixes the issue by only creating references to valid items and using pointer manipulation for the rest. I have also taken the liberty to remove the big `unsafe` blocks in place of targetted ones with a SAFETY comment. The approach closely mirrors the implementation of `Vec::retain_mut`.
**Note to reviewers:** The diff is easier to follow with whitespace hidden.
rustdoc: hide `#[repr]` if it isn't part of the public ABI
> [!IMPORTANT]
> Temporarily stacked on top of PR https://github.com/rust-lang/rust/pull/146527; only the last commit is relevant!
Follow-up to rust-lang/rust#115439.
Unblocks rust-lang/rust#116743, CC ``@dtolnay.``
Fixesrust-lang/rust#66401.
Fixesrust-lang/rust#128364.
Fixesrust-lang/rust#137440.
Only display the representation `#[repr(REPR)]` (where `REPR` is not `Rust` or `transparent`) of a given type if none of its variants (incl. the synthetic variants of structs) are `#[doc(hidden)]` and all of its fields are public and not `#[doc(hidden)]` since it's likely not meant to be considered part of the public ABI otherwise.
`--document-{private,hidden}-items` works as expected in this context, too.
Moreover, we now also factor in the presence of `#[doc(hidden)]` when checking whether to show `repr(transparent)` or not.
Rollup of 7 pull requests
Successful merges:
- rust-lang/rust#146556 (Fix duration_since panic on unix when std is built with integer overflow checks)
- rust-lang/rust#146679 (Clarify Display for error should not include source)
- rust-lang/rust#146753 (Improve the pretty print of UnstableFeature clause)
- rust-lang/rust#146894 (Improve derive suggestion of const param)
- rust-lang/rust#146950 (core: simplify `CStr::default()`)
- rust-lang/rust#146958 (Fix infinite recursion in Path::eq with String)
- rust-lang/rust#146971 (fix ICE in writeback due to bound regions)
r? `@ghost`
`@rustbot` modify labels: rollup
Memory was allocated via `Box::leak` and thence intended to be tracked
and deallocated manually, but the allocator was also leaked, not
tracked, and never dropped. Now it is dropped immediately.
According to my reading of the `Allocator` trait, if a copy of the
allocator remains live, then its allocations must remain live. Since
the B-tree has a copy of the allocator that will only be dropped after
the nodes, it's safe to not store the allocator in each node (which
would be a much more intrusive change).
Improve derive suggestion of const param
Make the suggestion not to remove the adt and use the name of the adt variant in the diagnostic.
r? `@BoxyUwU`
Fix duration_since panic on unix when std is built with integer overflow checks
Add a test for regression rust-lang/rust#146228, and turns out this test fails detects error when std is compiled with integer overflow checks.
Original regression was reverted in rust-lang/rust#146473.
First attempt to fix was in rust-lang/rust#146247; test and some code is copied from there, thanks `@eval-exec`
r? `@RalfJung`
library: std: sys: pal: uefi: Add some comments
I seemed to have forgotten that since I am using GET_PROTOCOL attribute for the std usecases, I did not need to close the protocols explicitly. So adding these comments as a note to future self not to waste time on the same thing again.
Make missed precondition-free float intrinsics safe
So, in my defence, these were both separated out from the other intrinsics in the file *and* had a different safety comment in the stable versions, so, I didn't notice them before. But, in my offence, the entire reason I did the previous PR was because I was using them for SIMD intrinsic fallbacks, and `fabs` is needed for those too, so, I don't really have an excuse.
Extra follow-up to rust-lang/rust#146683.
r? ```@RalfJung``` who reviewed the previous one
These don't appear to be used anywhere outside of the standard locations, at least.
fix 2 borrowck issues
fixes https://github.com/rust-lang/rust/issues/146467 cc ``@amandasystems``
our understanding here is as follows: region constraints from computing implied bounds gets `ConstraintCategory::Internal`. If there's a higher-ranked subtyping errors while computing implied bounds we then ended up with only `ConstraintCategory::Internal` and `ConstraintCategory::OutlivesUnnameablePlaceholder(_)` constraints.
The path was something like
- `'placeholderU2: 'placeholderU1` (`Internal`)
- `'placeholderU1: 'static` (`OutlivesUnnameablePlaceholder('placeholderU2)`)
It's generally somewhat subtle here as ideally relating placeholders doesn't introduce `'static` constraints. Relating the placeholders themselves will always error regardless, cc https://github.com/rust-lang/rust/pull/142623.
---
separately fixes https://github.com/rust-lang/rust/pull/145925#issuecomment-3303733357 by updating the location for deferred closure requirements inside of promoteds. I am not updating their category as doing so is 1) effort and 2) imo actually undesirable 🤔 see the comments in `TypeChecker::check_promoted` cc ``@lqd``
r? lqd
I seemed to have forgotten that since I am using GET_PROTOCOL attribute
for the std usecases, I did not need to close the protocols explicitly.
So adding these comments as a note to future self not to waste time on
the same thing again.
Signed-off-by: Ayush Singh <ayush@beagleboard.org>
