libtest: use binary search for --exact test filtering
When `--exact` is passed in, use binary search for O(f log n) lookups instead of an O(n) linear scan, under the assumption that f << n (which is true for the most relevant cases).
This is important for Miri, where the interpreted execution makes the linear scan very expensive.
I measured this against a repo with 1000 empty tests, running `cargo +stage1 miri nextest run test_00` (100 tests) under hyperfine:
* Before (linear scan): 49.7s ± 0.6s
* After (binary search): 41.9s ± 0.2s (-15.7%)
I also tried a few other variations (particularly swapping matching tests to the front of the list + truncating the list), but the index + swap_remove approach proved to be the fastest.
Questions:
- [ ] To be conservative, I've assumed that test_main can potentially receive an unsorted list of tests. Is this assumption correct?
deprecate `std::char` constants and functions
similar to how constants in those modules for numeric types have been deprecated. The `std::char` module contains:
Three stable constants that this PR deprecates. These already link to their associated constant equivalents.
- `MAX`
- `REPLACEMENT_CHARACTER`
- `UNICODE_VERSION`
two unstable constants that this PR removes. The constants are already stablized as associated constants on `char`.
- `MAX_LEN_UTF8`
- `MAX_LEN_UTF16`
Four stable functions that this PR deprecates. These already link to their method equivalents.
- `fn decode_utf16`
- `fn from_digit`
- `fn from_u32`
- `fn from_u32_unchecked⚠`
discussion at [#t-libs > should `std::char::{MIN, MAX}` be deprecated?](https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/should.20.60std.3A.3Achar.3A.3A.7BMIN.2C.20MAX.7D.60.20be.20deprecated.3F/with/579444750).
r? libs-api
In commit "test: Consolidate `Hexf`, `Hexi`, and the `Hex` trait" we
unintentionally lost the difference between float hex and bitwise hex
formatting; instead, the float hex was getting printed twice. Resolve
this by printing the integer hex whenever the `-` format modifier is
specified. This also makes things simpler because we no longer need to
keep track of whether an `impl DisplayHex` is a float with `.to_bits()`
available or an integer without it, we can always just try to print both
forms.
As a result, we can use a common error message for all validation
checks.
Refactor FnDecl and FnSig non-type fields into a new wrapper type
#### Why this Refactor?
This PR is part of an initial cleanup for the [arg splat experiment](https://github.com/rust-lang/rust/issues/153629), but it's a useful refactor by itself.
It refactors the non-type fields of `FnDecl`, `FnSig`, and `FnHeader` into a new packed wrapper types, based on this comment in the `splat` experiment PR:
https://github.com/rust-lang/rust/pull/153697#discussion_r3004637413
It also refactors some common `FnSig` creation settings into their own methods. I did this instead of creating a struct with defaults.
#### Relationship to `splat` Experiment
I don't think we can use functional struct updates (`..default()`) to create `FnDecl` and `FnSig`, because we need the bit-packing for the `splat` experiment.
Bit-packing will avoid breaking "type is small" assertions for commonly used types when `splat` is added.
This PR packs these types:
- ExternAbi: enum + `unwind` variants (38) -> 6 bits
- ImplicitSelfKind: enum variants (5) -> 3 bits
- lifetime_elision_allowed, safety, c_variadic: bool -> 1 bit
#### Minor Changes
Fixes some typos, and applies rustfmt to clippy files that got skipped somehow.
std: Update dependency on `wasi` crate
This commit updates the crate dependency that the standard library has on the `wasi` crate. This is now updated to depending explicitly on the `wasip1` crate and the `wasip2` crate published on crates.io. These crates are managed in the [same location][repo] as the `wasi` crate and represent a different versioning scheme which doesn't require multi-version WASI support to require depending on the same crate at multiple versions. The code in libstd is updated to reference `wasip1` and `wasip2` directly as well.
[repo]: https://github.com/bytecodealliance/wasi-rs
Document why `layout.align() + layout.size()` doesn't overflow
This addition looks suspicious and is safety critical, but is saved by the weird `Layout` invariants.
std: fix HashMap RNG docs wording
Fixes a wording typo in the top-level HashMap docs.
Changed "random number coroutine" to "random number generator" in the seed entropy paragraph.
This section is security-relevant, and "generator" is the correct term in RNG context.
Testing:
- Not run locally (docs-only text change).
fix: add aliasing rules for Box
This is a new revised version for the PR [139857](https://github.com/rust-lang/rust/pull/139857), sorry for the delayed reply. I've rewritten the sentence to closely mirror the wording from `Vec::from_raw_parts`, which clearly states the transfer of ownership and its consequences. This should make the aliasing requirements much clearer.
I opted not to include a note about `mem::forget` by default to keep the documentation focused on the primary contract, similar to `Vec`.
net::tcp/udp: fix docs about how set_nonblocking is implemented
`fcntl` `FIONBIO` doesn't even make sense, it should be `fcntl` `F_SETFL`. However, for some reason we are using `ioctl` by default -- except on Solaris where this doesn't seem to work very well.
Honestly what I would have expected is that we just always use `FileDesc::set_nonblocking` also for network sockets, but for some reason we don't and there are no comments explaining this choice. Cc @nikarh (for "vita") @joboet
docs: Fix typo in std/src/thready/scoped.rs
# Fix typo in std/src/thread/scoped.rs
## Why this pr
This PR fixes the typo mentioned in rust-lang/rust#155275.
I know this was originally fixed in rust-lang/rust#155325 and then in rust-lang/rust#155328.
But since the first issue was closed due to some ai slop and the second one was closed because the first one was already opened, it seems to me that this PR is still needed.
## What this pr does
This PR "just" fixes a typo inside the `std/src/thread/scoped.rs` file
Changing the comment from this:
```
/// borrow non-`'static` data from the outside the scope. See [`scope`] for
/// details.
```
to this:
```
/// borrow non-`'static` data from outside the scope. See [`scope`] for
/// details.
```
`impl Default for RepeatN`
This creates an empty iterator, like `repeat_n(value, 0)` but without
needing any such value at hand. There's precedent in many other
iterators that the `Default` is empty, like `slice::Iter`.
I found myself wanting this for rayon's `RepeatN` as it lowers to a
sequential iterator [here][1]. Since rayon is also optimizing to avoid
extra clones, it may end up with parallel splits that have count 0 and
no item value. Calling `std::iter::repeat_n(x, 0)` just drops that
value, but there's no way to construct the same result without a value
yet. This would be straightforward with an empty `Default`.
[1]: https://github.com/rayon-rs/rayon/blob/ae07384e3e0b238cea89f0c14891f351c65a5cee/src/iter/repeat.rs#L201-L202
r? libs-api (insta-stable)
Add Sized supertrait for CoerceUnsized and DispatchFromDyn
This is part of rust-lang/rust#149094. I did not include `Receiver` because I think it is correct to allow non-sized receivers.
Documenting the case of `Weak::upgrade` returning `None` when the value behind the reference is missing
Adds a clause to the documentation of `Weak` for `Arc` which was discussed in rust-lang/rust#154936.
Adds the same clause to the documentation of `Weak` for `Rc`, because the behavior is the same.
Add `TryFromIntError::kind` method and `IntErrorKind::NotAPowerOfTwo` variant
- ACP: rust-lang/libs-team#746
- Tracking issue: rust-lang/rust#153978
This pull request adds `kind` method to [`TryFromIntError`](https://doc.rust-lang.org/core/num/struct.TryFromIntError.html), which outputs the detailed cause of converting an integer failing.
This is primarily intended for use in cases where there are multiple causes for failure, such as converting from a large signed integer type to a small signed integer type.
At the moment, this method returns [`&IntErrorKind`](https://doc.rust-lang.org/core/num/enum.IntErrorKind.html). This type implements the `Copy` trait and could return `IntErrorKind`, but returns a reference to align with the behavior of [`ParseIntError::kind`](https://doc.rust-lang.org/core/num/struct.ParseIntError.html#method.kind). If it is not necessary to align the behavior of `TryFromIntError::kind` with `ParseIntError::kind`, I'll change this method to return `IntErrorKind`.
Before this pull request, `IntErrorKind` was only used by [`ParseIntError`](https://doc.rust-lang.org/core/num/struct.ParseIntError.html), but I changed it to be used by `TryFromIntError` as well, so I updated `IntErrorKind`'s documentation.
[`impl TryFrom<usize> for Alignment`](https://doc.rust-lang.org/std/ptr/struct.Alignment.html#impl-TryFrom%3Cusize%3E-for-Alignment) returns `TryFromIntError` as an error if the given value is not a power of two. However, `IntErrorKind` does not have a variant that represents this. So I added the variant `NotAPowerOfTwo` to represent this. For this variant to stabilize, both `try_from_int_error_kind` and `ptr_alignment_type` features must be stabilized.
Make `convert_while_ascii` unsafe
`convert_while_ascii` assumes `convert` only returns ASCII to ensure the output remains valid UTF-8. This adds that requirement as a safety precondition.
c-variadic: fix implementation on `avr`
tracking issue: https://github.com/rust-lang/rust/issues/44930
cc target maintainer @Patryk27
I ran into multiple issues, and although with this PR and a little harness I can run the test with qemu on avr, the implementation is perhaps not ideal.
The problem we found is that on `avr` the `c_int/c_uint` types are `i16/u16`, and this was not handled in the c-variadic checks. Luckily there is a field in the target configuration that contains the targets `c_int_width`. However, this field is not actually used in `core` at all, there the 16-bit targets are just hardcoded.
https://github.com/rust-lang/rust/blob/1500f0f47f5fe8ddcd6528f6c6c031b210b4eac5/library/core/src/ffi/primitives.rs#L174-L185
Perhaps we should expose this like endianness and pointer width?
---
Finally there are some changes to the test to make it compile with `no_std`.
This creates an empty iterator, like `repeat_n(value, 0)` but without
needing any such value at hand. There's precedent in many other
iterators that the `Default` is empty, like `slice::Iter`.
I found myself wanting this for rayon's `RepeatN` as it lowers to a
sequential iterator [here][1]. Since rayon is also optimizing to avoid
extra clones, it may end up with parallel splits that have count 0 and
no item value. Calling `std::iter::repeat_n(x, 0)` just drops that
value, but there's no way to construct the same result without a value
yet. This would be straightforward with an empty `Default`.
[1]: https://github.com/rayon-rs/rayon/blob/ae07384e3e0b238cea89f0c14891f351c65a5cee/src/iter/repeat.rs#L201-L202
Zac Harrold