Correct `std::prelude` comment
(Read the changed file first for context.)
First, `alloc` has no prelude.
Second, the docs for `v1` don't matter since the [prelude module] already has all the doc links. The `rust_2021` module for instance also doesnt have a convenient doc page. However as I understand glob imports still cant be used because the items dont have the same stabilisation versions.
[prelude module]: https://doc.rust-lang.org/std/prelude/index.html
docs(std): clarify remove_dir_all errors
When using `remove_dir_all`, I assumed that the function was idempotent and that I could always call it to remove a directory if it existed. That's not the case and it bit me in production, so I figured I'd submit this to clarify the docs.
Restructure and rename std thread_local internals to make it less of a maze
Every time I try to work on std's thread local internals, it feels like I'm trying to navigate a confusing maze made of macros, deeply nested modules, and types with multiple names/aliases. Time to clean it up a bit.
This PR:
- Exports `Key` with its own name (`Key`), instead of `__LocalKeyInner`
- Uses `pub macro` to put `__thread_local_inner` into a (unstable, hidden) module, removing `#[macro_export]`, removing it from the crate root.
- Removes the `__` from `__thread_local_inner`.
- Removes a few unnecessary `allow_internal_unstable` features from the macros
- Removes the `libstd_thread_internals` feature. (Merged with `thread_local_internals`.)
- And removes it from the unstable book
- Gets rid of the deeply nested modules for the `Key` definitions (`mod fast` / `mod os` / `mod statik`).
- Turns a `#[cfg]` mess into a single `cfg_if`, now that there's no `#[macro_export]` anymore that breaks with `cfg_if`.
- Simplifies the `cfg_if` conditions to not repeat the conditions.
- Removes useless `normalize-stderr-test`, which were left over from when the `Key` types had different names on different platforms.
- Removes a seemingly unnecessary `realstd` re-export on `cfg(test)`.
This PR changes nothing about the thread local implementation. That's for a later PR. (Which should hopefully be easier once all this stuff is a bit cleaned up.)
Spelling library
Split per https://github.com/rust-lang/rust/pull/110392
I can squash once people are happy w/ the changes. It's really uncommon for large sets of changes to be perfectly acceptable w/o at least some changes.
I probably won't have time to respond until tomorrow or the next day
Fix `std` compilation error for wasi+atomics
Fix https://github.com/rust-lang/rust/issues/109727
It seems that the `unsupported/once.rs` module isn't meant to exist at the same time as the `futex` module, as they have conflicting definitions.
I've solved this by defining the `once` module only if `not(target_feature = "atomics")`.
The `wasm32-unknown-unknown` target [similarly only defines the `once` module if `not(target_feature = "atomics")`](01c4f31927/library/std/src/sys/wasm/mod.rs (L69-L70)).
As show in [this block of code](01c4f31927/library/std/src/sys_common/once/mod.rs (L10-L34)), the `sys::once` module doesn't need to exist if `all(target_arch = "wasm32", target_feature = "atomics")`.
Update documentation wording on path 'try_exists' functions
Just eliminate the quadruple negation in `doesn't silently ignore errors unrelated to ... not existing.`
black_box doc corrections for clarification - Issue #107957
Made a complete pass through the docs to help resolve https://github.com/rust-lang/rust/issues/107957
No code changes, just documentation
`@rustbot` label +T-libs-api -T-libs
Updating Wake example to use new 'pin!' macro
Closes: https://github.com/rust-lang/rust/issues/109965
I have already had this reviewed and approved here: https://github.com/rust-lang/rust/pull/110026 . But because I had some git issues and chose the "nuke it" option as my solution it didn't get merged. I nuked it too quickly. I am sorry for trouble of reviewing twice.
Fix no_global_oom_handling build
`provide_sorted_batch` in core is incorrectly marked with `#[cfg(not(no_global_oom_handling))]` which prevents core from building with the cfg enabled.
Nothing in `core` allocates memory (including this function). The `cfg` gate is incorrect.
cc ``@dpaoliello``
r? ``@wesleywiser``
The cfg was added by #107191
Add shortcut for Grisu3 algorithm.
While Grisu3 is way more faster for most numbers compare to Dragon4, the fall back to Dragon4 procedure for certain numbers could cause some performance regressions compare to use Dragon4 directly. Mitigating the regression caused by falling back is important for a largely used core library.
In Grisu3 algorithm implementation, there's a shortcut to jump out earlier when the fractional or integrals cannot meet the requirement of requested digits. This could significantly improve the performance of converting floating number to string as it falls back even without starting trying the algorithm.
The original idea is from the [.NET implementation](https://github.com/dotnet/runtime/blob/main/src/libraries/System.Private.CoreLib/src/System/Number.Grisu3.cs#L602-L615) and the code was originally added in [this PR](https://github.com/dotnet/coreclr/pull/14646#issuecomment-350942050). This shortcut has been shipped long time ago and has been proved working.
Fix#110129
Check requested digit length and the fractional or integral parts of the number. Falls back earlier without trying the Grisu algorithm if the specific condition meets.
Fix#110129
Add `intrinsics::transmute_unchecked`
This takes a whole 3 lines in `compiler/` since it lowers to `CastKind::Transmute` in MIR *exactly* the same as the existing `intrinsics::transmute` does, it just doesn't have the fancy checking in `hir_typeck`.
Added to enable experimenting with the request in <https://github.com/rust-lang/rust/pull/106281#issuecomment-1496648190> and because the portable-simd folks might be interested for dependently-sized array-vector conversions.
It also simplifies a couple places in `core`.
See also https://github.com/rust-lang/rust/pull/108442#issuecomment-1474777273, where `CastKind::Transmute` was added having exactly these semantics before the lang meeting (which I wasn't in) independently expressed interest.
Limit read size in `File::read_to_end` loop
Fixes#110650.
Windows file reads have perf overhead that's proportional to the buffer size. When we have a reasonable expectation that we know the file size, we can set a reasonable upper bound for the size of the buffer in one read call.
This takes a whole 3 lines in `compiler/` since it lowers to `CastKind::Transmute` in MIR *exactly* the same as the existing `intrinsics::transmute` does, it just doesn't have the fancy checking in `hir_typeck`.
Added to enable experimenting with the request in <https://github.com/rust-lang/rust/pull/106281#issuecomment-1496648190> and because the portable-simd folks might be interested for dependently-sized array-vector conversions.
It also simplifies a couple places in `core`.
Report allocation errors as panics
OOM is now reported as a panic but with a custom payload type (`AllocErrorPanicPayload`) which holds the layout that was passed to `handle_alloc_error`.
This should be review one commit at a time:
- The first commit adds `AllocErrorPanicPayload` and changes allocation errors to always be reported as panics.
- The second commit removes `#[alloc_error_handler]` and the `alloc_error_hook` API.
ACP: https://github.com/rust-lang/libs-team/issues/192Closes#51540Closes#51245
More `IS_ZST` in `library`
I noticed that `post_inc_start` and `pre_dec_end` were doing this check in different ways
d19b64fb54/library/core/src/slice/iter/macros.rs (L76-L93)
so started making this PR, then added a few more I found since I was already making changes anyway.
Add offset_of! macro (RFC 3308)
Implements https://github.com/rust-lang/rfcs/pull/3308 (tracking issue #106655) by adding the built in macro `core::mem::offset_of`. Two of the future possibilities are also implemented:
* Nested field accesses (without array indexing)
* DST support (for `Sized` fields)
I wrote this a few months ago, before the RFC merged. Now that it's merged, I decided to rebase and finish it.
cc `@thomcc` (RFC author)
I noticed that `post_inc_start` and `pre_dec_end` were doing this check in different ways
d19b64fb54/library/core/src/slice/iter/macros.rs (L76-L93)
so started making this PR, then added a few more I found since I was already making changes anyway.
`provide_sorted_batch` in core is incorrectly marked with
`#[cfg(not(no_global_oom_handling))]` which prevents core
from building with the cfg enabled.
Nothing in core allocates memory including this function, so
the `cfg` gate is incorrect.
Specialize some `io::Read` and `io::Write` methods for `VecDeque<u8>` and `&[u8]`
This improves implementation of:
- `<&[u8]>::read_to_string`
- `VecDeque<u8>::read_to_end`
- `VecDeque<u8>::read_to_string`
- `VecDeque<u8>::write_vectored`
Added byte position range for `proc_macro::Span`
Currently, the [`Debug`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#impl-Debug-for-Span) implementation for [`proc_macro::Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#) calls the debug function implemented in the trait implementation of `server::Span` for the type `Rustc` in the `rustc-expand` crate.
The current implementation, of the referenced function, looks something like this:
```rust
fn debug(&mut self, span: Self::Span) -> String {
if self.ecx.ecfg.span_debug {
format!("{:?}", span)
} else {
format!("{:?} bytes({}..{})", span.ctxt(), span.lo().0, span.hi().0)
}
}
```
It returns the byte position of the [`Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#) as an interpolated string.
Because this is currently the only way to get a spans position in the file, I might lead someone, who is interested in this information, to parsing this interpolated string back into a range of bytes, which I think is a very non-rusty way.
The proposed `position()`, method implemented in this PR, gives the ability to directly get this info.
It returns a [`std::ops::Range`](https://doc.rust-lang.org/std/ops/struct.Range.html#) wrapping the lowest and highest byte of the [`Span`](https://doc.rust-lang.org/beta/proc_macro/struct.Span.html#).
I put it behind the `proc_macro_span` feature flag because many of the other functions that have a similar footprint also are annotated with it, I don't actually know if this is right.
It would be great if somebody could take a look at this, thank you very much in advanced.
