Updated std doctests for wasm
This updates some doctests that fail to run on wasm. We will soon be supporting cross-compiled doctests, and the test-various job fails to run these tests. These tests fail because wasm32-wasip1 does not support threads.
Rollup of 7 pull requests
Successful merges:
- #135562 (Add ignore value suggestion in closure body)
- #139635 (Finalize repeat expr inference behaviour with inferred repeat counts)
- #139668 (Handle regions equivalent to 'static in non_local_bounds)
- #140218 (HIR ty lowering: Clean up & refactor the lowering of type-relative paths)
- #140435 (use uX::from instead of _ as uX in non - const contexts)
- #141130 (rustc_on_unimplemented cleanups)
- #141286 (Querify `coroutine_hidden_types`)
Failed merges:
- #140247 (Don't build `ParamEnv` and do trait solving in `ItemCtxt`s when lowering IATs)
r? `@ghost`
`@rustbot` modify labels: rollup
limit impls of `VaArgSafe` to just types that are actually safe
tracking issue: https://github.com/rust-lang/rust/issues/44930
Retrieving 8- or 16-bit integer arguments from a `VaList` is not safe, because such types are subject to upcasting. See https://github.com/rust-lang/rust/issues/61275#issuecomment-2193942535 for more detail.
This PR also makes the instances of `VaArgSafe` visible in the documentation, and uses a private sealed trait to make sure users cannot create additional impls of `VaArgSafe`, which would almost certainly cause UB.
r? `@workingjubilee`
8 and 16-bit integers are subject to upcasting in C, and hence are not reliably safe. users should perform their own casting and deal with the consequences
Implement `ptr::try_cast_aligned` and `NonNull::try_cast_aligned`.
Implement three common methods on raw pointers and `NonNull`s: `try_cast_aligned`.
## Related links
- Tracking Issue: https://github.com/rust-lang/rust/issues/141221
## About `#[inline]`
Since the result of a call to `align_of` is a power of two known at compile time, the compiler is able to reduce a call to `try_cast_aligned` to only test and sete (or test and jne if followed by `unwrap`), at least on every tier 1 target's arch. This seemed like a good reason to `#[inline]` the function.
- https://godbolt.org/z/ocehvPWMx (raw inlining)
- https://godbolt.org/z/3qa4j4Yrn (comparison with no inlining)
use `Self` alias in self types rather than manually substituting it
Of the rougly 145 uses of `self: Ty` in the standard library, 5 of them don't use `Self` but instead choose to manually "substitute" the `impl`'s self type into the type.
This leads to weird behavior sometimes (https://github.com/rust-lang/rust/issues/140611#issuecomment-2883761300) -- **to be clear**, none of these usages actually trigger any bugs, but it's possible that they may break in the future (or at least lead to lints), so let's just "fix" them proactively.
`core_float_math`: Move functions to `math` module
When these functions were added in https://github.com/rust-lang/rust/pull/138087 It made a relatively common pattern for emulating these functions using an extension trait (which internally uses `libm`) much more fragile. If `core::f32` happened to be imported by the user (to access a constant, say), then that import in the module namespace would take precedence over the `f32` in the type namespace for resolving these functions, running headfirst into the stability attribute.
We ran into this in [Color](https://github.com/linebender/color) and chose to release the remedial 0.3.1 and 0.2.4, to allow downstream crates to build on `docs.rs`.
As these methods are perma-unstable, moving them into a new module should not have any long-term concerns, and ensures that this "breakage" doesn't adversely impact anyone else.
I believe that I've made the module unstable correctly. I presume that this does not require a test to make sure stable code can't depend on the module existing?
I've left the stability attribute on each function - happy to tweak this if a different pattern is more correct.
Tracking issue for `core_float_math`: https://github.com/rust-lang/rust/issues/137578.
This PR is as requested in https://github.com/rust-lang/rust/pull/138087.
r? `@tgross35`
Recommended reviewing with whitespace hidden.
(This is my first PR to `std/core`/this repository, as far as I can remember)
When these functions were added in
https://github.com/rust-lang/rust/pull/138087
It made a relatively common pattern for emulating
these functions using an extension trait (which
internally uses `libm`) much more fragile.
If `core::f32` happened to be imported by the user
(to access a constant, say), then that import in
the module namespace would take precedence over
`f32` in the type namespace for resolving these
functions, running headfirst into the stability
attribute.
We ran into this in Color -
https://github.com/linebender/color - and chose to
release the remedial 0.3.1 and 0.2.4, to allow
downstream crates to build on `docs.rs`.
As these methods are perma-unstable, moving them
into a new module should not have any long-term
concerns, and ensures that this breakage doesn't
adversely impact anyone else.
Stabilize the avx512 target features
This PR stabilizes the AVX512 target features - see [this comment](https://github.com/rust-lang/rust/issues/111137#issuecomment-2745821279).
Tracking Issue - #44839
The target feature UI tests have been changed to `x87` (chosen because this is very unlikely to stablize ever, please comment if some other feature will be better)
related: #111137
Use the existing Lemire (decimal -> float) and Dragon / Grisu algorithms
(float -> decimal) to add support for `f16`. This allows updating the
implementation for `Display` to the expected behavior for `Display`
(currently it prints the a hex bitwise representation), matching other
floats, and adds a `FromStr` implementation.
In order to avoid crashes when compiling with Cranelift or on targets
where f16 is not well supported, a fallback is used if
`cfg(target_has_reliable_f16)` is not true.
Initial implementation of `core_float_math`
Since [1], `compiler-builtins` makes a certain set of math symbols
weakly available on all platforms. This means we can begin exposing some
of the related functions in `core`, so begin this process here.
It is not possible to provide inherent methods in both `core` and `std`
while giving them different stability gates, so standalone functions are
added instead. This provides a way to experiment with the functionality
while unstable; once it is time to stabilize, they can be converted to
inherent.
For `f16` and `f128`, everything is unstable so we can move the inherent
methods.
The following are included to start:
* floor
* ceil
* round
* round_ties_even
* trunc
* fract
* mul_add
* div_euclid
* rem_euclid
* powi
* sqrt
* abs_sub
* cbrt
These mirror the set of functions that we have in `compiler-builtins`
since [1], with the exception of `powi` that has been there longer.
Details for each of the changes is in the commit messages.
Tracking issue: https://github.com/rust-lang/rust/issues/137578
[1]: https://github.com/rust-lang/compiler-builtins/pull/763
try-job: aarch64-gnu
tru-job: armhf-gnu
try-job: i686-msvc-1
try-job: test-various
try-job: x86_64-mingw-1
try-job: x86_64-mingw-2
Add as_ascii_unchecked() methods to char, u8, and str
This PR adds the `as_ascii_unchecked()` method to `char`, `u8`, and `str`, allowing users to convert these types to `ascii::Char`s (see #110998) in an `unsafe` context without first checking for validity. This method was already available for `[u8]`, so this PR makes the API more consistent across other types.
Add `#[must_use]` to Array::map
The output of Array::map is intended to be an array of the same size, and does not modify the original in place nor is it intended for side-effects. Thus, under normal circumstances it should be consumed.
See [discussion](https://internals.rust-lang.org/t/array-map-annotate-with-must-use/22813/26).
Attaching to tracking issue #75243
std: explain prefer `TryInto` over `TryFrom` when specifying traits bounds on generic function
Fixes#140761
This PR keeps the explanations of `Into` and `From` consistent and adds explanations for `TryInto` and `TryFrom`.
r? libs
This updates some doctests that fail to run on wasm. We will soon be
supporting cross-compiled doctests, and the test-various job fails to
run these tests. These tests fail because wasm32-wasip1 does not support
threads.
docs(library/core/src/pin): fix typo "necessarily" -> "necessary"
Fix a typo in [`library/core/src/pin.rs`](14662fabeb/library/core/src/pin.rs), from
> As we'll see later, this is **necessarily** from the time the value is first pinned until the end of its lifespan.
to
> As we'll see later, this is **necessary** from the time the value is first pinned until the end of its lifespan.
(my emphasis).
MaybeUninit::write: fix doc
# Fix doc for `MaybeUninit::write`
The documentation refers to the way `MaybeUninit` stores data internally. The property of not dropping content on context exit is the responsibility of `ManuallyDrop`.
Since [1], `compiler-builtins` makes a certain set of math symbols
weakly available on all platforms. This means we can begin exposing some
of the related functions in `core`, so begin this process here.
It is not possible to provide inherent methods in both `core` and `std`
while giving them different stability gates, so standalone functions are
added instead. This provides a way to experiment with the functionality
while unstable; once it is time to stabilize, they can be converted to
inherent.
For `f16` and `f128`, everything is unstable so we can move the inherent
methods.
The following are included to start:
* floor
* ceil
* round
* round_ties_even
* trunc
* fract
* mul_add
* div_euclid
* rem_euclid
* powi
* sqrt
* abs_sub
* cbrt
These mirror the set of functions that we have in `compiler-builtins`
since [1].
Tracking issue: https://github.com/rust-lang/rust/issues/137578
[1]: https://github.com/rust-lang/compiler-builtins/pull/763
The output of Array::map is intended to be an array of the same size, and does not modify the
original in place nor is it intended for side-effects. Thus, under normal circumstances it should be consumed.
See [discussion](https://internals.rust-lang.org/t/array-map-annotate-with-must-use/22813/26).
Attaching to tracking issue #75243
Use intrinsics for `{f16,f32,f64,f128}::{minimum,maximum}` operations
This PR creates intrinsics for `{f16,f32,f64,f64}::{minimum,maximum}` operations.
This wasn't done when those operations were added as the LLVM support was too weak but now that LLVM has libcalls for unsupported platforms we can finally use them.
Cranelift and GCC[^1] support are partial, Cranelift doesn't support `f16` and `f128`, while GCC doesn't support `f16`.
r? `@tgross35`
try-job: aarch64-gnu
try-job: dist-various-1
try-job: dist-various-2
[^1]: https://www.gnu.org/software///gnulib/manual/html_node/Functions-in-_003cmath_002eh_003e.html
remove 'unordered' atomic intrinsics
As their doc comment already indicates, these operations do not currently have a place in our memory model. The intrinsics were introduced to support a hack in compiler-builtins, but that hack recently got removed (see https://github.com/rust-lang/compiler-builtins/issues/788).
remove intrinsics::drop_in_place
This was only ever accidentally stable, and has been marked as deprecated since Rust 1.52, released almost 4 years ago. We've removed the old serialization `derive`s, maybe we can remove this one as well?
As suggested by ``@jhpratt,`` let's see what crater says for this one.
Implement (part of) ACP 429: add `DerefMut` to `Lazy[Cell/Lock]`
`DerefMut` is instantly stable, as a trait impl. That means this needs an FCP.
``@rustbot`` label +needs-fcp
https://github.com/rust-lang/libs-team/issues/429
