Replace black with ruff in `tidy`
`ruff` can both lint and format Python code (in fact, it should be a mostly drop-in replacement for `black` in terms of formatting), so it's not needed to use `black` anymore. This PR removes `black` and replaces it with `ruff`, to get rid of one Python dependency, and also to make Python formatting faster (although that's a small thing).
If we decide to merge this, we'll need to "reformat the world" - `ruff` is not perfectly compatible with `black`, and it also looks like `black` was actually ignoring some files before. I tried it locally (`./x test tidy --extra-checks=py:fmt --bless`) and it also reformatted some code in subtrees (e.g. `clippy` or `rustc_codegen_gcc`) - I'm not sure how to handle that.
Fix missing newlines that rustfmt removed.
fix trailing whitespace
Fix duplicate word.
Reformat panic reasons into a list
remove trailing whitespace 2 electric boogaloo
Change verbe tense.
Integrate suggestions
Improve comments for the default backtrace printer
The existing comments were misleading, confusing, and outdated.
Take this comment for example:
```
// Any frames between `__rust_begin_short_backtrace` and `__rust_end_short_backtrace`
// are omitted from the backtrace in short mode, `__rust_end_short_backtrace` will be
// called before the panic hook, so we won't ignore any frames if there is no
// invoke of `__rust_begin_short_backtrace`.
```
this is just wrong. here is an example (full) backtrace:
<details>
```
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
Running `/home/jyn/.local/lib/cargo/target/debug/example`
called `Option::unwrap()` on a `None` value
stack backtrace:
0: 0x56499698c595 - std::backtrace_rs::backtrace::libunwind::trace::h5ef2cc16e9a7415a
1: 0x56499698c595 - std::backtrace_rs::backtrace::trace_unsynchronized::h9b5e016e9075f714
2: 0x56499698c595 - std::sys_common::backtrace::_print_fmt::h2f62c7f9ff224e93
3: 0x56499698c595 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hbe51682735731910
4: 0x5649969aa26b - core::fmt::rt::Argument::fmt::h1994ab2b310d665e
5: 0x5649969aa26b - core::fmt::write::hade58a36d63468d7
6: 0x56499698a43f - std::io::Write::write_fmt::h16145587d801a9ab
7: 0x56499698c36e - std::sys_common::backtrace::_print::ha8082e56201dadb4
8: 0x56499698c36e - std::sys_common::backtrace::print::he30f96b4e7f6cbfd
9: 0x56499698d709 - std::panicking::default_hook::{{closure}}::hf0801f6b18a968d3
10: 0x56499698d4ac - std::panicking::default_hook::hd2defec7eda5aeb0
11: 0x56499698dc31 - std::panicking::rust_panic_with_hook::hde93283600065c53
12: 0x56499698daf3 - std::panicking::begin_panic_handler::{{closure}}::h5e151adbdb7ec0c1
13: 0x56499698ca59 - std::sys_common::backtrace::__rust_end_short_backtrace::he36a1407e0f77700
14: 0x56499698d7d4 - rust_begin_unwind
15: 0x5649969a9503 - core::panicking::panic_fmt::h2380d41365f95412
16: 0x5649969a958c - core::panicking::panic::h38cf8db80e8c6e67
17: 0x5649969a93e9 - core::option::unwrap_failed::he72696e53ff29a05
18: 0x5649969722b6 - core::option::Option<T>::unwrap::hb574dc0dc1703062
19: 0x5649969722b6 - example::main::h7a867aafacd93d75
20: 0x5649969721db - core::ops::function::FnOnce::call_once::h734f99a5e57291b7
21: 0x56499697226e - std::sys_common::backtrace::__rust_begin_short_backtrace::h02f5d58c351c4756
22: 0x564996972241 - std::rt::lang_start::{{closure}}::h8b134fe2c31a4355
23: 0x564996988662 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::h88d7bb571ee2aaf4
24: 0x564996988662 - std::panicking::try::do_call::hfb78dfb6599c871d
25: 0x564996988662 - std::panicking::try::habd041c8c4c8e50c
27: 0x564996988662 - std::rt::lang_start_internal::{{closure}}::h227591a6f9c0879e
28: 0x564996988662 - std::panicking::try::do_call::h3c5878333c38916a
29: 0x564996988662 - std::panicking::try::h5af7b3a127cdae70
31: 0x564996988662 - std::rt::lang_start_internal::hbc85e809eeace0dd
32: 0x56499697221a - std::rt::lang_start::ha1eb16922c9cb224
33: 0x5649969722ee - main
34: 0x7f031962a1ca - __libc_start_call_main
35: 0x7f031962a28b - __libc_start_main_impl
36: 0x5649969720a5 - _start
37: 0x0 - <unknown>
```
</details>
note particularly frames 13-21, from start_backtrace to end_backtrace. with PrintFmt::Short, these are the *only* frames that are printed; i.e. we are doing the exact opposite of the comment.
r? ``@saethlin``
clarify simd_relaxed_fma non-determinism
This is the safer spec in the sense that it is more likely to be satisfied by the backend -- and if people are okay with a non-deterministic result, I assume they don't care whether it's the same choice across all lanes or not?
Cc ``@calebzulawski`` ``@workingjubilee``
Rename `core_pattern_type` and `core_pattern_types` lib feature gates to `pattern_type_macro`
That's what the gates are actually gating, and the single char difference in naming was not helpful either
fixes#128987
Add lint against function pointer comparisons
This is kind of a follow-up to https://github.com/rust-lang/rust/pull/117758 where we added a lint against wide pointer comparisons for being ambiguous and unreliable; well function pointer comparisons are also unreliable. We should IMO follow a similar logic and warn people about it.
-----
## `unpredictable_function_pointer_comparisons`
*warn-by-default*
The `unpredictable_function_pointer_comparisons` lint checks comparison of function pointer as the operands.
### Example
```rust
fn foo() {}
let a = foo as fn();
let _ = a == foo;
```
### Explanation
Function pointers comparisons do not produce meaningful result since they are never guaranteed to be unique and could vary between different code generation units. Furthermore different function could have the same address after being merged together.
----
This PR also uplift the very similar `clippy::fn_address_comparisons` lint, which only linted on if one of the operand was an `ty::FnDef` while this PR lints proposes to lint on all `ty::FnPtr` and `ty::FnDef`.
```@rustbot``` labels +I-lang-nominated
~~Edit: Blocked on https://github.com/rust-lang/libs-team/issues/323 being accepted and it's follow-up pr~~
The existing comments were misleading, confusing, and wrong.
Take this comment for example:
```
// Any frames between `__rust_begin_short_backtrace` and `__rust_end_short_backtrace`
// are omitted from the backtrace in short mode, `__rust_end_short_backtrace` will be
// called before the panic hook, so we won't ignore any frames if there is no
// invoke of `__rust_begin_short_backtrace`.
```
this is just wrong. here is an example (full) backtrace:
```
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.01s
Running `/home/jyn/.local/lib/cargo/target/debug/example`
called `Option::unwrap()` on a `None` value
stack backtrace:
0: 0x56499698c595 - std::backtrace_rs::backtrace::libunwind::trace::h5ef2cc16e9a7415a
1: 0x56499698c595 - std::backtrace_rs::backtrace::trace_unsynchronized::h9b5e016e9075f714
2: 0x56499698c595 - std::sys_common::backtrace::_print_fmt::h2f62c7f9ff224e93
3: 0x56499698c595 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hbe51682735731910
4: 0x5649969aa26b - core::fmt::rt::Argument::fmt::h1994ab2b310d665e
5: 0x5649969aa26b - core::fmt::write::hade58a36d63468d7
6: 0x56499698a43f - std::io::Write::write_fmt::h16145587d801a9ab
7: 0x56499698c36e - std::sys_common::backtrace::_print::ha8082e56201dadb4
8: 0x56499698c36e - std::sys_common::backtrace::print::he30f96b4e7f6cbfd
9: 0x56499698d709 - std::panicking::default_hook::{{closure}}::hf0801f6b18a968d3
10: 0x56499698d4ac - std::panicking::default_hook::hd2defec7eda5aeb0
11: 0x56499698dc31 - std::panicking::rust_panic_with_hook::hde93283600065c53
12: 0x56499698daf3 - std::panicking::begin_panic_handler::{{closure}}::h5e151adbdb7ec0c1
13: 0x56499698ca59 - std::sys_common::backtrace::__rust_end_short_backtrace::he36a1407e0f77700
14: 0x56499698d7d4 - rust_begin_unwind
15: 0x5649969a9503 - core::panicking::panic_fmt::h2380d41365f95412
16: 0x5649969a958c - core::panicking::panic::h38cf8db80e8c6e67
17: 0x5649969a93e9 - core::option::unwrap_failed::he72696e53ff29a05
18: 0x5649969722b6 - core::option::Option<T>::unwrap::hb574dc0dc1703062
19: 0x5649969722b6 - example::main::h7a867aafacd93d75
20: 0x5649969721db - core::ops::function::FnOnce::call_once::h734f99a5e57291b7
21: 0x56499697226e - std::sys_common::backtrace::__rust_begin_short_backtrace::h02f5d58c351c4756
22: 0x564996972241 - std::rt::lang_start::{{closure}}::h8b134fe2c31a4355
23: 0x564996988662 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::h88d7bb571ee2aaf4
24: 0x564996988662 - std::panicking::try::do_call::hfb78dfb6599c871d
25: 0x564996988662 - std::panicking::try::habd041c8c4c8e50c
27: 0x564996988662 - std::rt::lang_start_internal::{{closure}}::h227591a6f9c0879e
28: 0x564996988662 - std::panicking::try::do_call::h3c5878333c38916a
29: 0x564996988662 - std::panicking::try::h5af7b3a127cdae70
31: 0x564996988662 - std::rt::lang_start_internal::hbc85e809eeace0dd
32: 0x56499697221a - std::rt::lang_start::ha1eb16922c9cb224
33: 0x5649969722ee - main
34: 0x7f031962a1ca - __libc_start_call_main
35: 0x7f031962a28b - __libc_start_main_impl
36: 0x5649969720a5 - _start
37: 0x0 - <unknown>
```
note particularly frames 13-21, from start_backtrace to end_backtrace. with PrintFmt::Short, these are the *only* frames that are printed; i.e. we are doing the exact opposite of the comment.
Update `NonZero` and `NonNull` to not field-project (per MCP#807)
https://github.com/rust-lang/compiler-team/issues/807#issuecomment-2506098540 was accepted, so this is the first PR towards moving the library to not using field projections into `[rustc_layout_scalar_valid_range_*]` types.
`NonZero` was already using `transmute` nearly everywhere, so there are very few changes to it.
`NonNull` needed more changes, but they're mostly simple, changing `.pointer` to `.as_ptr()`.
r? libs
cc #133324, which will tidy up some of the MIR from this a bit more, but isn't a blocker.
a release operation synchronizes with an acquire operation
Change:
1. `Calls to park _synchronize-with_ calls to unpark` to `Calls to unpark _synchronize-with_ calls to park`
2. `park synchronizes-with _all_ prior unpark operations` to `_all_ prior unpark operations synchronize-with park`
LLVM does not include an implementation of the va_arg instruction for
Xtensa. From what I understand, this is a conscious decision and
instead language frontends are encouraged to implement it themselves.
The rationale seems to be that loading values correctly requires
language and ABI-specific knowledge that LLVM lacks.
This is true of most architectures, and rustc already provides
implementation for a number of them. This commit extends the support to
include Xtensa.
See https://lists.llvm.org/pipermail/llvm-dev/2017-August/116337.html
for some discussion on the topic.
Unfortunately there does not seem to be a reference document for the
semantics of the va_list and va_arg on Xtensa. The most reliable source
is the GCC implementation, which this commit tries to follow. Clang also
provides its own compatible implementation.
This was tested for all the types that rustc allows in variadics.
Co-authored-by: Brian Tarricone <brian@tarricone.org>
Co-authored-by: Jonathan Bastien-Filiatrault <joe@x2a.org>
Co-authored-by: Paul Lietar <paul@lietar.net>
Approved in [ACP 491](https://github.com/rust-lang/libs-team/issues/491).
Remove the `unsafe` on `core::intrinsics::breakpoint()`, since it's a
safe intrinsic to call and has no prerequisites.
(Thanks to @zachs18 for figuring out the `bootstrap`/`not(bootstrap)`
logic.)
Use c"lit" for CStrings without unwrap
I've reviewed uses of `CString::new("lit")`.
Some could be changed to `c"lit"`. Some could be changed to `c"lit".to_owned()`, avoiding an `unwrap()`.
Many `CString` documentation examples could be simplified. I deliberately haven't changed all the examples to use the exact same expression, so that they can demonstrate many ways of creating `CString`s.
I've left UI tests mostly unchanged, because `c""` requires edition 2021, but most UI tests use 2015, and I didn't want to accidentally change what the tests are testing.
Stabilize `const_maybe_uninit_write`
Mark the following API const stable:
```rust
impl<T> MaybeUninit<T> {
pub const fn write(&mut self, val: T) -> &mut T;
}
```
This depends on `const_mut_refs` and [`const_maybe_uninit_assume_init`](https://github.com/rust-lang/rust/issues/86722), both of which have recently been stabilized.
Closes: <https://github.com/rust-lang/rust/issues/63567>
Mark the following API const stable:
impl<T> MaybeUninit<T> {
pub const fn write(&mut self, val: T) -> &mut T;
}
This depends on `const_mut_refs` and `const_maybe_uninit_assume_init`,
both of which have recently been stabilized.
Tracking issue: <https://github.com/rust-lang/rust/issues/63567>
add isatty doc alias for `is_terminal`
(first Rust contribution!)
This adds `isatty` as a doc alias for [`std::io::IsTerminal::is_terminal`](https://doc.rust-lang.org/stable/std/io/trait.IsTerminal.html#tymethod.is_terminal).
I think this change does meet the [doc alias policy](https://std-dev-guide.rust-lang.org/policy/doc-alias.html). This would be especially useful because searching "rust isatty" gets you the `isatty` crate which is deprecated in favor of `atty`. `atty` is unmaintained and you might get to `is-terminal`, which will finally tell you that the function you're looking for has been in `std` all along.
The Windows implementation of `is_terminal()` doesn't use `isatty`, but that hasn't been a problem for the analogous cases of `create_dir()`'s alias `mkdir` or `remove_dir()`/`rmdir`.
Stabilize unsigned and float variants of `num_midpoint` feature
This PR proposes that we stabilize the unsigned variants of the [`num_midpoint`](https://github.com/rust-lang/rust/issues/110840#issue-1684506201) feature as well as the floats variants, since they are not subject to any unresolved questions, which is equivalent to doing `(a + b) / 2` (and `(a + b) >> 1`) in a sufficiently large number.
The stabilized API surface would be:
```rust
/// Calculates the middle point of `self` and `rhs`.
///
/// `midpoint(a, b)` is `(a + b) / 2` as if it were performed in a sufficiently-large unsigned integral type.
/// This implies that the result is always rounded towards negative infinity and that no overflow will ever occur.
impl u{8,16,32,64,128,size} {
pub const fn midpoint(self, rhs: Self) -> Self;
}
impl NonZeroU{8,16,32,64,size} {
pub const fn midpoint(self, rhs: Self) -> Self;
}
impl f{32,64} {
pub const fn midpoint(self, rhs: Self) -> Self;
}
```
The signed variants `u{8,16,32,64,128,size}` would remain gated, until a decision is made about the rounding mode, in other words that the [unresolved questions](https://github.com/rust-lang/rust/issues/110840#issue-1684506201) are resolved.
cc `@rust-lang/libs-api`
cc `@scottmcm`
r? libs-api
Mark `slice::copy_from_slice` unstably const
Tracking issue #131415
I used `const_eval_select` for runtime and const panic functions because const formatting isn't available yet.
Add diagnostic item for `std::ops::ControlFlow`
This will be used in Clippy to detect useless conversions done through `ControlFlow::map_break()` and `ControlFlow::map_continue()`.
