Otherwise code like this
#![no_implicit_prelude]
fn main() {
::std::todo!();
::std::unimplemented!();
}
will fail to compile, which is unfortunate and presumably unintended.
This changes many invocations of `panic!` in a `macro_rules!` definition
to invocations of `$crate::panic!`, which makes the invocations hygienic.
Note that this does not make the built-in macro `assert!` hygienic.
Drop support for all cloudabi targets
`cloudabi` is a tier-3 target, and [it is no longer being maintained upstream][no].
This PR drops supports for cloudabi targets. Those targets are:
* aarch64-unknown-cloudabi
* armv7-unknown-cloudabi
* i686-unknown-cloudabi
* x86_64-unknown-cloudabi
Since this drops supports for a target, I'd like somebody to tag `relnotes` label to this PR.
Some other issues:
* The tidy exception for `cloudabi` crate is still remained because
* `parking_lot v0.9.0` and `parking_lot v0.10.2` depends on `cloudabi v0.0.3`.
* `parking_lot v0.11.0` depends on `cloudabi v0.1.0`.
[no]: https://github.com/NuxiNL/cloudabi#note-this-project-is-unmaintained
Rollup of 10 pull requests
Successful merges:
- #76829 (stabilize const_int_pow)
- #79080 (MIR visitor: Don't treat debuginfo field access as a use of the struct)
- #79236 (const_generics: assert resolve hack causes an error)
- #79287 (Allow using generic trait methods in `const fn`)
- #79324 (Use Option::and_then instead of open-coding it)
- #79325 (Reduce boilerplate with the `?` operator)
- #79330 (Fix typo in comment)
- #79333 (doc typo)
- #79337 (Use Option::map instead of open coding it)
- #79343 (Add my (`@flip1995)` work mail to the mailmap)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Use Option::map instead of open coding it
r? `@jonas-schievink` since you're frequently sniping these minor cleanups anyway.
`@rustbot` modify labels +C-cleanup +T-compiler
Allow using generic trait methods in `const fn`
Next step for https://github.com/rust-lang/rust/issues/67792, this now also allows code like the following:
```rust
struct S;
impl const PartialEq for S {
fn eq(&self, _: &S) -> bool {
true
}
}
const fn equals_self<T: PartialEq>(t: &T) -> bool {
*t == *t
}
pub const EQ: bool = equals_self(&S);
```
This works by threading const-ness of trait predicates through trait selection, in particular through `ParamCandidate`, and exposing it in the resulting `ImplSource`.
Since this change makes two bounds `T: Trait` and `T: ?const Trait` that only differ in their const-ness be treated like different bounds, candidate winnowing has been changed to drop the `?const` candidate in favor of the const candidate, to avoid ambiguities when both a const and a non-const bound is present.
const_generics: assert resolve hack causes an error
prevent the min_const_generics `HACK`s in resolve from triggering a fallback path which successfully compiles so that we don't have to worry about future compat issues when removing it
r? `@eddyb` cc `@varkor`
Change slice::to_vec to not use extend_from_slice
I saw this [Zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/String.3A.3Afrom%28.26str%29.20wonky.20codegen/near/216164455), and didn't see any update from it, so I thought I'd try to fix it. This converts `to_vec` to no longer use `extend_from_slice`, but relies on knowing that the allocated capacity is the same size as the input.
[Godbolt new v1](https://rust.godbolt.org/z/1bcWKG)
[Godbolt new v2 w/ drop guard](https://rust.godbolt.org/z/5jn76K)
[Godbolt old version](https://rust.godbolt.org/z/e4ePav)
After some amount of iteration, there are now two specializations for `to_vec`, one for `Copy` types that use memcpy, and one for clone types which is the original from this PR.
This is then used inside of `impl<T: Clone> FromIterator<Iter::Slice<T>> for Vec<T>` which is essentially equivalent to `&[T] -> Vec<T>`, instead of previous specialization of the `extend` function. This is because extend has to reason more about existing capacity by calling `reserve` on an existing vec, and thus produces worse asm.
Downsides: This allocates the exact capacity, so I think if many items are added to this `Vec` after, it might need to allocate whereas extending may not. I also noticed the number of faults went up in the benchmarks, but not sure where from exactly.
Fixes#79242
If a `macro_rules!` recursively builds up a nested nonterminal
(passing it to a proc-macro at each step), we will end up repeatedly
pretty-printing/retokenizing the same nonterminals. Unfortunately, the
'probable equality' check we do has a non-trivial cost, which leads to a
blowup in compilation time.
As a workaround, we cache the result of the 'probable equality' check,
which eliminates the compilation time blowup for the linked issue. This
commit only touches a single file (other than adding tests), so it
should be easy to backport.
The proper solution is to remove the pretty-print/retokenize hack
entirely. However, this will almost certainly break a large number of
crates that were relying on hygiene bugs created by using the reparsed
`TokenStream`. As a result, we will definitely not want to backport
such a change.
Impl Default for PhantomPinned
`PhantomPinned` is just a marker type, with an obvious default value (the only value). So I can't think of a reason not to do this. Sure, it's used in exotic situations with unsafe code. But the people writing that code can decide for themselves if they can derive `Default`, and in many situations the derived impl will make sense:
```rust
#[derive(Default)]
struct NeedsPin {
marker: PhantomPinned,
buf: [u8; 1024],
ptr_to_data: Option<*const u8>,
}
```
Stabilize `IpAddr::is_ipv4` and `is_ipv6` as const
Insta-stabilize the methods `is_ipv4` and `is_ipv6` of `std::net::IpAddr` as const, in the same way as [PR#76198](https://github.com/rust-lang/rust/pull/76198).
Possible because of the recent stabilization of const control flow.
Part of #76225 and #76205.
Also stabilize constctlz for const ctlz_nonzero.
The public methods stabilized const by this commit are:
* `{i*,u*}::checked_pow`
* `{i*,u*}::saturating_pow`
* `{i*,u*}::wrapping_pow`
* `{i*,u*}::overflowing_pow`
* `{i*,u*}::pow`
* `u*::next_power_of_two`
* `u*::checked_next_power_of_two`
* `u*::wrapping_next_power_of_two` (the method itself is still unstable)
Insta-stabilize the methods `is_ipv4` and `is_ipv6` of `IpAddr`.
Possible because of the recent stabilization of const control flow.
Also adds a test for these methods in a const context.
Change `-Z fewer-names` into an optional boolean flag and allow using it
to either discard value names when true or retain them when false,
regardless of other settings.
This also required adding a loop guard in case clone panics
Add specialization for copy
There is a better version for copy, so I've added specialization for that function
and hopefully that should speed it up even more.
Switch FromIter<slice::Iter> to use `to_vec`
Test different unrolling version for to_vec
Revert to impl
From benchmarking, it appears this version is faster
