Stabilize all stable methods of `Ipv4Addr`, `Ipv6Addr` and `IpAddr` as const
This PR stabilizes all currently stable methods of `Ipv4Addr`, `Ipv6Addr` and `IpAddr` as const.
Tracking issue: #76205
`Ipv4Addr` (`const_ipv4`):
- `octets`
- `is_loopback`
- `is_private`
- `is_link_local`
- `is_multicast`
- `is_broadcast`
- `is_docmentation`
- `to_ipv6_compatible`
- `to_ipv6_mapped`
`Ipv6Addr` (`const_ipv6`):
- `segments`
- `is_unspecified`
- `is_loopback`
- `is_multicast`
- `to_ipv4`
`IpAddr` (`const_ip`):
- `is_unspecified`
- `is_loopback`
- `is_multicast`
## Motivation
The ip methods seem like prime candidates to be made const: their behavior is defined by an external spec, and based solely on the byte contents of an address. These methods have been made unstable const in the beginning of September, after the necessary const integer arithmetic was stabilized.
There is currently a PR open (#78802) to change the internal representation of `IpAddr{4,6}` from `libc` types to a byte array. This does not have any impact on the constness of the methods.
## Implementation
Most of the stabilizations are straightforward, with the exception of `Ipv6Addr::segments`, which uses the unstable feature `const_fn_transmute`. The code could be rewritten to equivalent stable code, but this leads to worse code generation (#75085).
This is why `segments` gets marked with `#[rustc_allow_const_fn_unstable(const_fn_transmute)]`, like the already const-stable `Ipv6Addr::new`, the justification being that a const-stable alternative implementation exists https://github.com/rust-lang/rust/pull/76206#issuecomment-685044184.
## Future posibilities
This PR const-stabilizes all currently stable ip methods, however there are also a number of unstable methods under the `ip` feature (#27709). These methods are already unstable const. There is a PR open (#76098) to stabilize those methods, which could include const-stabilization. However, stabilizing those methods as const is dependent on `Ipv4Addr::octets` and `Ipv6Addr::segments` (covered by this PR).
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
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.
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.
replace `#[allow_internal_unstable]` with `#[rustc_allow_const_fn_unstable]` for `const fn`s
`#[allow_internal_unstable]` is currently used to side-step feature gate and stability checks.
While it was originally only meant to be used only on macros, its use was expanded to `const fn`s.
This pr adds stricter checks for the usage of `#[allow_internal_unstable]` (only on macros) and introduces the `#[rustc_allow_const_fn_unstable]` attribute for usage on `const fn`s.
This pr does not change any of the functionality associated with the use of `#[allow_internal_unstable]` on macros or the usage of `#[rustc_allow_const_fn_unstable]` (instead of `#[allow_internal_unstable]`) on `const fn`s (see https://github.com/rust-lang/rust/issues/69399#issuecomment-712911540).
Note: The check for `#[rustc_allow_const_fn_unstable]` currently only validates that the attribute is used on a function, because I don't know how I would check if the function is a `const fn` at the place of the check. I therefore openend this as a 'draft pull request'.
Closesrust-lang/rust#69399
r? @oli-obk
warning: the operation is ineffective. Consider reducing it to
`self.segments()[0]`
--> library/std/src/net/ip.rs:1265:9
|
1265 | (self.segments()[0] & 0xffff) == 0xfe80
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `#[warn(clippy::identity_op)]` on by default
= help: for further information visit
https://rust-lang.github.io/rust-clippy/master/index.html#identity_op
warning: the operation is ineffective. Consider reducing it to
`self.segments()[1]`
--> library/std/src/net/ip.rs:1266:16
|
1266 | && (self.segments()[1] & 0xffff) == 0
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: for further information visit
https://rust-lang.github.io/rust-clippy/master/index.html#identity_op
warning: the operation is ineffective. Consider reducing it to
`self.segments()[2]`
--> library/std/src/net/ip.rs:1267:16
|
1267 | && (self.segments()[2] & 0xffff) == 0
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: for further information visit
https://rust-lang.github.io/rust-clippy/master/index.html#identity_op
warning: the operation is ineffective. Consider reducing it to
`self.segments()[3]`
--> library/std/src/net/ip.rs:1268:16
|
1268 | && (self.segments()[3] & 0xffff) == 0
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: for further information visit
https://rust-lang.github.io/rust-clippy/master/index.html#identity_op
Signed-off-by: wcampbell <wcampbell1995@gmail.com>
warning: struct update has no effect, all the fields in the struct have
already been specified
--> library/std/src/net/addr.rs:367:19
|
367 | ..unsafe { mem::zeroed() }
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `#[warn(clippy::needless_update)]` on by default
= help: for further information visit
https://rust-lang.github.io/rust-clippy/master/index.html#needless_update
Make delegation methods of `std::net::IpAddr` unstably const
Make the following methods of `std::net::IpAddr` unstable const under the `const_ip` feature:
- `is_unspecified`
- `is_loopback`
- `is_global`
- `is_multicast`
Also adds a test for these methods in a const context.
Possible because these methods delegate to the inner `Ipv4Addr` or `Ipv6Addr`, which were made const ([PR#76205](https://github.com/rust-lang/rust/pull/76142) and [PR#76206](https://github.com/rust-lang/rust/pull/76206)), and the recent stabilization of const control flow.
Part of #76205
r? @ecstatic-morse
Make the following methods of `std::net::IpAddr` unstable const under the `const_ip` feature:
- `is_unspecified`
- `is_loopback`
- `is_global`
- `is_multicast`
Also adds a test for these methods in a const context.
Possible because these methods delegate to the inner `Ipv4Addr` or `Ipv6Addr`, which were made const, and the recent stabilization of const control flow.
Part of #76205
Convert many files to intra-doc links
Helps with https://github.com/rust-lang/rust/issues/75080
r? @poliorcetics
I recommend reviewing one commit at a time, but the diff is small enough you can do it all at once if you like :)
Make all methods of `std::net::Ipv4Addr` const
Make the following methods of `std::net::Ipv4Addr` unstable const under the `const_ipv4` feature:
- `octets`
- `is_loopback`
- `is_private`
- `is_link_local`
- `is_global` (unstable)
- `is_shared` (unstable)
- `is_ietf_protocol_assignment` (unstable)
- `is_benchmarking` (unstable)
- `is_reserved` (unstable)
- `is_multicast`
- `is_broadcast`
- `is_documentation`
- `to_ipv6_compatible`
- `to_ipv6_mapped`
This would make all methods of `Ipv6Addr` const.
Of these methods, `is_global`, `is_broadcast`, `to_ipv6_compatible`, and `to_ipv6_mapped` require a change in implementation.
Part of #76205
- Use intra-doc links for `std::io` in `std::fs`
- Use intra-doc links for File::read in unix/ext/fs.rs
- Remove explicit intra-doc links for `true` in `net/addr.rs`
- Use intra-doc links in alloc/src/sync.rs
- Use intra-doc links in src/ascii.rs
- Switch to intra-doc links in alloc/rc.rs
- Use intra-doc links in core/pin.rs
- Use intra-doc links in std/prelude
- Use shorter links in `std/fs.rs`
`io` is already in scope.
Makes the following methods of `std::net::Ipv4Addr` unstable const under the `const_ipv4` feature:
- `is_global`
- `is_reserved`
- `is_broadcast`
- `to_ipv6_compatible`
- `to_ipv6_mapped`
This results in all methods of `Ipv4Addr` being const.
Also adds tests for these methods in a const context.
Make the following methods of `std::net::Ipv6Addr` unstable const under the `const_ipv6` feature:
- `segments`
- `is_unspecified`
- `is_loopback`
- `is_global` (unstable)
- `is_unique_local`
- `is_unicast_link_local_strict`
- `is_documentation`
- `multicast_scope`
- `is_multicast`
- `to_ipv4_mapped`
- `to_ipv4`
Changed the implementation of `is_unspecified` and `is_loopback` to use a `match` instead of `==`.
Part of #76205
Constify the following methods of `std::net::Ipv4Addr`:
- `octets`
- `is_loopback`
- `is_private`
- `is_link_local`
- `is_shared`
- `is_ietf_protocol_assignment`
- `is_benchmarking`
- `is_multicast`
- `is_documentation`
Also insta-stabilizes these methods as const.
Possible because of the stabilization of const integer arithmetic and control flow.
