rename ptr::from_exposed_addr -> ptr::with_exposed_provenance
As discussed on [Zulip](https://rust-lang.zulipchat.com/#narrow/stream/136281-t-opsem/topic/To.20expose.20or.20not.20to.20expose/near/427757066).
The old name, `from_exposed_addr`, makes little sense as it's not the address that is exposed, it's the provenance. (`ptr.expose_addr()` stays unchanged as we haven't found a better option yet. The intended interpretation is "expose the provenance and return the address".)
The new name nicely matches `ptr::without_provenance`.
This PR aims to pin down exactly what restricted_std is meant to achieve
and what it isn't.
This commit fixes https://github.com/rust-lang/wg-cargo-std-aware/issues/87
by explaining why the error appears and what the choices the user has.
The error describes how std cannot function without knowing about some
form of OS/platform support. Any features of std that work without an
OS should be moved to core/alloc (see https://github.com/rust-lang/rust/issues/27242https://github.com/rust-lang/rust/issues/103765).
Note that the message says "platform" and "environment" because, since
https://github.com/rust-lang/rust/pull/120232, libstd can be built for
some JSON targets. This is still unsupported (all JSON targets probably
should be unstable https://github.com/rust-lang/wg-cargo-std-aware/issues/90),
but a JSON target with the right configuration should hopefully have
some partial libstd support.
I propose closing https://github.com/rust-lang/wg-cargo-std-aware/issues/69
as "Won't fix" since any support of std without properly configured os,
vendor or env fields is very fragile considering future upgrades of Rust
or dependencies. In addition there's no likely path to it being fixed
long term (making std buildable for all targets being the only
solution). This is distinct from tier 3 platforms with limited std
support implemented (and as such aren't restricted_std) because these
platforms can conceptually work in the future and std support should
mainly improve over time.
The alternative to closing https://github.com/rust-lang/wg-cargo-std-aware/issues/69
is a new crate feature for std which escapes the restricted_std
mechanism in build.rs. It could be used with the -Zbuild-std-features
flag if we keep it permanently unstable, which I hope we can do anyway.
A minor side-effect in this scenario is that std wouldn't be marked as
unstable if documentation for it were generated with build-std.
Refactor stack overflow handling
Currently, every platform must implement a `Guard` that protects a thread from stack overflow. However, UNIX is the only platform that actually does so. Windows has a different mechanism for detecting stack overflow, while the other platforms don't detect it at all. Also, the UNIX stack overflow handling is split between `sys::pal::unix::stack_overflow`, which implements the signal handler, and `sys::pal::unix::thread`, which detects/installs guard pages.
This PR cleans this by getting rid of `Guard` and unifying UNIX stack overflow handling inside `stack_overflow` (commit 1). Therefore we can get rid of `sys_common::thread_info`, which stores `Guard` and the current `Thread` handle and move the `thread::current` TLS variable into `thread` (commit 2).
The second commit is not strictly speaking necessary. To keep the implementation clean, I've included it here, but if it causes too much noise, I can split it out without any trouble.
Eliminate `UbChecks` for non-standard libraries
The purpose of this PR is to allow other passes to treat `UbChecks` as constants in MIR for optimization after #122629.
r? RalfJung
Soft-destabilize `RustcEncodable` & `RustcDecodable`, remove from prelude in next edition
cc rust-lang/libs-team#272
Any use of `RustcEncodable` and `RustcDecodable` now triggers a deny-by-default lint. The derives have been removed from the 2024 prelude. I specifically chose **not** to document this in the module-level documentation, as the presence in existing preludes is not documented (which I presume is intentional).
This does not implement the proposed change for `rustfix`, which I will be looking into shortly.
With regard to the items in the preludes being stable, this should not be an issue because #15702 has been resolved.
r? libs-api
Update `RwLock` deadlock example to not use shadowing
Tweak variable names in the deadlock example to remove any potential confusion that the behavior is somehow shadowing-related.
unix fs: Make hurd using explicit new rather than From
408c0ea216 ("unix time module now return result") dropped the From impl for SystemTime, breaking the hurd build (and probably the horizon build)
Fixes#123032
warning: casting raw pointers to the same type and constness is unnecessary (`*mut V` -> `*mut V`)
--> library\alloc\src\collections\btree\map\entry.rs:357:31
|
357 | let val_ptr = root.borrow_mut().push(self.key, value) as *mut V;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `root.borrow_mut().push
(self.key, value)`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
warning: casting to the same type is unnecessary (`usize` -> `usize`)
--> library\alloc\src\ffi\c_str.rs:411:56
|
411 | let slice = slice::from_raw_parts_mut(ptr, len as usize);
| ^^^^^^^^^^^^ help: try: `len`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
warning: casting raw pointers to the same type and constness is unnecessary (`*mut T` -> `*mut T`)
--> library\alloc\src\slice.rs:516:25
|
516 | (buf.as_mut_ptr() as *mut T).add(buf.len()),
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `buf.as_mut_ptr()`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
warning: casting raw pointers to the same type and constness is unnecessary (`*mut T` -> `*mut T`)
--> library\alloc\src\slice.rs:537:21
|
537 | (buf.as_mut_ptr() as *mut T).add(buf.len()),
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `buf.as_mut_ptr()`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
warning: casting raw pointers to the same type and constness is unnecessary (`*const ()` -> `*const ()`)
--> library\alloc\src\task.rs:151:13
|
151 | waker as *const (),
| ^^^^^^^^^^^^^^^^^^ help: try: `waker`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
warning: casting raw pointers to the same type and constness is unnecessary (`*const ()` -> `*const ()`)
--> library\alloc\src\task.rs:323:13
|
323 | waker as *const (),
| ^^^^^^^^^^^^^^^^^^ help: try: `waker`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
warning: casting to the same type is unnecessary (`usize` -> `usize`)
--> library\std\src\sys_common\net.rs:110:21
|
110 | assert!(len as usize >= mem::size_of::<c::sockaddr_in>());
| ^^^^^^^^^^^^ help: try: `len`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
warning: casting to the same type is unnecessary (`usize` -> `usize`)
--> library\std\src\sys_common\net.rs:116:21
|
116 | assert!(len as usize >= mem::size_of::<c::sockaddr_in6>());
| ^^^^^^^^^^^^ help: try: `len`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast
std:🧵 refine available_parallelism for solaris/illumos.
Rather than the system-wide available cpus fallback solution, we fetch the cpus bound to the current process.
panic-in-panic-hook: formatting a message that's just a string is risk-free
This slightly improves the output in the 'panic while processing panic' case if the panic message does not involve any formatting. Follow-up to https://github.com/rust-lang/rust/pull/122930.
r? ``@Amanieu``
