Avoid codegen for Result::into_ok in lang_start
This extra codegen seems to be the cause for the regressions in max-rss on #86034. While LLVM will certainly optimize the dead code away, avoiding it's generation in the first place seems good, particularly when it is so simple.
#86034 produced this [diff](https://gist.github.com/Mark-Simulacrum/95c7599883093af3b960c35ffadf4dab#file-86034-diff) for a simple `fn main() {}`. With this PR, that diff [becomes limited to just a few extra IR instructions](https://gist.github.com/Mark-Simulacrum/95c7599883093af3b960c35ffadf4dab#file-88988-from-pre-diff) -- no extra functions.
Note that these are pre-optimization; LLVM surely will eliminate this during optimization. However, that optimization can end up generating more work and bump memory usage, and this eliminates that.
Allow `panic!("{}", computed_str)` in const fn.
Special-case `panic!("{}", arg)` and translate it to `panic_display(&arg)`. `panic_display` will behave like `panic_any` in cosnt eval and behave like `panic!(format_args!("{}", arg))` in runtime.
This should bring Rust 2015 and 2021 to feature parity in terms of `const_panic`; and hopefully would unblock the stabilisation of #51999.
`@rustbot` modify labels: +T-compiler +T-libs +A-const-eval +A-const-fn
r? `@oli-obk`
Add chown functions to std::os::unix::fs to change the owner and group of files
This is a straightforward wrapper that uses the existing helpers for C
string handling and errno handling.
Having this available is convenient for UNIX utility programs written in
Rust, and avoids having to call unsafe functions like `libc::chown`
directly and handle errors manually, in a program that may otherwise be
entirely safe code.
In addition, these functions provide a more Rustic interface by
accepting appropriate traits and using `None` rather than `-1`.
Add TcpListener::into_incoming and IntoIncoming
The `incoming` method is really useful, however for some use cases the borrow
this introduces is needlessly restricting. Thus, an owned variant is added.
r? ``@joshtriplett``
The RefCell is now borrowed exactly once. In addition a code sequence
that contains an unwrap that is guaranteed to never panic at runtime is
replaced with get_or_insert_with, which makes the intended behavior
clearer and will not emit code to panic even without optimizations.
Previously the thread name would first be heap allocated and then
re-allocated to add a nul terminator. Now it will be heap allocated only
once with nul terminator added form the start.
This is a straightforward wrapper that uses the existing helpers for C
string handling and errno handling.
Having this available is convenient for UNIX utility programs written in
Rust, and avoids having to call unsafe functions like `libc::chown`
directly and handle errors manually, in a program that may otherwise be
entirely safe code.
In addition, these functions provide a more Rustic interface by
accepting appropriate traits and using `None` rather than `-1`.
This works by doing two things:
- Adding links that are specific to the crate. Since not all primitive
items are defined in `core` (due to lang_items), these need to use
relative links and not intra-doc links.
- Duplicating `primitive_docs` in both core and std. This allows not needing CARGO_PKG_NAME to build the standard library. It also adds a tidy check to make sure they stay the same.
As discussed in #88576, raw handle values in Windows can be null, such
as in `windows_subsystem` mode, or when consoles are detached from a
process. So, don't use `NonNull` to hold them, don't assert that they're
not null, and remove `OwnedHandle`'s `repr(transparent)`. Introduce a
new `HandleOrNull` type, similar to `HandleOrInvalid`, to cover the FFI
use case.
More symbolic doc aliases
A bunch of small changes, mostly adding `#[doc(alias = "…")]` entries for symbolic `"…"`.
Also a small change in documentation of `const` keywords.
Document when to use Windows' `symlink_dir` vs. `symlink_file`
It was previously unclear why there are two functions and when they should be used.
Fixes: #88635
Add links in docs for some primitive types
This pull request adds additional links in existing documentation of some of the primitive types.
Where items are linked only once, I have used the `[link](destination)` format. For items in `std`, I have linked directly to the HTML, since although the primitives are in `core`, they are not displayed on `core` documentation. I was unsure of what length I should keep lines of documentation to, so I tried to keep them within reason.
Additionally, I have avoided excessively linking to keywords like `self` when they are not relevant to the documentation. I can add these links if it would be an improvement.
I hope this can improve Rust. Please let me know if there's anything I did wrong!
