For `libc` types that will be initialized in FFI calls, we can just use
`MaybeUninit` and then pass around raw pointers.
For `sun_path_offset()`, which really wants `offset_of`, all callers
have a real `sockaddr_un` available, so we can use that reference.
This renames `std::io::IoVec` to `std::io::IoSlice` and
`std::io::IoVecMut` to `std::io::IoSliceMut`, and stabilizes
`std::io::IoSlice`, `std::io::IoSliceMut`,
`std::io::Read::read_vectored`, and `std::io::Write::write_vectored`.
Closes#58452
Add vectored read and write support
This functionality has lived for a while in the tokio ecosystem, where
it can improve performance by minimizing copies.
r? @alexcrichton
Cosmetic improvements to doc comments
This has been factored out from https://github.com/rust-lang/rust/pull/58036 to only include changes to documentation comments (throughout the rustc codebase).
r? @steveklabnik
Once you're happy with this, maybe we could get it through with r=1, so it doesn't constantly get invalidated? (I'm not sure this will be an issue, but just in case...) Anyway, thanks for your advice so far!
Ever since we added a Cargo-based build system for the compiler the
standard library has always been a little special, it's never been able
to depend on crates.io crates for runtime dependencies. This has been a
result of various limitations, namely that Cargo doesn't understand that
crates from crates.io depend on libcore, so Cargo tries to build crates
before libcore is finished.
I had an idea this afternoon, however, which lifts the strategy
from #52919 to directly depend on crates.io crates from the standard
library. After all is said and done this removes a whopping three
submodules that we need to manage!
The basic idea here is that for any crate `std` depends on it adds an
*optional* dependency on an empty crate on crates.io, in this case named
`rustc-std-workspace-core`. This crate is overridden via `[patch]` in
this repository to point to a local crate we write, and *that* has a
`path` dependency on libcore.
Note that all `no_std` crates also depend on `compiler_builtins`, but if
we're not using submodules we can publish `compiler_builtins` to
crates.io and all crates can depend on it anyway! The basic strategy
then looks like:
* The standard library (or some transitive dep) decides to depend on a
crate `foo`.
* The standard library adds
```toml
[dependencies]
foo = { version = "0.1", features = ['rustc-dep-of-std'] }
```
* The crate `foo` has an optional dependency on `rustc-std-workspace-core`
* The crate `foo` has an optional dependency on `compiler_builtins`
* The crate `foo` has a feature `rustc-dep-of-std` which activates these
crates and any other necessary infrastructure in the crate.
A sample commit for `dlmalloc` [turns out to be quite simple][commit].
After that all `no_std` crates should largely build "as is" and still be
publishable on crates.io! Notably they should be able to continue to use
stable Rust if necessary, since the `rename-dependency` feature of Cargo
is soon stabilizing.
As a proof of concept, this commit removes the `dlmalloc`,
`libcompiler_builtins`, and `libc` submodules from this repository. Long
thorns in our side these are now gone for good and we can directly
depend on crates.io! It's hoped that in the long term we can bring in
other crates as necessary, but for now this is largely intended to
simply make it easier to manage these crates and remove submodules.
This should be a transparent non-breaking change for all users, but one
possible stickler is that this almost for sure breaks out-of-tree
`std`-building tools like `xargo` and `cargo-xbuild`. I think it should
be relatively easy to get them working, however, as all that's needed is
an entry in the `[patch]` section used to build the standard library.
Hopefully we can work with these tools to solve this problem!
[commit]: 28ee12db81
We've seen sporadic QE failures in the timeout tests on this assertion:
assert!(kind == ErrorKind::WouldBlock || kind == ErrorKind::TimedOut);
So there's an error, but not either of the expected kinds. Adding a
format to show the kind revealed `ErrorKind::Interrupted` (`EINTR`).
For the cases that were using `read`, we can just use `read_exact` to
keep trying after interruption. For those using `recv_from`, we have to
manually loop until we get a non-interrupted result.
Unix sockets on redox
This is done using the ipcd daemon. It's not exactly like unix sockets because there is not actually a physical file for the path, but it's close enough for a basic implementation :)
This allows mio-uds and tokio-uds to work with a few modifications as well, which is exciting!
Android abstract unix domain sockets AddressKind correction
The prior check causes abstract unix domain sockets to return AddressKind::Unnamed instead of AddressKind::Abstract on Android.
Other than the immediately proceeding comment "macOS seems to return a len of 16 and a zeroed sun_path for unnamed addresses" the check as-implemented does not seem to have alternative explanation. I couldn't find an alternative explanation while stepping though git blame. I suspect the AddressKind::Unnamed nonzero check should instead be if macos, length 16, and zeroed array. @sfackler could you comment on this, the code as-is is the same from your initial addition of abstract uds support.
Add documentation links to the original type for various OS-specific
extension traits and normalize the language for introducing such traits.
Also, remove some outdated comments around the extension trait
definitions.
