Indicate that multiplication in Layout::array cannot overflow
Since https://github.com/rust-lang/rust/pull/113113, we have added a check that skips calling into the allocator at all if `capacity == 0`. The global, default allocator will not actually try to allocate though; it returns a dangling pointer explicitly. However, these two checks are not merged/deduplicated by LLVM and so we're comparing to zero twice whenever vectors are allocated/grown. Probably cheap, but also potentially expensive in code size and seems like an unfortunate miss.
This removes that extra check by telling LLVM that the multiplication as part of Layout::array can't overflow, turning the original non-zero value into a zero value afterwards. In my checks locally this successfully drops the duplicate comparisons.
See https://rust.godbolt.org/z/b6nPP9dcK for a code example.
```rust
pub fn foo(elements: usize) -> Vec<u32> {
Vec::with_capacity(elements)
}
```
r? `@scottmcm` since you touched this in a32305a80f - curious if you have thoughts on doing this / can confirm my model of this being correct.
Use an absolute path to the NUL device
While a bare "NUL" *should* be redirected to the NUL device, especially in this simple case, let's be explicit that we aren't opening a file called "NUL" and instead open it directly.
This will also set a good example for people copying std code.
r? libs
Update windows-bindgen and define `INVALID_HANDLE_VALUE` ourselves
We generate bindings to the Windows API via the `windows-bindgen` crate, which is ultimately what's also used to generate the `windows-sys` and `windows` crates. However, there currently is some custom sauce just for std which makes it a bit different from the vanilla bindings. I would love for us to reduce and eventually remove the differences entirely so that std is using the exact same bindings as everyone else. Maybe in the future we can even just have a normal dependency on `windows-sys`.
This PR removes one of those special things. Our definition of `INVALID_HANDLE_VALUE` relies on an experimental nightly feature for strict provenance, so lets bring that back in house. It also excludes it from the codegen step though that isn't strictly necessary as we override it in any case.
This PR also updates windows-bingen to 0.52.0.
Improve rewind documentation
The persistent use of an internal cursor for readers is expected for buffer data types that aren't read all at once, but for files it leads to the confusing situation where calling `read_to_end` on the same file handle multiple times only returns the contents of the file for the first call. This PR adds a note to the documentation clarifying that in that case, `rewind()` must first be called.
I'm unsure if this is the right location for the docs update. Maybe it should also be duplicated on `File`?
Cache flags for `ty::Const`
Not sure if this has been attempted yet, but worth a shot. It does make the code simpler in `rustc_type_ir`, since we can assume that consts have a `flags` method that is no-cost.
r? `@ghost`
This allows LLVM to optimize comparisons to zero before & after the
multiplication into one, saving on code size and eliminating an (always
true) branch from most Vec allocations.
Fix fn_sig_for_fn_abi and the coroutine transform for generators
There were three issues previously:
* The self argument was pinned, despite Iterator::next taking an unpinned mutable reference.
* A resume argument was passed, despite Iterator::next not having one.
* The return value was CoroutineState<Item, ()> rather than Option<Item>
While these things just so happened to work with the LLVM backend, cg_clif does much stricter checks when trying to assign a value to a place. In addition it can't handle the mismatch between the amount of arguments specified by the FnAbi and the FnSig.
There were three issues previously:
* The self argument was pinned, despite Iterator::next taking an
unpinned mutable reference.
* A resume argument was passed, despite Iterator::next not having one.
* The return value was CoroutineState<Item, ()> rather than Option<Item>
While these things just so happened to work with the LLVM backend,
cg_clif does much stricter checks when trying to assign a value to a
place. In addition it can't handle the mismatch between the amount of
arguments specified by the FnAbi and the FnSig.
Don't print "private fields" on empty tuple structs
Closes#118180.
While working on this I also noticed that empty struct variants are also rendered rather awkwardly. I'll make another issue for that, since I don't know what the correct rendering would be.
Pass flags to `rustdoc` shim without env. vars
Discussed here: https://github.com/rust-lang/rust/pull/116448#issuecomment-1748785961. Since it was not really documented why these flags were passed through the shim, I guess that the only way to find out if it's really needed... is to remove it :)
r? `@petrochenkov`
Miri: GC the dead_alloc_map too
dead_alloc_map is the last piece of state in the interpreter I can find that leaks. With this PR, all of the long-term memory growth I can find in Miri with programs that do things like run a big `loop {` or run property tests is attributable to some data structure properties in borrow tracking, and is _extremely_ slow.
My only gripe with the commit in this PR is that I don't have a new test for it. I'd like to have a regression test for this, but it would have to be statistical I think because the peak memory of a process that Linux reports is not exactly the same run-to-run. Which means it would have to not be very sensitive to slow leaks (some guesswork suggests for acceptable CI time we would be checking for like 10% memory growth over a minute or two, which is still pretty fast IMO).
Unless someone has a better idea for how to detect a regression, I think on balance I'm fine with manually keeping an eye on the memory use situation.
r? RalfJung
print query map for deadlock when using parallel front end
print query map for deadlock when using parallel front end, so that we can analyze where and why deadlock occurs
Rework supertrait lint once again
I accidentally pushed the wrong commits because I totally didn't check I was on the right computer when updating #118026.
Sorry, this should address all the nits in #118026.
r? lcnr
improve tool-only help for multiple `#[default]` variants
When defining an enum with multiple `#[default]` variants, we emit a tool-only suggestion for every `#[default]`ed variant to remove all other `#[default]`s. This PR improves the suggestion to correctly handle the cases where one variant has multiple `#[default]`s and where different `#[default]`s have the same span due to macro expansions.
fixes https://github.com/rust-lang/rust/issues/118119
kmc-solid: I/O safety
Adds the I/O safety API (#87329) for socket file descriptors in [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets. All new public items are gated by the `solid_ext` library feature.
This PR adds the following public types and traits:
std::os::solid::io::AsFd
std::os::solid::io::BorrowedFd
std::os::solid::io::OwnedFd
std::os::solid::prelude::AsFd (re-export)
std::os::solid::prelude::BorrowedFd (re-export)
std::os::solid::prelude::OwnedFd (re-export)
And trait implementations:
From<std::net::TcpListener> for std::os::solid::io::OwnedFd
From<std::net::TcpStream> for std::os::solid::io::OwnedFd
From<std::net::UdpSocket> for std::os::solid::io::OwnedFd
From<std::os::solid::io::OwnedFd> for std::net::TcpListener
From<std::os::solid::io::OwnedFd> for std::net::TcpStream
From<std::os::solid::io::OwnedFd> for std::net::UdpSocket
std::fmt::Debug for std::os::solid::io::BorrowedFd<'_>
std::fmt::Debug for std::os::solid::io::OwnedFd
std::io::IsTerminal for std::os::solid::io::BorrowedFd<'_>
std::io::IsTerminal for std::os::solid::io::OwnedFd
std::os::fd::AsRawFd for std::os::solid::io::BorrowedFd<'_>
std::os::fd::AsRawFd for std::os::solid::io::OwnedFd
std::os::fd::FromRawFd for std::os::solid::io::OwnedFd
std::os::fd::IntoRawFd for std::os::solid::io::OwnedFd
std::os::solid::io::AsFd for &impl std::os::solid::io::AsFd
std::os::solid::io::AsFd for &mut impl std::os::solid::io::AsFd
std::os::solid::io::AsFd for Arc<impl std::os::solid::io::AsFd>
std::os::solid::io::AsFd for Box<impl std::os::solid::io::AsFd>
std::os::solid::io::AsFd for Rc<impl std::os::solid::io::AsFd>
std::os::solid::io::AsFd for std::net::TcpListener
std::os::solid::io::AsFd for std::net::TcpStream
std::os::solid::io::AsFd for std::net::UdpSocket
std::os::solid::io::AsFd for std::os::solid::io::BorrowedFd<'_>
std::os::solid::io::AsFd for std::os::solid::io::OwnedFd
Taking advantage of the above change, this PR also refactors the internal details of `std::sys::solid::net` to match the design of other targets, e.g., by redefining `Socket` as a newtype of `OwnedFd`.
Fix some clippy lints for library/std/src/sys/windows
These issues were shown by running `x clippy` on `library/std` and filtering for `windows/` paths. I think running clippy on the full std would be great but I wanted to start smaller and with something that's hopefully easier to review. It'd be good to eventually run clippy in CI but that's a bigger conversation.
I've created separate commits for each clippy lint fixed (with the commit title set to the lint name) and reviewed the changes myself. Most of the fixes here are trivial.
r? libs
Remove `PredicateKind::ClosureKind`
We don't need the `ClosureKind` predicate kind -- instead, `Fn`-family trait goals are left as ambiguous, and we only need to make progress on `FnOnce` projection goals for inference purposes.
This is similar to how we do confirmation of `Fn`-family trait and projection goals in the new trait solver, which also doesn't use the `ClosureKind` predicate.
Some hacky logic is added in the second commit so that we can keep the error messages the same.
Rollup of 6 pull requests
Successful merges:
- #118012 (Add support for global allocation in smir)
- #118013 (Enable Rust to use the EHCont security feature of Windows)
- #118100 (Enable profiler in dist-powerpc64-linux)
- #118142 (Tighten up link attributes for llvm-wrapper bindings)
- #118147 (Fix some unnecessary casts)
- #118161 (Allow defining opaques in `check_coroutine_obligations`)
r? `@ghost`
`@rustbot` modify labels: rollup
Allow defining opaques in `check_coroutine_obligations`
In the new trait solver, when an obligation stalls on an unresolved coroutine witness, we will stash away the *root* obligation, even if the stalled obligation is only a distant descendent of the root obligation, since the new solver is purely recursive.
This means that we may need to reprocess alias-relate obligations (and others) which may define opaque types in the new solver. Currently, we use the coroutine's def id as the defining anchor in `check_coroutine_obligations`, which will allow defining no opaque types, resulting in errors like:
```
error[E0271]: type mismatch resolving `{coroutine@<source>:6:5: 6:17} <: impl Clone`
--> <source>:6:5
|
6 | / move |_: ()| {
7 | | let () = yield ();
8 | | }
| |_____^ types differ
```
So this PR fixes the defining anchor and does the same trick as `check_opaque_well_formed`, where we manually compare opaques that were defined against their hidden types to make sure they weren't defined differently when processing these stalled coroutine obligations.
r? `@lcnr` cc `@cjgillot`
Tighten up link attributes for llvm-wrapper bindings
Fixes https://github.com/rust-lang/rust/issues/118084 by moving all of the declarations of symbols from `llvm_rust` into a separate extern block with `#[link(name = "llvm-wrapper", kind = "static")]`.
This also renames `LLVMTimeTraceProfiler*` to `LLVMRustTimeTraceProfiler*` because those are functions from `llvm_rust`.
r? tmiasko
