Avoid a gratuitous 10s wait in a stress test
`stress_recv_timeout_two_threads`, in the mpmc and mpsc testsuites, is a stress test of the `recv_timeout` function. This test processes and ignores timeouts, and just ensures that every sent value gets received. As such, the exact length of the timeouts is not critical, only that the timeout and sleep durations ensure that at least one timeout occurred.
The current tests have 100 iterations, half of which sleep for 200ms, causing the test to take 10s. This represents around 2/3rds of the *total* runtime of the `library/std` testsuite, and is the only standard library test that takes more than a second.
Reduce this to 50 iterations where half of them sleep for 10ms, causing the test to take 0.25s.
Add a check that at least one timeout occurred.
`stress_recv_timeout_two_threads`, in the mpmc and mpsc testsuites,
is a stress test of the `recv_timeout` function. This test processes and
ignores timeouts, and just ensures that every sent value gets received.
As such, the exact length of the timeouts is not critical, only that
the timeout and sleep durations ensure that at least one timeout
occurred.
The current tests have 100 iterations, half of which sleep for 200ms,
causing the test to take 10s. This represents around 2/3rds of the
*total* runtime of the `library/std` testsuite.
Reduce this to 50 iterations where half of them sleep for 10ms, causing
the test to take 0.25s.
Add a check that at least one timeout occurred.
In PR 90877 T-lang decided not to remove `intrinsics::pref_align_of`.
However, the intrinsic and its supporting code
1. is a nightly feature, so can be removed at compiler/libs discretion
2. requires considerable effort in the compiler to support, as it
necessarily complicates every single site reasoning about alignment
3. has been justified based on relevance to codegen, but it is only a
requirement for C++ (not C, not Rust) stack frame layout for AIX,
in ways Rust would not consider even with increased C++ interop
4. is only used by rustc to overalign some globals, not correctness
5. can be adequately replaced by other rules for globals, as it mostly
affects alignments for a few types under 16 bytes of alignment
6. has only one clear benefactor: automating C -> Rust translation
for GNU extensions like `__alignof`
7. such code was likely intended to be `alignof` or `_Alignof`,
because the GNU extension is a "false friend" of the C keyword,
which makes the choice to support such a mapping very questionable
8. makes it easy to do incorrect codegen in the compiler by its mere
presence as usual Rust rules of alignment (e.g. `size == align * N`)
do not hold with preferred alignment
The implementation is clearly damaging the code quality of the compiler.
Thus it is within the compiler team's purview to simply rip it out.
If T-lang wishes to have this intrinsic restored for c2rust's benefit,
it would have to use a radically different implementation that somehow
does not cause internal incorrectness.
Until then, remove the intrinsic and its supporting code, as one tool
and an ill-considered GCC extension cannot justify risking correctness.
Because we touch a fair amount of the compiler to change this at all,
and unfortunately the duplication of AbiAndPrefAlign is deep-rooted,
we keep an "AbiAlign" type which we can wean code off later.
coretests: move float tests from num to floats module and use a more flexible macro to generate them
This makes some progress on https://github.com/rust-lang/rust/issues/141726 by moving the float tests in `num` to `floats` and using a newer, more flexible macro to generate them. We also newly run these tests on f16 and f128 in const, and at runtime in Miri and for hosts where that works well enough.
I didn't yet deduplicate any tests or port the existing `floats::f*` tests to the macro, that can happen in a future PR.
try-job: x86_64-gnu-aux
Compute number of digits instead of relying on constant value for u128 display code
As discussed in https://github.com/rust-lang/rust/pull/142098/files#r2132084991, the code should reuse the same logic as the rest of file instead of using a constant value.
r? `@tamird`
unsafe keyword docs: emphasize that an unsafe fn in a trait does not get to choose its safety contract
Inspired by discussion in https://github.com/rust-lang/rust/issues/139368.
Cc `@hanna-kruppe`
Reexport types from `c_size_t` in `std`
These are unstably available in `core` and should be in `std` too, but are not currently reexported. Resolve this here.
Tracking issue: https://github.com/rust-lang/rust/issues/88345
Fix AIX build
Fixrust-lang/rust#141543.
`getenv` was moved out of this file to `sys::env::getenv` in rust-lang/rust#140143. Replace its usage with `std::env::var_os`, the publicly exposed version. This matches the other usages of the same function in this file.
Optimize `Seek::stream_len` impl for `File`
It uses the file metadata on Unix with a fallback for files incorrectly reported as zero-sized. It uses `GetFileSizeEx` on Windows.
This reduces the number of syscalls needed for determining the file size of an open file from 3 to 1.
It uses the file metadata on Unix with a fallback for files incorrectly
reported as zero-sized. It uses `GetFileSizeEx` on Windows.
This reduces the number of syscalls needed for determining the file size
of an open file from 3 to 1.
UnsafePinned: also include the effects of UnsafeCell
This tackles https://github.com/rust-lang/rust/issues/137750 by including an `UnsafeCell` in `UnsafePinned`, thus imbuing it with all the usual properties of interior mutability (no `noalias` nor `dereferenceable` on shared refs, special treatment by Miri's aliasing model). The soundness issue is not fixed yet because coroutine lowering does not use `UnsafePinned`.
The RFC said that `UnsafePinned` would not permit mutability on shared references, but since then, https://github.com/rust-lang/rust/issues/137750 has demonstrated that this is not tenable. In the face of those examples, I propose that we do the "obvious" thing and permit shared mutable state inside `UnsafePinned`. This seems loosely consistent with the fact that we allow going from `Pin<&mut T>` to `&T` (where the former can be aliased with other pointers that perform mutation, and hence the same goes for the latter) -- but the `as_ref` example shows that we in fact would need to add this `UnsafeCell` even if we didn't have a safe conversion to `&T`, since for the compiler and Miri, `&T` and `Pin<&T>` are basically the same type.
To make this possible, I had to remove the `Copy` and `Clone` impls for `UnsafePinned`.
Tracking issue: https://github.com/rust-lang/rust/issues/125735
Cc ``@rust-lang/lang`` ``@rust-lang/opsem`` ``@Sky9x``
I don't think this needs FCP since the type is still unstable -- we'll finally decide whether we like this approach when `UnsafePinned` is moved towards stabilization (IOW, this PR is reversible). However, I'd still like to make sure that the lang team is okay with the direction I am proposing here.
This was introduced before `#[panic_handler]` was stable, but should no
longer be needed. Additionally, we only need it for
`builtins-test-intrinsics`, not as a dependency of `compiler-builtins`.
Create a crate that handles pulling from and pushing to rust-lang/rust.
This can be invoked with the following:
$ cargo run -p josh-sync -- rustc-pull
$ RUSTC_GIT=/path/to/rust/checkout cargo run -p josh-sync -- rustc-push <username>
The submodule was causing issues in rust-lang/rust, so eliminiate it
here. `build-musl` is also removed from `libm-test`'s default features
so the crate doesn't need to be built by default.
exact_div: add tests
tracking issue: rust-lang/rust#139911
I neglected to add tests in my last PR (rust-lang/rust#141237), so I've added them here.
r? ``@workingjubilee`` (Feel free to reroll, I just picked you since you reviewed the last one.)
Lightly tweak docs for BTree{Map,Set}::extract_if
- Move explanations into comments to match style
- Explain the second examples
- Make variable names match the data structure
Related rust-lang/rust#70530
make `OsString::new` and `PathBuf::new` unstably const
Since #129041, `String::into_bytes` is `const`, which allows making `OsString::new` and `PathBuf::new` unstably const now.
Not sure what the exact process for this is; does it need an ACP?
