Faster fmt::Display of 128-bit integers, without unsafe pointer
In followup of #135265, hereby the 128-bit part.
* Batches per 16 instead of 19 digits
* Buffer access as array insteaf of unsafe pointer
* Added test coverage for i128 and u128
r? tgross35 ChrisDenton
Mark `core::slice::memchr` as `#[doc(hidden)]`
It's purely internal, and not intended to be a public API, even on nightly. This stops it showing up and being misleading in rustdoc search.
It also mirrors the (also internal) `core::slice::sort` module.
docs: Small clarification on the usage of read_to_string and read_to_end trait methods
Small clarification on the usage of read_to_string and read_to_end trait methods. The goal is to make it clear that these trait methods will become locked up if attempting to read to the end of stdin (which is a bit non-sensical unless the other end closes the pipe).
Fixes: rust-lang/rust#141714
core::ptr: deduplicate more method docs
used `rg -Fxf library/core/src/ptr/{const,mut}_ptr.rs` to find duplicated doc comments, and `diff -u` after copying them to files to ensure they are actually identical.
`sed 's| */// *||'` was then used to translate the doc comments to plain markdown.
part of https://github.com/rust-lang/rust/issues/139190
use `#[naked]` for `__rust_probestack`
Let's see if this works now.
Previously this change was in https://github.com/rust-lang/compiler-builtins/pull/897, but we decided to wait until `compiler-builtins` was a subtree (and also `cfg(bootstrap)` is gone now).
r? ``@tgross35`` cc ``@bjorn3``
try-job: `dist-various*`
try-job: `test-various*`
Stabilize keylocker
This PR stabilizes the feature flag `keylocker_x86` (tracking issue rust-lang/rust#134813).
# Public API
The 2 `x86` target features `kl` and `widekl`, and the associated intrinsics in stdarch.
These target features are very specialized, and are only used to signal the presence of the corresponding CPU instruction. They don't have any nontrivial interaction with the ABI (contrary to something like AVX), and serve the only purpose of enabling 11 stdarch intrinsics, all of which have been implemented and propagated to rustc via a stdarch submodule update.
Also, these were added way back in LLVM12, and as the minimum LLVM required for rustc is LLVM19, we are safe in that front too!
# Associated PRs
- rust-lang/rust#134814
- rust-lang/stdarch#1706
- rust-lang/rust#136831 (stdarch submodule update)
- rust-lang/stdarch#1795 (stabilizing the runtime detection and intrinsics)
- rust-lang/rust#141964 (stdarch submodule update for the stabilization of the runtime detection and intrinsics)
As all of the required tasks have been done (adding the target features to rustc, implementing their runtime detection in std_detect and implementing the associated intrinsics in core_arch), these target features can be stabilized now.
cc ````@rust-lang/lang````
cc ````@rust-lang/libs-api```` for the intrinsics and runtime detection
I don't think anyone else worked on this feature, so no one else to ping, maybe cc ````@Amanieu.```` I will send the reference pr soon.
Specify the behavior of `file!`
This takes the current behavior of `file!` and documents it so it is safe to make assumptions about.
For example, Cargo could provide a `CARGO_RUSTC_CURRENT_DIR` as a base path for `file!`.
Example use cases
- Being able to look up test assets relative to the current file ([example](b9026bf654/tests/testsuite/cargo_add/add_basic/mod.rs (L34)))
- Inline snapshotting libraries being able to update Rust source code ([example](b9026bf654/tests/testsuite/alt_registry.rs (L36-L45)))
See rust-lang/cargo#3946 for more context.
T-libs-api discussed two solutions in rust-lang/libs-team#478
- `file_absolute!`:
- Has less meaning in other build tools like buck2
- Bakes in the assumption that a full path is available (e.g. with trim-paths)
- Specifying `file!`s behavior (this PR):
- Leaves it to the user to deal with trim-paths
- Even though `file!` is currently unspecified, changing it would likely have too large of an impact on the ecosystem at this time.
A future possibility is that rustc could have a flag that controls modifies the base path used for `file!`.
That seems purely additive with specifying the behavior and we do not want to block on it.
It would also likely be too disruptive for Cargo users (as mentioned). However, we tried to keep this in mind when specifying the behavior.
Enable Non-determinism of float operations in Miri and change std tests
Links to [#4208](https://github.com/rust-lang/miri/issues/4208) and [#3555](https://github.com/rust-lang/miri/issues/3555) in Miri.
Non-determinism of floating point operations was disabled in rust-lang/rust#137594 because it breaks the tests and doc-tests in core/coretests and std. This PR enables some of them.
This pr includes the following changes:
- Enables the float non-determinism but with a lower relative error of 4ULP instead of 16ULP
- These operations now have a fixed output based on the C23 standard, except the pow operations, this is tracked in [#4286](https://github.com/rust-lang/miri/issues/4286#issue-3010677983)
- Changes tests that made incorrect assumptions about the operations, not to make that assumption anymore (from `assert_eq!` to `assert_approx_eq!`.
- Changed the doctests of the stdlib of these operations to compare against fixed constants instead of `f*::EPSILON`, which now succeed with Miri and `-Zmiri-many-seeds`
- Added a constant `APPROX_DELTA` in `std/tests/floats/f32.rs` which is used for approximation tests, but with a different value when run in Miri. This is to make these tests succeed.
- Added tests in the float tests of Miri to test the C23 behaviour.
Fixes https://github.com/rust-lang/miri/issues/4208
This takes the current behavior of `file!` and documents it so it is
safe to make assumptions about.
For example, Cargo could provide a `CARGO_RUSTC_CURRENT_DIR` as a base
path for `file!`.
Example use cases
- Being able to look up test assets relative to the current file
([example](b9026bf654/tests/testsuite/cargo_add/add_basic/mod.rs (L34)))
- Inline snapshotting libraries being able to update Rust source code
([example](b9026bf654/tests/testsuite/alt_registry.rs (L36-L45)))
T-libs-api discussed two solutions
- `file_absolute!`:
- Has less meaning in other build tools like buck2
- Bakes in the assumption that a full path is available (e.g. with
trim-paths)
- Specifying `file!`s behavior (this PR):
- Leaves it to the user to deal with trim-paths
- Even though `file!` is currently unspecified, changing it would
likely have too large of an impact on the ecosystem at this time.
A future possibility is that rustc could have a flag that controls
modifies the base path used for `file!`.
That seems purely additive with specifying the behavior and we do not
want to block on it.
It would also likely be too disruptive for Cargo users (as mentioned).
However, we tried to keep this in mind when specifying the behavior.
It's purely internal, and not intended to be a public API, even on
nightly. This stops it showing up and being misleading in rustdoc
search.
It also mirrors the (also internal) `core::slice::sort` module.
Stabilize `sha512`, `sm3` and `sm4` for x86
This PR stabilizes the feature flag `sha512_sm_x86` (tracking issue rust-lang/rust#126624).
# Public API
The 3 `x86` target features `sha512`, `sm3` and `sm4`, and the associated intrinsics in stdarch.
These target features are very specialized, and are only used to signal the presence of the corresponding CPU instruction. They don't have any nontrivial interaction with the ABI (contrary to something like AVX), and serve the only purpose of enabling 10 stdarch intrinsics, all of which have been implemented and propagated to rustc via a stdarch submodule update.
Also, these were added in LLVM17, and as the minimum LLVM required for rustc is LLVM19, we are safe in that front too!
# Associated PRs
- rust-lang/rust#126704
- rust-lang/stdarch#1592
- rust-lang/stdarch#1790
- rust-lang/rust#140389 (stdarch submodule update)
- rust-lang/stdarch#1796 (stabilizing the runtime detection and intrinsics)
- rust-lang/rust#141964 (stdarch submodule update for the stabilization of the runtime detection and intrinsics)
As all of the required tasks have been done (adding the target features to rustc, implementing their runtime detection in std_detect and implementing the associated intrinsics in core_arch), these target features can be stabilized now.
cc `@rust-lang/lang`
cc `@rust-lang/libs-api` for the intrinsics and runtime detection
I don't think anyone else worked on this feature, so no one else to ping, maybe cc `@Amanieu.` I will send the reference pr soon.
De-duplicate f16 & f128 doctest attributes
Now that rustdoc supports `#[doc(test(attr(...)))]` at every level, thanks to https://github.com/rust-lang/rust/pull/140560, we can de-duplicate the f16 & f128 doctest attributes.
Unfortunately we can de-duplicate the `cfg`s attribute as rustdoc would complain about missing `main`, but it's already much better than before.
Addresses https://github.com/rust-lang/rust/pull/140323/files#r2062702761
r? `@tgross35`
Stabilize `tcp_quickack`
to stabilise the quickack part for now, tcp_deferaccept had been added at a later stage.
The related API calls are the following
```rust
// std::os::linux::net
// sealed trait, implemented for std::net::TcpStream
pub trait TcpStreamExt: Sealed{
fn quickack(&self) -> io::Result<bool>;
fn set_quickack(&self, quickack: bool) -> io::Result<()>;
}
```
Closes: https://github.com/rust-lang/rust/issues/96256
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.
The `build.rs` entrypoint returns early for some targets, so emscripten
and OpenBSD were not getting check-cfg set. Emit these earlier to avoid
the `unexpected_cfgs` lint.
On the ILP32 `x86_64-unknown-linux-gnux32` target, `usize` is 32 bits so
there is a sub-register alignment warning. Specify the 64-bit `r`
registers, which matches the current default as well as the size of the
other operands in the routines.
There are a few places that violate this lint, which showed up in
rust-lang/rust CI (the relevent module is gated behind
`kernel_user_helpers` which is only set for `armv4t`, `armv5te`, and
`arm-linux-androideabi`; none of these are tested in compiler-builtins
CI). Add new `unsafe { /* ... */ }` blocks where needed to address this.
Some blocks should get a more thorough review of their preconditions, so
their safety comments are left as `FIXME`s.
`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.
Many of `std`'s dependency have a dependency on the crates.io
`compiler-builtins` when used with the feature
`rustc-std-workspace-core`. Use a Cargo patch to select the in-tree
version instead.
`compiler-builtins` is also added as a dependency of
`rustc-std-workspace-core` so these crates can remove their crates.io
dependency in the future.
