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Auto merge of #117736 - TaKO8Ki:rollup-fjrtmlb, r=TaKO8Ki
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Rollup of 6 pull requests

Successful merges:

 - #116762 (Fixup `Atomic*::from_ptr` safety docs)
 - #117645 (Extend builtin/auto trait args with error when they have >1 argument)
 - #117694 (Move `BorrowedBuf` and `BorrowedCursor` from `std:io` to `core::io`)
 - #117705 (triagebot.toml: use inclusive language)
 - #117723 (speed up `x clean`)
 - #117724 (Restore rustc shim error message)

r? `@ghost`
`@rustbot` modify labels: rollup
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bors committed Nov 9, 2023
2 parents d8dbf7c + f5195c5 commit 492e57c
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1 change: 1 addition & 0 deletions compiler/rustc_span/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,7 @@
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
#![feature(array_windows)]
#![feature(cfg_match)]
#![feature(core_io_borrowed_buf)]
#![feature(if_let_guard)]
#![feature(let_chains)]
#![feature(min_specialization)]
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21 changes: 15 additions & 6 deletions compiler/rustc_trait_selection/src/traits/select/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -2389,12 +2389,21 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
)
});

let obligation = Obligation::new(
self.tcx(),
cause.clone(),
param_env,
ty::TraitRef::new(self.tcx(), trait_def_id, [normalized_ty]),
);
let tcx = self.tcx();
let trait_ref = if tcx.generics_of(trait_def_id).params.len() == 1 {
ty::TraitRef::new(tcx, trait_def_id, [normalized_ty])
} else {
// If this is an ill-formed auto/built-in trait, then synthesize
// new error args for the missing generics.
let err_args = ty::GenericArgs::extend_with_error(
tcx,
trait_def_id,
&[normalized_ty.into()],
);
ty::TraitRef::new(tcx, trait_def_id, err_args)
};

let obligation = Obligation::new(self.tcx(), cause.clone(), param_env, trait_ref);
obligations.push(obligation);
obligations
})
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Original file line number Diff line number Diff line change
@@ -1,10 +1,6 @@
#![unstable(feature = "read_buf", issue = "78485")]

#[cfg(test)]
mod tests;
#![unstable(feature = "core_io_borrowed_buf", issue = "117693")]

use crate::fmt::{self, Debug, Formatter};
use crate::io::{Result, Write};
use crate::mem::{self, MaybeUninit};
use crate::{cmp, ptr};

Expand Down Expand Up @@ -303,16 +299,3 @@ impl<'a> BorrowedCursor<'a> {
self.buf.filled += buf.len();
}
}

impl<'a> Write for BorrowedCursor<'a> {
fn write(&mut self, buf: &[u8]) -> Result<usize> {
let amt = cmp::min(buf.len(), self.capacity());
self.append(&buf[..amt]);
Ok(amt)
}

#[inline]
fn flush(&mut self) -> Result<()> {
Ok(())
}
}
6 changes: 6 additions & 0 deletions library/core/src/io/mod.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,6 @@
//! Traits, helpers, and type definitions for core I/O functionality.

mod borrowed_buf;

#[unstable(feature = "core_io_borrowed_buf", issue = "117693")]
pub use self::borrowed_buf::{BorrowedBuf, BorrowedCursor};
2 changes: 2 additions & 0 deletions library/core/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -369,6 +369,8 @@ pub mod async_iter;
pub mod cell;
pub mod char;
pub mod ffi;
#[unstable(feature = "core_io_borrowed_buf", issue = "117693")]
pub mod io;
pub mod iter;
pub mod net;
pub mod option;
Expand Down
124 changes: 81 additions & 43 deletions library/core/src/sync/atomic.rs
Original file line number Diff line number Diff line change
Expand Up @@ -4,26 +4,12 @@
//! threads, and are the building blocks of other concurrent
//! types.
//!
//! Rust atomics currently follow the same rules as [C++20 atomics][cpp], specifically `atomic_ref`.
//! Basically, creating a *shared reference* to one of the Rust atomic types corresponds to creating
//! an `atomic_ref` in C++; the `atomic_ref` is destroyed when the lifetime of the shared reference
//! ends. (A Rust atomic type that is exclusively owned or behind a mutable reference does *not*
//! correspond to an "atomic object" in C++, since it can be accessed via non-atomic operations.)
//!
//! This module defines atomic versions of a select number of primitive
//! types, including [`AtomicBool`], [`AtomicIsize`], [`AtomicUsize`],
//! [`AtomicI8`], [`AtomicU16`], etc.
//! Atomic types present operations that, when used correctly, synchronize
//! updates between threads.
//!
//! Each method takes an [`Ordering`] which represents the strength of
//! the memory barrier for that operation. These orderings are the
//! same as the [C++20 atomic orderings][1]. For more information see the [nomicon][2].
//!
//! [cpp]: https://en.cppreference.com/w/cpp/atomic
//! [1]: https://en.cppreference.com/w/cpp/atomic/memory_order
//! [2]: ../../../nomicon/atomics.html
//!
//! Atomic variables are safe to share between threads (they implement [`Sync`])
//! but they do not themselves provide the mechanism for sharing and follow the
//! [threading model](../../../std/thread/index.html#the-threading-model) of Rust.
Expand All @@ -36,6 +22,75 @@
//! the constant initializers like [`AtomicBool::new`]. Atomic statics
//! are often used for lazy global initialization.
//!
//! ## Memory model for atomic accesses
//!
//! Rust atomics currently follow the same rules as [C++20 atomics][cpp], specifically `atomic_ref`.
//! Basically, creating a *shared reference* to one of the Rust atomic types corresponds to creating
//! an `atomic_ref` in C++; the `atomic_ref` is destroyed when the lifetime of the shared reference
//! ends. (A Rust atomic type that is exclusively owned or behind a mutable reference does *not*
//! correspond to an "atomic object" in C++, since it can be accessed via non-atomic operations.)
//!
//! [cpp]: https://en.cppreference.com/w/cpp/atomic
//!
//! Each method takes an [`Ordering`] which represents the strength of
//! the memory barrier for that operation. These orderings are the
//! same as the [C++20 atomic orderings][1]. For more information see the [nomicon][2].
//!
//! [1]: https://en.cppreference.com/w/cpp/atomic/memory_order
//! [2]: ../../../nomicon/atomics.html
//!
//! Since C++ does not support mixing atomic and non-atomic accesses, or non-synchronized
//! different-sized accesses to the same data, Rust does not support those operations either.
//! Note that both of those restrictions only apply if the accesses are non-synchronized.
//!
//! ```rust,no_run undefined_behavior
//! use std::sync::atomic::{AtomicU16, AtomicU8, Ordering};
//! use std::mem::transmute;
//! use std::thread;
//!
//! let atomic = AtomicU16::new(0);
//!
//! thread::scope(|s| {
//! // This is UB: mixing atomic and non-atomic accesses
//! s.spawn(|| atomic.store(1, Ordering::Relaxed));
//! s.spawn(|| unsafe { atomic.as_ptr().write(2) });
//! });
//!
//! thread::scope(|s| {
//! // This is UB: even reads are not allowed to be mixed
//! s.spawn(|| atomic.load(Ordering::Relaxed));
//! s.spawn(|| unsafe { atomic.as_ptr().read() });
//! });
//!
//! thread::scope(|s| {
//! // This is fine, `join` synchronizes the code in a way such that atomic
//! // and non-atomic accesses can't happen "at the same time"
//! let handle = s.spawn(|| atomic.store(1, Ordering::Relaxed));
//! handle.join().unwrap();
//! s.spawn(|| unsafe { atomic.as_ptr().write(2) });
//! });
//!
//! thread::scope(|s| {
//! // This is UB: using different-sized atomic accesses to the same data
//! s.spawn(|| atomic.store(1, Ordering::Relaxed));
//! s.spawn(|| unsafe {
//! let differently_sized = transmute::<&AtomicU16, &AtomicU8>(&atomic);
//! differently_sized.store(2, Ordering::Relaxed);
//! });
//! });
//!
//! thread::scope(|s| {
//! // This is fine, `join` synchronizes the code in a way such that
//! // differently-sized accesses can't happen "at the same time"
//! let handle = s.spawn(|| atomic.store(1, Ordering::Relaxed));
//! handle.join().unwrap();
//! s.spawn(|| unsafe {
//! let differently_sized = transmute::<&AtomicU16, &AtomicU8>(&atomic);
//! differently_sized.store(2, Ordering::Relaxed);
//! });
//! });
//! ```
//!
//! # Portability
//!
//! All atomic types in this module are guaranteed to be [lock-free] if they're
Expand Down Expand Up @@ -383,16 +438,12 @@ impl AtomicBool {
/// * `ptr` must be aligned to `align_of::<AtomicBool>()` (note that on some platforms this can
/// be bigger than `align_of::<bool>()`).
/// * `ptr` must be [valid] for both reads and writes for the whole lifetime `'a`.
/// * Non-atomic accesses to the value behind `ptr` must have a happens-before relationship
/// with atomic accesses via the returned value (or vice-versa).
/// * In other words, time periods where the value is accessed atomically may not overlap
/// with periods where the value is accessed non-atomically.
/// * This requirement is trivially satisfied if `ptr` is never used non-atomically for the
/// duration of lifetime `'a`. Most use cases should be able to follow this guideline.
/// * This requirement is also trivially satisfied if all accesses (atomic or not) are done
/// from the same thread.
/// * You must adhere to the [Memory model for atomic accesses]. In particular, it is not
/// allowed to mix atomic and non-atomic accesses, or atomic accesses of different sizes,
/// without synchronization.
///
/// [valid]: crate::ptr#safety
/// [Memory model for atomic accesses]: self#memory-model-for-atomic-accesses
#[stable(feature = "atomic_from_ptr", since = "CURRENT_RUSTC_VERSION")]
#[rustc_const_unstable(feature = "const_atomic_from_ptr", issue = "108652")]
pub const unsafe fn from_ptr<'a>(ptr: *mut bool) -> &'a AtomicBool {
Expand Down Expand Up @@ -1185,18 +1236,12 @@ impl<T> AtomicPtr<T> {
/// * `ptr` must be aligned to `align_of::<AtomicPtr<T>>()` (note that on some platforms this
/// can be bigger than `align_of::<*mut T>()`).
/// * `ptr` must be [valid] for both reads and writes for the whole lifetime `'a`.
/// * Non-atomic accesses to the value behind `ptr` must have a happens-before relationship
/// with atomic accesses via the returned value (or vice-versa).
/// * In other words, time periods where the value is accessed atomically may not overlap
/// with periods where the value is accessed non-atomically.
/// * This requirement is trivially satisfied if `ptr` is never used non-atomically for the
/// duration of lifetime `'a`. Most use cases should be able to follow this guideline.
/// * This requirement is also trivially satisfied if all accesses (atomic or not) are done
/// from the same thread.
/// * This method should not be used to create overlapping or mixed-size atomic accesses, as
/// these are not supported by the memory model.
/// * You must adhere to the [Memory model for atomic accesses]. In particular, it is not
/// allowed to mix atomic and non-atomic accesses, or atomic accesses of different sizes,
/// without synchronization.
///
/// [valid]: crate::ptr#safety
/// [Memory model for atomic accesses]: self#memory-model-for-atomic-accesses
#[stable(feature = "atomic_from_ptr", since = "CURRENT_RUSTC_VERSION")]
#[rustc_const_unstable(feature = "const_atomic_from_ptr", issue = "108652")]
pub const unsafe fn from_ptr<'a>(ptr: *mut *mut T) -> &'a AtomicPtr<T> {
Expand Down Expand Up @@ -2167,19 +2212,12 @@ macro_rules! atomic_int {
`align_of::<", stringify!($atomic_type), ">()` (note that on some platforms this \
can be bigger than `align_of::<", stringify!($int_type), ">()`).")]
/// * `ptr` must be [valid] for both reads and writes for the whole lifetime `'a`.
/// * Non-atomic accesses to the value behind `ptr` must have a happens-before
/// relationship with atomic accesses via the returned value (or vice-versa).
/// * In other words, time periods where the value is accessed atomically may not
/// overlap with periods where the value is accessed non-atomically.
/// * This requirement is trivially satisfied if `ptr` is never used non-atomically
/// for the duration of lifetime `'a`. Most use cases should be able to follow
/// this guideline.
/// * This requirement is also trivially satisfied if all accesses (atomic or not) are
/// done from the same thread.
/// * This method should not be used to create overlapping or mixed-size atomic
/// accesses, as these are not supported by the memory model.
/// * You must adhere to the [Memory model for atomic accesses]. In particular, it is not
/// allowed to mix atomic and non-atomic accesses, or atomic accesses of different sizes,
/// without synchronization.
///
/// [valid]: crate::ptr#safety
/// [Memory model for atomic accesses]: self#memory-model-for-atomic-accesses
#[stable(feature = "atomic_from_ptr", since = "CURRENT_RUSTC_VERSION")]
#[rustc_const_unstable(feature = "const_atomic_from_ptr", issue = "108652")]
pub const unsafe fn from_ptr<'a>(ptr: *mut $int_type) -> &'a $atomic_type {
Expand Down
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
use super::BorrowedBuf;
use crate::mem::MaybeUninit;
use core::io::BorrowedBuf;
use core::mem::MaybeUninit;

/// Test that BorrowedBuf has the correct numbers when created with new
#[test]
Expand Down
1 change: 1 addition & 0 deletions library/core/tests/io/mod.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
mod borrowed_buf;
2 changes: 2 additions & 0 deletions library/core/tests/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
#![feature(const_likely)]
#![feature(const_location_fields)]
#![feature(core_intrinsics)]
#![feature(core_io_borrowed_buf)]
#![feature(core_private_bignum)]
#![feature(core_private_diy_float)]
#![feature(dec2flt)]
Expand Down Expand Up @@ -135,6 +136,7 @@ mod fmt;
mod future;
mod hash;
mod intrinsics;
mod io;
mod iter;
mod lazy;
#[cfg(test)]
Expand Down
14 changes: 14 additions & 0 deletions library/std/src/io/impls.rs
Original file line number Diff line number Diff line change
Expand Up @@ -528,3 +528,17 @@ impl<A: Allocator> Write for VecDeque<u8, A> {
Ok(())
}
}

#[unstable(feature = "read_buf", issue = "78485")]
impl<'a> io::Write for core::io::BorrowedCursor<'a> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
let amt = cmp::min(buf.len(), self.capacity());
self.append(&buf[..amt]);
Ok(amt)
}

#[inline]
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
3 changes: 1 addition & 2 deletions library/std/src/io/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -330,7 +330,7 @@ pub use self::{
};

#[unstable(feature = "read_buf", issue = "78485")]
pub use self::readbuf::{BorrowedBuf, BorrowedCursor};
pub use core::io::{BorrowedBuf, BorrowedCursor};
pub(crate) use error::const_io_error;

mod buffered;
Expand All @@ -339,7 +339,6 @@ mod cursor;
mod error;
mod impls;
pub mod prelude;
mod readbuf;
mod stdio;
mod util;

Expand Down
1 change: 1 addition & 0 deletions library/std/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -310,6 +310,7 @@
// tidy-alphabetical-start
#![feature(char_internals)]
#![feature(core_intrinsics)]
#![feature(core_io_borrowed_buf)]
#![feature(duration_constants)]
#![feature(error_generic_member_access)]
#![feature(error_in_core)]
Expand Down
3 changes: 3 additions & 0 deletions src/bootstrap/src/bin/rustc.rs
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,9 @@ fn main() {
let args = env::args_os().skip(1).collect::<Vec<_>>();
let arg = |name| args.windows(2).find(|args| args[0] == name).and_then(|args| args[1].to_str());

// We don't use the stage in this shim, but let's parse it to make sure that we're invoked
// by bootstrap, or that we provide a helpful error message if not.
bin_helpers::parse_rustc_stage();
let verbose = bin_helpers::parse_rustc_verbose();

// Detect whether or not we're a build script depending on whether --target
Expand Down
1 change: 0 additions & 1 deletion src/bootstrap/src/core/build_steps/clean.rs
Original file line number Diff line number Diff line change
Expand Up @@ -139,7 +139,6 @@ fn clean_specific_stage(build: &Build, stage: u32) {
fn clean_default(build: &Build) {
rm_rf(&build.out.join("tmp"));
rm_rf(&build.out.join("dist"));
rm_rf(&build.out.join("bootstrap"));
rm_rf(&build.out.join("rustfmt.stamp"));

for host in &build.hosts {
Expand Down
1 change: 0 additions & 1 deletion src/bootstrap/src/utils/bin_helpers.rs
Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,6 @@ pub(crate) fn parse_rustc_verbose() -> usize {
/// Parses the value of the "RUSTC_STAGE" environment variable and returns it as a `String`.
///
/// If "RUSTC_STAGE" was not set, the program will be terminated with 101.
#[allow(unused)]
pub(crate) fn parse_rustc_stage() -> String {
std::env::var("RUSTC_STAGE").unwrap_or_else(|_| {
// Don't panic here; it's reasonable to try and run these shims directly. Give a helpful error instead.
Expand Down
10 changes: 10 additions & 0 deletions tests/ui/auto-traits/has-arguments.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,10 @@
#![feature(auto_traits)]

auto trait Trait1<'outer> {}
//~^ ERROR auto traits cannot have generic parameters

fn f<'a>(x: impl Trait1<'a>) {}

fn main() {
f("");
}
11 changes: 11 additions & 0 deletions tests/ui/auto-traits/has-arguments.stderr
Original file line number Diff line number Diff line change
@@ -0,0 +1,11 @@
error[E0567]: auto traits cannot have generic parameters
--> $DIR/has-arguments.rs:3:18
|
LL | auto trait Trait1<'outer> {}
| ------^^^^^^^^ help: remove the parameters
| |
| auto trait cannot have generic parameters

error: aborting due to previous error

For more information about this error, try `rustc --explain E0567`.
2 changes: 1 addition & 1 deletion triagebot.toml
Original file line number Diff line number Diff line change
Expand Up @@ -579,7 +579,7 @@ Otherwise, you can ignore this comment.
message = "`src/tools/x` was changed. Bump version of Cargo.toml in `src/tools/x` so tidy will suggest installing the new version."

[mentions."src/tools/tidy/src/deps.rs"]
message = "Third-party dependency whitelist may have been modified! You must ensure that any new dependencies have compatible licenses before merging."
message = "The list of allowed third-party dependencies may have been modified! You must ensure that any new dependencies have compatible licenses before merging."
cc = ["@davidtwco", "@wesleywiser"]

[mentions."src/bootstrap/src/core/config"]
Expand Down

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