Auto merge of #106866 - matthiaskrgr:rollup-r063s44, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #105526 (libcore: make result of iter::from_generator Clone)
 - #106563 (Fix `unused_braces` on generic const expr macro call)
 - #106661 (Stop probing for statx unless necessary)
 - #106820 (Deprioritize fulfillment errors that come from expansions.)
 - #106828 (rustdoc: remove `docblock` class from notable trait popover)
 - #106849 (Allocate one less vec while parsing arrays)
 - #106855 (rustdoc: few small cleanups)
 - #106860 (Remove various double spaces in the libraries.)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_lint/src/unused.rs

@@ -1105,6 +1105,7 @@ impl UnusedDelimLint for UnusedBraces {
  || matches!(expr.kind, ast::ExprKind::Lit(_)))
  && !cx.sess().source_map().is_multiline(value.span)
  && value.attrs.is_empty()
+ && !expr.span.from_expansion()
  && !value.span.from_expansion()
  && !inner.span.from_expansion()
  {

compiler/rustc_parse/src/parser/expr.rs

@@ -1475,9 +1475,8 @@ impl<'a> Parser<'a> {
  } else if self.eat(&token::Comma) {
  // Vector with two or more elements.
  let sep = SeqSep::trailing_allowed(token::Comma);
- let (remaining_exprs, _) = self.parse_seq_to_end(close, sep, |p| p.parse_expr())?;
- let mut exprs = vec![first_expr];
- exprs.extend(remaining_exprs);
+ let (mut exprs, _) = self.parse_seq_to_end(close, sep, |p| p.parse_expr())?;
+ exprs.insert(0, first_expr);
  ExprKind::Array(exprs)
  } else {
  // Vector with one element

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -454,9 +454,11 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
  }
  }
 
- for (error, suppressed) in iter::zip(errors, is_suppressed) {
- if !suppressed {
- self.report_fulfillment_error(error, body_id);
+ for from_expansion in [false, true] {
+ for (error, suppressed) in iter::zip(errors, &is_suppressed) {
+ if !suppressed && error.obligation.cause.span.from_expansion() == from_expansion {
+ self.report_fulfillment_error(error, body_id);
+ }
  }
  }
 

library/alloc/src/alloc.rs

@@ -20,7 +20,7 @@ use core::marker::Destruct;
 mod tests;
 
 extern "Rust" {
- // These are the magic symbols to call the global allocator.  rustc generates
+ // These are the magic symbols to call the global allocator. rustc generates
  // them to call `__rg_alloc` etc. if there is a `#[global_allocator]` attribute
  // (the code expanding that attribute macro generates those functions), or to call
  // the default implementations in std (`__rdl_alloc` etc. in `library/std/src/alloc.rs`)
@@ -353,7 +353,7 @@ pub(crate) const unsafe fn box_free<T: ?Sized, A: ~const Allocator + ~const Dest
 
 #[cfg(not(no_global_oom_handling))]
 extern "Rust" {
- // This is the magic symbol to call the global alloc error handler.  rustc generates
+ // This is the magic symbol to call the global alloc error handler. rustc generates
  // it to call `__rg_oom` if there is a `#[alloc_error_handler]`, or to call the
  // default implementations below (`__rdl_oom`) otherwise.
  fn __rust_alloc_error_handler(size: usize, align: usize) -> !;

library/alloc/src/rc.rs

@@ -2179,7 +2179,7 @@ pub struct Weak<T: ?Sized> {
  // This is a `NonNull` to allow optimizing the size of this type in enums,
  // but it is not necessarily a valid pointer.
  // `Weak::new` sets this to `usize::MAX` so that it doesn’t need
- // to allocate space on the heap.  That's not a value a real pointer
+ // to allocate space on the heap. That's not a value a real pointer
  // will ever have because RcBox has alignment at least 2.
  // This is only possible when `T: Sized`; unsized `T` never dangle.
  ptr: NonNull<RcBox<T>>,

library/alloc/src/sync.rs

@@ -295,7 +295,7 @@ pub struct Weak<T: ?Sized> {
  // This is a `NonNull` to allow optimizing the size of this type in enums,
  // but it is not necessarily a valid pointer.
  // `Weak::new` sets this to `usize::MAX` so that it doesn’t need
- // to allocate space on the heap.  That's not a value a real pointer
+ // to allocate space on the heap. That's not a value a real pointer
  // will ever have because RcBox has alignment at least 2.
  // This is only possible when `T: Sized`; unsized `T` never dangle.
  ptr: NonNull<ArcInner<T>>,
@@ -1656,7 +1656,7 @@ impl<T: ?Sized> Arc<T> {
  //
  // The acquire label here ensures a happens-before relationship with any
  // writes to `strong` (in particular in `Weak::upgrade`) prior to decrements
- // of the `weak` count (via `Weak::drop`, which uses release).  If the upgraded
+ // of the `weak` count (via `Weak::drop`, which uses release). If the upgraded
  // weak ref was never dropped, the CAS here will fail so we do not care to synchronize.
  if self.inner().weak.compare_exchange(1, usize::MAX, Acquire, Relaxed).is_ok() {
  // This needs to be an `Acquire` to synchronize with the decrement of the `strong`
@@ -1712,7 +1712,7 @@ unsafe impl<#[may_dangle] T: ?Sized> Drop for Arc<T> {
  }
 
  // This fence is needed to prevent reordering of use of the data and
- // deletion of the data.  Because it is marked `Release`, the decreasing
+ // deletion of the data. Because it is marked `Release`, the decreasing
  // of the reference count synchronizes with this `Acquire` fence. This
  // means that use of the data happens before decreasing the reference
  // count, which happens before this fence, which happens before the
@@ -2172,7 +2172,7 @@ impl<T: ?Sized> Clone for Weak<T> {
  } else {
  return Weak { ptr: self.ptr };
  };
- // See comments in Arc::clone() for why this is relaxed.  This can use a
+ // See comments in Arc::clone() for why this is relaxed. This can use a
  // fetch_add (ignoring the lock) because the weak count is only locked
  // where are *no other* weak pointers in existence. (So we can't be
  // running this code in that case).

library/alloc/src/vec/into_iter.rs

@@ -40,7 +40,7 @@ pub struct IntoIter<
  // to avoid dropping the allocator twice we need to wrap it into ManuallyDrop
  pub(super) alloc: ManuallyDrop<A>,
  pub(super) ptr: *const T,
- pub(super) end: *const T, // If T is a ZST, this is actually ptr+len.  This encoding is picked so that
+ pub(super) end: *const T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that
  // ptr == end is a quick test for the Iterator being empty, that works
  // for both ZST and non-ZST.
 }
@@ -146,9 +146,9 @@ impl<T, A: Allocator> IntoIter<T, A> {
  let mut this = ManuallyDrop::new(self);
 
  // SAFETY: This allocation originally came from a `Vec`, so it passes
- // all those checks.  We have `this.buf` ≤ `this.ptr` ≤ `this.end`,
+ // all those checks. We have `this.buf` ≤ `this.ptr` ≤ `this.end`,
  // so the `sub_ptr`s below cannot wrap, and will produce a well-formed
- // range.  `end` ≤ `buf + cap`, so the range will be in-bounds.
+ // range. `end` ≤ `buf + cap`, so the range will be in-bounds.
  // Taking `alloc` is ok because nothing else is going to look at it,
  // since our `Drop` impl isn't going to run so there's no more code.
  unsafe {

library/alloc/src/vec/is_zero.rs

@@ -57,7 +57,7 @@ unsafe impl<T: IsZero, const N: usize> IsZero for [T; N] {
  #[inline]
  fn is_zero(&self) -> bool {
  // Because this is generated as a runtime check, it's not obvious that
- // it's worth doing if the array is really long.  The threshold here
+ // it's worth doing if the array is really long. The threshold here
  // is largely arbitrary, but was picked because as of 2022-07-01 LLVM
  // fails to const-fold the check in `vec![[1; 32]; n]`
  // See https://github.com/rust-lang/rust/pull/97581#issuecomment-1166628022

library/alloc/src/vec/mod.rs

@@ -2429,7 +2429,7 @@ impl<T: Clone, A: Allocator> Vec<T, A> {
  self.reserve(range.len());
 
  // SAFETY:
- // - `slice::range` guarantees  that the given range is valid for indexing self
+ // - `slice::range` guarantees that the given range is valid for indexing self
  unsafe {
  self.spec_extend_from_within(range);
  }
@@ -2686,7 +2686,7 @@ impl<T: Clone, A: Allocator + Clone> Clone for Vec<T, A> {
 
  // HACK(japaric): with cfg(test) the inherent `[T]::to_vec` method, which is
  // required for this method definition, is not available. Instead use the
- // `slice::to_vec`  function which is only available with cfg(test)
+ // `slice::to_vec` function which is only available with cfg(test)
  // NB see the slice::hack module in slice.rs for more information
  #[cfg(test)]
  fn clone(&self) -> Self {

library/alloc/tests/vec.rs

@@ -1849,7 +1849,7 @@ fn test_stable_pointers() {
  }
 
  // Test that, if we reserved enough space, adding and removing elements does not
- // invalidate references into the vector (such as `v0`).  This test also
+ // invalidate references into the vector (such as `v0`). This test also
  // runs in Miri, which would detect such problems.
  // Note that this test does *not* constitute a stable guarantee that all these functions do not
  // reallocate! Only what is explicitly documented at

library/core/src/array/iter.rs

@@ -109,8 +109,8 @@ impl<T, const N: usize> IntoIter<T, N> {
  /// use std::array::IntoIter;
  /// use std::mem::MaybeUninit;
  ///
- /// # // Hi! Thanks for reading the code.  This is restricted to `Copy` because
- /// # // otherwise it could leak.  A fully-general version this would need a drop
+ /// # // Hi! Thanks for reading the code. This is restricted to `Copy` because
+ /// # // otherwise it could leak. A fully-general version this would need a drop
  /// # // guard to handle panics from the iterator, but this works for an example.
  /// fn next_chunk<T: Copy, const N: usize>(
  /// it: &mut impl Iterator<Item = T>,
@@ -211,7 +211,7 @@ impl<T, const N: usize> IntoIter<T, N> {
  let initialized = 0..0;
 
  // SAFETY: We're telling it that none of the elements are initialized,
- // which is trivially true.  And ∀N: usize, 0 <= N.
+ // which is trivially true. And ∀N: usize, 0 <= N.
  unsafe { Self::new_unchecked(buffer, initialized) }
  }
 

library/core/src/iter/range.rs

@@ -756,7 +756,7 @@ impl<A: Step> Iterator for ops::Range<A> {
  where
  Self: TrustedRandomAccessNoCoerce,
  {
- // SAFETY: The TrustedRandomAccess contract requires that callers only  pass an index
+ // SAFETY: The TrustedRandomAccess contract requires that callers only pass an index
  // that is in bounds.
  // Additionally Self: TrustedRandomAccess is only implemented for Copy types
  // which means even repeated reads of the same index would be safe.

library/core/src/iter/sources/from_generator.rs

@@ -1,3 +1,4 @@
+use crate::fmt;
 use crate::ops::{Generator, GeneratorState};
 use crate::pin::Pin;
 
@@ -23,14 +24,21 @@ use crate::pin::Pin;
 /// ```
 #[inline]
 #[unstable(feature = "iter_from_generator", issue = "43122", reason = "generators are unstable")]
-pub fn from_generator<G: Generator<Return = ()> + Unpin>(
- generator: G,
-) -> impl Iterator<Item = G::Yield> {
+pub fn from_generator<G: Generator<Return = ()> + Unpin>(generator: G) -> FromGenerator<G> {
  FromGenerator(generator)
 }
 
-struct FromGenerator<G>(G);
+/// An iterator over the values yielded by an underlying generator.
+///
+/// This `struct` is created by the [`iter::from_generator()`] function. See its documentation for
+/// more.
+///
+/// [`iter::from_generator()`]: from_generator
+#[unstable(feature = "iter_from_generator", issue = "43122", reason = "generators are unstable")]
+#[derive(Clone)]
+pub struct FromGenerator<G>(G);
 
+#[unstable(feature = "iter_from_generator", issue = "43122", reason = "generators are unstable")]
 impl<G: Generator<Return = ()> + Unpin> Iterator for FromGenerator<G> {
  type Item = G::Yield;
 
@@ -41,3 +49,10 @@ impl<G: Generator<Return = ()> + Unpin> Iterator for FromGenerator<G> {
  }
  }
 }
+
+#[unstable(feature = "iter_from_generator", issue = "43122", reason = "generators are unstable")]
+impl<G> fmt::Debug for FromGenerator<G> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_struct("FromGenerator").finish()
+ }
+}

library/core/src/num/dec2flt/fpu.rs

@@ -26,7 +26,7 @@ mod fpu_precision {
  /// Developer's Manual (Volume 1).
  ///
  /// The only field which is relevant for the following code is PC, Precision Control. This
- /// field determines the precision of the operations performed by the  FPU. It can be set to:
+ /// field determines the precision of the operations performed by the FPU. It can be set to:
  /// - 0b00, single precision i.e., 32-bits
  /// - 0b10, double precision i.e., 64-bits
  /// - 0b11, double extended precision i.e., 80-bits (default state)

library/core/src/num/int_macros.rs

@@ -1538,7 +1538,7 @@ macro_rules! int_impl {
  ///
  /// ```
  /// #![feature(bigint_helper_methods)]
- /// // Only the  most significant word is signed.
+ /// // Only the most significant word is signed.
  /// //
  #[doc = concat!("// 10 MAX (a = 10 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
  #[doc = concat!("// + -5 9 (b = -5 × 2^", stringify!($BITS), " + 9)")]
@@ -1646,7 +1646,7 @@ macro_rules! int_impl {
  ///
  /// ```
  /// #![feature(bigint_helper_methods)]
- /// // Only the  most significant word is signed.
+ /// // Only the most significant word is signed.
  /// //
  #[doc = concat!("// 6 8 (a = 6 × 2^", stringify!($BITS), " + 8)")]
  #[doc = concat!("// - -5 9 (b = -5 × 2^", stringify!($BITS), " + 9)")]

library/core/src/pin.rs

@@ -753,7 +753,7 @@ impl<P: DerefMut> Pin<P> {
 impl<'a, T: ?Sized> Pin<&'a T> {
  /// Constructs a new pin by mapping the interior value.
  ///
- /// For example, if you  wanted to get a `Pin` of a field of something,
+ /// For example, if you wanted to get a `Pin` of a field of something,
  /// you could use this to get access to that field in one line of code.
  /// However, there are several gotchas with these "pinning projections";
  /// see the [`pin` module] documentation for further details on that topic.
@@ -856,7 +856,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
 
  /// Construct a new pin by mapping the interior value.
  ///
- /// For example, if you  wanted to get a `Pin` of a field of something,
+ /// For example, if you wanted to get a `Pin` of a field of something,
  /// you could use this to get access to that field in one line of code.
  /// However, there are several gotchas with these "pinning projections";
  /// see the [`pin` module] documentation for further details on that topic.

library/core/src/ptr/mod.rs

@@ -1701,7 +1701,7 @@ pub(crate) const unsafe fn align_offset<T: Sized>(p: *const T, a: usize) -> usiz
  // offset is not a multiple of `stride`, the input pointer was misaligned and no pointer
  // offset will be able to produce a `p` aligned to the specified `a`.
  //
- // The naive `-p (mod a)` equation  inhibits LLVM's ability to select instructions
+ // The naive `-p (mod a)` equation inhibits LLVM's ability to select instructions
  // like `lea`. We compute `(round_up_to_next_alignment(p, a) - p)` instead. This
  // redistributes operations around the load-bearing, but pessimizing `and` instruction
  // sufficiently for LLVM to be able to utilize the various optimizations it knows about.

library/core/src/slice/iter.rs

@@ -65,7 +65,7 @@ fn size_from_ptr<T>(_: *const T) -> usize {
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 pub struct Iter<'a, T: 'a> {
  ptr: NonNull<T>,
- end: *const T, // If T is a ZST, this is actually ptr+len.  This encoding is picked so that
+ end: *const T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that
  // ptr == end is a quick test for the Iterator being empty, that works
  // for both ZST and non-ZST.
  _marker: PhantomData<&'a T>,
@@ -186,7 +186,7 @@ impl<T> AsRef<[T]> for Iter<'_, T> {
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 pub struct IterMut<'a, T: 'a> {
  ptr: NonNull<T>,
- end: *mut T, // If T is a ZST, this is actually ptr+len.  This encoding is picked so that
+ end: *mut T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that
  // ptr == end is a quick test for the Iterator being empty, that works
  // for both ZST and non-ZST.
  _marker: PhantomData<&'a mut T>,

library/core/src/slice/iter/macros.rs

@@ -23,7 +23,7 @@ macro_rules! len {
  $self.end.addr().wrapping_sub(start.as_ptr().addr())
  } else {
  // We know that `start <= end`, so can do better than `offset_from`,
- // which needs to deal in signed.  By setting appropriate flags here
+ // which needs to deal in signed. By setting appropriate flags here
  // we can tell LLVM this, which helps it remove bounds checks.
  // SAFETY: By the type invariant, `start <= end`
  let diff = unsafe { unchecked_sub($self.end.addr(), start.as_ptr().addr()) };

library/core/src/slice/mod.rs

@@ -703,7 +703,7 @@ impl<T> [T] {
 
  // Because this function is first compiled in isolation,
  // this check tells LLVM that the indexing below is
- // in-bounds.  Then after inlining -- once the actual
+ // in-bounds. Then after inlining -- once the actual
  // lengths of the slices are known -- it's removed.
  let (a, b) = (&mut a[..n], &mut b[..n]);
 
@@ -1248,7 +1248,7 @@ impl<T> [T] {
  ArrayChunksMut::new(self)
  }
 
- /// Returns an iterator over overlapping windows of `N` elements of  a slice,
+ /// Returns an iterator over overlapping windows of `N` elements of a slice,
  /// starting at the beginning of the slice.
  ///
  /// This is the const generic equivalent of [`windows`].
@@ -2476,7 +2476,7 @@ impl<T> [T] {
  let mid = left + size / 2;
 
  // SAFETY: the while condition means `size` is strictly positive, so
- // `size/2 < size`.  Thus `left + size/2 < left + size`, which
+ // `size/2 < size`. Thus `left + size/2 < left + size`, which
  // coupled with the `left + size <= self.len()` invariant means
  // we have `left + size/2 < self.len()`, and this is in-bounds.
  let cmp = f(unsafe { self.get_unchecked(mid) });

library/core/src/slice/sort.rs

@@ -18,9 +18,9 @@ struct CopyOnDrop<T> {
 
 impl<T> Drop for CopyOnDrop<T> {
  fn drop(&mut self) {
- // SAFETY:  This is a helper class.
- //  Please refer to its usage for correctness.
- //  Namely, one must be sure that `src` and `dst` does not overlap as required by `ptr::copy_nonoverlapping`.
+ // SAFETY: This is a helper class.
+ // Please refer to its usage for correctness.
+ // Namely, one must be sure that `src` and `dst` does not overlap as required by `ptr::copy_nonoverlapping`.
  unsafe {
  ptr::copy_nonoverlapping(self.src, self.dest, 1);
  }

library/core/tests/slice.rs

@@ -1488,7 +1488,7 @@ mod slice_index {
  // optional:
  //
  // one or more similar inputs for which data[input] succeeds,
- // and the corresponding output as an array.  This helps validate
+ // and the corresponding output as an array. This helps validate
  // "critical points" where an input range straddles the boundary
  // between valid and invalid.
  // (such as the input `len..len`, which is just barely valid)

library/std/src/fs.rs

@@ -1512,7 +1512,7 @@ impl FileType {
  }
 
  /// Tests whether this file type represents a regular file.
- /// The result is  mutually exclusive to the results of
+ /// The result is mutually exclusive to the results of
  /// [`is_dir`] and [`is_symlink`]; only zero or one of these
  /// tests may pass.
  ///