Auto merge of rust-lang#82430 - Dylan-DPC:rollup-nu4kfyc, r=Dylan-DPC

Rollup of 12 pull requests

Successful merges:

 - rust-lang#79423 (Enable smart punctuation)
 - rust-lang#81154 (Improve design of `assert_len`)
 - rust-lang#81235 (Improve suggestion for tuple struct pattern matching errors.)
 - rust-lang#81769 (Suggest `return`ing tail expressions that match return type)
 - rust-lang#81837 (Slight perf improvement on char::to_ascii_lowercase)
 - rust-lang#81969 (Avoid `cfg_if` in `std::os`)
 - rust-lang#81984 (Make WASI's `hard_link` behavior match other platforms.)
 - rust-lang#82091 (use PlaceRef abstractions more consistently)
 - rust-lang#82128 (add diagnostic items for OsString/PathBuf/Owned as well as to_vec on slice)
 - rust-lang#82166 (add s390x-unknown-linux-musl target)
 - rust-lang#82234 (Remove query parameters when skipping search results)
 - rust-lang#82255 (Make `treat_err_as_bug` Option<NonZeroUsize>)

Failed merges:

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

Author: bors

alloc/src/borrow.rs

@@ -31,6 +31,7 @@ where
 /// implementing the `Clone` trait. But `Clone` works only for going from `&T`
 /// to `T`. The `ToOwned` trait generalizes `Clone` to construct owned data
 /// from any borrow of a given type.
+#[cfg_attr(not(test), rustc_diagnostic_item = "ToOwned")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait ToOwned {
     /// The resulting type after obtaining ownership.

alloc/src/collections/vec_deque/mod.rs

@@ -1063,7 +1063,7 @@ impl<T> VecDeque<T> {
     where
         R: RangeBounds<usize>,
     {
-        let Range { start, end } = range.assert_len(self.len());
+        let Range { start, end } = slice::range(range, ..self.len());
         let tail = self.wrap_add(self.tail, start);
         let head = self.wrap_add(self.tail, end);
         (tail, head)

alloc/src/lib.rs

@@ -115,14 +115,14 @@
 #![feature(or_patterns)]
 #![feature(pattern)]
 #![feature(ptr_internals)]
-#![feature(range_bounds_assert_len)]
 #![feature(rustc_attrs)]
 #![feature(receiver_trait)]
 #![cfg_attr(bootstrap, feature(min_const_generics))]
 #![feature(min_specialization)]
 #![feature(set_ptr_value)]
 #![feature(slice_ptr_get)]
 #![feature(slice_ptr_len)]
+#![feature(slice_range)]
 #![feature(staged_api)]
 #![feature(str_internals)]
 #![feature(trusted_len)]

alloc/src/slice.rs

@@ -92,6 +92,8 @@ use crate::borrow::ToOwned;
 use crate::boxed::Box;
 use crate::vec::Vec;
 
+#[unstable(feature = "slice_range", issue = "76393")]
+pub use core::slice::range;
 #[unstable(feature = "array_chunks", issue = "74985")]
 pub use core::slice::ArrayChunks;
 #[unstable(feature = "array_chunks", issue = "74985")]
@@ -220,6 +222,7 @@ mod hack {
 }
 
 #[lang = "slice_alloc"]
+#[cfg_attr(not(test), rustc_diagnostic_item = "slice")]
 #[cfg(not(test))]
 impl<T> [T] {
     /// Sorts the slice.

alloc/src/string.rs

@@ -49,6 +49,7 @@ use core::iter::{FromIterator, FusedIterator};
 use core::ops::Bound::{Excluded, Included, Unbounded};
 use core::ops::{self, Add, AddAssign, Index, IndexMut, Range, RangeBounds};
 use core::ptr;
+use core::slice;
 use core::str::{lossy, pattern::Pattern};
 
 use crate::borrow::{Cow, ToOwned};
@@ -1510,14 +1511,14 @@ impl String {
         // of the vector version. The data is just plain bytes.
         // Because the range removal happens in Drop, if the Drain iterator is leaked,
         // the removal will not happen.
-        let Range { start, end } = range.assert_len(self.len());
+        let Range { start, end } = slice::range(range, ..self.len());
         assert!(self.is_char_boundary(start));
         assert!(self.is_char_boundary(end));
 
         // Take out two simultaneous borrows. The &mut String won't be accessed
         // until iteration is over, in Drop.
         let self_ptr = self as *mut _;
-        // SAFETY: `assert_len` and `is_char_boundary` do the appropriate bounds checks.
+        // SAFETY: `slice::range` and `is_char_boundary` do the appropriate bounds checks.
         let chars_iter = unsafe { self.get_unchecked(start..end) }.chars();
 
         Drain { start, end, iter: chars_iter, string: self_ptr }
@@ -2174,6 +2175,7 @@ impl FromStr for String {
 /// implementation for free.
 ///
 /// [`Display`]: fmt::Display
+#[cfg_attr(not(test), rustc_diagnostic_item = "ToString")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait ToString {
     /// Converts the given value to a `String`.

alloc/src/vec/mod.rs

@@ -1651,7 +1651,7 @@ impl<T, A: Allocator> Vec<T, A> {
         // the hole, and the vector length is restored to the new length.
         //
         let len = self.len();
-        let Range { start, end } = range.assert_len(len);
+        let Range { start, end } = slice::range(range, ..len);
 
         unsafe {
             // set self.vec length's to start, to be safe in case Drain is leaked
@@ -2037,11 +2037,11 @@ impl<T: Clone, A: Allocator> Vec<T, A> {
     where
         R: RangeBounds<usize>,
     {
-        let range = src.assert_len(self.len());
+        let range = slice::range(src, ..self.len());
         self.reserve(range.len());
 
         // SAFETY:
-        // - `assert_len` 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);
         }

core/benches/ascii.rs

@@ -66,6 +66,8 @@ macro_rules! benches {
 use test::black_box;
 use test::Bencher;
 
+const ASCII_CASE_MASK: u8 = 0b0010_0000;
+
 benches! {
     fn case00_alloc_only(_bytes: &mut [u8]) {}
 
@@ -204,7 +206,7 @@ benches! {
             }
         }
         for byte in bytes {
-            *byte &= !((is_ascii_lowercase(*byte) as u8) << 5)
+            *byte &= !((is_ascii_lowercase(*byte) as u8) * ASCII_CASE_MASK)
         }
     }
 
@@ -216,7 +218,7 @@ benches! {
             }
         }
         for byte in bytes {
-            *byte -= (is_ascii_lowercase(*byte) as u8) << 5
+            *byte -= (is_ascii_lowercase(*byte) as u8) * ASCII_CASE_MASK
         }
     }
 

core/benches/char/methods.rs

@@ -35,3 +35,13 @@ fn bench_to_digit_radix_var(b: &mut Bencher) {
             .min()
     })
 }
+
+#[bench]
+fn bench_to_ascii_uppercase(b: &mut Bencher) {
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_ascii_uppercase()).min())
+}
+
+#[bench]
+fn bench_to_ascii_lowercase(b: &mut Bencher) {
+    b.iter(|| CHARS.iter().cycle().take(10_000).map(|c| c.to_ascii_lowercase()).min())
+}

core/src/char/methods.rs

@@ -1088,7 +1088,11 @@ impl char {
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
     #[inline]
     pub fn to_ascii_uppercase(&self) -> char {
-        if self.is_ascii() { (*self as u8).to_ascii_uppercase() as char } else { *self }
+        if self.is_ascii_lowercase() {
+            (*self as u8).ascii_change_case_unchecked() as char
+        } else {
+            *self
+        }
     }
 
     /// Makes a copy of the value in its ASCII lower case equivalent.
@@ -1116,7 +1120,11 @@ impl char {
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
     #[inline]
     pub fn to_ascii_lowercase(&self) -> char {
-        if self.is_ascii() { (*self as u8).to_ascii_lowercase() as char } else { *self }
+        if self.is_ascii_uppercase() {
+            (*self as u8).ascii_change_case_unchecked() as char
+        } else {
+            *self
+        }
     }
 
     /// Checks that two values are an ASCII case-insensitive match.

core/src/num/mod.rs

@@ -152,6 +152,9 @@ impl isize {
      usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
 }
 
+/// If 6th bit set ascii is upper case.
+const ASCII_CASE_MASK: u8 = 0b0010_0000;
+
 #[lang = "u8"]
 impl u8 {
     uint_impl! { u8, u8, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
@@ -195,7 +198,7 @@ impl u8 {
     #[inline]
     pub fn to_ascii_uppercase(&self) -> u8 {
         // Unset the fifth bit if this is a lowercase letter
-        *self & !((self.is_ascii_lowercase() as u8) << 5)
+        *self & !((self.is_ascii_lowercase() as u8) * ASCII_CASE_MASK)
     }
 
     /// Makes a copy of the value in its ASCII lower case equivalent.
@@ -218,7 +221,13 @@ impl u8 {
     #[inline]
     pub fn to_ascii_lowercase(&self) -> u8 {
         // Set the fifth bit if this is an uppercase letter
-        *self | ((self.is_ascii_uppercase() as u8) << 5)
+        *self | (self.is_ascii_uppercase() as u8 * ASCII_CASE_MASK)
+    }
+
+    /// Assumes self is ascii
+    #[inline]
+    pub(crate) fn ascii_change_case_unchecked(&self) -> u8 {
+        *self ^ ASCII_CASE_MASK
     }
 
     /// Checks that two values are an ASCII case-insensitive match.