Rollup of 7 pull requests

compiler/rustc_typeck/src/check/op.rs

@@ -57,9 +57,28 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     )
                     .is_ok()
                 {
-                    // Suppress this error, since we already emitted
-                    // a deref suggestion in check_overloaded_binop
-                    err.downgrade_to_delayed_bug();
+                    // If LHS += RHS is an error, but *LHS += RHS is successful, then we will have
+                    // emitted a better suggestion during error handling in check_overloaded_binop.
+                    if self
+                        .lookup_op_method(
+                            lhs_ty,
+                            Some(rhs_ty),
+                            Some(rhs),
+                            Op::Binary(op, IsAssign::Yes),
+                            expected,
+                        )
+                        .is_err()
+                    {
+                        err.downgrade_to_delayed_bug();
+                    } else {
+                        // Otherwise, it's valid to suggest dereferencing the LHS here.
+                        err.span_suggestion_verbose(
+                            lhs.span.shrink_to_lo(),
+                            "consider dereferencing the left-hand side of this operation",
+                            "*",
+                            Applicability::MaybeIncorrect,
+                        );
+                    }
                 }
             }
         });

library/alloc/src/collections/btree/dedup_sorted_iter.rs

@@ -3,7 +3,9 @@ use core::iter::Peekable;
 /// A iterator for deduping the key of a sorted iterator.
 /// When encountering the duplicated key, only the last key-value pair is yielded.
 ///
-/// Used by [`BTreeMap::bulk_build_from_sorted_iter`].
+/// Used by [`BTreeMap::bulk_build_from_sorted_iter`][1].
+///
+/// [1]: crate::collections::BTreeMap::bulk_build_from_sorted_iter
 pub struct DedupSortedIter<K, V, I>
 where
     I: Iterator<Item = (K, V)>,

library/core/src/char/methods.rs

@@ -746,10 +746,19 @@ impl char {
     /// assert!(!'中'.is_lowercase());
     /// assert!(!' '.is_lowercase());
     /// ```
+    ///
+    /// In a const context:
+    ///
+    /// ```
+    /// #![feature(const_unicode_case_lookup)]
+    /// const CAPITAL_DELTA_IS_LOWERCASE: bool = 'Δ'.is_lowercase();
+    /// assert!(!CAPITAL_DELTA_IS_LOWERCASE);
+    /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")]
     #[inline]
-    pub fn is_lowercase(self) -> bool {
+    pub const fn is_lowercase(self) -> bool {
         match self {
             'a'..='z' => true,
             c => c > '\x7f' && unicode::Lowercase(c),
@@ -779,10 +788,19 @@ impl char {
     /// assert!(!'中'.is_uppercase());
     /// assert!(!' '.is_uppercase());
     /// ```
+    ///
+    /// In a const context:
+    ///
+    /// ```
+    /// #![feature(const_unicode_case_lookup)]
+    /// const CAPITAL_DELTA_IS_UPPERCASE: bool = 'Δ'.is_uppercase();
+    /// assert!(CAPITAL_DELTA_IS_UPPERCASE);
+    /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")]
     #[inline]
-    pub fn is_uppercase(self) -> bool {
+    pub const fn is_uppercase(self) -> bool {
         match self {
             'A'..='Z' => true,
             c => c > '\x7f' && unicode::Uppercase(c),

library/core/src/lib.rs

@@ -143,6 +143,7 @@
 #![feature(const_type_id)]
 #![feature(const_type_name)]
 #![feature(const_default_impls)]
+#![feature(const_unicode_case_lookup)]
 #![feature(const_unsafecell_get_mut)]
 #![feature(core_panic)]
 #![feature(duration_consts_float)]

library/core/src/unicode/unicode_data.rs

@@ -1,7 +1,8 @@
 ///! This file is generated by src/tools/unicode-table-generator; do not edit manually!
 
+#[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")]
 #[inline(always)]
-fn bitset_search<
+const fn bitset_search<
     const N: usize,
     const CHUNK_SIZE: usize,
     const N1: usize,
@@ -17,14 +18,18 @@ fn bitset_search<
     let bucket_idx = (needle / 64) as usize;
     let chunk_map_idx = bucket_idx / CHUNK_SIZE;
     let chunk_piece = bucket_idx % CHUNK_SIZE;
-    let chunk_idx = if let Some(&v) = chunk_idx_map.get(chunk_map_idx) {
-        v
+    // FIXME: const-hack: Revert to `slice::get` after `const_slice_index`
+    // feature stabilizes.
+    let chunk_idx = if chunk_map_idx < chunk_idx_map.len() {
+        chunk_idx_map[chunk_map_idx]
     } else {
         return false;
     };
     let idx = bitset_chunk_idx[chunk_idx as usize][chunk_piece] as usize;
-    let word = if let Some(word) = bitset_canonical.get(idx) {
-        *word
+    // FIXME: const-hack: Revert to `slice::get` after `const_slice_index`
+    // feature stabilizes.
+    let word = if idx < bitset_canonical.len() {
+        bitset_canonical[idx]
     } else {
         let (real_idx, mapping) = bitset_canonicalized[idx - bitset_canonical.len()];
         let mut word = bitset_canonical[real_idx as usize];
@@ -318,14 +323,14 @@ pub mod grapheme_extend {
 
 #[rustfmt::skip]
 pub mod lowercase {
-    static BITSET_CHUNKS_MAP: [u8; 123] = [
+    const BITSET_CHUNKS_MAP: &'static [u8; 123] = &[
         14, 17, 0, 0, 9, 0, 0, 12, 13, 10, 0, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 4, 1, 0, 15, 0, 8, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 18, 0,
         3, 0, 0, 7,
     ];
-    static BITSET_INDEX_CHUNKS: [[u8; 16]; 19] = [
+    const BITSET_INDEX_CHUNKS: &'static [[u8; 16]; 19] = &[
         [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
         [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 59, 0, 0],
         [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 14, 55, 0],
@@ -346,7 +351,7 @@ pub mod lowercase {
         [16, 49, 2, 20, 66, 9, 57, 0, 0, 0, 0, 0, 0, 0, 0, 0],
         [63, 39, 54, 12, 73, 61, 18, 1, 6, 62, 71, 19, 68, 69, 3, 44],
     ];
-    static BITSET_CANONICAL: [u64; 55] = [
+    const BITSET_CANONICAL: &'static [u64; 55] = &[
         0b0000000000000000000000000000000000000000000000000000000000000000,
         0b1111111111111111110000000000000000000000000011111111111111111111,
         0b1010101010101010101010101010101010101010101010101010100000000010,
@@ -403,13 +408,14 @@ pub mod lowercase {
         0b1110011111111111111111111111111111111111111111110000000000000000,
         0b1110101111000000000000000000000000001111111111111111111111111100,
     ];
-    static BITSET_MAPPING: [(u8, u8); 20] = [
+    const BITSET_MAPPING: &'static [(u8, u8); 20] = &[
         (0, 64), (1, 188), (1, 183), (1, 176), (1, 109), (1, 124), (1, 126), (1, 66), (1, 70),
         (1, 77), (2, 146), (2, 144), (2, 83), (3, 12), (3, 6), (4, 156), (4, 78), (5, 187),
         (6, 132), (7, 93),
     ];
 
-    pub fn lookup(c: char) -> bool {
+    #[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")]
+    pub const fn lookup(c: char) -> bool {
         super::bitset_search(
             c as u32,
             &BITSET_CHUNKS_MAP,
@@ -454,14 +460,14 @@ pub mod n {
 
 #[rustfmt::skip]
 pub mod uppercase {
-    static BITSET_CHUNKS_MAP: [u8; 125] = [
+    const BITSET_CHUNKS_MAP: &'static [u8; 125] = &[
         12, 15, 6, 6, 0, 6, 6, 2, 4, 11, 6, 16, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
         6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
         6, 6, 6, 5, 6, 14, 6, 10, 6, 6, 1, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
         6, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 13, 6, 6,
         6, 6, 9, 6, 3,
     ];
-    static BITSET_INDEX_CHUNKS: [[u8; 16]; 17] = [
+    const BITSET_INDEX_CHUNKS: &'static [[u8; 16]; 17] = &[
         [43, 43, 5, 34, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 5, 1],
         [43, 43, 5, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43],
         [43, 43, 39, 43, 43, 43, 43, 43, 17, 17, 62, 17, 42, 29, 24, 23],
@@ -480,7 +486,7 @@ pub mod uppercase {
         [57, 19, 2, 18, 10, 47, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43],
         [57, 37, 17, 27, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43],
     ];
-    static BITSET_CANONICAL: [u64; 43] = [
+    const BITSET_CANONICAL: &'static [u64; 43] = &[
         0b0000011111111111111111111111111000000000000000000000000000000000,
         0b0000000000111111111111111111111111111111111111111111111111111111,
         0b0101010101010101010101010101010101010101010101010101010000000001,
@@ -525,13 +531,14 @@ pub mod uppercase {
         0b1111011111111111000000000000000000000000000000000000000000000000,
         0b1111111100000000111111110000000000111111000000001111111100000000,
     ];
-    static BITSET_MAPPING: [(u8, u8); 25] = [
+    const BITSET_MAPPING: &'static [(u8, u8); 25] = &[
         (0, 187), (0, 177), (0, 171), (0, 167), (0, 164), (0, 32), (0, 47), (0, 51), (0, 121),
         (0, 117), (0, 109), (1, 150), (1, 148), (1, 142), (1, 134), (1, 131), (1, 64), (2, 164),
         (2, 146), (2, 20), (3, 146), (3, 140), (3, 134), (4, 178), (4, 171),
     ];
 
-    pub fn lookup(c: char) -> bool {
+    #[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")]
+    pub const fn lookup(c: char) -> bool {
         super::bitset_search(
             c as u32,
             &BITSET_CHUNKS_MAP,

library/std/src/alloc.rs

@@ -68,7 +68,10 @@ pub use alloc_crate::alloc::*;
 /// The default memory allocator provided by the operating system.
 ///
 /// This is based on `malloc` on Unix platforms and `HeapAlloc` on Windows,
-/// plus related functions.
+/// plus related functions. However, it is not valid to mix use of the backing
+/// system allocator with `System`, as this implementation may include extra
+/// work, such as to serve alignment requests greater than the alignment
+/// provided directly by the backing system allocator.
 ///
 /// This type implements the `GlobalAlloc` trait and Rust programs by default
 /// work as if they had this definition:

library/std/src/fs.rs

@@ -19,7 +19,7 @@ use crate::sys::fs as fs_imp;
 use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 use crate::time::SystemTime;
 
-/// A reference to an open file on the filesystem.
+/// An object providing access to an open file on the filesystem.
 ///
 /// An instance of a `File` can be read and/or written depending on what options
 /// it was opened with. Files also implement [`Seek`] to alter the logical cursor

src/ci/docker/host-x86_64/mingw-check/Dockerfile

@@ -45,7 +45,8 @@ ENV SCRIPT python3 ../x.py --stage 2 test src/tools/expand-yaml-anchors && \
            python3 ../x.py test --stage 0 src/tools/compiletest && \
            python3 ../x.py test --stage 2 src/tools/tidy && \
            python3 ../x.py test --stage 0 core alloc std test proc_macro && \
-           python3 ../x.py doc --stage 0 library/test && \
+           # Build both public and internal documentation.
+           RUSTDOCFLAGS="--document-private-items" python3 ../x.py doc --stage 0 library/test && \
            /scripts/validate-toolstate.sh && \
            /scripts/validate-error-codes.sh && \
            reuse lint && \

src/librustdoc/html/static/css/rustdoc.css

@@ -1883,10 +1883,6 @@ in storage.js plus the media query with (min-width: 701px)
 		background-color: var(--sidebar-background-color);
 	}
 
-	.source nav:not(.sidebar).sub {
-		margin-left: 32px;
-	}
-
 	.content {
 		margin-left: 0px;
 	}

src/test/ui/typeck/assign-non-lval-needs-deref.rs

@@ -0,0 +1,19 @@
+// issue #101376
+
+use std::ops::AddAssign;
+struct Foo;
+
+impl AddAssign<()> for Foo {
+    fn add_assign(&mut self, _: ()) {}
+}
+
+impl AddAssign<()> for &mut Foo {
+    fn add_assign(&mut self, _: ()) {}
+}
+
+fn main() {
+    (&mut Foo) += ();
+    //~^ ERROR invalid left-hand side of assignment
+    //~| NOTE cannot assign to this expression
+    //~| HELP consider dereferencing the left-hand side of this operation
+}

src/test/ui/typeck/assign-non-lval-needs-deref.stderr

@@ -0,0 +1,16 @@
+error[E0067]: invalid left-hand side of assignment
+  --> $DIR/assign-non-lval-needs-deref.rs:15:16
+   |
+LL |     (&mut Foo) += ();
+   |     ---------- ^^
+   |     |
+   |     cannot assign to this expression
+   |
+help: consider dereferencing the left-hand side of this operation
+   |
+LL |     *(&mut Foo) += ();
+   |     +
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0067`.

src/tools/unicode-table-generator/src/range_search.rs

@@ -1,5 +1,6 @@
+#[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")]
 #[inline(always)]
-fn bitset_search<
+const fn bitset_search<
     const N: usize,
     const CHUNK_SIZE: usize,
     const N1: usize,
@@ -15,14 +16,18 @@ fn bitset_search<
     let bucket_idx = (needle / 64) as usize;
     let chunk_map_idx = bucket_idx / CHUNK_SIZE;
     let chunk_piece = bucket_idx % CHUNK_SIZE;
-    let chunk_idx = if let Some(&v) = chunk_idx_map.get(chunk_map_idx) {
-        v
+    // FIXME: const-hack: Revert to `slice::get` after `const_slice_index`
+    // feature stabilizes.
+    let chunk_idx = if chunk_map_idx < chunk_idx_map.len() {
+        chunk_idx_map[chunk_map_idx]
     } else {
         return false;
     };
     let idx = bitset_chunk_idx[chunk_idx as usize][chunk_piece] as usize;
-    let word = if let Some(word) = bitset_canonical.get(idx) {
-        *word
+    // FIXME: const-hack: Revert to `slice::get` after `const_slice_index`
+    // feature stabilizes.
+    let word = if idx < bitset_canonical.len() {
+        bitset_canonical[idx]
     } else {
         let (real_idx, mapping) = bitset_canonicalized[idx - bitset_canonical.len()];
         let mut word = bitset_canonical[real_idx as usize];

src/tools/unicode-table-generator/src/raw_emitter.rs

@@ -76,15 +76,15 @@ impl RawEmitter {
 
         writeln!(
             &mut self.file,
-            "static BITSET_CANONICAL: [u64; {}] = [{}];",
+            "const BITSET_CANONICAL: &'static [u64; {}] = &[{}];",
             canonicalized.canonical_words.len(),
             fmt_list(canonicalized.canonical_words.iter().map(|v| Bits(*v))),
         )
         .unwrap();
         self.bytes_used += 8 * canonicalized.canonical_words.len();
         writeln!(
             &mut self.file,
-            "static BITSET_MAPPING: [(u8, u8); {}] = [{}];",
+            "const BITSET_MAPPING: &'static [(u8, u8); {}] = &[{}];",
             canonicalized.canonicalized_words.len(),
             fmt_list(&canonicalized.canonicalized_words),
         )
@@ -96,7 +96,12 @@ impl RawEmitter {
 
         self.blank_line();
 
-        writeln!(&mut self.file, "pub fn lookup(c: char) -> bool {{").unwrap();
+        writeln!(
+            &mut self.file,
+            r#"#[rustc_const_unstable(feature = "const_unicode_case_lookup", issue = "101400")]"#
+        )
+        .unwrap();
+        writeln!(&mut self.file, "pub const fn lookup(c: char) -> bool {{").unwrap();
         writeln!(&mut self.file, "    super::bitset_search(",).unwrap();
         writeln!(&mut self.file, "        c as u32,").unwrap();
         writeln!(&mut self.file, "        &BITSET_CHUNKS_MAP,").unwrap();
@@ -130,15 +135,15 @@ impl RawEmitter {
 
         writeln!(
             &mut self.file,
-            "static BITSET_CHUNKS_MAP: [u8; {}] = [{}];",
+            "const BITSET_CHUNKS_MAP: &'static [u8; {}] = &[{}];",
             chunk_indices.len(),
             fmt_list(&chunk_indices),
         )
         .unwrap();
         self.bytes_used += chunk_indices.len();
         writeln!(
             &mut self.file,
-            "static BITSET_INDEX_CHUNKS: [[u8; {}]; {}] = [{}];",
+            "const BITSET_INDEX_CHUNKS: &'static [[u8; {}]; {}] = &[{}];",
             chunk_length,
             chunks.len(),
             fmt_list(chunks.iter()),