Auto merge of rust-lang#80180 - JohnTitor:rollup-a31s996, r=JohnTitor

Rollup of 7 pull requests

Successful merges:

 - rust-lang#78083 (Stabilize or_insert_with_key)
 - rust-lang#79211 (Add the "async" and "promise" doc aliases to `core::future::Future`)
 - rust-lang#79612 (Switch some links in compiler/ to intra-doc links)
 - rust-lang#80068 (Add `&mut` as an alias for 'reference' primitive)
 - rust-lang#80129 (docs: Edit rustc_ast::token::Token)
 - rust-lang#80133 (Suppress `CONST_ITEM_MUTATION` lint if a dereference occurs anywhere)
 - rust-lang#80155 (Fix typo)

Failed merges:

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

compiler/rustc_ast/src/token.rs

@@ -434,7 +434,7 @@ impl Token {
             || self == &OpenDelim(Paren)
     }
 
-    /// Returns `true` if the token is any literal
+    /// Returns `true` if the token is any literal.
     pub fn is_lit(&self) -> bool {
         match self.kind {
             Literal(..) => true,

compiler/rustc_data_structures/src/graph/iterate/mod.rs

@@ -149,8 +149,6 @@ struct Event<N> {
 /// those successors), we will pop off that node's `Settled` event.
 ///
 /// [CLR]: https://en.wikipedia.org/wiki/Introduction_to_Algorithms
-/// [`NodeStatus`]: ./enum.NodeStatus.html
-/// [`TriColorVisitor::node_examined`]: ./trait.TriColorVisitor.html#method.node_examined
 pub struct TriColorDepthFirstSearch<'graph, G>
 where
     G: ?Sized + DirectedGraph + WithNumNodes + WithSuccessors,

compiler/rustc_data_structures/src/sorted_map/index_map.rs

@@ -24,8 +24,7 @@ use rustc_index::vec::{Idx, IndexVec};
 /// to insert into the middle of the sorted array. Users should avoid mutating this data structure
 /// in-place.
 ///
-/// [`IndexVec`]: ../../rustc_index/vec/struct.IndexVec.html
-/// [`SortedMap`]: ../sorted_map/struct.SortedMap.html
+/// [`SortedMap`]: super::SortedMap
 #[derive(Clone, Debug)]
 pub struct SortedIndexMultiMap<I: Idx, K, V> {
     /// The elements of the map in insertion order.

compiler/rustc_data_structures/src/sso/map.rs

@@ -40,7 +40,7 @@ const SSO_ARRAY_SIZE: usize = 8;
 //   into_keys/into_values (unstable)
 //   all raw_entry-related
 //   PartialEq/Eq (requires sorting the array)
-//   Entry::or_insert_with_key (unstable)
+//   Entry::or_insert_with_key
 //   Vacant/Occupied entries and related
 //
 // FIXME: In HashMap most methods accepting key reference

compiler/rustc_errors/src/diagnostic.rs

@@ -138,8 +138,6 @@ impl Diagnostic {
     ///
     /// This span is *not* considered a ["primary span"][`MultiSpan`]; only
     /// the `Span` supplied when creating the diagnostic is primary.
-    ///
-    /// [`MultiSpan`]: ../rustc_span/struct.MultiSpan.html
     pub fn span_label<T: Into<String>>(&mut self, span: Span, label: T) -> &mut Self {
         self.span.push_span_label(span, label.into());
         self

compiler/rustc_index/src/bit_set.rs

@@ -27,7 +27,6 @@ pub const WORD_BITS: usize = WORD_BYTES * 8;
 /// to or greater than the domain size. All operations that involve two bitsets
 /// will panic if the bitsets have differing domain sizes.
 ///
-/// [`GrowableBitSet`]: struct.GrowableBitSet.html
 #[derive(Eq, PartialEq, Decodable, Encodable)]
 pub struct BitSet<T> {
     domain_size: usize,

compiler/rustc_lexer/src/unescape.rs

@@ -201,7 +201,7 @@ fn scan_escape(first_char: char, chars: &mut Chars<'_>, mode: Mode) -> Result<ch
                 return Err(EscapeError::NoBraceInUnicodeEscape);
             }
 
-            // First characrer must be a hexadecimal digit.
+            // First character must be a hexadecimal digit.
             let mut n_digits = 1;
             let mut value: u32 = match chars.next().ok_or(EscapeError::UnclosedUnicodeEscape)? {
                 '_' => return Err(EscapeError::LeadingUnderscoreUnicodeEscape),

compiler/rustc_mir/src/dataflow/impls/liveness.rs

@@ -11,7 +11,7 @@ use crate::dataflow::{AnalysisDomain, Backward, GenKill, GenKillAnalysis};
 /// exist. See [this `mir-dataflow` test][flow-test] for an example. You almost never want to use
 /// this analysis without also looking at the results of [`MaybeBorrowedLocals`].
 ///
-/// [`MaybeBorrowedLocals`]: ../struct.MaybeBorrowedLocals.html
+/// [`MaybeBorrowedLocals`]: super::MaybeBorrowedLocals
 /// [flow-test]: https://github.com/rust-lang/rust/blob/a08c47310c7d49cbdc5d7afb38408ba519967ecd/src/test/ui/mir-dataflow/liveness-ptr.rs
 /// [liveness]: https://en.wikipedia.org/wiki/Live_variable_analysis
 pub struct MaybeLiveLocals;

compiler/rustc_mir/src/transform/check_const_item_mutation.rs

@@ -66,12 +66,14 @@ impl<'a, 'tcx> ConstMutationChecker<'a, 'tcx> {
         location: Location,
         decorate: impl for<'b> FnOnce(LintDiagnosticBuilder<'b>) -> DiagnosticBuilder<'b>,
     ) {
-        // Don't lint on borrowing/assigning to a dereference
-        // e.g:
+        // Don't lint on borrowing/assigning when a dereference is involved.
+        // If we 'leave' the temporary via a dereference, we must
+        // be modifying something else
         //
         // `unsafe { *FOO = 0; *BAR.field = 1; }`
         // `unsafe { &mut *FOO }`
-        if !matches!(place.projection.last(), Some(PlaceElem::Deref)) {
+        // `unsafe { (*ARRAY)[0] = val; }
+        if !place.projection.iter().any(|p| matches!(p, PlaceElem::Deref)) {
             let source_info = self.body.source_info(location);
             let lint_root = self.body.source_scopes[source_info.scope]
                 .local_data

library/alloc/src/collections/btree/map/entry.rs

@@ -116,15 +116,16 @@ impl<'a, K: Ord, V> Entry<'a, K, V> {
         }
     }
 
-    #[unstable(feature = "or_insert_with_key", issue = "71024")]
-    /// Ensures a value is in the entry by inserting, if empty, the result of the default function,
-    /// which takes the key as its argument, and returns a mutable reference to the value in the
-    /// entry.
+    /// Ensures a value is in the entry by inserting, if empty, the result of the default function.
+    /// This method allows for generating key-derived values for insertion by providing the default
+    /// function a reference to the key that was moved during the `.entry(key)` method call.
+    ///
+    /// The reference to the moved key is provided so that cloning or copying the key is
+    /// unnecessary, unlike with `.or_insert_with(|| ... )`.
     ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(or_insert_with_key)]
     /// use std::collections::BTreeMap;
     ///
     /// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
@@ -134,6 +135,7 @@ impl<'a, K: Ord, V> Entry<'a, K, V> {
     /// assert_eq!(map["poneyland"], 9);
     /// ```
     #[inline]
+    #[stable(feature = "or_insert_with_key", since = "1.50.0")]
     pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut V {
         match self {
             Occupied(entry) => entry.into_mut(),

library/std/src/collections/hash/map.rs

@@ -2219,14 +2219,16 @@ impl<'a, K, V> Entry<'a, K, V> {
         }
     }
 
-    /// Ensures a value is in the entry by inserting, if empty, the result of the default function,
-    /// which takes the key as its argument, and returns a mutable reference to the value in the
-    /// entry.
+    /// Ensures a value is in the entry by inserting, if empty, the result of the default function.
+    /// This method allows for generating key-derived values for insertion by providing the default
+    /// function a reference to the key that was moved during the `.entry(key)` method call.
+    ///
+    /// The reference to the moved key is provided so that cloning or copying the key is
+    /// unnecessary, unlike with `.or_insert_with(|| ... )`.
     ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(or_insert_with_key)]
     /// use std::collections::HashMap;
     ///
     /// let mut map: HashMap<&str, usize> = HashMap::new();
@@ -2236,7 +2238,7 @@ impl<'a, K, V> Entry<'a, K, V> {
     /// assert_eq!(map["poneyland"], 9);
     /// ```
     #[inline]
-    #[unstable(feature = "or_insert_with_key", issue = "71024")]
+    #[stable(feature = "or_insert_with_key", since = "1.50.0")]
     pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut V {
         match self {
             Occupied(entry) => entry.into_mut(),

library/std/src/keyword_docs.rs

@@ -2196,6 +2196,7 @@ mod where_keyword {}
 
 // 2018 Edition keywords
 
+#[doc(alias = "promise")]
 #[doc(keyword = "async")]
 //
 /// Return a [`Future`] instead of blocking the current thread.

library/std/src/primitive_docs.rs

@@ -924,6 +924,7 @@ mod prim_usize {}
 
 #[doc(primitive = "reference")]
 #[doc(alias = "&")]
+#[doc(alias = "&mut")]
 //
 /// References, both shared and mutable.
 ///

src/test/ui/lint/lint-const-item-mutation.rs

@@ -30,6 +30,8 @@ const MUTABLE: Mutable = Mutable { msg: "" };
 const MUTABLE2: Mutable2 = Mutable2 { msg: "", other: String::new() };
 const VEC: Vec<i32> = Vec::new();
 const PTR: *mut () = 1 as *mut _;
+const PTR_TO_ARRAY: *mut [u32; 4] = 0x12345678 as _;
+const ARRAY_OF_PTR: [*mut u32; 1] = [1 as *mut _];
 
 fn main() {
     ARRAY[0] = 5; //~ WARN attempting to modify
@@ -55,4 +57,10 @@ fn main() {
     // Test that we don't warn when converting a raw pointer
     // into a mutable reference
     unsafe { &mut *PTR };
+
+    // Test that we don't warn when there's a dereference involved.
+    // If we ever 'leave' the const via a deference, we're going
+    // to end up modifying something other than the temporary
+    unsafe { (*PTR_TO_ARRAY)[0] = 1 };
+    unsafe { *ARRAY_OF_PTR[0] = 25; }
 }

src/test/ui/lint/lint-const-item-mutation.stderr

@@ -1,5 +1,5 @@
 warning: attempting to modify a `const` item
-  --> $DIR/lint-const-item-mutation.rs:35:5
+  --> $DIR/lint-const-item-mutation.rs:37:5
    |
 LL |     ARRAY[0] = 5;
    |     ^^^^^^^^^^^^
@@ -13,7 +13,7 @@ LL | const ARRAY: [u8; 1] = [25];
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: attempting to modify a `const` item
-  --> $DIR/lint-const-item-mutation.rs:36:5
+  --> $DIR/lint-const-item-mutation.rs:38:5
    |
 LL |     MY_STRUCT.field = false;
    |     ^^^^^^^^^^^^^^^^^^^^^^^
@@ -26,7 +26,7 @@ LL | const MY_STRUCT: MyStruct = MyStruct { field: true, inner_array: ['a'], raw
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: attempting to modify a `const` item
-  --> $DIR/lint-const-item-mutation.rs:37:5
+  --> $DIR/lint-const-item-mutation.rs:39:5
    |
 LL |     MY_STRUCT.inner_array[0] = 'b';
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -39,7 +39,7 @@ LL | const MY_STRUCT: MyStruct = MyStruct { field: true, inner_array: ['a'], raw
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: taking a mutable reference to a `const` item
-  --> $DIR/lint-const-item-mutation.rs:38:5
+  --> $DIR/lint-const-item-mutation.rs:40:5
    |
 LL |     MY_STRUCT.use_mut();
    |     ^^^^^^^^^^^^^^^^^^^
@@ -58,7 +58,7 @@ LL | const MY_STRUCT: MyStruct = MyStruct { field: true, inner_array: ['a'], raw
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: taking a mutable reference to a `const` item
-  --> $DIR/lint-const-item-mutation.rs:39:5
+  --> $DIR/lint-const-item-mutation.rs:41:5
    |
 LL |     &mut MY_STRUCT;
    |     ^^^^^^^^^^^^^^
@@ -72,7 +72,7 @@ LL | const MY_STRUCT: MyStruct = MyStruct { field: true, inner_array: ['a'], raw
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: taking a mutable reference to a `const` item
-  --> $DIR/lint-const-item-mutation.rs:40:5
+  --> $DIR/lint-const-item-mutation.rs:42:5
    |
 LL |     (&mut MY_STRUCT).use_mut();
    |     ^^^^^^^^^^^^^^^^
@@ -86,7 +86,7 @@ LL | const MY_STRUCT: MyStruct = MyStruct { field: true, inner_array: ['a'], raw
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: attempting to modify a `const` item
-  --> $DIR/lint-const-item-mutation.rs:52:5
+  --> $DIR/lint-const-item-mutation.rs:54:5
    |
 LL |     MUTABLE2.msg = "wow";
    |     ^^^^^^^^^^^^^^^^^^^^
@@ -99,7 +99,7 @@ LL | const MUTABLE2: Mutable2 = Mutable2 { msg: "", other: String::new() };
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: taking a mutable reference to a `const` item
-  --> $DIR/lint-const-item-mutation.rs:53:5
+  --> $DIR/lint-const-item-mutation.rs:55:5
    |
 LL |     VEC.push(0);
    |     ^^^^^^^^^^^