Auto merge of rust-lang#93220 - matthiaskrgr:rollup-9bkrlk0, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#90666 (Stabilize arc_new_cyclic)
 - rust-lang#91122 (impl Not for !)
 - rust-lang#93068 (Fix spacing for `·` between stability and source)
 - rust-lang#93103 (Tweak `expr.await` desugaring `Span`)
 - rust-lang#93113 (Unify search input and buttons size)
 - rust-lang#93168 (update uclibc instructions for new toolchain, add link from platforms doc)
 - rust-lang#93185 (rustdoc: Make some `pub` items crate-private)
 - rust-lang#93196 (Remove dead code from build_helper)

Failed merges:

 - rust-lang#93188 (rustdoc: fix bump down typing search on Safari)

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

Author: bors

compiler/rustc_ast_lowering/src/expr.rs

@@ -625,18 +625,18 @@ impl<'hir> LoweringContext<'_, 'hir> {
     ///     }
     /// }
     /// ```
-    fn lower_expr_await(&mut self, await_span: Span, expr: &Expr) -> hir::ExprKind<'hir> {
-        let dot_await_span = expr.span.shrink_to_hi().to(await_span);
+    fn lower_expr_await(&mut self, dot_await_span: Span, expr: &Expr) -> hir::ExprKind<'hir> {
+        let full_span = expr.span.to(dot_await_span);
         match self.generator_kind {
             Some(hir::GeneratorKind::Async(_)) => {}
             Some(hir::GeneratorKind::Gen) | None => {
                 let mut err = struct_span_err!(
                     self.sess,
-                    await_span,
+                    dot_await_span,
                     E0728,
                     "`await` is only allowed inside `async` functions and blocks"
                 );
-                err.span_label(await_span, "only allowed inside `async` functions and blocks");
+                err.span_label(dot_await_span, "only allowed inside `async` functions and blocks");
                 if let Some(item_sp) = self.current_item {
                     err.span_label(item_sp, "this is not `async`");
                 }
@@ -646,7 +646,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let span = self.mark_span_with_reason(DesugaringKind::Await, dot_await_span, None);
         let gen_future_span = self.mark_span_with_reason(
             DesugaringKind::Await,
-            await_span,
+            full_span,
             self.allow_gen_future.clone(),
         );
         let expr = self.lower_expr_mut(expr);
@@ -699,9 +699,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let loop_hir_id = self.lower_node_id(loop_node_id);
         let ready_arm = {
             let x_ident = Ident::with_dummy_span(sym::result);
-            let (x_pat, x_pat_hid) = self.pat_ident(span, x_ident);
-            let x_expr = self.expr_ident(span, x_ident, x_pat_hid);
-            let ready_field = self.single_pat_field(span, x_pat);
+            let (x_pat, x_pat_hid) = self.pat_ident(gen_future_span, x_ident);
+            let x_expr = self.expr_ident(gen_future_span, x_ident, x_pat_hid);
+            let ready_field = self.single_pat_field(gen_future_span, x_pat);
             let ready_pat = self.pat_lang_item_variant(
                 span,
                 hir::LangItem::PollReady,
@@ -711,7 +711,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let break_x = self.with_loop_scope(loop_node_id, move |this| {
                 let expr_break =
                     hir::ExprKind::Break(this.lower_loop_destination(None), Some(x_expr));
-                this.arena.alloc(this.expr(span, expr_break, ThinVec::new()))
+                this.arena.alloc(this.expr(gen_future_span, expr_break, ThinVec::new()))
             });
             self.arm(ready_pat, break_x)
         };
@@ -783,7 +783,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         // `match ::std::future::IntoFuture::into_future(<expr>) { ... }`
         let into_future_span = self.mark_span_with_reason(
             DesugaringKind::Await,
-            await_span,
+            dot_await_span,
             self.allow_into_future.clone(),
         );
         let into_future_expr = self.expr_call_lang_item_fn(

library/alloc/src/rc.rs

@@ -374,33 +374,51 @@ impl<T> Rc<T> {
         }
     }
 
-    /// Constructs a new `Rc<T>` using a weak reference to itself. Attempting
-    /// to upgrade the weak reference before this function returns will result
-    /// in a `None` value. However, the weak reference may be cloned freely and
-    /// stored for use at a later time.
+    /// Constructs a new `Rc<T>` using a closure `data_fn` that has access to a
+    /// weak reference to the constructing `Rc<T>`.
+    ///
+    /// Generally, a structure circularly referencing itself, either directly or
+    /// indirectly, should not hold a strong reference to prevent a memory leak.
+    /// In `data_fn`, initialization of `T` can make use of the weak reference
+    /// by cloning and storing it inside `T` for use at a later time.
+    ///
+    /// Since the new `Rc<T>` is not fully-constructed until `Rc<T>::new_cyclic`
+    /// returns, calling [`upgrade`] on the weak reference inside `data_fn` will
+    /// fail and result in a `None` value.
+    ///
+    /// # Panics
+    /// If `data_fn` panics, the panic is propagated to the caller, and the
+    /// temporary [`Weak<T>`] is dropped normally.
     ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(arc_new_cyclic)]
     /// #![allow(dead_code)]
     /// use std::rc::{Rc, Weak};
     ///
     /// struct Gadget {
-    ///     self_weak: Weak<Self>,
-    ///     // ... more fields
+    ///     me: Weak<Gadget>,
     /// }
+    ///
     /// impl Gadget {
-    ///     pub fn new() -> Rc<Self> {
-    ///         Rc::new_cyclic(|self_weak| {
-    ///             Gadget { self_weak: self_weak.clone(), /* ... */ }
-    ///         })
+    ///     /// Construct a reference counted Gadget.
+    ///     fn new() -> Rc<Self> {
+    ///         Rc::new_cyclic(|me| Gadget { me: me.clone() })
+    ///     }
+    ///
+    ///     /// Return a reference counted pointer to Self.
+    ///     fn me(&self) -> Rc<Self> {
+    ///         self.me.upgrade().unwrap()
     ///     }
     /// }
     /// ```
+    /// [`upgrade`]: Weak::upgrade
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "arc_new_cyclic", issue = "75861")]
-    pub fn new_cyclic(data_fn: impl FnOnce(&Weak<T>) -> T) -> Rc<T> {
+    #[stable(feature = "arc_new_cyclic", since = "1.60.0")]
+    pub fn new_cyclic<F>(data_fn: F) -> Rc<T>
+    where
+        F: FnOnce(&Weak<T>) -> T,
+    {
         // Construct the inner in the "uninitialized" state with a single
         // weak reference.
         let uninit_ptr: NonNull<_> = Box::leak(box RcBox {

library/alloc/src/sync.rs

@@ -351,30 +351,51 @@ impl<T> Arc<T> {
         unsafe { Self::from_inner(Box::leak(x).into()) }
     }
 
-    /// Constructs a new `Arc<T>` using a weak reference to itself. Attempting
-    /// to upgrade the weak reference before this function returns will result
-    /// in a `None` value. However, the weak reference may be cloned freely and
-    /// stored for use at a later time.
+    /// Constructs a new `Arc<T>` using a closure `data_fn` that has access to
+    /// a weak reference to the constructing `Arc<T>`.
     ///
-    /// # Examples
+    /// Generally, a structure circularly referencing itself, either directly or
+    /// indirectly, should not hold a strong reference to prevent a memory leak.
+    /// In `data_fn`, initialization of `T` can make use of the weak reference
+    /// by cloning and storing it inside `T` for use at a later time.
+    ///
+    /// Since the new `Arc<T>` is not fully-constructed until
+    /// `Arc<T>::new_cyclic` returns, calling [`upgrade`] on the weak
+    /// reference inside `data_fn` will fail and result in a `None` value.
+    ///
+    /// # Panics
+    /// If `data_fn` panics, the panic is propagated to the caller, and the
+    /// temporary [`Weak<T>`] is dropped normally.
+    ///
+    /// # Example
     /// ```
-    /// #![feature(arc_new_cyclic)]
     /// #![allow(dead_code)]
-    ///
     /// use std::sync::{Arc, Weak};
     ///
-    /// struct Foo {
-    ///     me: Weak<Foo>,
+    /// struct Gadget {
+    ///     me: Weak<Gadget>,
     /// }
     ///
-    /// let foo = Arc::new_cyclic(|me| Foo {
-    ///     me: me.clone(),
-    /// });
+    /// impl Gadget {
+    ///     /// Construct a reference counted Gadget.
+    ///     fn new() -> Arc<Self> {
+    ///         Arc::new_cyclic(|me| Gadget { me: me.clone() })
+    ///     }
+    ///
+    ///     /// Return a reference counted pointer to Self.
+    ///     fn me(&self) -> Arc<Self> {
+    ///         self.me.upgrade().unwrap()
+    ///     }
+    /// }
     /// ```
+    /// [`upgrade`]: Weak::upgrade
     #[cfg(not(no_global_oom_handling))]
     #[inline]
-    #[unstable(feature = "arc_new_cyclic", issue = "75861")]
-    pub fn new_cyclic(data_fn: impl FnOnce(&Weak<T>) -> T) -> Arc<T> {
+    #[stable(feature = "arc_new_cyclic", since = "1.60.0")]
+    pub fn new_cyclic<F>(data_fn: F) -> Arc<T>
+    where
+        F: FnOnce(&Weak<T>) -> T,
+    {
         // Construct the inner in the "uninitialized" state with a single
         // weak reference.
         let uninit_ptr: NonNull<_> = Box::leak(box ArcInner {

library/core/src/ops/bit.rs

@@ -68,6 +68,17 @@ macro_rules! not_impl {
 
 not_impl! { bool usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 
+#[stable(feature = "not_never", since = "1.60.0")]
+#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
+impl const Not for ! {
+    type Output = !;
+
+    #[inline]
+    fn not(self) -> ! {
+        match self {}
+    }
+}
+
 /// The bitwise AND operator `&`.
 ///
 /// Note that `Rhs` is `Self` by default, but this is not mandatory.

library/core/tests/ops.rs

@@ -232,3 +232,9 @@ fn deref_on_ref() {
     let y = deref(&mut x);
     assert_eq!(y, 4);
 }
+
+#[test]
+#[allow(unreachable_code)]
+fn test_not_never() {
+    if !return () {}
+}

src/build_helper/lib.rs

@@ -55,12 +55,6 @@ pub fn restore_library_path() {
     }
 }
 
-/// Run the command, printing what we are running.
-pub fn run_verbose(cmd: &mut Command) {
-    println!("running: {:?}", cmd);
-    run(cmd);
-}
-
 pub fn run(cmd: &mut Command) {
     if !try_run(cmd) {
         std::process::exit(1);
@@ -108,16 +102,6 @@ pub fn try_run_suppressed(cmd: &mut Command) -> bool {
     output.status.success()
 }
 
-pub fn gnu_target(target: &str) -> &str {
-    match target {
-        "i686-pc-windows-msvc" => "i686-pc-win32",
-        "x86_64-pc-windows-msvc" => "x86_64-pc-win32",
-        "i686-pc-windows-gnu" => "i686-w64-mingw32",
-        "x86_64-pc-windows-gnu" => "x86_64-w64-mingw32",
-        s => s,
-    }
-}
-
 pub fn make(host: &str) -> PathBuf {
     if host.contains("dragonfly")
         || host.contains("freebsd")

src/doc/rustc/src/SUMMARY.md

@@ -15,6 +15,7 @@
 - [Platform Support](platform-support.md)
     - [Template for target-specific documentation](platform-support/TEMPLATE.md)
     - [aarch64-apple-ios-sim](platform-support/aarch64-apple-ios-sim.md)
+    - [armv7-unknown-linux-uclibceabihf](platform-support/armv7-unknown-linux-uclibceabihf.md)
     - [\*-kmc-solid_\*](platform-support/kmc-solid.md)
     - [x86_64-unknown-none](platform-support/x86_64-unknown-none.md)
     - [wasm64-unknown-unknown](platform-support/wasm64-unknown-unknown.md)

src/doc/rustc/src/platform-support.md

@@ -220,7 +220,7 @@ target | std | host | notes
 `armv6-unknown-netbsd-eabihf` | ? |  |
 `armv6k-nintendo-3ds` | * |  | ARMv6K Nintendo 3DS, Horizon (Requires devkitARM toolchain)
 `armv7-apple-ios` | ✓ |  | ARMv7 iOS, Cortex-a8
-`armv7-unknown-linux-uclibceabihf` | ✓ | ? | ARMv7 Linux uClibc
+[`armv7-unknown-linux-uclibceabihf`](platform-support/armv7-unknown-linux-uclibceabihf.md) | ✓ | ? | ARMv7 Linux uClibc
 `armv7-unknown-freebsd` | ✓ | ✓ | ARMv7 FreeBSD
 `armv7-unknown-netbsd-eabihf` | ✓ | ✓ |
 `armv7-wrs-vxworks-eabihf` | ? |  |

src/doc/rustc/src/platform-support/armv7-unknown-linux-uclibceabihf.md

@@ -18,7 +18,7 @@ This target is cross compiled, and requires a cross toolchain.  You can find sui
 
 Compiling rust for this target has been tested on `x86_64` linux hosts.  Other host types have not been tested, but may work, if you can find a suitable cross compilation toolchain for them.
 
-If you don't already have a suitable toolchain, download one [here](https://toolchains.bootlin.com/downloads/releases/toolchains/armv7-eabihf/tarballs/armv7-eabihf--uclibc--bleeding-edge-2020.08-1.tar.bz2), and unpack it into a directory.
+If you don't already have a suitable toolchain, download one [here](https://toolchains.bootlin.com/downloads/releases/toolchains/armv7-eabihf/tarballs/armv7-eabihf--uclibc--bleeding-edge-2021.11-1.tar.bz2), and unpack it into a directory.
 
 ### Configure rust
 

src/librustdoc/clean/types.rs

@@ -429,7 +429,7 @@ impl Item {
 
     /// Convenience wrapper around [`Self::from_def_id_and_parts`] which converts
     /// `hir_id` to a [`DefId`]
-    pub fn from_hir_id_and_parts(
+    crate fn from_hir_id_and_parts(
         hir_id: hir::HirId,
         name: Option<Symbol>,
         kind: ItemKind,
@@ -438,7 +438,7 @@ impl Item {
         Item::from_def_id_and_parts(cx.tcx.hir().local_def_id(hir_id).to_def_id(), name, kind, cx)
     }
 
-    pub fn from_def_id_and_parts(
+    crate fn from_def_id_and_parts(
         def_id: DefId,
         name: Option<Symbol>,
         kind: ItemKind,
@@ -456,7 +456,7 @@ impl Item {
         )
     }
 
-    pub fn from_def_id_and_attrs_and_parts(
+    crate fn from_def_id_and_attrs_and_parts(
         def_id: DefId,
         name: Option<Symbol>,
         kind: ItemKind,
@@ -984,26 +984,26 @@ crate fn collapse_doc_fragments(doc_strings: &[DocFragment]) -> String {
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 crate struct ItemLink {
     /// The original link written in the markdown
-    pub(crate) link: String,
+    crate link: String,
     /// The link text displayed in the HTML.
     ///
     /// This may not be the same as `link` if there was a disambiguator
     /// in an intra-doc link (e.g. \[`fn@f`\])
-    pub(crate) link_text: String,
-    pub(crate) did: DefId,
+    crate link_text: String,
+    crate did: DefId,
     /// The url fragment to append to the link
-    pub(crate) fragment: Option<UrlFragment>,
+    crate fragment: Option<UrlFragment>,
 }
 
 pub struct RenderedLink {
     /// The text the link was original written as.
     ///
     /// This could potentially include disambiguators and backticks.
-    pub(crate) original_text: String,
+    crate original_text: String,
     /// The text to display in the HTML
-    pub(crate) new_text: String,
+    crate new_text: String,
     /// The URL to put in the `href`
-    pub(crate) href: String,
+    crate href: String,
 }
 
 /// The attributes on an [`Item`], including attributes like `#[derive(...)]` and `#[inline]`,