Rollup of 5 pull requests

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1727,7 +1727,7 @@ impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
     }
 
     fn print_const(self, ct: ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
-        self.pretty_print_const(ct, true)
+        self.pretty_print_const(ct, false)
     }
 
     fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {

compiler/rustc_trait_selection/src/traits/const_evaluatable.rs

@@ -185,14 +185,20 @@ pub fn is_const_evaluatable<'cx, 'tcx>(
         }
         let concrete = infcx.const_eval_resolve(param_env, uv.expand(), Some(span));
         match concrete {
-            Err(ErrorHandled::TooGeneric) => Err(if !uv.has_infer_types_or_consts() {
+            Err(ErrorHandled::TooGeneric) => Err(if uv.has_infer_types_or_consts() {
+                NotConstEvaluatable::MentionsInfer
+            } else if uv.has_param_types_or_consts() {
                 infcx
                     .tcx
                     .sess
                     .delay_span_bug(span, &format!("unexpected `TooGeneric` for {:?}", uv));
                 NotConstEvaluatable::MentionsParam
             } else {
-                NotConstEvaluatable::MentionsInfer
+                let guar = infcx.tcx.sess.delay_span_bug(
+                    span,
+                    format!("Missing value for constant, but no error reported?"),
+                );
+                NotConstEvaluatable::Error(guar)
             }),
             Err(ErrorHandled::Linted) => {
                 let reported = infcx
@@ -240,8 +246,11 @@ pub fn is_const_evaluatable<'cx, 'tcx>(
 
             Err(ErrorHandled::TooGeneric) => Err(if uv.has_infer_types_or_consts() {
                 NotConstEvaluatable::MentionsInfer
-                } else {
+                } else if uv.has_param_types_or_consts() {
                 NotConstEvaluatable::MentionsParam
+            } else {
+                let guar = infcx.tcx.sess.delay_span_bug(span, format!("Missing value for constant, but no error reported?"));
+                NotConstEvaluatable::Error(guar)
             }),
             Err(ErrorHandled::Linted) => {
                 let reported =

compiler/rustc_ty_utils/src/instance.rs

@@ -280,6 +280,11 @@ fn resolve_associated_item<'tcx>(
                 return Ok(None);
             }
 
+            // If the item does not have a value, then we cannot return an instance.
+            if !leaf_def.item.defaultness.has_value() {
+                return Ok(None);
+            }
+
             let substs = tcx.erase_regions(substs);
 
             // Check if we just resolved an associated `const` declaration from

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

@@ -178,6 +178,8 @@ pub struct BTreeMap<
     length: usize,
     /// `ManuallyDrop` to control drop order (needs to be dropped after all the nodes).
     pub(super) alloc: ManuallyDrop<A>,
+    // For dropck; the `Box` avoids making the `Unpin` impl more strict than before
+    _marker: PhantomData<crate::boxed::Box<(K, V)>>,
 }
 
 #[stable(feature = "btree_drop", since = "1.7.0")]
@@ -187,6 +189,19 @@ unsafe impl<#[may_dangle] K, #[may_dangle] V, A: Allocator + Clone> Drop for BTr
     }
 }
 
+// FIXME: This implementation is "wrong", but changing it would be a breaking change.
+// (The bounds of the automatic `UnwindSafe` implementation have been like this since Rust 1.50.)
+// Maybe we can fix it nonetheless with a crater run, or if the `UnwindSafe`
+// traits are deprecated, or disarmed (no longer causing hard errors) in the future.
+#[stable(feature = "btree_unwindsafe", since = "1.64.0")]
+impl<K, V, A: Allocator + Clone> core::panic::UnwindSafe for BTreeMap<K, V, A>
+where
+    A: core::panic::UnwindSafe,
+    K: core::panic::RefUnwindSafe,
+    V: core::panic::RefUnwindSafe,
+{
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<K: Clone, V: Clone, A: Allocator + Clone> Clone for BTreeMap<K, V, A> {
     fn clone(&self) -> BTreeMap<K, V, A> {
@@ -204,6 +219,7 @@ impl<K: Clone, V: Clone, A: Allocator + Clone> Clone for BTreeMap<K, V, A> {
                         root: Some(Root::new(alloc.clone())),
                         length: 0,
                         alloc: ManuallyDrop::new(alloc),
+                        _marker: PhantomData,
                     };
 
                     {
@@ -567,7 +583,7 @@ impl<K, V> BTreeMap<K, V> {
     #[rustc_const_unstable(feature = "const_btree_new", issue = "71835")]
     #[must_use]
     pub const fn new() -> BTreeMap<K, V> {
-        BTreeMap { root: None, length: 0, alloc: ManuallyDrop::new(Global) }
+        BTreeMap { root: None, length: 0, alloc: ManuallyDrop::new(Global), _marker: PhantomData }
     }
 }
 
@@ -593,6 +609,7 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
             root: mem::replace(&mut self.root, None),
             length: mem::replace(&mut self.length, 0),
             alloc: self.alloc.clone(),
+            _marker: PhantomData,
         });
     }
 
@@ -615,7 +632,7 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     /// ```
     #[unstable(feature = "btreemap_alloc", issue = "32838")]
     pub fn new_in(alloc: A) -> BTreeMap<K, V, A> {
-        BTreeMap { root: None, length: 0, alloc: ManuallyDrop::new(alloc) }
+        BTreeMap { root: None, length: 0, alloc: ManuallyDrop::new(alloc), _marker: PhantomData }
     }
 }
 
@@ -1320,7 +1337,12 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
         let (new_left_len, right_len) = Root::calc_split_length(total_num, &left_root, &right_root);
         self.length = new_left_len;
 
-        BTreeMap { root: Some(right_root), length: right_len, alloc: self.alloc.clone() }
+        BTreeMap {
+            root: Some(right_root),
+            length: right_len,
+            alloc: self.alloc.clone(),
+            _marker: PhantomData,
+        }
     }
 
     /// Creates an iterator that visits all elements (key-value pairs) in
@@ -1445,7 +1467,7 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
         let mut root = Root::new(alloc.clone());
         let mut length = 0;
         root.bulk_push(DedupSortedIter::new(iter.into_iter()), &mut length, alloc.clone());
-        BTreeMap { root: Some(root), length, alloc: ManuallyDrop::new(alloc) }
+        BTreeMap { root: Some(root), length, alloc: ManuallyDrop::new(alloc), _marker: PhantomData }
     }
 }
 

library/core/src/ops/control_flow.rs

@@ -195,6 +195,41 @@ impl<B, C> ControlFlow<B, C> {
             ControlFlow::Break(x) => ControlFlow::Break(f(x)),
         }
     }
+
+    /// Converts the `ControlFlow` into an `Option` which is `Some` if the
+    /// `ControlFlow` was `Continue` and `None` otherwise.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(control_flow_enum)]
+    /// use std::ops::ControlFlow;
+    ///
+    /// assert_eq!(ControlFlow::<i32, String>::Break(3).continue_value(), None);
+    /// assert_eq!(ControlFlow::<String, i32>::Continue(3).continue_value(), Some(3));
+    /// ```
+    #[inline]
+    #[unstable(feature = "control_flow_enum", reason = "new API", issue = "75744")]
+    pub fn continue_value(self) -> Option<C> {
+        match self {
+            ControlFlow::Continue(x) => Some(x),
+            ControlFlow::Break(..) => None,
+        }
+    }
+
+    /// Maps `ControlFlow<B, C>` to `ControlFlow<B, T>` by applying a function
+    /// to the continue value in case it exists.
+    #[inline]
+    #[unstable(feature = "control_flow_enum", reason = "new API", issue = "75744")]
+    pub fn map_continue<T, F>(self, f: F) -> ControlFlow<B, T>
+    where
+        F: FnOnce(C) -> T,
+    {
+        match self {
+            ControlFlow::Continue(x) => ControlFlow::Continue(f(x)),
+            ControlFlow::Break(x) => ControlFlow::Break(x),
+        }
+    }
 }
 
 /// These are used only as part of implementing the iterator adapters.

library/std/src/os/fd/owned.rs

@@ -356,7 +356,7 @@ impl From<OwnedFd> for crate::net::UdpSocket {
     }
 }
 
-#[stable(feature = "io_safety", since = "1.63.0")]
+#[stable(feature = "asfd_ptrs", since = "1.64.0")]
 /// This impl allows implementing traits that require `AsFd` on Arc.
 /// ```
 /// # #[cfg(any(unix, target_os = "wasi"))] mod group_cfg {
@@ -379,7 +379,7 @@ impl<T: AsFd> AsFd for crate::sync::Arc<T> {
     }
 }
 
-#[stable(feature = "io_safety", since = "1.63.0")]
+#[stable(feature = "asfd_ptrs", since = "1.64.0")]
 impl<T: AsFd> AsFd for Box<T> {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {

src/test/rustdoc/const-generics/add-impl.rs

@@ -7,7 +7,7 @@ pub struct Simd<T, const WIDTH: usize> {
     inner: T,
 }
 
-// @has foo/struct.Simd.html '//div[@id="trait-implementations-list"]//h3[@class="code-header in-band"]' 'impl Add<Simd<u8, 16_usize>> for Simd<u8, 16>'
+// @has foo/struct.Simd.html '//div[@id="trait-implementations-list"]//h3[@class="code-header in-band"]' 'impl Add<Simd<u8, 16>> for Simd<u8, 16>'
 impl Add for Simd<u8, 16> {
     type Output = Self;
 

src/test/rustdoc/const-generics/const-generic-defaults.rs

@@ -1,5 +1,5 @@
 #![crate_name = "foo"]
 
 // @has foo/struct.Foo.html '//pre[@class="rust struct"]' \
-//      'pub struct Foo<const M: usize = 10_usize, const N: usize = M, T = i32>(_);'
+//      'pub struct Foo<const M: usize = 10, const N: usize = M, T = i32>(_);'
 pub struct Foo<const M: usize = 10, const N: usize = M, T = i32>(T);

src/test/rustdoc/const-generics/const-generics-docs.rs

@@ -19,8 +19,8 @@ pub use extern_crate::WTrait;
 
 // @has foo/trait.Trait.html '//pre[@class="rust trait"]' \
 //      'pub trait Trait<const N: usize>'
-// @has - '//*[@id="impl-Trait%3C1_usize%3E-for-u8"]//h3[@class="code-header in-band"]' 'impl Trait<1_usize> for u8'
-// @has - '//*[@id="impl-Trait%3C2_usize%3E-for-u8"]//h3[@class="code-header in-band"]' 'impl Trait<2_usize> for u8'
+// @has - '//*[@id="impl-Trait%3C1%3E-for-u8"]//h3[@class="code-header in-band"]' 'impl Trait<1> for u8'
+// @has - '//*[@id="impl-Trait%3C2%3E-for-u8"]//h3[@class="code-header in-band"]' 'impl Trait<2> for u8'
 // @has - '//*[@id="impl-Trait%3C{1%20+%202}%3E-for-u8"]//h3[@class="code-header in-band"]' 'impl Trait<{1 + 2}> for u8'
 // @has - '//*[@id="impl-Trait%3CN%3E-for-%5Bu8%3B%20N%5D"]//h3[@class="code-header in-band"]' \
 //      'impl<const N: usize> Trait<N> for [u8; N]'

src/test/ui-fulldeps/internal-lints/rustc_pass_by_value_self.rs

@@ -44,11 +44,11 @@ struct WithParameters<T, const N: usize, M = u32> {
 }
 
 impl<T> WithParameters<T, 1> {
-    fn with_ref(&self) {} //~ ERROR passing `WithParameters<T, 1_usize>` by reference
+    fn with_ref(&self) {} //~ ERROR passing `WithParameters<T, 1>` by reference
 }
 
 impl<T> WithParameters<T, 1, u8> {
-    fn with_ref(&self) {} //~ ERROR passing `WithParameters<T, 1_usize, u8>` by reference
+    fn with_ref(&self) {} //~ ERROR passing `WithParameters<T, 1, u8>` by reference
 }
 
 fn main() {}

src/test/ui-fulldeps/internal-lints/rustc_pass_by_value_self.stderr

@@ -22,17 +22,17 @@ error: passing `Foo` by reference
 LL |     fn with_ref(&self) {}
    |                 ^^^^^ help: try passing by value: `Foo`
 
-error: passing `WithParameters<T, 1_usize>` by reference
+error: passing `WithParameters<T, 1>` by reference
   --> $DIR/rustc_pass_by_value_self.rs:47:17
    |
 LL |     fn with_ref(&self) {}
-   |                 ^^^^^ help: try passing by value: `WithParameters<T, 1_usize>`
+   |                 ^^^^^ help: try passing by value: `WithParameters<T, 1>`
 
-error: passing `WithParameters<T, 1_usize, u8>` by reference
+error: passing `WithParameters<T, 1, u8>` by reference
   --> $DIR/rustc_pass_by_value_self.rs:51:17
    |
 LL |     fn with_ref(&self) {}
-   |                 ^^^^^ help: try passing by value: `WithParameters<T, 1_usize, u8>`
+   |                 ^^^^^ help: try passing by value: `WithParameters<T, 1, u8>`
 
 error: aborting due to 5 previous errors
 

src/test/ui/array-slice-vec/match_arr_unknown_len.stderr

@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/match_arr_unknown_len.rs:3:9
    |
 LL |         [1, 2] => true,
-   |         ^^^^^^ expected `2_usize`, found `N`
+   |         ^^^^^^ expected `2`, found `N`
    |
    = note: expected array `[u32; 2]`
               found array `[u32; N]`

src/test/ui/btreemap/btreemap_dropck.rs

@@ -0,0 +1,16 @@
+struct PrintOnDrop<'a>(&'a str);
+
+impl Drop for PrintOnDrop<'_> {
+    fn drop(&mut self) {
+        println!("printint: {}", self.0);
+    }
+}
+
+use std::collections::BTreeMap;
+use std::iter::FromIterator;
+
+fn main() {
+    let s = String::from("Hello World!");
+    let _map = BTreeMap::from_iter([((), PrintOnDrop(&s))]);
+    drop(s); //~ ERROR cannot move out of `s` because it is borrowed
+}

src/test/ui/btreemap/btreemap_dropck.stderr

@@ -0,0 +1,13 @@
+error[E0505]: cannot move out of `s` because it is borrowed
+  --> $DIR/btreemap_dropck.rs:15:10
+   |
+LL |     let _map = BTreeMap::from_iter([((), PrintOnDrop(&s))]);
+   |                                                      -- borrow of `s` occurs here
+LL |     drop(s);
+   |          ^ move out of `s` occurs here
+LL | }
+   | - borrow might be used here, when `_map` is dropped and runs the `Drop` code for type `BTreeMap`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0505`.

src/test/ui/const-generics/associated-type-bound-fail.stderr

@@ -4,7 +4,7 @@ error[E0277]: the trait bound `u16: Bar<N>` is not satisfied
 LL |     type Assoc = u16;
    |                  ^^^ the trait `Bar<N>` is not implemented for `u16`
    |
-   = help: the trait `Bar<3_usize>` is implemented for `u16`
+   = help: the trait `Bar<3>` is implemented for `u16`
 note: required by a bound in `Foo::Assoc`
   --> $DIR/associated-type-bound-fail.rs:4:17
    |

src/test/ui/const-generics/defaults/generic-expr-default-concrete.stderr

@@ -2,10 +2,10 @@ error[E0308]: mismatched types
   --> $DIR/generic-expr-default-concrete.rs:10:5
    |
 LL |     Foo::<10, 12>
-   |     ^^^^^^^^^^^^^ expected `11_usize`, found `12_usize`
+   |     ^^^^^^^^^^^^^ expected `11`, found `12`
    |
-   = note: expected type `11_usize`
-              found type `12_usize`
+   = note: expected type `11`
+              found type `12`
 
 error: aborting due to previous error
 

src/test/ui/const-generics/defaults/mismatch.rs

@@ -1,22 +1,22 @@
-pub struct Example<const N: usize=13>;
-pub struct Example2<T=u32, const N: usize=13>(T);
-pub struct Example3<const N: usize=13, T=u32>(T);
-pub struct Example4<const N: usize=13, const M: usize=4>;
+pub struct Example<const N: usize = 13>;
+pub struct Example2<T = u32, const N: usize = 13>(T);
+pub struct Example3<const N: usize = 13, T = u32>(T);
+pub struct Example4<const N: usize = 13, const M: usize = 4>;
 
 fn main() {
-    let e: Example::<13> = ();
+    let e: Example<13> = ();
     //~^ Error: mismatched types
     //~| expected struct `Example`
-    let e: Example2::<u32, 13> = ();
+    let e: Example2<u32, 13> = ();
     //~^ Error: mismatched types
     //~| expected struct `Example2`
-    let e: Example3::<13, u32> = ();
+    let e: Example3<13, u32> = ();
     //~^ Error: mismatched types
     //~| expected struct `Example3`
-    let e: Example3::<7> = ();
+    let e: Example3<7> = ();
     //~^ Error: mismatched types
-    //~| expected struct `Example3<7_usize>`
-    let e: Example4::<7> = ();
+    //~| expected struct `Example3<7>`
+    let e: Example4<7> = ();
     //~^ Error: mismatched types
-    //~| expected struct `Example4<7_usize>`
+    //~| expected struct `Example4<7>`
 }