Auto merge of #73617 - Dylan-DPC:rollup-zugh80o, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #71660 (impl PartialEq<Vec<B>> for &[A], &mut [A])
 - #72623 (Prefer accessible paths in 'use' suggestions)
 - #73502 (Add E0765)
 - #73580 (deprecate wrapping_offset_from)
 - #73582 (Miri: replace many bug! by span_bug!)
 - #73585 (Do not send a notification for P-high stable regressions)

Failed merges:

 - #73581 (Create 0766 error code)

r? @ghost

32 files changed, 277 insertions, 129 deletions

diff --git a/src/liballoc/tests/vec.rs b/src/liballoc/tests/vec.rs
index baa02b8997f..ffff543b07f 100644
--- a/src/liballoc/tests/vec.rs
+++ b/src/liballoc/tests/vec.rs
@@ -1,5 +1,6 @@
 use std::borrow::Cow;
 use std::collections::TryReserveError::*;
+use std::fmt::Debug;
 use std::mem::size_of;
 use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::vec::{Drain, IntoIter};
@@ -1573,3 +1574,56 @@ fn test_push_growth_strategy() {
         }
     }
 }
+
+macro_rules! generate_assert_eq_vec_and_prim {
+    ($name:ident<$B:ident>($type:ty)) => {
+        fn $name<A: PartialEq<$B> + Debug, $B: Debug>(a: Vec<A>, b: $type) {
+            assert!(a == b);
+            assert_eq!(a, b);
+        }
+    };
+}
+
+generate_assert_eq_vec_and_prim! { assert_eq_vec_and_slice  <B>(&[B])   }
+generate_assert_eq_vec_and_prim! { assert_eq_vec_and_array_3<B>([B; 3]) }
+
+#[test]
+fn partialeq_vec_and_prim() {
+    assert_eq_vec_and_slice(vec![1, 2, 3], &[1, 2, 3]);
+    assert_eq_vec_and_array_3(vec![1, 2, 3], [1, 2, 3]);
+}
+
+macro_rules! assert_partial_eq_valid {
+    ($a2:ident, $a3:ident; $b2:ident, $b3: ident) => {
+        assert!($a2 == $b2);
+        assert!($a2 != $b3);
+        assert!($a3 != $b2);
+        assert!($a3 == $b3);
+        assert_eq!($a2, $b2);
+        assert_ne!($a2, $b3);
+        assert_ne!($a3, $b2);
+        assert_eq!($a3, $b3);
+    };
+}
+
+#[test]
+fn partialeq_vec_full() {
+    let vec2: Vec<_> = vec![1, 2];
+    let vec3: Vec<_> = vec![1, 2, 3];
+    let slice2: &[_] = &[1, 2];
+    let slice3: &[_] = &[1, 2, 3];
+    let slicemut2: &[_] = &mut [1, 2];
+    let slicemut3: &[_] = &mut [1, 2, 3];
+    let array2: [_; 2] = [1, 2];
+    let array3: [_; 3] = [1, 2, 3];
+    let arrayref2: &[_; 2] = &[1, 2];
+    let arrayref3: &[_; 3] = &[1, 2, 3];
+
+    assert_partial_eq_valid!(vec2,vec3; vec2,vec3);
+    assert_partial_eq_valid!(vec2,vec3; slice2,slice3);
+    assert_partial_eq_valid!(vec2,vec3; slicemut2,slicemut3);
+    assert_partial_eq_valid!(slice2,slice3; vec2,vec3);
+    assert_partial_eq_valid!(slicemut2,slicemut3; vec2,vec3);
+    assert_partial_eq_valid!(vec2,vec3; array2,array3);
+    assert_partial_eq_valid!(vec2,vec3; arrayref2,arrayref3);
+}
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index 0531084d0e4..fc8a992e170 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -2342,12 +2342,12 @@ impl<'a, T: 'a + Copy> Extend<&'a T> for Vec<T> {
 }
 
 macro_rules! __impl_slice_eq1 {
-    ([$($vars:tt)*] $lhs:ty, $rhs:ty, $($constraints:tt)*) => {
-        #[stable(feature = "rust1", since = "1.0.0")]
+    ([$($vars:tt)*] $lhs:ty, $rhs:ty $(where $ty:ty: $bound:ident)?, #[$stability:meta]) => {
+        #[$stability]
         impl<A, B, $($vars)*> PartialEq<$rhs> for $lhs
         where
             A: PartialEq<B>,
-            $($constraints)*
+            $($ty: $bound)?
         {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool { self[..] == other[..] }
@@ -2357,18 +2357,23 @@ macro_rules! __impl_slice_eq1 {
     }
 }
 
-__impl_slice_eq1! { [] Vec<A>, Vec<B>, }
-__impl_slice_eq1! { [] Vec<A>, &[B], }
-__impl_slice_eq1! { [] Vec<A>, &mut [B], }
-__impl_slice_eq1! { [] Cow<'_, [A]>, Vec<B>, A: Clone }
-__impl_slice_eq1! { [] Cow<'_, [A]>, &[B], A: Clone }
-__impl_slice_eq1! { [] Cow<'_, [A]>, &mut [B], A: Clone }
-__impl_slice_eq1! { [const N: usize] Vec<A>, [B; N], [B; N]: LengthAtMost32 }
-__impl_slice_eq1! { [const N: usize] Vec<A>, &[B; N], [B; N]: LengthAtMost32 }
+__impl_slice_eq1! { [] Vec<A>, Vec<B>, #[stable(feature = "rust1", since = "1.0.0")] }
+__impl_slice_eq1! { [] Vec<A>, &[B], #[stable(feature = "rust1", since = "1.0.0")] }
+__impl_slice_eq1! { [] Vec<A>, &mut [B], #[stable(feature = "rust1", since = "1.0.0")] }
+__impl_slice_eq1! { [] &[A], Vec<B>, #[stable(feature = "partialeq_vec_for_ref_slice", since = "1.46.0")] }
+__impl_slice_eq1! { [] &mut [A], Vec<B>, #[stable(feature = "partialeq_vec_for_ref_slice", since = "1.46.0")] }
+__impl_slice_eq1! { [] Cow<'_, [A]>, Vec<B> where A: Clone, #[stable(feature = "rust1", since = "1.0.0")] }
+__impl_slice_eq1! { [] Cow<'_, [A]>, &[B] where A: Clone, #[stable(feature = "rust1", since = "1.0.0")] }
+__impl_slice_eq1! { [] Cow<'_, [A]>, &mut [B] where A: Clone, #[stable(feature = "rust1", since = "1.0.0")] }
+__impl_slice_eq1! { [const N: usize] Vec<A>, [B; N] where [B; N]: LengthAtMost32, #[stable(feature = "rust1", since = "1.0.0")] }
+__impl_slice_eq1! { [const N: usize] Vec<A>, &[B; N] where [B; N]: LengthAtMost32, #[stable(feature = "rust1", since = "1.0.0")] }
 
 // NOTE: some less important impls are omitted to reduce code bloat
 // FIXME(Centril): Reconsider this?
 //__impl_slice_eq1! { [const N: usize] Vec<A>, &mut [B; N], [B; N]: LengthAtMost32 }
+//__impl_slice_eq1! { [const N: usize] [A; N], Vec<B>, [A; N]: LengthAtMost32 }
+//__impl_slice_eq1! { [const N: usize] &[A; N], Vec<B>, [A; N]: LengthAtMost32 }
+//__impl_slice_eq1! { [const N: usize] &mut [A; N], Vec<B>, [A; N]: LengthAtMost32 }
 //__impl_slice_eq1! { [const N: usize] Cow<'a, [A]>, [B; N], [B; N]: LengthAtMost32 }
 //__impl_slice_eq1! { [const N: usize] Cow<'a, [A]>, &[B; N], [B; N]: LengthAtMost32 }
 //__impl_slice_eq1! { [const N: usize] Cow<'a, [A]>, &mut [B; N], [B; N]: LengthAtMost32 }
diff --git a/src/libcore/ptr/const_ptr.rs b/src/libcore/ptr/const_ptr.rs
index e39d18d7733..acc09ddc014 100644
--- a/src/libcore/ptr/const_ptr.rs
+++ b/src/libcore/ptr/const_ptr.rs
@@ -330,6 +330,12 @@ impl<T: ?Sized> *const T {
     /// assert_eq!(ptr2.wrapping_offset_from(ptr1), 2);
     /// ```
     #[unstable(feature = "ptr_wrapping_offset_from", issue = "41079")]
+    #[rustc_deprecated(
+        since = "1.46.0",
+        reason = "Pointer distances across allocation \
+        boundaries are not typically meaningful. \
+        Use integer subtraction if you really need this."
+    )]
     #[inline]
     pub fn wrapping_offset_from(self, origin: *const T) -> isize
     where
diff --git a/src/libcore/ptr/mut_ptr.rs b/src/libcore/ptr/mut_ptr.rs
index 40b5e4e2234..2bbeb95965e 100644
--- a/src/libcore/ptr/mut_ptr.rs
+++ b/src/libcore/ptr/mut_ptr.rs
@@ -380,11 +380,18 @@ impl<T: ?Sized> *mut T {
     /// assert_eq!(ptr2.wrapping_offset_from(ptr1), 2);
     /// ```
     #[unstable(feature = "ptr_wrapping_offset_from", issue = "41079")]
+    #[rustc_deprecated(
+        since = "1.46.0",
+        reason = "Pointer distances across allocation \
+        boundaries are not typically meaningful. \
+        Use integer subtraction if you really need this."
+    )]
     #[inline]
     pub fn wrapping_offset_from(self, origin: *const T) -> isize
     where
         T: Sized,
     {
+        #[allow(deprecated_in_future, deprecated)]
         (self as *const T).wrapping_offset_from(origin)
     }
 
diff --git a/src/librustc_error_codes/error_codes.rs b/src/librustc_error_codes/error_codes.rs
index 738b3bc7539..6a5e23adafa 100644
--- a/src/librustc_error_codes/error_codes.rs
+++ b/src/librustc_error_codes/error_codes.rs
@@ -445,6 +445,7 @@ E0761: include_str!("./error_codes/E0761.md"),
 E0762: include_str!("./error_codes/E0762.md"),
 E0763: include_str!("./error_codes/E0763.md"),
 E0764: include_str!("./error_codes/E0764.md"),
+E0765: include_str!("./error_codes/E0765.md"),
 ;
 //  E0006, // merged with E0005
 //  E0008, // cannot bind by-move into a pattern guard
diff --git a/src/librustc_error_codes/error_codes/E0765.md b/src/librustc_error_codes/error_codes/E0765.md
new file mode 100644
index 00000000000..456e3f3e9e4
--- /dev/null
+++ b/src/librustc_error_codes/error_codes/E0765.md
@@ -0,0 +1,13 @@
+A double quote string (`"`) was not terminated.
+
+Erroneous code example:
+
+```compile_fail,E0765
+let s = "; // error!
+```
+
+To fix this error, add the missing double quote at the end of the string:
+
+```
+let s = ""; // ok!
+```
diff --git a/src/librustc_mir/interpret/cast.rs b/src/librustc_mir/interpret/cast.rs
index cfe856abe36..60cf21552e9 100644
--- a/src/librustc_mir/interpret/cast.rs
+++ b/src/librustc_mir/interpret/cast.rs
@@ -52,7 +52,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         }
 
                         if self.tcx.has_attr(def_id, sym::rustc_args_required_const) {
-                            bug!("reifying a fn ptr that requires const arguments");
+                            span_bug!(
+                                self.cur_span(),
+                                "reifying a fn ptr that requires const arguments"
+                            );
                         }
 
                         let instance = ty::Instance::resolve_for_fn_ptr(
@@ -66,7 +69,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         let fn_ptr = self.memory.create_fn_alloc(FnVal::Instance(instance));
                         self.write_scalar(fn_ptr, dest)?;
                     }
-                    _ => bug!("reify fn pointer on {:?}", src.layout.ty),
+                    _ => span_bug!(self.cur_span(), "reify fn pointer on {:?}", src.layout.ty),
                 }
             }
 
@@ -77,7 +80,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         // No change to value
                         self.write_immediate(*src, dest)?;
                     }
-                    _ => bug!("fn to unsafe fn cast on {:?}", cast_ty),
+                    _ => span_bug!(self.cur_span(), "fn to unsafe fn cast on {:?}", cast_ty),
                 }
             }
 
@@ -99,7 +102,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         let fn_ptr = self.memory.create_fn_alloc(FnVal::Instance(instance));
                         self.write_scalar(fn_ptr, dest)?;
                     }
-                    _ => bug!("closure fn pointer on {:?}", src.layout.ty),
+                    _ => span_bug!(self.cur_span(), "closure fn pointer on {:?}", src.layout.ty),
                 }
             }
         }
@@ -162,7 +165,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 assert!(src.layout.ty.is_unsafe_ptr());
                 return match *src {
                     Immediate::ScalarPair(data, _) => Ok(data.into()),
-                    Immediate::Scalar(..) => bug!(
+                    Immediate::Scalar(..) => span_bug!(
+                        self.cur_span(),
                         "{:?} input to a fat-to-thin cast ({:?} -> {:?})",
                         *src,
                         src.layout.ty,
@@ -216,7 +220,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             }
 
             // Casts to bool are not permitted by rustc, no need to handle them here.
-            _ => bug!("invalid int to {:?} cast", cast_ty),
+            _ => span_bug!(self.cur_span(), "invalid int to {:?} cast", cast_ty),
         }
     }
 
@@ -248,7 +252,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             // float -> f64
             Float(FloatTy::F64) => Scalar::from_f64(f.convert(&mut false).value),
             // That's it.
-            _ => bug!("invalid float to {:?} cast", dest_ty),
+            _ => span_bug!(self.cur_span(), "invalid float to {:?} cast", dest_ty),
         }
     }
 
@@ -287,7 +291,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 self.write_immediate(val, dest)
             }
 
-            _ => bug!("invalid unsizing {:?} -> {:?}", src.layout.ty, cast_ty),
+            _ => {
+                span_bug!(self.cur_span(), "invalid unsizing {:?} -> {:?}", src.layout.ty, cast_ty)
+            }
         }
     }
 
@@ -307,7 +313,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 assert_eq!(def_a, def_b);
                 if def_a.is_box() || def_b.is_box() {
                     if !def_a.is_box() || !def_b.is_box() {
-                        bug!("invalid unsizing between {:?} -> {:?}", src.layout.ty, cast_ty.ty);
+                        span_bug!(
+                            self.cur_span(),
+                            "invalid unsizing between {:?} -> {:?}",
+                            src.layout.ty,
+                            cast_ty.ty
+                        );
                     }
                     return self.unsize_into_ptr(
                         src,
@@ -335,7 +346,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 }
                 Ok(())
             }
-            _ => bug!("unsize_into: invalid conversion: {:?} -> {:?}", src.layout, dest.layout),
+            _ => span_bug!(
+                self.cur_span(),
+                "unsize_into: invalid conversion: {:?} -> {:?}",
+                src.layout,
+                dest.layout
+            ),
         }
     }
 }
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs
index 22f4691c22b..ceacbbe5139 100644
--- a/src/librustc_mir/interpret/eval_context.rs
+++ b/src/librustc_mir/interpret/eval_context.rs
@@ -536,7 +536,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         if sized_size == Size::ZERO {
                             return Ok(None);
                         } else {
-                            bug!("Fields cannot be extern types, unless they are at offset 0")
+                            span_bug!(
+                                self.cur_span(),
+                                "Fields cannot be extern types, unless they are at offset 0"
+                            )
                         }
                     }
                 };
@@ -584,7 +587,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
             ty::Foreign(_) => Ok(None),
 
-            _ => bug!("size_and_align_of::<{:?}> not supported", layout.ty),
+            _ => span_bug!(self.cur_span(), "size_and_align_of::<{:?}> not supported", layout.ty),
         }
     }
     #[inline]
diff --git a/src/librustc_mir/interpret/intrinsics.rs b/src/librustc_mir/interpret/intrinsics.rs
index ac28ccd1815..31bdc45a2ea 100644
--- a/src/librustc_mir/interpret/intrinsics.rs
+++ b/src/librustc_mir/interpret/intrinsics.rs
@@ -135,7 +135,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let bits = self.force_bits(val, layout_of.size)?;
                 let kind = match layout_of.abi {
                     Abi::Scalar(ref scalar) => scalar.value,
-                    _ => bug!("{} called on invalid type {:?}", intrinsic_name, ty),
+                    _ => span_bug!(
+                        self.cur_span(),
+                        "{} called on invalid type {:?}",
+                        intrinsic_name,
+                        ty
+                    ),
                 };
                 let (nonzero, intrinsic_name) = match intrinsic_name {
                     sym::cttz_nonzero => (true, sym::cttz),
diff --git a/src/librustc_mir/interpret/operand.rs b/src/librustc_mir/interpret/operand.rs
index 35e433c4bd5..38948ee5384 100644
--- a/src/librustc_mir/interpret/operand.rs
+++ b/src/librustc_mir/interpret/operand.rs
@@ -311,7 +311,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         if let Ok(imm) = self.try_read_immediate(op)? {
             Ok(imm)
         } else {
-            bug!("primitive read failed for type: {:?}", op.layout.ty);
+            span_bug!(self.cur_span(), "primitive read failed for type: {:?}", op.layout.ty);
         }
     }
 
@@ -360,9 +360,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let val = if offset.bytes() == 0 { a } else { b };
                 Immediate::from(val)
             }
-            Immediate::Scalar(val) => {
-                bug!("field access on non aggregate {:#?}, {:#?}", val, op.layout)
-            }
+            Immediate::Scalar(val) => span_bug!(
+                self.cur_span(),
+                "field access on non aggregate {:#?}, {:#?}",
+                val,
+                op.layout
+            ),
         };
         Ok(OpTy { op: Operand::Immediate(immediate), layout: field_layout })
     }
@@ -545,7 +548,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             ty::ConstKind::Infer(..)
             | ty::ConstKind::Bound(..)
             | ty::ConstKind::Placeholder(..) => {
-                bug!("eval_const_to_op: Unexpected ConstKind {:?}", val)
+                span_bug!(self.cur_span(), "eval_const_to_op: Unexpected ConstKind {:?}", val)
             }
             ty::ConstKind::Value(val_val) => val_val,
         };
@@ -656,7 +659,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                             .discriminants(def_id, *self.tcx)
                             .find(|(_, var)| var.val == discr_bits)
                     }
-                    _ => bug!("tagged layout for non-adt non-generator"),
+                    _ => span_bug!(self.cur_span(), "tagged layout for non-adt non-generator"),
                 }
                 .ok_or_else(|| err_ub!(InvalidTag(tag_val.erase_tag())))?;
                 // Return the cast value, and the index.
diff --git a/src/librustc_mir/interpret/operator.rs b/src/librustc_mir/interpret/operator.rs
index d651267f82b..60712293534 100644
--- a/src/librustc_mir/interpret/operator.rs
+++ b/src/librustc_mir/interpret/operator.rs
@@ -61,7 +61,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             Le => l <= r,
             Gt => l > r,
             Ge => l >= r,
-            _ => bug!("Invalid operation on char: {:?}", bin_op),
+            _ => span_bug!(self.cur_span(), "Invalid operation on char: {:?}", bin_op),
         };
         (Scalar::from_bool(res), false, self.tcx.types.bool)
     }
@@ -84,7 +84,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             BitAnd => l & r,
             BitOr => l | r,
             BitXor => l ^ r,
-            _ => bug!("Invalid operation on bool: {:?}", bin_op),
+            _ => span_bug!(self.cur_span(), "Invalid operation on bool: {:?}", bin_op),
         };
         (Scalar::from_bool(res), false, self.tcx.types.bool)
     }
@@ -110,7 +110,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             Mul => ((l * r).value.into(), ty),
             Div => ((l / r).value.into(), ty),
             Rem => ((l % r).value.into(), ty),
-            _ => bug!("invalid float op: `{:?}`", bin_op),
+            _ => span_bug!(self.cur_span(), "invalid float op: `{:?}`", bin_op),
         };
         (val, false, ty)
     }
@@ -154,7 +154,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
         // For the remaining ops, the types must be the same on both sides
         if left_layout.ty != right_layout.ty {
-            bug!(
+            span_bug!(
+                self.cur_span(),
                 "invalid asymmetric binary op {:?}: {:?} ({:?}), {:?} ({:?})",
                 bin_op,
                 l,
@@ -251,7 +252,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 ));
             }
 
-            _ => bug!(
+            _ => span_bug!(
+                self.cur_span(),
                 "invalid binary op {:?}: {:?}, {:?} (both {:?})",
                 bin_op,
                 l,
@@ -333,7 +335,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
                 M::binary_ptr_op(self, bin_op, left, right)
             }
-            _ => bug!("Invalid MIR: bad LHS type for binop: {:?}", left.layout.ty),
+            _ => span_bug!(
+                self.cur_span(),
+                "Invalid MIR: bad LHS type for binop: {:?}",
+                left.layout.ty
+            ),
         }
     }
 
@@ -367,7 +373,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let val = val.to_bool()?;
                 let res = match un_op {
                     Not => !val,
-                    _ => bug!("Invalid bool op {:?}", un_op),
+                    _ => span_bug!(self.cur_span(), "Invalid bool op {:?}", un_op),
                 };
                 Ok((Scalar::from_bool(res), false, self.tcx.types.bool))
             }
@@ -375,7 +381,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let res = match (un_op, fty) {
                     (Neg, FloatTy::F32) => Scalar::from_f32(-val.to_f32()?),
                     (Neg, FloatTy::F64) => Scalar::from_f64(-val.to_f64()?),
-                    _ => bug!("Invalid float op {:?}", un_op),
+                    _ => span_bug!(self.cur_span(), "Invalid float op {:?}", un_op),
                 };
                 Ok((res, false, layout.ty))
             }
diff --git a/src/librustc_mir/interpret/terminator.rs b/src/librustc_mir/interpret/terminator.rs
index 1d57fce3973..0f3fbcf8195 100644
--- a/src/librustc_mir/interpret/terminator.rs
+++ b/src/librustc_mir/interpret/terminator.rs
@@ -232,7 +232,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                     ty::FnDef(..) => instance_ty.fn_sig(*self.tcx).abi(),
                     ty::Closure(..) => Abi::RustCall,
                     ty::Generator(..) => Abi::Rust,
-                    _ => bug!("unexpected callee ty: {:?}", instance_ty),
+                    _ => span_bug!(self.cur_span(), "unexpected callee ty: {:?}", instance_ty),
                 }
             };
             let normalize_abi = |abi| match abi {
diff --git a/src/librustc_parse/lexer/mod.rs b/src/librustc_parse/lexer/mod.rs
index 2e3cf4e746a..8e74c3847bc 100644
--- a/src/librustc_parse/lexer/mod.rs
+++ b/src/librustc_parse/lexer/mod.rs
@@ -353,8 +353,15 @@ impl<'a> StringReader<'a> {
             }
             rustc_lexer::LiteralKind::Str { terminated } => {
                 if !terminated {
-                    self.fatal_span_(start, suffix_start, "unterminated double quote string")
-                        .raise()
+                    self.sess
+                        .span_diagnostic
+                        .struct_span_fatal_with_code(
+                            self.mk_sp(start, suffix_start),
+                            "unterminated double quote string",
+                            error_code!(E0765),
+                        )
+                        .emit();
+                    FatalError.raise();
                 }
                 (token::Str, Mode::Str, 1, 1) // " "
             }
diff --git a/src/librustc_resolve/diagnostics.rs b/src/librustc_resolve/diagnostics.rs
index bd2ce5a72e8..bb88b8191f1 100644
--- a/src/librustc_resolve/diagnostics.rs
+++ b/src/librustc_resolve/diagnostics.rs
@@ -49,6 +49,7 @@ crate struct ImportSuggestion {
     pub did: Option<DefId>,
     pub descr: &'static str,
     pub path: Path,
+    pub accessible: bool,
 }
 
 /// Adjust the impl span so that just the `impl` keyword is taken by removing
@@ -640,9 +641,11 @@ impl<'a> Resolver<'a> {
         let mut candidates = Vec::new();
         let mut seen_modules = FxHashSet::default();
         let not_local_module = crate_name.name != kw::Crate;
-        let mut worklist = vec![(start_module, Vec::<ast::PathSegment>::new(), not_local_module)];
+        let mut worklist =
+            vec![(start_module, Vec::<ast::PathSegment>::new(), true, not_local_module)];
 
-        while let Some((in_module, path_segments, in_module_is_extern)) = worklist.pop() {
+        while let Some((in_module, path_segments, accessible, in_module_is_extern)) = worklist.pop()
+        {
             // We have to visit module children in deterministic order to avoid
             // instabilities in reported imports (#43552).
             in_module.for_each_child(self, |this, ident, ns, name_binding| {
@@ -650,11 +653,20 @@ impl<'a> Resolver<'a> {
                 if name_binding.is_import() && !name_binding.is_extern_crate() {
                     return;
                 }
+
                 // avoid non-importable candidates as well
                 if !name_binding.is_importable() {
                     return;
                 }
 
+                let child_accessible =
+                    accessible && this.is_accessible_from(name_binding.vis, parent_scope.module);
+
+                // do not venture inside inaccessible items of other crates
+                if in_module_is_extern && !child_accessible {
+                    return;
+                }
+
                 // collect results based on the filter function
                 // avoid suggesting anything from the same module in which we are resolving
                 if ident.name == lookup_ident.name
@@ -673,22 +685,29 @@ impl<'a> Resolver<'a> {
 
                         segms.push(ast::PathSegment::from_ident(ident));
                         let path = Path { span: name_binding.span, segments: segms };
-                        // the entity is accessible in the following cases:
-                        // 1. if it's defined in the same crate, it's always
-                        // accessible (since private entities can be made public)
-                        // 2. if it's defined in another crate, it's accessible
-                        // only if both the module is public and the entity is
-                        // declared as public (due to pruning, we don't explore
-                        // outside crate private modules => no need to check this)
-                        if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
-                            let did = match res {
-                                Res::Def(DefKind::Ctor(..), did) => this.parent(did),
-                                _ => res.opt_def_id(),
-                            };
-                            if candidates.iter().all(|v: &ImportSuggestion| v.did != did) {
-                                candidates.push(ImportSuggestion { did, descr: res.descr(), path });
+                        let did = match res {
+                            Res::Def(DefKind::Ctor(..), did) => this.parent(did),
+                            _ => res.opt_def_id(),
+                        };
+
+                        if child_accessible {
+                            // Remove invisible match if exists
+                            if let Some(idx) = candidates
+                                .iter()
+                                .position(|v: &ImportSuggestion| v.did == did && !v.accessible)
+                            {
+                                candidates.remove(idx);
                             }
                         }
+
+                        if candidates.iter().all(|v: &ImportSuggestion| v.did != did) {
+                            candidates.push(ImportSuggestion {
+                                did,
+                                descr: res.descr(),
+                                path,
+                                accessible: child_accessible,
+                            });
+                        }
                     }
                 }
 
@@ -701,20 +720,22 @@ impl<'a> Resolver<'a> {
                     let is_extern_crate_that_also_appears_in_prelude =
                         name_binding.is_extern_crate() && lookup_ident.span.rust_2018();
 
-                    let is_visible_to_user =
-                        !in_module_is_extern || name_binding.vis == ty::Visibility::Public;
-
-                    if !is_extern_crate_that_also_appears_in_prelude && is_visible_to_user {
-                        // add the module to the lookup
+                    if !is_extern_crate_that_also_appears_in_prelude {
                         let is_extern = in_module_is_extern || name_binding.is_extern_crate();
+                        // add the module to the lookup
                         if seen_modules.insert(module.def_id().unwrap()) {
-                            worklist.push((module, path_segments, is_extern));
+                            worklist.push((module, path_segments, child_accessible, is_extern));
                         }
                     }
                 }
             })
         }
 
+        // If only some candidates are accessible, take just them
+        if !candidates.iter().all(|v: &ImportSuggestion| !v.accessible) {
+            candidates = candidates.into_iter().filter(|x| x.accessible).collect();
+        }
+
         candidates
     }
 
diff --git a/src/librustc_resolve/late/diagnostics.rs b/src/librustc_resolve/late/diagnostics.rs
index 05ef0aa0bb6..478698ba20c 100644
--- a/src/librustc_resolve/late/diagnostics.rs
+++ b/src/librustc_resolve/late/diagnostics.rs
@@ -887,7 +887,12 @@ impl<'a> LateResolutionVisitor<'a, '_, '_> {
                         let path = Path { span: name_binding.span, segments: path_segments };
                         result = Some((
                             module,
-                            ImportSuggestion { did: Some(def_id), descr: "module", path },
+                            ImportSuggestion {
+                                did: Some(def_id),
+                                descr: "module",
+                                path,
+                                accessible: true,
+                            },
                         ));
                     } else {
                         // add the module to the lookup
diff --git a/src/test/rustdoc-ui/test-compile-fail3.stderr b/src/test/rustdoc-ui/test-compile-fail3.stderr
index 7a2f1815ed8..fab801b3bea 100644
--- a/src/test/rustdoc-ui/test-compile-fail3.stderr
+++ b/src/test/rustdoc-ui/test-compile-fail3.stderr
@@ -1,4 +1,4 @@
-error: unterminated double quote string
+error[E0765]: unterminated double quote string
  --> $DIR/test-compile-fail3.rs:3:1
   |
 3 | "fail
@@ -6,3 +6,4 @@ error: unterminated double quote string
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0765`.
diff --git a/src/test/rustdoc-ui/unparseable-doc-test.stdout b/src/test/rustdoc-ui/unparseable-doc-test.stdout
index 4ea6455d3aa..29cb22e2e4b 100644
--- a/src/test/rustdoc-ui/unparseable-doc-test.stdout
+++ b/src/test/rustdoc-ui/unparseable-doc-test.stdout
@@ -5,7 +5,7 @@ test $DIR/unparseable-doc-test.rs - foo (line 6) ... FAILED
 failures:
 
 ---- $DIR/unparseable-doc-test.rs - foo (line 6) stdout ----
-error: unterminated double quote string
+error[E0765]: unterminated double quote string
   --> $DIR/unparseable-doc-test.rs:8:1
    |
 LL | "unterminated
@@ -13,6 +13,7 @@ LL | "unterminated
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0765`.
 Couldn't compile the test.
 
 failures:
diff --git a/src/test/ui/codemap_tests/tab_2.stderr b/src/test/ui/codemap_tests/tab_2.stderr
index 70414bbd953..0bfdc3ac265 100644
--- a/src/test/ui/codemap_tests/tab_2.stderr
+++ b/src/test/ui/codemap_tests/tab_2.stderr
@@ -1,4 +1,4 @@
-error: unterminated double quote string
+error[E0765]: unterminated double quote string
   --> $DIR/tab_2.rs:4:7
    |
 LL |                   """;
@@ -8,3 +8,4 @@ LL | | }
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0765`.
diff --git a/src/test/ui/hygiene/globs.stderr b/src/test/ui/hygiene/globs.stderr
index 8f6b7aca8fd..6dcbf055a8b 100644
--- a/src/test/ui/hygiene/globs.stderr
+++ b/src/test/ui/hygiene/globs.stderr
@@ -23,14 +23,10 @@ LL | |     }
    | |_____- in this macro invocation
    |
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider importing one of these items
+help: consider importing this function
    |
 LL | use bar::g;
    |
-LL | use foo::test2::test::g;
-   |
-LL | use foo::test::g;
-   |
 
 error[E0425]: cannot find function `f` in this scope
   --> $DIR/globs.rs:61:12
diff --git a/src/test/ui/issues/issue-26545.rs b/src/test/ui/issues/issue-26545.rs
new file mode 100644
index 00000000000..5652ee74706
--- /dev/null
+++ b/src/test/ui/issues/issue-26545.rs
@@ -0,0 +1,12 @@
+mod foo {
+    pub struct B(pub ());
+}
+
+mod baz {
+    fn foo() {
+        B(());
+        //~^ ERROR cannot find function, tuple struct or tuple variant `B` in this scope [E0425]
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/issues/issue-26545.stderr b/src/test/ui/issues/issue-26545.stderr
new file mode 100644
index 00000000000..d3c86692501
--- /dev/null
+++ b/src/test/ui/issues/issue-26545.stderr
@@ -0,0 +1,14 @@
+error[E0425]: cannot find function, tuple struct or tuple variant `B` in this scope
+  --> $DIR/issue-26545.rs:7:9
+   |
+LL |         B(());
+   |         ^ not found in this scope
+   |
+help: consider importing this tuple struct
+   |
+LL |     use foo::B;
+   |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0425`.
diff --git a/src/test/ui/issues/issue-35675.rs b/src/test/ui/issues/issue-35675.rs
index 7876811a9ac..683761667d4 100644
--- a/src/test/ui/issues/issue-35675.rs
+++ b/src/test/ui/issues/issue-35675.rs
@@ -33,7 +33,7 @@ fn qux() -> Some {
 fn main() {}
 
 mod x {
-    enum Enum {
+    pub enum Enum {
         Variant1,
         Variant2(),
         Variant3(usize),
diff --git a/src/test/ui/issues/issue-42944.rs b/src/test/ui/issues/issue-42944.rs
index cc365dc4c93..a088f91554d 100644
--- a/src/test/ui/issues/issue-42944.rs
+++ b/src/test/ui/issues/issue-42944.rs
@@ -1,20 +1,20 @@
 mod foo {
-    pub struct B(());
+    pub struct Bx(());
 }
 
 mod bar {
-    use foo::B;
+    use foo::Bx;
 
     fn foo() {
-        B(());
-        //~^ ERROR expected function, tuple struct or tuple variant, found struct `B` [E0423]
+        Bx(());
+        //~^ ERROR expected function, tuple struct or tuple variant, found struct `Bx` [E0423]
     }
 }
 
 mod baz {
     fn foo() {
-        B(());
-        //~^ ERROR cannot find function, tuple struct or tuple variant `B` in this scope [E0425]
+        Bx(());
+        //~^ ERROR cannot find function, tuple struct or tuple variant `Bx` in this scope [E0425]
     }
 }
 
diff --git a/src/test/ui/issues/issue-42944.stderr b/src/test/ui/issues/issue-42944.stderr
index e7e251e39c0..9fad43757ba 100644
--- a/src/test/ui/issues/issue-42944.stderr
+++ b/src/test/ui/issues/issue-42944.stderr
@@ -1,18 +1,18 @@
-error[E0423]: expected function, tuple struct or tuple variant, found struct `B`
+error[E0423]: expected function, tuple struct or tuple variant, found struct `Bx`
   --> $DIR/issue-42944.rs:9:9
    |
-LL |         B(());
-   |         ^ constructor is not visible here due to private fields
+LL |         Bx(());
+   |         ^^ constructor is not visible here due to private fields
 
-error[E0425]: cannot find function, tuple struct or tuple variant `B` in this scope
+error[E0425]: cannot find function, tuple struct or tuple variant `Bx` in this scope
   --> $DIR/issue-42944.rs:16:9
    |
-LL |         B(());
-   |         ^ not found in this scope
+LL |         Bx(());
+   |         ^^ not found in this scope
    |
 help: consider importing this tuple struct
    |
-LL |     use foo::B;
+LL |     use foo::Bx;
    |
 
 error: aborting due to 2 previous errors
diff --git a/src/test/ui/issues/issue-4366-2.stderr b/src/test/ui/issues/issue-4366-2.stderr
index ecee595d4ab..a86ec7fabea 100644
--- a/src/test/ui/issues/issue-4366-2.stderr
+++ b/src/test/ui/issues/issue-4366-2.stderr
@@ -15,12 +15,10 @@ error[E0423]: expected function, found module `foo`
 LL |     foo();
    |     ^^^ not a function
    |
-help: consider importing one of these items instead
+help: consider importing this function instead
    |
 LL | use foo::foo;
    |
-LL | use m1::foo;
-   |
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/issues/issue-4366.stderr b/src/test/ui/issues/issue-4366.stderr
index a094180572d..469ea93e904 100644
--- a/src/test/ui/issues/issue-4366.stderr
+++ b/src/test/ui/issues/issue-4366.stderr
@@ -4,12 +4,10 @@ error[E0425]: cannot find function `foo` in this scope
 LL |         fn sub() -> isize { foo(); 1 }
    |                             ^^^ not found in this scope
    |
-help: consider importing one of these items
+help: consider importing this function
    |
 LL |         use foo::foo;
    |
-LL |         use m1::foo;
-   |
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-44078.stderr b/src/test/ui/issues/issue-44078.stderr
index 43b49e46312..daf67219f4d 100644
--- a/src/test/ui/issues/issue-44078.stderr
+++ b/src/test/ui/issues/issue-44078.stderr
@@ -1,4 +1,4 @@
-error: unterminated double quote string
+error[E0765]: unterminated double quote string
   --> $DIR/issue-44078.rs:2:8
    |
 LL |       "😊"";
@@ -8,3 +8,4 @@ LL | | }
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0765`.
diff --git a/src/test/ui/parser/unbalanced-doublequote.stderr b/src/test/ui/parser/unbalanced-doublequote.stderr
index 4d98515c224..94b300a7bd7 100644
--- a/src/test/ui/parser/unbalanced-doublequote.stderr
+++ b/src/test/ui/parser/unbalanced-doublequote.stderr
@@ -1,4 +1,4 @@
-error: unterminated double quote string
+error[E0765]: unterminated double quote string
   --> $DIR/unbalanced-doublequote.rs:5:5
    |
 LL | /     "
@@ -7,3 +7,4 @@ LL | | }
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0765`.
diff --git a/src/test/ui/privacy/privacy-ns1.stderr b/src/test/ui/privacy/privacy-ns1.stderr
index 4d2af735fa6..eda9d4c128d 100644
--- a/src/test/ui/privacy/privacy-ns1.stderr
+++ b/src/test/ui/privacy/privacy-ns1.stderr
@@ -11,14 +11,10 @@ help: a unit struct with a similar name exists
    |
 LL |     Baz();
    |     ^^^
-help: consider importing one of these items instead
-   |
-LL | use foo1::Bar;
+help: consider importing this function instead
    |
 LL | use foo2::Bar;
    |
-LL | use foo3::Bar;
-   |
 
 error[E0425]: cannot find function, tuple struct or tuple variant `Bar` in this scope
   --> $DIR/privacy-ns1.rs:51:5
@@ -33,14 +29,10 @@ help: a unit struct with a similar name exists
    |
 LL |     Baz();
    |     ^^^
-help: consider importing one of these items
-   |
-LL | use foo1::Bar;
+help: consider importing this function
    |
 LL | use foo2::Bar;
    |
-LL | use foo3::Bar;
-   |
 
 error[E0412]: cannot find type `Bar` in this scope
   --> $DIR/privacy-ns1.rs:52:17
@@ -55,14 +47,10 @@ help: a struct with a similar name exists
    |
 LL |     let _x: Box<Baz>;
    |                 ^^^
-help: consider importing one of these items
+help: consider importing this trait
    |
 LL | use foo1::Bar;
    |
-LL | use foo2::Bar;
-   |
-LL | use foo3::Bar;
-   |
 
 error[E0107]: wrong number of const arguments: expected 0, found 1
   --> $DIR/privacy-ns1.rs:35:17
diff --git a/src/test/ui/privacy/privacy-ns2.stderr b/src/test/ui/privacy/privacy-ns2.stderr
index f1aa523742a..d7d9b835275 100644
--- a/src/test/ui/privacy/privacy-ns2.stderr
+++ b/src/test/ui/privacy/privacy-ns2.stderr
@@ -4,14 +4,10 @@ error[E0423]: expected function, tuple struct or tuple variant, found trait `Bar
 LL |     Bar();
    |     ^^^ not a function, tuple struct or tuple variant
    |
-help: consider importing one of these items instead
-   |
-LL | use foo1::Bar;
+help: consider importing this function instead
    |
 LL | use foo2::Bar;
    |
-LL | use foo3::Bar;
-   |
 
 error[E0423]: expected function, tuple struct or tuple variant, found trait `Bar`
   --> $DIR/privacy-ns2.rs:26:5
@@ -26,14 +22,10 @@ help: a unit struct with a similar name exists
    |
 LL |     Baz();
    |     ^^^
-help: consider importing one of these items instead
-   |
-LL | use foo1::Bar;
+help: consider importing this function instead
    |
 LL | use foo2::Bar;
    |
-LL | use foo3::Bar;
-   |
 
 error[E0573]: expected type, found function `Bar`
   --> $DIR/privacy-ns2.rs:43:14
@@ -45,14 +37,10 @@ help: use `=` if you meant to assign
    |
 LL |     let _x = Bar();
    |            ^
-help: consider importing one of these items instead
+help: consider importing this trait instead
    |
 LL | use foo1::Bar;
    |
-LL | use foo2::Bar;
-   |
-LL | use foo3::Bar;
-   |
 
 error[E0603]: trait `Bar` is private
   --> $DIR/privacy-ns2.rs:63:15
diff --git a/src/test/ui/resolve/issue-21221-1.stderr b/src/test/ui/resolve/issue-21221-1.stderr
index d3e19534353..538eeead9fc 100644
--- a/src/test/ui/resolve/issue-21221-1.stderr
+++ b/src/test/ui/resolve/issue-21221-1.stderr
@@ -25,11 +25,8 @@ LL | use mul1::Mul;
    |
 LL | use mul2::Mul;
    |
-LL | use mul3::Mul;
-   |
-LL | use mul4::Mul;
+LL | use std::ops::Mul;
    |
-     and 2 other candidates
 
 error[E0405]: cannot find trait `ThisTraitReallyDoesntExistInAnyModuleReally` in this scope
   --> $DIR/issue-21221-1.rs:63:6
diff --git a/triagebot.toml b/triagebot.toml
index fc2dbb8d440..5361a618d4e 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -113,7 +113,7 @@ topic = "P-critical #{number} {title}"
 message_on_add = "@*WG-prioritization* issue #{number} has been assigned `P-critical`."
 
 [notify-zulip."P-high"]
-required_labels = ["regression-from-stable-to-*"]
+required_labels = ["regression-from-stable-to-[bn]*"] # only nightly and beta regressions
 zulip_stream = 227806 # #t-compiler/wg-prioritization
 topic = "P-high regression #{number} {title}"
 message_on_add = "@*WG-prioritization* issue #{number} has been assigned `P-high` and is a regression."