diff --git a/src/doc/book b/src/doc/book
index 6fb3705e52303..c8841f2841a2d 160000
--- a/src/doc/book
+++ b/src/doc/book
@@ -1 +1 @@
-Subproject commit 6fb3705e5230311b096d47f7e2c91f9ce24393d0
+Subproject commit c8841f2841a2d26124319ddadd1b6a245f9a1856
diff --git a/src/doc/nomicon b/src/doc/nomicon
index 9f797e65e6bcc..411197b0e7759 160000
--- a/src/doc/nomicon
+++ b/src/doc/nomicon
@@ -1 +1 @@
-Subproject commit 9f797e65e6bcc79419975b17aff8e21c9adc039f
+Subproject commit 411197b0e77590c967e37e8f6ec681abd359afe8
diff --git a/src/doc/reference b/src/doc/reference
index e2f11fe4d6a5e..89dd146154474 160000
--- a/src/doc/reference
+++ b/src/doc/reference
@@ -1 +1 @@
-Subproject commit e2f11fe4d6a5ecb471c70323197da43c70cb96b6
+Subproject commit 89dd146154474559536d5d4049a03831c501deea
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
index cb369ae95ca36..edd2a7e687358 160000
--- a/src/doc/rust-by-example
+++ b/src/doc/rust-by-example
@@ -1 +1 @@
-Subproject commit cb369ae95ca36b841960182d26f6d5d9b2e3cc18
+Subproject commit edd2a7e687358712608896730c083cb76c7b401a
diff --git a/src/liballoc/benches/btree/set.rs b/src/liballoc/benches/btree/set.rs
index d9e75ab7fa4ef..2518506b9b5f3 100644
--- a/src/liballoc/benches/btree/set.rs
+++ b/src/liballoc/benches/btree/set.rs
@@ -62,6 +62,22 @@ pub fn clone_100_and_clear(b: &mut Bencher) {
     b.iter(|| src.clone().clear())
 }
 
+#[bench]
+pub fn clone_100_and_drain_all(b: &mut Bencher) {
+    let src = pos(100);
+    b.iter(|| src.clone().drain_filter(|_| true).count())
+}
+
+#[bench]
+pub fn clone_100_and_drain_half(b: &mut Bencher) {
+    let src = pos(100);
+    b.iter(|| {
+        let mut set = src.clone();
+        assert_eq!(set.drain_filter(|i| i % 2 == 0).count(), 100 / 2);
+        assert_eq!(set.len(), 100 / 2);
+    })
+}
+
 #[bench]
 pub fn clone_100_and_into_iter(b: &mut Bencher) {
     let src = pos(100);
@@ -115,6 +131,22 @@ pub fn clone_10k_and_clear(b: &mut Bencher) {
     b.iter(|| src.clone().clear())
 }
 
+#[bench]
+pub fn clone_10k_and_drain_all(b: &mut Bencher) {
+    let src = pos(10_000);
+    b.iter(|| src.clone().drain_filter(|_| true).count())
+}
+
+#[bench]
+pub fn clone_10k_and_drain_half(b: &mut Bencher) {
+    let src = pos(10_000);
+    b.iter(|| {
+        let mut set = src.clone();
+        assert_eq!(set.drain_filter(|i| i % 2 == 0).count(), 10_000 / 2);
+        assert_eq!(set.len(), 10_000 / 2);
+    })
+}
+
 #[bench]
 pub fn clone_10k_and_into_iter(b: &mut Bencher) {
     let src = pos(10_000);
diff --git a/src/liballoc/benches/lib.rs b/src/liballoc/benches/lib.rs
index 951477a24c8ed..f31717d9fd517 100644
--- a/src/liballoc/benches/lib.rs
+++ b/src/liballoc/benches/lib.rs
@@ -1,3 +1,4 @@
+#![feature(btree_drain_filter)]
 #![feature(map_first_last)]
 #![feature(repr_simd)]
 #![feature(test)]
diff --git a/src/liballoc/collections/btree/map.rs b/src/liballoc/collections/btree/map.rs
index bde66c406af7f..bbeced1751d14 100644
--- a/src/liballoc/collections/btree/map.rs
+++ b/src/liballoc/collections/btree/map.rs
@@ -1256,6 +1256,48 @@ impl<K: Ord, V> BTreeMap<K, V> {
         right
     }
 
+    /// Creates an iterator which uses a closure to determine if an element should be removed.
+    ///
+    /// If the closure returns true, the element is removed from the map and yielded.
+    /// If the closure returns false, or panics, the element remains in the map and will not be
+    /// yielded.
+    ///
+    /// Note that `drain_filter` lets you mutate every value in the filter closure, regardless of
+    /// whether you choose to keep or remove it.
+    ///
+    /// If the iterator is only partially consumed or not consumed at all, each of the remaining
+    /// elements will still be subjected to the closure and removed and dropped if it returns true.
+    ///
+    /// It is unspecified how many more elements will be subjected to the closure
+    /// if a panic occurs in the closure, or a panic occurs while dropping an element,
+    /// or if the `DrainFilter` value is leaked.
+    ///
+    /// # Examples
+    ///
+    /// Splitting a map into even and odd keys, reusing the original map:
+    ///
+    /// ```
+    /// #![feature(btree_drain_filter)]
+    /// use std::collections::BTreeMap;
+    ///
+    /// let mut map: BTreeMap<i32, i32> = (0..8).map(|x| (x, x)).collect();
+    /// let evens: BTreeMap<_, _> = map.drain_filter(|k, _v| k % 2 == 0).collect();
+    /// let odds = map;
+    /// assert_eq!(evens.keys().copied().collect::<Vec<_>>(), vec![0, 2, 4, 6]);
+    /// assert_eq!(odds.keys().copied().collect::<Vec<_>>(), vec![1, 3, 5, 7]);
+    /// ```
+    #[unstable(feature = "btree_drain_filter", issue = "70530")]
+    pub fn drain_filter<F>(&mut self, pred: F) -> DrainFilter<'_, K, V, F>
+    where
+        F: FnMut(&K, &mut V) -> bool,
+    {
+        DrainFilter { pred, inner: self.drain_filter_inner() }
+    }
+    pub(super) fn drain_filter_inner(&mut self) -> DrainFilterInner<'_, K, V> {
+        let front = self.root.as_mut().map(|r| r.as_mut().first_leaf_edge());
+        DrainFilterInner { length: &mut self.length, cur_leaf_edge: front }
+    }
+
     /// Calculates the number of elements if it is incorrect.
     fn recalc_length(&mut self) {
         fn dfs<'a, K, V>(node: NodeRef<marker::Immut<'a>, K, V, marker::LeafOrInternal>) -> usize
@@ -1653,6 +1695,124 @@ impl<K, V> Clone for Values<'_, K, V> {
     }
 }
 
+/// An iterator produced by calling `drain_filter` on BTreeMap.
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+pub struct DrainFilter<'a, K, V, F>
+where
+    K: 'a + Ord, // This Ord bound should be removed before stabilization.
+    V: 'a,
+    F: 'a + FnMut(&K, &mut V) -> bool,
+{
+    pred: F,
+    inner: DrainFilterInner<'a, K, V>,
+}
+pub(super) struct DrainFilterInner<'a, K, V>
+where
+    K: 'a + Ord,
+    V: 'a,
+{
+    length: &'a mut usize,
+    cur_leaf_edge: Option<Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>>,
+}
+
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+impl<'a, K, V, F> Drop for DrainFilter<'a, K, V, F>
+where
+    K: 'a + Ord,
+    V: 'a,
+    F: 'a + FnMut(&K, &mut V) -> bool,
+{
+    fn drop(&mut self) {
+        self.for_each(drop);
+    }
+}
+
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+impl<'a, K, V, F> fmt::Debug for DrainFilter<'a, K, V, F>
+where
+    K: 'a + fmt::Debug + Ord,
+    V: 'a + fmt::Debug,
+    F: 'a + FnMut(&K, &mut V) -> bool,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("DrainFilter").field(&self.inner.peek()).finish()
+    }
+}
+
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+impl<'a, K, V, F> Iterator for DrainFilter<'a, K, V, F>
+where
+    K: 'a + Ord,
+    V: 'a,
+    F: 'a + FnMut(&K, &mut V) -> bool,
+{
+    type Item = (K, V);
+
+    fn next(&mut self) -> Option<(K, V)> {
+        self.inner.next(&mut self.pred)
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+impl<'a, K, V> DrainFilterInner<'a, K, V>
+where
+    K: 'a + Ord,
+    V: 'a,
+{
+    /// Allow Debug implementations to predict the next element.
+    pub(super) fn peek(&self) -> Option<(&K, &V)> {
+        let edge = self.cur_leaf_edge.as_ref()?;
+        edge.reborrow().next_kv().ok().map(|kv| kv.into_kv())
+    }
+
+    unsafe fn next_kv(
+        &mut self,
+    ) -> Option<Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, marker::KV>> {
+        let edge = self.cur_leaf_edge.as_ref()?;
+        ptr::read(edge).next_kv().ok()
+    }
+
+    /// Implementation of a typical `DrainFilter::next` method, given the predicate.
+    pub(super) fn next<F>(&mut self, pred: &mut F) -> Option<(K, V)>
+    where
+        F: FnMut(&K, &mut V) -> bool,
+    {
+        while let Some(kv) = unsafe { self.next_kv() } {
+            let (k, v) = unsafe { ptr::read(&kv) }.into_kv_mut();
+            if pred(k, v) {
+                *self.length -= 1;
+                let (k, v, leaf_edge_location) = kv.remove_kv_tracking();
+                // `remove_kv_tracking` has either preserved or invalidated `self.cur_leaf_edge`
+                if let Some(node) = leaf_edge_location {
+                    match search::search_tree(node, &k) {
+                        search::SearchResult::Found(_) => unreachable!(),
+                        search::SearchResult::GoDown(leaf) => self.cur_leaf_edge = Some(leaf),
+                    }
+                };
+                return Some((k, v));
+            }
+            self.cur_leaf_edge = Some(kv.next_leaf_edge());
+        }
+        None
+    }
+
+    /// Implementation of a typical `DrainFilter::size_hint` method.
+    pub(super) fn size_hint(&self) -> (usize, Option<usize>) {
+        (0, Some(*self.length))
+    }
+}
+
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+impl<K, V, F> FusedIterator for DrainFilter<'_, K, V, F>
+where
+    K: Ord,
+    F: FnMut(&K, &mut V) -> bool,
+{
+}
+
 #[stable(feature = "btree_range", since = "1.17.0")]
 impl<'a, K, V> Iterator for Range<'a, K, V> {
     type Item = (&'a K, &'a V);
@@ -2531,12 +2691,31 @@ impl<'a, K: Ord, V> OccupiedEntry<'a, K, V> {
     fn remove_kv(self) -> (K, V) {
         *self.length -= 1;
 
-        let (small_leaf, old_key, old_val) = match self.handle.force() {
+        let (old_key, old_val, _) = self.handle.remove_kv_tracking();
+        (old_key, old_val)
+    }
+}
+
+impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, marker::KV> {
+    /// Removes a key/value-pair from the map, and returns that pair, as well as
+    /// the whereabouts of the leaf edge corresponding to that former pair:
+    /// if None is returned, the leaf edge is still the left leaf edge of the KV handle;
+    /// if a node is returned, it heads the subtree where the leaf edge may be found.
+    fn remove_kv_tracking(
+        self,
+    ) -> (K, V, Option<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>>) {
+        let mut levels_down_handled: isize;
+        let (small_leaf, old_key, old_val) = match self.force() {
             Leaf(leaf) => {
+                levels_down_handled = 1; // handled at same level, but affects only the right side
                 let (hole, old_key, old_val) = leaf.remove();
                 (hole.into_node(), old_key, old_val)
             }
             Internal(mut internal) => {
+                // Replace the location freed in the internal node with the next KV,
+                // and remove that next KV from its leaf.
+                levels_down_handled = unsafe { ptr::read(&internal).into_node().height() } as isize;
+
                 let key_loc = internal.kv_mut().0 as *mut K;
                 let val_loc = internal.kv_mut().1 as *mut V;
 
@@ -2556,27 +2735,39 @@ impl<'a, K: Ord, V> OccupiedEntry<'a, K, V> {
         let mut cur_node = small_leaf.forget_type();
         while cur_node.len() < node::MIN_LEN {
             match handle_underfull_node(cur_node) {
-                AtRoot => break,
+                AtRoot(root) => {
+                    cur_node = root;
+                    break;
+                }
                 EmptyParent(_) => unreachable!(),
                 Merged(parent) => {
+                    levels_down_handled -= 1;
                     if parent.len() == 0 {
                         // We must be at the root
-                        parent.into_root_mut().pop_level();
+                        let root = parent.into_root_mut();
+                        root.pop_level();
+                        cur_node = root.as_mut();
                         break;
                     } else {
                         cur_node = parent.forget_type();
                     }
                 }
-                Stole(_) => break,
+                Stole(internal_node) => {
+                    levels_down_handled -= 1;
+                    cur_node = internal_node.forget_type();
+                    // This internal node might be underfull, but only if it's the root.
+                    break;
+                }
             }
         }
 
-        (old_key, old_val)
+        let leaf_edge_location = if levels_down_handled > 0 { None } else { Some(cur_node) };
+        (old_key, old_val, leaf_edge_location)
     }
 }
 
 enum UnderflowResult<'a, K, V> {
-    AtRoot,
+    AtRoot(NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>),
     EmptyParent(NodeRef<marker::Mut<'a>, K, V, marker::Internal>),
     Merged(NodeRef<marker::Mut<'a>, K, V, marker::Internal>),
     Stole(NodeRef<marker::Mut<'a>, K, V, marker::Internal>),
@@ -2585,10 +2776,9 @@ enum UnderflowResult<'a, K, V> {
 fn handle_underfull_node<K, V>(
     node: NodeRef<marker::Mut<'_>, K, V, marker::LeafOrInternal>,
 ) -> UnderflowResult<'_, K, V> {
-    let parent = if let Ok(parent) = node.ascend() {
-        parent
-    } else {
-        return AtRoot;
+    let parent = match node.ascend() {
+        Ok(parent) => parent,
+        Err(root) => return AtRoot(root),
     };
 
     let (is_left, mut handle) = match parent.left_kv() {
diff --git a/src/liballoc/collections/btree/set.rs b/src/liballoc/collections/btree/set.rs
index b100ce754caad..0b02223def4f8 100644
--- a/src/liballoc/collections/btree/set.rs
+++ b/src/liballoc/collections/btree/set.rs
@@ -8,8 +8,8 @@ use core::fmt::{self, Debug};
 use core::iter::{FromIterator, FusedIterator, Peekable};
 use core::ops::{BitAnd, BitOr, BitXor, RangeBounds, Sub};
 
+use super::map::{BTreeMap, Keys};
 use super::Recover;
-use crate::collections::btree_map::{self, BTreeMap, Keys};
 
 // FIXME(conventions): implement bounded iterators
 
@@ -102,7 +102,7 @@ impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Debug)]
 pub struct IntoIter<T> {
-    iter: btree_map::IntoIter<T, ()>,
+    iter: super::map::IntoIter<T, ()>,
 }
 
 /// An iterator over a sub-range of items in a `BTreeSet`.
@@ -115,7 +115,7 @@ pub struct IntoIter<T> {
 #[derive(Debug)]
 #[stable(feature = "btree_range", since = "1.17.0")]
 pub struct Range<'a, T: 'a> {
-    iter: btree_map::Range<'a, T, ()>,
+    iter: super::map::Range<'a, T, ()>,
 }
 
 /// Core of SymmetricDifference and Union.
@@ -944,6 +944,41 @@ impl<T: Ord> BTreeSet<T> {
     {
         BTreeSet { map: self.map.split_off(key) }
     }
+
+    /// Creates an iterator which uses a closure to determine if a value should be removed.
+    ///
+    /// If the closure returns true, then the value is removed and yielded.
+    /// If the closure returns false, the value will remain in the list and will not be yielded
+    /// by the iterator.
+    ///
+    /// If the iterator is only partially consumed or not consumed at all, each of the remaining
+    /// values will still be subjected to the closure and removed and dropped if it returns true.
+    ///
+    /// It is unspecified how many more values will be subjected to the closure
+    /// if a panic occurs in the closure, or if a panic occurs while dropping a value, or if the
+    /// `DrainFilter` itself is leaked.
+    ///
+    /// # Examples
+    ///
+    /// Splitting a set into even and odd values, reusing the original set:
+    ///
+    /// ```
+    /// #![feature(btree_drain_filter)]
+    /// use std::collections::BTreeSet;
+    ///
+    /// let mut set: BTreeSet<i32> = (0..8).collect();
+    /// let evens: BTreeSet<_> = set.drain_filter(|v| v % 2 == 0).collect();
+    /// let odds = set;
+    /// assert_eq!(evens.into_iter().collect::<Vec<_>>(), vec![0, 2, 4, 6]);
+    /// assert_eq!(odds.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 7]);
+    /// ```
+    #[unstable(feature = "btree_drain_filter", issue = "70530")]
+    pub fn drain_filter<'a, F>(&'a mut self, pred: F) -> DrainFilter<'a, T, F>
+    where
+        F: 'a + FnMut(&T) -> bool,
+    {
+        DrainFilter { pred, inner: self.map.drain_filter_inner() }
+    }
 }
 
 impl<T> BTreeSet<T> {
@@ -1055,6 +1090,66 @@ impl<'a, T> IntoIterator for &'a BTreeSet<T> {
     }
 }
 
+/// An iterator produced by calling `drain_filter` on BTreeSet.
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+pub struct DrainFilter<'a, T, F>
+where
+    T: 'a + Ord,
+    F: 'a + FnMut(&T) -> bool,
+{
+    pred: F,
+    inner: super::map::DrainFilterInner<'a, T, ()>,
+}
+
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+impl<'a, T, F> Drop for DrainFilter<'a, T, F>
+where
+    T: 'a + Ord,
+    F: 'a + FnMut(&T) -> bool,
+{
+    fn drop(&mut self) {
+        self.for_each(drop);
+    }
+}
+
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+impl<'a, T, F> fmt::Debug for DrainFilter<'a, T, F>
+where
+    T: 'a + Ord + fmt::Debug,
+    F: 'a + FnMut(&T) -> bool,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("DrainFilter").field(&self.inner.peek().map(|(k, _)| k)).finish()
+    }
+}
+
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+impl<'a, 'f, T, F> Iterator for DrainFilter<'a, T, F>
+where
+    T: 'a + Ord,
+    F: 'a + 'f + FnMut(&T) -> bool,
+{
+    type Item = T;
+
+    fn next(&mut self) -> Option<T> {
+        let pred = &mut self.pred;
+        let mut mapped_pred = |k: &T, _v: &mut ()| pred(k);
+        self.inner.next(&mut mapped_pred).map(|(k, _)| k)
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+#[unstable(feature = "btree_drain_filter", issue = "70530")]
+impl<'a, T, F> FusedIterator for DrainFilter<'a, T, F>
+where
+    T: 'a + Ord,
+    F: 'a + FnMut(&T) -> bool,
+{
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Ord> Extend<T> for BTreeSet<T> {
     #[inline]
diff --git a/src/liballoc/macros.rs b/src/liballoc/macros.rs
index 422d3486f92b2..4bc0c3a079d5c 100644
--- a/src/liballoc/macros.rs
+++ b/src/liballoc/macros.rs
@@ -36,6 +36,9 @@
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow_internal_unstable(box_syntax)]
 macro_rules! vec {
+    () => (
+        $crate::vec::Vec::new()
+    );
     ($elem:expr; $n:expr) => (
         $crate::vec::from_elem($elem, $n)
     );
@@ -51,6 +54,9 @@ macro_rules! vec {
 // NB see the slice::hack module in slice.rs for more information
 #[cfg(test)]
 macro_rules! vec {
+    () => (
+        $crate::vec::Vec::new()
+    );
     ($elem:expr; $n:expr) => (
         $crate::vec::from_elem($elem, $n)
     );
diff --git a/src/liballoc/tests/btree/map.rs b/src/liballoc/tests/btree/map.rs
index e28b71510ce71..14f12ca2d779a 100644
--- a/src/liballoc/tests/btree/map.rs
+++ b/src/liballoc/tests/btree/map.rs
@@ -5,7 +5,7 @@ use std::fmt::Debug;
 use std::iter::FromIterator;
 use std::ops::Bound::{self, Excluded, Included, Unbounded};
 use std::ops::RangeBounds;
-use std::panic::catch_unwind;
+use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::rc::Rc;
 use std::sync::atomic::{AtomicUsize, Ordering};
 
@@ -609,6 +609,263 @@ fn test_range_mut() {
     }
 }
 
+mod test_drain_filter {
+    use super::*;
+
+    #[test]
+    fn empty() {
+        let mut map: BTreeMap<i32, i32> = BTreeMap::new();
+        map.drain_filter(|_, _| unreachable!("there's nothing to decide on"));
+        assert!(map.is_empty());
+    }
+
+    #[test]
+    fn consuming_nothing() {
+        let pairs = (0..3).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        assert!(map.drain_filter(|_, _| false).eq(std::iter::empty()));
+    }
+
+    #[test]
+    fn consuming_all() {
+        let pairs = (0..3).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.clone().collect();
+        assert!(map.drain_filter(|_, _| true).eq(pairs));
+    }
+
+    #[test]
+    fn mutating_and_keeping() {
+        let pairs = (0..3).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        assert!(
+            map.drain_filter(|_, v| {
+                *v += 6;
+                false
+            })
+            .eq(std::iter::empty())
+        );
+        assert!(map.keys().copied().eq(0..3));
+        assert!(map.values().copied().eq(6..9));
+    }
+
+    #[test]
+    fn mutating_and_removing() {
+        let pairs = (0..3).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        assert!(
+            map.drain_filter(|_, v| {
+                *v += 6;
+                true
+            })
+            .eq((0..3).map(|i| (i, i + 6)))
+        );
+        assert!(map.is_empty());
+    }
+
+    #[test]
+    fn underfull_keeping_all() {
+        let pairs = (0..3).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        map.drain_filter(|_, _| false);
+        assert!(map.keys().copied().eq(0..3));
+    }
+
+    #[test]
+    fn underfull_removing_one() {
+        let pairs = (0..3).map(|i| (i, i));
+        for doomed in 0..3 {
+            let mut map: BTreeMap<_, _> = pairs.clone().collect();
+            map.drain_filter(|i, _| *i == doomed);
+            assert_eq!(map.len(), 2);
+        }
+    }
+
+    #[test]
+    fn underfull_keeping_one() {
+        let pairs = (0..3).map(|i| (i, i));
+        for sacred in 0..3 {
+            let mut map: BTreeMap<_, _> = pairs.clone().collect();
+            map.drain_filter(|i, _| *i != sacred);
+            assert!(map.keys().copied().eq(sacred..=sacred));
+        }
+    }
+
+    #[test]
+    fn underfull_removing_all() {
+        let pairs = (0..3).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        map.drain_filter(|_, _| true);
+        assert!(map.is_empty());
+    }
+
+    #[test]
+    fn height_0_keeping_all() {
+        let pairs = (0..NODE_CAPACITY).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        map.drain_filter(|_, _| false);
+        assert!(map.keys().copied().eq(0..NODE_CAPACITY));
+    }
+
+    #[test]
+    fn height_0_removing_one() {
+        let pairs = (0..NODE_CAPACITY).map(|i| (i, i));
+        for doomed in 0..NODE_CAPACITY {
+            let mut map: BTreeMap<_, _> = pairs.clone().collect();
+            map.drain_filter(|i, _| *i == doomed);
+            assert_eq!(map.len(), NODE_CAPACITY - 1);
+        }
+    }
+
+    #[test]
+    fn height_0_keeping_one() {
+        let pairs = (0..NODE_CAPACITY).map(|i| (i, i));
+        for sacred in 0..NODE_CAPACITY {
+            let mut map: BTreeMap<_, _> = pairs.clone().collect();
+            map.drain_filter(|i, _| *i != sacred);
+            assert!(map.keys().copied().eq(sacred..=sacred));
+        }
+    }
+
+    #[test]
+    fn height_0_removing_all() {
+        let pairs = (0..NODE_CAPACITY).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        map.drain_filter(|_, _| true);
+        assert!(map.is_empty());
+    }
+
+    #[test]
+    fn height_0_keeping_half() {
+        let mut map: BTreeMap<_, _> = (0..16).map(|i| (i, i)).collect();
+        assert_eq!(map.drain_filter(|i, _| *i % 2 == 0).count(), 8);
+        assert_eq!(map.len(), 8);
+    }
+
+    #[test]
+    fn height_1_removing_all() {
+        let pairs = (0..MIN_INSERTS_HEIGHT_1).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        map.drain_filter(|_, _| true);
+        assert!(map.is_empty());
+    }
+
+    #[test]
+    fn height_1_removing_one() {
+        let pairs = (0..MIN_INSERTS_HEIGHT_1).map(|i| (i, i));
+        for doomed in 0..MIN_INSERTS_HEIGHT_1 {
+            let mut map: BTreeMap<_, _> = pairs.clone().collect();
+            map.drain_filter(|i, _| *i == doomed);
+            assert_eq!(map.len(), MIN_INSERTS_HEIGHT_1 - 1);
+        }
+    }
+
+    #[test]
+    fn height_1_keeping_one() {
+        let pairs = (0..MIN_INSERTS_HEIGHT_1).map(|i| (i, i));
+        for sacred in 0..MIN_INSERTS_HEIGHT_1 {
+            let mut map: BTreeMap<_, _> = pairs.clone().collect();
+            map.drain_filter(|i, _| *i != sacred);
+            assert!(map.keys().copied().eq(sacred..=sacred));
+        }
+    }
+
+    #[cfg(not(miri))] // Miri is too slow
+    #[test]
+    fn height_2_removing_one() {
+        let pairs = (0..MIN_INSERTS_HEIGHT_2).map(|i| (i, i));
+        for doomed in (0..MIN_INSERTS_HEIGHT_2).step_by(12) {
+            let mut map: BTreeMap<_, _> = pairs.clone().collect();
+            map.drain_filter(|i, _| *i == doomed);
+            assert_eq!(map.len(), MIN_INSERTS_HEIGHT_2 - 1);
+        }
+    }
+
+    #[cfg(not(miri))] // Miri is too slow
+    #[test]
+    fn height_2_keeping_one() {
+        let pairs = (0..MIN_INSERTS_HEIGHT_2).map(|i| (i, i));
+        for sacred in (0..MIN_INSERTS_HEIGHT_2).step_by(12) {
+            let mut map: BTreeMap<_, _> = pairs.clone().collect();
+            map.drain_filter(|i, _| *i != sacred);
+            assert!(map.keys().copied().eq(sacred..=sacred));
+        }
+    }
+
+    #[test]
+    fn height_2_removing_all() {
+        let pairs = (0..MIN_INSERTS_HEIGHT_2).map(|i| (i, i));
+        let mut map: BTreeMap<_, _> = pairs.collect();
+        map.drain_filter(|_, _| true);
+        assert!(map.is_empty());
+    }
+
+    #[test]
+    fn drop_panic_leak() {
+        static PREDS: AtomicUsize = AtomicUsize::new(0);
+        static DROPS: AtomicUsize = AtomicUsize::new(0);
+
+        struct D;
+        impl Drop for D {
+            fn drop(&mut self) {
+                if DROPS.fetch_add(1, Ordering::SeqCst) == 1 {
+                    panic!("panic in `drop`");
+                }
+            }
+        }
+
+        let mut map = BTreeMap::new();
+        map.insert(0, D);
+        map.insert(4, D);
+        map.insert(8, D);
+
+        catch_unwind(move || {
+            drop(map.drain_filter(|i, _| {
+                PREDS.fetch_add(1usize << i, Ordering::SeqCst);
+                true
+            }))
+        })
+        .ok();
+
+        assert_eq!(PREDS.load(Ordering::SeqCst), 0x011);
+        assert_eq!(DROPS.load(Ordering::SeqCst), 3);
+    }
+
+    #[test]
+    fn pred_panic_leak() {
+        static PREDS: AtomicUsize = AtomicUsize::new(0);
+        static DROPS: AtomicUsize = AtomicUsize::new(0);
+
+        struct D;
+        impl Drop for D {
+            fn drop(&mut self) {
+                DROPS.fetch_add(1, Ordering::SeqCst);
+            }
+        }
+
+        let mut map = BTreeMap::new();
+        map.insert(0, D);
+        map.insert(4, D);
+        map.insert(8, D);
+
+        catch_unwind(AssertUnwindSafe(|| {
+            drop(map.drain_filter(|i, _| {
+                PREDS.fetch_add(1usize << i, Ordering::SeqCst);
+                match i {
+                    0 => true,
+                    _ => panic!(),
+                }
+            }))
+        }))
+        .ok();
+
+        assert_eq!(PREDS.load(Ordering::SeqCst), 0x011);
+        assert_eq!(DROPS.load(Ordering::SeqCst), 1);
+        assert_eq!(map.len(), 2);
+        assert_eq!(map.first_entry().unwrap().key(), &4);
+        assert_eq!(map.last_entry().unwrap().key(), &8);
+    }
+}
+
 #[test]
 fn test_borrow() {
     // make sure these compile -- using the Borrow trait
diff --git a/src/liballoc/tests/btree/set.rs b/src/liballoc/tests/btree/set.rs
index 1a2b62d026b2e..136018b9f7df5 100644
--- a/src/liballoc/tests/btree/set.rs
+++ b/src/liballoc/tests/btree/set.rs
@@ -1,5 +1,7 @@
 use std::collections::BTreeSet;
 use std::iter::FromIterator;
+use std::panic::{catch_unwind, AssertUnwindSafe};
+use std::sync::atomic::{AtomicU32, Ordering};
 
 use super::DeterministicRng;
 
@@ -302,6 +304,85 @@ fn test_is_subset() {
     assert_eq!(is_subset(&[99, 100], &large), false);
 }
 
+#[test]
+fn test_drain_filter() {
+    let mut x: BTreeSet<_> = [1].iter().copied().collect();
+    let mut y: BTreeSet<_> = [1].iter().copied().collect();
+
+    x.drain_filter(|_| true);
+    y.drain_filter(|_| false);
+    assert_eq!(x.len(), 0);
+    assert_eq!(y.len(), 1);
+}
+
+#[test]
+fn test_drain_filter_drop_panic_leak() {
+    static PREDS: AtomicU32 = AtomicU32::new(0);
+    static DROPS: AtomicU32 = AtomicU32::new(0);
+
+    #[derive(PartialEq, Eq, PartialOrd, Ord)]
+    struct D(i32);
+    impl Drop for D {
+        fn drop(&mut self) {
+            if DROPS.fetch_add(1, Ordering::SeqCst) == 1 {
+                panic!("panic in `drop`");
+            }
+        }
+    }
+
+    let mut set = BTreeSet::new();
+    set.insert(D(0));
+    set.insert(D(4));
+    set.insert(D(8));
+
+    catch_unwind(move || {
+        drop(set.drain_filter(|d| {
+            PREDS.fetch_add(1u32 << d.0, Ordering::SeqCst);
+            true
+        }))
+    })
+    .ok();
+
+    assert_eq!(PREDS.load(Ordering::SeqCst), 0x011);
+    assert_eq!(DROPS.load(Ordering::SeqCst), 3);
+}
+
+#[test]
+fn test_drain_filter_pred_panic_leak() {
+    static PREDS: AtomicU32 = AtomicU32::new(0);
+    static DROPS: AtomicU32 = AtomicU32::new(0);
+
+    #[derive(PartialEq, Eq, PartialOrd, Ord)]
+    struct D(i32);
+    impl Drop for D {
+        fn drop(&mut self) {
+            DROPS.fetch_add(1, Ordering::SeqCst);
+        }
+    }
+
+    let mut set = BTreeSet::new();
+    set.insert(D(0));
+    set.insert(D(4));
+    set.insert(D(8));
+
+    catch_unwind(AssertUnwindSafe(|| {
+        drop(set.drain_filter(|d| {
+            PREDS.fetch_add(1u32 << d.0, Ordering::SeqCst);
+            match d.0 {
+                0 => true,
+                _ => panic!(),
+            }
+        }))
+    }))
+    .ok();
+
+    assert_eq!(PREDS.load(Ordering::SeqCst), 0x011);
+    assert_eq!(DROPS.load(Ordering::SeqCst), 1);
+    assert_eq!(set.len(), 2);
+    assert_eq!(set.first().unwrap().0, 4);
+    assert_eq!(set.last().unwrap().0, 8);
+}
+
 #[test]
 fn test_clear() {
     let mut x = BTreeSet::new();
diff --git a/src/liballoc/tests/lib.rs b/src/liballoc/tests/lib.rs
index ea75f8903c368..ad6feaeebc67f 100644
--- a/src/liballoc/tests/lib.rs
+++ b/src/liballoc/tests/lib.rs
@@ -1,5 +1,6 @@
 #![feature(allocator_api)]
 #![feature(box_syntax)]
+#![feature(btree_drain_filter)]
 #![feature(drain_filter)]
 #![feature(exact_size_is_empty)]
 #![feature(map_first_last)]
diff --git a/src/libcore/array/iter.rs b/src/libcore/array/iter.rs
index 80eaae0d4afb5..f6b8d4ba08146 100644
--- a/src/libcore/array/iter.rs
+++ b/src/libcore/array/iter.rs
@@ -39,7 +39,7 @@ where
     alive: Range<usize>,
 }
 
-impl<T, const N: usize> IntoIter<T, { N }>
+impl<T, const N: usize> IntoIter<T, N>
 where
     [T; N]: LengthAtMost32,
 {
@@ -99,7 +99,7 @@ where
 }
 
 #[stable(feature = "array_value_iter_impls", since = "1.40.0")]
-impl<T, const N: usize> Iterator for IntoIter<T, { N }>
+impl<T, const N: usize> Iterator for IntoIter<T, N>
 where
     [T; N]: LengthAtMost32,
 {
@@ -146,7 +146,7 @@ where
 }
 
 #[stable(feature = "array_value_iter_impls", since = "1.40.0")]
-impl<T, const N: usize> DoubleEndedIterator for IntoIter<T, { N }>
+impl<T, const N: usize> DoubleEndedIterator for IntoIter<T, N>
 where
     [T; N]: LengthAtMost32,
 {
@@ -182,7 +182,7 @@ where
 }
 
 #[stable(feature = "array_value_iter_impls", since = "1.40.0")]
-impl<T, const N: usize> Drop for IntoIter<T, { N }>
+impl<T, const N: usize> Drop for IntoIter<T, N>
 where
     [T; N]: LengthAtMost32,
 {
@@ -195,7 +195,7 @@ where
 }
 
 #[stable(feature = "array_value_iter_impls", since = "1.40.0")]
-impl<T, const N: usize> ExactSizeIterator for IntoIter<T, { N }>
+impl<T, const N: usize> ExactSizeIterator for IntoIter<T, N>
 where
     [T; N]: LengthAtMost32,
 {
@@ -210,17 +210,17 @@ where
 }
 
 #[stable(feature = "array_value_iter_impls", since = "1.40.0")]
-impl<T, const N: usize> FusedIterator for IntoIter<T, { N }> where [T; N]: LengthAtMost32 {}
+impl<T, const N: usize> FusedIterator for IntoIter<T, N> where [T; N]: LengthAtMost32 {}
 
 // The iterator indeed reports the correct length. The number of "alive"
 // elements (that will still be yielded) is the length of the range `alive`.
 // This range is decremented in length in either `next` or `next_back`. It is
 // always decremented by 1 in those methods, but only if `Some(_)` is returned.
 #[stable(feature = "array_value_iter_impls", since = "1.40.0")]
-unsafe impl<T, const N: usize> TrustedLen for IntoIter<T, { N }> where [T; N]: LengthAtMost32 {}
+unsafe impl<T, const N: usize> TrustedLen for IntoIter<T, N> where [T; N]: LengthAtMost32 {}
 
 #[stable(feature = "array_value_iter_impls", since = "1.40.0")]
-impl<T: Clone, const N: usize> Clone for IntoIter<T, { N }>
+impl<T: Clone, const N: usize> Clone for IntoIter<T, N>
 where
     [T; N]: LengthAtMost32,
 {
@@ -249,7 +249,7 @@ where
 }
 
 #[stable(feature = "array_value_iter_impls", since = "1.40.0")]
-impl<T: fmt::Debug, const N: usize> fmt::Debug for IntoIter<T, { N }>
+impl<T: fmt::Debug, const N: usize> fmt::Debug for IntoIter<T, N>
 where
     [T; N]: LengthAtMost32,
 {
diff --git a/src/librustc_codegen_llvm/abi.rs b/src/librustc_codegen_llvm/abi.rs
index 38dd879de7d59..4b667001ad133 100644
--- a/src/librustc_codegen_llvm/abi.rs
+++ b/src/librustc_codegen_llvm/abi.rs
@@ -10,17 +10,15 @@ use rustc_codegen_ssa::mir::place::PlaceRef;
 use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::MemFlags;
 use rustc_middle::bug;
-use rustc_middle::ty::layout::{self};
+pub use rustc_middle::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
 use rustc_middle::ty::Ty;
 use rustc_target::abi::call::ArgAbi;
-use rustc_target::abi::{HasDataLayout, LayoutOf};
-
-use libc::c_uint;
-
-pub use rustc_middle::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
 pub use rustc_target::abi::call::*;
+use rustc_target::abi::{self, HasDataLayout, Int, LayoutOf};
 pub use rustc_target::spec::abi::Abi;
 
+use libc::c_uint;
+
 macro_rules! for_each_kind {
     ($flags: ident, $f: ident, $($kind: ident),+) => ({
         $(if $flags.contains(ArgAttribute::$kind) { $f(llvm::Attribute::$kind) })+
@@ -443,11 +441,11 @@ impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             PassMode::Indirect(ref attrs, _) => apply(attrs, Some(self.ret.layout.llvm_type(bx))),
             _ => {}
         }
-        if let layout::Abi::Scalar(ref scalar) = self.ret.layout.abi {
+        if let abi::Abi::Scalar(ref scalar) = self.ret.layout.abi {
             // If the value is a boolean, the range is 0..2 and that ultimately
             // become 0..0 when the type becomes i1, which would be rejected
             // by the LLVM verifier.
-            if let layout::Int(..) = scalar.value {
+            if let Int(..) = scalar.value {
                 if !scalar.is_bool() {
                     let range = scalar.valid_range_exclusive(bx);
                     if range.start != range.end {
diff --git a/src/librustc_codegen_llvm/builder.rs b/src/librustc_codegen_llvm/builder.rs
index 35946fb71c3e0..da9060f043f81 100644
--- a/src/librustc_codegen_llvm/builder.rs
+++ b/src/librustc_codegen_llvm/builder.rs
@@ -16,9 +16,10 @@ use rustc_codegen_ssa::MemFlags;
 use rustc_data_structures::const_cstr;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_hir::def_id::DefId;
-use rustc_middle::ty::layout::{self, Align, Size, TyAndLayout};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::config::{self, Sanitizer};
+use rustc_target::abi::{self, Align, Size};
 use rustc_target::spec::{HasTargetSpec, Target};
 use std::borrow::Cow;
 use std::ffi::CStr;
@@ -60,8 +61,8 @@ impl BackendTypes for Builder<'_, 'll, 'tcx> {
     type DIVariable = <CodegenCx<'ll, 'tcx> as BackendTypes>::DIVariable;
 }
 
-impl ty::layout::HasDataLayout for Builder<'_, '_, '_> {
-    fn data_layout(&self) -> &ty::layout::TargetDataLayout {
+impl abi::HasDataLayout for Builder<'_, '_, '_> {
+    fn data_layout(&self) -> &abi::TargetDataLayout {
         self.cx.data_layout()
     }
 }
@@ -84,7 +85,7 @@ impl HasTargetSpec for Builder<'_, '_, 'tcx> {
     }
 }
 
-impl ty::layout::LayoutOf for Builder<'_, '_, 'tcx> {
+impl abi::LayoutOf for Builder<'_, '_, 'tcx> {
     type Ty = Ty<'tcx>;
     type TyAndLayout = TyAndLayout<'tcx>;
 
@@ -435,17 +436,17 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         fn scalar_load_metadata<'a, 'll, 'tcx>(
             bx: &mut Builder<'a, 'll, 'tcx>,
             load: &'ll Value,
-            scalar: &layout::Scalar,
+            scalar: &abi::Scalar,
         ) {
             let vr = scalar.valid_range.clone();
             match scalar.value {
-                layout::Int(..) => {
+                abi::Int(..) => {
                     let range = scalar.valid_range_exclusive(bx);
                     if range.start != range.end {
                         bx.range_metadata(load, range);
                     }
                 }
-                layout::Pointer if vr.start() < vr.end() && !vr.contains(&0) => {
+                abi::Pointer if vr.start() < vr.end() && !vr.contains(&0) => {
                     bx.nonnull_metadata(load);
                 }
                 _ => {}
@@ -465,16 +466,16 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             }
             let llval = const_llval.unwrap_or_else(|| {
                 let load = self.load(place.llval, place.align);
-                if let layout::Abi::Scalar(ref scalar) = place.layout.abi {
+                if let abi::Abi::Scalar(ref scalar) = place.layout.abi {
                     scalar_load_metadata(self, load, scalar);
                 }
                 load
             });
             OperandValue::Immediate(to_immediate(self, llval, place.layout))
-        } else if let layout::Abi::ScalarPair(ref a, ref b) = place.layout.abi {
+        } else if let abi::Abi::ScalarPair(ref a, ref b) = place.layout.abi {
             let b_offset = a.value.size(self).align_to(b.value.align(self).abi);
 
-            let mut load = |i, scalar: &layout::Scalar, align| {
+            let mut load = |i, scalar: &abi::Scalar, align| {
                 let llptr = self.struct_gep(place.llval, i as u64);
                 let load = self.load(llptr, align);
                 scalar_load_metadata(self, load, scalar);
diff --git a/src/librustc_codegen_llvm/common.rs b/src/librustc_codegen_llvm/common.rs
index 01c8e02fdc2ba..1415fedf11a27 100644
--- a/src/librustc_codegen_llvm/common.rs
+++ b/src/librustc_codegen_llvm/common.rs
@@ -2,26 +2,24 @@
 
 //! Code that is useful in various codegen modules.
 
-use crate::consts;
+use crate::consts::{self, const_alloc_to_llvm};
+pub use crate::context::CodegenCx;
 use crate::llvm::{self, BasicBlock, Bool, ConstantInt, False, OperandBundleDef, True};
 use crate::type_::Type;
 use crate::type_of::LayoutLlvmExt;
 use crate::value::Value;
-use log::debug;
-use rustc_codegen_ssa::traits::*;
-use rustc_middle::bug;
 
-use crate::consts::const_alloc_to_llvm;
+use rustc_ast::ast::Mutability;
 use rustc_codegen_ssa::mir::place::PlaceRef;
+use rustc_codegen_ssa::traits::*;
+use rustc_middle::bug;
 use rustc_middle::mir::interpret::{Allocation, GlobalAlloc, Scalar};
-use rustc_middle::ty::layout::{self, HasDataLayout, LayoutOf, Size, TyAndLayout};
-
-use libc::{c_char, c_uint};
-
-use rustc_ast::ast::Mutability;
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_span::symbol::Symbol;
+use rustc_target::abi::{self, HasDataLayout, LayoutOf, Pointer, Size};
 
-pub use crate::context::CodegenCx;
+use libc::{c_char, c_uint};
+use log::debug;
 
 /*
 * A note on nomenclature of linking: "extern", "foreign", and "upcall".
@@ -229,12 +227,7 @@ impl ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         })
     }
 
-    fn scalar_to_backend(
-        &self,
-        cv: Scalar,
-        layout: &layout::Scalar,
-        llty: &'ll Type,
-    ) -> &'ll Value {
+    fn scalar_to_backend(&self, cv: Scalar, layout: &abi::Scalar, llty: &'ll Type) -> &'ll Value {
         let bitsize = if layout.is_bool() { 1 } else { layout.value.size(self).bits() };
         match cv {
             Scalar::Raw { size: 0, .. } => {
@@ -244,7 +237,7 @@ impl ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             Scalar::Raw { data, size } => {
                 assert_eq!(size as u64, layout.value.size(self).bytes());
                 let llval = self.const_uint_big(self.type_ix(bitsize), data);
-                if layout.value == layout::Pointer {
+                if layout.value == Pointer {
                     unsafe { llvm::LLVMConstIntToPtr(llval, llty) }
                 } else {
                     self.const_bitcast(llval, llty)
@@ -278,7 +271,7 @@ impl ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                         1,
                     )
                 };
-                if layout.value != layout::Pointer {
+                if layout.value != Pointer {
                     unsafe { llvm::LLVMConstPtrToInt(llval, llty) }
                 } else {
                     self.const_bitcast(llval, llty)
diff --git a/src/librustc_codegen_llvm/consts.rs b/src/librustc_codegen_llvm/consts.rs
index db92f3d382f6e..2d5564abfb2c8 100644
--- a/src/librustc_codegen_llvm/consts.rs
+++ b/src/librustc_codegen_llvm/consts.rs
@@ -16,12 +16,11 @@ use rustc_middle::mir::interpret::{
     read_target_uint, Allocation, ConstValue, ErrorHandled, Pointer,
 };
 use rustc_middle::mir::mono::MonoItem;
-use rustc_middle::ty::layout::{self, Align, LayoutOf, Size};
 use rustc_middle::ty::{self, Instance, Ty};
 use rustc_middle::{bug, span_bug};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::Span;
-use rustc_target::abi::HasDataLayout;
+use rustc_target::abi::{Align, HasDataLayout, LayoutOf, Primitive, Scalar, Size};
 
 use std::ffi::CStr;
 
@@ -56,7 +55,7 @@ pub fn const_alloc_to_llvm(cx: &CodegenCx<'ll, '_>, alloc: &Allocation) -> &'ll
             as u64;
         llvals.push(cx.scalar_to_backend(
             Pointer::new(alloc_id, Size::from_bytes(ptr_offset)).into(),
-            &layout::Scalar { value: layout::Primitive::Pointer, valid_range: 0..=!0 },
+            &Scalar { value: Primitive::Pointer, valid_range: 0..=!0 },
             cx.type_i8p(),
         ));
         next_offset = offset + pointer_size;
diff --git a/src/librustc_codegen_llvm/context.rs b/src/librustc_codegen_llvm/context.rs
index add1f46a56d37..99a825823c3cd 100644
--- a/src/librustc_codegen_llvm/context.rs
+++ b/src/librustc_codegen_llvm/context.rs
@@ -14,14 +14,13 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_middle::bug;
 use rustc_middle::mir::mono::CodegenUnit;
-use rustc_middle::ty::layout::{
-    HasParamEnv, LayoutError, LayoutOf, PointeeInfo, Size, TyAndLayout, VariantIdx,
-};
+use rustc_middle::ty::layout::{HasParamEnv, LayoutError, TyAndLayout};
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
 use rustc_session::config::{self, CFGuard, DebugInfo};
 use rustc_session::Session;
 use rustc_span::source_map::{Span, DUMMY_SP};
 use rustc_span::symbol::Symbol;
+use rustc_target::abi::{HasDataLayout, LayoutOf, PointeeInfo, Size, TargetDataLayout, VariantIdx};
 use rustc_target::spec::{HasTargetSpec, Target};
 
 use std::cell::{Cell, RefCell};
@@ -817,8 +816,8 @@ impl<'b, 'tcx> CodegenCx<'b, 'tcx> {
     }
 }
 
-impl ty::layout::HasDataLayout for CodegenCx<'ll, 'tcx> {
-    fn data_layout(&self) -> &ty::layout::TargetDataLayout {
+impl HasDataLayout for CodegenCx<'ll, 'tcx> {
+    fn data_layout(&self) -> &TargetDataLayout {
         &self.tcx.data_layout
     }
 }
diff --git a/src/librustc_codegen_llvm/debuginfo/metadata.rs b/src/librustc_codegen_llvm/debuginfo/metadata.rs
index b90c7e51ccd69..a9e21c056a3eb 100644
--- a/src/librustc_codegen_llvm/debuginfo/metadata.rs
+++ b/src/librustc_codegen_llvm/debuginfo/metadata.rs
@@ -34,9 +34,7 @@ use rustc_middle::ich::NodeIdHashingMode;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::mir::interpret::truncate;
 use rustc_middle::mir::{self, Field, GeneratorLayout};
-use rustc_middle::ty::layout::{
-    self, Align, Integer, IntegerExt, LayoutOf, PrimitiveExt, Size, TyAndLayout, VariantIdx,
-};
+use rustc_middle::ty::layout::{self, IntegerExt, PrimitiveExt, TyAndLayout};
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
 use rustc_middle::ty::Instance;
 use rustc_middle::ty::{self, AdtKind, ParamEnv, Ty, TyCtxt};
@@ -44,7 +42,9 @@ use rustc_middle::{bug, span_bug};
 use rustc_session::config::{self, DebugInfo};
 use rustc_span::symbol::{Interner, Symbol};
 use rustc_span::{self, FileName, Span};
-use rustc_target::abi::HasDataLayout;
+use rustc_target::abi::{Abi, Align, DiscriminantKind, HasDataLayout, Integer, LayoutOf};
+use rustc_target::abi::{Int, Pointer, F32, F64};
+use rustc_target::abi::{Primitive, Size, VariantIdx, Variants};
 
 use libc::{c_longlong, c_uint};
 use std::collections::hash_map::Entry;
@@ -1364,7 +1364,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
         };
 
         match self.layout.variants {
-            layout::Variants::Single { index } => {
+            Variants::Single { index } => {
                 if let ty::Adt(adt, _) = &self.enum_type.kind {
                     if adt.variants.is_empty() {
                         return vec![];
@@ -1399,8 +1399,8 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                     discriminant: None,
                 }]
             }
-            layout::Variants::Multiple {
-                discr_kind: layout::DiscriminantKind::Tag,
+            Variants::Multiple {
+                discr_kind: DiscriminantKind::Tag,
                 discr_index,
                 ref variants,
                 ..
@@ -1457,9 +1457,9 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                     })
                     .collect()
             }
-            layout::Variants::Multiple {
+            Variants::Multiple {
                 discr_kind:
-                    layout::DiscriminantKind::Niche { ref niche_variants, niche_start, dataful_variant },
+                    DiscriminantKind::Niche { ref niche_variants, niche_start, dataful_variant },
                 ref discr,
                 ref variants,
                 discr_index,
@@ -1592,7 +1592,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
 // Creates `MemberDescription`s for the fields of a single enum variant.
 struct VariantMemberDescriptionFactory<'ll, 'tcx> {
     /// Cloned from the `layout::Struct` describing the variant.
-    offsets: Vec<layout::Size>,
+    offsets: Vec<Size>,
     args: Vec<(String, Ty<'tcx>)>,
     discriminant_type_metadata: Option<&'ll DIType>,
     span: Span,
@@ -1777,7 +1777,7 @@ fn prepare_enum_metadata(
     // <unknown>
     let file_metadata = unknown_file_metadata(cx);
 
-    let discriminant_type_metadata = |discr: layout::Primitive| {
+    let discriminant_type_metadata = |discr: Primitive| {
         let enumerators_metadata: Vec<_> = match enum_type.kind {
             ty::Adt(def, _) => def
                 .discriminants(cx.tcx)
@@ -1870,10 +1870,8 @@ fn prepare_enum_metadata(
     let layout = cx.layout_of(enum_type);
 
     if let (
-        &layout::Abi::Scalar(_),
-        &layout::Variants::Multiple {
-            discr_kind: layout::DiscriminantKind::Tag, ref discr, ..
-        },
+        &Abi::Scalar(_),
+        &Variants::Multiple { discr_kind: DiscriminantKind::Tag, ref discr, .. },
     ) = (&layout.abi, &layout.variants)
     {
         return FinalMetadata(discriminant_type_metadata(discr.value));
@@ -1881,16 +1879,11 @@ fn prepare_enum_metadata(
 
     if use_enum_fallback(cx) {
         let discriminant_type_metadata = match layout.variants {
-            layout::Variants::Single { .. }
-            | layout::Variants::Multiple {
-                discr_kind: layout::DiscriminantKind::Niche { .. },
-                ..
-            } => None,
-            layout::Variants::Multiple {
-                discr_kind: layout::DiscriminantKind::Tag,
-                ref discr,
-                ..
-            } => Some(discriminant_type_metadata(discr.value)),
+            Variants::Single { .. }
+            | Variants::Multiple { discr_kind: DiscriminantKind::Niche { .. }, .. } => None,
+            Variants::Multiple { discr_kind: DiscriminantKind::Tag, ref discr, .. } => {
+                Some(discriminant_type_metadata(discr.value))
+            }
         };
 
         let enum_metadata = {
@@ -1938,10 +1931,10 @@ fn prepare_enum_metadata(
     };
     let discriminator_metadata = match layout.variants {
         // A single-variant enum has no discriminant.
-        layout::Variants::Single { .. } => None,
+        Variants::Single { .. } => None,
 
-        layout::Variants::Multiple {
-            discr_kind: layout::DiscriminantKind::Niche { .. },
+        Variants::Multiple {
+            discr_kind: DiscriminantKind::Niche { .. },
             ref discr,
             discr_index,
             ..
@@ -1951,10 +1944,10 @@ fn prepare_enum_metadata(
             let align = discr.value.align(cx);
 
             let discr_type = match discr.value {
-                layout::Int(t, _) => t,
-                layout::F32 => Integer::I32,
-                layout::F64 => Integer::I64,
-                layout::Pointer => cx.data_layout().ptr_sized_integer(),
+                Int(t, _) => t,
+                F32 => Integer::I32,
+                F64 => Integer::I64,
+                Pointer => cx.data_layout().ptr_sized_integer(),
             }
             .to_ty(cx.tcx, false);
 
@@ -1976,11 +1969,8 @@ fn prepare_enum_metadata(
             }
         }
 
-        layout::Variants::Multiple {
-            discr_kind: layout::DiscriminantKind::Tag,
-            ref discr,
-            discr_index,
-            ..
+        Variants::Multiple {
+            discr_kind: DiscriminantKind::Tag, ref discr, discr_index, ..
         } => {
             let discr_type = discr.value.to_ty(cx.tcx);
             let (size, align) = cx.size_and_align_of(discr_type);
@@ -2005,8 +1995,8 @@ fn prepare_enum_metadata(
     };
 
     let mut outer_fields = match layout.variants {
-        layout::Variants::Single { .. } => vec![],
-        layout::Variants::Multiple { .. } => {
+        Variants::Single { .. } => vec![],
+        Variants::Multiple { .. } => {
             let tuple_mdf = TupleMemberDescriptionFactory {
                 ty: enum_type,
                 component_types: outer_field_tys,
diff --git a/src/librustc_codegen_llvm/debuginfo/mod.rs b/src/librustc_codegen_llvm/debuginfo/mod.rs
index 848c973c15b51..f04ac58650411 100644
--- a/src/librustc_codegen_llvm/debuginfo/mod.rs
+++ b/src/librustc_codegen_llvm/debuginfo/mod.rs
@@ -8,35 +8,35 @@ use self::namespace::mangled_name_of_instance;
 use self::type_names::compute_debuginfo_type_name;
 use self::utils::{create_DIArray, is_node_local_to_unit, DIB};
 
+use crate::abi::FnAbi;
+use crate::builder::Builder;
+use crate::common::CodegenCx;
 use crate::llvm;
 use crate::llvm::debuginfo::{
     DIArray, DIBuilder, DIFile, DIFlags, DILexicalBlock, DISPFlags, DIScope, DIType, DIVariable,
 };
-use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LOCAL_CRATE};
-use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
-
-use crate::abi::FnAbi;
-use crate::builder::Builder;
-use crate::common::CodegenCx;
 use crate::value::Value;
+
+use rustc_ast::ast;
 use rustc_codegen_ssa::debuginfo::type_names;
 use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
+use rustc_codegen_ssa::traits::*;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LOCAL_CRATE};
 use rustc_index::vec::IndexVec;
 use rustc_middle::mir;
+use rustc_middle::ty::layout::HasTyCtxt;
+use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
 use rustc_middle::ty::{self, Instance, ParamEnv, Ty};
 use rustc_session::config::{self, DebugInfo};
+use rustc_span::symbol::Symbol;
+use rustc_span::{self, BytePos, Span};
+use rustc_target::abi::{LayoutOf, Primitive, Size};
 
 use libc::c_uint;
 use log::debug;
-use std::cell::RefCell;
-
-use rustc_ast::ast;
-use rustc_codegen_ssa::traits::*;
-use rustc_middle::ty::layout::{self, HasTyCtxt, LayoutOf, Size};
-use rustc_span::symbol::Symbol;
-use rustc_span::{self, BytePos, Span};
 use smallvec::SmallVec;
+use std::cell::RefCell;
 
 mod create_scope_map;
 pub mod gdb;
@@ -60,7 +60,7 @@ pub struct CrateDebugContext<'a, 'tcx> {
     llmod: &'a llvm::Module,
     builder: &'a mut DIBuilder<'a>,
     created_files: RefCell<FxHashMap<(Option<String>, Option<String>), &'a DIFile>>,
-    created_enum_disr_types: RefCell<FxHashMap<(DefId, layout::Primitive), &'a DIType>>,
+    created_enum_disr_types: RefCell<FxHashMap<(DefId, Primitive), &'a DIType>>,
 
     type_map: RefCell<TypeMap<'a, 'tcx>>,
     namespace_map: RefCell<DefIdMap<&'a DIScope>>,
diff --git a/src/librustc_codegen_llvm/intrinsic.rs b/src/librustc_codegen_llvm/intrinsic.rs
index 23f6c0a942036..bc7a9c566b476 100644
--- a/src/librustc_codegen_llvm/intrinsic.rs
+++ b/src/librustc_codegen_llvm/intrinsic.rs
@@ -7,23 +7,22 @@ use crate::type_::Type;
 use crate::type_of::LayoutLlvmExt;
 use crate::va_arg::emit_va_arg;
 use crate::value::Value;
+
 use rustc_ast::ast;
 use rustc_codegen_ssa::base::{compare_simd_types, to_immediate, wants_msvc_seh};
+use rustc_codegen_ssa::common::span_invalid_monomorphization_error;
 use rustc_codegen_ssa::common::{IntPredicate, TypeKind};
 use rustc_codegen_ssa::glue;
 use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
 use rustc_codegen_ssa::mir::place::PlaceRef;
+use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::MemFlags;
 use rustc_hir as hir;
-use rustc_middle::ty::layout::{self, FnAbiExt, HasTyCtxt, LayoutOf, Primitive};
+use rustc_middle::ty::layout::{FnAbiExt, HasTyCtxt};
 use rustc_middle::ty::{self, Ty};
 use rustc_middle::{bug, span_bug};
-use rustc_target::abi::HasDataLayout;
-
-use rustc_codegen_ssa::common::span_invalid_monomorphization_error;
-use rustc_codegen_ssa::traits::*;
-
 use rustc_span::Span;
+use rustc_target::abi::{self, HasDataLayout, LayoutOf, Primitive};
 
 use std::cmp::Ordering;
 use std::{i128, iter, u128};
@@ -145,7 +144,7 @@ impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> {
             }
             "va_arg" => {
                 match fn_abi.ret.layout.abi {
-                    layout::Abi::Scalar(ref scalar) => {
+                    abi::Abi::Scalar(ref scalar) => {
                         match scalar.value {
                             Primitive::Int(..) => {
                                 if self.cx().size_of(ret_ty).bytes() < 4 {
diff --git a/src/librustc_codegen_llvm/lib.rs b/src/librustc_codegen_llvm/lib.rs
index 8a16d098a8bef..939f9e9c2a0c7 100644
--- a/src/librustc_codegen_llvm/lib.rs
+++ b/src/librustc_codegen_llvm/lib.rs
@@ -23,11 +23,10 @@ use rustc_codegen_ssa::back::write::{CodegenContext, FatLTOInput, ModuleConfig};
 use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::ModuleCodegen;
 use rustc_codegen_ssa::{CodegenResults, CompiledModule};
-use rustc_errors::{FatalError, Handler};
+use rustc_errors::{ErrorReported, FatalError, Handler};
 use rustc_middle::dep_graph::{DepGraph, WorkProduct};
 use rustc_middle::middle::cstore::{EncodedMetadata, MetadataLoaderDyn};
 use rustc_middle::ty::{self, TyCtxt};
-use rustc_middle::util::common::ErrorReported;
 use rustc_serialize::json;
 use rustc_session::config::{self, OptLevel, OutputFilenames, PrintRequest};
 use rustc_session::Session;
diff --git a/src/librustc_codegen_llvm/mono_item.rs b/src/librustc_codegen_llvm/mono_item.rs
index fe1537fbd021d..326e2f1bab046 100644
--- a/src/librustc_codegen_llvm/mono_item.rs
+++ b/src/librustc_codegen_llvm/mono_item.rs
@@ -7,11 +7,11 @@ use crate::type_of::LayoutLlvmExt;
 use log::debug;
 use rustc_codegen_ssa::traits::*;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
+pub use rustc_middle::mir::mono::MonoItem;
 use rustc_middle::mir::mono::{Linkage, Visibility};
-use rustc_middle::ty::layout::{FnAbiExt, LayoutOf};
+use rustc_middle::ty::layout::FnAbiExt;
 use rustc_middle::ty::{Instance, TypeFoldable};
-
-pub use rustc_middle::mir::mono::MonoItem;
+use rustc_target::abi::LayoutOf;
 
 impl PreDefineMethods<'tcx> for CodegenCx<'ll, 'tcx> {
     fn predefine_static(
diff --git a/src/librustc_codegen_llvm/type_.rs b/src/librustc_codegen_llvm/type_.rs
index c06d2e6a01ac2..854eff3173380 100644
--- a/src/librustc_codegen_llvm/type_.rs
+++ b/src/librustc_codegen_llvm/type_.rs
@@ -12,9 +12,10 @@ use rustc_codegen_ssa::common::TypeKind;
 use rustc_codegen_ssa::traits::*;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_middle::bug;
-use rustc_middle::ty::layout::{self, Align, Size, TyAndLayout};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::Ty;
 use rustc_target::abi::call::{CastTarget, FnAbi, Reg};
+use rustc_target::abi::{Align, Integer, Size};
 
 use std::fmt;
 use std::ptr;
@@ -114,14 +115,14 @@ impl CodegenCx<'ll, 'tcx> {
 
     crate fn type_pointee_for_align(&self, align: Align) -> &'ll Type {
         // FIXME(eddyb) We could find a better approximation if ity.align < align.
-        let ity = layout::Integer::approximate_align(self, align);
+        let ity = Integer::approximate_align(self, align);
         self.type_from_integer(ity)
     }
 
     /// Return a LLVM type that has at most the required alignment,
     /// and exactly the required size, as a best-effort padding array.
     crate fn type_padding_filler(&self, size: Size, align: Align) -> &'ll Type {
-        let unit = layout::Integer::approximate_align(self, align);
+        let unit = Integer::approximate_align(self, align);
         let size = size.bytes();
         let unit_size = unit.size().bytes();
         assert_eq!(size % unit_size, 0);
diff --git a/src/librustc_codegen_llvm/type_of.rs b/src/librustc_codegen_llvm/type_of.rs
index 350f7be5a9d8d..d9e71f0c2212e 100644
--- a/src/librustc_codegen_llvm/type_of.rs
+++ b/src/librustc_codegen_llvm/type_of.rs
@@ -4,10 +4,12 @@ use crate::type_::Type;
 use log::debug;
 use rustc_codegen_ssa::traits::*;
 use rustc_middle::bug;
-use rustc_middle::ty::layout::{self, Align, FnAbiExt, LayoutOf, PointeeInfo, Size, TyAndLayout};
+use rustc_middle::ty::layout::{FnAbiExt, TyAndLayout};
 use rustc_middle::ty::print::obsolete::DefPathBasedNames;
 use rustc_middle::ty::{self, Ty, TypeFoldable};
-use rustc_target::abi::TyAndLayoutMethods;
+use rustc_target::abi::{Abi, Align, FieldPlacement};
+use rustc_target::abi::{Int, Pointer, F32, F64};
+use rustc_target::abi::{LayoutOf, PointeeInfo, Scalar, Size, TyAndLayoutMethods, Variants};
 
 use std::fmt::Write;
 
@@ -17,8 +19,8 @@ fn uncached_llvm_type<'a, 'tcx>(
     defer: &mut Option<(&'a Type, TyAndLayout<'tcx>)>,
 ) -> &'a Type {
     match layout.abi {
-        layout::Abi::Scalar(_) => bug!("handled elsewhere"),
-        layout::Abi::Vector { ref element, count } => {
+        Abi::Scalar(_) => bug!("handled elsewhere"),
+        Abi::Vector { ref element, count } => {
             // LLVM has a separate type for 64-bit SIMD vectors on X86 called
             // `x86_mmx` which is needed for some SIMD operations. As a bit of a
             // hack (all SIMD definitions are super unstable anyway) we
@@ -37,7 +39,7 @@ fn uncached_llvm_type<'a, 'tcx>(
                 return cx.type_vector(element, count);
             }
         }
-        layout::Abi::ScalarPair(..) => {
+        Abi::ScalarPair(..) => {
             return cx.type_struct(
                 &[
                     layout.scalar_pair_element_llvm_type(cx, 0, false),
@@ -46,7 +48,7 @@ fn uncached_llvm_type<'a, 'tcx>(
                 false,
             );
         }
-        layout::Abi::Uninhabited | layout::Abi::Aggregate { .. } => {}
+        Abi::Uninhabited | Abi::Aggregate { .. } => {}
     }
 
     let name = match layout.ty.kind {
@@ -61,14 +63,14 @@ fn uncached_llvm_type<'a, 'tcx>(
             let mut name = String::with_capacity(32);
             let printer = DefPathBasedNames::new(cx.tcx, true, true);
             printer.push_type_name(layout.ty, &mut name, false);
-            if let (&ty::Adt(def, _), &layout::Variants::Single { index })
+            if let (&ty::Adt(def, _), &Variants::Single { index })
                  = (&layout.ty.kind, &layout.variants)
             {
                 if def.is_enum() && !def.variants.is_empty() {
                     write!(&mut name, "::{}", def.variants[index].ident).unwrap();
                 }
             }
-            if let (&ty::Generator(_, substs, _), &layout::Variants::Single { index })
+            if let (&ty::Generator(_, substs, _), &Variants::Single { index })
                  = (&layout.ty.kind, &layout.variants)
             {
                 write!(&mut name, "::{}", substs.as_generator().variant_name(index)).unwrap();
@@ -79,7 +81,7 @@ fn uncached_llvm_type<'a, 'tcx>(
     };
 
     match layout.fields {
-        layout::FieldPlacement::Union(_) => {
+        FieldPlacement::Union(_) => {
             let fill = cx.type_padding_filler(layout.size, layout.align.abi);
             let packed = false;
             match name {
@@ -91,10 +93,10 @@ fn uncached_llvm_type<'a, 'tcx>(
                 }
             }
         }
-        layout::FieldPlacement::Array { count, .. } => {
+        FieldPlacement::Array { count, .. } => {
             cx.type_array(layout.field(cx, 0).llvm_type(cx), count)
         }
-        layout::FieldPlacement::Arbitrary { .. } => match name {
+        FieldPlacement::Arbitrary { .. } => match name {
             None => {
                 let (llfields, packed) = struct_llfields(cx, layout);
                 cx.type_struct(&llfields, packed)
@@ -189,7 +191,7 @@ pub trait LayoutLlvmExt<'tcx> {
     fn scalar_llvm_type_at<'a>(
         &self,
         cx: &CodegenCx<'a, 'tcx>,
-        scalar: &layout::Scalar,
+        scalar: &Scalar,
         offset: Size,
     ) -> &'a Type;
     fn scalar_pair_element_llvm_type<'a>(
@@ -205,19 +207,16 @@ pub trait LayoutLlvmExt<'tcx> {
 impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
     fn is_llvm_immediate(&self) -> bool {
         match self.abi {
-            layout::Abi::Scalar(_) | layout::Abi::Vector { .. } => true,
-            layout::Abi::ScalarPair(..) => false,
-            layout::Abi::Uninhabited | layout::Abi::Aggregate { .. } => self.is_zst(),
+            Abi::Scalar(_) | Abi::Vector { .. } => true,
+            Abi::ScalarPair(..) => false,
+            Abi::Uninhabited | Abi::Aggregate { .. } => self.is_zst(),
         }
     }
 
     fn is_llvm_scalar_pair(&self) -> bool {
         match self.abi {
-            layout::Abi::ScalarPair(..) => true,
-            layout::Abi::Uninhabited
-            | layout::Abi::Scalar(_)
-            | layout::Abi::Vector { .. }
-            | layout::Abi::Aggregate { .. } => false,
+            Abi::ScalarPair(..) => true,
+            Abi::Uninhabited | Abi::Scalar(_) | Abi::Vector { .. } | Abi::Aggregate { .. } => false,
         }
     }
 
@@ -233,7 +232,7 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
     /// of that field's type - this is useful for taking the address of
     /// that field and ensuring the struct has the right alignment.
     fn llvm_type<'a>(&self, cx: &CodegenCx<'a, 'tcx>) -> &'a Type {
-        if let layout::Abi::Scalar(ref scalar) = self.abi {
+        if let Abi::Scalar(ref scalar) = self.abi {
             // Use a different cache for scalars because pointers to DSTs
             // can be either fat or thin (data pointers of fat pointers).
             if let Some(&llty) = cx.scalar_lltypes.borrow().get(&self.ty) {
@@ -255,7 +254,7 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
 
         // Check the cache.
         let variant_index = match self.variants {
-            layout::Variants::Single { index } => Some(index),
+            Variants::Single { index } => Some(index),
             _ => None,
         };
         if let Some(&llty) = cx.lltypes.borrow().get(&(self.ty, variant_index)) {
@@ -293,7 +292,7 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
     }
 
     fn immediate_llvm_type<'a>(&self, cx: &CodegenCx<'a, 'tcx>) -> &'a Type {
-        if let layout::Abi::Scalar(ref scalar) = self.abi {
+        if let Abi::Scalar(ref scalar) = self.abi {
             if scalar.is_bool() {
                 return cx.type_i1();
             }
@@ -304,14 +303,14 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
     fn scalar_llvm_type_at<'a>(
         &self,
         cx: &CodegenCx<'a, 'tcx>,
-        scalar: &layout::Scalar,
+        scalar: &Scalar,
         offset: Size,
     ) -> &'a Type {
         match scalar.value {
-            layout::Int(i, _) => cx.type_from_integer(i),
-            layout::F32 => cx.type_f32(),
-            layout::F64 => cx.type_f64(),
-            layout::Pointer => {
+            Int(i, _) => cx.type_from_integer(i),
+            F32 => cx.type_f32(),
+            F64 => cx.type_f64(),
+            Pointer => {
                 // If we know the alignment, pick something better than i8.
                 let pointee = if let Some(pointee) = self.pointee_info_at(cx, offset) {
                     cx.type_pointee_for_align(pointee.align)
@@ -343,7 +342,7 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
         }
 
         let (a, b) = match self.abi {
-            layout::Abi::ScalarPair(ref a, ref b) => (a, b),
+            Abi::ScalarPair(ref a, ref b) => (a, b),
             _ => bug!("TyAndLayout::scalar_pair_element_llty({:?}): not applicable", self),
         };
         let scalar = [a, b][index];
@@ -365,21 +364,19 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> {
 
     fn llvm_field_index(&self, index: usize) -> u64 {
         match self.abi {
-            layout::Abi::Scalar(_) | layout::Abi::ScalarPair(..) => {
+            Abi::Scalar(_) | Abi::ScalarPair(..) => {
                 bug!("TyAndLayout::llvm_field_index({:?}): not applicable", self)
             }
             _ => {}
         }
         match self.fields {
-            layout::FieldPlacement::Union(_) => {
+            FieldPlacement::Union(_) => {
                 bug!("TyAndLayout::llvm_field_index({:?}): not applicable", self)
             }
 
-            layout::FieldPlacement::Array { .. } => index as u64,
+            FieldPlacement::Array { .. } => index as u64,
 
-            layout::FieldPlacement::Arbitrary { .. } => {
-                1 + (self.fields.memory_index(index) as u64) * 2
-            }
+            FieldPlacement::Arbitrary { .. } => 1 + (self.fields.memory_index(index) as u64) * 2,
         }
     }
 
diff --git a/src/librustc_codegen_llvm/va_arg.rs b/src/librustc_codegen_llvm/va_arg.rs
index 42e9f60e95cb5..8bc3579800ea8 100644
--- a/src/librustc_codegen_llvm/va_arg.rs
+++ b/src/librustc_codegen_llvm/va_arg.rs
@@ -6,8 +6,9 @@ use rustc_codegen_ssa::mir::operand::OperandRef;
 use rustc_codegen_ssa::traits::{
     BaseTypeMethods, BuilderMethods, ConstMethods, DerivedTypeMethods,
 };
-use rustc_middle::ty::layout::{Align, HasDataLayout, HasTyCtxt, LayoutOf, Size};
+use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_middle::ty::Ty;
+use rustc_target::abi::{Align, HasDataLayout, LayoutOf, Size};
 
 #[allow(dead_code)]
 fn round_pointer_up_to_alignment(
diff --git a/src/librustc_codegen_ssa/base.rs b/src/librustc_codegen_ssa/base.rs
index 9e6a3b23323d8..0297415155553 100644
--- a/src/librustc_codegen_ssa/base.rs
+++ b/src/librustc_codegen_ssa/base.rs
@@ -31,14 +31,14 @@ use rustc_data_structures::profiling::print_time_passes_entry;
 use rustc_data_structures::sync::{par_iter, Lock, ParallelIterator};
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
+use rustc_hir::lang_items::StartFnLangItem;
 use rustc_index::vec::Idx;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::middle::cstore::EncodedMetadata;
 use rustc_middle::middle::cstore::{self, LinkagePreference};
 use rustc_middle::middle::lang_items;
-use rustc_middle::middle::lang_items::StartFnLangItem;
 use rustc_middle::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem};
-use rustc_middle::ty::layout::{self, Align, HasTyCtxt, LayoutOf, TyAndLayout, VariantIdx};
+use rustc_middle::ty::layout::{self, HasTyCtxt, TyAndLayout};
 use rustc_middle::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
@@ -47,6 +47,7 @@ use rustc_session::config::{self, EntryFnType, Lto};
 use rustc_session::Session;
 use rustc_span::Span;
 use rustc_symbol_mangling::test as symbol_names_test;
+use rustc_target::abi::{Abi, Align, LayoutOf, Scalar, VariantIdx};
 
 use std::cmp;
 use std::ops::{Deref, DerefMut};
@@ -343,7 +344,7 @@ pub fn to_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     val: Bx::Value,
     layout: layout::TyAndLayout<'_>,
 ) -> Bx::Value {
-    if let layout::Abi::Scalar(ref scalar) = layout.abi {
+    if let Abi::Scalar(ref scalar) = layout.abi {
         return to_immediate_scalar(bx, val, scalar);
     }
     val
@@ -352,7 +353,7 @@ pub fn to_immediate<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 pub fn to_immediate_scalar<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     bx: &mut Bx,
     val: Bx::Value,
-    scalar: &layout::Scalar,
+    scalar: &Scalar,
 ) -> Bx::Value {
     if scalar.is_bool() {
         return bx.trunc(val, bx.cx().type_i1());
diff --git a/src/librustc_codegen_ssa/common.rs b/src/librustc_codegen_ssa/common.rs
index 8de04b730e170..0d0321ec4ae5e 100644
--- a/src/librustc_codegen_ssa/common.rs
+++ b/src/librustc_codegen_ssa/common.rs
@@ -1,17 +1,16 @@
 #![allow(non_camel_case_types, non_snake_case)]
 
 use rustc_errors::struct_span_err;
+use rustc_hir as hir;
+use rustc_hir::def_id::DefId;
+use rustc_hir::LangItem;
 use rustc_middle::ty::{Ty, TyCtxt};
 use rustc_session::Session;
 use rustc_span::Span;
 
 use crate::base;
-use crate::traits::*;
-use rustc_hir::def_id::DefId;
-use rustc_middle::middle::lang_items::LangItem;
-
 use crate::traits::BuilderMethods;
-use rustc_hir as hir;
+use crate::traits::*;
 
 pub enum IntPredicate {
     IntEQ,
diff --git a/src/librustc_codegen_ssa/lib.rs b/src/librustc_codegen_ssa/lib.rs
index bf2f92a473fe8..bf8441562c55b 100644
--- a/src/librustc_codegen_ssa/lib.rs
+++ b/src/librustc_codegen_ssa/lib.rs
@@ -21,10 +21,10 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def_id::CrateNum;
+use rustc_hir::LangItem;
 use rustc_middle::dep_graph::WorkProduct;
 use rustc_middle::middle::cstore::{CrateSource, LibSource, NativeLibrary};
 use rustc_middle::middle::dependency_format::Dependencies;
-use rustc_middle::middle::lang_items::LangItem;
 use rustc_middle::ty::query::Providers;
 use rustc_session::config::{OutputFilenames, OutputType, RUST_CGU_EXT};
 use rustc_span::symbol::Symbol;
diff --git a/src/librustc_codegen_ssa/mir/analyze.rs b/src/librustc_codegen_ssa/mir/analyze.rs
index ec3de274b8a83..221f36fed362d 100644
--- a/src/librustc_codegen_ssa/mir/analyze.rs
+++ b/src/librustc_codegen_ssa/mir/analyze.rs
@@ -12,7 +12,8 @@ use rustc_middle::mir::visit::{
 };
 use rustc_middle::mir::{self, Location, TerminatorKind};
 use rustc_middle::ty;
-use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
+use rustc_middle::ty::layout::HasTyCtxt;
+use rustc_target::abi::LayoutOf;
 
 pub fn non_ssa_locals<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     fx: &FunctionCx<'a, 'tcx, Bx>,
diff --git a/src/librustc_codegen_ssa/mir/block.rs b/src/librustc_codegen_ssa/mir/block.rs
index e71a63b7f3080..aab1a51cdd737 100644
--- a/src/librustc_codegen_ssa/mir/block.rs
+++ b/src/librustc_codegen_ssa/mir/block.rs
@@ -9,14 +9,15 @@ use crate::meth;
 use crate::traits::*;
 use crate::MemFlags;
 
+use rustc_hir::lang_items;
 use rustc_index::vec::Idx;
-use rustc_middle::middle::lang_items;
 use rustc_middle::mir;
 use rustc_middle::mir::AssertKind;
-use rustc_middle::ty::layout::{self, FnAbiExt, HasTyCtxt, LayoutOf};
+use rustc_middle::ty::layout::{FnAbiExt, HasTyCtxt};
 use rustc_middle::ty::{self, Instance, Ty, TypeFoldable};
 use rustc_span::{source_map::Span, symbol::Symbol};
 use rustc_target::abi::call::{ArgAbi, FnAbi, PassMode};
+use rustc_target::abi::{self, LayoutOf};
 use rustc_target::spec::abi::Abi;
 
 use std::borrow::Cow;
@@ -591,7 +592,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 // we can do what we like. Here, we declare that transmuting
                 // into an uninhabited type is impossible, so anything following
                 // it must be unreachable.
-                assert_eq!(fn_abi.ret.layout.abi, layout::Abi::Uninhabited);
+                assert_eq!(fn_abi.ret.layout.abi, abi::Abi::Uninhabited);
                 bx.unreachable();
             }
             return;
@@ -994,7 +995,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 // the load would just produce `OperandValue::Ref` instead
                 // of the `OperandValue::Immediate` we need for the call.
                 llval = bx.load(llval, align);
-                if let layout::Abi::Scalar(ref scalar) = arg.layout.abi {
+                if let abi::Abi::Scalar(ref scalar) = arg.layout.abi {
                     if scalar.is_bool() {
                         bx.range_metadata(llval, 0..2);
                     }
diff --git a/src/librustc_codegen_ssa/mir/constant.rs b/src/librustc_codegen_ssa/mir/constant.rs
index 9770d04aa99dd..298aa25f0321f 100644
--- a/src/librustc_codegen_ssa/mir/constant.rs
+++ b/src/librustc_codegen_ssa/mir/constant.rs
@@ -3,9 +3,10 @@ use crate::traits::*;
 use rustc_index::vec::Idx;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::{ConstValue, ErrorHandled};
-use rustc_middle::ty::layout::{self, HasTyCtxt};
+use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::source_map::Span;
+use rustc_target::abi::Abi;
 
 use super::FunctionCx;
 
@@ -87,7 +88,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         if let Some(prim) = field.try_to_scalar() {
                             let layout = bx.layout_of(field_ty);
                             let scalar = match layout.abi {
-                                layout::Abi::Scalar(ref x) => x,
+                                Abi::Scalar(ref x) => x,
                                 _ => bug!("from_const: invalid ByVal layout: {:#?}", layout),
                             };
                             bx.scalar_to_backend(prim, scalar, bx.immediate_backend_type(layout))
diff --git a/src/librustc_codegen_ssa/mir/debuginfo.rs b/src/librustc_codegen_ssa/mir/debuginfo.rs
index 4eefb37ba0d42..5501ed5128d4d 100644
--- a/src/librustc_codegen_ssa/mir/debuginfo.rs
+++ b/src/librustc_codegen_ssa/mir/debuginfo.rs
@@ -3,11 +3,10 @@ use rustc_hir::def_id::CrateNum;
 use rustc_index::vec::IndexVec;
 use rustc_middle::mir;
 use rustc_middle::ty;
-use rustc_middle::ty::layout::{LayoutOf, Size};
 use rustc_session::config::DebugInfo;
-
 use rustc_span::symbol::{kw, Symbol};
 use rustc_span::{BytePos, Span};
+use rustc_target::abi::{LayoutOf, Size};
 
 use super::operand::OperandValue;
 use super::place::PlaceRef;
diff --git a/src/librustc_codegen_ssa/mir/operand.rs b/src/librustc_codegen_ssa/mir/operand.rs
index 7545882a0eacb..69f11ed57ac5d 100644
--- a/src/librustc_codegen_ssa/mir/operand.rs
+++ b/src/librustc_codegen_ssa/mir/operand.rs
@@ -8,8 +8,9 @@ use crate::MemFlags;
 
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::{ConstValue, ErrorHandled, Pointer, Scalar};
-use rustc_middle::ty::layout::{self, Align, LayoutOf, Size, TyAndLayout};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::Ty;
+use rustc_target::abi::{Abi, Align, LayoutOf, Size};
 
 use std::fmt;
 
@@ -78,7 +79,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
         let val = match val {
             ConstValue::Scalar(x) => {
                 let scalar = match layout.abi {
-                    layout::Abi::Scalar(ref x) => x,
+                    Abi::Scalar(ref x) => x,
                     _ => bug!("from_const: invalid ByVal layout: {:#?}", layout),
                 };
                 let llval = bx.scalar_to_backend(x, scalar, bx.immediate_backend_type(layout));
@@ -86,7 +87,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
             }
             ConstValue::Slice { data, start, end } => {
                 let a_scalar = match layout.abi {
-                    layout::Abi::ScalarPair(ref a, _) => a,
+                    Abi::ScalarPair(ref a, _) => a,
                     _ => bug!("from_const: invalid ScalarPair layout: {:#?}", layout),
                 };
                 let a = Scalar::from(Pointer::new(
@@ -161,7 +162,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
         llval: V,
         layout: TyAndLayout<'tcx>,
     ) -> Self {
-        let val = if let layout::Abi::ScalarPair(ref a, ref b) = layout.abi {
+        let val = if let Abi::ScalarPair(ref a, ref b) = layout.abi {
             debug!("Operand::from_immediate_or_packed_pair: unpacking {:?} @ {:?}", llval, layout);
 
             // Deconstruct the immediate aggregate.
@@ -199,7 +200,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
             }
 
             // Extract a scalar component from a pair.
-            (OperandValue::Pair(a_llval, b_llval), &layout::Abi::ScalarPair(ref a, ref b)) => {
+            (OperandValue::Pair(a_llval, b_llval), &Abi::ScalarPair(ref a, ref b)) => {
                 if offset.bytes() == 0 {
                     assert_eq!(field.size, a.value.size(bx.cx()));
                     OperandValue::Immediate(a_llval)
@@ -211,7 +212,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> {
             }
 
             // `#[repr(simd)]` types are also immediate.
-            (OperandValue::Immediate(llval), &layout::Abi::Vector { .. }) => {
+            (OperandValue::Immediate(llval), &Abi::Vector { .. }) => {
                 OperandValue::Immediate(bx.extract_element(llval, bx.cx().const_usize(i as u64)))
             }
 
@@ -305,7 +306,7 @@ impl<'a, 'tcx, V: CodegenObject> OperandValue<V> {
             }
             OperandValue::Pair(a, b) => {
                 let (a_scalar, b_scalar) = match dest.layout.abi {
-                    layout::Abi::ScalarPair(ref a, ref b) => (a, b),
+                    Abi::ScalarPair(ref a, ref b) => (a, b),
                     _ => bug!("store_with_flags: invalid ScalarPair layout: {:#?}", dest.layout),
                 };
                 let b_offset = a_scalar.value.size(bx).align_to(b_scalar.value.align(bx).abi);
diff --git a/src/librustc_codegen_ssa/mir/place.rs b/src/librustc_codegen_ssa/mir/place.rs
index 1237e70aa36f1..9b1148df65135 100644
--- a/src/librustc_codegen_ssa/mir/place.rs
+++ b/src/librustc_codegen_ssa/mir/place.rs
@@ -8,8 +8,10 @@ use crate::MemFlags;
 
 use rustc_middle::mir;
 use rustc_middle::mir::tcx::PlaceTy;
-use rustc_middle::ty::layout::{self, Align, HasTyCtxt, LayoutOf, TyAndLayout, VariantIdx};
+use rustc_middle::ty::layout::{HasTyCtxt, TyAndLayout};
 use rustc_middle::ty::{self, Ty};
+use rustc_target::abi::{Abi, Align, DiscriminantKind, FieldPlacement, Int};
+use rustc_target::abi::{LayoutOf, VariantIdx, Variants};
 
 #[derive(Copy, Clone, Debug)]
 pub struct PlaceRef<'tcx, V> {
@@ -66,7 +68,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
     }
 
     pub fn len<Cx: ConstMethods<'tcx, Value = V>>(&self, cx: &Cx) -> V {
-        if let layout::FieldPlacement::Array { count, .. } = self.layout.fields {
+        if let FieldPlacement::Array { count, .. } = self.layout.fields {
             if self.layout.is_unsized() {
                 assert_eq!(count, 0);
                 self.llextra.unwrap()
@@ -94,7 +96,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
             // Unions and newtypes only use an offset of 0.
             let llval = if offset.bytes() == 0 {
                 self.llval
-            } else if let layout::Abi::ScalarPair(ref a, ref b) = self.layout.abi {
+            } else if let Abi::ScalarPair(ref a, ref b) = self.layout.abi {
                 // Offsets have to match either first or second field.
                 assert_eq!(offset, a.value.size(bx.cx()).align_to(b.value.align(bx.cx()).abi));
                 bx.struct_gep(self.llval, 1)
@@ -198,7 +200,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
             return bx.cx().const_undef(cast_to);
         }
         let (discr_scalar, discr_kind, discr_index) = match self.layout.variants {
-            layout::Variants::Single { index } => {
+            Variants::Single { index } => {
                 let discr_val = self
                     .layout
                     .ty
@@ -206,7 +208,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
                     .map_or(index.as_u32() as u128, |discr| discr.val);
                 return bx.cx().const_uint_big(cast_to, discr_val);
             }
-            layout::Variants::Multiple { ref discr, ref discr_kind, discr_index, .. } => {
+            Variants::Multiple { ref discr, ref discr_kind, discr_index, .. } => {
                 (discr, discr_kind, discr_index)
             }
         };
@@ -217,22 +219,18 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
 
         // Decode the discriminant (specifically if it's niche-encoded).
         match *discr_kind {
-            layout::DiscriminantKind::Tag => {
+            DiscriminantKind::Tag => {
                 let signed = match discr_scalar.value {
                     // We use `i1` for bytes that are always `0` or `1`,
                     // e.g., `#[repr(i8)] enum E { A, B }`, but we can't
                     // let LLVM interpret the `i1` as signed, because
                     // then `i1 1` (i.e., `E::B`) is effectively `i8 -1`.
-                    layout::Int(_, signed) => !discr_scalar.is_bool() && signed,
+                    Int(_, signed) => !discr_scalar.is_bool() && signed,
                     _ => false,
                 };
                 bx.intcast(encoded_discr.immediate(), cast_to, signed)
             }
-            layout::DiscriminantKind::Niche {
-                dataful_variant,
-                ref niche_variants,
-                niche_start,
-            } => {
+            DiscriminantKind::Niche { dataful_variant, ref niche_variants, niche_start } => {
                 // Rebase from niche values to discriminants, and check
                 // whether the result is in range for the niche variants.
                 let niche_llty = bx.cx().immediate_backend_type(encoded_discr.layout);
@@ -311,14 +309,10 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
             return;
         }
         match self.layout.variants {
-            layout::Variants::Single { index } => {
+            Variants::Single { index } => {
                 assert_eq!(index, variant_index);
             }
-            layout::Variants::Multiple {
-                discr_kind: layout::DiscriminantKind::Tag,
-                discr_index,
-                ..
-            } => {
+            Variants::Multiple { discr_kind: DiscriminantKind::Tag, discr_index, .. } => {
                 let ptr = self.project_field(bx, discr_index);
                 let to =
                     self.layout.ty.discriminant_for_variant(bx.tcx(), variant_index).unwrap().val;
@@ -328,9 +322,9 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
                     ptr.align,
                 );
             }
-            layout::Variants::Multiple {
+            Variants::Multiple {
                 discr_kind:
-                    layout::DiscriminantKind::Niche { dataful_variant, ref niche_variants, niche_start },
+                    DiscriminantKind::Niche { dataful_variant, ref niche_variants, niche_start },
                 discr_index,
                 ..
             } => {
diff --git a/src/librustc_codegen_ssa/mir/rvalue.rs b/src/librustc_codegen_ssa/mir/rvalue.rs
index 66ce50c482a6f..6543b33822f71 100644
--- a/src/librustc_codegen_ssa/mir/rvalue.rs
+++ b/src/librustc_codegen_ssa/mir/rvalue.rs
@@ -8,13 +8,14 @@ use crate::traits::*;
 use crate::MemFlags;
 
 use rustc_apfloat::{ieee, Float, Round, Status};
-use rustc_middle::middle::lang_items::ExchangeMallocFnLangItem;
+use rustc_hir::lang_items::ExchangeMallocFnLangItem;
 use rustc_middle::mir;
 use rustc_middle::ty::cast::{CastTy, IntTy};
-use rustc_middle::ty::layout::{self, HasTyCtxt, LayoutOf};
+use rustc_middle::ty::layout::HasTyCtxt;
 use rustc_middle::ty::{self, adjustment::PointerCast, Instance, Ty, TyCtxt};
 use rustc_span::source_map::{Span, DUMMY_SP};
 use rustc_span::symbol::sym;
+use rustc_target::abi::{Abi, Int, LayoutOf, Variants};
 
 use std::{i128, u128};
 
@@ -292,7 +293,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         let r_t_out = CastTy::from_ty(cast.ty).expect("bad output type for cast");
                         let ll_t_in = bx.cx().immediate_backend_type(operand.layout);
                         match operand.layout.variants {
-                            layout::Variants::Single { index } => {
+                            Variants::Single { index } => {
                                 if let Some(discr) =
                                     operand.layout.ty.discriminant_for_variant(bx.tcx(), index)
                                 {
@@ -311,13 +312,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                                     );
                                 }
                             }
-                            layout::Variants::Multiple { .. } => {}
+                            Variants::Multiple { .. } => {}
                         }
                         let llval = operand.immediate();
 
                         let mut signed = false;
-                        if let layout::Abi::Scalar(ref scalar) = operand.layout.abi {
-                            if let layout::Int(_, s) = scalar.value {
+                        if let Abi::Scalar(ref scalar) = operand.layout.abi {
+                            if let Int(_, s) = scalar.value {
                                 // We use `i1` for bytes that are always `0` or `1`,
                                 // e.g., `#[repr(i8)] enum E { A, B }`, but we can't
                                 // let LLVM interpret the `i1` as signed, because
diff --git a/src/librustc_codegen_ssa/traits/backend.rs b/src/librustc_codegen_ssa/traits/backend.rs
index 1474edd8aa09a..91be123beb0bc 100644
--- a/src/librustc_codegen_ssa/traits/backend.rs
+++ b/src/librustc_codegen_ssa/traits/backend.rs
@@ -3,17 +3,18 @@ use super::CodegenObject;
 use crate::ModuleCodegen;
 
 use rustc_ast::expand::allocator::AllocatorKind;
+use rustc_errors::ErrorReported;
 use rustc_middle::dep_graph::DepGraph;
 use rustc_middle::middle::cstore::{EncodedMetadata, MetadataLoaderDyn};
-use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, TyAndLayout};
+use rustc_middle::ty::layout::{HasTyCtxt, TyAndLayout};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{Ty, TyCtxt};
-use rustc_middle::util::common::ErrorReported;
 use rustc_session::{
     config::{self, OutputFilenames, PrintRequest},
     Session,
 };
 use rustc_span::symbol::Symbol;
+use rustc_target::abi::LayoutOf;
 
 pub use rustc_data_structures::sync::MetadataRef;
 
diff --git a/src/librustc_codegen_ssa/traits/builder.rs b/src/librustc_codegen_ssa/traits/builder.rs
index d59ea387b86ba..caba7ebef593b 100644
--- a/src/librustc_codegen_ssa/traits/builder.rs
+++ b/src/librustc_codegen_ssa/traits/builder.rs
@@ -12,8 +12,9 @@ use crate::mir::operand::OperandRef;
 use crate::mir::place::PlaceRef;
 use crate::MemFlags;
 
-use rustc_middle::ty::layout::{Align, HasParamEnv, Size};
+use rustc_middle::ty::layout::HasParamEnv;
 use rustc_middle::ty::Ty;
+use rustc_target::abi::{Align, Size};
 use rustc_target::spec::HasTargetSpec;
 
 use std::iter::TrustedLen;
diff --git a/src/librustc_codegen_ssa/traits/consts.rs b/src/librustc_codegen_ssa/traits/consts.rs
index e5e1aa658e62e..6b58dea794bcb 100644
--- a/src/librustc_codegen_ssa/traits/consts.rs
+++ b/src/librustc_codegen_ssa/traits/consts.rs
@@ -1,9 +1,9 @@
 use super::BackendTypes;
 use crate::mir::place::PlaceRef;
-use rustc_middle::mir::interpret::Allocation;
-use rustc_middle::mir::interpret::Scalar;
-use rustc_middle::ty::layout;
+use rustc_middle::mir::interpret::{Allocation, Scalar};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_span::Symbol;
+use rustc_target::abi::{self, Size};
 
 pub trait ConstMethods<'tcx>: BackendTypes {
     // Constant constructors
@@ -26,17 +26,12 @@ pub trait ConstMethods<'tcx>: BackendTypes {
     fn const_to_opt_uint(&self, v: Self::Value) -> Option<u64>;
     fn const_to_opt_u128(&self, v: Self::Value, sign_ext: bool) -> Option<u128>;
 
-    fn scalar_to_backend(
-        &self,
-        cv: Scalar,
-        layout: &layout::Scalar,
-        llty: Self::Type,
-    ) -> Self::Value;
+    fn scalar_to_backend(&self, cv: Scalar, layout: &abi::Scalar, llty: Self::Type) -> Self::Value;
     fn from_const_alloc(
         &self,
-        layout: layout::TyAndLayout<'tcx>,
+        layout: TyAndLayout<'tcx>,
         alloc: &Allocation,
-        offset: layout::Size,
+        offset: Size,
     ) -> PlaceRef<'tcx, Self::Value>;
 
     fn const_ptrcast(&self, val: Self::Value, ty: Self::Type) -> Self::Value;
diff --git a/src/librustc_codegen_ssa/traits/debuginfo.rs b/src/librustc_codegen_ssa/traits/debuginfo.rs
index 4e84c096822ef..34be1cfdd8844 100644
--- a/src/librustc_codegen_ssa/traits/debuginfo.rs
+++ b/src/librustc_codegen_ssa/traits/debuginfo.rs
@@ -3,10 +3,10 @@ use crate::mir::debuginfo::{FunctionDebugContext, VariableKind};
 use rustc_ast::ast::Name;
 use rustc_hir::def_id::CrateNum;
 use rustc_middle::mir;
-use rustc_middle::ty::layout::Size;
 use rustc_middle::ty::{Instance, Ty};
 use rustc_span::{SourceFile, Span};
 use rustc_target::abi::call::FnAbi;
+use rustc_target::abi::Size;
 
 pub trait DebugInfoMethods<'tcx>: BackendTypes {
     fn create_vtable_metadata(&self, ty: Ty<'tcx>, vtable: Self::Value);
diff --git a/src/librustc_codegen_ssa/traits/statics.rs b/src/librustc_codegen_ssa/traits/statics.rs
index 50df08614345f..a6462b358347b 100644
--- a/src/librustc_codegen_ssa/traits/statics.rs
+++ b/src/librustc_codegen_ssa/traits/statics.rs
@@ -1,6 +1,6 @@
 use super::BackendTypes;
 use rustc_hir::def_id::DefId;
-use rustc_middle::ty::layout::Align;
+use rustc_target::abi::Align;
 
 pub trait StaticMethods: BackendTypes {
     fn static_addr_of(&self, cv: Self::Value, align: Align, kind: Option<&str>) -> Self::Value;
diff --git a/src/librustc_codegen_ssa/traits/type_.rs b/src/librustc_codegen_ssa/traits/type_.rs
index 383be6dfcb5ea..703479b74bef8 100644
--- a/src/librustc_codegen_ssa/traits/type_.rs
+++ b/src/librustc_codegen_ssa/traits/type_.rs
@@ -3,10 +3,11 @@ use super::Backend;
 use super::HasCodegen;
 use crate::common::TypeKind;
 use crate::mir::place::PlaceRef;
-use rustc_middle::ty::layout::{self, TyAndLayout};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::DUMMY_SP;
 use rustc_target::abi::call::{ArgAbi, CastTarget, FnAbi, Reg};
+use rustc_target::abi::Integer;
 
 // This depends on `Backend` and not `BackendTypes`, because consumers will probably want to use
 // `LayoutOf` or `HasTyCtxt`. This way, they don't have to add a constraint on it themselves.
@@ -53,8 +54,8 @@ pub trait DerivedTypeMethods<'tcx>: BaseTypeMethods<'tcx> + MiscMethods<'tcx> {
         }
     }
 
-    fn type_from_integer(&self, i: layout::Integer) -> Self::Type {
-        use rustc_middle::ty::layout::Integer::*;
+    fn type_from_integer(&self, i: Integer) -> Self::Type {
+        use Integer::*;
         match i {
             I8 => self.type_i8(),
             I16 => self.type_i16(),
diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index 8f8c2eae6e27d..ccbce01d6c12e 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -22,10 +22,8 @@ use rustc_ast::ast;
 use rustc_codegen_ssa::{traits::CodegenBackend, CodegenResults};
 use rustc_data_structures::profiling::print_time_passes_entry;
 use rustc_data_structures::sync::SeqCst;
-use rustc_errors::{
-    registry::{InvalidErrorCode, Registry},
-    PResult,
-};
+use rustc_errors::registry::{InvalidErrorCode, Registry};
+use rustc_errors::{ErrorReported, PResult};
 use rustc_feature::{find_gated_cfg, UnstableFeatures};
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_interface::util::{collect_crate_types, get_builtin_codegen_backend};
@@ -34,7 +32,6 @@ use rustc_lint::LintStore;
 use rustc_metadata::locator;
 use rustc_middle::middle::cstore::MetadataLoader;
 use rustc_middle::ty::TyCtxt;
-use rustc_middle::util::common::ErrorReported;
 use rustc_save_analysis as save;
 use rustc_save_analysis::DumpHandler;
 use rustc_serialize::json::{self, ToJson};
diff --git a/src/librustc_driver/pretty.rs b/src/librustc_driver/pretty.rs
index 87777bd674bf2..78a271810b288 100644
--- a/src/librustc_driver/pretty.rs
+++ b/src/librustc_driver/pretty.rs
@@ -2,12 +2,12 @@
 
 use rustc_ast::ast;
 use rustc_ast_pretty::pprust;
+use rustc_errors::ErrorReported;
 use rustc_hir as hir;
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_hir_pretty as pprust_hir;
 use rustc_middle::hir::map as hir_map;
 use rustc_middle::ty::{self, TyCtxt};
-use rustc_middle::util::common::ErrorReported;
 use rustc_mir::util::{write_mir_graphviz, write_mir_pretty};
 use rustc_session::config::{Input, PpMode, PpSourceMode};
 use rustc_session::Session;
diff --git a/src/librustc_infer/infer/error_reporting/nice_region_error/different_lifetimes.rs b/src/librustc_infer/infer/error_reporting/nice_region_error/different_lifetimes.rs
index 3836bd9afa8b6..d206a30d526cb 100644
--- a/src/librustc_infer/infer/error_reporting/nice_region_error/different_lifetimes.rs
+++ b/src/librustc_infer/infer/error_reporting/nice_region_error/different_lifetimes.rs
@@ -5,9 +5,8 @@ use crate::infer::error_reporting::nice_region_error::util::AnonymousParamInfo;
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::infer::lexical_region_resolve::RegionResolutionError;
 use crate::infer::SubregionOrigin;
-use rustc_middle::util::common::ErrorReported;
 
-use rustc_errors::struct_span_err;
+use rustc_errors::{struct_span_err, ErrorReported};
 
 impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
     /// Print the error message for lifetime errors when both the concerned regions are anonymous.
diff --git a/src/librustc_infer/infer/error_reporting/nice_region_error/mod.rs b/src/librustc_infer/infer/error_reporting/nice_region_error/mod.rs
index 4613c43ba07af..2aed3d9a469fb 100644
--- a/src/librustc_infer/infer/error_reporting/nice_region_error/mod.rs
+++ b/src/librustc_infer/infer/error_reporting/nice_region_error/mod.rs
@@ -1,9 +1,8 @@
 use crate::infer::lexical_region_resolve::RegionResolutionError;
 use crate::infer::lexical_region_resolve::RegionResolutionError::*;
 use crate::infer::InferCtxt;
-use rustc_errors::DiagnosticBuilder;
+use rustc_errors::{DiagnosticBuilder, ErrorReported};
 use rustc_middle::ty::{self, TyCtxt};
-use rustc_middle::util::common::ErrorReported;
 use rustc_span::source_map::Span;
 
 mod different_lifetimes;
diff --git a/src/librustc_infer/infer/error_reporting/nice_region_error/outlives_closure.rs b/src/librustc_infer/infer/error_reporting/nice_region_error/outlives_closure.rs
index 028148b17db18..70c302710430b 100644
--- a/src/librustc_infer/infer/error_reporting/nice_region_error/outlives_closure.rs
+++ b/src/librustc_infer/infer/error_reporting/nice_region_error/outlives_closure.rs
@@ -4,9 +4,9 @@
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::infer::lexical_region_resolve::RegionResolutionError::SubSupConflict;
 use crate::infer::SubregionOrigin;
+use rustc_errors::ErrorReported;
 use rustc_hir::{Expr, ExprKind::Closure, Node};
 use rustc_middle::ty::RegionKind;
-use rustc_middle::util::common::ErrorReported;
 
 impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
     /// Print the error message for lifetime errors when binding escapes a closure.
diff --git a/src/librustc_infer/infer/error_reporting/nice_region_error/static_impl_trait.rs b/src/librustc_infer/infer/error_reporting/nice_region_error/static_impl_trait.rs
index 34653f2dc0db8..7f3ec852e41de 100644
--- a/src/librustc_infer/infer/error_reporting/nice_region_error/static_impl_trait.rs
+++ b/src/librustc_infer/infer/error_reporting/nice_region_error/static_impl_trait.rs
@@ -3,9 +3,8 @@
 use crate::infer::error_reporting::msg_span_from_free_region;
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::infer::lexical_region_resolve::RegionResolutionError;
-use rustc_errors::Applicability;
+use rustc_errors::{Applicability, ErrorReported};
 use rustc_middle::ty::{BoundRegion, FreeRegion, RegionKind};
-use rustc_middle::util::common::ErrorReported;
 
 impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
     /// Print the error message for lifetime errors when the return type is a static impl Trait.
diff --git a/src/librustc_infer/infer/error_reporting/nice_region_error/trait_impl_difference.rs b/src/librustc_infer/infer/error_reporting/nice_region_error/trait_impl_difference.rs
index a2cd54b48d520..695f3e47fb5d7 100644
--- a/src/librustc_infer/infer/error_reporting/nice_region_error/trait_impl_difference.rs
+++ b/src/librustc_infer/infer/error_reporting/nice_region_error/trait_impl_difference.rs
@@ -4,8 +4,8 @@ use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::infer::lexical_region_resolve::RegionResolutionError;
 use crate::infer::{Subtype, ValuePairs};
 use crate::traits::ObligationCauseCode::CompareImplMethodObligation;
+use rustc_errors::ErrorReported;
 use rustc_middle::ty::Ty;
-use rustc_middle::util::common::ErrorReported;
 use rustc_span::Span;
 
 impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
diff --git a/src/librustc_interface/interface.rs b/src/librustc_interface/interface.rs
index a50e802ac2ec6..8e929b7daa850 100644
--- a/src/librustc_interface/interface.rs
+++ b/src/librustc_interface/interface.rs
@@ -8,9 +8,9 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::Lrc;
 use rustc_data_structures::OnDrop;
 use rustc_errors::registry::Registry;
+use rustc_errors::ErrorReported;
 use rustc_lint::LintStore;
 use rustc_middle::ty;
-use rustc_middle::util::common::ErrorReported;
 use rustc_parse::new_parser_from_source_str;
 use rustc_session::config::{self, ErrorOutputType, Input, OutputFilenames};
 use rustc_session::early_error;
diff --git a/src/librustc_interface/passes.rs b/src/librustc_interface/passes.rs
index e3fc4fa52fb61..609c80a2b7905 100644
--- a/src/librustc_interface/passes.rs
+++ b/src/librustc_interface/passes.rs
@@ -9,7 +9,7 @@ use rustc_codegen_ssa::back::link::emit_metadata;
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::sync::{par_iter, Lrc, Once, ParallelIterator, WorkerLocal};
 use rustc_data_structures::{box_region_allow_access, declare_box_region_type, parallel};
-use rustc_errors::PResult;
+use rustc_errors::{ErrorReported, PResult};
 use rustc_expand::base::ExtCtxt;
 use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
 use rustc_hir::definitions::Definitions;
@@ -21,7 +21,6 @@ use rustc_middle::middle;
 use rustc_middle::middle::cstore::{CrateStore, MetadataLoader, MetadataLoaderDyn};
 use rustc_middle::ty::steal::Steal;
 use rustc_middle::ty::{self, GlobalCtxt, ResolverOutputs, TyCtxt};
-use rustc_middle::util::common::ErrorReported;
 use rustc_mir as mir;
 use rustc_mir_build as mir_build;
 use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str};
diff --git a/src/librustc_interface/queries.rs b/src/librustc_interface/queries.rs
index 995776552dd18..6a62d754f2891 100644
--- a/src/librustc_interface/queries.rs
+++ b/src/librustc_interface/queries.rs
@@ -4,6 +4,7 @@ use crate::passes::{self, BoxedResolver, QueryContext};
 use rustc_ast::{self, ast};
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::sync::{Lrc, Once, WorkerLocal};
+use rustc_errors::ErrorReported;
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_hir::Crate;
 use rustc_incremental::DepGraphFuture;
@@ -12,7 +13,6 @@ use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::DepGraph;
 use rustc_middle::ty::steal::Steal;
 use rustc_middle::ty::{GlobalCtxt, ResolverOutputs, TyCtxt};
-use rustc_middle::util::common::ErrorReported;
 use rustc_session::config::{OutputFilenames, OutputType};
 use rustc_session::{output::find_crate_name, Session};
 use rustc_span::symbol::sym;
diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs
index 646febec72334..cff86e8f21837 100644
--- a/src/librustc_lint/builtin.rs
+++ b/src/librustc_lint/builtin.rs
@@ -36,12 +36,13 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::{GenericParamKind, PatKind};
 use rustc_hir::{HirIdSet, Node};
 use rustc_middle::lint::LintDiagnosticBuilder;
-use rustc_middle::ty::{self, layout::VariantIdx, Ty, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::lint::FutureIncompatibleInfo;
 use rustc_span::edition::Edition;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::{BytePos, Span};
+use rustc_target::abi::VariantIdx;
 use rustc_trait_selection::traits::misc::can_type_implement_copy;
 
 use crate::nonstandard_style::{method_context, MethodLateContext};
diff --git a/src/librustc_lint/context.rs b/src/librustc_lint/context.rs
index 12543cf83ddb2..1747a78d36a4c 100644
--- a/src/librustc_lint/context.rs
+++ b/src/librustc_lint/context.rs
@@ -29,12 +29,13 @@ use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
 use rustc_middle::lint::LintDiagnosticBuilder;
 use rustc_middle::middle::privacy::AccessLevels;
 use rustc_middle::middle::stability;
-use rustc_middle::ty::layout::{LayoutError, LayoutOf, TyAndLayout};
+use rustc_middle::ty::layout::{LayoutError, TyAndLayout};
 use rustc_middle::ty::{self, print::Printer, subst::GenericArg, Ty, TyCtxt};
 use rustc_session::lint::{add_elided_lifetime_in_path_suggestion, BuiltinLintDiagnostics};
 use rustc_session::lint::{FutureIncompatibleInfo, Level, Lint, LintBuffer, LintId};
 use rustc_session::Session;
 use rustc_span::{symbol::Symbol, MultiSpan, Span, DUMMY_SP};
+use rustc_target::abi::LayoutOf;
 
 use std::slice;
 
diff --git a/src/librustc_lint/early.rs b/src/librustc_lint/early.rs
index 34da29c974777..018e9da243c70 100644
--- a/src/librustc_lint/early.rs
+++ b/src/librustc_lint/early.rs
@@ -104,6 +104,11 @@ impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T>
         run_early_pass!(self, check_pat_post, p);
     }
 
+    fn visit_anon_const(&mut self, c: &'a ast::AnonConst) {
+        run_early_pass!(self, check_anon_const, c);
+        ast_visit::walk_anon_const(self, c);
+    }
+
     fn visit_expr(&mut self, e: &'a ast::Expr) {
         self.with_lint_attrs(e.id, &e.attrs, |cx| {
             run_early_pass!(cx, check_expr, e);
diff --git a/src/librustc_lint/lib.rs b/src/librustc_lint/lib.rs
index 97261759aeb28..af1fad2c6608b 100644
--- a/src/librustc_lint/lib.rs
+++ b/src/librustc_lint/lib.rs
@@ -104,6 +104,7 @@ macro_rules! early_lint_passes {
             $args,
             [
                 UnusedParens: UnusedParens,
+                UnusedBraces: UnusedBraces,
                 UnusedImportBraces: UnusedImportBraces,
                 UnsafeCode: UnsafeCode,
                 AnonymousParameters: AnonymousParameters,
@@ -275,6 +276,7 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
         UNUSED_FEATURES,
         UNUSED_LABELS,
         UNUSED_PARENS,
+        UNUSED_BRACES,
         REDUNDANT_SEMICOLONS
     );
 
diff --git a/src/librustc_lint/passes.rs b/src/librustc_lint/passes.rs
index ace154714458e..c9e12afedbbab 100644
--- a/src/librustc_lint/passes.rs
+++ b/src/librustc_lint/passes.rs
@@ -170,6 +170,7 @@ macro_rules! early_lint_methods {
             fn check_stmt(a: &ast::Stmt);
             fn check_arm(a: &ast::Arm);
             fn check_pat(a: &ast::Pat);
+            fn check_anon_const(a: &ast::AnonConst);
             fn check_pat_post(a: &ast::Pat);
             fn check_expr(a: &ast::Expr);
             fn check_expr_post(a: &ast::Expr);
diff --git a/src/librustc_lint/types.rs b/src/librustc_lint/types.rs
index 52ec8cd938156..a6e1ed84c8708 100644
--- a/src/librustc_lint/types.rs
+++ b/src/librustc_lint/types.rs
@@ -10,12 +10,13 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::{is_range_literal, ExprKind, Node};
 use rustc_index::vec::Idx;
 use rustc_middle::mir::interpret::{sign_extend, truncate};
-use rustc_middle::ty::layout::{self, IntegerExt, LayoutOf, SizeSkeleton, VariantIdx};
+use rustc_middle::ty::layout::{IntegerExt, SizeSkeleton};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, AdtKind, ParamEnv, Ty, TyCtxt};
 use rustc_span::source_map;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
+use rustc_target::abi::{DiscriminantKind, Integer, LayoutOf, VariantIdx, Variants};
 use rustc_target::spec::abi::Abi;
 
 use log::debug;
@@ -150,7 +151,7 @@ fn report_bin_hex_error(
     val: u128,
     negative: bool,
 ) {
-    let size = layout::Integer::from_attr(&cx.tcx, ty).size();
+    let size = Integer::from_attr(&cx.tcx, ty).size();
     cx.struct_span_lint(OVERFLOWING_LITERALS, expr.span, |lint| {
         let (t, actually) = match ty {
             attr::IntType::SignedInt(t) => {
@@ -1034,8 +1035,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for VariantSizeDifferences {
                 | Err(ty::layout::LayoutError::SizeOverflow(_)) => return,
             };
             let (variants, tag) = match layout.variants {
-                layout::Variants::Multiple {
-                    discr_kind: layout::DiscriminantKind::Tag,
+                Variants::Multiple {
+                    discr_kind: DiscriminantKind::Tag,
                     ref discr,
                     ref variants,
                     ..
diff --git a/src/librustc_lint/unused.rs b/src/librustc_lint/unused.rs
index 78a67ae6afe73..c74b399555a8a 100644
--- a/src/librustc_lint/unused.rs
+++ b/src/librustc_lint/unused.rs
@@ -1,5 +1,7 @@
+use crate::Lint;
 use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 use rustc_ast::ast;
+use rustc_ast::ast::{ExprKind, StmtKind};
 use rustc_ast::attr;
 use rustc_ast::util::parser;
 use rustc_ast_pretty::pprust;
@@ -315,16 +317,58 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedAttributes {
     }
 }
 
-declare_lint! {
-    pub(super) UNUSED_PARENS,
-    Warn,
-    "`if`, `match`, `while` and `return` do not need parentheses"
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+enum UnusedDelimsCtx {
+    FunctionArg,
+    MethodArg,
+    AssignedValue,
+    IfCond,
+    WhileCond,
+    ForIterExpr,
+    MatchScrutineeExpr,
+    ReturnValue,
+    BlockRetValue,
+    LetScrutineeExpr,
+    ArrayLenExpr,
+    AnonConst,
 }
 
-declare_lint_pass!(UnusedParens => [UNUSED_PARENS]);
+impl From<UnusedDelimsCtx> for &'static str {
+    fn from(ctx: UnusedDelimsCtx) -> &'static str {
+        match ctx {
+            UnusedDelimsCtx::FunctionArg => "function argument",
+            UnusedDelimsCtx::MethodArg => "method argument",
+            UnusedDelimsCtx::AssignedValue => "assigned value",
+            UnusedDelimsCtx::IfCond => "`if` condition",
+            UnusedDelimsCtx::WhileCond => "`while` condition",
+            UnusedDelimsCtx::ForIterExpr => "`for` iterator expression",
+            UnusedDelimsCtx::MatchScrutineeExpr => "`match` scrutinee expression",
+            UnusedDelimsCtx::ReturnValue => "`return` value",
+            UnusedDelimsCtx::BlockRetValue => "block return value",
+            UnusedDelimsCtx::LetScrutineeExpr => "`let` scrutinee expression",
+            UnusedDelimsCtx::ArrayLenExpr | UnusedDelimsCtx::AnonConst => "const expression",
+        }
+    }
+}
 
-impl UnusedParens {
-    fn is_expr_parens_necessary(inner: &ast::Expr, followed_by_block: bool) -> bool {
+/// Used by both `UnusedParens` and `UnusedBraces` to prevent code duplication.
+trait UnusedDelimLint {
+    const DELIM_STR: &'static str;
+
+    // this cannot be a constant is it refers to a static.
+    fn lint(&self) -> &'static Lint;
+
+    fn check_unused_delims_expr(
+        &self,
+        cx: &EarlyContext<'_>,
+        value: &ast::Expr,
+        ctx: UnusedDelimsCtx,
+        followed_by_block: bool,
+        left_pos: Option<BytePos>,
+        right_pos: Option<BytePos>,
+    );
+
+    fn is_expr_delims_necessary(inner: &ast::Expr, followed_by_block: bool) -> bool {
         followed_by_block
             && match inner.kind {
                 ast::ExprKind::Ret(_) | ast::ExprKind::Break(..) => true,
@@ -332,98 +376,41 @@ impl UnusedParens {
             }
     }
 
-    fn check_unused_parens_expr(
+    fn emit_unused_delims_expr(
         &self,
         cx: &EarlyContext<'_>,
         value: &ast::Expr,
-        msg: &str,
-        followed_by_block: bool,
+        ctx: UnusedDelimsCtx,
         left_pos: Option<BytePos>,
         right_pos: Option<BytePos>,
     ) {
-        match value.kind {
-            ast::ExprKind::Paren(ref inner) => {
-                if !Self::is_expr_parens_necessary(inner, followed_by_block)
-                    && value.attrs.is_empty()
-                    && !value.span.from_expansion()
-                {
-                    let expr_text =
-                        if let Ok(snippet) = cx.sess().source_map().span_to_snippet(value.span) {
-                            snippet
-                        } else {
-                            pprust::expr_to_string(value)
-                        };
-                    let keep_space = (
-                        left_pos.map(|s| s >= value.span.lo()).unwrap_or(false),
-                        right_pos.map(|s| s <= value.span.hi()).unwrap_or(false),
-                    );
-                    Self::remove_outer_parens(cx, value.span, &expr_text, msg, keep_space);
-                }
-            }
-            ast::ExprKind::Let(_, ref expr) => {
-                // FIXME(#60336): Properly handle `let true = (false && true)`
-                // actually needing the parenthesis.
-                self.check_unused_parens_expr(
-                    cx,
-                    expr,
-                    "`let` head expression",
-                    followed_by_block,
-                    None,
-                    None,
-                );
-            }
-            _ => {}
-        }
+        let expr_text = if let Ok(snippet) = cx.sess().source_map().span_to_snippet(value.span) {
+            snippet
+        } else {
+            pprust::expr_to_string(value)
+        };
+        let keep_space = (
+            left_pos.map(|s| s >= value.span.lo()).unwrap_or(false),
+            right_pos.map(|s| s <= value.span.hi()).unwrap_or(false),
+        );
+        self.emit_unused_delims(cx, value.span, &expr_text, ctx.into(), keep_space);
     }
 
-    fn check_unused_parens_pat(
+    fn emit_unused_delims(
         &self,
-        cx: &EarlyContext<'_>,
-        value: &ast::Pat,
-        avoid_or: bool,
-        avoid_mut: bool,
-    ) {
-        use ast::{BindingMode, Mutability, PatKind};
-
-        if let PatKind::Paren(inner) = &value.kind {
-            match inner.kind {
-                // The lint visitor will visit each subpattern of `p`. We do not want to lint
-                // any range pattern no matter where it occurs in the pattern. For something like
-                // `&(a..=b)`, there is a recursive `check_pat` on `a` and `b`, but we will assume
-                // that if there are unnecessary parens they serve a purpose of readability.
-                PatKind::Range(..) => return,
-                // Avoid `p0 | .. | pn` if we should.
-                PatKind::Or(..) if avoid_or => return,
-                // Avoid `mut x` and `mut x @ p` if we should:
-                PatKind::Ident(BindingMode::ByValue(Mutability::Mut), ..) if avoid_mut => return,
-                // Otherwise proceed with linting.
-                _ => {}
-            }
-
-            let pattern_text =
-                if let Ok(snippet) = cx.sess().source_map().span_to_snippet(value.span) {
-                    snippet
-                } else {
-                    pprust::pat_to_string(value)
-                };
-            Self::remove_outer_parens(cx, value.span, &pattern_text, "pattern", (false, false));
-        }
-    }
-
-    fn remove_outer_parens(
         cx: &EarlyContext<'_>,
         span: Span,
         pattern: &str,
         msg: &str,
         keep_space: (bool, bool),
     ) {
-        cx.struct_span_lint(UNUSED_PARENS, span, |lint| {
-            let span_msg = format!("unnecessary parentheses around {}", msg);
+        cx.struct_span_lint(self.lint(), span, |lint| {
+            let span_msg = format!("unnecessary {} around {}", Self::DELIM_STR, msg);
             let mut err = lint.build(&span_msg);
             let mut ate_left_paren = false;
             let mut ate_right_paren = false;
             let parens_removed = pattern.trim_matches(|c| match c {
-                '(' => {
+                '(' | '{' => {
                     if ate_left_paren {
                         false
                     } else {
@@ -431,7 +418,7 @@ impl UnusedParens {
                         true
                     }
                 }
-                ')' => {
+                ')' | '}' => {
                     if ate_right_paren {
                         false
                     } else {
@@ -457,61 +444,51 @@ impl UnusedParens {
                 replace
             };
 
-            err.span_suggestion_short(
-                span,
-                "remove these parentheses",
-                replace,
-                Applicability::MachineApplicable,
-            );
+            let suggestion = format!("remove these {}", Self::DELIM_STR);
+
+            err.span_suggestion_short(span, &suggestion, replace, Applicability::MachineApplicable);
             err.emit();
         });
     }
-}
 
-impl EarlyLintPass for UnusedParens {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
         use rustc_ast::ast::ExprKind::*;
-        let (value, msg, followed_by_block, left_pos, right_pos) = match e.kind {
-            Let(ref pat, ..) => {
-                self.check_unused_parens_pat(cx, pat, false, false);
-                return;
-            }
-
+        let (value, ctx, followed_by_block, left_pos, right_pos) = match e.kind {
             If(ref cond, ref block, ..) => {
                 let left = e.span.lo() + rustc_span::BytePos(2);
                 let right = block.span.lo();
-                (cond, "`if` condition", true, Some(left), Some(right))
+                (cond, UnusedDelimsCtx::IfCond, true, Some(left), Some(right))
             }
 
             While(ref cond, ref block, ..) => {
                 let left = e.span.lo() + rustc_span::BytePos(5);
                 let right = block.span.lo();
-                (cond, "`while` condition", true, Some(left), Some(right))
+                (cond, UnusedDelimsCtx::WhileCond, true, Some(left), Some(right))
             }
 
-            ForLoop(ref pat, ref cond, ref block, ..) => {
-                self.check_unused_parens_pat(cx, pat, false, false);
-                (cond, "`for` head expression", true, None, Some(block.span.lo()))
+            ForLoop(_, ref cond, ref block, ..) => {
+                (cond, UnusedDelimsCtx::ForIterExpr, true, None, Some(block.span.lo()))
             }
 
             Match(ref head, _) => {
                 let left = e.span.lo() + rustc_span::BytePos(5);
-                (head, "`match` head expression", true, Some(left), None)
+                (head, UnusedDelimsCtx::MatchScrutineeExpr, true, Some(left), None)
             }
 
             Ret(Some(ref value)) => {
                 let left = e.span.lo() + rustc_span::BytePos(3);
-                (value, "`return` value", false, Some(left), None)
+                (value, UnusedDelimsCtx::ReturnValue, false, Some(left), None)
             }
 
-            Assign(_, ref value, _) => (value, "assigned value", false, None, None),
-            AssignOp(.., ref value) => (value, "assigned value", false, None, None),
+            Assign(_, ref value, _) | AssignOp(.., ref value) => {
+                (value, UnusedDelimsCtx::AssignedValue, false, None, None)
+            }
             // either function/method call, or something this lint doesn't care about
             ref call_or_other => {
-                let (args_to_check, call_kind) = match *call_or_other {
-                    Call(_, ref args) => (&args[..], "function"),
-                    // first "argument" is self (which sometimes needs parens)
-                    MethodCall(_, ref args) => (&args[1..], "method"),
+                let (args_to_check, ctx) = match *call_or_other {
+                    Call(_, ref args) => (&args[..], UnusedDelimsCtx::FunctionArg),
+                    // first "argument" is self (which sometimes needs delims)
+                    MethodCall(_, ref args) => (&args[1..], UnusedDelimsCtx::MethodArg),
                     // actual catch-all arm
                     _ => {
                         return;
@@ -524,14 +501,152 @@ impl EarlyLintPass for UnusedParens {
                 if e.span.ctxt().outer_expn_data().call_site.from_expansion() {
                     return;
                 }
-                let msg = format!("{} argument", call_kind);
                 for arg in args_to_check {
-                    self.check_unused_parens_expr(cx, arg, &msg, false, None, None);
+                    self.check_unused_delims_expr(cx, arg, ctx, false, None, None);
                 }
                 return;
             }
         };
-        self.check_unused_parens_expr(cx, &value, msg, followed_by_block, left_pos, right_pos);
+        self.check_unused_delims_expr(cx, &value, ctx, followed_by_block, left_pos, right_pos);
+    }
+
+    fn check_stmt(&mut self, cx: &EarlyContext<'_>, s: &ast::Stmt) {
+        match s.kind {
+            StmtKind::Local(ref local) => {
+                if let Some(ref value) = local.init {
+                    self.check_unused_delims_expr(
+                        cx,
+                        &value,
+                        UnusedDelimsCtx::AssignedValue,
+                        false,
+                        None,
+                        None,
+                    );
+                }
+            }
+            StmtKind::Expr(ref expr) => {
+                self.check_unused_delims_expr(
+                    cx,
+                    &expr,
+                    UnusedDelimsCtx::BlockRetValue,
+                    false,
+                    None,
+                    None,
+                );
+            }
+            _ => {}
+        }
+    }
+
+    fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
+        use ast::ItemKind::*;
+
+        if let Const(.., Some(expr)) | Static(.., Some(expr)) = &item.kind {
+            self.check_unused_delims_expr(
+                cx,
+                expr,
+                UnusedDelimsCtx::AssignedValue,
+                false,
+                None,
+                None,
+            );
+        }
+    }
+}
+
+declare_lint! {
+    pub(super) UNUSED_PARENS,
+    Warn,
+    "`if`, `match`, `while` and `return` do not need parentheses"
+}
+
+declare_lint_pass!(UnusedParens => [UNUSED_PARENS]);
+
+impl UnusedDelimLint for UnusedParens {
+    const DELIM_STR: &'static str = "parentheses";
+
+    fn lint(&self) -> &'static Lint {
+        UNUSED_PARENS
+    }
+
+    fn check_unused_delims_expr(
+        &self,
+        cx: &EarlyContext<'_>,
+        value: &ast::Expr,
+        ctx: UnusedDelimsCtx,
+        followed_by_block: bool,
+        left_pos: Option<BytePos>,
+        right_pos: Option<BytePos>,
+    ) {
+        match value.kind {
+            ast::ExprKind::Paren(ref inner) => {
+                if !Self::is_expr_delims_necessary(inner, followed_by_block)
+                    && value.attrs.is_empty()
+                    && !value.span.from_expansion()
+                {
+                    self.emit_unused_delims_expr(cx, value, ctx, left_pos, right_pos)
+                }
+            }
+            ast::ExprKind::Let(_, ref expr) => {
+                // FIXME(#60336): Properly handle `let true = (false && true)`
+                // actually needing the parenthesis.
+                self.check_unused_delims_expr(
+                    cx,
+                    expr,
+                    UnusedDelimsCtx::LetScrutineeExpr,
+                    followed_by_block,
+                    None,
+                    None,
+                );
+            }
+            _ => {}
+        }
+    }
+}
+
+impl UnusedParens {
+    fn check_unused_parens_pat(
+        &self,
+        cx: &EarlyContext<'_>,
+        value: &ast::Pat,
+        avoid_or: bool,
+        avoid_mut: bool,
+    ) {
+        use ast::{BindingMode, Mutability, PatKind};
+
+        if let PatKind::Paren(inner) = &value.kind {
+            match inner.kind {
+                // The lint visitor will visit each subpattern of `p`. We do not want to lint
+                // any range pattern no matter where it occurs in the pattern. For something like
+                // `&(a..=b)`, there is a recursive `check_pat` on `a` and `b`, but we will assume
+                // that if there are unnecessary parens they serve a purpose of readability.
+                PatKind::Range(..) => return,
+                // Avoid `p0 | .. | pn` if we should.
+                PatKind::Or(..) if avoid_or => return,
+                // Avoid `mut x` and `mut x @ p` if we should:
+                PatKind::Ident(BindingMode::ByValue(Mutability::Mut), ..) if avoid_mut => return,
+                // Otherwise proceed with linting.
+                _ => {}
+            }
+
+            let pattern_text =
+                if let Ok(snippet) = cx.sess().source_map().span_to_snippet(value.span) {
+                    snippet
+                } else {
+                    pprust::pat_to_string(value)
+                };
+            self.emit_unused_delims(cx, value.span, &pattern_text, "pattern", (false, false));
+        }
+    }
+}
+
+impl EarlyLintPass for UnusedParens {
+    fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
+        if let ExprKind::Let(ref pat, ..) | ExprKind::ForLoop(ref pat, ..) = e.kind {
+            self.check_unused_parens_pat(cx, pat, false, false);
+        }
+
+        <Self as UnusedDelimLint>::check_expr(self, cx, e)
     }
 
     fn check_pat(&mut self, cx: &EarlyContext<'_>, p: &ast::Pat) {
@@ -556,22 +671,16 @@ impl EarlyLintPass for UnusedParens {
         }
     }
 
-    fn check_stmt(&mut self, cx: &EarlyContext<'_>, s: &ast::Stmt) {
-        use ast::StmtKind::*;
-
-        match s.kind {
-            Local(ref local) => {
-                self.check_unused_parens_pat(cx, &local.pat, false, false);
+    fn check_anon_const(&mut self, cx: &EarlyContext<'_>, c: &ast::AnonConst) {
+        self.check_unused_delims_expr(cx, &c.value, UnusedDelimsCtx::AnonConst, false, None, None);
+    }
 
-                if let Some(ref value) = local.init {
-                    self.check_unused_parens_expr(cx, &value, "assigned value", false, None, None);
-                }
-            }
-            Expr(ref expr) => {
-                self.check_unused_parens_expr(cx, &expr, "block return value", false, None, None);
-            }
-            _ => {}
+    fn check_stmt(&mut self, cx: &EarlyContext<'_>, s: &ast::Stmt) {
+        if let StmtKind::Local(ref local) = s.kind {
+            self.check_unused_parens_pat(cx, &local.pat, false, false);
         }
+
+        <Self as UnusedDelimLint>::check_stmt(self, cx, s)
     }
 
     fn check_param(&mut self, cx: &EarlyContext<'_>, param: &ast::Param) {
@@ -587,6 +696,16 @@ impl EarlyLintPass for UnusedParens {
             match &r.kind {
                 &ast::TyKind::TraitObject(..) => {}
                 &ast::TyKind::ImplTrait(_, ref bounds) if bounds.len() > 1 => {}
+                &ast::TyKind::Array(_, ref len) => {
+                    self.check_unused_delims_expr(
+                        cx,
+                        &len.value,
+                        UnusedDelimsCtx::ArrayLenExpr,
+                        false,
+                        None,
+                        None,
+                    );
+                }
                 _ => {
                     let pattern_text =
                         if let Ok(snippet) = cx.sess().source_map().span_to_snippet(ty.span) {
@@ -595,19 +714,134 @@ impl EarlyLintPass for UnusedParens {
                             pprust::ty_to_string(ty)
                         };
 
-                    Self::remove_outer_parens(cx, ty.span, &pattern_text, "type", (false, false));
+                    self.emit_unused_delims(cx, ty.span, &pattern_text, "type", (false, false));
                 }
             }
         }
     }
 
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
-        use ast::ItemKind::*;
+        <Self as UnusedDelimLint>::check_item(self, cx, item)
+    }
+}
 
-        if let Const(.., Some(expr)) | Static(.., Some(expr)) = &item.kind {
-            self.check_unused_parens_expr(cx, expr, "assigned value", false, None, None);
+declare_lint! {
+    pub(super) UNUSED_BRACES,
+    Warn,
+    "unnecessary braces around an expression"
+}
+
+declare_lint_pass!(UnusedBraces => [UNUSED_BRACES]);
+
+impl UnusedDelimLint for UnusedBraces {
+    const DELIM_STR: &'static str = "braces";
+
+    fn lint(&self) -> &'static Lint {
+        UNUSED_BRACES
+    }
+
+    fn check_unused_delims_expr(
+        &self,
+        cx: &EarlyContext<'_>,
+        value: &ast::Expr,
+        ctx: UnusedDelimsCtx,
+        followed_by_block: bool,
+        left_pos: Option<BytePos>,
+        right_pos: Option<BytePos>,
+    ) {
+        match value.kind {
+            ast::ExprKind::Block(ref inner, None)
+                if inner.rules == ast::BlockCheckMode::Default =>
+            {
+                // emit a warning under the following conditions:
+                //
+                // - the block does not have a label
+                // - the block is not `unsafe`
+                // - the block contains exactly one expression (do not lint `{ expr; }`)
+                // - `followed_by_block` is true and the internal expr may contain a `{`
+                // - the block is not multiline (do not lint multiline match arms)
+                //      ```
+                //      match expr {
+                //          Pattern => {
+                //              somewhat_long_expression
+                //          }
+                //          // ...
+                //      }
+                //      ```
+                // - the block has no attribute and was not created inside a macro
+                // - if the block is an `anon_const`, the inner expr must be a literal
+                //      (do not lint `struct A<const N: usize>; let _: A<{ 2 + 3 }>;`)
+                //
+                // FIXME(const_generics): handle paths when #67075 is fixed.
+                if let [stmt] = inner.stmts.as_slice() {
+                    if let ast::StmtKind::Expr(ref expr) = stmt.kind {
+                        if !Self::is_expr_delims_necessary(expr, followed_by_block)
+                            && (ctx != UnusedDelimsCtx::AnonConst
+                                || matches!(expr.kind, ast::ExprKind::Lit(_)))
+                            // array length expressions are checked during `check_anon_const` and `check_ty`,
+                            // once as `ArrayLenExpr` and once as `AnonConst`.
+                            //
+                            // As we do not want to lint this twice, we do not emit an error for
+                            // `ArrayLenExpr` if `AnonConst` would do the same.
+                            && (ctx != UnusedDelimsCtx::ArrayLenExpr
+                                || !matches!(expr.kind, ast::ExprKind::Lit(_)))
+                            && !cx.sess().source_map().is_multiline(value.span)
+                            && value.attrs.is_empty()
+                            && !value.span.from_expansion()
+                        {
+                            self.emit_unused_delims_expr(cx, value, ctx, left_pos, right_pos)
+                        }
+                    }
+                }
+            }
+            ast::ExprKind::Let(_, ref expr) => {
+                // FIXME(#60336): Properly handle `let true = (false && true)`
+                // actually needing the parenthesis.
+                self.check_unused_delims_expr(
+                    cx,
+                    expr,
+                    UnusedDelimsCtx::LetScrutineeExpr,
+                    followed_by_block,
+                    None,
+                    None,
+                );
+            }
+            _ => {}
+        }
+    }
+}
+
+impl EarlyLintPass for UnusedBraces {
+    fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
+        <Self as UnusedDelimLint>::check_expr(self, cx, e)
+    }
+
+    fn check_anon_const(&mut self, cx: &EarlyContext<'_>, c: &ast::AnonConst) {
+        self.check_unused_delims_expr(cx, &c.value, UnusedDelimsCtx::AnonConst, false, None, None);
+    }
+
+    fn check_stmt(&mut self, cx: &EarlyContext<'_>, s: &ast::Stmt) {
+        <Self as UnusedDelimLint>::check_stmt(self, cx, s)
+    }
+
+    fn check_ty(&mut self, cx: &EarlyContext<'_>, ty: &ast::Ty) {
+        if let &ast::TyKind::Paren(ref r) = &ty.kind {
+            if let ast::TyKind::Array(_, ref len) = r.kind {
+                self.check_unused_delims_expr(
+                    cx,
+                    &len.value,
+                    UnusedDelimsCtx::ArrayLenExpr,
+                    false,
+                    None,
+                    None,
+                );
+            }
         }
     }
+
+    fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
+        <Self as UnusedDelimLint>::check_item(self, cx, item)
+    }
 }
 
 declare_lint! {
diff --git a/src/librustc_macros/src/query.rs b/src/librustc_macros/src/query.rs
index 08dc854e9ff59..7ed77304a90e1 100644
--- a/src/librustc_macros/src/query.rs
+++ b/src/librustc_macros/src/query.rs
@@ -356,9 +356,11 @@ fn add_query_description_impl(
                 quote! { #t }
             })
             .unwrap_or(quote! { _ });
+        // expr is a `Block`, meaning that `{ #expr }` gets expanded
+        // to `{ { stmts... } }`, which triggers the `unused_braces` lint.
         quote! {
             #[inline]
-            #[allow(unused_variables)]
+            #[allow(unused_variables, unused_braces)]
             fn cache_on_disk(
                 #tcx: TyCtxt<'tcx>,
                 #key: Self::Key,
diff --git a/src/librustc_metadata/rmeta/decoder.rs b/src/librustc_metadata/rmeta/decoder.rs
index 004c5f2ebb7f4..1cb5dcb465c72 100644
--- a/src/librustc_metadata/rmeta/decoder.rs
+++ b/src/librustc_metadata/rmeta/decoder.rs
@@ -18,13 +18,13 @@ use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc_hir::definitions::DefPathTable;
 use rustc_hir::definitions::{DefKey, DefPath, DefPathData, DefPathHash};
+use rustc_hir::lang_items;
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_middle::dep_graph::{self, DepNode, DepNodeExt, DepNodeIndex};
 use rustc_middle::hir::exports::Export;
 use rustc_middle::middle::cstore::{CrateSource, ExternCrate};
 use rustc_middle::middle::cstore::{ForeignModule, LinkagePreference, NativeLibrary};
 use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
-use rustc_middle::middle::lang_items;
 use rustc_middle::mir::interpret::{AllocDecodingSession, AllocDecodingState};
 use rustc_middle::mir::{self, interpret, BodyAndCache, Promoted};
 use rustc_middle::ty::codec::TyDecoder;
diff --git a/src/librustc_metadata/rmeta/encoder.rs b/src/librustc_metadata/rmeta/encoder.rs
index f6e2730cb5761..417c548690779 100644
--- a/src/librustc_metadata/rmeta/encoder.rs
+++ b/src/librustc_metadata/rmeta/encoder.rs
@@ -15,6 +15,7 @@ use rustc_hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX,
 use rustc_hir::definitions::DefPathTable;
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
 use rustc_hir::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor};
+use rustc_hir::lang_items;
 use rustc_hir::{AnonConst, GenericParamKind};
 use rustc_index::vec::Idx;
 use rustc_middle::hir::map::Map;
@@ -25,17 +26,16 @@ use rustc_middle::middle::dependency_format::Linkage;
 use rustc_middle::middle::exported_symbols::{
     metadata_symbol_name, ExportedSymbol, SymbolExportLevel,
 };
-use rustc_middle::middle::lang_items;
 use rustc_middle::mir::{self, interpret};
 use rustc_middle::traits::specialization_graph;
 use rustc_middle::ty::codec::{self as ty_codec, TyEncoder};
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::{self, SymbolName, Ty, TyCtxt};
 use rustc_serialize::{opaque, Encodable, Encoder, SpecializedEncoder};
 use rustc_session::config::{self, CrateType};
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::{self, ExternalSource, FileName, SourceFile, Span};
+use rustc_target::abi::VariantIdx;
 use std::hash::Hash;
 use std::num::NonZeroUsize;
 use std::path::Path;
diff --git a/src/librustc_metadata/rmeta/mod.rs b/src/librustc_metadata/rmeta/mod.rs
index d0ad76b0fc7ea..d6260c536aa18 100644
--- a/src/librustc_metadata/rmeta/mod.rs
+++ b/src/librustc_metadata/rmeta/mod.rs
@@ -8,11 +8,11 @@ use rustc_data_structures::sync::MetadataRef;
 use rustc_hir as hir;
 use rustc_hir::def::CtorKind;
 use rustc_hir::def_id::{DefId, DefIndex};
+use rustc_hir::lang_items;
 use rustc_index::vec::IndexVec;
 use rustc_middle::hir::exports::Export;
 use rustc_middle::middle::cstore::{DepKind, ForeignModule, LinkagePreference, NativeLibrary};
 use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
-use rustc_middle::middle::lang_items;
 use rustc_middle::mir;
 use rustc_middle::ty::{self, ReprOptions, Ty};
 use rustc_serialize::opaque::Encoder;
diff --git a/src/librustc_middle/arena.rs b/src/librustc_middle/arena.rs
index fcf6989043a54..e3dec59478c1f 100644
--- a/src/librustc_middle/arena.rs
+++ b/src/librustc_middle/arena.rs
@@ -11,7 +11,7 @@
 macro_rules! arena_types {
     ($macro:path, $args:tt, $tcx:lifetime) => (
         $macro!($args, [
-            [] layouts: rustc_middle::ty::layout::Layout,
+            [] layouts: rustc_target::abi::Layout,
             [] generics: rustc_middle::ty::Generics,
             [] trait_def: rustc_middle::ty::TraitDef,
             [] adt_def: rustc_middle::ty::AdtDef,
@@ -106,7 +106,7 @@ macro_rules! arena_types {
                 String
             >,
             [few] get_lib_features: rustc_middle::middle::lib_features::LibFeatures,
-            [few] defined_lib_features: rustc_middle::middle::lang_items::LanguageItems,
+            [few] defined_lib_features: rustc_hir::lang_items::LanguageItems,
             [few] visible_parent_map: rustc_hir::def_id::DefIdMap<rustc_hir::def_id::DefId>,
             [few] foreign_module: rustc_middle::middle::cstore::ForeignModule,
             [few] foreign_modules: Vec<rustc_middle::middle::cstore::ForeignModule>,
diff --git a/src/librustc_middle/ich/mod.rs b/src/librustc_middle/ich/mod.rs
index 516e3ed979c7c..c8fb2bf39cc80 100644
--- a/src/librustc_middle/ich/mod.rs
+++ b/src/librustc_middle/ich/mod.rs
@@ -4,7 +4,6 @@ pub use self::hcx::{
     hash_stable_trait_impls, NodeIdHashingMode, StableHashingContext, StableHashingContextProvider,
 };
 use rustc_span::symbol::{sym, Symbol};
-pub use rustc_span::CachingSourceMapView;
 
 mod hcx;
 
diff --git a/src/librustc_middle/middle/lang_items.rs b/src/librustc_middle/middle/lang_items.rs
index 36560371587a5..0f98c338c16b1 100644
--- a/src/librustc_middle/middle/lang_items.rs
+++ b/src/librustc_middle/middle/lang_items.rs
@@ -7,17 +7,13 @@
 //! * Traits that represent operators; e.g., `Add`, `Sub`, `Index`.
 //! * Functions called by the compiler itself.
 
-pub use self::LangItem::*;
-
 use crate::ty::{self, TyCtxt};
 
 use rustc_hir::def_id::DefId;
+use rustc_hir::LangItem;
 use rustc_span::Span;
 use rustc_target::spec::PanicStrategy;
 
-pub use rustc_hir::weak_lang_items::link_name;
-pub use rustc_hir::{LangItem, LanguageItems};
-
 impl<'tcx> TyCtxt<'tcx> {
     /// Returns the `DefId` for a given `LangItem`.
     /// If not found, fatally aborts compilation.
diff --git a/src/librustc_middle/mir/interpret/allocation.rs b/src/librustc_middle/mir/interpret/allocation.rs
index 0e75f34629e0e..8b9f09774853a 100644
--- a/src/librustc_middle/mir/interpret/allocation.rs
+++ b/src/librustc_middle/mir/interpret/allocation.rs
@@ -7,14 +7,12 @@ use std::ops::{Deref, DerefMut, Range};
 
 use rustc_ast::ast::Mutability;
 use rustc_data_structures::sorted_map::SortedMap;
-use rustc_target::abi::HasDataLayout;
+use rustc_target::abi::{Align, HasDataLayout, Size};
 
 use super::{
     read_target_uint, write_target_uint, AllocId, InterpResult, Pointer, Scalar, ScalarMaybeUndef,
 };
 
-use crate::ty::layout::{Align, Size};
-
 // NOTE: When adding new fields, make sure to adjust the `Snapshot` impl in
 // `src/librustc_mir/interpret/snapshot.rs`.
 #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
diff --git a/src/librustc_middle/mir/interpret/error.rs b/src/librustc_middle/mir/interpret/error.rs
index c46ab89d0049c..135665ee012a9 100644
--- a/src/librustc_middle/mir/interpret/error.rs
+++ b/src/librustc_middle/mir/interpret/error.rs
@@ -1,7 +1,7 @@
 use super::{AllocId, CheckInAllocMsg, Pointer, RawConst, ScalarMaybeUndef};
 
 use crate::mir::interpret::ConstValue;
-use crate::ty::layout::{Align, LayoutError, Size};
+use crate::ty::layout::LayoutError;
 use crate::ty::query::TyCtxtAt;
 use crate::ty::tls;
 use crate::ty::{self, layout, Ty};
@@ -14,6 +14,7 @@ use rustc_hir::definitions::DefPathData;
 use rustc_macros::HashStable;
 use rustc_session::CtfeBacktrace;
 use rustc_span::{def_id::DefId, Pos, Span};
+use rustc_target::abi::{Align, Size};
 use std::{any::Any, fmt, mem};
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, HashStable, RustcEncodable, RustcDecodable)]
diff --git a/src/librustc_middle/mir/interpret/mod.rs b/src/librustc_middle/mir/interpret/mod.rs
index 10c3a06da0810..96bf694d8fa67 100644
--- a/src/librustc_middle/mir/interpret/mod.rs
+++ b/src/librustc_middle/mir/interpret/mod.rs
@@ -109,10 +109,10 @@ use rustc_data_structures::tiny_list::TinyList;
 use rustc_hir::def_id::DefId;
 use rustc_macros::HashStable;
 use rustc_serialize::{Decodable, Encodable, Encoder};
+use rustc_target::abi::{Endian, Size};
 
 use crate::mir;
 use crate::ty::codec::TyDecoder;
-use crate::ty::layout::{self, Size};
 use crate::ty::subst::GenericArgKind;
 use crate::ty::{self, Instance, Ty, TyCtxt};
 
@@ -521,22 +521,22 @@ impl<'tcx> AllocMap<'tcx> {
 
 #[inline]
 pub fn write_target_uint(
-    endianness: layout::Endian,
+    endianness: Endian,
     mut target: &mut [u8],
     data: u128,
 ) -> Result<(), io::Error> {
     let len = target.len();
     match endianness {
-        layout::Endian::Little => target.write_uint128::<LittleEndian>(data, len),
-        layout::Endian::Big => target.write_uint128::<BigEndian>(data, len),
+        Endian::Little => target.write_uint128::<LittleEndian>(data, len),
+        Endian::Big => target.write_uint128::<BigEndian>(data, len),
     }
 }
 
 #[inline]
-pub fn read_target_uint(endianness: layout::Endian, mut source: &[u8]) -> Result<u128, io::Error> {
+pub fn read_target_uint(endianness: Endian, mut source: &[u8]) -> Result<u128, io::Error> {
     match endianness {
-        layout::Endian::Little => source.read_uint128::<LittleEndian>(source.len()),
-        layout::Endian::Big => source.read_uint128::<BigEndian>(source.len()),
+        Endian::Little => source.read_uint128::<LittleEndian>(source.len()),
+        Endian::Big => source.read_uint128::<BigEndian>(source.len()),
     }
 }
 
diff --git a/src/librustc_middle/mir/interpret/pointer.rs b/src/librustc_middle/mir/interpret/pointer.rs
index d22207bd81651..7549d902dfbfe 100644
--- a/src/librustc_middle/mir/interpret/pointer.rs
+++ b/src/librustc_middle/mir/interpret/pointer.rs
@@ -1,8 +1,7 @@
 use super::{AllocId, InterpResult};
 
-use crate::ty::layout::{self, HasDataLayout, Size};
-
 use rustc_macros::HashStable;
+use rustc_target::abi::{HasDataLayout, Size};
 
 use std::convert::TryFrom;
 use std::fmt::{self, Display};
@@ -37,7 +36,7 @@ impl Display for CheckInAllocMsg {
 // Pointer arithmetic
 ////////////////////////////////////////////////////////////////////////////////
 
-pub trait PointerArithmetic: layout::HasDataLayout {
+pub trait PointerArithmetic: HasDataLayout {
     // These are not supposed to be overridden.
 
     #[inline(always)]
@@ -100,7 +99,7 @@ pub trait PointerArithmetic: layout::HasDataLayout {
     }
 }
 
-impl<T: layout::HasDataLayout> PointerArithmetic for T {}
+impl<T: HasDataLayout> PointerArithmetic for T {}
 
 /// `Pointer` is generic over the type that represents a reference to `Allocation`s,
 /// thus making it possible for the most convenient representation to be used in
diff --git a/src/librustc_middle/mir/interpret/value.rs b/src/librustc_middle/mir/interpret/value.rs
index bf4ee8488238f..f3c1c87dad484 100644
--- a/src/librustc_middle/mir/interpret/value.rs
+++ b/src/librustc_middle/mir/interpret/value.rs
@@ -6,12 +6,9 @@ use rustc_apfloat::{
     Float,
 };
 use rustc_macros::HashStable;
-use rustc_target::abi::TargetDataLayout;
+use rustc_target::abi::{HasDataLayout, Size, TargetDataLayout};
 
-use crate::ty::{
-    layout::{HasDataLayout, Size},
-    ParamEnv, Ty, TyCtxt,
-};
+use crate::ty::{ParamEnv, Ty, TyCtxt};
 
 use super::{sign_extend, truncate, AllocId, Allocation, InterpResult, Pointer, PointerArithmetic};
 
diff --git a/src/librustc_middle/mir/mod.rs b/src/librustc_middle/mir/mod.rs
index 9ba9d816d0f3f..20ac2970ad3a5 100644
--- a/src/librustc_middle/mir/mod.rs
+++ b/src/librustc_middle/mir/mod.rs
@@ -6,7 +6,6 @@ use crate::mir::interpret::{GlobalAlloc, Scalar};
 use crate::mir::visit::MirVisitable;
 use crate::ty::adjustment::PointerCast;
 use crate::ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
-use crate::ty::layout::VariantIdx;
 use crate::ty::print::{FmtPrinter, Printer};
 use crate::ty::subst::{Subst, SubstsRef};
 use crate::ty::{
@@ -16,6 +15,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, Namespace};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{self, GeneratorKind};
+use rustc_target::abi::VariantIdx;
 
 use polonius_engine::Atom;
 pub use rustc_ast::ast::Mutability;
diff --git a/src/librustc_middle/mir/tcx.rs b/src/librustc_middle/mir/tcx.rs
index feb6631926712..06b27c5e8b329 100644
--- a/src/librustc_middle/mir/tcx.rs
+++ b/src/librustc_middle/mir/tcx.rs
@@ -4,11 +4,11 @@
  */
 
 use crate::mir::*;
-use crate::ty::layout::VariantIdx;
 use crate::ty::subst::Subst;
 use crate::ty::util::IntTypeExt;
 use crate::ty::{self, Ty, TyCtxt};
 use rustc_hir as hir;
+use rustc_target::abi::VariantIdx;
 
 #[derive(Copy, Clone, Debug, TypeFoldable)]
 pub struct PlaceTy<'tcx> {
diff --git a/src/librustc_middle/query/mod.rs b/src/librustc_middle/query/mod.rs
index c1ece6275092d..2ffbbfb1762d3 100644
--- a/src/librustc_middle/query/mod.rs
+++ b/src/librustc_middle/query/mod.rs
@@ -738,7 +738,7 @@ rustc_queries! {
 
         query layout_raw(
             env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>
-        ) -> Result<&'tcx ty::layout::Layout, ty::layout::LayoutError<'tcx>> {
+        ) -> Result<&'tcx rustc_target::abi::Layout, ty::layout::LayoutError<'tcx>> {
             desc { "computing layout of `{}`", env.value }
         }
     }
diff --git a/src/librustc_middle/ty/context.rs b/src/librustc_middle/ty/context.rs
index be889f66228d5..95d0c758d08de 100644
--- a/src/librustc_middle/ty/context.rs
+++ b/src/librustc_middle/ty/context.rs
@@ -11,8 +11,6 @@ use crate::lint::{struct_lint_level, LintSource};
 use crate::middle;
 use crate::middle::cstore::CrateStoreDyn;
 use crate::middle::cstore::EncodedMetadata;
-use crate::middle::lang_items;
-use crate::middle::lang_items::PanicLocationLangItem;
 use crate::middle::resolve_lifetime::{self, ObjectLifetimeDefault};
 use crate::middle::stability;
 use crate::mir::interpret::{Allocation, ConstValue, Scalar};
@@ -21,7 +19,6 @@ use crate::mir::{
 };
 use crate::traits;
 use crate::traits::{Clause, Clauses, Goal, GoalKind, Goals};
-use crate::ty::layout::{Layout, TargetDataLayout, VariantIdx};
 use crate::ty::query;
 use crate::ty::steal::Steal;
 use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef};
@@ -38,7 +35,6 @@ use crate::ty::{ConstVid, FloatVar, FloatVid, IntVar, IntVid, TyVar, TyVid};
 use crate::ty::{ExistentialPredicate, InferTy, ParamTy, PolyFnSig, Predicate, ProjectionTy};
 use crate::ty::{InferConst, ParamConst};
 use crate::ty::{List, TyKind, TyS};
-use crate::util::common::ErrorReported;
 use rustc_ast::ast;
 use rustc_ast::expand::allocator::AllocatorKind;
 use rustc_ast::node_id::NodeMap;
@@ -50,10 +46,13 @@ use rustc_data_structures::stable_hasher::{
     hash_stable_hashmap, HashStable, StableHasher, StableVec,
 };
 use rustc_data_structures::sync::{self, Lock, Lrc, WorkerLocal};
+use rustc_errors::ErrorReported;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId, LOCAL_CRATE};
 use rustc_hir::definitions::{DefPathData, DefPathHash, Definitions};
+use rustc_hir::lang_items;
+use rustc_hir::lang_items::PanicLocationLangItem;
 use rustc_hir::{HirId, Node, TraitCandidate};
 use rustc_hir::{ItemKind, ItemLocalId, ItemLocalMap, ItemLocalSet};
 use rustc_index::vec::{Idx, IndexVec};
@@ -65,6 +64,7 @@ use rustc_session::Session;
 use rustc_span::source_map::MultiSpan;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
+use rustc_target::abi::{Layout, TargetDataLayout, VariantIdx};
 use rustc_target::spec::abi;
 
 use smallvec::SmallVec;
@@ -1203,7 +1203,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     /// Obtain all lang items of this crate and all dependencies (recursively)
-    pub fn lang_items(self) -> &'tcx middle::lang_items::LanguageItems {
+    pub fn lang_items(self) -> &'tcx rustc_hir::lang_items::LanguageItems {
         self.get_lang_items(LOCAL_CRATE)
     }
 
diff --git a/src/librustc_middle/ty/instance.rs b/src/librustc_middle/ty/instance.rs
index fcfee0fea85af..5d47a6e13f488 100644
--- a/src/librustc_middle/ty/instance.rs
+++ b/src/librustc_middle/ty/instance.rs
@@ -1,10 +1,10 @@
 use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
-use crate::middle::lang_items::DropInPlaceFnLangItem;
 use crate::ty::print::{FmtPrinter, Printer};
 use crate::ty::{self, SubstsRef, Ty, TyCtxt, TypeFoldable};
 use rustc_data_structures::AtomicRef;
 use rustc_hir::def::Namespace;
 use rustc_hir::def_id::{CrateNum, DefId};
+use rustc_hir::lang_items::DropInPlaceFnLangItem;
 use rustc_macros::HashStable;
 
 use std::fmt;
diff --git a/src/librustc_middle/ty/layout.rs b/src/librustc_middle/ty/layout.rs
index 54fde52ba3a77..a2c5bcf119ef6 100644
--- a/src/librustc_middle/ty/layout.rs
+++ b/src/librustc_middle/ty/layout.rs
@@ -14,7 +14,7 @@ use rustc_span::DUMMY_SP;
 use rustc_target::abi::call::{
     ArgAbi, ArgAttribute, ArgAttributes, Conv, FnAbi, PassMode, Reg, RegKind,
 };
-pub use rustc_target::abi::*;
+use rustc_target::abi::*;
 use rustc_target::spec::{abi::Abi as SpecAbi, HasTargetSpec};
 
 use std::cmp;
diff --git a/src/librustc_middle/ty/mod.rs b/src/librustc_middle/ty/mod.rs
index 43982439d47c8..3d1893d3bd07b 100644
--- a/src/librustc_middle/ty/mod.rs
+++ b/src/librustc_middle/ty/mod.rs
@@ -11,14 +11,12 @@ use crate::hir::exports::ExportMap;
 use crate::ich::StableHashingContext;
 use crate::infer::canonical::Canonical;
 use crate::middle::cstore::CrateStoreDyn;
-use crate::middle::lang_items::{FnMutTraitLangItem, FnOnceTraitLangItem, FnTraitLangItem};
 use crate::middle::resolve_lifetime::ObjectLifetimeDefault;
 use crate::mir::interpret::ErrorHandled;
 use crate::mir::GeneratorLayout;
 use crate::mir::ReadOnlyBodyAndCache;
 use crate::traits::{self, Reveal};
 use crate::ty;
-use crate::ty::layout::VariantIdx;
 use crate::ty::subst::{InternalSubsts, Subst, SubstsRef};
 use crate::ty::util::{Discr, IntTypeExt};
 use crate::ty::walk::TypeWalker;
@@ -35,6 +33,7 @@ use rustc_data_structures::sync::{self, par_iter, Lrc, ParallelIterator};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Namespace, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, CRATE_DEF_INDEX};
+use rustc_hir::lang_items::{FnMutTraitLangItem, FnOnceTraitLangItem, FnTraitLangItem};
 use rustc_hir::{Constness, GlobMap, Node, TraitMap};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_macros::HashStable;
@@ -43,7 +42,7 @@ use rustc_session::DataTypeKind;
 use rustc_span::hygiene::ExpnId;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
-use rustc_target::abi::Align;
+use rustc_target::abi::{Align, VariantIdx};
 
 use std::cell::RefCell;
 use std::cmp::{self, Ordering};
@@ -2078,7 +2077,7 @@ pub struct AdtDef {
     /// The `DefId` of the struct, enum or union item.
     pub did: DefId,
     /// Variants of the ADT. If this is a struct or union, then there will be a single variant.
-    pub variants: IndexVec<self::layout::VariantIdx, VariantDef>,
+    pub variants: IndexVec<VariantIdx, VariantDef>,
     /// Flags of the ADT (e.g., is this a struct? is this non-exhaustive?).
     flags: AdtFlags,
     /// Repr options provided by the user.
diff --git a/src/librustc_middle/ty/print/pretty.rs b/src/librustc_middle/ty/print/pretty.rs
index 5c365a57cd12d..a8b7b6a4b97a4 100644
--- a/src/librustc_middle/ty/print/pretty.rs
+++ b/src/librustc_middle/ty/print/pretty.rs
@@ -1,7 +1,7 @@
 use crate::middle::cstore::{ExternCrate, ExternCrateSource};
 use crate::middle::region;
 use crate::mir::interpret::{sign_extend, truncate, AllocId, ConstValue, Pointer, Scalar};
-use crate::ty::layout::{Integer, IntegerExt, Size};
+use crate::ty::layout::IntegerExt;
 use crate::ty::subst::{GenericArg, GenericArgKind, Subst};
 use crate::ty::{self, DefIdTree, ParamConst, Ty, TyCtxt, TypeFoldable};
 use rustc_apfloat::ieee::{Double, Single};
@@ -13,6 +13,7 @@ use rustc_hir::def::{DefKind, Namespace};
 use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
 use rustc_span::symbol::{kw, Symbol};
+use rustc_target::abi::{Integer, Size};
 use rustc_target::spec::abi::Abi;
 
 use std::cell::Cell;
diff --git a/src/librustc_middle/ty/query/mod.rs b/src/librustc_middle/ty/query/mod.rs
index 744237520fbfd..9986eb88dc326 100644
--- a/src/librustc_middle/ty/query/mod.rs
+++ b/src/librustc_middle/ty/query/mod.rs
@@ -7,7 +7,6 @@ use crate::middle::codegen_fn_attrs::CodegenFnAttrs;
 use crate::middle::cstore::{CrateSource, DepKind, NativeLibraryKind};
 use crate::middle::cstore::{ExternCrate, ForeignModule, LinkagePreference, NativeLibrary};
 use crate::middle::exported_symbols::{ExportedSymbol, SymbolExportLevel};
-use crate::middle::lang_items::{LangItem, LanguageItems};
 use crate::middle::lib_features::LibFeatures;
 use crate::middle::privacy::AccessLevels;
 use crate::middle::region;
@@ -34,16 +33,17 @@ use crate::ty::steal::Steal;
 use crate::ty::subst::{GenericArg, SubstsRef};
 use crate::ty::util::AlwaysRequiresDrop;
 use crate::ty::{self, AdtSizedConstraint, CrateInherentImpls, ParamEnvAnd, Ty, TyCtxt};
-use crate::util::common::ErrorReported;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_data_structures::profiling::ProfileCategory::*;
 use rustc_data_structures::stable_hasher::StableVec;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::Lrc;
+use rustc_errors::ErrorReported;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId};
+use rustc_hir::lang_items::{LangItem, LanguageItems};
 use rustc_hir::{Crate, HirIdSet, ItemLocalId, TraitCandidate};
 use rustc_index::vec::IndexVec;
 use rustc_session::config::{EntryFnType, OptLevel, OutputFilenames, SymbolManglingVersion};
diff --git a/src/librustc_middle/ty/structural_impls.rs b/src/librustc_middle/ty/structural_impls.rs
index 429791d09a49c..0ac4466d34f5c 100644
--- a/src/librustc_middle/ty/structural_impls.rs
+++ b/src/librustc_middle/ty/structural_impls.rs
@@ -254,7 +254,7 @@ CloneTypeFoldableAndLiftImpls! {
     (),
     bool,
     usize,
-    crate::ty::layout::VariantIdx,
+    ::rustc_target::abi::VariantIdx,
     u64,
     String,
     crate::middle::region::Scope,
diff --git a/src/librustc_middle/ty/sty.rs b/src/librustc_middle/ty/sty.rs
index 57df50dc1a05d..99e3b88f5052c 100644
--- a/src/librustc_middle/ty/sty.rs
+++ b/src/librustc_middle/ty/sty.rs
@@ -10,7 +10,6 @@ use crate::middle::region;
 use crate::mir::interpret::ConstValue;
 use crate::mir::interpret::{LitToConstInput, Scalar};
 use crate::mir::Promoted;
-use crate::ty::layout::VariantIdx;
 use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef};
 use crate::ty::{
     self, AdtDef, DefIdTree, Discr, Ty, TyCtxt, TypeFlags, TypeFoldable, WithConstness,
@@ -24,6 +23,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_index::vec::Idx;
 use rustc_macros::HashStable;
 use rustc_span::symbol::{kw, Symbol};
+use rustc_target::abi::{Size, VariantIdx};
 use rustc_target::spec::abi;
 use smallvec::SmallVec;
 use std::borrow::Cow;
@@ -2501,7 +2501,7 @@ impl<'tcx> ConstKind<'tcx> {
     }
 
     #[inline]
-    pub fn try_to_bits(&self, size: ty::layout::Size) -> Option<u128> {
+    pub fn try_to_bits(&self, size: Size) -> Option<u128> {
         if let ConstKind::Value(val) = self { val.try_to_bits(size) } else { None }
     }
 }
diff --git a/src/librustc_middle/ty/util.rs b/src/librustc_middle/ty/util.rs
index dab367a6639ed..86575b013335c 100644
--- a/src/librustc_middle/ty/util.rs
+++ b/src/librustc_middle/ty/util.rs
@@ -2,24 +2,24 @@
 
 use crate::ich::NodeIdHashingMode;
 use crate::mir::interpret::{sign_extend, truncate};
-use crate::ty::layout::{Integer, IntegerExt, Size};
+use crate::ty::layout::IntegerExt;
 use crate::ty::query::TyCtxtAt;
 use crate::ty::subst::{GenericArgKind, InternalSubsts, Subst, SubstsRef};
 use crate::ty::TyKind::*;
 use crate::ty::{self, DefIdTree, GenericParamDefKind, Ty, TyCtxt, TypeFoldable};
-use crate::util::common::ErrorReported;
 use rustc_apfloat::Float as _;
 use rustc_ast::ast;
 use rustc_attr::{self as attr, SignedInt, UnsignedInt};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_errors::ErrorReported;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
 use rustc_hir::definitions::DefPathData;
 use rustc_macros::HashStable;
 use rustc_span::Span;
-use rustc_target::abi::TargetDataLayout;
+use rustc_target::abi::{Integer, Size, TargetDataLayout};
 use smallvec::SmallVec;
 use std::{cmp, fmt};
 
diff --git a/src/librustc_middle/util/common.rs b/src/librustc_middle/util/common.rs
index 19b43bfd16241..1e09702bf27ca 100644
--- a/src/librustc_middle/util/common.rs
+++ b/src/librustc_middle/util/common.rs
@@ -8,8 +8,6 @@ use std::time::{Duration, Instant};
 #[cfg(test)]
 mod tests;
 
-pub use rustc_errors::ErrorReported;
-
 pub fn to_readable_str(mut val: usize) -> String {
     let mut groups = vec![];
     loop {
diff --git a/src/librustc_mir/borrow_check/diagnostics/mod.rs b/src/librustc_mir/borrow_check/diagnostics/mod.rs
index 2991f29949aa0..619ae0ff8faa1 100644
--- a/src/librustc_mir/borrow_check/diagnostics/mod.rs
+++ b/src/librustc_mir/borrow_check/diagnostics/mod.rs
@@ -9,10 +9,10 @@ use rustc_middle::mir::{
     AggregateKind, Constant, Field, Local, LocalInfo, LocalKind, Location, Operand, Place,
     PlaceRef, ProjectionElem, Rvalue, Statement, StatementKind, Terminator, TerminatorKind,
 };
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::print::Print;
 use rustc_middle::ty::{self, DefIdTree, Ty, TyCtxt};
 use rustc_span::Span;
+use rustc_target::abi::VariantIdx;
 
 use super::borrow_set::BorrowData;
 use super::MirBorrowckCtxt;
diff --git a/src/librustc_mir/borrow_check/type_check/mod.rs b/src/librustc_mir/borrow_check/type_check/mod.rs
index 1d66bd13c6fe6..cedae94ab89fe 100644
--- a/src/librustc_mir/borrow_check/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/type_check/mod.rs
@@ -24,13 +24,13 @@ use rustc_middle::mir::*;
 use rustc_middle::ty::adjustment::PointerCast;
 use rustc_middle::ty::cast::CastTy;
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::subst::{GenericArgKind, Subst, SubstsRef, UserSubsts};
 use rustc_middle::ty::{
     self, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, RegionVid, ToPolyTraitRef, Ty,
     TyCtxt, UserType, UserTypeAnnotationIndex,
 };
 use rustc_span::{Span, DUMMY_SP};
+use rustc_target::abi::VariantIdx;
 use rustc_trait_selection::infer::InferCtxtExt as _;
 use rustc_trait_selection::opaque_types::{GenerateMemberConstraints, InferCtxtExt};
 use rustc_trait_selection::traits::error_reporting::InferCtxtExt as _;
diff --git a/src/librustc_mir/borrow_check/universal_regions.rs b/src/librustc_mir/borrow_check/universal_regions.rs
index c31f5a57ebc22..4d67d7204ca6e 100644
--- a/src/librustc_mir/borrow_check/universal_regions.rs
+++ b/src/librustc_mir/borrow_check/universal_regions.rs
@@ -17,10 +17,10 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::DiagnosticBuilder;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
+use rustc_hir::lang_items;
 use rustc_hir::{BodyOwnerKind, HirId};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_infer::infer::{InferCtxt, NLLRegionVariableOrigin};
-use rustc_middle::middle::lang_items;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef};
 use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt};
diff --git a/src/librustc_mir/const_eval/eval_queries.rs b/src/librustc_mir/const_eval/eval_queries.rs
index c30d41e6a9222..238a2dfdd8f49 100644
--- a/src/librustc_mir/const_eval/eval_queries.rs
+++ b/src/librustc_mir/const_eval/eval_queries.rs
@@ -9,8 +9,9 @@ use rustc_hir::def::DefKind;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::{ConstEvalErr, ErrorHandled};
 use rustc_middle::traits::Reveal;
-use rustc_middle::ty::{self, layout, layout::LayoutOf, subst::Subst, TyCtxt};
+use rustc_middle::ty::{self, subst::Subst, TyCtxt};
 use rustc_span::source_map::Span;
+use rustc_target::abi::{Abi, LayoutOf};
 use std::convert::TryInto;
 
 pub fn note_on_undefined_behavior_error() -> &'static str {
@@ -106,8 +107,8 @@ pub(super) fn op_to_const<'tcx>(
     // the usual cases of extracting e.g. a `usize`, without there being a real use case for the
     // `Undef` situation.
     let try_as_immediate = match op.layout.abi {
-        layout::Abi::Scalar(..) => true,
-        layout::Abi::ScalarPair(..) => match op.layout.ty.kind {
+        Abi::Scalar(..) => true,
+        Abi::ScalarPair(..) => match op.layout.ty.kind {
             ty::Ref(_, inner, _) => match inner.kind {
                 ty::Slice(elem) => elem == ecx.tcx.types.u8,
                 ty::Str => true,
diff --git a/src/librustc_mir/const_eval/mod.rs b/src/librustc_mir/const_eval/mod.rs
index 78d1e8989a2f5..e1146ef30d131 100644
--- a/src/librustc_mir/const_eval/mod.rs
+++ b/src/librustc_mir/const_eval/mod.rs
@@ -3,9 +3,9 @@
 use std::convert::TryFrom;
 
 use rustc_middle::mir;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::{source_map::DUMMY_SP, symbol::Symbol};
+use rustc_target::abi::VariantIdx;
 
 use crate::interpret::{intern_const_alloc_recursive, ConstValue, InternKind, InterpCx};
 
diff --git a/src/librustc_mir/dataflow/framework/mod.rs b/src/librustc_mir/dataflow/framework/mod.rs
index 91c4b5ad634cb..d85e2c0761f19 100644
--- a/src/librustc_mir/dataflow/framework/mod.rs
+++ b/src/librustc_mir/dataflow/framework/mod.rs
@@ -36,8 +36,8 @@ use rustc_hir::def_id::DefId;
 use rustc_index::bit_set::{BitSet, HybridBitSet};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_middle::mir::{self, BasicBlock, Location};
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::{self, TyCtxt};
+use rustc_target::abi::VariantIdx;
 
 mod cursor;
 mod engine;
diff --git a/src/librustc_mir/dataflow/impls/mod.rs b/src/librustc_mir/dataflow/impls/mod.rs
index 3ffa771cb05a1..65c9e29bd10ec 100644
--- a/src/librustc_mir/dataflow/impls/mod.rs
+++ b/src/librustc_mir/dataflow/impls/mod.rs
@@ -5,8 +5,8 @@
 use rustc_index::bit_set::BitSet;
 use rustc_index::vec::Idx;
 use rustc_middle::mir::{self, Body, Location};
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::{self, TyCtxt};
+use rustc_target::abi::VariantIdx;
 
 use super::MoveDataParamEnv;
 
diff --git a/src/librustc_mir/interpret/cast.rs b/src/librustc_mir/interpret/cast.rs
index 215c7bb747593..67696aa2da8b0 100644
--- a/src/librustc_mir/interpret/cast.rs
+++ b/src/librustc_mir/interpret/cast.rs
@@ -7,10 +7,10 @@ use rustc_ast::ast::FloatTy;
 use rustc_middle::mir::interpret::{InterpResult, PointerArithmetic, Scalar};
 use rustc_middle::mir::CastKind;
 use rustc_middle::ty::adjustment::PointerCast;
-use rustc_middle::ty::layout::{self, Size, TyAndLayout};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::{self, Ty, TypeAndMut, TypeFoldable};
 use rustc_span::symbol::sym;
-use rustc_target::abi::LayoutOf;
+use rustc_target::abi::{LayoutOf, Size, Variants};
 
 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     pub fn cast(
@@ -132,7 +132,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
         // Handle cast from a univariant (ZST) enum.
         match src.layout.variants {
-            layout::Variants::Single { index } => {
+            Variants::Single { index } => {
                 if let Some(discr) = src.layout.ty.discriminant_for_variant(*self.tcx, index) {
                     assert!(src.layout.is_zst());
                     let discr_layout = self.layout_of(discr.ty)?;
@@ -141,7 +141,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         .into());
                 }
             }
-            layout::Variants::Multiple { .. } => {}
+            Variants::Multiple { .. } => {}
         }
 
         // Handle casting the metadata away from a fat pointer.
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs
index d204be7f80674..0b1ffe62eaaf3 100644
--- a/src/librustc_mir/interpret/eval_context.rs
+++ b/src/librustc_mir/interpret/eval_context.rs
@@ -13,11 +13,12 @@ use rustc_middle::mir;
 use rustc_middle::mir::interpret::{
     sign_extend, truncate, AllocId, FrameInfo, GlobalId, InterpResult, Pointer, Scalar,
 };
-use rustc_middle::ty::layout::{self, Align, HasDataLayout, LayoutOf, Size, TyAndLayout};
+use rustc_middle::ty::layout::{self, TyAndLayout};
 use rustc_middle::ty::query::TyCtxtAt;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
 use rustc_span::source_map::{self, Span, DUMMY_SP};
+use rustc_target::abi::{Align, HasDataLayout, LayoutOf, Size, TargetDataLayout};
 
 use super::{
     Immediate, MPlaceTy, Machine, MemPlace, MemPlaceMeta, Memory, OpTy, Operand, Place, PlaceTy,
@@ -176,7 +177,7 @@ impl<'mir, 'tcx, Tag, Extra> Frame<'mir, 'tcx, Tag, Extra> {
 
 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> HasDataLayout for InterpCx<'mir, 'tcx, M> {
     #[inline]
-    fn data_layout(&self) -> &layout::TargetDataLayout {
+    fn data_layout(&self) -> &TargetDataLayout {
         &self.tcx.data_layout
     }
 }
diff --git a/src/librustc_mir/interpret/intrinsics.rs b/src/librustc_mir/interpret/intrinsics.rs
index c5f7a94969b2d..5b65a49b47d76 100644
--- a/src/librustc_mir/interpret/intrinsics.rs
+++ b/src/librustc_mir/interpret/intrinsics.rs
@@ -11,11 +11,11 @@ use rustc_middle::mir::{
     BinOp,
 };
 use rustc_middle::ty;
-use rustc_middle::ty::layout::{LayoutOf, Primitive, Size};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::Span;
+use rustc_target::abi::{Abi, LayoutOf, Primitive, Size};
 
 use super::{ImmTy, InterpCx, Machine, OpTy, PlaceTy};
 
@@ -136,7 +136,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 let val = self.read_scalar(args[0])?.not_undef()?;
                 let bits = self.force_bits(val, layout_of.size)?;
                 let kind = match layout_of.abi {
-                    ty::layout::Abi::Scalar(ref scalar) => scalar.value,
+                    Abi::Scalar(ref scalar) => scalar.value,
                     _ => bug!("{} called on invalid type {:?}", intrinsic_name, ty),
                 };
                 let (nonzero, intrinsic_name) = match intrinsic_name {
diff --git a/src/librustc_mir/interpret/intrinsics/caller_location.rs b/src/librustc_mir/interpret/intrinsics/caller_location.rs
index 37b01d6db3b41..5fcee1f25bbc3 100644
--- a/src/librustc_mir/interpret/intrinsics/caller_location.rs
+++ b/src/librustc_mir/interpret/intrinsics/caller_location.rs
@@ -1,6 +1,6 @@
 use std::convert::TryFrom;
 
-use rustc_middle::middle::lang_items::PanicLocationLangItem;
+use rustc_hir::lang_items::PanicLocationLangItem;
 use rustc_middle::ty::subst::Subst;
 use rustc_span::{Span, Symbol};
 use rustc_target::abi::LayoutOf;
diff --git a/src/librustc_mir/interpret/memory.rs b/src/librustc_mir/interpret/memory.rs
index 9443ae116fcfd..04a927c69a687 100644
--- a/src/librustc_mir/interpret/memory.rs
+++ b/src/librustc_mir/interpret/memory.rs
@@ -11,11 +11,10 @@ use std::collections::VecDeque;
 use std::convert::TryFrom;
 use std::ptr;
 
+use rustc_ast::ast::Mutability;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_middle::ty::layout::{Align, HasDataLayout, Size, TargetDataLayout};
 use rustc_middle::ty::{self, query::TyCtxtAt, Instance, ParamEnv};
-
-use rustc_ast::ast::Mutability;
+use rustc_target::abi::{Align, HasDataLayout, Size, TargetDataLayout};
 
 use super::{
     AllocId, AllocMap, Allocation, AllocationExtra, CheckInAllocMsg, ErrorHandled, GlobalAlloc,
diff --git a/src/librustc_mir/interpret/operand.rs b/src/librustc_mir/interpret/operand.rs
index 24639fece46be..c91cbb7550bc2 100644
--- a/src/librustc_mir/interpret/operand.rs
+++ b/src/librustc_mir/interpret/operand.rs
@@ -10,12 +10,12 @@ pub use rustc_middle::mir::interpret::ScalarMaybeUndef;
 use rustc_middle::mir::interpret::{
     sign_extend, truncate, AllocId, ConstValue, GlobalId, InterpResult, Pointer, Scalar,
 };
-use rustc_middle::ty::layout::{
-    self, HasDataLayout, IntegerExt, LayoutOf, PrimitiveExt, Size, TyAndLayout, VariantIdx,
-};
+use rustc_middle::ty::layout::{IntegerExt, PrimitiveExt, TyAndLayout};
 use rustc_middle::ty::print::{FmtPrinter, PrettyPrinter, Printer};
 use rustc_middle::ty::Ty;
 use rustc_middle::{mir, ty};
+use rustc_target::abi::{Abi, DiscriminantKind, HasDataLayout, Integer, LayoutOf, Size};
+use rustc_target::abi::{VariantIdx, Variants};
 use std::fmt::Write;
 
 /// An `Immediate` represents a single immediate self-contained Rust value.
@@ -266,7 +266,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         };
 
         match mplace.layout.abi {
-            layout::Abi::Scalar(..) => {
+            Abi::Scalar(..) => {
                 let scalar = self.memory.get_raw(ptr.alloc_id)?.read_scalar(
                     self,
                     ptr,
@@ -274,7 +274,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 )?;
                 Ok(Some(ImmTy { imm: scalar.into(), layout: mplace.layout }))
             }
-            layout::Abi::ScalarPair(ref a, ref b) => {
+            Abi::ScalarPair(ref a, ref b) => {
                 // We checked `ptr_align` above, so all fields will have the alignment they need.
                 // We would anyway check against `ptr_align.restrict_for_offset(b_offset)`,
                 // which `ptr.offset(b_offset)` cannot possibly fail to satisfy.
@@ -587,7 +587,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         trace!("read_discriminant_value {:#?}", rval.layout);
 
         let (discr_layout, discr_kind, discr_index) = match rval.layout.variants {
-            layout::Variants::Single { index } => {
+            Variants::Single { index } => {
                 let discr_val = rval
                     .layout
                     .ty
@@ -595,12 +595,9 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                     .map_or(u128::from(index.as_u32()), |discr| discr.val);
                 return Ok((discr_val, index));
             }
-            layout::Variants::Multiple {
-                discr: ref discr_layout,
-                ref discr_kind,
-                discr_index,
-                ..
-            } => (discr_layout, discr_kind, discr_index),
+            Variants::Multiple { discr: ref discr_layout, ref discr_kind, discr_index, .. } => {
+                (discr_layout, discr_kind, discr_index)
+            }
         };
 
         // read raw discriminant value
@@ -610,7 +607,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         trace!("discr value: {:?}", raw_discr);
         // post-process
         Ok(match *discr_kind {
-            layout::DiscriminantKind::Tag => {
+            DiscriminantKind::Tag => {
                 let bits_discr = raw_discr
                     .not_undef()
                     .and_then(|raw_discr| self.force_bits(raw_discr, discr_val.layout.size))
@@ -627,7 +624,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                         .expect("tagged layout corresponds to adt")
                         .repr
                         .discr_type();
-                    let size = layout::Integer::from_attr(self, discr_ty).size();
+                    let size = Integer::from_attr(self, discr_ty).size();
                     truncate(sexted, size)
                 } else {
                     bits_discr
@@ -648,11 +645,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 .ok_or_else(|| err_ub!(InvalidDiscriminant(raw_discr.erase_tag())))?;
                 (real_discr, index.0)
             }
-            layout::DiscriminantKind::Niche {
-                dataful_variant,
-                ref niche_variants,
-                niche_start,
-            } => {
+            DiscriminantKind::Niche { dataful_variant, ref niche_variants, niche_start } => {
                 let variants_start = niche_variants.start().as_u32();
                 let variants_end = niche_variants.end().as_u32();
                 let raw_discr = raw_discr
diff --git a/src/librustc_mir/interpret/operator.rs b/src/librustc_mir/interpret/operator.rs
index e81cd8b3d00d7..0aa7e98f3edfa 100644
--- a/src/librustc_mir/interpret/operator.rs
+++ b/src/librustc_mir/interpret/operator.rs
@@ -4,11 +4,8 @@ use rustc_apfloat::Float;
 use rustc_ast::ast::FloatTy;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::{InterpResult, Scalar};
-use rustc_middle::ty::{
-    self,
-    layout::{LayoutOf, TyAndLayout},
-    Ty,
-};
+use rustc_middle::ty::{self, layout::TyAndLayout, Ty};
+use rustc_target::abi::LayoutOf;
 
 use super::{ImmTy, Immediate, InterpCx, Machine, PlaceTy};
 
diff --git a/src/librustc_mir/interpret/place.rs b/src/librustc_mir/interpret/place.rs
index f7c1a3cadb881..85d02abd64a1d 100644
--- a/src/librustc_mir/interpret/place.rs
+++ b/src/librustc_mir/interpret/place.rs
@@ -8,10 +8,10 @@ use std::hash::Hash;
 use rustc_macros::HashStable;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::truncate;
-use rustc_middle::ty::layout::{
-    self, Align, HasDataLayout, LayoutOf, PrimitiveExt, Size, TyAndLayout, VariantIdx,
-};
+use rustc_middle::ty::layout::{PrimitiveExt, TyAndLayout};
 use rustc_middle::ty::{self, Ty};
+use rustc_target::abi::{Abi, Align, DiscriminantKind, FieldPlacement};
+use rustc_target::abi::{HasDataLayout, LayoutOf, Size, VariantIdx, Variants};
 
 use super::{
     AllocId, AllocMap, Allocation, AllocationExtra, ImmTy, Immediate, InterpCx, InterpResult,
@@ -219,7 +219,7 @@ impl<'tcx, Tag> MPlaceTy<'tcx, Tag> {
             // Go through the layout.  There are lots of types that support a length,
             // e.g., SIMD types.
             match self.layout.fields {
-                layout::FieldPlacement::Array { count, .. } => Ok(count),
+                FieldPlacement::Array { count, .. } => Ok(count),
                 _ => bug!("len not supported on sized type {:?}", self.layout.ty),
             }
         }
@@ -437,7 +437,7 @@ where
     ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::PointerTag>> {
         // Not using the layout method because we want to compute on u64
         match base.layout.fields {
-            layout::FieldPlacement::Array { stride, .. } => {
+            FieldPlacement::Array { stride, .. } => {
                 let len = base.len(self)?;
                 if index >= len {
                     // This can only be reached in ConstProp and non-rustc-MIR.
@@ -463,7 +463,7 @@ where
     {
         let len = base.len(self)?; // also asserts that we have a type where this makes sense
         let stride = match base.layout.fields {
-            layout::FieldPlacement::Array { stride, .. } => stride,
+            FieldPlacement::Array { stride, .. } => stride,
             _ => bug!("mplace_array_fields: expected an array layout"),
         };
         let layout = base.layout.field(self, 0)?;
@@ -493,7 +493,7 @@ where
         // Not using layout method because that works with usize, and does not work with slices
         // (that have count 0 in their layout).
         let from_offset = match base.layout.fields {
-            layout::FieldPlacement::Array { stride, .. } => stride * from, // `Size` multiplication is checked
+            FieldPlacement::Array { stride, .. } => stride * from, // `Size` multiplication is checked
             _ => bug!("Unexpected layout of index access: {:#?}", base.layout),
         };
 
@@ -802,7 +802,7 @@ where
         match value {
             Immediate::Scalar(scalar) => {
                 match dest.layout.abi {
-                    layout::Abi::Scalar(_) => {} // fine
+                    Abi::Scalar(_) => {} // fine
                     _ => {
                         bug!("write_immediate_to_mplace: invalid Scalar layout: {:#?}", dest.layout)
                     }
@@ -819,7 +819,7 @@ where
                 // We would anyway check against `ptr_align.restrict_for_offset(b_offset)`,
                 // which `ptr.offset(b_offset)` cannot possibly fail to satisfy.
                 let (a, b) = match dest.layout.abi {
-                    layout::Abi::ScalarPair(ref a, ref b) => (&a.value, &b.value),
+                    Abi::ScalarPair(ref a, ref b) => (&a.value, &b.value),
                     _ => bug!(
                         "write_immediate_to_mplace: invalid ScalarPair layout: {:#?}",
                         dest.layout
@@ -1067,11 +1067,11 @@ where
         }
 
         match dest.layout.variants {
-            layout::Variants::Single { index } => {
+            Variants::Single { index } => {
                 assert_eq!(index, variant_index);
             }
-            layout::Variants::Multiple {
-                discr_kind: layout::DiscriminantKind::Tag,
+            Variants::Multiple {
+                discr_kind: DiscriminantKind::Tag,
                 discr: ref discr_layout,
                 discr_index,
                 ..
@@ -1091,9 +1091,9 @@ where
                 let discr_dest = self.place_field(dest, discr_index)?;
                 self.write_scalar(Scalar::from_uint(discr_val, size), discr_dest)?;
             }
-            layout::Variants::Multiple {
+            Variants::Multiple {
                 discr_kind:
-                    layout::DiscriminantKind::Niche { dataful_variant, ref niche_variants, niche_start },
+                    DiscriminantKind::Niche { dataful_variant, ref niche_variants, niche_start },
                 discr: ref discr_layout,
                 discr_index,
                 ..
diff --git a/src/librustc_mir/interpret/step.rs b/src/librustc_mir/interpret/step.rs
index 5fb0a081648e8..a00b1c8ba9ba7 100644
--- a/src/librustc_mir/interpret/step.rs
+++ b/src/librustc_mir/interpret/step.rs
@@ -4,7 +4,7 @@
 
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::{InterpResult, Scalar};
-use rustc_middle::ty::layout::LayoutOf;
+use rustc_target::abi::LayoutOf;
 
 use super::{InterpCx, Machine};
 
diff --git a/src/librustc_mir/interpret/terminator.rs b/src/librustc_mir/interpret/terminator.rs
index 8e7abcd09c233..f6f82633acae1 100644
--- a/src/librustc_mir/interpret/terminator.rs
+++ b/src/librustc_mir/interpret/terminator.rs
@@ -1,10 +1,11 @@
 use std::borrow::Cow;
 use std::convert::TryFrom;
 
-use rustc_middle::ty::layout::{self, LayoutOf, TyAndLayout};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::Instance;
 use rustc_middle::{mir, ty};
 use rustc_span::source_map::Span;
+use rustc_target::abi::{self, LayoutOf};
 use rustc_target::spec::abi::Abi;
 
 use super::{
@@ -150,12 +151,12 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             // Different valid ranges are okay (once we enforce validity,
             // that will take care to make it UB to leave the range, just
             // like for transmute).
-            (layout::Abi::Scalar(ref caller), layout::Abi::Scalar(ref callee)) => {
+            (abi::Abi::Scalar(ref caller), abi::Abi::Scalar(ref callee)) => {
                 caller.value == callee.value
             }
             (
-                layout::Abi::ScalarPair(ref caller1, ref caller2),
-                layout::Abi::ScalarPair(ref callee1, ref callee2),
+                abi::Abi::ScalarPair(ref caller1, ref caller2),
+                abi::Abi::ScalarPair(ref callee1, ref callee2),
             ) => caller1.value == callee1.value && caller2.value == callee2.value,
             // Be conservative
             _ => false,
diff --git a/src/librustc_mir/interpret/traits.rs b/src/librustc_mir/interpret/traits.rs
index ed882e107411d..fb9401c7d8f28 100644
--- a/src/librustc_mir/interpret/traits.rs
+++ b/src/librustc_mir/interpret/traits.rs
@@ -1,8 +1,8 @@
 use std::convert::TryFrom;
 
 use rustc_middle::mir::interpret::{InterpResult, Pointer, PointerArithmetic, Scalar};
-use rustc_middle::ty::layout::{Align, HasDataLayout, LayoutOf, Size};
 use rustc_middle::ty::{self, Instance, Ty, TypeFoldable};
+use rustc_target::abi::{Align, HasDataLayout, LayoutOf, Size};
 
 use super::{FnVal, InterpCx, Machine, MemoryKind};
 
diff --git a/src/librustc_mir/interpret/validity.rs b/src/librustc_mir/interpret/validity.rs
index 0ca565d86787a..701e394415bbd 100644
--- a/src/librustc_mir/interpret/validity.rs
+++ b/src/librustc_mir/interpret/validity.rs
@@ -11,8 +11,9 @@ use std::ops::RangeInclusive;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_middle::ty;
-use rustc_middle::ty::layout::{self, LayoutOf, TyAndLayout, VariantIdx};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_span::symbol::{sym, Symbol};
+use rustc_target::abi::{Abi, LayoutOf, Scalar, VariantIdx, Variants};
 
 use std::hash::Hash;
 
@@ -180,7 +181,7 @@ impl<'rt, 'mir, 'tcx, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, 'tcx, M
     fn aggregate_field_path_elem(&mut self, layout: TyAndLayout<'tcx>, field: usize) -> PathElem {
         // First, check if we are projecting to a variant.
         match layout.variants {
-            layout::Variants::Multiple { discr_index, .. } => {
+            Variants::Multiple { discr_index, .. } => {
                 if discr_index == field {
                     return match layout.ty.kind {
                         ty::Adt(def, ..) if def.is_enum() => PathElem::EnumTag,
@@ -189,7 +190,7 @@ impl<'rt, 'mir, 'tcx, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, 'tcx, M
                     };
                 }
             }
-            layout::Variants::Single { .. } => {}
+            Variants::Single { .. } => {}
         }
 
         // Now we know we are projecting to a field, so figure out which one.
@@ -226,11 +227,11 @@ impl<'rt, 'mir, 'tcx, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, 'tcx, M
             ty::Adt(def, ..) if def.is_enum() => {
                 // we might be projecting *to* a variant, or to a field *in* a variant.
                 match layout.variants {
-                    layout::Variants::Single { index } => {
+                    Variants::Single { index } => {
                         // Inside a variant
                         PathElem::Field(def.variants[index].fields[field].ident.name)
                     }
-                    layout::Variants::Multiple { .. } => bug!("we handled variants above"),
+                    Variants::Multiple { .. } => bug!("we handled variants above"),
                 }
             }
 
@@ -539,7 +540,7 @@ impl<'rt, 'mir, 'tcx, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, 'tcx, M
     fn visit_scalar(
         &mut self,
         op: OpTy<'tcx, M::PointerTag>,
-        scalar_layout: &layout::Scalar,
+        scalar_layout: &Scalar,
     ) -> InterpResult<'tcx> {
         let value = self.ecx.read_scalar(op)?;
         let valid_range = &scalar_layout.valid_range;
@@ -685,22 +686,22 @@ impl<'rt, 'mir, 'tcx, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
         // scalars, we do the same check on every "level" (e.g., first we check
         // MyNewtype and then the scalar in there).
         match op.layout.abi {
-            layout::Abi::Uninhabited => {
+            Abi::Uninhabited => {
                 throw_validation_failure!(
                     format_args!("a value of uninhabited type {:?}", op.layout.ty),
                     self.path
                 );
             }
-            layout::Abi::Scalar(ref scalar_layout) => {
+            Abi::Scalar(ref scalar_layout) => {
                 self.visit_scalar(op, scalar_layout)?;
             }
-            layout::Abi::ScalarPair { .. } | layout::Abi::Vector { .. } => {
+            Abi::ScalarPair { .. } | Abi::Vector { .. } => {
                 // These have fields that we already visited above, so we already checked
                 // all their scalar-level restrictions.
                 // There is also no equivalent to `rustc_layout_scalar_valid_range_start`
                 // that would make skipping them here an issue.
             }
-            layout::Abi::Aggregate { .. } => {
+            Abi::Aggregate { .. } => {
                 // Nothing to do.
             }
         }
diff --git a/src/librustc_mir/interpret/visitor.rs b/src/librustc_mir/interpret/visitor.rs
index 11170164cf35b..0207ee9a3e952 100644
--- a/src/librustc_mir/interpret/visitor.rs
+++ b/src/librustc_mir/interpret/visitor.rs
@@ -3,7 +3,8 @@
 
 use rustc_middle::mir::interpret::InterpResult;
 use rustc_middle::ty;
-use rustc_middle::ty::layout::{self, TyAndLayout, VariantIdx};
+use rustc_middle::ty::layout::TyAndLayout;
+use rustc_target::abi::{FieldPlacement, VariantIdx, Variants};
 
 use super::{InterpCx, MPlaceTy, Machine, OpTy};
 
@@ -207,10 +208,10 @@ macro_rules! make_value_visitor {
 
                 // Visit the fields of this value.
                 match v.layout().fields {
-                    layout::FieldPlacement::Union(fields) => {
+                    FieldPlacement::Union(fields) => {
                         self.visit_union(v, fields)?;
                     },
-                    layout::FieldPlacement::Arbitrary { ref offsets, .. } => {
+                    FieldPlacement::Arbitrary { ref offsets, .. } => {
                         // FIXME: We collect in a vec because otherwise there are lifetime
                         // errors: Projecting to a field needs access to `ecx`.
                         let fields: Vec<InterpResult<'tcx, Self::V>> =
@@ -220,7 +221,7 @@ macro_rules! make_value_visitor {
                             .collect();
                         self.visit_aggregate(v, fields.into_iter())?;
                     },
-                    layout::FieldPlacement::Array { .. } => {
+                    FieldPlacement::Array { .. } => {
                         // Let's get an mplace first.
                         let mplace = v.to_op(self.ecx())?.assert_mem_place(self.ecx());
                         // Now we can go over all the fields.
@@ -237,7 +238,7 @@ macro_rules! make_value_visitor {
                 match v.layout().variants {
                     // If this is a multi-variant layout, find the right variant and proceed
                     // with *its* fields.
-                    layout::Variants::Multiple { .. } => {
+                    Variants::Multiple { .. } => {
                         let op = v.to_op(self.ecx())?;
                         let idx = self.ecx().read_discriminant(op)?.1;
                         let inner = v.project_downcast(self.ecx(), idx)?;
@@ -246,7 +247,7 @@ macro_rules! make_value_visitor {
                         self.visit_variant(v, idx, inner)
                     }
                     // For single-variant layouts, we already did anything there is to do.
-                    layout::Variants::Single { .. } => Ok(())
+                    Variants::Single { .. } => Ok(())
                 }
             }
         }
diff --git a/src/librustc_mir/monomorphize/collector.rs b/src/librustc_mir/monomorphize/collector.rs
index 1106eba104682..1032ff413af41 100644
--- a/src/librustc_mir/monomorphize/collector.rs
+++ b/src/librustc_mir/monomorphize/collector.rs
@@ -181,9 +181,9 @@ use rustc_data_structures::sync::{par_iter, MTLock, MTRef, ParallelIterator};
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, DefIdMap, LOCAL_CRATE};
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
+use rustc_hir::lang_items::{ExchangeMallocFnLangItem, StartFnLangItem};
 use rustc_index::bit_set::GrowableBitSet;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
-use rustc_middle::middle::lang_items::{ExchangeMallocFnLangItem, StartFnLangItem};
 use rustc_middle::mir::interpret::{AllocId, ConstValue};
 use rustc_middle::mir::interpret::{ErrorHandled, GlobalAlloc, Scalar};
 use rustc_middle::mir::mono::{InstantiationMode, MonoItem};
diff --git a/src/librustc_mir/shim.rs b/src/librustc_mir/shim.rs
index 98a95801f1b40..16aade9d1a61f 100644
--- a/src/librustc_mir/shim.rs
+++ b/src/librustc_mir/shim.rs
@@ -1,10 +1,10 @@
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_middle::mir::*;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::subst::{InternalSubsts, Subst};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
+use rustc_target::abi::VariantIdx;
 
 use rustc_index::vec::{Idx, IndexVec};
 
diff --git a/src/librustc_mir/transform/check_consts/validation.rs b/src/librustc_mir/transform/check_consts/validation.rs
index c8320a1561ae8..8d509c0d8b01c 100644
--- a/src/librustc_mir/transform/check_consts/validation.rs
+++ b/src/librustc_mir/transform/check_consts/validation.rs
@@ -1,10 +1,10 @@
 //! The `Visitor` responsible for actually checking a `mir::Body` for invalid operations.
 
 use rustc_errors::struct_span_err;
+use rustc_hir::lang_items;
 use rustc_hir::{def_id::DefId, HirId};
 use rustc_index::bit_set::BitSet;
 use rustc_infer::infer::TyCtxtInferExt;
-use rustc_middle::middle::lang_items;
 use rustc_middle::mir::visit::{MutatingUseContext, NonMutatingUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::*;
 use rustc_middle::ty::cast::CastTy;
diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs
index f1ddf3c635f7a..8116ec7991546 100644
--- a/src/librustc_mir/transform/const_prop.rs
+++ b/src/librustc_mir/transform/const_prop.rs
@@ -19,13 +19,12 @@ use rustc_middle::mir::{
     SourceInfo, SourceScope, SourceScopeData, Statement, StatementKind, Terminator, TerminatorKind,
     UnOp, RETURN_PLACE,
 };
-use rustc_middle::ty::layout::{
-    HasDataLayout, HasTyCtxt, LayoutError, LayoutOf, Size, TargetDataLayout, TyAndLayout,
-};
+use rustc_middle::ty::layout::{HasTyCtxt, LayoutError, TyAndLayout};
 use rustc_middle::ty::subst::{InternalSubsts, Subst};
 use rustc_middle::ty::{self, ConstKind, Instance, ParamEnv, Ty, TyCtxt, TypeFoldable};
 use rustc_session::lint;
 use rustc_span::{def_id::DefId, Span};
+use rustc_target::abi::{HasDataLayout, LayoutOf, Size, TargetDataLayout};
 use rustc_trait_selection::traits;
 
 use crate::const_eval::error_to_const_error;
diff --git a/src/librustc_mir/transform/elaborate_drops.rs b/src/librustc_mir/transform/elaborate_drops.rs
index fc382312aeb50..8a612c9c5da11 100644
--- a/src/librustc_mir/transform/elaborate_drops.rs
+++ b/src/librustc_mir/transform/elaborate_drops.rs
@@ -13,9 +13,9 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_hir as hir;
 use rustc_index::bit_set::BitSet;
 use rustc_middle::mir::*;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::Span;
+use rustc_target::abi::VariantIdx;
 use std::fmt;
 
 pub struct ElaborateDrops;
diff --git a/src/librustc_mir/transform/generator.rs b/src/librustc_mir/transform/generator.rs
index 230a835b910d2..4fadd99cbaff0 100644
--- a/src/librustc_mir/transform/generator.rs
+++ b/src/librustc_mir/transform/generator.rs
@@ -63,10 +63,10 @@ use rustc_index::bit_set::{BitMatrix, BitSet};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_middle::mir::visit::{MutVisitor, PlaceContext, Visitor};
 use rustc_middle::mir::*;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::GeneratorSubsts;
 use rustc_middle::ty::{self, AdtDef, Ty, TyCtxt};
+use rustc_target::abi::VariantIdx;
 use std::borrow::Cow;
 use std::iter;
 
diff --git a/src/librustc_mir/transform/uninhabited_enum_branching.rs b/src/librustc_mir/transform/uninhabited_enum_branching.rs
index 38a9194e5c55d..0a08c13b479aa 100644
--- a/src/librustc_mir/transform/uninhabited_enum_branching.rs
+++ b/src/librustc_mir/transform/uninhabited_enum_branching.rs
@@ -5,8 +5,9 @@ use rustc_middle::mir::{
     BasicBlock, BasicBlockData, Body, BodyAndCache, Local, Operand, Rvalue, StatementKind,
     TerminatorKind,
 };
-use rustc_middle::ty::layout::{Abi, TyAndLayout, Variants};
+use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::{Ty, TyCtxt};
+use rustc_target::abi::{Abi, Variants};
 
 pub struct UninhabitedEnumBranching;
 
diff --git a/src/librustc_mir/util/aggregate.rs b/src/librustc_mir/util/aggregate.rs
index b22dbf40b5019..e77d264b7ce5c 100644
--- a/src/librustc_mir/util/aggregate.rs
+++ b/src/librustc_mir/util/aggregate.rs
@@ -1,7 +1,7 @@
 use rustc_index::vec::Idx;
 use rustc_middle::mir::*;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::{Ty, TyCtxt};
+use rustc_target::abi::VariantIdx;
 
 use std::iter::TrustedLen;
 
diff --git a/src/librustc_mir/util/elaborate_drops.rs b/src/librustc_mir/util/elaborate_drops.rs
index 7063ed1edc822..1d1a5140aae24 100644
--- a/src/librustc_mir/util/elaborate_drops.rs
+++ b/src/librustc_mir/util/elaborate_drops.rs
@@ -1,13 +1,13 @@
 use crate::util::patch::MirPatch;
 use rustc_hir as hir;
+use rustc_hir::lang_items;
 use rustc_index::vec::Idx;
-use rustc_middle::middle::lang_items;
 use rustc_middle::mir::*;
 use rustc_middle::traits::Reveal;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::util::IntTypeExt;
 use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_target::abi::VariantIdx;
 use std::fmt;
 
 use std::convert::TryInto;
diff --git a/src/librustc_mir/util/pretty.rs b/src/librustc_mir/util/pretty.rs
index bd7725c1b5af3..38989269c7c37 100644
--- a/src/librustc_mir/util/pretty.rs
+++ b/src/librustc_mir/util/pretty.rs
@@ -9,7 +9,8 @@ use rustc_middle::mir::interpret::{
 };
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::*;
-use rustc_middle::ty::{self, layout::Size, TyCtxt, TypeFoldable, TypeVisitor};
+use rustc_middle::ty::{self, TyCtxt, TypeFoldable, TypeVisitor};
+use rustc_target::abi::Size;
 use std::collections::BTreeSet;
 use std::fmt::Display;
 use std::fmt::Write as _;
diff --git a/src/librustc_mir_build/build/matches/mod.rs b/src/librustc_mir_build/build/matches/mod.rs
index d205ce254d3b2..d353950c4367f 100644
--- a/src/librustc_mir_build/build/matches/mod.rs
+++ b/src/librustc_mir_build/build/matches/mod.rs
@@ -10,16 +10,16 @@ use crate::build::ForGuard::{self, OutsideGuard, RefWithinGuard};
 use crate::build::{BlockAnd, BlockAndExtension, Builder};
 use crate::build::{GuardFrame, GuardFrameLocal, LocalsForNode};
 use crate::hair::{self, *};
-use rustc_middle::middle::region;
-use rustc_middle::mir::*;
-use rustc_middle::ty::layout::VariantIdx;
-use rustc_middle::ty::{self, CanonicalUserTypeAnnotation, Ty};
+use rustc_ast::ast::Name;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::HirId;
 use rustc_index::bit_set::BitSet;
+use rustc_middle::middle::region;
+use rustc_middle::mir::*;
+use rustc_middle::ty::{self, CanonicalUserTypeAnnotation, Ty};
 use rustc_span::Span;
+use rustc_target::abi::VariantIdx;
 use smallvec::{smallvec, SmallVec};
-use rustc_ast::ast::Name;
 
 // helper functions, broken out by category:
 mod simplify;
diff --git a/src/librustc_mir_build/build/matches/simplify.rs b/src/librustc_mir_build/build/matches/simplify.rs
index 664f56ae5e456..d74d8b5c7f318 100644
--- a/src/librustc_mir_build/build/matches/simplify.rs
+++ b/src/librustc_mir_build/build/matches/simplify.rs
@@ -15,12 +15,13 @@
 use crate::build::matches::{Ascription, Binding, Candidate, MatchPair};
 use crate::build::Builder;
 use crate::hair::{self, *};
+use rustc_attr::{SignedInt, UnsignedInt};
+use rustc_hir::RangeEnd;
 use rustc_middle::mir::interpret::truncate;
 use rustc_middle::mir::Place;
 use rustc_middle::ty;
-use rustc_middle::ty::layout::{Integer, IntegerExt, Size};
-use rustc_attr::{SignedInt, UnsignedInt};
-use rustc_hir::RangeEnd;
+use rustc_middle::ty::layout::IntegerExt;
+use rustc_target::abi::{Integer, Size};
 
 use std::mem;
 
diff --git a/src/librustc_mir_build/build/matches/test.rs b/src/librustc_mir_build/build/matches/test.rs
index 01b3cfb7ba05b..42242d772a42a 100644
--- a/src/librustc_mir_build/build/matches/test.rs
+++ b/src/librustc_mir_build/build/matches/test.rs
@@ -9,14 +9,14 @@ use crate::build::matches::{Candidate, MatchPair, Test, TestKind};
 use crate::build::Builder;
 use crate::hair::pattern::compare_const_vals;
 use crate::hair::*;
-use rustc_middle::mir::*;
-use rustc_middle::ty::layout::VariantIdx;
-use rustc_middle::ty::util::IntTypeExt;
-use rustc_middle::ty::{self, adjustment::PointerCast, Ty};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::RangeEnd;
 use rustc_index::bit_set::BitSet;
+use rustc_middle::mir::*;
+use rustc_middle::ty::util::IntTypeExt;
+use rustc_middle::ty::{self, adjustment::PointerCast, Ty};
 use rustc_span::symbol::sym;
+use rustc_target::abi::VariantIdx;
 
 use std::cmp::Ordering;
 
@@ -362,7 +362,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         place: Place<'tcx>,
         mut ty: Ty<'tcx>,
     ) {
-        use rustc_middle::middle::lang_items::EqTraitLangItem;
+        use rustc_hir::lang_items::EqTraitLangItem;
 
         let mut expect = self.literal_operand(source_info.span, value);
         let mut val = Operand::Copy(place);
diff --git a/src/librustc_mir_build/build/mod.rs b/src/librustc_mir_build/build/mod.rs
index c4eb9803b425f..23ab00d536fe4 100644
--- a/src/librustc_mir_build/build/mod.rs
+++ b/src/librustc_mir_build/build/mod.rs
@@ -2,17 +2,17 @@ use crate::build;
 use crate::build::scope::DropKind;
 use crate::hair::cx::Cx;
 use crate::hair::{BindingMode, LintLevel, PatKind};
-use rustc_middle::middle::lang_items;
-use rustc_middle::middle::region;
-use rustc_middle::mir::*;
-use rustc_middle::ty::subst::Subst;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
 use rustc_attr::{self as attr, UnwindAttr};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
+use rustc_hir::lang_items;
 use rustc_hir::{GeneratorKind, HirIdMap, Node};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_infer::infer::TyCtxtInferExt;
+use rustc_middle::middle::region;
+use rustc_middle::mir::*;
+use rustc_middle::ty::subst::Subst;
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
 use rustc_span::symbol::kw;
 use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
diff --git a/src/librustc_mir_build/hair/constant.rs b/src/librustc_mir_build/hair/constant.rs
index 667f29337c2b6..e5af0b5bd6bed 100644
--- a/src/librustc_mir_build/hair/constant.rs
+++ b/src/librustc_mir_build/hair/constant.rs
@@ -2,8 +2,9 @@ use rustc_ast::ast;
 use rustc_middle::mir::interpret::{
     truncate, Allocation, ConstValue, LitToConstError, LitToConstInput, Scalar,
 };
-use rustc_middle::ty::{self, layout::Size, ParamEnv, TyCtxt, TyS};
+use rustc_middle::ty::{self, ParamEnv, TyCtxt, TyS};
 use rustc_span::symbol::Symbol;
+use rustc_target::abi::Size;
 
 crate fn lit_to_const<'tcx>(
     tcx: TyCtxt<'tcx>,
diff --git a/src/librustc_mir_build/hair/cx/mod.rs b/src/librustc_mir_build/hair/cx/mod.rs
index 13a476775db02..503bd26d51fcc 100644
--- a/src/librustc_mir_build/hair/cx/mod.rs
+++ b/src/librustc_mir_build/hair/cx/mod.rs
@@ -14,11 +14,11 @@ use rustc_index::vec::Idx;
 use rustc_infer::infer::InferCtxt;
 use rustc_middle::middle::region;
 use rustc_middle::mir::interpret::{LitToConstError, LitToConstInput};
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::subst::Subst;
 use rustc_middle::ty::subst::{GenericArg, InternalSubsts};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::symbol::{sym, Symbol};
+use rustc_target::abi::VariantIdx;
 use rustc_trait_selection::infer::InferCtxtExt;
 
 #[derive(Clone)]
diff --git a/src/librustc_mir_build/hair/mod.rs b/src/librustc_mir_build/hair/mod.rs
index fadfc7660d4f9..601e4412512ab 100644
--- a/src/librustc_mir_build/hair/mod.rs
+++ b/src/librustc_mir_build/hair/mod.rs
@@ -11,10 +11,10 @@ use rustc_middle::infer::canonical::Canonical;
 use rustc_middle::middle::region;
 use rustc_middle::mir::{BinOp, BorrowKind, Field, UnOp};
 use rustc_middle::ty::adjustment::PointerCast;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{AdtDef, Const, Ty, UpvarSubsts, UserType};
 use rustc_span::Span;
+use rustc_target::abi::VariantIdx;
 
 crate mod constant;
 crate mod cx;
diff --git a/src/librustc_mir_build/hair/pattern/_match.rs b/src/librustc_mir_build/hair/pattern/_match.rs
index 03f668d562e78..8c0843124f4f1 100644
--- a/src/librustc_mir_build/hair/pattern/_match.rs
+++ b/src/librustc_mir_build/hair/pattern/_match.rs
@@ -236,15 +236,16 @@ use super::{compare_const_vals, PatternFoldable, PatternFolder};
 use super::{FieldPat, Pat, PatKind, PatRange};
 
 use rustc_attr::{SignedInt, UnsignedInt};
+use rustc_errors::ErrorReported;
 use rustc_hir::def_id::DefId;
 use rustc_hir::{HirId, RangeEnd};
 use rustc_middle::mir::interpret::{truncate, AllocId, ConstValue, Pointer, Scalar};
 use rustc_middle::mir::Field;
-use rustc_middle::ty::layout::{Integer, IntegerExt, Size, VariantIdx};
+use rustc_middle::ty::layout::IntegerExt;
 use rustc_middle::ty::{self, Const, Ty, TyCtxt, TypeFoldable, VariantDef};
-use rustc_middle::util::common::ErrorReported;
 use rustc_session::lint;
 use rustc_span::{Span, DUMMY_SP};
+use rustc_target::abi::{Integer, Size, VariantIdx};
 
 use arena::TypedArena;
 
diff --git a/src/librustc_mir_build/hair/pattern/mod.rs b/src/librustc_mir_build/hair/pattern/mod.rs
index f15d2fc5caa03..2b6d8e920f5ed 100644
--- a/src/librustc_mir_build/hair/pattern/mod.rs
+++ b/src/librustc_mir_build/hair/pattern/mod.rs
@@ -19,13 +19,13 @@ use rustc_middle::mir::interpret::{get_slice_bytes, sign_extend, ConstValue, Err
 use rustc_middle::mir::interpret::{LitToConstError, LitToConstInput};
 use rustc_middle::mir::UserTypeProjection;
 use rustc_middle::mir::{BorrowKind, Field, Mutability};
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::subst::{GenericArg, SubstsRef};
 use rustc_middle::ty::{self, AdtDef, DefIdTree, Region, Ty, TyCtxt, UserType};
 use rustc_middle::ty::{
     CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations,
 };
 use rustc_span::{Span, DUMMY_SP};
+use rustc_target::abi::VariantIdx;
 
 use std::cmp::Ordering;
 use std::fmt;
@@ -1047,8 +1047,8 @@ crate fn compare_const_vals<'tcx>(
             }
             ty::Int(ity) => {
                 use rustc_attr::SignedInt;
-                use rustc_middle::ty::layout::{Integer, IntegerExt};
-                let size = Integer::from_attr(&tcx, SignedInt(ity)).size();
+                use rustc_middle::ty::layout::IntegerExt;
+                let size = rustc_target::abi::Integer::from_attr(&tcx, SignedInt(ity)).size();
                 let a = sign_extend(a, size);
                 let b = sign_extend(b, size);
                 Some((a as i128).cmp(&(b as i128)))
diff --git a/src/librustc_parse/parser/expr.rs b/src/librustc_parse/parser/expr.rs
index b205a4b322229..cbff99f8da612 100644
--- a/src/librustc_parse/parser/expr.rs
+++ b/src/librustc_parse/parser/expr.rs
@@ -638,6 +638,7 @@ impl<'a> Parser<'a> {
                     ExprKind::MethodCall(_, _) => "a method call",
                     ExprKind::Call(_, _) => "a function call",
                     ExprKind::Await(_) => "`.await`",
+                    ExprKind::Err => return Ok(with_postfix),
                     _ => unreachable!("parse_dot_or_call_expr_with_ shouldn't produce this"),
                 }
             );
diff --git a/src/librustc_passes/intrinsicck.rs b/src/librustc_passes/intrinsicck.rs
index 11096c693e630..cc1af630cdd3c 100644
--- a/src/librustc_passes/intrinsicck.rs
+++ b/src/librustc_passes/intrinsicck.rs
@@ -4,10 +4,11 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
 use rustc_index::vec::Idx;
-use rustc_middle::ty::layout::{LayoutError, Pointer, SizeSkeleton, VariantIdx};
+use rustc_middle::ty::layout::{LayoutError, SizeSkeleton};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::{sym, Span};
+use rustc_target::abi::{Pointer, VariantIdx};
 use rustc_target::spec::abi::Abi::RustIntrinsic;
 
 fn check_mod_intrinsics(tcx: TyCtxt<'_>, module_def_id: DefId) {
diff --git a/src/librustc_passes/layout_test.rs b/src/librustc_passes/layout_test.rs
index 9fa3225851ba1..da8ab727ed3aa 100644
--- a/src/librustc_passes/layout_test.rs
+++ b/src/librustc_passes/layout_test.rs
@@ -3,16 +3,10 @@ use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
 use rustc_hir::ItemKind;
-use rustc_middle::ty::layout::HasDataLayout;
-use rustc_middle::ty::layout::HasParamEnv;
-use rustc_middle::ty::layout::HasTyCtxt;
-use rustc_middle::ty::layout::LayoutOf;
-use rustc_middle::ty::layout::TargetDataLayout;
-use rustc_middle::ty::layout::TyAndLayout;
-use rustc_middle::ty::ParamEnv;
-use rustc_middle::ty::Ty;
-use rustc_middle::ty::TyCtxt;
+use rustc_middle::ty::layout::{HasParamEnv, HasTyCtxt, TyAndLayout};
+use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
 use rustc_span::symbol::sym;
+use rustc_target::abi::{HasDataLayout, LayoutOf, TargetDataLayout};
 
 pub fn test_layout(tcx: TyCtxt<'_>) {
     if tcx.features().rustc_attrs {
diff --git a/src/librustc_passes/weak_lang_items.rs b/src/librustc_passes/weak_lang_items.rs
index 8d11af15b56ff..8e56ef0da5237 100644
--- a/src/librustc_passes/weak_lang_items.rs
+++ b/src/librustc_passes/weak_lang_items.rs
@@ -4,8 +4,8 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
+use rustc_hir::lang_items;
 use rustc_hir::weak_lang_items::WEAK_ITEMS_REFS;
-use rustc_middle::middle::lang_items;
 use rustc_middle::middle::lang_items::whitelisted;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config;
diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs
index 75c5dfb8d18b0..21f43b6fd4f64 100644
--- a/src/librustc_resolve/lib.rs
+++ b/src/librustc_resolve/lib.rs
@@ -2808,7 +2808,7 @@ impl<'a> Resolver<'a> {
             ast::Path {
                 span,
                 segments: iter::once(Ident::with_dummy_span(kw::PathRoot))
-                    .chain({ path_str.split("::").skip(1).map(Ident::from_str) })
+                    .chain(path_str.split("::").skip(1).map(Ident::from_str))
                     .map(|i| self.new_ast_path_segment(i))
                     .collect(),
             }
diff --git a/src/librustc_target/spec/windows_base.rs b/src/librustc_target/spec/windows_base.rs
index 188548b41fe75..5f59ca8a5a311 100644
--- a/src/librustc_target/spec/windows_base.rs
+++ b/src/librustc_target/spec/windows_base.rs
@@ -60,6 +60,8 @@ pub fn opts() -> TargetOptions {
             "-lgcc".to_string(),
             "-lgcc_eh".to_string(),
             "-lpthread".to_string(),
+            // libpthread depends on libmsvcrt, so we need to link it *again*.
+            "-lmsvcrt".to_string(),
             "-lkernel32".to_string(),
         ],
     );
diff --git a/src/librustc_trait_selection/infer.rs b/src/librustc_trait_selection/infer.rs
index d7a2e720a6d0b..24eb22fbd00b1 100644
--- a/src/librustc_trait_selection/infer.rs
+++ b/src/librustc_trait_selection/infer.rs
@@ -2,11 +2,11 @@ use crate::traits::query::outlives_bounds::InferCtxtExt as _;
 use crate::traits::{self, TraitEngine, TraitEngineExt};
 
 use rustc_hir as hir;
+use rustc_hir::lang_items;
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::traits::ObligationCause;
 use rustc_middle::arena::ArenaAllocatable;
 use rustc_middle::infer::canonical::{Canonical, CanonicalizedQueryResponse, QueryResponse};
-use rustc_middle::middle::lang_items;
 use rustc_middle::traits::query::Fallible;
 use rustc_middle::ty::{self, Ty, TypeFoldable};
 use rustc_span::{Span, DUMMY_SP};
diff --git a/src/librustc_trait_selection/traits/mod.rs b/src/librustc_trait_selection/traits/mod.rs
index 3ef44a198417a..928554a6d418e 100644
--- a/src/librustc_trait_selection/traits/mod.rs
+++ b/src/librustc_trait_selection/traits/mod.rs
@@ -24,13 +24,13 @@ use crate::infer::outlives::env::OutlivesEnvironment;
 use crate::infer::{InferCtxt, RegionckMode, TyCtxtInferExt};
 use crate::traits::error_reporting::InferCtxtExt as _;
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
+use rustc_errors::ErrorReported;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_middle::middle::region;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::{InternalSubsts, SubstsRef};
 use rustc_middle::ty::{self, GenericParamDefKind, ToPredicate, Ty, TyCtxt, WithConstness};
-use rustc_middle::util::common::ErrorReported;
 use rustc_span::{Span, DUMMY_SP};
 
 use std::fmt::Debug;
diff --git a/src/librustc_trait_selection/traits/object_safety.rs b/src/librustc_trait_selection/traits/object_safety.rs
index 3877c7f8a8c8e..20b3fa908d201 100644
--- a/src/librustc_trait_selection/traits/object_safety.rs
+++ b/src/librustc_trait_selection/traits/object_safety.rs
@@ -420,7 +420,7 @@ fn virtual_call_violation_for_method<'tcx>(
         } else {
             // Do sanity check to make sure the receiver actually has the layout of a pointer.
 
-            use rustc_middle::ty::layout::Abi;
+            use rustc_target::abi::Abi;
 
             let param_env = tcx.param_env(method.def_id);
 
diff --git a/src/librustc_trait_selection/traits/on_unimplemented.rs b/src/librustc_trait_selection/traits/on_unimplemented.rs
index 23c3bd46d2d80..cf29c4249c019 100644
--- a/src/librustc_trait_selection/traits/on_unimplemented.rs
+++ b/src/librustc_trait_selection/traits/on_unimplemented.rs
@@ -1,13 +1,11 @@
 use fmt_macros::{Parser, Piece, Position};
 
-use rustc_middle::ty::{self, GenericParamDefKind, TyCtxt};
-use rustc_middle::util::common::ErrorReported;
-
 use rustc_ast::ast::{MetaItem, NestedMetaItem};
 use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashMap;
-use rustc_errors::struct_span_err;
+use rustc_errors::{struct_span_err, ErrorReported};
 use rustc_hir::def_id::DefId;
+use rustc_middle::ty::{self, GenericParamDefKind, TyCtxt};
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
 
diff --git a/src/librustc_trait_selection/traits/select.rs b/src/librustc_trait_selection/traits/select.rs
index 1e5a1edd4d8ee..3d95824cdf00e 100644
--- a/src/librustc_trait_selection/traits/select.rs
+++ b/src/librustc_trait_selection/traits/select.rs
@@ -39,9 +39,9 @@ use rustc_ast::attr;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
+use rustc_hir::lang_items;
 use rustc_index::bit_set::GrowableBitSet;
 use rustc_middle::dep_graph::{DepKind, DepNodeIndex};
-use rustc_middle::middle::lang_items;
 use rustc_middle::ty::fast_reject;
 use rustc_middle::ty::relate::TypeRelation;
 use rustc_middle::ty::subst::{Subst, SubstsRef};
diff --git a/src/librustc_trait_selection/traits/wf.rs b/src/librustc_trait_selection/traits/wf.rs
index 59b56d673fb00..1eb41e0b4d1ae 100644
--- a/src/librustc_trait_selection/traits/wf.rs
+++ b/src/librustc_trait_selection/traits/wf.rs
@@ -3,7 +3,7 @@ use crate::opaque_types::required_region_bounds;
 use crate::traits::{self, AssocTypeBoundData};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
-use rustc_middle::middle::lang_items;
+use rustc_hir::lang_items;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness};
 use rustc_span::symbol::{kw, Ident};
diff --git a/src/librustc_ty/common_traits.rs b/src/librustc_ty/common_traits.rs
index 597bc8546045d..265b811571afe 100644
--- a/src/librustc_ty/common_traits.rs
+++ b/src/librustc_ty/common_traits.rs
@@ -1,7 +1,7 @@
 //! Queries for checking whether a type implements one of a few common traits.
 
+use rustc_hir::lang_items;
 use rustc_infer::infer::TyCtxtInferExt;
-use rustc_middle::middle::lang_items;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::DUMMY_SP;
 use rustc_trait_selection::traits;
diff --git a/src/librustc_typeck/astconv.rs b/src/librustc_typeck/astconv.rs
index 932032bb2b45f..c3ebcbfc832d1 100644
--- a/src/librustc_typeck/astconv.rs
+++ b/src/librustc_typeck/astconv.rs
@@ -6,18 +6,18 @@
 // ignore-tidy-filelength
 
 use crate::collect::PlaceholderHirTyCollector;
-use crate::middle::lang_items::SizedTraitLangItem;
 use crate::middle::resolve_lifetime as rl;
 use crate::require_c_abi_if_c_variadic;
-use crate::util::common::ErrorReported;
 use rustc_ast::ast;
 use rustc_ast::util::lev_distance::find_best_match_for_name;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::ErrorReported;
 use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticId, FatalError};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Namespace, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{walk_generics, Visitor as _};
+use rustc_hir::lang_items::SizedTraitLangItem;
 use rustc_hir::{Constness, GenericArg, GenericArgs};
 use rustc_middle::ty::subst::{self, InternalSubsts, Subst, SubstsRef};
 use rustc_middle::ty::{
diff --git a/src/librustc_typeck/check/cast.rs b/src/librustc_typeck/check/cast.rs
index 7f1631a620499..5de0184f2bba9 100644
--- a/src/librustc_typeck/check/cast.rs
+++ b/src/librustc_typeck/check/cast.rs
@@ -32,11 +32,10 @@ use super::FnCtxt;
 
 use crate::hir::def_id::DefId;
 use crate::type_error_struct;
-use crate::util::common::ErrorReported;
 use rustc_ast::ast;
-use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder};
+use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, ErrorReported};
 use rustc_hir as hir;
-use rustc_middle::middle::lang_items;
+use rustc_hir::lang_items;
 use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::cast::{CastKind, CastTy};
 use rustc_middle::ty::error::TypeError;
diff --git a/src/librustc_typeck/check/closure.rs b/src/librustc_typeck/check/closure.rs
index 415b5103104a1..922d9ca6485bb 100644
--- a/src/librustc_typeck/check/closure.rs
+++ b/src/librustc_typeck/check/closure.rs
@@ -3,9 +3,10 @@
 use super::{check_fn, Expectation, FnCtxt, GeneratorTypes};
 
 use crate::astconv::AstConv;
-use crate::middle::{lang_items, region};
+use crate::middle::region;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
+use rustc_hir::lang_items;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::LateBoundRegionConversionTime;
 use rustc_infer::infer::{InferOk, InferResult};
diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs
index 9e45793fcdc72..24db25a1f3456 100644
--- a/src/librustc_typeck/check/compare_method.rs
+++ b/src/librustc_typeck/check/compare_method.rs
@@ -1,4 +1,4 @@
-use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticId};
+use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticId, ErrorReported};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit;
@@ -8,7 +8,6 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::subst::{InternalSubsts, Subst};
 use rustc_middle::ty::util::ExplicitSelf;
 use rustc_middle::ty::{self, GenericParamDefKind, TyCtxt};
-use rustc_middle::util::common::ErrorReported;
 use rustc_span::Span;
 use rustc_trait_selection::traits::error_reporting::InferCtxtExt;
 use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode, Reveal};
diff --git a/src/librustc_typeck/check/dropck.rs b/src/librustc_typeck/check/dropck.rs
index a44a607a70335..72220d93d929d 100644
--- a/src/librustc_typeck/check/dropck.rs
+++ b/src/librustc_typeck/check/dropck.rs
@@ -1,8 +1,7 @@
 use crate::check::regionck::RegionCtxt;
 use crate::hir;
 use crate::hir::def_id::DefId;
-use crate::util::common::ErrorReported;
-use rustc_errors::struct_span_err;
+use rustc_errors::{struct_span_err, ErrorReported};
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::{InferOk, RegionckMode, TyCtxtInferExt};
 use rustc_infer::traits::TraitEngineExt as _;
diff --git a/src/librustc_typeck/check/expr.rs b/src/librustc_typeck/check/expr.rs
index bfcb6fe35fe75..9c57ffaf055ac 100644
--- a/src/librustc_typeck/check/expr.rs
+++ b/src/librustc_typeck/check/expr.rs
@@ -15,19 +15,19 @@ use crate::check::FnCtxt;
 use crate::check::Needs;
 use crate::check::TupleArgumentsFlag::DontTupleArguments;
 use crate::type_error_struct;
-use crate::util::common::ErrorReported;
 
 use rustc_ast::ast;
 use rustc_ast::util::lev_distance::find_best_match_for_name;
 use rustc_data_structures::fx::FxHashMap;
+use rustc_errors::ErrorReported;
 use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticBuilder, DiagnosticId};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::def_id::DefId;
+use rustc_hir::lang_items;
 use rustc_hir::{ExprKind, QPath};
 use rustc_infer::infer;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
-use rustc_middle::middle::lang_items;
 use rustc_middle::ty;
 use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability,
diff --git a/src/librustc_typeck/check/method/suggest.rs b/src/librustc_typeck/check/method/suggest.rs
index c8632086771f9..add706b5fcc9a 100644
--- a/src/librustc_typeck/check/method/suggest.rs
+++ b/src/librustc_typeck/check/method/suggest.rs
@@ -2,7 +2,6 @@
 //! found or is otherwise invalid.
 
 use crate::check::FnCtxt;
-use crate::middle::lang_items::FnOnceTraitLangItem;
 use rustc_ast::ast;
 use rustc_ast::util::lev_distance;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
@@ -11,6 +10,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Namespace, Res};
 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc_hir::intravisit;
+use rustc_hir::lang_items::FnOnceTraitLangItem;
 use rustc_hir::{ExprKind, Node, QPath};
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_middle::hir::map as hir_map;
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 6249e1d49779e..c3a4c0c873354 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -88,18 +88,19 @@ mod wfcheck;
 pub mod writeback;
 
 use crate::astconv::{AstConv, GenericArgCountMismatch, PathSeg};
-use crate::middle::lang_items;
 use rustc_ast::ast;
 use rustc_ast::util::parser::ExprPrecedence;
 use rustc_attr as attr;
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::ErrorReported;
 use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticBuilder, DiagnosticId};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId, LOCAL_CRATE};
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
+use rustc_hir::lang_items;
 use rustc_hir::{ExprKind, GenericArg, HirIdMap, Item, ItemKind, Node, PatKind, QPath};
 use rustc_index::vec::Idx;
 use rustc_infer::infer::canonical::{Canonical, OriginalQueryValues, QueryResponse};
@@ -114,7 +115,6 @@ use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability, PointerCast,
 };
 use rustc_middle::ty::fold::{TypeFoldable, TypeFolder};
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::subst::{
     GenericArgKind, InternalSubsts, Subst, SubstsRef, UserSelfTy, UserSubsts,
@@ -132,6 +132,7 @@ use rustc_span::hygiene::DesugaringKind;
 use rustc_span::source_map::{original_sp, DUMMY_SP};
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::{self, BytePos, MultiSpan, Span};
+use rustc_target::abi::VariantIdx;
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::infer::InferCtxtExt as _;
 use rustc_trait_selection::opaque_types::{InferCtxtExt as _, OpaqueTypeDecl};
@@ -151,7 +152,7 @@ use std::ops::{self, Deref};
 use std::slice;
 
 use crate::require_c_abi_if_c_variadic;
-use crate::util::common::{indenter, ErrorReported};
+use crate::util::common::indenter;
 use crate::TypeAndSubsts;
 
 use self::autoderef::Autoderef;
diff --git a/src/librustc_typeck/check/wfcheck.rs b/src/librustc_typeck/check/wfcheck.rs
index 6419113219162..30a53cbc397e8 100644
--- a/src/librustc_typeck/check/wfcheck.rs
+++ b/src/librustc_typeck/check/wfcheck.rs
@@ -7,8 +7,8 @@ use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::itemlikevisit::ParItemLikeVisitor;
+use rustc_hir::lang_items;
 use rustc_hir::ItemKind;
-use rustc_middle::middle::lang_items;
 use rustc_middle::ty::subst::{InternalSubsts, Subst};
 use rustc_middle::ty::trait_def::TraitSpecializationKind;
 use rustc_middle::ty::{
diff --git a/src/librustc_typeck/coherence/builtin.rs b/src/librustc_typeck/coherence/builtin.rs
index 32963b6a1f085..384a22d010e56 100644
--- a/src/librustc_typeck/coherence/builtin.rs
+++ b/src/librustc_typeck/coherence/builtin.rs
@@ -4,11 +4,11 @@
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
+use rustc_hir::lang_items::UnsizeTraitLangItem;
 use rustc_hir::ItemKind;
 use rustc_infer::infer;
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::{RegionckMode, TyCtxtInferExt};
-use rustc_middle::middle::lang_items::UnsizeTraitLangItem;
 use rustc_middle::middle::region;
 use rustc_middle::ty::adjustment::CoerceUnsizedInfo;
 use rustc_middle::ty::TypeFoldable;
diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs
index 30887f840321b..13c6670f6b226 100644
--- a/src/librustc_typeck/collect.rs
+++ b/src/librustc_typeck/collect.rs
@@ -17,7 +17,6 @@
 use crate::astconv::{AstConv, Bounds, SizedByDefault};
 use crate::check::intrinsic::intrinsic_operation_unsafety;
 use crate::constrained_generic_params as cgp;
-use crate::middle::lang_items;
 use crate::middle::resolve_lifetime as rl;
 use rustc_ast::ast;
 use rustc_ast::ast::{Ident, MetaItemKind};
@@ -29,6 +28,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
+use rustc_hir::weak_lang_items;
 use rustc_hir::{GenericParamKind, Node, Unsafety};
 use rustc_middle::hir::map::blocks::FnLikeNode;
 use rustc_middle::hir::map::Map;
@@ -2569,7 +2569,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
     if tcx.is_weak_lang_item(id) {
         codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL;
     }
-    if let Some(name) = lang_items::link_name(&attrs) {
+    if let Some(name) = weak_lang_items::link_name(&attrs) {
         codegen_fn_attrs.export_name = Some(name);
         codegen_fn_attrs.link_name = Some(name);
     }
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index 1927b9c99e175..7ea6c1c17869a 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -89,7 +89,7 @@ mod outlives;
 mod structured_errors;
 mod variance;
 
-use rustc_errors::struct_span_err;
+use rustc_errors::{struct_span_err, ErrorReported};
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::Node;
@@ -100,7 +100,6 @@ use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::util;
-use rustc_middle::util::common::ErrorReported;
 use rustc_session::config::EntryFnType;
 use rustc_span::{Span, DUMMY_SP};
 use rustc_target::spec::abi::Abi;
diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index 9f327b0b743d8..73df844a91b80 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -1,5 +1,6 @@
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
+use rustc_hir::lang_items;
 use rustc_middle::ty::{self, Region, RegionVid, TypeFoldable};
 use rustc_trait_selection::traits::auto_trait::{self, AutoTraitResult};
 
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index f8e44bc5a1ab7..e027db8b56c00 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -17,7 +17,6 @@ use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
-use rustc_middle::middle::lang_items;
 use rustc_middle::middle::resolve_lifetime as rl;
 use rustc_middle::middle::stability;
 use rustc_middle::ty::fold::TypeFolder;
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 7b3fd82479ebb..2e5ecacee12df 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -15,15 +15,15 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::def_id::{CrateNum, DefId};
+use rustc_hir::lang_items;
 use rustc_hir::Mutability;
 use rustc_index::vec::IndexVec;
-use rustc_middle::middle::lang_items;
 use rustc_middle::middle::stability;
-use rustc_middle::ty::layout::VariantIdx;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::source_map::DUMMY_SP;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{self, FileName};
+use rustc_target::abi::VariantIdx;
 use rustc_target::spec::abi::Abi;
 
 use crate::clean::cfg::Cfg;
diff --git a/src/librustdoc/test.rs b/src/librustdoc/test.rs
index f9e9a07914d69..7841d5eef58a8 100644
--- a/src/librustdoc/test.rs
+++ b/src/librustdoc/test.rs
@@ -1,12 +1,12 @@
 use rustc_ast::ast;
 use rustc_ast::with_globals;
 use rustc_data_structures::sync::Lrc;
+use rustc_errors::ErrorReported;
 use rustc_feature::UnstableFeatures;
 use rustc_hir as hir;
 use rustc_hir::intravisit;
 use rustc_interface::interface;
 use rustc_middle::hir::map::Map;
-use rustc_middle::util::common::ErrorReported;
 use rustc_session::{self, config, DiagnosticOutput, Session};
 use rustc_span::edition::Edition;
 use rustc_span::source_map::SourceMap;
diff --git a/src/libstd/sys/windows/handle.rs b/src/libstd/sys/windows/handle.rs
index f2ad057b6b624..d00381792e351 100644
--- a/src/libstd/sys/windows/handle.rs
+++ b/src/libstd/sys/windows/handle.rs
@@ -115,8 +115,7 @@ impl RawHandle {
     ) -> io::Result<Option<usize>> {
         let len = cmp::min(buf.len(), <c::DWORD>::max_value() as usize) as c::DWORD;
         let mut amt = 0;
-        let res =
-            cvt({ c::ReadFile(self.0, buf.as_ptr() as c::LPVOID, len, &mut amt, overlapped) });
+        let res = cvt(c::ReadFile(self.0, buf.as_ptr() as c::LPVOID, len, &mut amt, overlapped));
         match res {
             Ok(_) => Ok(Some(amt as usize)),
             Err(e) => {
@@ -139,7 +138,7 @@ impl RawHandle {
         unsafe {
             let mut bytes = 0;
             let wait = if wait { c::TRUE } else { c::FALSE };
-            let res = cvt({ c::GetOverlappedResult(self.raw(), overlapped, &mut bytes, wait) });
+            let res = cvt(c::GetOverlappedResult(self.raw(), overlapped, &mut bytes, wait));
             match res {
                 Ok(_) => Ok(bytes as usize),
                 Err(e) => {
diff --git a/src/test/incremental/const-generics/issue-61516.rs b/src/test/incremental/const-generics/issue-61516.rs
index a7465b77267a5..a193bf998dc73 100644
--- a/src/test/incremental/const-generics/issue-61516.rs
+++ b/src/test/incremental/const-generics/issue-61516.rs
@@ -4,7 +4,7 @@
 
 struct FakeArray<T, const N: usize>(T);
 
-impl<T, const N: usize> FakeArray<T, { N }> {
+impl<T, const N: usize> FakeArray<T, N> {
     fn len(&self) -> usize {
         N
     }
diff --git a/src/test/ui-fulldeps/undef_mask.rs b/src/test/ui-fulldeps/undef_mask.rs
index cbf1b63d22b0f..656d0b451bc2b 100644
--- a/src/test/ui-fulldeps/undef_mask.rs
+++ b/src/test/ui-fulldeps/undef_mask.rs
@@ -5,9 +5,10 @@
 #![feature(rustc_private)]
 
 extern crate rustc_middle;
+extern crate rustc_target;
 
 use rustc_middle::mir::interpret::UndefMask;
-use rustc_middle::ty::layout::Size;
+use rustc_target::abi::Size;
 
 fn main() {
     let mut mask = UndefMask::new(Size::from_bytes(500), false);
diff --git a/src/test/ui/array-slice-vec/vec-fixed-length.rs b/src/test/ui/array-slice-vec/vec-fixed-length.rs
index 5db02ee066bbe..908c39c7951c0 100644
--- a/src/test/ui/array-slice-vec/vec-fixed-length.rs
+++ b/src/test/ui/array-slice-vec/vec-fixed-length.rs
@@ -9,7 +9,7 @@ fn test_big_vec() {}
 #[cfg(target_pointer_width = "64")]
 fn test_big_vec()
 {
-    assert_eq!(size_of::<[u8; (1 << 32)]>(), (1 << 32));
+    assert_eq!(size_of::<[u8; 1 << 32]>(), (1 << 32));
 }
 
 fn main() {
diff --git a/src/test/ui/block-fn-coerce.rs b/src/test/ui/block-fn-coerce.rs
index fc5f51d46b255..d993ad9945974 100644
--- a/src/test/ui/block-fn-coerce.rs
+++ b/src/test/ui/block-fn-coerce.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 
 fn force<F>(f: F) -> isize where F: FnOnce() -> isize { return f(); }
 
diff --git a/src/test/ui/cleanup-rvalue-scopes.rs b/src/test/ui/cleanup-rvalue-scopes.rs
index f51f13abf792f..c5dd87c0f5a1f 100644
--- a/src/test/ui/cleanup-rvalue-scopes.rs
+++ b/src/test/ui/cleanup-rvalue-scopes.rs
@@ -1,5 +1,5 @@
 // run-pass
-
+#![allow(unused_braces)]
 #![allow(non_snake_case)]
 #![allow(unused_variables)]
 // Test that destructors for rvalue temporaries run either at end of
diff --git a/src/test/ui/coerce/coerce-expect-unsized.rs b/src/test/ui/coerce/coerce-expect-unsized.rs
index b44aa6ab37760..d486fdf73aba8 100644
--- a/src/test/ui/coerce/coerce-expect-unsized.rs
+++ b/src/test/ui/coerce/coerce-expect-unsized.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 #![feature(box_syntax)]
 
 use std::cell::RefCell;
diff --git a/src/test/ui/coerce/coerce-overloaded-autoderef.rs b/src/test/ui/coerce/coerce-overloaded-autoderef.rs
index 3fe18103ef8c3..d5484607c8b52 100644
--- a/src/test/ui/coerce/coerce-overloaded-autoderef.rs
+++ b/src/test/ui/coerce/coerce-overloaded-autoderef.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 #![allow(dead_code)]
 // pretty-expanded FIXME #23616
 
diff --git a/src/test/ui/const-generics/issues/issue-62504.rs b/src/test/ui/const-generics/issues/issue-62504.rs
index cd3cfaac3b95b..212e16253f6b8 100644
--- a/src/test/ui/const-generics/issues/issue-62504.rs
+++ b/src/test/ui/const-generics/issues/issue-62504.rs
@@ -7,13 +7,13 @@ trait HasSize {
     const SIZE: usize;
 }
 
-impl<const X: usize> HasSize for ArrayHolder<{ X }> {
+impl<const X: usize> HasSize for ArrayHolder<X> {
     const SIZE: usize = X;
 }
 
 struct ArrayHolder<const X: usize>([u32; X]);
 
-impl<const X: usize> ArrayHolder<{ X }> {
+impl<const X: usize> ArrayHolder<X> {
     pub const fn new() -> Self {
         ArrayHolder([0; Self::SIZE])
         //~^ ERROR: mismatched types
diff --git a/src/test/ui/const-generics/issues/issue-70125-2.rs b/src/test/ui/const-generics/issues/issue-70125-2.rs
index ea7a68c2f93d9..a3eca0dd7d965 100644
--- a/src/test/ui/const-generics/issues/issue-70125-2.rs
+++ b/src/test/ui/const-generics/issues/issue-70125-2.rs
@@ -13,4 +13,4 @@ trait Foo<const X: usize> {
     }
 }
 
-impl Foo<{3}> for () {}
+impl Foo<3> for () {}
diff --git a/src/test/ui/const-generics/unused_braces.rs b/src/test/ui/const-generics/unused_braces.rs
new file mode 100644
index 0000000000000..05234faf71420
--- /dev/null
+++ b/src/test/ui/const-generics/unused_braces.rs
@@ -0,0 +1,13 @@
+// check-pass
+#![warn(unused_braces)]
+
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+struct A<const N: usize>;
+
+fn main() {
+    let _: A<7>; // ok
+    let _: A<{ 7 }>; //~ WARN unnecessary braces
+    let _: A<{ 3 + 5 }>; // ok
+}
diff --git a/src/test/ui/const-generics/unused_braces.stderr b/src/test/ui/const-generics/unused_braces.stderr
new file mode 100644
index 0000000000000..fc3da6096e7d4
--- /dev/null
+++ b/src/test/ui/const-generics/unused_braces.stderr
@@ -0,0 +1,20 @@
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+  --> $DIR/unused_braces.rs:4:12
+   |
+LL | #![feature(const_generics)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: unnecessary braces around const expression
+  --> $DIR/unused_braces.rs:11:14
+   |
+LL |     let _: A<{ 7 }>;
+   |              ^^^^^ help: remove these braces
+   |
+note: the lint level is defined here
+  --> $DIR/unused_braces.rs:2:9
+   |
+LL | #![warn(unused_braces)]
+   |         ^^^^^^^^^^^^^
+
diff --git a/src/test/ui/consts/const-block.rs b/src/test/ui/consts/const-block.rs
index 7172a34c8cfeb..ec99c70f6e0b9 100644
--- a/src/test/ui/consts/const-block.rs
+++ b/src/test/ui/consts/const-block.rs
@@ -1,5 +1,5 @@
 // run-pass
-
+#![allow(unused_braces)]
 #![allow(dead_code)]
 #![allow(unused_unsafe)]
 
diff --git a/src/test/ui/expr-block-generic-unique1.rs b/src/test/ui/expr-block-generic-unique1.rs
index c14191f2ffcb5..d081cb2be7ee3 100644
--- a/src/test/ui/expr-block-generic-unique1.rs
+++ b/src/test/ui/expr-block-generic-unique1.rs
@@ -1,5 +1,5 @@
 // run-pass
-
+#![allow(unused_braces)]
 #![feature(box_syntax)]
 
 fn test_generic<T, F>(expected: Box<T>, eq: F) where T: Clone, F: FnOnce(Box<T>, Box<T>) -> bool {
diff --git a/src/test/ui/expr-block-generic-unique2.rs b/src/test/ui/expr-block-generic-unique2.rs
index 90ebc02931ad1..9362eb86fc309 100644
--- a/src/test/ui/expr-block-generic-unique2.rs
+++ b/src/test/ui/expr-block-generic-unique2.rs
@@ -1,5 +1,5 @@
 // run-pass
-
+#![allow(unused_braces)]
 #![feature(box_syntax)]
 
 fn test_generic<T, F>(expected: T, eq: F) where T: Clone, F: FnOnce(T, T) -> bool {
diff --git a/src/test/ui/expr-block-generic.rs b/src/test/ui/expr-block-generic.rs
index ec93f59722d0c..29c7c42219c73 100644
--- a/src/test/ui/expr-block-generic.rs
+++ b/src/test/ui/expr-block-generic.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 
 fn test_generic<T: Clone, F>(expected: T, eq: F) where F: FnOnce(T, T) -> bool {
     let actual: T = { expected.clone() };
diff --git a/src/test/ui/expr-block-unique.rs b/src/test/ui/expr-block-unique.rs
index fe1a7d9f1fb31..eff3fd3a15152 100644
--- a/src/test/ui/expr-block-unique.rs
+++ b/src/test/ui/expr-block-unique.rs
@@ -1,5 +1,5 @@
 // run-pass
-
+#![allow(unused_braces)]
 #![feature(box_syntax)]
 
 pub fn main() { let x: Box<_> = { box 100 }; assert_eq!(*x, 100); }
diff --git a/src/test/ui/expr-block.rs b/src/test/ui/expr-block.rs
index 549ccf9774f43..ff87595c934e9 100644
--- a/src/test/ui/expr-block.rs
+++ b/src/test/ui/expr-block.rs
@@ -1,10 +1,7 @@
 // run-pass
-
+#![allow(unused_braces)]
 #![allow(dead_code)]
 
-
-
-
 // Tests for standalone blocks as expressions
 
 fn test_basic() { let rs: bool = { true }; assert!((rs)); }
diff --git a/src/test/ui/expr-fn.rs b/src/test/ui/expr-fn.rs
index af809f563fc04..253cbfd5d38fa 100644
--- a/src/test/ui/expr-fn.rs
+++ b/src/test/ui/expr-fn.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 
 fn test_int() {
     fn f() -> isize { 10 }
diff --git a/src/test/ui/functions-closures/closure-inference.rs b/src/test/ui/functions-closures/closure-inference.rs
index 96878445245bc..1877414f09942 100644
--- a/src/test/ui/functions-closures/closure-inference.rs
+++ b/src/test/ui/functions-closures/closure-inference.rs
@@ -1,5 +1,5 @@
 // run-pass
-
+#![allow(unused_braces)]
 
 fn foo(i: isize) -> isize { i + 1 }
 
diff --git a/src/test/ui/functions-closures/closure-inference2.rs b/src/test/ui/functions-closures/closure-inference2.rs
index f2dfa5888aac5..4ce132e86caa4 100644
--- a/src/test/ui/functions-closures/closure-inference2.rs
+++ b/src/test/ui/functions-closures/closure-inference2.rs
@@ -1,6 +1,6 @@
 // run-pass
 // Test a rather underspecified example:
-
+#![allow(unused_braces)]
 
 pub fn main() {
     let f = {|i| i};
diff --git a/src/test/ui/intrinsics/intrinsic-move-val-cleanups.rs b/src/test/ui/intrinsics/intrinsic-move-val-cleanups.rs
index a2068429af5ea..9804c421db081 100644
--- a/src/test/ui/intrinsics/intrinsic-move-val-cleanups.rs
+++ b/src/test/ui/intrinsics/intrinsic-move-val-cleanups.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 #![allow(unused_unsafe)]
 #![allow(unreachable_code)]
 // ignore-emscripten no threads support
diff --git a/src/test/ui/issues/issue-23898.rs b/src/test/ui/issues/issue-23898.rs
index a8787f279b71b..3de365675ad22 100644
--- a/src/test/ui/issues/issue-23898.rs
+++ b/src/test/ui/issues/issue-23898.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_parens)]
 #![allow(non_camel_case_types)]
 
 // Note: This test was used to demonstrate #5873 (now #23898).
diff --git a/src/test/ui/issues/issue-28777.rs b/src/test/ui/issues/issue-28777.rs
index 74de00adadbda..1f426b7185e8f 100644
--- a/src/test/ui/issues/issue-28777.rs
+++ b/src/test/ui/issues/issue-28777.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 fn main() {
     let v1 = { 1 + {2} * {3} };
     let v2 =   1 + {2} * {3}  ;
diff --git a/src/test/ui/lint/lint-unnecessary-parens.rs b/src/test/ui/lint/lint-unnecessary-parens.rs
index 5ce1f57608132..623cd04d9bce3 100644
--- a/src/test/ui/lint/lint-unnecessary-parens.rs
+++ b/src/test/ui/lint/lint-unnecessary-parens.rs
@@ -48,11 +48,11 @@ fn main() {
     if (true) {} //~ ERROR unnecessary parentheses around `if` condition
     while (true) {} //~ ERROR unnecessary parentheses around `while` condition
     //~^ WARN denote infinite loops with
-    match (true) { //~ ERROR unnecessary parentheses around `match` head expression
+    match (true) { //~ ERROR unnecessary parentheses around `match` scrutinee expression
         _ => {}
     }
-    if let 1 = (1) {} //~ ERROR unnecessary parentheses around `let` head expression
-    while let 1 = (2) {} //~ ERROR unnecessary parentheses around `let` head expression
+    if let 1 = (1) {} //~ ERROR unnecessary parentheses around `let` scrutinee expression
+    while let 1 = (2) {} //~ ERROR unnecessary parentheses around `let` scrutinee expression
     let v = X { y: false };
     // struct lits needs parens, so these shouldn't warn.
     if (v == X { y: true }) {}
diff --git a/src/test/ui/lint/lint-unnecessary-parens.stderr b/src/test/ui/lint/lint-unnecessary-parens.stderr
index 8858c95327322..15184ba36ae85 100644
--- a/src/test/ui/lint/lint-unnecessary-parens.stderr
+++ b/src/test/ui/lint/lint-unnecessary-parens.stderr
@@ -72,19 +72,19 @@ LL |     while (true) {}
    |
    = note: `#[warn(while_true)]` on by default
 
-error: unnecessary parentheses around `match` head expression
+error: unnecessary parentheses around `match` scrutinee expression
   --> $DIR/lint-unnecessary-parens.rs:51:11
    |
 LL |     match (true) {
    |           ^^^^^^ help: remove these parentheses
 
-error: unnecessary parentheses around `let` head expression
+error: unnecessary parentheses around `let` scrutinee expression
   --> $DIR/lint-unnecessary-parens.rs:54:16
    |
 LL |     if let 1 = (1) {}
    |                ^^^ help: remove these parentheses
 
-error: unnecessary parentheses around `let` head expression
+error: unnecessary parentheses around `let` scrutinee expression
   --> $DIR/lint-unnecessary-parens.rs:55:19
    |
 LL |     while let 1 = (2) {}
diff --git a/src/test/ui/lint/unused_braces.rs b/src/test/ui/lint/unused_braces.rs
new file mode 100644
index 0000000000000..de456ee6c230c
--- /dev/null
+++ b/src/test/ui/lint/unused_braces.rs
@@ -0,0 +1,31 @@
+// check-pass
+#![warn(unused_braces, unused_parens)]
+
+fn main() {
+    let _ = (7);
+    //~^WARN unnecessary parentheses
+
+    let _ = { 7 };
+    //~^ WARN unnecessary braces
+
+    if let 7 = { 7 } {
+        //~^ WARN unnecessary braces
+    }
+
+    let _: [u8; { 3 }];
+    //~^ WARN unnecessary braces
+
+    // do not emit error for multiline blocks.
+    let _ = {
+        7
+    };
+
+    // do not emit error for unsafe blocks.
+    let _ = unsafe { 7 };
+
+    // do not emit error, as the `{` would then
+    // be parsed as part of the `return`.
+    if { return } {
+
+    }
+}
diff --git a/src/test/ui/lint/unused_braces.stderr b/src/test/ui/lint/unused_braces.stderr
new file mode 100644
index 0000000000000..72f425ffc3e01
--- /dev/null
+++ b/src/test/ui/lint/unused_braces.stderr
@@ -0,0 +1,36 @@
+warning: unnecessary parentheses around assigned value
+  --> $DIR/unused_braces.rs:5:13
+   |
+LL |     let _ = (7);
+   |             ^^^ help: remove these parentheses
+   |
+note: the lint level is defined here
+  --> $DIR/unused_braces.rs:2:24
+   |
+LL | #![warn(unused_braces, unused_parens)]
+   |                        ^^^^^^^^^^^^^
+
+warning: unnecessary braces around assigned value
+  --> $DIR/unused_braces.rs:8:13
+   |
+LL |     let _ = { 7 };
+   |             ^^^^^ help: remove these braces
+   |
+note: the lint level is defined here
+  --> $DIR/unused_braces.rs:2:9
+   |
+LL | #![warn(unused_braces, unused_parens)]
+   |         ^^^^^^^^^^^^^
+
+warning: unnecessary braces around `let` scrutinee expression
+  --> $DIR/unused_braces.rs:11:16
+   |
+LL |     if let 7 = { 7 } {
+   |                ^^^^^ help: remove these braces
+
+warning: unnecessary braces around const expression
+  --> $DIR/unused_braces.rs:15:17
+   |
+LL |     let _: [u8; { 3 }];
+   |                 ^^^^^ help: remove these braces
+
diff --git a/src/test/ui/lint/unused_parens_borrow.rs b/src/test/ui/lint/unused_parens_borrow.rs
new file mode 100644
index 0000000000000..98dbbecfedde6
--- /dev/null
+++ b/src/test/ui/lint/unused_parens_borrow.rs
@@ -0,0 +1,22 @@
+// check-pass
+#![warn(unused_braces)]
+
+// changing `&{ expr }` to `&expr` changes the semantic of the program
+// so we should not warn this case
+
+#[repr(packed)]
+struct A {
+    a: u8,
+    b: u32,
+}
+
+fn main() {
+    let a = A {
+        a: 42,
+        b: 1729,
+    };
+
+    let _ = &{ a.b };
+    let _ = { a.b };
+    //~^ WARN unnecessary braces
+}
diff --git a/src/test/ui/lint/unused_parens_borrow.stderr b/src/test/ui/lint/unused_parens_borrow.stderr
new file mode 100644
index 0000000000000..7e3839ae4e014
--- /dev/null
+++ b/src/test/ui/lint/unused_parens_borrow.stderr
@@ -0,0 +1,12 @@
+warning: unnecessary braces around assigned value
+  --> $DIR/unused_parens_borrow.rs:20:13
+   |
+LL |     let _ = { a.b };
+   |             ^^^^^^^ help: remove these braces
+   |
+note: the lint level is defined here
+  --> $DIR/unused_parens_borrow.rs:2:9
+   |
+LL | #![warn(unused_braces)]
+   |         ^^^^^^^^^^^^^
+
diff --git a/src/test/ui/lint/unused_parens_remove_json_suggestion.stderr b/src/test/ui/lint/unused_parens_remove_json_suggestion.stderr
index c3bf77a3a6f2d..5fb67fd7c95a3 100644
--- a/src/test/ui/lint/unused_parens_remove_json_suggestion.stderr
+++ b/src/test/ui/lint/unused_parens_remove_json_suggestion.stderr
@@ -46,14 +46,14 @@ LL |     while(true && false) {
    |          ^^^^^^^^^^^^^^^ help: remove these parentheses
 
 "}
-{"message":"unnecessary parentheses around `for` head expression","code":{"code":"unused_parens","explanation":null},"level":"error","spans":[{"file_name":"$DIR/unused_parens_remove_json_suggestion.rs","byte_start":987,"byte_end":995,"line_start":44,"line_end":44,"column_start":18,"column_end":26,"is_primary":true,"text":[{"text":"        for _ in (0 .. 3){
+{"message":"unnecessary parentheses around `for` iterator expression","code":{"code":"unused_parens","explanation":null},"level":"error","spans":[{"file_name":"$DIR/unused_parens_remove_json_suggestion.rs","byte_start":987,"byte_end":995,"line_start":44,"line_end":44,"column_start":18,"column_end":26,"is_primary":true,"text":[{"text":"        for _ in (0 .. 3){
   --> $DIR/unused_parens_remove_json_suggestion.rs:44:18
    |
 LL |         for _ in (0 .. 3){
    |                  ^^^^^^^^ help: remove these parentheses
 
 "}
-{"message":"unnecessary parentheses around `for` head expression","code":{"code":"unused_parens","explanation":null},"level":"error","spans":[{"file_name":"$DIR/unused_parens_remove_json_suggestion.rs","byte_start":1088,"byte_end":1096,"line_start":49,"line_end":49,"column_start":14,"column_end":22,"is_primary":true,"text":[{"text":"    for _ in (0 .. 3) {
+{"message":"unnecessary parentheses around `for` iterator expression","code":{"code":"unused_parens","explanation":null},"level":"error","spans":[{"file_name":"$DIR/unused_parens_remove_json_suggestion.rs","byte_start":1088,"byte_end":1096,"line_start":49,"line_end":49,"column_start":14,"column_end":22,"is_primary":true,"text":[{"text":"    for _ in (0 .. 3) {
   --> $DIR/unused_parens_remove_json_suggestion.rs:49:14
    |
 LL |     for _ in (0 .. 3) {
diff --git a/src/test/ui/parser/issue-70552-ascription-in-parens-after-call.rs b/src/test/ui/parser/issue-70552-ascription-in-parens-after-call.rs
new file mode 100644
index 0000000000000..9b6dd7db4beb3
--- /dev/null
+++ b/src/test/ui/parser/issue-70552-ascription-in-parens-after-call.rs
@@ -0,0 +1,3 @@
+fn main() {
+    expr as fun()(:); //~ ERROR expected expression
+}
diff --git a/src/test/ui/parser/issue-70552-ascription-in-parens-after-call.stderr b/src/test/ui/parser/issue-70552-ascription-in-parens-after-call.stderr
new file mode 100644
index 0000000000000..f03c92e1b1f17
--- /dev/null
+++ b/src/test/ui/parser/issue-70552-ascription-in-parens-after-call.stderr
@@ -0,0 +1,8 @@
+error: expected expression, found `:`
+  --> $DIR/issue-70552-ascription-in-parens-after-call.rs:2:19
+   |
+LL |     expr as fun()(:);
+   |                   ^ expected expression
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/range.rs b/src/test/ui/range.rs
index 82983e37ea18e..f3f7508d12434 100644
--- a/src/test/ui/range.rs
+++ b/src/test/ui/range.rs
@@ -1,5 +1,5 @@
 // run-pass
-
+#![allow(unused_braces)]
 #![allow(unused_comparisons)]
 #![allow(dead_code)]
 #![allow(unused_mut)]
diff --git a/src/test/ui/range_inclusive.rs b/src/test/ui/range_inclusive.rs
index 68d9bf7d26b69..540b35e0392de 100644
--- a/src/test/ui/range_inclusive.rs
+++ b/src/test/ui/range_inclusive.rs
@@ -1,7 +1,7 @@
 // run-pass
 // Test inclusive range syntax.
-
 #![feature(range_is_empty)]
+#![allow(unused_braces)]
 #![allow(unused_comparisons)]
 
 use std::ops::RangeToInclusive;
diff --git a/src/test/ui/structs-enums/empty-tag.rs b/src/test/ui/structs-enums/empty-tag.rs
index 56a438200c00b..271ab72c74fc1 100644
--- a/src/test/ui/structs-enums/empty-tag.rs
+++ b/src/test/ui/structs-enums/empty-tag.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 #![allow(non_camel_case_types)]
 
 #[derive(Copy, Clone, Debug)]
diff --git a/src/test/ui/type-alias-impl-trait/assoc-type-const.rs b/src/test/ui/type-alias-impl-trait/assoc-type-const.rs
index 2907c21c6203c..7f3f86e4df009 100644
--- a/src/test/ui/type-alias-impl-trait/assoc-type-const.rs
+++ b/src/test/ui/type-alias-impl-trait/assoc-type-const.rs
@@ -18,16 +18,16 @@ trait MyTrait<'a, const C: usize> {
     const MY_CONST: usize;
 }
 
-impl<'a, const C: usize> MyTrait<'a, { C }> for MyStruct<{ C }> {
+impl<'a, const C: usize> MyTrait<'a, C> for MyStruct<C> {
     type MyItem = u8;
     const MY_CONST: usize = C;
 }
 
-impl<'a, I, const C: usize> UnwrapItemsExt<'a, { C }> for I {
-    type Iter = impl MyTrait<'a, { C }>;
+impl<'a, I, const C: usize> UnwrapItemsExt<'a, C> for I {
+    type Iter = impl MyTrait<'a, C>;
 
     fn unwrap_items(self) -> Self::Iter {
-        MyStruct::<{ C }> {}
+        MyStruct::<C> {}
     }
 }
 
diff --git a/src/test/ui/unsized-locals/unsized-exprs-rpass.rs b/src/test/ui/unsized-locals/unsized-exprs-rpass.rs
index bc64fcdec2e39..24c2758a0a255 100644
--- a/src/test/ui/unsized-locals/unsized-exprs-rpass.rs
+++ b/src/test/ui/unsized-locals/unsized-exprs-rpass.rs
@@ -1,5 +1,5 @@
 // run-pass
-
+#![allow(unused_braces, unused_parens)]
 #![feature(unsized_tuple_coercion, unsized_locals)]
 
 struct A<X: ?Sized>(X);
@@ -30,7 +30,6 @@ fn main() {
         *foo()
     });
     udrop::<[u8]>({*foo()});
-    #[allow(unused_parens)]
     udrop::<[u8]>((*foo()));
     udrop::<[u8]>((*tfoo()).1);
     *afoo() + 42;
diff --git a/src/test/ui/weird-exprs.rs b/src/test/ui/weird-exprs.rs
index ca68a5af0ddca..d812bbd011e0e 100644
--- a/src/test/ui/weird-exprs.rs
+++ b/src/test/ui/weird-exprs.rs
@@ -5,7 +5,7 @@
 #![allow(non_camel_case_types)]
 #![allow(dead_code)]
 #![allow(unreachable_code)]
-#![allow(unused_parens)]
+#![allow(unused_braces, unused_parens)]
 
 #![recursion_limit = "256"]
 
diff --git a/src/test/ui/zero-sized/zero-sized-tuple-struct.rs b/src/test/ui/zero-sized/zero-sized-tuple-struct.rs
index 6c438720e5d86..2208590f7d61b 100644
--- a/src/test/ui/zero-sized/zero-sized-tuple-struct.rs
+++ b/src/test/ui/zero-sized/zero-sized-tuple-struct.rs
@@ -1,4 +1,5 @@
 // run-pass
+#![allow(unused_braces)]
 #![allow(unused_assignments)]
 
 // Make sure that the constructor args are codegened for zero-sized tuple structs