diff --git a/src/librustc_mir/borrow_check/nll/constraint_generation.rs b/src/librustc_mir/borrow_check/nll/constraint_generation.rs
index 055568f0a27a2..95c3299693b68 100644
--- a/src/librustc_mir/borrow_check/nll/constraint_generation.rs
+++ b/src/librustc_mir/borrow_check/nll/constraint_generation.rs
@@ -3,12 +3,15 @@ use crate::borrow_check::location::LocationTable;
 use crate::borrow_check::nll::ToRegionVid;
 use crate::borrow_check::nll::facts::AllFacts;
 use crate::borrow_check::nll::region_infer::values::LivenessValues;
+use crate::borrow_check::places_conflict;
 use rustc::infer::InferCtxt;
 use rustc::mir::visit::TyContext;
 use rustc::mir::visit::Visitor;
-use rustc::mir::{BasicBlock, BasicBlockData, Location, Body, Place, PlaceBase, Rvalue};
-use rustc::mir::{SourceInfo, Statement, Terminator};
-use rustc::mir::UserTypeProjection;
+use rustc::mir::{
+    BasicBlock, BasicBlockData, Body, Local, Location, Place, PlaceBase, Projection,
+    ProjectionElem, Rvalue, SourceInfo, Statement, StatementKind, Terminator, TerminatorKind,
+    UserTypeProjection,
+};
 use rustc::ty::fold::TypeFoldable;
 use rustc::ty::{self, ClosureSubsts, GeneratorSubsts, RegionVid, Ty};
 use rustc::ty::subst::SubstsRef;
@@ -27,6 +30,7 @@ pub(super) fn generate_constraints<'cx, 'tcx>(
         liveness_constraints,
         location_table,
         all_facts,
+        body,
     };
 
     for (bb, data) in body.basic_blocks().iter_enumerated() {
@@ -41,6 +45,7 @@ struct ConstraintGeneration<'cg, 'cx, 'tcx> {
     location_table: &'cg LocationTable,
     liveness_constraints: &'cg mut LivenessValues<RegionVid>,
     borrow_set: &'cg BorrowSet<'tcx>,
+    body: &'cg Body<'tcx>,
 }
 
 impl<'cg, 'cx, 'tcx> Visitor<'tcx> for ConstraintGeneration<'cg, 'cx, 'tcx> {
@@ -114,6 +119,17 @@ impl<'cg, 'cx, 'tcx> Visitor<'tcx> for ConstraintGeneration<'cg, 'cx, 'tcx> {
                 self.location_table
                     .start_index(location.successor_within_block()),
             ));
+
+            // If there are borrows on this now dead local, we need to record them as `killed`.
+            if let StatementKind::StorageDead(ref local) = statement.kind {
+                record_killed_borrows_for_local(
+                    all_facts,
+                    self.borrow_set,
+                    self.location_table,
+                    local,
+                    location,
+                );
+            }
         }
 
         self.super_statement(statement, location);
@@ -127,20 +143,7 @@ impl<'cg, 'cx, 'tcx> Visitor<'tcx> for ConstraintGeneration<'cg, 'cx, 'tcx> {
     ) {
         // When we see `X = ...`, then kill borrows of
         // `(*X).foo` and so forth.
-        if let Some(all_facts) = self.all_facts {
-            if let Place {
-                base: PlaceBase::Local(temp),
-                projection: None,
-            } = place {
-                if let Some(borrow_indices) = self.borrow_set.local_map.get(temp) {
-                    all_facts.killed.reserve(borrow_indices.len());
-                    for &borrow_index in borrow_indices {
-                        let location_index = self.location_table.mid_index(location);
-                        all_facts.killed.push((borrow_index, location_index));
-                    }
-                }
-            }
-        }
+        self.record_killed_borrows_for_place(place, location);
 
         self.super_assign(place, rvalue, location);
     }
@@ -167,6 +170,14 @@ impl<'cg, 'cx, 'tcx> Visitor<'tcx> for ConstraintGeneration<'cg, 'cx, 'tcx> {
             }
         }
 
+        // A `Call` terminator's return value can be a local which has borrows,
+        // so we need to record those as `killed` as well.
+        if let TerminatorKind::Call { ref destination, .. } = terminator.kind {
+            if let Some((place, _)) = destination {
+                self.record_killed_borrows_for_place(place, location);
+            }
+        }
+
         self.super_terminator(terminator, location);
     }
 
@@ -201,4 +212,96 @@ impl<'cx, 'cg, 'tcx> ConstraintGeneration<'cx, 'cg, 'tcx> {
                 self.liveness_constraints.add_element(vid, location);
             });
     }
+
+    /// When recording facts for Polonius, records the borrows on the specified place
+    /// as `killed`. For example, when assigning to a local, or on a call's return destination.
+    fn record_killed_borrows_for_place(&mut self, place: &Place<'tcx>, location: Location) {
+        if let Some(all_facts) = self.all_facts {
+            // Depending on the `Place` we're killing:
+            // - if it's a local, or a single deref of a local,
+            //   we kill all the borrows on the local.
+            // - if it's a deeper projection, we have to filter which
+            //   of the borrows are killed: the ones whose `borrowed_place`
+            //   conflicts with the `place`.
+            match place {
+                Place {
+                    base: PlaceBase::Local(local),
+                    projection: None,
+                } |
+                Place {
+                    base: PlaceBase::Local(local),
+                    projection: Some(box Projection {
+                        base: None,
+                        elem: ProjectionElem::Deref,
+                    }),
+                } => {
+                    debug!(
+                        "Recording `killed` facts for borrows of local={:?} at location={:?}",
+                        local, location
+                    );
+
+                    record_killed_borrows_for_local(
+                        all_facts,
+                        self.borrow_set,
+                        self.location_table,
+                        local,
+                        location,
+                    );
+                }
+
+                Place {
+                    base: PlaceBase::Static(_),
+                    ..
+                } => {
+                    // Ignore kills of static or static mut variables.
+                }
+
+                Place {
+                    base: PlaceBase::Local(local),
+                    projection: Some(_),
+                } => {
+                    // Kill conflicting borrows of the innermost local.
+                    debug!(
+                        "Recording `killed` facts for borrows of \
+                            innermost projected local={:?} at location={:?}",
+                        local, location
+                    );
+
+                    if let Some(borrow_indices) = self.borrow_set.local_map.get(local) {
+                        for &borrow_index in borrow_indices {
+                            let places_conflict = places_conflict::places_conflict(
+                                self.infcx.tcx,
+                                self.body,
+                                &self.borrow_set.borrows[borrow_index].borrowed_place,
+                                place,
+                                places_conflict::PlaceConflictBias::NoOverlap,
+                            );
+
+                            if places_conflict {
+                                let location_index = self.location_table.mid_index(location);
+                                all_facts.killed.push((borrow_index, location_index));
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+/// When recording facts for Polonius, records the borrows on the specified local as `killed`.
+fn record_killed_borrows_for_local(
+    all_facts: &mut AllFacts,
+    borrow_set: &BorrowSet<'_>,
+    location_table: &LocationTable,
+    local: &Local,
+    location: Location,
+) {
+    if let Some(borrow_indices) = borrow_set.local_map.get(local) {
+        all_facts.killed.reserve(borrow_indices.len());
+        for &borrow_index in borrow_indices {
+            let location_index = location_table.mid_index(location);
+            all_facts.killed.push((borrow_index, location_index));
+        }
+    }
 }
diff --git a/src/test/ui/borrowck/borrowck-escaping-closure-error-2.polonius.stderr b/src/test/ui/borrowck/borrowck-escaping-closure-error-2.polonius.stderr
new file mode 100644
index 0000000000000..89af8764557ff
--- /dev/null
+++ b/src/test/ui/borrowck/borrowck-escaping-closure-error-2.polonius.stderr
@@ -0,0 +1,16 @@
+error[E0597]: `books` does not live long enough
+  --> $DIR/borrowck-escaping-closure-error-2.rs:11:17
+   |
+LL |     Box::new(|| books.push(4))
+   |     ------------^^^^^---------
+   |     |        |  |
+   |     |        |  borrowed value does not live long enough
+   |     |        value captured here
+   |     borrow later used here
+LL |
+LL | }
+   | - `books` dropped here while still borrowed
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/borrowck/borrowck-migrate-to-nll.edition.stderr b/src/test/ui/borrowck/borrowck-migrate-to-nll.edition.stderr
index 663164cfc2c1c..d97883ad47a50 100644
--- a/src/test/ui/borrowck/borrowck-migrate-to-nll.edition.stderr
+++ b/src/test/ui/borrowck/borrowck-migrate-to-nll.edition.stderr
@@ -1,5 +1,5 @@
 warning[E0507]: cannot move out of `foo` in pattern guard
-  --> $DIR/borrowck-migrate-to-nll.rs:25:18
+  --> $DIR/borrowck-migrate-to-nll.rs:26:18
    |
 LL |                 (|| { let bar = foo; bar.take() })();
    |                  ^^             ---
diff --git a/src/test/ui/borrowck/borrowck-migrate-to-nll.rs b/src/test/ui/borrowck/borrowck-migrate-to-nll.rs
index 5b7018df91931..a64df9df25948 100644
--- a/src/test/ui/borrowck/borrowck-migrate-to-nll.rs
+++ b/src/test/ui/borrowck/borrowck-migrate-to-nll.rs
@@ -10,6 +10,7 @@
 // just ignore it instead:
 
 // ignore-compare-mode-nll
+// ignore-compare-mode-polonius
 
 // revisions: zflag edition
 //[zflag]compile-flags: -Z borrowck=migrate
diff --git a/src/test/ui/borrowck/borrowck-migrate-to-nll.zflag.stderr b/src/test/ui/borrowck/borrowck-migrate-to-nll.zflag.stderr
index 663164cfc2c1c..d97883ad47a50 100644
--- a/src/test/ui/borrowck/borrowck-migrate-to-nll.zflag.stderr
+++ b/src/test/ui/borrowck/borrowck-migrate-to-nll.zflag.stderr
@@ -1,5 +1,5 @@
 warning[E0507]: cannot move out of `foo` in pattern guard
-  --> $DIR/borrowck-migrate-to-nll.rs:25:18
+  --> $DIR/borrowck-migrate-to-nll.rs:26:18
    |
 LL |                 (|| { let bar = foo; bar.take() })();
    |                  ^^             ---
diff --git a/src/test/ui/borrowck/issue-45983.migrate.stderr b/src/test/ui/borrowck/issue-45983.migrate.stderr
index 3a6b2f69a1ffc..c1564cf07e68a 100644
--- a/src/test/ui/borrowck/issue-45983.migrate.stderr
+++ b/src/test/ui/borrowck/issue-45983.migrate.stderr
@@ -1,5 +1,5 @@
 error: borrowed data cannot be stored outside of its closure
-  --> $DIR/issue-45983.rs:19:27
+  --> $DIR/issue-45983.rs:20:27
    |
 LL |     let x = None;
    |         - borrowed data cannot be stored into here...
diff --git a/src/test/ui/borrowck/issue-45983.nll.stderr b/src/test/ui/borrowck/issue-45983.nll.stderr
index 94360b65ffe36..dff0b4cebace9 100644
--- a/src/test/ui/borrowck/issue-45983.nll.stderr
+++ b/src/test/ui/borrowck/issue-45983.nll.stderr
@@ -1,5 +1,5 @@
 error[E0521]: borrowed data escapes outside of closure
-  --> $DIR/issue-45983.rs:19:18
+  --> $DIR/issue-45983.rs:20:18
    |
 LL |     let x = None;
    |         - `x` is declared here, outside of the closure body
@@ -9,7 +9,7 @@ LL |     give_any(|y| x = Some(y));
    |               `y` is a reference that is only valid in the closure body
 
 error[E0594]: cannot assign to `x`, as it is not declared as mutable
-  --> $DIR/issue-45983.rs:19:18
+  --> $DIR/issue-45983.rs:20:18
    |
 LL |     let x = None;
    |         - help: consider changing this to be mutable: `mut x`
diff --git a/src/test/ui/borrowck/issue-45983.rs b/src/test/ui/borrowck/issue-45983.rs
index a2656f5939aa1..3cd282077424b 100644
--- a/src/test/ui/borrowck/issue-45983.rs
+++ b/src/test/ui/borrowck/issue-45983.rs
@@ -7,6 +7,7 @@
 // revisions, don't worry about the --compare-mode=nll on this test.
 
 // ignore-compare-mode-nll
+// ignore-compare-mode-polonius
 
 //[nll]compile-flags: -Z borrowck=mir
 
diff --git a/src/test/ui/borrowck/promote-ref-mut-in-let-issue-46557.polonius.stderr b/src/test/ui/borrowck/promote-ref-mut-in-let-issue-46557.polonius.stderr
new file mode 100644
index 0000000000000..a5b2e8762746c
--- /dev/null
+++ b/src/test/ui/borrowck/promote-ref-mut-in-let-issue-46557.polonius.stderr
@@ -0,0 +1,59 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/promote-ref-mut-in-let-issue-46557.rs:5:21
+   |
+LL |     let ref mut x = 1234543;
+   |                     ^^^^^^^ creates a temporary which is freed while still in use
+LL |     x
+   |     - borrow later used here
+LL | }
+   | - temporary value is freed at the end of this statement
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/promote-ref-mut-in-let-issue-46557.rs:10:25
+   |
+LL |     let (ref mut x, ) = (1234543, );
+   |                         ^^^^^^^^^^^ creates a temporary which is freed while still in use
+LL |     x
+   |     - borrow later used here
+LL | }
+   | - temporary value is freed at the end of this statement
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error[E0515]: cannot return value referencing temporary value
+  --> $DIR/promote-ref-mut-in-let-issue-46557.rs:15:5
+   |
+LL |       match 1234543 {
+   |       ^     ------- temporary value created here
+   |  _____|
+   | |
+LL | |         ref mut x => x
+LL | |     }
+   | |_____^ returns a value referencing data owned by the current function
+
+error[E0515]: cannot return value referencing temporary value
+  --> $DIR/promote-ref-mut-in-let-issue-46557.rs:21:5
+   |
+LL |       match (123443,) {
+   |       ^     --------- temporary value created here
+   |  _____|
+   | |
+LL | |         (ref mut x,) => x,
+LL | |     }
+   | |_____^ returns a value referencing data owned by the current function
+
+error[E0515]: cannot return reference to temporary value
+  --> $DIR/promote-ref-mut-in-let-issue-46557.rs:27:5
+   |
+LL |     &mut 1234543
+   |     ^^^^^-------
+   |     |    |
+   |     |    temporary value created here
+   |     returns a reference to data owned by the current function
+
+error: aborting due to 5 previous errors
+
+Some errors have detailed explanations: E0515, E0716.
+For more information about an error, try `rustc --explain E0515`.
diff --git a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.migrate2015.stderr b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.migrate2015.stderr
index 565e433f77361..88e9ced03ddde 100644
--- a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.migrate2015.stderr
+++ b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.migrate2015.stderr
@@ -1,5 +1,5 @@
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:18:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:19:5
    |
 LL |     let shared = &v;
    |                  -- immutable borrow occurs here
@@ -11,7 +11,7 @@ LL |     v.extend(shared);
    |     mutable borrow occurs here
 
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:28:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:29:5
    |
 LL |     v.extend(&v);
    |     ^^------^--^
@@ -21,7 +21,7 @@ LL |     v.extend(&v);
    |     mutable borrow occurs here
 
 warning: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:39:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:40:5
    |
 LL |     let shared = &v;
    |                  -- immutable borrow occurs here
diff --git a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.migrate2018.stderr b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.migrate2018.stderr
index 565e433f77361..88e9ced03ddde 100644
--- a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.migrate2018.stderr
+++ b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.migrate2018.stderr
@@ -1,5 +1,5 @@
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:18:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:19:5
    |
 LL |     let shared = &v;
    |                  -- immutable borrow occurs here
@@ -11,7 +11,7 @@ LL |     v.extend(shared);
    |     mutable borrow occurs here
 
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:28:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:29:5
    |
 LL |     v.extend(&v);
    |     ^^------^--^
@@ -21,7 +21,7 @@ LL |     v.extend(&v);
    |     mutable borrow occurs here
 
 warning: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:39:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:40:5
    |
 LL |     let shared = &v;
    |                  -- immutable borrow occurs here
diff --git a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.nll2015.stderr b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.nll2015.stderr
index 730741c7a9ae2..52017394e898e 100644
--- a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.nll2015.stderr
+++ b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.nll2015.stderr
@@ -1,5 +1,5 @@
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:18:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:19:5
    |
 LL |     let shared = &v;
    |                  -- immutable borrow occurs here
@@ -10,7 +10,7 @@ LL |     v.extend(shared);
    |     mutable borrow occurs here
 
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:28:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:29:5
    |
 LL |     v.extend(&v);
    |     ^^------^--^
@@ -20,7 +20,7 @@ LL |     v.extend(&v);
    |     mutable borrow occurs here
 
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:39:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:40:5
    |
 LL |     let shared = &v;
    |                  -- immutable borrow occurs here
diff --git a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.nll2018.stderr b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.nll2018.stderr
index 730741c7a9ae2..52017394e898e 100644
--- a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.nll2018.stderr
+++ b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.nll2018.stderr
@@ -1,5 +1,5 @@
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:18:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:19:5
    |
 LL |     let shared = &v;
    |                  -- immutable borrow occurs here
@@ -10,7 +10,7 @@ LL |     v.extend(shared);
    |     mutable borrow occurs here
 
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:28:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:29:5
    |
 LL |     v.extend(&v);
    |     ^^------^--^
@@ -20,7 +20,7 @@ LL |     v.extend(&v);
    |     mutable borrow occurs here
 
 error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
-  --> $DIR/two-phase-reservation-sharing-interference-2.rs:39:5
+  --> $DIR/two-phase-reservation-sharing-interference-2.rs:40:5
    |
 LL |     let shared = &v;
    |                  -- immutable borrow occurs here
diff --git a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.rs b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.rs
index de1af3aaa05e4..14f687c23780c 100644
--- a/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.rs
+++ b/src/test/ui/borrowck/two-phase-reservation-sharing-interference-2.rs
@@ -3,6 +3,7 @@
 // everyone else.
 
 //ignore-compare-mode-nll
+//ignore-compare-mode-polonius
 
 //revisions: migrate2015 migrate2018 nll2015 nll2018
 
diff --git a/src/test/ui/borrowck/two-phase-surprise-no-conflict.polonius.stderr b/src/test/ui/borrowck/two-phase-surprise-no-conflict.polonius.stderr
new file mode 100644
index 0000000000000..7b246426a2333
--- /dev/null
+++ b/src/test/ui/borrowck/two-phase-surprise-no-conflict.polonius.stderr
@@ -0,0 +1,148 @@
+error[E0503]: cannot use `self.cx` because it was mutably borrowed
+  --> $DIR/two-phase-surprise-no-conflict.rs:21:23
+   |
+LL |         let _mut_borrow = &mut *self;
+   |                           ---------- borrow of `*self` occurs here
+LL |         let _access = self.cx;
+   |                       ^^^^^^^ use of borrowed `*self`
+LL |
+LL |         _mut_borrow;
+   |         ----------- borrow later used here
+
+error[E0502]: cannot borrow `*self` as mutable because it is also borrowed as immutable
+  --> $DIR/two-phase-surprise-no-conflict.rs:57:17
+   |
+LL |                 self.hash_expr(&self.cx_mut.body(eid).value);
+   |                 ^^^^^---------^^-----------^^^^^^^^^^^^^^^^^
+   |                 |    |          |
+   |                 |    |          immutable borrow occurs here
+   |                 |    immutable borrow later used by call
+   |                 mutable borrow occurs here
+
+error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:119:51
+   |
+LL |     reg.register_static(Box::new(TrivialPass::new(&mut reg.sess_mut)));
+   |     --- ---------------                           ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+   |     |   |
+   |     |   first borrow later used by call
+   |     first mutable borrow occurs here
+
+error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:122:54
+   |
+LL |     reg.register_bound(Box::new(TrivialPass::new_mut(&mut reg.sess_mut)));
+   |     --- --------------                               ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+   |     |   |
+   |     |   first borrow later used by call
+   |     first mutable borrow occurs here
+
+error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:125:53
+   |
+LL |     reg.register_univ(Box::new(TrivialPass::new_mut(&mut reg.sess_mut)));
+   |     --- -------------                               ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+   |     |   |
+   |     |   first borrow later used by call
+   |     first mutable borrow occurs here
+
+error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:128:44
+   |
+LL |     reg.register_ref(&TrivialPass::new_mut(&mut reg.sess_mut));
+   |     --- ------------                       ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+   |     |   |
+   |     |   first borrow later used by call
+   |     first mutable borrow occurs here
+
+error[E0502]: cannot borrow `*reg` as mutable because it is also borrowed as immutable
+  --> $DIR/two-phase-surprise-no-conflict.rs:138:5
+   |
+LL |     reg.register_bound(Box::new(CapturePass::new(&reg.sess_mut)));
+   |     ^^^^--------------^^^^^^^^^^^^^^^^^^^^^^^^^^^-------------^^^
+   |     |   |                                        |
+   |     |   |                                        immutable borrow occurs here
+   |     |   immutable borrow later used by call
+   |     mutable borrow occurs here
+
+error[E0502]: cannot borrow `*reg` as mutable because it is also borrowed as immutable
+  --> $DIR/two-phase-surprise-no-conflict.rs:141:5
+   |
+LL |     reg.register_univ(Box::new(CapturePass::new(&reg.sess_mut)));
+   |     ^^^^-------------^^^^^^^^^^^^^^^^^^^^^^^^^^^-------------^^^
+   |     |   |                                       |
+   |     |   |                                       immutable borrow occurs here
+   |     |   immutable borrow later used by call
+   |     mutable borrow occurs here
+
+error[E0502]: cannot borrow `*reg` as mutable because it is also borrowed as immutable
+  --> $DIR/two-phase-surprise-no-conflict.rs:144:5
+   |
+LL |     reg.register_ref(&CapturePass::new(&reg.sess_mut));
+   |     ^^^^------------^^^^^^^^^^^^^^^^^^^-------------^^
+   |     |   |                              |
+   |     |   |                              immutable borrow occurs here
+   |     |   immutable borrow later used by call
+   |     mutable borrow occurs here
+
+error[E0499]: cannot borrow `*reg` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:154:5
+   |
+LL |     reg.register_bound(Box::new(CapturePass::new_mut(&mut reg.sess_mut)));
+   |     ^^^^--------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-----------------^^^
+   |     |   |                                            |
+   |     |   |                                            first mutable borrow occurs here
+   |     |   first borrow later used by call
+   |     second mutable borrow occurs here
+
+error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:154:54
+   |
+LL |     reg.register_bound(Box::new(CapturePass::new_mut(&mut reg.sess_mut)));
+   |     --- --------------                               ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+   |     |   |
+   |     |   first borrow later used by call
+   |     first mutable borrow occurs here
+
+error[E0499]: cannot borrow `*reg` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:158:5
+   |
+LL |     reg.register_univ(Box::new(CapturePass::new_mut(&mut reg.sess_mut)));
+   |     ^^^^-------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-----------------^^^
+   |     |   |                                           |
+   |     |   |                                           first mutable borrow occurs here
+   |     |   first borrow later used by call
+   |     second mutable borrow occurs here
+
+error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:158:53
+   |
+LL |     reg.register_univ(Box::new(CapturePass::new_mut(&mut reg.sess_mut)));
+   |     --- -------------                               ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+   |     |   |
+   |     |   first borrow later used by call
+   |     first mutable borrow occurs here
+
+error[E0499]: cannot borrow `*reg` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:162:5
+   |
+LL |     reg.register_ref(&CapturePass::new_mut(&mut reg.sess_mut));
+   |     ^^^^------------^^^^^^^^^^^^^^^^^^^^^^^-----------------^^
+   |     |   |                                  |
+   |     |   |                                  first mutable borrow occurs here
+   |     |   first borrow later used by call
+   |     second mutable borrow occurs here
+
+error[E0499]: cannot borrow `reg.sess_mut` as mutable more than once at a time
+  --> $DIR/two-phase-surprise-no-conflict.rs:162:44
+   |
+LL |     reg.register_ref(&CapturePass::new_mut(&mut reg.sess_mut));
+   |     --- ------------                       ^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
+   |     |   |
+   |     |   first borrow later used by call
+   |     first mutable borrow occurs here
+
+error: aborting due to 15 previous errors
+
+Some errors have detailed explanations: E0499, E0502, E0503.
+For more information about an error, try `rustc --explain E0499`.
diff --git a/src/test/ui/consts/promote_const_let.polonius.stderr b/src/test/ui/consts/promote_const_let.polonius.stderr
new file mode 100644
index 0000000000000..cf41bd7bdb1eb
--- /dev/null
+++ b/src/test/ui/consts/promote_const_let.polonius.stderr
@@ -0,0 +1,29 @@
+error[E0597]: `y` does not live long enough
+  --> $DIR/promote_const_let.rs:4:9
+   |
+LL |     let x: &'static u32 = {
+   |         - borrow later stored here
+LL |         let y = 42;
+LL |         &y
+   |         ^^ borrowed value does not live long enough
+LL |     };
+   |     - `y` dropped here while still borrowed
+
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/promote_const_let.rs:6:28
+   |
+LL |       let x: &'static u32 = &{
+   |  ____________------------____^
+   | |            |
+   | |            type annotation requires that borrow lasts for `'static`
+LL | |         let y = 42;
+LL | |         y
+LL | |     };
+   | |_____^ creates a temporary which is freed while still in use
+LL |   }
+   |   - temporary value is freed at the end of this statement
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0597, E0716.
+For more information about an error, try `rustc --explain E0597`.
diff --git a/src/test/ui/dropck/dropck_trait_cycle_checked.polonius.stderr b/src/test/ui/dropck/dropck_trait_cycle_checked.polonius.stderr
new file mode 100644
index 0000000000000..dbcb0fcebb73d
--- /dev/null
+++ b/src/test/ui/dropck/dropck_trait_cycle_checked.polonius.stderr
@@ -0,0 +1,74 @@
+error[E0597]: `o2` does not live long enough
+  --> $DIR/dropck_trait_cycle_checked.rs:111:13
+   |
+LL |     o1.set0(&o2);
+   |             ^^^ borrowed value does not live long enough
+...
+LL | }
+   | -
+   | |
+   | `o2` dropped here while still borrowed
+   | borrow might be used here, when `o2` is dropped and runs the destructor for type `std::boxed::Box<dyn Obj<'_>>`
+
+error[E0597]: `o3` does not live long enough
+  --> $DIR/dropck_trait_cycle_checked.rs:112:13
+   |
+LL |     o1.set1(&o3);
+   |             ^^^ borrowed value does not live long enough
+...
+LL | }
+   | -
+   | |
+   | `o3` dropped here while still borrowed
+   | borrow might be used here, when `o3` is dropped and runs the destructor for type `std::boxed::Box<dyn Obj<'_>>`
+
+error[E0597]: `o2` does not live long enough
+  --> $DIR/dropck_trait_cycle_checked.rs:113:13
+   |
+LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
+   |                                                                               -------- cast requires that `o2` is borrowed for `'static`
+...
+LL |     o2.set0(&o2);
+   |             ^^^ borrowed value does not live long enough
+...
+LL | }
+   | - `o2` dropped here while still borrowed
+
+error[E0597]: `o3` does not live long enough
+  --> $DIR/dropck_trait_cycle_checked.rs:114:13
+   |
+LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
+   |                                                                                         -------- cast requires that `o3` is borrowed for `'static`
+...
+LL |     o2.set1(&o3);
+   |             ^^^ borrowed value does not live long enough
+...
+LL | }
+   | - `o3` dropped here while still borrowed
+
+error[E0597]: `o1` does not live long enough
+  --> $DIR/dropck_trait_cycle_checked.rs:115:13
+   |
+LL |     o3.set0(&o1);
+   |             ^^^ borrowed value does not live long enough
+LL |     o3.set1(&o2);
+LL | }
+   | -
+   | |
+   | `o1` dropped here while still borrowed
+   | borrow might be used here, when `o1` is dropped and runs the destructor for type `std::boxed::Box<dyn Obj<'_>>`
+
+error[E0597]: `o2` does not live long enough
+  --> $DIR/dropck_trait_cycle_checked.rs:116:13
+   |
+LL |     let (o1, o2, o3): (Box<dyn Obj>, Box<dyn Obj>, Box<dyn Obj>) = (O::new(), O::new(), O::new());
+   |                                                                               -------- cast requires that `o2` is borrowed for `'static`
+...
+LL |     o3.set1(&o2);
+   |             ^^^ borrowed value does not live long enough
+LL | }
+   | - `o2` dropped here while still borrowed
+
+error: aborting due to 6 previous errors
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/emit-artifact-notifications.polonius.stderr b/src/test/ui/emit-artifact-notifications.polonius.stderr
new file mode 100644
index 0000000000000..47b48b399c25c
--- /dev/null
+++ b/src/test/ui/emit-artifact-notifications.polonius.stderr
@@ -0,0 +1 @@
+{"artifact":"$TEST_BUILD_DIR/emit-artifact-notifications.polonius/libemit_artifact_notifications.rmeta","emit":"metadata"}
diff --git a/src/test/ui/feature-gates/feature-gate-nll.rs b/src/test/ui/feature-gates/feature-gate-nll.rs
index ec5eacd162547..8ec752409ab00 100644
--- a/src/test/ui/feature-gates/feature-gate-nll.rs
+++ b/src/test/ui/feature-gates/feature-gate-nll.rs
@@ -3,6 +3,7 @@
 
 // Don't use compare-mode=nll, since that turns on NLL.
 // ignore-compare-mode-nll
+// ignore-compare-mode-polonius
 
 #![feature(rustc_attrs)]
 
diff --git a/src/test/ui/feature-gates/feature-gate-nll.stderr b/src/test/ui/feature-gates/feature-gate-nll.stderr
index 37542d52dc2ce..e5b28bbfa2477 100644
--- a/src/test/ui/feature-gates/feature-gate-nll.stderr
+++ b/src/test/ui/feature-gates/feature-gate-nll.stderr
@@ -1,5 +1,5 @@
 warning[E0502]: cannot borrow `*x.1` as immutable because it is also borrowed as mutable
-  --> $DIR/feature-gate-nll.rs:14:13
+  --> $DIR/feature-gate-nll.rs:15:13
    |
 LL |     let m = &mut x;
    |             ------ mutable borrow occurs here
@@ -14,7 +14,7 @@ LL |     m;
    = note: for more information, try `rustc --explain E0729`
 
 error: compilation successful
-  --> $DIR/feature-gate-nll.rs:10:1
+  --> $DIR/feature-gate-nll.rs:11:1
    |
 LL | / fn main() {
 LL | |     let mut x = (33, &0);
diff --git a/src/test/ui/generator/ref-escapes-but-not-over-yield.polonius.stderr b/src/test/ui/generator/ref-escapes-but-not-over-yield.polonius.stderr
new file mode 100644
index 0000000000000..530bf368f676e
--- /dev/null
+++ b/src/test/ui/generator/ref-escapes-but-not-over-yield.polonius.stderr
@@ -0,0 +1,20 @@
+error[E0597]: `b` does not live long enough
+  --> $DIR/ref-escapes-but-not-over-yield.rs:11:13
+   |
+LL |       let mut b = move || {
+   |  _________________-
+LL | |         yield();
+LL | |         let b = 5;
+LL | |         a = &b;
+   | |             ^^ borrowed value does not live long enough
+LL | |
+LL | |     };
+   | |     -
+   | |     |
+   | |     `b` dropped here while still borrowed
+   | |_____... and the borrow might be used here, when that temporary is dropped and runs the destructor for generator
+   |       a temporary with access to the borrow is created here ...
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0597`.
diff --git a/src/test/ui/hrtb/issue-30786.migrate.stderr b/src/test/ui/hrtb/issue-30786.migrate.stderr
index 9a4f877282245..e7deca7644b0e 100644
--- a/src/test/ui/hrtb/issue-30786.migrate.stderr
+++ b/src/test/ui/hrtb/issue-30786.migrate.stderr
@@ -1,11 +1,11 @@
 error: implementation of `Stream` is not general enough
-  --> $DIR/issue-30786.rs:107:22
+  --> $DIR/issue-30786.rs:108:22
    |
 LL |     let map = source.map(|x: &_| x);
    |                      ^^^
    |
-   = note: `Stream` would have to be implemented for the type `&'0 mut Map<Repeat, [closure@$DIR/issue-30786.rs:107:26: 107:35]>`, for any lifetime `'0`
-   = note: but `Stream` is actually implemented for the type `&'1 mut Map<Repeat, [closure@$DIR/issue-30786.rs:107:26: 107:35]>`, for some specific lifetime `'1`
+   = note: `Stream` would have to be implemented for the type `&'0 mut Map<Repeat, [closure@$DIR/issue-30786.rs:108:26: 108:35]>`, for any lifetime `'0`
+   = note: but `Stream` is actually implemented for the type `&'1 mut Map<Repeat, [closure@$DIR/issue-30786.rs:108:26: 108:35]>`, for some specific lifetime `'1`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/hrtb/issue-30786.nll.stderr b/src/test/ui/hrtb/issue-30786.nll.stderr
index 5c865d76851d3..8614d86d93ac3 100644
--- a/src/test/ui/hrtb/issue-30786.nll.stderr
+++ b/src/test/ui/hrtb/issue-30786.nll.stderr
@@ -1,11 +1,11 @@
 error: higher-ranked subtype error
-  --> $DIR/issue-30786.rs:111:18
+  --> $DIR/issue-30786.rs:112:18
    |
 LL |     let filter = map.filter(|x: &_| true);
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: higher-ranked subtype error
-  --> $DIR/issue-30786.rs:113:17
+  --> $DIR/issue-30786.rs:114:17
    |
 LL |     let count = filter.count(); // Assert that we still have a valid stream.
    |                 ^^^^^^^^^^^^^^
diff --git a/src/test/ui/hrtb/issue-30786.rs b/src/test/ui/hrtb/issue-30786.rs
index 321b83c3459d0..b9920a1950498 100644
--- a/src/test/ui/hrtb/issue-30786.rs
+++ b/src/test/ui/hrtb/issue-30786.rs
@@ -12,6 +12,7 @@
 // revisions, don't worry about the --compare-mode=nll on this test.
 
 // ignore-compare-mode-nll
+// ignore-compare-mode-polonius
 
 //[nll]compile-flags: -Z borrowck=mir
 
diff --git a/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.migrate.stderr b/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.migrate.stderr
index 479b724ad18f1..2e99572d01828 100644
--- a/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.migrate.stderr
+++ b/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.migrate.stderr
@@ -1,5 +1,5 @@
 warning[E0713]: borrow may still be in use when destructor runs
-  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:51:5
+  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:52:5
    |
 LL | fn scribbled<'a>(s: Scribble<'a>) -> &'a mut u32 {
    |              -- lifetime `'a` defined here
@@ -14,7 +14,7 @@ LL | }
    = note: for more information, try `rustc --explain E0729`
 
 warning[E0713]: borrow may still be in use when destructor runs
-  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:62:5
+  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:63:5
    |
 LL | fn boxed_scribbled<'a>(s: Box<Scribble<'a>>) -> &'a mut u32 {
    |                    -- lifetime `'a` defined here
@@ -29,7 +29,7 @@ LL | }
    = note: for more information, try `rustc --explain E0729`
 
 warning[E0713]: borrow may still be in use when destructor runs
-  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:73:5
+  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:74:5
    |
 LL | fn boxed_boxed_scribbled<'a>(s: Box<Box<Scribble<'a>>>) -> &'a mut u32 {
    |                          -- lifetime `'a` defined here
@@ -44,7 +44,7 @@ LL | }
    = note: for more information, try `rustc --explain E0729`
 
 error: compilation successful
-  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:80:1
+  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:81:1
    |
 LL | / fn main() {
 LL | |     let mut x = 1;
diff --git a/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.nll.stderr b/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.nll.stderr
index 1b9fb0499260c..45b22511d27d6 100644
--- a/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.nll.stderr
+++ b/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.nll.stderr
@@ -1,5 +1,5 @@
 error[E0713]: borrow may still be in use when destructor runs
-  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:51:5
+  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:52:5
    |
 LL | fn scribbled<'a>(s: Scribble<'a>) -> &'a mut u32 {
    |              -- lifetime `'a` defined here
@@ -10,7 +10,7 @@ LL | }
    | - here, drop of `s` needs exclusive access to `*s.0`, because the type `Scribble<'_>` implements the `Drop` trait
 
 error[E0713]: borrow may still be in use when destructor runs
-  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:62:5
+  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:63:5
    |
 LL | fn boxed_scribbled<'a>(s: Box<Scribble<'a>>) -> &'a mut u32 {
    |                    -- lifetime `'a` defined here
@@ -21,7 +21,7 @@ LL | }
    | - here, drop of `s` needs exclusive access to `*s.0`, because the type `Scribble<'_>` implements the `Drop` trait
 
 error[E0713]: borrow may still be in use when destructor runs
-  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:73:5
+  --> $DIR/issue-45696-scribble-on-boxed-borrow.rs:74:5
    |
 LL | fn boxed_boxed_scribbled<'a>(s: Box<Box<Scribble<'a>>>) -> &'a mut u32 {
    |                          -- lifetime `'a` defined here
diff --git a/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.rs b/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.rs
index f568efa487cd7..9f261884f3d2d 100644
--- a/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.rs
+++ b/src/test/ui/issues/issue-45696-scribble-on-boxed-borrow.rs
@@ -7,6 +7,7 @@
 
 // revisions: nll migrate
 // ignore-compare-mode-nll
+// ignore-compare-mode-polonius
 
 // This test is going to pass in the migrate revision, because the AST-borrowck
 // accepted this code in the past (see notes below). So we use `#[rustc_error]`
diff --git a/src/test/ui/nll/get_default.polonius.stderr b/src/test/ui/nll/get_default.polonius.stderr
new file mode 100644
index 0000000000000..2df6d5d61fc46
--- /dev/null
+++ b/src/test/ui/nll/get_default.polonius.stderr
@@ -0,0 +1,15 @@
+error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable
+  --> $DIR/get_default.rs:32:17
+   |
+LL |         match map.get() {
+   |               --- immutable borrow occurs here
+LL |             Some(v) => {
+LL |                 map.set(String::new()); // Both AST and MIR error here
+   |                 ^^^ mutable borrow occurs here
+LL |
+LL |                 return v;
+   |                        - immutable borrow later used here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0502`.
diff --git a/src/test/ui/nll/issue-46589.rs b/src/test/ui/nll/issue-46589.rs
index 8c0c356e96721..0a4c20d15159f 100644
--- a/src/test/ui/nll/issue-46589.rs
+++ b/src/test/ui/nll/issue-46589.rs
@@ -1,3 +1,9 @@
+// This tests passes in Polonius mode, so is skipped in the automated compare-mode.
+// We will manually check it passes in Polonius tests, as we can't have a test here
+// which conditionally passes depending on a test revision/compile-flags.
+
+// ignore-compare-mode-polonius
+
 struct Foo;
 
 impl Foo {
diff --git a/src/test/ui/nll/issue-46589.stderr b/src/test/ui/nll/issue-46589.stderr
index 397909a436610..82cd364eeffd0 100644
--- a/src/test/ui/nll/issue-46589.stderr
+++ b/src/test/ui/nll/issue-46589.stderr
@@ -1,5 +1,5 @@
 error[E0499]: cannot borrow `**other` as mutable more than once at a time
-  --> $DIR/issue-46589.rs:17:21
+  --> $DIR/issue-46589.rs:23:21
    |
 LL |         *other = match (*other).get_self() {
    |                        -------- first mutable borrow occurs here
diff --git a/src/test/ui/nll/loan_ends_mid_block_pair.polonius.stderr b/src/test/ui/nll/loan_ends_mid_block_pair.polonius.stderr
new file mode 100644
index 0000000000000..eb8442b31d7c7
--- /dev/null
+++ b/src/test/ui/nll/loan_ends_mid_block_pair.polonius.stderr
@@ -0,0 +1,15 @@
+error[E0506]: cannot assign to `data.0` because it is borrowed
+  --> $DIR/loan_ends_mid_block_pair.rs:12:5
+   |
+LL |     let c = &mut data.0;
+   |             ----------- borrow of `data.0` occurs here
+LL |     capitalize(c);
+LL |     data.0 = 'e';
+   |     ^^^^^^^^^^^^ assignment to borrowed `data.0` occurs here
+...
+LL |     capitalize(c);
+   |                - borrow later used here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0506`.
diff --git a/src/test/ui/nll/polonius/assignment-kills-loans.rs b/src/test/ui/nll/polonius/assignment-kills-loans.rs
new file mode 100644
index 0000000000000..a80c62d19d5a6
--- /dev/null
+++ b/src/test/ui/nll/polonius/assignment-kills-loans.rs
@@ -0,0 +1,88 @@
+#![allow(dead_code)]
+
+// This tests the various kinds of assignments there are. Polonius used to generate `killed`
+// facts only on simple assigments, but not projections, incorrectly causing errors to be emitted
+// for code accepted by NLL. They are all variations from example code in the NLL RFC.
+
+// check-pass
+// compile-flags: -Z borrowck=mir -Z polonius
+// ignore-compare-mode-nll
+
+struct List<T> {
+    value: T,
+    next: Option<Box<List<T>>>,
+}
+
+// Assignment to a local: the `list` assignment should clear the existing
+// borrows of `list.value` and `list.next`
+fn assignment_to_local<T>(mut list: &mut List<T>) -> Vec<&mut T> {
+    let mut result = vec![];
+    loop {
+        result.push(&mut list.value);
+        if let Some(n) = list.next.as_mut() {
+            list = n;
+        } else {
+            return result;
+        }
+    }
+}
+
+// Assignment to a deref projection: the `*list` assignment should clear the existing
+// borrows of `list.value` and `list.next`
+fn assignment_to_deref_projection<T>(mut list: Box<&mut List<T>>) -> Vec<&mut T> {
+    let mut result = vec![];
+    loop {
+        result.push(&mut list.value);
+        if let Some(n) = list.next.as_mut() {
+            *list = n;
+        } else {
+            return result;
+        }
+    }
+}
+
+// Assignment to a field projection: the `list.0` assignment should clear the existing
+// borrows of `list.0.value` and `list.0.next`
+fn assignment_to_field_projection<T>(mut list: (&mut List<T>,)) -> Vec<&mut T> {
+    let mut result = vec![];
+    loop {
+        result.push(&mut list.0.value);
+        if let Some(n) = list.0.next.as_mut() {
+            list.0 = n;
+        } else {
+            return result;
+        }
+    }
+}
+
+// Assignment to a deref field projection: the `*list.0` assignment should clear the existing
+// borrows of `list.0.value` and `list.0.next`
+fn assignment_to_deref_field_projection<T>(mut list: (Box<&mut List<T>>,)) -> Vec<&mut T> {
+    let mut result = vec![];
+    loop {
+        result.push(&mut list.0.value);
+        if let Some(n) = list.0.next.as_mut() {
+            *list.0 = n;
+        } else {
+            return result;
+        }
+    }
+}
+
+// Similar to `assignment_to_deref_field_projection` but through a longer projection chain
+fn assignment_through_projection_chain<T>(
+    mut list: (((((Box<&mut List<T>>,),),),),),
+) -> Vec<&mut T> {
+    let mut result = vec![];
+    loop {
+        result.push(&mut ((((list.0).0).0).0).0.value);
+        if let Some(n) = ((((list.0).0).0).0).0.next.as_mut() {
+            *((((list.0).0).0).0).0 = n;
+        } else {
+            return result;
+        }
+    }
+}
+
+fn main() {
+}
diff --git a/src/test/ui/nll/polonius/assignment-to-differing-field.rs b/src/test/ui/nll/polonius/assignment-to-differing-field.rs
new file mode 100644
index 0000000000000..c0ba1b983fc35
--- /dev/null
+++ b/src/test/ui/nll/polonius/assignment-to-differing-field.rs
@@ -0,0 +1,50 @@
+#![allow(dead_code)]
+
+// Compared to `assignment-kills-loans.rs`, we check here
+// that we do not kill too many borrows. Assignments to the `.1`
+// field projections should leave the borrows on `.0` intact.
+
+// compile-flags: -Z borrowck=mir -Z polonius
+// ignore-compare-mode-nll
+
+struct List<T> {
+    value: T,
+    next: Option<Box<List<T>>>,
+}
+
+
+fn assignment_to_field_projection<'a, T>(
+    mut list: (&'a mut List<T>, &'a mut List<T>),
+) -> Vec<&'a mut T> {
+    let mut result = vec![];
+    loop {
+        result.push(&mut (list.0).value);
+        //~^ ERROR cannot borrow `list.0.value` as mutable
+
+        if let Some(n) = (list.0).next.as_mut() {
+        //~^ ERROR cannot borrow `list.0.next` as mutable
+            list.1 = n;
+        } else {
+            return result;
+        }
+    }
+}
+
+fn assignment_through_projection_chain<'a, T>(
+    mut list: (((((Box<&'a mut List<T>>, Box<&'a mut List<T>>),),),),),
+) -> Vec<&'a mut T> {
+    let mut result = vec![];
+    loop {
+        result.push(&mut ((((list.0).0).0).0).0.value);
+        //~^ ERROR cannot borrow `list.0.0.0.0.0.value` as mutable
+
+        if let Some(n) = ((((list.0).0).0).0).0.next.as_mut() {
+        //~^ ERROR cannot borrow `list.0.0.0.0.0.next` as mutable
+            *((((list.0).0).0).0).1 = n;
+        } else {
+            return result;
+        }
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/nll/polonius/assignment-to-differing-field.stderr b/src/test/ui/nll/polonius/assignment-to-differing-field.stderr
new file mode 100644
index 0000000000000..07ca021b53bce
--- /dev/null
+++ b/src/test/ui/nll/polonius/assignment-to-differing-field.stderr
@@ -0,0 +1,51 @@
+error[E0499]: cannot borrow `list.0.value` as mutable more than once at a time
+  --> $DIR/assignment-to-differing-field.rs:21:21
+   |
+LL | fn assignment_to_field_projection<'a, T>(
+   |                                   -- lifetime `'a` defined here
+...
+LL |         result.push(&mut (list.0).value);
+   |                     ^^^^^^^^^^^^^^^^^^^ mutable borrow starts here in previous iteration of loop
+...
+LL |             return result;
+   |                    ------ returning this value requires that `list.0.value` is borrowed for `'a`
+
+error[E0499]: cannot borrow `list.0.next` as mutable more than once at a time
+  --> $DIR/assignment-to-differing-field.rs:24:26
+   |
+LL | fn assignment_to_field_projection<'a, T>(
+   |                                   -- lifetime `'a` defined here
+...
+LL |         if let Some(n) = (list.0).next.as_mut() {
+   |                          ^^^^^^^^^^^^^---------
+   |                          |
+   |                          mutable borrow starts here in previous iteration of loop
+   |                          argument requires that `list.0.next` is borrowed for `'a`
+
+error[E0499]: cannot borrow `list.0.0.0.0.0.value` as mutable more than once at a time
+  --> $DIR/assignment-to-differing-field.rs:38:21
+   |
+LL | fn assignment_through_projection_chain<'a, T>(
+   |                                        -- lifetime `'a` defined here
+...
+LL |         result.push(&mut ((((list.0).0).0).0).0.value);
+   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ mutable borrow starts here in previous iteration of loop
+...
+LL |             return result;
+   |                    ------ returning this value requires that `list.0.0.0.0.0.value` is borrowed for `'a`
+
+error[E0499]: cannot borrow `list.0.0.0.0.0.next` as mutable more than once at a time
+  --> $DIR/assignment-to-differing-field.rs:41:26
+   |
+LL | fn assignment_through_projection_chain<'a, T>(
+   |                                        -- lifetime `'a` defined here
+...
+LL |         if let Some(n) = ((((list.0).0).0).0).0.next.as_mut() {
+   |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^---------
+   |                          |
+   |                          mutable borrow starts here in previous iteration of loop
+   |                          argument requires that `list.0.0.0.0.0.next` is borrowed for `'a`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0499`.
diff --git a/src/test/ui/nll/polonius/call-kills-loans.rs b/src/test/ui/nll/polonius/call-kills-loans.rs
new file mode 100644
index 0000000000000..57dc140110246
--- /dev/null
+++ b/src/test/ui/nll/polonius/call-kills-loans.rs
@@ -0,0 +1,24 @@
+// `Call` terminators can write to a local which has existing loans
+// and those need to be killed like a regular assignment to a local.
+// This is a simplified version of issue 47680, is correctly accepted
+// by NLL but was incorrectly rejected by Polonius because of these
+// missing `killed` facts.
+
+// check-pass
+// compile-flags: -Z borrowck=mir -Z polonius
+// ignore-compare-mode-nll
+
+struct Thing;
+
+impl Thing {
+    fn next(&mut self) -> &mut Self { unimplemented!() }
+}
+
+fn main() {
+    let mut temp = &mut Thing;
+
+    loop {
+        let v = temp.next();
+        temp = v; // accepted by NLL, was incorrectly rejected by Polonius
+    }
+}
diff --git a/src/test/ui/nll/polonius/issue-46589.rs b/src/test/ui/nll/polonius/issue-46589.rs
new file mode 100644
index 0000000000000..b5792587ff0ec
--- /dev/null
+++ b/src/test/ui/nll/polonius/issue-46589.rs
@@ -0,0 +1,32 @@
+// This test is a copy of `ui/nll/issue-46589.rs` which fails in NLL but succeeds in Polonius.
+// As we can't have a test here which conditionally passes depending on a test
+// revision/compile-flags. We ensure here that it passes in Polonius mode.
+
+// check-pass
+// compile-flags: -Z borrowck=mir -Z polonius
+// ignore-compare-mode-nll
+
+struct Foo;
+
+impl Foo {
+    fn get_self(&mut self) -> Option<&mut Self> {
+        Some(self)
+    }
+
+    fn new_self(&mut self) -> &mut Self {
+        self
+    }
+
+    fn trigger_bug(&mut self) {
+        let other = &mut (&mut *self);
+
+        *other = match (*other).get_self() {
+            Some(s) => s,
+            None => (*other).new_self()
+        };
+
+        let c = other;
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/nll/polonius-smoke-test.rs b/src/test/ui/nll/polonius/polonius-smoke-test.rs
similarity index 100%
rename from src/test/ui/nll/polonius-smoke-test.rs
rename to src/test/ui/nll/polonius/polonius-smoke-test.rs
diff --git a/src/test/ui/nll/polonius-smoke-test.stderr b/src/test/ui/nll/polonius/polonius-smoke-test.stderr
similarity index 100%
rename from src/test/ui/nll/polonius-smoke-test.stderr
rename to src/test/ui/nll/polonius/polonius-smoke-test.stderr
diff --git a/src/test/ui/nll/polonius/storagedead-kills-loans.rs b/src/test/ui/nll/polonius/storagedead-kills-loans.rs
new file mode 100644
index 0000000000000..ff801cbf9f35d
--- /dev/null
+++ b/src/test/ui/nll/polonius/storagedead-kills-loans.rs
@@ -0,0 +1,29 @@
+// Whenever a `StorageDead` MIR statement destroys a value `x`,
+// we should kill all loans of `x`. This is extracted from `rand 0.4.6`,
+// is correctly accepted by NLL but was incorrectly rejected by
+// Polonius because of these missing `killed` facts.
+
+// check-pass
+// compile-flags: -Z borrowck=mir -Z polonius
+// ignore-compare-mode-nll
+
+use std::{io, mem};
+use std::io::Read;
+
+#[allow(dead_code)]
+fn fill(r: &mut dyn Read, mut buf: &mut [u8]) -> io::Result<()> {
+    while buf.len() > 0 {
+        match r.read(buf).unwrap() {
+            0 => return Err(io::Error::new(io::ErrorKind::Other,
+                                           "end of file reached")),
+            n => buf = &mut mem::replace(&mut buf, &mut [])[n..],
+            // ^- Polonius had multiple errors on the previous line (where NLL has none)
+            // as it didn't know `buf` was killed here, and would
+            // incorrectly reject both the borrow expression, and the assignment.
+        }
+    }
+    Ok(())
+}
+
+fn main() {
+}
diff --git a/src/test/ui/nll/return-ref-mut-issue-46557.polonius.stderr b/src/test/ui/nll/return-ref-mut-issue-46557.polonius.stderr
new file mode 100644
index 0000000000000..8e3cf59cffb44
--- /dev/null
+++ b/src/test/ui/nll/return-ref-mut-issue-46557.polonius.stderr
@@ -0,0 +1,15 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/return-ref-mut-issue-46557.rs:4:21
+   |
+LL |     let ref mut x = 1234543;
+   |                     ^^^^^^^ creates a temporary which is freed while still in use
+LL |     x
+   |     - borrow later used here
+LL | }
+   | - temporary value is freed at the end of this statement
+   |
+   = note: consider using a `let` binding to create a longer lived value
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0716`.
diff --git a/src/test/ui/save-analysis/emit-notifications.polonius.stderr b/src/test/ui/save-analysis/emit-notifications.polonius.stderr
new file mode 100644
index 0000000000000..a1a1b8c63dac3
--- /dev/null
+++ b/src/test/ui/save-analysis/emit-notifications.polonius.stderr
@@ -0,0 +1,2 @@
+{"artifact":"$TEST_BUILD_DIR/save-analysis/emit-notifications.polonius/save-analysis/libemit_notifications.json","emit":"save-analysis"}
+{"artifact":"$TEST_BUILD_DIR/save-analysis/emit-notifications.polonius/libemit_notifications.rlib","emit":"link"}
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.polonius.stderr b/src/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.polonius.stderr
new file mode 100644
index 0000000000000..4b906f75149af
--- /dev/null
+++ b/src/test/ui/unboxed-closures/unboxed-closures-failed-recursive-fn-1.polonius.stderr
@@ -0,0 +1,60 @@
+error[E0597]: `factorial` does not live long enough
+  --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:15:17
+   |
+LL |     let f = |x: u32| -> u32 {
+   |             --------------- value captured here
+LL |         let g = factorial.as_ref().unwrap();
+   |                 ^^^^^^^^^ borrowed value does not live long enough
+...
+LL | }
+   | -
+   | |
+   | `factorial` dropped here while still borrowed
+   | borrow might be used here, when `factorial` is dropped and runs the destructor for type `std::option::Option<std::boxed::Box<dyn std::ops::Fn(u32) -> u32>>`
+
+error[E0506]: cannot assign to `factorial` because it is borrowed
+  --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:20:5
+   |
+LL |     let f = |x: u32| -> u32 {
+   |             --------------- borrow of `factorial` occurs here
+LL |         let g = factorial.as_ref().unwrap();
+   |                 --------- borrow occurs due to use in closure
+...
+LL |     factorial = Some(Box::new(f));
+   |     ^^^^^^^^^
+   |     |
+   |     assignment to borrowed `factorial` occurs here
+   |     borrow later used here
+
+error[E0597]: `factorial` does not live long enough
+  --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:28:17
+   |
+LL |     let f = |x: u32| -> u32 {
+   |             --------------- value captured here
+LL |         let g = factorial.as_ref().unwrap();
+   |                 ^^^^^^^^^ borrowed value does not live long enough
+...
+LL | }
+   | -
+   | |
+   | `factorial` dropped here while still borrowed
+   | borrow might be used here, when `factorial` is dropped and runs the destructor for type `std::option::Option<std::boxed::Box<dyn std::ops::Fn(u32) -> u32>>`
+
+error[E0506]: cannot assign to `factorial` because it is borrowed
+  --> $DIR/unboxed-closures-failed-recursive-fn-1.rs:33:5
+   |
+LL |     let f = |x: u32| -> u32 {
+   |             --------------- borrow of `factorial` occurs here
+LL |         let g = factorial.as_ref().unwrap();
+   |                 --------- borrow occurs due to use in closure
+...
+LL |     factorial = Some(Box::new(f));
+   |     ^^^^^^^^^
+   |     |
+   |     assignment to borrowed `factorial` occurs here
+   |     borrow later used here
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0506, E0597.
+For more information about an error, try `rustc --explain E0506`.