NLL: Updates to diagnostic output in `test/ui`.

7 files changed, 59 insertions, 18 deletions

diff --git a/src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.nll.stderr b/src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.nll.stderr
index 172828b9a40..3282fbba6c5 100644
--- a/src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.nll.stderr
+++ b/src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.nll.stderr
@@ -1,50 +1,66 @@
 error[E0596]: cannot borrow immutable item `x` as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:63:24
    |
+LL | fn deref_mut_field1(x: Own<Point>) {
+   |                     - help: consider changing this to be mutable: `mut x`
 LL |     let __isize = &mut x.y; //~ ERROR cannot borrow
    |                        ^ cannot borrow as mutable
 
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:75:10
    |
+LL | fn deref_extend_mut_field1(x: &Own<Point>) -> &mut isize {
+   |                               ----------- help: consider changing this to be a mutable reference: `&mut Own<Point>`
 LL |     &mut x.y //~ ERROR cannot borrow
-   |          ^ cannot borrow as mutable
+   |          ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0596]: cannot borrow immutable item `x` as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:98:5
    |
+LL | fn assign_field1<'a>(x: Own<Point>) {
+   |                      - help: consider changing this to be mutable: `mut x`
 LL |     x.y = 3; //~ ERROR cannot borrow
    |     ^ cannot borrow as mutable
 
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:102:5
    |
+LL | fn assign_field2<'a>(x: &'a Own<Point>) {
+   |                         -------------- help: consider changing this to be a mutable reference: `&mut Own<Point>`
 LL |     x.y = 3; //~ ERROR cannot borrow
-   |     ^ cannot borrow as mutable
+   |     ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0596]: cannot borrow immutable item `x` as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:119:5
    |
+LL | fn deref_mut_method1(x: Own<Point>) {
+   |                      - help: consider changing this to be mutable: `mut x`
 LL |     x.set(0, 0); //~ ERROR cannot borrow
    |     ^ cannot borrow as mutable
 
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:131:5
    |
+LL | fn deref_extend_mut_method1(x: &Own<Point>) -> &mut isize {
+   |                                ----------- help: consider changing this to be a mutable reference: `&mut Own<Point>`
 LL |     x.y_mut() //~ ERROR cannot borrow
-   |     ^ cannot borrow as mutable
+   |     ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0596]: cannot borrow immutable item `x` as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:139:6
    |
+LL | fn assign_method1<'a>(x: Own<Point>) {
+   |                       - help: consider changing this to be mutable: `mut x`
 LL |     *x.y_mut() = 3; //~ ERROR cannot borrow
    |      ^ cannot borrow as mutable
 
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:143:6
    |
+LL | fn assign_method2<'a>(x: &'a Own<Point>) {
+   |                          -------------- help: consider changing this to be a mutable reference: `&mut Own<Point>`
 LL |     *x.y_mut() = 3; //~ ERROR cannot borrow
-   |      ^ cannot borrow as mutable
+   |      ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error: aborting due to 8 previous errors
 
diff --git a/src/test/ui/span/borrowck-borrow-overloaded-deref-mut.nll.stderr b/src/test/ui/span/borrowck-borrow-overloaded-deref-mut.nll.stderr
index 24abe85de76..0b1bfd8cee6 100644
--- a/src/test/ui/span/borrowck-borrow-overloaded-deref-mut.nll.stderr
+++ b/src/test/ui/span/borrowck-borrow-overloaded-deref-mut.nll.stderr
@@ -1,26 +1,34 @@
 error[E0596]: cannot borrow immutable item `x` as mutable
   --> $DIR/borrowck-borrow-overloaded-deref-mut.rs:39:25
    |
+LL | fn deref_mut1(x: Own<isize>) {
+   |               - help: consider changing this to be mutable: `mut x`
 LL |     let __isize = &mut *x; //~ ERROR cannot borrow
    |                         ^ cannot borrow as mutable
 
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-borrow-overloaded-deref-mut.rs:51:11
    |
+LL | fn deref_extend_mut1<'a>(x: &'a Own<isize>) -> &'a mut isize {
+   |                             -------------- help: consider changing this to be a mutable reference: `&mut Own<isize>`
 LL |     &mut **x //~ ERROR cannot borrow
-   |           ^^ cannot borrow as mutable
+   |           ^^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0596]: cannot borrow immutable item `x` as mutable
   --> $DIR/borrowck-borrow-overloaded-deref-mut.rs:59:6
    |
+LL | fn assign1<'a>(x: Own<isize>) {
+   |                - help: consider changing this to be mutable: `mut x`
 LL |     *x = 3; //~ ERROR cannot borrow
    |      ^ cannot borrow as mutable
 
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-borrow-overloaded-deref-mut.rs:63:6
    |
+LL | fn assign2<'a>(x: &'a Own<isize>) {
+   |                   -------------- help: consider changing this to be a mutable reference: `&mut Own<isize>`
 LL |     **x = 3; //~ ERROR cannot borrow
-   |      ^^ cannot borrow as mutable
+   |      ^^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/span/borrowck-call-is-borrow-issue-12224.nll.stderr b/src/test/ui/span/borrowck-call-is-borrow-issue-12224.nll.stderr
index 26e9ea4dc0b..c4bdef21de4 100644
--- a/src/test/ui/span/borrowck-call-is-borrow-issue-12224.nll.stderr
+++ b/src/test/ui/span/borrowck-call-is-borrow-issue-12224.nll.stderr
@@ -15,16 +15,18 @@ LL | |     }));
 error[E0596]: cannot borrow immutable item `*f` as mutable
   --> $DIR/borrowck-call-is-borrow-issue-12224.rs:35:5
    |
+LL | fn test2<F>(f: &F) where F: FnMut() {
+   |                -- help: consider changing this to be a mutable reference: `&mut F`
 LL |     (*f)();
-   |     ^^^^ cannot borrow as mutable
+   |     ^^^^ `f` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0596]: cannot borrow immutable item `*f.f` as mutable
   --> $DIR/borrowck-call-is-borrow-issue-12224.rs:44:5
    |
+LL | fn test4(f: &Test) {
+   |             ----- help: consider changing this to be a mutable reference: `&mut Test<'_>`
 LL |     f.f.call_mut(())
-   |     ^^^ cannot borrow as mutable
-   |
-   = note: the value which is causing this path not to be mutable is...: `*f`
+   |     ^^^ `f` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0507]: cannot move out of borrowed content
   --> $DIR/borrowck-call-is-borrow-issue-12224.rs:66:13
diff --git a/src/test/ui/span/borrowck-call-method-from-mut-aliasable.nll.stderr b/src/test/ui/span/borrowck-call-method-from-mut-aliasable.nll.stderr
index 43934bf4aee..0bc614589e3 100644
--- a/src/test/ui/span/borrowck-call-method-from-mut-aliasable.nll.stderr
+++ b/src/test/ui/span/borrowck-call-method-from-mut-aliasable.nll.stderr
@@ -1,8 +1,11 @@
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-call-method-from-mut-aliasable.rs:27:5
    |
+LL | fn b(x: &Foo) {
+   |         ---- help: consider changing this to be a mutable reference: `&mut Foo`
+LL |     x.f();
 LL |     x.h(); //~ ERROR cannot borrow
-   |     ^ cannot borrow as mutable
+   |     ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/span/borrowck-fn-in-const-b.nll.stderr b/src/test/ui/span/borrowck-fn-in-const-b.nll.stderr
index d3c6fd66599..1cb2c92833c 100644
--- a/src/test/ui/span/borrowck-fn-in-const-b.nll.stderr
+++ b/src/test/ui/span/borrowck-fn-in-const-b.nll.stderr
@@ -1,8 +1,10 @@
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-fn-in-const-b.rs:17:9
    |
+LL |     fn broken(x: &Vec<String>) {
+   |                  ------------ help: consider changing this to be a mutable reference: `&mut std::vec::Vec<std::string::String>`
 LL |         x.push(format!("this is broken"));
-   |         ^ cannot borrow as mutable
+   |         ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/span/borrowck-object-mutability.nll.stderr b/src/test/ui/span/borrowck-object-mutability.nll.stderr
index 9b5e084bd37..cf615eed556 100644
--- a/src/test/ui/span/borrowck-object-mutability.nll.stderr
+++ b/src/test/ui/span/borrowck-object-mutability.nll.stderr
@@ -1,16 +1,20 @@
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-object-mutability.rs:19:5
    |
+LL | fn borrowed_receiver(x: &Foo) {
+   |                         ---- help: consider changing this to be a mutable reference: `&mut Foo`
+LL |     x.borrowed();
 LL |     x.borrowed_mut(); //~ ERROR cannot borrow
-   |     ^ cannot borrow as mutable
+   |     ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-object-mutability.rs:29:5
    |
+LL | fn owned_receiver(x: Box<Foo>) {
+   |                   - help: consider changing this to be mutable: `mut x`
+LL |     x.borrowed();
 LL |     x.borrowed_mut(); //~ ERROR cannot borrow
    |     ^ cannot borrow as mutable
-   |
-   = note: the value which is causing this path not to be mutable is...: `x`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/span/mut-arg-hint.nll.stderr b/src/test/ui/span/mut-arg-hint.nll.stderr
index 8e1cb9720e2..cd19059fdae 100644
--- a/src/test/ui/span/mut-arg-hint.nll.stderr
+++ b/src/test/ui/span/mut-arg-hint.nll.stderr
@@ -1,20 +1,26 @@
 error[E0596]: cannot borrow immutable item `*a` as mutable
   --> $DIR/mut-arg-hint.rs:13:9
    |
+LL |     fn foo(mut a: &String) {
+   |                   ------- help: consider changing this to be a mutable reference: `&mut std::string::String`
 LL |         a.push_str("bar"); //~ ERROR cannot borrow immutable borrowed content
-   |         ^ cannot borrow as mutable
+   |         ^ `a` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0596]: cannot borrow immutable item `*a` as mutable
   --> $DIR/mut-arg-hint.rs:18:5
    |
+LL | pub fn foo<'a>(mut a: &'a String) {
+   |                       ---------- help: consider changing this to be a mutable reference: `&mut std::string::String`
 LL |     a.push_str("foo"); //~ ERROR cannot borrow immutable borrowed content
-   |     ^ cannot borrow as mutable
+   |     ^ `a` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error[E0596]: cannot borrow immutable item `*a` as mutable
   --> $DIR/mut-arg-hint.rs:25:9
    |
+LL |     pub fn foo(mut a: &String) {
+   |                       ------- help: consider changing this to be a mutable reference: `&mut std::string::String`
 LL |         a.push_str("foo"); //~ ERROR cannot borrow immutable borrowed content
-   |         ^ cannot borrow as mutable
+   |         ^ `a` is a `&` reference, so the data it refers to cannot be borrowed as mutable
 
 error: aborting due to 3 previous errors