Point at call span that introduced obligation for the arg

13 files changed, 103 insertions, 46 deletions

diff --git a/src/test/ui/suggestions/async-fn-ctor-passed-as-arg-where-it-should-have-been-called.stderr b/src/test/ui/suggestions/async-fn-ctor-passed-as-arg-where-it-should-have-been-called.stderr
index 300c2a66c29..78ebb3d6bfc 100644
--- a/src/test/ui/suggestions/async-fn-ctor-passed-as-arg-where-it-should-have-been-called.stderr
+++ b/src/test/ui/suggestions/async-fn-ctor-passed-as-arg-where-it-should-have-been-called.stderr
@@ -5,7 +5,9 @@ LL | async fn foo() {}
    |          --- consider calling this function
 ...
 LL |     bar(foo);
-   |         ^^^ `fn() -> impl Future {foo}` is not a future
+   |     --- ^^^ `fn() -> impl Future {foo}` is not a future
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Future` is not implemented for `fn() -> impl Future {foo}`
 note: required by a bound in `bar`
@@ -24,7 +26,9 @@ error[E0277]: `[closure@$DIR/async-fn-ctor-passed-as-arg-where-it-should-have-be
 LL |     let async_closure = async || ();
    |                         -------- consider calling this closure
 LL |     bar(async_closure);
-   |         ^^^^^^^^^^^^^ `[closure@$DIR/async-fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:11:25: 11:36]` is not a future
+   |     --- ^^^^^^^^^^^^^ `[closure@$DIR/async-fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:11:25: 11:36]` is not a future
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Future` is not implemented for `[closure@$DIR/async-fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:11:25: 11:36]`
 note: required by a bound in `bar`
diff --git a/src/test/ui/suggestions/fn-ctor-passed-as-arg-where-it-should-have-been-called.stderr b/src/test/ui/suggestions/fn-ctor-passed-as-arg-where-it-should-have-been-called.stderr
index 93048107e59..b111df49f6e 100644
--- a/src/test/ui/suggestions/fn-ctor-passed-as-arg-where-it-should-have-been-called.stderr
+++ b/src/test/ui/suggestions/fn-ctor-passed-as-arg-where-it-should-have-been-called.stderr
@@ -5,7 +5,9 @@ LL | fn foo() -> impl T<O=()> { S }
    |    --- consider calling this function
 ...
 LL |     bar(foo);
-   |         ^^^ the trait `T` is not implemented for `fn() -> impl T {foo}`
+   |     --- ^^^ the trait `T` is not implemented for `fn() -> impl T {foo}`
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `bar`
   --> $DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:14:16
@@ -23,7 +25,9 @@ error[E0277]: the trait bound `[closure@$DIR/fn-ctor-passed-as-arg-where-it-shou
 LL |     let closure = || S;
    |                   -- consider calling this closure
 LL |     bar(closure);
-   |         ^^^^^^^ the trait `T` is not implemented for `[closure@$DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:18:19: 18:23]`
+   |     --- ^^^^^^^ the trait `T` is not implemented for `[closure@$DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:18:19: 18:23]`
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `bar`
   --> $DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:14:16
diff --git a/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr b/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr
index 39bde52c55a..71779ecb729 100644
--- a/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr
+++ b/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr
@@ -2,7 +2,9 @@ error[E0277]: the trait bound `&S: Trait` is not satisfied
   --> $DIR/imm-ref-trait-object-literal.rs:12:7
    |
 LL |   foo(&s);
-   |       ^^ the trait `Trait` is not implemented for `&S`
+   |   --- ^^ the trait `Trait` is not implemented for `&S`
+   |   |
+   |   required by a bound introduced by this call
    |
    = help: the following implementations were found:
              <&'a mut S as Trait>
@@ -20,10 +22,11 @@ error[E0277]: the trait bound `S: Trait` is not satisfied
   --> $DIR/imm-ref-trait-object-literal.rs:13:7
    |
 LL |   foo(s);
-   |       ^
-   |       |
-   |       expected an implementor of trait `Trait`
-   |       help: consider mutably borrowing here: `&mut s`
+   |   --- ^
+   |   |   |
+   |   |   expected an implementor of trait `Trait`
+   |   |   help: consider mutably borrowing here: `&mut s`
+   |   required by a bound introduced by this call
    |
 note: required by a bound in `foo`
   --> $DIR/imm-ref-trait-object-literal.rs:7:11
diff --git a/src/test/ui/suggestions/impl-trait-with-missing-bounds.stderr b/src/test/ui/suggestions/impl-trait-with-missing-bounds.stderr
index bb7919ebb79..229c4b824f2 100644
--- a/src/test/ui/suggestions/impl-trait-with-missing-bounds.stderr
+++ b/src/test/ui/suggestions/impl-trait-with-missing-bounds.stderr
@@ -2,7 +2,9 @@ error[E0277]: `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
   --> $DIR/impl-trait-with-missing-bounds.rs:14:13
    |
 LL |         qux(constraint);
-   |             ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         --- ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         |
+   |         required by a bound introduced by this call
    |
    = help: the trait `Debug` is not implemented for `<impl Iterator as Iterator>::Item`
 note: required by a bound in `qux`
@@ -19,7 +21,9 @@ error[E0277]: `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
   --> $DIR/impl-trait-with-missing-bounds.rs:22:13
    |
 LL |         qux(constraint);
-   |             ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         --- ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         |
+   |         required by a bound introduced by this call
    |
    = help: the trait `Debug` is not implemented for `<impl Iterator as Iterator>::Item`
 note: required by a bound in `qux`
@@ -36,7 +40,9 @@ error[E0277]: `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
   --> $DIR/impl-trait-with-missing-bounds.rs:30:13
    |
 LL |         qux(constraint);
-   |             ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         --- ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         |
+   |         required by a bound introduced by this call
    |
    = help: the trait `Debug` is not implemented for `<impl Iterator as Iterator>::Item`
 note: required by a bound in `qux`
@@ -53,7 +59,9 @@ error[E0277]: `<impl Iterator + std::fmt::Debug as Iterator>::Item` doesn't impl
   --> $DIR/impl-trait-with-missing-bounds.rs:37:13
    |
 LL |         qux(constraint);
-   |             ^^^^^^^^^^ `<impl Iterator + std::fmt::Debug as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         --- ^^^^^^^^^^ `<impl Iterator + std::fmt::Debug as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         |
+   |         required by a bound introduced by this call
    |
    = help: the trait `Debug` is not implemented for `<impl Iterator + std::fmt::Debug as Iterator>::Item`
 note: required by a bound in `qux`
@@ -70,7 +78,9 @@ error[E0277]: `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
   --> $DIR/impl-trait-with-missing-bounds.rs:6:13
    |
 LL |         qux(constraint);
-   |             ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         --- ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         |
+   |         required by a bound introduced by this call
    |
    = help: the trait `Debug` is not implemented for `<impl Iterator as Iterator>::Item`
 note: required by a bound in `qux`
@@ -87,7 +97,9 @@ error[E0277]: `<impl Iterator as Iterator>::Item` doesn't implement `Debug`
   --> $DIR/impl-trait-with-missing-bounds.rs:45:13
    |
 LL |         qux(constraint);
-   |             ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         --- ^^^^^^^^^^ `<impl Iterator as Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   |         |
+   |         required by a bound introduced by this call
    |
    = help: the trait `Debug` is not implemented for `<impl Iterator as Iterator>::Item`
 note: required by a bound in `qux`
diff --git a/src/test/ui/suggestions/issue-62843.stderr b/src/test/ui/suggestions/issue-62843.stderr
index b2be09a4c7f..93251b2c8db 100644
--- a/src/test/ui/suggestions/issue-62843.stderr
+++ b/src/test/ui/suggestions/issue-62843.stderr
@@ -2,10 +2,11 @@ error[E0277]: expected a `FnMut<(char,)>` closure, found `String`
   --> $DIR/issue-62843.rs:4:32
    |
 LL |     println!("{:?}", line.find(pattern));
-   |                                ^^^^^^^
-   |                                |
-   |                                expected an implementor of trait `Pattern<'_>`
-   |                                help: consider borrowing here: `&pattern`
+   |                           ---- ^^^^^^^
+   |                           |    |
+   |                           |    expected an implementor of trait `Pattern<'_>`
+   |                           |    help: consider borrowing here: `&pattern`
+   |                           required by a bound introduced by this call
    |
    = note: the trait bound `String: Pattern<'_>` is not satisfied
    = note: required because of the requirements on the impl of `Pattern<'_>` for `String`
diff --git a/src/test/ui/suggestions/issue-79843-impl-trait-with-missing-bounds-on-async-fn.stderr b/src/test/ui/suggestions/issue-79843-impl-trait-with-missing-bounds-on-async-fn.stderr
index cd1a8c4be8e..a3ab0b8efb0 100644
--- a/src/test/ui/suggestions/issue-79843-impl-trait-with-missing-bounds-on-async-fn.stderr
+++ b/src/test/ui/suggestions/issue-79843-impl-trait-with-missing-bounds-on-async-fn.stderr
@@ -2,7 +2,9 @@ error[E0277]: `<impl Foo as Foo>::Bar` cannot be sent between threads safely
   --> $DIR/issue-79843-impl-trait-with-missing-bounds-on-async-fn.rs:14:20
    |
 LL |     assert_is_send(&bar);
-   |                    ^^^^ `<impl Foo as Foo>::Bar` cannot be sent between threads safely
+   |     -------------- ^^^^ `<impl Foo as Foo>::Bar` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Send` is not implemented for `<impl Foo as Foo>::Bar`
 note: required by a bound in `assert_is_send`
@@ -19,7 +21,9 @@ error[E0277]: `<impl Foo as Foo>::Bar` cannot be sent between threads safely
   --> $DIR/issue-79843-impl-trait-with-missing-bounds-on-async-fn.rs:24:20
    |
 LL |     assert_is_send(&bar);
-   |                    ^^^^ `<impl Foo as Foo>::Bar` cannot be sent between threads safely
+   |     -------------- ^^^^ `<impl Foo as Foo>::Bar` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Send` is not implemented for `<impl Foo as Foo>::Bar`
 note: required by a bound in `assert_is_send`
diff --git a/src/test/ui/suggestions/issue-84973-2.stderr b/src/test/ui/suggestions/issue-84973-2.stderr
index df1eeb7a2b8..c1a7a2e101d 100644
--- a/src/test/ui/suggestions/issue-84973-2.stderr
+++ b/src/test/ui/suggestions/issue-84973-2.stderr
@@ -2,10 +2,11 @@ error[E0277]: the trait bound `i32: Tr` is not satisfied
   --> $DIR/issue-84973-2.rs:11:9
    |
 LL |     foo(a);
-   |         ^
-   |         |
-   |         expected an implementor of trait `Tr`
-   |         help: consider mutably borrowing here: `&mut a`
+   |     --- ^
+   |     |   |
+   |     |   expected an implementor of trait `Tr`
+   |     |   help: consider mutably borrowing here: `&mut a`
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `foo`
   --> $DIR/issue-84973-2.rs:7:11
diff --git a/src/test/ui/suggestions/issue-84973-blacklist.stderr b/src/test/ui/suggestions/issue-84973-blacklist.stderr
index 2ffe2f5a2b6..72d9f5d26a2 100644
--- a/src/test/ui/suggestions/issue-84973-blacklist.stderr
+++ b/src/test/ui/suggestions/issue-84973-blacklist.stderr
@@ -2,7 +2,9 @@ error[E0277]: the trait bound `String: Copy` is not satisfied
   --> $DIR/issue-84973-blacklist.rs:15:12
    |
 LL |     f_copy("".to_string());
-   |            ^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
+   |     ------ ^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `f_copy`
   --> $DIR/issue-84973-blacklist.rs:6:14
@@ -14,7 +16,9 @@ error[E0277]: the trait bound `S: Clone` is not satisfied
   --> $DIR/issue-84973-blacklist.rs:16:13
    |
 LL |     f_clone(S);
-   |             ^ the trait `Clone` is not implemented for `S`
+   |     ------- ^ the trait `Clone` is not implemented for `S`
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `f_clone`
   --> $DIR/issue-84973-blacklist.rs:7:15
@@ -39,7 +43,9 @@ error[E0277]: the size for values of type `dyn Fn()` cannot be known at compilat
   --> $DIR/issue-84973-blacklist.rs:22:13
    |
 LL |     f_sized(*ref_cl);
-   |             ^^^^^^^ doesn't have a size known at compile-time
+   |     ------- ^^^^^^^ doesn't have a size known at compile-time
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Sized` is not implemented for `dyn Fn()`
 note: required by a bound in `f_sized`
@@ -52,7 +58,9 @@ error[E0277]: `Rc<{integer}>` cannot be sent between threads safely
   --> $DIR/issue-84973-blacklist.rs:28:12
    |
 LL |     f_send(rc);
-   |            ^^ `Rc<{integer}>` cannot be sent between threads safely
+   |     ------ ^^ `Rc<{integer}>` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
    = help: the trait `Send` is not implemented for `Rc<{integer}>`
 note: required by a bound in `f_send`
diff --git a/src/test/ui/suggestions/issue-84973-negative.stderr b/src/test/ui/suggestions/issue-84973-negative.stderr
index bd1cf6ba614..14b32d8515c 100644
--- a/src/test/ui/suggestions/issue-84973-negative.stderr
+++ b/src/test/ui/suggestions/issue-84973-negative.stderr
@@ -2,7 +2,9 @@ error[E0277]: the trait bound `i32: Tr` is not satisfied
   --> $DIR/issue-84973-negative.rs:10:9
    |
 LL |     bar(a);
-   |         ^ the trait `Tr` is not implemented for `i32`
+   |     --- ^ the trait `Tr` is not implemented for `i32`
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `bar`
   --> $DIR/issue-84973-negative.rs:5:11
@@ -14,10 +16,11 @@ error[E0277]: the trait bound `f32: Tr` is not satisfied
   --> $DIR/issue-84973-negative.rs:11:9
    |
 LL |     bar(b);
-   |         ^
-   |         |
-   |         expected an implementor of trait `Tr`
-   |         help: consider borrowing here: `&b`
+   |     --- ^
+   |     |   |
+   |     |   expected an implementor of trait `Tr`
+   |     |   help: consider borrowing here: `&b`
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `bar`
   --> $DIR/issue-84973-negative.rs:5:11
diff --git a/src/test/ui/suggestions/issue-84973.stderr b/src/test/ui/suggestions/issue-84973.stderr
index 649517b7d99..169d0cccb43 100644
--- a/src/test/ui/suggestions/issue-84973.stderr
+++ b/src/test/ui/suggestions/issue-84973.stderr
@@ -2,10 +2,11 @@ error[E0277]: the trait bound `Fancy: SomeTrait` is not satisfied
   --> $DIR/issue-84973.rs:6:24
    |
 LL |     let o = Other::new(f);
-   |                        ^
-   |                        |
-   |                        expected an implementor of trait `SomeTrait`
-   |                        help: consider borrowing here: `&f`
+   |             ---------- ^
+   |             |          |
+   |             |          expected an implementor of trait `SomeTrait`
+   |             |          help: consider borrowing here: `&f`
+   |             required by a bound introduced by this call
    |
 note: required by `Other::<'a, G>::new`
   --> $DIR/issue-84973.rs:27:5
diff --git a/src/test/ui/suggestions/mut-borrow-needed-by-trait.stderr b/src/test/ui/suggestions/mut-borrow-needed-by-trait.stderr
index 3b71d5cee93..e6a22313900 100644
--- a/src/test/ui/suggestions/mut-borrow-needed-by-trait.stderr
+++ b/src/test/ui/suggestions/mut-borrow-needed-by-trait.stderr
@@ -2,7 +2,9 @@ error[E0277]: the trait bound `&dyn std::io::Write: std::io::Write` is not satis
   --> $DIR/mut-borrow-needed-by-trait.rs:17:29
    |
 LL |     let fp = BufWriter::new(fp);
-   |                             ^^ the trait `std::io::Write` is not implemented for `&dyn std::io::Write`
+   |              -------------- ^^ the trait `std::io::Write` is not implemented for `&dyn std::io::Write`
+   |              |
+   |              required by a bound introduced by this call
    |
    = note: `std::io::Write` is implemented for `&mut dyn std::io::Write`, but not for `&dyn std::io::Write`
 note: required by `BufWriter::<W>::new`
diff --git a/src/test/ui/suggestions/restrict-type-argument.stderr b/src/test/ui/suggestions/restrict-type-argument.stderr
index b62502fb6a2..551a7c5060f 100644
--- a/src/test/ui/suggestions/restrict-type-argument.stderr
+++ b/src/test/ui/suggestions/restrict-type-argument.stderr
@@ -2,7 +2,9 @@ error[E0277]: `impl Sync` cannot be sent between threads safely
   --> $DIR/restrict-type-argument.rs:4:13
    |
 LL |     is_send(val);
-   |             ^^^ `impl Sync` cannot be sent between threads safely
+   |     ------- ^^^ `impl Sync` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `is_send`
   --> $DIR/restrict-type-argument.rs:1:15
@@ -18,7 +20,9 @@ error[E0277]: `S` cannot be sent between threads safely
   --> $DIR/restrict-type-argument.rs:8:13
    |
 LL |     is_send(val);
-   |             ^^^ `S` cannot be sent between threads safely
+   |     ------- ^^^ `S` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `is_send`
   --> $DIR/restrict-type-argument.rs:1:15
@@ -34,7 +38,9 @@ error[E0277]: `S` cannot be sent between threads safely
   --> $DIR/restrict-type-argument.rs:12:13
    |
 LL |     is_send(val);
-   |             ^^^ `S` cannot be sent between threads safely
+   |     ------- ^^^ `S` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `is_send`
   --> $DIR/restrict-type-argument.rs:1:15
@@ -50,7 +56,9 @@ error[E0277]: `S` cannot be sent between threads safely
   --> $DIR/restrict-type-argument.rs:20:13
    |
 LL |     is_send(val);
-   |             ^^^ `S` cannot be sent between threads safely
+   |     ------- ^^^ `S` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `is_send`
   --> $DIR/restrict-type-argument.rs:1:15
@@ -66,7 +74,9 @@ error[E0277]: `S` cannot be sent between threads safely
   --> $DIR/restrict-type-argument.rs:24:13
    |
 LL |     is_send(val);
-   |             ^^^ `S` cannot be sent between threads safely
+   |     ------- ^^^ `S` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `is_send`
   --> $DIR/restrict-type-argument.rs:1:15
@@ -82,7 +92,9 @@ error[E0277]: `S` cannot be sent between threads safely
   --> $DIR/restrict-type-argument.rs:28:13
    |
 LL |     is_send(val);
-   |             ^^^ `S` cannot be sent between threads safely
+   |     ------- ^^^ `S` cannot be sent between threads safely
+   |     |
+   |     required by a bound introduced by this call
    |
 note: required by a bound in `is_send`
   --> $DIR/restrict-type-argument.rs:1:15
diff --git a/src/test/ui/suggestions/suggest-change-mut.stderr b/src/test/ui/suggestions/suggest-change-mut.stderr
index 1f14ebae841..8dfab8dfa17 100644
--- a/src/test/ui/suggestions/suggest-change-mut.stderr
+++ b/src/test/ui/suggestions/suggest-change-mut.stderr
@@ -2,7 +2,9 @@ error[E0277]: the trait bound `&T: std::io::Read` is not satisfied
   --> $DIR/suggest-change-mut.rs:12:48
    |
 LL |         let mut stream_reader = BufReader::new(&stream);
-   |                                                ^^^^^^^ the trait `std::io::Read` is not implemented for `&T`
+   |                                 -------------- ^^^^^^^ the trait `std::io::Read` is not implemented for `&T`
+   |                                 |
+   |                                 required by a bound introduced by this call
    |
 note: required by `BufReader::<R>::new`
   --> $SRC_DIR/std/src/io/buffered/bufreader.rs:LL:COL