Point at `impl` blocks when they introduce unmet obligations

Group obligations by `impl` block that introduced them.

6 files changed, 53 insertions, 38 deletions

diff --git a/src/test/ui/derives/derive-assoc-type-not-impl.stderr b/src/test/ui/derives/derive-assoc-type-not-impl.stderr
index 1080f947732..45a906a3947 100644
--- a/src/test/ui/derives/derive-assoc-type-not-impl.stderr
+++ b/src/test/ui/derives/derive-assoc-type-not-impl.stderr
@@ -13,12 +13,16 @@ LL | struct NotClone;
 LL |     Bar::<NotClone> { x: 1 }.clone();
    |                              ^^^^^ method cannot be called on `Bar<NotClone>` due to unsatisfied trait bounds
    |
-   = note: the following trait bounds were not satisfied:
-           `NotClone: Clone`
-           which is required by `Bar<NotClone>: Clone`
+note: the following trait bounds were not satisfied because of the requirements of the implementation of `Clone` for `_`:
+      `NotClone: Clone`
+  --> $DIR/derive-assoc-type-not-impl.rs:6:10
+   |
+LL | #[derive(Clone)]
+   |          ^^^^^
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `clone`, perhaps you need to implement it:
            candidate #1: `Clone`
+   = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `NotClone` with `#[derive(Clone)]`
    |
 LL | #[derive(Clone)]
diff --git a/src/test/ui/generic-associated-types/method-unsatified-assoc-type-predicate.rs b/src/test/ui/generic-associated-types/method-unsatified-assoc-type-predicate.rs
index 6db249221b8..8b6f7c41a7c 100644
--- a/src/test/ui/generic-associated-types/method-unsatified-assoc-type-predicate.rs
+++ b/src/test/ui/generic-associated-types/method-unsatified-assoc-type-predicate.rs
@@ -12,6 +12,7 @@ trait M {
 }
 
 impl<T: X<Y<i32> = i32>> M for T {}
+//~^ NOTE the following trait bounds were not satisfied
 
 struct S;
 //~^ NOTE method `f` not found for this
@@ -26,7 +27,6 @@ fn f(a: S) {
     a.f();
     //~^ ERROR the method `f` exists for struct `S`, but its trait bounds were not satisfied
     //~| NOTE method cannot be called on `S` due to unsatisfied trait bounds
-    //~| NOTE the following trait bounds were not satisfied:
 }
 
 fn main() {}
diff --git a/src/test/ui/generic-associated-types/method-unsatified-assoc-type-predicate.stderr b/src/test/ui/generic-associated-types/method-unsatified-assoc-type-predicate.stderr
index 8af9fbed872..3eeb9540e73 100644
--- a/src/test/ui/generic-associated-types/method-unsatified-assoc-type-predicate.stderr
+++ b/src/test/ui/generic-associated-types/method-unsatified-assoc-type-predicate.stderr
@@ -1,5 +1,5 @@
 error[E0599]: the method `f` exists for struct `S`, but its trait bounds were not satisfied
-  --> $DIR/method-unsatified-assoc-type-predicate.rs:26:7
+  --> $DIR/method-unsatified-assoc-type-predicate.rs:27:7
    |
 LL | struct S;
    | ---------
@@ -11,9 +11,12 @@ LL | struct S;
 LL |     a.f();
    |       ^ method cannot be called on `S` due to unsatisfied trait bounds
    |
-   = note: the following trait bounds were not satisfied:
-           `<S as X>::Y<i32> = i32`
-           which is required by `S: M`
+note: the following trait bounds were not satisfied because of the requirements of the implementation of `M` for `_`:
+      `<S as X>::Y<i32> = i32`
+  --> $DIR/method-unsatified-assoc-type-predicate.rs:14:26
+   |
+LL | impl<T: X<Y<i32> = i32>> M for T {}
+   |                          ^     ^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/hrtb/issue-30786.migrate.stderr b/src/test/ui/hrtb/issue-30786.migrate.stderr
index a769872d83a..a497c6257da 100644
--- a/src/test/ui/hrtb/issue-30786.migrate.stderr
+++ b/src/test/ui/hrtb/issue-30786.migrate.stderr
@@ -10,13 +10,14 @@ LL | pub struct Map<S, F> {
 LL |     let filter = map.filterx(|x: &_| true);
    |                      ^^^^^^^ method cannot be called on `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>` due to unsatisfied trait bounds
    |
-   = note: the following trait bounds were not satisfied:
-           `&'a mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
-           which is required by `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
-           `&'a mut &Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
-           which is required by `&Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
-           `&'a mut &mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
-           which is required by `&mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
+note: the following trait bounds were not satisfied because of the requirements of the implementation of `StreamExt` for `_`:
+      `&'a mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
+      `&'a mut &Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
+      `&'a mut &mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
+  --> $DIR/issue-30786.rs:106:9
+   |
+LL | impl<T> StreamExt for T where for<'a> &'a mut T: Stream {}
+   |         ^^^^^^^^^     ^
 
 error[E0599]: the method `countx` exists for struct `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>`, but its trait bounds were not satisfied
   --> $DIR/issue-30786.rs:141:24
@@ -30,13 +31,14 @@ LL | pub struct Filter<S, F> {
 LL |     let count = filter.countx();
    |                        ^^^^^^ method cannot be called on `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>` due to unsatisfied trait bounds
    |
-   = note: the following trait bounds were not satisfied:
-           `&'a mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
-           which is required by `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: StreamExt`
-           `&'a mut &Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
-           which is required by `&Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: StreamExt`
-           `&'a mut &mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
-           which is required by `&mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: StreamExt`
+note: the following trait bounds were not satisfied because of the requirements of the implementation of `StreamExt` for `_`:
+      `&'a mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
+      `&'a mut &Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
+      `&'a mut &mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
+  --> $DIR/issue-30786.rs:106:9
+   |
+LL | impl<T> StreamExt for T where for<'a> &'a mut T: Stream {}
+   |         ^^^^^^^^^     ^
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/hrtb/issue-30786.nll.stderr b/src/test/ui/hrtb/issue-30786.nll.stderr
index a769872d83a..a497c6257da 100644
--- a/src/test/ui/hrtb/issue-30786.nll.stderr
+++ b/src/test/ui/hrtb/issue-30786.nll.stderr
@@ -10,13 +10,14 @@ LL | pub struct Map<S, F> {
 LL |     let filter = map.filterx(|x: &_| true);
    |                      ^^^^^^^ method cannot be called on `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>` due to unsatisfied trait bounds
    |
-   = note: the following trait bounds were not satisfied:
-           `&'a mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
-           which is required by `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
-           `&'a mut &Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
-           which is required by `&Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
-           `&'a mut &mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
-           which is required by `&mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
+note: the following trait bounds were not satisfied because of the requirements of the implementation of `StreamExt` for `_`:
+      `&'a mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
+      `&'a mut &Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
+      `&'a mut &mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
+  --> $DIR/issue-30786.rs:106:9
+   |
+LL | impl<T> StreamExt for T where for<'a> &'a mut T: Stream {}
+   |         ^^^^^^^^^     ^
 
 error[E0599]: the method `countx` exists for struct `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>`, but its trait bounds were not satisfied
   --> $DIR/issue-30786.rs:141:24
@@ -30,13 +31,14 @@ LL | pub struct Filter<S, F> {
 LL |     let count = filter.countx();
    |                        ^^^^^^ method cannot be called on `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>` due to unsatisfied trait bounds
    |
-   = note: the following trait bounds were not satisfied:
-           `&'a mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
-           which is required by `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: StreamExt`
-           `&'a mut &Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
-           which is required by `&Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: StreamExt`
-           `&'a mut &mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
-           which is required by `&mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: StreamExt`
+note: the following trait bounds were not satisfied because of the requirements of the implementation of `StreamExt` for `_`:
+      `&'a mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
+      `&'a mut &Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
+      `&'a mut &mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
+  --> $DIR/issue-30786.rs:106:9
+   |
+LL | impl<T> StreamExt for T where for<'a> &'a mut T: Stream {}
+   |         ^^^^^^^^^     ^
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/specialization/defaultimpl/specialization-trait-not-implemented.stderr b/src/test/ui/specialization/defaultimpl/specialization-trait-not-implemented.stderr
index ce981bc0098..81e2a9a1ffc 100644
--- a/src/test/ui/specialization/defaultimpl/specialization-trait-not-implemented.stderr
+++ b/src/test/ui/specialization/defaultimpl/specialization-trait-not-implemented.stderr
@@ -20,8 +20,12 @@ LL | struct MyStruct;
 LL |     println!("{}", MyStruct.foo_one());
    |                             ^^^^^^^ method cannot be called on `MyStruct` due to unsatisfied trait bounds
    |
-   = note: the following trait bounds were not satisfied:
-           `MyStruct: Foo`
+note: the following trait bounds were not satisfied because of the requirements of the implementation of `Foo` for `_`:
+      `MyStruct: Foo`
+  --> $DIR/specialization-trait-not-implemented.rs:14:17
+   |
+LL | default impl<T> Foo for T {
+   |                 ^^^     ^
 note: the following trait must be implemented
   --> $DIR/specialization-trait-not-implemented.rs:7:1
    |