Report cycle error using 'deepest' obligation in the cycle

8 files changed, 38 insertions, 19 deletions

diff --git a/src/test/incremental/const-generics/hash-tyvid-regression-1.rs b/src/test/incremental/const-generics/hash-tyvid-regression-1.rs
index b5a0108a0a3..5ff7b19d894 100644
--- a/src/test/incremental/const-generics/hash-tyvid-regression-1.rs
+++ b/src/test/incremental/const-generics/hash-tyvid-regression-1.rs
@@ -9,7 +9,8 @@ where
     use std::convert::TryFrom;
     <[T; N.get()]>::try_from(())
     //~^ error: the trait bound
-    //~^^ error: mismatched types
+    //~| error: the trait bound
+    //~| error: mismatched types
 }
 
 fn main() {}
diff --git a/src/test/ui/traits/cycle-cache-err-60010.rs b/src/test/ui/traits/cycle-cache-err-60010.rs
index 88f0bd87253..94e718317e7 100644
--- a/src/test/ui/traits/cycle-cache-err-60010.rs
+++ b/src/test/ui/traits/cycle-cache-err-60010.rs
@@ -25,7 +25,7 @@ struct Runtime<DB: Database> {
 }
 struct SalsaStorage {
     _parse: <ParseQuery as Query<RootDatabase>>::Data,
-    //~^ ERROR overflow evaluating the requirement `RootDatabase: SourceDatabase`
+    //~^ ERROR overflow
 }
 
 impl Database for RootDatabase {
diff --git a/src/test/ui/traits/cycle-cache-err-60010.stderr b/src/test/ui/traits/cycle-cache-err-60010.stderr
index 91c2bd6c3b2..9452e11e302 100644
--- a/src/test/ui/traits/cycle-cache-err-60010.stderr
+++ b/src/test/ui/traits/cycle-cache-err-60010.stderr
@@ -1,9 +1,27 @@
-error[E0275]: overflow evaluating the requirement `RootDatabase: SourceDatabase`
+error[E0275]: overflow evaluating the requirement `SalsaStorage: RefUnwindSafe`
   --> $DIR/cycle-cache-err-60010.rs:27:13
    |
 LL |     _parse: <ParseQuery as Query<RootDatabase>>::Data,
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: required because it appears within the type `*const SalsaStorage`
+   = note: required because it appears within the type `Unique<SalsaStorage>`
+   = note: required because it appears within the type `Box<SalsaStorage>`
+note: required because it appears within the type `Runtime<RootDatabase>`
+  --> $DIR/cycle-cache-err-60010.rs:23:8
+   |
+LL | struct Runtime<DB: Database> {
+   |        ^^^^^^^
+note: required because it appears within the type `RootDatabase`
+  --> $DIR/cycle-cache-err-60010.rs:20:8
+   |
+LL | struct RootDatabase {
+   |        ^^^^^^^^^^^^
+note: required because of the requirements on the impl of `SourceDatabase` for `RootDatabase`
+  --> $DIR/cycle-cache-err-60010.rs:44:9
+   |
+LL | impl<T> SourceDatabase for T
+   |         ^^^^^^^^^^^^^^     ^
 note: required because of the requirements on the impl of `Query<RootDatabase>` for `ParseQuery`
   --> $DIR/cycle-cache-err-60010.rs:37:10
    |
diff --git a/src/test/ui/traits/inductive-overflow/lifetime.rs b/src/test/ui/traits/inductive-overflow/lifetime.rs
index 072c46bc21e..8be42fc4ad0 100644
--- a/src/test/ui/traits/inductive-overflow/lifetime.rs
+++ b/src/test/ui/traits/inductive-overflow/lifetime.rs
@@ -15,8 +15,8 @@ impl<'a> Y for C<'a> {
 struct C<'a>(&'a ());
 struct X<T: Y>(T::P);
 
-impl<T: NotAuto> NotAuto for Box<T> {}
-impl<T: Y> NotAuto for X<T> where T::P: NotAuto {} //~ NOTE: required
+impl<T: NotAuto> NotAuto for Box<T> {} //~ NOTE: required
+impl<T: Y> NotAuto for X<T> where T::P: NotAuto {}
 impl<'a> NotAuto for C<'a> {}
 
 fn is_send<S: NotAuto>() {}
@@ -26,6 +26,6 @@ fn main() {
     // Should only be a few notes.
     is_send::<X<C<'static>>>();
     //~^ ERROR overflow evaluating
-    //~| 2 redundant requirements hidden
+    //~| 3 redundant requirements hidden
     //~| required because of
 }
diff --git a/src/test/ui/traits/inductive-overflow/lifetime.stderr b/src/test/ui/traits/inductive-overflow/lifetime.stderr
index 2905deb940f..2ffcdb0e1c6 100644
--- a/src/test/ui/traits/inductive-overflow/lifetime.stderr
+++ b/src/test/ui/traits/inductive-overflow/lifetime.stderr
@@ -1,15 +1,15 @@
-error[E0275]: overflow evaluating the requirement `Box<X<C<'_>>>: NotAuto`
+error[E0275]: overflow evaluating the requirement `X<C<'_>>: NotAuto`
   --> $DIR/lifetime.rs:27:5
    |
 LL |     is_send::<X<C<'static>>>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
    |
-note: required because of the requirements on the impl of `NotAuto` for `X<C<'_>>`
-  --> $DIR/lifetime.rs:19:12
+note: required because of the requirements on the impl of `NotAuto` for `Box<X<C<'_>>>`
+  --> $DIR/lifetime.rs:18:18
    |
-LL | impl<T: Y> NotAuto for X<T> where T::P: NotAuto {}
-   |            ^^^^^^^     ^^^^
-   = note: 2 redundant requirements hidden
+LL | impl<T: NotAuto> NotAuto for Box<T> {}
+   |                  ^^^^^^^     ^^^^^^
+   = note: 3 redundant requirements hidden
    = note: required because of the requirements on the impl of `NotAuto` for `X<C<'static>>`
 note: required by a bound in `is_send`
   --> $DIR/lifetime.rs:22:15
diff --git a/src/test/ui/traits/inductive-overflow/simultaneous.stderr b/src/test/ui/traits/inductive-overflow/simultaneous.stderr
index 7eb1c9ffb3b..230c2638c50 100644
--- a/src/test/ui/traits/inductive-overflow/simultaneous.stderr
+++ b/src/test/ui/traits/inductive-overflow/simultaneous.stderr
@@ -1,4 +1,4 @@
-error[E0275]: overflow evaluating the requirement `{integer}: Tweedledee`
+error[E0275]: overflow evaluating the requirement `{integer}: Tweedledum`
   --> $DIR/simultaneous.rs:18:5
    |
 LL |     is_ee(4);
diff --git a/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr b/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
index ac7bbd272c7..86b3f87d34d 100644
--- a/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
+++ b/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
@@ -5,10 +5,10 @@ LL |     type Foo = impl std::fmt::Debug;
    |                ^^^^^^^^^^^^^^^^^^^^
    |
 note: ...which requires type-checking `m::bar`...
-  --> $DIR/auto-trait-leakage3.rs:14:5
+  --> $DIR/auto-trait-leakage3.rs:15:9
    |
-LL |     pub fn bar() {
-   |     ^^^^^^^^^^^^
+LL |         is_send(foo());
+   |         ^^^^^^^
    = note: ...which requires evaluating trait selection obligation `impl std::fmt::Debug: std::marker::Send`...
    = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
 note: cycle used when checking item types in module `m`
diff --git a/src/test/ui/type-alias-impl-trait/inference-cycle.stderr b/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
index ac0ca8e048c..4c5921c7f66 100644
--- a/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
+++ b/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
@@ -5,10 +5,10 @@ LL |     type Foo = impl std::fmt::Debug;
    |                ^^^^^^^^^^^^^^^^^^^^
    |
 note: ...which requires type-checking `m::bar`...
-  --> $DIR/inference-cycle.rs:14:5
+  --> $DIR/inference-cycle.rs:15:9
    |
-LL |     pub fn bar() {
-   |     ^^^^^^^^^^^^
+LL |         is_send(foo()); // Today: error
+   |         ^^^^^^^
    = note: ...which requires evaluating trait selection obligation `impl std::fmt::Debug: std::marker::Send`...
    = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
 note: cycle used when checking item types in module `m`