Auto merge of #64546 - weiznich:bugfix/rfc-2451-rerebalance-tests, r=nikomatsakis

Bugfix/rfc 2451 rerebalance tests

r? @nikomatsakis

Fixes #64412
Depends/Contains on #64414

cc #55437 and #63599

34 files changed, 531 insertions, 17 deletions

diff --git a/src/librustc/traits/coherence.rs b/src/librustc/traits/coherence.rs
index 039973d80db..4696d4da58e 100644
--- a/src/librustc/traits/coherence.rs
+++ b/src/librustc/traits/coherence.rs
@@ -378,7 +378,15 @@ fn orphan_check_trait_ref<'tcx>(
         //      Let Ti be the first such type.
         //     - No uncovered type parameters P1..=Pn may appear in T0..Ti (excluding Ti)
         //
-        for input_ty in trait_ref.input_types() {
+        fn uncover_fundamental_ty(ty: Ty<'_>) -> Vec<Ty<'_>> {
+            if fundamental_ty(ty) {
+                ty.walk_shallow().flat_map(|ty| uncover_fundamental_ty(ty)).collect()
+            } else {
+                vec![ty]
+            }
+        }
+
+        for input_ty in trait_ref.input_types().flat_map(uncover_fundamental_ty) {
             debug!("orphan_check_trait_ref: check ty `{:?}`", input_ty);
             if ty_is_local(tcx, input_ty, in_crate) {
                 debug!("orphan_check_trait_ref: ty_is_local `{:?}`", input_ty);
diff --git a/src/test/ui/coherence/auxiliary/coherence_lib.rs b/src/test/ui/coherence/auxiliary/coherence_lib.rs
index 9a5ec824306..c22819831ab 100644
--- a/src/test/ui/coherence/auxiliary/coherence_lib.rs
+++ b/src/test/ui/coherence/auxiliary/coherence_lib.rs
@@ -5,11 +5,11 @@ pub trait Remote {
 }
 
 pub trait Remote1<T> {
-    fn foo(&self, t: T) { }
+    fn foo(&self, _t: T) { }
 }
 
 pub trait Remote2<T, U> {
-    fn foo(&self, t: T, u: U) { }
+    fn foo(&self, _t: T, _u: U) { }
 }
 
 pub struct Pair<T,U>(T,U);
diff --git a/src/test/ui/coherence/impl-foreign[foreign]-for-foreign.rs b/src/test/ui/coherence/impl-foreign[foreign]-for-foreign.rs
new file mode 100644
index 00000000000..b08fedc5e11
--- /dev/null
+++ b/src/test/ui/coherence/impl-foreign[foreign]-for-foreign.rs
@@ -0,0 +1,17 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl Remote1<u32> for f64 {
+    //~^ ERROR only traits defined in the current crate
+    // | can be implemented for arbitrary types [E0117]
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl-foreign[foreign]-for-foreign.stderr b/src/test/ui/coherence/impl-foreign[foreign]-for-foreign.stderr
new file mode 100644
index 00000000000..04e96f29230
--- /dev/null
+++ b/src/test/ui/coherence/impl-foreign[foreign]-for-foreign.stderr
@@ -0,0 +1,12 @@
+error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
+  --> $DIR/impl-foreign[foreign]-for-foreign.rs:12:1
+   |
+LL | impl Remote1<u32> for f64 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^ impl doesn't use types inside crate
+   |
+   = note: the impl does not reference only types defined in this crate
+   = note: define and implement a trait or new type instead
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0117`.
diff --git a/src/test/ui/coherence/impl-foreign[foreign]-for-local.rs b/src/test/ui/coherence/impl-foreign[foreign]-for-local.rs
new file mode 100644
index 00000000000..33e85c16476
--- /dev/null
+++ b/src/test/ui/coherence/impl-foreign[foreign]-for-local.rs
@@ -0,0 +1,16 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+// check-pass
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl Remote1<u32> for Local {
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[foreign[t]_local]-for-foreign.rs b/src/test/ui/coherence/impl[t]-foreign[foreign[t]_local]-for-foreign.rs
new file mode 100644
index 00000000000..54d4bf04a58
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[foreign[t]_local]-for-foreign.rs
@@ -0,0 +1,14 @@
+#![feature(re_rebalance_coherence)]
+
+// check-pass
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+impl<T> Remote2<Rc<T>, Local> for usize { }
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[foreign]-for-fundamental[t].rs b/src/test/ui/coherence/impl[t]-foreign[foreign]-for-fundamental[t].rs
new file mode 100644
index 00000000000..66a4d9d2734
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[foreign]-for-fundamental[t].rs
@@ -0,0 +1,20 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<u32> for Box<T> {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+impl<'a, T> Remote1<u32> for &'a T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[foreign]-for-fundamental[t].stderr b/src/test/ui/coherence/impl[t]-foreign[foreign]-for-fundamental[t].stderr
new file mode 100644
index 00000000000..2467097b1a8
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[foreign]-for-fundamental[t].stderr
@@ -0,0 +1,19 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[foreign]-for-fundamental[t].rs:12:1
+   |
+LL | impl<T> Remote1<u32> for Box<T> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[foreign]-for-fundamental[t].rs:16:1
+   |
+LL | impl<'a, T> Remote1<u32> for &'a T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[foreign]-for-t.rs b/src/test/ui/coherence/impl[t]-foreign[foreign]-for-t.rs
new file mode 100644
index 00000000000..0a67ebcbba4
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[foreign]-for-t.rs
@@ -0,0 +1,16 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<u32> for T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[foreign]-for-t.stderr b/src/test/ui/coherence/impl[t]-foreign[foreign]-for-t.stderr
new file mode 100644
index 00000000000..5c28406f113
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[foreign]-for-t.stderr
@@ -0,0 +1,11 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[foreign]-for-t.rs:12:1
+   |
+LL | impl<T> Remote1<u32> for T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-foreign.rs b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-foreign.rs
new file mode 100644
index 00000000000..71598dae96a
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-foreign.rs
@@ -0,0 +1,20 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<Box<T>> for u32 {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+impl<'a, T> Remote1<&'a T> for u32 {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-foreign.stderr b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-foreign.stderr
new file mode 100644
index 00000000000..dd970265079
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-foreign.stderr
@@ -0,0 +1,19 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[fundamental[t]]-for-foreign.rs:12:1
+   |
+LL | impl<T> Remote1<Box<T>> for u32 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[fundamental[t]]-for-foreign.rs:16:1
+   |
+LL | impl<'a, T> Remote1<&'a T> for u32 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-fundamental[t].rs b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-fundamental[t].rs
new file mode 100644
index 00000000000..7bf0306f29b
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-fundamental[t].rs
@@ -0,0 +1,19 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<'a, T> Remote1<Box<T>> for &'a T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+impl<'a, T> Remote1<&'a T> for Box<T> {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-fundamental[t].stderr b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-fundamental[t].stderr
new file mode 100644
index 00000000000..eec57fccea7
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-fundamental[t].stderr
@@ -0,0 +1,19 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[fundamental[t]]-for-fundamental[t].rs:12:1
+   |
+LL | impl<'a, T> Remote1<Box<T>> for &'a T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[fundamental[t]]-for-fundamental[t].rs:15:1
+   |
+LL | impl<'a, T> Remote1<&'a T> for Box<T> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-local.rs b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-local.rs
new file mode 100644
index 00000000000..54d577c7492
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-local.rs
@@ -0,0 +1,17 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+// check-pass
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<Box<T>> for Local {}
+
+impl<'a, T> Remote1<&'a T> for Local {}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-t.rs b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-t.rs
new file mode 100644
index 00000000000..7af929006ef
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-t.rs
@@ -0,0 +1,19 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<Box<T>> for T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+impl<'a, T> Remote1<&'a T> for T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-t.stderr b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-t.stderr
new file mode 100644
index 00000000000..e017c3ffe6c
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]]-for-t.stderr
@@ -0,0 +1,19 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[fundamental[t]]-for-t.rs:12:1
+   |
+LL | impl<T> Remote1<Box<T>> for T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[fundamental[t]]-for-t.rs:15:1
+   |
+LL | impl<'a, T> Remote1<&'a T> for T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]_local]-for-foreign.rs b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]_local]-for-foreign.rs
new file mode 100644
index 00000000000..24e0f309c45
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]_local]-for-foreign.rs
@@ -0,0 +1,20 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote2<Box<T>, Local> for u32 {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+impl<'a, T> Remote2<&'a T, Local> for u32 {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[fundamental[t]_local]-for-foreign.stderr b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]_local]-for-foreign.stderr
new file mode 100644
index 00000000000..3d8561956ae
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[fundamental[t]_local]-for-foreign.stderr
@@ -0,0 +1,19 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[fundamental[t]_local]-for-foreign.rs:12:1
+   |
+LL | impl<T> Remote2<Box<T>, Local> for u32 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[fundamental[t]_local]-for-foreign.rs:16:1
+   |
+LL | impl<'a, T> Remote2<&'a T, Local> for u32 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[local]-for-foreign.rs b/src/test/ui/coherence/impl[t]-foreign[local]-for-foreign.rs
new file mode 100644
index 00000000000..81cf3c3f6ec
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[local]-for-foreign.rs
@@ -0,0 +1,16 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+// check-pass
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<Local> for Rc<T> {}
+impl<T> Remote1<Local> for Vec<Box<T>> {}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[local]-for-fundamental[t].rs b/src/test/ui/coherence/impl[t]-foreign[local]-for-fundamental[t].rs
new file mode 100644
index 00000000000..54425b6d708
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[local]-for-fundamental[t].rs
@@ -0,0 +1,20 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<Local> for Box<T> {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+impl<T> Remote1<Local> for &T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[local]-for-fundamental[t].stderr b/src/test/ui/coherence/impl[t]-foreign[local]-for-fundamental[t].stderr
new file mode 100644
index 00000000000..7859665a7bb
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[local]-for-fundamental[t].stderr
@@ -0,0 +1,19 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[local]-for-fundamental[t].rs:12:1
+   |
+LL | impl<T> Remote1<Local> for Box<T> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[local]-for-fundamental[t].rs:16:1
+   |
+LL | impl<T> Remote1<Local> for &T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[local]-for-local.rs b/src/test/ui/coherence/impl[t]-foreign[local]-for-local.rs
new file mode 100644
index 00000000000..6b1d93cd944
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[local]-for-local.rs
@@ -0,0 +1,15 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+// check-pass
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl Remote1<Local> for Local {}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[local]-for-t.rs b/src/test/ui/coherence/impl[t]-foreign[local]-for-t.rs
new file mode 100644
index 00000000000..6f35c6c9dbc
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[local]-for-t.rs
@@ -0,0 +1,16 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<Local> for T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[local]-for-t.stderr b/src/test/ui/coherence/impl[t]-foreign[local]-for-t.stderr
new file mode 100644
index 00000000000..be7de8cccb4
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[local]-for-t.stderr
@@ -0,0 +1,11 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[local]-for-t.rs:12:1
+   |
+LL | impl<T> Remote1<Local> for T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[local_fundamental[t]]-for-foreign.rs b/src/test/ui/coherence/impl[t]-foreign[local_fundamental[t]]-for-foreign.rs
new file mode 100644
index 00000000000..be0875d0110
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[local_fundamental[t]]-for-foreign.rs
@@ -0,0 +1,19 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+// check-pass
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+struct Local2<T>(Rc<T>);
+
+impl<T> Remote2<Local, Box<T>> for u32 {}
+impl<'a, T> Remote2<Local, &'a T> for u32 {}
+impl<T> Remote2<Local2<T>, Box<T>> for u32 {}
+impl<'a, T> Remote2<Local2<T>, &'a T> for u32 {}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[t]-for-foreign.rs b/src/test/ui/coherence/impl[t]-foreign[t]-for-foreign.rs
new file mode 100644
index 00000000000..5e89c207733
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[t]-for-foreign.rs
@@ -0,0 +1,16 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<T> for u32 {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[t]-for-foreign.stderr b/src/test/ui/coherence/impl[t]-foreign[t]-for-foreign.stderr
new file mode 100644
index 00000000000..5544729b5d6
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[t]-for-foreign.stderr
@@ -0,0 +1,11 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[t]-for-foreign.rs:12:1
+   |
+LL | impl<T> Remote1<T> for u32 {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[t]-for-fundamental.rs b/src/test/ui/coherence/impl[t]-foreign[t]-for-fundamental.rs
new file mode 100644
index 00000000000..300a2c4d48a
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[t]-for-fundamental.rs
@@ -0,0 +1,20 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<T> for Box<T> {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+impl<'a, A, B> Remote1<A> for &'a B {
+    //~^ ERROR type parameter `B` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[t]-for-fundamental.stderr b/src/test/ui/coherence/impl[t]-foreign[t]-for-fundamental.stderr
new file mode 100644
index 00000000000..be8cc29a6e5
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[t]-for-fundamental.stderr
@@ -0,0 +1,19 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[t]-for-fundamental.rs:12:1
+   |
+LL | impl<T> Remote1<T> for Box<T> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error[E0210]: type parameter `B` must be used as the type parameter for some local type (e.g., `MyStruct<B>`)
+  --> $DIR/impl[t]-foreign[t]-for-fundamental.rs:16:1
+   |
+LL | impl<'a, A, B> Remote1<A> for &'a B {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `B` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/impl[t]-foreign[t]-for-local.rs b/src/test/ui/coherence/impl[t]-foreign[t]-for-local.rs
new file mode 100644
index 00000000000..769147ea7ea
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[t]-for-local.rs
@@ -0,0 +1,15 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+// check-pass
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<T> for Local {}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[t]-for-t.rs b/src/test/ui/coherence/impl[t]-foreign[t]-for-t.rs
new file mode 100644
index 00000000000..c8513380ff7
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[t]-for-t.rs
@@ -0,0 +1,16 @@
+#![feature(re_rebalance_coherence)]
+
+// compile-flags:--crate-name=test
+// aux-build:coherence_lib.rs
+
+extern crate coherence_lib as lib;
+use lib::*;
+use std::rc::Rc;
+
+struct Local;
+
+impl<T> Remote1<T> for T {
+    //~^ ERROR type parameter `T` must be used as the type parameter for some local type
+}
+
+fn main() {}
diff --git a/src/test/ui/coherence/impl[t]-foreign[t]-for-t.stderr b/src/test/ui/coherence/impl[t]-foreign[t]-for-t.stderr
new file mode 100644
index 00000000000..de857afd20b
--- /dev/null
+++ b/src/test/ui/coherence/impl[t]-foreign[t]-for-t.stderr
@@ -0,0 +1,11 @@
+error[E0210]: type parameter `T` must be used as the type parameter for some local type (e.g., `MyStruct<T>`)
+  --> $DIR/impl[t]-foreign[t]-for-t.rs:12:1
+   |
+LL | impl<T> Remote1<T> for T {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^ type parameter `T` must be used as the type parameter for some local type
+   |
+   = note: only traits defined in the current crate can be implemented for a type parameter
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0210`.
diff --git a/src/test/ui/coherence/re-rebalance-coherence-rpass.rs b/src/test/ui/coherence/re-rebalance-coherence-rpass.rs
deleted file mode 100644
index bacd3b89fad..00000000000
--- a/src/test/ui/coherence/re-rebalance-coherence-rpass.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-#![allow(dead_code)]
-#![feature(re_rebalance_coherence)]
-
-// run-pass
-// aux-build:re_rebalance_coherence_lib.rs
-
-extern crate re_rebalance_coherence_lib as lib;
-use lib::*;
-
-struct Oracle;
-impl Backend for Oracle {}
-impl<'a, T:'a, Tab> QueryFragment<Oracle> for BatchInsert<'a, T, Tab> {}
-
-fn main() {}