Make rustc build with new chalk

compiler/rustc_traits/src/chalk/db.rs

@@ -142,6 +142,8 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
             Some(CoerceUnsized)
         } else if lang_items.dispatch_from_dyn_trait() == Some(def_id) {
             Some(DispatchFromDyn)
+        } else if lang_items.tuple_trait() == Some(def_id) {
+            Some(Tuple)
         } else {
             None
         };
@@ -570,6 +572,7 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
             CoerceUnsized => lang_items.coerce_unsized_trait(),
             DiscriminantKind => lang_items.discriminant_kind_trait(),
             DispatchFromDyn => lang_items.dispatch_from_dyn_trait(),
+            Tuple => lang_items.tuple_trait(),
         };
         def_id.map(chalk_ir::TraitId)
     }

compiler/rustc_traits/src/chalk/lowering.rs

@@ -507,9 +507,6 @@ impl<'tcx> LowerInto<'tcx, Region<'tcx>> for &chalk_ir::Lifetime<RustInterner<'t
                 name: ty::BoundRegionKind::BrAnon(p.idx as u32, None),
             }),
             chalk_ir::LifetimeData::Static => return interner.tcx.lifetimes.re_static,
-            chalk_ir::LifetimeData::Empty(_) => {
-                bug!("Chalk should not have been passed an empty lifetime.")
-            }
             chalk_ir::LifetimeData::Erased => return interner.tcx.lifetimes.re_erased,
             chalk_ir::LifetimeData::Phantom(void, _) => match *void {},
         };

src/test/ui/chalkify/closure.rs

@@ -1,5 +1,3 @@
-// known-bug: unknown
-// FIXME(chalk): Chalk needs support for the Tuple trait
 // compile-flags: -Z chalk
 
 fn main() -> () {
@@ -26,7 +24,7 @@ fn main() -> () {
     let mut c = b;
 
     c();
-    b(); // FIXME: reenable when this is fixed ~ ERROR
+    b(); //~ ERROR
 
     // FIXME(chalk): this doesn't quite work
     /*

src/test/ui/chalkify/closure.stderr

@@ -1,80 +1,22 @@
-error[E0277]: `()` is not a tuple
+error[E0382]: borrow of moved value: `b`
-  --> $DIR/closure.rs:7:5
+  --> $DIR/closure.rs:27:5
-   |
-LL |     t();
-   |     ^^^ the trait `Tuple` is not implemented for `()`
-   |
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | fn main() -> () where (): Tuple {
-   |                 +++++++++++++++
-
-error[E0277]: `()` is not a tuple
-  --> $DIR/closure.rs:13:5
    |
+LL |     let mut c = b;
+   |                 - value moved here
+...
 LL |     b();
-   |     ^^^ the trait `Tuple` is not implemented for `()`
+   |     ^ value borrowed here after move
    |
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
+note: closure cannot be moved more than once as it is not `Copy` due to moving the variable `a` out of its environment
+  --> $DIR/closure.rs:20:9
    |
-LL | fn main() -> () where (): Tuple {
+LL |         a = 1;
-   |                 +++++++++++++++
+   |         ^
+help: consider mutably borrowing `b`
+   |
+LL |     let mut c = &mut b;
+   |                 ++++
 
-error[E0277]: `()` is not a tuple
+error: aborting due to previous error
-  --> $DIR/closure.rs:17:5
-   |
-LL |     c();
-   |     ^^^ the trait `Tuple` is not implemented for `()`
-   |
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | fn main() -> () where (): Tuple {
-   |                 +++++++++++++++
 
-error[E0277]: `()` is not a tuple
+For more information about this error, try `rustc --explain E0382`.
-  --> $DIR/closure.rs:18:5
-   |
-LL |     b();
-   |     ^^^ the trait `Tuple` is not implemented for `()`
-   |
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | fn main() -> () where (): Tuple {
-   |                 +++++++++++++++
-
-error[E0277]: `()` is not a tuple
-  --> $DIR/closure.rs:24:5
-   |
-LL |     b();
-   |     ^^^ the trait `Tuple` is not implemented for `()`
-   |
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | fn main() -> () where (): Tuple {
-   |                 +++++++++++++++
-
-error[E0277]: `()` is not a tuple
-  --> $DIR/closure.rs:28:5
-   |
-LL |     c();
-   |     ^^^ the trait `Tuple` is not implemented for `()`
-   |
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | fn main() -> () where (): Tuple {
-   |                 +++++++++++++++
-
-error[E0277]: `()` is not a tuple
-  --> $DIR/closure.rs:29:5
-   |
-LL |     b(); // FIXME: reenable when this is fixed ~ ERROR
-   |     ^^^ the trait `Tuple` is not implemented for `()`
-   |
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | fn main() -> () where (): Tuple {
-   |                 +++++++++++++++
-
-error: aborting due to 7 previous errors
-
-For more information about this error, try `rustc --explain E0277`.

src/test/ui/chalkify/trait-objects.rs

@@ -1,5 +1,4 @@
-// known-bug: unknown
+// check-pass
-// FIXME(chalk): Chalk needs support for the Tuple trait
 // compile-flags: -Z chalk
 
 use std::fmt::Display;

src/test/ui/chalkify/trait-objects.stderr

@@ -1,32 +0,0 @@
-error: the type `&dyn Fn(i32) -> _` is not well-formed (chalk)
-  --> $DIR/trait-objects.rs:11:12
-   |
-LL |     let f: &dyn Fn(i32) -> _ = &|x| x + x;
-   |            ^^^^^^^^^^^^^^^^^
-
-error[E0277]: `(i32,)` is not a tuple
-  --> $DIR/trait-objects.rs:12:5
-   |
-LL |     f(2);
-   |     ^^^^ the trait `Tuple` is not implemented for `(i32,)`
-   |
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | fn main() where (i32,): Tuple {
-   |           +++++++++++++++++++
-
-error[E0277]: expected a `Fn<(i32,)>` closure, found `dyn Fn(i32) -> i32`
-  --> $DIR/trait-objects.rs:12:5
-   |
-LL |     f(2);
-   |     ^^^^ expected an `Fn<(i32,)>` closure, found `dyn Fn(i32) -> i32`
-   |
-   = help: the trait `Fn<(i32,)>` is not implemented for `dyn Fn(i32) -> i32`
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | fn main() where dyn Fn(i32) -> i32: Fn<(i32,)> {
-   |           ++++++++++++++++++++++++++++++++++++
-
-error: aborting due to 3 previous errors
-
-For more information about this error, try `rustc --explain E0277`.