Handle trait/impl GAC mismatches when inferring missing/placeholder types
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index 4f35aca..86fe275 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -244,7 +244,8 @@ fn infer_type_if_missing<'tcx>(fcx: &FnCtxt<'_, 'tcx>, node: Node<'tcx>) -> Opti
impl_def_id,
impl_trait_ref.args,
);
- Some(tcx.type_of(trait_item_def_id).instantiate(tcx, args))
+ tcx.check_args_compatible(trait_item_def_id, args)
+ .then(|| tcx.type_of(trait_item_def_id).instantiate(tcx, args))
} else {
Some(fcx.next_ty_var(span))
}
diff --git a/tests/crashes/124833.rs b/tests/crashes/124833.rs
deleted file mode 100644
index f1c4847..0000000
--- a/tests/crashes/124833.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-//@ known-bug: rust-lang/rust#124833
-#![feature(generic_const_items)]
-
-trait Trait {
- const C<'a>: &'a str;
-}
-
-impl Trait for () {
- const C<'a>: = "C";
-}
diff --git a/tests/ui/generic-const-items/assoc-const-missing-type.rs b/tests/ui/generic-const-items/assoc-const-missing-type.rs
index 80f282e..93160f0 100644
--- a/tests/ui/generic-const-items/assoc-const-missing-type.rs
+++ b/tests/ui/generic-const-items/assoc-const-missing-type.rs
@@ -5,6 +5,7 @@
trait Trait {
const K<T>: T;
+ const Q<'a>: &'a str;
}
impl Trait for () {
@@ -12,6 +13,9 @@ impl Trait for () {
//~^ ERROR missing type for `const` item
//~| ERROR mismatched types
//~| ERROR mismatched types
+ const Q = "";
+ //~^ ERROR missing type for `const` item
+ //~| ERROR lifetime parameters or bounds on const `Q` do not match the trait declaration
}
fn main() {}
diff --git a/tests/ui/generic-const-items/assoc-const-missing-type.stderr b/tests/ui/generic-const-items/assoc-const-missing-type.stderr
index 158e9a0..6f35c09 100644
--- a/tests/ui/generic-const-items/assoc-const-missing-type.stderr
+++ b/tests/ui/generic-const-items/assoc-const-missing-type.stderr
@@ -1,5 +1,5 @@
error[E0308]: mismatched types
- --> $DIR/assoc-const-missing-type.rs:11:18
+ --> $DIR/assoc-const-missing-type.rs:12:18
|
LL | const K<T> = ();
| - ^^ expected type parameter `T`, found `()`
@@ -10,13 +10,28 @@
found unit type `()`
error: missing type for `const` item
- --> $DIR/assoc-const-missing-type.rs:11:15
+ --> $DIR/assoc-const-missing-type.rs:12:15
|
LL | const K<T> = ();
| ^ help: provide a type for the associated constant: `()`
+error[E0195]: lifetime parameters or bounds on const `Q` do not match the trait declaration
+ --> $DIR/assoc-const-missing-type.rs:16:12
+ |
+LL | const Q<'a>: &'a str;
+ | ---- lifetimes in impl do not match this const in trait
+...
+LL | const Q = "";
+ | ^ lifetimes do not match const in trait
+
+error: missing type for `const` item
+ --> $DIR/assoc-const-missing-type.rs:16:12
+ |
+LL | const Q = "";
+ | ^ help: provide a type for the associated constant: `: &str`
+
error[E0308]: mismatched types
- --> $DIR/assoc-const-missing-type.rs:11:18
+ --> $DIR/assoc-const-missing-type.rs:12:18
|
LL | const K<T> = ();
| - ^^ expected type parameter `T`, found `()`
@@ -27,6 +42,7 @@
found unit type `()`
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-error: aborting due to 3 previous errors
+error: aborting due to 5 previous errors
-For more information about this error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0195, E0308.
+For more information about an error, try `rustc --explain E0195`.
