Merging upstream version 1.67.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

26 files changed, 305 insertions, 57 deletions

diff --git a/src/test/ui/const-generics/defaults/rp_impl_trait_fail.stderr b/src/test/ui/const-generics/defaults/rp_impl_trait_fail.stderr
index f2e7777ce..a46bd5352 100644
--- a/src/test/ui/const-generics/defaults/rp_impl_trait_fail.stderr
+++ b/src/test/ui/const-generics/defaults/rp_impl_trait_fail.stderr
@@ -18,9 +18,7 @@ LL |
 LL |     1_u32
    |     ----- return type was inferred to be `u32` here
    |
-   = help: the following other types implement trait `Traitor<N, M>`:
-             <u32 as Traitor<N, 2>>
-             <u64 as Traitor<1, 2>>
+   = help: the trait `Traitor<N, 2>` is implemented for `u32`
 
 error[E0277]: the trait bound `u64: Traitor` is not satisfied
   --> $DIR/rp_impl_trait_fail.rs:21:13
@@ -31,9 +29,7 @@ LL |
 LL |     1_u64
    |     ----- return type was inferred to be `u64` here
    |
-   = help: the following other types implement trait `Traitor<N, M>`:
-             <u32 as Traitor<N, 2>>
-             <u64 as Traitor<1, 2>>
+   = help: the trait `Traitor<1, 2>` is implemented for `u64`
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/const-generics/defaults/self-referential.rs b/src/test/ui/const-generics/defaults/self-referential.rs
new file mode 100644
index 000000000..14a870dc3
--- /dev/null
+++ b/src/test/ui/const-generics/defaults/self-referential.rs
@@ -0,0 +1,4 @@
+trait Foo<const M: u8, const M: u8 = M> {}
+//~^ ERROR the name `M` is already used for a generic parameter in this item's generic parameters
+impl Foo<2> for () {}
+fn main() {}
diff --git a/src/test/ui/const-generics/defaults/self-referential.stderr b/src/test/ui/const-generics/defaults/self-referential.stderr
new file mode 100644
index 000000000..170c1f7f7
--- /dev/null
+++ b/src/test/ui/const-generics/defaults/self-referential.stderr
@@ -0,0 +1,11 @@
+error[E0403]: the name `M` is already used for a generic parameter in this item's generic parameters
+  --> $DIR/self-referential.rs:1:30
+   |
+LL | trait Foo<const M: u8, const M: u8 = M> {}
+   |                 -            ^ already used
+   |                 |
+   |                 first use of `M`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0403`.
diff --git a/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/const_equate_assoc_consts.rs b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/const_equate_assoc_consts.rs
new file mode 100644
index 000000000..e8f89cb1a
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/const_equate_assoc_consts.rs
@@ -0,0 +1,27 @@
+// check-pass
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+
+trait Trait {
+    const ASSOC: usize;
+}
+impl<T> Trait for T {
+    const ASSOC: usize = std::mem::size_of::<T>();
+}
+
+struct Foo<T: Trait>([u8; T::ASSOC])
+where
+    [(); T::ASSOC]:;
+
+fn bar<T: Trait>()
+where
+    [(); T::ASSOC]:,
+{
+    let _: Foo<T> = Foo::<_>(make());
+}
+
+fn make() -> ! {
+    todo!()
+}
+
+fn main() {}
diff --git a/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/doesnt_unify_evaluatable.rs b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/doesnt_unify_evaluatable.rs
new file mode 100644
index 000000000..c8f7553da
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/doesnt_unify_evaluatable.rs
@@ -0,0 +1,15 @@
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+
+trait Trait {
+    const ASSOC: usize;
+}
+
+fn foo<T: Trait, U: Trait>() where [(); U::ASSOC]:, {
+    bar::<{ T::ASSOC }>();
+    //~^ ERROR: unconstrained generic constant
+}
+
+fn bar<const N: usize>() {}
+
+fn main() {}
diff --git a/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/doesnt_unify_evaluatable.stderr b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/doesnt_unify_evaluatable.stderr
new file mode 100644
index 000000000..e4a0cabe5
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/doesnt_unify_evaluatable.stderr
@@ -0,0 +1,10 @@
+error: unconstrained generic constant
+  --> $DIR/doesnt_unify_evaluatable.rs:9:11
+   |
+LL |     bar::<{ T::ASSOC }>();
+   |           ^^^^^^^^^^^^
+   |
+   = help: try adding a `where` bound using this expression: `where [(); { T::ASSOC }]:`
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/dropck_unifies_assoc_consts.rs b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/dropck_unifies_assoc_consts.rs
new file mode 100644
index 000000000..274caa1e9
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/dropck_unifies_assoc_consts.rs
@@ -0,0 +1,20 @@
+// check-pass
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+
+trait Trait {
+    const ASSOC: usize;
+}
+
+struct Foo<T: Trait>(T)
+where
+    [(); T::ASSOC]:;
+
+impl<T: Trait> Drop for Foo<T>
+where
+    [(); T::ASSOC]:,
+{
+    fn drop(&mut self) {}
+}
+
+fn main() {}
diff --git a/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/unifies_evaluatable.rs b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/unifies_evaluatable.rs
new file mode 100644
index 000000000..6597b9f2b
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/assoc_const_unification/unifies_evaluatable.rs
@@ -0,0 +1,18 @@
+// check-pass
+
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+
+trait Trait {
+    const ASSOC: usize;
+}
+
+fn foo<T: Trait, U: Trait>() where [(); T::ASSOC]:, {
+    bar::<{ T::ASSOC }>();
+}
+
+fn bar<const N: usize>() -> [(); N] {
+    [(); N]
+}
+
+fn main() {}
diff --git a/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.rs b/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.rs
new file mode 100644
index 000000000..6093fc70b
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.rs
@@ -0,0 +1,22 @@
+#![feature(generic_const_exprs, generic_arg_infer)]
+#![allow(incomplete_features)]
+
+// minimized repro for #105205
+//
+// the `foo::<_, L>` call results in a `WellFormed(_)` obligation and a
+// `ConstEvaluatable(Unevaluated(_ + 1 + L))` obligation. Attempting to fulfill the latter
+// unifies the `_` with `Expr(L - 1)` from the paramenv which turns the `WellFormed`
+// obligation into `WellFormed(Expr(L - 1))`
+
+fn foo<const N: usize, const M: usize>(_: [(); N + 1 + M]) {}
+
+fn ice<const L: usize>()
+where
+    [(); (L - 1) + 1 + L]:,
+{
+    foo::<_, L>([(); L + 1 + L]);
+    //~^ ERROR: mismatched types
+    //~^^ ERROR: unconstrained generic constant
+}
+
+fn main() {}
diff --git a/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.stderr b/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.stderr
new file mode 100644
index 000000000..da5194696
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.stderr
@@ -0,0 +1,20 @@
+error[E0308]: mismatched types
+  --> $DIR/wf_obligation.rs:17:17
+   |
+LL |     foo::<_, L>([(); L + 1 + L]);
+   |                 ^^^^^^^^^^^^^^^ expected `N + 1 + M`, found `L + 1 + L`
+   |
+   = note: expected constant `N + 1 + M`
+              found constant `L + 1 + L`
+
+error: unconstrained generic constant
+  --> $DIR/wf_obligation.rs:17:22
+   |
+LL |     foo::<_, L>([(); L + 1 + L]);
+   |                      ^^^^^^^^^
+   |
+   = help: try adding a `where` bound using this expression: `where [(); L + 1 + L]:`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/const-generics/generic_const_exprs/issue-102768.stderr b/src/test/ui/const-generics/generic_const_exprs/issue-102768.stderr
index 9deb9b265..8278edabe 100644
--- a/src/test/ui/const-generics/generic_const_exprs/issue-102768.stderr
+++ b/src/test/ui/const-generics/generic_const_exprs/issue-102768.stderr
@@ -11,7 +11,7 @@ LL |     type Y<'a>;
    |          ^ --
 help: add missing lifetime argument
    |
-LL |     fn f2<'a>(arg: Box<dyn X<Y<'a, 1> = &'a ()>>) {}
+LL |     fn f2<'a>(arg: Box<dyn X<Y<'_, 1> = &'a ()>>) {}
    |                                +++
 
 error[E0107]: this associated type takes 0 generic arguments but 1 generic argument was supplied
diff --git a/src/test/ui/const-generics/generic_const_exprs/issue-80742.stderr b/src/test/ui/const-generics/generic_const_exprs/issue-80742.stderr
index 1b502642e..bf1b411ee 100644
--- a/src/test/ui/const-generics/generic_const_exprs/issue-80742.stderr
+++ b/src/test/ui/const-generics/generic_const_exprs/issue-80742.stderr
@@ -2,15 +2,18 @@ error[E0080]: evaluation of `Inline::<dyn std::fmt::Debug>::{constant#0}` failed
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
    |
 LL |     intrinsics::size_of::<T>()
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |     |
-   |     size_of called on unsized type `dyn Debug`
-   |     inside `std::mem::size_of::<dyn Debug>` at $SRC_DIR/core/src/mem/mod.rs:LL:COL
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ size_of called on unsized type `dyn Debug`
+   |
+note: inside `std::mem::size_of::<dyn Debug>`
+  --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
    |
-  ::: $DIR/issue-80742.rs:22:10
+LL |     intrinsics::size_of::<T>()
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: inside `Inline::<dyn Debug>::{constant#0}`
+  --> $DIR/issue-80742.rs:22:10
    |
 LL |     [u8; size_of::<T>() + 1]: ,
-   |          -------------- inside `Inline::<dyn Debug>::{constant#0}` at $DIR/issue-80742.rs:22:10
+   |          ^^^^^^^^^^^^^^
 
 error[E0599]: the function or associated item `new` exists for struct `Inline<dyn Debug>`, but its trait bounds were not satisfied
   --> $DIR/issue-80742.rs:30:36
@@ -33,15 +36,18 @@ error[E0080]: evaluation of `Inline::<dyn std::fmt::Debug>::{constant#0}` failed
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
    |
 LL |     intrinsics::size_of::<T>()
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |     |
-   |     size_of called on unsized type `dyn Debug`
-   |     inside `std::mem::size_of::<dyn Debug>` at $SRC_DIR/core/src/mem/mod.rs:LL:COL
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ size_of called on unsized type `dyn Debug`
+   |
+note: inside `std::mem::size_of::<dyn Debug>`
+  --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
    |
-  ::: $DIR/issue-80742.rs:14:10
+LL |     intrinsics::size_of::<T>()
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: inside `Inline::<dyn Debug>::{constant#0}`
+  --> $DIR/issue-80742.rs:14:10
    |
 LL |     [u8; size_of::<T>() + 1]: ,
-   |          -------------- inside `Inline::<dyn Debug>::{constant#0}` at $DIR/issue-80742.rs:14:10
+   |          ^^^^^^^^^^^^^^
 
 error[E0277]: the size for values of type `dyn Debug` cannot be known at compilation time
   --> $DIR/issue-80742.rs:30:15
diff --git a/src/test/ui/const-generics/generic_const_exprs/issue-99705.rs b/src/test/ui/const-generics/generic_const_exprs/issue-99705.rs
new file mode 100644
index 000000000..75b57b621
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/issue-99705.rs
@@ -0,0 +1,33 @@
+// check-pass
+#![crate_type = "lib"]
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+pub trait MyIterator {
+    type Output;
+}
+
+pub trait Foo {
+    const ABC: usize;
+}
+
+pub struct IteratorStruct<const N: usize>{
+
+}
+
+pub struct Bar<const N: usize> {
+    pub data: [usize; N]
+}
+
+impl<const N: usize> MyIterator for IteratorStruct<N> {
+    type Output = Bar<N>;
+}
+
+pub fn test1<T: Foo>() -> impl MyIterator<Output = Bar<{T::ABC}>> where [(); T::ABC]: Sized {
+    IteratorStruct::<{T::ABC}>{}
+}
+
+pub trait Baz<const N: usize>{}
+impl<const N: usize> Baz<N> for Bar<N> {}
+pub fn test2<T: Foo>() -> impl MyIterator<Output = impl Baz<{ T::ABC }>> where [(); T::ABC]: Sized {
+    IteratorStruct::<{T::ABC}>{}
+}
diff --git a/src/test/ui/const-generics/generic_const_exprs/normed_to_param_is_evaluatable.rs b/src/test/ui/const-generics/generic_const_exprs/normed_to_param_is_evaluatable.rs
new file mode 100644
index 000000000..b37b354ae
--- /dev/null
+++ b/src/test/ui/const-generics/generic_const_exprs/normed_to_param_is_evaluatable.rs
@@ -0,0 +1,12 @@
+// check-pass
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features, unused_braces)]
+
+#[rustfmt::skip]
+fn foo<const N: usize>() {
+    bar::<{{{{{{ N }}}}}}>();
+}
+
+fn bar<const N: usize>() {}
+
+fn main() {}
diff --git a/src/test/ui/const-generics/conservative_is_privately_uninhabited_uses_correct_param_env-1.rs b/src/test/ui/const-generics/inhabited-assoc-ty-ice-1.rs
index c9e26c302..b385406b0 100644
--- a/src/test/ui/const-generics/conservative_is_privately_uninhabited_uses_correct_param_env-1.rs
+++ b/src/test/ui/const-generics/inhabited-assoc-ty-ice-1.rs
@@ -2,7 +2,7 @@
 #![feature(generic_const_exprs)]
 #![allow(incomplete_features)]
 
-// This tests that the `conservative_is_privately_uninhabited` fn doesn't cause
+// This tests that the inhabited check doesn't cause
 // ICEs by trying to evaluate `T::ASSOC` with an incorrect `ParamEnv`.
 
 trait Foo {
diff --git a/src/test/ui/const-generics/conservative_is_privately_uninhabited_uses_correct_param_env-2.rs b/src/test/ui/const-generics/inhabited-assoc-ty-ice-2.rs
index 3017920fc..216d29c7c 100644
--- a/src/test/ui/const-generics/conservative_is_privately_uninhabited_uses_correct_param_env-2.rs
+++ b/src/test/ui/const-generics/inhabited-assoc-ty-ice-2.rs
@@ -2,7 +2,7 @@
 #![feature(generic_const_exprs)]
 #![allow(incomplete_features)]
 
-// This tests that the `conservative_is_privately_uninhabited` fn doesn't cause
+// This tests that the inhabited check doesn't cause
 // ICEs by trying to evaluate `T::ASSOC` with an incorrect `ParamEnv`.
 
 trait Foo {
diff --git a/src/test/ui/const-generics/invariant.rs b/src/test/ui/const-generics/invariant.rs
index ee191b65c..39d658be6 100644
--- a/src/test/ui/const-generics/invariant.rs
+++ b/src/test/ui/const-generics/invariant.rs
@@ -24,7 +24,8 @@ where
 fn covariant(
     v: &'static Foo<for<'a> fn(&'a ())>
 ) -> &'static Foo<fn(&'static ())> {
-    v //~ ERROR mismatched types
+    v
+    //~^ ERROR mismatched types
 }
 
 fn main() {
diff --git a/src/test/ui/const-generics/issues/issue-100313.stderr b/src/test/ui/const-generics/issues/issue-100313.stderr
index f3ce357c2..d4b486376 100644
--- a/src/test/ui/const-generics/issues/issue-100313.stderr
+++ b/src/test/ui/const-generics/issues/issue-100313.stderr
@@ -2,13 +2,18 @@ error[E0080]: evaluation of constant value failed
   --> $DIR/issue-100313.rs:10:13
    |
 LL |             *(B as *const bool as *mut bool) = false;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ writing to alloc7 which is read-only
+   |
+note: inside `T::<&true>::set_false`
+  --> $DIR/issue-100313.rs:10:13
+   |
+LL |             *(B as *const bool as *mut bool) = false;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |             |
-   |             writing to alloc7 which is read-only
-   |             inside `T::<&true>::set_false` at $DIR/issue-100313.rs:10:13
-...
+note: inside `_`
+  --> $DIR/issue-100313.rs:18:5
+   |
 LL |     x.set_false();
-   |     ------------- inside `_` at $DIR/issue-100313.rs:18:5
+   |     ^^^^^^^^^^^^^
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-82956.stderr b/src/test/ui/const-generics/issues/issue-82956.stderr
index c8b999da9..d2320293e 100644
--- a/src/test/ui/const-generics/issues/issue-82956.stderr
+++ b/src/test/ui/const-generics/issues/issue-82956.stderr
@@ -2,7 +2,7 @@ error[E0433]: failed to resolve: use of undeclared type `IntoIter`
   --> $DIR/issue-82956.rs:25:24
    |
 LL |         let mut iter = IntoIter::new(self);
-   |                        ^^^^^^^^ not found in this scope
+   |                        ^^^^^^^^ use of undeclared type `IntoIter`
    |
 help: consider importing one of these items
    |
diff --git a/src/test/ui/const-generics/issues/issue-83765.stderr b/src/test/ui/const-generics/issues/issue-83765.stderr
index 4becf3a36..d7b2b006c 100644
--- a/src/test/ui/const-generics/issues/issue-83765.stderr
+++ b/src/test/ui/const-generics/issues/issue-83765.stderr
@@ -1,15 +1,15 @@
-error[E0391]: cycle detected when resolving instance `<LazyUpdim<'_, T, { T::DIM }, DIM> as TensorDimension>::DIM`
+error[E0391]: cycle detected when resolving instance `<LazyUpdim<'_, T, <T as TensorDimension>::DIM, DIM> as TensorDimension>::DIM`
   --> $DIR/issue-83765.rs:5:5
    |
 LL |     const DIM: usize;
    |     ^^^^^^^^^^^^^^^^
    |
-note: ...which requires computing candidate for `<LazyUpdim<'_, T, { T::DIM }, DIM> as TensorDimension>`...
+note: ...which requires computing candidate for `<LazyUpdim<'_, T, <T as TensorDimension>::DIM, DIM> as TensorDimension>`...
   --> $DIR/issue-83765.rs:4:1
    |
 LL | trait TensorDimension {
    | ^^^^^^^^^^^^^^^^^^^^^
-   = note: ...which again requires resolving instance `<LazyUpdim<'_, T, { T::DIM }, DIM> as TensorDimension>::DIM`, completing the cycle
+   = note: ...which again requires resolving instance `<LazyUpdim<'_, T, <T as TensorDimension>::DIM, DIM> as TensorDimension>::DIM`, completing the cycle
 note: cycle used when computing candidate for `<LazyUpdim<'_, T, { T::DIM }, DIM> as TensorDimension>`
   --> $DIR/issue-83765.rs:4:1
    |
diff --git a/src/test/ui/const-generics/issues/issue-85031-2.rs b/src/test/ui/const-generics/issues/issue-85031-2.rs
new file mode 100644
index 000000000..4908fb296
--- /dev/null
+++ b/src/test/ui/const-generics/issues/issue-85031-2.rs
@@ -0,0 +1,18 @@
+// check-pass
+// known-bug
+
+// This should not compile, as the compiler should not know
+// `A - 0` is satisfied `?x - 0` if `?x` is inferred to `A`.
+#![allow(incomplete_features)]
+#![feature(generic_const_exprs)]
+
+pub struct Ref<'a>(&'a i32);
+
+impl<'a> Ref<'a> {
+    pub fn foo<const A: usize>() -> [(); A - 0] {
+        //~^ WARN function cannot
+        Self::foo()
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/const-generics/issues/issue-85031-2.stderr b/src/test/ui/const-generics/issues/issue-85031-2.stderr
new file mode 100644
index 000000000..fc6905768
--- /dev/null
+++ b/src/test/ui/const-generics/issues/issue-85031-2.stderr
@@ -0,0 +1,14 @@
+warning: function cannot return without recursing
+  --> $DIR/issue-85031-2.rs:12:5
+   |
+LL |     pub fn foo<const A: usize>() -> [(); A - 0] {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot return without recursing
+LL |
+LL |         Self::foo()
+   |         ----------- recursive call site
+   |
+   = help: a `loop` may express intention better if this is on purpose
+   = note: `#[warn(unconditional_recursion)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/src/test/ui/const-generics/min_const_generics/macro-fail.rs b/src/test/ui/const-generics/min_const_generics/macro-fail.rs
index f83518fc9..7fb69032e 100644
--- a/src/test/ui/const-generics/min_const_generics/macro-fail.rs
+++ b/src/test/ui/const-generics/min_const_generics/macro-fail.rs
@@ -14,7 +14,6 @@ impl<const N: usize> Marker<N> for Example<N> {}
 fn make_marker() -> impl Marker<gimme_a_const!(marker)> {
   //~^ ERROR: type provided when a constant was expected
   Example::<gimme_a_const!(marker)>
-  //~^ ERROR: type provided when a constant was expected
 }
 
 fn from_marker(_: impl Marker<{
@@ -34,9 +33,7 @@ fn main() {
   }>;
 
   let _fail = Example::<external_macro!()>;
-  //~^ ERROR: type provided when a constant was expected
 
   let _fail = Example::<gimme_a_const!()>;
-  //~^ ERROR: type provided when a constant was expected
-  //~| ERROR unexpected end of macro invocation
+  //~^ ERROR unexpected end of macro invocation
 }
diff --git a/src/test/ui/const-generics/min_const_generics/macro-fail.stderr b/src/test/ui/const-generics/min_const_generics/macro-fail.stderr
index d5dd70d9b..9f73b91aa 100644
--- a/src/test/ui/const-generics/min_const_generics/macro-fail.stderr
+++ b/src/test/ui/const-generics/min_const_generics/macro-fail.stderr
@@ -1,5 +1,5 @@
 error: expected type, found `{`
-  --> $DIR/macro-fail.rs:29:27
+  --> $DIR/macro-fail.rs:28:27
    |
 LL | fn make_marker() -> impl Marker<gimme_a_const!(marker)> {
    |                                 ----------------------
@@ -13,7 +13,7 @@ LL |       ($rusty: ident) => {{ let $rusty = 3; *&$rusty }}
    = note: this error originates in the macro `gimme_a_const` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: expected type, found `{`
-  --> $DIR/macro-fail.rs:29:27
+  --> $DIR/macro-fail.rs:28:27
    |
 LL |   Example::<gimme_a_const!(marker)>
    |             ----------------------
@@ -46,13 +46,19 @@ LL |     let _fail = Example::<external_macro!()>;
    = note: this error originates in the macro `external_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: unexpected end of macro invocation
-  --> $DIR/macro-fail.rs:39:25
+  --> $DIR/macro-fail.rs:37:25
    |
 LL |     macro_rules! gimme_a_const {
    |     -------------------------- when calling this macro
 ...
 LL |   let _fail = Example::<gimme_a_const!()>;
    |                         ^^^^^^^^^^^^^^^^ missing tokens in macro arguments
+   |
+note: while trying to match meta-variable `$rusty:ident`
+  --> $DIR/macro-fail.rs:28:8
+   |
+LL |       ($rusty: ident) => {{ let $rusty = 3; *&$rusty }}
+   |        ^^^^^^^^^^^^^
 
 error[E0747]: type provided when a constant was expected
   --> $DIR/macro-fail.rs:14:33
@@ -60,24 +66,6 @@ error[E0747]: type provided when a constant was expected
 LL | fn make_marker() -> impl Marker<gimme_a_const!(marker)> {
    |                                 ^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0747]: type provided when a constant was expected
-  --> $DIR/macro-fail.rs:16:13
-   |
-LL |   Example::<gimme_a_const!(marker)>
-   |             ^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0747]: type provided when a constant was expected
-  --> $DIR/macro-fail.rs:36:25
-   |
-LL |   let _fail = Example::<external_macro!()>;
-   |                         ^^^^^^^^^^^^^^^^^
-
-error[E0747]: type provided when a constant was expected
-  --> $DIR/macro-fail.rs:39:25
-   |
-LL |   let _fail = Example::<gimme_a_const!()>;
-   |                         ^^^^^^^^^^^^^^^^
-
-error: aborting due to 8 previous errors
+error: aborting due to 5 previous errors
 
 For more information about this error, try `rustc --explain E0747`.
diff --git a/src/test/ui/const-generics/projection-as-arg-const.rs b/src/test/ui/const-generics/projection-as-arg-const.rs
new file mode 100644
index 000000000..903548c75
--- /dev/null
+++ b/src/test/ui/const-generics/projection-as-arg-const.rs
@@ -0,0 +1,20 @@
+// This is currently not possible to use projections as const generics.
+// More information about this available here:
+// https://github.com/rust-lang/rust/pull/104443#discussion_r1029375633
+
+pub trait Identity {
+    type Identity;
+}
+
+impl<T> Identity for T {
+    type Identity = Self;
+}
+
+pub fn foo<const X: <i32 as Identity>::Identity>() {
+//~^ ERROR
+    assert!(X == 12);
+}
+
+fn main() {
+    foo::<12>();
+}
diff --git a/src/test/ui/const-generics/projection-as-arg-const.stderr b/src/test/ui/const-generics/projection-as-arg-const.stderr
new file mode 100644
index 000000000..803ed9c95
--- /dev/null
+++ b/src/test/ui/const-generics/projection-as-arg-const.stderr
@@ -0,0 +1,11 @@
+error: `<i32 as Identity>::Identity` is forbidden as the type of a const generic parameter
+  --> $DIR/projection-as-arg-const.rs:13:21
+   |
+LL | pub fn foo<const X: <i32 as Identity>::Identity>() {
+   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the only supported types are integers, `bool` and `char`
+   = help: more complex types are supported with `#![feature(adt_const_params)]`
+
+error: aborting due to previous error
+