Do not emit ConstEvaluatable goals if type-const

Author: JohnTitor

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -438,6 +438,10 @@ fn const_evaluatable_predicates_of<'tcx>(
                     return;
                 }
 
+                if self.tcx.is_type_const(uv.def) {
+                    return;
+                }
+
                 let span = self.tcx.def_span(uv.def);
                 self.preds.insert((ty::ClauseKind::ConstEvaluatable(c).upcast(self.tcx), span));
             }

compiler/rustc_trait_selection/src/traits/wf.rs

@@ -1016,17 +1016,19 @@ impl<'a, 'tcx> TypeVisitor<TyCtxt<'tcx>> for WfPredicates<'a, 'tcx> {
         match c.kind() {
             ty::ConstKind::Unevaluated(uv) => {
                 if !c.has_escaping_bound_vars() {
-                    let predicate = ty::Binder::dummy(ty::PredicateKind::Clause(
-                        ty::ClauseKind::ConstEvaluatable(c),
-                    ));
-                    let cause = self.cause(ObligationCauseCode::WellFormed(None));
-                    self.out.push(traits::Obligation::with_depth(
-                        tcx,
-                        cause,
-                        self.recursion_depth,
-                        self.param_env,
-                        predicate,
-                    ));
+                    if !tcx.is_type_const(uv.def) {
+                        let predicate = ty::Binder::dummy(ty::PredicateKind::Clause(
+                            ty::ClauseKind::ConstEvaluatable(c),
+                        ));
+                        let cause = self.cause(ObligationCauseCode::WellFormed(None));
+                        self.out.push(traits::Obligation::with_depth(
+                            tcx,
+                            cause,
+                            self.recursion_depth,
+                            self.param_env,
+                            predicate,
+                        ));
+                    }
 
                     if matches!(tcx.def_kind(uv.def), DefKind::AssocConst { .. })
                         && tcx.def_kind(tcx.parent(uv.def)) == (DefKind::Impl { of_trait: false })

tests/ui/const-generics/type-const-ice-issue-151631.rs

@@ -0,0 +1,18 @@
+// issue: <https://github.com/rust-lang/rust/issues/151631>
+//@ compile-flags: -Znext-solver
+#![feature(min_generic_const_args)]
+#![expect(incomplete_features)]
+
+trait SuperTrait {}
+trait Trait: SuperTrait {
+    type const K: u32;
+}
+impl Trait for () { //~ ERROR: the trait bound `(): SuperTrait` is not satisfied
+    type const K: u32 = const { 1 };
+}
+
+fn check(_: impl Trait<K = 0>) {}
+
+fn main() {
+    check(()); //~ ERROR: the trait bound `(): SuperTrait` is not satisfied
+}

tests/ui/const-generics/type-const-ice-issue-151631.stderr

@@ -0,0 +1,37 @@
+error[E0277]: the trait bound `(): SuperTrait` is not satisfied
+  --> $DIR/type-const-ice-issue-151631.rs:10:16
+   |
+LL | impl Trait for () {
+   |                ^^ the trait `SuperTrait` is not implemented for `()`
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/type-const-ice-issue-151631.rs:6:1
+   |
+LL | trait SuperTrait {}
+   | ^^^^^^^^^^^^^^^^
+note: required by a bound in `Trait`
+  --> $DIR/type-const-ice-issue-151631.rs:7:14
+   |
+LL | trait Trait: SuperTrait {
+   |              ^^^^^^^^^^ required by this bound in `Trait`
+
+error[E0277]: the trait bound `(): SuperTrait` is not satisfied
+  --> $DIR/type-const-ice-issue-151631.rs:17:5
+   |
+LL |     check(());
+   |     ^^^^^^^^^ the trait `SuperTrait` is not implemented for `()`
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/type-const-ice-issue-151631.rs:6:1
+   |
+LL | trait SuperTrait {}
+   | ^^^^^^^^^^^^^^^^
+note: required by a bound in `Trait`
+  --> $DIR/type-const-ice-issue-151631.rs:7:14
+   |
+LL | trait Trait: SuperTrait {
+   |              ^^^^^^^^^^ required by this bound in `Trait`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.