From 5d1b6bfc6ad95298fe3637857976945bd6ae9d9d Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Tue, 10 Dec 2024 02:28:02 +0000
Subject: [PATCH] Validate self in host predicates correctly

---
 .../src/collect/predicates_of.rs              | 11 ++++++++--
 .../dont-ice-on-const-pred-for-bounds.rs      | 22 +++++++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 tests/ui/traits/const-traits/dont-ice-on-const-pred-for-bounds.rs

diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index ca2597e79fd14..1a6c0a934360c 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -711,12 +711,19 @@ pub(super) fn assert_only_contains_predicates_from<'tcx>(
                             `{filter:?}` implied bounds: {clause:?}"
                         );
                     }
+                    ty::ClauseKind::HostEffect(host_effect_predicate) => {
+                        assert_eq!(
+                            host_effect_predicate.self_ty(),
+                            ty,
+                            "expected `Self` predicate when computing \
+                            `{filter:?}` implied bounds: {clause:?}"
+                        );
+                    }
 
                     ty::ClauseKind::RegionOutlives(_)
                     | ty::ClauseKind::ConstArgHasType(_, _)
                     | ty::ClauseKind::WellFormed(_)
-                    | ty::ClauseKind::ConstEvaluatable(_)
-                    | ty::ClauseKind::HostEffect(..) => {
+                    | ty::ClauseKind::ConstEvaluatable(_) => {
                         bug!(
                             "unexpected non-`Self` predicate when computing \
                             `{filter:?}` implied bounds: {clause:?}"
diff --git a/tests/ui/traits/const-traits/dont-ice-on-const-pred-for-bounds.rs b/tests/ui/traits/const-traits/dont-ice-on-const-pred-for-bounds.rs
new file mode 100644
index 0000000000000..2295c2c3857c7
--- /dev/null
+++ b/tests/ui/traits/const-traits/dont-ice-on-const-pred-for-bounds.rs
@@ -0,0 +1,22 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/133526>.
+
+// Ensures we don't ICE when we encounter a `HostEffectPredicate` when computing
+// the "item super predicates" for `Assoc`.
+
+//@ compile-flags: -Znext-solver
+//@ check-pass
+
+#![feature(const_trait_impl)]
+
+#[const_trait]
+trait Trait {
+    type Assoc: const Trait;
+}
+
+const fn needs_trait<T: ~const Trait>() {}
+
+fn test<T: Trait>() {
+    const { needs_trait::<T::Assoc>() };
+}
+
+fn main() {}