diff options
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/operand.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/ty/relate.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/const_evaluatable.rs | 7 |
3 files changed, 11 insertions, 0 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs index 6619a40b085..221e359d24a 100644 --- a/compiler/rustc_const_eval/src/interpret/operand.rs +++ b/compiler/rustc_const_eval/src/interpret/operand.rs @@ -561,6 +561,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { ty::ConstKind::Param(_) | ty::ConstKind::Placeholder(..) => { throw_inval!(TooGeneric) } + // FIXME(generic_const_exprs): `ConstKind::Expr` should be able to be evaluated ty::ConstKind::Expr(_) => throw_inval!(TooGeneric), ty::ConstKind::Error(reported) => { throw_inval!(AlreadyReported(reported)) diff --git a/compiler/rustc_middle/src/ty/relate.rs b/compiler/rustc_middle/src/ty/relate.rs index decd99de3c4..8b460bfe044 100644 --- a/compiler/rustc_middle/src/ty/relate.rs +++ b/compiler/rustc_middle/src/ty/relate.rs @@ -650,6 +650,9 @@ pub fn super_relate_consts<'tcx, R: TypeRelation<'tcx>>( (ty::ConstKind::Unevaluated(_), ty::ConstKind::Unevaluated(_)) if tcx.features().generic_const_exprs => { + // FIXME(generic_const_exprs): this spurriously fails when relating two assoc consts + // i.e. `<T as Trait>::ASSOC eq <T as Trait>::ASSOC` would return `false`. Wheras if + // both were behind an anon const that gets normalized away here it would succeed. if let (Ok(Some(a)), Ok(Some(b))) = ( tcx.expand_abstract_consts(a), tcx.expand_abstract_consts(b), diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs index 42d50b68c6d..b72bc42fa65 100644 --- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs +++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs @@ -149,6 +149,13 @@ fn satisfied_from_param_env<'tcx>( } else if let ty::ConstKind::Expr(e) = c.kind() { e.visit_with(self) } else { + // FIXME(generic_const_exprs): This doesn't recurse into `<T as Trait<U>>::ASSOC`'s substs. + // This is currently unobservable as `<T as Trait<{ U + 1 }>>::ASSOC` creates an anon const + // with its own `ConstEvaluatable` bound in the param env which we will visit separately. + // + // If we start allowing directly writing `ConstKind::Expr` without an intermediate anon const + // this will be incorrect. It might be worth investigating making `predicates_of` elaborate + // all of the `ConstEvaluatable` bounds rather than having a visitor here. ControlFlow::CONTINUE } } |