rust-analyzer

diff --git a/crates/hir-ty/src/dyn_compatibility.rs b/crates/hir-ty/src/dyn_compatibility.rs
index d4b3751cf5..b87c998217 100644
--- a/crates/hir-ty/src/dyn_compatibility.rs
+++ b/crates/hir-ty/src/dyn_compatibility.rs

@@ -138,6 +138,9 @@ pub fn generics_require_sized_self(db: &dyn HirDatabase, def: GenericDefId) -> b

let interner = DbInterner::new_with(db, Some(krate), None);

let predicates = db.generic_predicates_ns(def);

+ // FIXME: We should use `explicit_predicates_of` here, which hasn't been implemented to

+ // rust-analyzer yet

+ // https://github.com/rust-lang/rust/blob/ddaf12390d3ffb7d5ba74491a48f3cd528e5d777/compiler/rustc_hir_analysis/src/collect/predicates_of.rs#L490

elaborate::elaborate(interner, predicates.iter().copied()).any(|pred| {

match pred.kind().skip_binder() {

ClauseKind::Trait(trait_pred) => {

diff --git a/crates/hir-ty/src/dyn_compatibility/tests.rs b/crates/hir-ty/src/dyn_compatibility/tests.rs
index 4ffa455084..04a9ba7992 100644
--- a/crates/hir-ty/src/dyn_compatibility/tests.rs
+++ b/crates/hir-ty/src/dyn_compatibility/tests.rs

@@ -253,7 +253,8 @@ trait Bar<T> {

trait Baz : Bar<Self> {

}

"#,

- [("Bar", vec![]), ("Baz", vec![SizedSelf, SelfReferential])],

+ // FIXME: We should also report `SizedSelf` here

+ [("Bar", vec![]), ("Baz", vec![SelfReferential])],

);

}

diff --git a/crates/hir-ty/src/lower_nextsolver.rs b/crates/hir-ty/src/lower_nextsolver.rs
index c6a8fa81ed..5c29befe12 100644
--- a/crates/hir-ty/src/lower_nextsolver.rs
+++ b/crates/hir-ty/src/lower_nextsolver.rs

@@ -1358,6 +1358,9 @@ where

}

+ // FIXME: rustc gathers more predicates by recursing through resulting trait predicates.

+ // See https://github.com/rust-lang/rust/blob/76c5ed2847cdb26ef2822a3a165d710f6b772217/compiler/rustc_hir_analysis/src/collect/predicates_of.rs#L689-L715

(

GenericPredicates(predicates.is_empty().not().then(|| predicates.into())),

create_diagnostics(ctx.diagnostics),

diff --git a/crates/hir-ty/src/next_solver/interner.rs b/crates/hir-ty/src/next_solver/interner.rs
index 0f512fdaf8..7b6e8a1073 100644
--- a/crates/hir-ty/src/next_solver/interner.rs
+++ b/crates/hir-ty/src/next_solver/interner.rs

@@ -5,7 +5,7 @@ use base_db::Crate;

use chalk_ir::{ProgramClauseImplication, SeparatorTraitRef, Variances};

use hir_def::lang_item::LangItem;

use hir_def::signatures::{FieldData, FnFlags, ImplFlags, StructFlags, TraitFlags};

-use hir_def::{AdtId, BlockId, TypeAliasId, VariantId};

+use hir_def::{AdtId, BlockId, GenericDefId, TypeAliasId, VariantId};

use hir_def::{AttrDefId, Lookup};

use hir_def::{CallableDefId, EnumVariantId, ItemContainerId, StructId, UnionId};

use intern::sym::non_exhaustive;

@@ -1334,6 +1334,13 @@ impl<'db> rustc_type_ir::Interner for DbInterner<'db> {

.db()

.generic_predicates_ns(def_id.0.into())

.iter()

+ .filter(|p| match p.kind().skip_binder() {

+ rustc_type_ir::ClauseKind::Trait(tr) => match tr.self_ty().kind() {

+ rustc_type_ir::TyKind::Param(param) => param.index == 0,

+ _ => false,

+ },

+ _ => true,

+ })

.cloned()

.map(|p| (p, Span::dummy()))

.collect();

@@ -1345,10 +1352,24 @@ impl<'db> rustc_type_ir::Interner for DbInterner<'db> {

self,

def_id: Self::DefId,

) -> EarlyBinder<Self, impl IntoIterator<Item = (Self::Clause, Self::Span)>> {

+ fn is_self_or_assoc(ty: Ty<'_>) -> bool {

+ match ty.kind() {

+ rustc_type_ir::TyKind::Param(param) => param.index == 0,

+ rustc_type_ir::TyKind::Alias(rustc_type_ir::AliasTyKind::Projection, alias) => {

+ is_self_or_assoc(alias.self_ty())

+ }

+ _ => false,

+ }

let predicates: Vec<(Clause<'db>, Span)> = self

.db()

.generic_predicates_ns(def_id.try_into().unwrap())

.iter()

+ .filter(|p| match p.kind().skip_binder() {

+ rustc_type_ir::ClauseKind::Trait(tr) => is_self_or_assoc(tr.self_ty()),

+ _ => true,

+ })

.cloned()

.map(|p| (p, Span::dummy()))

.collect();

diff --git a/crates/hir-ty/src/tests/regression/new_solver.rs b/crates/hir-ty/src/tests/regression/new_solver.rs
index 4df788638a..595f285bd9 100644
--- a/crates/hir-ty/src/tests/regression/new_solver.rs
+++ b/crates/hir-ty/src/tests/regression/new_solver.rs

@@ -116,3 +116,34 @@ fn main() {

"#]],

);

}

+#[test]

+fn no_infinite_loop_on_super_predicates_elaboration() {

+ check_infer(

+ r#"

+//- minicore: sized

+trait DimMax<Other: Dimension> {

+ type Output: Dimension;

+trait Dimension: DimMax<<Self as Dimension>:: Smaller, Output = Self> {

+ type Smaller: Dimension;

+fn test<T, U>(t: T)

+where

+ T: DimMax<U>,

+ U: Dimension,

+ let t: <T as DimMax<U>>::Output = loop {};

+"#,

+ expect![[r#"

+ 182..183 't': T

+ 230..280 '{ ... {}; }': ()

+ 240..241 't': <T as DimMax<U>>::Output

+ 270..277 'loop {}': !

+ 275..277 '{}': ()

+ "#]],

+ )