14 files changed, 667 insertions, 77 deletions

diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index abc0e7532..66b3418f2 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -18,9 +18,9 @@ ena = "0.14.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 scoped-tls = "1"
-chalk-solve = { version = "0.60", default-features = false }
-chalk-ir = "0.60"
-chalk-recursive = "0.60"
+chalk-solve = { version = "0.64", default-features = false }
+chalk-ir = "0.64"
+chalk-recursive = "0.64"
 la-arena = { version = "0.2.0", path = "../../lib/arena" }
 
 stdx = { path = "../stdx", version = "0.0.0" }
diff --git a/crates/hir_ty/src/autoderef.rs b/crates/hir_ty/src/autoderef.rs
index 71bc436e6..2c07494a9 100644
--- a/crates/hir_ty/src/autoderef.rs
+++ b/crates/hir_ty/src/autoderef.rs
@@ -36,6 +36,7 @@ pub(crate) fn deref(
     krate: CrateId,
     ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
+    let _p = profile::span("deref");
     if let Some(derefed) = builtin_deref(&ty.goal.value) {
         Some(Canonical { value: derefed, binders: ty.goal.binders.clone() })
     } else {
@@ -56,6 +57,7 @@ fn deref_by_trait(
     krate: CrateId,
     ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
+    let _p = profile::span("deref_by_trait");
     let deref_trait = match db.lang_item(krate, "deref".into())? {
         LangItemTarget::TraitId(it) => it,
         _ => return None,
diff --git a/crates/hir_ty/src/db.rs b/crates/hir_ty/src/db.rs
index 1690926ad..9da0a02e3 100644
--- a/crates/hir_ty/src/db.rs
+++ b/crates/hir_ty/src/db.rs
@@ -70,6 +70,7 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     fn trait_environment(&self, def: GenericDefId) -> Arc<crate::TraitEnvironment>;
 
     #[salsa::invoke(crate::lower::generic_defaults_query)]
+    #[salsa::cycle(crate::lower::generic_defaults_recover)]
     fn generic_defaults(&self, def: GenericDefId) -> Arc<[Binders<Ty>]>;
 
     #[salsa::invoke(InherentImpls::inherent_impls_in_crate_query)]
@@ -128,13 +129,21 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
         id: chalk_db::AssociatedTyValueId,
     ) -> Arc<chalk_db::AssociatedTyValue>;
 
-    #[salsa::invoke(crate::traits::trait_solve_query)]
+    #[salsa::invoke(trait_solve_wait)]
+    #[salsa::transparent]
     fn trait_solve(
         &self,
         krate: CrateId,
         goal: crate::Canonical<crate::InEnvironment<crate::DomainGoal>>,
     ) -> Option<crate::Solution>;
 
+    #[salsa::invoke(crate::traits::trait_solve_query)]
+    fn trait_solve_query(
+        &self,
+        krate: CrateId,
+        goal: crate::Canonical<crate::InEnvironment<crate::DomainGoal>>,
+    ) -> Option<crate::Solution>;
+
     #[salsa::invoke(chalk_db::program_clauses_for_chalk_env_query)]
     fn program_clauses_for_chalk_env(
         &self,
@@ -156,6 +165,15 @@ fn infer_wait(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult>
     db.infer_query(def)
 }
 
+fn trait_solve_wait(
+    db: &dyn HirDatabase,
+    krate: CrateId,
+    goal: crate::Canonical<crate::InEnvironment<crate::DomainGoal>>,
+) -> Option<crate::Solution> {
+    let _p = profile::span("trait_solve::wait");
+    db.trait_solve_query(krate, goal)
+}
+
 #[test]
 fn hir_database_is_object_safe() {
     fn _assert_object_safe(_: &dyn HirDatabase) {}
diff --git a/crates/hir_ty/src/diagnostics/decl_check.rs b/crates/hir_ty/src/diagnostics/decl_check.rs
index 1c9f9ede7..075dc4131 100644
--- a/crates/hir_ty/src/diagnostics/decl_check.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check.rs
@@ -35,6 +35,8 @@ use crate::{
 };
 
 mod allow {
+    pub(super) const BAD_STYLE: &str = "bad_style";
+    pub(super) const NONSTANDARD_STYLE: &str = "nonstandard_style";
     pub(super) const NON_SNAKE_CASE: &str = "non_snake_case";
     pub(super) const NON_UPPER_CASE_GLOBAL: &str = "non_upper_case_globals";
     pub(super) const NON_CAMEL_CASE_TYPES: &str = "non_camel_case_types";
@@ -83,10 +85,39 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     }
 
     /// Checks whether not following the convention is allowed for this item.
-    ///
-    /// Currently this method doesn't check parent attributes.
-    fn allowed(&self, id: AttrDefId, allow_name: &str) -> bool {
-        self.db.attrs(id).by_key("allow").tt_values().any(|tt| tt.to_string().contains(allow_name))
+    fn allowed(&self, id: AttrDefId, allow_name: &str, recursing: bool) -> bool {
+        let is_allowed = |def_id| {
+            let attrs = self.db.attrs(def_id);
+            // don't bug the user about directly no_mangle annotated stuff, they can't do anything about it
+            (!recursing && attrs.by_key("no_mangle").exists())
+                || attrs.by_key("allow").tt_values().any(|tt| {
+                    let allows = tt.to_string();
+                    allows.contains(allow_name)
+                        || allows.contains(allow::BAD_STYLE)
+                        || allows.contains(allow::NONSTANDARD_STYLE)
+                })
+        };
+
+        is_allowed(id)
+            // go upwards one step or give up
+            || match id {
+                AttrDefId::ModuleId(m) => m.containing_module(self.db.upcast()).map(|v| v.into()),
+                AttrDefId::FunctionId(f) => Some(f.lookup(self.db.upcast()).container.into()),
+                AttrDefId::StaticId(sid) => Some(sid.lookup(self.db.upcast()).container.into()),
+                AttrDefId::ConstId(cid) => Some(cid.lookup(self.db.upcast()).container.into()),
+                AttrDefId::TraitId(tid) => Some(tid.lookup(self.db.upcast()).container.into()),
+                AttrDefId::ImplId(iid) => Some(iid.lookup(self.db.upcast()).container.into()),
+                // These warnings should not explore macro definitions at all
+                AttrDefId::MacroDefId(_) => None,
+                // Will never occur under an enum/struct/union/type alias
+                AttrDefId::AdtId(_) => None,
+                AttrDefId::FieldId(_) => None,
+                AttrDefId::EnumVariantId(_) => None,
+                AttrDefId::TypeAliasId(_) => None,
+                AttrDefId::GenericParamId(_) => None,
+            }
+            .map(|mid| self.allowed(mid, allow_name, true))
+            .unwrap_or(false)
     }
 
     fn validate_func(&mut self, func: FunctionId) {
@@ -109,7 +140,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
         }
 
         // Check whether non-snake case identifiers are allowed for this function.
-        if self.allowed(func.into(), allow::NON_SNAKE_CASE) {
+        if self.allowed(func.into(), allow::NON_SNAKE_CASE, false) {
             return;
         }
 
@@ -328,8 +359,9 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     fn validate_struct(&mut self, struct_id: StructId) {
         let data = self.db.struct_data(struct_id);
 
-        let non_camel_case_allowed = self.allowed(struct_id.into(), allow::NON_CAMEL_CASE_TYPES);
-        let non_snake_case_allowed = self.allowed(struct_id.into(), allow::NON_SNAKE_CASE);
+        let non_camel_case_allowed =
+            self.allowed(struct_id.into(), allow::NON_CAMEL_CASE_TYPES, false);
+        let non_snake_case_allowed = self.allowed(struct_id.into(), allow::NON_SNAKE_CASE, false);
 
         // Check the structure name.
         let struct_name = data.name.to_string();
@@ -461,7 +493,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
         let data = self.db.enum_data(enum_id);
 
         // Check whether non-camel case names are allowed for this enum.
-        if self.allowed(enum_id.into(), allow::NON_CAMEL_CASE_TYPES) {
+        if self.allowed(enum_id.into(), allow::NON_CAMEL_CASE_TYPES, false) {
             return;
         }
 
@@ -584,7 +616,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     fn validate_const(&mut self, const_id: ConstId) {
         let data = self.db.const_data(const_id);
 
-        if self.allowed(const_id.into(), allow::NON_UPPER_CASE_GLOBAL) {
+        if self.allowed(const_id.into(), allow::NON_UPPER_CASE_GLOBAL, false) {
             return;
         }
 
@@ -632,7 +664,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
             return;
         }
 
-        if self.allowed(static_id.into(), allow::NON_UPPER_CASE_GLOBAL) {
+        if self.allowed(static_id.into(), allow::NON_UPPER_CASE_GLOBAL, false) {
             return;
         }
 
@@ -867,23 +899,116 @@ fn main() {
     fn allow_attributes() {
         check_diagnostics(
             r#"
-            #[allow(non_snake_case)]
-    fn NonSnakeCaseName(SOME_VAR: u8) -> u8{
-        let OtherVar = SOME_VAR + 1;
-        OtherVar
+#[allow(non_snake_case)]
+fn NonSnakeCaseName(SOME_VAR: u8) -> u8{
+    // cov_flags generated output from elsewhere in this file
+    extern "C" {
+        #[no_mangle]
+        static lower_case: u8;
     }
 
-    #[allow(non_snake_case, non_camel_case_types)]
-    pub struct some_type {
-        SOME_FIELD: u8,
-        SomeField: u16,
+    let OtherVar = SOME_VAR + 1;
+    OtherVar
+}
+
+#[allow(nonstandard_style)]
+mod CheckNonstandardStyle {
+    fn HiImABadFnName() {}
+}
+
+#[allow(bad_style)]
+mod CheckBadStyle {
+    fn HiImABadFnName() {}
+}
+
+mod F {
+    #![allow(non_snake_case)]
+    fn CheckItWorksWithModAttr(BAD_NAME_HI: u8) {}
+}
+
+#[allow(non_snake_case, non_camel_case_types)]
+pub struct some_type {
+    SOME_FIELD: u8,
+    SomeField: u16,
+}
+
+#[allow(non_upper_case_globals)]
+pub const some_const: u8 = 10;
+
+#[allow(non_upper_case_globals)]
+pub static SomeStatic: u8 = 10;
+    "#,
+        );
     }
 
-    #[allow(non_upper_case_globals)]
-    pub const some_const: u8 = 10;
+    #[test]
+    fn allow_attributes_crate_attr() {
+        check_diagnostics(
+            r#"
+#![allow(non_snake_case)]
 
-    #[allow(non_upper_case_globals)]
-    pub static SomeStatic: u8 = 10;
+mod F {
+    fn CheckItWorksWithCrateAttr(BAD_NAME_HI: u8) {}
+}
+    "#,
+        );
+    }
+
+    #[test]
+    #[ignore]
+    fn bug_trait_inside_fn() {
+        // FIXME:
+        // This is broken, and in fact, should not even be looked at by this
+        // lint in the first place. There's weird stuff going on in the
+        // collection phase.
+        // It's currently being brought in by:
+        // * validate_func on `a` recursing into modules
+        // * then it finds the trait and then the function while iterating
+        //   through modules
+        // * then validate_func is called on Dirty
+        // * ... which then proceeds to look at some unknown module taking no
+        //   attrs from either the impl or the fn a, and then finally to the root
+        //   module
+        //
+        // It should find the attribute on the trait, but it *doesn't even see
+        // the trait* as far as I can tell.
+
+        check_diagnostics(
+            r#"
+trait T { fn a(); }
+struct U {}
+impl T for U {
+    fn a() {
+        // this comes out of bitflags, mostly
+        #[allow(non_snake_case)]
+        trait __BitFlags {
+            const HiImAlsoBad: u8 = 2;
+            #[inline]
+            fn Dirty(&self) -> bool {
+                false
+            }
+        }
+
+    }
+}
+    "#,
+        );
+    }
+
+    #[test]
+    #[ignore]
+    fn bug_traits_arent_checked() {
+        // FIXME: Traits and functions in traits aren't currently checked by
+        // r-a, even though rustc will complain about them.
+        check_diagnostics(
+            r#"
+trait BAD_TRAIT {
+    // ^^^^^^^^^ Trait `BAD_TRAIT` should have CamelCase name, e.g. `BadTrait`
+    fn BAD_FUNCTION();
+    // ^^^^^^^^^^^^ Function `BAD_FUNCTION` should have snake_case name, e.g. `bad_function`
+    fn BadFunction();
+    // ^^^^^^^^^^^^ Function `BadFunction` should have snake_case name, e.g. `bad_function`
+}
     "#,
         );
     }
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index e7c9dabc2..4fb7d9cf2 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -9,6 +9,7 @@ use std::{
 
 use chalk_ir::BoundVar;
 use hir_def::{
+    body,
     db::DefDatabase,
     find_path,
     generics::TypeParamProvenance,
@@ -18,7 +19,7 @@ use hir_def::{
     visibility::Visibility,
     AssocContainerId, Lookup, ModuleId, TraitId,
 };
-use hir_expand::name::Name;
+use hir_expand::{hygiene::Hygiene, name::Name};
 
 use crate::{
     const_from_placeholder_idx, db::HirDatabase, from_assoc_type_id, from_foreign_def_id,
@@ -997,6 +998,18 @@ impl HirDisplay for TypeRef {
                 write!(f, "dyn ")?;
                 f.write_joined(bounds, " + ")?;
             }
+            TypeRef::Macro(macro_call) => {
+                let macro_call = macro_call.to_node(f.db.upcast());
+                let ctx = body::LowerCtx::with_hygiene(&Hygiene::new_unhygienic());
+                match macro_call.path() {
+                    Some(path) => match Path::from_src(path, &ctx) {
+                        Some(path) => path.hir_fmt(f)?,
+                        None => write!(f, "{{macro}}")?,
+                    },
+                    None => write!(f, "{{macro}}")?,
+                }
+                write!(f, "!(..)")?;
+            }
             TypeRef::Error => write!(f, "{{error}}")?,
         }
         Ok(())
diff --git a/crates/hir_ty/src/infer/unify.rs b/crates/hir_ty/src/infer/unify.rs
index a887e20b0..d8e0b4320 100644
--- a/crates/hir_ty/src/infer/unify.rs
+++ b/crates/hir_ty/src/infer/unify.rs
@@ -332,6 +332,10 @@ impl InferenceTable {
                 | (TyKind::Slice(ty1), TyKind::Slice(ty2)) => self.unify_inner(ty1, ty2, depth + 1),
                 _ => true, /* we checked equals_ctor already */
             }
+        } else if let (TyKind::Closure(.., substs1), TyKind::Closure(.., substs2)) =
+            (ty1.kind(&Interner), ty2.kind(&Interner))
+        {
+            self.unify_substs(substs1, substs2, depth + 1)
         } else {
             self.unify_inner_trivial(&ty1, &ty2, depth)
         }
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index 113234fa4..0505fa4ae 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -56,6 +56,7 @@ pub use mapping::{
     to_foreign_def_id, to_placeholder_idx,
 };
 pub use traits::TraitEnvironment;
+pub use utils::all_super_traits;
 pub use walk::TypeWalk;
 
 pub use chalk_ir::{
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index a035686bc..c99dd8d0a 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -5,12 +5,14 @@
 //!  - Building the type for an item: This happens through the `type_for_def` query.
 //!
 //! This usually involves resolving names, collecting generic arguments etc.
+use std::cell::{Cell, RefCell};
 use std::{iter, sync::Arc};
 
 use base_db::CrateId;
 use chalk_ir::{cast::Cast, fold::Shift, interner::HasInterner, Mutability, Safety};
 use hir_def::{
     adt::StructKind,
+    body::{Expander, LowerCtx},
     builtin_type::BuiltinType,
     generics::{TypeParamProvenance, WherePredicate, WherePredicateTypeTarget},
     path::{GenericArg, Path, PathSegment, PathSegments},
@@ -20,10 +22,11 @@ use hir_def::{
     GenericDefId, HasModule, ImplId, LocalFieldId, Lookup, StaticId, StructId, TraitId,
     TypeAliasId, TypeParamId, UnionId, VariantId,
 };
-use hir_expand::name::Name;
+use hir_expand::{name::Name, ExpandResult};
 use la_arena::ArenaMap;
 use smallvec::SmallVec;
 use stdx::impl_from;
+use syntax::ast;
 
 use crate::{
     db::HirDatabase,
@@ -50,7 +53,7 @@ pub struct TyLoweringContext<'a> {
     /// possible currently, so this should be fine for now.
     pub type_param_mode: TypeParamLoweringMode,
     pub impl_trait_mode: ImplTraitLoweringMode,
-    impl_trait_counter: std::cell::Cell<u16>,
+    impl_trait_counter: Cell<u16>,
     /// When turning `impl Trait` into opaque types, we have to collect the
     /// bounds at the same time to get the IDs correct (without becoming too
     /// complicated). I don't like using interior mutability (as for the
@@ -59,16 +62,17 @@ pub struct TyLoweringContext<'a> {
     /// we're grouping the mutable data (the counter and this field) together
     /// with the immutable context (the references to the DB and resolver).
     /// Splitting this up would be a possible fix.
-    opaque_type_data: std::cell::RefCell<Vec<ReturnTypeImplTrait>>,
+    opaque_type_data: RefCell<Vec<ReturnTypeImplTrait>>,
+    expander: RefCell<Option<Expander>>,
 }
 
 impl<'a> TyLoweringContext<'a> {
     pub fn new(db: &'a dyn HirDatabase, resolver: &'a Resolver) -> Self {
-        let impl_trait_counter = std::cell::Cell::new(0);
+        let impl_trait_counter = Cell::new(0);
         let impl_trait_mode = ImplTraitLoweringMode::Disallowed;
         let type_param_mode = TypeParamLoweringMode::Placeholder;
         let in_binders = DebruijnIndex::INNERMOST;
-        let opaque_type_data = std::cell::RefCell::new(Vec::new());
+        let opaque_type_data = RefCell::new(Vec::new());
         Self {
             db,
             resolver,
@@ -77,6 +81,7 @@ impl<'a> TyLoweringContext<'a> {
             impl_trait_counter,
             type_param_mode,
             opaque_type_data,
+            expander: RefCell::new(None),
         }
     }
 
@@ -86,15 +91,18 @@ impl<'a> TyLoweringContext<'a> {
         f: impl FnOnce(&TyLoweringContext) -> T,
     ) -> T {
         let opaque_ty_data_vec = self.opaque_type_data.replace(Vec::new());
+        let expander = self.expander.replace(None);
         let new_ctx = Self {
             in_binders: debruijn,
-            impl_trait_counter: std::cell::Cell::new(self.impl_trait_counter.get()),
-            opaque_type_data: std::cell::RefCell::new(opaque_ty_data_vec),
+            impl_trait_counter: Cell::new(self.impl_trait_counter.get()),
+            opaque_type_data: RefCell::new(opaque_ty_data_vec),
+            expander: RefCell::new(expander),
             ..*self
         };
         let result = f(&new_ctx);
         self.impl_trait_counter.set(new_ctx.impl_trait_counter.get());
         self.opaque_type_data.replace(new_ctx.opaque_type_data.into_inner());
+        self.expander.replace(new_ctx.expander.into_inner());
         result
     }
 
@@ -287,6 +295,53 @@ impl<'a> TyLoweringContext<'a> {
                     }
                 }
             }
+            TypeRef::Macro(macro_call) => {
+                let (expander, recursion_start) = {
+                    let mut expander = self.expander.borrow_mut();
+                    if expander.is_some() {
+                        (Some(expander), false)
+                    } else {
+                        if let Some(module_id) = self.resolver.module() {
+                            *expander = Some(Expander::new(
+                                self.db.upcast(),
+                                macro_call.file_id,
+                                module_id,
+                            ));
+                            (Some(expander), true)
+                        } else {
+                            (None, false)
+                        }
+                    }
+                };
+                let ty = if let Some(mut expander) = expander {
+                    let expander_mut = expander.as_mut().unwrap();
+                    let macro_call = macro_call.to_node(self.db.upcast());
+                    match expander_mut.enter_expand::<ast::Type>(self.db.upcast(), macro_call) {
+                        Ok(ExpandResult { value: Some((mark, expanded)), .. }) => {
+                            let ctx =
+                                LowerCtx::new(self.db.upcast(), expander_mut.current_file_id());
+                            let type_ref = TypeRef::from_ast(&ctx, expanded);
+
+                            drop(expander);
+                            let ty = self.lower_ty(&type_ref);
+
+                            self.expander
+                                .borrow_mut()
+                                .as_mut()
+                                .unwrap()
+                                .exit(self.db.upcast(), mark);
+                            Some(ty)
+                        }
+                        _ => None,
+                    }
+                } else {
+                    None
+                };
+                if recursion_start {
+                    *self.expander.borrow_mut() = None;
+                }
+                ty.unwrap_or_else(|| TyKind::Error.intern(&Interner))
+            }
             TypeRef::Error => TyKind::Error.intern(&Interner),
         };
         (ty, res)
@@ -359,17 +414,16 @@ impl<'a> TyLoweringContext<'a> {
                     self.lower_trait_ref_from_resolved_path(trait_, resolved_segment, self_ty);
                 let ty = if remaining_segments.len() == 1 {
                     let segment = remaining_segments.first().unwrap();
-                    let found = associated_type_by_name_including_super_traits(
-                        self.db,
-                        trait_ref,
-                        &segment.name,
-                    );
+                    let found = self
+                        .db
+                        .trait_data(trait_ref.hir_trait_id())
+                        .associated_type_by_name(&segment.name);
                     match found {
-                        Some((super_trait_ref, associated_ty)) => {
+                        Some(associated_ty) => {
                             // FIXME handle type parameters on the segment
                             TyKind::Alias(AliasTy::Projection(ProjectionTy {
                                 associated_ty_id: to_assoc_type_id(associated_ty),
-                                substitution: super_trait_ref.substitution,
+                                substitution: trait_ref.substitution,
                             }))
                             .intern(&Interner)
                         }
@@ -1034,6 +1088,27 @@ pub(crate) fn generic_defaults_query(
     defaults
 }
 
+pub(crate) fn generic_defaults_recover(
+    db: &dyn HirDatabase,
+    _cycle: &[String],
+    def: &GenericDefId,
+) -> Arc<[Binders<Ty>]> {
+    let generic_params = generics(db.upcast(), *def);
+
+    // we still need one default per parameter
+    let defaults = generic_params
+        .iter()
+        .enumerate()
+        .map(|(idx, _)| {
+            let ty = TyKind::Error.intern(&Interner);
+
+            crate::make_only_type_binders(idx, ty)
+        })
+        .collect();
+
+    defaults
+}
+
 fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
     let data = db.function_data(def);
     let resolver = def.resolver(db.upcast());
diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs
index 3693e3284..48bbcfd9f 100644
--- a/crates/hir_ty/src/method_resolution.rs
+++ b/crates/hir_ty/src/method_resolution.rs
@@ -246,29 +246,39 @@ pub struct InherentImpls {
 
 impl InherentImpls {
     pub(crate) fn inherent_impls_in_crate_query(db: &dyn HirDatabase, krate: CrateId) -> Arc<Self> {
-        let mut map: FxHashMap<_, Vec<_>> = FxHashMap::default();
+        let mut impls = Self { map: FxHashMap::default() };
 
         let crate_def_map = db.crate_def_map(krate);
-        for (_module_id, module_data) in crate_def_map.modules() {
-            for impl_id in module_data.scope.impls() {
-                let data = db.impl_data(impl_id);
-                if data.target_trait.is_some() {
-                    continue;
+        collect_def_map(db, &crate_def_map, &mut impls);
+
+        return Arc::new(impls);
+
+        fn collect_def_map(db: &dyn HirDatabase, def_map: &DefMap, impls: &mut InherentImpls) {
+            for (_module_id, module_data) in def_map.modules() {
+                for impl_id in module_data.scope.impls() {
+                    let data = db.impl_data(impl_id);
+                    if data.target_trait.is_some() {
+                        continue;
+                    }
+
+                    let self_ty = db.impl_self_ty(impl_id);
+                    let fp = TyFingerprint::for_inherent_impl(self_ty.skip_binders());
+                    if let Some(fp) = fp {
+                        impls.map.entry(fp).or_default().push(impl_id);
+                    }
+                    // `fp` should only be `None` in error cases (either erroneous code or incomplete name resolution)
                 }
 
-                let self_ty = db.impl_self_ty(impl_id);
-                let fp = TyFingerprint::for_inherent_impl(self_ty.skip_binders());
-                if let Some(fp) = fp {
-                    map.entry(fp).or_default().push(impl_id);
+                // To better support custom derives, collect impls in all unnamed const items.
+                // const _: () = { ... };
+                for konst in module_data.scope.unnamed_consts() {
+                    let body = db.body(konst.into());
+                    for (_, block_def_map) in body.blocks(db.upcast()) {
+                        collect_def_map(db, &block_def_map, impls);
+                    }
                 }
-                // `fp` should only be `None` in error cases (either erroneous code or incomplete name resolution)
             }
         }
-
-        // NOTE: We're not collecting inherent impls from unnamed consts here, we intentionally only
-        // support trait impls there.
-
-        Arc::new(Self { map })
     }
 
     pub fn for_self_ty(&self, self_ty: &Ty) -> &[ImplId] {
diff --git a/crates/hir_ty/src/tests/macros.rs b/crates/hir_ty/src/tests/macros.rs
index b8e373ed8..6588aa46c 100644
--- a/crates/hir_ty/src/tests/macros.rs
+++ b/crates/hir_ty/src/tests/macros.rs
@@ -1074,3 +1074,202 @@ fn macro_in_arm() {
         "#]],
     );
 }
+
+#[test]
+fn macro_in_type_alias_position() {
+    check_infer(
+        r#"
+        macro_rules! U32 {
+            () => { u32 };
+        }
+
+        trait Foo {
+            type Ty;
+        }
+
+        impl<T> Foo for T {
+            type Ty = U32!();
+        }
+
+        type TayTo = U32!();
+
+        fn testy() {
+            let a: <() as Foo>::Ty;
+            let b: TayTo;
+        }
+        "#,
+        expect![[r#"
+            147..196 '{     ...yTo; }': ()
+            157..158 'a': u32
+            185..186 'b': u32
+        "#]],
+    );
+}
+
+#[test]
+fn nested_macro_in_type_alias_position() {
+    check_infer(
+        r#"
+        macro_rules! U32Inner2 {
+            () => { u32 };
+        }
+
+        macro_rules! U32Inner1 {
+            () => { U32Inner2!() };
+        }
+
+        macro_rules! U32 {
+            () => { U32Inner1!() };
+        }
+
+        trait Foo {
+            type Ty;
+        }
+
+        impl<T> Foo for T {
+            type Ty = U32!();
+        }
+
+        type TayTo = U32!();
+
+        fn testy() {
+            let a: <() as Foo>::Ty;
+            let b: TayTo;
+        }
+        "#,
+        expect![[r#"
+            259..308 '{     ...yTo; }': ()
+            269..270 'a': u32
+            297..298 'b': u32
+        "#]],
+    );
+}
+
+#[test]
+fn macros_in_type_alias_position_generics() {
+    check_infer(
+        r#"
+        struct Foo<A, B>(A, B);
+
+        macro_rules! U32 {
+            () => { u32 };
+        }
+
+        macro_rules! Bar {
+            () => { Foo<U32!(), U32!()> };
+        }
+
+        trait Moo {
+            type Ty;
+        }
+
+        impl<T> Moo for T {
+            type Ty = Bar!();
+        }
+
+        type TayTo = Bar!();
+
+        fn main() {
+            let a: <() as Moo>::Ty;
+            let b: TayTo;
+        }
+        "#,
+        expect![[r#"
+            228..277 '{     ...yTo; }': ()
+            238..239 'a': Foo<u32, u32>
+            266..267 'b': Foo<u32, u32>
+        "#]],
+    );
+}
+
+#[test]
+fn macros_in_type_position() {
+    check_infer(
+        r#"
+        struct Foo<A, B>(A, B);
+
+        macro_rules! U32 {
+            () => { u32 };
+        }
+
+        macro_rules! Bar {
+            () => { Foo<U32!(), U32!()> };
+        }
+
+        fn main() {
+            let a: Bar!();
+        }
+        "#,
+        expect![[r#"
+            133..155 '{     ...!(); }': ()
+            143..144 'a': Foo<u32, u32>
+        "#]],
+    );
+}
+
+#[test]
+fn macros_in_type_generics() {
+    check_infer(
+        r#"
+        struct Foo<A, B>(A, B);
+
+        macro_rules! U32 {
+            () => { u32 };
+        }
+
+        macro_rules! Bar {
+            () => { Foo<U32!(), U32!()> };
+        }
+
+        trait Moo {
+            type Ty;
+        }
+
+        impl<T> Moo for T {
+            type Ty = Foo<Bar!(), Bar!()>;
+        }
+
+        type TayTo = Foo<Bar!(), U32!()>;
+
+        fn main() {
+            let a: <() as Moo>::Ty;
+            let b: TayTo;
+        }
+        "#,
+        expect![[r#"
+            254..303 '{     ...yTo; }': ()
+            264..265 'a': Foo<Foo<u32, u32>, Foo<u32, u32>>
+            292..293 'b': Foo<Foo<u32, u32>, u32>
+        "#]],
+    );
+}
+
+#[test]
+fn infinitely_recursive_macro_type() {
+    check_infer(
+        r#"
+        struct Bar<T, X>(T, X);
+
+        macro_rules! Foo {
+            () => { Foo!() }
+        }
+
+        macro_rules! U32 {
+            () => { u32 }
+        }
+
+        type A = Foo!();
+        type B = Bar<Foo!(), U32!()>;
+
+        fn main() {
+            let a: A;
+            let b: B;
+        }
+        "#,
+        expect![[r#"
+            166..197 '{     ...: B; }': ()
+            176..177 'a': {unknown}
+            190..191 'b': Bar<{unknown}, u32>
+        "#]],
+    );
+}
diff --git a/crates/hir_ty/src/tests/method_resolution.rs b/crates/hir_ty/src/tests/method_resolution.rs
index 4b2c82b41..a4c132bc5 100644
--- a/crates/hir_ty/src/tests/method_resolution.rs
+++ b/crates/hir_ty/src/tests/method_resolution.rs
@@ -1294,7 +1294,7 @@ mod b {
 }
 
 #[test]
-fn impl_in_unnamed_const() {
+fn trait_impl_in_unnamed_const() {
     check_types(
         r#"
 struct S;
@@ -1314,3 +1314,38 @@ fn f() {
     "#,
     );
 }
+
+#[test]
+fn inherent_impl_in_unnamed_const() {
+    check_types(
+        r#"
+struct S;
+
+const _: () = {
+    impl S {
+        fn method(&self) -> u16 { 0 }
+
+        pub(super) fn super_method(&self) -> u16 { 0 }
+
+        pub(crate) fn crate_method(&self) -> u16 { 0 }
+
+        pub fn pub_method(&self) -> u16 { 0 }
+    }
+};
+
+fn f() {
+    S.method();
+  //^^^^^^^^^^ u16
+
+    S.super_method();
+  //^^^^^^^^^^^^^^^^ u16
+
+    S.crate_method();
+  //^^^^^^^^^^^^^^^^ u16
+
+    S.pub_method();
+  //^^^^^^^^^^^^^^ u16
+}
+    "#,
+    );
+}
diff --git a/crates/hir_ty/src/tests/regression.rs b/crates/hir_ty/src/tests/regression.rs
index 9cd9f473d..d14f5c9bb 100644
--- a/crates/hir_ty/src/tests/regression.rs
+++ b/crates/hir_ty/src/tests/regression.rs
@@ -1012,3 +1012,41 @@ fn lifetime_from_chalk_during_deref() {
         "#,
     )
 }
+
+#[test]
+fn issue_8686() {
+    check_infer(
+        r#"
+pub trait Try: FromResidual {
+    type Output;
+    type Residual;
+}
+pub trait FromResidual<R = <Self as Try>::Residual> {
+     fn from_residual(residual: R) -> Self;
+}
+
+struct ControlFlow<B, C>;
+impl<B, C> Try for ControlFlow<B, C> {
+    type Output = C;
+    type Residual = ControlFlow<B, !>;
+}
+impl<B, C> FromResidual for ControlFlow<B, C> {
+    fn from_residual(r: ControlFlow<B, !>) -> Self { ControlFlow }
+}
+
+fn test() {
+    ControlFlow::from_residual(ControlFlow::<u32, !>);
+}
+        "#,
+        expect![[r#"
+            144..152 'residual': R
+            365..366 'r': ControlFlow<B, !>
+            395..410 '{ ControlFlow }': ControlFlow<B, C>
+            397..408 'ControlFlow': ControlFlow<B, C>
+            424..482 '{     ...!>); }': ()
+            430..456 'Contro...sidual': fn from_residual<ControlFlow<u32, {unknown}>, ControlFlow<u32, !>>(ControlFlow<u32, !>) -> ControlFlow<u32, {unknown}>
+            430..479 'Contro...2, !>)': ControlFlow<u32, {unknown}>
+            457..478 'Contro...32, !>': ControlFlow<u32, !>
+        "#]],
+    );
+}
diff --git a/crates/hir_ty/src/tests/simple.rs b/crates/hir_ty/src/tests/simple.rs
index 84c5c05fd..0eefd70f2 100644
--- a/crates/hir_ty/src/tests/simple.rs
+++ b/crates/hir_ty/src/tests/simple.rs
@@ -1029,6 +1029,42 @@ fn infer_in_elseif() {
 }
 
 #[test]
+fn infer_closure_unify() {
+    check_infer(
+        r#"
+        fn foo(f: bool) {
+            let a = |x| x;
+            let b = |x| x;
+            let id = if f { a } else { b };
+            id(123);
+        }
+        "#,
+        expect![[r#"
+            7..8 'f': bool
+            16..106 '{     ...23); }': ()
+            26..27 'a': |i32| -> i32
+            30..35 '|x| x': |i32| -> i32
+            31..32 'x': i32
+            34..35 'x': i32
+            45..46 'b': |i32| -> i32
+            49..54 '|x| x': |i32| -> i32
+            50..51 'x': i32
+            53..54 'x': i32
+            64..66 'id': |i32| -> i32
+            69..90 'if f {... { b }': |i32| -> i32
+            72..73 'f': bool
+            74..79 '{ a }': |i32| -> i32
+            76..77 'a': |i32| -> i32
+            85..90 '{ b }': |i32| -> i32
+            87..88 'b': |i32| -> i32
+            96..98 'id': |i32| -> i32
+            96..103 'id(123)': i32
+            99..102 '123': i32
+        "#]],
+    )
+}
+
+#[test]
 fn infer_if_match_with_return() {
     check_infer(
         r#"
@@ -1765,6 +1801,24 @@ fn main() {
 }
 
 #[test]
+fn shadowing_primitive_with_inner_items() {
+    check_types(
+        r#"
+struct i32;
+struct Foo;
+
+impl i32 { fn foo(&self) -> Foo { Foo } }
+
+fn main() {
+    fn inner() {}
+    let x: i32 = i32;
+    x.foo();
+        //^ Foo
+}"#,
+    );
+}
+
+#[test]
 fn not_shadowing_primitive_by_module() {
     check_types(
         r#"
diff --git a/crates/hir_ty/src/utils.rs b/crates/hir_ty/src/utils.rs
index 5f6cb052a..2f490fb92 100644
--- a/crates/hir_ty/src/utils.rs
+++ b/crates/hir_ty/src/utils.rs
@@ -1,6 +1,8 @@
 //! Helper functions for working with def, which don't need to be a separate
 //! query, but can't be computed directly from `*Data` (ie, which need a `db`).
 
+use std::iter;
+
 use chalk_ir::{fold::Shift, BoundVar, DebruijnIndex};
 use hir_def::{
     db::DefDatabase,
@@ -14,8 +16,12 @@ use hir_def::{
     AssocContainerId, GenericDefId, Lookup, TraitId, TypeAliasId, TypeParamId,
 };
 use hir_expand::name::{name, Name};
+use rustc_hash::FxHashSet;
 
-use crate::{db::HirDatabase, Interner, Substitution, TraitRef, TraitRefExt, TyKind, WhereClause};
+use crate::{
+    db::HirDatabase, ChalkTraitId, Interner, Substitution, TraitRef, TraitRefExt, TyKind,
+    WhereClause,
+};
 
 fn direct_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> Vec<TraitId> {
     let resolver = trait_.resolver(db);
@@ -78,7 +84,7 @@ fn direct_super_trait_refs(db: &dyn HirDatabase, trait_ref: &TraitRef) -> Vec<Tr
 
 /// Returns an iterator over the whole super trait hierarchy (including the
 /// trait itself).
-pub(super) fn all_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> Vec<TraitId> {
+pub fn all_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> Vec<TraitId> {
     // we need to take care a bit here to avoid infinite loops in case of cycles
     // (i.e. if we have `trait A: B; trait B: A;`)
     let mut result = vec![trait_];
@@ -102,25 +108,35 @@ pub(super) fn all_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> Vec<Tra
 /// `all_super_traits` is that we keep track of type parameters; for example if
 /// we have `Self: Trait<u32, i32>` and `Trait<T, U>: OtherTrait<U>` we'll get
 /// `Self: OtherTrait<i32>`.
-pub(super) fn all_super_trait_refs(db: &dyn HirDatabase, trait_ref: TraitRef) -> Vec<TraitRef> {
-    // FIXME: replace by Chalk's `super_traits`, maybe make this a query
+pub(super) fn all_super_trait_refs(db: &dyn HirDatabase, trait_ref: TraitRef) -> SuperTraits {
+    SuperTraits { db, seen: iter::once(trait_ref.trait_id).collect(), stack: vec![trait_ref] }
+}
 
-    // we need to take care a bit here to avoid infinite loops in case of cycles
-    // (i.e. if we have `trait A: B; trait B: A;`)
-    let mut result = vec![trait_ref];
-    let mut i = 0;
-    while i < result.len() {
-        let t = &result[i];
-        // yeah this is quadratic, but trait hierarchies should be flat
-        // enough that this doesn't matter
-        for tt in direct_super_trait_refs(db, t) {
-            if !result.iter().any(|tr| tr.trait_id == tt.trait_id) {
-                result.push(tt);
-            }
+pub(super) struct SuperTraits<'a> {
+    db: &'a dyn HirDatabase,
+    stack: Vec<TraitRef>,
+    seen: FxHashSet<ChalkTraitId>,
+}
+
+impl<'a> SuperTraits<'a> {
+    fn elaborate(&mut self, trait_ref: &TraitRef) {
+        let mut trait_refs = direct_super_trait_refs(self.db, trait_ref);
+        trait_refs.retain(|tr| !self.seen.contains(&tr.trait_id));
+        self.stack.extend(trait_refs);
+    }
+}
+
+impl<'a> Iterator for SuperTraits<'a> {
+    type Item = TraitRef;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if let Some(next) = self.stack.pop() {
+            self.elaborate(&next);
+            Some(next)
+        } else {
+            None
         }
-        i += 1;
     }
-    result
 }
 
 pub(super) fn associated_type_by_name_including_super_traits(
@@ -128,7 +144,7 @@ pub(super) fn associated_type_by_name_including_super_traits(
     trait_ref: TraitRef,
     name: &Name,
 ) -> Option<(TraitRef, TypeAliasId)> {
-    all_super_trait_refs(db, trait_ref).into_iter().find_map(|t| {
+    all_super_trait_refs(db, trait_ref).find_map(|t| {
         let assoc_type = db.trait_data(t.hir_trait_id()).associated_type_by_name(name)?;
         Some((t, assoc_type))
     })