24 files changed, 92 insertions, 84 deletions

diff --git a/crates/hir_def/Cargo.toml b/crates/hir_def/Cargo.toml
index 7ef966cd2..535221294 100644
--- a/crates/hir_def/Cargo.toml
+++ b/crates/hir_def/Cargo.toml
@@ -20,9 +20,9 @@ fst = { version = "0.4", default-features = false }
 itertools = "0.10.0"
 indexmap = "1.4.0"
 smallvec = "1.4.0"
+la-arena = { version = "0.2.0", path = "../../lib/arena" }
 
 stdx = { path = "../stdx", version = "0.0.0" }
-arena = { path = "../arena", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
diff --git a/crates/hir_def/src/adt.rs b/crates/hir_def/src/adt.rs
index 236d6f1b7..06f0b9b18 100644
--- a/crates/hir_def/src/adt.rs
+++ b/crates/hir_def/src/adt.rs
@@ -2,13 +2,13 @@
 
 use std::sync::Arc;
 
-use arena::{map::ArenaMap, Arena};
 use base_db::CrateId;
 use either::Either;
 use hir_expand::{
     name::{AsName, Name},
     InFile,
 };
+use la_arena::{Arena, ArenaMap};
 use syntax::ast::{self, NameOwner, VisibilityOwner};
 use tt::{Delimiter, DelimiterKind, Leaf, Subtree, TokenTree};
 
diff --git a/crates/hir_def/src/attr.rs b/crates/hir_def/src/attr.rs
index 9e6426b31..1b09ff816 100644
--- a/crates/hir_def/src/attr.rs
+++ b/crates/hir_def/src/attr.rs
@@ -2,12 +2,12 @@
 
 use std::{ops, sync::Arc};
 
-use arena::map::ArenaMap;
 use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 use hir_expand::{hygiene::Hygiene, name::AsName, AstId, InFile};
 use itertools::Itertools;
+use la_arena::ArenaMap;
 use mbe::ast_to_token_tree;
 use syntax::{
     ast::{self, AstNode, AttrsOwner},
diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index d07004b9d..344f0b6c0 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -8,7 +8,6 @@ pub mod scope;
 
 use std::{mem, ops::Index, sync::Arc};
 
-use arena::{map::ArenaMap, Arena};
 use base_db::CrateId;
 use cfg::CfgOptions;
 use drop_bomb::DropBomb;
@@ -17,6 +16,7 @@ use hir_expand::{
     ast_id_map::AstIdMap, diagnostics::DiagnosticSink, hygiene::Hygiene, AstId, ExpandResult,
     HirFileId, InFile, MacroDefId,
 };
+use la_arena::{Arena, ArenaMap};
 use rustc_hash::FxHashMap;
 use syntax::{ast, AstNode, AstPtr};
 use test_utils::mark;
diff --git a/crates/hir_def/src/body/lower.rs b/crates/hir_def/src/body/lower.rs
index 6be1eaade..4ce5e5b72 100644
--- a/crates/hir_def/src/body/lower.rs
+++ b/crates/hir_def/src/body/lower.rs
@@ -3,13 +3,13 @@
 
 use std::{any::type_name, sync::Arc};
 
-use arena::Arena;
 use either::Either;
 use hir_expand::{
     hygiene::Hygiene,
     name::{name, AsName, Name},
     ExpandError, HirFileId, MacroDefId, MacroDefKind,
 };
+use la_arena::Arena;
 use rustc_hash::FxHashMap;
 use syntax::{
     ast::{
@@ -386,6 +386,10 @@ impl ExprCollector<'_> {
                 let expr = e.expr().map(|e| self.collect_expr(e));
                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
             }
+            ast::Expr::YieldExpr(e) => {
+                let expr = e.expr().map(|e| self.collect_expr(e));
+                self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
+            }
             ast::Expr::RecordExpr(e) => {
                 let path = e.path().and_then(|path| self.expander.parse_path(path));
                 let mut field_ptrs = Vec::new();
@@ -581,7 +585,7 @@ impl ExprCollector<'_> {
         match res.value {
             Some((mark, expansion)) => {
                 // FIXME: Statements are too complicated to recover from error for now.
-                // It is because we don't have any hygenine for local variable expansion right now.
+                // It is because we don't have any hygiene for local variable expansion right now.
                 if T::can_cast(syntax::SyntaxKind::MACRO_STMTS) && res.err.is_some() {
                     self.expander.exit(self.db, mark);
                     collector(self, None);
@@ -959,7 +963,7 @@ impl ExprCollector<'_> {
 
     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Vec<PatId>, Option<usize>) {
         // Find the location of the `..`, if there is one. Note that we do not
-        // consider the possiblity of there being multiple `..` here.
+        // consider the possibility of there being multiple `..` here.
         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
         // We want to skip the `..` pattern here, since we account for it above.
         let args = args
diff --git a/crates/hir_def/src/body/scope.rs b/crates/hir_def/src/body/scope.rs
index 9142bc05b..49f1427b4 100644
--- a/crates/hir_def/src/body/scope.rs
+++ b/crates/hir_def/src/body/scope.rs
@@ -1,8 +1,8 @@
 //! Name resolution for expressions.
 use std::sync::Arc;
 
-use arena::{Arena, Idx};
 use hir_expand::name::Name;
+use la_arena::{Arena, Idx};
 use rustc_hash::FxHashMap;
 
 use crate::{
@@ -194,7 +194,7 @@ mod tests {
             let mut buf = String::new();
             let off: usize = offset.into();
             buf.push_str(&code[..off]);
-            buf.push_str("<|>marker");
+            buf.push_str("$0marker");
             buf.push_str(&code[off..]);
             buf
         };
@@ -231,7 +231,7 @@ mod tests {
             r"
             fn quux(foo: i32) {
                 let f = |bar, baz: i32| {
-                    <|>
+                    $0
                 };
             }",
             &["bar", "baz", "foo"],
@@ -243,7 +243,7 @@ mod tests {
         do_check(
             r"
             fn quux() {
-                f(|x| <|> );
+                f(|x| $0 );
             }",
             &["x"],
         );
@@ -254,7 +254,7 @@ mod tests {
         do_check(
             r"
             fn quux() {
-                z.f(|x| <|> );
+                z.f(|x| $0 );
             }",
             &["x"],
         );
@@ -267,7 +267,7 @@ mod tests {
             fn quux() {
                 loop {
                     let x = ();
-                    <|>
+                    $0
                 };
             }",
             &["x"],
@@ -281,7 +281,7 @@ mod tests {
             fn quux() {
                 match () {
                     Some(x) => {
-                        <|>
+                        $0
                     }
                 };
             }",
@@ -294,7 +294,7 @@ mod tests {
         do_check(
             r"
             fn foo(x: String) {
-                let x : &str = &x<|>;
+                let x : &str = &x$0;
             }",
             &["x"],
         );
@@ -307,7 +307,7 @@ mod tests {
 fn foo() {
     match Some(()) {
         opt @ Some(unit) => {
-            <|>
+            $0
         }
         _ => {}
     }
@@ -330,7 +330,7 @@ fn foo() {
 
             fn foo() {
                 mac!();
-                <|>
+                $0
             }
         ",
             &[],
@@ -343,7 +343,7 @@ fn foo() {
             r"
             fn foo() {
                 trait {}
-                <|>
+                $0
             }
         ",
             &[],
@@ -391,7 +391,7 @@ fn foo(x: i32, y: u32) {
         let z = x * 2;
     }
     {
-        let t = x<|> * 3;
+        let t = x$0 * 3;
     }
 }
 "#,
@@ -404,7 +404,7 @@ fn foo(x: i32, y: u32) {
         do_check_local_name(
             r#"
 fn foo(x: String) {
-    let x : &str = &x<|>;
+    let x : &str = &x$0;
 }
 "#,
             7,
@@ -417,7 +417,7 @@ fn foo(x: String) {
             r"
 fn foo(x: String) {
     let x : &str = &x;
-    x<|>
+    x$0
 }
 ",
             28,
@@ -430,7 +430,7 @@ fn foo(x: String) {
             r"
 fn foo() {
     if let Some(&from) = bar() {
-        from<|>;
+        from$0;
     }
 }
 ",
@@ -446,7 +446,7 @@ fn foo() {
 fn test() {
     let foo: Option<f32> = None;
     while let Option::Some(spam) = foo {
-        spam<|>
+        spam$0
     }
 }
 "#,
diff --git a/crates/hir_def/src/db.rs b/crates/hir_def/src/db.rs
index d3bf5b34c..6ef9fe790 100644
--- a/crates/hir_def/src/db.rs
+++ b/crates/hir_def/src/db.rs
@@ -1,9 +1,9 @@
 //! Defines database & queries for name resolution.
 use std::sync::Arc;
 
-use arena::map::ArenaMap;
 use base_db::{salsa, CrateId, SourceDatabase, Upcast};
 use hir_expand::{db::AstDatabase, HirFileId};
+use la_arena::ArenaMap;
 use syntax::SmolStr;
 
 use crate::{
diff --git a/crates/hir_def/src/expr.rs b/crates/hir_def/src/expr.rs
index 6a481769d..5be838f4a 100644
--- a/crates/hir_def/src/expr.rs
+++ b/crates/hir_def/src/expr.rs
@@ -1,6 +1,6 @@
 //! This module describes hir-level representation of expressions.
 //!
-//! This representaion is:
+//! This representation is:
 //!
 //! 1. Identity-based. Each expression has an `id`, so we can distinguish
 //!    between different `1` in `1 + 1`.
@@ -12,8 +12,8 @@
 //!
 //! See also a neighboring `body` module.
 
-use arena::{Idx, RawId};
 use hir_expand::name::Name;
+use la_arena::{Idx, RawIdx};
 use syntax::ast::RangeOp;
 
 use crate::{
@@ -24,7 +24,7 @@ use crate::{
 
 pub type ExprId = Idx<Expr>;
 pub(crate) fn dummy_expr_id() -> ExprId {
-    ExprId::from_raw(RawId::from(!0))
+    ExprId::from_raw(RawIdx::from(!0))
 }
 
 pub type PatId = Idx<Pat>;
@@ -99,6 +99,9 @@ pub enum Expr {
     Return {
         expr: Option<ExprId>,
     },
+    Yield {
+        expr: Option<ExprId>,
+    },
     RecordLit {
         path: Option<Path>,
         fields: Vec<RecordLitField>,
@@ -294,7 +297,7 @@ impl Expr {
                 }
             }
             Expr::Continue { .. } => {}
-            Expr::Break { expr, .. } | Expr::Return { expr } => {
+            Expr::Break { expr, .. } | Expr::Return { expr } | Expr::Yield { expr } => {
                 if let Some(expr) = expr {
                     f(*expr);
                 }
diff --git a/crates/hir_def/src/find_path.rs b/crates/hir_def/src/find_path.rs
index 02613c4c4..4a212d291 100644
--- a/crates/hir_def/src/find_path.rs
+++ b/crates/hir_def/src/find_path.rs
@@ -410,7 +410,7 @@ mod tests {
         let code = r#"
             //- /main.rs
             struct S;
-            <|>
+            $0
         "#;
         check_found_path(code, "S", "S", "crate::S", "self::S");
     }
@@ -420,7 +420,7 @@ mod tests {
         let code = r#"
             //- /main.rs
             enum E { A }
-            <|>
+            $0
         "#;
         check_found_path(code, "E::A", "E::A", "E::A", "E::A");
     }
@@ -432,7 +432,7 @@ mod tests {
             mod foo {
                 pub struct S;
             }
-            <|>
+            $0
         "#;
         check_found_path(code, "foo::S", "foo::S", "crate::foo::S", "self::foo::S");
     }
@@ -446,7 +446,7 @@ mod tests {
             mod bar;
             struct S;
             //- /foo/bar.rs
-            <|>
+            $0
         "#;
         check_found_path(code, "super::S", "super::S", "crate::foo::S", "super::S");
     }
@@ -457,7 +457,7 @@ mod tests {
             //- /main.rs
             mod foo;
             //- /foo.rs
-            <|>
+            $0
         "#;
         check_found_path(code, "self", "self", "crate::foo", "self");
     }
@@ -468,7 +468,7 @@ mod tests {
             //- /main.rs
             mod foo;
             //- /foo.rs
-            <|>
+            $0
         "#;
         check_found_path(code, "crate", "crate", "crate", "crate");
     }
@@ -480,7 +480,7 @@ mod tests {
             mod foo;
             struct S;
             //- /foo.rs
-            <|>
+            $0
         "#;
         check_found_path(code, "crate::S", "crate::S", "crate::S", "crate::S");
     }
@@ -489,7 +489,7 @@ mod tests {
     fn different_crate() {
         let code = r#"
             //- /main.rs crate:main deps:std
-            <|>
+            $0
             //- /std.rs crate:std
             pub struct S;
         "#;
@@ -501,7 +501,7 @@ mod tests {
         let code = r#"
             //- /main.rs crate:main deps:std
             extern crate std as std_renamed;
-            <|>
+            $0
             //- /std.rs crate:std
             pub struct S;
         "#;
@@ -523,7 +523,7 @@ mod tests {
             //- /main.rs crate:main deps:syntax
 
             use syntax::ast;
-            <|>
+            $0
 
             //- /lib.rs crate:syntax
             pub mod ast {
@@ -543,7 +543,7 @@ mod tests {
         let code = r#"
             //- /main.rs crate:main deps:syntax
 
-            <|>
+            $0
 
             //- /lib.rs crate:syntax
             pub mod ast {
@@ -569,7 +569,7 @@ mod tests {
                 mod foo { pub(super) struct S; }
                 pub(crate) use foo::*;
             }
-            <|>
+            $0
         "#;
         check_found_path(code, "bar::S", "bar::S", "crate::bar::S", "self::bar::S");
     }
@@ -582,7 +582,7 @@ mod tests {
                 mod foo { pub(super) struct S; }
                 pub(crate) use foo::S as U;
             }
-            <|>
+            $0
         "#;
         check_found_path(code, "bar::U", "bar::U", "crate::bar::U", "self::bar::U");
     }
@@ -591,7 +591,7 @@ mod tests {
     fn different_crate_reexport() {
         let code = r#"
             //- /main.rs crate:main deps:std
-            <|>
+            $0
             //- /std.rs crate:std deps:core
             pub use core::S;
             //- /core.rs crate:core
@@ -604,7 +604,7 @@ mod tests {
     fn prelude() {
         let code = r#"
             //- /main.rs crate:main deps:std
-            <|>
+            $0
             //- /std.rs crate:std
             pub mod prelude { pub struct S; }
             #[prelude_import]
@@ -617,7 +617,7 @@ mod tests {
     fn enum_variant_from_prelude() {
         let code = r#"
             //- /main.rs crate:main deps:std
-            <|>
+            $0
             //- /std.rs crate:std
             pub mod prelude {
                 pub enum Option<T> { Some(T), None }
@@ -637,7 +637,7 @@ mod tests {
             pub mod foo;
             pub mod baz;
             struct S;
-            <|>
+            $0
             //- /foo.rs
             pub mod bar { pub struct S; }
             //- /baz.rs
@@ -654,7 +654,7 @@ mod tests {
             pub mod bar { pub struct S; }
             use bar::S;
             //- /foo.rs
-            <|>
+            $0
         "#;
         // crate::S would be shorter, but using private imports seems wrong
         check_found_path(code, "crate::bar::S", "crate::bar::S", "crate::bar::S", "crate::bar::S");
@@ -668,7 +668,7 @@ mod tests {
             pub mod bar;
             pub mod baz;
             //- /bar.rs
-            <|>
+            $0
             //- /foo.rs
             pub use super::baz;
             pub struct S;
@@ -683,7 +683,7 @@ mod tests {
         mark::check!(prefer_std_paths);
         let code = r#"
         //- /main.rs crate:main deps:alloc,std
-        <|>
+        $0
 
         //- /std.rs crate:std deps:alloc
         pub mod sync {
@@ -711,7 +711,7 @@ mod tests {
         //- /main.rs crate:main deps:core,std
         #![no_std]
 
-        <|>
+        $0
 
         //- /std.rs crate:std deps:core
 
@@ -740,7 +740,7 @@ mod tests {
         //- /main.rs crate:main deps:alloc,std
         #![no_std]
 
-        <|>
+        $0
 
         //- /std.rs crate:std deps:alloc
 
@@ -767,7 +767,7 @@ mod tests {
     fn prefer_shorter_paths_if_not_alloc() {
         let code = r#"
         //- /main.rs crate:main deps:megaalloc,std
-        <|>
+        $0
 
         //- /std.rs crate:std deps:megaalloc
         pub mod sync {
@@ -790,7 +790,7 @@ mod tests {
     fn builtins_are_in_scope() {
         let code = r#"
         //- /main.rs
-        <|>
+        $0
 
         pub mod primitive {
             pub use u8;
diff --git a/crates/hir_def/src/generics.rs b/crates/hir_def/src/generics.rs
index 9b5b886c2..3ace3be1f 100644
--- a/crates/hir_def/src/generics.rs
+++ b/crates/hir_def/src/generics.rs
@@ -4,13 +4,13 @@
 //! in rustc.
 use std::sync::Arc;
 
-use arena::{map::ArenaMap, Arena};
 use base_db::FileId;
 use either::Either;
 use hir_expand::{
     name::{name, AsName, Name},
     InFile,
 };
+use la_arena::{Arena, ArenaMap};
 use syntax::ast::{self, GenericParamsOwner, NameOwner, TypeBoundsOwner};
 
 use crate::{
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index b6f510731..ff62928df 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -11,7 +11,6 @@ use std::{
     sync::Arc,
 };
 
-use arena::{Arena, Idx, RawId};
 use ast::{AstNode, NameOwner, StructKind};
 use base_db::CrateId;
 use either::Either;
@@ -21,6 +20,7 @@ use hir_expand::{
     name::{name, AsName, Name},
     HirFileId, InFile,
 };
+use la_arena::{Arena, Idx, RawIdx};
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
 use syntax::{ast, match_ast};
@@ -145,7 +145,6 @@ impl ItemTree {
                 macro_calls,
                 macro_rules,
                 macro_defs,
-                exprs,
                 vis,
                 generics,
             } = &mut **data;
@@ -167,7 +166,6 @@ impl ItemTree {
             macro_calls.shrink_to_fit();
             macro_rules.shrink_to_fit();
             macro_defs.shrink_to_fit();
-            exprs.shrink_to_fit();
 
             vis.arena.shrink_to_fit();
             generics.arena.shrink_to_fit();
@@ -296,7 +294,6 @@ struct ItemTreeData {
     macro_calls: Arena<MacroCall>,
     macro_rules: Arena<MacroRules>,
     macro_defs: Arena<MacroDef>,
-    exprs: Arena<Expr>,
 
     vis: ItemVisibilities,
     generics: GenericParamsStorage,
@@ -461,7 +458,7 @@ macro_rules! impl_index {
     };
 }
 
-impl_index!(fields: Field, variants: Variant, exprs: Expr);
+impl_index!(fields: Field, variants: Variant);
 
 impl Index<RawVisibilityId> for ItemTree {
     type Output = RawVisibility;
@@ -664,11 +661,6 @@ pub struct MacroDef {
     pub ast_id: FileAstId<ast::MacroDef>,
 }
 
-// NB: There's no `FileAstId` for `Expr`. The only case where this would be useful is for array
-// lengths, but we don't do much with them yet.
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct Expr;
-
 macro_rules! impl_froms {
     ($e:ident { $($v:ident ($t:ty)),* $(,)? }) => {
         $(
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 3b206ef85..5e71ca42c 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -683,12 +683,12 @@ impl Ctx {
     }
 
     fn next_field_idx(&self) -> Idx<Field> {
-        Idx::from_raw(RawId::from(
+        Idx::from_raw(RawIdx::from(
             self.tree.data.as_ref().map_or(0, |data| data.fields.len() as u32),
         ))
     }
     fn next_variant_idx(&self) -> Idx<Variant> {
-        Idx::from_raw(RawId::from(
+        Idx::from_raw(RawIdx::from(
             self.tree.data.as_ref().map_or(0, |data| data.variants.len() as u32),
         ))
     }
diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index 211cb2faf..08ed920c6 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -52,12 +52,12 @@ mod test_db;
 
 use std::hash::{Hash, Hasher};
 
-use arena::Idx;
 use base_db::{impl_intern_key, salsa, CrateId};
 use hir_expand::{
     ast_id_map::FileAstId, eager::expand_eager_macro, hygiene::Hygiene, AstId, HirFileId, InFile,
     MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
 };
+use la_arena::Idx;
 use syntax::ast;
 
 use crate::builtin_type::BuiltinType;
diff --git a/crates/hir_def/src/nameres.rs b/crates/hir_def/src/nameres.rs
index 5682e122d..50acc3f54 100644
--- a/crates/hir_def/src/nameres.rs
+++ b/crates/hir_def/src/nameres.rs
@@ -56,9 +56,9 @@ mod tests;
 
 use std::sync::Arc;
 
-use arena::Arena;
 use base_db::{CrateId, Edition, FileId};
 use hir_expand::{diagnostics::DiagnosticSink, name::Name, InFile};
+use la_arena::Arena;
 use rustc_hash::FxHashMap;
 use stdx::format_to;
 use syntax::ast;
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 77017e4ea..0cd61698c 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -267,7 +267,7 @@ impl DefCollector<'_> {
 
         // Resolve all indeterminate resolved imports again
         // As some of the macros will expand newly import shadowing partial resolved imports
-        // FIXME: We maybe could skip this, if we handle the Indetermine imports in `resolve_imports`
+        // FIXME: We maybe could skip this, if we handle the indeterminate imports in `resolve_imports`
         // correctly
         let partial_resolved = self.resolved_imports.iter().filter_map(|directive| {
             if let PartialResolvedImport::Indeterminate(_) = directive.status {
@@ -402,7 +402,7 @@ impl DefCollector<'_> {
 
     /// Define a proc macro
     ///
-    /// A proc macro is similar to normal macro scope, but it would not visiable in legacy textual scoped.
+    /// A proc macro is similar to normal macro scope, but it would not visible in legacy textual scoped.
     /// And unconditionally exported.
     fn define_proc_macro(&mut self, name: Name, macro_: MacroDefId) {
         self.update(
@@ -592,7 +592,7 @@ impl DefCollector<'_> {
                     // XXX: urgh, so this works by accident! Here, we look at
                     // the enum data, and, in theory, this might require us to
                     // look back at the crate_def_map, creating a cycle. For
-                    // example, `enum E { crate::some_macro!(); }`. Luckely, the
+                    // example, `enum E { crate::some_macro!(); }`. Luckily, the
                     // only kind of macro that is allowed inside enum is a
                     // `cfg_macro`, and we don't need to run name resolution for
                     // it, but this is sheer luck!
@@ -655,7 +655,7 @@ impl DefCollector<'_> {
         &mut self,
         module_id: LocalModuleId,
         resolutions: &[(Option<Name>, PerNs)],
-        // All resolutions are imported with this visibility; the visibilies in
+        // All resolutions are imported with this visibility; the visibilities in
         // the `PerNs` values are ignored and overwritten
         vis: Visibility,
         import_type: ImportType,
@@ -1469,8 +1469,8 @@ impl ModCollector<'_, '_> {
 #[cfg(test)]
 mod tests {
     use crate::{db::DefDatabase, test_db::TestDB};
-    use arena::Arena;
     use base_db::{fixture::WithFixture, SourceDatabase};
+    use la_arena::Arena;
 
     use super::*;
 
diff --git a/crates/hir_def/src/nameres/tests/incremental.rs b/crates/hir_def/src/nameres/tests/incremental.rs
index 8981fa7c9..509e1bbbc 100644
--- a/crates/hir_def/src/nameres/tests/incremental.rs
+++ b/crates/hir_def/src/nameres/tests/incremental.rs
@@ -28,7 +28,7 @@ fn typing_inside_a_function_should_not_invalidate_def_map() {
     check_def_map_is_not_recomputed(
         r"
         //- /lib.rs
-        mod foo;<|>
+        mod foo;$0
 
         use crate::foo::bar::Baz;
 
@@ -81,7 +81,7 @@ fn typing_inside_a_macro_should_not_invalidate_def_map() {
         pub mod bar;
 
         //- /foo/bar.rs
-        <|>
+        $0
         m!(X);
         ",
     );
diff --git a/crates/hir_def/src/path.rs b/crates/hir_def/src/path.rs
index a99f73882..e34cd7f2f 100644
--- a/crates/hir_def/src/path.rs
+++ b/crates/hir_def/src/path.rs
@@ -305,6 +305,7 @@ pub use hir_expand::name as __name;
 macro_rules! __known_path {
     (core::iter::IntoIterator) => {};
     (core::result::Result) => {};
+    (core::option::Option) => {};
     (core::ops::Range) => {};
     (core::ops::RangeFrom) => {};
     (core::ops::RangeFull) => {};
diff --git a/crates/hir_def/src/path/lower.rs b/crates/hir_def/src/path/lower.rs
index 8a01e6eea..9518ac109 100644
--- a/crates/hir_def/src/path/lower.rs
+++ b/crates/hir_def/src/path/lower.rs
@@ -123,7 +123,7 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
     // We follow what it did anyway :)
     if segments.len() == 1 && kind == PathKind::Plain {
         if let Some(_macro_call) = path.syntax().parent().and_then(ast::MacroCall::cast) {
-            if let Some(crate_id) = hygiene.local_inner_macros() {
+            if let Some(crate_id) = hygiene.local_inner_macros(path) {
                 kind = PathKind::DollarCrate(crate_id);
             }
         }
diff --git a/crates/hir_def/src/per_ns.rs b/crates/hir_def/src/per_ns.rs
index 74665c588..a594afce6 100644
--- a/crates/hir_def/src/per_ns.rs
+++ b/crates/hir_def/src/per_ns.rs
@@ -7,7 +7,7 @@ use hir_expand::MacroDefId;
 
 use crate::{item_scope::ItemInNs, visibility::Visibility, ModuleDefId};
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct PerNs {
     pub types: Option<(ModuleDefId, Visibility)>,
     pub values: Option<(ModuleDefId, Visibility)>,
diff --git a/crates/hir_def/src/resolver.rs b/crates/hir_def/src/resolver.rs
index 129f1dbac..85ddc2c47 100644
--- a/crates/hir_def/src/resolver.rs
+++ b/crates/hir_def/src/resolver.rs
@@ -27,7 +27,7 @@ use crate::{
 
 #[derive(Debug, Clone, Default)]
 pub struct Resolver {
-    // FIXME: all usages generally call `.rev`, so maybe reverse once in consturciton?
+    // FIXME: all usages generally call `.rev`, so maybe reverse once in construction?
     scopes: Vec<Scope>,
 }
 
@@ -258,7 +258,7 @@ impl Resolver {
     ) -> Option<ResolveValueResult> {
         let n_segments = path.segments.len();
         let tmp = name![self];
-        let first_name = if path.is_self() { &tmp } else { &path.segments.first()? };
+        let first_name = if path.is_self() { &tmp } else { path.segments.first()? };
         let skip_to_mod = path.kind != PathKind::Plain && !path.is_self();
         for scope in self.scopes.iter().rev() {
             match scope {
@@ -490,6 +490,7 @@ pub enum ScopeDef {
 
 impl Scope {
     fn process_names(&self, db: &dyn DefDatabase, f: &mut dyn FnMut(Name, ScopeDef)) {
+        let mut seen = FxHashSet::default();
         match self {
             Scope::ModuleScope(m) => {
                 // FIXME: should we provide `self` here?
@@ -503,7 +504,9 @@ impl Scope {
                     f(name.clone(), ScopeDef::PerNs(def));
                 });
                 m.crate_def_map[m.module_id].scope.legacy_macros().for_each(|(name, macro_)| {
-                    f(name.clone(), ScopeDef::PerNs(PerNs::macros(macro_, Visibility::Public)));
+                    let scope = PerNs::macros(macro_, Visibility::Public);
+                    seen.insert((name.clone(), scope));
+                    f(name.clone(), ScopeDef::PerNs(scope));
                 });
                 m.crate_def_map.extern_prelude.iter().for_each(|(name, &def)| {
                     f(name.clone(), ScopeDef::PerNs(PerNs::types(def, Visibility::Public)));
@@ -514,7 +517,10 @@ impl Scope {
                 if let Some(prelude) = m.crate_def_map.prelude {
                     let prelude_def_map = db.crate_def_map(prelude.krate);
                     prelude_def_map[prelude.local_id].scope.entries().for_each(|(name, def)| {
-                        f(name.clone(), ScopeDef::PerNs(def));
+                        let seen_tuple = (name.clone(), def);
+                        if !seen.contains(&seen_tuple) {
+                            f(seen_tuple.0, ScopeDef::PerNs(def));
+                        }
                     });
                 }
             }
diff --git a/crates/hir_def/src/src.rs b/crates/hir_def/src/src.rs
index f67244b46..751d4c052 100644
--- a/crates/hir_def/src/src.rs
+++ b/crates/hir_def/src/src.rs
@@ -1,7 +1,7 @@
 //! Utilities for mapping between hir IDs and the surface syntax.
 
-use arena::map::ArenaMap;
 use hir_expand::InFile;
+use la_arena::ArenaMap;
 
 use crate::{db::DefDatabase, item_tree::ItemTreeNode, AssocItemLoc, ItemLoc};
 
diff --git a/crates/hir_def/src/trace.rs b/crates/hir_def/src/trace.rs
index fd64e7018..6e6ceb8e4 100644
--- a/crates/hir_def/src/trace.rs
+++ b/crates/hir_def/src/trace.rs
@@ -9,7 +9,7 @@
 //! absolute offsets. The `Trace` structure (inspired, at least in name, by
 //! Kotlin's `BindingTrace`) allows use the same code to compute both
 //! projections.
-use arena::{map::ArenaMap, Arena, Idx, RawId};
+use la_arena::{Arena, ArenaMap, Idx, RawIdx};
 
 pub(crate) struct Trace<T, V> {
     arena: Option<Arena<T>>,
@@ -30,7 +30,7 @@ impl<T, V> Trace<T, V> {
         let id = if let Some(arena) = &mut self.arena {
             arena.alloc(data())
         } else {
-            let id = Idx::<T>::from_raw(RawId::from(self.len));
+            let id = Idx::<T>::from_raw(RawIdx::from(self.len));
             self.len += 1;
             id
         };
diff --git a/crates/hir_def/src/type_ref.rs b/crates/hir_def/src/type_ref.rs
index ae93d0d10..049b2e462 100644
--- a/crates/hir_def/src/type_ref.rs
+++ b/crates/hir_def/src/type_ref.rs
@@ -159,6 +159,8 @@ impl TypeRef {
             ast::Type::DynTraitType(inner) => {
                 TypeRef::DynTrait(type_bounds_from_ast(ctx, inner.type_bound_list()))
             }
+            // FIXME: Macros in type position are not yet supported.
+            ast::Type::MacroType(_) => TypeRef::Error,
         }
     }
 
diff --git a/crates/hir_def/src/visibility.rs b/crates/hir_def/src/visibility.rs
index e6e0853a3..f3bc9d680 100644
--- a/crates/hir_def/src/visibility.rs
+++ b/crates/hir_def/src/visibility.rs
@@ -85,7 +85,7 @@ impl RawVisibility {
 }
 
 /// Visibility of an item, with the path resolved.
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum Visibility {
     /// Visibility is restricted to a certain module.
     Module(ModuleId),