Rollup merge of #101497 - lnicola:rust-analyzer-2022-09-06, r=lnicola

⬆️ rust-analyzer

r? `@ghost`

.github/workflows/ci.yaml

@@ -14,7 +14,7 @@ env:
   CARGO_NET_RETRY: 10
   CI: 1
   RUST_BACKTRACE: short
-  RUSTFLAGS: "-D warnings -W unreachable-pub -W rust-2021-compatibility"
+  RUSTFLAGS: "-D warnings -W unreachable-pub -W bare-trait-objects"
   RUSTUP_MAX_RETRIES: 10
 
 jobs:
@@ -110,9 +110,9 @@ jobs:
       - run: npm ci
         working-directory: ./editors/code
 
-#    - run: npm audit || { sleep 10 && npm audit; } || { sleep 30 && npm audit; }
+      #    - run: npm audit || { sleep 10 && npm audit; } || { sleep 30 && npm audit; }
-#      if: runner.os == 'Linux'
+      #      if: runner.os == 'Linux'
-#      working-directory: ./editors/code
+      #      working-directory: ./editors/code
 
       - run: npm run lint
         working-directory: ./editors/code

.github/workflows/release.yaml

@@ -248,7 +248,7 @@ jobs:
         if: github.ref == 'refs/heads/release' && (github.repository == 'rust-analyzer/rust-analyzer' || github.repository == 'rust-lang/rust-analyzer')
         working-directory: ./editors/code
         # token from https://dev.azure.com/rust-analyzer/
-        run: npx ovsx publish --pat ${{ secrets.OPENVSX_TOKEN }} --packagePath ../../dist/rust-analyzer-*.vsix
+        run: npx ovsx publish --pat ${{ secrets.OPENVSX_TOKEN }} --packagePath ../../dist/rust-analyzer-*.vsix || true
 
       - name: Publish Extension (Code Marketplace, nightly)
         if: github.ref != 'refs/heads/release' && (github.repository == 'rust-analyzer/rust-analyzer' || github.repository == 'rust-lang/rust-analyzer')
@@ -258,4 +258,4 @@ jobs:
       - name: Publish Extension (OpenVSX, nightly)
         if: github.ref != 'refs/heads/release' && (github.repository == 'rust-analyzer/rust-analyzer' || github.repository == 'rust-lang/rust-analyzer')
         working-directory: ./editors/code
-        run: npx ovsx publish --pat ${{ secrets.OPENVSX_TOKEN }} --packagePath ../../dist/rust-analyzer-*.vsix
+        run: npx ovsx publish --pat ${{ secrets.OPENVSX_TOKEN }} --packagePath ../../dist/rust-analyzer-*.vsix || true

crates/hir-def/src/body.rs

@@ -250,6 +250,10 @@ pub type PatSource = InFile<PatPtr>;
 
 pub type LabelPtr = AstPtr<ast::Label>;
 pub type LabelSource = InFile<LabelPtr>;
+
+pub type FieldPtr = AstPtr<ast::RecordExprField>;
+pub type FieldSource = InFile<FieldPtr>;
+
 /// An item body together with the mapping from syntax nodes to HIR expression
 /// IDs. This is needed to go from e.g. a position in a file to the HIR
 /// expression containing it; but for type inference etc., we want to operate on
@@ -264,18 +268,18 @@ pub type LabelSource = InFile<LabelPtr>;
 #[derive(Default, Debug, Eq, PartialEq)]
 pub struct BodySourceMap {
     expr_map: FxHashMap<ExprSource, ExprId>,
-    expr_map_back: ArenaMap<ExprId, Result<ExprSource, SyntheticSyntax>>,
+    expr_map_back: ArenaMap<ExprId, ExprSource>,
 
     pat_map: FxHashMap<PatSource, PatId>,
-    pat_map_back: ArenaMap<PatId, Result<PatSource, SyntheticSyntax>>,
+    pat_map_back: ArenaMap<PatId, PatSource>,
 
     label_map: FxHashMap<LabelSource, LabelId>,
     label_map_back: ArenaMap<LabelId, LabelSource>,
 
     /// We don't create explicit nodes for record fields (`S { record_field: 92 }`).
     /// Instead, we use id of expression (`92`) to identify the field.
-    field_map: FxHashMap<InFile<AstPtr<ast::RecordExprField>>, ExprId>,
+    field_map: FxHashMap<FieldSource, ExprId>,
-    field_map_back: FxHashMap<ExprId, InFile<AstPtr<ast::RecordExprField>>>,
+    field_map_back: FxHashMap<ExprId, FieldSource>,
 
     expansions: FxHashMap<InFile<AstPtr<ast::MacroCall>>, HirFileId>,
 
@@ -420,7 +424,7 @@ impl Index<LabelId> for Body {
 // Perhaps `expr_syntax` and `expr_id`?
 impl BodySourceMap {
     pub fn expr_syntax(&self, expr: ExprId) -> Result<ExprSource, SyntheticSyntax> {
-        self.expr_map_back[expr].clone()
+        self.expr_map_back.get(expr).cloned().ok_or(SyntheticSyntax)
     }
 
     pub fn node_expr(&self, node: InFile<&ast::Expr>) -> Option<ExprId> {
@@ -434,7 +438,7 @@ impl BodySourceMap {
     }
 
     pub fn pat_syntax(&self, pat: PatId) -> Result<PatSource, SyntheticSyntax> {
-        self.pat_map_back[pat].clone()
+        self.pat_map_back.get(pat).cloned().ok_or(SyntheticSyntax)
     }
 
     pub fn node_pat(&self, node: InFile<&ast::Pat>) -> Option<PatId> {
@@ -456,9 +460,10 @@ impl BodySourceMap {
         self.label_map.get(&src).cloned()
     }
 
-    pub fn field_syntax(&self, expr: ExprId) -> InFile<AstPtr<ast::RecordExprField>> {
+    pub fn field_syntax(&self, expr: ExprId) -> FieldSource {
         self.field_map_back[&expr].clone()
     }
+
     pub fn node_field(&self, node: InFile<&ast::RecordExprField>) -> Option<ExprId> {
         let src = node.map(AstPtr::new);
         self.field_map.get(&src).cloned()

crates/hir-def/src/body/lower.rs

@@ -24,7 +24,7 @@ use syntax::{
 
 use crate::{
     adt::StructKind,
-    body::{Body, BodySourceMap, Expander, LabelSource, PatPtr, SyntheticSyntax},
+    body::{Body, BodySourceMap, Expander, ExprPtr, LabelPtr, LabelSource, PatPtr},
     body::{BodyDiagnostic, ExprSource, PatSource},
     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
     db::DefDatabase,
@@ -150,21 +150,21 @@ impl ExprCollector<'_> {
         LowerCtx::new(self.db, self.expander.current_file_id)
     }
 
-    fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
+    fn alloc_expr(&mut self, expr: Expr, ptr: ExprPtr) -> ExprId {
         let src = self.expander.to_source(ptr);
-        let id = self.make_expr(expr, Ok(src.clone()));
+        let id = self.make_expr(expr, src.clone());
         self.source_map.expr_map.insert(src, id);
         id
     }
     // desugared exprs don't have ptr, that's wrong and should be fixed
     // somehow.
     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
-        self.make_expr(expr, Err(SyntheticSyntax))
+        self.body.exprs.alloc(expr)
     }
     fn missing_expr(&mut self) -> ExprId {
         self.alloc_expr_desugared(Expr::Missing)
     }
-    fn make_expr(&mut self, expr: Expr, src: Result<ExprSource, SyntheticSyntax>) -> ExprId {
+    fn make_expr(&mut self, expr: Expr, src: ExprSource) -> ExprId {
         let id = self.body.exprs.alloc(expr);
         self.source_map.expr_map_back.insert(id, src);
         id
@@ -172,20 +172,20 @@ impl ExprCollector<'_> {
 
     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
         let src = self.expander.to_source(ptr);
-        let id = self.make_pat(pat, Ok(src.clone()));
+        let id = self.make_pat(pat, src.clone());
         self.source_map.pat_map.insert(src, id);
         id
     }
     fn missing_pat(&mut self) -> PatId {
-        self.make_pat(Pat::Missing, Err(SyntheticSyntax))
+        self.body.pats.alloc(Pat::Missing)
     }
-    fn make_pat(&mut self, pat: Pat, src: Result<PatSource, SyntheticSyntax>) -> PatId {
+    fn make_pat(&mut self, pat: Pat, src: PatSource) -> PatId {
         let id = self.body.pats.alloc(pat);
         self.source_map.pat_map_back.insert(id, src);
         id
     }
 
-    fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
+    fn alloc_label(&mut self, label: Label, ptr: LabelPtr) -> LabelId {
         let src = self.expander.to_source(ptr);
         let id = self.make_label(label, src.clone());
         self.source_map.label_map.insert(src, id);
@@ -550,20 +550,6 @@ impl ExprCollector<'_> {
                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
                 }
             }
-            ast::Expr::MacroStmts(e) => {
-                let statements: Box<[_]> =
-                    e.statements().filter_map(|s| self.collect_stmt(s)).collect();
-                let tail = e.expr().map(|e| self.collect_expr(e));
-
-                if e.syntax().children().next().is_none() {
-                    // HACK: make sure that macros that expand to nothing aren't treated as a `()`
-                    // expression when used in block tail position.
-                    cov_mark::hit!(empty_macro_in_trailing_position_is_removed);
-                    return None;
-                }
-
-                self.alloc_expr(Expr::MacroStmts { tail, statements }, syntax_ptr)
-            }
             ast::Expr::UnderscoreExpr(_) => self.alloc_expr(Expr::Underscore, syntax_ptr),
         })
     }
@@ -640,11 +626,46 @@ impl ExprCollector<'_> {
         }
     }
 
-    fn collect_stmt(&mut self, s: ast::Stmt) -> Option<Statement> {
+    fn collect_macro_as_stmt(
+        &mut self,
+        statements: &mut Vec<Statement>,
+        mac: ast::MacroExpr,
+    ) -> Option<ExprId> {
+        let mac_call = mac.macro_call()?;
+        let syntax_ptr = AstPtr::new(&ast::Expr::from(mac));
+        let macro_ptr = AstPtr::new(&mac_call);
+        let expansion = self.collect_macro_call(
+            mac_call,
+            macro_ptr,
+            false,
+            |this, expansion: Option<ast::MacroStmts>| match expansion {
+                Some(expansion) => {
+                    expansion.statements().for_each(|stmt| this.collect_stmt(statements, stmt));
+                    expansion.expr().and_then(|expr| match expr {
+                        ast::Expr::MacroExpr(mac) => this.collect_macro_as_stmt(statements, mac),
+                        expr => Some(this.collect_expr(expr)),
+                    })
+                }
+                None => None,
+            },
+        );
+        match expansion {
+            Some(tail) => {
+                // Make the macro-call point to its expanded expression so we can query
+                // semantics on syntax pointers to the macro
+                let src = self.expander.to_source(syntax_ptr);
+                self.source_map.expr_map.insert(src, tail);
+                Some(tail)
+            }
+            None => None,
+        }
+    }
+
+    fn collect_stmt(&mut self, statements: &mut Vec<Statement>, s: ast::Stmt) {
         match s {
             ast::Stmt::LetStmt(stmt) => {
                 if self.check_cfg(&stmt).is_none() {
-                    return None;
+                    return;
                 }
                 let pat = self.collect_pat_opt(stmt.pat());
                 let type_ref =
@@ -654,61 +675,26 @@ impl ExprCollector<'_> {
                     .let_else()
                     .and_then(|let_else| let_else.block_expr())
                     .map(|block| self.collect_block(block));
-                Some(Statement::Let { pat, type_ref, initializer, else_branch })
+                statements.push(Statement::Let { pat, type_ref, initializer, else_branch });
             }
             ast::Stmt::ExprStmt(stmt) => {
                 let expr = stmt.expr();
-                if let Some(expr) = &expr {
+                match &expr {
-                    if self.check_cfg(expr).is_none() {
+                    Some(expr) if self.check_cfg(expr).is_none() => return,
-                        return None;
+                    _ => (),
-                    }
                 }
                 let has_semi = stmt.semicolon_token().is_some();
                 // Note that macro could be expanded to multiple statements
-                if let Some(expr @ ast::Expr::MacroExpr(mac)) = &expr {
+                if let Some(ast::Expr::MacroExpr(mac)) = expr {
-                    let mac_call = mac.macro_call()?;
+                    if let Some(expr) = self.collect_macro_as_stmt(statements, mac) {
-                    let syntax_ptr = AstPtr::new(expr);
+                        statements.push(Statement::Expr { expr, has_semi })
-                    let macro_ptr = AstPtr::new(&mac_call);
-                    let stmt = self.collect_macro_call(
-                        mac_call,
-                        macro_ptr,
-                        false,
-                        |this, expansion: Option<ast::MacroStmts>| match expansion {
-                            Some(expansion) => {
-                                let statements = expansion
-                                    .statements()
-                                    .filter_map(|stmt| this.collect_stmt(stmt))
-                                    .collect();
-                                let tail = expansion.expr().map(|expr| this.collect_expr(expr));
-
-                                let mac_stmts = this.alloc_expr(
-                                    Expr::MacroStmts { tail, statements },
-                                    AstPtr::new(&ast::Expr::MacroStmts(expansion)),
-                                );
-
-                                Some(mac_stmts)
                     }
-                            None => None,
-                        },
-                    );
-
-                    let expr = match stmt {
-                        Some(expr) => {
-                            // Make the macro-call point to its expanded expression so we can query
-                            // semantics on syntax pointers to the macro
-                            let src = self.expander.to_source(syntax_ptr);
-                            self.source_map.expr_map.insert(src, expr);
-                            expr
-                        }
-                        None => self.alloc_expr(Expr::Missing, syntax_ptr),
-                    };
-                    Some(Statement::Expr { expr, has_semi })
                 } else {
                     let expr = self.collect_expr_opt(expr);
-                    Some(Statement::Expr { expr, has_semi })
+                    statements.push(Statement::Expr { expr, has_semi });
                 }
             }
-            ast::Stmt::Item(_item) => None,
+            ast::Stmt::Item(_item) => (),
         }
     }
 
@@ -729,9 +715,12 @@ impl ExprCollector<'_> {
         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
         let prev_local_module = mem::replace(&mut self.expander.module, module);
 
-        let mut statements: Vec<_> =
+        let mut statements = Vec::new();
-            block.statements().filter_map(|s| self.collect_stmt(s)).collect();
+        block.statements().for_each(|s| self.collect_stmt(&mut statements, s));
-        let tail = block.tail_expr().and_then(|e| self.maybe_collect_expr(e));
+        let tail = block.tail_expr().and_then(|e| match e {
+            ast::Expr::MacroExpr(mac) => self.collect_macro_as_stmt(&mut statements, mac),
+            expr => self.maybe_collect_expr(expr),
+        });
         let tail = tail.or_else(|| {
             let stmt = statements.pop()?;
             if let Statement::Expr { expr, has_semi: false } = stmt {

crates/hir-def/src/body/pretty.rs

@@ -422,19 +422,6 @@ impl<'a> Printer<'a> {
                 }
                 w!(self, "}}");
             }
-            Expr::MacroStmts { statements, tail } => {
-                w!(self, "{{ // macro statements");
-                self.indented(|p| {
-                    for stmt in statements.iter() {
-                        p.print_stmt(stmt);
-                    }
-                    if let Some(tail) = tail {
-                        p.print_expr(*tail);
-                    }
-                });
-                self.newline();
-                w!(self, "}}");
-            }
         }
     }
 

crates/hir-def/src/body/scope.rs

@@ -47,16 +47,9 @@ pub struct ScopeData {
 impl ExprScopes {
     pub(crate) fn expr_scopes_query(db: &dyn DefDatabase, def: DefWithBodyId) -> Arc<ExprScopes> {
         let body = db.body(def);
-        Arc::new(ExprScopes::new(&*body))
+        let mut scopes = ExprScopes::new(&*body);
-    }
+        scopes.shrink_to_fit();
-
+        Arc::new(scopes)
-    fn new(body: &Body) -> ExprScopes {
-        let mut scopes =
-            ExprScopes { scopes: Arena::default(), scope_by_expr: FxHashMap::default() };
-        let mut root = scopes.root_scope();
-        scopes.add_params_bindings(body, root, &body.params);
-        compute_expr_scopes(body.body_expr, body, &mut scopes, &mut root);
-        scopes
     }
 
     pub fn entries(&self, scope: ScopeId) -> &[ScopeEntry] {
@@ -89,6 +82,17 @@ impl ExprScopes {
     pub fn scope_by_expr(&self) -> &FxHashMap<ExprId, ScopeId> {
         &self.scope_by_expr
     }
+}
+
+impl ExprScopes {
+    fn new(body: &Body) -> ExprScopes {
+        let mut scopes =
+            ExprScopes { scopes: Arena::default(), scope_by_expr: FxHashMap::default() };
+        let mut root = scopes.root_scope();
+        scopes.add_params_bindings(body, root, &body.params);
+        compute_expr_scopes(body.body_expr, body, &mut scopes, &mut root);
+        scopes
+    }
 
     fn root_scope(&mut self) -> ScopeId {
         self.scopes.alloc(ScopeData { parent: None, block: None, label: None, entries: vec![] })
@@ -138,6 +142,13 @@ impl ExprScopes {
     fn set_scope(&mut self, node: ExprId, scope: ScopeId) {
         self.scope_by_expr.insert(node, scope);
     }
+
+    fn shrink_to_fit(&mut self) {
+        let ExprScopes { scopes, scope_by_expr } = self;
+        scopes.shrink_to_fit();
+        scopes.values_mut().for_each(|it| it.entries.shrink_to_fit());
+        scope_by_expr.shrink_to_fit();
+    }
 }
 
 fn compute_block_scopes(
@@ -176,9 +187,6 @@ fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope
 
     scopes.set_scope(expr, *scope);
     match &body[expr] {
-        Expr::MacroStmts { statements, tail } => {
-            compute_block_scopes(statements, *tail, body, scopes, scope);
-        }
         Expr::Block { statements, tail, id, label } => {
             let mut scope = scopes.new_block_scope(*scope, *id, make_label(label));
             // Overwrite the old scope for the block expr, so that every block scope can be found

crates/hir-def/src/expr.rs

@@ -206,10 +206,6 @@ pub enum Expr {
     Unsafe {
         body: ExprId,
     },
-    MacroStmts {
-        statements: Box<[Statement]>,
-        tail: Option<ExprId>,
-    },
     Array(Array),
     Literal(Literal),
     Underscore,
@@ -263,7 +259,7 @@ impl Expr {
             Expr::Let { expr, .. } => {
                 f(*expr);
             }
-            Expr::MacroStmts { tail, statements } | Expr::Block { statements, tail, .. } => {
+            Expr::Block { statements, tail, .. } => {
                 for stmt in statements.iter() {
                     match stmt {
                         Statement::Let { initializer, .. } => {

crates/hir-def/src/nameres.rs

@@ -64,7 +64,7 @@ use hir_expand::{name::Name, InFile, MacroCallId, MacroDefId};
 use itertools::Itertools;
 use la_arena::Arena;
 use profile::Count;
-use rustc_hash::FxHashMap;
+use rustc_hash::{FxHashMap, FxHashSet};
 use stdx::format_to;
 use syntax::{ast, SmolStr};
 
@@ -98,7 +98,11 @@ pub struct DefMap {
     /// The prelude module for this crate. This either comes from an import
     /// marked with the `prelude_import` attribute, or (in the normal case) from
     /// a dependency (`std` or `core`).
+    /// The prelude is empty for non-block DefMaps (unless `#[prelude_import]` was used,
+    /// but that attribute is nightly and when used in a block, it affects resolution globally
+    /// so we aren't handling this correctly anyways).
     prelude: Option<ModuleId>,
+    /// The extern prelude is only populated for non-block DefMaps
     extern_prelude: FxHashMap<Name, ModuleId>,
 
     /// Side table for resolving derive helpers.
@@ -114,6 +118,8 @@ pub struct DefMap {
     registered_attrs: Vec<SmolStr>,
     /// Custom tool modules registered with `#![register_tool]`.
     registered_tools: Vec<SmolStr>,
+    /// Unstable features of Rust enabled with `#![feature(A, B)]`.
+    unstable_features: FxHashSet<SmolStr>,
 
     edition: Edition,
     recursion_limit: Option<u32>,
@@ -284,6 +290,7 @@ impl DefMap {
             modules,
             registered_attrs: Vec::new(),
             registered_tools: Vec::new(),
+            unstable_features: FxHashSet::default(),
             diagnostics: Vec::new(),
         }
     }
@@ -314,6 +321,10 @@ impl DefMap {
         &self.registered_attrs
     }
 
+    pub fn is_unstable_feature_enabled(&self, feature: &str) -> bool {
+        self.unstable_features.contains(feature)
+    }
+
     pub fn root(&self) -> LocalModuleId {
         self.root
     }
@@ -479,6 +490,7 @@ impl DefMap {
             registered_tools,
             fn_proc_macro_mapping,
             derive_helpers_in_scope,
+            unstable_features,
             proc_macro_loading_error: _,
             block: _,
             edition: _,
@@ -496,6 +508,7 @@ impl DefMap {
         registered_tools.shrink_to_fit();
         fn_proc_macro_mapping.shrink_to_fit();
         derive_helpers_in_scope.shrink_to_fit();
+        unstable_features.shrink_to_fit();
         for (_, module) in modules.iter_mut() {
             module.children.shrink_to_fit();
             module.scope.shrink_to_fit();

crates/hir-def/src/nameres/collector.rs

@@ -294,6 +294,17 @@ impl DefCollector<'_> {
                     continue;
                 }
 
+                if *attr_name == hir_expand::name![feature] {
+                    let features =
+                        attr.parse_path_comma_token_tree().into_iter().flatten().filter_map(
+                            |feat| match feat.segments() {
+                                [name] => Some(name.to_smol_str()),
+                                _ => None,
+                            },
+                        );
+                    self.def_map.unstable_features.extend(features);
+                }
+
                 let attr_is_register_like = *attr_name == hir_expand::name![register_attr]
                     || *attr_name == hir_expand::name![register_tool];
                 if !attr_is_register_like {
@@ -501,10 +512,9 @@ impl DefCollector<'_> {
             Edition::Edition2021 => name![rust_2021],
         };
 
-        let path_kind = if self.def_map.edition == Edition::Edition2015 {
+        let path_kind = match self.def_map.edition {
-            PathKind::Plain
+            Edition::Edition2015 => PathKind::Plain,
-        } else {
+            _ => PathKind::Abs,
-            PathKind::Abs
         };
         let path =
             ModPath::from_segments(path_kind, [krate.clone(), name![prelude], edition].into_iter());
@@ -524,7 +534,6 @@ impl DefCollector<'_> {
             match per_ns.types {
                 Some((ModuleDefId::ModuleId(m), _)) => {
                     self.def_map.prelude = Some(m);
-                    return;
                 }
                 types => {
                     tracing::debug!(
@@ -839,7 +848,10 @@ impl DefCollector<'_> {
                 tracing::debug!("resolved import {:?} ({:?}) to {:?}", name, import, def);
 
                 // extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658
-                if import.is_extern_crate && module_id == self.def_map.root {
+                if import.is_extern_crate
+                    && self.def_map.block.is_none()
+                    && module_id == self.def_map.root
+                {
                     if let (Some(ModuleDefId::ModuleId(def)), Some(name)) = (def.take_types(), name)
                     {
                         self.def_map.extern_prelude.insert(name.clone(), def);

crates/hir-def/src/nameres/mod_resolution.rs

@@ -65,6 +65,7 @@ impl ModDir {
         name: &Name,
         attr_path: Option<&SmolStr>,
     ) -> Result<(FileId, bool, ModDir), Box<[String]>> {
+        let name = name.unescaped();
         let orig_file_id = file_id.original_file(db.upcast());
 
         let mut candidate_files = ArrayVec::<_, 2>::new();
@@ -73,12 +74,10 @@ impl ModDir {
                 candidate_files.push(self.dir_path.join_attr(attr_path, self.root_non_dir_owner))
             }
             None if file_id.is_include_macro(db.upcast()) => {
-                let name = name.unescaped();
                 candidate_files.push(format!("{}.rs", name));
                 candidate_files.push(format!("{}/mod.rs", name));
             }
             None => {
-                let name = name.unescaped();
                 candidate_files.push(format!("{}{}.rs", self.dir_path.0, name));
                 candidate_files.push(format!("{}{}/mod.rs", self.dir_path.0, name));
             }

crates/hir-def/src/nameres/tests/mod_resolution.rs

@@ -127,7 +127,15 @@ mod r#async;
 use self::r#async::Bar;
 
 //- /async.rs
+mod foo;
+mod r#async;
 pub struct Bar;
+
+//- /async/foo.rs
+pub struct Foo;
+
+//- /async/async.rs
+pub struct Baz;
 "#,
         expect![[r#"
             crate
@@ -136,6 +144,14 @@ pub struct Bar;
 
             crate::r#async
             Bar: t v
+            foo: t
+            r#async: t
+
+            crate::r#async::foo
+            Foo: t v
+
+            crate::r#async::r#async
+            Baz: t v
         "#]],
     );
 }

crates/hir-def/src/resolver.rs

@@ -31,12 +31,10 @@ pub struct Resolver {
     ///
     /// When using, you generally want to process the scopes in reverse order,
     /// there's `scopes` *method* for that.
-    ///
-    /// Invariant: There exists at least one Scope::ModuleScope at the start of the vec.
     scopes: Vec<Scope>,
+    module_scope: ModuleItemMap,
 }
 
-// FIXME how to store these best
 #[derive(Debug, Clone)]
 struct ModuleItemMap {
     def_map: Arc<DefMap>,
@@ -53,7 +51,7 @@ struct ExprScope {
 #[derive(Debug, Clone)]
 enum Scope {
     /// All the items and imported names of a module
-    ModuleScope(ModuleItemMap),
+    BlockScope(ModuleItemMap),
     /// Brings the generic parameters of an item into scope
     GenericParams { def: GenericDefId, params: Interned<GenericParams> },
     /// Brings `Self` in `impl` block into scope
@@ -127,24 +125,6 @@ impl Resolver {
         }
     }
 
-    fn scopes(&self) -> impl Iterator<Item = &Scope> {
-        self.scopes.iter().rev()
-    }
-
-    fn resolve_module_path(
-        &self,
-        db: &dyn DefDatabase,
-        path: &ModPath,
-        shadow: BuiltinShadowMode,
-    ) -> PerNs {
-        let (item_map, module) = self.module_scope();
-        let (module_res, segment_index) = item_map.resolve_path(db, module, path, shadow);
-        if segment_index.is_some() {
-            return PerNs::none();
-        }
-        module_res
-    }
-
     pub fn resolve_module_path_in_items(&self, db: &dyn DefDatabase, path: &ModPath) -> PerNs {
         self.resolve_module_path(db, path, BuiltinShadowMode::Module)
     }
@@ -155,7 +135,7 @@ impl Resolver {
         db: &dyn DefDatabase,
         path: &ModPath,
     ) -> Option<PerNs> {
-        let (item_map, module) = self.module_scope();
+        let (item_map, module) = self.item_scope();
         let (module_res, idx) = item_map.resolve_path(db, module, path, BuiltinShadowMode::Module);
         match module_res.take_types()? {
             ModuleDefId::TraitId(it) => {
@@ -183,37 +163,38 @@ impl Resolver {
     ) -> Option<(TypeNs, Option<usize>)> {
         let first_name = path.segments().first()?;
         let skip_to_mod = path.kind != PathKind::Plain;
+        if skip_to_mod {
+            return self.module_scope.resolve_path_in_type_ns(db, path);
+        }
+
+        let remaining_idx = || if path.segments().len() == 1 { None } else { Some(1) };
+
         for scope in self.scopes() {
             match scope {
                 Scope::ExprScope(_) => continue,
-                Scope::GenericParams { .. } | Scope::ImplDefScope(_) if skip_to_mod => continue,
-
                 Scope::GenericParams { params, def } => {
                     if let Some(id) = params.find_type_by_name(first_name, *def) {
-                        let idx = if path.segments().len() == 1 { None } else { Some(1) };
+                        return Some((TypeNs::GenericParam(id), remaining_idx()));
-                        return Some((TypeNs::GenericParam(id), idx));
                     }
                 }
-                Scope::ImplDefScope(impl_) => {
+                &Scope::ImplDefScope(impl_) => {
                     if first_name == &name![Self] {
-                        let idx = if path.segments().len() == 1 { None } else { Some(1) };
+                        return Some((TypeNs::SelfType(impl_), remaining_idx()));
-                        return Some((TypeNs::SelfType(*impl_), idx));
                     }
                 }
-                Scope::AdtScope(adt) => {
+                &Scope::AdtScope(adt) => {
                     if first_name == &name![Self] {
-                        let idx = if path.segments().len() == 1 { None } else { Some(1) };
+                        return Some((TypeNs::AdtSelfType(adt), remaining_idx()));
-                        return Some((TypeNs::AdtSelfType(*adt), idx));
                     }
                 }
-                Scope::ModuleScope(m) => {
+                Scope::BlockScope(m) => {
                     if let Some(res) = m.resolve_path_in_type_ns(db, path) {
                         return Some(res);
                     }
                 }
             }
         }
-        None
+        self.module_scope.resolve_path_in_type_ns(db, path)
     }
 
     pub fn resolve_path_in_type_ns_fully(
@@ -235,7 +216,7 @@ impl Resolver {
     ) -> Option<Visibility> {
         match visibility {
             RawVisibility::Module(_) => {
-                let (item_map, module) = self.module_scope();
+                let (item_map, module) = self.item_scope();
                 item_map.resolve_visibility(db, module, visibility)
             }
             RawVisibility::Public => Some(Visibility::Public),
@@ -251,18 +232,14 @@ impl Resolver {
         let tmp = name![self];
         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() {
+        if skip_to_mod {
-            match scope {
+            return self.module_scope.resolve_path_in_value_ns(db, path);
-                Scope::AdtScope(_)
-                | Scope::ExprScope(_)
-                | Scope::GenericParams { .. }
-                | Scope::ImplDefScope(_)
-                    if skip_to_mod =>
-                {
-                    continue
         }
 
-                Scope::ExprScope(scope) if n_segments <= 1 => {
+        for scope in self.scopes() {
+            match scope {
+                Scope::ExprScope(_) if n_segments > 1 => continue,
+                Scope::ExprScope(scope) => {
                     let entry = scope
                         .expr_scopes
                         .entries(scope.scope_id)
@@ -273,44 +250,39 @@ impl Resolver {
                         return Some(ResolveValueResult::ValueNs(ValueNs::LocalBinding(e.pat())));
                     }
                 }
-                Scope::ExprScope(_) => continue,
-
                 Scope::GenericParams { params, def } if n_segments > 1 => {
                     if let Some(id) = params.find_type_by_name(first_name, *def) {
                         let ty = TypeNs::GenericParam(id);
                         return Some(ResolveValueResult::Partial(ty, 1));
                     }
                 }
-                Scope::GenericParams { params, def } if n_segments == 1 => {
+                Scope::GenericParams { .. } if n_segments != 1 => continue,
+                Scope::GenericParams { params, def } => {
                     if let Some(id) = params.find_const_by_name(first_name, *def) {
                         let val = ValueNs::GenericParam(id);
                         return Some(ResolveValueResult::ValueNs(val));
                     }
                 }
-                Scope::GenericParams { .. } => continue,
 
-                Scope::ImplDefScope(impl_) => {
+                &Scope::ImplDefScope(impl_) => {
                     if first_name == &name![Self] {
-                        if n_segments > 1 {
+                        return Some(if n_segments > 1 {
-                            let ty = TypeNs::SelfType(*impl_);
+                            ResolveValueResult::Partial(TypeNs::SelfType(impl_), 1)
-                            return Some(ResolveValueResult::Partial(ty, 1));
                         } else {
-                            return Some(ResolveValueResult::ValueNs(ValueNs::ImplSelf(*impl_)));
+                            ResolveValueResult::ValueNs(ValueNs::ImplSelf(impl_))
+                        });
                     }
                 }
-                }
-                Scope::AdtScope(adt) => {
-                    if n_segments == 1 {
                 // bare `Self` doesn't work in the value namespace in a struct/enum definition
-                        continue;
+                Scope::AdtScope(_) if n_segments == 1 => continue,
-                    }
+                Scope::AdtScope(adt) => {
                     if first_name == &name![Self] {
                         let ty = TypeNs::AdtSelfType(*adt);
                         return Some(ResolveValueResult::Partial(ty, 1));
                     }
                 }
 
-                Scope::ModuleScope(m) => {
+                Scope::BlockScope(m) => {
                     if let Some(def) = m.resolve_path_in_value_ns(db, path) {
                         return Some(def);
                     }
@@ -318,16 +290,17 @@ impl Resolver {
             }
         }
 
+        if let res @ Some(_) = self.module_scope.resolve_path_in_value_ns(db, path) {
+            return res;
+        }
+
         // If a path of the shape `u16::from_le_bytes` failed to resolve at all, then we fall back
         // to resolving to the primitive type, to allow this to still work in the presence of
         // `use core::u16;`.
         if path.kind == PathKind::Plain && path.segments().len() > 1 {
-            match BuiltinType::by_name(&path.segments()[0]) {
+            if let Some(builtin) = BuiltinType::by_name(&path.segments()[0]) {
-                Some(builtin) => {
                 return Some(ResolveValueResult::Partial(TypeNs::BuiltinType(builtin), 1));
             }
-                None => {}
-            }
         }
 
         None
@@ -345,7 +318,7 @@ impl Resolver {
     }
 
     pub fn resolve_path_as_macro(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<MacroId> {
-        let (item_map, module) = self.module_scope();
+        let (item_map, module) = self.item_scope();
         item_map.resolve_path(db, module, path, BuiltinShadowMode::Other).0.take_macros()
     }
 
@@ -395,30 +368,43 @@ impl Resolver {
         for scope in self.scopes() {
             scope.process_names(&mut res, db);
         }
+        let ModuleItemMap { ref def_map, module_id } = self.module_scope;
+        // FIXME: should we provide `self` here?
+        // f(
+        //     Name::self_param(),
+        //     PerNs::types(Resolution::Def {
+        //         def: m.module.into(),
+        //     }),
+        // );
+        def_map[module_id].scope.entries().for_each(|(name, def)| {
+            res.add_per_ns(name, def);
+        });
+        def_map[module_id].scope.legacy_macros().for_each(|(name, macs)| {
+            macs.iter().for_each(|&mac| {
+                res.add(name, ScopeDef::ModuleDef(ModuleDefId::MacroId(MacroId::from(mac))));
+            })
+        });
+        def_map.extern_prelude().for_each(|(name, &def)| {
+            res.add(name, ScopeDef::ModuleDef(ModuleDefId::ModuleId(def)));
+        });
+        BUILTIN_SCOPE.iter().for_each(|(name, &def)| {
+            res.add_per_ns(name, def);
+        });
+        if let Some(prelude) = def_map.prelude() {
+            let prelude_def_map = prelude.def_map(db);
+            for (name, def) in prelude_def_map[prelude.local_id].scope.entries() {
+                res.add_per_ns(name, def)
+            }
+        }
         res.map
     }
 
     pub fn traits_in_scope(&self, db: &dyn DefDatabase) -> FxHashSet<TraitId> {
         let mut traits = FxHashSet::default();
+
         for scope in self.scopes() {
             match scope {
-                Scope::ModuleScope(m) => {
+                Scope::BlockScope(m) => traits.extend(m.def_map[m.module_id].scope.traits()),
-                    if let Some(prelude) = m.def_map.prelude() {
-                        let prelude_def_map = prelude.def_map(db);
-                        traits.extend(prelude_def_map[prelude.local_id].scope.traits());
-                    }
-                    traits.extend(m.def_map[m.module_id].scope.traits());
-
-                    // Add all traits that are in scope because of the containing DefMaps
-                    m.def_map.with_ancestor_maps(db, m.module_id, &mut |def_map, module| {
-                        if let Some(prelude) = def_map.prelude() {
-                            let prelude_def_map = prelude.def_map(db);
-                            traits.extend(prelude_def_map[prelude.local_id].scope.traits());
-                        }
-                        traits.extend(def_map[module].scope.traits());
-                        None::<()>
-                    });
-                }
                 &Scope::ImplDefScope(impl_) => {
                     if let Some(target_trait) = &db.impl_data(impl_).target_trait {
                         if let Some(TypeNs::TraitId(trait_)) =
@@ -431,35 +417,28 @@ impl Resolver {
                 _ => (),
             }
         }
+
+        // Fill in the prelude traits
+        if let Some(prelude) = self.module_scope.def_map.prelude() {
+            let prelude_def_map = prelude.def_map(db);
+            traits.extend(prelude_def_map[prelude.local_id].scope.traits());
+        }
+        // Fill in module visible traits
+        traits.extend(self.module_scope.def_map[self.module_scope.module_id].scope.traits());
         traits
     }
 
-    fn module_scope(&self) -> (&DefMap, LocalModuleId) {
-        self.scopes()
-            .find_map(|scope| match scope {
-                Scope::ModuleScope(m) => Some((&*m.def_map, m.module_id)),
-                _ => None,
-            })
-            .expect("module scope invariant violated")
-    }
-
     pub fn module(&self) -> ModuleId {
-        let (def_map, local_id) = self.module_scope();
+        let (def_map, local_id) = self.item_scope();
         def_map.module_id(local_id)
     }
 
     pub fn krate(&self) -> CrateId {
-        self.def_map().krate()
+        self.module_scope.def_map.krate()
     }
 
     pub fn def_map(&self) -> &DefMap {
-        self.scopes
+        self.item_scope().0
-            .get(0)
-            .and_then(|scope| match scope {
-                Scope::ModuleScope(m) => Some(&m.def_map),
-                _ => None,
-            })
-            .expect("module scope invariant violated")
     }
 
     pub fn where_predicates_in_scope(
@@ -488,6 +467,36 @@ impl Resolver {
     }
 }
 
+impl Resolver {
+    fn scopes(&self) -> impl Iterator<Item = &Scope> {
+        self.scopes.iter().rev()
+    }
+
+    fn resolve_module_path(
+        &self,
+        db: &dyn DefDatabase,
+        path: &ModPath,
+        shadow: BuiltinShadowMode,
+    ) -> PerNs {
+        let (item_map, module) = self.item_scope();
+        let (module_res, segment_index) = item_map.resolve_path(db, module, path, shadow);
+        if segment_index.is_some() {
+            return PerNs::none();
+        }
+        module_res
+    }
+
+    /// The innermost block scope that contains items or the module scope that contains this resolver.
+    fn item_scope(&self) -> (&DefMap, LocalModuleId) {
+        self.scopes()
+            .find_map(|scope| match scope {
+                Scope::BlockScope(m) => Some((&*m.def_map, m.module_id)),
+                _ => None,
+            })
+            .unwrap_or((&self.module_scope.def_map, self.module_scope.module_id))
+    }
+}
+
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum ScopeDef {
     ModuleDef(ModuleDefId),
@@ -502,14 +511,7 @@ pub enum ScopeDef {
 impl Scope {
     fn process_names(&self, acc: &mut ScopeNames, db: &dyn DefDatabase) {
         match self {
-            Scope::ModuleScope(m) => {
+            Scope::BlockScope(m) => {
-                // FIXME: should we provide `self` here?
-                // f(
-                //     Name::self_param(),
-                //     PerNs::types(Resolution::Def {
-                //         def: m.module.into(),
-                //     }),
-                // );
                 m.def_map[m.module_id].scope.entries().for_each(|(name, def)| {
                     acc.add_per_ns(name, def);
                 });
@@ -521,18 +523,6 @@ impl Scope {
                         );
                     })
                 });
-                m.def_map.extern_prelude().for_each(|(name, &def)| {
-                    acc.add(name, ScopeDef::ModuleDef(ModuleDefId::ModuleId(def)));
-                });
-                BUILTIN_SCOPE.iter().for_each(|(name, &def)| {
-                    acc.add_per_ns(name, def);
-                });
-                if let Some(prelude) = m.def_map.prelude() {
-                    let prelude_def_map = prelude.def_map(db);
-                    for (name, def) in prelude_def_map[prelude.local_id].scope.entries() {
-                        acc.add_per_ns(name, def)
-                    }
-                }
             }
             Scope::GenericParams { params, def: parent } => {
                 let parent = *parent;
@@ -596,7 +586,7 @@ pub fn resolver_for_scope(
         if let Some(block) = scopes.block(scope) {
             if let Some(def_map) = db.block_def_map(block) {
                 let root = def_map.root();
-                r = r.push_module_scope(def_map, root);
+                r = r.push_block_scope(def_map, root);
                 // FIXME: This adds as many module scopes as there are blocks, but resolving in each
                 // already traverses all parents, so this is O(n²). I think we could only store the
                 // innermost module scope instead?
@@ -623,8 +613,8 @@ impl Resolver {
         self.push_scope(Scope::ImplDefScope(impl_def))
     }
 
-    fn push_module_scope(self, def_map: Arc<DefMap>, module_id: LocalModuleId) -> Resolver {
+    fn push_block_scope(self, def_map: Arc<DefMap>, module_id: LocalModuleId) -> Resolver {
-        self.push_scope(Scope::ModuleScope(ModuleItemMap { def_map, module_id }))
+        self.push_scope(Scope::BlockScope(ModuleItemMap { def_map, module_id }))
     }
 
     fn push_expr_scope(
@@ -768,14 +758,19 @@ pub trait HasResolver: Copy {
 impl HasResolver for ModuleId {
     fn resolver(self, db: &dyn DefDatabase) -> Resolver {
         let mut def_map = self.def_map(db);
-        let mut modules: SmallVec<[_; 2]> = smallvec![(def_map.clone(), self.local_id)];
+        let mut modules: SmallVec<[_; 1]> = smallvec![];
+        let mut module_id = self.local_id;
         while let Some(parent) = def_map.parent() {
+            modules.push((def_map, module_id));
             def_map = parent.def_map(db);
-            modules.push((def_map.clone(), parent.local_id));
+            module_id = parent.local_id;
         }
-        let mut resolver = Resolver { scopes: Vec::with_capacity(modules.len()) };
+        let mut resolver = Resolver {
+            scopes: Vec::with_capacity(modules.len()),
+            module_scope: ModuleItemMap { def_map, module_id },
+        };
         for (def_map, module) in modules.into_iter().rev() {
-            resolver = resolver.push_module_scope(def_map, module);
+            resolver = resolver.push_block_scope(def_map, module);
         }
         resolver
     }

crates/hir-expand/src/lib.rs

@@ -969,7 +969,7 @@ impl ExpandTo {
         if parent.kind() == MACRO_EXPR
             && parent
                 .parent()
-                .map_or(true, |p| matches!(p.kind(), EXPR_STMT | STMT_LIST | MACRO_STMTS))
+                .map_or(false, |p| matches!(p.kind(), EXPR_STMT | STMT_LIST | MACRO_STMTS))
         {
             return ExpandTo::Statements;
         }

crates/hir-expand/src/name.rs

@@ -336,6 +336,7 @@ pub mod known {
         test,
         test_case,
         recursion_limit,
+        feature,
         // Safe intrinsics
         abort,
         add_with_overflow,

crates/hir-ty/src/autoderef.rs

@@ -104,8 +104,7 @@ pub(crate) fn deref(table: &mut InferenceTable<'_>, ty: Ty) -> Option<Ty> {
 
 fn builtin_deref(ty: &Ty) -> Option<&Ty> {
     match ty.kind(Interner) {
-        TyKind::Ref(.., ty) => Some(ty),
+        TyKind::Ref(.., ty) | TyKind::Raw(.., ty) => Some(ty),
-        TyKind::Raw(.., ty) => Some(ty),
         _ => None,
     }
 }

crates/hir-ty/src/diagnostics/expr.rs

@@ -159,12 +159,7 @@ impl ExprValidator {
         }
 
         let pattern_arena = Arena::new();
-        let cx = MatchCheckCtx {
+        let cx = MatchCheckCtx::new(self.owner.module(db.upcast()), self.owner, db, &pattern_arena);
-            module: self.owner.module(db.upcast()),
-            body: self.owner,
-            db,
-            pattern_arena: &pattern_arena,
-        };
 
         let mut m_arms = Vec::with_capacity(arms.len());
         let mut has_lowering_errors = false;

crates/hir-ty/src/diagnostics/match_check/deconstruct_pat.rs

@@ -52,7 +52,10 @@ use hir_def::{EnumVariantId, HasModule, LocalFieldId, VariantId};
 use smallvec::{smallvec, SmallVec};
 use stdx::never;
 
-use crate::{infer::normalize, AdtId, Interner, Scalar, Ty, TyExt, TyKind};
+use crate::{
+    infer::normalize, inhabitedness::is_enum_variant_uninhabited_from, AdtId, Interner, Scalar, Ty,
+    TyExt, TyKind,
+};
 
 use super::{
     is_box,
@@ -557,8 +560,8 @@ impl SplitWildcard {
             TyKind::Scalar(Scalar::Bool) => smallvec![make_range(0, 1, Scalar::Bool)],
             // TyKind::Array(..) if ... => unhandled(),
             TyKind::Array(..) | TyKind::Slice(..) => unhandled(),
-            &TyKind::Adt(AdtId(hir_def::AdtId::EnumId(enum_id)), ..) => {
+            TyKind::Adt(AdtId(hir_def::AdtId::EnumId(enum_id)), subst) => {
-                let enum_data = cx.db.enum_data(enum_id);
+                let enum_data = cx.db.enum_data(*enum_id);
 
                 // If the enum is declared as `#[non_exhaustive]`, we treat it as if it had an
                 // additional "unknown" constructor.
@@ -591,14 +594,15 @@ impl SplitWildcard {
                 let mut ctors: SmallVec<[_; 1]> = enum_data
                     .variants
                     .iter()
-                    .filter(|&(_, _v)| {
+                    .map(|(local_id, _)| EnumVariantId { parent: *enum_id, local_id })
+                    .filter(|&variant| {
                         // If `exhaustive_patterns` is enabled, we exclude variants known to be
                         // uninhabited.
                         let is_uninhabited = is_exhaustive_pat_feature
-                            && unimplemented!("after MatchCheckCtx.feature_exhaustive_patterns()");
+                            && is_enum_variant_uninhabited_from(variant, subst, cx.module, cx.db);
                         !is_uninhabited
                     })
-                    .map(|(local_id, _)| Variant(EnumVariantId { parent: enum_id, local_id }))
+                    .map(Variant)
                     .collect();
 
                 if is_secretly_empty || is_declared_nonexhaustive {

crates/hir-ty/src/diagnostics/match_check/usefulness.rs

@@ -277,7 +277,7 @@ use hir_def::{AdtId, DefWithBodyId, HasModule, ModuleId};
 use smallvec::{smallvec, SmallVec};
 use typed_arena::Arena;
 
-use crate::{db::HirDatabase, Ty, TyExt};
+use crate::{db::HirDatabase, inhabitedness::is_ty_uninhabited_from, Ty, TyExt};
 
 use super::deconstruct_pat::{Constructor, DeconstructedPat, Fields, SplitWildcard};
 
@@ -289,14 +289,28 @@ pub(crate) struct MatchCheckCtx<'a, 'p> {
     pub(crate) db: &'a dyn HirDatabase,
     /// Lowered patterns from arms plus generated by the check.
     pub(crate) pattern_arena: &'p Arena<DeconstructedPat<'p>>,
+    exhaustive_patterns: bool,
 }
 
 impl<'a, 'p> MatchCheckCtx<'a, 'p> {
-    pub(super) fn is_uninhabited(&self, _ty: &Ty) -> bool {
+    pub(crate) fn new(
-        // FIXME(iDawer) implement exhaustive_patterns feature. More info in:
+        module: ModuleId,
-        // Tracking issue for RFC 1872: exhaustive_patterns feature https://github.com/rust-lang/rust/issues/51085
+        body: DefWithBodyId,
+        db: &'a dyn HirDatabase,
+        pattern_arena: &'p Arena<DeconstructedPat<'p>>,
+    ) -> Self {
+        let def_map = db.crate_def_map(module.krate());
+        let exhaustive_patterns = def_map.is_unstable_feature_enabled("exhaustive_patterns");
+        Self { module, body, db, pattern_arena, exhaustive_patterns }
+    }
+
+    pub(super) fn is_uninhabited(&self, ty: &Ty) -> bool {
+        if self.feature_exhaustive_patterns() {
+            is_ty_uninhabited_from(ty, self.module, self.db)
+        } else {
             false
         }
+    }
 
     /// Returns whether the given type is an enum from another crate declared `#[non_exhaustive]`.
     pub(super) fn is_foreign_non_exhaustive_enum(&self, ty: &Ty) -> bool {
@@ -311,10 +325,9 @@ impl<'a, 'p> MatchCheckCtx<'a, 'p> {
         }
     }
 
-    // Rust feature described as "Allows exhaustive pattern matching on types that contain uninhabited types."
+    // Rust's unstable feature described as "Allows exhaustive pattern matching on types that contain uninhabited types."
     pub(super) fn feature_exhaustive_patterns(&self) -> bool {
-        // FIXME see MatchCheckCtx::is_uninhabited
+        self.exhaustive_patterns
-        false
     }
 }
 

crates/hir-ty/src/infer.rs

@@ -182,7 +182,7 @@ pub(crate) type InferResult<T> = Result<InferOk<T>, TypeError>;
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub enum InferenceDiagnostic {
     NoSuchField { expr: ExprId },
-    BreakOutsideOfLoop { expr: ExprId },
+    BreakOutsideOfLoop { expr: ExprId, is_break: bool },
     MismatchedArgCount { call_expr: ExprId, expected: usize, found: usize },
 }
 
@@ -418,18 +418,45 @@ pub(crate) struct InferenceContext<'a> {
 
 #[derive(Clone, Debug)]
 struct BreakableContext {
+    /// Whether this context contains at least one break expression.
     may_break: bool,
+    /// The coercion target of the context.
     coerce: CoerceMany,
+    /// The optional label of the context.
     label: Option<name::Name>,
+    kind: BreakableKind,
+}
+
+#[derive(Clone, Debug)]
+enum BreakableKind {
+    Block,
+    Loop,
+    /// A border is something like an async block, closure etc. Anything that prevents
+    /// breaking/continuing through
+    Border,
 }
 
 fn find_breakable<'c>(
     ctxs: &'c mut [BreakableContext],
     label: Option<&name::Name>,
 ) -> Option<&'c mut BreakableContext> {
+    let mut ctxs = ctxs
+        .iter_mut()
+        .rev()
+        .take_while(|it| matches!(it.kind, BreakableKind::Block | BreakableKind::Loop));
     match label {
-        Some(_) => ctxs.iter_mut().rev().find(|ctx| ctx.label.as_ref() == label),
+        Some(_) => ctxs.find(|ctx| ctx.label.as_ref() == label),
-        None => ctxs.last_mut(),
+        None => ctxs.find(|ctx| matches!(ctx.kind, BreakableKind::Loop)),
+    }
+}
+
+fn find_continuable<'c>(
+    ctxs: &'c mut [BreakableContext],
+    label: Option<&name::Name>,
+) -> Option<&'c mut BreakableContext> {
+    match label {
+        Some(_) => find_breakable(ctxs, label).filter(|it| matches!(it.kind, BreakableKind::Loop)),
+        None => find_breakable(ctxs, label),
     }
 }
 

crates/hir-ty/src/infer/expr.rs

@@ -10,7 +10,7 @@ use chalk_ir::{
     cast::Cast, fold::Shift, DebruijnIndex, GenericArgData, Mutability, TyVariableKind,
 };
 use hir_def::{
-    expr::{ArithOp, Array, BinaryOp, CmpOp, Expr, ExprId, Literal, Statement, UnaryOp},
+    expr::{ArithOp, Array, BinaryOp, CmpOp, Expr, ExprId, LabelId, Literal, Statement, UnaryOp},
     generics::TypeOrConstParamData,
     path::{GenericArg, GenericArgs},
     resolver::resolver_for_expr,
@@ -23,7 +23,7 @@ use syntax::ast::RangeOp;
 use crate::{
     autoderef::{self, Autoderef},
     consteval,
-    infer::coerce::CoerceMany,
+    infer::{coerce::CoerceMany, find_continuable, BreakableKind},
     lower::{
         const_or_path_to_chalk, generic_arg_to_chalk, lower_to_chalk_mutability, ParamLoweringMode,
     },
@@ -120,32 +120,37 @@ impl<'a> InferenceContext<'a> {
                 let ty = match label {
                     Some(_) => {
                         let break_ty = self.table.new_type_var();
-                        self.breakables.push(BreakableContext {
+                        let (breaks, ty) = self.with_breakable_ctx(
-                            may_break: false,
+                            BreakableKind::Block,
-                            coerce: CoerceMany::new(break_ty.clone()),
+                            break_ty.clone(),
-                            label: label.map(|label| self.body[label].name.clone()),
+                            *label,
-                        });
+                            |this| {
-                        let ty = self.infer_block(
+                                this.infer_block(
                                     tgt_expr,
                                     statements,
                                     *tail,
                                     &Expectation::has_type(break_ty),
+                                )
+                            },
                         );
-                        let ctxt = self.breakables.pop().expect("breakable stack broken");
+                        breaks.unwrap_or(ty)
-                        if ctxt.may_break {
-                            ctxt.coerce.complete()
-                        } else {
-                            ty
-                        }
                     }
                     None => self.infer_block(tgt_expr, statements, *tail, expected),
                 };
                 self.resolver = old_resolver;
                 ty
             }
-            Expr::Unsafe { body } | Expr::Const { body } => self.infer_expr(*body, expected),
+            Expr::Unsafe { body } => self.infer_expr(*body, expected),
+            Expr::Const { body } => {
+                self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| {
+                    this.infer_expr(*body, expected)
+                })
+                .1
+            }
             Expr::TryBlock { body } => {
-                let _inner = self.infer_expr(*body, expected);
+                self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| {
+                    let _inner = this.infer_expr(*body, expected);
+                });
                 // FIXME should be std::result::Result<{inner}, _>
                 self.err_ty()
             }
@@ -154,7 +159,10 @@ impl<'a> InferenceContext<'a> {
                 let prev_diverges = mem::replace(&mut self.diverges, Diverges::Maybe);
                 let prev_ret_ty = mem::replace(&mut self.return_ty, ret_ty.clone());
 
-                let inner_ty = self.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
+                let (_, inner_ty) =
+                    self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| {
+                        this.infer_expr_coerce(*body, &Expectation::has_type(ret_ty))
+                    });
 
                 self.diverges = prev_diverges;
                 self.return_ty = prev_ret_ty;
@@ -166,54 +174,44 @@ impl<'a> InferenceContext<'a> {
                 TyKind::OpaqueType(opaque_ty_id, Substitution::from1(Interner, inner_ty))
                     .intern(Interner)
             }
-            Expr::Loop { body, label } => {
+            &Expr::Loop { body, label } => {
-                self.breakables.push(BreakableContext {
+                let ty = self.table.new_type_var();
-                    may_break: false,
+                let (breaks, ()) =
-                    coerce: CoerceMany::new(self.table.new_type_var()),
+                    self.with_breakable_ctx(BreakableKind::Loop, ty, label, |this| {
-                    label: label.map(|label| self.body[label].name.clone()),
+                        this.infer_expr(body, &Expectation::has_type(TyBuilder::unit()));
                     });
-                self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit()));
 
-                let ctxt = self.breakables.pop().expect("breakable stack broken");
+                match breaks {
-
+                    Some(breaks) => {
-                if ctxt.may_break {
                         self.diverges = Diverges::Maybe;
-                    ctxt.coerce.complete()
+                        breaks
-                } else {
+                    }
-                    TyKind::Never.intern(Interner)
+                    None => TyKind::Never.intern(Interner),
                 }
             }
-            Expr::While { condition, body, label } => {
+            &Expr::While { condition, body, label } => {
-                self.breakables.push(BreakableContext {
+                self.with_breakable_ctx(BreakableKind::Loop, self.err_ty(), label, |this| {
-                    may_break: false,
+                    this.infer_expr(
-                    coerce: CoerceMany::new(self.err_ty()),
+                        condition,
-                    label: label.map(|label| self.body[label].name.clone()),
-                });
-                self.infer_expr(
-                    *condition,
                         &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(Interner)),
                     );
-                self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit()));
+                    this.infer_expr(body, &Expectation::has_type(TyBuilder::unit()));
-                let _ctxt = self.breakables.pop().expect("breakable stack broken");
+                });
+
                 // the body may not run, so it diverging doesn't mean we diverge
                 self.diverges = Diverges::Maybe;
                 TyBuilder::unit()
             }
-            Expr::For { iterable, body, pat, label } => {
+            &Expr::For { iterable, body, pat, label } => {
-                let iterable_ty = self.infer_expr(*iterable, &Expectation::none());
+                let iterable_ty = self.infer_expr(iterable, &Expectation::none());
-
-                self.breakables.push(BreakableContext {
-                    may_break: false,
-                    coerce: CoerceMany::new(self.err_ty()),
-                    label: label.map(|label| self.body[label].name.clone()),
-                });
                 let pat_ty =
                     self.resolve_associated_type(iterable_ty, self.resolve_into_iter_item());
 
-                self.infer_pat(*pat, &pat_ty, BindingMode::default());
+                self.infer_pat(pat, &pat_ty, BindingMode::default());
+                self.with_breakable_ctx(BreakableKind::Loop, self.err_ty(), label, |this| {
+                    this.infer_expr(body, &Expectation::has_type(TyBuilder::unit()));
+                });
 
-                self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit()));
-                let _ctxt = self.breakables.pop().expect("breakable stack broken");
                 // the body may not run, so it diverging doesn't mean we diverge
                 self.diverges = Diverges::Maybe;
                 TyBuilder::unit()
@@ -269,7 +267,9 @@ impl<'a> InferenceContext<'a> {
                 let prev_diverges = mem::replace(&mut self.diverges, Diverges::Maybe);
                 let prev_ret_ty = mem::replace(&mut self.return_ty, ret_ty.clone());
 
-                self.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
+                self.with_breakable_ctx(BreakableKind::Border, self.err_ty(), None, |this| {
+                    this.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
+                });
 
                 self.diverges = prev_diverges;
                 self.return_ty = prev_ret_ty;
@@ -372,37 +372,45 @@ impl<'a> InferenceContext<'a> {
                 let resolver = resolver_for_expr(self.db.upcast(), self.owner, tgt_expr);
                 self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or_else(|| self.err_ty())
             }
-            Expr::Continue { .. } => TyKind::Never.intern(Interner),
+            Expr::Continue { label } => {
-            Expr::Break { expr, label } => {
+                if let None = find_continuable(&mut self.breakables, label.as_ref()) {
-                let mut coerce = match find_breakable(&mut self.breakables, label.as_ref()) {
+                    self.push_diagnostic(InferenceDiagnostic::BreakOutsideOfLoop {
-                    Some(ctxt) => {
+                        expr: tgt_expr,
-                        // avoiding the borrowck
+                        is_break: false,
-                        mem::replace(
+                    });
-                            &mut ctxt.coerce,
-                            CoerceMany::new(self.result.standard_types.unknown.clone()),
-                        )
-                    }
-                    None => CoerceMany::new(self.result.standard_types.unknown.clone()),
                 };
-
+                TyKind::Never.intern(Interner)
+            }
+            Expr::Break { expr, label } => {
                 let val_ty = if let Some(expr) = *expr {
                     self.infer_expr(expr, &Expectation::none())
                 } else {
                     TyBuilder::unit()
                 };
 
+                match find_breakable(&mut self.breakables, label.as_ref()) {
+                    Some(ctxt) => {
+                        // avoiding the borrowck
+                        let mut coerce = mem::replace(
+                            &mut ctxt.coerce,
+                            CoerceMany::new(self.result.standard_types.unknown.clone()),
+                        );
+
                         // FIXME: create a synthetic `()` during lowering so we have something to refer to here?
                         coerce.coerce(self, *expr, &val_ty);
 
-                if let Some(ctxt) = find_breakable(&mut self.breakables, label.as_ref()) {
+                        let ctxt = find_breakable(&mut self.breakables, label.as_ref())
+                            .expect("breakable stack changed during coercion");
                         ctxt.coerce = coerce;
                         ctxt.may_break = true;
-                } else {
+                    }
+                    None => {
                         self.push_diagnostic(InferenceDiagnostic::BreakOutsideOfLoop {
                             expr: tgt_expr,
+                            is_break: true,
                         });
-                };
+                    }
-
+                }
                 TyKind::Never.intern(Interner)
             }
             Expr::Return { expr } => {
@@ -794,9 +802,6 @@ impl<'a> InferenceContext<'a> {
                     None => self.table.new_float_var(),
                 },
             },
-            Expr::MacroStmts { tail, statements } => {
-                self.infer_block(tgt_expr, statements, *tail, expected)
-            }
             Expr::Underscore => {
                 // Underscore expressions may only appear in assignee expressions,
                 // which are handled by `infer_assignee_expr()`, so any underscore
@@ -1475,4 +1480,20 @@ impl<'a> InferenceContext<'a> {
             },
         })
     }
+
+    fn with_breakable_ctx<T>(
+        &mut self,
+        kind: BreakableKind,
+        ty: Ty,
+        label: Option<LabelId>,
+        cb: impl FnOnce(&mut Self) -> T,
+    ) -> (Option<Ty>, T) {
+        self.breakables.push({
+            let label = label.map(|label| self.body[label].name.clone());
+            BreakableContext { kind, may_break: false, coerce: CoerceMany::new(ty), label }
+        });
+        let res = cb(self);
+        let ctx = self.breakables.pop().expect("breakable stack broken");
+        (ctx.may_break.then(|| ctx.coerce.complete()), res)
+    }
 }

crates/hir-ty/src/inhabitedness.rs

@@ -0,0 +1,173 @@
+//! Type inhabitedness logic.
+use std::ops::ControlFlow::{self, Break, Continue};
+
+use chalk_ir::{
+    visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor},
+    DebruijnIndex,
+};
+use hir_def::{
+    adt::VariantData, attr::Attrs, type_ref::ConstScalar, visibility::Visibility, AdtId,
+    EnumVariantId, HasModule, Lookup, ModuleId, VariantId,
+};
+
+use crate::{
+    db::HirDatabase, Binders, ConcreteConst, Const, ConstValue, Interner, Substitution, Ty, TyKind,
+};
+
+/// Checks whether a type is visibly uninhabited from a particular module.
+pub(crate) fn is_ty_uninhabited_from(ty: &Ty, target_mod: ModuleId, db: &dyn HirDatabase) -> bool {
+    let mut uninhabited_from = UninhabitedFrom { target_mod, db };
+    let inhabitedness = ty.visit_with(&mut uninhabited_from, DebruijnIndex::INNERMOST);
+    inhabitedness == BREAK_VISIBLY_UNINHABITED
+}
+
+/// Checks whether a variant is visibly uninhabited from a particular module.
+pub(crate) fn is_enum_variant_uninhabited_from(
+    variant: EnumVariantId,
+    subst: &Substitution,
+    target_mod: ModuleId,
+    db: &dyn HirDatabase,
+) -> bool {
+    let enum_data = db.enum_data(variant.parent);
+    let vars_attrs = db.variants_attrs(variant.parent);
+    let is_local = variant.parent.lookup(db.upcast()).container.krate() == target_mod.krate();
+
+    let mut uninhabited_from = UninhabitedFrom { target_mod, db };
+    let inhabitedness = uninhabited_from.visit_variant(
+        variant.into(),
+        &enum_data.variants[variant.local_id].variant_data,
+        subst,
+        &vars_attrs[variant.local_id],
+        is_local,
+    );
+    inhabitedness == BREAK_VISIBLY_UNINHABITED
+}
+
+struct UninhabitedFrom<'a> {
+    target_mod: ModuleId,
+    db: &'a dyn HirDatabase,
+}
+
+const CONTINUE_OPAQUELY_INHABITED: ControlFlow<VisiblyUninhabited> = Continue(());
+const BREAK_VISIBLY_UNINHABITED: ControlFlow<VisiblyUninhabited> = Break(VisiblyUninhabited);
+#[derive(PartialEq, Eq)]
+struct VisiblyUninhabited;
+
+impl TypeVisitor<Interner> for UninhabitedFrom<'_> {
+    type BreakTy = VisiblyUninhabited;
+
+    fn as_dyn(&mut self) -> &mut dyn TypeVisitor<Interner, BreakTy = VisiblyUninhabited> {
+        self
+    }
+
+    fn visit_ty(
+        &mut self,
+        ty: &Ty,
+        outer_binder: DebruijnIndex,
+    ) -> ControlFlow<VisiblyUninhabited> {
+        match ty.kind(Interner) {
+            TyKind::Adt(adt, subst) => self.visit_adt(adt.0, subst),
+            TyKind::Never => BREAK_VISIBLY_UNINHABITED,
+            TyKind::Tuple(..) => ty.super_visit_with(self, outer_binder),
+            TyKind::Array(item_ty, len) => match try_usize_const(len) {
+                Some(0) | None => CONTINUE_OPAQUELY_INHABITED,
+                Some(1..) => item_ty.super_visit_with(self, outer_binder),
+            },
+
+            TyKind::Ref(..) | _ => CONTINUE_OPAQUELY_INHABITED,
+        }
+    }
+
+    fn interner(&self) -> Interner {
+        Interner
+    }
+}
+
+impl UninhabitedFrom<'_> {
+    fn visit_adt(&mut self, adt: AdtId, subst: &Substitution) -> ControlFlow<VisiblyUninhabited> {
+        let attrs = self.db.attrs(adt.into());
+        let adt_non_exhaustive = attrs.by_key("non_exhaustive").exists();
+        let is_local = adt.module(self.db.upcast()).krate() == self.target_mod.krate();
+        if adt_non_exhaustive && !is_local {
+            return CONTINUE_OPAQUELY_INHABITED;
+        }
+
+        // An ADT is uninhabited iff all its variants uninhabited.
+        match adt {
+            // rustc: For now, `union`s are never considered uninhabited.
+            AdtId::UnionId(_) => CONTINUE_OPAQUELY_INHABITED,
+            AdtId::StructId(s) => {
+                let struct_data = self.db.struct_data(s);
+                self.visit_variant(s.into(), &struct_data.variant_data, subst, &attrs, is_local)
+            }
+            AdtId::EnumId(e) => {
+                let vars_attrs = self.db.variants_attrs(e);
+                let enum_data = self.db.enum_data(e);
+
+                for (local_id, enum_var) in enum_data.variants.iter() {
+                    let variant_inhabitedness = self.visit_variant(
+                        EnumVariantId { parent: e, local_id }.into(),
+                        &enum_var.variant_data,
+                        subst,
+                        &vars_attrs[local_id],
+                        is_local,
+                    );
+                    match variant_inhabitedness {
+                        Break(VisiblyUninhabited) => continue,
+                        Continue(()) => return CONTINUE_OPAQUELY_INHABITED,
+                    }
+                }
+                BREAK_VISIBLY_UNINHABITED
+            }
+        }
+    }
+
+    fn visit_variant(
+        &mut self,
+        variant: VariantId,
+        variant_data: &VariantData,
+        subst: &Substitution,
+        attrs: &Attrs,
+        is_local: bool,
+    ) -> ControlFlow<VisiblyUninhabited> {
+        let non_exhaustive_field_list = attrs.by_key("non_exhaustive").exists();
+        if non_exhaustive_field_list && !is_local {
+            return CONTINUE_OPAQUELY_INHABITED;
+        }
+
+        let is_enum = matches!(variant, VariantId::EnumVariantId(..));
+        let field_tys = self.db.field_types(variant);
+        let field_vis = self.db.field_visibilities(variant);
+
+        for (fid, _) in variant_data.fields().iter() {
+            self.visit_field(field_vis[fid], &field_tys[fid], subst, is_enum)?;
+        }
+        CONTINUE_OPAQUELY_INHABITED
+    }
+
+    fn visit_field(
+        &mut self,
+        vis: Visibility,
+        ty: &Binders<Ty>,
+        subst: &Substitution,
+        is_enum: bool,
+    ) -> ControlFlow<VisiblyUninhabited> {
+        if is_enum || vis.is_visible_from(self.db.upcast(), self.target_mod) {
+            let ty = ty.clone().substitute(Interner, subst);
+            ty.visit_with(self, DebruijnIndex::INNERMOST)
+        } else {
+            CONTINUE_OPAQUELY_INHABITED
+        }
+    }
+}
+
+fn try_usize_const(c: &Const) -> Option<u128> {
+    let data = &c.data(Interner);
+    if data.ty.kind(Interner) != &TyKind::Scalar(chalk_ir::Scalar::Uint(chalk_ir::UintTy::Usize)) {
+        return None;
+    }
+    match data.value {
+        ConstValue::Concrete(ConcreteConst { interned: ConstScalar::UInt(value) }) => Some(value),
+        _ => None,
+    }
+}

crates/hir-ty/src/lib.rs

@@ -14,6 +14,7 @@ mod chalk_db;
 mod chalk_ext;
 pub mod consteval;
 mod infer;
+mod inhabitedness;
 mod interner;
 mod lower;
 mod mapping;

crates/hir-ty/src/lower.rs

@@ -1,8 +1,8 @@
 //! Methods for lowering the HIR to types. There are two main cases here:
 //!
 //!  - Lowering a type reference like `&usize` or `Option<foo::bar::Baz>` to a
-//!    type: The entry point for this is `Ty::from_hir`.
+//!    type: The entry point for this is `TyLoweringContext::lower_ty`.
-//!  - Building the type for an item: This happens through the `type_for_def` query.
+//!  - Building the type for an item: This happens through the `ty` query.
 //!
 //! This usually involves resolving names, collecting generic arguments etc.
 use std::{
@@ -47,7 +47,7 @@ use crate::{
     consteval::{intern_const_scalar, path_to_const, unknown_const, unknown_const_as_generic},
     db::HirDatabase,
     make_binders,
-    mapping::ToChalk,
+    mapping::{from_chalk_trait_id, ToChalk},
     static_lifetime, to_assoc_type_id, to_chalk_trait_id, to_placeholder_idx,
     utils::Generics,
     utils::{all_super_trait_refs, associated_type_by_name_including_super_traits, generics},
@@ -332,7 +332,10 @@ impl<'a> TyLoweringContext<'a> {
             TypeRef::Macro(macro_call) => {
                 let (mut expander, recursion_start) = {
                     match RefMut::filter_map(self.expander.borrow_mut(), Option::as_mut) {
+                        // There already is an expander here, this means we are already recursing
                         Ok(expander) => (expander, false),
+                        // No expander was created yet, so we are at the start of the expansion recursion
+                        // and therefore have to create an expander.
                         Err(expander) => (
                             RefMut::map(expander, |it| {
                                 it.insert(Expander::new(
@@ -362,9 +365,14 @@ impl<'a> TyLoweringContext<'a> {
                                 .exit(self.db.upcast(), mark);
                             Some(ty)
                         }
-                        _ => None,
+                        _ => {
+                            drop(expander);
+                            None
+                        }
                     }
                 };
+
+                // drop the expander, resetting it to pre-recursion state
                 if recursion_start {
                     *self.expander.borrow_mut() = None;
                 }
@@ -974,13 +982,44 @@ impl<'a> TyLoweringContext<'a> {
     fn lower_dyn_trait(&self, bounds: &[Interned<TypeBound>]) -> Ty {
         let self_ty = TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(Interner);
         let bounds = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
-            QuantifiedWhereClauses::from_iter(
+            let bounds =
+                bounds.iter().flat_map(|b| ctx.lower_type_bound(b, self_ty.clone(), false));
+
+            let mut auto_traits = SmallVec::<[_; 8]>::new();
+            let mut regular_traits = SmallVec::<[_; 2]>::new();
+            let mut other_bounds = SmallVec::<[_; 8]>::new();
+            for bound in bounds {
+                if let Some(id) = bound.trait_id() {
+                    if ctx.db.trait_data(from_chalk_trait_id(id)).is_auto {
+                        auto_traits.push(bound);
+                    } else {
+                        regular_traits.push(bound);
+                    }
+                } else {
+                    other_bounds.push(bound);
+                }
+            }
+
+            if regular_traits.len() > 1 {
+                return None;
+            }
+
+            auto_traits.sort_unstable_by_key(|b| b.trait_id().unwrap());
+            auto_traits.dedup();
+
+            Some(QuantifiedWhereClauses::from_iter(
                 Interner,
-                bounds.iter().flat_map(|b| ctx.lower_type_bound(b, self_ty.clone(), false)),
+                regular_traits.into_iter().chain(other_bounds).chain(auto_traits),
-            )
+            ))
         });
+
+        if let Some(bounds) = bounds {
             let bounds = crate::make_single_type_binders(bounds);
             TyKind::Dyn(DynTy { bounds, lifetime: static_lifetime() }).intern(Interner)
+        } else {
+            // FIXME: report error (additional non-auto traits)
+            TyKind::Error.intern(Interner)
+        }
     }
 
     fn lower_impl_trait(

crates/hir-ty/src/tests/macros.rs

@@ -193,8 +193,6 @@ fn expr_macro_def_expanded_in_various_places() {
             !0..6 '1isize': isize
             !0..6 '1isize': isize
             !0..6 '1isize': isize
-            !0..6 '1isize': isize
-            !0..6 '1isize': isize
             39..442 '{     ...!(); }': ()
             73..94 'spam!(...am!())': {unknown}
             100..119 'for _ ...!() {}': ()
@@ -276,8 +274,6 @@ fn expr_macro_rules_expanded_in_various_places() {
             !0..6 '1isize': isize
             !0..6 '1isize': isize
             !0..6 '1isize': isize
-            !0..6 '1isize': isize
-            !0..6 '1isize': isize
             53..456 '{     ...!(); }': ()
             87..108 'spam!(...am!())': {unknown}
             114..133 'for _ ...!() {}': ()
@@ -312,7 +308,6 @@ fn expr_macro_expanded_in_stmts() {
         }
         "#,
         expect![[r#"
-            !0..8 'leta=();': ()
             !3..4 'a': ()
             !5..7 '()': ()
             57..84 '{     ...); } }': ()
@@ -321,7 +316,7 @@ fn expr_macro_expanded_in_stmts() {
 }
 
 #[test]
-fn recurisve_macro_expanded_in_stmts() {
+fn recursive_macro_expanded_in_stmts() {
     check_infer(
         r#"
         macro_rules! ng {
@@ -340,11 +335,6 @@ fn recurisve_macro_expanded_in_stmts() {
         }
         "#,
         expect![[r#"
-            !0..7 'leta=3;': ()
-            !0..13 'ng!{[leta=3]}': ()
-            !0..13 'ng!{[leta=]3}': ()
-            !0..13 'ng!{[leta]=3}': ()
-            !0..13 'ng!{[let]a=3}': ()
             !3..4 'a': i32
             !5..6 '3': i32
             196..237 '{     ...= a; }': ()
@@ -369,8 +359,6 @@ fn recursive_inner_item_macro_rules() {
         "#,
         expect![[r#"
             !0..1 '1': i32
-            !0..7 'mac!($)': ()
-            !0..26 'macro_...>{1};}': ()
             107..143 '{     ...!(); }': ()
             129..130 'a': i32
         "#]],

crates/hir-ty/src/tests/regression.rs

@@ -573,7 +573,6 @@ fn issue_6811() {
         }
         "#,
         expect![[r#"
-            !0..16 'let_a=...t_b=1;': ()
             !3..5 '_a': i32
             !6..7 '1': i32
             !11..13 '_b': i32
@@ -1679,7 +1678,6 @@ fn main() {
 
 #[test]
 fn trailing_empty_macro() {
-    cov_mark::check!(empty_macro_in_trailing_position_is_removed);
     check_no_mismatches(
         r#"
 macro_rules! m2 {

crates/hir-ty/src/tests/simple.rs

@@ -2549,7 +2549,6 @@ impl B for Astruct {}
         expect![[r#"
             569..573 'self': Box<[T], A>
             602..634 '{     ...     }': Vec<T, A>
-            612..628 'unimpl...ted!()': Vec<T, A>
             648..761 '{     ...t]); }': ()
             658..661 'vec': Vec<i32, Global>
             664..679 '<[_]>::into_vec': fn into_vec<i32, Global>(Box<[i32], Global>) -> Vec<i32, Global>
@@ -3070,3 +3069,17 @@ fn main() {
         "#,
     );
 }
+
+#[test]
+fn nested_break() {
+    check_no_mismatches(
+        r#"
+fn func() {
+    let int = loop {
+        break 0;
+        break (break 0);
+    };
+}
+    "#,
+    );
+}

crates/hir-ty/src/tests/traits.rs

@@ -3833,3 +3833,95 @@ fn test() {
 "#,
     )
 }
+
+#[test]
+fn dyn_multiple_auto_traits_in_different_order() {
+    check_no_mismatches(
+        r#"
+auto trait Send {}
+auto trait Sync {}
+
+fn f(t: &(dyn Sync + Send)) {}
+fn g(t: &(dyn Send + Sync)) {
+    f(t);
+}
+        "#,
+    );
+
+    check_no_mismatches(
+        r#"
+auto trait Send {}
+auto trait Sync {}
+trait T {}
+
+fn f(t: &(dyn T + Send + Sync)) {}
+fn g(t: &(dyn Sync + T + Send)) {
+    f(t);
+}
+        "#,
+    );
+
+    check_infer_with_mismatches(
+        r#"
+auto trait Send {}
+auto trait Sync {}
+trait T1 {}
+trait T2 {}
+
+fn f(t: &(dyn T1 + T2 + Send + Sync)) {}
+fn g(t: &(dyn Sync + T2 + T1 + Send)) {
+    f(t);
+}
+        "#,
+        expect![[r#"
+            68..69 't': &{unknown}
+            101..103 '{}': ()
+            109..110 't': &{unknown}
+            142..155 '{     f(t); }': ()
+            148..149 'f': fn f(&{unknown})
+            148..152 'f(t)': ()
+            150..151 't': &{unknown}
+        "#]],
+    );
+
+    check_no_mismatches(
+        r#"
+auto trait Send {}
+auto trait Sync {}
+trait T {
+    type Proj: Send + Sync;
+}
+
+fn f(t: &(dyn T<Proj = ()>  + Send + Sync)) {}
+fn g(t: &(dyn Sync + T<Proj = ()> + Send)) {
+    f(t);
+}
+        "#,
+    );
+}
+
+#[test]
+fn dyn_duplicate_auto_trait() {
+    check_no_mismatches(
+        r#"
+auto trait Send {}
+
+fn f(t: &(dyn Send + Send)) {}
+fn g(t: &(dyn Send)) {
+    f(t);
+}
+        "#,
+    );
+
+    check_no_mismatches(
+        r#"
+auto trait Send {}
+trait T {}
+
+fn f(t: &(dyn T + Send + Send)) {}
+fn g(t: &(dyn T + Send)) {
+    f(t);
+}
+        "#,
+    );
+}

crates/hir/src/diagnostics.rs

@@ -124,6 +124,7 @@ pub struct NoSuchField {
 #[derive(Debug)]
 pub struct BreakOutsideOfLoop {
     pub expr: InFile<AstPtr<ast::Expr>>,
+    pub is_break: bool,
 }
 
 #[derive(Debug)]

crates/hir/src/lib.rs

@@ -1216,11 +1216,11 @@ impl DefWithBody {
                     let field = source_map.field_syntax(*expr);
                     acc.push(NoSuchField { field }.into())
                 }
-                hir_ty::InferenceDiagnostic::BreakOutsideOfLoop { expr } => {
+                &hir_ty::InferenceDiagnostic::BreakOutsideOfLoop { expr, is_break } => {
                     let expr = source_map
-                        .expr_syntax(*expr)
+                        .expr_syntax(expr)
                         .expect("break outside of loop in synthetic syntax");
-                    acc.push(BreakOutsideOfLoop { expr }.into())
+                    acc.push(BreakOutsideOfLoop { expr, is_break }.into())
                 }
                 hir_ty::InferenceDiagnostic::MismatchedArgCount { call_expr, expected, found } => {
                     match source_map.expr_syntax(*call_expr) {

crates/hir/src/source_analyzer.rs

@@ -140,11 +140,19 @@ impl SourceAnalyzer {
     ) -> Option<InFile<ast::Expr>> {
         let macro_file = self.body_source_map()?.node_macro_file(expr.as_ref())?;
         let expanded = db.parse_or_expand(macro_file)?;
-
+        let res = if let Some(stmts) = ast::MacroStmts::cast(expanded.clone()) {
-        let res = match ast::MacroCall::cast(expanded.clone()) {
+            match stmts.expr()? {
-            Some(call) => self.expand_expr(db, InFile::new(macro_file, call))?,
+                ast::Expr::MacroExpr(mac) => {
-            _ => InFile::new(macro_file, ast::Expr::cast(expanded)?),
+                    self.expand_expr(db, InFile::new(macro_file, mac.macro_call()?))?
+                }
+                expr => InFile::new(macro_file, expr),
+            }
+        } else if let Some(call) = ast::MacroCall::cast(expanded.clone()) {
+            self.expand_expr(db, InFile::new(macro_file, call))?
+        } else {
+            InFile::new(macro_file, ast::Expr::cast(expanded)?)
         };
+
         Some(res)
     }
 

crates/ide-assists/src/handlers/convert_two_arm_bool_match_to_matches_macro.rs

@@ -0,0 +1,294 @@
+use syntax::ast::{self, AstNode};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: convert_two_arm_bool_match_to_matches_macro
+//
+// Convert 2-arm match that evaluates to a boolean into the equivalent matches! invocation.
+//
+// ```
+// fn main() {
+//     match scrutinee$0 {
+//         Some(val) if val.cond() => true,
+//         _ => false,
+//     }
+// }
+// ```
+// ->
+// ```
+// fn main() {
+//     matches!(scrutinee, Some(val) if val.cond())
+// }
+// ```
+pub(crate) fn convert_two_arm_bool_match_to_matches_macro(
+    acc: &mut Assists,
+    ctx: &AssistContext<'_>,
+) -> Option<()> {
+    let match_expr = ctx.find_node_at_offset::<ast::MatchExpr>()?;
+    let match_arm_list = match_expr.match_arm_list()?;
+    let mut arms = match_arm_list.arms();
+    let first_arm = arms.next()?;
+    let second_arm = arms.next()?;
+    if arms.next().is_some() {
+        cov_mark::hit!(non_two_arm_match);
+        return None;
+    }
+    let first_arm_expr = first_arm.expr();
+    let second_arm_expr = second_arm.expr();
+
+    let invert_matches = if is_bool_literal_expr(&first_arm_expr, true)
+        && is_bool_literal_expr(&second_arm_expr, false)
+    {
+        false
+    } else if is_bool_literal_expr(&first_arm_expr, false)
+        && is_bool_literal_expr(&second_arm_expr, true)
+    {
+        true
+    } else {
+        cov_mark::hit!(non_invert_bool_literal_arms);
+        return None;
+    };
+
+    let target_range = ctx.sema.original_range(match_expr.syntax()).range;
+    let expr = match_expr.expr()?;
+
+    acc.add(
+        AssistId("convert_two_arm_bool_match_to_matches_macro", AssistKind::RefactorRewrite),
+        "Convert to matches!",
+        target_range,
+        |builder| {
+            let mut arm_str = String::new();
+            if let Some(ref pat) = first_arm.pat() {
+                arm_str += &pat.to_string();
+            }
+            if let Some(ref guard) = first_arm.guard() {
+                arm_str += &format!(" {}", &guard.to_string());
+            }
+            if invert_matches {
+                builder.replace(target_range, format!("!matches!({}, {})", expr, arm_str));
+            } else {
+                builder.replace(target_range, format!("matches!({}, {})", expr, arm_str));
+            }
+        },
+    )
+}
+
+fn is_bool_literal_expr(expr: &Option<ast::Expr>, expect_bool: bool) -> bool {
+    if let Some(ast::Expr::Literal(lit)) = expr {
+        if let ast::LiteralKind::Bool(b) = lit.kind() {
+            return b == expect_bool;
+        }
+    }
+
+    return false;
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::{check_assist, check_assist_not_applicable, check_assist_target};
+
+    use super::convert_two_arm_bool_match_to_matches_macro;
+
+    #[test]
+    fn not_applicable_outside_of_range_left() {
+        check_assist_not_applicable(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    $0 match a {
+        Some(_val) => true,
+        _ => false
+    }
+}
+        "#,
+        );
+    }
+
+    #[test]
+    fn not_applicable_non_two_arm_match() {
+        cov_mark::check!(non_two_arm_match);
+        check_assist_not_applicable(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    match a$0 {
+        Some(3) => true,
+        Some(4) => true,
+        _ => false
+    }
+}
+        "#,
+        );
+    }
+
+    #[test]
+    fn not_applicable_non_bool_literal_arms() {
+        cov_mark::check!(non_invert_bool_literal_arms);
+        check_assist_not_applicable(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    match a$0 {
+        Some(val) => val == 3,
+        _ => false
+    }
+}
+        "#,
+        );
+    }
+    #[test]
+    fn not_applicable_both_false_arms() {
+        cov_mark::check!(non_invert_bool_literal_arms);
+        check_assist_not_applicable(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    match a$0 {
+        Some(val) => false,
+        _ => false
+    }
+}
+        "#,
+        );
+    }
+
+    #[test]
+    fn not_applicable_both_true_arms() {
+        cov_mark::check!(non_invert_bool_literal_arms);
+        check_assist_not_applicable(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    match a$0 {
+        Some(val) => true,
+        _ => true
+    }
+}
+        "#,
+        );
+    }
+
+    #[test]
+    fn convert_simple_case() {
+        check_assist(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    match a$0 {
+        Some(_val) => true,
+        _ => false
+    }
+}
+"#,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    matches!(a, Some(_val))
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn convert_simple_invert_case() {
+        check_assist(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    match a$0 {
+        Some(_val) => false,
+        _ => true
+    }
+}
+"#,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    !matches!(a, Some(_val))
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn convert_with_guard_case() {
+        check_assist(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    match a$0 {
+        Some(val) if val > 3 => true,
+        _ => false
+    }
+}
+"#,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    matches!(a, Some(val) if val > 3)
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn convert_enum_match_cases() {
+        check_assist(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+enum X { A, B }
+
+fn foo(a: X) -> bool {
+    match a$0 {
+        X::A => true,
+        _ => false
+    }
+}
+"#,
+            r#"
+enum X { A, B }
+
+fn foo(a: X) -> bool {
+    matches!(a, X::A)
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn convert_target_simple() {
+        check_assist_target(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+fn foo(a: Option<u32>) -> bool {
+    match a$0 {
+        Some(val) => true,
+        _ => false
+    }
+}
+"#,
+            r#"match a {
+        Some(val) => true,
+        _ => false
+    }"#,
+        );
+    }
+
+    #[test]
+    fn convert_target_complex() {
+        check_assist_target(
+            convert_two_arm_bool_match_to_matches_macro,
+            r#"
+enum E { X, Y }
+
+fn main() {
+    match E::X$0 {
+        E::X => true,
+        _ => false,
+    }
+}
+"#,
+            "match E::X {
+        E::X => true,
+        _ => false,
+    }",
+        );
+    }
+}

crates/ide-assists/src/handlers/extract_struct_from_enum_variant.rs

@@ -101,21 +101,22 @@ pub(crate) fn extract_struct_from_enum_variant(
                 });
             }
 
-            let indent = enum_ast.indent_level();
             let generic_params = enum_ast
                 .generic_param_list()
                 .and_then(|known_generics| extract_generic_params(&known_generics, &field_list));
             let generics = generic_params.as_ref().map(|generics| generics.clone_for_update());
             let def =
                 create_struct_def(variant_name.clone(), &variant, &field_list, generics, &enum_ast);
+
+            let enum_ast = variant.parent_enum();
+            let indent = enum_ast.indent_level();
             def.reindent_to(indent);
 
-            let start_offset = &variant.parent_enum().syntax().clone();
+            ted::insert_all(
-            ted::insert_all_raw(
+                ted::Position::before(enum_ast.syntax()),
-                ted::Position::before(start_offset),
                 vec![
                     def.syntax().clone().into(),
-                    make::tokens::whitespace(&format!("\n\n{}", indent)).into(),
+                    make::tokens::whitespace(&format!("\n\n{indent}")).into(),
                 ],
             );
 
@@ -227,7 +228,7 @@ fn tag_generics_in_variant(ty: &ast::Type, generics: &mut [(ast::GenericParam, b
 }
 
 fn create_struct_def(
-    variant_name: ast::Name,
+    name: ast::Name,
     variant: &ast::Variant,
     field_list: &Either<ast::RecordFieldList, ast::TupleFieldList>,
     generics: Option<ast::GenericParamList>,
@@ -269,43 +270,27 @@ fn create_struct_def(
             field_list.into()
         }
     };
-
     field_list.reindent_to(IndentLevel::single());
 
-    let strukt = make::struct_(enum_vis, variant_name, generics, field_list).clone_for_update();
+    let strukt = make::struct_(enum_vis, name, generics, field_list).clone_for_update();
 
-    // FIXME: Consider making this an actual function somewhere (like in `AttrsOwnerEdit`) after some deliberation
+    // take comments from variant
-    let attrs_and_docs = |node: &SyntaxNode| {
+    ted::insert_all(
-        let mut select_next_ws = false;
+        ted::Position::first_child_of(strukt.syntax()),
-        node.children_with_tokens().filter(move |child| {
+        take_all_comments(variant.syntax()),
-            let accept = match child.kind() {
+    );
-                ATTR | COMMENT => {
-                    select_next_ws = true;
-                    return true;
-                }
-                WHITESPACE if select_next_ws => true,
-                _ => false,
-            };
-            select_next_ws = false;
-
-            accept
-        })
-    };
-
-    // copy attributes & comments from variant
-    let variant_attrs = attrs_and_docs(variant.syntax())
-        .map(|tok| match tok.kind() {
-            WHITESPACE => make::tokens::single_newline().into(),
-            _ => tok,
-        })
-        .collect();
-    ted::insert_all(ted::Position::first_child_of(strukt.syntax()), variant_attrs);
 
     // copy attributes from enum
     ted::insert_all(
         ted::Position::first_child_of(strukt.syntax()),
-        enum_.attrs().map(|it| it.syntax().clone_for_update().into()).collect(),
+        enum_
+            .attrs()
+            .flat_map(|it| {
+                vec![it.syntax().clone_for_update().into(), make::tokens::single_newline().into()]
+            })
+            .collect(),
     );
+
     strukt
 }
 
@@ -346,16 +331,48 @@ fn update_variant(variant: &ast::Variant, generics: Option<ast::GenericParamList
         })
         .unwrap_or_else(|| make::ty(&name.text()));
 
+    // change from a record to a tuple field list
     let tuple_field = make::tuple_field(None, ty);
-    let replacement = make::variant(
+    let field_list = make::tuple_field_list(iter::once(tuple_field)).clone_for_update();
-        name,
+    ted::replace(variant.field_list()?.syntax(), field_list.syntax());
-        Some(ast::FieldList::TupleFieldList(make::tuple_field_list(iter::once(tuple_field)))),
+
-    )
+    // remove any ws after the name
-    .clone_for_update();
+    if let Some(ws) = name
-    ted::replace(variant.syntax(), replacement.syntax());
+        .syntax()
+        .siblings_with_tokens(syntax::Direction::Next)
+        .find_map(|tok| tok.into_token().filter(|tok| tok.kind() == WHITESPACE))
+    {
+        ted::remove(SyntaxElement::Token(ws));
+    }
+
     Some(())
 }
 
+// Note: this also detaches whitespace after comments,
+// since `SyntaxNode::splice_children` (and by extension `ted::insert_all_raw`)
+// detaches nodes. If we only took the comments, we'd leave behind the old whitespace.
+fn take_all_comments(node: &SyntaxNode) -> Vec<SyntaxElement> {
+    let mut remove_next_ws = false;
+    node.children_with_tokens()
+        .filter_map(move |child| match child.kind() {
+            COMMENT => {
+                remove_next_ws = true;
+                child.detach();
+                Some(child)
+            }
+            WHITESPACE if remove_next_ws => {
+                remove_next_ws = false;
+                child.detach();
+                Some(make::tokens::single_newline().into())
+            }
+            _ => {
+                remove_next_ws = false;
+                None
+            }
+        })
+        .collect()
+}
+
 fn apply_references(
     insert_use_cfg: InsertUseConfig,
     segment: ast::PathSegment,
@@ -480,10 +497,14 @@ enum En<T> { Var(Var<T>) }"#,
     fn test_extract_struct_carries_over_attributes() {
         check_assist(
             extract_struct_from_enum_variant,
-            r#"#[derive(Debug)]
+            r#"
+#[derive(Debug)]
 #[derive(Clone)]
 enum Enum { Variant{ field: u32$0 } }"#,
-            r#"#[derive(Debug)]#[derive(Clone)] struct Variant{ field: u32 }
+            r#"
+#[derive(Debug)]
+#[derive(Clone)]
+struct Variant{ field: u32 }
 
 #[derive(Debug)]
 #[derive(Clone)]
@@ -614,7 +635,7 @@ enum A { One(One) }"#,
     }
 
     #[test]
-    fn test_extract_struct_keep_comments_and_attrs_on_variant_struct() {
+    fn test_extract_struct_move_struct_variant_comments() {
         check_assist(
             extract_struct_from_enum_variant,
             r#"
@@ -631,19 +652,19 @@ enum A {
 /* comment */
 // other
 /// comment
-#[attr]
 struct One{
     a: u32
 }
 
 enum A {
+    #[attr]
     One(One)
 }"#,
         );
     }
 
     #[test]
-    fn test_extract_struct_keep_comments_and_attrs_on_variant_tuple() {
+    fn test_extract_struct_move_tuple_variant_comments() {
         check_assist(
             extract_struct_from_enum_variant,
             r#"
@@ -658,10 +679,10 @@ enum A {
 /* comment */
 // other
 /// comment
-#[attr]
 struct One(u32, u32);
 
 enum A {
+    #[attr]
     One(One)
 }"#,
         );

crates/ide-assists/src/handlers/replace_or_with_or_else.rs

@@ -0,0 +1,364 @@
+use ide_db::{
+    assists::{AssistId, AssistKind},
+    famous_defs::FamousDefs,
+};
+use syntax::{
+    ast::{self, make, Expr, HasArgList},
+    AstNode,
+};
+
+use crate::{AssistContext, Assists};
+
+// Assist: replace_or_with_or_else
+//
+// Replace `unwrap_or` with `unwrap_or_else` and `ok_or` with `ok_or_else`.
+//
+// ```
+// # //- minicore:option
+// fn foo() {
+//     let a = Some(1);
+//     a.unwra$0p_or(2);
+// }
+// ```
+// ->
+// ```
+// fn foo() {
+//     let a = Some(1);
+//     a.unwrap_or_else(|| 2);
+// }
+// ```
+pub(crate) fn replace_or_with_or_else(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
+    let call: ast::MethodCallExpr = ctx.find_node_at_offset()?;
+
+    let kind = is_option_or_result(call.receiver()?, ctx)?;
+
+    let (name, arg_list) = (call.name_ref()?, call.arg_list()?);
+
+    let mut map_or = false;
+
+    let replace = match &*name.text() {
+        "unwrap_or" => "unwrap_or_else".to_string(),
+        "or" => "or_else".to_string(),
+        "ok_or" if kind == Kind::Option => "ok_or_else".to_string(),
+        "map_or" => {
+            map_or = true;
+            "map_or_else".to_string()
+        }
+        _ => return None,
+    };
+
+    let arg = match arg_list.args().collect::<Vec<_>>().as_slice() {
+        [] => make::arg_list(Vec::new()),
+        [first] => {
+            let param = into_closure(first);
+            make::arg_list(vec![param])
+        }
+        [first, second] if map_or => {
+            let param = into_closure(first);
+            make::arg_list(vec![param, second.clone()])
+        }
+        _ => return None,
+    };
+
+    acc.add(
+        AssistId("replace_or_with_or_else", AssistKind::RefactorRewrite),
+        format!("Replace {} with {}", name.text(), replace),
+        call.syntax().text_range(),
+        |builder| {
+            builder.replace(name.syntax().text_range(), replace);
+            builder.replace_ast(arg_list, arg)
+        },
+    )
+}
+
+fn into_closure(param: &Expr) -> Expr {
+    (|| {
+        if let ast::Expr::CallExpr(call) = param {
+            if call.arg_list()?.args().count() == 0 {
+                Some(call.expr()?.clone())
+            } else {
+                None
+            }
+        } else {
+            None
+        }
+    })()
+    .unwrap_or_else(|| make::expr_closure(None, param.clone()))
+}
+
+// Assist: replace_or_else_with_or
+//
+// Replace `unwrap_or_else` with `unwrap_or` and `ok_or_else` with `ok_or`.
+//
+// ```
+// # //- minicore:option
+// fn foo() {
+//     let a = Some(1);
+//     a.unwra$0p_or_else(|| 2);
+// }
+// ```
+// ->
+// ```
+// fn foo() {
+//     let a = Some(1);
+//     a.unwrap_or(2);
+// }
+// ```
+pub(crate) fn replace_or_else_with_or(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
+    let call: ast::MethodCallExpr = ctx.find_node_at_offset()?;
+
+    let kind = is_option_or_result(call.receiver()?, ctx)?;
+
+    let (name, arg_list) = (call.name_ref()?, call.arg_list()?);
+
+    let mut map_or = false;
+    let replace = match &*name.text() {
+        "unwrap_or_else" => "unwrap_or".to_string(),
+        "or_else" => "or".to_string(),
+        "ok_or_else" if kind == Kind::Option => "ok_or".to_string(),
+        "map_or_else" => {
+            map_or = true;
+            "map_or".to_string()
+        }
+        _ => return None,
+    };
+
+    let arg = match arg_list.args().collect::<Vec<_>>().as_slice() {
+        [] => make::arg_list(Vec::new()),
+        [first] => {
+            let param = into_call(first);
+            make::arg_list(vec![param])
+        }
+        [first, second] if map_or => {
+            let param = into_call(first);
+            make::arg_list(vec![param, second.clone()])
+        }
+        _ => return None,
+    };
+
+    acc.add(
+        AssistId("replace_or_else_with_or", AssistKind::RefactorRewrite),
+        format!("Replace {} with {}", name.text(), replace),
+        call.syntax().text_range(),
+        |builder| {
+            builder.replace(name.syntax().text_range(), replace);
+            builder.replace_ast(arg_list, arg)
+        },
+    )
+}
+
+fn into_call(param: &Expr) -> Expr {
+    (|| {
+        if let ast::Expr::ClosureExpr(closure) = param {
+            if closure.param_list()?.params().count() == 0 {
+                Some(closure.body()?.clone())
+            } else {
+                None
+            }
+        } else {
+            None
+        }
+    })()
+    .unwrap_or_else(|| make::expr_call(param.clone(), make::arg_list(Vec::new())))
+}
+
+#[derive(PartialEq, Eq)]
+enum Kind {
+    Option,
+    Result,
+}
+
+fn is_option_or_result(receiver: Expr, ctx: &AssistContext<'_>) -> Option<Kind> {
+    let ty = ctx.sema.type_of_expr(&receiver)?.adjusted().as_adt()?.as_enum()?;
+    let option_enum =
+        FamousDefs(&ctx.sema, ctx.sema.scope(receiver.syntax())?.krate()).core_option_Option();
+
+    if let Some(option_enum) = option_enum {
+        if ty == option_enum {
+            return Some(Kind::Option);
+        }
+    }
+
+    let result_enum =
+        FamousDefs(&ctx.sema, ctx.sema.scope(receiver.syntax())?.krate()).core_result_Result();
+
+    if let Some(result_enum) = result_enum {
+        if ty == result_enum {
+            return Some(Kind::Result);
+        }
+    }
+
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::{check_assist, check_assist_not_applicable};
+
+    use super::*;
+
+    #[test]
+    fn replace_or_with_or_else_simple() {
+        check_assist(
+            replace_or_with_or_else,
+            r#"
+//- minicore: option
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_$0or(2);
+}
+"#,
+            r#"
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_or_else(|| 2);
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn replace_or_with_or_else_call() {
+        check_assist(
+            replace_or_with_or_else,
+            r#"
+//- minicore: option
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_$0or(x());
+}
+"#,
+            r#"
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_or_else(x);
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn replace_or_with_or_else_block() {
+        check_assist(
+            replace_or_with_or_else,
+            r#"
+//- minicore: option
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_$0or({
+        let mut x = bar();
+        for i in 0..10 {
+            x += i;
+        }
+        x
+    });
+}
+"#,
+            r#"
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_or_else(|| {
+        let mut x = bar();
+        for i in 0..10 {
+            x += i;
+        }
+        x
+    });
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn replace_or_else_with_or_simple() {
+        check_assist(
+            replace_or_else_with_or,
+            r#"
+//- minicore: option
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_$0or_else(|| 2);
+}
+"#,
+            r#"
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_or(2);
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn replace_or_else_with_or_call() {
+        check_assist(
+            replace_or_else_with_or,
+            r#"
+//- minicore: option
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_$0or_else(x);
+}
+"#,
+            r#"
+fn foo() {
+    let foo = Some(1);
+    return foo.unwrap_or(x());
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn replace_or_else_with_or_result() {
+        check_assist(
+            replace_or_else_with_or,
+            r#"
+//- minicore: result
+fn foo() {
+    let foo = Ok(1);
+    return foo.unwrap_$0or_else(x);
+}
+"#,
+            r#"
+fn foo() {
+    let foo = Ok(1);
+    return foo.unwrap_or(x());
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn replace_or_else_with_or_map() {
+        check_assist(
+            replace_or_else_with_or,
+            r#"
+//- minicore: result
+fn foo() {
+    let foo = Ok("foo");
+    return foo.map$0_or_else(|| 42, |v| v.len());
+}
+"#,
+            r#"
+fn foo() {
+    let foo = Ok("foo");
+    return foo.map_or(42, |v| v.len());
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn replace_or_else_with_or_not_applicable() {
+        check_assist_not_applicable(
+            replace_or_else_with_or,
+            r#"
+fn foo() {
+    let foo = Ok(1);
+    return foo.unwrap_$0or_else(x);
+}
+"#,
+        )
+    }
+}

crates/ide-assists/src/handlers/replace_turbofish_with_explicit_type.rs

@@ -1,5 +1,6 @@
+use hir::HirDisplay;
 use syntax::{
-    ast::{Expr, GenericArg},
+    ast::{Expr, GenericArg, GenericArgList},
     ast::{LetStmt, Type::InferType},
     AstNode, TextRange,
 };
@@ -34,21 +35,7 @@ pub(crate) fn replace_turbofish_with_explicit_type(
 
     let initializer = let_stmt.initializer()?;
 
-    let generic_args = match &initializer {
+    let generic_args = generic_arg_list(&initializer)?;
-        Expr::MethodCallExpr(ce) => ce.generic_arg_list()?,
-        Expr::CallExpr(ce) => {
-            if let Expr::PathExpr(pe) = ce.expr()? {
-                pe.path()?.segment()?.generic_arg_list()?
-            } else {
-                cov_mark::hit!(not_applicable_if_non_path_function_call);
-                return None;
-            }
-        }
-        _ => {
-            cov_mark::hit!(not_applicable_if_non_function_call_initializer);
-            return None;
-        }
-    };
 
     // Find range of ::<_>
     let colon2 = generic_args.coloncolon_token()?;
@@ -65,7 +52,16 @@ pub(crate) fn replace_turbofish_with_explicit_type(
 
     // An improvement would be to check that this is correctly part of the return value of the
     // function call, or sub in the actual return type.
-    let turbofish_type = &turbofish_args[0];
+    let returned_type = match ctx.sema.type_of_expr(&initializer) {
+        Some(returned_type) if !returned_type.original.contains_unknown() => {
+            let module = ctx.sema.scope(let_stmt.syntax())?.module();
+            returned_type.original.display_source_code(ctx.db(), module.into()).ok()?
+        }
+        _ => {
+            cov_mark::hit!(fallback_to_turbofish_type_if_type_info_not_available);
+            turbofish_args[0].to_string()
+        }
+    };
 
     let initializer_start = initializer.syntax().text_range().start();
     if ctx.offset() > turbofish_range.end() || ctx.offset() < initializer_start {
@@ -83,7 +79,7 @@ pub(crate) fn replace_turbofish_with_explicit_type(
             "Replace turbofish with explicit type",
             TextRange::new(initializer_start, turbofish_range.end()),
             |builder| {
-                builder.insert(ident_range.end(), format!(": {}", turbofish_type));
+                builder.insert(ident_range.end(), format!(": {}", returned_type));
                 builder.delete(turbofish_range);
             },
         );
@@ -98,7 +94,7 @@ pub(crate) fn replace_turbofish_with_explicit_type(
             "Replace `_` with turbofish type",
             turbofish_range,
             |builder| {
-                builder.replace(underscore_range, turbofish_type.to_string());
+                builder.replace(underscore_range, returned_type);
                 builder.delete(turbofish_range);
             },
         );
@@ -107,6 +103,26 @@ pub(crate) fn replace_turbofish_with_explicit_type(
     None
 }
 
+fn generic_arg_list(expr: &Expr) -> Option<GenericArgList> {
+    match expr {
+        Expr::MethodCallExpr(expr) => expr.generic_arg_list(),
+        Expr::CallExpr(expr) => {
+            if let Expr::PathExpr(pe) = expr.expr()? {
+                pe.path()?.segment()?.generic_arg_list()
+            } else {
+                cov_mark::hit!(not_applicable_if_non_path_function_call);
+                return None;
+            }
+        }
+        Expr::AwaitExpr(expr) => generic_arg_list(&expr.expr()?),
+        Expr::TryExpr(expr) => generic_arg_list(&expr.expr()?),
+        _ => {
+            cov_mark::hit!(not_applicable_if_non_function_call_initializer);
+            None
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -115,6 +131,7 @@ mod tests {
 
     #[test]
     fn replaces_turbofish_for_vec_string() {
+        cov_mark::check!(fallback_to_turbofish_type_if_type_info_not_available);
         check_assist(
             replace_turbofish_with_explicit_type,
             r#"
@@ -135,6 +152,7 @@ fn main() {
     #[test]
     fn replaces_method_calls() {
         // foo.make() is a method call which uses a different expr in the let initializer
+        cov_mark::check!(fallback_to_turbofish_type_if_type_info_not_available);
         check_assist(
             replace_turbofish_with_explicit_type,
             r#"
@@ -237,6 +255,110 @@ fn make<T>() -> T {}
 fn main() {
     let a = make$0::<Vec<String>, i32>();
 }
+"#,
+        );
+    }
+
+    #[test]
+    fn replaces_turbofish_for_known_type() {
+        check_assist(
+            replace_turbofish_with_explicit_type,
+            r#"
+fn make<T>() -> T {}
+fn main() {
+    let a = make$0::<i32>();
+}
+"#,
+            r#"
+fn make<T>() -> T {}
+fn main() {
+    let a: i32 = make();
+}
+"#,
+        );
+        check_assist(
+            replace_turbofish_with_explicit_type,
+            r#"
+//- minicore: option
+fn make<T>() -> T {}
+fn main() {
+    let a = make$0::<Option<bool>>();
+}
+"#,
+            r#"
+fn make<T>() -> T {}
+fn main() {
+    let a: Option<bool> = make();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn replaces_turbofish_not_same_type() {
+        check_assist(
+            replace_turbofish_with_explicit_type,
+            r#"
+//- minicore: option
+fn make<T>() -> Option<T> {}
+fn main() {
+    let a = make$0::<u128>();
+}
+"#,
+            r#"
+fn make<T>() -> Option<T> {}
+fn main() {
+    let a: Option<u128> = make();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn replaces_turbofish_for_type_with_defaulted_generic_param() {
+        check_assist(
+            replace_turbofish_with_explicit_type,
+            r#"
+struct HasDefault<T, U = i32>(T, U);
+fn make<T>() -> HasDefault<T> {}
+fn main() {
+    let a = make$0::<bool>();
+}
+"#,
+            r#"
+struct HasDefault<T, U = i32>(T, U);
+fn make<T>() -> HasDefault<T> {}
+fn main() {
+    let a: HasDefault<bool> = make();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn replaces_turbofish_try_await() {
+        check_assist(
+            replace_turbofish_with_explicit_type,
+            r#"
+//- minicore: option, future
+struct Fut<T>(T);
+impl<T> core::future::Future for Fut<T> {
+    type Output = Option<T>;
+}
+fn make<T>() -> Fut<T> {}
+fn main() {
+    let a = make$0::<bool>().await?;
+}
+"#,
+            r#"
+struct Fut<T>(T);
+impl<T> core::future::Future for Fut<T> {
+    type Output = Option<T>;
+}
+fn make<T>() -> Fut<T> {}
+fn main() {
+    let a: bool = make().await?;
+}
 "#,
         );
     }

crates/ide-assists/src/handlers/unmerge_match_arm.rs

@@ -0,0 +1,293 @@
+use syntax::{
+    algo::neighbor,
+    ast::{self, edit::IndentLevel, make, AstNode},
+    ted::{self, Position},
+    Direction, SyntaxKind, T,
+};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: unmerge_match_arm
+//
+// Splits the current match with a `|` pattern into two arms with identical bodies.
+//
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+//     match action {
+//         Action::Move(..) $0| Action::Stop => foo(),
+//     }
+// }
+// ```
+// ->
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+//     match action {
+//         Action::Move(..) => foo(),
+//         Action::Stop => foo(),
+//     }
+// }
+// ```
+pub(crate) fn unmerge_match_arm(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
+    let pipe_token = ctx.find_token_syntax_at_offset(T![|])?;
+    let or_pat = ast::OrPat::cast(pipe_token.parent()?)?.clone_for_update();
+    let match_arm = ast::MatchArm::cast(or_pat.syntax().parent()?)?;
+    let match_arm_body = match_arm.expr()?;
+
+    // We don't need to check for leading pipe because it is directly under `MatchArm`
+    // without `OrPat`.
+
+    let new_parent = match_arm.syntax().parent()?;
+    let old_parent_range = new_parent.text_range();
+
+    acc.add(
+        AssistId("unmerge_match_arm", AssistKind::RefactorRewrite),
+        "Unmerge match arm",
+        pipe_token.text_range(),
+        |edit| {
+            let pats_after = pipe_token
+                .siblings_with_tokens(Direction::Next)
+                .filter_map(|it| ast::Pat::cast(it.into_node()?));
+            // FIXME: We should add a leading pipe if the original arm has one.
+            let new_match_arm = make::match_arm(
+                pats_after,
+                match_arm.guard().and_then(|guard| guard.condition()),
+                match_arm_body,
+            )
+            .clone_for_update();
+
+            let mut pipe_index = pipe_token.index();
+            if pipe_token
+                .prev_sibling_or_token()
+                .map_or(false, |it| it.kind() == SyntaxKind::WHITESPACE)
+            {
+                pipe_index -= 1;
+            }
+            or_pat.syntax().splice_children(
+                pipe_index..or_pat.syntax().children_with_tokens().count(),
+                Vec::new(),
+            );
+
+            let mut insert_after_old_arm = Vec::new();
+
+            // A comma can be:
+            //  - After the arm. In this case we always want to insert a comma after the newly
+            //    inserted arm.
+            //  - Missing after the arm, with no arms after. In this case we want to insert a
+            //    comma before the newly inserted arm. It can not be necessary if there arm
+            //    body is a block, but we don't bother to check that.
+            //  - Missing after the arm with arms after, if the arm body is a block. In this case
+            //    we don't want to insert a comma at all.
+            let has_comma_after =
+                std::iter::successors(match_arm.syntax().last_child_or_token(), |it| {
+                    it.prev_sibling_or_token()
+                })
+                .map(|it| it.kind())
+                .skip_while(|it| it.is_trivia())
+                .next()
+                    == Some(T![,]);
+            let has_arms_after = neighbor(&match_arm, Direction::Next).is_some();
+            if !has_comma_after && !has_arms_after {
+                insert_after_old_arm.push(make::token(T![,]).into());
+            }
+
+            let indent = IndentLevel::from_node(match_arm.syntax());
+            insert_after_old_arm.push(make::tokens::whitespace(&format!("\n{indent}")).into());
+
+            insert_after_old_arm.push(new_match_arm.syntax().clone().into());
+
+            ted::insert_all_raw(Position::after(match_arm.syntax()), insert_after_old_arm);
+
+            if has_comma_after {
+                ted::insert_raw(
+                    Position::last_child_of(new_match_arm.syntax()),
+                    make::token(T![,]),
+                );
+            }
+
+            edit.replace(old_parent_range, new_parent.to_string());
+        },
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::{check_assist, check_assist_not_applicable};
+
+    use super::*;
+
+    #[test]
+    fn unmerge_match_arm_single_pipe() {
+        check_assist(
+            unmerge_match_arm,
+            r#"
+#[derive(Debug)]
+enum X { A, B, C }
+
+fn main() {
+    let x = X::A;
+    let y = match x {
+        X::A $0| X::B => { 1i32 }
+        X::C => { 2i32 }
+    };
+}
+"#,
+            r#"
+#[derive(Debug)]
+enum X { A, B, C }
+
+fn main() {
+    let x = X::A;
+    let y = match x {
+        X::A => { 1i32 }
+        X::B => { 1i32 }
+        X::C => { 2i32 }
+    };
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn unmerge_match_arm_guard() {
+        check_assist(
+            unmerge_match_arm,
+            r#"
+#[derive(Debug)]
+enum X { A, B, C }
+
+fn main() {
+    let x = X::A;
+    let y = match x {
+        X::A $0| X::B if true => { 1i32 }
+        _ => { 2i32 }
+    };
+}
+"#,
+            r#"
+#[derive(Debug)]
+enum X { A, B, C }
+
+fn main() {
+    let x = X::A;
+    let y = match x {
+        X::A if true => { 1i32 }
+        X::B if true => { 1i32 }
+        _ => { 2i32 }
+    };
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn unmerge_match_arm_leading_pipe() {
+        check_assist_not_applicable(
+            unmerge_match_arm,
+            r#"
+
+fn main() {
+    let y = match 0 {
+        |$0 0 => { 1i32 }
+        1 => { 2i32 }
+    };
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn unmerge_match_arm_multiple_pipes() {
+        check_assist(
+            unmerge_match_arm,
+            r#"
+#[derive(Debug)]
+enum X { A, B, C, D, E }
+
+fn main() {
+    let x = X::A;
+    let y = match x {
+        X::A | X::B |$0 X::C | X::D => 1i32,
+        X::E => 2i32,
+    };
+}
+"#,
+            r#"
+#[derive(Debug)]
+enum X { A, B, C, D, E }
+
+fn main() {
+    let x = X::A;
+    let y = match x {
+        X::A | X::B => 1i32,
+        X::C | X::D => 1i32,
+        X::E => 2i32,
+    };
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn unmerge_match_arm_inserts_comma_if_required() {
+        check_assist(
+            unmerge_match_arm,
+            r#"
+#[derive(Debug)]
+enum X { A, B }
+
+fn main() {
+    let x = X::A;
+    let y = match x {
+        X::A $0| X::B => 1i32
+    };
+}
+"#,
+            r#"
+#[derive(Debug)]
+enum X { A, B }
+
+fn main() {
+    let x = X::A;
+    let y = match x {
+        X::A => 1i32,
+        X::B => 1i32
+    };
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn unmerge_match_arm_inserts_comma_if_had_after() {
+        check_assist(
+            unmerge_match_arm,
+            r#"
+#[derive(Debug)]
+enum X { A, B }
+
+fn main() {
+    let x = X::A;
+    match x {
+        X::A $0| X::B => {},
+    }
+}
+"#,
+            r#"
+#[derive(Debug)]
+enum X { A, B }
+
+fn main() {
+    let x = X::A;
+    match x {
+        X::A => {},
+        X::B => {},
+    }
+}
+"#,
+        );
+    }
+}

crates/ide-assists/src/lib.rs

@@ -122,6 +122,7 @@ mod handlers {
     mod convert_let_else_to_match;
     mod convert_tuple_struct_to_named_struct;
     mod convert_to_guarded_return;
+    mod convert_two_arm_bool_match_to_matches_macro;
     mod convert_while_to_loop;
     mod destructure_tuple_binding;
     mod expand_glob_import;
@@ -179,12 +180,14 @@ mod handlers {
     mod replace_try_expr_with_match;
     mod replace_derive_with_manual_impl;
     mod replace_if_let_with_match;
+    mod replace_or_with_or_else;
     mod introduce_named_generic;
     mod replace_let_with_if_let;
     mod replace_qualified_name_with_use;
     mod replace_string_with_char;
     mod replace_turbofish_with_explicit_type;
     mod split_import;
+    mod unmerge_match_arm;
     mod sort_items;
     mod toggle_ignore;
     mod unmerge_use;
@@ -215,6 +218,7 @@ mod handlers {
             convert_let_else_to_match::convert_let_else_to_match,
             convert_to_guarded_return::convert_to_guarded_return,
             convert_tuple_struct_to_named_struct::convert_tuple_struct_to_named_struct,
+            convert_two_arm_bool_match_to_matches_macro::convert_two_arm_bool_match_to_matches_macro,
             convert_while_to_loop::convert_while_to_loop,
             destructure_tuple_binding::destructure_tuple_binding,
             expand_glob_import::expand_glob_import,
@@ -273,11 +277,14 @@ mod handlers {
             replace_if_let_with_match::replace_if_let_with_match,
             replace_if_let_with_match::replace_match_with_if_let,
             replace_let_with_if_let::replace_let_with_if_let,
+            replace_or_with_or_else::replace_or_else_with_or,
+            replace_or_with_or_else::replace_or_with_or_else,
             replace_turbofish_with_explicit_type::replace_turbofish_with_explicit_type,
             replace_qualified_name_with_use::replace_qualified_name_with_use,
             sort_items::sort_items,
             split_import::split_import,
             toggle_ignore::toggle_ignore,
+            unmerge_match_arm::unmerge_match_arm,
             unmerge_use::unmerge_use,
             unnecessary_async::unnecessary_async,
             unwrap_block::unwrap_block,

crates/ide-assists/src/tests/generated.rs

@@ -472,6 +472,26 @@ impl Point {
     )
 }
 
+#[test]
+fn doctest_convert_two_arm_bool_match_to_matches_macro() {
+    check_doc_test(
+        "convert_two_arm_bool_match_to_matches_macro",
+        r#####"
+fn main() {
+    match scrutinee$0 {
+        Some(val) if val.cond() => true,
+        _ => false,
+    }
+}
+"#####,
+        r#####"
+fn main() {
+    matches!(scrutinee, Some(val) if val.cond())
+}
+"#####,
+    )
+}
+
 #[test]
 fn doctest_convert_while_to_loop() {
     check_doc_test(
@@ -2009,6 +2029,46 @@ fn handle(action: Action) {
     )
 }
 
+#[test]
+fn doctest_replace_or_else_with_or() {
+    check_doc_test(
+        "replace_or_else_with_or",
+        r#####"
+//- minicore:option
+fn foo() {
+    let a = Some(1);
+    a.unwra$0p_or_else(|| 2);
+}
+"#####,
+        r#####"
+fn foo() {
+    let a = Some(1);
+    a.unwrap_or(2);
+}
+"#####,
+    )
+}
+
+#[test]
+fn doctest_replace_or_with_or_else() {
+    check_doc_test(
+        "replace_or_with_or_else",
+        r#####"
+//- minicore:option
+fn foo() {
+    let a = Some(1);
+    a.unwra$0p_or(2);
+}
+"#####,
+        r#####"
+fn foo() {
+    let a = Some(1);
+    a.unwrap_or_else(|| 2);
+}
+"#####,
+    )
+}
+
 #[test]
 fn doctest_replace_qualified_name_with_use() {
     check_doc_test(
@@ -2207,6 +2267,32 @@ fn arithmetics {
     )
 }
 
+#[test]
+fn doctest_unmerge_match_arm() {
+    check_doc_test(
+        "unmerge_match_arm",
+        r#####"
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move(..) $0| Action::Stop => foo(),
+    }
+}
+"#####,
+        r#####"
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move(..) => foo(),
+        Action::Stop => foo(),
+    }
+}
+"#####,
+    )
+}
+
 #[test]
 fn doctest_unmerge_use() {
     check_doc_test(

crates/ide-completion/src/completions/expr.rs

@@ -282,14 +282,26 @@ pub(crate) fn complete_expr_path(
                         }
                     }
 
-                    if let Some(ty) = innermost_ret_ty {
+                    if let Some(ret_ty) = innermost_ret_ty {
                         add_keyword(
                             "return",
-                            match (in_block_expr, ty.is_unit()) {
+                            match (ret_ty.is_unit(), in_block_expr) {
-                                (true, true) => "return ;",
+                                (true, true) => {
-                                (true, false) => "return;",
+                                    cov_mark::hit!(return_unit_block);
-                                (false, true) => "return $0",
+                                    "return;"
-                                (false, false) => "return",
+                                }
+                                (true, false) => {
+                                    cov_mark::hit!(return_unit_no_block);
+                                    "return"
+                                }
+                                (false, true) => {
+                                    cov_mark::hit!(return_value_block);
+                                    "return $0;"
+                                }
+                                (false, false) => {
+                                    cov_mark::hit!(return_value_no_block);
+                                    "return $0"
+                                }
                             },
                         );
                     }

crates/ide-completion/src/tests/expression.rs

@@ -1,7 +1,7 @@
 //! Completion tests for expressions.
 use expect_test::{expect, Expect};
 
-use crate::tests::{completion_list, BASE_ITEMS_FIXTURE};
+use crate::tests::{check_edit, completion_list, BASE_ITEMS_FIXTURE};
 
 fn check(ra_fixture: &str, expect: Expect) {
     let actual = completion_list(&format!("{}{}", BASE_ITEMS_FIXTURE, ra_fixture));
@@ -670,3 +670,39 @@ fn main() {
         "#]],
     );
 }
+
+#[test]
+fn return_unit_block() {
+    cov_mark::check!(return_unit_block);
+    check_edit("return", r#"fn f() { if true { $0 } }"#, r#"fn f() { if true { return; } }"#);
+}
+
+#[test]
+fn return_unit_no_block() {
+    cov_mark::check!(return_unit_no_block);
+    check_edit(
+        "return",
+        r#"fn f() { match () { () => $0 } }"#,
+        r#"fn f() { match () { () => return } }"#,
+    );
+}
+
+#[test]
+fn return_value_block() {
+    cov_mark::check!(return_value_block);
+    check_edit(
+        "return",
+        r#"fn f() -> i32 { if true { $0 } }"#,
+        r#"fn f() -> i32 { if true { return $0; } }"#,
+    );
+}
+
+#[test]
+fn return_value_no_block() {
+    cov_mark::check!(return_value_no_block);
+    check_edit(
+        "return",
+        r#"fn f() -> i32 { match () { () => $0 } }"#,
+        r#"fn f() -> i32 { match () { () => return $0 } }"#,
+    );
+}

crates/ide-db/src/syntax_helpers/node_ext.rs

@@ -315,7 +315,6 @@ pub fn for_each_tail_expr(expr: &ast::Expr, cb: &mut dyn FnMut(&ast::Expr)) {
         | ast::Expr::IndexExpr(_)
         | ast::Expr::Literal(_)
         | ast::Expr::MacroExpr(_)
-        | ast::Expr::MacroStmts(_)
         | ast::Expr::MethodCallExpr(_)
         | ast::Expr::ParenExpr(_)
         | ast::Expr::PathExpr(_)

crates/ide-diagnostics/src/handlers/break_outside_of_loop.rs

@@ -7,9 +7,10 @@ pub(crate) fn break_outside_of_loop(
     ctx: &DiagnosticsContext<'_>,
     d: &hir::BreakOutsideOfLoop,
 ) -> Diagnostic {
+    let construct = if d.is_break { "break" } else { "continue" };
     Diagnostic::new(
         "break-outside-of-loop",
-        "break outside of loop",
+        format!("{construct} outside of loop"),
         ctx.sema.diagnostics_display_range(d.expr.clone().map(|it| it.into())).range,
     )
 }
@@ -19,11 +20,122 @@ mod tests {
     use crate::tests::check_diagnostics;
 
     #[test]
-    fn break_outside_of_loop() {
+    fn outside_of_loop() {
         check_diagnostics(
             r#"
-fn foo() { break; }
+fn foo() {
+    break;
   //^^^^^ error: break outside of loop
+    break 'a;
+  //^^^^^^^^ error: break outside of loop
+    continue;
+  //^^^^^^^^ error: continue outside of loop
+    continue 'a;
+  //^^^^^^^^^^^ error: continue outside of loop
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn try_blocks_are_borders() {
+        check_diagnostics(
+            r#"
+fn foo() {
+    'a: loop {
+        try {
+                break;
+              //^^^^^ error: break outside of loop
+                break 'a;
+              //^^^^^^^^ error: break outside of loop
+                continue;
+              //^^^^^^^^ error: continue outside of loop
+                continue 'a;
+              //^^^^^^^^^^^ error: continue outside of loop
+        };
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn async_blocks_are_borders() {
+        check_diagnostics(
+            r#"
+fn foo() {
+    'a: loop {
+        try {
+                break;
+              //^^^^^ error: break outside of loop
+                break 'a;
+              //^^^^^^^^ error: break outside of loop
+                continue;
+              //^^^^^^^^ error: continue outside of loop
+                continue 'a;
+              //^^^^^^^^^^^ error: continue outside of loop
+        };
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn closures_are_borders() {
+        check_diagnostics(
+            r#"
+fn foo() {
+    'a: loop {
+        try {
+                break;
+              //^^^^^ error: break outside of loop
+                break 'a;
+              //^^^^^^^^ error: break outside of loop
+                continue;
+              //^^^^^^^^ error: continue outside of loop
+                continue 'a;
+              //^^^^^^^^^^^ error: continue outside of loop
+        };
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn blocks_pass_through() {
+        check_diagnostics(
+            r#"
+fn foo() {
+    'a: loop {
+        {
+            break;
+            break 'a;
+            continue;
+            continue 'a;
+        }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn label_blocks() {
+        check_diagnostics(
+            r#"
+fn foo() {
+    'a: {
+        break;
+      //^^^^^ error: break outside of loop
+        break 'a;
+        continue;
+      //^^^^^^^^ error: continue outside of loop
+        continue 'a;
+      //^^^^^^^^^^^ error: continue outside of loop
+    }
+}
 "#,
         );
     }

crates/ide-diagnostics/src/handlers/missing_match_arms.rs

@@ -947,6 +947,50 @@ fn f() {
         );
     }
 
+    mod rust_unstable {
+        use super::*;
+
+        #[test]
+        fn rfc_1872_exhaustive_patterns() {
+            check_diagnostics_no_bails(
+                r"
+//- minicore: option, result
+#![feature(exhaustive_patterns)]
+enum Void {}
+fn test() {
+    match None::<!> { None => () }
+    match Result::<u8, !>::Ok(2) { Ok(_) => () }
+    match Result::<u8, Void>::Ok(2) { Ok(_) => () }
+    match (2, loop {}) {}
+    match Result::<!, !>::Ok(loop {}) {}
+    match (&loop {}) {} // https://github.com/rust-lang/rust/issues/50642#issuecomment-388234919
+    //    ^^^^^^^^^^ error: missing match arm: type `&!` is non-empty
+}",
+            );
+        }
+
+        #[test]
+        fn rfc_1872_private_uninhabitedness() {
+            check_diagnostics_no_bails(
+                r"
+//- minicore: option
+//- /lib.rs crate:lib
+#![feature(exhaustive_patterns)]
+pub struct PrivatelyUninhabited { private_field: Void }
+enum Void {}
+fn test_local(x: Option<PrivatelyUninhabited>) {
+    match x {}
+} //      ^ error: missing match arm: `None` not covered
+//- /main.rs crate:main deps:lib
+#![feature(exhaustive_patterns)]
+fn test(x: Option<lib::PrivatelyUninhabited>) {
+    match x {}
+    //    ^ error: missing match arm: `None` and `Some(_)` not covered
+}",
+            );
+        }
+    }
+
     mod false_negatives {
         //! The implementation of match checking here is a work in progress. As we roll this out, we
         //! prefer false negatives to false positives (ideally there would be no false positives). This

crates/ide/src/inlay_hints.rs

@@ -1910,7 +1910,7 @@ impl<T> Vec<T> {
 pub struct Box<T> {}
 
 trait Display {}
-trait Sync {}
+auto trait Sync {}
 
 fn main() {
     // The block expression wrapping disables the constructor hint hiding logic

crates/parser/src/grammar/paths.rs

@@ -118,6 +118,11 @@ fn opt_path_type_args(p: &mut Parser<'_>, mode: Mode) {
     match mode {
         Mode::Use => {}
         Mode::Type => {
+            // test typepathfn_with_coloncolon
+            // type F = Start::(Middle) -> (Middle)::End;
+            if p.at(T![::]) && p.nth_at(2, T!['(']) {
+                p.bump(T![::]);
+            }
             // test path_fn_trait_args
             // type F = Box<Fn(i32) -> ()>;
             if p.at(T!['(']) {

crates/parser/src/syntax_kind/generated.rs

@@ -262,33 +262,117 @@ pub enum SyntaxKind {
 use self::SyntaxKind::*;
 impl SyntaxKind {
     pub fn is_keyword(self) -> bool {
-        match self {
+        matches!(
-            AS_KW | ASYNC_KW | AWAIT_KW | BOX_KW | BREAK_KW | CONST_KW | CONTINUE_KW | CRATE_KW
+            self,
-            | DYN_KW | ELSE_KW | ENUM_KW | EXTERN_KW | FALSE_KW | FN_KW | FOR_KW | IF_KW
+            AS_KW
-            | IMPL_KW | IN_KW | LET_KW | LOOP_KW | MACRO_KW | MATCH_KW | MOD_KW | MOVE_KW
+                | ASYNC_KW
-            | MUT_KW | PUB_KW | REF_KW | RETURN_KW | SELF_KW | SELF_TYPE_KW | STATIC_KW
+                | AWAIT_KW
-            | STRUCT_KW | SUPER_KW | TRAIT_KW | TRUE_KW | TRY_KW | TYPE_KW | UNSAFE_KW | USE_KW
+                | BOX_KW
-            | WHERE_KW | WHILE_KW | YIELD_KW | AUTO_KW | DEFAULT_KW | EXISTENTIAL_KW | UNION_KW
+                | BREAK_KW
-            | RAW_KW | MACRO_RULES_KW => true,
+                | CONST_KW
-            _ => false,
+                | CONTINUE_KW
-        }
+                | CRATE_KW
+                | DYN_KW
+                | ELSE_KW
+                | ENUM_KW
+                | EXTERN_KW
+                | FALSE_KW
+                | FN_KW
+                | FOR_KW
+                | IF_KW
+                | IMPL_KW
+                | IN_KW
+                | LET_KW
+                | LOOP_KW
+                | MACRO_KW
+                | MATCH_KW
+                | MOD_KW
+                | MOVE_KW
+                | MUT_KW
+                | PUB_KW
+                | REF_KW
+                | RETURN_KW
+                | SELF_KW
+                | SELF_TYPE_KW
+                | STATIC_KW
+                | STRUCT_KW
+                | SUPER_KW
+                | TRAIT_KW
+                | TRUE_KW
+                | TRY_KW
+                | TYPE_KW
+                | UNSAFE_KW
+                | USE_KW
+                | WHERE_KW
+                | WHILE_KW
+                | YIELD_KW
+                | AUTO_KW
+                | DEFAULT_KW
+                | EXISTENTIAL_KW
+                | UNION_KW
+                | RAW_KW
+                | MACRO_RULES_KW
+        )
     }
     pub fn is_punct(self) -> bool {
-        match self {
+        matches!(
-            SEMICOLON | COMMA | L_PAREN | R_PAREN | L_CURLY | R_CURLY | L_BRACK | R_BRACK
+            self,
-            | L_ANGLE | R_ANGLE | AT | POUND | TILDE | QUESTION | DOLLAR | AMP | PIPE | PLUS
+            SEMICOLON
-            | STAR | SLASH | CARET | PERCENT | UNDERSCORE | DOT | DOT2 | DOT3 | DOT2EQ | COLON
+                | COMMA
-            | COLON2 | EQ | EQ2 | FAT_ARROW | BANG | NEQ | MINUS | THIN_ARROW | LTEQ | GTEQ
+                | L_PAREN
-            | PLUSEQ | MINUSEQ | PIPEEQ | AMPEQ | CARETEQ | SLASHEQ | STAREQ | PERCENTEQ | AMP2
+                | R_PAREN
-            | PIPE2 | SHL | SHR | SHLEQ | SHREQ => true,
+                | L_CURLY
-            _ => false,
+                | R_CURLY
-        }
+                | L_BRACK
+                | R_BRACK
+                | L_ANGLE
+                | R_ANGLE
+                | AT
+                | POUND
+                | TILDE
+                | QUESTION
+                | DOLLAR
+                | AMP
+                | PIPE
+                | PLUS
+                | STAR
+                | SLASH
+                | CARET
+                | PERCENT
+                | UNDERSCORE
+                | DOT
+                | DOT2
+                | DOT3
+                | DOT2EQ
+                | COLON
+                | COLON2
+                | EQ
+                | EQ2
+                | FAT_ARROW
+                | BANG
+                | NEQ
+                | MINUS
+                | THIN_ARROW
+                | LTEQ
+                | GTEQ
+                | PLUSEQ
+                | MINUSEQ
+                | PIPEEQ
+                | AMPEQ
+                | CARETEQ
+                | SLASHEQ
+                | STAREQ
+                | PERCENTEQ
+                | AMP2
+                | PIPE2
+                | SHL
+                | SHR
+                | SHLEQ
+                | SHREQ
+        )
     }
     pub fn is_literal(self) -> bool {
-        match self {
+        matches!(self, INT_NUMBER | FLOAT_NUMBER | CHAR | BYTE | STRING | BYTE_STRING)
-            INT_NUMBER | FLOAT_NUMBER | CHAR | BYTE | STRING | BYTE_STRING => true,
-            _ => false,
-        }
     }
     pub fn from_keyword(ident: &str) -> Option<SyntaxKind> {
         let kw = match ident {

crates/parser/test_data/parser/inline/ok/0202_typepathfn_with_coloncolon.rast

@@ -0,0 +1,43 @@
+SOURCE_FILE
+  TYPE_ALIAS
+    TYPE_KW "type"
+    WHITESPACE " "
+    NAME
+      IDENT "F"
+    WHITESPACE " "
+    EQ "="
+    WHITESPACE " "
+    PATH_TYPE
+      PATH
+        PATH
+          PATH_SEGMENT
+            NAME_REF
+              IDENT "Start"
+            COLON2 "::"
+            PARAM_LIST
+              L_PAREN "("
+              PARAM
+                PATH_TYPE
+                  PATH
+                    PATH_SEGMENT
+                      NAME_REF
+                        IDENT "Middle"
+              R_PAREN ")"
+            WHITESPACE " "
+            RET_TYPE
+              THIN_ARROW "->"
+              WHITESPACE " "
+              PAREN_TYPE
+                L_PAREN "("
+                PATH_TYPE
+                  PATH
+                    PATH_SEGMENT
+                      NAME_REF
+                        IDENT "Middle"
+                R_PAREN ")"
+        COLON2 "::"
+        PATH_SEGMENT
+          NAME_REF
+            IDENT "End"
+    SEMICOLON ";"
+  WHITESPACE "\n"

crates/parser/test_data/parser/inline/ok/0202_typepathfn_with_coloncolon.rs

@@ -0,0 +1 @@
+type F = Start::(Middle) -> (Middle)::End;

crates/rust-analyzer/src/global_state.rs

@@ -116,6 +116,7 @@ pub(crate) struct GlobalStateSnapshot {
     pub(crate) semantic_tokens_cache: Arc<Mutex<FxHashMap<Url, SemanticTokens>>>,
     vfs: Arc<RwLock<(vfs::Vfs, NoHashHashMap<FileId, LineEndings>)>>,
     pub(crate) workspaces: Arc<Vec<ProjectWorkspace>>,
+    pub(crate) proc_macros_loaded: bool,
 }
 
 impl std::panic::UnwindSafe for GlobalStateSnapshot {}
@@ -256,6 +257,7 @@ impl GlobalState {
             check_fixes: Arc::clone(&self.diagnostics.check_fixes),
             mem_docs: self.mem_docs.clone(),
             semantic_tokens_cache: Arc::clone(&self.semantic_tokens_cache),
+            proc_macros_loaded: !self.fetch_build_data_queue.last_op_result().0.is_empty(),
         }
     }
 

crates/rust-analyzer/src/handlers.rs

@@ -1504,7 +1504,11 @@ pub(crate) fn handle_semantic_tokens_full(
     let text = snap.analysis.file_text(file_id)?;
     let line_index = snap.file_line_index(file_id)?;
 
-    let highlights = snap.analysis.highlight(snap.config.highlighting_config(), file_id)?;
+    let mut highlight_config = snap.config.highlighting_config();
+    // Avoid flashing a bunch of unresolved references when the proc-macro servers haven't been spawned yet.
+    highlight_config.syntactic_name_ref_highlighting = !snap.proc_macros_loaded;
+
+    let highlights = snap.analysis.highlight(highlight_config, file_id)?;
     let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
 
     // Unconditionally cache the tokens
@@ -1523,7 +1527,11 @@ pub(crate) fn handle_semantic_tokens_full_delta(
     let text = snap.analysis.file_text(file_id)?;
     let line_index = snap.file_line_index(file_id)?;
 
-    let highlights = snap.analysis.highlight(snap.config.highlighting_config(), file_id)?;
+    let mut highlight_config = snap.config.highlighting_config();
+    // Avoid flashing a bunch of unresolved references when the proc-macro servers haven't been spawned yet.
+    highlight_config.syntactic_name_ref_highlighting = !snap.proc_macros_loaded;
+
+    let highlights = snap.analysis.highlight(highlight_config, file_id)?;
     let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
 
     let mut cache = snap.semantic_tokens_cache.lock();

crates/rust-analyzer/src/reload.rs

@@ -347,8 +347,8 @@ impl GlobalState {
                             error
                         })
                     })
-                    .collect();
+                    .collect()
-            }
+            };
         }
 
         let watch = match files_config.watcher {

crates/syntax/rust.ungram

@@ -343,7 +343,6 @@ Expr =
 | Literal
 | LoopExpr
 | MacroExpr
-| MacroStmts
 | MatchExpr
 | MethodCallExpr
 | ParenExpr

crates/syntax/src/ast/generated/nodes.rs

@@ -1526,7 +1526,6 @@ pub enum Expr {
     Literal(Literal),
     LoopExpr(LoopExpr),
     MacroExpr(MacroExpr),
-    MacroStmts(MacroStmts),
     MatchExpr(MatchExpr),
     MethodCallExpr(MethodCallExpr),
     ParenExpr(ParenExpr),
@@ -3169,10 +3168,7 @@ impl From<ConstArg> for GenericArg {
 }
 impl AstNode for GenericArg {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(kind, TYPE_ARG | ASSOC_TYPE_ARG | LIFETIME_ARG | CONST_ARG)
-            TYPE_ARG | ASSOC_TYPE_ARG | LIFETIME_ARG | CONST_ARG => true,
-            _ => false,
-        }
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
@@ -3237,12 +3233,23 @@ impl From<TupleType> for Type {
 }
 impl AstNode for Type {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
-            ARRAY_TYPE | DYN_TRAIT_TYPE | FN_PTR_TYPE | FOR_TYPE | IMPL_TRAIT_TYPE | INFER_TYPE
+            kind,
-            | MACRO_TYPE | NEVER_TYPE | PAREN_TYPE | PATH_TYPE | PTR_TYPE | REF_TYPE
+            ARRAY_TYPE
-            | SLICE_TYPE | TUPLE_TYPE => true,
+                | DYN_TRAIT_TYPE
-            _ => false,
+                | FN_PTR_TYPE
-        }
+                | FOR_TYPE
+                | IMPL_TRAIT_TYPE
+                | INFER_TYPE
+                | MACRO_TYPE
+                | NEVER_TYPE
+                | PAREN_TYPE
+                | PATH_TYPE
+                | PTR_TYPE
+                | REF_TYPE
+                | SLICE_TYPE
+                | TUPLE_TYPE
+        )
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
@@ -3334,9 +3341,6 @@ impl From<LoopExpr> for Expr {
 impl From<MacroExpr> for Expr {
     fn from(node: MacroExpr) -> Expr { Expr::MacroExpr(node) }
 }
-impl From<MacroStmts> for Expr {
-    fn from(node: MacroStmts) -> Expr { Expr::MacroStmts(node) }
-}
 impl From<MatchExpr> for Expr {
     fn from(node: MatchExpr) -> Expr { Expr::MatchExpr(node) }
 }
@@ -3384,15 +3388,41 @@ impl From<UnderscoreExpr> for Expr {
 }
 impl AstNode for Expr {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
-            ARRAY_EXPR | AWAIT_EXPR | BIN_EXPR | BLOCK_EXPR | BOX_EXPR | BREAK_EXPR | CALL_EXPR
+            kind,
-            | CAST_EXPR | CLOSURE_EXPR | CONTINUE_EXPR | FIELD_EXPR | FOR_EXPR | IF_EXPR
+            ARRAY_EXPR
-            | INDEX_EXPR | LITERAL | LOOP_EXPR | MACRO_EXPR | MACRO_STMTS | MATCH_EXPR
+                | AWAIT_EXPR
-            | METHOD_CALL_EXPR | PAREN_EXPR | PATH_EXPR | PREFIX_EXPR | RANGE_EXPR
+                | BIN_EXPR
-            | RECORD_EXPR | REF_EXPR | RETURN_EXPR | TRY_EXPR | TUPLE_EXPR | WHILE_EXPR
+                | BLOCK_EXPR
-            | YIELD_EXPR | LET_EXPR | UNDERSCORE_EXPR => true,
+                | BOX_EXPR
-            _ => false,
+                | BREAK_EXPR
-        }
+                | CALL_EXPR
+                | CAST_EXPR
+                | CLOSURE_EXPR
+                | CONTINUE_EXPR
+                | FIELD_EXPR
+                | FOR_EXPR
+                | IF_EXPR
+                | INDEX_EXPR
+                | LITERAL
+                | LOOP_EXPR
+                | MACRO_EXPR
+                | MATCH_EXPR
+                | METHOD_CALL_EXPR
+                | PAREN_EXPR
+                | PATH_EXPR
+                | PREFIX_EXPR
+                | RANGE_EXPR
+                | RECORD_EXPR
+                | REF_EXPR
+                | RETURN_EXPR
+                | TRY_EXPR
+                | TUPLE_EXPR
+                | WHILE_EXPR
+                | YIELD_EXPR
+                | LET_EXPR
+                | UNDERSCORE_EXPR
+        )
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
@@ -3413,7 +3443,6 @@ impl AstNode for Expr {
             LITERAL => Expr::Literal(Literal { syntax }),
             LOOP_EXPR => Expr::LoopExpr(LoopExpr { syntax }),
             MACRO_EXPR => Expr::MacroExpr(MacroExpr { syntax }),
-            MACRO_STMTS => Expr::MacroStmts(MacroStmts { syntax }),
             MATCH_EXPR => Expr::MatchExpr(MatchExpr { syntax }),
             METHOD_CALL_EXPR => Expr::MethodCallExpr(MethodCallExpr { syntax }),
             PAREN_EXPR => Expr::ParenExpr(ParenExpr { syntax }),
@@ -3452,7 +3481,6 @@ impl AstNode for Expr {
             Expr::Literal(it) => &it.syntax,
             Expr::LoopExpr(it) => &it.syntax,
             Expr::MacroExpr(it) => &it.syntax,
-            Expr::MacroStmts(it) => &it.syntax,
             Expr::MatchExpr(it) => &it.syntax,
             Expr::MethodCallExpr(it) => &it.syntax,
             Expr::ParenExpr(it) => &it.syntax,
@@ -3521,11 +3549,25 @@ impl From<Use> for Item {
 }
 impl AstNode for Item {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
-            CONST | ENUM | EXTERN_BLOCK | EXTERN_CRATE | FN | IMPL | MACRO_CALL | MACRO_RULES
+            kind,
-            | MACRO_DEF | MODULE | STATIC | STRUCT | TRAIT | TYPE_ALIAS | UNION | USE => true,
+            CONST
-            _ => false,
+                | ENUM
-        }
+                | EXTERN_BLOCK
+                | EXTERN_CRATE
+                | FN
+                | IMPL
+                | MACRO_CALL
+                | MACRO_RULES
+                | MACRO_DEF
+                | MODULE
+                | STATIC
+                | STRUCT
+                | TRAIT
+                | TYPE_ALIAS
+                | UNION
+                | USE
+        )
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
@@ -3629,12 +3671,25 @@ impl From<ConstBlockPat> for Pat {
 }
 impl AstNode for Pat {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
-            IDENT_PAT | BOX_PAT | REST_PAT | LITERAL_PAT | MACRO_PAT | OR_PAT | PAREN_PAT
+            kind,
-            | PATH_PAT | WILDCARD_PAT | RANGE_PAT | RECORD_PAT | REF_PAT | SLICE_PAT
+            IDENT_PAT
-            | TUPLE_PAT | TUPLE_STRUCT_PAT | CONST_BLOCK_PAT => true,
+                | BOX_PAT
-            _ => false,
+                | REST_PAT
-        }
+                | LITERAL_PAT
+                | MACRO_PAT
+                | OR_PAT
+                | PAREN_PAT
+                | PATH_PAT
+                | WILDCARD_PAT
+                | RANGE_PAT
+                | RECORD_PAT
+                | REF_PAT
+                | SLICE_PAT
+                | TUPLE_PAT
+                | TUPLE_STRUCT_PAT
+                | CONST_BLOCK_PAT
+        )
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
@@ -3686,12 +3741,7 @@ impl From<TupleFieldList> for FieldList {
     fn from(node: TupleFieldList) -> FieldList { FieldList::TupleFieldList(node) }
 }
 impl AstNode for FieldList {
-    fn can_cast(kind: SyntaxKind) -> bool {
+    fn can_cast(kind: SyntaxKind) -> bool { matches!(kind, RECORD_FIELD_LIST | TUPLE_FIELD_LIST) }
-        match kind {
-            RECORD_FIELD_LIST | TUPLE_FIELD_LIST => true,
-            _ => false,
-        }
-    }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
             RECORD_FIELD_LIST => FieldList::RecordFieldList(RecordFieldList { syntax }),
@@ -3717,12 +3767,7 @@ impl From<Union> for Adt {
     fn from(node: Union) -> Adt { Adt::Union(node) }
 }
 impl AstNode for Adt {
-    fn can_cast(kind: SyntaxKind) -> bool {
+    fn can_cast(kind: SyntaxKind) -> bool { matches!(kind, ENUM | STRUCT | UNION) }
-        match kind {
-            ENUM | STRUCT | UNION => true,
-            _ => false,
-        }
-    }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
             ENUM => Adt::Enum(Enum { syntax }),
@@ -3753,12 +3798,7 @@ impl From<TypeAlias> for AssocItem {
     fn from(node: TypeAlias) -> AssocItem { AssocItem::TypeAlias(node) }
 }
 impl AstNode for AssocItem {
-    fn can_cast(kind: SyntaxKind) -> bool {
+    fn can_cast(kind: SyntaxKind) -> bool { matches!(kind, CONST | FN | MACRO_CALL | TYPE_ALIAS) }
-        match kind {
-            CONST | FN | MACRO_CALL | TYPE_ALIAS => true,
-            _ => false,
-        }
-    }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
             CONST => AssocItem::Const(Const { syntax }),
@@ -3791,12 +3831,7 @@ impl From<TypeAlias> for ExternItem {
     fn from(node: TypeAlias) -> ExternItem { ExternItem::TypeAlias(node) }
 }
 impl AstNode for ExternItem {
-    fn can_cast(kind: SyntaxKind) -> bool {
+    fn can_cast(kind: SyntaxKind) -> bool { matches!(kind, FN | MACRO_CALL | STATIC | TYPE_ALIAS) }
-        match kind {
-            FN | MACRO_CALL | STATIC | TYPE_ALIAS => true,
-            _ => false,
-        }
-    }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
             FN => ExternItem::Fn(Fn { syntax }),
@@ -3827,10 +3862,7 @@ impl From<TypeParam> for GenericParam {
 }
 impl AstNode for GenericParam {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(kind, CONST_PARAM | LIFETIME_PARAM | TYPE_PARAM)
-            CONST_PARAM | LIFETIME_PARAM | TYPE_PARAM => true,
-            _ => false,
-        }
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         let res = match syntax.kind() {
@@ -3856,12 +3888,7 @@ impl AnyHasArgList {
     }
 }
 impl AstNode for AnyHasArgList {
-    fn can_cast(kind: SyntaxKind) -> bool {
+    fn can_cast(kind: SyntaxKind) -> bool { matches!(kind, CALL_EXPR | METHOD_CALL_EXPR) }
-        match kind {
-            CALL_EXPR | METHOD_CALL_EXPR => true,
-            _ => false,
-        }
-    }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasArgList { syntax })
     }
@@ -3875,7 +3902,8 @@ impl AnyHasAttrs {
 }
 impl AstNode for AnyHasAttrs {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
+            kind,
             MACRO_CALL
                 | SOURCE_FILE
                 | CONST
@@ -3942,9 +3970,8 @@ impl AstNode for AnyHasAttrs {
                 | MATCH_ARM
                 | IDENT_PAT
                 | REST_PAT
-            | RECORD_PAT_FIELD => true,
+                | RECORD_PAT_FIELD
-            _ => false,
+        )
-        }
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasAttrs { syntax })
@@ -3959,12 +3986,29 @@ impl AnyHasDocComments {
 }
 impl AstNode for AnyHasDocComments {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
-            MACRO_CALL | SOURCE_FILE | CONST | ENUM | EXTERN_BLOCK | EXTERN_CRATE | FN | IMPL
+            kind,
-            | MACRO_RULES | MACRO_DEF | MODULE | STATIC | STRUCT | TRAIT | TYPE_ALIAS | UNION
+            MACRO_CALL
-            | USE | RECORD_FIELD | TUPLE_FIELD | VARIANT => true,
+                | SOURCE_FILE
-            _ => false,
+                | CONST
-        }
+                | ENUM
+                | EXTERN_BLOCK
+                | EXTERN_CRATE
+                | FN
+                | IMPL
+                | MACRO_RULES
+                | MACRO_DEF
+                | MODULE
+                | STATIC
+                | STRUCT
+                | TRAIT
+                | TYPE_ALIAS
+                | UNION
+                | USE
+                | RECORD_FIELD
+                | TUPLE_FIELD
+                | VARIANT
+        )
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasDocComments { syntax })
@@ -3979,10 +4023,7 @@ impl AnyHasGenericParams {
 }
 impl AstNode for AnyHasGenericParams {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(kind, ENUM | FN | IMPL | STRUCT | TRAIT | TYPE_ALIAS | UNION)
-            ENUM | FN | IMPL | STRUCT | TRAIT | TYPE_ALIAS | UNION => true,
-            _ => false,
-        }
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasGenericParams { syntax })
@@ -3996,12 +4037,7 @@ impl AnyHasLoopBody {
     }
 }
 impl AstNode for AnyHasLoopBody {
-    fn can_cast(kind: SyntaxKind) -> bool {
+    fn can_cast(kind: SyntaxKind) -> bool { matches!(kind, FOR_EXPR | LOOP_EXPR | WHILE_EXPR) }
-        match kind {
-            FOR_EXPR | LOOP_EXPR | WHILE_EXPR => true,
-            _ => false,
-        }
-    }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasLoopBody { syntax })
     }
@@ -4014,12 +4050,7 @@ impl AnyHasModuleItem {
     }
 }
 impl AstNode for AnyHasModuleItem {
-    fn can_cast(kind: SyntaxKind) -> bool {
+    fn can_cast(kind: SyntaxKind) -> bool { matches!(kind, MACRO_ITEMS | SOURCE_FILE | ITEM_LIST) }
-        match kind {
-            MACRO_ITEMS | SOURCE_FILE | ITEM_LIST => true,
-            _ => false,
-        }
-    }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasModuleItem { syntax })
     }
@@ -4033,12 +4064,27 @@ impl AnyHasName {
 }
 impl AstNode for AnyHasName {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
-            CONST | ENUM | FN | MACRO_RULES | MACRO_DEF | MODULE | STATIC | STRUCT | TRAIT
+            kind,
-            | TYPE_ALIAS | UNION | RENAME | SELF_PARAM | RECORD_FIELD | VARIANT | CONST_PARAM
+            CONST
-            | TYPE_PARAM | IDENT_PAT => true,
+                | ENUM
-            _ => false,
+                | FN
-        }
+                | MACRO_RULES
+                | MACRO_DEF
+                | MODULE
+                | STATIC
+                | STRUCT
+                | TRAIT
+                | TYPE_ALIAS
+                | UNION
+                | RENAME
+                | SELF_PARAM
+                | RECORD_FIELD
+                | VARIANT
+                | CONST_PARAM
+                | TYPE_PARAM
+                | IDENT_PAT
+        )
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasName { syntax })
@@ -4053,10 +4099,10 @@ impl AnyHasTypeBounds {
 }
 impl AstNode for AnyHasTypeBounds {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
-            ASSOC_TYPE_ARG | TRAIT | TYPE_ALIAS | LIFETIME_PARAM | TYPE_PARAM | WHERE_PRED => true,
+            kind,
-            _ => false,
+            ASSOC_TYPE_ARG | TRAIT | TYPE_ALIAS | LIFETIME_PARAM | TYPE_PARAM | WHERE_PRED
-        }
+        )
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasTypeBounds { syntax })
@@ -4071,13 +4117,26 @@ impl AnyHasVisibility {
 }
 impl AstNode for AnyHasVisibility {
     fn can_cast(kind: SyntaxKind) -> bool {
-        match kind {
+        matches!(
-            CONST | ENUM | EXTERN_CRATE | FN | IMPL | MACRO_RULES | MACRO_DEF | MODULE | STATIC
+            kind,
-            | STRUCT | TRAIT | TYPE_ALIAS | UNION | USE | RECORD_FIELD | TUPLE_FIELD | VARIANT => {
+            CONST
-                true
+                | ENUM
-            }
+                | EXTERN_CRATE
-            _ => false,
+                | FN
-        }
+                | IMPL
+                | MACRO_RULES
+                | MACRO_DEF
+                | MODULE
+                | STATIC
+                | STRUCT
+                | TRAIT
+                | TYPE_ALIAS
+                | UNION
+                | USE
+                | RECORD_FIELD
+                | TUPLE_FIELD
+                | VARIANT
+        )
     }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
         Self::can_cast(syntax.kind()).then(|| AnyHasVisibility { syntax })

crates/syntax/src/ast/make.rs

@@ -25,7 +25,7 @@ pub mod ext {
         return from_text(&name.text());
 
         fn from_text(text: &str) -> ast::IdentPat {
-            ast_from_text(&format!("fn f({}: ())", text))
+            ast_from_text(&format!("fn f({text}: ())"))
         }
     }
     pub fn ident_path(ident: &str) -> ast::Path {
@@ -60,10 +60,10 @@ pub mod ext {
         expr_from_text("todo!()")
     }
     pub fn expr_ty_default(ty: &ast::Type) -> ast::Expr {
-        expr_from_text(&format!("{}::default()", ty))
+        expr_from_text(&format!("{ty}::default()"))
     }
     pub fn expr_ty_new(ty: &ast::Type) -> ast::Expr {
-        expr_from_text(&format!("{}::new()", ty))
+        expr_from_text(&format!("{ty}::new()"))
     }
 
     pub fn zero_number() -> ast::Expr {
@@ -92,18 +92,20 @@ pub mod ext {
         ty_path(ident_path("bool"))
     }
     pub fn ty_option(t: ast::Type) -> ast::Type {
-        ty_from_text(&format!("Option<{}>", t))
+        ty_from_text(&format!("Option<{t}>"))
     }
     pub fn ty_result(t: ast::Type, e: ast::Type) -> ast::Type {
-        ty_from_text(&format!("Result<{}, {}>", t, e))
+        ty_from_text(&format!("Result<{t}, {e}>"))
     }
 }
 
-pub fn name(text: &str) -> ast::Name {
+pub fn name(name: &str) -> ast::Name {
-    ast_from_text(&format!("mod {}{};", raw_ident_esc(text), text))
+    let raw_escape = raw_ident_esc(name);
+    ast_from_text(&format!("mod {raw_escape}{name};"))
 }
-pub fn name_ref(text: &str) -> ast::NameRef {
+pub fn name_ref(name_ref: &str) -> ast::NameRef {
-    ast_from_text(&format!("fn f() {{ {}{}; }}", raw_ident_esc(text), text))
+    let raw_escape = raw_ident_esc(name_ref);
+    ast_from_text(&format!("fn f() {{ {raw_escape}{name_ref}; }}"))
 }
 fn raw_ident_esc(ident: &str) -> &'static str {
     let is_keyword = parser::SyntaxKind::from_keyword(ident).is_some();
@@ -118,10 +120,10 @@ pub fn lifetime(text: &str) -> ast::Lifetime {
     let mut text = text;
     let tmp;
     if never!(!text.starts_with('\'')) {
-        tmp = format!("'{}", text);
+        tmp = format!("'{text}");
         text = &tmp;
     }
-    ast_from_text(&format!("fn f<{}>() {{ }}", text))
+    ast_from_text(&format!("fn f<{text}>() {{ }}"))
 }
 
 // FIXME: replace stringly-typed constructor with a family of typed ctors, a-la
@@ -142,16 +144,16 @@ pub fn ty_tuple(types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
         contents.push(',');
     }
 
-    ty_from_text(&format!("({})", contents))
+    ty_from_text(&format!("({contents})"))
 }
 pub fn ty_ref(target: ast::Type, exclusive: bool) -> ast::Type {
-    ty_from_text(&if exclusive { format!("&mut {}", target) } else { format!("&{}", target) })
+    ty_from_text(&if exclusive { format!("&mut {target}") } else { format!("&{target}") })
 }
 pub fn ty_path(path: ast::Path) -> ast::Type {
     ty_from_text(&path.to_string())
 }
 fn ty_from_text(text: &str) -> ast::Type {
-    ast_from_text(&format!("type _T = {};", text))
+    ast_from_text(&format!("type _T = {text};"))
 }
 
 pub fn assoc_item_list() -> ast::AssocItemList {
@@ -171,7 +173,7 @@ pub fn impl_(
         Some(params) => params.to_string(),
         None => String::new(),
     };
-    ast_from_text(&format!("impl{} {}{} {{}}", params, ty, ty_params))
+    ast_from_text(&format!("impl{params} {ty}{ty_params} {{}}"))
 }
 
 pub fn impl_trait(
@@ -180,7 +182,7 @@ pub fn impl_trait(
     ty_params: Option<ast::GenericParamList>,
 ) -> ast::Impl {
     let ty_params = ty_params.map_or_else(String::new, |params| params.to_string());
-    ast_from_text(&format!("impl{2} {} for {}{2} {{}}", trait_, ty, ty_params))
+    ast_from_text(&format!("impl{ty_params} {trait_} for {ty}{ty_params} {{}}"))
 }
 
 pub(crate) fn generic_arg_list() -> ast::GenericArgList {
@@ -188,13 +190,13 @@ pub(crate) fn generic_arg_list() -> ast::GenericArgList {
 }
 
 pub fn path_segment(name_ref: ast::NameRef) -> ast::PathSegment {
-    ast_from_text(&format!("type __ = {};", name_ref))
+    ast_from_text(&format!("type __ = {name_ref};"))
 }
 
 pub fn path_segment_ty(type_ref: ast::Type, trait_ref: Option<ast::PathType>) -> ast::PathSegment {
     let text = match trait_ref {
-        Some(trait_ref) => format!("fn f(x: <{} as {}>) {{}}", type_ref, trait_ref),
+        Some(trait_ref) => format!("fn f(x: <{type_ref} as {trait_ref}>) {{}}"),
-        None => format!("fn f(x: <{}>) {{}}", type_ref),
+        None => format!("fn f(x: <{type_ref}>) {{}}"),
     };
     ast_from_text(&text)
 }
@@ -212,15 +214,15 @@ pub fn path_segment_crate() -> ast::PathSegment {
 }
 
 pub fn path_unqualified(segment: ast::PathSegment) -> ast::Path {
-    ast_from_text(&format!("type __ = {};", segment))
+    ast_from_text(&format!("type __ = {segment};"))
 }
 
 pub fn path_qualified(qual: ast::Path, segment: ast::PathSegment) -> ast::Path {
-    ast_from_text(&format!("{}::{}", qual, segment))
+    ast_from_text(&format!("{qual}::{segment}"))
 }
 // FIXME: path concatenation operation doesn't make sense as AST op.
 pub fn path_concat(first: ast::Path, second: ast::Path) -> ast::Path {
-    ast_from_text(&format!("type __ = {}::{};", first, second))
+    ast_from_text(&format!("type __ = {first}::{second};"))
 }
 
 pub fn path_from_segments(
@@ -229,20 +231,20 @@ pub fn path_from_segments(
 ) -> ast::Path {
     let segments = segments.into_iter().map(|it| it.syntax().clone()).join("::");
     ast_from_text(&if is_abs {
-        format!("fn f(x: ::{}) {{}}", segments)
+        format!("fn f(x: ::{segments}) {{}}")
     } else {
-        format!("fn f(x: {}) {{}}", segments)
+        format!("fn f(x: {segments}) {{}}")
     })
 }
 
 pub fn join_paths(paths: impl IntoIterator<Item = ast::Path>) -> ast::Path {
     let paths = paths.into_iter().map(|it| it.syntax().clone()).join("::");
-    ast_from_text(&format!("type __ = {};", paths))
+    ast_from_text(&format!("type __ = {paths};"))
 }
 
 // FIXME: should not be pub
 pub fn path_from_text(text: &str) -> ast::Path {
-    ast_from_text(&format!("fn main() {{ let test = {}; }}", text))
+    ast_from_text(&format!("fn main() {{ let test = {text}; }}"))
 }
 
 pub fn use_tree_glob() -> ast::UseTree {
@@ -257,50 +259,50 @@ pub fn use_tree(
     let mut buf = "use ".to_string();
     buf += &path.syntax().to_string();
     if let Some(use_tree_list) = use_tree_list {
-        format_to!(buf, "::{}", use_tree_list);
+        format_to!(buf, "::{use_tree_list}");
     }
     if add_star {
         buf += "::*";
     }
 
     if let Some(alias) = alias {
-        format_to!(buf, " {}", alias);
+        format_to!(buf, " {alias}");
     }
     ast_from_text(&buf)
 }
 
 pub fn use_tree_list(use_trees: impl IntoIterator<Item = ast::UseTree>) -> ast::UseTreeList {
     let use_trees = use_trees.into_iter().map(|it| it.syntax().clone()).join(", ");
-    ast_from_text(&format!("use {{{}}};", use_trees))
+    ast_from_text(&format!("use {{{use_trees}}};"))
 }
 
 pub fn use_(visibility: Option<ast::Visibility>, use_tree: ast::UseTree) -> ast::Use {
     let visibility = match visibility {
         None => String::new(),
-        Some(it) => format!("{} ", it),
+        Some(it) => format!("{it} "),
     };
-    ast_from_text(&format!("{}use {};", visibility, use_tree))
+    ast_from_text(&format!("{visibility}use {use_tree};"))
 }
 
 pub fn record_expr(path: ast::Path, fields: ast::RecordExprFieldList) -> ast::RecordExpr {
-    ast_from_text(&format!("fn f() {{ {} {} }}", path, fields))
+    ast_from_text(&format!("fn f() {{ {path} {fields} }}"))
 }
 
 pub fn record_expr_field_list(
     fields: impl IntoIterator<Item = ast::RecordExprField>,
 ) -> ast::RecordExprFieldList {
     let fields = fields.into_iter().join(", ");
-    ast_from_text(&format!("fn f() {{ S {{ {} }} }}", fields))
+    ast_from_text(&format!("fn f() {{ S {{ {fields} }} }}"))
 }
 
 pub fn record_expr_field(name: ast::NameRef, expr: Option<ast::Expr>) -> ast::RecordExprField {
     return match expr {
-        Some(expr) => from_text(&format!("{}: {}", name, expr)),
+        Some(expr) => from_text(&format!("{name}: {expr}")),
         None => from_text(&name.to_string()),
     };
 
     fn from_text(text: &str) -> ast::RecordExprField {
-        ast_from_text(&format!("fn f() {{ S {{ {}, }} }}", text))
+        ast_from_text(&format!("fn f() {{ S {{ {text}, }} }}"))
     }
 }
 
@@ -311,9 +313,9 @@ pub fn record_field(
 ) -> ast::RecordField {
     let visibility = match visibility {
         None => String::new(),
-        Some(it) => format!("{} ", it),
+        Some(it) => format!("{it} "),
     };
-    ast_from_text(&format!("struct S {{ {}{}: {}, }}", visibility, name, ty))
+    ast_from_text(&format!("struct S {{ {visibility}{name}: {ty}, }}"))
 }
 
 // TODO
@@ -323,13 +325,13 @@ pub fn block_expr(
 ) -> ast::BlockExpr {
     let mut buf = "{\n".to_string();
     for stmt in stmts.into_iter() {
-        format_to!(buf, "    {}\n", stmt);
+        format_to!(buf, "    {stmt}\n");
     }
     if let Some(tail_expr) = tail_expr {
-        format_to!(buf, "    {}\n", tail_expr);
+        format_to!(buf, "    {tail_expr}\n");
     }
     buf += "}";
-    ast_from_text(&format!("fn f() {}", buf))
+    ast_from_text(&format!("fn f() {buf}"))
 }
 
 /// Ideally this function wouldn't exist since it involves manual indenting.
@@ -343,18 +345,18 @@ pub fn hacky_block_expr_with_comments(
     let mut buf = "{\n".to_string();
     for node_or_token in elements.into_iter() {
         match node_or_token {
-            rowan::NodeOrToken::Node(n) => format_to!(buf, "    {}\n", n),
+            rowan::NodeOrToken::Node(n) => format_to!(buf, "    {n}\n"),
             rowan::NodeOrToken::Token(t) if t.kind() == SyntaxKind::COMMENT => {
-                format_to!(buf, "    {}\n", t)
+                format_to!(buf, "    {t}\n")
             }
             _ => (),
         }
     }
     if let Some(tail_expr) = tail_expr {
-        format_to!(buf, "    {}\n", tail_expr);
+        format_to!(buf, "    {tail_expr}\n");
     }
     buf += "}";
-    ast_from_text(&format!("fn f() {}", buf))
+    ast_from_text(&format!("fn f() {buf}"))
 }
 
 pub fn expr_unit() -> ast::Expr {
@@ -362,7 +364,7 @@ pub fn expr_unit() -> ast::Expr {
 }
 pub fn expr_literal(text: &str) -> ast::Literal {
     assert_eq!(text.trim(), text);
-    ast_from_text(&format!("fn f() {{ let _ = {}; }}", text))
+    ast_from_text(&format!("fn f() {{ let _ = {text}; }}"))
 }
 
 pub fn expr_empty_block() -> ast::Expr {
@@ -373,41 +375,41 @@ pub fn expr_path(path: ast::Path) -> ast::Expr {
 }
 pub fn expr_continue(label: Option<ast::Lifetime>) -> ast::Expr {
     match label {
-        Some(label) => expr_from_text(&format!("continue {}", label)),
+        Some(label) => expr_from_text(&format!("continue {label}")),
         None => expr_from_text("continue"),
     }
 }
 // Consider `op: SyntaxKind` instead for nicer syntax at the call-site?
 pub fn expr_bin_op(lhs: ast::Expr, op: ast::BinaryOp, rhs: ast::Expr) -> ast::Expr {
-    expr_from_text(&format!("{} {} {}", lhs, op, rhs))
+    expr_from_text(&format!("{lhs} {op} {rhs}"))
 }
 pub fn expr_break(label: Option<ast::Lifetime>, expr: Option<ast::Expr>) -> ast::Expr {
     let mut s = String::from("break");
 
     if let Some(label) = label {
-        format_to!(s, " {}", label);
+        format_to!(s, " {label}");
     }
 
     if let Some(expr) = expr {
-        format_to!(s, " {}", expr);
+        format_to!(s, " {expr}");
     }
 
     expr_from_text(&s)
 }
 pub fn expr_return(expr: Option<ast::Expr>) -> ast::Expr {
     match expr {
-        Some(expr) => expr_from_text(&format!("return {}", expr)),
+        Some(expr) => expr_from_text(&format!("return {expr}")),
         None => expr_from_text("return"),
     }
 }
 pub fn expr_try(expr: ast::Expr) -> ast::Expr {
-    expr_from_text(&format!("{}?", expr))
+    expr_from_text(&format!("{expr}?"))
 }
 pub fn expr_await(expr: ast::Expr) -> ast::Expr {
-    expr_from_text(&format!("{}.await", expr))
+    expr_from_text(&format!("{expr}.await"))
 }
 pub fn expr_match(expr: ast::Expr, match_arm_list: ast::MatchArmList) -> ast::Expr {
-    expr_from_text(&format!("match {} {}", expr, match_arm_list))
+    expr_from_text(&format!("match {expr} {match_arm_list}"))
 }
 pub fn expr_if(
     condition: ast::Expr,
@@ -415,66 +417,67 @@ pub fn expr_if(
     else_branch: Option<ast::ElseBranch>,
 ) -> ast::Expr {
     let else_branch = match else_branch {
-        Some(ast::ElseBranch::Block(block)) => format!("else {}", block),
+        Some(ast::ElseBranch::Block(block)) => format!("else {block}"),
-        Some(ast::ElseBranch::IfExpr(if_expr)) => format!("else {}", if_expr),
+        Some(ast::ElseBranch::IfExpr(if_expr)) => format!("else {if_expr}"),
         None => String::new(),
     };
-    expr_from_text(&format!("if {} {} {}", condition, then_branch, else_branch))
+    expr_from_text(&format!("if {condition} {then_branch} {else_branch}"))
 }
 pub fn expr_for_loop(pat: ast::Pat, expr: ast::Expr, block: ast::BlockExpr) -> ast::Expr {
-    expr_from_text(&format!("for {} in {} {}", pat, expr, block))
+    expr_from_text(&format!("for {pat} in {expr} {block}"))
 }
 
 pub fn expr_loop(block: ast::BlockExpr) -> ast::Expr {
-    expr_from_text(&format!("loop {}", block))
+    expr_from_text(&format!("loop {block}"))
 }
 
 pub fn expr_prefix(op: SyntaxKind, expr: ast::Expr) -> ast::Expr {
     let token = token(op);
-    expr_from_text(&format!("{}{}", token, expr))
+    expr_from_text(&format!("{token}{expr}"))
 }
 pub fn expr_call(f: ast::Expr, arg_list: ast::ArgList) -> ast::Expr {
-    expr_from_text(&format!("{}{}", f, arg_list))
+    expr_from_text(&format!("{f}{arg_list}"))
 }
 pub fn expr_method_call(
     receiver: ast::Expr,
     method: ast::NameRef,
     arg_list: ast::ArgList,
 ) -> ast::Expr {
-    expr_from_text(&format!("{}.{}{}", receiver, method, arg_list))
+    expr_from_text(&format!("{receiver}.{method}{arg_list}"))
 }
 pub fn expr_macro_call(f: ast::Expr, arg_list: ast::ArgList) -> ast::Expr {
-    expr_from_text(&format!("{}!{}", f, arg_list))
+    expr_from_text(&format!("{f}!{arg_list}"))
 }
 pub fn expr_ref(expr: ast::Expr, exclusive: bool) -> ast::Expr {
-    expr_from_text(&if exclusive { format!("&mut {}", expr) } else { format!("&{}", expr) })
+    expr_from_text(&if exclusive { format!("&mut {expr}") } else { format!("&{expr}") })
 }
 pub fn expr_closure(pats: impl IntoIterator<Item = ast::Param>, expr: ast::Expr) -> ast::Expr {
     let params = pats.into_iter().join(", ");
-    expr_from_text(&format!("|{}| {}", params, expr))
+    expr_from_text(&format!("|{params}| {expr}"))
 }
 pub fn expr_field(receiver: ast::Expr, field: &str) -> ast::Expr {
-    expr_from_text(&format!("{}.{}", receiver, field))
+    expr_from_text(&format!("{receiver}.{field}"))
 }
 pub fn expr_paren(expr: ast::Expr) -> ast::Expr {
-    expr_from_text(&format!("({})", expr))
+    expr_from_text(&format!("({expr})"))
 }
 pub fn expr_tuple(elements: impl IntoIterator<Item = ast::Expr>) -> ast::Expr {
     let expr = elements.into_iter().format(", ");
-    expr_from_text(&format!("({})", expr))
+    expr_from_text(&format!("({expr})"))
 }
 pub fn expr_assignment(lhs: ast::Expr, rhs: ast::Expr) -> ast::Expr {
-    expr_from_text(&format!("{} = {}", lhs, rhs))
+    expr_from_text(&format!("{lhs} = {rhs}"))
 }
 fn expr_from_text(text: &str) -> ast::Expr {
-    ast_from_text(&format!("const C: () = {};", text))
+    ast_from_text(&format!("const C: () = {text};"))
 }
 pub fn expr_let(pattern: ast::Pat, expr: ast::Expr) -> ast::LetExpr {
-    ast_from_text(&format!("const _: () = while let {} = {} {{}};", pattern, expr))
+    ast_from_text(&format!("const _: () = while let {pattern} = {expr} {{}};"))
 }
 
 pub fn arg_list(args: impl IntoIterator<Item = ast::Expr>) -> ast::ArgList {
-    ast_from_text(&format!("fn main() {{ ()({}) }}", args.into_iter().format(", ")))
+    let args = args.into_iter().format(", ");
+    ast_from_text(&format!("fn main() {{ ()({args}) }}"))
 }
 
 pub fn ident_pat(ref_: bool, mut_: bool, name: ast::Name) -> ast::IdentPat {
@@ -485,7 +488,7 @@ pub fn ident_pat(ref_: bool, mut_: bool, name: ast::Name) -> ast::IdentPat {
     if mut_ {
         s.push_str("mut ");
     }
-    format_to!(s, "{}", name);
+    format_to!(s, "{name}");
     s.push_str(": ())");
     ast_from_text(&s)
 }
@@ -494,7 +497,7 @@ pub fn wildcard_pat() -> ast::WildcardPat {
     return from_text("_");
 
     fn from_text(text: &str) -> ast::WildcardPat {
-        ast_from_text(&format!("fn f({}: ())", text))
+        ast_from_text(&format!("fn f({text}: ())"))
     }
 }
 
@@ -502,7 +505,7 @@ pub fn literal_pat(lit: &str) -> ast::LiteralPat {
     return from_text(lit);
 
     fn from_text(text: &str) -> ast::LiteralPat {
-        ast_from_text(&format!("fn f() {{ match x {{ {} => {{}} }} }}", text))
+        ast_from_text(&format!("fn f() {{ match x {{ {text} => {{}} }} }}"))
     }
 }
 
@@ -515,10 +518,10 @@ pub fn tuple_pat(pats: impl IntoIterator<Item = ast::Pat>) -> ast::TuplePat {
     if count == 1 {
         pats_str.push(',');
     }
-    return from_text(&format!("({})", pats_str));
+    return from_text(&format!("({pats_str})"));
 
     fn from_text(text: &str) -> ast::TuplePat {
-        ast_from_text(&format!("fn f({}: ())", text))
+        ast_from_text(&format!("fn f({text}: ())"))
     }
 }
 
@@ -527,46 +530,46 @@ pub fn tuple_struct_pat(
     pats: impl IntoIterator<Item = ast::Pat>,
 ) -> ast::TupleStructPat {
     let pats_str = pats.into_iter().join(", ");
-    return from_text(&format!("{}({})", path, pats_str));
+    return from_text(&format!("{path}({pats_str})"));
 
     fn from_text(text: &str) -> ast::TupleStructPat {
-        ast_from_text(&format!("fn f({}: ())", text))
+        ast_from_text(&format!("fn f({text}: ())"))
     }
 }
 
 pub fn record_pat(path: ast::Path, pats: impl IntoIterator<Item = ast::Pat>) -> ast::RecordPat {
     let pats_str = pats.into_iter().join(", ");
-    return from_text(&format!("{} {{ {} }}", path, pats_str));
+    return from_text(&format!("{path} {{ {pats_str} }}"));
 
     fn from_text(text: &str) -> ast::RecordPat {
-        ast_from_text(&format!("fn f({}: ())", text))
+        ast_from_text(&format!("fn f({text}: ())"))
     }
 }
 
 pub fn record_pat_with_fields(path: ast::Path, fields: ast::RecordPatFieldList) -> ast::RecordPat {
-    ast_from_text(&format!("fn f({} {}: ()))", path, fields))
+    ast_from_text(&format!("fn f({path} {fields}: ()))"))
 }
 
 pub fn record_pat_field_list(
     fields: impl IntoIterator<Item = ast::RecordPatField>,
 ) -> ast::RecordPatFieldList {
     let fields = fields.into_iter().join(", ");
-    ast_from_text(&format!("fn f(S {{ {} }}: ()))", fields))
+    ast_from_text(&format!("fn f(S {{ {fields} }}: ()))"))
 }
 
 pub fn record_pat_field(name_ref: ast::NameRef, pat: ast::Pat) -> ast::RecordPatField {
-    ast_from_text(&format!("fn f(S {{ {}: {} }}: ()))", name_ref, pat))
+    ast_from_text(&format!("fn f(S {{ {name_ref}: {pat} }}: ()))"))
 }
 
 pub fn record_pat_field_shorthand(name_ref: ast::NameRef) -> ast::RecordPatField {
-    ast_from_text(&format!("fn f(S {{ {} }}: ()))", name_ref))
+    ast_from_text(&format!("fn f(S {{ {name_ref} }}: ()))"))
 }
 
 /// Returns a `BindPat` if the path has just one segment, a `PathPat` otherwise.
 pub fn path_pat(path: ast::Path) -> ast::Pat {
     return from_text(&path.to_string());
     fn from_text(text: &str) -> ast::Pat {
-        ast_from_text(&format!("fn f({}: ())", text))
+        ast_from_text(&format!("fn f({text}: ())"))
     }
 }
 
@@ -577,12 +580,12 @@ pub fn match_arm(
 ) -> ast::MatchArm {
     let pats_str = pats.into_iter().join(" | ");
     return match guard {
-        Some(guard) => from_text(&format!("{} if {} => {}", pats_str, guard, expr)),
+        Some(guard) => from_text(&format!("{pats_str} if {guard} => {expr}")),
-        None => from_text(&format!("{} => {}", pats_str, expr)),
+        None => from_text(&format!("{pats_str} => {expr}")),
     };
 
     fn from_text(text: &str) -> ast::MatchArm {
-        ast_from_text(&format!("fn f() {{ match () {{{}}} }}", text))
+        ast_from_text(&format!("fn f() {{ match () {{{text}}} }}"))
     }
 }
 
@@ -592,10 +595,10 @@ pub fn match_arm_with_guard(
     expr: ast::Expr,
 ) -> ast::MatchArm {
     let pats_str = pats.into_iter().join(" | ");
-    return from_text(&format!("{} if {} => {}", pats_str, guard, expr));
+    return from_text(&format!("{pats_str} if {guard} => {expr}"));
 
     fn from_text(text: &str) -> ast::MatchArm {
-        ast_from_text(&format!("fn f() {{ match () {{{}}} }}", text))
+        ast_from_text(&format!("fn f() {{ match () {{{text}}} }}"))
     }
 }
 
@@ -605,13 +608,14 @@ pub fn match_arm_list(arms: impl IntoIterator<Item = ast::MatchArm>) -> ast::Mat
         .map(|arm| {
             let needs_comma = arm.expr().map_or(true, |it| !it.is_block_like());
             let comma = if needs_comma { "," } else { "" };
-            format!("    {}{}\n", arm.syntax(), comma)
+            let arm = arm.syntax();
+            format!("    {arm}{comma}\n")
         })
         .collect::<String>();
     return from_text(&arms_str);
 
     fn from_text(text: &str) -> ast::MatchArmList {
-        ast_from_text(&format!("fn f() {{ match () {{\n{}}} }}", text))
+        ast_from_text(&format!("fn f() {{ match () {{\n{text}}} }}"))
     }
 }
 
@@ -620,10 +624,10 @@ pub fn where_pred(
     bounds: impl IntoIterator<Item = ast::TypeBound>,
 ) -> ast::WherePred {
     let bounds = bounds.into_iter().join(" + ");
-    return from_text(&format!("{}: {}", path, bounds));
+    return from_text(&format!("{path}: {bounds}"));
 
     fn from_text(text: &str) -> ast::WherePred {
-        ast_from_text(&format!("fn f() where {} {{ }}", text))
+        ast_from_text(&format!("fn f() where {text} {{ }}"))
     }
 }
 
@@ -632,7 +636,7 @@ pub fn where_clause(preds: impl IntoIterator<Item = ast::WherePred>) -> ast::Whe
     return from_text(preds.as_str());
 
     fn from_text(text: &str) -> ast::WhereClause {
-        ast_from_text(&format!("fn f() where {} {{ }}", text))
+        ast_from_text(&format!("fn f() where {text} {{ }}"))
     }
 }
 
@@ -642,19 +646,19 @@ pub fn let_stmt(
     initializer: Option<ast::Expr>,
 ) -> ast::LetStmt {
     let mut text = String::new();
-    format_to!(text, "let {}", pattern);
+    format_to!(text, "let {pattern}");
     if let Some(ty) = ty {
-        format_to!(text, ": {}", ty);
+        format_to!(text, ": {ty}");
     }
     match initializer {
-        Some(it) => format_to!(text, " = {};", it),
+        Some(it) => format_to!(text, " = {it};"),
         None => format_to!(text, ";"),
     };
-    ast_from_text(&format!("fn f() {{ {} }}", text))
+    ast_from_text(&format!("fn f() {{ {text} }}"))
 }
 pub fn expr_stmt(expr: ast::Expr) -> ast::ExprStmt {
     let semi = if expr.is_block_like() { "" } else { ";" };
-    ast_from_text(&format!("fn f() {{ {}{} (); }}", expr, semi))
+    ast_from_text(&format!("fn f() {{ {expr}{semi} (); }}"))
 }
 
 pub fn item_const(
@@ -665,13 +669,13 @@ pub fn item_const(
 ) -> ast::Const {
     let visibility = match visibility {
         None => String::new(),
-        Some(it) => format!("{} ", it),
+        Some(it) => format!("{it} "),
     };
-    ast_from_text(&format!("{} const {}: {} = {};", visibility, name, ty, expr))
+    ast_from_text(&format!("{visibility} const {name}: {ty} = {expr};"))
 }
 
 pub fn param(pat: ast::Pat, ty: ast::Type) -> ast::Param {
-    ast_from_text(&format!("fn f({}: {}) {{ }}", pat, ty))
+    ast_from_text(&format!("fn f({pat}: {ty}) {{ }}"))
 }
 
 pub fn self_param() -> ast::SelfParam {
@@ -679,7 +683,7 @@ pub fn self_param() -> ast::SelfParam {
 }
 
 pub fn ret_type(ty: ast::Type) -> ast::RetType {
-    ast_from_text(&format!("fn f() -> {} {{ }}", ty))
+    ast_from_text(&format!("fn f() -> {ty} {{ }}"))
 }
 
 pub fn param_list(
@@ -688,30 +692,30 @@ pub fn param_list(
 ) -> ast::ParamList {
     let args = pats.into_iter().join(", ");
     let list = match self_param {
-        Some(self_param) if args.is_empty() => format!("fn f({}) {{ }}", self_param),
+        Some(self_param) if args.is_empty() => format!("fn f({self_param}) {{ }}"),
-        Some(self_param) => format!("fn f({}, {}) {{ }}", self_param, args),
+        Some(self_param) => format!("fn f({self_param}, {args}) {{ }}"),
-        None => format!("fn f({}) {{ }}", args),
+        None => format!("fn f({args}) {{ }}"),
     };
     ast_from_text(&list)
 }
 
 pub fn type_param(name: ast::Name, ty: Option<ast::TypeBoundList>) -> ast::TypeParam {
     let bound = match ty {
-        Some(it) => format!(": {}", it),
+        Some(it) => format!(": {it}"),
         None => String::new(),
     };
-    ast_from_text(&format!("fn f<{}{}>() {{ }}", name, bound))
+    ast_from_text(&format!("fn f<{name}{bound}>() {{ }}"))
 }
 
 pub fn lifetime_param(lifetime: ast::Lifetime) -> ast::LifetimeParam {
-    ast_from_text(&format!("fn f<{}>() {{ }}", lifetime))
+    ast_from_text(&format!("fn f<{lifetime}>() {{ }}"))
 }
 
 pub fn generic_param_list(
     pats: impl IntoIterator<Item = ast::GenericParam>,
 ) -> ast::GenericParamList {
     let args = pats.into_iter().join(", ");
-    ast_from_text(&format!("fn f<{}>() {{ }}", args))
+    ast_from_text(&format!("fn f<{args}>() {{ }}"))
 }
 
 pub fn visibility_pub_crate() -> ast::Visibility {
@@ -724,33 +728,33 @@ pub fn visibility_pub() -> ast::Visibility {
 
 pub fn tuple_field_list(fields: impl IntoIterator<Item = ast::TupleField>) -> ast::TupleFieldList {
     let fields = fields.into_iter().join(", ");
-    ast_from_text(&format!("struct f({});", fields))
+    ast_from_text(&format!("struct f({fields});"))
 }
 
 pub fn record_field_list(
     fields: impl IntoIterator<Item = ast::RecordField>,
 ) -> ast::RecordFieldList {
     let fields = fields.into_iter().join(", ");
-    ast_from_text(&format!("struct f {{ {} }}", fields))
+    ast_from_text(&format!("struct f {{ {fields} }}"))
 }
 
 pub fn tuple_field(visibility: Option<ast::Visibility>, ty: ast::Type) -> ast::TupleField {
     let visibility = match visibility {
         None => String::new(),
-        Some(it) => format!("{} ", it),
+        Some(it) => format!("{it} "),
     };
-    ast_from_text(&format!("struct f({}{});", visibility, ty))
+    ast_from_text(&format!("struct f({visibility}{ty});"))
 }
 
 pub fn variant(name: ast::Name, field_list: Option<ast::FieldList>) -> ast::Variant {
     let field_list = match field_list {
         None => String::new(),
         Some(it) => match it {
-            ast::FieldList::RecordFieldList(record) => format!(" {}", record),
+            ast::FieldList::RecordFieldList(record) => format!(" {record}"),
-            ast::FieldList::TupleFieldList(tuple) => format!("{}", tuple),
+            ast::FieldList::TupleFieldList(tuple) => format!("{tuple}"),
         },
     };
-    ast_from_text(&format!("enum f {{ {}{} }}", name, field_list))
+    ast_from_text(&format!("enum f {{ {name}{field_list} }}"))
 }
 
 pub fn fn_(
@@ -763,23 +767,22 @@ pub fn fn_(
     is_async: bool,
 ) -> ast::Fn {
     let type_params = match type_params {
-        Some(type_params) => format!("{}", type_params),
+        Some(type_params) => format!("{type_params}"),
         None => "".into(),
     };
     let ret_type = match ret_type {
-        Some(ret_type) => format!("{} ", ret_type),
+        Some(ret_type) => format!("{ret_type} "),
         None => "".into(),
     };
     let visibility = match visibility {
         None => String::new(),
-        Some(it) => format!("{} ", it),
+        Some(it) => format!("{it} "),
     };
 
     let async_literal = if is_async { "async " } else { "" };
 
     ast_from_text(&format!(
-        "{}{}fn {}{}{} {}{}",
+        "{visibility}{async_literal}fn {fn_name}{type_params}{params} {ret_type}{body}",
-        visibility, async_literal, fn_name, type_params, params, ret_type, body
     ))
 }
 
@@ -793,13 +796,10 @@ pub fn struct_(
     let type_params = generic_param_list.map_or_else(String::new, |it| it.to_string());
     let visibility = match visibility {
         None => String::new(),
-        Some(it) => format!("{} ", it),
+        Some(it) => format!("{it} "),
     };
 
-    ast_from_text(&format!(
+    ast_from_text(&format!("{visibility}struct {strukt_name}{type_params}{field_list}{semicolon}",))
-        "{}struct {}{}{}{}",
-        visibility, strukt_name, type_params, field_list, semicolon
-    ))
 }
 
 #[track_caller]
@@ -808,7 +808,8 @@ fn ast_from_text<N: AstNode>(text: &str) -> N {
     let node = match parse.tree().syntax().descendants().find_map(N::cast) {
         Some(it) => it,
         None => {
-            panic!("Failed to make ast node `{}` from text {}", std::any::type_name::<N>(), text)
+            let node = std::any::type_name::<N>();
+            panic!("Failed to make ast node `{node}` from text {text}")
         }
     };
     let node = node.clone_subtree();
@@ -824,7 +825,7 @@ pub fn token(kind: SyntaxKind) -> SyntaxToken {
         .descendants_with_tokens()
         .filter_map(|it| it.into_token())
         .find(|it| it.kind() == kind)
-        .unwrap_or_else(|| panic!("unhandled token: {:?}", kind))
+        .unwrap_or_else(|| panic!("unhandled token: {kind:?}"))
 }
 
 pub mod tokens {
@@ -863,7 +864,7 @@ pub mod tokens {
 
     pub fn literal(text: &str) -> SyntaxToken {
         assert_eq!(text.trim(), text);
-        let lit: ast::Literal = super::ast_from_text(&format!("fn f() {{ let _ = {}; }}", text));
+        let lit: ast::Literal = super::ast_from_text(&format!("fn f() {{ let _ = {text}; }}"));
         lit.syntax().first_child_or_token().unwrap().into_token().unwrap()
     }
 

crates/syntax/src/ast/token_ext.rs

@@ -322,7 +322,7 @@ impl ast::IntNumber {
 
     pub fn float_value(&self) -> Option<f64> {
         let (_, text, _) = self.split_into_parts();
-        text.parse::<f64>().ok()
+        text.replace('_', "").parse::<f64>().ok()
     }
 }
 
@@ -361,7 +361,7 @@ impl ast::FloatNumber {
 
     pub fn value(&self) -> Option<f64> {
         let (text, _) = self.split_into_parts();
-        text.parse::<f64>().ok()
+        text.replace('_', "").parse::<f64>().ok()
     }
 }
 
@@ -397,6 +397,15 @@ mod tests {
         assert_eq!(IntNumber { syntax: make::tokens::literal(lit) }.suffix(), expected.into());
     }
 
+    fn check_float_value(lit: &str, expected: impl Into<Option<f64>> + Copy) {
+        assert_eq!(FloatNumber { syntax: make::tokens::literal(lit) }.value(), expected.into());
+        assert_eq!(IntNumber { syntax: make::tokens::literal(lit) }.float_value(), expected.into());
+    }
+
+    fn check_int_value(lit: &str, expected: impl Into<Option<u128>>) {
+        assert_eq!(IntNumber { syntax: make::tokens::literal(lit) }.value(), expected.into());
+    }
+
     #[test]
     fn test_float_number_suffix() {
         check_float_suffix("123.0", None);
@@ -437,6 +446,14 @@ mod tests {
         check_string_value(r"\nfoobar", "\nfoobar");
         check_string_value(r"C:\\Windows\\System32\\", "C:\\Windows\\System32\\");
     }
+
+    #[test]
+    fn test_value_underscores() {
+        check_float_value("3.141592653589793_f64", 3.141592653589793_f64);
+        check_float_value("1__0.__0__f32", 10.0);
+        check_int_value("0b__1_0_", 2);
+        check_int_value("1_1_1_1_1_1", 111111);
+    }
 }
 
 impl ast::Char {

crates/syntax/src/tests/sourcegen_ast.rs

@@ -169,10 +169,7 @@ fn generate_nodes(kinds: KindsSrc<'_>, grammar: &AstSrc) -> String {
                 quote! {
                     impl AstNode for #name {
                         fn can_cast(kind: SyntaxKind) -> bool {
-                            match kind {
+                            matches!(kind, #(#kinds)|*)
-                                #(#kinds)|* => true,
-                                _ => false,
-                            }
                         }
                         fn cast(syntax: SyntaxNode) -> Option<Self> {
                             let res = match syntax.kind() {
@@ -253,10 +250,7 @@ fn generate_nodes(kinds: KindsSrc<'_>, grammar: &AstSrc) -> String {
                     }
                     impl AstNode for #name {
                         fn can_cast(kind: SyntaxKind) -> bool {
-                            match kind {
+                            matches!(kind, #(#kinds)|*)
-                                #(#kinds)|* => true,
-                                _ => false,
-                            }
                         }
                         fn cast(syntax: SyntaxNode) -> Option<Self> {
                             Self::can_cast(syntax.kind()).then(|| #name { syntax })
@@ -410,24 +404,17 @@ fn generate_syntax_kinds(grammar: KindsSrc<'_>) -> String {
 
         impl SyntaxKind {
             pub fn is_keyword(self) -> bool {
-                match self {
+                matches!(self, #(#all_keywords)|*)
-                    #(#all_keywords)|* => true,
-                    _ => false,
-                }
             }
 
             pub fn is_punct(self) -> bool {
-                match self {
+
-                    #(#punctuation)|* => true,
+                matches!(self, #(#punctuation)|*)
-                    _ => false,
+
-                }
             }
 
             pub fn is_literal(self) -> bool {
-                match self {
+                matches!(self, #(#literals)|*)
-                    #(#literals)|* => true,
-                    _ => false,
-                }
             }
 
             pub fn from_keyword(ident: &str) -> Option<SyntaxKind> {

lib/la-arena/src/lib.rs

@@ -322,6 +322,43 @@ impl<T> Arena<T> {
             .map(|(idx, value)| (Idx::from_raw(RawIdx(idx as u32)), value))
     }
 
+    /// Returns an iterator over the arena’s values.
+    ///
+    /// ```
+    /// let mut arena = la_arena::Arena::new();
+    /// let idx1 = arena.alloc(20);
+    /// let idx2 = arena.alloc(40);
+    /// let idx3 = arena.alloc(60);
+    ///
+    /// let mut iterator = arena.values();
+    /// assert_eq!(iterator.next(), Some(&20));
+    /// assert_eq!(iterator.next(), Some(&40));
+    /// assert_eq!(iterator.next(), Some(&60));
+    /// ```
+    pub fn values(&mut self) -> impl Iterator<Item = &T> + ExactSizeIterator + DoubleEndedIterator {
+        self.data.iter()
+    }
+
+    /// Returns an iterator over the arena’s mutable values.
+    ///
+    /// ```
+    /// let mut arena = la_arena::Arena::new();
+    /// let idx1 = arena.alloc(20);
+    ///
+    /// assert_eq!(arena[idx1], 20);
+    ///
+    /// let mut iterator = arena.values_mut();
+    /// *iterator.next().unwrap() = 10;
+    /// drop(iterator);
+    ///
+    /// assert_eq!(arena[idx1], 10);
+    /// ```
+    pub fn values_mut(
+        &mut self,
+    ) -> impl Iterator<Item = &mut T> + ExactSizeIterator + DoubleEndedIterator {
+        self.data.iter_mut()
+    }
+
     /// Reallocates the arena to make it take up as little space as possible.
     pub fn shrink_to_fit(&mut self) {
         self.data.shrink_to_fit();