21 files changed, 205 insertions, 209 deletions

diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index 8afdac801..c65446df4 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -4,10 +4,7 @@
 use std::sync::Arc;
 
 use ra_arena::{impl_arena_id, Arena, RawId};
-use ra_syntax::{
-    ast::{self, NameOwner, StructKind, TypeAscriptionOwner},
-    TreeArc,
-};
+use ra_syntax::ast::{self, NameOwner, StructKind, TypeAscriptionOwner};
 
 use crate::{
     type_ref::TypeRef, AsName, AstDatabase, Crate, DefDatabase, Enum, EnumVariant, FieldSource,
@@ -59,11 +56,11 @@ impl StructData {
         struct_: Struct,
     ) -> Arc<StructData> {
         let src = struct_.source(db);
-        Arc::new(StructData::new(&*src.ast))
+        Arc::new(StructData::new(&src.ast))
     }
 }
 
-fn variants(enum_def: &ast::EnumDef) -> impl Iterator<Item = &ast::EnumVariant> {
+fn variants(enum_def: &ast::EnumDef) -> impl Iterator<Item = ast::EnumVariant> {
     enum_def.variant_list().into_iter().flat_map(|it| it.variants())
 }
 
@@ -71,9 +68,9 @@ impl EnumVariant {
     pub(crate) fn source_impl(
         self,
         db: &(impl DefDatabase + AstDatabase),
-    ) -> Source<TreeArc<ast::EnumVariant>> {
+    ) -> Source<ast::EnumVariant> {
         let src = self.parent.source(db);
-        let ast = variants(&*src.ast)
+        let ast = variants(&src.ast)
             .zip(db.enum_data(self.parent).variants.iter())
             .find(|(_syntax, (id, _))| *id == self.id)
             .unwrap()
@@ -96,7 +93,7 @@ impl EnumData {
     pub(crate) fn enum_data_query(db: &(impl DefDatabase + AstDatabase), e: Enum) -> Arc<EnumData> {
         let src = e.source(db);
         let name = src.ast.name().map(|n| n.as_name());
-        let variants = variants(&*src.ast)
+        let variants = variants(&src.ast)
             .map(|var| EnumVariantData {
                 name: var.name().map(|it| it.as_name()),
                 variant_data: Arc::new(VariantData::new(var.kind())),
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 4fb5844f4..779764590 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -4,10 +4,7 @@ pub(crate) mod docs;
 use std::sync::Arc;
 
 use ra_db::{CrateId, Edition, FileId, SourceRootId};
-use ra_syntax::{
-    ast::{self, NameOwner, TypeAscriptionOwner},
-    TreeArc,
-};
+use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
 
 use crate::{
     adt::{EnumVariantId, StructFieldId, VariantDef},
@@ -155,8 +152,8 @@ impl_froms!(
 );
 
 pub enum ModuleSource {
-    SourceFile(TreeArc<ast::SourceFile>),
-    Module(TreeArc<ast::Module>),
+    SourceFile(ast::SourceFile),
+    Module(ast::Module),
 }
 
 impl ModuleSource {
@@ -199,7 +196,7 @@ impl Module {
         self,
         db: &impl HirDatabase,
         import: ImportId,
-    ) -> Either<TreeArc<ast::UseTree>, TreeArc<ast::ExternCrateItem>> {
+    ) -> Either<ast::UseTree, ast::ExternCrateItem> {
         let src = self.definition_source(db);
         let (_, source_map) = db.raw_items_with_source_map(src.file_id);
         source_map.get(&src.ast, import)
@@ -321,8 +318,8 @@ pub struct StructField {
 
 #[derive(Debug)]
 pub enum FieldSource {
-    Named(TreeArc<ast::NamedFieldDef>),
-    Pos(TreeArc<ast::PosFieldDef>),
+    Named(ast::NamedFieldDef),
+    Pos(ast::PosFieldDef),
 }
 
 impl StructField {
@@ -736,7 +733,7 @@ impl ConstData {
         konst: Const,
     ) -> Arc<ConstData> {
         let node = konst.source(db).ast;
-        const_data_for(&*node)
+        const_data_for(&node)
     }
 
     pub(crate) fn static_data_query(
@@ -744,7 +741,7 @@ impl ConstData {
         konst: Static,
     ) -> Arc<ConstData> {
         let node = konst.source(db).ast;
-        const_data_for(&*node)
+        const_data_for(&node)
     }
 }
 
diff --git a/crates/ra_hir/src/code_model/docs.rs b/crates/ra_hir/src/code_model/docs.rs
index 007ef315d..a2b4d8e97 100644
--- a/crates/ra_hir/src/code_model/docs.rs
+++ b/crates/ra_hir/src/code_model/docs.rs
@@ -71,21 +71,21 @@ pub(crate) fn documentation_query(
     def: DocDef,
 ) -> Option<Documentation> {
     match def {
-        DocDef::Module(it) => docs_from_ast(&*it.declaration_source(db)?.ast),
+        DocDef::Module(it) => docs_from_ast(&it.declaration_source(db)?.ast),
         DocDef::StructField(it) => match it.source(db).ast {
-            FieldSource::Named(named) => docs_from_ast(&*named),
+            FieldSource::Named(named) => docs_from_ast(&named),
             FieldSource::Pos(..) => None,
         },
-        DocDef::Struct(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::Enum(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::EnumVariant(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::Static(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::Const(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::Function(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::Union(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::Trait(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::TypeAlias(it) => docs_from_ast(&*it.source(db).ast),
-        DocDef::MacroDef(it) => docs_from_ast(&*it.source(db).ast),
+        DocDef::Struct(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::Enum(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::EnumVariant(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::Static(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::Const(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::Function(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::Union(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::Trait(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::TypeAlias(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::MacroDef(it) => docs_from_ast(&it.source(db).ast),
     }
 }
 
diff --git a/crates/ra_hir/src/code_model/src.rs b/crates/ra_hir/src/code_model/src.rs
index 72451e0e7..32bd9c661 100644
--- a/crates/ra_hir/src/code_model/src.rs
+++ b/crates/ra_hir/src/code_model/src.rs
@@ -1,4 +1,4 @@
-use ra_syntax::{ast, TreeArc};
+use ra_syntax::ast;
 
 use crate::{
     ids::AstItemDef, AstDatabase, Const, DefDatabase, Enum, EnumVariant, FieldSource, Function,
@@ -34,7 +34,7 @@ impl Module {
     pub fn declaration_source(
         self,
         db: &(impl DefDatabase + AstDatabase),
-    ) -> Option<Source<TreeArc<ast::Module>>> {
+    ) -> Option<Source<ast::Module>> {
         let def_map = db.crate_def_map(self.krate);
         let decl = def_map[self.module_id].declaration?;
         let ast = decl.to_node(db);
@@ -49,62 +49,62 @@ impl HasSource for StructField {
     }
 }
 impl HasSource for Struct {
-    type Ast = TreeArc<ast::StructDef>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::StructDef>> {
+    type Ast = ast::StructDef;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::StructDef> {
         self.id.source(db)
     }
 }
 impl HasSource for Union {
-    type Ast = TreeArc<ast::StructDef>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::StructDef>> {
+    type Ast = ast::StructDef;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::StructDef> {
         self.id.source(db)
     }
 }
 impl HasSource for Enum {
-    type Ast = TreeArc<ast::EnumDef>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::EnumDef>> {
+    type Ast = ast::EnumDef;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::EnumDef> {
         self.id.source(db)
     }
 }
 impl HasSource for EnumVariant {
-    type Ast = TreeArc<ast::EnumVariant>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::EnumVariant>> {
+    type Ast = ast::EnumVariant;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::EnumVariant> {
         self.source_impl(db)
     }
 }
 impl HasSource for Function {
-    type Ast = TreeArc<ast::FnDef>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::FnDef>> {
+    type Ast = ast::FnDef;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::FnDef> {
         self.id.source(db)
     }
 }
 impl HasSource for Const {
-    type Ast = TreeArc<ast::ConstDef>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::ConstDef>> {
+    type Ast = ast::ConstDef;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::ConstDef> {
         self.id.source(db)
     }
 }
 impl HasSource for Static {
-    type Ast = TreeArc<ast::StaticDef>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::StaticDef>> {
+    type Ast = ast::StaticDef;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::StaticDef> {
         self.id.source(db)
     }
 }
 impl HasSource for Trait {
-    type Ast = TreeArc<ast::TraitDef>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::TraitDef>> {
+    type Ast = ast::TraitDef;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::TraitDef> {
         self.id.source(db)
     }
 }
 impl HasSource for TypeAlias {
-    type Ast = TreeArc<ast::TypeAliasDef>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::TypeAliasDef>> {
+    type Ast = ast::TypeAliasDef;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::TypeAliasDef> {
         self.id.source(db)
     }
 }
 impl HasSource for MacroDef {
-    type Ast = TreeArc<ast::MacroCall>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::MacroCall>> {
+    type Ast = ast::MacroCall;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::MacroCall> {
         Source { file_id: self.id.0.file_id(), ast: self.id.0.to_node(db) }
     }
 }
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index da9f3e32d..358365176 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use parking_lot::Mutex;
 use ra_db::{salsa, SourceDatabase};
-use ra_syntax::{ast, Parse, SmolStr, SyntaxNode, TreeArc};
+use ra_syntax::{ast, Parse, SmolStr, SyntaxNode};
 
 use crate::{
     adt::{EnumData, StructData},
@@ -62,11 +62,11 @@ pub trait AstDatabase: InternDatabase {
 
     #[salsa::transparent]
     #[salsa::invoke(crate::source_id::AstIdMap::file_item_query)]
-    fn ast_id_to_node(&self, file_id: HirFileId, ast_id: ErasedFileAstId) -> TreeArc<SyntaxNode>;
+    fn ast_id_to_node(&self, file_id: HirFileId, ast_id: ErasedFileAstId) -> SyntaxNode;
 
     #[salsa::transparent]
     #[salsa::invoke(crate::ids::HirFileId::parse_or_expand_query)]
-    fn parse_or_expand(&self, file_id: HirFileId) -> Option<TreeArc<SyntaxNode>>;
+    fn parse_or_expand(&self, file_id: HirFileId) -> Option<SyntaxNode>;
 
     #[salsa::invoke(crate::ids::HirFileId::parse_macro_query)]
     fn parse_macro(&self, macro_file: ids::MacroFile) -> Option<Parse<SyntaxNode>>;
diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index c97f0656d..0290483b3 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -1,6 +1,6 @@
 use std::{any::Any, fmt};
 
-use ra_syntax::{ast, AstNode, AstPtr, SyntaxNode, SyntaxNodePtr, TextRange, TreeArc};
+use ra_syntax::{ast, AstNode, AstPtr, SyntaxNode, SyntaxNodePtr, TextRange};
 use relative_path::RelativePathBuf;
 
 use crate::{HirDatabase, HirFileId, Name};
@@ -33,9 +33,9 @@ pub trait AstDiagnostic {
 }
 
 impl dyn Diagnostic {
-    pub fn syntax_node(&self, db: &impl HirDatabase) -> TreeArc<SyntaxNode> {
+    pub fn syntax_node(&self, db: &impl HirDatabase) -> SyntaxNode {
         let node = db.parse_or_expand(self.file()).unwrap();
-        self.syntax_node_ptr().to_node(&*node).to_owned()
+        self.syntax_node_ptr().to_node(&node)
     }
 
     pub fn downcast_ref<D: Diagnostic>(&self) -> Option<&D> {
@@ -143,11 +143,11 @@ impl Diagnostic for MissingFields {
 }
 
 impl AstDiagnostic for MissingFields {
-    type AST = TreeArc<ast::NamedFieldList>;
+    type AST = ast::NamedFieldList;
 
     fn ast(&self, db: &impl HirDatabase) -> Self::AST {
         let root = db.parse_or_expand(self.file()).unwrap();
-        let node = self.syntax_node_ptr().to_node(&*root);
-        ast::NamedFieldList::cast(&node).unwrap().to_owned()
+        let node = self.syntax_node_ptr().to_node(&root);
+        ast::NamedFieldList::cast(node).unwrap()
     }
 }
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index 3a97d97ce..70af3f119 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -550,7 +550,7 @@ where
         self.exprs.alloc(block)
     }
 
-    fn collect_expr(&mut self, expr: &ast::Expr) -> ExprId {
+    fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
         let syntax_ptr = SyntaxNodePtr::new(expr.syntax());
         match expr.kind() {
             ast::ExprKind::IfExpr(e) => {
@@ -565,7 +565,8 @@ where
                         .map(|b| match b {
                             ast::ElseBranch::Block(it) => self.collect_block(it),
                             ast::ElseBranch::IfExpr(elif) => {
-                                let expr: &ast::Expr = ast::Expr::cast(elif.syntax()).unwrap();
+                                let expr: ast::Expr =
+                                    ast::Expr::cast(elif.syntax().clone()).unwrap();
                                 self.collect_expr(expr)
                             }
                         })
@@ -582,7 +583,7 @@ where
                     let else_branch = e.else_branch().map(|b| match b {
                         ast::ElseBranch::Block(it) => self.collect_block(it),
                         ast::ElseBranch::IfExpr(elif) => {
-                            let expr: &ast::Expr = ast::Expr::cast(elif.syntax()).unwrap();
+                            let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
                             self.collect_expr(expr)
                         }
                     });
@@ -689,7 +690,7 @@ where
                 let struct_lit = if let Some(nfl) = e.named_field_list() {
                     let fields = nfl
                         .fields()
-                        .inspect(|field| field_ptrs.push(AstPtr::new(*field)))
+                        .inspect(|field| field_ptrs.push(AstPtr::new(field)))
                         .map(|field| StructLitField {
                             name: field
                                 .name_ref()
@@ -699,7 +700,7 @@ where
                                 self.collect_expr(e)
                             } else if let Some(nr) = field.name_ref() {
                                 // field shorthand
-                                let id = self.exprs.alloc(Expr::Path(Path::from_name_ref(nr)));
+                                let id = self.exprs.alloc(Expr::Path(Path::from_name_ref(&nr)));
                                 self.source_map
                                     .expr_map
                                     .insert(SyntaxNodePtr::new(nr.syntax()), id);
@@ -837,7 +838,7 @@ where
                 let ast_id = self
                     .db
                     .ast_id_map(self.current_file_id)
-                    .ast_id(e)
+                    .ast_id(&e)
                     .with_file_id(self.current_file_id);
 
                 if let Some(path) = e.path().and_then(Path::from_ast) {
@@ -845,11 +846,11 @@ where
                         let call_id = MacroCallLoc { def: def.id, ast_id }.id(self.db);
                         let file_id = call_id.as_file(MacroFileKind::Expr);
                         if let Some(node) = self.db.parse_or_expand(file_id) {
-                            if let Some(expr) = ast::Expr::cast(&*node) {
+                            if let Some(expr) = ast::Expr::cast(node) {
                                 log::debug!("macro expansion {}", expr.syntax().debug_dump());
                                 let old_file_id =
                                     std::mem::replace(&mut self.current_file_id, file_id);
-                                let id = self.collect_expr(&expr);
+                                let id = self.collect_expr(expr);
                                 self.current_file_id = old_file_id;
                                 return id;
                             }
@@ -863,7 +864,7 @@ where
         }
     }
 
-    fn collect_expr_opt(&mut self, expr: Option<&ast::Expr>) -> ExprId {
+    fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
         if let Some(expr) = expr {
             self.collect_expr(expr)
         } else {
@@ -871,7 +872,7 @@ where
         }
     }
 
-    fn collect_block(&mut self, block: &ast::Block) -> ExprId {
+    fn collect_block(&mut self, block: ast::Block) -> ExprId {
         let statements = block
             .statements()
             .map(|s| match s.kind() {
@@ -890,7 +891,7 @@ where
         self.alloc_expr(Expr::Block { statements, tail }, SyntaxNodePtr::new(block.syntax()))
     }
 
-    fn collect_block_opt(&mut self, block: Option<&ast::Block>) -> ExprId {
+    fn collect_block_opt(&mut self, block: Option<ast::Block>) -> ExprId {
         if let Some(block) = block {
             self.collect_block(block)
         } else {
@@ -898,7 +899,7 @@ where
         }
     }
 
-    fn collect_pat(&mut self, pat: &ast::Pat) -> PatId {
+    fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
         let pattern = match pat.kind() {
             ast::PatKind::BindPat(bp) => {
                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
@@ -932,7 +933,8 @@ where
                 let mut fields: Vec<_> = field_pat_list
                     .bind_pats()
                     .filter_map(|bind_pat| {
-                        let ast_pat = ast::Pat::cast(bind_pat.syntax()).expect("bind pat is a pat");
+                        let ast_pat =
+                            ast::Pat::cast(bind_pat.syntax().clone()).expect("bind pat is a pat");
                         let pat = self.collect_pat(ast_pat);
                         let name = bind_pat.name()?.as_name();
                         Some(FieldPat { name, pat })
@@ -953,11 +955,11 @@ where
             ast::PatKind::LiteralPat(_) => Pat::Missing,
             ast::PatKind::SlicePat(_) | ast::PatKind::RangePat(_) => Pat::Missing,
         };
-        let ptr = AstPtr::new(pat);
+        let ptr = AstPtr::new(&pat);
         self.alloc_pat(pattern, Either::A(ptr))
     }
 
-    fn collect_pat_opt(&mut self, pat: Option<&ast::Pat>) -> PatId {
+    fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
         if let Some(pat) = pat {
             self.collect_pat(pat)
         } else {
@@ -965,20 +967,20 @@ where
         }
     }
 
-    fn collect_const_body(&mut self, node: &ast::ConstDef) {
+    fn collect_const_body(&mut self, node: ast::ConstDef) {
         let body = self.collect_expr_opt(node.body());
         self.body_expr = Some(body);
     }
 
-    fn collect_static_body(&mut self, node: &ast::StaticDef) {
+    fn collect_static_body(&mut self, node: ast::StaticDef) {
         let body = self.collect_expr_opt(node.body());
         self.body_expr = Some(body);
     }
 
-    fn collect_fn_body(&mut self, node: &ast::FnDef) {
+    fn collect_fn_body(&mut self, node: ast::FnDef) {
         if let Some(param_list) = node.param_list() {
             if let Some(self_param) = param_list.self_param() {
-                let ptr = AstPtr::new(self_param);
+                let ptr = AstPtr::new(&self_param);
                 let param_pat = self.alloc_pat(
                     Pat::Bind {
                         name: SELF_PARAM,
@@ -1027,17 +1029,17 @@ pub(crate) fn body_with_source_map_query(
         DefWithBody::Const(ref c) => {
             let src = c.source(db);
             collector = ExprCollector::new(def, src.file_id, def.resolver(db), db);
-            collector.collect_const_body(&src.ast)
+            collector.collect_const_body(src.ast)
         }
         DefWithBody::Function(ref f) => {
             let src = f.source(db);
             collector = ExprCollector::new(def, src.file_id, def.resolver(db), db);
-            collector.collect_fn_body(&src.ast)
+            collector.collect_fn_body(src.ast)
         }
         DefWithBody::Static(ref s) => {
             let src = s.source(db);
             collector = ExprCollector::new(def, src.file_id, def.resolver(db), db);
-            collector.collect_static_body(&src.ast)
+            collector.collect_static_body(src.ast)
         }
     }
 
diff --git a/crates/ra_hir/src/expr/scope.rs b/crates/ra_hir/src/expr/scope.rs
index 28fd52684..6589b782c 100644
--- a/crates/ra_hir/src/expr/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -190,7 +190,7 @@ mod tests {
 
         let (db, _source_root, file_id) = MockDatabase::with_single_file(&code);
         let file = db.parse(file_id).ok().unwrap();
-        let marker: &ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap();
+        let marker: ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap();
         let analyzer = SourceAnalyzer::new(&db, file_id, marker.syntax(), None);
 
         let scopes = analyzer.scopes();
@@ -290,10 +290,10 @@ mod tests {
         let file = db.parse(file_id).ok().unwrap();
         let expected_name = find_node_at_offset::<ast::Name>(file.syntax(), expected_offset.into())
             .expect("failed to find a name at the target offset");
-        let name_ref: &ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap();
+        let name_ref: ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap();
         let analyzer = SourceAnalyzer::new(&db, file_id, name_ref.syntax(), None);
 
-        let local_name_entry = analyzer.resolve_local_name(name_ref).unwrap();
+        let local_name_entry = analyzer.resolve_local_name(&name_ref).unwrap();
         let local_name =
             local_name_entry.ptr().either(|it| it.syntax_node_ptr(), |it| it.syntax_node_ptr());
         assert_eq!(local_name.range(), expected_name.syntax().range());
diff --git a/crates/ra_hir/src/expr/validation.rs b/crates/ra_hir/src/expr/validation.rs
index c2a10a0b5..82a06ca25 100644
--- a/crates/ra_hir/src/expr/validation.rs
+++ b/crates/ra_hir/src/expr/validation.rs
@@ -79,7 +79,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             .and_then(StructLit::cast)
             .and_then(|lit| lit.named_field_list())
         {
-            let field_list_ptr = AstPtr::new(field_list_node);
+            let field_list_ptr = AstPtr::new(&field_list_node);
             self.sink.push(MissingFields {
                 file: file_id,
                 field_list: field_list_ptr,
diff --git a/crates/ra_hir/src/generics.rs b/crates/ra_hir/src/generics.rs
index 07a59193f..bcbb4988d 100644
--- a/crates/ra_hir/src/generics.rs
+++ b/crates/ra_hir/src/generics.rs
@@ -76,17 +76,17 @@ impl GenericParams {
         generics.parent_params = parent.map(|p| db.generic_params(p));
         let start = generics.parent_params.as_ref().map(|p| p.params.len()).unwrap_or(0) as u32;
         match def {
-            GenericDef::Function(it) => generics.fill(&*it.source(db).ast, start),
-            GenericDef::Struct(it) => generics.fill(&*it.source(db).ast, start),
-            GenericDef::Union(it) => generics.fill(&*it.source(db).ast, start),
-            GenericDef::Enum(it) => generics.fill(&*it.source(db).ast, start),
+            GenericDef::Function(it) => generics.fill(&it.source(db).ast, start),
+            GenericDef::Struct(it) => generics.fill(&it.source(db).ast, start),
+            GenericDef::Union(it) => generics.fill(&it.source(db).ast, start),
+            GenericDef::Enum(it) => generics.fill(&it.source(db).ast, start),
             GenericDef::Trait(it) => {
                 // traits get the Self type as an implicit first type parameter
                 generics.params.push(GenericParam { idx: start, name: SELF_TYPE, default: None });
-                generics.fill(&*it.source(db).ast, start + 1);
+                generics.fill(&it.source(db).ast, start + 1);
             }
-            GenericDef::TypeAlias(it) => generics.fill(&*it.source(db).ast, start),
-            GenericDef::ImplBlock(it) => generics.fill(&*it.source(db).ast, start),
+            GenericDef::TypeAlias(it) => generics.fill(&it.source(db).ast, start),
+            GenericDef::ImplBlock(it) => generics.fill(&it.source(db).ast, start),
             GenericDef::EnumVariant(_) => {}
         }
 
@@ -102,9 +102,9 @@ impl GenericParams {
         }
     }
 
-    fn fill_params(&mut self, params: &ast::TypeParamList, start: u32) {
+    fn fill_params(&mut self, params: ast::TypeParamList, start: u32) {
         for (idx, type_param) in params.type_params().enumerate() {
-            let name = type_param.name().map(AsName::as_name).unwrap_or_else(Name::missing);
+            let name = type_param.name().map_or_else(Name::missing, |it| it.as_name());
             let default = type_param.default_type().and_then(|t| t.path()).and_then(Path::from_ast);
 
             let param = GenericParam { idx: idx as u32 + start, name: name.clone(), default };
@@ -121,7 +121,7 @@ impl GenericParams {
         }
     }
 
-    fn fill_where_predicates(&mut self, where_clause: &ast::WhereClause) {
+    fn fill_where_predicates(&mut self, where_clause: ast::WhereClause) {
         for pred in where_clause.predicates() {
             let type_ref = match pred.type_ref() {
                 Some(type_ref) => type_ref,
@@ -134,7 +134,7 @@ impl GenericParams {
         }
     }
 
-    fn add_where_predicate_from_bound(&mut self, bound: &ast::TypeBound, type_ref: TypeRef) {
+    fn add_where_predicate_from_bound(&mut self, bound: ast::TypeBound, type_ref: TypeRef) {
         let path = bound
             .type_ref()
             .and_then(|tr| match tr.kind() {
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index 83f5c3f39..05a18eb56 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -6,7 +6,7 @@ use std::{
 use mbe::MacroRules;
 use ra_db::{salsa, FileId};
 use ra_prof::profile;
-use ra_syntax::{ast, AstNode, Parse, SyntaxNode, TreeArc};
+use ra_syntax::{ast, AstNode, Parse, SyntaxNode};
 
 use crate::{AstDatabase, AstId, DefDatabase, FileAstId, InternDatabase, Module, Source};
 
@@ -58,11 +58,11 @@ impl HirFileId {
     pub(crate) fn parse_or_expand_query(
         db: &impl AstDatabase,
         file_id: HirFileId,
-    ) -> Option<TreeArc<SyntaxNode>> {
+    ) -> Option<SyntaxNode> {
         match file_id.0 {
-            HirFileIdRepr::File(file_id) => Some(db.parse(file_id).tree().syntax().to_owned()),
+            HirFileIdRepr::File(file_id) => Some(db.parse(file_id).tree().syntax().clone()),
             HirFileIdRepr::Macro(macro_file) => {
-                db.parse_macro(macro_file).map(|it| it.tree().to_owned())
+                db.parse_macro(macro_file).map(|it| it.syntax_node())
             }
         }
     }
@@ -123,7 +123,7 @@ pub struct MacroDefId(pub(crate) AstId<ast::MacroCall>);
 pub(crate) fn macro_def_query(db: &impl AstDatabase, id: MacroDefId) -> Option<Arc<MacroRules>> {
     let macro_call = id.0.to_node(db);
     let arg = macro_call.token_tree()?;
-    let (tt, _) = mbe::ast_to_token_tree(arg).or_else(|| {
+    let (tt, _) = mbe::ast_to_token_tree(&arg).or_else(|| {
         log::warn!("fail on macro_def to token tree: {:#?}", arg);
         None
     })?;
@@ -138,7 +138,7 @@ pub(crate) fn macro_arg_query(db: &impl AstDatabase, id: MacroCallId) -> Option<
     let loc = id.loc(db);
     let macro_call = loc.ast_id.to_node(db);
     let arg = macro_call.token_tree()?;
-    let (tt, _) = mbe::ast_to_token_tree(arg)?;
+    let (tt, _) = mbe::ast_to_token_tree(&arg)?;
     Some(Arc::new(tt))
 }
 
@@ -262,7 +262,7 @@ pub(crate) trait AstItemDef<N: AstNode>: salsa::InternKey + Clone {
         let loc = ItemLoc { module: ctx.module, ast_id: ast_id.with_file_id(ctx.file_id) };
         Self::intern(ctx.db, loc)
     }
-    fn source(self, db: &(impl AstDatabase + DefDatabase)) -> Source<TreeArc<N>> {
+    fn source(self, db: &(impl AstDatabase + DefDatabase)) -> Source<N> {
         let loc = self.lookup_intern(db);
         let ast = loc.ast_id.to_node(db);
         Source { file_id: loc.ast_id.file_id(), ast }
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index ce134b27a..8e62cf66d 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -4,7 +4,7 @@ use std::sync::Arc;
 use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
 use ra_syntax::{
     ast::{self, AstNode},
-    AstPtr, SourceFile, TreeArc,
+    AstPtr, SourceFile,
 };
 
 use crate::{
@@ -28,9 +28,9 @@ impl ImplSourceMap {
         self.map.insert(impl_id, AstPtr::new(impl_block))
     }
 
-    pub fn get(&self, source: &ModuleSource, impl_id: ImplId) -> TreeArc<ast::ImplBlock> {
+    pub fn get(&self, source: &ModuleSource, impl_id: ImplId) -> ast::ImplBlock {
         let file = match source {
-            ModuleSource::SourceFile(file) => &*file,
+            ModuleSource::SourceFile(file) => file.clone(),
             ModuleSource::Module(m) => m.syntax().ancestors().find_map(SourceFile::cast).unwrap(),
         };
 
@@ -45,8 +45,8 @@ pub struct ImplBlock {
 }
 
 impl HasSource for ImplBlock {
-    type Ast = TreeArc<ast::ImplBlock>;
-    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<TreeArc<ast::ImplBlock>> {
+    type Ast = ast::ImplBlock;
+    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::ImplBlock> {
         let source_map = db.impls_in_module_with_source_map(self.module).1;
         let src = self.module.definition_source(db);
         Source { file_id: src.file_id, ast: source_map.get(&src.ast, self.impl_id) }
@@ -132,9 +132,9 @@ impl ImplData {
             item_list
                 .impl_items()
                 .map(|item_node| match item_node.kind() {
-                    ast::ImplItemKind::FnDef(it) => Function { id: ctx.to_def(it) }.into(),
-                    ast::ImplItemKind::ConstDef(it) => Const { id: ctx.to_def(it) }.into(),
-                    ast::ImplItemKind::TypeAliasDef(it) => TypeAlias { id: ctx.to_def(it) }.into(),
+                    ast::ImplItemKind::FnDef(it) => Function { id: ctx.to_def(&it) }.into(),
+                    ast::ImplItemKind::ConstDef(it) => Const { id: ctx.to_def(&it) }.into(),
+                    ast::ImplItemKind::TypeAliasDef(it) => TypeAlias { id: ctx.to_def(&it) }.into(),
                 })
                 .collect()
         } else {
@@ -202,20 +202,20 @@ impl ModuleImplBlocks {
 
         let src = m.module.definition_source(db);
         let node = match &src.ast {
-            ModuleSource::SourceFile(node) => node.syntax(),
+            ModuleSource::SourceFile(node) => node.syntax().clone(),
             ModuleSource::Module(node) => {
-                node.item_list().expect("inline module should have item list").syntax()
+                node.item_list().expect("inline module should have item list").syntax().clone()
             }
         };
 
         for impl_block_ast in node.children().filter_map(ast::ImplBlock::cast) {
-            let impl_block = ImplData::from_ast(db, src.file_id, m.module, impl_block_ast);
+            let impl_block = ImplData::from_ast(db, src.file_id, m.module, &impl_block_ast);
             let id = m.impls.alloc(impl_block);
             for &impl_item in &m.impls[id].items {
                 m.impls_by_def.insert(impl_item, id);
             }
 
-            source_map.insert(id, impl_block_ast);
+            source_map.insert(id, &impl_block_ast);
         }
 
         m
diff --git a/crates/ra_hir/src/lang_item.rs b/crates/ra_hir/src/lang_item.rs
index 0443d4d9a..fd6609fb8 100644
--- a/crates/ra_hir/src/lang_item.rs
+++ b/crates/ra_hir/src/lang_item.rs
@@ -1,7 +1,7 @@
 use rustc_hash::FxHashMap;
 use std::sync::Arc;
 
-use ra_syntax::{ast::AttrsOwner, SmolStr, TreeArc};
+use ra_syntax::{ast::AttrsOwner, SmolStr};
 
 use crate::{
     AstDatabase, Crate, DefDatabase, Enum, Function, HasSource, HirDatabase, ImplBlock, Module,
@@ -95,7 +95,7 @@ impl LangItems {
         // Look for impl targets
         for impl_block in module.impl_blocks(db) {
             let src = impl_block.source(db);
-            if let Some(lang_item_name) = lang_item_name(&*src.ast) {
+            if let Some(lang_item_name) = lang_item_name(&src.ast) {
                 self.items
                     .entry(lang_item_name)
                     .or_insert_with(|| LangItemTarget::ImplBlock(impl_block));
@@ -137,11 +137,11 @@ impl LangItems {
         item: T,
         constructor: fn(T) -> LangItemTarget,
     ) where
-        T: Copy + HasSource<Ast = TreeArc<N>>,
+        T: Copy + HasSource<Ast = N>,
         N: AttrsOwner,
     {
         let node = item.source(db).ast;
-        if let Some(lang_item_name) = lang_item_name(&*node) {
+        if let Some(lang_item_name) = lang_item_name(&node) {
             self.items.entry(lang_item_name).or_insert_with(|| constructor(item));
         }
     }
diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
index 40c9d6002..c589f8aba 100644
--- a/crates/ra_hir/src/name.rs
+++ b/crates/ra_hir/src/name.rs
@@ -75,7 +75,7 @@ impl AsName for ast::Name {
     }
 }
 
-impl<'a> AsName for ast::FieldKind<'a> {
+impl AsName for ast::FieldKind {
     fn as_name(&self) -> Name {
         match self {
             ast::FieldKind::Name(nr) => nr.as_name(),
diff --git a/crates/ra_hir/src/nameres/raw.rs b/crates/ra_hir/src/nameres/raw.rs
index 46b2bef5b..8517f3c43 100644
--- a/crates/ra_hir/src/nameres/raw.rs
+++ b/crates/ra_hir/src/nameres/raw.rs
@@ -3,7 +3,7 @@ use std::{ops::Index, sync::Arc};
 use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
 use ra_syntax::{
     ast::{self, AttrsOwner, NameOwner},
-    AstNode, AstPtr, SmolStr, SourceFile, TreeArc,
+    AstNode, AstPtr, SmolStr, SourceFile,
 };
 use test_utils::tested_by;
 
@@ -32,7 +32,7 @@ pub struct ImportSourceMap {
 }
 
 type ImportSourcePtr = Either<AstPtr<ast::UseTree>, AstPtr<ast::ExternCrateItem>>;
-type ImportSource = Either<TreeArc<ast::UseTree>, TreeArc<ast::ExternCrateItem>>;
+type ImportSource = Either<ast::UseTree, ast::ExternCrateItem>;
 
 impl ImportSourcePtr {
     fn to_node(self, file: &SourceFile) -> ImportSource {
@@ -50,11 +50,11 @@ impl ImportSourceMap {
 
     pub(crate) fn get(&self, source: &ModuleSource, import: ImportId) -> ImportSource {
         let file = match source {
-            ModuleSource::SourceFile(file) => &*file,
+            ModuleSource::SourceFile(file) => file.clone(),
             ModuleSource::Module(m) => m.syntax().ancestors().find_map(SourceFile::cast).unwrap(),
         };
 
-        self.map[import].to_node(file)
+        self.map[import].to_node(&file)
     }
 }
 
@@ -76,8 +76,8 @@ impl RawItems {
             source_map: ImportSourceMap::default(),
         };
         if let Some(node) = db.parse_or_expand(file_id) {
-            if let Some(source_file) = ast::SourceFile::cast(&node) {
-                collector.process_module(None, &*source_file);
+            if let Some(source_file) = ast::SourceFile::cast(node) {
+                collector.process_module(None, source_file);
             }
         }
         (Arc::new(collector.raw_items), Arc::new(collector.source_map))
@@ -188,7 +188,7 @@ struct RawItemsCollector {
 }
 
 impl RawItemsCollector {
-    fn process_module(&mut self, current_module: Option<Module>, body: &impl ast::ModuleItemOwner) {
+    fn process_module(&mut self, current_module: Option<Module>, body: impl ast::ModuleItemOwner) {
         for item_or_macro in body.items_with_macros() {
             match item_or_macro {
                 ast::ItemOrMacro::Macro(m) => self.add_macro(current_module, m),
@@ -197,7 +197,7 @@ impl RawItemsCollector {
         }
     }
 
-    fn add_item(&mut self, current_module: Option<Module>, item: &ast::ModuleItem) {
+    fn add_item(&mut self, current_module: Option<Module>, item: ast::ModuleItem) {
         let (kind, name) = match item.kind() {
             ast::ModuleItemKind::Module(module) => {
                 self.add_module(current_module, module);
@@ -216,7 +216,7 @@ impl RawItemsCollector {
                 return;
             }
             ast::ModuleItemKind::StructDef(it) => {
-                let id = self.source_ast_id_map.ast_id(it);
+                let id = self.source_ast_id_map.ast_id(&it);
                 let name = it.name();
                 if it.is_union() {
                     (DefKind::Union(id), name)
@@ -225,22 +225,22 @@ impl RawItemsCollector {
                 }
             }
             ast::ModuleItemKind::EnumDef(it) => {
-                (DefKind::Enum(self.source_ast_id_map.ast_id(it)), it.name())
+                (DefKind::Enum(self.source_ast_id_map.ast_id(&it)), it.name())
             }
             ast::ModuleItemKind::FnDef(it) => {
-                (DefKind::Function(self.source_ast_id_map.ast_id(it)), it.name())
+                (DefKind::Function(self.source_ast_id_map.ast_id(&it)), it.name())
             }
             ast::ModuleItemKind::TraitDef(it) => {
-                (DefKind::Trait(self.source_ast_id_map.ast_id(it)), it.name())
+                (DefKind::Trait(self.source_ast_id_map.ast_id(&it)), it.name())
             }
             ast::ModuleItemKind::TypeAliasDef(it) => {
-                (DefKind::TypeAlias(self.source_ast_id_map.ast_id(it)), it.name())
+                (DefKind::TypeAlias(self.source_ast_id_map.ast_id(&it)), it.name())
             }
             ast::ModuleItemKind::ConstDef(it) => {
-                (DefKind::Const(self.source_ast_id_map.ast_id(it)), it.name())
+                (DefKind::Const(self.source_ast_id_map.ast_id(&it)), it.name())
             }
             ast::ModuleItemKind::StaticDef(it) => {
-                (DefKind::Static(self.source_ast_id_map.ast_id(it)), it.name())
+                (DefKind::Static(self.source_ast_id_map.ast_id(&it)), it.name())
             }
         };
         if let Some(name) = name {
@@ -250,14 +250,14 @@ impl RawItemsCollector {
         }
     }
 
-    fn add_module(&mut self, current_module: Option<Module>, module: &ast::Module) {
+    fn add_module(&mut self, current_module: Option<Module>, module: ast::Module) {
         let name = match module.name() {
             Some(it) => it.as_name(),
             None => return,
         };
 
-        let attr_path = extract_mod_path_attribute(module);
-        let ast_id = self.source_ast_id_map.ast_id(module);
+        let attr_path = extract_mod_path_attribute(&module);
+        let ast_id = self.source_ast_id_map.ast_id(&module);
         if module.has_semi() {
             let item =
                 self.raw_items.modules.alloc(ModuleData::Declaration { name, ast_id, attr_path });
@@ -278,10 +278,10 @@ impl RawItemsCollector {
         tested_by!(name_res_works_for_broken_modules);
     }
 
-    fn add_use_item(&mut self, current_module: Option<Module>, use_item: &ast::UseItem) {
+    fn add_use_item(&mut self, current_module: Option<Module>, use_item: ast::UseItem) {
         let is_prelude = use_item.has_atom_attr("prelude_import");
 
-        Path::expand_use_item(use_item, |path, use_tree, is_glob, alias| {
+        Path::expand_use_item(&use_item, |path, use_tree, is_glob, alias| {
             let import_data =
                 ImportData { path, alias, is_glob, is_prelude, is_extern_crate: false };
             self.push_import(current_module, import_data, Either::A(AstPtr::new(use_tree)));
@@ -291,11 +291,11 @@ impl RawItemsCollector {
     fn add_extern_crate_item(
         &mut self,
         current_module: Option<Module>,
-        extern_crate: &ast::ExternCrateItem,
+        extern_crate: ast::ExternCrateItem,
     ) {
         if let Some(name_ref) = extern_crate.name_ref() {
-            let path = Path::from_name_ref(name_ref);
-            let alias = extern_crate.alias().and_then(|a| a.name()).map(AsName::as_name);
+            let path = Path::from_name_ref(&name_ref);
+            let alias = extern_crate.alias().and_then(|a| a.name()).map(|it| it.as_name());
             let import_data = ImportData {
                 path,
                 alias,
@@ -303,18 +303,18 @@ impl RawItemsCollector {
                 is_prelude: false,
                 is_extern_crate: true,
             };
-            self.push_import(current_module, import_data, Either::B(AstPtr::new(extern_crate)));
+            self.push_import(current_module, import_data, Either::B(AstPtr::new(&extern_crate)));
         }
     }
 
-    fn add_macro(&mut self, current_module: Option<Module>, m: &ast::MacroCall) {
+    fn add_macro(&mut self, current_module: Option<Module>, m: ast::MacroCall) {
         let path = match m.path().and_then(Path::from_ast) {
             Some(it) => it,
             _ => return,
         };
 
         let name = m.name().map(|it| it.as_name());
-        let ast_id = self.source_ast_id_map.ast_id(m);
+        let ast_id = self.source_ast_id_map.ast_id(&m);
         let export = m.has_atom_attr("macro_export");
         let m = self.raw_items.macros.alloc(MacroData { ast_id, path, name, export });
         self.push_item(current_module, RawItem::Macro(m));
diff --git a/crates/ra_hir/src/path.rs b/crates/ra_hir/src/path.rs
index bce9d2d4b..882db7681 100644
--- a/crates/ra_hir/src/path.rs
+++ b/crates/ra_hir/src/path.rs
@@ -47,9 +47,9 @@ pub enum PathKind {
 
 impl Path {
     /// Calls `cb` with all paths, represented by this use item.
-    pub fn expand_use_item<'a>(
-        item: &'a ast::UseItem,
-        mut cb: impl FnMut(Path, &'a ast::UseTree, bool, Option<Name>),
+    pub fn expand_use_item(
+        item: &ast::UseItem,
+        mut cb: impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
     ) {
         if let Some(tree) = item.use_tree() {
             expand_use_tree(None, tree, &mut cb);
@@ -57,7 +57,7 @@ impl Path {
     }
 
     /// Converts an `ast::Path` to `Path`. Works with use trees.
-    pub fn from_ast(mut path: &ast::Path) -> Option<Path> {
+    pub fn from_ast(mut path: ast::Path) -> Option<Path> {
         let mut kind = PathKind::Plain;
         let mut segments = Vec::new();
         loop {
@@ -87,7 +87,7 @@ impl Path {
                     break;
                 }
             }
-            path = match qualifier(path) {
+            path = match qualifier(&path) {
                 Some(it) => it,
                 None => break,
             };
@@ -95,7 +95,7 @@ impl Path {
         segments.reverse();
         return Some(Path { kind, segments });
 
-        fn qualifier(path: &ast::Path) -> Option<&ast::Path> {
+        fn qualifier(path: &ast::Path) -> Option<ast::Path> {
             if let Some(q) = path.qualifier() {
                 return Some(q);
             }
@@ -136,7 +136,7 @@ impl Path {
 }
 
 impl GenericArgs {
-    pub(crate) fn from_ast(node: &ast::TypeArgList) -> Option<GenericArgs> {
+    pub(crate) fn from_ast(node: ast::TypeArgList) -> Option<GenericArgs> {
         let mut args = Vec::new();
         for type_arg in node.type_args() {
             let type_ref = TypeRef::from_ast_opt(type_arg.type_ref());
@@ -160,10 +160,10 @@ impl From<Name> for Path {
     }
 }
 
-fn expand_use_tree<'a>(
+fn expand_use_tree(
     prefix: Option<Path>,
-    tree: &'a ast::UseTree,
-    cb: &mut impl FnMut(Path, &'a ast::UseTree, bool, Option<Name>),
+    tree: ast::UseTree,
+    cb: &mut impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
 ) {
     if let Some(use_tree_list) = tree.use_tree_list() {
         let prefix = match tree.path() {
@@ -188,7 +188,7 @@ fn expand_use_tree<'a>(
                 if let Some(segment) = ast_path.segment() {
                     if segment.kind() == Some(ast::PathSegmentKind::SelfKw) {
                         if let Some(prefix) = prefix {
-                            cb(prefix, tree, false, alias);
+                            cb(prefix, &tree, false, alias);
                             return;
                         }
                     }
@@ -196,7 +196,7 @@ fn expand_use_tree<'a>(
             }
             if let Some(path) = convert_path(prefix, ast_path) {
                 let is_glob = tree.has_star();
-                cb(path, tree, is_glob, alias)
+                cb(path, &tree, is_glob, alias)
             }
             // FIXME: report errors somewhere
             // We get here if we do
@@ -204,7 +204,7 @@ fn expand_use_tree<'a>(
     }
 }
 
-fn convert_path(prefix: Option<Path>, path: &ast::Path) -> Option<Path> {
+fn convert_path(prefix: Option<Path>, path: ast::Path) -> Option<Path> {
     let prefix =
         if let Some(qual) = path.qualifier() { Some(convert_path(prefix, qual)?) } else { prefix };
     let segment = path.segment()?;
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 071c1bb18..e7bc4df97 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -37,7 +37,7 @@ pub fn module_from_file_id(db: &impl HirDatabase, file_id: FileId) -> Option<Mod
 pub fn module_from_declaration(
     db: &impl HirDatabase,
     file_id: FileId,
-    decl: &ast::Module,
+    decl: ast::Module,
 ) -> Option<Module> {
     let parent_module = module_from_file_id(db, file_id);
     let child_name = decl.name();
@@ -50,8 +50,8 @@ pub fn module_from_declaration(
 /// Locates the module by position in the source code.
 pub fn module_from_position(db: &impl HirDatabase, position: FilePosition) -> Option<Module> {
     let parse = db.parse(position.file_id);
-    match find_node_at_offset::<ast::Module>(parse.tree().syntax(), position.offset) {
-        Some(m) if !m.has_semi() => module_from_inline(db, position.file_id, m),
+    match &find_node_at_offset::<ast::Module>(parse.tree().syntax(), position.offset) {
+        Some(m) if !m.has_semi() => module_from_inline(db, position.file_id, m.clone()),
         _ => module_from_file_id(db, position.file_id),
     }
 }
@@ -59,12 +59,12 @@ pub fn module_from_position(db: &impl HirDatabase, position: FilePosition) -> Op
 fn module_from_inline(
     db: &impl HirDatabase,
     file_id: FileId,
-    module: &ast::Module,
+    module: ast::Module,
 ) -> Option<Module> {
     assert!(!module.has_semi());
     let file_id = file_id.into();
     let ast_id_map = db.ast_id_map(file_id);
-    let item_id = ast_id_map.ast_id(module).with_file_id(file_id);
+    let item_id = ast_id_map.ast_id(&module).with_file_id(file_id);
     module_from_source(db, file_id, Some(item_id))
 }
 
@@ -127,16 +127,16 @@ fn try_get_resolver_for_node(
     file_id: FileId,
     node: &SyntaxNode,
 ) -> Option<Resolver> {
-    if let Some(module) = ast::Module::cast(node) {
+    if let Some(module) = ast::Module::cast(node.clone()) {
         Some(module_from_declaration(db, file_id, module)?.resolver(db))
-    } else if let Some(_) = ast::SourceFile::cast(node) {
+    } else if let Some(_) = ast::SourceFile::cast(node.clone()) {
         Some(module_from_source(db, file_id.into(), None)?.resolver(db))
-    } else if let Some(s) = ast::StructDef::cast(node) {
+    } else if let Some(s) = ast::StructDef::cast(node.clone()) {
         let module = module_from_child_node(db, file_id, s.syntax())?;
-        Some(struct_from_module(db, module, s).resolver(db))
-    } else if let Some(e) = ast::EnumDef::cast(node) {
+        Some(struct_from_module(db, module, &s).resolver(db))
+    } else if let Some(e) = ast::EnumDef::cast(node.clone()) {
         let module = module_from_child_node(db, file_id, e.syntax())?;
-        Some(enum_from_module(db, module, e).resolver(db))
+        Some(enum_from_module(db, module, &e).resolver(db))
     } else if node.kind() == FN_DEF || node.kind() == CONST_DEF || node.kind() == STATIC_DEF {
         Some(def_with_body_from_child_node(db, file_id, node)?.resolver(db))
     } else {
@@ -153,14 +153,14 @@ fn def_with_body_from_child_node(
     let module = module_from_child_node(db, file_id, node)?;
     let ctx = LocationCtx::new(db, module, file_id.into());
     node.ancestors().find_map(|node| {
-        if let Some(def) = ast::FnDef::cast(node) {
-            return Some(Function { id: ctx.to_def(def) }.into());
+        if let Some(def) = ast::FnDef::cast(node.clone()) {
+            return Some(Function { id: ctx.to_def(&def) }.into());
         }
-        if let Some(def) = ast::ConstDef::cast(node) {
-            return Some(Const { id: ctx.to_def(def) }.into());
+        if let Some(def) = ast::ConstDef::cast(node.clone()) {
+            return Some(Const { id: ctx.to_def(&def) }.into());
         }
-        if let Some(def) = ast::StaticDef::cast(node) {
-            return Some(Static { id: ctx.to_def(def) }.into());
+        if let Some(def) = ast::StaticDef::cast(node.clone()) {
+            return Some(Static { id: ctx.to_def(&def) }.into());
         }
         None
     })
@@ -237,7 +237,7 @@ impl SourceAnalyzer {
             SourceAnalyzer {
                 resolver: node
                     .ancestors()
-                    .find_map(|node| try_get_resolver_for_node(db, file_id, node))
+                    .find_map(|node| try_get_resolver_for_node(db, file_id, &node))
                     .unwrap_or_default(),
                 body_source_map: None,
                 infer: None,
@@ -257,17 +257,17 @@ impl SourceAnalyzer {
     }
 
     pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
-        let expr_id = self.body_source_map.as_ref()?.node_expr(call.into())?;
+        let expr_id = self.body_source_map.as_ref()?.node_expr(&call.clone().into())?;
         self.infer.as_ref()?.method_resolution(expr_id)
     }
 
     pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<crate::StructField> {
-        let expr_id = self.body_source_map.as_ref()?.node_expr(field.into())?;
+        let expr_id = self.body_source_map.as_ref()?.node_expr(&field.clone().into())?;
         self.infer.as_ref()?.field_resolution(expr_id)
     }
 
     pub fn resolve_variant(&self, struct_lit: &ast::StructLit) -> Option<crate::VariantDef> {
-        let expr_id = self.body_source_map.as_ref()?.node_expr(struct_lit.into())?;
+        let expr_id = self.body_source_map.as_ref()?.node_expr(&struct_lit.clone().into())?;
         self.infer.as_ref()?.variant_resolution(expr_id)
     }
 
@@ -290,18 +290,18 @@ impl SourceAnalyzer {
 
     pub fn resolve_path(&self, db: &impl HirDatabase, path: &ast::Path) -> Option<PathResolution> {
         if let Some(path_expr) = path.syntax().parent().and_then(ast::PathExpr::cast) {
-            let expr_id = self.body_source_map.as_ref()?.node_expr(path_expr.into())?;
+            let expr_id = self.body_source_map.as_ref()?.node_expr(&path_expr.into())?;
             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_expr(expr_id) {
                 return Some(PathResolution::AssocItem(assoc));
             }
         }
         if let Some(path_pat) = path.syntax().parent().and_then(ast::PathPat::cast) {
-            let pat_id = self.body_source_map.as_ref()?.node_pat(path_pat.into())?;
+            let pat_id = self.body_source_map.as_ref()?.node_pat(&path_pat.into())?;
             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_pat(pat_id) {
                 return Some(PathResolution::AssocItem(assoc));
             }
         }
-        let hir_path = crate::Path::from_ast(path)?;
+        let hir_path = crate::Path::from_ast(path.clone())?;
         let res = self.resolver.resolve_path_without_assoc_items(db, &hir_path);
         let res = res.clone().take_types().or_else(|| res.take_values())?;
         let res = match res {
@@ -343,12 +343,12 @@ impl SourceAnalyzer {
         // FIXME: at least, this should work with any DefWithBody, but ideally
         // this should be hir-based altogether
         let fn_def = pat.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
-        let ptr = Either::A(AstPtr::new(pat.into()));
+        let ptr = Either::A(AstPtr::new(&ast::Pat::from(pat.clone())));
         fn_def
             .syntax()
             .descendants()
             .filter_map(ast::NameRef::cast)
-            .filter(|name_ref| match self.resolve_local_name(*name_ref) {
+            .filter(|name_ref| match self.resolve_local_name(&name_ref) {
                 None => false,
                 Some(entry) => entry.ptr() == ptr,
             })
@@ -411,7 +411,7 @@ fn scope_for(
     node: &SyntaxNode,
 ) -> Option<ScopeId> {
     node.ancestors()
-        .map(SyntaxNodePtr::new)
+        .map(|it| SyntaxNodePtr::new(&it))
         .filter_map(|ptr| source_map.syntax_expr(ptr))
         .find_map(|it| scopes.scope_for(it))
 }
diff --git a/crates/ra_hir/src/source_id.rs b/crates/ra_hir/src/source_id.rs
index 6cdb90141..51cd65dda 100644
--- a/crates/ra_hir/src/source_id.rs
+++ b/crates/ra_hir/src/source_id.rs
@@ -5,7 +5,7 @@ use std::{
 };
 
 use ra_arena::{impl_arena_id, Arena, RawId};
-use ra_syntax::{ast, AstNode, SyntaxNode, SyntaxNodePtr, TreeArc};
+use ra_syntax::{ast, AstNode, SyntaxNode, SyntaxNodePtr};
 
 use crate::{AstDatabase, HirFileId};
 
@@ -42,9 +42,9 @@ impl<N: AstNode> AstId<N> {
         self.file_id
     }
 
-    pub(crate) fn to_node(&self, db: &impl AstDatabase) -> TreeArc<N> {
+    pub(crate) fn to_node(&self, db: &impl AstDatabase) -> N {
         let syntax_node = db.ast_id_to_node(self.file_id, self.file_ast_id.raw);
-        N::cast(&syntax_node).unwrap().to_owned()
+        N::cast(syntax_node).unwrap()
     }
 }
 
@@ -93,7 +93,7 @@ pub struct AstIdMap {
 impl AstIdMap {
     pub(crate) fn ast_id_map_query(db: &impl AstDatabase, file_id: HirFileId) -> Arc<AstIdMap> {
         let map = if let Some(node) = db.parse_or_expand(file_id) {
-            AstIdMap::from_source(&*node)
+            AstIdMap::from_source(&node)
         } else {
             AstIdMap::default()
         };
@@ -104,9 +104,9 @@ impl AstIdMap {
         db: &impl AstDatabase,
         file_id: HirFileId,
         ast_id: ErasedFileAstId,
-    ) -> TreeArc<SyntaxNode> {
+    ) -> SyntaxNode {
         let node = db.parse_or_expand(file_id).unwrap();
-        db.ast_id_map(file_id).arena[ast_id].to_node(&*node).to_owned()
+        db.ast_id_map(file_id).arena[ast_id].to_node(&node)
     }
 
     pub(crate) fn ast_id<N: AstNode>(&self, item: &N) -> FileAstId<N> {
@@ -131,7 +131,7 @@ impl AstIdMap {
         // change parent's id. This means that, say, adding a new function to a
         // trait does not change ids of top-level items, which helps caching.
         bfs(node, |it| {
-            if let Some(module_item) = ast::ModuleItem::cast(it) {
+            if let Some(module_item) = ast::ModuleItem::cast(it.clone()) {
                 res.alloc(module_item.syntax());
             } else if let Some(macro_call) = ast::MacroCall::cast(it) {
                 res.alloc(macro_call.syntax());
@@ -146,8 +146,8 @@ impl AstIdMap {
 }
 
 /// Walks the subtree in bfs order, calling `f` for each node.
-fn bfs(node: &SyntaxNode, mut f: impl FnMut(&SyntaxNode)) {
-    let mut curr_layer = vec![node];
+fn bfs(node: &SyntaxNode, mut f: impl FnMut(SyntaxNode)) {
+    let mut curr_layer = vec![node.clone()];
     let mut next_layer = vec![];
     while !curr_layer.is_empty() {
         curr_layer.drain(..).for_each(|node| {
diff --git a/crates/ra_hir/src/traits.rs b/crates/ra_hir/src/traits.rs
index fc0368303..de26f1a68 100644
--- a/crates/ra_hir/src/traits.rs
+++ b/crates/ra_hir/src/traits.rs
@@ -31,9 +31,9 @@ impl TraitData {
             item_list
                 .impl_items()
                 .map(|item_node| match item_node.kind() {
-                    ast::ImplItemKind::FnDef(it) => Function { id: ctx.to_def(it) }.into(),
-                    ast::ImplItemKind::ConstDef(it) => Const { id: ctx.to_def(it) }.into(),
-                    ast::ImplItemKind::TypeAliasDef(it) => TypeAlias { id: ctx.to_def(it) }.into(),
+                    ast::ImplItemKind::FnDef(it) => Function { id: ctx.to_def(&it) }.into(),
+                    ast::ImplItemKind::ConstDef(it) => Const { id: ctx.to_def(&it) }.into(),
+                    ast::ImplItemKind::TypeAliasDef(it) => TypeAlias { id: ctx.to_def(&it) }.into(),
                 })
                 .collect()
         } else {
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index 2410602a6..265740e54 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -3086,7 +3086,7 @@ fn type_at_pos(db: &MockDatabase, pos: FilePosition) -> String {
     let file = db.parse(pos.file_id).ok().unwrap();
     let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();
     let analyzer = SourceAnalyzer::new(db, pos.file_id, expr.syntax(), Some(pos.offset));
-    let ty = analyzer.type_of(db, expr).unwrap();
+    let ty = analyzer.type_of(db, &expr).unwrap();
     ty.display(db).to_string()
 }
 
@@ -3126,7 +3126,7 @@ fn infer(content: &str) -> String {
         types.sort_by_key(|(ptr, _)| (ptr.range().start(), ptr.range().end()));
         for (syntax_ptr, ty) in &types {
             let node = syntax_ptr.to_node(source_file.syntax());
-            let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node) {
+            let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node.clone()) {
                 (self_param.self_kw_token().range(), "self".to_string())
             } else {
                 (syntax_ptr.range(), node.text().to_string().replace("\n", " "))
@@ -3137,7 +3137,7 @@ fn infer(content: &str) -> String {
 
     for node in source_file.syntax().descendants() {
         if node.kind() == FN_DEF || node.kind() == CONST_DEF || node.kind() == STATIC_DEF {
-            let analyzer = SourceAnalyzer::new(&db, file_id, node, None);
+            let analyzer = SourceAnalyzer::new(&db, file_id, &node, None);
             infer_def(analyzer.inference_result(), analyzer.body_source_map());
         }
     }
@@ -3179,7 +3179,7 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
         let node =
             algo::find_token_at_offset(file.syntax(), pos.offset).right_biased().unwrap().parent();
         let events = db.log_executed(|| {
-            SourceAnalyzer::new(&db, pos.file_id, node, None);
+            SourceAnalyzer::new(&db, pos.file_id, &node, None);
         });
         assert!(format!("{:?}", events).contains("infer"))
     }
@@ -3200,7 +3200,7 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
         let node =
             algo::find_token_at_offset(file.syntax(), pos.offset).right_biased().unwrap().parent();
         let events = db.log_executed(|| {
-            SourceAnalyzer::new(&db, pos.file_id, node, None);
+            SourceAnalyzer::new(&db, pos.file_id, &node, None);
         });
         assert!(!format!("{:?}", events).contains("infer"), "{:#?}", events)
     }
diff --git a/crates/ra_hir/src/type_ref.rs b/crates/ra_hir/src/type_ref.rs
index 8aa807648..8536ae44a 100644
--- a/crates/ra_hir/src/type_ref.rs
+++ b/crates/ra_hir/src/type_ref.rs
@@ -56,7 +56,7 @@ pub enum TypeRef {
 
 impl TypeRef {
     /// Converts an `ast::TypeRef` to a `hir::TypeRef`.
-    pub(crate) fn from_ast(node: &ast::TypeRef) -> Self {
+    pub(crate) fn from_ast(node: ast::TypeRef) -> Self {
         use ra_syntax::ast::TypeRefKind::*;
         match node.kind() {
             ParenType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
@@ -95,7 +95,7 @@ impl TypeRef {
         }
     }
 
-    pub(crate) fn from_ast_opt(node: Option<&ast::TypeRef>) -> Self {
+    pub(crate) fn from_ast_opt(node: Option<ast::TypeRef>) -> Self {
         if let Some(node) = node {
             TypeRef::from_ast(node)
         } else {