22 files changed, 200 insertions, 89 deletions

diff --git a/Cargo.lock b/Cargo.lock
index c7809a65a..24dea133d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -162,9 +162,9 @@ checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
 [[package]]
 name = "chalk-derive"
-version = "0.21.0"
+version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1df0dbb57d74b4acd20f20fa66ab2acd09776b79eaeb9d8f947b2f3e01c40bf"
+checksum = "c3cb438e961fd7f1183dc5e0bdcfd09253bf9b90592cf665d1ce6787d8a4908f"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -174,9 +174,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-ir"
-version = "0.21.0"
+version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "44361a25dbdb1dc428f56ad7a3c21ba9ca12f3225c26a47919ff6fcb10a583d4"
+checksum = "bb332abfcb015b148c6fbab39b1d13282745b0f7f312019dd8e138f5f3f0855d"
 dependencies = [
  "chalk-derive",
  "lazy_static",
@@ -184,9 +184,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-recursive"
-version = "0.21.0"
+version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd89556b98de156d5eaf21077d297cd2198628f10f2df140798ea3a5dd84bc86"
+checksum = "e7c7673f10c5fa1acf7fa07d4f4c5917cbcf161ed3a952d14530c79950de32d2"
 dependencies = [
  "chalk-derive",
  "chalk-ir",
@@ -197,9 +197,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-solve"
-version = "0.21.0"
+version = "0.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a886da37a0dc457057d86f78f026f7a09c6d8088aa13f4f4127fdb8dc80119a3"
+checksum = "802de4eff72e5a5d2828e6c07224c74d66949dc6308aff025d0ae2871a11b4eb"
 dependencies = [
  "chalk-derive",
  "chalk-ir",
@@ -214,9 +214,9 @@ dependencies = [
 
 [[package]]
 name = "chrono"
-version = "0.4.13"
+version = "0.4.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c74d84029116787153e02106bf53e66828452a4b325cc8652b788b5967c0a0b6"
+checksum = "942f72db697d8767c22d46a598e01f2d3b475501ea43d0db4f16d90259182d0b"
 dependencies = [
  "num-integer",
  "num-traits",
@@ -1264,9 +1264,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_lexer"
-version = "671.0.0"
+version = "673.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "22e1221f3bfa2943c942cf8da319ab2346887f8757778c29c7f1822cd27b521f"
+checksum = "f6b71fa1285bdefe5fb61e59b63d6cc246abf337f4acafdd620d721bc488e671"
 dependencies = [
  "unicode-xid",
 ]
diff --git a/crates/assists/src/handlers/add_missing_impl_members.rs b/crates/assists/src/handlers/add_missing_impl_members.rs
index 81b61ebf8..83a2ada9a 100644
--- a/crates/assists/src/handlers/add_missing_impl_members.rs
+++ b/crates/assists/src/handlers/add_missing_impl_members.rs
@@ -48,7 +48,6 @@ enum AddMissingImplMembersMode {
 //     fn foo(&self) -> u32 {
 //         ${0:todo!()}
 //     }
-//
 // }
 // ```
 pub(crate) fn add_missing_impl_members(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
@@ -89,8 +88,8 @@ pub(crate) fn add_missing_impl_members(acc: &mut Assists, ctx: &AssistContext) -
 // impl Trait for () {
 //     Type X = ();
 //     fn foo(&self) {}
-//     $0fn bar(&self) {}
 //
+//     $0fn bar(&self) {}
 // }
 // ```
 pub(crate) fn add_missing_default_members(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
@@ -240,15 +239,18 @@ struct S;
 
 impl Foo for S {
     fn bar(&self) {}
+
     $0type Output;
+
     const CONST: usize = 42;
+
     fn foo(&self) {
         todo!()
     }
+
     fn baz(&self) {
         todo!()
     }
-
 }"#,
         );
     }
@@ -281,10 +283,10 @@ struct S;
 
 impl Foo for S {
     fn bar(&self) {}
+
     fn foo(&self) {
         ${0:todo!()}
     }
-
 }"#,
         );
     }
@@ -599,6 +601,7 @@ trait Foo {
 struct S;
 impl Foo for S {
     $0type Output;
+
     fn foo(&self) {
         todo!()
     }
@@ -708,4 +711,56 @@ impl Tr for () {
 }"#,
         )
     }
+
+    #[test]
+    fn test_whitespace_fixup_preserves_bad_tokens() {
+        check_assist(
+            add_missing_impl_members,
+            r#"
+trait Tr {
+    fn foo();
+}
+
+impl Tr for ()<|> {
+    +++
+}"#,
+            r#"
+trait Tr {
+    fn foo();
+}
+
+impl Tr for () {
+    fn foo() {
+        ${0:todo!()}
+    }
+    +++
+}"#,
+        )
+    }
+
+    #[test]
+    fn test_whitespace_fixup_preserves_comments() {
+        check_assist(
+            add_missing_impl_members,
+            r#"
+trait Tr {
+    fn foo();
+}
+
+impl Tr for ()<|> {
+    // very important
+}"#,
+            r#"
+trait Tr {
+    fn foo();
+}
+
+impl Tr for () {
+    fn foo() {
+        ${0:todo!()}
+    }
+    // very important
+}"#,
+        )
+    }
 }
diff --git a/crates/assists/src/lib.rs b/crates/assists/src/lib.rs
index ae90d68a3..c589b08dc 100644
--- a/crates/assists/src/lib.rs
+++ b/crates/assists/src/lib.rs
@@ -66,13 +66,13 @@ pub struct GroupLabel(pub String);
 
 #[derive(Debug, Clone)]
 pub struct Assist {
-    id: AssistId,
+    pub id: AssistId,
     /// Short description of the assist, as shown in the UI.
     label: String,
-    group: Option<GroupLabel>,
+    pub group: Option<GroupLabel>,
     /// Target ranges are used to sort assists: the smaller the target range,
     /// the more specific assist is, and so it should be sorted first.
-    target: TextRange,
+    pub target: TextRange,
 }
 
 #[derive(Debug, Clone)]
@@ -82,6 +82,11 @@ pub struct ResolvedAssist {
 }
 
 impl Assist {
+    fn new(id: AssistId, label: String, group: Option<GroupLabel>, target: TextRange) -> Assist {
+        assert!(label.starts_with(char::is_uppercase));
+        Assist { id, label, group, target }
+    }
+
     /// Return all the assists applicable at the given position.
     ///
     /// Assists are returned in the "unresolved" state, that is only labels are
@@ -114,30 +119,8 @@ impl Assist {
         acc.finish_resolved()
     }
 
-    pub(crate) fn new(
-        id: AssistId,
-        label: String,
-        group: Option<GroupLabel>,
-        target: TextRange,
-    ) -> Assist {
-        assert!(label.starts_with(|c: char| c.is_uppercase()));
-        Assist { id, label, group, target }
-    }
-
-    pub fn id(&self) -> AssistId {
-        self.id
-    }
-
-    pub fn label(&self) -> String {
-        self.label.clone()
-    }
-
-    pub fn group(&self) -> Option<GroupLabel> {
-        self.group.clone()
-    }
-
-    pub fn target(&self) -> TextRange {
-        self.target
+    pub fn label(&self) -> &str {
+        self.label.as_str()
     }
 }
 
diff --git a/crates/assists/src/tests/generated.rs b/crates/assists/src/tests/generated.rs
index d16e6fb0a..173567003 100644
--- a/crates/assists/src/tests/generated.rs
+++ b/crates/assists/src/tests/generated.rs
@@ -82,8 +82,8 @@ trait Trait {
 impl Trait for () {
     Type X = ();
     fn foo(&self) {}
-    $0fn bar(&self) {}
 
+    $0fn bar(&self) {}
 }
 "#####,
     )
@@ -115,7 +115,6 @@ impl Trait<u32> for () {
     fn foo(&self) -> u32 {
         ${0:todo!()}
     }
-
 }
 "#####,
     )
diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index 83b5013a9..a319b0ce8 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -16,9 +16,9 @@ ena = "0.14.0"
 log = "0.4.8"
 rustc-hash = "1.1.0"
 scoped-tls = "1"
-chalk-solve = { version = "0.21.0" }
-chalk-ir = { version = "0.21.0" }
-chalk-recursive = { version = "0.21.0" }
+chalk-solve = { version = "0.23.0" }
+chalk-ir = { version = "0.23.0" }
+chalk-recursive = { version = "0.23.0" }
 
 stdx = { path = "../stdx" }
 hir_def = { path = "../hir_def" }
diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index 1c3abb18f..14cd3a2b4 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -170,11 +170,11 @@ fn solve(
     let mut solve = || {
         if is_chalk_print() {
             let logging_db = LoggingRustIrDatabase::new(context);
-            let solution = solver.solve_limited(&logging_db, goal, should_continue);
+            let solution = solver.solve_limited(&logging_db, goal, &should_continue);
             log::debug!("chalk program:\n{}", logging_db);
             solution
         } else {
-            solver.solve_limited(&context, goal, should_continue)
+            solver.solve_limited(&context, goal, &should_continue)
         }
     };
 
diff --git a/crates/proc_macro_api/src/lib.rs b/crates/proc_macro_api/src/lib.rs
index 15db57eb2..d5e87cf7d 100644
--- a/crates/proc_macro_api/src/lib.rs
+++ b/crates/proc_macro_api/src/lib.rs
@@ -89,9 +89,8 @@ impl ProcMacroClient {
                 macros
                     .into_iter()
                     .filter_map(|(name, kind)| {
-                        // FIXME: Support custom derive only for now.
                         match kind {
-                            ProcMacroKind::CustomDerive => {
+                            ProcMacroKind::CustomDerive | ProcMacroKind::FuncLike => {
                                 let name = SmolStr::new(&name);
                                 let expander: Arc<dyn tt::TokenExpander> =
                                     Arc::new(ProcMacroProcessExpander {
@@ -101,7 +100,8 @@ impl ProcMacroClient {
                                     });
                                 Some((name, expander))
                             }
-                            _ => None,
+                            // FIXME: Attribute macro are currently unsupported.
+                            ProcMacroKind::Attr => None,
                         }
                     })
                     .collect()
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 74f73655a..e05ffc768 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -859,10 +859,10 @@ pub(crate) fn handle_resolve_code_action(
         .map(|it| it.into_iter().filter_map(from_proto::assist_kind).collect());
 
     let assists = snap.analysis.resolved_assists(&snap.config.assist, frange)?;
-    let (id_string, index) = split_once(&params.id, ':').unwrap();
+    let (id, index) = split_once(&params.id, ':').unwrap();
     let index = index.parse::<usize>().unwrap();
     let assist = &assists[index];
-    assert!(assist.assist.id().0 == id_string);
+    assert!(assist.assist.id.0 == id);
     Ok(to_proto::resolved_code_action(&snap, assist.clone())?.edit)
 }
 
diff --git a/crates/rust-analyzer/src/lsp_ext.rs b/crates/rust-analyzer/src/lsp_ext.rs
index 3976b6529..e1a28b1b4 100644
--- a/crates/rust-analyzer/src/lsp_ext.rs
+++ b/crates/rust-analyzer/src/lsp_ext.rs
@@ -237,8 +237,13 @@ pub enum Status {
     Invalid,
 }
 
+#[derive(Deserialize, Serialize)]
+pub struct StatusParams {
+    pub status: Status,
+}
+
 impl Notification for StatusNotification {
-    type Params = Status;
+    type Params = StatusParams;
     const METHOD: &'static str = "rust-analyzer/status";
 }
 
diff --git a/crates/rust-analyzer/src/reload.rs b/crates/rust-analyzer/src/reload.rs
index a2cfb4e0d..505505a77 100644
--- a/crates/rust-analyzer/src/reload.rs
+++ b/crates/rust-analyzer/src/reload.rs
@@ -13,6 +13,7 @@ use crate::{
     lsp_ext,
     main_loop::Task,
 };
+use lsp_ext::StatusParams;
 
 impl GlobalState {
     pub(crate) fn update_configuration(&mut self, config: Config) {
@@ -85,7 +86,9 @@ impl GlobalState {
                 Status::Invalid => lsp_ext::Status::Invalid,
                 Status::NeedsReload => lsp_ext::Status::NeedsReload,
             };
-            self.send_notification::<lsp_ext::StatusNotification>(lsp_status);
+            self.send_notification::<lsp_ext::StatusNotification>(StatusParams {
+                status: lsp_status,
+            });
         }
     }
     pub(crate) fn fetch_workspaces(&mut self) {
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index 8a2cfa2ae..535de2f71 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -704,10 +704,10 @@ pub(crate) fn unresolved_code_action(
     index: usize,
 ) -> Result<lsp_ext::CodeAction> {
     let res = lsp_ext::CodeAction {
-        title: assist.label(),
-        id: Some(format!("{}:{}", assist.id().0.to_owned(), index.to_string())),
-        group: assist.group().filter(|_| snap.config.client_caps.code_action_group).map(|gr| gr.0),
-        kind: Some(code_action_kind(assist.id().1)),
+        title: assist.label().to_string(),
+        id: Some(format!("{}:{}", assist.id.0, index.to_string())),
+        group: assist.group.filter(|_| snap.config.client_caps.code_action_group).map(|gr| gr.0),
+        kind: Some(code_action_kind(assist.id.1)),
         edit: None,
         is_preferred: None,
     };
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index 47e351f9d..ec3132da8 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 [dependencies]
 itertools = "0.9.0"
 rowan = "0.10.0"
-rustc_lexer = { version = "671.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "673.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 arrayvec = "0.5.1"
 once_cell = "1.3.1"
diff --git a/crates/syntax/src/ast/edit.rs b/crates/syntax/src/ast/edit.rs
index 190746e09..060b20966 100644
--- a/crates/syntax/src/ast/edit.rs
+++ b/crates/syntax/src/ast/edit.rs
@@ -91,29 +91,52 @@ impl ast::AssocItemList {
             res = make_multiline(res);
         }
         items.into_iter().for_each(|it| res = res.append_item(it));
-        res
+        res.fixup_trailing_whitespace().unwrap_or(res)
     }
 
     #[must_use]
     pub fn append_item(&self, item: ast::AssocItem) -> ast::AssocItemList {
-        let (indent, position) = match self.assoc_items().last() {
+        let (indent, position, whitespace) = match self.assoc_items().last() {
             Some(it) => (
                 leading_indent(it.syntax()).unwrap_or_default().to_string(),
                 InsertPosition::After(it.syntax().clone().into()),
+                "\n\n",
             ),
             None => match self.l_curly_token() {
                 Some(it) => (
                     "    ".to_string() + &leading_indent(self.syntax()).unwrap_or_default(),
                     InsertPosition::After(it.into()),
+                    "\n",
                 ),
                 None => return self.clone(),
             },
         };
-        let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
+        let ws = tokens::WsBuilder::new(&format!("{}{}", whitespace, indent));
         let to_insert: ArrayVec<[SyntaxElement; 2]> =
             [ws.ws().into(), item.syntax().clone().into()].into();
         self.insert_children(position, to_insert)
     }
+
+    /// Remove extra whitespace between last item and closing curly brace.
+    fn fixup_trailing_whitespace(&self) -> Option<ast::AssocItemList> {
+        let first_token_after_items =
+            self.assoc_items().last()?.syntax().next_sibling_or_token()?;
+        let last_token_before_curly = self.r_curly_token()?.prev_sibling_or_token()?;
+        if last_token_before_curly != first_token_after_items {
+            // there is something more between last item and
+            // right curly than just whitespace - bail out
+            return None;
+        }
+        let whitespace =
+            last_token_before_curly.clone().into_token().and_then(ast::Whitespace::cast)?;
+        let text = whitespace.syntax().text();
+        let newline = text.rfind("\n")?;
+        let keep = tokens::WsBuilder::new(&text[newline..]);
+        Some(self.replace_children(
+            first_token_after_items..=last_token_before_curly,
+            std::iter::once(keep.ws().into()),
+        ))
+    }
 }
 
 impl ast::RecordExprFieldList {
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md
index 1be01fd88..2e3133449 100644
--- a/docs/dev/lsp-extensions.md
+++ b/docs/dev/lsp-extensions.md
@@ -412,7 +412,13 @@ Reloads project information (that is, re-executes `cargo metadata`).
 
 **Method:** `rust-analyzer/status`
 
-**Notification:** `"loading" | "ready" | "invalid" | "needsReload"`
+**Notification:**
+
+```typescript
+interface StatusParams {
+    status: "loading" | "ready" | "invalid" | "needsReload",
+}
+```
 
 This notification is sent from server to client.
 The client can use it to display persistent status to the user (in modline).
diff --git a/docs/dev/style.md b/docs/dev/style.md
index 963a6d73d..8effddcda 100644
--- a/docs/dev/style.md
+++ b/docs/dev/style.md
@@ -176,6 +176,35 @@ fn frobnicate(walrus: Option<Walrus>) {
 }
 ```
 
+# Getters & Setters
+
+If a field can have any value without breaking invariants, make the field public.
+Conversely, if there is an invariant, document it, enforce it in the "constructor" function, make the field private, and provide a getter.
+Never provide setters.
+
+Getters should return borrowed data:
+
+```
+struct Person {
+    // Invariant: never empty
+    first_name: String,
+    middle_name: Option<String>
+}
+
+// Good
+impl Person {
+    fn first_name(&self) -> &str { self.first_name.as_str() }
+    fn middle_name(&self) -> Option<&str> { self.middle_name.as_ref() }
+}
+
+// Not as good
+impl Person {
+    fn first_name(&self) -> String { self.first_name.clone() }
+    fn middle_name(&self) -> &Option<String> { &self.middle_name }
+}
+```
+
+
 # Premature Pessimization
 
 Avoid writing code which is slower than it needs to be.
diff --git a/editors/code/src/ctx.ts b/editors/code/src/ctx.ts
index 6e767babf..543f7e02e 100644
--- a/editors/code/src/ctx.ts
+++ b/editors/code/src/ctx.ts
@@ -36,7 +36,7 @@ export class Ctx {
 
         res.pushCleanup(client.start());
         await client.onReady();
-        client.onNotification(ra.status, (status) => res.setStatus(status));
+        client.onNotification(ra.status, (params) => res.setStatus(params.status));
         return res;
     }
 
diff --git a/editors/code/src/lsp_ext.ts b/editors/code/src/lsp_ext.ts
index 494d51c83..8663737a6 100644
--- a/editors/code/src/lsp_ext.ts
+++ b/editors/code/src/lsp_ext.ts
@@ -8,7 +8,10 @@ export const analyzerStatus = new lc.RequestType<null, string, void>("rust-analy
 export const memoryUsage = new lc.RequestType<null, string, void>("rust-analyzer/memoryUsage");
 
 export type Status = "loading" | "ready" | "invalid" | "needsReload";
-export const status = new lc.NotificationType<Status>("rust-analyzer/status");
+export interface StatusParams {
+    status: Status;
+}
+export const status = new lc.NotificationType<StatusParams>("rust-analyzer/status");
 
 export const reloadWorkspace = new lc.RequestType<null, null, void>("rust-analyzer/reloadWorkspace");
 
diff --git a/xtask/src/codegen.rs b/xtask/src/codegen.rs
index 78a84f68d..98acd7fa6 100644
--- a/xtask/src/codegen.rs
+++ b/xtask/src/codegen.rs
@@ -15,7 +15,11 @@ use std::{
     path::{Path, PathBuf},
 };
 
-use crate::{not_bash::fs2, project_root, Result};
+use crate::{
+    ensure_rustfmt,
+    not_bash::{fs2, pushenv, run},
+    project_root, Result,
+};
 
 pub use self::{
     gen_assists_docs::{generate_assists_docs, generate_assists_tests},
@@ -62,6 +66,18 @@ fn update(path: &Path, contents: &str, mode: Mode) -> Result<()> {
     }
 }
 
+const PREAMBLE: &str = "Generated file, do not edit by hand, see `xtask/src/codegen`";
+
+fn reformat(text: impl std::fmt::Display) -> Result<String> {
+    let _e = pushenv("RUSTUP_TOOLCHAIN", "stable");
+    ensure_rustfmt()?;
+    let stdout = run!(
+        "rustfmt --config-path {} --config fn_single_line=true", project_root().join("rustfmt.toml").display();
+        <text.to_string().as_bytes()
+    )?;
+    Ok(format!("//! {}\n\n{}\n", PREAMBLE, stdout))
+}
+
 fn extract_comment_blocks(text: &str) -> Vec<Vec<String>> {
     do_extract_comment_blocks(text, false).into_iter().map(|(_line, block)| block).collect()
 }
diff --git a/xtask/src/codegen/gen_assists_docs.rs b/xtask/src/codegen/gen_assists_docs.rs
index 526941f73..4f4968594 100644
--- a/xtask/src/codegen/gen_assists_docs.rs
+++ b/xtask/src/codegen/gen_assists_docs.rs
@@ -3,7 +3,7 @@
 use std::{fmt, fs, path::Path};
 
 use crate::{
-    codegen::{self, extract_comment_blocks_with_empty_lines, Location, Mode},
+    codegen::{self, extract_comment_blocks_with_empty_lines, reformat, Location, Mode, PREAMBLE},
     project_root, rust_files, Result,
 };
 
@@ -15,7 +15,7 @@ pub fn generate_assists_tests(mode: Mode) -> Result<()> {
 pub fn generate_assists_docs(mode: Mode) -> Result<()> {
     let assists = Assist::collect()?;
     let contents = assists.into_iter().map(|it| it.to_string()).collect::<Vec<_>>().join("\n\n");
-    let contents = contents.trim().to_string() + "\n";
+    let contents = format!("//{}\n{}\n", PREAMBLE, contents.trim());
     let dst = project_root().join("docs/user/generated_assists.adoc");
     codegen::update(&dst, &contents, mode)
 }
@@ -134,7 +134,7 @@ r#####"
 
         buf.push_str(&test)
     }
-    let buf = crate::reformat(buf)?;
+    let buf = reformat(buf)?;
     codegen::update(&project_root().join(codegen::ASSISTS_TESTS), &buf, mode)
 }
 
diff --git a/xtask/src/codegen/gen_feature_docs.rs b/xtask/src/codegen/gen_feature_docs.rs
index 31bc3839d..3f0013e82 100644
--- a/xtask/src/codegen/gen_feature_docs.rs
+++ b/xtask/src/codegen/gen_feature_docs.rs
@@ -3,14 +3,14 @@
 use std::{fmt, fs, path::PathBuf};
 
 use crate::{
-    codegen::{self, extract_comment_blocks_with_empty_lines, Location, Mode},
+    codegen::{self, extract_comment_blocks_with_empty_lines, Location, Mode, PREAMBLE},
     project_root, rust_files, Result,
 };
 
 pub fn generate_feature_docs(mode: Mode) -> Result<()> {
     let features = Feature::collect()?;
     let contents = features.into_iter().map(|it| it.to_string()).collect::<Vec<_>>().join("\n\n");
-    let contents = contents.trim().to_string() + "\n";
+    let contents = format!("//{}\n{}\n", PREAMBLE, contents.trim());
     let dst = project_root().join("docs/user/generated_features.adoc");
     codegen::update(&dst, &contents, mode)?;
     Ok(())
diff --git a/xtask/src/codegen/gen_syntax.rs b/xtask/src/codegen/gen_syntax.rs
index dd1f4d6a2..df3ec22c8 100644
--- a/xtask/src/codegen/gen_syntax.rs
+++ b/xtask/src/codegen/gen_syntax.rs
@@ -14,7 +14,7 @@ use ungrammar::{rust_grammar, Grammar, Rule};
 
 use crate::{
     ast_src::{AstEnumSrc, AstNodeSrc, AstSrc, Cardinality, Field, KindsSrc, KINDS_SRC},
-    codegen::{self, update, Mode},
+    codegen::{self, reformat, update, Mode},
     project_root, Result,
 };
 
@@ -61,7 +61,7 @@ fn generate_tokens(grammar: &AstSrc) -> Result<String> {
         }
     });
 
-    let pretty = crate::reformat(quote! {
+    let pretty = reformat(quote! {
         use crate::{SyntaxKind::{self, *}, SyntaxToken, ast::AstToken};
         #(#tokens)*
     })?
@@ -261,7 +261,7 @@ fn generate_nodes(kinds: KindsSrc<'_>, grammar: &AstSrc) -> Result<String> {
         }
     }
 
-    let pretty = crate::reformat(res)?;
+    let pretty = reformat(res)?;
     Ok(pretty)
 }
 
@@ -383,7 +383,7 @@ fn generate_syntax_kinds(grammar: KindsSrc<'_>) -> Result<String> {
         }
     };
 
-    crate::reformat(ast)
+    reformat(ast)
 }
 
 fn to_upper_snake_case(s: &str) -> String {
diff --git a/xtask/src/lib.rs b/xtask/src/lib.rs
index 807ef587c..f3ad81ba7 100644
--- a/xtask/src/lib.rs
+++ b/xtask/src/lib.rs
@@ -62,17 +62,6 @@ pub fn run_rustfmt(mode: Mode) -> Result<()> {
     Ok(())
 }
 
-fn reformat(text: impl std::fmt::Display) -> Result<String> {
-    let _e = pushenv("RUSTUP_TOOLCHAIN", "stable");
-    ensure_rustfmt()?;
-    let stdout = run!(
-        "rustfmt --config-path {} --config fn_single_line=true", project_root().join("rustfmt.toml").display();
-        <text.to_string().as_bytes()
-    )?;
-    let preamble = "Generated file, do not edit by hand, see `xtask/src/codegen`";
-    Ok(format!("//! {}\n\n{}\n", preamble, stdout))
-}
-
 fn ensure_rustfmt() -> Result<()> {
     let out = run!("rustfmt --version")?;
     if !out.contains("stable") {