41 files changed, 269 insertions, 221 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 2386c8f3a..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",
@@ -1097,6 +1097,7 @@ dependencies = [
  "mbe",
  "memmap",
  "proc_macro_api",
+ "proc_macro_test",
  "serde_derive",
  "test_utils",
  "toolchain",
@@ -1104,6 +1105,10 @@ dependencies = [
 ]
 
 [[package]]
+name = "proc_macro_test"
+version = "0.0.0"
+
+[[package]]
 name = "profile"
 version = "0.0.0"
 dependencies = [
@@ -1259,9 +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/ast_transform.rs b/crates/assists/src/ast_transform.rs
index 4c41c16d8..5216862ba 100644
--- a/crates/assists/src/ast_transform.rs
+++ b/crates/assists/src/ast_transform.rs
@@ -7,6 +7,17 @@ use syntax::{
     ast::{self, AstNode},
 };
 
+pub fn apply<'a, N: AstNode>(transformer: &dyn AstTransform<'a>, node: N) -> N {
+    SyntaxRewriter::from_fn(|element| match element {
+        syntax::SyntaxElement::Node(n) => {
+            let replacement = transformer.get_substitution(&n)?;
+            Some(replacement.into())
+        }
+        _ => None,
+    })
+    .rewrite_ast(&node)
+}
+
 pub trait AstTransform<'a> {
     fn get_substitution(&self, node: &syntax::SyntaxNode) -> Option<syntax::SyntaxNode>;
 
@@ -107,10 +118,7 @@ impl<'a> SubstituteTypeParams<'a> {
             ast::Type::PathType(path_type) => path_type.path()?,
             _ => return None,
         };
-        // FIXME: use `hir::Path::from_src` instead.
-        #[allow(deprecated)]
-        let path = hir::Path::from_ast(path)?;
-        let resolution = self.source_scope.resolve_hir_path(&path)?;
+        let resolution = self.source_scope.speculative_resolve(&path)?;
         match resolution {
             hir::PathResolution::TypeParam(tp) => Some(self.substs.get(&tp)?.syntax().clone()),
             _ => None,
@@ -146,10 +154,7 @@ impl<'a> QualifyPaths<'a> {
             // don't try to qualify `Fn(Foo) -> Bar` paths, they are in prelude anyway
             return None;
         }
-        // FIXME: use `hir::Path::from_src` instead.
-        #[allow(deprecated)]
-        let hir_path = hir::Path::from_ast(p.clone());
-        let resolution = self.source_scope.resolve_hir_path(&hir_path?)?;
+        let resolution = self.source_scope.speculative_resolve(&p)?;
         match resolution {
             PathResolution::Def(def) => {
                 let found_path = from.find_use_path(self.source_scope.db.upcast(), def)?;
@@ -175,17 +180,6 @@ impl<'a> QualifyPaths<'a> {
     }
 }
 
-pub fn apply<'a, N: AstNode>(transformer: &dyn AstTransform<'a>, node: N) -> N {
-    SyntaxRewriter::from_fn(|element| match element {
-        syntax::SyntaxElement::Node(n) => {
-            let replacement = transformer.get_substitution(&n)?;
-            Some(replacement.into())
-        }
-        _ => None,
-    })
-    .rewrite_ast(&node)
-}
-
 impl<'a> AstTransform<'a> for QualifyPaths<'a> {
     fn get_substitution(&self, node: &syntax::SyntaxNode) -> Option<syntax::SyntaxNode> {
         self.get_substitution_inner(node).or_else(|| self.previous.get_substitution(node))
diff --git a/crates/assists/src/handlers/auto_import.rs b/crates/assists/src/handlers/auto_import.rs
index cce789972..b9ec3f10b 100644
--- a/crates/assists/src/handlers/auto_import.rs
+++ b/crates/assists/src/handlers/auto_import.rs
@@ -53,7 +53,7 @@ pub(crate) fn auto_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
             |builder| {
                 insert_use_statement(
                     &auto_import_assets.syntax_under_caret,
-                    &import,
+                    &import.to_string(),
                     ctx,
                     builder.text_edit_builder(),
                 );
diff --git a/crates/assists/src/handlers/expand_glob_import.rs b/crates/assists/src/handlers/expand_glob_import.rs
index f690ec343..81d0af2f3 100644
--- a/crates/assists/src/handlers/expand_glob_import.rs
+++ b/crates/assists/src/handlers/expand_glob_import.rs
@@ -1,3 +1,4 @@
+use either::Either;
 use hir::{AssocItem, MacroDef, ModuleDef, Name, PathResolution, ScopeDef, SemanticsScope};
 use ide_db::{
     defs::{classify_name_ref, Definition, NameRefClass},
@@ -10,8 +11,6 @@ use crate::{
     AssistId, AssistKind,
 };
 
-use either::Either;
-
 // Assist: expand_glob_import
 //
 // Expands glob imports.
@@ -40,11 +39,15 @@ use either::Either;
 pub(crate) fn expand_glob_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let star = ctx.find_token_at_offset(T![*])?;
     let mod_path = find_mod_path(&star)?;
+    let module = match ctx.sema.resolve_path(&mod_path)? {
+        PathResolution::Def(ModuleDef::Module(it)) => it,
+        _ => return None,
+    };
 
     let source_file = ctx.source_file();
     let scope = ctx.sema.scope_at_offset(source_file.syntax(), ctx.offset());
 
-    let defs_in_mod = find_defs_in_mod(ctx, scope, &mod_path)?;
+    let defs_in_mod = find_defs_in_mod(ctx, scope, module)?;
     let name_refs_in_source_file =
         source_file.syntax().descendants().filter_map(ast::NameRef::cast).collect();
     let used_names = find_used_names(ctx, defs_in_mod, name_refs_in_source_file);
@@ -82,17 +85,8 @@ impl Def {
 fn find_defs_in_mod(
     ctx: &AssistContext,
     from: SemanticsScope<'_>,
-    path: &ast::Path,
+    module: hir::Module,
 ) -> Option<Vec<Def>> {
-    let hir_path = ctx.sema.lower_path(&path)?;
-    let module = if let Some(PathResolution::Def(ModuleDef::Module(module))) =
-        from.resolve_hir_path_qualifier(&hir_path)
-    {
-        module
-    } else {
-        return None;
-    };
-
     let module_scope = module.scope(ctx.db(), from.module());
 
     let mut defs = vec![];
diff --git a/crates/assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
index 4bcdae7ba..d62e06b4a 100644
--- a/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
+++ b/crates/assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -106,7 +106,12 @@ fn insert_import(
     if let Some(mut mod_path) = mod_path {
         mod_path.segments.pop();
         mod_path.segments.push(variant_hir_name.clone());
-        insert_use_statement(path.syntax(), &mod_path, ctx, builder.text_edit_builder());
+        insert_use_statement(
+            path.syntax(),
+            &mod_path.to_string(),
+            ctx,
+            builder.text_edit_builder(),
+        );
     }
     Some(())
 }
diff --git a/crates/assists/src/handlers/replace_qualified_name_with_use.rs b/crates/assists/src/handlers/replace_qualified_name_with_use.rs
index 011bf1106..470e5f8ff 100644
--- a/crates/assists/src/handlers/replace_qualified_name_with_use.rs
+++ b/crates/assists/src/handlers/replace_qualified_name_with_use.rs
@@ -1,5 +1,5 @@
-use hir;
-use syntax::{algo::SyntaxRewriter, ast, match_ast, AstNode, SmolStr, SyntaxNode};
+use syntax::{algo::SyntaxRewriter, ast, match_ast, AstNode, SyntaxNode, TextRange};
+use test_utils::mark;
 
 use crate::{
     utils::{find_insert_use_container, insert_use_statement},
@@ -28,12 +28,19 @@ pub(crate) fn replace_qualified_name_with_use(
     if path.syntax().ancestors().find_map(ast::Use::cast).is_some() {
         return None;
     }
-
-    let hir_path = ctx.sema.lower_path(&path)?;
-    let segments = collect_hir_path_segments(&hir_path)?;
-    if segments.len() < 2 {
+    if path.qualifier().is_none() {
+        mark::hit!(dont_import_trivial_paths);
         return None;
     }
+    let path_to_import = path.to_string().clone();
+    let path_to_import = match path.segment()?.generic_arg_list() {
+        Some(generic_args) => {
+            let generic_args_start =
+                generic_args.syntax().text_range().start() - path.syntax().text_range().start();
+            &path_to_import[TextRange::up_to(generic_args_start)]
+        }
+        None => path_to_import.as_str(),
+    };
 
     let target = path.syntax().text_range();
     acc.add(
@@ -41,12 +48,16 @@ pub(crate) fn replace_qualified_name_with_use(
         "Replace qualified path with use",
         target,
         |builder| {
-            let path_to_import = hir_path.mod_path().clone();
             let container = match find_insert_use_container(path.syntax(), ctx) {
                 Some(c) => c,
                 None => return,
             };
-            insert_use_statement(path.syntax(), &path_to_import, ctx, builder.text_edit_builder());
+            insert_use_statement(
+                path.syntax(),
+                &path_to_import.to_string(),
+                ctx,
+                builder.text_edit_builder(),
+            );
 
             // Now that we've brought the name into scope, re-qualify all paths that could be
             // affected (that is, all paths inside the node we added the `use` to).
@@ -58,26 +69,6 @@ pub(crate) fn replace_qualified_name_with_use(
     )
 }
 
-fn collect_hir_path_segments(path: &hir::Path) -> Option<Vec<SmolStr>> {
-    let mut ps = Vec::<SmolStr>::with_capacity(10);
-    match path.kind() {
-        hir::PathKind::Abs => ps.push("".into()),
-        hir::PathKind::Crate => ps.push("crate".into()),
-        hir::PathKind::Plain => {}
-        hir::PathKind::Super(0) => ps.push("self".into()),
-        hir::PathKind::Super(lvl) => {
-            let mut chain = "super".to_string();
-            for _ in 0..*lvl {
-                chain += "::super";
-            }
-            ps.push(chain.into());
-        }
-        hir::PathKind::DollarCrate(_) => return None,
-    }
-    ps.extend(path.segments().iter().map(|it| it.name.to_string().into()));
-    Some(ps)
-}
-
 /// Adds replacements to `re` that shorten `path` in all descendants of `node`.
 fn shorten_paths(rewriter: &mut SyntaxRewriter<'static>, node: SyntaxNode, path: ast::Path) {
     for child in node.children() {
@@ -467,7 +458,8 @@ impl Debug for Foo {
     }
 
     #[test]
-    fn test_replace_not_applicable_one_segment() {
+    fn dont_import_trivial_paths() {
+        mark::check!(dont_import_trivial_paths);
         check_assist_not_applicable(
             replace_qualified_name_with_use,
             r"
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/utils/insert_use.rs b/crates/assists/src/utils/insert_use.rs
index 50a62ee82..49096a67c 100644
--- a/crates/assists/src/utils/insert_use.rs
+++ b/crates/assists/src/utils/insert_use.rs
@@ -5,7 +5,6 @@
 use std::iter::successors;
 
 use either::Either;
-use hir::{self, ModPath};
 use syntax::{
     ast::{self, NameOwner, VisibilityOwner},
     AstNode, AstToken, Direction, SmolStr,
@@ -35,11 +34,11 @@ pub(crate) fn find_insert_use_container(
 pub(crate) fn insert_use_statement(
     // Ideally the position of the cursor, used to
     position: &SyntaxNode,
-    path_to_import: &ModPath,
+    path_to_import: &str,
     ctx: &AssistContext,
     builder: &mut TextEditBuilder,
 ) {
-    let target = path_to_import.to_string().split("::").map(SmolStr::new).collect::<Vec<_>>();
+    let target = path_to_import.split("::").map(SmolStr::new).collect::<Vec<_>>();
     let container = find_insert_use_container(position, ctx);
 
     if let Some(container) = container {
diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index 5dc3ae3b1..c442654dd 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -12,6 +12,7 @@ use hir_def::{
     docs::Documentation,
     expr::{BindingAnnotation, Pat, PatId},
     import_map,
+    path::ModPath,
     per_ns::PerNs,
     resolver::{HasResolver, Resolver},
     src::HasSource as _,
@@ -344,11 +345,7 @@ impl Module {
 
     /// Finds a path that can be used to refer to the given item from within
     /// this module, if possible.
-    pub fn find_use_path(
-        self,
-        db: &dyn DefDatabase,
-        item: impl Into<ItemInNs>,
-    ) -> Option<hir_def::path::ModPath> {
+    pub fn find_use_path(self, db: &dyn DefDatabase, item: impl Into<ItemInNs>) -> Option<ModPath> {
         hir_def::find_path::find_path(db, item.into(), self.into())
     }
 }
@@ -1126,7 +1123,7 @@ impl ImplDef {
             .value
             .attrs()
             .filter_map(|it| {
-                let path = hir_def::path::ModPath::from_src(it.path()?, &hygenic)?;
+                let path = ModPath::from_src(it.path()?, &hygenic)?;
                 if path.as_ident()?.to_string() == "derive" {
                     Some(it)
                 } else {
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 4ae2bd085..8961ba8fd 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -48,7 +48,7 @@ pub use hir_def::{
     builtin_type::BuiltinType,
     docs::Documentation,
     nameres::ModuleSource,
-    path::{ModPath, Path, PathKind},
+    path::ModPath,
     type_ref::{Mutability, TypeRef},
 };
 pub use hir_expand::{
@@ -60,4 +60,7 @@ pub use hir_ty::display::HirDisplay;
 // These are negative re-exports: pub using these names is forbidden, they
 // should remain private to hir internals.
 #[allow(unused)]
-use hir_expand::hygiene::Hygiene;
+use {
+    hir_def::path::{Path, PathKind},
+    hir_expand::hygiene::Hygiene,
+};
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index d8beac98a..c693176fa 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -6,7 +6,7 @@ use std::{cell::RefCell, fmt, iter::successors};
 
 use base_db::{FileId, FileRange};
 use hir_def::{
-    resolver::{self, HasResolver, Resolver},
+    resolver::{self, HasResolver, Resolver, TypeNs},
     AsMacroCall, FunctionId, TraitId, VariantId,
 };
 use hir_expand::{hygiene::Hygiene, name::AsName, ExpansionInfo};
@@ -22,12 +22,11 @@ use crate::{
     db::HirDatabase,
     diagnostics::Diagnostic,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
-    source_analyzer::{resolve_hir_path, resolve_hir_path_qualifier, SourceAnalyzer},
+    source_analyzer::{resolve_hir_path, SourceAnalyzer},
     AssocItem, Callable, Crate, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef,
     Module, ModuleDef, Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, TypeRef,
     VariantDef,
 };
-use resolver::TypeNs;
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum PathResolution {
@@ -112,14 +111,13 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
     pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
         self.imp.expand(macro_call)
     }
-
-    pub fn expand_hypothetical(
+    pub fn speculative_expand(
         &self,
         actual_macro_call: &ast::MacroCall,
         hypothetical_args: &ast::TokenTree,
         token_to_map: SyntaxToken,
     ) -> Option<(SyntaxNode, SyntaxToken)> {
-        self.imp.expand_hypothetical(actual_macro_call, hypothetical_args, token_to_map)
+        self.imp.speculative_expand(actual_macro_call, hypothetical_args, token_to_map)
     }
 
     pub fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
@@ -229,10 +227,6 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.resolve_variant(record_lit).map(VariantDef::from)
     }
 
-    pub fn lower_path(&self, path: &ast::Path) -> Option<Path> {
-        self.imp.lower_path(path)
-    }
-
     pub fn resolve_bind_pat_to_const(&self, pat: &ast::IdentPat) -> Option<ModuleDef> {
         self.imp.resolve_bind_pat_to_const(pat)
     }
@@ -311,7 +305,7 @@ impl<'db> SemanticsImpl<'db> {
         Some(node)
     }
 
-    fn expand_hypothetical(
+    fn speculative_expand(
         &self,
         actual_macro_call: &ast::MacroCall,
         hypothetical_args: &ast::TokenTree,
@@ -468,11 +462,6 @@ impl<'db> SemanticsImpl<'db> {
         self.analyze(record_lit.syntax()).resolve_variant(self.db, record_lit)
     }
 
-    fn lower_path(&self, path: &ast::Path) -> Option<Path> {
-        let src = self.find_file(path.syntax().clone());
-        Path::from_src(path.clone(), &Hygiene::new(self.db.upcast(), src.file_id.into()))
-    }
-
     fn resolve_bind_pat_to_const(&self, pat: &ast::IdentPat) -> Option<ModuleDef> {
         self.analyze(pat.syntax()).resolve_bind_pat_to_const(self.db, pat)
     }
@@ -756,31 +745,10 @@ impl<'a> SemanticsScope<'a> {
 
     /// Resolve a path as-if it was written at the given scope. This is
     /// necessary a heuristic, as it doesn't take hygiene into account.
-    pub fn resolve_hypothetical(&self, path: &ast::Path) -> Option<PathResolution> {
+    pub fn speculative_resolve(&self, path: &ast::Path) -> Option<PathResolution> {
         let hygiene = Hygiene::new(self.db.upcast(), self.file_id);
         let path = Path::from_src(path.clone(), &hygiene)?;
-        self.resolve_hir_path(&path)
-    }
-
-    pub fn resolve_hir_path(&self, path: &Path) -> Option<PathResolution> {
-        resolve_hir_path(self.db, &self.resolver, path)
-    }
-
-    /// Resolves a path where we know it is a qualifier of another path.
-    ///
-    /// For example, if we have:
-    /// ```
-    /// mod my {
-    ///     pub mod foo {
-    ///         struct Bar;
-    ///     }
-    ///
-    ///     pub fn foo() {}
-    /// }
-    /// ```
-    /// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
-    pub fn resolve_hir_path_qualifier(&self, path: &Path) -> Option<PathResolution> {
-        resolve_hir_path_qualifier(self.db, &self.resolver, path)
+        resolve_hir_path(self.db, &self.resolver, &path)
     }
 }
 
diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs
index 8750584f9..1d13c4f1d 100644
--- a/crates/hir/src/source_analyzer.rs
+++ b/crates/hir/src/source_analyzer.rs
@@ -13,6 +13,7 @@ use hir_def::{
         Body, BodySourceMap,
     },
     expr::{ExprId, Pat, PatId},
+    path::{ModPath, Path, PathKind},
     resolver::{resolver_for_scope, Resolver, TypeNs, ValueNs},
     AsMacroCall, DefWithBodyId, FieldId, FunctionId, LocalFieldId, VariantId,
 };
@@ -28,8 +29,7 @@ use syntax::{
 
 use crate::{
     db::HirDatabase, semantics::PathResolution, Adt, Const, EnumVariant, Field, Function, Local,
-    MacroDef, ModPath, ModuleDef, Path, PathKind, Static, Struct, Trait, Type, TypeAlias,
-    TypeParam,
+    MacroDef, ModuleDef, Static, Struct, Trait, Type, TypeAlias, TypeParam,
 };
 use base_db::CrateId;
 
@@ -508,7 +508,7 @@ pub(crate) fn resolve_hir_path(
 /// }
 /// ```
 /// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
-pub(crate) fn resolve_hir_path_qualifier(
+fn resolve_hir_path_qualifier(
     db: &dyn HirDatabase,
     resolver: &Resolver,
     path: &Path,
diff --git a/crates/hir_def/src/path.rs b/crates/hir_def/src/path.rs
index 74d26f08b..99395667d 100644
--- a/crates/hir_def/src/path.rs
+++ b/crates/hir_def/src/path.rs
@@ -154,12 +154,6 @@ pub enum GenericArg {
 
 impl Path {
     /// Converts an `ast::Path` to `Path`. Works with use trees.
-    #[deprecated = "Doesn't handle hygiene, don't add new calls, remove old ones"]
-    pub fn from_ast(path: ast::Path) -> Option<Path> {
-        lower::lower_path(path, &Hygiene::new_unhygienic())
-    }
-
-    /// Converts an `ast::Path` to `Path`. Works with use trees.
     /// It correctly handles `$crate` based path from macro call.
     pub fn from_src(path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
         lower::lower_path(path, hygiene)
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 255323717..14cd3a2b4 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 
 use base_db::CrateId;
 use chalk_ir::cast::Cast;
-use chalk_solve::Solver;
+use chalk_solve::{logging_db::LoggingRustIrDatabase, Solver};
 use hir_def::{lang_item::LangItemTarget, TraitId};
 
 use crate::{db::HirDatabase, DebruijnIndex, Substs};
@@ -166,16 +166,25 @@ fn solve(
         }
         remaining > 0
     };
+
     let mut solve = || {
-        let solution = solver.solve_limited(&context, goal, should_continue);
-        log::debug!("solve({:?}) => {:?}", goal, solution);
-        solution
+        if is_chalk_print() {
+            let logging_db = LoggingRustIrDatabase::new(context);
+            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)
+        }
     };
+
     // don't set the TLS for Chalk unless Chalk debugging is active, to make
     // extra sure we only use it for debugging
     let solution =
         if is_chalk_debug() { chalk::tls::set_current_program(db, solve) } else { solve() };
 
+    log::debug!("solve({:?}) => {:?}", goal, solution);
+
     solution
 }
 
@@ -183,6 +192,10 @@ fn is_chalk_debug() -> bool {
     std::env::var("CHALK_DEBUG").is_ok()
 }
 
+fn is_chalk_print() -> bool {
+    std::env::var("CHALK_PRINT").is_ok()
+}
+
 fn solution_from_chalk(
     db: &dyn HirDatabase,
     solution: chalk_solve::Solution<Interner>,
diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index b33653417..17c83b6a4 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -240,20 +240,23 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         Substs::empty().to_chalk(self.db)
     }
 
-    fn trait_name(&self, _trait_id: chalk_ir::TraitId<Interner>) -> String {
-        unimplemented!()
+    fn trait_name(&self, trait_id: chalk_ir::TraitId<Interner>) -> String {
+        let id = from_chalk(self.db, trait_id);
+        self.db.trait_data(id).name.to_string()
     }
-    fn adt_name(&self, _struct_id: chalk_ir::AdtId<Interner>) -> String {
-        unimplemented!()
+    // FIXME: lookup names
+    fn adt_name(&self, struct_id: chalk_ir::AdtId<Interner>) -> String {
+        let datum = self.db.struct_datum(self.krate, struct_id);
+        format!("{:?}", datum.name(&Interner))
     }
-    fn assoc_type_name(&self, _assoc_ty_id: chalk_ir::AssocTypeId<Interner>) -> String {
-        unimplemented!()
+    fn assoc_type_name(&self, assoc_ty_id: chalk_ir::AssocTypeId<Interner>) -> String {
+        format!("Assoc_{}", assoc_ty_id.0)
     }
-    fn opaque_type_name(&self, _opaque_ty_id: chalk_ir::OpaqueTyId<Interner>) -> String {
-        unimplemented!()
+    fn opaque_type_name(&self, opaque_ty_id: chalk_ir::OpaqueTyId<Interner>) -> String {
+        format!("Opaque_{}", opaque_ty_id.0)
     }
-    fn fn_def_name(&self, _fn_def_id: chalk_ir::FnDefId<Interner>) -> String {
-        unimplemented!()
+    fn fn_def_name(&self, fn_def_id: chalk_ir::FnDefId<Interner>) -> String {
+        format!("fn_{}", fn_def_id.0)
     }
 }
 
diff --git a/crates/ide/src/completion/completion_context.rs b/crates/ide/src/completion/completion_context.rs
index 3857dce67..85456a66f 100644
--- a/crates/ide/src/completion/completion_context.rs
+++ b/crates/ide/src/completion/completion_context.rs
@@ -185,7 +185,7 @@ impl<'a> CompletionContext<'a> {
             };
             if let (Some(actual_expansion), Some(hypothetical_expansion)) = (
                 ctx.sema.expand(&actual_macro_call),
-                ctx.sema.expand_hypothetical(
+                ctx.sema.speculative_expand(
                     &actual_macro_call,
                     &hypothetical_args,
                     fake_ident_token,
diff --git a/crates/ide/src/inlay_hints.rs b/crates/ide/src/inlay_hints.rs
index 002adf915..596bc872d 100644
--- a/crates/ide/src/inlay_hints.rs
+++ b/crates/ide/src/inlay_hints.rs
@@ -43,7 +43,7 @@ pub struct InlayHint {
 // rust-analyzer shows additional information inline with the source code.
 // Editors usually render this using read-only virtual text snippets interspersed with code.
 //
-// rust-analyzer shows hits for
+// rust-analyzer shows hints for
 //
 // * types of local variables
 // * names of function arguments
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/proc_macro_srv/Cargo.toml b/crates/proc_macro_srv/Cargo.toml
index 7171f0808..a468b5560 100644
--- a/crates/proc_macro_srv/Cargo.toml
+++ b/crates/proc_macro_srv/Cargo.toml
@@ -21,7 +21,9 @@ test_utils = { path = "../test_utils" }
 [dev-dependencies]
 cargo_metadata = "0.11.1"
 difference = "2.0.0"
-# used as proc macro test target
+
+# used as proc macro test targets
 serde_derive = "1.0.106"
+proc_macro_test = { path = "../proc_macro_test" }
 
 toolchain = { path = "../toolchain" }
diff --git a/crates/proc_macro_srv/src/tests/mod.rs b/crates/proc_macro_srv/src/tests/mod.rs
index 8e6f28abd..1a827cbd7 100644
--- a/crates/proc_macro_srv/src/tests/mod.rs
+++ b/crates/proc_macro_srv/src/tests/mod.rs
@@ -35,7 +35,7 @@ SUBTREE $
 
 #[test]
 fn test_derive_proc_macro_list() {
-    let res = list("serde_derive", "1.0").join("\n");
+    let res = list("serde_derive", "1").join("\n");
 
     assert_eq_text!(
         &res,
@@ -43,3 +43,16 @@ fn test_derive_proc_macro_list() {
 Deserialize [CustomDerive]"#
     );
 }
+
+/// Tests that we find and classify non-derive macros correctly.
+#[test]
+fn list_test_macros() {
+    let res = list("proc_macro_test", "0.0.0").join("\n");
+
+    assert_eq_text!(
+        &res,
+        r#"function_like_macro [FuncLike]
+attribute_macro [Attr]
+DummyTrait [CustomDerive]"#
+    );
+}
diff --git a/crates/proc_macro_srv/src/tests/utils.rs b/crates/proc_macro_srv/src/tests/utils.rs
index 5828512d6..36942147d 100644
--- a/crates/proc_macro_srv/src/tests/utils.rs
+++ b/crates/proc_macro_srv/src/tests/utils.rs
@@ -13,7 +13,7 @@ mod fixtures {
     // Use current project metadata to get the proc-macro dylib path
     pub fn dylib_path(crate_name: &str, version: &str) -> std::path::PathBuf {
         let command = Command::new(toolchain::cargo())
-            .args(&["check", "--message-format", "json"])
+            .args(&["check", "--tests", "--message-format", "json"])
             .output()
             .unwrap()
             .stdout;
diff --git a/crates/proc_macro_test/Cargo.toml b/crates/proc_macro_test/Cargo.toml
new file mode 100644
index 000000000..7b0f64f31
--- /dev/null
+++ b/crates/proc_macro_test/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "proc_macro_test"
+version = "0.0.0"
+license = "MIT OR Apache-2.0"
+authors = ["rust-analyzer developers"]
+edition = "2018"
+
+[lib]
+doctest = false
+proc-macro = true
diff --git a/crates/proc_macro_test/src/lib.rs b/crates/proc_macro_test/src/lib.rs
new file mode 100644
index 000000000..ec2a114a3
--- /dev/null
+++ b/crates/proc_macro_test/src/lib.rs
@@ -0,0 +1,18 @@
+//! Exports a few trivial procedural macros for testing.
+
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn function_like_macro(args: TokenStream) -> TokenStream {
+    args
+}
+
+#[proc_macro_attribute]
+pub fn attribute_macro(_args: TokenStream, item: TokenStream) -> TokenStream {
+    item
+}
+
+#[proc_macro_derive(DummyTrait)]
+pub fn derive_macro(_item: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
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/ssr/src/resolving.rs b/crates/ssr/src/resolving.rs
index 4441fb426..b932132d5 100644
--- a/crates/ssr/src/resolving.rs
+++ b/crates/ssr/src/resolving.rs
@@ -212,13 +212,13 @@ impl<'db> ResolutionScope<'db> {
         // First try resolving the whole path. This will work for things like
         // `std::collections::HashMap`, but will fail for things like
         // `std::collections::HashMap::new`.
-        if let Some(resolution) = self.scope.resolve_hypothetical(&path) {
+        if let Some(resolution) = self.scope.speculative_resolve(&path) {
             return Some(resolution);
         }
         // Resolution failed, try resolving the qualifier (e.g. `std::collections::HashMap` and if
         // that succeeds, then iterate through the candidates on the resolved type with the provided
         // name.
-        let resolved_qualifier = self.scope.resolve_hypothetical(&path.qualifier()?)?;
+        let resolved_qualifier = self.scope.speculative_resolve(&path.qualifier()?)?;
         if let hir::PathResolution::Def(hir::ModuleDef::Adt(adt)) = resolved_qualifier {
             let name = path.segment()?.name_ref()?;
             adt.ty(self.scope.db).iterate_path_candidates(
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/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/.eslintignore b/editors/code/.eslintignore
new file mode 100644
index 000000000..3df5c860b
--- /dev/null
+++ b/editors/code/.eslintignore
@@ -0,0 +1,3 @@
+node_modules
+.eslintrc.js
+rollup.config.js
\ No newline at end of file
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/Cargo.toml b/xtask/Cargo.toml
index 1a1140b04..e9edbdd10 100644
--- a/xtask/Cargo.toml
+++ b/xtask/Cargo.toml
@@ -18,3 +18,4 @@ quote = "1.0.2"
 ungrammar = "1.1.1"
 walkdir = "2.3.1"
 write-json =  "0.1.0"
+# Avoid adding more dependencies to this crate
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") {