49 files changed, 1015 insertions, 529 deletions

diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index ac23e385e..c9ef4b420 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -2071,6 +2071,10 @@ impl Type {
         Some(adt.into())
     }
 
+    pub fn as_builtin(&self) -> Option<BuiltinType> {
+        self.ty.as_builtin().map(|inner| BuiltinType { inner })
+    }
+
     pub fn as_dyn_trait(&self) -> Option<Trait> {
         self.ty.dyn_trait().map(Into::into)
     }
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 8d13c7e04..cad8a7479 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -18,7 +18,7 @@ use hir_expand::{
     ast_id_map::FileAstId,
     hygiene::Hygiene,
     name::{name, AsName, Name},
-    HirFileId, InFile,
+    FragmentKind, HirFileId, InFile,
 };
 use la_arena::{Arena, Idx, RawIdx};
 use profile::Count;
@@ -656,6 +656,7 @@ pub struct MacroCall {
     /// Path to the called macro.
     pub path: Interned<ModPath>,
     pub ast_id: FileAstId<ast::MacroCall>,
+    pub fragment: FragmentKind,
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 5743b3386..fe348091d 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -624,7 +624,8 @@ impl<'a> Ctx<'a> {
     fn lower_macro_call(&mut self, m: &ast::MacroCall) -> Option<FileItemTreeId<MacroCall>> {
         let path = Interned::new(ModPath::from_src(self.db, m.path()?, &self.hygiene)?);
         let ast_id = self.source_ast_id_map.ast_id(m);
-        let res = MacroCall { path, ast_id };
+        let fragment = hir_expand::to_fragment_kind(m);
+        let res = MacroCall { path, ast_id, fragment };
         Some(id(self.data().macro_calls.alloc(res)))
     }
 
diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index da46f16f7..e96ca953f 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -62,7 +62,8 @@ use hir_expand::{
     ast_id_map::FileAstId,
     eager::{expand_eager_macro, ErrorEmitted, ErrorSink},
     hygiene::Hygiene,
-    AstId, AttrId, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
+    AstId, AttrId, FragmentKind, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId,
+    MacroDefKind,
 };
 use la_arena::Idx;
 use nameres::DefMap;
@@ -652,6 +653,7 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
         mut error_sink: &mut dyn FnMut(mbe::ExpandError),
     ) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro> {
+        let fragment = hir_expand::to_fragment_kind(self.value);
         let ast_id = AstId::new(self.file_id, db.ast_id_map(self.file_id).ast_id(self.value));
         let h = Hygiene::new(db.upcast(), self.file_id);
         let path = self.value.path().and_then(|path| path::ModPath::from_src(db, path, &h));
@@ -667,6 +669,7 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
 
         macro_call_as_call_id(
             &AstIdWithPath::new(ast_id.file_id, ast_id.value, path),
+            fragment,
             db,
             krate,
             resolver,
@@ -695,6 +698,7 @@ pub struct UnresolvedMacro {
 
 fn macro_call_as_call_id(
     call: &AstIdWithPath<ast::MacroCall>,
+    fragment: FragmentKind,
     db: &dyn db::DefDatabase,
     krate: CrateId,
     resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
@@ -718,7 +722,11 @@ fn macro_call_as_call_id(
         .map(MacroCallId::from)
     } else {
         Ok(def
-            .as_lazy_macro(db.upcast(), krate, MacroCallKind::FnLike { ast_id: call.ast_id })
+            .as_lazy_macro(
+                db.upcast(),
+                krate,
+                MacroCallKind::FnLike { ast_id: call.ast_id, fragment },
+            )
             .into())
     };
     Ok(res)
diff --git a/crates/hir_def/src/nameres.rs b/crates/hir_def/src/nameres.rs
index 1bc72ec1f..249af6fc8 100644
--- a/crates/hir_def/src/nameres.rs
+++ b/crates/hir_def/src/nameres.rs
@@ -629,7 +629,7 @@ mod diagnostics {
                 DiagnosticKind::UnresolvedProcMacro { ast } => {
                     let mut precise_location = None;
                     let (file, ast, name) = match ast {
-                        MacroCallKind::FnLike { ast_id } => {
+                        MacroCallKind::FnLike { ast_id, .. } => {
                             let node = ast_id.to_node(db.upcast());
                             (ast_id.file_id, SyntaxNodePtr::from(AstPtr::new(&node)), None)
                         }
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 05ceb1efb..e89136ed1 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -13,7 +13,7 @@ use hir_expand::{
     builtin_macro::find_builtin_macro,
     name::{AsName, Name},
     proc_macro::ProcMacroExpander,
-    AttrId, HirFileId, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
+    AttrId, FragmentKind, HirFileId, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
 };
 use hir_expand::{InFile, MacroCallLoc};
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -215,7 +215,7 @@ struct MacroDirective {
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 enum MacroDirectiveKind {
-    FnLike { ast_id: AstIdWithPath<ast::MacroCall> },
+    FnLike { ast_id: AstIdWithPath<ast::MacroCall>, fragment: FragmentKind },
     Derive { ast_id: AstIdWithPath<ast::Item>, derive_attr: AttrId },
 }
 
@@ -807,9 +807,10 @@ impl DefCollector<'_> {
         let mut res = ReachedFixedPoint::Yes;
         macros.retain(|directive| {
             match &directive.kind {
-                MacroDirectiveKind::FnLike { ast_id } => {
+                MacroDirectiveKind::FnLike { ast_id, fragment } => {
                     match macro_call_as_call_id(
                         ast_id,
+                        *fragment,
                         self.db,
                         self.def_map.krate,
                         |path| {
@@ -926,8 +927,9 @@ impl DefCollector<'_> {
 
         for directive in &self.unexpanded_macros {
             match &directive.kind {
-                MacroDirectiveKind::FnLike { ast_id, .. } => match macro_call_as_call_id(
+                MacroDirectiveKind::FnLike { ast_id, fragment } => match macro_call_as_call_id(
                     ast_id,
+                    *fragment,
                     self.db,
                     self.def_map.krate,
                     |path| {
@@ -1496,6 +1498,7 @@ impl ModCollector<'_, '_> {
         let mut error = None;
         match macro_call_as_call_id(
             &ast_id,
+            mac.fragment,
             self.def_collector.db,
             self.def_collector.def_map.krate,
             |path| {
@@ -1524,9 +1527,14 @@ impl ModCollector<'_, '_> {
             }
             Ok(Err(_)) => {
                 // Built-in macro failed eager expansion.
+
+                // FIXME: don't parse the file here
+                let fragment = hir_expand::to_fragment_kind(
+                    &ast_id.ast_id.to_node(self.def_collector.db.upcast()),
+                );
                 self.def_collector.def_map.diagnostics.push(DefDiagnostic::macro_error(
                     self.module_id,
-                    MacroCallKind::FnLike { ast_id: ast_id.ast_id },
+                    MacroCallKind::FnLike { ast_id: ast_id.ast_id, fragment },
                     error.unwrap().to_string(),
                 ));
                 return;
@@ -1543,7 +1551,7 @@ impl ModCollector<'_, '_> {
         self.def_collector.unexpanded_macros.push(MacroDirective {
             module_id: self.module_id,
             depth: self.macro_depth + 1,
-            kind: MacroDirectiveKind::FnLike { ast_id },
+            kind: MacroDirectiveKind::FnLike { ast_id, fragment: mac.fragment },
         });
     }
 
diff --git a/crates/hir_def/src/nameres/tests/incremental.rs b/crates/hir_def/src/nameres/tests/incremental.rs
index 227ecd162..d884a6eb4 100644
--- a/crates/hir_def/src/nameres/tests/incremental.rs
+++ b/crates/hir_def/src/nameres/tests/incremental.rs
@@ -137,6 +137,9 @@ m!(Z);
         });
         let n_recalculated_item_trees = events.iter().filter(|it| it.contains("item_tree")).count();
         assert_eq!(n_recalculated_item_trees, 6);
+        let n_reparsed_macros =
+            events.iter().filter(|it| it.contains("parse_macro_expansion")).count();
+        assert_eq!(n_reparsed_macros, 3);
     }
 
     let new_text = r#"
@@ -155,5 +158,8 @@ m!(Z);
         });
         let n_recalculated_item_trees = events.iter().filter(|it| it.contains("item_tree")).count();
         assert_eq!(n_recalculated_item_trees, 1);
+        let n_reparsed_macros =
+            events.iter().filter(|it| it.contains("parse_macro_expansion")).count();
+        assert_eq!(n_reparsed_macros, 0);
     }
 }
diff --git a/crates/hir_expand/src/builtin_macro.rs b/crates/hir_expand/src/builtin_macro.rs
index 179de61f9..af9802144 100644
--- a/crates/hir_expand/src/builtin_macro.rs
+++ b/crates/hir_expand/src/builtin_macro.rs
@@ -578,6 +578,7 @@ mod tests {
                     krate,
                     kind: MacroCallKind::FnLike {
                         ast_id: AstId::new(file_id.into(), ast_id_map.ast_id(&macro_call)),
+                        fragment: FragmentKind::Expr,
                     },
                 };
 
@@ -788,9 +789,9 @@ mod tests {
             r##"
             #[rustc_builtin_macro]
             macro_rules! concat {}
-            concat!("foo", "r", 0, r#"bar"#, false);
+            concat!("foo", "r", 0, r#"bar"#, "\n", false);
             "##,
-            expect![[r#""foor0barfalse""#]],
+            expect![[r#""foor0bar\nfalse""#]],
         );
     }
 }
diff --git a/crates/hir_expand/src/db.rs b/crates/hir_expand/src/db.rs
index d61f4b31a..6647e57e7 100644
--- a/crates/hir_expand/src/db.rs
+++ b/crates/hir_expand/src/db.rs
@@ -8,9 +8,7 @@ use parser::FragmentKind;
 use syntax::{
     algo::diff,
     ast::{self, NameOwner},
-    AstNode, GreenNode, Parse,
-    SyntaxKind::*,
-    SyntaxNode, SyntaxToken,
+    AstNode, GreenNode, Parse, SyntaxNode, SyntaxToken,
 };
 
 use crate::{
@@ -160,7 +158,7 @@ pub fn expand_hypothetical(
 
     let hypothetical_expansion = macro_def.expand(db, lazy_id, &tt);
 
-    let fragment_kind = to_fragment_kind(db, actual_macro_call);
+    let fragment_kind = macro_fragment_kind(db, actual_macro_call);
 
     let (node, tmap_2) =
         mbe::token_tree_to_syntax_node(&hypothetical_expansion.value, fragment_kind).ok()?;
@@ -226,7 +224,7 @@ fn parse_macro_expansion(
         None => return ExpandResult { value: None, err: result.err },
     };
 
-    let fragment_kind = to_fragment_kind(db, macro_file.macro_call_id);
+    let fragment_kind = macro_fragment_kind(db, macro_file.macro_call_id);
 
     log::debug!("expanded = {}", tt.as_debug_string());
     log::debug!("kind = {:?}", fragment_kind);
@@ -427,62 +425,15 @@ fn hygiene_frame(db: &dyn AstDatabase, file_id: HirFileId) -> Arc<HygieneFrame>
     Arc::new(HygieneFrame::new(db, file_id))
 }
 
-/// Given a `MacroCallId`, return what `FragmentKind` it belongs to.
-/// FIXME: Not completed
-fn to_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
-    let lazy_id = match id {
-        MacroCallId::LazyMacro(id) => id,
-        MacroCallId::EagerMacro(id) => {
-            return db.lookup_intern_eager_expansion(id).fragment;
-        }
-    };
-    let syn = db.lookup_intern_macro(lazy_id).kind.node(db).value;
-
-    let parent = match syn.parent() {
-        Some(it) => it,
-        None => return FragmentKind::Statements,
-    };
-
-    match parent.kind() {
-        MACRO_ITEMS | SOURCE_FILE => FragmentKind::Items,
-        MACRO_STMTS => FragmentKind::Statements,
-        MACRO_PAT => FragmentKind::Pattern,
-        MACRO_TYPE => FragmentKind::Type,
-        ITEM_LIST => FragmentKind::Items,
-        LET_STMT => {
-            // FIXME: Handle LHS Pattern
-            FragmentKind::Expr
+fn macro_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
+    match id {
+        MacroCallId::LazyMacro(id) => {
+            let loc: MacroCallLoc = db.lookup_intern_macro(id);
+            loc.kind.fragment_kind()
         }
-        EXPR_STMT => FragmentKind::Statements,
-        BLOCK_EXPR => FragmentKind::Statements,
-        ARG_LIST => FragmentKind::Expr,
-        TRY_EXPR => FragmentKind::Expr,
-        TUPLE_EXPR => FragmentKind::Expr,
-        PAREN_EXPR => FragmentKind::Expr,
-        ARRAY_EXPR => FragmentKind::Expr,
-        FOR_EXPR => FragmentKind::Expr,
-        PATH_EXPR => FragmentKind::Expr,
-        CLOSURE_EXPR => FragmentKind::Expr,
-        CONDITION => FragmentKind::Expr,
-        BREAK_EXPR => FragmentKind::Expr,
-        RETURN_EXPR => FragmentKind::Expr,
-        MATCH_EXPR => FragmentKind::Expr,
-        MATCH_ARM => FragmentKind::Expr,
-        MATCH_GUARD => FragmentKind::Expr,
-        RECORD_EXPR_FIELD => FragmentKind::Expr,
-        CALL_EXPR => FragmentKind::Expr,
-        INDEX_EXPR => FragmentKind::Expr,
-        METHOD_CALL_EXPR => FragmentKind::Expr,
-        FIELD_EXPR => FragmentKind::Expr,
-        AWAIT_EXPR => FragmentKind::Expr,
-        CAST_EXPR => FragmentKind::Expr,
-        REF_EXPR => FragmentKind::Expr,
-        PREFIX_EXPR => FragmentKind::Expr,
-        RANGE_EXPR => FragmentKind::Expr,
-        BIN_EXPR => FragmentKind::Expr,
-        _ => {
-            // Unknown , Just guess it is `Items`
-            FragmentKind::Items
+        MacroCallId::EagerMacro(id) => {
+            let loc: EagerCallLoc = db.lookup_intern_eager_expansion(id);
+            loc.fragment
         }
     }
 }
diff --git a/crates/hir_expand/src/eager.rs b/crates/hir_expand/src/eager.rs
index f12132f84..85491fe8b 100644
--- a/crates/hir_expand/src/eager.rs
+++ b/crates/hir_expand/src/eager.rs
@@ -175,8 +175,13 @@ fn lazy_expand(
 ) -> ExpandResult<Option<InFile<SyntaxNode>>> {
     let ast_id = db.ast_id_map(macro_call.file_id).ast_id(&macro_call.value);
 
+    let fragment = crate::to_fragment_kind(&macro_call.value);
     let id: MacroCallId = def
-        .as_lazy_macro(db, krate, MacroCallKind::FnLike { ast_id: macro_call.with_value(ast_id) })
+        .as_lazy_macro(
+            db,
+            krate,
+            MacroCallKind::FnLike { ast_id: macro_call.with_value(ast_id), fragment },
+        )
         .into();
 
     let err = db.macro_expand_error(id);
diff --git a/crates/hir_expand/src/lib.rs b/crates/hir_expand/src/lib.rs
index 0402640de..80ab3aeee 100644
--- a/crates/hir_expand/src/lib.rs
+++ b/crates/hir_expand/src/lib.rs
@@ -16,7 +16,9 @@ pub mod quote;
 pub mod eager;
 
 use either::Either;
+
 pub use mbe::{ExpandError, ExpandResult};
+pub use parser::FragmentKind;
 
 use std::hash::Hash;
 use std::sync::Arc;
@@ -290,7 +292,7 @@ pub struct MacroCallLoc {
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum MacroCallKind {
-    FnLike { ast_id: AstId<ast::MacroCall> },
+    FnLike { ast_id: AstId<ast::MacroCall>, fragment: FragmentKind },
     Derive { ast_id: AstId<ast::Item>, derive_name: String, derive_attr: AttrId },
 }
 
@@ -324,6 +326,13 @@ impl MacroCallKind {
             MacroCallKind::Derive { ast_id, .. } => Some(ast_id.to_node(db).syntax().clone()),
         }
     }
+
+    fn fragment_kind(&self) -> FragmentKind {
+        match self {
+            MacroCallKind::FnLike { fragment, .. } => *fragment,
+            MacroCallKind::Derive { .. } => FragmentKind::Items,
+        }
+    }
 }
 
 impl MacroCallId {
@@ -357,7 +366,6 @@ pub struct ExpansionInfo {
 }
 
 pub use mbe::Origin;
-use parser::FragmentKind;
 
 impl ExpansionInfo {
     pub fn call_node(&self) -> Option<InFile<SyntaxNode>> {
@@ -562,3 +570,59 @@ impl<N: AstNode> InFile<N> {
         self.with_value(self.value.syntax())
     }
 }
+
+/// Given a `MacroCallId`, return what `FragmentKind` it belongs to.
+/// FIXME: Not completed
+pub fn to_fragment_kind(call: &ast::MacroCall) -> FragmentKind {
+    use syntax::SyntaxKind::*;
+
+    let syn = call.syntax();
+
+    let parent = match syn.parent() {
+        Some(it) => it,
+        None => return FragmentKind::Statements,
+    };
+
+    match parent.kind() {
+        MACRO_ITEMS | SOURCE_FILE => FragmentKind::Items,
+        MACRO_STMTS => FragmentKind::Statements,
+        MACRO_PAT => FragmentKind::Pattern,
+        MACRO_TYPE => FragmentKind::Type,
+        ITEM_LIST => FragmentKind::Items,
+        LET_STMT => {
+            // FIXME: Handle LHS Pattern
+            FragmentKind::Expr
+        }
+        EXPR_STMT => FragmentKind::Statements,
+        BLOCK_EXPR => FragmentKind::Statements,
+        ARG_LIST => FragmentKind::Expr,
+        TRY_EXPR => FragmentKind::Expr,
+        TUPLE_EXPR => FragmentKind::Expr,
+        PAREN_EXPR => FragmentKind::Expr,
+        ARRAY_EXPR => FragmentKind::Expr,
+        FOR_EXPR => FragmentKind::Expr,
+        PATH_EXPR => FragmentKind::Expr,
+        CLOSURE_EXPR => FragmentKind::Expr,
+        CONDITION => FragmentKind::Expr,
+        BREAK_EXPR => FragmentKind::Expr,
+        RETURN_EXPR => FragmentKind::Expr,
+        MATCH_EXPR => FragmentKind::Expr,
+        MATCH_ARM => FragmentKind::Expr,
+        MATCH_GUARD => FragmentKind::Expr,
+        RECORD_EXPR_FIELD => FragmentKind::Expr,
+        CALL_EXPR => FragmentKind::Expr,
+        INDEX_EXPR => FragmentKind::Expr,
+        METHOD_CALL_EXPR => FragmentKind::Expr,
+        FIELD_EXPR => FragmentKind::Expr,
+        AWAIT_EXPR => FragmentKind::Expr,
+        CAST_EXPR => FragmentKind::Expr,
+        REF_EXPR => FragmentKind::Expr,
+        PREFIX_EXPR => FragmentKind::Expr,
+        RANGE_EXPR => FragmentKind::Expr,
+        BIN_EXPR => FragmentKind::Expr,
+        _ => {
+            // Unknown , Just guess it is `Items`
+            FragmentKind::Items
+        }
+    }
+}
diff --git a/crates/hir_expand/src/quote.rs b/crates/hir_expand/src/quote.rs
index c82487ef0..230a59964 100644
--- a/crates/hir_expand/src/quote.rs
+++ b/crates/hir_expand/src/quote.rs
@@ -196,8 +196,8 @@ impl_to_to_tokentrees! {
     tt::Literal => self { self };
     tt::Ident => self { self };
     tt::Punct => self { self };
-    &str => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into(), id: tt::TokenId::unspecified()}};
-    String => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into(), id: tt::TokenId::unspecified()}}
+    &str => self { tt::Literal{text: format!("\"{}\"", self.escape_debug()).into(), id: tt::TokenId::unspecified()}};
+    String => self { tt::Literal{text: format!("\"{}\"", self.escape_debug()).into(), id: tt::TokenId::unspecified()}}
 }
 
 #[cfg(test)]
diff --git a/crates/hir_ty/src/chalk_ext.rs b/crates/hir_ty/src/chalk_ext.rs
index 8c4542956..5232a7d80 100644
--- a/crates/hir_ty/src/chalk_ext.rs
+++ b/crates/hir_ty/src/chalk_ext.rs
@@ -1,8 +1,10 @@
 //! Various extensions traits for Chalk types.
 
-use chalk_ir::Mutability;
+use chalk_ir::{FloatTy, IntTy, Mutability, Scalar, UintTy};
 use hir_def::{
-    type_ref::Rawness, AssocContainerId, FunctionId, GenericDefId, HasModule, Lookup, TraitId,
+    builtin_type::{BuiltinFloat, BuiltinInt, BuiltinType, BuiltinUint},
+    type_ref::Rawness,
+    AssocContainerId, FunctionId, GenericDefId, HasModule, Lookup, TraitId,
 };
 
 use crate::{
@@ -18,6 +20,7 @@ pub trait TyExt {
     fn is_unknown(&self) -> bool;
 
     fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)>;
+    fn as_builtin(&self) -> Option<BuiltinType>;
     fn as_tuple(&self) -> Option<&Substitution>;
     fn as_fn_def(&self, db: &dyn HirDatabase) -> Option<FunctionId>;
     fn as_reference(&self) -> Option<(&Ty, Lifetime, Mutability)>;
@@ -59,6 +62,35 @@ impl TyExt for Ty {
         }
     }
 
+    fn as_builtin(&self) -> Option<BuiltinType> {
+        match self.kind(&Interner) {
+            TyKind::Str => Some(BuiltinType::Str),
+            TyKind::Scalar(Scalar::Bool) => Some(BuiltinType::Bool),
+            TyKind::Scalar(Scalar::Char) => Some(BuiltinType::Char),
+            TyKind::Scalar(Scalar::Float(fty)) => Some(BuiltinType::Float(match fty {
+                FloatTy::F64 => BuiltinFloat::F64,
+                FloatTy::F32 => BuiltinFloat::F32,
+            })),
+            TyKind::Scalar(Scalar::Int(ity)) => Some(BuiltinType::Int(match ity {
+                IntTy::Isize => BuiltinInt::Isize,
+                IntTy::I8 => BuiltinInt::I8,
+                IntTy::I16 => BuiltinInt::I16,
+                IntTy::I32 => BuiltinInt::I32,
+                IntTy::I64 => BuiltinInt::I64,
+                IntTy::I128 => BuiltinInt::I128,
+            })),
+            TyKind::Scalar(Scalar::Uint(ity)) => Some(BuiltinType::Uint(match ity {
+                UintTy::Usize => BuiltinUint::Usize,
+                UintTy::U8 => BuiltinUint::U8,
+                UintTy::U16 => BuiltinUint::U16,
+                UintTy::U32 => BuiltinUint::U32,
+                UintTy::U64 => BuiltinUint::U64,
+                UintTy::U128 => BuiltinUint::U128,
+            })),
+            _ => None,
+        }
+    }
+
     fn as_tuple(&self) -> Option<&Substitution> {
         match self.kind(&Interner) {
             TyKind::Tuple(_, substs) => Some(substs),
diff --git a/crates/ide/src/join_lines.rs b/crates/ide/src/join_lines.rs
index fe2a349e6..61dcbb399 100644
--- a/crates/ide/src/join_lines.rs
+++ b/crates/ide/src/join_lines.rs
@@ -1,3 +1,5 @@
+use std::convert::TryFrom;
+
 use ide_assists::utils::extract_trivial_expression;
 use itertools::Itertools;
 use syntax::{
@@ -65,14 +67,6 @@ fn remove_newlines(edit: &mut TextEditBuilder, token: &SyntaxToken, range: TextR
 
 fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextSize) {
     if token.kind() != WHITESPACE || token.text().bytes().filter(|&b| b == b'\n').count() != 1 {
-        let mut string_open_quote = false;
-        if let Some(string) = ast::String::cast(token.clone()) {
-            if let Some(range) = string.open_quote_text_range() {
-                cov_mark::hit!(join_string_literal);
-                string_open_quote = range.end() == offset;
-            }
-        }
-
         let n_spaces_after_line_break = {
             let suff = &token.text()[TextRange::new(
                 offset - token.text_range().start() + TextSize::of('\n'),
@@ -81,8 +75,23 @@ fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextS
             suff.bytes().take_while(|&b| b == b' ').count()
         };
 
+        let mut no_space = false;
+        if let Some(string) = ast::String::cast(token.clone()) {
+            if let Some(range) = string.open_quote_text_range() {
+                cov_mark::hit!(join_string_literal_open_quote);
+                no_space |= range.end() == offset;
+            }
+            if let Some(range) = string.close_quote_text_range() {
+                cov_mark::hit!(join_string_literal_close_quote);
+                no_space |= range.start()
+                    == offset
+                        + TextSize::of('\n')
+                        + TextSize::try_from(n_spaces_after_line_break).unwrap();
+            }
+        }
+
         let range = TextRange::at(offset, ((n_spaces_after_line_break + 1) as u32).into());
-        let replace_with = if string_open_quote { "" } else { " " };
+        let replace_with = if no_space { "" } else { " " };
         edit.replace(range, replace_with.to_string());
         return;
     }
@@ -797,22 +806,54 @@ fn foo() {
 
     #[test]
     fn join_string_literal() {
-        cov_mark::check!(join_string_literal);
-        check_join_lines(
-            r#"
+        {
+            cov_mark::check!(join_string_literal_open_quote);
+            check_join_lines(
+                r#"
 fn main() {
     $0"
 hello
 ";
 }
 "#,
-            r#"
+                r#"
 fn main() {
     $0"hello
 ";
 }
 "#,
-        );
+            );
+        }
+
+        {
+            cov_mark::check!(join_string_literal_close_quote);
+            check_join_lines(
+                r#"
+fn main() {
+    $0"hello
+";
+}
+"#,
+                r#"
+fn main() {
+    $0"hello";
+}
+"#,
+            );
+            check_join_lines(
+                r#"
+fn main() {
+    $0r"hello
+    ";
+}
+"#,
+                r#"
+fn main() {
+    $0r"hello";
+}
+"#,
+            );
+        }
 
         check_join_lines(
             r#"
diff --git a/crates/ide/src/references.rs b/crates/ide/src/references.rs
index 11ca7ec6b..ae492a264 100644
--- a/crates/ide/src/references.rs
+++ b/crates/ide/src/references.rs
@@ -65,7 +65,7 @@ pub(crate) fn find_all_refs(
             (find_def(&sema, &syntax, position)?, false)
         };
 
-    let mut usages = def.usages(sema).set_scope(search_scope).all();
+    let mut usages = def.usages(sema).set_scope(search_scope).include_self_refs().all();
     if is_literal_search {
         // filter for constructor-literals
         let refs = usages.references.values_mut();
@@ -1163,22 +1163,76 @@ fn foo<const FOO$0: usize>() -> usize {
     }
 
     #[test]
-    fn test_find_self_ty_in_trait_def() {
+    fn test_trait() {
         check(
             r#"
-trait Foo {
-    fn f() -> Self$0;
+trait Foo$0 where Self: {}
+
+impl Foo for () {}
+"#,
+            expect![[r#"
+                Foo Trait FileId(0) 0..24 6..9
+
+                FileId(0) 31..34
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_trait_self() {
+        check(
+            r#"
+trait Foo where Self$0 {
+    fn f() -> Self;
 }
+
+impl Foo for () {}
 "#,
             expect![[r#"
                 Self TypeParam FileId(0) 6..9 6..9
 
-                FileId(0) 26..30
+                FileId(0) 16..20
+                FileId(0) 37..41
             "#]],
         );
     }
 
     #[test]
+    fn test_self_ty() {
+        check(
+            r#"
+        struct $0Foo;
+
+        impl Foo where Self: {
+            fn f() -> Self;
+        }
+        "#,
+            expect![[r#"
+                Foo Struct FileId(0) 0..11 7..10
+
+                FileId(0) 18..21
+                FileId(0) 28..32
+                FileId(0) 50..54
+            "#]],
+        );
+        check(
+            r#"
+struct Foo;
+
+impl Foo where Self: {
+    fn f() -> Self$0;
+}
+"#,
+            expect![[r#"
+                impl Impl FileId(0) 13..57 18..21
+
+                FileId(0) 18..21
+                FileId(0) 28..32
+                FileId(0) 50..54
+            "#]],
+        );
+    }
+    #[test]
     fn test_self_variant_with_payload() {
         check(
             r#"
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index 175e7a31d..2bf953305 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -1888,4 +1888,21 @@ impl Foo {
             "error: Cannot rename `Self`",
         );
     }
+
+    #[test]
+    fn test_rename_ignores_self_ty() {
+        check(
+            "Fo0",
+            r#"
+struct $0Foo;
+
+impl Foo where Self: {}
+"#,
+            r#"
+struct Fo0;
+
+impl Fo0 where Self: {}
+"#,
+        );
+    }
 }
diff --git a/crates/ide/src/typing.rs b/crates/ide/src/typing.rs
index 82c732390..4ad49eca0 100644
--- a/crates/ide/src/typing.rs
+++ b/crates/ide/src/typing.rs
@@ -88,7 +88,7 @@ fn on_char_typed_inner(
 }
 
 /// Inserts a closing `}` when the user types an opening `{`, wrapping an existing expression in a
-/// block.
+/// block, or a part of a `use` item.
 fn on_opening_brace_typed(file: &Parse<SourceFile>, offset: TextSize) -> Option<TextEdit> {
     if !stdx::always!(file.tree().syntax().text().char_at(offset) == Some('{')) {
         return None;
@@ -99,30 +99,59 @@ fn on_opening_brace_typed(file: &Parse<SourceFile>, offset: TextSize) -> Option<
     // Remove the `{` to get a better parse tree, and reparse
     let file = file.reparse(&Indel::delete(brace_token.text_range()));
 
-    let mut expr: ast::Expr = find_node_at_offset(file.tree().syntax(), offset)?;
-    if expr.syntax().text_range().start() != offset {
-        return None;
+    if let Some(edit) = brace_expr(&file.tree(), offset) {
+        return Some(edit);
     }
 
-    // Enclose the outermost expression starting at `offset`
-    while let Some(parent) = expr.syntax().parent() {
-        if parent.text_range().start() != expr.syntax().text_range().start() {
-            break;
-        }
+    if let Some(edit) = brace_use_path(&file.tree(), offset) {
+        return Some(edit);
+    }
 
-        match ast::Expr::cast(parent) {
-            Some(parent) => expr = parent,
-            None => break,
+    return None;
+
+    fn brace_use_path(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
+        let segment: ast::PathSegment = find_node_at_offset(file.syntax(), offset)?;
+        if segment.syntax().text_range().start() != offset {
+            return None;
         }
-    }
 
-    // If it's a statement in a block, we don't know how many statements should be included
-    if ast::ExprStmt::can_cast(expr.syntax().parent()?.kind()) {
-        return None;
+        let tree: ast::UseTree = find_node_at_offset(file.syntax(), offset)?;
+
+        Some(TextEdit::insert(
+            tree.syntax().text_range().end() + TextSize::of("{"),
+            "}".to_string(),
+        ))
     }
 
-    // Insert `}` right after the expression.
-    Some(TextEdit::insert(expr.syntax().text_range().end() + TextSize::of("{"), "}".to_string()))
+    fn brace_expr(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
+        let mut expr: ast::Expr = find_node_at_offset(file.syntax(), offset)?;
+        if expr.syntax().text_range().start() != offset {
+            return None;
+        }
+
+        // Enclose the outermost expression starting at `offset`
+        while let Some(parent) = expr.syntax().parent() {
+            if parent.text_range().start() != expr.syntax().text_range().start() {
+                break;
+            }
+
+            match ast::Expr::cast(parent) {
+                Some(parent) => expr = parent,
+                None => break,
+            }
+        }
+
+        // If it's a statement in a block, we don't know how many statements should be included
+        if ast::ExprStmt::can_cast(expr.syntax().parent()?.kind()) {
+            return None;
+        }
+
+        // Insert `}` right after the expression.
+        Some(TextEdit::insert(
+            expr.syntax().text_range().end() + TextSize::of("{"),
+            "}".to_string(),
+        ))
+    }
 }
 
 /// Returns an edit which should be applied after `=` was typed. Primarily,
@@ -440,7 +469,7 @@ fn foo() -> { 92 }
     }
 
     #[test]
-    fn adds_closing_brace() {
+    fn adds_closing_brace_for_expr() {
         type_char(
             '{',
             r#"
@@ -519,4 +548,87 @@ fn f() {
             "#,
         );
     }
+
+    #[test]
+    fn adds_closing_brace_for_use_tree() {
+        type_char(
+            '{',
+            r#"
+use some::$0Path;
+            "#,
+            r#"
+use some::{Path};
+            "#,
+        );
+        type_char(
+            '{',
+            r#"
+use some::{Path, $0Other};
+            "#,
+            r#"
+use some::{Path, {Other}};
+            "#,
+        );
+        type_char(
+            '{',
+            r#"
+use some::{$0Path, Other};
+            "#,
+            r#"
+use some::{{Path}, Other};
+            "#,
+        );
+        type_char(
+            '{',
+            r#"
+use some::path::$0to::Item;
+            "#,
+            r#"
+use some::path::{to::Item};
+            "#,
+        );
+        type_char(
+            '{',
+            r#"
+use some::$0path::to::Item;
+            "#,
+            r#"
+use some::{path::to::Item};
+            "#,
+        );
+        type_char(
+            '{',
+            r#"
+use $0some::path::to::Item;
+            "#,
+            r#"
+use {some::path::to::Item};
+            "#,
+        );
+        type_char(
+            '{',
+            r#"
+use some::path::$0to::{Item};
+            "#,
+            r#"
+use some::path::{to::{Item}};
+            "#,
+        );
+        type_char(
+            '{',
+            r#"
+use $0Thing as _;
+            "#,
+            r#"
+use {Thing as _};
+            "#,
+        );
+
+        type_char_noop(
+            '{',
+            r#"
+use some::pa$0th::to::Item;
+            "#,
+        );
+    }
 }
diff --git a/crates/ide/src/typing/on_enter.rs b/crates/ide/src/typing/on_enter.rs
index 7d2db201a..81c4d95b1 100644
--- a/crates/ide/src/typing/on_enter.rs
+++ b/crates/ide/src/typing/on_enter.rs
@@ -54,6 +54,14 @@ pub(crate) fn on_enter(db: &RootDatabase, position: FilePosition) -> Option<Text
             cov_mark::hit!(indent_block_contents);
             return Some(edit);
         }
+
+        // Typing enter after the `{` of a use tree list.
+        if let Some(edit) = find_node_at_offset(file.syntax(), position.offset - TextSize::of('{'))
+            .and_then(|list| on_enter_in_use_tree_list(list, position))
+        {
+            cov_mark::hit!(indent_block_contents);
+            return Some(edit);
+        }
     }
 
     None
@@ -111,6 +119,21 @@ fn on_enter_in_block(block: ast::BlockExpr, position: FilePosition) -> Option<Te
     Some(edit)
 }
 
+fn on_enter_in_use_tree_list(list: ast::UseTreeList, position: FilePosition) -> Option<TextEdit> {
+    if list.syntax().text().contains_char('\n') {
+        return None;
+    }
+
+    let indent = IndentLevel::from_node(list.syntax());
+    let mut edit = TextEdit::insert(position.offset, format!("\n{}$0", indent + 1));
+    edit.union(TextEdit::insert(
+        list.r_curly_token()?.text_range().start(),
+        format!("\n{}", indent),
+    ))
+    .ok()?;
+    Some(edit)
+}
+
 fn block_contents(block: &ast::BlockExpr) -> Option<SyntaxNode> {
     let mut node = block.tail_expr().map(|e| e.syntax().clone());
 
@@ -484,4 +507,96 @@ fn f() {$0
         "#,
         );
     }
+
+    #[test]
+    fn indents_use_tree_list() {
+        do_check(
+            r#"
+use crate::{$0};
+            "#,
+            r#"
+use crate::{
+    $0
+};
+            "#,
+        );
+        do_check(
+            r#"
+use crate::{$0Object, path::to::OtherThing};
+            "#,
+            r#"
+use crate::{
+    $0Object, path::to::OtherThing
+};
+            "#,
+        );
+        do_check(
+            r#"
+use {crate::{$0Object, path::to::OtherThing}};
+            "#,
+            r#"
+use {crate::{
+    $0Object, path::to::OtherThing
+}};
+            "#,
+        );
+        do_check(
+            r#"
+use {
+    crate::{$0Object, path::to::OtherThing}
+};
+            "#,
+            r#"
+use {
+    crate::{
+        $0Object, path::to::OtherThing
+    }
+};
+            "#,
+        );
+    }
+
+    #[test]
+    fn does_not_indent_use_tree_list_when_not_at_curly_brace() {
+        do_check_noop(
+            r#"
+use path::{Thing$0};
+            "#,
+        );
+    }
+
+    #[test]
+    fn does_not_indent_use_tree_list_without_curly_braces() {
+        do_check_noop(
+            r#"
+use path::Thing$0;
+            "#,
+        );
+        do_check_noop(
+            r#"
+use path::$0Thing;
+            "#,
+        );
+        do_check_noop(
+            r#"
+use path::Thing$0};
+            "#,
+        );
+        do_check_noop(
+            r#"
+use path::{$0Thing;
+            "#,
+        );
+    }
+
+    #[test]
+    fn does_not_indent_multiline_use_tree_list() {
+        do_check_noop(
+            r#"
+use path::{$0
+    Thing
+};
+            "#,
+        );
+    }
 }
diff --git a/crates/ide_assists/src/handlers/convert_tuple_struct_to_named_struct.rs b/crates/ide_assists/src/handlers/convert_tuple_struct_to_named_struct.rs
index b5b5ada5e..70949ca35 100644
--- a/crates/ide_assists/src/handlers/convert_tuple_struct_to_named_struct.rs
+++ b/crates/ide_assists/src/handlers/convert_tuple_struct_to_named_struct.rs
@@ -107,7 +107,7 @@ fn edit_struct_references(
     names: &[ast::Name],
 ) {
     let strukt_def = Definition::ModuleDef(hir::ModuleDef::Adt(hir::Adt::Struct(strukt)));
-    let usages = strukt_def.usages(&ctx.sema).include_self_kw_refs(true).all();
+    let usages = strukt_def.usages(&ctx.sema).include_self_refs().all();
 
     let edit_node = |edit: &mut AssistBuilder, node: SyntaxNode| -> Option<()> {
         match_ast! {
diff --git a/crates/ide_assists/src/handlers/early_return.rs b/crates/ide_assists/src/handlers/early_return.rs
index c66f8c05d..5eb6a57f0 100644
--- a/crates/ide_assists/src/handlers/early_return.rs
+++ b/crates/ide_assists/src/handlers/early_return.rs
@@ -130,9 +130,7 @@ pub(crate) fn convert_to_guarded_return(acc: &mut Assists, ctx: &AssistContext)
                                 once(make::ident_pat(make::name("it")).into()),
                             );
                             let expr = {
-                                let name_ref = make::name_ref("it");
-                                let segment = make::path_segment(name_ref);
-                                let path = make::path_unqualified(segment);
+                                let path = make::ext::ident_path("it");
                                 make::expr_path(path)
                             };
                             make::match_arm(once(pat.into()), expr)
diff --git a/crates/ide_assists/src/handlers/expand_glob_import.rs b/crates/ide_assists/src/handlers/expand_glob_import.rs
index e3095f26b..da8d245e5 100644
--- a/crates/ide_assists/src/handlers/expand_glob_import.rs
+++ b/crates/ide_assists/src/handlers/expand_glob_import.rs
@@ -65,8 +65,7 @@ pub(crate) fn expand_glob_import(acc: &mut Assists, ctx: &AssistContext) -> Opti
 
             let names_to_import = find_names_to_import(ctx, refs_in_target, imported_defs);
             let expanded = make::use_tree_list(names_to_import.iter().map(|n| {
-                let path =
-                    make::path_unqualified(make::path_segment(make::name_ref(&n.to_string())));
+                let path = make::ext::ident_path(&n.to_string());
                 make::use_tree(path, None, None, false)
             }))
             .clone_for_update();
diff --git a/crates/ide_assists/src/handlers/extract_function.rs b/crates/ide_assists/src/handlers/extract_function.rs
index 4116985ae..6311afc1f 100644
--- a/crates/ide_assists/src/handlers/extract_function.rs
+++ b/crates/ide_assists/src/handlers/extract_function.rs
@@ -956,10 +956,10 @@ fn format_replacement(ctx: &AssistContext, fun: &Function, indent: IndentLevel)
     let args = fun.params.iter().map(|param| param.to_arg(ctx));
     let args = make::arg_list(args);
     let call_expr = if fun.self_param.is_some() {
-        let self_arg = make::expr_path(make_path_from_text("self"));
+        let self_arg = make::expr_path(make::ext::ident_path("self"));
         make::expr_method_call(self_arg, &fun.name, args)
     } else {
-        let func = make::expr_path(make_path_from_text(&fun.name));
+        let func = make::expr_path(make::ext::ident_path(&fun.name));
         make::expr_call(func, args)
     };
 
@@ -1054,11 +1054,11 @@ impl FlowHandler {
                 make::expr_if(condition, block, None)
             }
             FlowHandler::IfOption { action } => {
-                let path = make_path_from_text("Some");
+                let path = make::ext::ident_path("Some");
                 let value_pat = make::ident_pat(make::name("value"));
                 let pattern = make::tuple_struct_pat(path, iter::once(value_pat.into()));
                 let cond = make::condition(call_expr, Some(pattern.into()));
-                let value = make::expr_path(make_path_from_text("value"));
+                let value = make::expr_path(make::ext::ident_path("value"));
                 let action_expr = action.make_result_handler(Some(value));
                 let action_stmt = make::expr_stmt(action_expr);
                 let then = make::block_expr(iter::once(action_stmt.into()), None);
@@ -1068,14 +1068,14 @@ impl FlowHandler {
                 let some_name = "value";
 
                 let some_arm = {
-                    let path = make_path_from_text("Some");
+                    let path = make::ext::ident_path("Some");
                     let value_pat = make::ident_pat(make::name(some_name));
                     let pat = make::tuple_struct_pat(path, iter::once(value_pat.into()));
-                    let value = make::expr_path(make_path_from_text(some_name));
+                    let value = make::expr_path(make::ext::ident_path(some_name));
                     make::match_arm(iter::once(pat.into()), value)
                 };
                 let none_arm = {
-                    let path = make_path_from_text("None");
+                    let path = make::ext::ident_path("None");
                     let pat = make::path_pat(path);
                     make::match_arm(iter::once(pat), none.make_result_handler(None))
                 };
@@ -1087,17 +1087,17 @@ impl FlowHandler {
                 let err_name = "value";
 
                 let ok_arm = {
-                    let path = make_path_from_text("Ok");
+                    let path = make::ext::ident_path("Ok");
                     let value_pat = make::ident_pat(make::name(ok_name));
                     let pat = make::tuple_struct_pat(path, iter::once(value_pat.into()));
-                    let value = make::expr_path(make_path_from_text(ok_name));
+                    let value = make::expr_path(make::ext::ident_path(ok_name));
                     make::match_arm(iter::once(pat.into()), value)
                 };
                 let err_arm = {
-                    let path = make_path_from_text("Err");
+                    let path = make::ext::ident_path("Err");
                     let value_pat = make::ident_pat(make::name(err_name));
                     let pat = make::tuple_struct_pat(path, iter::once(value_pat.into()));
-                    let value = make::expr_path(make_path_from_text(err_name));
+                    let value = make::expr_path(make::ext::ident_path(err_name));
                     make::match_arm(iter::once(pat.into()), err.make_result_handler(Some(value)))
                 };
                 let arms = make::match_arm_list(vec![ok_arm, err_arm]);
@@ -1107,13 +1107,9 @@ impl FlowHandler {
     }
 }
 
-fn make_path_from_text(text: &str) -> ast::Path {
-    make::path_unqualified(make::path_segment(make::name_ref(text)))
-}
-
 fn path_expr_from_local(ctx: &AssistContext, var: Local) -> ast::Expr {
     let name = var.name(ctx.db()).unwrap().to_string();
-    make::expr_path(make_path_from_text(&name))
+    make::expr_path(make::ext::ident_path(&name))
 }
 
 fn format_function(
@@ -1179,7 +1175,7 @@ fn make_ret_ty(ctx: &AssistContext, module: hir::Module, fun: &Function) -> Opti
             fun_ty.make_ty(ctx, module)
         }
         FlowHandler::Try { kind: TryKind::Option } => {
-            make::ty_generic(make::name_ref("Option"), iter::once(fun_ty.make_ty(ctx, module)))
+            make::ext::ty_option(fun_ty.make_ty(ctx, module))
         }
         FlowHandler::Try { kind: TryKind::Result { ty: parent_ret_ty } } => {
             let handler_ty = parent_ret_ty
@@ -1187,29 +1183,21 @@ fn make_ret_ty(ctx: &AssistContext, module: hir::Module, fun: &Function) -> Opti
                 .nth(1)
                 .map(|ty| make_ty(&ty, ctx, module))
                 .unwrap_or_else(make::ty_unit);
-            make::ty_generic(
-                make::name_ref("Result"),
-                vec![fun_ty.make_ty(ctx, module), handler_ty],
-            )
+            make::ext::ty_result(fun_ty.make_ty(ctx, module), handler_ty)
         }
-        FlowHandler::If { .. } => make::ty("bool"),
+        FlowHandler::If { .. } => make::ext::ty_bool(),
         FlowHandler::IfOption { action } => {
             let handler_ty = action
                 .expr_ty(ctx)
                 .map(|ty| make_ty(&ty, ctx, module))
                 .unwrap_or_else(make::ty_unit);
-            make::ty_generic(make::name_ref("Option"), iter::once(handler_ty))
-        }
-        FlowHandler::MatchOption { .. } => {
-            make::ty_generic(make::name_ref("Option"), iter::once(fun_ty.make_ty(ctx, module)))
+            make::ext::ty_option(handler_ty)
         }
+        FlowHandler::MatchOption { .. } => make::ext::ty_option(fun_ty.make_ty(ctx, module)),
         FlowHandler::MatchResult { err } => {
             let handler_ty =
                 err.expr_ty(ctx).map(|ty| make_ty(&ty, ctx, module)).unwrap_or_else(make::ty_unit);
-            make::ty_generic(
-                make::name_ref("Result"),
-                vec![fun_ty.make_ty(ctx, module), handler_ty],
-            )
+            make::ext::ty_result(fun_ty.make_ty(ctx, module), handler_ty)
         }
     };
     Some(make::ret_type(ret_ty))
@@ -1296,7 +1284,7 @@ fn make_body(
                     TryKind::Option => "Some",
                     TryKind::Result { .. } => "Ok",
                 };
-                let func = make::expr_path(make_path_from_text(constructor));
+                let func = make::expr_path(make::ext::ident_path(constructor));
                 let args = make::arg_list(iter::once(tail_expr));
                 make::expr_call(func, args)
             })
@@ -1306,16 +1294,16 @@ fn make_body(
             with_tail_expr(block, lit_false.into())
         }
         FlowHandler::IfOption { .. } => {
-            let none = make::expr_path(make_path_from_text("None"));
+            let none = make::expr_path(make::ext::ident_path("None"));
             with_tail_expr(block, none)
         }
         FlowHandler::MatchOption { .. } => map_tail_expr(block, |tail_expr| {
-            let some = make::expr_path(make_path_from_text("Some"));
+            let some = make::expr_path(make::ext::ident_path("Some"));
             let args = make::arg_list(iter::once(tail_expr));
             make::expr_call(some, args)
         }),
         FlowHandler::MatchResult { .. } => map_tail_expr(block, |tail_expr| {
-            let ok = make::expr_path(make_path_from_text("Ok"));
+            let ok = make::expr_path(make::ext::ident_path("Ok"));
             let args = make::arg_list(iter::once(tail_expr));
             make::expr_call(ok, args)
         }),
@@ -1483,13 +1471,13 @@ fn make_rewritten_flow(handler: &FlowHandler, arg_expr: Option<ast::Expr>) -> Op
         FlowHandler::IfOption { .. } => {
             let expr = arg_expr.unwrap_or_else(|| make::expr_tuple(Vec::new()));
             let args = make::arg_list(iter::once(expr));
-            make::expr_call(make::expr_path(make_path_from_text("Some")), args)
+            make::expr_call(make::expr_path(make::ext::ident_path("Some")), args)
         }
-        FlowHandler::MatchOption { .. } => make::expr_path(make_path_from_text("None")),
+        FlowHandler::MatchOption { .. } => make::expr_path(make::ext::ident_path("None")),
         FlowHandler::MatchResult { .. } => {
             let expr = arg_expr.unwrap_or_else(|| make::expr_tuple(Vec::new()));
             let args = make::arg_list(iter::once(expr));
-            make::expr_call(make::expr_path(make_path_from_text("Err")), args)
+            make::expr_call(make::expr_path(make::ext::ident_path("Err")), args)
         }
     };
     Some(make::expr_return(Some(value)).clone_for_update())
diff --git a/crates/ide_assists/src/handlers/extract_variable.rs b/crates/ide_assists/src/handlers/extract_variable.rs
index 136b9a55b..ae084c86c 100644
--- a/crates/ide_assists/src/handlers/extract_variable.rs
+++ b/crates/ide_assists/src/handlers/extract_variable.rs
@@ -54,7 +54,7 @@ pub(crate) fn extract_variable(acc: &mut Assists, ctx: &AssistContext) -> Option
 
             let var_name = match &field_shorthand {
                 Some(it) => it.to_string(),
-                None => suggest_name::variable(&to_extract, &ctx.sema),
+                None => suggest_name::for_variable(&to_extract, &ctx.sema),
             };
             let expr_range = match &field_shorthand {
                 Some(it) => it.syntax().text_range().cover(to_extract.syntax().text_range()),
diff --git a/crates/ide_assists/src/handlers/generate_function.rs b/crates/ide_assists/src/handlers/generate_function.rs
index 6f95b1a07..bc9fc524b 100644
--- a/crates/ide_assists/src/handlers/generate_function.rs
+++ b/crates/ide_assists/src/handlers/generate_function.rs
@@ -175,7 +175,7 @@ impl FunctionBuilder {
     }
 
     fn render(self) -> FunctionTemplate {
-        let placeholder_expr = make::expr_todo();
+        let placeholder_expr = make::ext::expr_todo();
         let fn_body = make::block_expr(vec![], Some(placeholder_expr));
         let visibility = if self.needs_pub { Some(make::visibility_pub_crate()) } else { None };
         let mut fn_def = make::fn_(
diff --git a/crates/ide_assists/src/handlers/introduce_named_lifetime.rs b/crates/ide_assists/src/handlers/introduce_named_lifetime.rs
index 9f4f71d6c..68bc15120 100644
--- a/crates/ide_assists/src/handlers/introduce_named_lifetime.rs
+++ b/crates/ide_assists/src/handlers/introduce_named_lifetime.rs
@@ -89,14 +89,12 @@ fn generate_fn_def_assist(
         let loc_needing_lifetime =
             loc_needing_lifetime.and_then(|it| it.make_mut(builder).to_position());
 
-        add_lifetime_param(fn_def.get_or_create_generic_param_list(), new_lifetime_param);
-        ted::replace(
-            lifetime.syntax(),
-            make_ast_lifetime(new_lifetime_param).clone_for_update().syntax(),
+        fn_def.get_or_create_generic_param_list().add_generic_param(
+            make::lifetime_param(new_lifetime_param.clone()).clone_for_update().into(),
         );
-        loc_needing_lifetime.map(|position| {
-            ted::insert(position, make_ast_lifetime(new_lifetime_param).clone_for_update().syntax())
-        });
+        ted::replace(lifetime.syntax(), new_lifetime_param.clone_for_update().syntax());
+        loc_needing_lifetime
+            .map(|position| ted::insert(position, new_lifetime_param.clone_for_update().syntax()));
     })
 }
 
@@ -112,11 +110,10 @@ fn generate_impl_def_assist(
         let impl_def = builder.make_ast_mut(impl_def);
         let lifetime = builder.make_ast_mut(lifetime);
 
-        add_lifetime_param(impl_def.get_or_create_generic_param_list(), new_lifetime_param);
-        ted::replace(
-            lifetime.syntax(),
-            make_ast_lifetime(new_lifetime_param).clone_for_update().syntax(),
+        impl_def.get_or_create_generic_param_list().add_generic_param(
+            make::lifetime_param(new_lifetime_param.clone()).clone_for_update().into(),
         );
+        ted::replace(lifetime.syntax(), new_lifetime_param.clone_for_update().syntax());
     })
 }
 
@@ -124,31 +121,16 @@ fn generate_impl_def_assist(
 /// which is not in the list
 fn generate_unique_lifetime_param_name(
     existing_type_param_list: Option<ast::GenericParamList>,
-) -> Option<char> {
+) -> Option<ast::Lifetime> {
     match existing_type_param_list {
         Some(type_params) => {
-            let used_lifetime_params: FxHashSet<_> = type_params
-                .lifetime_params()
-                .map(|p| p.syntax().text().to_string()[1..].to_owned())
-                .collect();
-            (b'a'..=b'z').map(char::from).find(|c| !used_lifetime_params.contains(&c.to_string()))
+            let used_lifetime_params: FxHashSet<_> =
+                type_params.lifetime_params().map(|p| p.syntax().text().to_string()).collect();
+            ('a'..='z').map(|it| format!("'{}", it)).find(|it| !used_lifetime_params.contains(it))
         }
-        None => Some('a'),
+        None => Some("'a".to_string()),
     }
-}
-
-fn add_lifetime_param(type_params: ast::GenericParamList, new_lifetime_param: char) {
-    let generic_param =
-        make::generic_param(format!("'{}", new_lifetime_param), None).clone_for_update();
-    type_params.add_generic_param(generic_param);
-}
-
-fn make_ast_lifetime(new_lifetime_param: char) -> ast::Lifetime {
-    make::generic_param(format!("'{}", new_lifetime_param), None)
-        .syntax()
-        .descendants()
-        .find_map(ast::Lifetime::cast)
-        .unwrap()
+    .map(|it| make::lifetime(&it))
 }
 
 enum NeedsLifetime {
diff --git a/crates/ide_assists/src/handlers/merge_imports.rs b/crates/ide_assists/src/handlers/merge_imports.rs
index add7b8e37..3cd090737 100644
--- a/crates/ide_assists/src/handlers/merge_imports.rs
+++ b/crates/ide_assists/src/handlers/merge_imports.rs
@@ -27,14 +27,14 @@ pub(crate) fn merge_imports(acc: &mut Assists, ctx: &AssistContext) -> Option<()
     if let Some(use_item) = tree.syntax().parent().and_then(ast::Use::cast) {
         let (merged, to_remove) =
             next_prev().filter_map(|dir| neighbor(&use_item, dir)).find_map(|use_item2| {
-                try_merge_imports(&use_item, &use_item2, MergeBehavior::Full).zip(Some(use_item2))
+                try_merge_imports(&use_item, &use_item2, MergeBehavior::Crate).zip(Some(use_item2))
             })?;
 
         imports = Some((use_item, merged, to_remove));
     } else {
         let (merged, to_remove) =
             next_prev().filter_map(|dir| neighbor(&tree, dir)).find_map(|use_tree| {
-                try_merge_trees(&tree, &use_tree, MergeBehavior::Full).zip(Some(use_tree))
+                try_merge_trees(&tree, &use_tree, MergeBehavior::Crate).zip(Some(use_tree))
             })?;
 
         uses = Some((tree.clone(), merged, to_remove))
diff --git a/crates/ide_assists/src/handlers/move_bounds.rs b/crates/ide_assists/src/handlers/move_bounds.rs
index 011a28d44..fa3f76609 100644
--- a/crates/ide_assists/src/handlers/move_bounds.rs
+++ b/crates/ide_assists/src/handlers/move_bounds.rs
@@ -63,11 +63,7 @@ pub(crate) fn move_bounds_to_where_clause(acc: &mut Assists, ctx: &AssistContext
 }
 
 fn build_predicate(param: ast::TypeParam) -> Option<ast::WherePred> {
-    let path = {
-        let name_ref = make::name_ref(&param.name()?.syntax().to_string());
-        let segment = make::path_segment(name_ref);
-        make::path_unqualified(segment)
-    };
+    let path = make::ext::ident_path(&param.name()?.syntax().to_string());
     let predicate = make::where_pred(path, param.type_bound_list()?.bounds());
     Some(predicate.clone_for_update())
 }
diff --git a/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs b/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
index 694d897d1..10d9cec31 100644
--- a/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
+++ b/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
@@ -84,7 +84,7 @@ pub(crate) fn replace_derive_with_manual_impl(
         add_assist(acc, ctx, &attr, &args, &trait_path, Some(trait_), &adt)?;
     }
     if no_traits_found {
-        let trait_path = make::path_unqualified(make::path_segment(make::name_ref(trait_name)));
+        let trait_path = make::ext::ident_path(trait_name);
         add_assist(acc, ctx, &attr, &args, &trait_path, None, &adt)?;
     }
     Some(())
@@ -159,10 +159,8 @@ fn impl_def_from_trait(
     if trait_items.is_empty() {
         return None;
     }
-    let impl_def = make::impl_trait(
-        trait_path.clone(),
-        make::path_unqualified(make::path_segment(make::name_ref(&annotated_name.text()))),
-    );
+    let impl_def =
+        make::impl_trait(trait_path.clone(), make::ext::ident_path(&annotated_name.text()));
     let (impl_def, first_assoc_item) =
         add_trait_assoc_items_to_impl(sema, trait_items, trait_, impl_def, target_scope);
     Some((impl_def, first_assoc_item))
diff --git a/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs b/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs
index ff25b61ea..15420aedf 100644
--- a/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs
+++ b/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs
@@ -1,6 +1,9 @@
-use syntax::ast::{self, edit::AstNodeEdit, make, AstNode, GenericParamsOwner};
+use syntax::{
+    ast::{self, edit_in_place::GenericParamsOwnerEdit, make, AstNode},
+    ted,
+};
 
-use crate::{AssistContext, AssistId, AssistKind, Assists};
+use crate::{utils::suggest_name, AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: replace_impl_trait_with_generic
 //
@@ -17,30 +20,29 @@ pub(crate) fn replace_impl_trait_with_generic(
     acc: &mut Assists,
     ctx: &AssistContext,
 ) -> Option<()> {
-    let type_impl_trait = ctx.find_node_at_offset::<ast::ImplTraitType>()?;
-    let type_param = type_impl_trait.syntax().parent().and_then(ast::Param::cast)?;
-    let type_fn = type_param.syntax().ancestors().find_map(ast::Fn::cast)?;
+    let impl_trait_type = ctx.find_node_at_offset::<ast::ImplTraitType>()?;
+    let param = impl_trait_type.syntax().parent().and_then(ast::Param::cast)?;
+    let fn_ = param.syntax().ancestors().find_map(ast::Fn::cast)?;
 
-    let impl_trait_ty = type_impl_trait.type_bound_list()?;
+    let type_bound_list = impl_trait_type.type_bound_list()?;
 
-    let target = type_fn.syntax().text_range();
+    let target = fn_.syntax().text_range();
     acc.add(
         AssistId("replace_impl_trait_with_generic", AssistKind::RefactorRewrite),
         "Replace impl trait with generic",
         target,
         |edit| {
-            let generic_letter = impl_trait_ty.to_string().chars().next().unwrap().to_string();
+            let impl_trait_type = edit.make_ast_mut(impl_trait_type);
+            let fn_ = edit.make_ast_mut(fn_);
 
-            let generic_param_list = type_fn
-                .generic_param_list()
-                .unwrap_or_else(|| make::generic_param_list(None))
-                .append_param(make::generic_param(generic_letter.clone(), Some(impl_trait_ty)));
+            let type_param_name = suggest_name::for_generic_parameter(&impl_trait_type);
 
-            let new_type_fn = type_fn
-                .replace_descendant::<ast::Type>(type_impl_trait.into(), make::ty(&generic_letter))
-                .with_generic_param_list(generic_param_list);
+            let type_param = make::type_param(make::name(&type_param_name), Some(type_bound_list))
+                .clone_for_update();
+            let new_ty = make::ty(&type_param_name).clone_for_update();
 
-            edit.replace_ast(type_fn.clone(), new_type_fn);
+            ted::replace(impl_trait_type.syntax(), new_ty.syntax());
+            fn_.get_or_create_generic_param_list().add_generic_param(type_param.into())
         },
     )
 }
@@ -55,12 +57,8 @@ mod tests {
     fn replace_impl_trait_with_generic_params() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo<G>(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<G, B: Bar>(bar: B) {}
-            "#,
+            r#"fn foo<G>(bar: $0impl Bar) {}"#,
+            r#"fn foo<G, B: Bar>(bar: B) {}"#,
         );
     }
 
@@ -68,12 +66,8 @@ mod tests {
     fn replace_impl_trait_without_generic_params() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<B: Bar>(bar: B) {}
-            "#,
+            r#"fn foo(bar: $0impl Bar) {}"#,
+            r#"fn foo<B: Bar>(bar: B) {}"#,
         );
     }
 
@@ -81,12 +75,8 @@ mod tests {
     fn replace_two_impl_trait_with_generic_params() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo<G>(foo: impl Foo, bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<G, B: Bar>(foo: impl Foo, bar: B) {}
-            "#,
+            r#"fn foo<G>(foo: impl Foo, bar: $0impl Bar) {}"#,
+            r#"fn foo<G, B: Bar>(foo: impl Foo, bar: B) {}"#,
         );
     }
 
@@ -94,12 +84,8 @@ mod tests {
     fn replace_impl_trait_with_empty_generic_params() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo<>(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<B: Bar>(bar: B) {}
-            "#,
+            r#"fn foo<>(bar: $0impl Bar) {}"#,
+            r#"fn foo<B: Bar>(bar: B) {}"#,
         );
     }
 
@@ -108,13 +94,13 @@ mod tests {
         check_assist(
             replace_impl_trait_with_generic,
             r#"
-            fn foo<
-            >(bar: $0impl Bar) {}
-            "#,
+fn foo<
+>(bar: $0impl Bar) {}
+"#,
             r#"
-            fn foo<B: Bar
-            >(bar: B) {}
-            "#,
+fn foo<B: Bar
+>(bar: B) {}
+"#,
         );
     }
 
@@ -123,12 +109,8 @@ mod tests {
     fn replace_impl_trait_with_exist_generic_letter() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo<B>(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<B, C: Bar>(bar: C) {}
-            "#,
+            r#"fn foo<B>(bar: $0impl Bar) {}"#,
+            r#"fn foo<B, C: Bar>(bar: C) {}"#,
         );
     }
 
@@ -137,19 +119,19 @@ mod tests {
         check_assist(
             replace_impl_trait_with_generic,
             r#"
-            fn foo<
-                G: Foo,
-                F,
-                H,
-            >(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<
-                G: Foo,
-                F,
-                H, B: Bar
-            >(bar: B) {}
-            "#,
+fn foo<
+    G: Foo,
+    F,
+    H,
+>(bar: $0impl Bar) {}
+"#,
+            r#"
+fn foo<
+    G: Foo,
+    F,
+    H, B: Bar,
+>(bar: B) {}
+"#,
         );
     }
 
@@ -157,12 +139,8 @@ mod tests {
     fn replace_impl_trait_multiple() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo(bar: $0impl Foo + Bar) {}
-            "#,
-            r#"
-            fn foo<F: Foo + Bar>(bar: F) {}
-            "#,
+            r#"fn foo(bar: $0impl Foo + Bar) {}"#,
+            r#"fn foo<F: Foo + Bar>(bar: F) {}"#,
         );
     }
 }
diff --git a/crates/ide_assists/src/handlers/replace_let_with_if_let.rs b/crates/ide_assists/src/handlers/replace_let_with_if_let.rs
index be7e724b5..1ad0fa816 100644
--- a/crates/ide_assists/src/handlers/replace_let_with_if_let.rs
+++ b/crates/ide_assists/src/handlers/replace_let_with_if_let.rs
@@ -50,22 +50,19 @@ pub(crate) fn replace_let_with_if_let(acc: &mut Assists, ctx: &AssistContext) ->
         "Replace with if-let",
         target,
         |edit| {
-            let with_placeholder: ast::Pat = match happy_variant {
-                None => make::wildcard_pat().into(),
-                Some(var_name) => make::tuple_struct_pat(
-                    make::path_unqualified(make::path_segment(make::name_ref(var_name))),
-                    once(make::wildcard_pat().into()),
-                )
-                .into(),
+            let pat = match happy_variant {
+                None => original_pat,
+                Some(var_name) => {
+                    make::tuple_struct_pat(make::ext::ident_path(var_name), once(original_pat))
+                        .into()
+                }
             };
+
             let block =
-                make::block_expr(None, None).indent(IndentLevel::from_node(let_stmt.syntax()));
-            let if_ = make::expr_if(make::condition(init, Some(with_placeholder)), block, None);
+                make::ext::empty_block_expr().indent(IndentLevel::from_node(let_stmt.syntax()));
+            let if_ = make::expr_if(make::condition(init, Some(pat)), block, None);
             let stmt = make::expr_stmt(if_);
 
-            let placeholder = stmt.syntax().descendants().find_map(ast::WildcardPat::cast).unwrap();
-            let stmt = stmt.replace_descendant(placeholder.into(), original_pat);
-
             edit.replace_ast(ast::Stmt::from(let_stmt), ast::Stmt::from(stmt));
         },
     )
diff --git a/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs b/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
index a986a6ae8..0fec961b4 100644
--- a/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
+++ b/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
@@ -32,7 +32,7 @@ use ide_db::ty_filter::TryEnum;
 // fn main() {
 //     let x: Result<i32, i32> = Result::Ok(92);
 //     let y = match x {
-//         Ok(a) => a,
+//         Ok(it) => it,
 //         $0_ => unreachable!(),
 //     };
 // }
@@ -52,16 +52,17 @@ pub(crate) fn replace_unwrap_with_match(acc: &mut Assists, ctx: &AssistContext)
         "Replace unwrap with match",
         target,
         |builder| {
-            let ok_path = make::path_unqualified(make::path_segment(make::name_ref(happy_variant)));
-            let it = make::ident_pat(make::name("a")).into();
+            let ok_path = make::ext::ident_path(happy_variant);
+            let it = make::ident_pat(make::name("it")).into();
             let ok_tuple = make::tuple_struct_pat(ok_path, iter::once(it)).into();
 
-            let bind_path = make::path_unqualified(make::path_segment(make::name_ref("a")));
+            let bind_path = make::ext::ident_path("it");
             let ok_arm = make::match_arm(iter::once(ok_tuple), make::expr_path(bind_path));
 
-            let unreachable_call = make::expr_unreachable();
-            let err_arm =
-                make::match_arm(iter::once(make::wildcard_pat().into()), unreachable_call);
+            let err_arm = make::match_arm(
+                iter::once(make::wildcard_pat().into()),
+                make::ext::expr_unreachable(),
+            );
 
             let match_arm_list = make::match_arm_list(vec![ok_arm, err_arm]);
             let match_expr = make::expr_match(caller.clone(), match_arm_list)
@@ -110,7 +111,7 @@ fn i<T>(a: T) -> T { a }
 fn main() {
     let x: Result<i32, i32> = Result::Ok(92);
     let y = match i(x) {
-        Ok(a) => a,
+        Ok(it) => it,
         $0_ => unreachable!(),
     };
 }
@@ -136,7 +137,7 @@ fn i<T>(a: T) -> T { a }
 fn main() {
     let x = Option::Some(92);
     let y = match i(x) {
-        Some(a) => a,
+        Some(it) => it,
         $0_ => unreachable!(),
     };
 }
@@ -162,7 +163,7 @@ fn i<T>(a: T) -> T { a }
 fn main() {
     let x: Result<i32, i32> = Result::Ok(92);
     let y = match i(x) {
-        Ok(a) => a,
+        Ok(it) => it,
         $0_ => unreachable!(),
     }.count_zeroes();
 }
diff --git a/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs b/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
index e838630ea..2f1da82c7 100644
--- a/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
+++ b/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
@@ -54,9 +54,7 @@ pub(crate) fn wrap_return_type_in_result(acc: &mut Assists, ctx: &AssistContext)
 
             for ret_expr_arg in tail_return_expr_collector.exprs_to_wrap {
                 let ok_wrapped = make::expr_call(
-                    make::expr_path(make::path_unqualified(make::path_segment(make::name_ref(
-                        "Ok",
-                    )))),
+                    make::expr_path(make::ext::ident_path("Ok")),
                     make::arg_list(iter::once(ret_expr_arg.clone())),
                 );
                 builder.replace_ast(ret_expr_arg, ok_wrapped);
diff --git a/crates/ide_assists/src/tests.rs b/crates/ide_assists/src/tests.rs
index 9c2847998..0d3969c36 100644
--- a/crates/ide_assists/src/tests.rs
+++ b/crates/ide_assists/src/tests.rs
@@ -21,7 +21,7 @@ pub(crate) const TEST_CONFIG: AssistConfig = AssistConfig {
     snippet_cap: SnippetCap::new(true),
     allowed: None,
     insert_use: InsertUseConfig {
-        merge: Some(MergeBehavior::Full),
+        merge: Some(MergeBehavior::Crate),
         prefix_kind: hir::PrefixKind::Plain,
         group: true,
     },
diff --git a/crates/ide_assists/src/tests/generated.rs b/crates/ide_assists/src/tests/generated.rs
index 59bcef8fb..49c1a9776 100644
--- a/crates/ide_assists/src/tests/generated.rs
+++ b/crates/ide_assists/src/tests/generated.rs
@@ -1531,7 +1531,7 @@ enum Result<T, E> { Ok(T), Err(E) }
 fn main() {
     let x: Result<i32, i32> = Result::Ok(92);
     let y = match x {
-        Ok(a) => a,
+        Ok(it) => it,
         $0_ => unreachable!(),
     };
 }
diff --git a/crates/ide_assists/src/utils.rs b/crates/ide_assists/src/utils.rs
index 5a90ad715..0dcf20c61 100644
--- a/crates/ide_assists/src/utils.rs
+++ b/crates/ide_assists/src/utils.rs
@@ -159,8 +159,8 @@ pub fn add_trait_assoc_items_to_impl(
         match fn_def.body() {
             Some(_) => fn_def,
             None => {
-                let body =
-                    make::block_expr(None, Some(make::expr_todo())).indent(edit::IndentLevel(1));
+                let body = make::block_expr(None, Some(make::ext::expr_todo()))
+                    .indent(edit::IndentLevel(1));
                 fn_def.with_body(body)
             }
         }
diff --git a/crates/ide_assists/src/utils/suggest_name.rs b/crates/ide_assists/src/utils/suggest_name.rs
index deafcd630..b3aabeab3 100644
--- a/crates/ide_assists/src/utils/suggest_name.rs
+++ b/crates/ide_assists/src/utils/suggest_name.rs
@@ -6,7 +6,7 @@ use itertools::Itertools;
 use stdx::to_lower_snake_case;
 use syntax::{
     ast::{self, NameOwner},
-    match_ast, AstNode,
+    match_ast, AstNode, SmolStr,
 };
 
 /// Trait names, that will be ignored when in `impl Trait` and `dyn Trait`
@@ -57,6 +57,14 @@ const USELESS_METHODS: &[&str] = &[
     "iter_mut",
 ];
 
+pub(crate) fn for_generic_parameter(ty: &ast::ImplTraitType) -> SmolStr {
+    let c = ty
+        .type_bound_list()
+        .and_then(|bounds| bounds.syntax().text().char_at(0.into()))
+        .unwrap_or('T');
+    c.encode_utf8(&mut [0; 4]).into()
+}
+
 /// Suggest name of variable for given expression
 ///
 /// **NOTE**: it is caller's responsibility to guarantee uniqueness of the name.
@@ -75,7 +83,8 @@ const USELESS_METHODS: &[&str] = &[
 /// It also applies heuristics to filter out less informative names
 ///
 /// Currently it sticks to the first name found.
-pub(crate) fn variable(expr: &ast::Expr, sema: &Semantics<'_, RootDatabase>) -> String {
+// FIXME: Microoptimize and return a `SmolStr` here.
+pub(crate) fn for_variable(expr: &ast::Expr, sema: &Semantics<'_, RootDatabase>) -> String {
     // `from_param` does not benifit from stripping
     // it need the largest context possible
     // so we check firstmost
@@ -276,7 +285,7 @@ mod tests {
             frange.range,
             "selection is not an expression(yet contained in one)"
         );
-        let name = variable(&expr, &sema);
+        let name = for_variable(&expr, &sema);
         assert_eq!(&name, expected);
     }
 
diff --git a/crates/ide_completion/src/lib.rs b/crates/ide_completion/src/lib.rs
index e32633565..645349215 100644
--- a/crates/ide_completion/src/lib.rs
+++ b/crates/ide_completion/src/lib.rs
@@ -80,7 +80,7 @@ pub use crate::{
 //
 // And the auto import completions, enabled with the `rust-analyzer.completion.autoimport.enable` setting and the corresponding LSP client capabilities.
 // Those are the additional completion options with automatic `use` import and options from all project importable items,
-// fuzzy matched agains the completion imput.
+// fuzzy matched against the completion input.
 //
 // image::https://user-images.githubusercontent.com/48062697/113020667-b72ab880-917a-11eb-8778-716cf26a0eb3.gif[]
 
diff --git a/crates/ide_completion/src/test_utils.rs b/crates/ide_completion/src/test_utils.rs
index c9857ec5f..939fb2d47 100644
--- a/crates/ide_completion/src/test_utils.rs
+++ b/crates/ide_completion/src/test_utils.rs
@@ -20,7 +20,7 @@ pub(crate) const TEST_CONFIG: CompletionConfig = CompletionConfig {
     add_call_argument_snippets: true,
     snippet_cap: SnippetCap::new(true),
     insert_use: InsertUseConfig {
-        merge: Some(MergeBehavior::Full),
+        merge: Some(MergeBehavior::Crate),
         prefix_kind: PrefixKind::Plain,
         group: true,
     },
diff --git a/crates/ide_db/src/helpers/insert_use/tests.rs b/crates/ide_db/src/helpers/insert_use/tests.rs
index 048c213e2..248227d29 100644
--- a/crates/ide_db/src/helpers/insert_use/tests.rs
+++ b/crates/ide_db/src/helpers/insert_use/tests.rs
@@ -44,7 +44,7 @@ fn insert_not_group_empty() {
 
 #[test]
 fn insert_existing() {
-    check_full("std::fs", "use std::fs;", "use std::fs;")
+    check_crate("std::fs", "use std::fs;", "use std::fs;")
 }
 
 #[test]
@@ -249,7 +249,7 @@ use self::fmt;",
 
 #[test]
 fn insert_no_imports() {
-    check_full(
+    check_crate(
         "foo::bar",
         "fn main() {}",
         r"use foo::bar;
@@ -263,7 +263,7 @@ fn insert_empty_file() {
     cov_mark::check!(insert_group_empty_file);
     // empty files will get two trailing newlines
     // this is due to the test case insert_no_imports above
-    check_full(
+    check_crate(
         "foo::bar",
         "",
         r"use foo::bar;
@@ -290,7 +290,7 @@ fn insert_empty_module() {
 #[test]
 fn insert_after_inner_attr() {
     cov_mark::check!(insert_group_empty_inner_attr);
-    check_full(
+    check_crate(
         "foo::bar",
         r"#![allow(unused_imports)]",
         r"#![allow(unused_imports)]
@@ -301,7 +301,7 @@ use foo::bar;",
 
 #[test]
 fn insert_after_inner_attr2() {
-    check_full(
+    check_crate(
         "foo::bar",
         r"#![allow(unused_imports)]
 
@@ -371,12 +371,12 @@ fn main() {}"#,
 
 #[test]
 fn merge_groups() {
-    check_last("std::io", r"use std::fmt;", r"use std::{fmt, io};")
+    check_module("std::io", r"use std::fmt;", r"use std::{fmt, io};")
 }
 
 #[test]
 fn merge_groups_last() {
-    check_last(
+    check_module(
         "std::io",
         r"use std::fmt::{Result, Display};",
         r"use std::fmt::{Result, Display};
@@ -386,12 +386,12 @@ use std::io;",
 
 #[test]
 fn merge_last_into_self() {
-    check_last("foo::bar::baz", r"use foo::bar;", r"use foo::bar::{self, baz};");
+    check_module("foo::bar::baz", r"use foo::bar;", r"use foo::bar::{self, baz};");
 }
 
 #[test]
 fn merge_groups_full() {
-    check_full(
+    check_crate(
         "std::io",
         r"use std::fmt::{Result, Display};",
         r"use std::{fmt::{Result, Display}, io};",
@@ -400,17 +400,21 @@ fn merge_groups_full() {
 
 #[test]
 fn merge_groups_long_full() {
-    check_full("std::foo::bar::Baz", r"use std::foo::bar::Qux;", r"use std::foo::bar::{Baz, Qux};")
+    check_crate("std::foo::bar::Baz", r"use std::foo::bar::Qux;", r"use std::foo::bar::{Baz, Qux};")
 }
 
 #[test]
 fn merge_groups_long_last() {
-    check_last("std::foo::bar::Baz", r"use std::foo::bar::Qux;", r"use std::foo::bar::{Baz, Qux};")
+    check_module(
+        "std::foo::bar::Baz",
+        r"use std::foo::bar::Qux;",
+        r"use std::foo::bar::{Baz, Qux};",
+    )
 }
 
 #[test]
 fn merge_groups_long_full_list() {
-    check_full(
+    check_crate(
         "std::foo::bar::Baz",
         r"use std::foo::bar::{Qux, Quux};",
         r"use std::foo::bar::{Baz, Quux, Qux};",
@@ -419,7 +423,7 @@ fn merge_groups_long_full_list() {
 
 #[test]
 fn merge_groups_long_last_list() {
-    check_last(
+    check_module(
         "std::foo::bar::Baz",
         r"use std::foo::bar::{Qux, Quux};",
         r"use std::foo::bar::{Baz, Quux, Qux};",
@@ -428,7 +432,7 @@ fn merge_groups_long_last_list() {
 
 #[test]
 fn merge_groups_long_full_nested() {
-    check_full(
+    check_crate(
         "std::foo::bar::Baz",
         r"use std::foo::bar::{Qux, quux::{Fez, Fizz}};",
         r"use std::foo::bar::{Baz, Qux, quux::{Fez, Fizz}};",
@@ -437,7 +441,7 @@ fn merge_groups_long_full_nested() {
 
 #[test]
 fn merge_groups_long_last_nested() {
-    check_last(
+    check_module(
         "std::foo::bar::Baz",
         r"use std::foo::bar::{Qux, quux::{Fez, Fizz}};",
         r"use std::foo::bar::Baz;
@@ -447,7 +451,7 @@ use std::foo::bar::{Qux, quux::{Fez, Fizz}};",
 
 #[test]
 fn merge_groups_full_nested_deep() {
-    check_full(
+    check_crate(
         "std::foo::bar::quux::Baz",
         r"use std::foo::bar::{Qux, quux::{Fez, Fizz}};",
         r"use std::foo::bar::{Qux, quux::{Baz, Fez, Fizz}};",
@@ -456,7 +460,7 @@ fn merge_groups_full_nested_deep() {
 
 #[test]
 fn merge_groups_full_nested_long() {
-    check_full(
+    check_crate(
         "std::foo::bar::Baz",
         r"use std::{foo::bar::Qux};",
         r"use std::{foo::bar::{Baz, Qux}};",
@@ -465,7 +469,7 @@ fn merge_groups_full_nested_long() {
 
 #[test]
 fn merge_groups_last_nested_long() {
-    check_full(
+    check_crate(
         "std::foo::bar::Baz",
         r"use std::{foo::bar::Qux};",
         r"use std::{foo::bar::{Baz, Qux}};",
@@ -474,7 +478,7 @@ fn merge_groups_last_nested_long() {
 
 #[test]
 fn merge_groups_skip_pub() {
-    check_full(
+    check_crate(
         "std::io",
         r"pub use std::fmt::{Result, Display};",
         r"pub use std::fmt::{Result, Display};
@@ -484,7 +488,7 @@ use std::io;",
 
 #[test]
 fn merge_groups_skip_pub_crate() {
-    check_full(
+    check_crate(
         "std::io",
         r"pub(crate) use std::fmt::{Result, Display};",
         r"pub(crate) use std::fmt::{Result, Display};
@@ -494,7 +498,7 @@ use std::io;",
 
 #[test]
 fn merge_groups_skip_attributed() {
-    check_full(
+    check_crate(
         "std::io",
         r#"
 #[cfg(feature = "gated")] use std::fmt::{Result, Display};
@@ -509,7 +513,7 @@ use std::io;
 #[test]
 #[ignore] // FIXME: Support this
 fn split_out_merge() {
-    check_last(
+    check_module(
         "std::fmt::Result",
         r"use std::{fmt, io};",
         r"use std::fmt::{self, Result};
@@ -519,29 +523,33 @@ use std::io;",
 
 #[test]
 fn merge_into_module_import() {
-    check_full("std::fmt::Result", r"use std::{fmt, io};", r"use std::{fmt::{self, Result}, io};")
+    check_crate("std::fmt::Result", r"use std::{fmt, io};", r"use std::{fmt::{self, Result}, io};")
 }
 
 #[test]
 fn merge_groups_self() {
-    check_full("std::fmt::Debug", r"use std::fmt;", r"use std::fmt::{self, Debug};")
+    check_crate("std::fmt::Debug", r"use std::fmt;", r"use std::fmt::{self, Debug};")
 }
 
 #[test]
 fn merge_mod_into_glob() {
-    check_full("token::TokenKind", r"use token::TokenKind::*;", r"use token::TokenKind::{*, self};")
+    check_crate(
+        "token::TokenKind",
+        r"use token::TokenKind::*;",
+        r"use token::TokenKind::{*, self};",
+    )
     // FIXME: have it emit `use token::TokenKind::{self, *}`?
 }
 
 #[test]
 fn merge_self_glob() {
-    check_full("self", r"use self::*;", r"use self::{*, self};")
+    check_crate("self", r"use self::*;", r"use self::{*, self};")
     // FIXME: have it emit `use {self, *}`?
 }
 
 #[test]
 fn merge_glob_nested() {
-    check_full(
+    check_crate(
         "foo::bar::quux::Fez",
         r"use foo::bar::{Baz, quux::*};",
         r"use foo::bar::{Baz, quux::{self::*, Fez}};",
@@ -550,7 +558,7 @@ fn merge_glob_nested() {
 
 #[test]
 fn merge_nested_considers_first_segments() {
-    check_full(
+    check_crate(
         "hir_ty::display::write_bounds_like_dyn_trait",
         r"use hir_ty::{autoderef, display::{HirDisplayError, HirFormatter}, method_resolution};",
         r"use hir_ty::{autoderef, display::{HirDisplayError, HirFormatter, write_bounds_like_dyn_trait}, method_resolution};",
@@ -559,7 +567,7 @@ fn merge_nested_considers_first_segments() {
 
 #[test]
 fn skip_merge_last_too_long() {
-    check_last(
+    check_module(
         "foo::bar",
         r"use foo::bar::baz::Qux;",
         r"use foo::bar;
@@ -569,7 +577,7 @@ use foo::bar::baz::Qux;",
 
 #[test]
 fn skip_merge_last_too_long2() {
-    check_last(
+    check_module(
         "foo::bar::baz::Qux",
         r"use foo::bar;",
         r"use foo::bar;
@@ -592,7 +600,7 @@ fn merge_last_fail() {
     check_merge_only_fail(
         r"use foo::bar::{baz::{Qux, Fez}};",
         r"use foo::bar::{baaz::{Quux, Feez}};",
-        MergeBehavior::Last,
+        MergeBehavior::Module,
     );
 }
 
@@ -601,7 +609,7 @@ fn merge_last_fail1() {
     check_merge_only_fail(
         r"use foo::bar::{baz::{Qux, Fez}};",
         r"use foo::bar::baaz::{Quux, Feez};",
-        MergeBehavior::Last,
+        MergeBehavior::Module,
     );
 }
 
@@ -610,7 +618,7 @@ fn merge_last_fail2() {
     check_merge_only_fail(
         r"use foo::bar::baz::{Qux, Fez};",
         r"use foo::bar::{baaz::{Quux, Feez}};",
-        MergeBehavior::Last,
+        MergeBehavior::Module,
     );
 }
 
@@ -619,7 +627,7 @@ fn merge_last_fail3() {
     check_merge_only_fail(
         r"use foo::bar::baz::{Qux, Fez};",
         r"use foo::bar::baaz::{Quux, Feez};",
-        MergeBehavior::Last,
+        MergeBehavior::Module,
     );
 }
 
@@ -648,12 +656,12 @@ fn check(
     assert_eq_text!(ra_fixture_after, &result);
 }
 
-fn check_full(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Full), false, true)
+fn check_crate(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
+    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Crate), false, true)
 }
 
-fn check_last(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Last), false, true)
+fn check_module(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
+    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Module), false, true)
 }
 
 fn check_none(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
diff --git a/crates/ide_db/src/helpers/merge_imports.rs b/crates/ide_db/src/helpers/merge_imports.rs
index 3f5bbef7f..af2a51a4d 100644
--- a/crates/ide_db/src/helpers/merge_imports.rs
+++ b/crates/ide_db/src/helpers/merge_imports.rs
@@ -9,19 +9,19 @@ use syntax::ast::{
 /// What type of merges are allowed.
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum MergeBehavior {
-    /// Merge everything together creating deeply nested imports.
-    Full,
-    /// Only merge the last import level, doesn't allow import nesting.
-    Last,
+    /// Merge imports from the same crate into a single use statement.
+    Crate,
+    /// Merge imports from the same module into a single use statement.
+    Module,
 }
 
 impl MergeBehavior {
     #[inline]
     fn is_tree_allowed(&self, tree: &ast::UseTree) -> bool {
         match self {
-            MergeBehavior::Full => true,
+            MergeBehavior::Crate => true,
             // only simple single segment paths are allowed
-            MergeBehavior::Last => {
+            MergeBehavior::Module => {
                 tree.use_tree_list().is_none() && tree.path().map(path_len) <= Some(1)
             }
         }
@@ -137,7 +137,7 @@ fn recursive_merge(
                             None,
                             false,
                         );
-                        use_trees.insert(idx, make::glob_use_tree());
+                        use_trees.insert(idx, make::use_tree_glob());
                         continue;
                     }
 
@@ -153,7 +153,7 @@ fn recursive_merge(
                 }
             }
             Err(_)
-                if merge == MergeBehavior::Last
+                if merge == MergeBehavior::Module
                     && use_trees.len() > 0
                     && rhs_t.use_tree_list().is_some() =>
             {
diff --git a/crates/ide_db/src/search.rs b/crates/ide_db/src/search.rs
index 8f899ea56..67840602b 100644
--- a/crates/ide_db/src/search.rs
+++ b/crates/ide_db/src/search.rs
@@ -233,6 +233,13 @@ impl Definition {
             };
         }
 
+        if let Definition::SelfType(impl_) = self {
+            return match impl_.source(db).map(|src| src.value.syntax().text_range()) {
+                Some(range) => SearchScope::file_range(FileRange { file_id, range }),
+                None => SearchScope::single_file(file_id),
+            };
+        }
+
         if let Definition::GenericParam(hir::GenericParam::LifetimeParam(param)) = self {
             let range = match param.parent(db) {
                 hir::GenericDef::Function(it) => {
@@ -297,7 +304,7 @@ impl Definition {
     }
 
     pub fn usages<'a>(&'a self, sema: &'a Semantics<RootDatabase>) -> FindUsages<'a> {
-        FindUsages { def: self, sema, scope: None, include_self_kw_refs: false }
+        FindUsages { def: self, sema, scope: None, include_self_kw_refs: None }
     }
 }
 
@@ -305,12 +312,13 @@ pub struct FindUsages<'a> {
     def: &'a Definition,
     sema: &'a Semantics<'a, RootDatabase>,
     scope: Option<SearchScope>,
-    include_self_kw_refs: bool,
+    include_self_kw_refs: Option<hir::Type>,
 }
 
 impl<'a> FindUsages<'a> {
-    pub fn include_self_kw_refs(mut self, include: bool) -> FindUsages<'a> {
-        self.include_self_kw_refs = include;
+    /// Enable searching for `Self` when the definition is a type.
+    pub fn include_self_refs(mut self) -> FindUsages<'a> {
+        self.include_self_kw_refs = def_to_ty(self.sema, self.def);
         self
     }
 
@@ -354,13 +362,18 @@ impl<'a> FindUsages<'a> {
             }
         };
 
-        let name = match self.def.name(sema.db) {
-            Some(it) => it.to_string(),
+        let name = self.def.name(sema.db).or_else(|| {
+            self.include_self_kw_refs.as_ref().and_then(|ty| {
+                ty.as_adt()
+                    .map(|adt| adt.name(self.sema.db))
+                    .or_else(|| ty.as_builtin().map(|builtin| builtin.name()))
+            })
+        });
+        let name = match name {
+            Some(name) => name.to_string(),
             None => return,
         };
-
-        let pat = name.as_str();
-        let search_for_self = self.include_self_kw_refs;
+        let name = name.as_str();
 
         for (file_id, search_range) in search_scope {
             let text = sema.db.file_text(file_id);
@@ -369,51 +382,63 @@ impl<'a> FindUsages<'a> {
 
             let tree = Lazy::new(|| sema.parse(file_id).syntax().clone());
 
-            let mut handle_match = |idx: usize| -> bool {
+            for (idx, _) in text.match_indices(name) {
                 let offset: TextSize = idx.try_into().unwrap();
                 if !search_range.contains_inclusive(offset) {
-                    return false;
+                    continue;
                 }
 
                 if let Some(name) = sema.find_node_at_offset_with_descend(&tree, offset) {
-                    match name {
-                        ast::NameLike::NameRef(name_ref) => {
-                            if self.found_name_ref(&name_ref, sink) {
-                                return true;
-                            }
-                        }
-                        ast::NameLike::Name(name) => {
-                            if self.found_name(&name, sink) {
-                                return true;
-                            }
-                        }
-                        ast::NameLike::Lifetime(lifetime) => {
-                            if self.found_lifetime(&lifetime, sink) {
-                                return true;
-                            }
-                        }
+                    if match name {
+                        ast::NameLike::NameRef(name_ref) => self.found_name_ref(&name_ref, sink),
+                        ast::NameLike::Name(name) => self.found_name(&name, sink),
+                        ast::NameLike::Lifetime(lifetime) => self.found_lifetime(&lifetime, sink),
+                    } {
+                        return;
                     }
                 }
-
-                return false;
-            };
-
-            for (idx, _) in text.match_indices(pat) {
-                if handle_match(idx) {
-                    return;
-                }
             }
-
-            if search_for_self {
+            if let Some(self_ty) = &self.include_self_kw_refs {
                 for (idx, _) in text.match_indices("Self") {
-                    if handle_match(idx) {
-                        return;
+                    let offset: TextSize = idx.try_into().unwrap();
+                    if !search_range.contains_inclusive(offset) {
+                        continue;
+                    }
+
+                    if let Some(ast::NameLike::NameRef(name_ref)) =
+                        sema.find_node_at_offset_with_descend(&tree, offset)
+                    {
+                        if self.found_self_ty_name_ref(&self_ty, &name_ref, sink) {
+                            return;
+                        }
                     }
                 }
             }
         }
     }
 
+    fn found_self_ty_name_ref(
+        &self,
+        self_ty: &hir::Type,
+        name_ref: &ast::NameRef,
+        sink: &mut dyn FnMut(FileId, FileReference) -> bool,
+    ) -> bool {
+        match NameRefClass::classify(self.sema, &name_ref) {
+            Some(NameRefClass::Definition(Definition::SelfType(impl_)))
+                if impl_.self_ty(self.sema.db) == *self_ty =>
+            {
+                let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
+                let reference = FileReference {
+                    range,
+                    name: ast::NameLike::NameRef(name_ref.clone()),
+                    access: None,
+                };
+                sink(file_id, reference)
+            }
+            _ => false,
+        }
+    }
+
     fn found_lifetime(
         &self,
         lifetime: &ast::Lifetime,
@@ -429,7 +454,7 @@ impl<'a> FindUsages<'a> {
                 };
                 sink(file_id, reference)
             }
-            _ => false, // not a usage
+            _ => false,
         }
     }
 
@@ -448,42 +473,35 @@ impl<'a> FindUsages<'a> {
                 };
                 sink(file_id, reference)
             }
-            Some(NameRefClass::Definition(Definition::SelfType(impl_))) => {
-                let ty = impl_.self_ty(self.sema.db);
-
-                if let Some(adt) = ty.as_adt() {
-                    if &Definition::ModuleDef(ModuleDef::Adt(adt)) == self.def {
-                        let FileRange { file_id, range } =
-                            self.sema.original_range(name_ref.syntax());
-                        let reference = FileReference {
-                            range,
-                            name: ast::NameLike::NameRef(name_ref.clone()),
-                            access: None,
-                        };
-                        return sink(file_id, reference);
-                    }
+            Some(NameRefClass::Definition(def)) if self.include_self_kw_refs.is_some() => {
+                if self.include_self_kw_refs == def_to_ty(self.sema, &def) {
+                    let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
+                    let reference = FileReference {
+                        range,
+                        name: ast::NameLike::NameRef(name_ref.clone()),
+                        access: reference_access(&def, &name_ref),
+                    };
+                    sink(file_id, reference)
+                } else {
+                    false
                 }
-
-                false
             }
             Some(NameRefClass::FieldShorthand { local_ref: local, field_ref: field }) => {
                 let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
-                let reference = match self.def {
-                    Definition::Field(_) if &field == self.def => FileReference {
-                        range,
-                        name: ast::NameLike::NameRef(name_ref.clone()),
-                        access: reference_access(&field, &name_ref),
-                    },
-                    Definition::Local(l) if &local == l => FileReference {
-                        range,
-                        name: ast::NameLike::NameRef(name_ref.clone()),
-                        access: reference_access(&Definition::Local(local), &name_ref),
-                    },
-                    _ => return false, // not a usage
+                let access = match self.def {
+                    Definition::Field(_) if &field == self.def => {
+                        reference_access(&field, &name_ref)
+                    }
+                    Definition::Local(l) if &local == l => {
+                        reference_access(&Definition::Local(local), &name_ref)
+                    }
+                    _ => return false,
                 };
+                let reference =
+                    FileReference { range, name: ast::NameLike::NameRef(name_ref.clone()), access };
                 sink(file_id, reference)
             }
-            _ => false, // not a usage
+            _ => false,
         }
     }
 
@@ -513,11 +531,30 @@ impl<'a> FindUsages<'a> {
                     FileReference { range, name: ast::NameLike::Name(name.clone()), access: None };
                 sink(file_id, reference)
             }
-            _ => false, // not a usage
+            _ => false,
         }
     }
 }
 
+fn def_to_ty(sema: &Semantics<RootDatabase>, def: &Definition) -> Option<hir::Type> {
+    match def {
+        Definition::ModuleDef(def) => match def {
+            ModuleDef::Adt(adt) => Some(adt.ty(sema.db)),
+            ModuleDef::TypeAlias(it) => Some(it.ty(sema.db)),
+            ModuleDef::BuiltinType(it) => {
+                let graph = sema.db.crate_graph();
+                let krate = graph.iter().next()?;
+                let root_file = graph[krate].root_file_id;
+                let module = sema.to_module_def(root_file)?;
+                Some(it.ty(sema.db, module))
+            }
+            _ => None,
+        },
+        Definition::SelfType(it) => Some(it.self_ty(sema.db)),
+        _ => None,
+    }
+}
+
 fn reference_access(def: &Definition, name_ref: &ast::NameRef) -> Option<ReferenceAccess> {
     // Only Locals and Fields have accesses for now.
     if !matches!(def, Definition::Local(_) | Definition::Field(_)) {
diff --git a/crates/ide_db/src/ty_filter.rs b/crates/ide_db/src/ty_filter.rs
index 988ecd060..00678bf3e 100644
--- a/crates/ide_db/src/ty_filter.rs
+++ b/crates/ide_db/src/ty_filter.rs
@@ -43,7 +43,7 @@ impl TryEnum {
     pub fn sad_pattern(self) -> ast::Pat {
         match self {
             TryEnum::Result => make::tuple_struct_pat(
-                make::path_unqualified(make::path_segment(make::name_ref("Err"))),
+                make::ext::ident_path("Err"),
                 iter::once(make::wildcard_pat().into()),
             )
             .into(),
@@ -54,12 +54,12 @@ impl TryEnum {
     pub fn happy_pattern(self) -> ast::Pat {
         match self {
             TryEnum::Result => make::tuple_struct_pat(
-                make::path_unqualified(make::path_segment(make::name_ref("Ok"))),
+                make::ext::ident_path("Ok"),
                 iter::once(make::wildcard_pat().into()),
             )
             .into(),
             TryEnum::Option => make::tuple_struct_pat(
-                make::path_unqualified(make::path_segment(make::name_ref("Some"))),
+                make::ext::ident_path("Some"),
                 iter::once(make::wildcard_pat().into()),
             )
             .into(),
diff --git a/crates/project_model/src/cargo_workspace.rs b/crates/project_model/src/cargo_workspace.rs
index bc6e20341..b18699b77 100644
--- a/crates/project_model/src/cargo_workspace.rs
+++ b/crates/project_model/src/cargo_workspace.rs
@@ -201,31 +201,12 @@ impl CargoWorkspace {
         if let Some(parent) = cargo_toml.parent() {
             meta.current_dir(parent.to_path_buf());
         }
-        let target = if let Some(target) = config.target.as_ref() {
+        let target = if let Some(target) = &config.target {
             Some(target.clone())
+        } else if let stdout @ Some(_) = cargo_config_build_target(cargo_toml) {
+            stdout
         } else {
-            // cargo metadata defaults to giving information for _all_ targets.
-            // In the absence of a preference from the user, we use the host platform.
-            let mut rustc = Command::new(toolchain::rustc());
-            rustc.current_dir(cargo_toml.parent().unwrap()).arg("-vV");
-            log::debug!("Discovering host platform by {:?}", rustc);
-            match utf8_stdout(rustc) {
-                Ok(stdout) => {
-                    let field = "host: ";
-                    let target = stdout.lines().find_map(|l| l.strip_prefix(field));
-                    if let Some(target) = target {
-                        Some(target.to_string())
-                    } else {
-                        // If we fail to resolve the host platform, it's not the end of the world.
-                        log::info!("rustc -vV did not report host platform, got:\n{}", stdout);
-                        None
-                    }
-                }
-                Err(e) => {
-                    log::warn!("Failed to discover host platform: {}", e);
-                    None
-                }
-            }
+            rustc_discover_host_triple(cargo_toml)
         };
         if let Some(target) = target {
             meta.other_options(vec![String::from("--filter-platform"), target]);
@@ -368,3 +349,43 @@ impl CargoWorkspace {
         self.packages.iter().filter(|(_, v)| v.name == name).count() == 1
     }
 }
+
+fn rustc_discover_host_triple(cargo_toml: &AbsPath) -> Option<String> {
+    let mut rustc = Command::new(toolchain::rustc());
+    rustc.current_dir(cargo_toml.parent().unwrap()).arg("-vV");
+    log::debug!("Discovering host platform by {:?}", rustc);
+    match utf8_stdout(rustc) {
+        Ok(stdout) => {
+            let field = "host: ";
+            let target = stdout.lines().find_map(|l| l.strip_prefix(field));
+            if let Some(target) = target {
+                Some(target.to_string())
+            } else {
+                // If we fail to resolve the host platform, it's not the end of the world.
+                log::info!("rustc -vV did not report host platform, got:\n{}", stdout);
+                None
+            }
+        }
+        Err(e) => {
+            log::warn!("Failed to discover host platform: {}", e);
+            None
+        }
+    }
+}
+
+fn cargo_config_build_target(cargo_toml: &AbsPath) -> Option<String> {
+    let mut cargo_config = Command::new(toolchain::cargo());
+    cargo_config
+        .current_dir(cargo_toml.parent().unwrap())
+        .args(&["-Z", "unstable-options", "config", "get", "build.target"])
+        .env("RUSTC_BOOTSTRAP", "1");
+    // if successful we receive `build.target = "target-triple"`
+    log::debug!("Discovering cargo config target by {:?}", cargo_config);
+    match utf8_stdout(cargo_config) {
+        Ok(stdout) => stdout
+            .strip_prefix("build.target = \"")
+            .and_then(|stdout| stdout.strip_suffix('"'))
+            .map(ToOwned::to_owned),
+        Err(_) => None,
+    }
+}
diff --git a/crates/project_model/src/rustc_cfg.rs b/crates/project_model/src/rustc_cfg.rs
index 312708575..012eab256 100644
--- a/crates/project_model/src/rustc_cfg.rs
+++ b/crates/project_model/src/rustc_cfg.rs
@@ -2,9 +2,12 @@
 
 use std::process::Command;
 
+use anyhow::Result;
+use paths::AbsPath;
+
 use crate::{cfg_flag::CfgFlag, utf8_stdout};
 
-pub(crate) fn get(target: Option<&str>) -> Vec<CfgFlag> {
+pub(crate) fn get(cargo_toml: Option<&AbsPath>, target: Option<&str>) -> Vec<CfgFlag> {
     let _p = profile::span("rustc_cfg::get");
     let mut res = Vec::with_capacity(6 * 2 + 1);
 
@@ -16,19 +19,39 @@ pub(crate) fn get(target: Option<&str>) -> Vec<CfgFlag> {
         }
     }
 
-    let rustc_cfgs = {
-        let mut cmd = Command::new(toolchain::rustc());
-        cmd.args(&["--print", "cfg", "-O"]);
-        if let Some(target) = target {
-            cmd.args(&["--target", target]);
-        }
-        utf8_stdout(cmd)
-    };
-
-    match rustc_cfgs {
+    match get_rust_cfgs(cargo_toml, target) {
         Ok(rustc_cfgs) => res.extend(rustc_cfgs.lines().map(|it| it.parse().unwrap())),
         Err(e) => log::error!("failed to get rustc cfgs: {:#}", e),
     }
 
     res
 }
+
+fn get_rust_cfgs(cargo_toml: Option<&AbsPath>, target: Option<&str>) -> Result<String> {
+    let cargo_rust_cfgs = match cargo_toml {
+        Some(cargo_toml) => {
+            let mut cargo_config = Command::new(toolchain::cargo());
+            cargo_config
+                .current_dir(cargo_toml.parent().unwrap())
+                .args(&["-Z", "unstable-options", "rustc", "--print", "cfg"])
+                .env("RUSTC_BOOTSTRAP", "1");
+            if let Some(target) = target {
+                cargo_config.args(&["--target", target]);
+            }
+            utf8_stdout(cargo_config).ok()
+        }
+        None => None,
+    };
+    match cargo_rust_cfgs {
+        Some(stdout) => Ok(stdout),
+        None => {
+            // using unstable cargo features failed, fall back to using plain rustc
+            let mut cmd = Command::new(toolchain::rustc());
+            cmd.args(&["--print", "cfg", "-O"]);
+            if let Some(target) = target {
+                cmd.args(&["--target", target]);
+            }
+            utf8_stdout(cmd)
+        }
+    }
+}
diff --git a/crates/project_model/src/workspace.rs b/crates/project_model/src/workspace.rs
index 2fcd0f8fa..84c702fdf 100644
--- a/crates/project_model/src/workspace.rs
+++ b/crates/project_model/src/workspace.rs
@@ -143,7 +143,8 @@ impl ProjectWorkspace {
                 } else {
                     None
                 };
-                let rustc_cfg = rustc_cfg::get(config.target.as_deref());
+
+                let rustc_cfg = rustc_cfg::get(Some(&cargo_toml), config.target.as_deref());
                 ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg }
             }
         };
@@ -159,7 +160,7 @@ impl ProjectWorkspace {
             Some(path) => Some(Sysroot::load(path)?),
             None => None,
         };
-        let rustc_cfg = rustc_cfg::get(target);
+        let rustc_cfg = rustc_cfg::get(None, target);
         Ok(ProjectWorkspace::Json { project: project_json, sysroot, rustc_cfg })
     }
 
@@ -310,7 +311,7 @@ fn project_json_to_crate_graph(
 
             let target_cfgs = match krate.target.as_deref() {
                 Some(target) => {
-                    cfg_cache.entry(target).or_insert_with(|| rustc_cfg::get(Some(target)))
+                    cfg_cache.entry(target).or_insert_with(|| rustc_cfg::get(None, Some(target)))
                 }
                 None => &rustc_cfg,
             };
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 8879a9161..d83670bda 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -36,7 +36,7 @@ config_data! {
     struct ConfigData {
         /// The strategy to use when inserting new imports or merging imports.
         assist_importMergeBehavior |
-        assist_importMergeBehaviour: MergeBehaviorDef  = "\"full\"",
+        assist_importMergeBehaviour: MergeBehaviorDef  = "\"crate\"",
         /// The path structure for newly inserted paths to use.
         assist_importPrefix: ImportPrefixDef           = "\"plain\"",
         /// Group inserted imports by the [following order](https://rust-analyzer.github.io/manual.html#auto-import). Groups are separated by newlines.
@@ -604,8 +604,8 @@ impl Config {
         InsertUseConfig {
             merge: match self.data.assist_importMergeBehavior {
                 MergeBehaviorDef::None => None,
-                MergeBehaviorDef::Full => Some(MergeBehavior::Full),
-                MergeBehaviorDef::Last => Some(MergeBehavior::Last),
+                MergeBehaviorDef::Crate => Some(MergeBehavior::Crate),
+                MergeBehaviorDef::Module => Some(MergeBehavior::Module),
             },
             prefix_kind: match self.data.assist_importPrefix {
                 ImportPrefixDef::Plain => PrefixKind::Plain,
@@ -709,8 +709,10 @@ enum ManifestOrProjectJson {
 #[serde(rename_all = "snake_case")]
 enum MergeBehaviorDef {
     None,
-    Full,
-    Last,
+    #[serde(alias = "full")]
+    Crate,
+    #[serde(alias = "last")]
+    Module,
 }
 
 #[derive(Deserialize, Debug, Clone)]
@@ -867,11 +869,11 @@ fn field_props(field: &str, ty: &str, doc: &[&str], default: &str) -> serde_json
         },
         "MergeBehaviorDef" => set! {
             "type": "string",
-            "enum": ["none", "full", "last"],
+            "enum": ["none", "crate", "module"],
             "enumDescriptions": [
-                "No merging",
-                "Merge all layers of the import trees",
-                "Only merge the last layer of the import trees"
+                "Do not merge imports at all.",
+                "Merge imports from the same crate into a single `use` statement.",
+                "Merge imports from the same module into a single `use` statement."
             ],
         },
         "ImportPrefixDef" => set! {
diff --git a/crates/rust-analyzer/src/integrated_benchmarks.rs b/crates/rust-analyzer/src/integrated_benchmarks.rs
index 3dcbe397a..56de9681c 100644
--- a/crates/rust-analyzer/src/integrated_benchmarks.rs
+++ b/crates/rust-analyzer/src/integrated_benchmarks.rs
@@ -133,7 +133,7 @@ fn integrated_completion_benchmark() {
             add_call_argument_snippets: true,
             snippet_cap: SnippetCap::new(true),
             insert_use: InsertUseConfig {
-                merge: Some(MergeBehavior::Full),
+                merge: Some(MergeBehavior::Crate),
                 prefix_kind: hir::PrefixKind::ByCrate,
                 group: true,
             },
@@ -166,7 +166,7 @@ fn integrated_completion_benchmark() {
             add_call_argument_snippets: true,
             snippet_cap: SnippetCap::new(true),
             insert_use: InsertUseConfig {
-                merge: Some(MergeBehavior::Full),
+                merge: Some(MergeBehavior::Crate),
                 prefix_kind: hir::PrefixKind::ByCrate,
                 group: true,
             },
diff --git a/crates/syntax/src/ast/edit_in_place.rs b/crates/syntax/src/ast/edit_in_place.rs
index 04f97f368..168355555 100644
--- a/crates/syntax/src/ast/edit_in_place.rs
+++ b/crates/syntax/src/ast/edit_in_place.rs
@@ -195,18 +195,13 @@ impl ast::GenericParamList {
     pub fn add_generic_param(&self, generic_param: ast::GenericParam) {
         match self.generic_params().last() {
             Some(last_param) => {
-                let mut elems = Vec::new();
-                if !last_param
-                    .syntax()
-                    .siblings_with_tokens(Direction::Next)
-                    .any(|it| it.kind() == T![,])
-                {
-                    elems.push(make::token(T![,]).into());
-                    elems.push(make::tokens::single_space().into());
-                };
-                elems.push(generic_param.syntax().clone().into());
-                let after_last_param = Position::after(last_param.syntax());
-                ted::insert_all(after_last_param, elems);
+                let position = Position::after(last_param.syntax());
+                let elements = vec![
+                    make::token(T![,]).into(),
+                    make::tokens::single_space().into(),
+                    generic_param.syntax().clone().into(),
+                ];
+                ted::insert_all(position, elements);
             }
             None => {
                 let after_l_angle = Position::after(self.l_angle_token().unwrap());
diff --git a/crates/syntax/src/ast/make.rs b/crates/syntax/src/ast/make.rs
index 5a6687397..1998ad1f6 100644
--- a/crates/syntax/src/ast/make.rs
+++ b/crates/syntax/src/ast/make.rs
@@ -3,25 +3,55 @@
 //!
 //! Note that all functions here intended to be stupid constructors, which just
 //! assemble a finish node from immediate children. If you want to do something
-//! smarter than that, it probably doesn't belong in this module.
+//! smarter than that, it belongs to the `ext` submodule.
 //!
 //! Keep in mind that `from_text` functions should be kept private. The public
 //! API should require to assemble every node piecewise. The trick of
 //! `parse(format!())` we use internally is an implementation detail -- long
 //! term, it will be replaced with direct tree manipulation.
 use itertools::Itertools;
-use stdx::format_to;
+use stdx::{format_to, never};
 
 use crate::{ast, AstNode, SourceFile, SyntaxKind, SyntaxNode, SyntaxToken};
 
+/// While the parent module defines basic atomic "constructors", the `ext`
+/// module defines shortcuts for common things.
+///
+/// It's named `ext` rather than `shortcuts` just to keep it short.
+pub mod ext {
+    use super::*;
+
+    pub fn ident_path(ident: &str) -> ast::Path {
+        path_unqualified(path_segment(name_ref(ident)))
+    }
+
+    pub fn expr_unreachable() -> ast::Expr {
+        expr_from_text("unreachable!()")
+    }
+    pub fn expr_todo() -> ast::Expr {
+        expr_from_text("todo!()")
+    }
+    pub fn empty_block_expr() -> ast::BlockExpr {
+        block_expr(None, None)
+    }
+
+    pub fn ty_bool() -> ast::Type {
+        ty_path(ident_path("bool"))
+    }
+    pub fn ty_option(t: ast::Type) -> ast::Type {
+        ty_from_text(&format!("Option<{}>", t))
+    }
+    pub fn ty_result(t: ast::Type, e: ast::Type) -> ast::Type {
+        ty_from_text(&format!("Result<{}, {}>", t, e))
+    }
+}
+
 pub fn name(text: &str) -> ast::Name {
     ast_from_text(&format!("mod {}{};", raw_ident_esc(text), text))
 }
-
 pub fn name_ref(text: &str) -> ast::NameRef {
     ast_from_text(&format!("fn f() {{ {}{}; }}", raw_ident_esc(text), text))
 }
-
 fn raw_ident_esc(ident: &str) -> &'static str {
     let is_keyword = parser::SyntaxKind::from_keyword(ident).is_some();
     if is_keyword && !matches!(ident, "self" | "crate" | "super" | "Self") {
@@ -31,13 +61,23 @@ fn raw_ident_esc(ident: &str) -> &'static str {
     }
 }
 
+pub fn lifetime(text: &str) -> ast::Lifetime {
+    let mut text = text;
+    let tmp;
+    if never!(!text.starts_with('\'')) {
+        tmp = format!("'{}", text);
+        text = &tmp;
+    }
+    ast_from_text(&format!("fn f<{}>() {{ }}", text))
+}
+
 // FIXME: replace stringly-typed constructor with a family of typed ctors, a-la
 // `expr_xxx`.
 pub fn ty(text: &str) -> ast::Type {
-    ast_from_text(&format!("fn f() -> {} {{}}", text))
+    ty_from_text(text)
 }
 pub fn ty_unit() -> ast::Type {
-    ty("()")
+    ty_from_text("()")
 }
 pub fn ty_tuple(types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
     let mut count: usize = 0;
@@ -46,15 +86,16 @@ pub fn ty_tuple(types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
         contents.push(',');
     }
 
-    ty(&format!("({})", contents))
-}
-// FIXME: handle path to type
-pub fn ty_generic(name: ast::NameRef, types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
-    let contents = types.into_iter().join(", ");
-    ty(&format!("{}<{}>", name, contents))
+    ty_from_text(&format!("({})", contents))
 }
 pub fn ty_ref(target: ast::Type, exclusive: bool) -> ast::Type {
-    ty(&if exclusive { format!("&mut {}", target) } else { format!("&{}", target) })
+    ty_from_text(&if exclusive { format!("&mut {}", target) } else { format!("&{}", target) })
+}
+pub fn ty_path(path: ast::Path) -> ast::Type {
+    ty_from_text(&path.to_string())
+}
+fn ty_from_text(text: &str) -> ast::Type {
+    ast_from_text(&format!("type _T = {};", text))
 }
 
 pub fn assoc_item_list() -> ast::AssocItemList {
@@ -88,7 +129,7 @@ pub fn path_unqualified(segment: ast::PathSegment) -> ast::Path {
 pub fn path_qualified(qual: ast::Path, segment: ast::PathSegment) -> ast::Path {
     ast_from_text(&format!("{}::{}", qual, segment))
 }
-
+// FIXME: path concatenation operation doesn't make sense as AST op.
 pub fn path_concat(first: ast::Path, second: ast::Path) -> ast::Path {
     ast_from_text(&format!("{}::{}", first, second))
 }
@@ -104,15 +145,14 @@ pub fn path_from_segments(
         format!("use {};", segments)
     })
 }
-
+// FIXME: should not be pub
 pub fn path_from_text(text: &str) -> ast::Path {
     ast_from_text(&format!("fn main() {{ let test = {}; }}", text))
 }
 
-pub fn glob_use_tree() -> ast::UseTree {
+pub fn use_tree_glob() -> ast::UseTree {
     ast_from_text("use *;")
 }
-
 pub fn use_tree(
     path: ast::Path,
     use_tree_list: Option<ast::UseTreeList>,
@@ -207,15 +247,6 @@ pub fn expr_literal(text: &str) -> ast::Literal {
 pub fn expr_empty_block() -> ast::Expr {
     expr_from_text("{}")
 }
-pub fn expr_unimplemented() -> ast::Expr {
-    expr_from_text("unimplemented!()")
-}
-pub fn expr_unreachable() -> ast::Expr {
-    expr_from_text("unreachable!()")
-}
-pub fn expr_todo() -> ast::Expr {
-    expr_from_text("todo!()")
-}
 pub fn expr_path(path: ast::Path) -> ast::Expr {
     expr_from_text(&path.to_string())
 }
@@ -444,17 +475,6 @@ pub fn expr_stmt(expr: ast::Expr) -> ast::ExprStmt {
     ast_from_text(&format!("fn f() {{ {}{} (); }}", expr, semi))
 }
 
-pub fn token(kind: SyntaxKind) -> SyntaxToken {
-    tokens::SOURCE_FILE
-        .tree()
-        .syntax()
-        .clone_for_update()
-        .descendants_with_tokens()
-        .filter_map(|it| it.into_token())
-        .find(|it| it.kind() == kind)
-        .unwrap_or_else(|| panic!("unhandled token: {:?}", kind))
-}
-
 pub fn param(pat: ast::Pat, ty: ast::Type) -> ast::Param {
     ast_from_text(&format!("fn f({}: {}) {{ }}", pat, ty))
 }
@@ -476,7 +496,7 @@ pub fn param_list(
     ast_from_text(&list)
 }
 
-pub fn generic_param(name: String, ty: Option<ast::TypeBoundList>) -> ast::GenericParam {
+pub fn type_param(name: ast::Name, ty: Option<ast::TypeBoundList>) -> ast::TypeParam {
     let bound = match ty {
         Some(it) => format!(": {}", it),
         None => String::new(),
@@ -484,6 +504,10 @@ pub fn generic_param(name: String, ty: Option<ast::TypeBoundList>) -> ast::Gener
     ast_from_text(&format!("fn f<{}{}>() {{ }}", name, bound))
 }
 
+pub fn lifetime_param(lifetime: ast::Lifetime) -> ast::LifetimeParam {
+    ast_from_text(&format!("fn f<{}>() {{ }}", lifetime))
+}
+
 pub fn generic_param_list(
     pats: impl IntoIterator<Item = ast::GenericParam>,
 ) -> ast::GenericParamList {
@@ -588,6 +612,17 @@ fn unroot(n: SyntaxNode) -> SyntaxNode {
     SyntaxNode::new_root(n.green().into())
 }
 
+pub fn token(kind: SyntaxKind) -> SyntaxToken {
+    tokens::SOURCE_FILE
+        .tree()
+        .syntax()
+        .clone_for_update()
+        .descendants_with_tokens()
+        .filter_map(|it| it.into_token())
+        .find(|it| it.kind() == kind)
+        .unwrap_or_else(|| panic!("unhandled token: {:?}", kind))
+}
+
 pub mod tokens {
     use once_cell::sync::Lazy;