20 files changed, 324 insertions, 156 deletions

diff --git a/Cargo.lock b/Cargo.lock
index f50e9edd6..d8838cf2b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -300,7 +300,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dca26ee1f8d361640700bde38b2c37d8c22b3ce2d360e1fc1c74ea4b0aa7d775"
 dependencies = [
  "cfg-if 1.0.0",
- "crossbeam-utils 0.8.0",
+ "crossbeam-utils 0.8.1",
 ]
 
 [[package]]
@@ -311,18 +311,18 @@ checksum = "94af6efb46fef72616855b036a624cf27ba656ffc9be1b9a3c931cfc7749a9a9"
 dependencies = [
  "cfg-if 1.0.0",
  "crossbeam-epoch",
- "crossbeam-utils 0.8.0",
+ "crossbeam-utils 0.8.1",
 ]
 
 [[package]]
 name = "crossbeam-epoch"
-version = "0.9.0"
+version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec0f606a85340376eef0d6d8fec399e6d4a544d648386c6645eb6d0653b27d9f"
+checksum = "a1aaa739f95311c2c7887a76863f500026092fb1dce0161dab577e559ef3569d"
 dependencies = [
  "cfg-if 1.0.0",
  "const_fn",
- "crossbeam-utils 0.8.0",
+ "crossbeam-utils 0.8.1",
  "lazy_static",
  "memoffset",
  "scopeguard",
@@ -341,13 +341,12 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-utils"
-version = "0.8.0"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec91540d98355f690a86367e566ecad2e9e579f230230eb7c21398372be73ea5"
+checksum = "02d96d1e189ef58269ebe5b97953da3274d83a93af647c2ddd6f9dab28cedb8d"
 dependencies = [
  "autocfg",
  "cfg-if 1.0.0",
- "const_fn",
  "lazy_static",
 ]
 
@@ -865,9 +864,9 @@ dependencies = [
 
 [[package]]
 name = "lsp-types"
-version = "0.84.0"
+version = "0.85.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b95be71fe205e44de754185bcf86447b65813ce1ceb298f8d3793ade5fff08d"
+checksum = "857650f3e83fb62f89d15410414e0ed7d0735445020da398d37f65d20a5423b9"
 dependencies = [
  "base64",
  "bitflags",
@@ -929,9 +928,9 @@ dependencies = [
 
 [[package]]
 name = "memoffset"
-version = "0.5.6"
+version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "043175f069eda7b85febe4a74abbaeff828d9f8b448515d3151a14a3542811aa"
+checksum = "157b4208e3059a8f9e78d559edc658e13df41410cb3ae03979c83130067fdd87"
 dependencies = [
  "autocfg",
 ]
@@ -988,9 +987,9 @@ dependencies = [
 
 [[package]]
 name = "miow"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
+checksum = "ebd808424166322d4a38da87083bfddd3ac4c131334ed55856112eb06d46944d"
 dependencies = [
  "kernel32-sys",
  "net2",
@@ -1000,9 +999,9 @@ dependencies = [
 
 [[package]]
 name = "net2"
-version = "0.2.35"
+version = "0.2.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3ebc3ec692ed7c9a255596c67808dee269f64655d8baf7b4f0638e51ba1d6853"
+checksum = "d7cf75f38f16cb05ea017784dc6dbfd354f76c223dba37701734c4f5a9337d02"
 dependencies = [
  "cfg-if 0.1.10",
  "libc",
@@ -1298,7 +1297,7 @@ checksum = "9ab346ac5921dc62ffa9f89b7a773907511cdfa5490c572ae9be1be33e8afa4a"
 dependencies = [
  "crossbeam-channel 0.5.0",
  "crossbeam-deque",
- "crossbeam-utils 0.8.0",
+ "crossbeam-utils 0.8.1",
  "lazy_static",
  "num_cpus",
 ]
@@ -1396,9 +1395,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_lexer"
-version = "688.0.0"
+version = "691.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ebbdcc99bd015349093fcbae4780fda21416fec5d8843acfb3d1733e130cd4db"
+checksum = "44bc89d9ca7a78fb82e103b389362c55f03800745f8ba14e068b805cfaf783ec"
 dependencies = [
  "unicode-xid",
 ]
@@ -1436,7 +1435,7 @@ version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d8fadca2ab5de17acf66d744f4888049ca8f1bb9b8a1ab8afd9d032cc959c5dc"
 dependencies = [
- "crossbeam-utils 0.8.0",
+ "crossbeam-utils 0.8.1",
  "indexmap",
  "lock_api",
  "log",
@@ -1627,9 +1626,9 @@ version = "0.0.0"
 
 [[package]]
 name = "syn"
-version = "1.0.51"
+version = "1.0.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b4f34193997d92804d359ed09953e25d5138df6bcc055a71bf68ee89fdf9223"
+checksum = "8833e20724c24de12bbaba5ad230ea61c3eafb05b881c7c9d3cfe8638b187e68"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1899,9 +1898,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-segmentation"
-version = "1.7.0"
+version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db8716a166f290ff49dabc18b44aa407cb7c6dbe1aa0971b44b8a24b0ca35aae"
+checksum = "bb0d2e7be6ae3a5fa87eed5fb451aff96f2573d2694942e40543ae0bbe19c796"
 
 [[package]]
 name = "unicode-xid"
diff --git a/crates/assists/src/handlers/replace_qualified_name_with_use.rs b/crates/assists/src/handlers/replace_qualified_name_with_use.rs
index 8bdf9eea5..8193e45a8 100644
--- a/crates/assists/src/handlers/replace_qualified_name_with_use.rs
+++ b/crates/assists/src/handlers/replace_qualified_name_with_use.rs
@@ -407,7 +407,7 @@ impl std::fmt::Display<|> for Foo {
 }
 ",
             r"
-use std::fmt::{nested::Debug, Display};
+use std::fmt::{Display, nested::Debug};
 
 impl Display for Foo {
 }
diff --git a/crates/completion/src/completions/postfix.rs b/crates/completion/src/completions/postfix.rs
index 1785794cc..c8ba63cd3 100644
--- a/crates/completion/src/completions/postfix.rs
+++ b/crates/completion/src/completions/postfix.rs
@@ -5,7 +5,7 @@ mod format_like;
 use ide_db::ty_filter::TryEnum;
 use syntax::{
     ast::{self, AstNode, AstToken},
-    SyntaxKind::BLOCK_EXPR,
+    SyntaxKind::{BLOCK_EXPR, EXPR_STMT},
     TextRange, TextSize,
 };
 use text_edit::TextEdit;
@@ -221,9 +221,8 @@ pub(crate) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
     )
     .add_to(acc);
 
-    let parent_node = dot_receiver.syntax().parent().and_then(|p| p.parent());
-    if let Some(parent) = parent_node {
-        if parent.kind() == BLOCK_EXPR {
+    if let Some(parent) = dot_receiver.syntax().parent().and_then(|p| p.parent()) {
+        if matches!(parent.kind(), BLOCK_EXPR | EXPR_STMT) {
             postfix_snippet(
                 ctx,
                 cap,
@@ -390,6 +389,34 @@ fn main() {
     }
 
     #[test]
+    fn let_middle_block() {
+        check(
+            r#"
+fn main() {
+    baz.l<|>
+    res
+}
+"#,
+            expect![[r#"
+                sn box   Box::new(expr)
+                sn call  function(expr)
+                sn dbg   dbg!(expr)
+                sn dbgr  dbg!(&expr)
+                sn if    if expr {}
+                sn let   let
+                sn letm  let mut
+                sn match match expr {}
+                sn not   !expr
+                sn ok    Ok(expr)
+                sn ref   &expr
+                sn refm  &mut expr
+                sn some  Some(expr)
+                sn while while expr {}
+            "#]],
+        );
+    }
+
+    #[test]
     fn option_iflet() {
         check_edit(
             "ifl",
diff --git a/crates/completion/src/completions/qualified_path.rs b/crates/completion/src/completions/qualified_path.rs
index d9387054d..bc23bea3f 100644
--- a/crates/completion/src/completions/qualified_path.rs
+++ b/crates/completion/src/completions/qualified_path.rs
@@ -353,10 +353,10 @@ impl S {
 fn foo() { let _ = S::<|> }
 "#,
             expect![[r#"
-                ct C   const C: i32 = 42;
-                ta T   type T = i32;
-                fn a() fn a()
-                me b() fn b(&self)
+                ct C    const C: i32 = 42;
+                ta T    type T = i32;
+                fn a()  fn a()
+                me b(…) fn b(&self)
             "#]],
         );
     }
@@ -503,14 +503,14 @@ trait Sub: Super {
 fn foo<T: Sub>() { T::<|> }
 "#,
             expect![[r#"
-                ct C2          const C2: ();
-                ct CONST       const CONST: u8;
-                ta SubTy       type SubTy;
-                ta Ty          type Ty;
-                fn func()      fn func()
-                me method()    fn method(&self)
-                fn subfunc()   fn subfunc()
-                me submethod() fn submethod(&self)
+                ct C2           const C2: ();
+                ct CONST        const CONST: u8;
+                ta SubTy        type SubTy;
+                ta Ty           type Ty;
+                fn func()       fn func()
+                me method(…)    fn method(&self)
+                fn subfunc()    fn subfunc()
+                me submethod(…) fn submethod(&self)
             "#]],
         );
     }
@@ -543,14 +543,14 @@ impl<T> Sub for Wrap<T> {
 }
 "#,
             expect![[r#"
-                ct C2          const C2: () = ();
-                ct CONST       const CONST: u8 = 0;
-                ta SubTy       type SubTy;
-                ta Ty          type Ty;
-                fn func()      fn func()
-                me method()    fn method(&self)
-                fn subfunc()   fn subfunc()
-                me submethod() fn submethod(&self)
+                ct C2           const C2: () = ();
+                ct CONST        const CONST: u8 = 0;
+                ta SubTy        type SubTy;
+                ta Ty           type Ty;
+                fn func()       fn func()
+                me method(…)    fn method(&self)
+                fn subfunc()    fn subfunc()
+                me submethod(…) fn submethod(&self)
             "#]],
         );
     }
diff --git a/crates/completion/src/completions/trait_impl.rs b/crates/completion/src/completions/trait_impl.rs
index a14be9c73..e2fe44aff 100644
--- a/crates/completion/src/completions/trait_impl.rs
+++ b/crates/completion/src/completions/trait_impl.rs
@@ -139,7 +139,7 @@ fn add_function_impl(
 ) {
     let fn_name = func.name(ctx.db).to_string();
 
-    let label = if func.params(ctx.db).is_empty() {
+    let label = if func.assoc_fn_params(ctx.db).is_empty() {
         format!("fn {}()", fn_name)
     } else {
         format!("fn {}(..)", fn_name)
diff --git a/crates/completion/src/render/builder_ext.rs b/crates/completion/src/render/builder_ext.rs
index 37b0d0459..ce8718bd5 100644
--- a/crates/completion/src/render/builder_ext.rs
+++ b/crates/completion/src/render/builder_ext.rs
@@ -5,6 +5,7 @@ use test_utils::mark;
 
 use crate::{item::Builder, CompletionContext};
 
+#[derive(Debug)]
 pub(super) enum Params {
     Named(Vec<String>),
     Anonymous(usize),
@@ -24,7 +25,7 @@ impl Params {
 }
 
 impl Builder {
-    pub(super) fn should_add_parems(&self, ctx: &CompletionContext) -> bool {
+    fn should_add_parens(&self, ctx: &CompletionContext) -> bool {
         if !ctx.config.add_call_parenthesis {
             return false;
         }
@@ -58,7 +59,7 @@ impl Builder {
         name: String,
         params: Params,
     ) -> Builder {
-        if !self.should_add_parems(ctx) {
+        if !self.should_add_parens(ctx) {
             return self;
         }
 
diff --git a/crates/completion/src/render/function.rs b/crates/completion/src/render/function.rs
index 542383d7e..00e3eb203 100644
--- a/crates/completion/src/render/function.rs
+++ b/crates/completion/src/render/function.rs
@@ -2,6 +2,7 @@
 
 use hir::{HasSource, Type};
 use syntax::{ast::Fn, display::function_declaration};
+use test_utils::mark;
 
 use crate::{
     item::{CompletionItem, CompletionItemKind, CompletionKind, ImportToAdd},
@@ -22,7 +23,7 @@ pub(crate) fn render_fn<'a>(
 struct FunctionRender<'a> {
     ctx: RenderContext<'a>,
     name: String,
-    fn_: hir::Function,
+    func: hir::Function,
     ast_node: Fn,
 }
 
@@ -35,15 +36,15 @@ impl<'a> FunctionRender<'a> {
         let name = local_name.unwrap_or_else(|| fn_.name(ctx.db()).to_string());
         let ast_node = fn_.source(ctx.db()).value;
 
-        FunctionRender { ctx, name, fn_, ast_node }
+        FunctionRender { ctx, name, func: fn_, ast_node }
     }
 
     fn render(self, import_to_add: Option<ImportToAdd>) -> CompletionItem {
         let params = self.params();
         CompletionItem::new(CompletionKind::Reference, self.ctx.source_range(), self.name.clone())
             .kind(self.kind())
-            .set_documentation(self.ctx.docs(self.fn_))
-            .set_deprecated(self.ctx.is_deprecated(self.fn_))
+            .set_documentation(self.ctx.docs(self.func))
+            .set_deprecated(self.ctx.is_deprecated(self.func))
             .detail(self.detail())
             .add_call_parens(self.ctx.completion, self.name, params)
             .add_import(import_to_add)
@@ -67,27 +68,39 @@ impl<'a> FunctionRender<'a> {
     }
 
     fn params(&self) -> Params {
-        let params_ty = self.fn_.params(self.ctx.db());
-        let params = self
-            .ast_node
-            .param_list()
+        let ast_params = match self.ast_node.param_list() {
+            Some(it) => it,
+            None => return Params::Named(Vec::new()),
+        };
+
+        let mut params_pats = Vec::new();
+        let params_ty = if self.ctx.completion.dot_receiver.is_some() {
+            self.func.method_params(self.ctx.db()).unwrap_or_default()
+        } else {
+            if let Some(s) = ast_params.self_param() {
+                mark::hit!(parens_for_method_call_as_assoc_fn);
+                params_pats.push(Some(s.to_string()));
+            }
+            self.func.assoc_fn_params(self.ctx.db())
+        };
+        params_pats
+            .extend(ast_params.params().into_iter().map(|it| it.pat().map(|it| it.to_string())));
+
+        let params = params_pats
             .into_iter()
-            .flat_map(|it| it.params())
             .zip(params_ty)
-            .flat_map(|(it, param_ty)| {
-                if let Some(pat) = it.pat() {
-                    let name = pat.to_string();
-                    let arg = name.trim_start_matches("mut ").trim_start_matches('_');
-                    return Some(self.add_arg(arg, param_ty.ty()));
-                }
-                None
+            .flat_map(|(pat, param_ty)| {
+                let pat = pat?;
+                let name = pat.to_string();
+                let arg = name.trim_start_matches("mut ").trim_start_matches('_');
+                Some(self.add_arg(arg, param_ty.ty()))
             })
             .collect();
         Params::Named(params)
     }
 
     fn kind(&self) -> CompletionItemKind {
-        if self.fn_.self_param(self.ctx.db()).is_some() {
+        if self.func.self_param(self.ctx.db()).is_some() {
             CompletionItemKind::Method
         } else {
             CompletionItemKind::Function
@@ -173,6 +186,28 @@ fn bar(s: &S) {
     }
 
     #[test]
+    fn parens_for_method_call_as_assoc_fn() {
+        mark::check!(parens_for_method_call_as_assoc_fn);
+        check_edit(
+            "foo",
+            r#"
+struct S;
+impl S {
+    fn foo(&self) {}
+}
+fn main() { S::f<|> }
+"#,
+            r#"
+struct S;
+impl S {
+    fn foo(&self) {}
+}
+fn main() { S::foo(${1:&self})$0 }
+"#,
+        );
+    }
+
+    #[test]
     fn suppress_arg_snippets() {
         mark::check!(suppress_arg_snippets);
         check_edit_with_config(
diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index f06b5cd9f..4500050f1 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -744,14 +744,13 @@ impl Function {
         Some(SelfParam { func: self.id })
     }
 
-    pub fn params(self, db: &dyn HirDatabase) -> Vec<Param> {
+    pub fn assoc_fn_params(self, db: &dyn HirDatabase) -> Vec<Param> {
         let resolver = self.id.resolver(db.upcast());
         let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
         let environment = TraitEnvironment::lower(db, &resolver);
         db.function_data(self.id)
             .params
             .iter()
-            .skip(if self.self_param(db).is_some() { 1 } else { 0 })
             .map(|type_ref| {
                 let ty = Type {
                     krate: self.id.lookup(db.upcast()).container.module(db.upcast()).krate,
@@ -764,6 +763,14 @@ impl Function {
             })
             .collect()
     }
+    pub fn method_params(self, db: &dyn HirDatabase) -> Option<Vec<Param>> {
+        if self.self_param(db).is_none() {
+            return None;
+        }
+        let mut res = self.assoc_fn_params(db);
+        res.remove(0);
+        Some(res)
+    }
 
     pub fn is_unsafe(self, db: &dyn HirDatabase) -> bool {
         db.function_data(self.id).is_unsafe
@@ -799,6 +806,7 @@ impl From<Mutability> for Access {
     }
 }
 
+#[derive(Debug)]
 pub struct Param {
     ty: Type,
 }
diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index d10b1af01..33eb5e78c 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -14,8 +14,8 @@ use cfg::CfgOptions;
 use drop_bomb::DropBomb;
 use either::Either;
 use hir_expand::{
-    ast_id_map::AstIdMap, diagnostics::DiagnosticSink, hygiene::Hygiene, AstId, HirFileId, InFile,
-    MacroDefId,
+    ast_id_map::AstIdMap, diagnostics::DiagnosticSink, hygiene::Hygiene, AstId, ExpandResult,
+    HirFileId, InFile, MacroDefId,
 };
 use rustc_hash::FxHashMap;
 use syntax::{ast, AstNode, AstPtr};
@@ -102,11 +102,11 @@ impl Expander {
         db: &dyn DefDatabase,
         local_scope: Option<&ItemScope>,
         macro_call: ast::MacroCall,
-    ) -> Option<(Mark, T)> {
+    ) -> ExpandResult<Option<(Mark, T)>> {
         self.recursion_limit += 1;
         if self.recursion_limit > EXPANSION_RECURSION_LIMIT {
             mark::hit!(your_stack_belongs_to_me);
-            return None;
+            return ExpandResult::str_err("reached recursion limit during macro expansion".into());
         }
 
         let macro_call = InFile::new(self.current_file_id, &macro_call);
@@ -120,28 +120,55 @@ impl Expander {
             self.resolve_path_as_macro(db, &path)
         };
 
-        if let Some(call_id) = macro_call.as_call_id(db, self.crate_def_map.krate, resolver) {
-            let file_id = call_id.as_file();
-            if let Some(node) = db.parse_or_expand(file_id) {
-                if let Some(expr) = T::cast(node) {
-                    log::debug!("macro expansion {:#?}", expr.syntax());
-
-                    let mark = Mark {
-                        file_id: self.current_file_id,
-                        ast_id_map: mem::take(&mut self.ast_id_map),
-                        bomb: DropBomb::new("expansion mark dropped"),
-                    };
-                    self.cfg_expander.hygiene = Hygiene::new(db.upcast(), file_id);
-                    self.current_file_id = file_id;
-                    self.ast_id_map = db.ast_id_map(file_id);
-                    return Some((mark, expr));
+        let call_id = match macro_call.as_call_id(db, self.crate_def_map.krate, resolver) {
+            Some(it) => it,
+            None => {
+                // FIXME: this can mean other things too, but `as_call_id` doesn't provide enough
+                // info.
+                return ExpandResult::only_err(mbe::ExpandError::Other(
+                    "failed to parse or resolve macro invocation".into(),
+                ));
+            }
+        };
+
+        let err = db.macro_expand_error(call_id);
+
+        let file_id = call_id.as_file();
+
+        let raw_node = match db.parse_or_expand(file_id) {
+            Some(it) => it,
+            None => {
+                // Only `None` if the macro expansion produced no usable AST.
+                if err.is_none() {
+                    log::warn!("no error despite `parse_or_expand` failing");
                 }
+
+                return ExpandResult::only_err(err.unwrap_or_else(|| {
+                    mbe::ExpandError::Other("failed to parse macro invocation".into())
+                }));
             }
-        }
+        };
+
+        let node = match T::cast(raw_node) {
+            Some(it) => it,
+            None => {
+                // This can happen without being an error, so only forward previous errors.
+                return ExpandResult { value: None, err };
+            }
+        };
+
+        log::debug!("macro expansion {:#?}", node.syntax());
+
+        let mark = Mark {
+            file_id: self.current_file_id,
+            ast_id_map: mem::take(&mut self.ast_id_map),
+            bomb: DropBomb::new("expansion mark dropped"),
+        };
+        self.cfg_expander.hygiene = Hygiene::new(db.upcast(), file_id);
+        self.current_file_id = file_id;
+        self.ast_id_map = db.ast_id_map(file_id);
 
-        // FIXME: Instead of just dropping the error from expansion
-        // report it
-        None
+        ExpandResult { value: Some((mark, node)), err }
     }
 
     pub(crate) fn exit(&mut self, db: &dyn DefDatabase, mut mark: Mark) {
diff --git a/crates/hir_def/src/body/diagnostics.rs b/crates/hir_def/src/body/diagnostics.rs
index e57bdc133..1de7d30e2 100644
--- a/crates/hir_def/src/body/diagnostics.rs
+++ b/crates/hir_def/src/body/diagnostics.rs
@@ -2,11 +2,13 @@
 
 use hir_expand::diagnostics::DiagnosticSink;
 
-use crate::diagnostics::InactiveCode;
+use crate::diagnostics::{InactiveCode, MacroError, UnresolvedProcMacro};
 
 #[derive(Debug, Eq, PartialEq)]
 pub(crate) enum BodyDiagnostic {
     InactiveCode(InactiveCode),
+    MacroError(MacroError),
+    UnresolvedProcMacro(UnresolvedProcMacro),
 }
 
 impl BodyDiagnostic {
@@ -15,6 +17,12 @@ impl BodyDiagnostic {
             BodyDiagnostic::InactiveCode(diag) => {
                 sink.push(diag.clone());
             }
+            BodyDiagnostic::MacroError(diag) => {
+                sink.push(diag.clone());
+            }
+            BodyDiagnostic::UnresolvedProcMacro(diag) => {
+                sink.push(diag.clone());
+            }
         }
     }
 }
diff --git a/crates/hir_def/src/body/lower.rs b/crates/hir_def/src/body/lower.rs
index cd7958746..2c41c0005 100644
--- a/crates/hir_def/src/body/lower.rs
+++ b/crates/hir_def/src/body/lower.rs
@@ -8,7 +8,7 @@ use either::Either;
 use hir_expand::{
     hygiene::Hygiene,
     name::{name, AsName, Name},
-    HirFileId, MacroDefId, MacroDefKind,
+    ExpandError, HirFileId, MacroDefId, MacroDefKind,
 };
 use rustc_hash::FxHashMap;
 use syntax::{
@@ -25,7 +25,7 @@ use crate::{
     body::{Body, BodySourceMap, Expander, PatPtr, SyntheticSyntax},
     builtin_type::{BuiltinFloat, BuiltinInt},
     db::DefDatabase,
-    diagnostics::InactiveCode,
+    diagnostics::{InactiveCode, MacroError, UnresolvedProcMacro},
     expr::{
         dummy_expr_id, ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Literal,
         LogicOp, MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField, Statement,
@@ -561,7 +561,32 @@ impl ExprCollector<'_> {
                     self.alloc_expr(Expr::Missing, syntax_ptr)
                 } else {
                     let macro_call = self.expander.to_source(AstPtr::new(&e));
-                    match self.expander.enter_expand(self.db, Some(&self.body.item_scope), e) {
+                    let res = self.expander.enter_expand(self.db, Some(&self.body.item_scope), e);
+
+                    match res.err {
+                        Some(ExpandError::UnresolvedProcMacro) => {
+                            self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro(
+                                UnresolvedProcMacro {
+                                    file: self.expander.current_file_id,
+                                    node: syntax_ptr.clone().into(),
+                                    precise_location: None,
+                                    macro_name: None,
+                                },
+                            ));
+                        }
+                        Some(err) => {
+                            self.source_map.diagnostics.push(BodyDiagnostic::MacroError(
+                                MacroError {
+                                    file: self.expander.current_file_id,
+                                    node: syntax_ptr.clone().into(),
+                                    message: err.to_string(),
+                                },
+                            ));
+                        }
+                        None => {}
+                    }
+
+                    match res.value {
                         Some((mark, expansion)) => {
                             self.source_map
                                 .expansions
diff --git a/crates/hir_def/src/data.rs b/crates/hir_def/src/data.rs
index ff1ef0df6..146045938 100644
--- a/crates/hir_def/src/data.rs
+++ b/crates/hir_def/src/data.rs
@@ -257,7 +257,7 @@ fn collect_items(
                 let root = db.parse_or_expand(file_id).unwrap();
                 let call = ast_id_map.get(call.ast_id).to_node(&root);
 
-                if let Some((mark, mac)) = expander.enter_expand(db, None, call) {
+                if let Some((mark, mac)) = expander.enter_expand(db, None, call).value {
                     let src: InFile<ast::MacroItems> = expander.to_source(mac);
                     let item_tree = db.item_tree(src.file_id);
                     let iter =
diff --git a/crates/hir_expand/src/builtin_macro.rs b/crates/hir_expand/src/builtin_macro.rs
index aebbfc4df..7f4db106d 100644
--- a/crates/hir_expand/src/builtin_macro.rs
+++ b/crates/hir_expand/src/builtin_macro.rs
@@ -6,7 +6,7 @@ use crate::{
 
 use base_db::FileId;
 use either::Either;
-use mbe::parse_to_token_tree;
+use mbe::{parse_to_token_tree, ExpandResult};
 use parser::FragmentKind;
 use syntax::ast::{self, AstToken};
 
@@ -28,7 +28,7 @@ macro_rules! register_builtin {
                 db: &dyn AstDatabase,
                 id: LazyMacroId,
                 tt: &tt::Subtree,
-            ) -> Result<tt::Subtree, mbe::ExpandError> {
+            ) -> ExpandResult<tt::Subtree> {
                 let expander = match *self {
                     $( BuiltinFnLikeExpander::$kind => $expand, )*
                 };
@@ -42,7 +42,7 @@ macro_rules! register_builtin {
                 db: &dyn AstDatabase,
                 arg_id: EagerMacroId,
                 tt: &tt::Subtree,
-            ) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
+            ) -> ExpandResult<Option<(tt::Subtree, FragmentKind)>> {
                 let expander = match *self {
                     $( EagerExpander::$e_kind => $e_expand, )*
                 };
@@ -109,25 +109,28 @@ fn line_expand(
     _db: &dyn AstDatabase,
     _id: LazyMacroId,
     _tt: &tt::Subtree,
-) -> Result<tt::Subtree, mbe::ExpandError> {
+) -> ExpandResult<tt::Subtree> {
     // dummy implementation for type-checking purposes
     let line_num = 0;
     let expanded = quote! {
         #line_num
     };
 
-    Ok(expanded)
+    ExpandResult::ok(expanded)
 }
 
 fn stringify_expand(
     db: &dyn AstDatabase,
     id: LazyMacroId,
     _tt: &tt::Subtree,
-) -> Result<tt::Subtree, mbe::ExpandError> {
+) -> ExpandResult<tt::Subtree> {
     let loc = db.lookup_intern_macro(id);
 
     let macro_content = {
-        let arg = loc.kind.arg(db).ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
+        let arg = match loc.kind.arg(db) {
+            Some(arg) => arg,
+            None => return ExpandResult::only_err(mbe::ExpandError::UnexpectedToken),
+        };
         let macro_args = arg;
         let text = macro_args.text();
         let without_parens = TextSize::of('(')..text.len() - TextSize::of(')');
@@ -138,28 +141,28 @@ fn stringify_expand(
         #macro_content
     };
 
-    Ok(expanded)
+    ExpandResult::ok(expanded)
 }
 
 fn column_expand(
     _db: &dyn AstDatabase,
     _id: LazyMacroId,
     _tt: &tt::Subtree,
-) -> Result<tt::Subtree, mbe::ExpandError> {
+) -> ExpandResult<tt::Subtree> {
     // dummy implementation for type-checking purposes
     let col_num = 0;
     let expanded = quote! {
         #col_num
     };
 
-    Ok(expanded)
+    ExpandResult::ok(expanded)
 }
 
 fn assert_expand(
     _db: &dyn AstDatabase,
     _id: LazyMacroId,
     tt: &tt::Subtree,
-) -> Result<tt::Subtree, mbe::ExpandError> {
+) -> ExpandResult<tt::Subtree> {
     // A hacky implementation for goto def and hover
     // We expand `assert!(cond, arg1, arg2)` to
     // ```
@@ -191,14 +194,14 @@ fn assert_expand(
     let expanded = quote! {
         { { (##arg_tts); } }
     };
-    Ok(expanded)
+    ExpandResult::ok(expanded)
 }
 
 fn file_expand(
     _db: &dyn AstDatabase,
     _id: LazyMacroId,
     _tt: &tt::Subtree,
-) -> Result<tt::Subtree, mbe::ExpandError> {
+) -> ExpandResult<tt::Subtree> {
     // FIXME: RA purposefully lacks knowledge of absolute file names
     // so just return "".
     let file_name = "";
@@ -207,31 +210,33 @@ fn file_expand(
         #file_name
     };
 
-    Ok(expanded)
+    ExpandResult::ok(expanded)
 }
 
 fn compile_error_expand(
     _db: &dyn AstDatabase,
     _id: LazyMacroId,
     tt: &tt::Subtree,
-) -> Result<tt::Subtree, mbe::ExpandError> {
+) -> ExpandResult<tt::Subtree> {
     if tt.count() == 1 {
         if let tt::TokenTree::Leaf(tt::Leaf::Literal(it)) = &tt.token_trees[0] {
             let s = it.text.as_str();
             if s.contains('"') {
-                return Ok(quote! { loop { #it }});
+                return ExpandResult::ok(quote! { loop { #it }});
             }
         };
     }
 
-    Err(mbe::ExpandError::BindingError("Must be a string".into()))
+    ExpandResult::only_err(mbe::ExpandError::BindingError(
+        "`compile_error!` argument be a string".into(),
+    ))
 }
 
 fn format_args_expand(
     _db: &dyn AstDatabase,
     _id: LazyMacroId,
     tt: &tt::Subtree,
-) -> Result<tt::Subtree, mbe::ExpandError> {
+) -> ExpandResult<tt::Subtree> {
     // We expand `format_args!("", a1, a2)` to
     // ```
     // std::fmt::Arguments::new_v1(&[], &[
@@ -257,7 +262,7 @@ fn format_args_expand(
         args.push(current);
     }
     if args.is_empty() {
-        return Err(mbe::ExpandError::NoMatchingRule);
+        return ExpandResult::only_err(mbe::ExpandError::NoMatchingRule);
     }
     let _format_string = args.remove(0);
     let arg_tts = args.into_iter().flat_map(|arg| {
@@ -266,7 +271,7 @@ fn format_args_expand(
     let expanded = quote! {
         std::fmt::Arguments::new_v1(&[], &[##arg_tts])
     };
-    Ok(expanded)
+    ExpandResult::ok(expanded)
 }
 
 fn unquote_str(lit: &tt::Literal) -> Option<String> {
@@ -279,19 +284,24 @@ fn concat_expand(
     _db: &dyn AstDatabase,
     _arg_id: EagerMacroId,
     tt: &tt::Subtree,
-) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
+) -> ExpandResult<Option<(tt::Subtree, FragmentKind)>> {
     let mut text = String::new();
     for (i, t) in tt.token_trees.iter().enumerate() {
         match t {
             tt::TokenTree::Leaf(tt::Leaf::Literal(it)) if i % 2 == 0 => {
-                text += &unquote_str(&it).ok_or_else(|| mbe::ExpandError::ConversionError)?;
+                text += &match unquote_str(&it) {
+                    Some(s) => s,
+                    None => {
+                        return ExpandResult::only_err(mbe::ExpandError::ConversionError);
+                    }
+                };
             }
             tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if i % 2 == 1 && punct.char == ',' => (),
-            _ => return Err(mbe::ExpandError::UnexpectedToken),
+            _ => return ExpandResult::only_err(mbe::ExpandError::UnexpectedToken),
         }
     }
 
-    Ok((quote!(#text), FragmentKind::Expr))
+    ExpandResult::ok(Some((quote!(#text), FragmentKind::Expr)))
 }
 
 fn relative_file(
@@ -324,26 +334,35 @@ fn include_expand(
     db: &dyn AstDatabase,
     arg_id: EagerMacroId,
     tt: &tt::Subtree,
-) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
-    let path = parse_string(tt)?;
-    let file_id = relative_file(db, arg_id.into(), &path, false)
-        .ok_or_else(|| mbe::ExpandError::ConversionError)?;
-
-    // FIXME:
-    // Handle include as expression
-    let res = parse_to_token_tree(&db.file_text(file_id))
-        .ok_or_else(|| mbe::ExpandError::ConversionError)?
-        .0;
-
-    Ok((res, FragmentKind::Items))
+) -> ExpandResult<Option<(tt::Subtree, FragmentKind)>> {
+    let res = (|| {
+        let path = parse_string(tt)?;
+        let file_id = relative_file(db, arg_id.into(), &path, false)
+            .ok_or_else(|| mbe::ExpandError::ConversionError)?;
+
+        Ok(parse_to_token_tree(&db.file_text(file_id))
+            .ok_or_else(|| mbe::ExpandError::ConversionError)?
+            .0)
+    })();
+
+    match res {
+        Ok(res) => {
+            // FIXME:
+            // Handle include as expression
+            ExpandResult::ok(Some((res, FragmentKind::Items)))
+        }
+        Err(e) => ExpandResult::only_err(e),
+    }
 }
 
 fn include_bytes_expand(
     _db: &dyn AstDatabase,
     _arg_id: EagerMacroId,
     tt: &tt::Subtree,
-) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
-    let _path = parse_string(tt)?;
+) -> ExpandResult<Option<(tt::Subtree, FragmentKind)>> {
+    if let Err(e) = parse_string(tt) {
+        return ExpandResult::only_err(e);
+    }
 
     // FIXME: actually read the file here if the user asked for macro expansion
     let res = tt::Subtree {
@@ -353,15 +372,18 @@ fn include_bytes_expand(
             id: tt::TokenId::unspecified(),
         }))],
     };
-    Ok((res, FragmentKind::Expr))
+    ExpandResult::ok(Some((res, FragmentKind::Expr)))
 }
 
 fn include_str_expand(
     db: &dyn AstDatabase,
     arg_id: EagerMacroId,
     tt: &tt::Subtree,
-) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
-    let path = parse_string(tt)?;
+) -> ExpandResult<Option<(tt::Subtree, FragmentKind)>> {
+    let path = match parse_string(tt) {
+        Ok(it) => it,
+        Err(e) => return ExpandResult::only_err(e),
+    };
 
     // FIXME: we're not able to read excluded files (which is most of them because
     // it's unusual to `include_str!` a Rust file), but we can return an empty string.
@@ -370,14 +392,14 @@ fn include_str_expand(
     let file_id = match relative_file(db, arg_id.into(), &path, true) {
         Some(file_id) => file_id,
         None => {
-            return Ok((quote!(""), FragmentKind::Expr));
+            return ExpandResult::ok(Some((quote!(""), FragmentKind::Expr)));
         }
     };
 
     let text = db.file_text(file_id);
     let text = &*text;
 
-    Ok((quote!(#text), FragmentKind::Expr))
+    ExpandResult::ok(Some((quote!(#text), FragmentKind::Expr)))
 }
 
 fn get_env_inner(db: &dyn AstDatabase, arg_id: EagerMacroId, key: &str) -> Option<String> {
@@ -389,8 +411,11 @@ fn env_expand(
     db: &dyn AstDatabase,
     arg_id: EagerMacroId,
     tt: &tt::Subtree,
-) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
-    let key = parse_string(tt)?;
+) -> ExpandResult<Option<(tt::Subtree, FragmentKind)>> {
+    let key = match parse_string(tt) {
+        Ok(it) => it,
+        Err(e) => return ExpandResult::only_err(e),
+    };
 
     // FIXME:
     // If the environment variable is not defined int rustc, then a compilation error will be emitted.
@@ -402,21 +427,25 @@ fn env_expand(
     let s = get_env_inner(db, arg_id, &key).unwrap_or_else(|| "__RA_UNIMPLEMENTED__".to_string());
     let expanded = quote! { #s };
 
-    Ok((expanded, FragmentKind::Expr))
+    ExpandResult::ok(Some((expanded, FragmentKind::Expr)))
 }
 
 fn option_env_expand(
     db: &dyn AstDatabase,
     arg_id: EagerMacroId,
     tt: &tt::Subtree,
-) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
-    let key = parse_string(tt)?;
+) -> ExpandResult<Option<(tt::Subtree, FragmentKind)>> {
+    let key = match parse_string(tt) {
+        Ok(it) => it,
+        Err(e) => return ExpandResult::only_err(e),
+    };
+
     let expanded = match get_env_inner(db, arg_id, &key) {
         None => quote! { std::option::Option::None::<&str> },
         Some(s) => quote! { std::option::Some(#s) },
     };
 
-    Ok((expanded, FragmentKind::Expr))
+    ExpandResult::ok(Some((expanded, FragmentKind::Expr)))
 }
 
 #[cfg(test)]
@@ -485,7 +514,7 @@ mod tests {
                     }
                 });
 
-                let (subtree, fragment) = expander.expand(&db, arg_id, &parsed_args).unwrap();
+                let (subtree, fragment) = expander.expand(&db, arg_id, &parsed_args).value.unwrap();
                 let eager = EagerCallLoc {
                     def,
                     fragment,
diff --git a/crates/hir_expand/src/db.rs b/crates/hir_expand/src/db.rs
index ff50bfd82..4fd0ba290 100644
--- a/crates/hir_expand/src/db.rs
+++ b/crates/hir_expand/src/db.rs
@@ -30,8 +30,8 @@ impl TokenExpander {
     ) -> mbe::ExpandResult<tt::Subtree> {
         match self {
             TokenExpander::MacroRules(it) => it.expand(tt),
+            TokenExpander::Builtin(it) => it.expand(db, id, tt),
             // FIXME switch these to ExpandResult as well
-            TokenExpander::Builtin(it) => it.expand(db, id, tt).into(),
             TokenExpander::BuiltinDerive(it) => it.expand(db, id, tt).into(),
             TokenExpander::ProcMacro(_) => {
                 // We store the result in salsa db to prevent non-determinisc behavior in
diff --git a/crates/hir_expand/src/eager.rs b/crates/hir_expand/src/eager.rs
index 2f37d7189..ab6b4477c 100644
--- a/crates/hir_expand/src/eager.rs
+++ b/crates/hir_expand/src/eager.rs
@@ -65,7 +65,7 @@ pub fn expand_eager_macro(
     let subtree = to_subtree(&result)?;
 
     if let MacroDefKind::BuiltInEager(eager) = def.kind {
-        let (subtree, fragment) = eager.expand(db, arg_id, &subtree).ok()?;
+        let (subtree, fragment) = eager.expand(db, arg_id, &subtree).value?;
         let eager = EagerCallLoc {
             def,
             fragment,
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index 731457696..64fe8bd65 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -241,7 +241,7 @@ fn rename_to_self(
         return Err(RenameError("Method already has a self parameter".to_string()));
     }
 
-    let params = fn_def.params(sema.db);
+    let params = fn_def.assoc_fn_params(sema.db);
     let first_param =
         params.first().ok_or_else(|| RenameError("Method has no parameters".into()))?;
     let first_param_ty = first_param.ty();
diff --git a/crates/ide_db/src/helpers/insert_use.rs b/crates/ide_db/src/helpers/insert_use.rs
index 67e800fad..08d246c16 100644
--- a/crates/ide_db/src/helpers/insert_use.rs
+++ b/crates/ide_db/src/helpers/insert_use.rs
@@ -384,7 +384,7 @@ fn path_cmp_for_sort(a: Option<ast::Path>, b: Option<ast::Path>) -> Ordering {
 
 /// Path comparison func for binary searching for merging.
 fn path_cmp_bin_search(lhs: Option<ast::Path>, rhs: Option<ast::Path>) -> Ordering {
-    match (lhs.and_then(|path| path.segment()), rhs.and_then(|path| path.segment())) {
+    match (lhs.as_ref().and_then(first_segment), rhs.as_ref().and_then(first_segment)) {
         (None, None) => Ordering::Equal,
         (None, Some(_)) => Ordering::Less,
         (Some(_), None) => Ordering::Greater,
@@ -1082,6 +1082,15 @@ use std::io;",
     }
 
     #[test]
+    fn merge_nested_considers_first_segments() {
+        check_full(
+            "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};",
+        );
+    }
+
+    #[test]
     fn skip_merge_last_too_long() {
         check_last(
             "foo::bar",
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 08559b53a..0a055b039 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -21,7 +21,7 @@ env_logger = { version = "0.8.1", default-features = false }
 itertools = "0.9.0"
 jod-thread = "0.1.0"
 log = "0.4.8"
-lsp-types = { version = "0.84.0", features = ["proposed"] }
+lsp-types = { version = "0.85.0", features = ["proposed"] }
 parking_lot = "0.11.0"
 pico-args = "0.3.1"
 oorandom = "11.1.2"
diff --git a/crates/rust-analyzer/src/semantic_tokens.rs b/crates/rust-analyzer/src/semantic_tokens.rs
index e7991fd28..1daad1c98 100644
--- a/crates/rust-analyzer/src/semantic_tokens.rs
+++ b/crates/rust-analyzer/src/semantic_tokens.rs
@@ -27,7 +27,7 @@ macro_rules! define_semantic_token_types {
             SemanticTokenType::ENUM_MEMBER,
             SemanticTokenType::TYPE_PARAMETER,
             SemanticTokenType::FUNCTION,
-            SemanticTokenType::MEMBER,
+            SemanticTokenType::METHOD,
             SemanticTokenType::PROPERTY,
             SemanticTokenType::MACRO,
             SemanticTokenType::VARIABLE,
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index ce62babc3..c6a6f11e1 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 [dependencies]
 itertools = "0.9.0"
 rowan = "0.10.0"
-rustc_lexer = { version = "688.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "691.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 arrayvec = "0.5.1"
 once_cell = "1.3.1"