56 files changed, 1031 insertions, 392 deletions
diff --git a/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs b/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs
index 864373aa5..0621487e8 100644
--- a/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs
+++ b/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs
@@ -98,7 +98,7 @@ fn already_has_from_impl(
    };
    let var_ty = hir_enum_var.fields(sema.db)[0].signature_ty(sema.db);
-    e_ty.impls_trait(sema.db, from_trait, &[var_ty.clone()])
+    e_ty.impls_trait(sema.db, from_trait, &[var_ty])
 }
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/introduce_variable.rs b/crates/ra_assists/src/handlers/introduce_variable.rs
index 8d0f7e922..8c09e6bcd 100644
--- a/crates/ra_assists/src/handlers/introduce_variable.rs
+++ b/crates/ra_assists/src/handlers/introduce_variable.rs
@@ -124,7 +124,7 @@ fn anchor_stmt(expr: ast::Expr) -> Option<(SyntaxNode, bool)> {
            }
        }
-        if ast::Stmt::cast(node.clone().into()).is_some() {
+        if ast::Stmt::cast(node.clone()).is_some() {
            return Some((node, false));
        }
diff --git a/crates/ra_assists/src/handlers/merge_imports.rs b/crates/ra_assists/src/handlers/merge_imports.rs
index ef0ce0586..4be1238f1 100644
--- a/crates/ra_assists/src/handlers/merge_imports.rs
+++ b/crates/ra_assists/src/handlers/merge_imports.rs
@@ -30,7 +30,7 @@ pub(crate) fn merge_imports(ctx: AssistCtx) -> Option<Assist> {
            .filter_map(|dir| neighbor(&use_item, dir))
            .filter_map(|it| Some((it.clone(), it.use_tree()?)))
            .find_map(|(use_item, use_tree)| {
-                Some((try_merge_trees(&tree, &use_tree)?, use_item.clone()))
+                Some((try_merge_trees(&tree, &use_tree)?, use_item))
            })?;
        rewriter.replace_ast(&tree, &merged);
diff --git a/crates/ra_assists/src/handlers/split_import.rs b/crates/ra_assists/src/handlers/split_import.rs
index d9244f22d..f25826796 100644
--- a/crates/ra_assists/src/handlers/split_import.rs
+++ b/crates/ra_assists/src/handlers/split_import.rs
@@ -37,7 +37,7 @@ pub(crate) fn split_import(ctx: AssistCtx) -> Option<Assist> {
 #[cfg(test)]
 mod tests {
-    use crate::helpers::{check_assist, check_assist_target};
+    use crate::helpers::{check_assist, check_assist_not_applicable, check_assist_target};
    use super::*;
@@ -63,4 +63,9 @@ mod tests {
    fn split_import_target() {
        check_assist_target(split_import, "use crate::<|>db::{RootDatabase, FileSymbol}", "::");
    }
+    #[test]
+    fn issue4044() {
+        check_assist_not_applicable(split_import, "use crate::<|>:::self;")
+    }
 }
diff --git a/crates/ra_db/src/fixture.rs b/crates/ra_db/src/fixture.rs
index 7777ce81e..8248684ee 100644
--- a/crates/ra_db/src/fixture.rs
+++ b/crates/ra_db/src/fixture.rs
@@ -235,7 +235,7 @@ fn parse_meta(meta: &str) -> ParsedMeta {
            "env" => {
                for key in value.split(',') {
                    if let Some((k, v)) = split1(key, '=') {
-                        env.set(k.into(), v.into());
+                        env.set(k, v.into());
                    }
                }
            }
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index 5ddce98c6..ab14e2d5e 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -327,7 +327,7 @@ impl ExternSource {
        self.extern_paths.iter().find_map(|(root_path, id)| {
            if let Ok(rel_path) = path.strip_prefix(root_path) {
                let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
-                Some((id.clone(), rel_path))
+                Some((*id, rel_path))
            } else {
                None
            }
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 3801fce23..6e0d89466 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -759,6 +759,17 @@ impl MacroDef {
    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
        self.source(db).value.name().map(|it| it.as_name())
    }
+    /// Indicate it is a proc-macro
+    pub fn is_proc_macro(&self) -> bool {
+        match self.id.kind {
+            hir_expand::MacroDefKind::Declarative => false,
+            hir_expand::MacroDefKind::BuiltIn(_) => false,
+            hir_expand::MacroDefKind::BuiltInDerive(_) => false,
+            hir_expand::MacroDefKind::BuiltInEager(_) => false,
+            hir_expand::MacroDefKind::CustomDerive(_) => true,
+        }
+    }
 }
 /// Invariant: `inner.as_assoc_item(db).is_some()`
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 0b477f0e9..5d6edc45c 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -195,6 +195,10 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
        self.analyze(field.syntax()).resolve_record_field(self.db, field)
    }
+    pub fn resolve_record_field_pat(&self, field: &ast::RecordFieldPat) -> Option<StructField> {
+        self.analyze(field.syntax()).resolve_record_field_pat(self.db, field)
+    }
    pub fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<MacroDef> {
        let sa = self.analyze(macro_call.syntax());
        let macro_call = self.find_file(macro_call.syntax().clone()).with_value(macro_call);
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index 23af400b8..0ed6d0958 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -95,6 +95,7 @@ impl SourceAnalyzer {
    }
    fn pat_id(&self, pat: &ast::Pat) -> Option<PatId> {
+        // FIXME: macros, see `expr_id`
        let src = InFile { file_id: self.file_id, value: pat };
        self.body_source_map.as_ref()?.node_pat(src)
    }
@@ -167,6 +168,16 @@ impl SourceAnalyzer {
        Some((struct_field.into(), local))
    }
+    pub(crate) fn resolve_record_field_pat(
+        &self,
+        _db: &dyn HirDatabase,
+        field: &ast::RecordFieldPat,
+    ) -> Option<StructField> {
+        let pat_id = self.pat_id(&field.pat()?)?;
+        let struct_field = self.infer.as_ref()?.record_field_pat_resolution(pat_id)?;
+        Some(struct_field.into())
+    }
    pub(crate) fn resolve_macro_call(
        &self,
        db: &dyn HirDatabase,
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index 82a52804d..0caedd8d8 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -473,16 +473,14 @@ impl ExprCollector<'_> {
        self.collect_block_items(&block);
        let statements = block
            .statements()
-            .filter_map(|s| match s {
+            .map(|s| match s {
                ast::Stmt::LetStmt(stmt) => {
                    let pat = self.collect_pat_opt(stmt.pat());
                    let type_ref = stmt.ascribed_type().map(TypeRef::from_ast);
                    let initializer = stmt.initializer().map(|e| self.collect_expr(e));
-                    Some(Statement::Let { pat, type_ref, initializer })
+                    Statement::Let { pat, type_ref, initializer }
-                }
-                ast::Stmt::ExprStmt(stmt) => {
-                    Some(Statement::Expr(self.collect_expr_opt(stmt.expr())))
                }
+                ast::Stmt::ExprStmt(stmt) => Statement::Expr(self.collect_expr_opt(stmt.expr())),
            })
            .collect();
        let tail = block.expr().map(|e| self.collect_expr(e));
diff --git a/crates/ra_hir_def/src/body/scope.rs b/crates/ra_hir_def/src/body/scope.rs
index 4d489f692..fe4137176 100644
--- a/crates/ra_hir_def/src/body/scope.rs
+++ b/crates/ra_hir_def/src/body/scope.rs
@@ -157,6 +157,10 @@ fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope
            for arm in arms {
                let scope = scopes.new_scope(scope);
                scopes.add_bindings(body, scope, arm.pat);
+                if let Some(guard) = arm.guard {
+                    scopes.set_scope(guard, scope);
+                    compute_expr_scopes(guard, body, scopes, scope);
+                }
                scopes.set_scope(arm.expr, scope);
                compute_expr_scopes(arm.expr, body, scopes, scope);
            }
diff --git a/crates/ra_hir_expand/src/ast_id_map.rs b/crates/ra_hir_expand/src/ast_id_map.rs
index a3ca302c2..d19569245 100644
--- a/crates/ra_hir_expand/src/ast_id_map.rs
+++ b/crates/ra_hir_expand/src/ast_id_map.rs
@@ -66,7 +66,7 @@ impl AstIdMap {
        // change parent's id. This means that, say, adding a new function to a
        // trait does not change ids of top-level items, which helps caching.
        bfs(node, |it| {
-            if let Some(module_item) = ast::ModuleItem::cast(it.clone()) {
+            if let Some(module_item) = ast::ModuleItem::cast(it) {
                res.alloc(module_item.syntax());
            }
        });
diff --git a/crates/ra_hir_expand/src/builtin_macro.rs b/crates/ra_hir_expand/src/builtin_macro.rs
index f9d3787f6..3da137f2e 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -301,7 +301,7 @@ fn relative_file(db: &dyn AstDatabase, call_id: MacroCallId, path: &str) -> Opti
    }
    // Extern paths ?
-    let krate = db.relevant_crates(call_site).get(0)?.clone();
+    let krate = *db.relevant_crates(call_site).get(0)?;
    let (extern_source_id, relative_file) =
        db.crate_graph()[krate].extern_source.extern_path(path)?;
@@ -329,7 +329,7 @@ fn include_expand(
    // FIXME:
    // Handle include as expression
-    let res = parse_to_token_tree(&db.file_text(file_id.into()))
+    let res = parse_to_token_tree(&db.file_text(file_id))
        .ok_or_else(|| mbe::ExpandError::ConversionError)?
        .0;
@@ -340,7 +340,7 @@ fn get_env_inner(db: &dyn AstDatabase, arg_id: EagerMacroId, key: &str) -> Optio
    let call_id: MacroCallId = arg_id.into();
    let original_file = call_id.as_file().original_file(db);
-    let krate = db.relevant_crates(original_file).get(0)?.clone();
+    let krate = *db.relevant_crates(original_file).get(0)?;
    db.crate_graph()[krate].env.get(key)
 }
@@ -447,7 +447,7 @@ mod tests {
                    file_id: file_id.into(),
                };
-                let id: MacroCallId = db.intern_eager_expansion(eager.into()).into();
+                let id: MacroCallId = db.intern_eager_expansion(eager).into();
                id.as_file()
            }
        };
diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
index 177bdbcb0..04d3cd6a2 100644
--- a/crates/ra_hir_ty/Cargo.toml
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -27,9 +27,9 @@ test_utils = { path = "../test_utils" }
 scoped-tls = "1"
-chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "28cef6ff403d403e6ad2f3d27d944e9ffac1bce8" }
+chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "2c072cc830d04af5f10b390e6643327f85108282" }
-chalk-rust-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "28cef6ff403d403e6ad2f3d27d944e9ffac1bce8" }
+chalk-rust-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "2c072cc830d04af5f10b390e6643327f85108282" }
-chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "28cef6ff403d403e6ad2f3d27d944e9ffac1bce8" }
+chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "2c072cc830d04af5f10b390e6643327f85108282" }
 [dev-dependencies]
 insta = "0.16.0"
diff --git a/crates/ra_hir_ty/src/_match.rs b/crates/ra_hir_ty/src/_match.rs
index 688026a04..779e78574 100644
--- a/crates/ra_hir_ty/src/_match.rs
+++ b/crates/ra_hir_ty/src/_match.rs
@@ -235,10 +235,19 @@ impl From<PatId> for PatIdOrWild {
    }
 }
+impl From<&PatId> for PatIdOrWild {
+    fn from(pat_id: &PatId) -> Self {
+        Self::PatId(*pat_id)
+    }
+}
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum MatchCheckErr {
    NotImplemented,
    MalformedMatchArm,
+    /// Used when type inference cannot resolve the type of
+    /// a pattern or expression.
+    Unknown,
 }
 /// The return type of `is_useful` is either an indication of usefulness
@@ -290,10 +299,14 @@ impl PatStack {
        Self::from_slice(&self.0[1..])
    }
-    fn replace_head_with<T: Into<PatIdOrWild> + Copy>(&self, pat_ids: &[T]) -> PatStack {
+    fn replace_head_with<I, T>(&self, pats: I) -> PatStack
+    where
+        I: Iterator<Item = T>,
+        T: Into<PatIdOrWild>,
+    {
        let mut patterns: PatStackInner = smallvec![];
-        for pat in pat_ids {
+        for pat in pats {
-            patterns.push((*pat).into());
+            patterns.push(pat.into());
        }
        for pat in &self.0[1..] {
            patterns.push(*pat);
@@ -330,7 +343,7 @@ impl PatStack {
                    return Err(MatchCheckErr::NotImplemented);
                }
-                Some(self.replace_head_with(pat_ids))
+                Some(self.replace_head_with(pat_ids.iter()))
            }
            (Pat::Lit(lit_expr), Constructor::Bool(constructor_val)) => {
                match cx.body.exprs[lit_expr] {
@@ -382,7 +395,7 @@ impl PatStack {
                                new_patterns.push((*pat_id).into());
                            }
-                            Some(self.replace_head_with(&new_patterns))
+                            Some(self.replace_head_with(new_patterns.into_iter()))
                        } else {
                            return Err(MatchCheckErr::MalformedMatchArm);
                        }
@@ -390,13 +403,41 @@ impl PatStack {
                        // If there is no ellipsis in the tuple pattern, the number
                        // of patterns must equal the constructor arity.
                        if pat_ids.len() == constructor_arity {
-                            Some(self.replace_head_with(pat_ids))
+                            Some(self.replace_head_with(pat_ids.into_iter()))
                        } else {
                            return Err(MatchCheckErr::MalformedMatchArm);
                        }
                    }
                }
            }
+            (Pat::Record { args: ref arg_patterns, .. }, Constructor::Enum(e)) => {
+                let pat_id = self.head().as_id().expect("we know this isn't a wild");
+                if !enum_variant_matches(cx, pat_id, *e) {
+                    None
+                } else {
+                    match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
+                        VariantData::Record(struct_field_arena) => {
+                            // Here we treat any missing fields in the record as the wild pattern, as
+                            // if the record has ellipsis. We want to do this here even if the
+                            // record does not contain ellipsis, because it allows us to continue
+                            // enforcing exhaustiveness for the rest of the match statement.
+                            //
+                            // Creating the diagnostic for the missing field in the pattern
+                            // should be done in a different diagnostic.
+                            let patterns = struct_field_arena.iter().map(|(_, struct_field)| {
+                                arg_patterns
+                                    .iter()
+                                    .find(|pat| pat.name == struct_field.name)
+                                    .map(|pat| PatIdOrWild::from(pat.pat))
+                                    .unwrap_or(PatIdOrWild::Wild)
+                            });
+                            Some(self.replace_head_with(patterns))
+                        }
+                        _ => return Err(MatchCheckErr::Unknown),
+                    }
+                }
+            }
            (Pat::Or(_), _) => return Err(MatchCheckErr::NotImplemented),
            (_, _) => return Err(MatchCheckErr::NotImplemented),
        };
@@ -655,8 +696,8 @@ impl Constructor {
            Constructor::Enum(e) => {
                match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
                    VariantData::Tuple(struct_field_data) => struct_field_data.len(),
+                    VariantData::Record(struct_field_data) => struct_field_data.len(),
                    VariantData::Unit => 0,
-                    _ => return Err(MatchCheckErr::NotImplemented),
                }
            }
        };
@@ -695,10 +736,10 @@ fn pat_constructor(cx: &MatchCheckCtx, pat: PatIdOrWild) -> MatchCheckResult<Opt
            Expr::Literal(Literal::Bool(val)) => Some(Constructor::Bool(val)),
            _ => return Err(MatchCheckErr::NotImplemented),
        },
-        Pat::TupleStruct { .. } | Pat::Path(_) => {
+        Pat::TupleStruct { .. } | Pat::Path(_) | Pat::Record { .. } => {
            let pat_id = pat.as_id().expect("we already know this pattern is not a wild");
            let variant_id =
-                cx.infer.variant_resolution_for_pat(pat_id).ok_or(MatchCheckErr::NotImplemented)?;
+                cx.infer.variant_resolution_for_pat(pat_id).ok_or(MatchCheckErr::Unknown)?;
            match variant_id {
                VariantId::EnumVariantId(enum_variant_id) => {
                    Some(Constructor::Enum(enum_variant_id))
@@ -759,20 +800,22 @@ mod tests {
    pub(super) use insta::assert_snapshot;
    pub(super) use ra_db::fixture::WithFixture;
-    pub(super) use crate::test_db::TestDB;
+    pub(super) use crate::{diagnostics::MissingMatchArms, test_db::TestDB};
    pub(super) fn check_diagnostic_message(content: &str) -> String {
-        TestDB::with_single_file(content).0.diagnostics().0
+        TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().0
    }
    pub(super) fn check_diagnostic(content: &str) {
-        let diagnostic_count = TestDB::with_single_file(content).0.diagnostics().1;
+        let diagnostic_count =
+            TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().1;
        assert_eq!(1, diagnostic_count, "no diagnostic reported");
    }
    pub(super) fn check_no_diagnostic(content: &str) {
-        let diagnostic_count = TestDB::with_single_file(content).0.diagnostics().1;
+        let diagnostic_count =
+            TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().1;
        assert_eq!(0, diagnostic_count, "expected no diagnostic, found one");
    }
@@ -1532,6 +1575,236 @@ mod tests {
    }
    #[test]
+    fn enum_record_no_arms() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                }
+            }
+        ";
+        check_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_missing_arms() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { foo: true } => (),
+                }
+            }
+        ";
+        check_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { foo: true } => (),
+                    Either::A { foo: false } => (),
+                    Either::B => (),
+                }
+            }
+        ";
+        check_no_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_missing_field_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::B;
+                match a {
+                    Either::A { } => (),
+                    Either::B => (),
+                }
+            }
+        ";
+        // When `Either::A` is missing a struct member, we don't want
+        // to fire the missing match arm diagnostic. This should fire
+        // some other diagnostic.
+        check_no_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_missing_field_missing_match_arm() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::B;
+                match a {
+                    Either::A { } => (),
+                }
+            }
+        ";
+        // Even though `Either::A` is missing fields, we still want to fire
+        // the missing arm diagnostic here, since we know `Either::B` is missing.
+        check_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_no_diagnostic_wild() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { foo: _ } => (),
+                    Either::B => (),
+                }
+            }
+        ";
+        check_no_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_fields_out_of_order_missing_arm() {
+        let content = r"
+            enum Either {
+                A { foo: bool, bar: () },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { bar: (), foo: false } => (),
+                    Either::A { foo: true, bar: () } => (),
+                }
+            }
+        ";
+        check_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_fields_out_of_order_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A { foo: bool, bar: () },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { bar: (), foo: false } => (),
+                    Either::A { foo: true, bar: () } => (),
+                    Either::B => (),
+                }
+            }
+        ";
+        check_no_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_ellipsis_missing_arm() {
+        let content = r"
+             enum Either {
+                 A { foo: bool, bar: bool },
+                 B,
+             }
+             fn test_fn() {
+                 match Either::B {
+                     Either::A { foo: true, .. } => (),
+                     Either::B => (),
+                 }
+             }
+         ";
+        check_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_ellipsis_no_diagnostic() {
+        let content = r"
+             enum Either {
+                 A { foo: bool, bar: bool },
+                 B,
+             }
+             fn test_fn() {
+                 let a = Either::A { foo: true };
+                 match a {
+                     Either::A { foo: true, .. } => (),
+                     Either::A { foo: false, .. } => (),
+                     Either::B => (),
+                 }
+             }
+         ";
+        check_no_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_ellipsis_all_fields_missing_arm() {
+        let content = r"
+             enum Either {
+                 A { foo: bool, bar: bool },
+                 B,
+             }
+             fn test_fn() {
+                 let a = Either::B;
+                 match a {
+                     Either::A { .. } => (),
+                 }
+             }
+         ";
+        check_diagnostic(content);
+    }
+    #[test]
+    fn enum_record_ellipsis_all_fields_no_diagnostic() {
+        let content = r"
+             enum Either {
+                 A { foo: bool, bar: bool },
+                 B,
+             }
+             fn test_fn() {
+                 let a = Either::B;
+                 match a {
+                     Either::A { .. } => (),
+                     Either::B => (),
+                 }
+             }
+         ";
+        check_no_diagnostic(content);
+    }
+    #[test]
    fn enum_tuple_partial_ellipsis_no_diagnostic() {
        let content = r"
            enum Either {
@@ -1689,25 +1962,6 @@ mod false_negatives {
    }
    #[test]
-    fn enum_record() {
-        let content = r"
-            enum Either {
-                A { foo: u32 },
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A { foo: 5 } => (),
-                }
-            }
-        ";
-        // This is a false negative.
-        // We don't currently handle enum record types.
-        check_no_diagnostic(content);
-    }
-    #[test]
    fn internal_or() {
        let content = r"
            fn test_fn() {
@@ -1796,4 +2050,22 @@ mod false_negatives {
        // We don't currently handle tuple patterns with ellipsis.
        check_no_diagnostic(content);
    }
+    #[test]
+    fn struct_missing_arm() {
+        let content = r"
+            struct Foo {
+                a: bool,
+            }
+            fn test_fn(f: Foo) {
+                match f {
+                    Foo { a: true } => {},
+                }
+            }
+        ";
+        // This is a false negative.
+        // We don't currently handle structs.
+        check_no_diagnostic(content);
+    }
 }
diff --git a/crates/ra_hir_ty/src/db.rs b/crates/ra_hir_ty/src/db.rs
index 33da16b48..9e5dfeab3 100644
--- a/crates/ra_hir_ty/src/db.rs
+++ b/crates/ra_hir_ty/src/db.rs
@@ -107,6 +107,13 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
        krate: CrateId,
        goal: crate::Canonical<crate::InEnvironment<crate::Obligation>>,
    ) -> Option<crate::traits::Solution>;
+    #[salsa::invoke(crate::traits::chalk::program_clauses_for_chalk_env_query)]
+    fn program_clauses_for_chalk_env(
+        &self,
+        krate: CrateId,
+        env: chalk_ir::Environment<chalk::Interner>,
+    ) -> chalk_ir::ProgramClauses<chalk::Interner>;
 }
 fn infer_wait(db: &impl HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index b6d9b3438..dfb6a435f 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -127,6 +127,7 @@ pub struct InferenceResult {
    field_resolutions: FxHashMap<ExprId, StructFieldId>,
    /// For each field in record literal, records the field it resolves to.
    record_field_resolutions: FxHashMap<ExprId, StructFieldId>,
+    record_field_pat_resolutions: FxHashMap<PatId, StructFieldId>,
    /// For each struct literal, records the variant it resolves to.
    variant_resolutions: FxHashMap<ExprOrPatId, VariantId>,
    /// For each associated item record what it resolves to
@@ -147,6 +148,9 @@ impl InferenceResult {
    pub fn record_field_resolution(&self, expr: ExprId) -> Option<StructFieldId> {
        self.record_field_resolutions.get(&expr).copied()
    }
+    pub fn record_field_pat_resolution(&self, pat: PatId) -> Option<StructFieldId> {
+        self.record_field_pat_resolutions.get(&pat).copied()
+    }
    pub fn variant_resolution_for_expr(&self, id: ExprId) -> Option<VariantId> {
        self.variant_resolutions.get(&id.into()).copied()
    }
diff --git a/crates/ra_hir_ty/src/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index 8ec4d4ace..7c2ad4384 100644
--- a/crates/ra_hir_ty/src/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -7,6 +7,7 @@ use hir_def::{
    expr::{BindingAnnotation, Pat, PatId, RecordFieldPat},
    path::Path,
    type_ref::Mutability,
+    StructFieldId,
 };
 use hir_expand::name::Name;
 use test_utils::tested_by;
@@ -67,6 +68,11 @@ impl<'a> InferenceContext<'a> {
        let field_tys = def.map(|it| self.db.field_types(it)).unwrap_or_default();
        for subpat in subpats {
            let matching_field = var_data.as_ref().and_then(|it| it.field(&subpat.name));
+            if let Some(local_id) = matching_field {
+                let field_def = StructFieldId { parent: def.unwrap(), local_id };
+                self.result.record_field_pat_resolutions.insert(subpat.pat, field_def);
+            }
            let expected_ty =
                matching_field.map_or(Ty::Unknown, |field| field_tys[field].clone().subst(&substs));
            let expected_ty = self.normalize_associated_types_in(expected_ty);
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index 3a4d58bf9..8498d3d96 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -12,7 +12,7 @@ use ra_db::{
 };
 use stdx::format_to;
-use crate::{db::HirDatabase, expr::ExprValidator};
+use crate::{db::HirDatabase, diagnostics::Diagnostic, expr::ExprValidator};
 #[salsa::database(
    ra_db::SourceDatabaseExtStorage,
@@ -104,10 +104,7 @@ impl TestDB {
        panic!("Can't find module for file")
    }
-    // FIXME: don't duplicate this
+    fn diag<F: FnMut(&dyn Diagnostic)>(&self, mut cb: F) {
-    pub fn diagnostics(&self) -> (String, u32) {
-        let mut buf = String::new();
-        let mut count = 0;
        let crate_graph = self.crate_graph();
        for krate in crate_graph.iter() {
            let crate_def_map = self.crate_def_map(krate);
@@ -132,15 +129,36 @@ impl TestDB {
            for f in fns {
                let infer = self.infer(f.into());
-                let mut sink = DiagnosticSink::new(|d| {
+                let mut sink = DiagnosticSink::new(&mut cb);
-                    format_to!(buf, "{:?}: {}\n", d.syntax_node(self).text(), d.message());
-                    count += 1;
-                });
                infer.add_diagnostics(self, f, &mut sink);
                let mut validator = ExprValidator::new(f, infer, &mut sink);
                validator.validate_body(self);
            }
        }
+    }
+    pub fn diagnostics(&self) -> (String, u32) {
+        let mut buf = String::new();
+        let mut count = 0;
+        self.diag(|d| {
+            format_to!(buf, "{:?}: {}\n", d.syntax_node(self).text(), d.message());
+            count += 1;
+        });
+        (buf, count)
+    }
+    /// Like `diagnostics`, but filtered for a single diagnostic.
+    pub fn diagnostic<D: Diagnostic>(&self) -> (String, u32) {
+        let mut buf = String::new();
+        let mut count = 0;
+        self.diag(|d| {
+            // We want to filter diagnostics by the particular one we are testing for, to
+            // avoid surprising results in tests.
+            if d.downcast_ref::<D>().is_some() {
+                format_to!(buf, "{:?}: {}\n", d.syntax_node(self).text(), d.message());
+                count += 1;
+            };
+        });
        (buf, count)
    }
 }
diff --git a/crates/ra_hir_ty/src/tests/patterns.rs b/crates/ra_hir_ty/src/tests/patterns.rs
index 07cbc521a..6ea51d5d3 100644
--- a/crates/ra_hir_ty/src/tests/patterns.rs
+++ b/crates/ra_hir_ty/src/tests/patterns.rs
@@ -455,3 +455,29 @@ fn test() {
    "###
    );
 }
+#[test]
+fn infer_guard() {
+    assert_snapshot!(
+        infer(r#"
+struct S;
+impl S { fn foo(&self) -> bool { false } }
+fn main() {
+    match S {
+        s if s.foo() => (),
+    }
+}
+    "#), @"
+        [28; 32) 'self': &S
+        [42; 51) '{ false }': bool
+        [44; 49) 'false': bool
+        [65; 116) '{     ...   } }': ()
+        [71; 114) 'match ...     }': ()
+        [77; 78) 'S': S
+        [89; 90) 's': S
+        [94; 95) 's': S
+        [94; 101) 's.foo()': bool
+        [105; 107) '()': ()
+    ")
+}
diff --git a/crates/ra_hir_ty/src/traits.rs b/crates/ra_hir_ty/src/traits.rs
index 05791a848..6bc6d474c 100644
--- a/crates/ra_hir_ty/src/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -225,7 +225,7 @@ fn solution_from_chalk(
                None => unimplemented!(),
            })
            .collect();
-        let result = Canonical { value, num_vars: subst.binders.len() };
+        let result = Canonical { value, num_vars: subst.binders.len(&Interner) };
        SolutionVariables(result)
    };
    match solution {
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index e00a82db2..1ccb7c3b4 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -4,8 +4,8 @@ use std::{fmt, sync::Arc};
 use log::debug;
 use chalk_ir::{
-    cast::Cast, fold::shift::Shift, Goal, GoalData, Parameter, PlaceholderIndex, TypeName,
+    cast::Cast, fold::shift::Shift, interner::HasInterner, Goal, GoalData, Parameter,
-    UniverseIndex,
+    PlaceholderIndex, TypeName, UniverseIndex,
 };
 use hir_def::{AssocContainerId, AssocItemId, GenericDefId, HasModule, Lookup, TypeAliasId};
@@ -33,8 +33,10 @@ impl chalk_ir::interner::Interner for Interner {
    type InternedGoals = Vec<Goal<Self>>;
    type InternedSubstitution = Vec<Parameter<Self>>;
    type InternedProgramClause = chalk_ir::ProgramClauseData<Self>;
-    type InternedProgramClauses = Vec<chalk_ir::ProgramClause<Self>>;
+    type InternedProgramClauses = Arc<[chalk_ir::ProgramClause<Self>]>;
    type InternedQuantifiedWhereClauses = Vec<chalk_ir::QuantifiedWhereClause<Self>>;
+    type InternedParameterKinds = Vec<chalk_ir::ParameterKind<()>>;
+    type InternedCanonicalVarKinds = Vec<chalk_ir::ParameterKind<UniverseIndex>>;
    type Identifier = TypeAliasId;
    type DefId = InternId;
@@ -60,6 +62,27 @@ impl chalk_ir::interner::Interner for Interner {
        tls::with_current_program(|prog| Some(prog?.debug_alias(alias, fmt)))
    }
+    fn debug_projection_ty(
+        proj: &chalk_ir::ProjectionTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_projection_ty(proj, fmt)))
+    }
+    fn debug_opaque_ty(
+        opaque_ty: &chalk_ir::OpaqueTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_opaque_ty(opaque_ty, fmt)))
+    }
+    fn debug_opaque_ty_id(
+        opaque_ty_id: chalk_ir::OpaqueTyId<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_opaque_ty_id(opaque_ty_id, fmt)))
+    }
    fn debug_ty(ty: &chalk_ir::Ty<Interner>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
        tls::with_current_program(|prog| Some(prog?.debug_ty(ty, fmt)))
    }
@@ -202,15 +225,15 @@ impl chalk_ir::interner::Interner for Interner {
    fn intern_program_clauses(
        &self,
        data: impl IntoIterator<Item = chalk_ir::ProgramClause<Self>>,
-    ) -> Vec<chalk_ir::ProgramClause<Self>> {
+    ) -> Arc<[chalk_ir::ProgramClause<Self>]> {
        data.into_iter().collect()
    }
    fn program_clauses_data<'a>(
        &self,
-        clauses: &'a Vec<chalk_ir::ProgramClause<Self>>,
+        clauses: &'a Arc<[chalk_ir::ProgramClause<Self>]>,
    ) -> &'a [chalk_ir::ProgramClause<Self>] {
-        clauses
+        &clauses
    }
    fn intern_quantified_where_clauses(
@@ -226,6 +249,34 @@ impl chalk_ir::interner::Interner for Interner {
    ) -> &'a [chalk_ir::QuantifiedWhereClause<Self>] {
        clauses
    }
+    fn intern_parameter_kinds(
+        &self,
+        data: impl IntoIterator<Item = chalk_ir::ParameterKind<()>>,
+    ) -> Self::InternedParameterKinds {
+        data.into_iter().collect()
+    }
+    fn parameter_kinds_data<'a>(
+        &self,
+        parameter_kinds: &'a Self::InternedParameterKinds,
+    ) -> &'a [chalk_ir::ParameterKind<()>] {
+        &parameter_kinds
+    }
+    fn intern_canonical_var_kinds(
+        &self,
+        data: impl IntoIterator<Item = chalk_ir::ParameterKind<UniverseIndex>>,
+    ) -> Self::InternedCanonicalVarKinds {
+        data.into_iter().collect()
+    }
+    fn canonical_var_kinds_data<'a>(
+        &self,
+        canonical_var_kinds: &'a Self::InternedCanonicalVarKinds,
+    ) -> &'a [chalk_ir::ParameterKind<UniverseIndex>] {
+        &canonical_var_kinds
+    }
 }
 impl chalk_ir::interner::HasInterner for Interner {
@@ -268,9 +319,12 @@ impl ToChalk for Ty {
            Ty::Projection(proj_ty) => {
                let associated_ty_id = proj_ty.associated_ty.to_chalk(db);
                let substitution = proj_ty.parameters.to_chalk(db);
-                chalk_ir::AliasTy { associated_ty_id, substitution }
+                chalk_ir::AliasTy::Projection(chalk_ir::ProjectionTy {
-                    .cast(&Interner)
+                    associated_ty_id,
-                    .intern(&Interner)
+                    substitution,
+                })
+                .cast(&Interner)
+                .intern(&Interner)
            }
            Ty::Placeholder(id) => {
                let interned_id = db.intern_type_param_id(id);
@@ -314,16 +368,17 @@ impl ToChalk for Ty {
                );
                Ty::Placeholder(db.lookup_intern_type_param_id(interned_id))
            }
-            chalk_ir::TyData::Alias(proj) => {
+            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Projection(proj)) => {
                let associated_ty = from_chalk(db, proj.associated_ty_id);
                let parameters = from_chalk(db, proj.substitution);
                Ty::Projection(ProjectionTy { associated_ty, parameters })
            }
+            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(_)) => unimplemented!(),
            chalk_ir::TyData::Function(_) => unimplemented!(),
            chalk_ir::TyData::BoundVar(idx) => Ty::Bound(idx),
            chalk_ir::TyData::InferenceVar(_iv) => Ty::Unknown,
            chalk_ir::TyData::Dyn(where_clauses) => {
-                assert_eq!(where_clauses.bounds.binders.len(), 1);
+                assert_eq!(where_clauses.bounds.binders.len(&Interner), 1);
                let predicates = where_clauses
                    .bounds
                    .skip_binders()
@@ -404,6 +459,7 @@ impl ToChalk for TypeCtor {
        match type_name {
            TypeName::Struct(struct_id) => db.lookup_intern_type_ctor(struct_id.into()),
            TypeName::AssociatedType(type_id) => TypeCtor::AssociatedType(from_chalk(db, type_id)),
+            TypeName::OpaqueType(_) => unreachable!(),
            TypeName::Error => {
                // this should not be reached, since we don't represent TypeName::Error with TypeCtor
                unreachable!()
@@ -460,7 +516,8 @@ impl ToChalk for GenericPredicate {
            }
            GenericPredicate::Projection(projection_pred) => {
                let ty = projection_pred.ty.to_chalk(db).shifted_in(&Interner);
-                let alias = projection_pred.projection_ty.to_chalk(db).shifted_in(&Interner);
+                let projection = projection_pred.projection_ty.to_chalk(db).shifted_in(&Interner);
+                let alias = chalk_ir::AliasTy::Projection(projection);
                make_binders(chalk_ir::WhereClause::AliasEq(chalk_ir::AliasEq { alias, ty }), 0)
            }
            GenericPredicate::Error => panic!("tried passing GenericPredicate::Error to Chalk"),
@@ -481,7 +538,13 @@ impl ToChalk for GenericPredicate {
                GenericPredicate::Implemented(from_chalk(db, tr))
            }
            chalk_ir::WhereClause::AliasEq(projection_eq) => {
-                let projection_ty = from_chalk(db, projection_eq.alias);
+                let projection_ty = from_chalk(
+                    db,
+                    match projection_eq.alias {
+                        chalk_ir::AliasTy::Projection(p) => p,
+                        _ => unimplemented!(),
+                    },
+                );
                let ty = from_chalk(db, projection_eq.ty);
                GenericPredicate::Projection(super::ProjectionPredicate { projection_ty, ty })
            }
@@ -490,10 +553,10 @@ impl ToChalk for GenericPredicate {
 }
 impl ToChalk for ProjectionTy {
-    type Chalk = chalk_ir::AliasTy<Interner>;
+    type Chalk = chalk_ir::ProjectionTy<Interner>;
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::AliasTy<Interner> {
+    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::ProjectionTy<Interner> {
-        chalk_ir::AliasTy {
+        chalk_ir::ProjectionTy {
            associated_ty_id: self.associated_ty.to_chalk(db),
            substitution: self.parameters.to_chalk(db),
        }
@@ -501,7 +564,7 @@ impl ToChalk for ProjectionTy {
    fn from_chalk(
        db: &dyn HirDatabase,
-        projection_ty: chalk_ir::AliasTy<Interner>,
+        projection_ty: chalk_ir::ProjectionTy<Interner>,
    ) -> ProjectionTy {
        ProjectionTy {
            associated_ty: from_chalk(db, projection_ty.associated_ty_id),
@@ -514,7 +577,10 @@ impl ToChalk for super::ProjectionPredicate {
    type Chalk = chalk_ir::AliasEq<Interner>;
    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::AliasEq<Interner> {
-        chalk_ir::AliasEq { alias: self.projection_ty.to_chalk(db), ty: self.ty.to_chalk(db) }
+        chalk_ir::AliasEq {
+            alias: chalk_ir::AliasTy::Projection(self.projection_ty.to_chalk(db)),
+            ty: self.ty.to_chalk(db),
+        }
    }
    fn from_chalk(_db: &dyn HirDatabase, _normalize: chalk_ir::AliasEq<Interner>) -> Self {
@@ -540,17 +606,24 @@ impl ToChalk for Obligation {
 impl<T> ToChalk for Canonical<T>
 where
    T: ToChalk,
+    T::Chalk: HasInterner<Interner = Interner>,
 {
    type Chalk = chalk_ir::Canonical<T::Chalk>;
    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Canonical<T::Chalk> {
        let parameter = chalk_ir::ParameterKind::Ty(chalk_ir::UniverseIndex::ROOT);
        let value = self.value.to_chalk(db);
-        chalk_ir::Canonical { value, binders: vec![parameter; self.num_vars] }
+        chalk_ir::Canonical {
+            value,
+            binders: chalk_ir::CanonicalVarKinds::from(&Interner, vec![parameter; self.num_vars]),
+        }
    }
    fn from_chalk(db: &dyn HirDatabase, canonical: chalk_ir::Canonical<T::Chalk>) -> Canonical<T> {
-        Canonical { num_vars: canonical.binders.len(), value: from_chalk(db, canonical.value) }
+        Canonical {
+            num_vars: canonical.binders.len(&Interner),
+            value: from_chalk(db, canonical.value),
+        }
    }
 }
@@ -649,9 +722,15 @@ impl ToChalk for builtin::BuiltinImplAssocTyValueData {
    }
 }
-fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T> {
+fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T>
+where
+    T: HasInterner<Interner = Interner>,
+{
    chalk_ir::Binders::new(
-        std::iter::repeat(chalk_ir::ParameterKind::Ty(())).take(num_vars).collect(),
+        chalk_ir::ParameterKinds::from(
+            &Interner,
+            std::iter::repeat(chalk_ir::ParameterKind::Ty(())).take(num_vars),
+        ),
        value,
    )
 }
@@ -799,6 +878,28 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
        // FIXME tell Chalk about well-known traits (here and in trait_datum)
        None
    }
+    fn program_clauses_for_env(
+        &self,
+        environment: &chalk_ir::Environment<Interner>,
+    ) -> chalk_ir::ProgramClauses<Interner> {
+        self.db.program_clauses_for_chalk_env(self.krate, environment.clone())
+    }
+    fn opaque_ty_data(
+        &self,
+        _id: chalk_ir::OpaqueTyId<Interner>,
+    ) -> Arc<chalk_rust_ir::OpaqueTyDatum<Interner>> {
+        unimplemented!()
+    }
+}
+pub(crate) fn program_clauses_for_chalk_env_query(
+    db: &dyn HirDatabase,
+    krate: CrateId,
+    environment: chalk_ir::Environment<Interner>,
+) -> chalk_ir::ProgramClauses<Interner> {
+    chalk_solve::program_clauses_for_env(&ChalkContext { db, krate }, &environment)
 }
 pub(crate) fn associated_ty_data_query(
diff --git a/crates/ra_hir_ty/src/traits/chalk/tls.rs b/crates/ra_hir_ty/src/traits/chalk/tls.rs
index fa8e4d1ad..4867cb17e 100644
--- a/crates/ra_hir_ty/src/traits/chalk/tls.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/tls.rs
@@ -121,19 +121,38 @@ impl DebugContext<'_> {
        write!(fmt, "{}::{}", trait_data.name, type_alias_data.name)
    }
+    pub fn debug_opaque_ty_id(
+        &self,
+        opaque_ty_id: chalk_ir::OpaqueTyId<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Result<(), fmt::Error> {
+        fmt.debug_struct("OpaqueTyId").field("index", &opaque_ty_id.0).finish()
+    }
    pub fn debug_alias(
        &self,
-        alias: &AliasTy<Interner>,
+        alias_ty: &AliasTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Result<(), fmt::Error> {
+        match alias_ty {
+            AliasTy::Projection(projection_ty) => self.debug_projection_ty(projection_ty, fmt),
+            AliasTy::Opaque(opaque_ty) => self.debug_opaque_ty(opaque_ty, fmt),
+        }
+    }
+    pub fn debug_projection_ty(
+        &self,
+        projection_ty: &chalk_ir::ProjectionTy<Interner>,
        fmt: &mut fmt::Formatter<'_>,
    ) -> Result<(), fmt::Error> {
-        let type_alias: TypeAliasId = from_chalk(self.0, alias.associated_ty_id);
+        let type_alias: TypeAliasId = from_chalk(self.0, projection_ty.associated_ty_id);
        let type_alias_data = self.0.type_alias_data(type_alias);
        let trait_ = match type_alias.lookup(self.0.upcast()).container {
            AssocContainerId::TraitId(t) => t,
            _ => panic!("associated type not in trait"),
        };
        let trait_data = self.0.trait_data(trait_);
-        let params = alias.substitution.parameters(&Interner);
+        let params = projection_ty.substitution.parameters(&Interner);
        write!(fmt, "<{:?} as {}", &params[0], trait_data.name,)?;
        if params.len() > 1 {
            write!(
@@ -145,6 +164,14 @@ impl DebugContext<'_> {
        write!(fmt, ">::{}", type_alias_data.name)
    }
+    pub fn debug_opaque_ty(
+        &self,
+        opaque_ty: &chalk_ir::OpaqueTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Result<(), fmt::Error> {
+        write!(fmt, "{:?}", opaque_ty.opaque_ty_id)
+    }
    pub fn debug_ty(
        &self,
        ty: &chalk_ir::Ty<Interner>,
diff --git a/crates/ra_ide/src/completion/presentation.rs b/crates/ra_ide/src/completion/presentation.rs
index bb12a1bdc..f8dac1d54 100644
--- a/crates/ra_ide/src/completion/presentation.rs
+++ b/crates/ra_ide/src/completion/presentation.rs
@@ -161,6 +161,12 @@ impl Completions {
        name: Option<String>,
        macro_: hir::MacroDef,
    ) {
+        // FIXME: Currently proc-macro do not have ast-node,
+        // such that it does not have source
+        if macro_.is_proc_macro() {
+            return;
+        }
        let name = match name {
            Some(it) => it,
            None => return,
diff --git a/crates/ra_ide/src/extend_selection.rs b/crates/ra_ide/src/extend_selection.rs
index f5a063351..753d2ef6a 100644
--- a/crates/ra_ide/src/extend_selection.rs
+++ b/crates/ra_ide/src/extend_selection.rs
@@ -96,7 +96,7 @@ fn try_extend_selection(
        return Some(node.text_range());
    }
-    let node = shallowest_node(&node.into());
+    let node = shallowest_node(&node);
    if node.parent().map(|n| list_kinds.contains(&n.kind())) == Some(true) {
        if let Some(range) = extend_list_item(&node) {
diff --git a/crates/ra_ide/src/goto_definition.rs b/crates/ra_ide/src/goto_definition.rs
index 8aed94d16..9998ca5a3 100644
--- a/crates/ra_ide/src/goto_definition.rs
+++ b/crates/ra_ide/src/goto_definition.rs
@@ -62,10 +62,9 @@ pub(crate) enum ReferenceResult {
 impl ReferenceResult {
    fn to_vec(self) -> Vec<NavigationTarget> {
-        use self::ReferenceResult::*;
        match self {
-            Exact(target) => vec![target],
+            ReferenceResult::Exact(target) => vec![target],
-            Approximate(vec) => vec,
+            ReferenceResult::Approximate(vec) => vec,
        }
    }
 }
@@ -74,8 +73,6 @@ pub(crate) fn reference_definition(
    sema: &Semantics<RootDatabase>,
    name_ref: &ast::NameRef,
 ) -> ReferenceResult {
-    use self::ReferenceResult::*;
    let name_kind = classify_name_ref(sema, name_ref);
    if let Some(def) = name_kind {
        let def = def.definition();
@@ -91,7 +88,7 @@ pub(crate) fn reference_definition(
        .into_iter()
        .map(|s| s.to_nav(sema.db))
        .collect();
-    Approximate(navs)
+    ReferenceResult::Approximate(navs)
 }
 #[cfg(test)]
@@ -399,6 +396,25 @@ mod tests {
    }
    #[test]
+    fn goto_def_for_record_pat_fields() {
+        covers!(ra_ide_db::goto_def_for_record_field_pats);
+        check_goto(
+            r"
+            //- /lib.rs
+            struct Foo {
+                spam: u32,
+            }
+            fn bar(foo: Foo) -> Foo {
+                let Foo { spam<|>: _, } = foo
+            }
+            ",
+            "spam RECORD_FIELD_DEF FileId(1) [17; 26) [17; 21)",
+            "spam: u32|spam",
+        );
+    }
+    #[test]
    fn goto_def_for_record_fields_macros() {
        check_goto(
            r"
diff --git a/crates/ra_ide/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
index 214dcbb62..ccb1fc751 100644
--- a/crates/ra_ide/src/snapshots/highlighting.html
+++ b/crates/ra_ide/src/snapshots/highlighting.html
@@ -50,12 +50,12 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="keyword">fn</span> <span class="function declaration">main</span>() {
    <span class="macro">println!</span>(<span class="string_literal">"Hello, {}!"</span>, <span class="numeric_literal">92</span>);
-    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">vec</span> = Vec::new();
+    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">vec</span> = <span class="unresolved_reference">Vec</span>::<span class="unresolved_reference">new</span>();
    <span class="keyword control">if</span> <span class="keyword">true</span> {
        <span class="keyword">let</span> <span class="variable declaration">x</span> = <span class="numeric_literal">92</span>;
-        <span class="variable mutable">vec</span>.push(<span class="struct">Foo</span> { <span class="field">x</span>, <span class="field">y</span>: <span class="numeric_literal">1</span> });
+        <span class="variable mutable">vec</span>.<span class="unresolved_reference">push</span>(<span class="struct">Foo</span> { <span class="field">x</span>, <span class="field">y</span>: <span class="numeric_literal">1</span> });
    }
-    <span class="keyword unsafe">unsafe</span> { <span class="variable mutable">vec</span>.set_len(<span class="numeric_literal">0</span>); }
+    <span class="keyword unsafe">unsafe</span> { <span class="variable mutable">vec</span>.<span class="unresolved_reference">set_len</span>(<span class="numeric_literal">0</span>); }
    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">x</span> = <span class="numeric_literal">42</span>;
    <span class="keyword">let</span> <span class="variable declaration mutable">y</span> = &<span class="keyword">mut</span> <span class="variable mutable">x</span>;
diff --git a/crates/ra_ide/src/snapshots/rainbow_highlighting.html b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
index dddbfc0dd..3df82c45f 100644
--- a/crates/ra_ide/src/snapshots/rainbow_highlighting.html
+++ b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
@@ -28,11 +28,11 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 </style>
 <pre><code><span class="keyword">fn</span> <span class="function declaration">main</span>() {
    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span> = <span class="string_literal">"hello"</span>;
-    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="2705725358298919760" style="color: hsl(17,51%,74%);">x</span> = <span class="variable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span>.to_string();
+    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="2705725358298919760" style="color: hsl(17,51%,74%);">x</span> = <span class="variable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span>.<span class="unresolved_reference">to_string</span>();
-    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="3365759661443752373" style="color: hsl(127,76%,66%);">y</span> = <span class="variable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span>.to_string();
+    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="3365759661443752373" style="color: hsl(127,76%,66%);">y</span> = <span class="variable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span>.<span class="unresolved_reference">to_string</span>();
    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="794745962933817518" style="color: hsl(19,74%,76%);">x</span> = <span class="string_literal">"other color please!"</span>;
-    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="6717528807933952652" style="color: hsl(85,49%,84%);">y</span> = <span class="variable" data-binding-hash="794745962933817518" style="color: hsl(19,74%,76%);">x</span>.to_string();
+    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="6717528807933952652" style="color: hsl(85,49%,84%);">y</span> = <span class="variable" data-binding-hash="794745962933817518" style="color: hsl(19,74%,76%);">x</span>.<span class="unresolved_reference">to_string</span>();
 }
 <span class="keyword">fn</span> <span class="function declaration">bar</span>() {
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index 7b15b82bd..93d502875 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -239,20 +239,21 @@ fn highlight_element(
        NAME_REF if element.ancestors().any(|it| it.kind() == ATTR) => return None,
        NAME_REF => {
            let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap();
-            let name_kind = classify_name_ref(sema, &name_ref)?;
+            match classify_name_ref(sema, &name_ref) {
+                Some(name_kind) => match name_kind {
-            match name_kind {
+                    NameRefClass::Definition(def) => {
-                NameRefClass::Definition(def) => {
+                        if let Definition::Local(local) = &def {
-                    if let Definition::Local(local) = &def {
+                            if let Some(name) = local.name(db) {
-                        if let Some(name) = local.name(db) {
+                                let shadow_count =
-                            let shadow_count =
+                                    bindings_shadow_count.entry(name.clone()).or_default();
-                                bindings_shadow_count.entry(name.clone()).or_default();
+                                binding_hash = Some(calc_binding_hash(&name, *shadow_count))
-                            binding_hash = Some(calc_binding_hash(&name, *shadow_count))
+                            }
-                        }
+                        };
-                    };
+                        highlight_name(db, def)
-                    highlight_name(db, def)
+                    }
-                }
+                    NameRefClass::FieldShorthand { .. } => HighlightTag::Field.into(),
-                NameRefClass::FieldShorthand { .. } => HighlightTag::Field.into(),
+                },
+                None => HighlightTag::UnresolvedReference.into(),
            }
        }
diff --git a/crates/ra_ide/src/syntax_highlighting/tags.rs b/crates/ra_ide/src/syntax_highlighting/tags.rs
index e8b138e1a..f2c421654 100644
--- a/crates/ra_ide/src/syntax_highlighting/tags.rs
+++ b/crates/ra_ide/src/syntax_highlighting/tags.rs
@@ -38,6 +38,7 @@ pub enum HighlightTag {
    TypeParam,
    Union,
    Local,
+    UnresolvedReference,
 }
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
@@ -79,6 +80,7 @@ impl HighlightTag {
            HighlightTag::TypeParam => "type_param",
            HighlightTag::Union => "union",
            HighlightTag::Local => "variable",
+            HighlightTag::UnresolvedReference => "unresolved_reference",
        }
    }
 }
diff --git a/crates/ra_ide_db/src/defs.rs b/crates/ra_ide_db/src/defs.rs
index 49a8c74fb..785613b82 100644
--- a/crates/ra_ide_db/src/defs.rs
+++ b/crates/ra_ide_db/src/defs.rs
@@ -180,6 +180,7 @@ fn classify_name_inner(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Opti
    }
 }
+#[derive(Debug)]
 pub enum NameRefClass {
    Definition(Definition),
    FieldShorthand { local: Local, field: Definition },
@@ -229,6 +230,14 @@ pub fn classify_name_ref(
        }
    }
+    if let Some(record_field_pat) = ast::RecordFieldPat::cast(parent.clone()) {
+        tested_by!(goto_def_for_record_field_pats; force);
+        if let Some(field) = sema.resolve_record_field_pat(&record_field_pat) {
+            let field = Definition::StructField(field);
+            return Some(NameRefClass::Definition(field));
+        }
+    }
    if let Some(macro_call) = parent.ancestors().find_map(ast::MacroCall::cast) {
        tested_by!(goto_def_for_macros; force);
        if let Some(macro_def) = sema.resolve_macro_call(&macro_call) {
diff --git a/crates/ra_ide_db/src/marks.rs b/crates/ra_ide_db/src/marks.rs
index 4f0a22af0..03b4be21c 100644
--- a/crates/ra_ide_db/src/marks.rs
+++ b/crates/ra_ide_db/src/marks.rs
@@ -6,5 +6,6 @@ test_utils::marks![
    goto_def_for_fields
    goto_def_for_record_fields
    goto_def_for_field_init_shorthand
+    goto_def_for_record_field_pats
    search_filters_by_range
 ];
diff --git a/crates/ra_mbe/src/mbe_expander/matcher.rs b/crates/ra_mbe/src/mbe_expander/matcher.rs
index 2579382da..78f9efa1b 100644
--- a/crates/ra_mbe/src/mbe_expander/matcher.rs
+++ b/crates/ra_mbe/src/mbe_expander/matcher.rs
@@ -187,7 +187,11 @@ impl<'a> TtIter<'a> {
                _ => false,
            },
            Separator::Literal(lhs) => match fork.expect_literal() {
-                Ok(rhs) => rhs.text == lhs.text,
+                Ok(rhs) => match rhs {
+                    tt::Leaf::Literal(rhs) => rhs.text == lhs.text,
+                    tt::Leaf::Ident(rhs) => rhs.text == lhs.text,
+                    tt::Leaf::Punct(_) => false,
+                },
                _ => false,
            },
            Separator::Puncts(lhss) => lhss.iter().all(|lhs| match fork.expect_punct() {
@@ -202,6 +206,13 @@ impl<'a> TtIter<'a> {
    }
    pub(crate) fn expect_tt(&mut self) -> Result<tt::TokenTree, ()> {
+        match self.peek_n(0) {
+            Some(tt::TokenTree::Leaf(tt::Leaf::Punct(punct))) if punct.char == '\'' => {
+                return self.expect_lifetime();
+            }
+            _ => (),
+        }
        let tt = self.next().ok_or_else(|| ())?.clone();
        let punct = match tt {
            tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if punct.spacing == tt::Spacing::Joint => {
@@ -255,13 +266,21 @@ impl<'a> TtIter<'a> {
        }
    }
-    pub(crate) fn expect_lifetime(&mut self) -> Result<&tt::Ident, ()> {
+    pub(crate) fn expect_lifetime(&mut self) -> Result<tt::TokenTree, ()> {
-        let ident = self.expect_ident()?;
+        let punct = self.expect_punct()?;
-        // check if it start from "`"
+        if punct.char != '\'' {
-        if !ident.text.starts_with('\'') {
            return Err(());
        }
-        Ok(ident)
+        let ident = self.expect_ident()?;
+        Ok(tt::Subtree {
+            delimiter: None,
+            token_trees: vec![
+                tt::Leaf::Punct(punct.clone()).into(),
+                tt::Leaf::Ident(ident.clone()).into(),
+            ],
+        }
+        .into())
    }
    pub(crate) fn expect_fragment(
@@ -274,7 +293,10 @@ impl<'a> TtIter<'a> {
        }
        impl<'a> TreeSink for OffsetTokenSink<'a> {
-            fn token(&mut self, _kind: SyntaxKind, n_tokens: u8) {
+            fn token(&mut self, kind: SyntaxKind, mut n_tokens: u8) {
+                if kind == SyntaxKind::LIFETIME {
+                    n_tokens = 2;
+                }
                for _ in 0..n_tokens {
                    self.cursor = self.cursor.bump_subtree();
                }
@@ -286,7 +308,7 @@ impl<'a> TtIter<'a> {
            }
        }
-        let buffer = TokenBuffer::new(self.inner.as_slice());
+        let buffer = TokenBuffer::new(&self.inner.as_slice());
        let mut src = SubtreeTokenSource::new(&buffer);
        let mut sink = OffsetTokenSink { cursor: buffer.begin(), error: false };
@@ -422,7 +444,7 @@ fn match_meta_var(kind: &str, input: &mut TtIter) -> ExpandResult<Option<Fragmen
                "tt" => input.expect_tt().map(Some).map_err(|()| err!()),
                "lifetime" => input
                    .expect_lifetime()
-                    .map(|ident| Some(tt::Leaf::Ident(ident.clone()).into()))
+                    .map(|tt| Some(tt))
                    .map_err(|()| err!("expected lifetime")),
                "literal" => input
                    .expect_literal()
diff --git a/crates/ra_mbe/src/subtree_source.rs b/crates/ra_mbe/src/subtree_source.rs
index 91e324db9..d7866452d 100644
--- a/crates/ra_mbe/src/subtree_source.rs
+++ b/crates/ra_mbe/src/subtree_source.rs
@@ -50,6 +50,26 @@ impl<'a> SubtreeTokenSource<'a> {
    }
    fn get(&self, pos: usize) -> Ref<Option<TtToken>> {
+        fn is_lifetime(c: Cursor) -> Option<(Cursor, SmolStr)> {
+            let tkn = c.token_tree();
+            if let Some(tt::TokenTree::Leaf(tt::Leaf::Punct(punct))) = tkn {
+                if punct.char == '\'' {
+                    let next = c.bump();
+                    if let Some(tt::TokenTree::Leaf(tt::Leaf::Ident(ident))) = next.token_tree() {
+                        let res_cursor = next.bump();
+                        let text = SmolStr::new("'".to_string() + &ident.to_string());
+                        return Some((res_cursor, text));
+                    } else {
+                        panic!("Next token must be ident : {:#?}", next.token_tree());
+                    }
+                }
+            }
+            None
+        }
        if pos < self.cached.borrow().len() {
            return Ref::map(self.cached.borrow(), |c| &c[pos]);
        }
@@ -63,6 +83,12 @@ impl<'a> SubtreeTokenSource<'a> {
                    continue;
                }
+                if let Some((curr, text)) = is_lifetime(cursor) {
+                    cached.push(Some(TtToken { kind: LIFETIME, is_joint_to_next: false, text }));
+                    self.cached_cursor.set(curr);
+                    continue;
+                }
                match cursor.token_tree() {
                    Some(tt::TokenTree::Leaf(leaf)) => {
                        cached.push(Some(convert_leaf(&leaf)));
@@ -132,27 +158,28 @@ fn convert_literal(l: &tt::Literal) -> TtToken {
    let kind = lex_single_syntax_kind(&l.text)
        .map(|(kind, _error)| kind)
        .filter(|kind| kind.is_literal())
-        .unwrap_or_else(|| match l.text.as_ref() {
+        .unwrap_or_else(|| panic!("Fail to convert given literal {:#?}", &l));
-            "true" => T![true],
-            "false" => T![false],
-            _ => panic!("Fail to convert given literal {:#?}", &l),
-        });
    TtToken { kind, is_joint_to_next: false, text: l.text.clone() }
 }
 fn convert_ident(ident: &tt::Ident) -> TtToken {
-    let kind = if ident.text.starts_with('\'') {
+    let kind = match ident.text.as_ref() {
-        LIFETIME
+        "true" => T![true],
-    } else {
+        "false" => T![false],
-        SyntaxKind::from_keyword(ident.text.as_str()).unwrap_or(IDENT)
+        i if i.starts_with('\'') => LIFETIME,
+        _ => SyntaxKind::from_keyword(ident.text.as_str()).unwrap_or(IDENT),
    };
    TtToken { kind, is_joint_to_next: false, text: ident.text.clone() }
 }
 fn convert_punct(p: tt::Punct) -> TtToken {
-    let kind = SyntaxKind::from_char(p.char).unwrap();
+    let kind = match SyntaxKind::from_char(p.char) {
+        None => panic!("{:#?} is not a valid punct", p),
+        Some(kind) => kind,
+    };
    let text = {
        let mut buf = [0u8; 4];
        let s: &str = p.char.encode_utf8(&mut buf);
diff --git a/crates/ra_mbe/src/syntax_bridge.rs b/crates/ra_mbe/src/syntax_bridge.rs
index 31e9b22e7..2b4390eb2 100644
--- a/crates/ra_mbe/src/syntax_bridge.rs
+++ b/crates/ra_mbe/src/syntax_bridge.rs
@@ -271,7 +271,7 @@ struct RawConvertor<'a> {
    inner: std::slice::Iter<'a, RawToken>,
 }
-trait SrcToken {
+trait SrcToken: std::fmt::Debug {
    fn kind(&self) -> SyntaxKind;
    fn to_char(&self) -> Option<char>;
@@ -361,8 +361,12 @@ trait TokenConvertor {
                    Some(next) if next.kind().is_punct() => tt::Spacing::Joint,
                    _ => tt::Spacing::Alone,
                };
-                let char = token.to_char().expect("Token from lexer must be single char");
+                let char = match token.to_char() {
+                    Some(c) => c,
+                    None => {
+                        panic!("Token from lexer must be single char: token = {:#?}", token);
+                    }
+                };
                tt::Leaf::from(tt::Punct { char, spacing, id: self.id_alloc().alloc(range) }).into()
            }
        } else {
@@ -372,10 +376,29 @@ trait TokenConvertor {
                };
            }
            let leaf: tt::Leaf = match k {
-                T![true] | T![false] => make_leaf!(Literal),
+                T![true] | T![false] => make_leaf!(Ident),
-                IDENT | LIFETIME => make_leaf!(Ident),
+                IDENT => make_leaf!(Ident),
                k if k.is_keyword() => make_leaf!(Ident),
                k if k.is_literal() => make_leaf!(Literal),
+                LIFETIME => {
+                    let char_unit = TextUnit::from_usize(1);
+                    let r = TextRange::offset_len(range.start(), char_unit);
+                    let apostrophe = tt::Leaf::from(tt::Punct {
+                        char: '\'',
+                        spacing: tt::Spacing::Joint,
+                        id: self.id_alloc().alloc(r),
+                    });
+                    result.push(apostrophe.into());
+                    let r =
+                        TextRange::offset_len(range.start() + char_unit, range.len() - char_unit);
+                    let ident = tt::Leaf::from(tt::Ident {
+                        text: SmolStr::new(&token.to_text()[1..]),
+                        id: self.id_alloc().alloc(r),
+                    });
+                    result.push(ident.into());
+                    return;
+                }
                _ => return,
            };
@@ -455,6 +478,7 @@ impl Convertor {
    }
 }
+#[derive(Debug)]
 enum SynToken {
    Ordiniary(SyntaxToken),
    Punch(SyntaxToken, TextUnit),
@@ -592,11 +616,14 @@ fn delim_to_str(d: Option<tt::DelimiterKind>, closing: bool) -> SmolStr {
 }
 impl<'a> TreeSink for TtTreeSink<'a> {
-    fn token(&mut self, kind: SyntaxKind, n_tokens: u8) {
+    fn token(&mut self, kind: SyntaxKind, mut n_tokens: u8) {
        if kind == L_DOLLAR || kind == R_DOLLAR {
            self.cursor = self.cursor.bump_subtree();
            return;
        }
+        if kind == LIFETIME {
+            n_tokens = 2;
+        }
        let mut last = self.cursor;
        for _ in 0..n_tokens {
diff --git a/crates/ra_mbe/src/tests.rs b/crates/ra_mbe/src/tests.rs
index 5d1274d21..100ed41f2 100644
--- a/crates/ra_mbe/src/tests.rs
+++ b/crates/ra_mbe/src/tests.rs
@@ -215,6 +215,33 @@ SUBTREE $
 }
 #[test]
+fn test_lifetime_split() {
+    parse_macro(
+        r#"
+macro_rules! foo {
+    ($($t:tt)*) => { $($t)*}
+}
+"#,
+    )
+    .assert_expand(
+        r#"foo!(static bar: &'static str = "hello";);"#,
+        r#"
+SUBTREE $
+  IDENT   static 17
+  IDENT   bar 18
+  PUNCH   : [alone] 19
+  PUNCH   & [alone] 20
+  PUNCH   ' [joint] 21
+  IDENT   static 22
+  IDENT   str 23
+  PUNCH   = [alone] 24
+  LITERAL "hello" 25
+  PUNCH   ; [joint] 26
+"#,
+    );
+}
+#[test]
 fn test_expr_order() {
    let expanded = parse_macro(
        r#"
@@ -989,6 +1016,36 @@ fn test_literal() {
 }
 #[test]
+fn test_boolean_is_ident() {
+    parse_macro(
+        r#"
+        macro_rules! foo {
+              ($lit0:literal, $lit1:literal) => { const VALUE: (bool,bool) = ($lit0,$lit1); };
+        }
+"#,
+    )
+    .assert_expand(
+        r#"foo!(true,false);"#,
+        r#"
+SUBTREE $
+  IDENT   const 14
+  IDENT   VALUE 15
+  PUNCH   : [alone] 16
+  SUBTREE () 17
+    IDENT   bool 18
+    PUNCH   , [alone] 19
+    IDENT   bool 20
+  PUNCH   = [alone] 21
+  SUBTREE () 22
+    IDENT   true 29
+    PUNCH   , [joint] 25
+    IDENT   false 31
+  PUNCH   ; [alone] 28
+"#,
+    );
+}
+#[test]
 fn test_vis() {
    parse_macro(
        r#"
diff --git a/crates/ra_mbe/src/tt_iter.rs b/crates/ra_mbe/src/tt_iter.rs
index 100184e66..46c420718 100644
--- a/crates/ra_mbe/src/tt_iter.rs
+++ b/crates/ra_mbe/src/tt_iter.rs
@@ -40,9 +40,11 @@ impl<'a> TtIter<'a> {
        }
    }
-    pub(crate) fn expect_literal(&mut self) -> Result<&'a tt::Literal, ()> {
+    pub(crate) fn expect_literal(&mut self) -> Result<&'a tt::Leaf, ()> {
-        match self.expect_leaf()? {
+        let it = self.expect_leaf()?;
-            tt::Leaf::Literal(it) => Ok(it),
+        match it {
+            tt::Leaf::Literal(_) => Ok(it),
+            tt::Leaf::Ident(ident) if ident.text == "true" || ident.text == "false" => Ok(it),
            _ => Err(()),
        }
    }
diff --git a/crates/ra_proc_macro/src/lib.rs b/crates/ra_proc_macro/src/lib.rs
index b200fd126..004943b9e 100644
--- a/crates/ra_proc_macro/src/lib.rs
+++ b/crates/ra_proc_macro/src/lib.rs
@@ -2,7 +2,7 @@
 //!
 //! We separate proc-macro expanding logic to an extern program to allow
 //! different implementations (e.g. wasm or dylib loading). And this crate
-//! is used to provide basic infrastructure  for communication between two
+//! is used to provide basic infrastructure for communication between two
 //! processes: Client (RA itself), Server (the external program)
 mod rpc;
@@ -13,6 +13,7 @@ use process::{ProcMacroProcessSrv, ProcMacroProcessThread};
 use ra_tt::{SmolStr, Subtree};
 use std::{
    ffi::OsStr,
+    io,
    path::{Path, PathBuf},
    sync::Arc,
 };
@@ -57,14 +58,10 @@ pub struct ProcMacroClient {
 }
 impl ProcMacroClient {
-    pub fn extern_process<I, S>(
+    pub fn extern_process(
-        process_path: &Path,
+        process_path: PathBuf,
-        args: I,
+        args: impl IntoIterator<Item = impl AsRef<OsStr>>,
-    ) -> Result<ProcMacroClient, std::io::Error>
+    ) -> io::Result<ProcMacroClient> {
-    where
-        I: IntoIterator<Item = S>,
-        S: AsRef<OsStr>,
-    {
        let (thread, process) = ProcMacroProcessSrv::run(process_path, args)?;
        Ok(ProcMacroClient {
            kind: ProcMacroClientKind::Process { process: Arc::new(process), thread },
@@ -84,7 +81,7 @@ impl ProcMacroClient {
            ProcMacroClientKind::Process { process, .. } => {
                let macros = match process.find_proc_macros(dylib_path) {
                    Err(err) => {
-                        eprintln!("Fail to find proc macro. Error: {:#?}", err);
+                        eprintln!("Failed to find proc macros. Error: {:#?}", err);
                        return vec![];
                    }
                    Ok(macros) => macros,
diff --git a/crates/ra_proc_macro/src/msg.rs b/crates/ra_proc_macro/src/msg.rs
index aa95bcc8f..95d9b8804 100644
--- a/crates/ra_proc_macro/src/msg.rs
+++ b/crates/ra_proc_macro/src/msg.rs
@@ -1,4 +1,4 @@
-//! Defines messages for cross-process message based on `ndjson` wire protocol
+//! Defines messages for cross-process message passing based on `ndjson` wire protocol
 use std::{
    convert::TryFrom,
@@ -31,7 +31,7 @@ macro_rules! impl_try_from_response {
            fn try_from(value: Response) -> Result<Self, Self::Error> {
                match value {
                    Response::$tag(res) => Ok(res),
-                    _ => Err("Fail to convert from response"),
+                    _ => Err(concat!("Failed to convert response to ", stringify!($tag))),
                }
            }
        }
@@ -53,18 +53,16 @@ pub enum ErrorCode {
    ExpansionError,
 }
-pub trait Message: Sized + Serialize + DeserializeOwned {
+pub trait Message: Serialize + DeserializeOwned {
-    fn read(r: &mut impl BufRead) -> io::Result<Option<Self>> {
+    fn read(inp: &mut impl BufRead) -> io::Result<Option<Self>> {
-        let text = match read_json(r)? {
+        Ok(match read_json(inp)? {
-            None => return Ok(None),
+            None => None,
-            Some(text) => text,
+            Some(text) => Some(serde_json::from_str(&text)?),
-        };
+        })
-        let msg = serde_json::from_str(&text)?;
-        Ok(Some(msg))
    }
-    fn write(self, w: &mut impl Write) -> io::Result<()> {
+    fn write(self, out: &mut impl Write) -> io::Result<()> {
        let text = serde_json::to_string(&self)?;
-        write_json(w, &text)
+        write_json(out, &text)
    }
 }
@@ -73,15 +71,12 @@ impl Message for Response {}
 fn read_json(inp: &mut impl BufRead) -> io::Result<Option<String>> {
    let mut buf = String::new();
-    if inp.read_line(&mut buf)? == 0 {
+    inp.read_line(&mut buf)?;
-        return Ok(None);
+    buf.pop(); // Remove traling '\n'
-    }
+    Ok(match buf.len() {
-    // Remove ending '\n'
+        0 => None,
-    let buf = &buf[..buf.len() - 1];
+        _ => Some(buf),
-    if buf.is_empty() {
+    })
-        return Ok(None);
-    }
-    Ok(Some(buf.to_string()))
 }
 fn write_json(out: &mut impl Write, msg: &str) -> io::Result<()> {
diff --git a/crates/ra_proc_macro/src/process.rs b/crates/ra_proc_macro/src/process.rs
index f851570bc..673f80a7a 100644
--- a/crates/ra_proc_macro/src/process.rs
+++ b/crates/ra_proc_macro/src/process.rs
@@ -9,7 +9,7 @@ use crate::rpc::{ExpansionResult, ExpansionTask, ListMacrosResult, ListMacrosTas
 use io::{BufRead, BufReader};
 use std::{
    convert::{TryFrom, TryInto},
-    ffi::OsStr,
+    ffi::{OsStr, OsString},
    io::{self, Write},
    path::{Path, PathBuf},
    process::{Child, Command, Stdio},
@@ -28,66 +28,11 @@ pub(crate) struct ProcMacroProcessThread {
    handle: jod_thread::JoinHandle<()>,
 }
-struct Task {
-    req: Request,
-    result_tx: Sender<Option<Response>>,
-}
-struct Process {
-    path: PathBuf,
-    child: Child,
-}
-impl Drop for Process {
-    fn drop(&mut self) {
-        let _ = self.child.kill();
-    }
-}
-impl Process {
-    fn run<I, S>(process_path: &Path, args: I) -> Result<Process, io::Error>
-    where
-        I: IntoIterator<Item = S>,
-        S: AsRef<OsStr>,
-    {
-        let child = Command::new(process_path.clone())
-            .args(args)
-            .stdin(Stdio::piped())
-            .stdout(Stdio::piped())
-            .stderr(Stdio::null())
-            .spawn()?;
-        Ok(Process { path: process_path.into(), child })
-    }
-    fn restart(&mut self) -> Result<(), io::Error> {
-        let _ = self.child.kill();
-        self.child = Command::new(self.path.clone())
-            .stdin(Stdio::piped())
-            .stdout(Stdio::piped())
-            .stderr(Stdio::null())
-            .spawn()?;
-        Ok(())
-    }
-    fn stdio(&mut self) -> Option<(impl Write, impl BufRead)> {
-        let stdin = self.child.stdin.take()?;
-        let stdout = self.child.stdout.take()?;
-        let read = BufReader::new(stdout);
-        Some((stdin, read))
-    }
-}
 impl ProcMacroProcessSrv {
-    pub fn run<I, S>(
+    pub fn run(
-        process_path: &Path,
+        process_path: PathBuf,
-        args: I,
+        args: impl IntoIterator<Item = impl AsRef<OsStr>>,
-    ) -> Result<(ProcMacroProcessThread, ProcMacroProcessSrv), io::Error>
+    ) -> io::Result<(ProcMacroProcessThread, ProcMacroProcessSrv)> {
-    where
-        I: IntoIterator<Item = S>,
-        S: AsRef<OsStr>,
-    {
        let process = Process::run(process_path, args)?;
        let (task_tx, task_rx) = bounded(0);
@@ -197,11 +142,62 @@ fn client_loop(task_rx: Receiver<Task>, mut process: Process) {
    }
 }
+struct Task {
+    req: Request,
+    result_tx: Sender<Option<Response>>,
+}
+struct Process {
+    path: PathBuf,
+    args: Vec<OsString>,
+    child: Child,
+}
+impl Drop for Process {
+    fn drop(&mut self) {
+        let _ = self.child.kill();
+    }
+}
+impl Process {
+    fn run(
+        path: PathBuf,
+        args: impl IntoIterator<Item = impl AsRef<OsStr>>,
+    ) -> io::Result<Process> {
+        let args = args.into_iter().map(|s| s.as_ref().into()).collect();
+        let child = mk_child(&path, &args)?;
+        Ok(Process { path, args, child })
+    }
+    fn restart(&mut self) -> io::Result<()> {
+        let _ = self.child.kill();
+        self.child = mk_child(&self.path, &self.args)?;
+        Ok(())
+    }
+    fn stdio(&mut self) -> Option<(impl Write, impl BufRead)> {
+        let stdin = self.child.stdin.take()?;
+        let stdout = self.child.stdout.take()?;
+        let read = BufReader::new(stdout);
+        Some((stdin, read))
+    }
+}
+fn mk_child(path: &Path, args: impl IntoIterator<Item = impl AsRef<OsStr>>) -> io::Result<Child> {
+    Command::new(&path)
+        .args(args)
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::null())
+        .spawn()
+}
 fn send_request(
    mut writer: &mut impl Write,
    mut reader: &mut impl BufRead,
    req: Request,
-) -> Result<Option<Response>, io::Error> {
+) -> io::Result<Option<Response>> {
    req.write(&mut writer)?;
    Ok(Response::read(&mut reader)?)
 }
diff --git a/crates/ra_proc_macro/src/rpc.rs b/crates/ra_proc_macro/src/rpc.rs
index 66b3f55db..4ce485926 100644
--- a/crates/ra_proc_macro/src/rpc.rs
+++ b/crates/ra_proc_macro/src/rpc.rs
@@ -1,9 +1,9 @@
-//! Data struture serialization related stuffs for RPC
+//! Data struture serialization related stuff for RPC
 //!
-//! Define all necessary rpc serialization data structure,
+//! Defines all necessary rpc serialization data structures,
-//! which include ra_tt related data and some task messages.
+//! which includes `ra_tt` related data and some task messages.
-//! Although adding Serialize and Deserialize trait to ra_tt directly seem to be much easier,
+//! Although adding `Serialize` and `Deserialize` traits to `ra_tt` directly seems
-//! we deliberately duplicate the ra_tt struct with #[serde(with = "XXDef")]
+//! to be much easier, we deliberately duplicate `ra_tt` structs with `#[serde(with = "XXDef")]`
 //! for separation of code responsibility.
 use ra_tt::{
@@ -34,15 +34,15 @@ pub struct ListMacrosResult {
 pub struct ExpansionTask {
    /// Argument of macro call.
    ///
-    /// In custom derive that would be a struct or enum; in attribute-like macro - underlying
+    /// In custom derive this will be a struct or enum; in attribute-like macro - underlying
    /// item; in function-like macro - the macro body.
    #[serde(with = "SubtreeDef")]
    pub macro_body: Subtree,
-    /// Names of macros to expand.
+    /// Name of macro to expand.
    ///
-    /// In custom derive those are names of derived traits (`Serialize`, `Getters`, etc.). In
+    /// In custom derive this is the name of the derived trait (`Serialize`, `Getters`, etc.).
-    /// attribute-like and functiona-like macros - single name of macro itself (`show_streams`).
+    /// In attribute-like and function-like macros - single name of macro itself (`show_streams`).
    pub macro_name: String,
    /// Possible attributes for the attribute-like macros.
diff --git a/crates/ra_proc_macro_srv/src/cli.rs b/crates/ra_proc_macro_srv/src/cli.rs
index c771f2b38..5f1f3ba3c 100644
--- a/crates/ra_proc_macro_srv/src/cli.rs
+++ b/crates/ra_proc_macro_srv/src/cli.rs
@@ -2,55 +2,43 @@
 use crate::{expand_task, list_macros};
 use ra_proc_macro::msg::{self, Message};
 use std::io;
-fn read_request() -> Result<Option<msg::Request>, io::Error> {
-    let stdin = io::stdin();
-    let mut stdin = stdin.lock();
-    msg::Request::read(&mut stdin)
-}
-fn write_response(res: Result<msg::Response, String>) -> Result<(), io::Error> {
-    let msg: msg::Response = match res {
-        Ok(res) => res,
-        Err(err) => msg::Response::Error(msg::ResponseError {
-            code: msg::ErrorCode::ExpansionError,
-            message: err,
-        }),
-    };
-    let stdout = io::stdout();
-    let mut stdout = stdout.lock();
-    msg.write(&mut stdout)
-}
 pub fn run() {
    loop {
        let req = match read_request() {
            Err(err) => {
-                eprintln!("Read message error on ra_proc_macro_srv: {}", err.to_string());
+                eprintln!("Read message error on ra_proc_macro_srv: {}", err);
                continue;
            }
            Ok(None) => continue,
            Ok(Some(req)) => req,
        };
-        match req {
+        let res = match req {
-            msg::Request::ListMacro(task) => {
+            msg::Request::ListMacro(task) => Ok(msg::Response::ListMacro(list_macros(&task))),
-                if let Err(err) =
-                    write_response(list_macros(&task).map(|it| msg::Response::ListMacro(it)))
-                {
-                    eprintln!("Write message error on list macro: {}", err);
-                }
-            }
            msg::Request::ExpansionMacro(task) => {
-                if let Err(err) =
+                expand_task(&task).map(msg::Response::ExpansionMacro)
-                    write_response(expand_task(&task).map(|it| msg::Response::ExpansionMacro(it)))
-                {
-                    eprintln!("Write message error on expansion macro: {}", err);
-                }
            }
+        };
+        let msg = res.unwrap_or_else(|err| {
+            msg::Response::Error(msg::ResponseError {
+                code: msg::ErrorCode::ExpansionError,
+                message: err,
+            })
+        });
+        if let Err(err) = write_response(msg) {
+            eprintln!("Write message error: {}", err);
        }
    }
 }
+fn read_request() -> io::Result<Option<msg::Request>> {
+    msg::Request::read(&mut io::stdin().lock())
+}
+fn write_response(msg: msg::Response) -> io::Result<()> {
+    msg.write(&mut io::stdout().lock())
+}
diff --git a/crates/ra_proc_macro_srv/src/dylib.rs b/crates/ra_proc_macro_srv/src/dylib.rs
index 16bd7466e..d202eb0fd 100644
--- a/crates/ra_proc_macro_srv/src/dylib.rs
+++ b/crates/ra_proc_macro_srv/src/dylib.rs
@@ -9,43 +9,37 @@ use libloading::Library;
 use memmap::Mmap;
 use ra_proc_macro::ProcMacroKind;
-use std::io::Error as IoError;
+use std::io;
-use std::io::ErrorKind as IoErrorKind;
 const NEW_REGISTRAR_SYMBOL: &str = "_rustc_proc_macro_decls_";
-fn invalid_data_err(e: impl Into<Box<dyn std::error::Error + Send + Sync>>) -> IoError {
+fn invalid_data_err(e: impl Into<Box<dyn std::error::Error + Send + Sync>>) -> io::Error {
-    IoError::new(IoErrorKind::InvalidData, e)
+    io::Error::new(io::ErrorKind::InvalidData, e)
 }
 fn is_derive_registrar_symbol(symbol: &str) -> bool {
    symbol.contains(NEW_REGISTRAR_SYMBOL)
 }
-fn find_registrar_symbol(file: &Path) -> Result<Option<String>, IoError> {
+fn find_registrar_symbol(file: &Path) -> io::Result<Option<String>> {
    let file = File::open(file)?;
    let buffer = unsafe { Mmap::map(&file)? };
    let object = Object::parse(&buffer).map_err(invalid_data_err)?;
-    match object {
+    let name = match object {
        Object::Elf(elf) => {
            let symbols = elf.dynstrtab.to_vec().map_err(invalid_data_err)?;
-            let name =
+            symbols.into_iter().find(|s| is_derive_registrar_symbol(s)).map(&str::to_owned)
-                symbols.iter().find(|s| is_derive_registrar_symbol(s)).map(|s| s.to_string());
-            Ok(name)
-        }
-        Object::PE(pe) => {
-            let name = pe
-                .exports
-                .iter()
-                .flat_map(|s| s.name)
-                .find(|s| is_derive_registrar_symbol(s))
-                .map(|s| s.to_string());
-            Ok(name)
        }
+        Object::PE(pe) => pe
+            .exports
+            .iter()
+            .flat_map(|s| s.name)
+            .find(|s| is_derive_registrar_symbol(s))
+            .map(&str::to_owned),
        Object::Mach(Mach::Binary(binary)) => {
            let exports = binary.exports().map_err(invalid_data_err)?;
-            let name = exports
+            exports
                .iter()
                .map(|s| {
                    // In macos doc:
@@ -59,11 +53,11 @@ fn find_registrar_symbol(file: &Path) -> Result<Option<String>, IoError> {
                    }
                })
                .find(|s| is_derive_registrar_symbol(s))
-                .map(|s| s.to_string());
+                .map(&str::to_owned)
-            Ok(name)
        }
-        _ => Ok(None),
+        _ => return Ok(None),
-    }
+    };
+    return Ok(name);
 }
 /// Loads dynamic library in platform dependent manner.
@@ -93,15 +87,16 @@ fn load_library(file: &Path) -> Result<Library, libloading::Error> {
 }
 struct ProcMacroLibraryLibloading {
-    // Hold the dylib to prevent it for unloadeding
+    // Hold the dylib to prevent it from unloading
    _lib: Library,
    exported_macros: Vec<bridge::client::ProcMacro>,
 }
 impl ProcMacroLibraryLibloading {
-    fn open(file: &Path) -> Result<Self, IoError> {
+    fn open(file: &Path) -> io::Result<Self> {
-        let symbol_name = find_registrar_symbol(file)?
+        let symbol_name = find_registrar_symbol(file)?.ok_or_else(|| {
-            .ok_or(invalid_data_err(format!("Cannot find registrar symbol in file {:?}", file)))?;
+            invalid_data_err(format!("Cannot find registrar symbol in file {}", file.display()))
+        })?;
        let lib = load_library(file).map_err(invalid_data_err)?;
        let exported_macros = {
@@ -121,18 +116,16 @@ pub struct Expander {
 }
 impl Expander {
-    pub fn new<P: AsRef<Path>>(lib: &P) -> Result<Expander, String> {
+    pub fn new(lib: &Path) -> Result<Expander, String> {
-        let mut libs = vec![];
+        // Some libraries for dynamic loading require canonicalized path even when it is
-        /* Some libraries for dynamic loading require canonicalized path (even when it is
+        // already absolute
-        already absolute
+        let lib = lib
-        */
+            .canonicalize()
-        let lib =
+            .unwrap_or_else(|err| panic!("Cannot canonicalize {}: {:?}", lib.display(), err));
-            lib.as_ref().canonicalize().expect(&format!("Cannot canonicalize {:?}", lib.as_ref()));
        let library = ProcMacroLibraryImpl::open(&lib).map_err(|e| e.to_string())?;
-        libs.push(library);
-        Ok(Expander { libs })
+        Ok(Expander { libs: vec![library] })
    }
    pub fn expand(
@@ -176,7 +169,6 @@ impl Expander {
                            parsed_attributes,
                            parsed_body,
                        );
                        return res.map(|it| it.subtree);
                    }
                    _ => continue,
@@ -187,26 +179,21 @@ impl Expander {
        Err(bridge::PanicMessage::String("Nothing to expand".to_string()))
    }
-    pub fn list_macros(&self) -> Result<Vec<(String, ProcMacroKind)>, bridge::PanicMessage> {
+    pub fn list_macros(&self) -> Vec<(String, ProcMacroKind)> {
-        let mut result = vec![];
+        self.libs
+            .iter()
-        for lib in &self.libs {
+            .flat_map(|it| &it.exported_macros)
-            for proc_macro in &lib.exported_macros {
+            .map(|proc_macro| match proc_macro {
-                let res = match proc_macro {
+                bridge::client::ProcMacro::CustomDerive { trait_name, .. } => {
-                    bridge::client::ProcMacro::CustomDerive { trait_name, .. } => {
+                    (trait_name.to_string(), ProcMacroKind::CustomDerive)
-                        (trait_name.to_string(), ProcMacroKind::CustomDerive)
+                }
-                    }
+                bridge::client::ProcMacro::Bang { name, .. } => {
-                    bridge::client::ProcMacro::Bang { name, .. } => {
+                    (name.to_string(), ProcMacroKind::FuncLike)
-                        (name.to_string(), ProcMacroKind::FuncLike)
+                }
-                    }
+                bridge::client::ProcMacro::Attr { name, .. } => {
-                    bridge::client::ProcMacro::Attr { name, .. } => {
+                    (name.to_string(), ProcMacroKind::Attr)
-                        (name.to_string(), ProcMacroKind::Attr)
+                }
-                    }
+            })
-                };
+            .collect()
-                result.push(res);
-            }
-        }
-        Ok(result)
    }
 }
diff --git a/crates/ra_proc_macro_srv/src/lib.rs b/crates/ra_proc_macro_srv/src/lib.rs
index c62b0ed89..3aca859db 100644
--- a/crates/ra_proc_macro_srv/src/lib.rs
+++ b/crates/ra_proc_macro_srv/src/lib.rs
@@ -3,10 +3,10 @@
 //! This library is able to call compiled Rust custom derive dynamic libraries on arbitrary code.
 //! The general idea here is based on https://github.com/fedochet/rust-proc-macro-expander.
 //!
-//! But we change some several design for fitting RA needs:
+//! But we adapt it to better fit RA needs:
 //!
-//! * We use `ra_tt` for proc-macro `TokenStream` server, it is easy to manipute and interact with
+//! * We use `ra_tt` for proc-macro `TokenStream` server, it is easier to manipulate and interact with
-//!   RA then proc-macro2 token stream.
+//!   RA than `proc-macro2` token stream.
 //! * By **copying** the whole rustc `lib_proc_macro` code, we are able to build this with `stable`
 //!   rustc rather than `unstable`. (Although in gerenal ABI compatibility is still an issue)
@@ -21,36 +21,28 @@ mod dylib;
 use proc_macro::bridge::client::TokenStream;
 use ra_proc_macro::{ExpansionResult, ExpansionTask, ListMacrosResult, ListMacrosTask};
+use std::path::Path;
 pub(crate) fn expand_task(task: &ExpansionTask) -> Result<ExpansionResult, String> {
-    let expander = dylib::Expander::new(&task.lib)
+    let expander = create_expander(&task.lib);
-        .expect(&format!("Cannot expand with provided libraries: ${:?}", &task.lib));
    match expander.expand(&task.macro_name, &task.macro_body, task.attributes.as_ref()) {
        Ok(expansion) => Ok(ExpansionResult { expansion }),
        Err(msg) => {
-            let reason = format!(
+            Err(format!("Cannot perform expansion for {}: error {:?}", &task.macro_name, msg))
-                "Cannot perform expansion for {}: error {:?}!",
-                &task.macro_name,
-                msg.as_str()
-            );
-            Err(reason)
        }
    }
 }
-pub(crate) fn list_macros(task: &ListMacrosTask) -> Result<ListMacrosResult, String> {
+pub(crate) fn list_macros(task: &ListMacrosTask) -> ListMacrosResult {
-    let expander = dylib::Expander::new(&task.lib)
+    let expander = create_expander(&task.lib);
-        .expect(&format!("Cannot expand with provided libraries: ${:?}", &task.lib));
-    match expander.list_macros() {
+    ListMacrosResult { macros: expander.list_macros() }
-        Ok(macros) => Ok(ListMacrosResult { macros }),
+}
-        Err(msg) => {
-            let reason =
+fn create_expander(lib: &Path) -> dylib::Expander {
-                format!("Cannot perform expansion for {:?}: error {:?}!", &task.lib, msg.as_str());
+    dylib::Expander::new(lib)
-            Err(reason)
+        .unwrap_or_else(|err| panic!("Cannot create expander for {}: {:?}", lib.display(), err))
-        }
-    }
 }
 pub mod cli;
diff --git a/crates/ra_proc_macro_srv/src/rustc_server.rs b/crates/ra_proc_macro_srv/src/rustc_server.rs
index ec0d35692..f481d70b2 100644
--- a/crates/ra_proc_macro_srv/src/rustc_server.rs
+++ b/crates/ra_proc_macro_srv/src/rustc_server.rs
@@ -6,7 +6,7 @@
 //! The original idea from fedochet is using proc-macro2 as backend,
 //! we use ra_tt instead for better intergation with RA.
 //!
-//! FIXME: No span and source file informatin is implemented yet
+//! FIXME: No span and source file information is implemented yet
 use crate::proc_macro::bridge::{self, server};
 use ra_tt as tt;
@@ -76,7 +76,16 @@ impl Extend<TokenTree> for TokenStream {
 impl Extend<TokenStream> for TokenStream {
    fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
        for item in streams {
-            self.subtree.token_trees.extend(&mut item.into_iter())
+            for tkn in item {
+                match tkn {
+                    tt::TokenTree::Subtree(subtree) if subtree.delimiter.is_none() => {
+                        self.subtree.token_trees.extend(subtree.token_trees);
+                    }
+                    _ => {
+                        self.subtree.token_trees.push(tkn);
+                    }
+                }
+            }
        }
    }
 }
diff --git a/crates/ra_proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt b/crates/ra_proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
index 24507d98d..1f5d940fa 100644
--- a/crates/ra_proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
+++ b/crates/ra_proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
@@ -25,8 +25,7 @@ SUBTREE $
      SUBTREE () 4294967295
        IDENT   feature 4294967295
        PUNCH   = [alone] 4294967295
-        SUBTREE $
+        LITERAL "cargo-clippy" 0
-          LITERAL "cargo-clippy" 0
        PUNCH   , [alone] 4294967295
        IDENT   allow 4294967295
        SUBTREE () 4294967295
diff --git a/crates/ra_proc_macro_srv/src/tests/utils.rs b/crates/ra_proc_macro_srv/src/tests/utils.rs
index 1ee409449..2139ec7a4 100644
--- a/crates/ra_proc_macro_srv/src/tests/utils.rs
+++ b/crates/ra_proc_macro_srv/src/tests/utils.rs
@@ -60,6 +60,6 @@ pub fn list(crate_name: &str, version: &str) -> Vec<String> {
    let path = fixtures::dylib_path(crate_name, version);
    let task = ListMacrosTask { lib: path };
-    let res = list_macros(&task).unwrap();
+    let res = list_macros(&task);
    res.macros.into_iter().map(|(name, kind)| format!("{} [{:?}]", name, kind)).collect()
 }
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index b50cda06f..84008b2e3 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -303,8 +303,7 @@ pub fn load_extern_resources(
                    if message.target.kind.contains(&"proc-macro".to_string()) {
                        let package_id = message.package_id;
                        // Skip rmeta file
-                        if let Some(filename) =
+                        if let Some(filename) = message.filenames.iter().find(|name| is_dylib(name))
-                            message.filenames.iter().filter(|name| is_dylib(name)).next()
                        {
                            res.proc_dylib_paths.insert(package_id, filename.clone());
                        }
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index ea41bf85d..06df8495c 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -10,8 +10,8 @@ use ra_text_edit::TextEditBuilder;
 use rustc_hash::FxHashMap;
 use crate::{
-    AstNode, Direction, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxNodePtr, SyntaxToken,
+    AstNode, Direction, NodeOrToken, SyntaxElement, SyntaxKind, SyntaxNode, SyntaxNodePtr,
-    TextRange, TextUnit,
+    SyntaxToken, TextRange, TextUnit,
 };
 /// Returns ancestors of the node at the offset, sorted by length. This should
@@ -90,6 +90,10 @@ pub fn neighbor<T: AstNode>(me: &T, direction: Direction) -> Option<T> {
    me.syntax().siblings(direction).skip(1).find_map(T::cast)
 }
+pub fn has_errors(node: &SyntaxNode) -> bool {
+    node.children().any(|it| it.kind() == SyntaxKind::ERROR)
+}
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub enum InsertPosition<T> {
    First,
diff --git a/crates/ra_syntax/src/ast/edit.rs b/crates/ra_syntax/src/ast/edit.rs
index 9e5411ee5..26e4576ff 100644
--- a/crates/ra_syntax/src/ast/edit.rs
+++ b/crates/ra_syntax/src/ast/edit.rs
@@ -307,7 +307,11 @@ impl ast::UseTree {
        fn split_path_prefix(prefix: &ast::Path) -> Option<ast::Path> {
            let parent = prefix.parent_path()?;
-            let mut res = make::path_unqualified(parent.segment()?);
+            let segment = parent.segment()?;
+            if algo::has_errors(segment.syntax()) {
+                return None;
+            }
+            let mut res = make::path_unqualified(segment);
            for p in iter::successors(parent.parent_path(), |it| it.parent_path()) {
                res = make::path_qualified(res, p.segment()?);
            }
diff --git a/crates/rust-analyzer/src/bin/args.rs b/crates/rust-analyzer/src/bin/args.rs
index 5e19253a6..b14409c39 100644
--- a/crates/rust-analyzer/src/bin/args.rs
+++ b/crates/rust-analyzer/src/bin/args.rs
@@ -84,7 +84,7 @@ impl Args {
                if matches.contains(["-h", "--help"]) {
                    eprintln!(
                        "\
-ra-cli-parse
+rust-analyzer parse
 USAGE:
    rust-analyzer parse [FLAGS]
@@ -104,7 +104,7 @@ FLAGS:
                if matches.contains(["-h", "--help"]) {
                    eprintln!(
                        "\
-ra-cli-symbols
+rust-analyzer symbols
 USAGE:
    rust-analyzer highlight [FLAGS]
@@ -123,7 +123,7 @@ FLAGS:
                if matches.contains(["-h", "--help"]) {
                    eprintln!(
                        "\
-ra-cli-highlight
+rust-analyzer highlight
 USAGE:
    rust-analyzer highlight [FLAGS]
@@ -143,7 +143,7 @@ FLAGS:
                if matches.contains(["-h", "--help"]) {
                    eprintln!(
                        "\
-ra-cli-analysis-stats
+rust-analyzer analysis-stats
 USAGE:
    rust-analyzer analysis-stats [FLAGS] [OPTIONS] [PATH]
@@ -193,7 +193,7 @@ ARGS:
                if matches.contains(["-h", "--help"]) {
                    eprintln!(
                        "\
-rust-analyzer-analysis-bench
+rust-analyzer analysis-bench
 USAGE:
    rust-analyzer analysis-bench [FLAGS] [OPTIONS]
@@ -236,7 +236,7 @@ ARGS:
                if matches.contains(["-h", "--help"]) {
                    eprintln!(
                        "\
-ra-cli-diagnostics
+rust-analyzer diagnostics
 USAGE:
    rust-analyzer diagnostics [FLAGS] [PATH]
@@ -269,7 +269,7 @@ ARGS:
            _ => {
                eprintln!(
                    "\
-ra-cli
+rust-analyzer
 USAGE:
    rust-analyzer <SUBCOMMAND>
@@ -281,6 +281,8 @@ SUBCOMMANDS:
    analysis-bench
    analysis-stats
    highlight
+    diagnostics
+    proc-macro
    parse
    symbols"
                );
diff --git a/crates/rust-analyzer/src/bin/main.rs b/crates/rust-analyzer/src/bin/main.rs
index 28b67cfe2..e8d5dad65 100644
--- a/crates/rust-analyzer/src/bin/main.rs
+++ b/crates/rust-analyzer/src/bin/main.rs
@@ -51,7 +51,7 @@ fn main() -> Result<()> {
            cli::diagnostics(path.as_ref(), load_output_dirs, with_proc_macro, all)?
        }
-        args::Command::ProcMacro => run_proc_macro_sv()?,
+        args::Command::ProcMacro => run_proc_macro_srv()?,
        args::Command::RunServer => run_server()?,
        args::Command::Version => println!("rust-analyzer {}", env!("REV")),
    }
@@ -65,7 +65,7 @@ fn setup_logging() -> Result<()> {
    Ok(())
 }
-fn run_proc_macro_sv() -> Result<()> {
+fn run_proc_macro_srv() -> Result<()> {
    ra_proc_macro_srv::cli::run();
    Ok(())
 }
diff --git a/crates/rust-analyzer/src/cli/load_cargo.rs b/crates/rust-analyzer/src/cli/load_cargo.rs
index 762f776fe..d0a71120a 100644
--- a/crates/rust-analyzer/src/cli/load_cargo.rs
+++ b/crates/rust-analyzer/src/cli/load_cargo.rs
@@ -76,7 +76,7 @@ pub(crate) fn load_cargo(
        ProcMacroClient::dummy()
    } else {
        let path = std::env::current_exe()?;
-        ProcMacroClient::extern_process(&path, &["proc-macro"]).unwrap()
+        ProcMacroClient::extern_process(path, &["proc-macro"]).unwrap()
    };
    let host = load(&source_roots, ws, &mut vfs, receiver, extern_dirs, &proc_macro_client);
    Ok((host, source_roots))
diff --git a/crates/rust-analyzer/src/conv.rs b/crates/rust-analyzer/src/conv.rs
index f47d931fd..d0218dcbf 100644
--- a/crates/rust-analyzer/src/conv.rs
+++ b/crates/rust-analyzer/src/conv.rs
@@ -24,7 +24,9 @@ use crate::{
    world::WorldSnapshot,
    Result,
 };
-use semantic_tokens::{ATTRIBUTE, BUILTIN_TYPE, ENUM_MEMBER, LIFETIME, TYPE_ALIAS, UNION};
+use semantic_tokens::{
+    ATTRIBUTE, BUILTIN_TYPE, ENUM_MEMBER, LIFETIME, TYPE_ALIAS, UNION, UNRESOLVED_REFERENCE,
+};
 pub trait Conv {
    type Output;
@@ -381,6 +383,7 @@ impl Conv for Highlight {
            HighlightTag::Comment => SemanticTokenType::COMMENT,
            HighlightTag::Attribute => ATTRIBUTE,
            HighlightTag::Keyword => SemanticTokenType::KEYWORD,
+            HighlightTag::UnresolvedReference => UNRESOLVED_REFERENCE,
        };
        for modifier in self.modifiers.iter() {
diff --git a/crates/rust-analyzer/src/semantic_tokens.rs b/crates/rust-analyzer/src/semantic_tokens.rs
index 865fa3b1c..10fe696f6 100644
--- a/crates/rust-analyzer/src/semantic_tokens.rs
+++ b/crates/rust-analyzer/src/semantic_tokens.rs
@@ -10,6 +10,8 @@ pub(crate) const ENUM_MEMBER: SemanticTokenType = SemanticTokenType::new("enumMe
 pub(crate) const LIFETIME: SemanticTokenType = SemanticTokenType::new("lifetime");
 pub(crate) const TYPE_ALIAS: SemanticTokenType = SemanticTokenType::new("typeAlias");
 pub(crate) const UNION: SemanticTokenType = SemanticTokenType::new("union");
+pub(crate) const UNRESOLVED_REFERENCE: SemanticTokenType =
+    SemanticTokenType::new("unresolvedReference");
 pub(crate) const CONSTANT: SemanticTokenModifier = SemanticTokenModifier::new("constant");
 pub(crate) const CONTROL_FLOW: SemanticTokenModifier = SemanticTokenModifier::new("controlFlow");
@@ -43,6 +45,7 @@ pub(crate) const SUPPORTED_TYPES: &[SemanticTokenType] = &[
    LIFETIME,
    TYPE_ALIAS,
    UNION,
+    UNRESOLVED_REFERENCE,
 ];
 pub(crate) const SUPPORTED_MODIFIERS: &[SemanticTokenModifier] = &[
diff --git a/crates/rust-analyzer/src/world.rs b/crates/rust-analyzer/src/world.rs
index f2ad453fa..8e1744bf9 100644
--- a/crates/rust-analyzer/src/world.rs
+++ b/crates/rust-analyzer/src/world.rs
@@ -148,20 +148,17 @@ impl WorldState {
        let proc_macro_client = match &config.proc_macro_srv {
            None => ProcMacroClient::dummy(),
-            Some((path, args)) => {
+            Some((path, args)) => match ProcMacroClient::extern_process(path.into(), args) {
-                let path = std::path::Path::new(path);
+                Ok(it) => it,
-                match ProcMacroClient::extern_process(path, args) {
+                Err(err) => {
-                    Ok(it) => it,
+                    log::error!(
-                    Err(err) => {
+                        "Fail to run ra_proc_macro_srv from path {}, error: {:?}",
-                        log::error!(
+                        path,
-                            "Fail to run ra_proc_macro_srv from path {}, error : {}",
+                        err
-                            path.to_string_lossy(),
+                    );
-                            err
+                    ProcMacroClient::dummy()
-                        );
-                        ProcMacroClient::dummy()
-                    }
                }
-            }
+            },
        };
        workspaces
@@ -184,7 +181,7 @@ impl WorldState {
        let mut analysis_host = AnalysisHost::new(lru_capacity);
        analysis_host.apply_change(change);
        WorldState {
-            config: config,
+            config,
            roots: folder_roots,
            workspaces: Arc::new(workspaces),
            analysis_host,