15 files changed, 165 insertions, 80 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 5690040a7..72c9b466f 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -937,7 +937,7 @@ impl TypeAlias {
     }
 
     pub fn type_ref(self, db: &impl DefDatabase) -> Option<TypeRef> {
-        db.type_alias_data(self).type_ref.clone()
+        db.type_alias_data(self.id).type_ref.clone()
     }
 
     pub fn ty(self, db: &impl HirDatabase) -> Ty {
@@ -945,7 +945,7 @@ impl TypeAlias {
     }
 
     pub fn name(self, db: &impl DefDatabase) -> Name {
-        db.type_alias_data(self).name.clone()
+        db.type_alias_data(self.id).name.clone()
     }
 }
 
diff --git a/crates/ra_hir/src/code_model/attrs.rs b/crates/ra_hir/src/code_model/attrs.rs
index 9e304217c..96da8c88c 100644
--- a/crates/ra_hir/src/code_model/attrs.rs
+++ b/crates/ra_hir/src/code_model/attrs.rs
@@ -5,10 +5,9 @@ use crate::{
     Adt, Const, Enum, EnumVariant, FieldSource, Function, HasSource, MacroDef, Module, Static,
     Struct, StructField, Trait, TypeAlias, Union,
 };
-use hir_def::attr::Attr;
+use hir_def::attr::{Attr, Attrs};
 use hir_expand::hygiene::Hygiene;
 use ra_syntax::ast;
-use std::sync::Arc;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum AttrDef {
@@ -37,17 +36,17 @@ impl_froms!(
     MacroDef
 );
 
-pub trait Attrs {
-    fn attrs(&self, db: &impl HirDatabase) -> Option<Arc<[Attr]>>;
+pub trait HasAttrs {
+    fn attrs(&self, db: &impl HirDatabase) -> Attrs;
 }
 
-pub(crate) fn attributes_query(
-    db: &(impl DefDatabase + AstDatabase),
-    def: AttrDef,
-) -> Option<Arc<[Attr]>> {
+pub(crate) fn attributes_query(db: &(impl DefDatabase + AstDatabase), def: AttrDef) -> Attrs {
     match def {
         AttrDef::Module(it) => {
-            let src = it.declaration_source(db)?;
+            let src = match it.declaration_source(db) {
+                Some(it) => it,
+                None => return Attrs::default(),
+            };
             let hygiene = Hygiene::new(db, src.file_id);
             Attr::from_attrs_owner(&src.value, &hygiene)
         }
@@ -57,7 +56,7 @@ pub(crate) fn attributes_query(
                 let hygiene = Hygiene::new(db, src.file_id);
                 Attr::from_attrs_owner(&named, &hygiene)
             }
-            FieldSource::Pos(..) => None,
+            FieldSource::Pos(..) => Attrs::default(),
         },
         AttrDef::Adt(it) => match it {
             Adt::Struct(it) => attrs_from_ast(it, db),
@@ -74,7 +73,7 @@ pub(crate) fn attributes_query(
     }
 }
 
-fn attrs_from_ast<T, D>(node: T, db: &D) -> Option<Arc<[Attr]>>
+fn attrs_from_ast<T, D>(node: T, db: &D) -> Attrs
 where
     T: HasSource,
     T::Ast: ast::AttrsOwner,
@@ -85,8 +84,8 @@ where
     Attr::from_attrs_owner(&src.value, &hygiene)
 }
 
-impl<T: Into<AttrDef> + Copy> Attrs for T {
-    fn attrs(&self, db: &impl HirDatabase) -> Option<Arc<[Attr]>> {
+impl<T: Into<AttrDef> + Copy> HasAttrs for T {
+    fn attrs(&self, db: &impl HirDatabase) -> Attrs {
         db.attrs((*self).into())
     }
 }
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index ed0d68001..1cfcb2fd2 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -2,7 +2,7 @@
 
 use std::sync::Arc;
 
-use hir_def::attr::Attr;
+use hir_def::attr::Attrs;
 use ra_db::salsa;
 use ra_syntax::SmolStr;
 
@@ -16,16 +16,15 @@ use crate::{
         CallableDef, FnSig, GenericPredicate, InferenceResult, Namespace, Substs, Ty, TypableDef,
         TypeCtor,
     },
-    type_alias::TypeAliasData,
     Const, ConstData, Crate, DefWithBody, FnData, Function, GenericDef, ImplBlock, Module, Static,
-    StructField, Trait, TypeAlias,
+    StructField, Trait,
 };
 
 pub use hir_def::db::{
     BodyQuery, BodyWithSourceMapQuery, CrateDefMapQuery, DefDatabase2, DefDatabase2Storage,
     EnumDataQuery, ExprScopesQuery, GenericParamsQuery, ImplDataQuery, InternDatabase,
     InternDatabaseStorage, RawItemsQuery, RawItemsWithSourceMapQuery, StructDataQuery,
-    TraitDataQuery,
+    TraitDataQuery, TypeAliasDataQuery,
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, MacroArgQuery, MacroDefQuery, MacroExpandQuery,
@@ -39,9 +38,6 @@ pub trait DefDatabase: HirDebugDatabase + DefDatabase2 {
     #[salsa::invoke(FnData::fn_data_query)]
     fn fn_data(&self, func: Function) -> Arc<FnData>;
 
-    #[salsa::invoke(TypeAliasData::type_alias_data_query)]
-    fn type_alias_data(&self, typ: TypeAlias) -> Arc<TypeAliasData>;
-
     #[salsa::invoke(ConstData::const_data_query)]
     fn const_data(&self, konst: Const) -> Arc<ConstData>;
 
@@ -61,7 +57,7 @@ pub trait DefDatabase: HirDebugDatabase + DefDatabase2 {
     fn documentation(&self, def: crate::DocDef) -> Option<crate::Documentation>;
 
     #[salsa::invoke(crate::code_model::attrs::attributes_query)]
-    fn attrs(&self, def: crate::AttrDef) -> Option<Arc<[Attr]>>;
+    fn attrs(&self, def: crate::AttrDef) -> Attrs;
 }
 
 #[salsa::query_group(HirDatabaseStorage)]
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 8c6834392..8535629ca 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -32,7 +32,6 @@ pub mod db;
 pub mod source_binder;
 
 mod ids;
-mod type_alias;
 mod ty;
 mod impl_block;
 mod expr;
@@ -52,7 +51,7 @@ mod marks;
 
 pub use crate::{
     code_model::{
-        attrs::{AttrDef, Attrs},
+        attrs::{AttrDef, HasAttrs},
         docs::{DocDef, Docs, Documentation},
         src::{HasBodySource, HasSource},
         Adt, AssocItem, Const, ConstData, Container, Crate, CrateDependency, DefWithBody, Enum,
diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index 0e961ca12..7a9d0fdf4 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -1,6 +1,6 @@
 //! A higher level attributes based on TokenTree, with also some shortcuts.
 
-use std::sync::Arc;
+use std::{ops, sync::Arc};
 
 use hir_expand::hygiene::Hygiene;
 use mbe::ast_to_token_tree;
@@ -13,6 +13,28 @@ use tt::Subtree;
 
 use crate::path::Path;
 
+#[derive(Default, Debug, Clone, PartialEq, Eq)]
+pub struct Attrs {
+    entries: Option<Arc<[Attr]>>,
+}
+
+impl ops::Deref for Attrs {
+    type Target = [Attr];
+
+    fn deref(&self) -> &[Attr] {
+        match &self.entries {
+            Some(it) => &*it,
+            None => &[],
+        }
+    }
+}
+
+impl Attrs {
+    pub fn has_atom(&self, atom: &str) -> bool {
+        self.iter().any(|it| it.is_simple_atom(atom))
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Attr {
     pub(crate) path: Path,
@@ -43,13 +65,15 @@ impl Attr {
         Some(Attr { path, input })
     }
 
-    pub fn from_attrs_owner(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Option<Arc<[Attr]>> {
+    pub fn from_attrs_owner(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Attrs {
         let mut attrs = owner.attrs().peekable();
-        if attrs.peek().is_none() {
+        let entries = if attrs.peek().is_none() {
             // Avoid heap allocation
-            return None;
-        }
-        Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).collect())
+            None
+        } else {
+            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).collect())
+        };
+        Attrs { entries }
     }
 
     pub fn is_simple_atom(&self, name: &str) -> bool {
diff --git a/crates/ra_hir_def/src/db.rs b/crates/ra_hir_def/src/db.rs
index 844f8bbe8..5bbdaa4b2 100644
--- a/crates/ra_hir_def/src/db.rs
+++ b/crates/ra_hir_def/src/db.rs
@@ -15,7 +15,8 @@ use crate::{
         CrateDefMap,
     },
     traits::TraitData,
-    DefWithBodyId, EnumId, GenericDefId, ImplId, ItemLoc, StructOrUnionId, TraitId,
+    type_alias::TypeAliasData,
+    DefWithBodyId, EnumId, GenericDefId, ImplId, ItemLoc, StructOrUnionId, TraitId, TypeAliasId,
 };
 
 #[salsa::query_group(InternDatabaseStorage)]
@@ -64,6 +65,9 @@ pub trait DefDatabase2: InternDatabase + AstDatabase {
     #[salsa::invoke(TraitData::trait_data_query)]
     fn trait_data(&self, e: TraitId) -> Arc<TraitData>;
 
+    #[salsa::invoke(TypeAliasData::type_alias_data_query)]
+    fn type_alias_data(&self, e: TypeAliasId) -> Arc<TypeAliasData>;
+
     #[salsa::invoke(Body::body_with_source_map_query)]
     fn body_with_source_map(&self, def: DefWithBodyId) -> (Arc<Body>, Arc<BodySourceMap>);
 
diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index d579f5c7e..268144462 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -20,6 +20,7 @@ pub mod body;
 pub mod generics;
 pub mod traits;
 pub mod resolver;
+pub mod type_alias;
 
 #[cfg(test)]
 mod test_db;
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index aae3dcadf..7902293e8 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -12,7 +12,7 @@ use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
 use crate::{
-    attr::Attr,
+    attr::Attrs,
     db::DefDatabase2,
     nameres::{
         diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint,
@@ -549,7 +549,7 @@ where
         // `#[macro_use] extern crate` is hoisted to imports macros before collecting
         // any other items.
         for item in items {
-            if self.is_cfg_enabled(item.attrs()) {
+            if self.is_cfg_enabled(&item.attrs) {
                 if let raw::RawItemKind::Import(import_id) = item.kind {
                     let import = self.raw_items[import_id].clone();
                     if import.is_extern_crate && import.is_macro_use {
@@ -560,10 +560,10 @@ where
         }
 
         for item in items {
-            if self.is_cfg_enabled(item.attrs()) {
+            if self.is_cfg_enabled(&item.attrs) {
                 match item.kind {
                     raw::RawItemKind::Module(m) => {
-                        self.collect_module(&self.raw_items[m], item.attrs())
+                        self.collect_module(&self.raw_items[m], &item.attrs)
                     }
                     raw::RawItemKind::Import(import_id) => self
                         .def_collector
@@ -585,9 +585,9 @@ where
         }
     }
 
-    fn collect_module(&mut self, module: &raw::ModuleData, attrs: &[Attr]) {
+    fn collect_module(&mut self, module: &raw::ModuleData, attrs: &Attrs) {
         let path_attr = self.path_attr(attrs);
-        let is_macro_use = self.is_macro_use(attrs);
+        let is_macro_use = attrs.has_atom("macro_use");
         match module {
             // inline module, just recurse
             raw::ModuleData::Definition { name, items, ast_id } => {
@@ -779,17 +779,13 @@ where
         }
     }
 
-    fn is_cfg_enabled(&self, attrs: &[Attr]) -> bool {
+    fn is_cfg_enabled(&self, attrs: &Attrs) -> bool {
         attrs.iter().all(|attr| attr.is_cfg_enabled(&self.def_collector.cfg_options) != Some(false))
     }
 
-    fn path_attr<'a>(&self, attrs: &'a [Attr]) -> Option<&'a SmolStr> {
+    fn path_attr<'a>(&self, attrs: &'a Attrs) -> Option<&'a SmolStr> {
         attrs.iter().find_map(|attr| attr.as_path())
     }
-
-    fn is_macro_use<'a>(&self, attrs: &'a [Attr]) -> bool {
-        attrs.iter().any(|attr| attr.is_simple_atom("macro_use"))
-    }
 }
 
 fn is_macro_rules(path: &Path) -> bool {
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index 7c68fd638..55a9634f8 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -16,7 +16,12 @@ use ra_syntax::{
 };
 use test_utils::tested_by;
 
-use crate::{attr::Attr, db::DefDatabase2, path::Path, FileAstId, HirFileId, ModuleSource, Source};
+use crate::{
+    attr::{Attr, Attrs},
+    db::DefDatabase2,
+    path::Path,
+    FileAstId, HirFileId, ModuleSource, Source,
+};
 
 /// `RawItems` is a set of top-level items in a file (except for impls).
 ///
@@ -129,21 +134,12 @@ impl Index<Impl> for RawItems {
     }
 }
 
-// Avoid heap allocation on items without attributes.
-type Attrs = Option<Arc<[Attr]>>;
-
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub(super) struct RawItem {
-    attrs: Attrs,
+    pub(super) attrs: Attrs,
     pub(super) kind: RawItemKind,
 }
 
-impl RawItem {
-    pub(super) fn attrs(&self) -> &[Attr] {
-        self.attrs.as_ref().map_or(&[], |it| &*it)
-    }
-}
-
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub(super) enum RawItemKind {
     Module(Module),
diff --git a/crates/ra_hir/src/type_alias.rs b/crates/ra_hir_def/src/type_alias.rs
index 392f244cf..c0b49aa7c 100644
--- a/crates/ra_hir/src/type_alias.rs
+++ b/crates/ra_hir_def/src/type_alias.rs
@@ -2,28 +2,24 @@
 
 use std::sync::Arc;
 
-use hir_def::type_ref::TypeRef;
 use hir_expand::name::{AsName, Name};
 
 use ra_syntax::ast::NameOwner;
 
-use crate::{
-    db::{AstDatabase, DefDatabase},
-    HasSource, TypeAlias,
-};
+use crate::{db::DefDatabase2, type_ref::TypeRef, HasSource, Lookup, TypeAliasId};
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct TypeAliasData {
-    pub(crate) name: Name,
-    pub(crate) type_ref: Option<TypeRef>,
+    pub name: Name,
+    pub type_ref: Option<TypeRef>,
 }
 
 impl TypeAliasData {
     pub(crate) fn type_alias_data_query(
-        db: &(impl DefDatabase + AstDatabase),
-        typ: TypeAlias,
+        db: &impl DefDatabase2,
+        typ: TypeAliasId,
     ) -> Arc<TypeAliasData> {
-        let node = typ.source(db).value;
+        let node = typ.lookup(db).source(db).value;
         let name = node.name().map_or_else(Name::missing, |n| n.as_name());
         let type_ref = node.type_ref().map(TypeRef::from_ast);
         Arc::new(TypeAliasData { name, type_ref })
diff --git a/crates/ra_ide_api/src/completion/presentation.rs b/crates/ra_ide_api/src/completion/presentation.rs
index b20329459..bd464d193 100644
--- a/crates/ra_ide_api/src/completion/presentation.rs
+++ b/crates/ra_ide_api/src/completion/presentation.rs
@@ -1,6 +1,6 @@
 //! This modules takes care of rendering various definitions as completion items.
 
-use hir::{db::HirDatabase, Attrs, Docs, HasSource, HirDisplay, ScopeDef, Ty, TypeWalk};
+use hir::{db::HirDatabase, Docs, HasAttrs, HasSource, HirDisplay, ScopeDef, Ty, TypeWalk};
 use join_to_string::join;
 use ra_syntax::ast::NameOwner;
 use test_utils::tested_by;
@@ -285,11 +285,8 @@ impl Completions {
     }
 }
 
-fn is_deprecated(node: impl Attrs, db: &impl HirDatabase) -> bool {
-    match node.attrs(db) {
-        None => false,
-        Some(attrs) => attrs.iter().any(|x| x.is_simple_atom("deprecated")),
-    }
+fn is_deprecated(node: impl HasAttrs, db: &impl HirDatabase) -> bool {
+    node.attrs(db).has_atom("deprecated")
 }
 
 fn has_non_default_type_params(def: hir::GenericDef, db: &db::RootDatabase) -> bool {
diff --git a/crates/ra_ide_api/src/expand_macro.rs b/crates/ra_ide_api/src/expand_macro.rs
index 7dbf33a16..673301b10 100644
--- a/crates/ra_ide_api/src/expand_macro.rs
+++ b/crates/ra_ide_api/src/expand_macro.rs
@@ -40,7 +40,7 @@ fn expand_macro_recur(
     let analyzer = hir::SourceAnalyzer::new(db, source, None);
     let expansion = analyzer.expand(db, macro_call)?;
     let macro_file_id = expansion.file_id();
-    let expanded: SyntaxNode = db.parse_or_expand(macro_file_id)?;
+    let mut expanded: SyntaxNode = db.parse_or_expand(macro_file_id)?;
 
     let children = expanded.descendants().filter_map(ast::MacroCall::cast);
     let mut replaces = FxHashMap::default();
@@ -49,7 +49,14 @@ fn expand_macro_recur(
         let node = hir::Source::new(macro_file_id, &child);
         let new_node = expand_macro_recur(db, source, node)?;
 
-        replaces.insert(child.syntax().clone().into(), new_node.into());
+        // Replace the whole node if it is root
+        // `replace_descendants` will not replace the parent node
+        // but `SyntaxNode::descendants include itself
+        if expanded == *child.syntax() {
+            expanded = new_node;
+        } else {
+            replaces.insert(child.syntax().clone().into(), new_node.into());
+        }
     }
 
     Some(replace_descendants(&expanded, &replaces))
@@ -217,4 +224,27 @@ fn some_thing() -> u32 {
 }
 "###);
     }
+
+    #[test]
+    fn macro_expand_match_ast_inside_let_statement() {
+        let res = check_expand_macro(
+            r#"
+        //- /lib.rs
+        macro_rules! match_ast {
+            (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };        
+            (match ($node:expr) {}) => {{}};
+        }        
+
+        fn main() {        
+            let p = f(|it| {
+                let res = mat<|>ch_ast! { match c {}};
+                Some(res)
+            })?;
+        }
+        "#,
+        );
+
+        assert_eq!(res.name, "match_ast");
+        assert_snapshot!(res.expansion, @r###"{}"###);
+    }
 }
diff --git a/crates/ra_ide_api/src/typing.rs b/crates/ra_ide_api/src/typing.rs
index d51132f73..21e5be9b3 100644
--- a/crates/ra_ide_api/src/typing.rs
+++ b/crates/ra_ide_api/src/typing.rs
@@ -40,9 +40,13 @@ pub(crate) fn on_enter(db: &RootDatabase, position: FilePosition) -> Option<Sour
     }
 
     let prefix = comment.prefix();
-    if position.offset
-        < comment.syntax().text_range().start() + TextUnit::of_str(prefix) + TextUnit::from(1)
-    {
+    let comment_range = comment.syntax().text_range();
+    if position.offset < comment_range.start() + TextUnit::of_str(prefix) + TextUnit::from(1) {
+        return None;
+    }
+
+    // Continuing non-doc line comments (like this one :) ) is annoying
+    if prefix == "//" && comment_range.end() == position.offset {
         return None;
     }
 
@@ -247,6 +251,30 @@ impl S {
 }
 ",
         );
+        do_check(
+            r"
+fn main() {
+    // Fix<|> me
+    let x = 1 + 1;
+}
+",
+            r"
+fn main() {
+    // Fix
+    // <|> me
+    let x = 1 + 1;
+}
+",
+        );
+        do_check_noop(
+            r"
+fn main() {
+    // Fix me<|>
+    let x = 1 + 1;
+}
+",
+        );
+
         do_check_noop(r"<|>//! docz");
     }
 
diff --git a/crates/ra_lsp_server/src/lib.rs b/crates/ra_lsp_server/src/lib.rs
index 0e5dbbbd5..9c36402b0 100644
--- a/crates/ra_lsp_server/src/lib.rs
+++ b/crates/ra_lsp_server/src/lib.rs
@@ -1,6 +1,26 @@
-//! FIXME: write short doc here
-
+//! Implementation of the LSP for rust-analyzer.
+//!
+//! This crate takes Rust-specific analysis results from ra_ide_api and
+//! translates into LSP types.
+//!
+//! It also is the root of all state. `world` module defines the bulk of the
+//! state, and `main_loop` module defines the rules for modifying it.
 #![recursion_limit = "512"]
+
+#[allow(unused)]
+macro_rules! println {
+    ($($tt:tt)*) => {
+        compile_error!("stdout is locked, use eprintln")
+    };
+}
+
+#[allow(unused)]
+macro_rules! print {
+    ($($tt:tt)*) => {
+        compile_error!("stdout is locked, use eprint")
+    };
+}
+
 mod caps;
 mod cargo_target_spec;
 mod conv;
diff --git a/crates/ra_lsp_server/src/main.rs b/crates/ra_lsp_server/src/main.rs
index 7d9a1d054..e13c8ca14 100644
--- a/crates/ra_lsp_server/src/main.rs
+++ b/crates/ra_lsp_server/src/main.rs
@@ -1,8 +1,7 @@
-//! FIXME: write short doc here
+//! `ra_lsp_server` binary
 
 use flexi_logger::{Duplicate, Logger};
 use lsp_server::Connection;
-
 use ra_lsp_server::{show_message, Result, ServerConfig};
 use ra_prof;