257 files changed, 3843 insertions, 1859 deletions

diff --git a/crates/ra_assists/src/assist_ctx.rs b/crates/ra_assists/src/assist_ctx.rs
index c45262efa..189cad7d0 100644
--- a/crates/ra_assists/src/assist_ctx.rs
+++ b/crates/ra_assists/src/assist_ctx.rs
@@ -1,8 +1,10 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_db::FileRange;
 use ra_fmt::{leading_indent, reindent};
 use ra_syntax::{
-    algo::{find_covering_element, find_node_at_offset},
+    algo::{self, find_covering_element, find_node_at_offset},
     AstNode, SourceFile, SyntaxElement, SyntaxNode, SyntaxToken, TextRange, TextUnit,
     TokenAtOffset,
 };
@@ -177,6 +179,10 @@ impl AssistBuilder {
         &mut self.edit
     }
 
+    pub(crate) fn replace_ast<N: AstNode>(&mut self, old: N, new: N) {
+        algo::diff(old.syntax(), new.syntax()).into_text_edit(&mut self.edit)
+    }
+
     fn build(self) -> AssistAction {
         AssistAction {
             edit: self.edit.finish(),
diff --git a/crates/ra_assists/src/assists/add_derive.rs b/crates/ra_assists/src/assists/add_derive.rs
index 9c88644df..77ecc33c9 100644
--- a/crates/ra_assists/src/assists/add_derive.rs
+++ b/crates/ra_assists/src/assists/add_derive.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_syntax::{
     ast::{self, AstNode, AttrsOwner},
@@ -13,7 +15,7 @@ pub(crate) fn add_derive(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist>
     ctx.add_action(AssistId("add_derive"), "add `#[derive]`", |edit| {
         let derive_attr = nominal
             .attrs()
-            .filter_map(|x| x.as_call())
+            .filter_map(|x| x.as_simple_call())
             .filter(|(name, _arg)| name == "derive")
             .map(|(_name, arg)| arg)
             .next();
diff --git a/crates/ra_assists/src/assists/add_explicit_type.rs b/crates/ra_assists/src/assists/add_explicit_type.rs
index 78f0f7f28..8c83dc987 100644
--- a/crates/ra_assists/src/assists/add_explicit_type.rs
+++ b/crates/ra_assists/src/assists/add_explicit_type.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::{db::HirDatabase, HirDisplay, Ty};
 use ra_syntax::{
     ast::{self, AstNode, LetStmt, NameOwner},
diff --git a/crates/ra_assists/src/assists/add_impl.rs b/crates/ra_assists/src/assists/add_impl.rs
index 4b61f4031..94801fbc9 100644
--- a/crates/ra_assists/src/assists/add_impl.rs
+++ b/crates/ra_assists/src/assists/add_impl.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use format_buf::format;
 use hir::db::HirDatabase;
 use join_to_string::join;
diff --git a/crates/ra_assists/src/assists/add_missing_impl_members.rs b/crates/ra_assists/src/assists/add_missing_impl_members.rs
index 23da1e65f..565b96fb5 100644
--- a/crates/ra_assists/src/assists/add_missing_impl_members.rs
+++ b/crates/ra_assists/src/assists/add_missing_impl_members.rs
@@ -1,10 +1,12 @@
+//! FIXME: write short doc here
+
 use hir::{db::HirDatabase, HasSource};
 use ra_syntax::{
-    ast::{self, make, AstNode, NameOwner},
+    ast::{self, edit, make, AstNode, NameOwner},
     SmolStr,
 };
 
-use crate::{ast_editor::AstEditor, Assist, AssistCtx, AssistId};
+use crate::{Assist, AssistCtx, AssistId};
 
 #[derive(PartialEq)]
 enum AddMissingImplMembersMode {
@@ -75,37 +77,32 @@ fn add_missing_impl_members_inner(
 
     ctx.add_action(AssistId(assist_id), label, |edit| {
         let n_existing_items = impl_item_list.impl_items().count();
-        let items = missing_items.into_iter().map(|it| match it {
-            ast::ImplItem::FnDef(def) => strip_docstring(add_body(def).into()),
-            _ => strip_docstring(it),
-        });
-        let mut ast_editor = AstEditor::new(impl_item_list);
-
-        ast_editor.append_items(items);
-
-        let first_new_item = ast_editor.ast().impl_items().nth(n_existing_items).unwrap();
-        let cursor_position = first_new_item.syntax().text_range().start();
-        ast_editor.into_text_edit(edit.text_edit_builder());
-
+        let items = missing_items
+            .into_iter()
+            .map(|it| match it {
+                ast::ImplItem::FnDef(def) => ast::ImplItem::FnDef(add_body(def)),
+                _ => it,
+            })
+            .map(|it| edit::strip_attrs_and_docs(&it));
+        let new_impl_item_list = impl_item_list.append_items(items);
+        let cursor_position = {
+            let first_new_item = new_impl_item_list.impl_items().nth(n_existing_items).unwrap();
+            first_new_item.syntax().text_range().start()
+        };
+
+        edit.replace_ast(impl_item_list, new_impl_item_list);
         edit.set_cursor(cursor_position);
     });
 
     ctx.build()
 }
 
-fn strip_docstring(item: ast::ImplItem) -> ast::ImplItem {
-    let mut ast_editor = AstEditor::new(item);
-    ast_editor.strip_attrs_and_docs();
-    ast_editor.ast().to_owned()
-}
-
 fn add_body(fn_def: ast::FnDef) -> ast::FnDef {
-    let mut ast_editor = AstEditor::new(fn_def.clone());
     if fn_def.body().is_none() {
-        let body = make::block_from_expr(make::expr_unimplemented());
-        ast_editor.set_body(&body);
+        fn_def.with_body(make::block_from_expr(make::expr_unimplemented()))
+    } else {
+        fn_def
     }
-    ast_editor.ast().to_owned()
 }
 
 /// Given an `ast::ImplBlock`, resolves the target trait (the one being
@@ -332,5 +329,4 @@ impl Foo for S {
 }",
         )
     }
-
 }
diff --git a/crates/ra_assists/src/assists/apply_demorgan.rs b/crates/ra_assists/src/assists/apply_demorgan.rs
new file mode 100644
index 000000000..5f2b0dd18
--- /dev/null
+++ b/crates/ra_assists/src/assists/apply_demorgan.rs
@@ -0,0 +1,102 @@
+//! This contains the functions associated with the demorgan assist.
+//! This assist transforms boolean expressions of the form `!a || !b` into
+//! `!(a && b)`.
+use hir::db::HirDatabase;
+use ra_syntax::ast::{self, AstNode};
+use ra_syntax::SyntaxNode;
+
+use crate::{Assist, AssistCtx, AssistId};
+
+/// Assist for applying demorgan's law
+///
+/// This transforms expressions of the form `!l || !r` into `!(l && r)`.
+/// This also works with `&&`. This assist can only be applied with the cursor
+/// on either `||` or `&&`, with both operands being a negation of some kind.
+/// This means something of the form `!x` or `x != y`.
+pub(crate) fn apply_demorgan(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let expr = ctx.node_at_offset::<ast::BinExpr>()?;
+    let op = expr.op_kind()?;
+    let op_range = expr.op_token()?.text_range();
+    let opposite_op = opposite_logic_op(op)?;
+    let cursor_in_range = ctx.frange.range.is_subrange(&op_range);
+    if !cursor_in_range {
+        return None;
+    }
+    let lhs = expr.lhs()?.syntax().clone();
+    let lhs_range = lhs.text_range();
+    let rhs = expr.rhs()?.syntax().clone();
+    let rhs_range = rhs.text_range();
+    let not_lhs = undo_negation(lhs)?;
+    let not_rhs = undo_negation(rhs)?;
+
+    ctx.add_action(AssistId("apply_demorgan"), "apply demorgan's law", |edit| {
+        edit.target(op_range);
+        edit.replace(op_range, opposite_op);
+        edit.replace(lhs_range, format!("!({}", not_lhs));
+        edit.replace(rhs_range, format!("{})", not_rhs));
+    });
+    ctx.build()
+}
+
+// Return the opposite text for a given logical operator, if it makes sense
+fn opposite_logic_op(kind: ast::BinOp) -> Option<&'static str> {
+    match kind {
+        ast::BinOp::BooleanOr => Some("&&"),
+        ast::BinOp::BooleanAnd => Some("||"),
+        _ => None,
+    }
+}
+
+// This function tries to undo unary negation, or inequality
+fn undo_negation(node: SyntaxNode) -> Option<String> {
+    match ast::Expr::cast(node)? {
+        ast::Expr::BinExpr(bin) => match bin.op_kind()? {
+            ast::BinOp::NegatedEqualityTest => {
+                let lhs = bin.lhs()?.syntax().text();
+                let rhs = bin.rhs()?.syntax().text();
+                Some(format!("{} == {}", lhs, rhs))
+            }
+            _ => None,
+        },
+        ast::Expr::PrefixExpr(pe) => match pe.op_kind()? {
+            ast::PrefixOp::Not => {
+                let child = pe.expr()?.syntax().text();
+                Some(String::from(child))
+            }
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use crate::helpers::{check_assist, check_assist_not_applicable};
+
+    #[test]
+    fn demorgan_turns_and_into_or() {
+        check_assist(apply_demorgan, "fn f() { !x &&<|> !x }", "fn f() { !(x ||<|> x) }")
+    }
+
+    #[test]
+    fn demorgan_turns_or_into_and() {
+        check_assist(apply_demorgan, "fn f() { !x ||<|> !x }", "fn f() { !(x &&<|> x) }")
+    }
+
+    #[test]
+    fn demorgan_removes_inequality() {
+        check_assist(apply_demorgan, "fn f() { x != x ||<|> !x }", "fn f() { !(x == x &&<|> x) }")
+    }
+
+    #[test]
+    fn demorgan_doesnt_apply_with_cursor_not_on_op() {
+        check_assist_not_applicable(apply_demorgan, "fn f() { <|> !x || !x }")
+    }
+
+    #[test]
+    fn demorgan_doesnt_apply_when_operands_arent_negated_already() {
+        check_assist_not_applicable(apply_demorgan, "fn f() { x ||<|> x }")
+    }
+}
diff --git a/crates/ra_assists/src/assists/auto_import.rs b/crates/ra_assists/src/assists/auto_import.rs
index 5aae98546..02c58e7c6 100644
--- a/crates/ra_assists/src/assists/auto_import.rs
+++ b/crates/ra_assists/src/assists/auto_import.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::{self, db::HirDatabase};
 use ra_text_edit::TextEditBuilder;
 
@@ -448,7 +450,6 @@ fn make_assist_add_in_tree_list(
         fmt_segments_raw(target, &mut buf);
         edit.insert(offset, buf);
     } else {
-
     }
 }
 
@@ -512,7 +513,7 @@ pub fn collect_hir_path_segments(path: &hir::Path) -> Option<Vec<SmolStr>> {
         hir::PathKind::Plain => {}
         hir::PathKind::Self_ => ps.push("self".into()),
         hir::PathKind::Super => ps.push("super".into()),
-        hir::PathKind::Type(_) => return None,
+        hir::PathKind::Type(_) | hir::PathKind::DollarCrate(_) => return None,
     }
     for s in path.segments.iter() {
         ps.push(s.name.to_string().into());
diff --git a/crates/ra_assists/src/assists/change_visibility.rs b/crates/ra_assists/src/assists/change_visibility.rs
index 60c74debc..df92c6b67 100644
--- a/crates/ra_assists/src/assists/change_visibility.rs
+++ b/crates/ra_assists/src/assists/change_visibility.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_syntax::{
     ast::{self, NameOwner, VisibilityOwner},
diff --git a/crates/ra_assists/src/assists/fill_match_arms.rs b/crates/ra_assists/src/assists/fill_match_arms.rs
index db82db89a..7335cce09 100644
--- a/crates/ra_assists/src/assists/fill_match_arms.rs
+++ b/crates/ra_assists/src/assists/fill_match_arms.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::iter;
 
 use hir::{db::HirDatabase, Adt, HasSource};
diff --git a/crates/ra_assists/src/assists/flip_binexpr.rs b/crates/ra_assists/src/assists/flip_binexpr.rs
index b55b36a8e..c51035282 100644
--- a/crates/ra_assists/src/assists/flip_binexpr.rs
+++ b/crates/ra_assists/src/assists/flip_binexpr.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_syntax::ast::{AstNode, BinExpr, BinOp};
 
diff --git a/crates/ra_assists/src/assists/flip_comma.rs b/crates/ra_assists/src/assists/flip_comma.rs
index 5ee7561bc..e31cc5e7d 100644
--- a/crates/ra_assists/src/assists/flip_comma.rs
+++ b/crates/ra_assists/src/assists/flip_comma.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_syntax::{algo::non_trivia_sibling, Direction, T};
 
diff --git a/crates/ra_assists/src/assists/inline_local_variable.rs b/crates/ra_assists/src/assists/inline_local_variable.rs
index eedb29199..9bd64decc 100644
--- a/crates/ra_assists/src/assists/inline_local_variable.rs
+++ b/crates/ra_assists/src/assists/inline_local_variable.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_syntax::{
     ast::{self, AstNode, AstToken},
diff --git a/crates/ra_assists/src/assists/introduce_variable.rs b/crates/ra_assists/src/assists/introduce_variable.rs
index 470ffe120..43378c4b0 100644
--- a/crates/ra_assists/src/assists/introduce_variable.rs
+++ b/crates/ra_assists/src/assists/introduce_variable.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use format_buf::format;
 use hir::db::HirDatabase;
 use ra_syntax::{
diff --git a/crates/ra_assists/src/assists/merge_match_arms.rs b/crates/ra_assists/src/assists/merge_match_arms.rs
index 3b6a99895..17baa98f9 100644
--- a/crates/ra_assists/src/assists/merge_match_arms.rs
+++ b/crates/ra_assists/src/assists/merge_match_arms.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use crate::{Assist, AssistCtx, AssistId, TextRange, TextUnit};
 use hir::db::HirDatabase;
 use ra_syntax::ast::{AstNode, MatchArm};
diff --git a/crates/ra_assists/src/assists/move_bounds.rs b/crates/ra_assists/src/assists/move_bounds.rs
index fd4bdc55c..f791d22b0 100644
--- a/crates/ra_assists/src/assists/move_bounds.rs
+++ b/crates/ra_assists/src/assists/move_bounds.rs
@@ -1,11 +1,13 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_syntax::{
-    ast::{self, make, AstNode, NameOwner, TypeBoundsOwner},
+    ast::{self, edit, make, AstNode, NameOwner, TypeBoundsOwner},
     SyntaxElement,
     SyntaxKind::*,
 };
 
-use crate::{ast_editor::AstEditor, Assist, AssistCtx, AssistId};
+use crate::{Assist, AssistCtx, AssistId};
 
 pub(crate) fn move_bounds_to_where_clause(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
     let type_param_list = ctx.node_at_offset::<ast::TypeParamList>()?;
@@ -39,14 +41,12 @@ pub(crate) fn move_bounds_to_where_clause(mut ctx: AssistCtx<impl HirDatabase>)
                 .type_params()
                 .filter(|it| it.type_bound_list().is_some())
                 .map(|type_param| {
-                    let without_bounds =
-                        AstEditor::new(type_param.clone()).remove_bounds().ast().clone();
+                    let without_bounds = type_param.remove_bounds();
                     (type_param, without_bounds)
                 });
 
-            let mut ast_editor = AstEditor::new(type_param_list.clone());
-            ast_editor.replace_descendants(new_params);
-            ast_editor.into_text_edit(edit.text_edit_builder());
+            let new_type_param_list = edit::replace_descendants(&type_param_list, new_params);
+            edit.replace_ast(type_param_list.clone(), new_type_param_list);
 
             let where_clause = {
                 let predicates = type_param_list.type_params().filter_map(build_predicate);
diff --git a/crates/ra_assists/src/assists/move_guard.rs b/crates/ra_assists/src/assists/move_guard.rs
index 699221e33..51aea6334 100644
--- a/crates/ra_assists/src/assists/move_guard.rs
+++ b/crates/ra_assists/src/assists/move_guard.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_syntax::{
     ast,
diff --git a/crates/ra_assists/src/assists/raw_string.rs b/crates/ra_assists/src/assists/raw_string.rs
index 200aaa59a..2d2e31e51 100644
--- a/crates/ra_assists/src/assists/raw_string.rs
+++ b/crates/ra_assists/src/assists/raw_string.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use hir::db::HirDatabase;
 use ra_syntax::{ast::AstNode, ast::Literal, TextRange, TextUnit};
 use rustc_lexer;
diff --git a/crates/ra_assists/src/assists/remove_dbg.rs b/crates/ra_assists/src/assists/remove_dbg.rs
index 870133fda..1a7e2b305 100644
--- a/crates/ra_assists/src/assists/remove_dbg.rs
+++ b/crates/ra_assists/src/assists/remove_dbg.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use crate::{Assist, AssistCtx, AssistId};
 use hir::db::HirDatabase;
 use ra_syntax::{
diff --git a/crates/ra_assists/src/assists/replace_if_let_with_match.rs b/crates/ra_assists/src/assists/replace_if_let_with_match.rs
index 401835c57..749ff338a 100644
--- a/crates/ra_assists/src/assists/replace_if_let_with_match.rs
+++ b/crates/ra_assists/src/assists/replace_if_let_with_match.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use format_buf::format;
 use hir::db::HirDatabase;
 use ra_fmt::extract_trivial_expression;
diff --git a/crates/ra_assists/src/assists/split_import.rs b/crates/ra_assists/src/assists/split_import.rs
index 2c1edddb9..fe3e64af5 100644
--- a/crates/ra_assists/src/assists/split_import.rs
+++ b/crates/ra_assists/src/assists/split_import.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::iter::successors;
 
 use hir::db::HirDatabase;
@@ -49,13 +51,13 @@ mod tests {
     fn split_import_works_with_trees() {
         check_assist(
             split_import,
-            "use algo:<|>:visitor::{Visitor, visit}",
-            "use algo::{<|>visitor::{Visitor, visit}}",
+            "use crate:<|>:db::{RootDatabase, FileSymbol}",
+            "use crate::{<|>db::{RootDatabase, FileSymbol}}",
         )
     }
 
     #[test]
     fn split_import_target() {
-        check_assist_target(split_import, "use algo::<|>visitor::{Visitor, visit}", "::");
+        check_assist_target(split_import, "use crate::<|>db::{RootDatabase, FileSymbol}", "::");
     }
 }
diff --git a/crates/ra_assists/src/ast_editor.rs b/crates/ra_assists/src/ast_editor.rs
deleted file mode 100644
index 2a685f26e..000000000
--- a/crates/ra_assists/src/ast_editor.rs
+++ /dev/null
@@ -1,315 +0,0 @@
-use std::{iter, ops::RangeInclusive};
-
-use arrayvec::ArrayVec;
-use rustc_hash::FxHashMap;
-
-use ra_fmt::leading_indent;
-use ra_syntax::{
-    algo,
-    ast::{self, TypeBoundsOwner},
-    AstNode, Direction, InsertPosition, SyntaxElement,
-    SyntaxKind::*,
-    T,
-};
-use ra_text_edit::TextEditBuilder;
-
-pub struct AstEditor<N: AstNode> {
-    original_ast: N,
-    ast: N,
-}
-
-impl<N: AstNode> AstEditor<N> {
-    pub fn new(node: N) -> AstEditor<N>
-    where
-        N: Clone,
-    {
-        AstEditor { original_ast: node.clone(), ast: node }
-    }
-
-    pub fn into_text_edit(self, builder: &mut TextEditBuilder) {
-        for (from, to) in algo::diff(&self.original_ast.syntax(), self.ast().syntax()) {
-            builder.replace(from.text_range(), to.to_string())
-        }
-    }
-
-    pub fn ast(&self) -> &N {
-        &self.ast
-    }
-
-    pub fn replace_descendants<T: AstNode>(
-        &mut self,
-        replacement_map: impl Iterator<Item = (T, T)>,
-    ) -> &mut Self {
-        let map = replacement_map
-            .map(|(from, to)| (from.syntax().clone().into(), to.syntax().clone().into()))
-            .collect::<FxHashMap<_, _>>();
-        let new_syntax = algo::replace_descendants(self.ast.syntax(), &map);
-        self.ast = N::cast(new_syntax).unwrap();
-        self
-    }
-
-    #[must_use]
-    fn insert_children(
-        &self,
-        position: InsertPosition<SyntaxElement>,
-        mut to_insert: impl Iterator<Item = SyntaxElement>,
-    ) -> N {
-        let new_syntax = algo::insert_children(self.ast().syntax(), position, &mut to_insert);
-        N::cast(new_syntax).unwrap()
-    }
-
-    #[must_use]
-    fn replace_children(
-        &self,
-        to_delete: RangeInclusive<SyntaxElement>,
-        mut to_insert: impl Iterator<Item = SyntaxElement>,
-    ) -> N {
-        let new_syntax = algo::replace_children(self.ast().syntax(), to_delete, &mut to_insert);
-        N::cast(new_syntax).unwrap()
-    }
-
-    fn do_make_multiline(&mut self) {
-        let l_curly =
-            match self.ast().syntax().children_with_tokens().find(|it| it.kind() == T!['{']) {
-                Some(it) => it,
-                None => return,
-            };
-        let sibling = match l_curly.next_sibling_or_token() {
-            Some(it) => it,
-            None => return,
-        };
-        let existing_ws = match sibling.as_token() {
-            None => None,
-            Some(tok) if tok.kind() != WHITESPACE => None,
-            Some(ws) => {
-                if ws.text().contains('\n') {
-                    return;
-                }
-                Some(ws.clone())
-            }
-        };
-
-        let indent = leading_indent(self.ast().syntax()).unwrap_or("".into());
-        let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
-        let to_insert = iter::once(ws.ws().into());
-        self.ast = match existing_ws {
-            None => self.insert_children(InsertPosition::After(l_curly), to_insert),
-            Some(ws) => {
-                self.replace_children(RangeInclusive::new(ws.clone().into(), ws.into()), to_insert)
-            }
-        };
-    }
-}
-
-impl AstEditor<ast::RecordFieldList> {
-    pub fn append_field(&mut self, field: &ast::RecordField) {
-        self.insert_field(InsertPosition::Last, field)
-    }
-
-    pub fn insert_field(
-        &mut self,
-        position: InsertPosition<&'_ ast::RecordField>,
-        field: &ast::RecordField,
-    ) {
-        let is_multiline = self.ast().syntax().text().contains_char('\n');
-        let ws;
-        let space = if is_multiline {
-            ws = tokens::WsBuilder::new(&format!(
-                "\n{}    ",
-                leading_indent(self.ast().syntax()).unwrap_or("".into())
-            ));
-            ws.ws()
-        } else {
-            tokens::single_space()
-        };
-
-        let mut to_insert: ArrayVec<[SyntaxElement; 4]> = ArrayVec::new();
-        to_insert.push(space.into());
-        to_insert.push(field.syntax().clone().into());
-        to_insert.push(tokens::comma().into());
-
-        macro_rules! after_l_curly {
-            () => {{
-                let anchor = match self.l_curly() {
-                    Some(it) => it,
-                    None => return,
-                };
-                InsertPosition::After(anchor)
-            }};
-        }
-
-        macro_rules! after_field {
-            ($anchor:expr) => {
-                if let Some(comma) = $anchor
-                    .syntax()
-                    .siblings_with_tokens(Direction::Next)
-                    .find(|it| it.kind() == T![,])
-                {
-                    InsertPosition::After(comma)
-                } else {
-                    to_insert.insert(0, tokens::comma().into());
-                    InsertPosition::After($anchor.syntax().clone().into())
-                }
-            };
-        };
-
-        let position = match position {
-            InsertPosition::First => after_l_curly!(),
-            InsertPosition::Last => {
-                if !is_multiline {
-                    // don't insert comma before curly
-                    to_insert.pop();
-                }
-                match self.ast().fields().last() {
-                    Some(it) => after_field!(it),
-                    None => after_l_curly!(),
-                }
-            }
-            InsertPosition::Before(anchor) => {
-                InsertPosition::Before(anchor.syntax().clone().into())
-            }
-            InsertPosition::After(anchor) => after_field!(anchor),
-        };
-
-        self.ast = self.insert_children(position, to_insert.iter().cloned());
-    }
-
-    fn l_curly(&self) -> Option<SyntaxElement> {
-        self.ast().syntax().children_with_tokens().find(|it| it.kind() == T!['{'])
-    }
-}
-
-impl AstEditor<ast::ItemList> {
-    pub fn append_items(&mut self, items: impl Iterator<Item = ast::ImplItem>) {
-        if !self.ast().syntax().text().contains_char('\n') {
-            self.do_make_multiline();
-        }
-        items.for_each(|it| self.append_item(it));
-    }
-
-    pub fn append_item(&mut self, item: ast::ImplItem) {
-        let (indent, position) = match self.ast().impl_items().last() {
-            Some(it) => (
-                leading_indent(it.syntax()).unwrap_or_default().to_string(),
-                InsertPosition::After(it.syntax().clone().into()),
-            ),
-            None => match self.l_curly() {
-                Some(it) => (
-                    "    ".to_string() + &leading_indent(self.ast().syntax()).unwrap_or_default(),
-                    InsertPosition::After(it),
-                ),
-                None => return,
-            },
-        };
-        let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
-        let to_insert: ArrayVec<[SyntaxElement; 2]> =
-            [ws.ws().into(), item.syntax().clone().into()].into();
-        self.ast = self.insert_children(position, to_insert.into_iter());
-    }
-
-    fn l_curly(&self) -> Option<SyntaxElement> {
-        self.ast().syntax().children_with_tokens().find(|it| it.kind() == T!['{'])
-    }
-}
-
-impl AstEditor<ast::ImplItem> {
-    pub fn strip_attrs_and_docs(&mut self) {
-        while let Some(start) = self
-            .ast()
-            .syntax()
-            .children_with_tokens()
-            .find(|it| it.kind() == ATTR || it.kind() == COMMENT)
-        {
-            let end = match &start.next_sibling_or_token() {
-                Some(el) if el.kind() == WHITESPACE => el.clone(),
-                Some(_) | None => start.clone(),
-            };
-            self.ast = self.replace_children(RangeInclusive::new(start, end), iter::empty());
-        }
-    }
-}
-
-impl AstEditor<ast::FnDef> {
-    pub fn set_body(&mut self, body: &ast::Block) {
-        let mut to_insert: ArrayVec<[SyntaxElement; 2]> = ArrayVec::new();
-        let old_body_or_semi: SyntaxElement = if let Some(old_body) = self.ast().body() {
-            old_body.syntax().clone().into()
-        } else if let Some(semi) = self.ast().semicolon_token() {
-            to_insert.push(tokens::single_space().into());
-            semi.into()
-        } else {
-            to_insert.push(tokens::single_space().into());
-            to_insert.push(body.syntax().clone().into());
-            self.ast = self.insert_children(InsertPosition::Last, to_insert.into_iter());
-            return;
-        };
-        to_insert.push(body.syntax().clone().into());
-        let replace_range = RangeInclusive::new(old_body_or_semi.clone(), old_body_or_semi);
-        self.ast = self.replace_children(replace_range, to_insert.into_iter())
-    }
-}
-
-impl AstEditor<ast::TypeParam> {
-    pub fn remove_bounds(&mut self) -> &mut Self {
-        let colon = match self.ast.colon_token() {
-            Some(it) => it,
-            None => return self,
-        };
-        let end = match self.ast.type_bound_list() {
-            Some(it) => it.syntax().clone().into(),
-            None => colon.clone().into(),
-        };
-        self.ast = self.replace_children(RangeInclusive::new(colon.into(), end), iter::empty());
-        self
-    }
-}
-
-mod tokens {
-    use once_cell::sync::Lazy;
-    use ra_syntax::{AstNode, Parse, SourceFile, SyntaxKind::*, SyntaxToken, T};
-
-    static SOURCE_FILE: Lazy<Parse<SourceFile>> = Lazy::new(|| SourceFile::parse(",\n; ;"));
-
-    pub(crate) fn comma() -> SyntaxToken {
-        SOURCE_FILE
-            .tree()
-            .syntax()
-            .descendants_with_tokens()
-            .filter_map(|it| it.into_token())
-            .find(|it| it.kind() == T![,])
-            .unwrap()
-    }
-
-    pub(crate) fn single_space() -> SyntaxToken {
-        SOURCE_FILE
-            .tree()
-            .syntax()
-            .descendants_with_tokens()
-            .filter_map(|it| it.into_token())
-            .find(|it| it.kind() == WHITESPACE && it.text().as_str() == " ")
-            .unwrap()
-    }
-
-    #[allow(unused)]
-    pub(crate) fn single_newline() -> SyntaxToken {
-        SOURCE_FILE
-            .tree()
-            .syntax()
-            .descendants_with_tokens()
-            .filter_map(|it| it.into_token())
-            .find(|it| it.kind() == WHITESPACE && it.text().as_str() == "\n")
-            .unwrap()
-    }
-
-    pub(crate) struct WsBuilder(SourceFile);
-
-    impl WsBuilder {
-        pub(crate) fn new(text: &str) -> WsBuilder {
-            WsBuilder(SourceFile::parse(text).ok().unwrap())
-        }
-        pub(crate) fn ws(&self) -> SyntaxToken {
-            self.0.syntax().first_child_or_token().unwrap().into_token().unwrap()
-        }
-    }
-
-}
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 3ca3320f7..d2376c475 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -7,7 +7,6 @@
 
 mod assist_ctx;
 mod marks;
-pub mod ast_editor;
 
 use hir::db::HirDatabase;
 use itertools::Itertools;
@@ -93,6 +92,7 @@ mod assists {
     mod add_derive;
     mod add_explicit_type;
     mod add_impl;
+    mod apply_demorgan;
     mod flip_comma;
     mod flip_binexpr;
     mod change_visibility;
@@ -114,6 +114,7 @@ mod assists {
             add_derive::add_derive,
             add_explicit_type::add_explicit_type,
             add_impl::add_impl,
+            apply_demorgan::apply_demorgan,
             change_visibility::change_visibility,
             fill_match_arms::fill_match_arms,
             merge_match_arms::merge_match_arms,
diff --git a/crates/ra_assists/src/marks.rs b/crates/ra_assists/src/marks.rs
index a29f9f658..c20e4db9e 100644
--- a/crates/ra_assists/src/marks.rs
+++ b/crates/ra_assists/src/marks.rs
@@ -1,3 +1,5 @@
+//! See test_utils/src/marks.rs
+
 test_utils::marks!(
     introduce_var_in_comment_is_not_applicable
     test_introduce_var_expr_stmt
diff --git a/crates/ra_batch/src/lib.rs b/crates/ra_batch/src/lib.rs
index ffc9e16bb..a5fc2a23e 100644
--- a/crates/ra_batch/src/lib.rs
+++ b/crates/ra_batch/src/lib.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::{collections::HashSet, error::Error, path::Path};
 
 use rustc_hash::FxHashMap;
@@ -5,7 +7,7 @@ use rustc_hash::FxHashMap;
 use crossbeam_channel::{unbounded, Receiver};
 use ra_db::{CrateGraph, FileId, SourceRootId};
 use ra_ide_api::{AnalysisChange, AnalysisHost, FeatureFlags};
-use ra_project_model::{PackageRoot, ProjectWorkspace};
+use ra_project_model::{get_rustc_cfg_options, PackageRoot, ProjectWorkspace};
 use ra_vfs::{RootEntry, Vfs, VfsChange, VfsTask, Watch};
 use ra_vfs_glob::RustPackageFilterBuilder;
 
@@ -39,11 +41,17 @@ pub fn load_cargo(root: &Path) -> Result<(AnalysisHost, FxHashMap<SourceRootId,
         sender,
         Watch(false),
     );
-    let (crate_graph, _crate_names) = ws.to_crate_graph(&mut |path: &Path| {
-        let vfs_file = vfs.load(path);
-        log::debug!("vfs file {:?} -> {:?}", path, vfs_file);
-        vfs_file.map(vfs_file_to_id)
-    });
+
+    // FIXME: cfg options?
+    let default_cfg_options =
+        get_rustc_cfg_options().atom("test".into()).atom("debug_assertion".into());
+
+    let (crate_graph, _crate_names) =
+        ws.to_crate_graph(&default_cfg_options, &mut |path: &Path| {
+            let vfs_file = vfs.load(path);
+            log::debug!("vfs file {:?} -> {:?}", path, vfs_file);
+            vfs_file.map(vfs_file_to_id)
+        });
     log::debug!("crate graph: {:?}", crate_graph);
 
     let source_roots = roots
diff --git a/crates/ra_cfg/Cargo.toml b/crates/ra_cfg/Cargo.toml
new file mode 100644
index 000000000..b28affc3a
--- /dev/null
+++ b/crates/ra_cfg/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+edition = "2018"
+name = "ra_cfg"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+
+[dependencies]
+rustc-hash = "1.0.1"
+
+ra_syntax = { path = "../ra_syntax" }
+tt = { path = "../ra_tt", package = "ra_tt" }
+
+[dev-dependencies]
+mbe = { path = "../ra_mbe", package = "ra_mbe" }
diff --git a/crates/ra_cfg/src/cfg_expr.rs b/crates/ra_cfg/src/cfg_expr.rs
new file mode 100644
index 000000000..39d71851c
--- /dev/null
+++ b/crates/ra_cfg/src/cfg_expr.rs
@@ -0,0 +1,132 @@
+//! The condition expression used in `#[cfg(..)]` attributes.
+//!
+//! See: https://doc.rust-lang.org/reference/conditional-compilation.html#conditional-compilation
+
+use std::slice::Iter as SliceIter;
+
+use ra_syntax::SmolStr;
+use tt::{Leaf, Subtree, TokenTree};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum CfgExpr {
+    Invalid,
+    Atom(SmolStr),
+    KeyValue { key: SmolStr, value: SmolStr },
+    All(Vec<CfgExpr>),
+    Any(Vec<CfgExpr>),
+    Not(Box<CfgExpr>),
+}
+
+impl CfgExpr {
+    /// Fold the cfg by querying all basic `Atom` and `KeyValue` predicates.
+    pub fn fold(&self, query: &dyn Fn(&SmolStr, Option<&SmolStr>) -> bool) -> Option<bool> {
+        match self {
+            CfgExpr::Invalid => None,
+            CfgExpr::Atom(name) => Some(query(name, None)),
+            CfgExpr::KeyValue { key, value } => Some(query(key, Some(value))),
+            CfgExpr::All(preds) => {
+                preds.iter().try_fold(true, |s, pred| Some(s && pred.fold(query)?))
+            }
+            CfgExpr::Any(preds) => {
+                preds.iter().try_fold(false, |s, pred| Some(s || pred.fold(query)?))
+            }
+            CfgExpr::Not(pred) => pred.fold(query).map(|s| !s),
+        }
+    }
+}
+
+pub fn parse_cfg(tt: &Subtree) -> CfgExpr {
+    next_cfg_expr(&mut tt.token_trees.iter()).unwrap_or(CfgExpr::Invalid)
+}
+
+fn next_cfg_expr(it: &mut SliceIter<tt::TokenTree>) -> Option<CfgExpr> {
+    let name = match it.next() {
+        None => return None,
+        Some(TokenTree::Leaf(Leaf::Ident(ident))) => ident.text.clone(),
+        Some(_) => return Some(CfgExpr::Invalid),
+    };
+
+    // Peek
+    let ret = match it.as_slice().first() {
+        Some(TokenTree::Leaf(Leaf::Punct(punct))) if punct.char == '=' => {
+            match it.as_slice().get(1) {
+                Some(TokenTree::Leaf(Leaf::Literal(literal))) => {
+                    it.next();
+                    it.next();
+                    // FIXME: escape? raw string?
+                    let value =
+                        SmolStr::new(literal.text.trim_start_matches('"').trim_end_matches('"'));
+                    CfgExpr::KeyValue { key: name, value }
+                }
+                _ => return Some(CfgExpr::Invalid),
+            }
+        }
+        Some(TokenTree::Subtree(subtree)) => {
+            it.next();
+            let mut sub_it = subtree.token_trees.iter();
+            let mut subs = std::iter::from_fn(|| next_cfg_expr(&mut sub_it)).collect();
+            match name.as_str() {
+                "all" => CfgExpr::All(subs),
+                "any" => CfgExpr::Any(subs),
+                "not" => CfgExpr::Not(Box::new(subs.pop().unwrap_or(CfgExpr::Invalid))),
+                _ => CfgExpr::Invalid,
+            }
+        }
+        _ => CfgExpr::Atom(name),
+    };
+
+    // Eat comma separator
+    if let Some(TokenTree::Leaf(Leaf::Punct(punct))) = it.as_slice().first() {
+        if punct.char == ',' {
+            it.next();
+        }
+    }
+    Some(ret)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use mbe::ast_to_token_tree;
+    use ra_syntax::ast::{self, AstNode};
+
+    fn assert_parse_result(input: &str, expected: CfgExpr) {
+        let source_file = ast::SourceFile::parse(input).ok().unwrap();
+        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
+        let (tt, _) = ast_to_token_tree(&tt).unwrap();
+        assert_eq!(parse_cfg(&tt), expected);
+    }
+
+    #[test]
+    fn test_cfg_expr_parser() {
+        assert_parse_result("#![cfg(foo)]", CfgExpr::Atom("foo".into()));
+        assert_parse_result("#![cfg(foo,)]", CfgExpr::Atom("foo".into()));
+        assert_parse_result(
+            "#![cfg(not(foo))]",
+            CfgExpr::Not(Box::new(CfgExpr::Atom("foo".into()))),
+        );
+        assert_parse_result("#![cfg(foo(bar))]", CfgExpr::Invalid);
+
+        // Only take the first
+        assert_parse_result(r#"#![cfg(foo, bar = "baz")]"#, CfgExpr::Atom("foo".into()));
+
+        assert_parse_result(
+            r#"#![cfg(all(foo, bar = "baz"))]"#,
+            CfgExpr::All(vec![
+                CfgExpr::Atom("foo".into()),
+                CfgExpr::KeyValue { key: "bar".into(), value: "baz".into() },
+            ]),
+        );
+
+        assert_parse_result(
+            r#"#![cfg(any(not(), all(), , bar = "baz",))]"#,
+            CfgExpr::Any(vec![
+                CfgExpr::Not(Box::new(CfgExpr::Invalid)),
+                CfgExpr::All(vec![]),
+                CfgExpr::Invalid,
+                CfgExpr::KeyValue { key: "bar".into(), value: "baz".into() },
+            ]),
+        );
+    }
+}
diff --git a/crates/ra_cfg/src/lib.rs b/crates/ra_cfg/src/lib.rs
new file mode 100644
index 000000000..e1c92fbba
--- /dev/null
+++ b/crates/ra_cfg/src/lib.rs
@@ -0,0 +1,61 @@
+//! ra_cfg defines conditional compiling options, `cfg` attibute parser and evaluator
+use std::iter::IntoIterator;
+
+use ra_syntax::SmolStr;
+use rustc_hash::FxHashSet;
+
+mod cfg_expr;
+
+pub use cfg_expr::{parse_cfg, CfgExpr};
+
+/// Configuration options used for conditional compilition on items with `cfg` attributes.
+/// We have two kind of options in different namespaces: atomic options like `unix`, and
+/// key-value options like `target_arch="x86"`.
+///
+/// Note that for key-value options, one key can have multiple values (but not none).
+/// `feature` is an example. We have both `feature="foo"` and `feature="bar"` if features
+/// `foo` and `bar` are both enabled. And here, we store key-value options as a set of tuple
+/// of key and value in `key_values`.
+///
+/// See: https://doc.rust-lang.org/reference/conditional-compilation.html#set-configuration-options
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub struct CfgOptions {
+    atoms: FxHashSet<SmolStr>,
+    key_values: FxHashSet<(SmolStr, SmolStr)>,
+}
+
+impl CfgOptions {
+    pub fn check(&self, cfg: &CfgExpr) -> Option<bool> {
+        cfg.fold(&|key, value| match value {
+            None => self.atoms.contains(key),
+            Some(value) => self.key_values.contains(&(key.clone(), value.clone())),
+        })
+    }
+
+    pub fn is_cfg_enabled(&self, attr: &tt::Subtree) -> Option<bool> {
+        self.check(&parse_cfg(attr))
+    }
+
+    pub fn atom(mut self, name: SmolStr) -> CfgOptions {
+        self.atoms.insert(name);
+        self
+    }
+
+    pub fn key_value(mut self, key: SmolStr, value: SmolStr) -> CfgOptions {
+        self.key_values.insert((key, value));
+        self
+    }
+
+    /// Shortcut to set features
+    pub fn features(mut self, iter: impl IntoIterator<Item = SmolStr>) -> CfgOptions {
+        for feat in iter {
+            self = self.key_value("feature".into(), feat);
+        }
+        self
+    }
+
+    pub fn remove_atom(mut self, name: &SmolStr) -> CfgOptions {
+        self.atoms.remove(name);
+        self
+    }
+}
diff --git a/crates/ra_cli/Cargo.toml b/crates/ra_cli/Cargo.toml
index d42ac3ad4..67e727a88 100644
--- a/crates/ra_cli/Cargo.toml
+++ b/crates/ra_cli/Cargo.toml
@@ -6,7 +6,7 @@ authors = ["rust-analyzer developers"]
 publish = false
 
 [dependencies]
-pico-args = "0.2.0"
+pico-args = "0.3.0"
 flexi_logger = "0.14.0"
 indicatif = "0.11.0"
 
diff --git a/crates/ra_cli/src/analysis_bench.rs b/crates/ra_cli/src/analysis_bench.rs
index 01b96ec58..727f1e62b 100644
--- a/crates/ra_cli/src/analysis_bench.rs
+++ b/crates/ra_cli/src/analysis_bench.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::{
     path::{Path, PathBuf},
     sync::Arc,
diff --git a/crates/ra_cli/src/analysis_stats.rs b/crates/ra_cli/src/analysis_stats.rs
index 6b1e44a2c..a8a110bd9 100644
--- a/crates/ra_cli/src/analysis_stats.rs
+++ b/crates/ra_cli/src/analysis_stats.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::{collections::HashSet, fmt::Write, path::Path, time::Instant};
 
 use ra_db::SourceDatabase;
diff --git a/crates/ra_cli/src/help.rs b/crates/ra_cli/src/help.rs
index 2a74b8733..d3c4c7d0b 100644
--- a/crates/ra_cli/src/help.rs
+++ b/crates/ra_cli/src/help.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 pub const GLOBAL_HELP: &str = "ra-cli
 
 USAGE:
diff --git a/crates/ra_cli/src/main.rs b/crates/ra_cli/src/main.rs
index 8b91ba3e9..2405eb4f4 100644
--- a/crates/ra_cli/src/main.rs
+++ b/crates/ra_cli/src/main.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 mod analysis_stats;
 mod analysis_bench;
 mod help;
@@ -93,7 +95,7 @@ fn main() -> Result<()> {
                 (true, true) => Err("Invalid flags: -q conflicts with -v")?,
             };
             let memory_usage = matches.contains("--memory-usage");
-            let only: Option<String> = matches.value_from_str(["-o", "--only"])?;
+            let only: Option<String> = matches.opt_value_from_str(["-o", "--only"])?;
             let path = {
                 let mut trailing = matches.free()?;
                 if trailing.len() != 1 {
@@ -115,9 +117,9 @@ fn main() -> Result<()> {
                 return Ok(());
             }
             let verbose = matches.contains(["-v", "--verbose"]);
-            let path: String = matches.value_from_str("--path")?.unwrap_or_default();
-            let highlight_path = matches.value_from_str("--highlight")?;
-            let complete_path = matches.value_from_str("--complete")?;
+            let path: String = matches.opt_value_from_str("--path")?.unwrap_or_default();
+            let highlight_path = matches.opt_value_from_str("--highlight")?;
+            let complete_path = matches.opt_value_from_str("--complete")?;
             if highlight_path.is_some() && complete_path.is_some() {
                 panic!("either --highlight or --complete must be set, not both")
             }
diff --git a/crates/ra_db/Cargo.toml b/crates/ra_db/Cargo.toml
index 2fac07bc5..c141f1a88 100644
--- a/crates/ra_db/Cargo.toml
+++ b/crates/ra_db/Cargo.toml
@@ -10,4 +10,5 @@ relative-path = "0.4.0"
 rustc-hash = "1.0"
 
 ra_syntax = { path = "../ra_syntax" }
+ra_cfg = { path = "../ra_cfg" }
 ra_prof = { path = "../ra_prof" }
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index a1ace61b6..23148096c 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -1,13 +1,15 @@
-/// This module specifies the input to rust-analyzer. In some sense, this is
-/// **the** most important module, because all other fancy stuff is strictly
-/// derived from this input.
-///
-/// Note that neither this module, nor any other part of the analyzer's core do
-/// actual IO. See `vfs` and `project_model` in the `ra_lsp_server` crate for how
-/// actual IO is done and lowered to input.
+//! This module specifies the input to rust-analyzer. In some sense, this is
+//! **the** most important module, because all other fancy stuff is strictly
+//! derived from this input.
+//!
+//! Note that neither this module, nor any other part of the analyzer's core do
+//! actual IO. See `vfs` and `project_model` in the `ra_lsp_server` crate for how
+//! actual IO is done and lowered to input.
+
 use relative_path::{RelativePath, RelativePathBuf};
 use rustc_hash::FxHashMap;
 
+use ra_cfg::CfgOptions;
 use ra_syntax::SmolStr;
 use rustc_hash::FxHashSet;
 
@@ -108,11 +110,12 @@ struct CrateData {
     file_id: FileId,
     edition: Edition,
     dependencies: Vec<Dependency>,
+    cfg_options: CfgOptions,
 }
 
 impl CrateData {
-    fn new(file_id: FileId, edition: Edition) -> CrateData {
-        CrateData { file_id, edition, dependencies: Vec::new() }
+    fn new(file_id: FileId, edition: Edition, cfg_options: CfgOptions) -> CrateData {
+        CrateData { file_id, edition, dependencies: Vec::new(), cfg_options }
     }
 
     fn add_dep(&mut self, name: SmolStr, crate_id: CrateId) {
@@ -133,13 +136,22 @@ impl Dependency {
 }
 
 impl CrateGraph {
-    pub fn add_crate_root(&mut self, file_id: FileId, edition: Edition) -> CrateId {
+    pub fn add_crate_root(
+        &mut self,
+        file_id: FileId,
+        edition: Edition,
+        cfg_options: CfgOptions,
+    ) -> CrateId {
         let crate_id = CrateId(self.arena.len() as u32);
-        let prev = self.arena.insert(crate_id, CrateData::new(file_id, edition));
+        let prev = self.arena.insert(crate_id, CrateData::new(file_id, edition, cfg_options));
         assert!(prev.is_none());
         crate_id
     }
 
+    pub fn cfg_options(&self, crate_id: CrateId) -> &CfgOptions {
+        &self.arena[&crate_id].cfg_options
+    }
+
     pub fn add_dep(
         &mut self,
         from: CrateId,
@@ -220,14 +232,14 @@ impl CrateGraph {
 
 #[cfg(test)]
 mod tests {
-    use super::{CrateGraph, Edition::Edition2018, FileId, SmolStr};
+    use super::{CfgOptions, CrateGraph, Edition::Edition2018, FileId, SmolStr};
 
     #[test]
     fn it_should_panic_because_of_cycle_dependencies() {
         let mut graph = CrateGraph::default();
-        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018);
-        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018);
-        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018);
+        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018, CfgOptions::default());
+        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018, CfgOptions::default());
+        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018, CfgOptions::default());
         assert!(graph.add_dep(crate1, SmolStr::new("crate2"), crate2).is_ok());
         assert!(graph.add_dep(crate2, SmolStr::new("crate3"), crate3).is_ok());
         assert!(graph.add_dep(crate3, SmolStr::new("crate1"), crate1).is_err());
@@ -236,9 +248,9 @@ mod tests {
     #[test]
     fn it_works() {
         let mut graph = CrateGraph::default();
-        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018);
-        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018);
-        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018);
+        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018, CfgOptions::default());
+        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018, CfgOptions::default());
+        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018, CfgOptions::default());
         assert!(graph.add_dep(crate1, SmolStr::new("crate2"), crate2).is_ok());
         assert!(graph.add_dep(crate2, SmolStr::new("crate3"), crate3).is_ok());
     }
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index c54791b7a..603daed37 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -32,11 +32,10 @@ pub trait CheckCanceled {
 
     fn catch_canceled<F, T>(&self, f: F) -> Result<T, Canceled>
     where
-        Self: Sized,
+        Self: Sized + panic::RefUnwindSafe,
         F: FnOnce(&Self) -> T + panic::UnwindSafe,
     {
-        let this = panic::AssertUnwindSafe(self);
-        panic::catch_unwind(|| f(*this)).map_err(|err| match err.downcast::<Canceled>() {
+        panic::catch_unwind(|| f(self)).map_err(|err| match err.downcast::<Canceled>() {
             Ok(canceled) => *canceled,
             Err(payload) => panic::resume_unwind(payload),
         })
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index d9bed4dda..cc117f84d 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -15,6 +15,7 @@ once_cell = "1.0.1"
 
 ra_syntax = { path = "../ra_syntax" }
 ra_arena = { path = "../ra_arena" }
+ra_cfg = { path = "../ra_cfg" }
 ra_db = { path = "../ra_db" }
 mbe = { path = "../ra_mbe", package = "ra_mbe" }
 tt = { path = "../ra_tt", package = "ra_tt" }
diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index fbb4ff4d8..99d286215 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -133,7 +133,7 @@ impl VariantData {
                     .fields()
                     .enumerate()
                     .map(|(i, fd)| StructFieldData {
-                        name: Name::tuple_field_name(i),
+                        name: Name::new_tuple_field(i),
                         type_ref: TypeRef::from_ast_opt(fd.type_ref()),
                     })
                     .collect();
diff --git a/crates/ra_hir/src/attr.rs b/crates/ra_hir/src/attr.rs
new file mode 100644
index 000000000..f67e80bfd
--- /dev/null
+++ b/crates/ra_hir/src/attr.rs
@@ -0,0 +1,80 @@
+//! A higher level attributes based on TokenTree, with also some shortcuts.
+
+use std::sync::Arc;
+
+use mbe::ast_to_token_tree;
+use ra_cfg::CfgOptions;
+use ra_syntax::{
+    ast::{self, AstNode, AttrsOwner},
+    SmolStr,
+};
+use tt::Subtree;
+
+use crate::{db::AstDatabase, path::Path, HirFileId, Source};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct Attr {
+    pub(crate) path: Path,
+    pub(crate) input: Option<AttrInput>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum AttrInput {
+    Literal(SmolStr),
+    TokenTree(Subtree),
+}
+
+impl Attr {
+    pub(crate) fn from_src(
+        Source { file_id, ast }: Source<ast::Attr>,
+        db: &impl AstDatabase,
+    ) -> Option<Attr> {
+        let path = Path::from_src(Source { file_id, ast: ast.path()? }, db)?;
+        let input = match ast.input() {
+            None => None,
+            Some(ast::AttrInput::Literal(lit)) => {
+                // FIXME: escape? raw string?
+                let value = lit.syntax().first_token()?.text().trim_matches('"').into();
+                Some(AttrInput::Literal(value))
+            }
+            Some(ast::AttrInput::TokenTree(tt)) => {
+                Some(AttrInput::TokenTree(ast_to_token_tree(&tt)?.0))
+            }
+        };
+
+        Some(Attr { path, input })
+    }
+
+    pub(crate) fn from_attrs_owner(
+        file_id: HirFileId,
+        owner: &dyn AttrsOwner,
+        db: &impl AstDatabase,
+    ) -> Option<Arc<[Attr]>> {
+        let mut attrs = owner.attrs().peekable();
+        if attrs.peek().is_none() {
+            // Avoid heap allocation
+            return None;
+        }
+        Some(attrs.flat_map(|ast| Attr::from_src(Source { file_id, ast }, db)).collect())
+    }
+
+    pub(crate) fn is_simple_atom(&self, name: &str) -> bool {
+        // FIXME: Avoid cloning
+        self.path.as_ident().map_or(false, |s| s.to_string() == name)
+    }
+
+    pub(crate) fn as_cfg(&self) -> Option<&Subtree> {
+        if self.is_simple_atom("cfg") {
+            match &self.input {
+                Some(AttrInput::TokenTree(subtree)) => Some(subtree),
+                _ => None,
+            }
+        } else {
+            None
+        }
+    }
+
+    pub(crate) fn is_cfg_enabled(&self, cfg_options: &CfgOptions) -> Option<bool> {
+        cfg_options.is_cfg_enabled(self.as_cfg()?)
+    }
+}
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 20413cb3d..e3a7e8e3c 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 pub(crate) mod src;
 pub(crate) mod docs;
 
@@ -339,10 +341,14 @@ pub struct Struct {
 }
 
 impl Struct {
-    pub fn module(self, db: &impl HirDatabase) -> Module {
+    pub fn module(self, db: &impl DefDatabase) -> Module {
         self.id.module(db)
     }
 
+    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
+        self.module(db).krate(db)
+    }
+
     pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
         db.struct_data(self).name.clone()
     }
@@ -423,10 +429,14 @@ pub struct Enum {
 }
 
 impl Enum {
-    pub fn module(self, db: &impl HirDatabase) -> Module {
+    pub fn module(self, db: &impl DefDatabase) -> Module {
         self.id.module(db)
     }
 
+    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
+        self.module(db).krate(db)
+    }
+
     pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
         db.enum_data(self).name.clone()
     }
@@ -514,7 +524,7 @@ impl Adt {
         }
     }
 
-    pub(crate) fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
+    pub fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
         match self {
             Adt::Struct(s) => s.module(db),
             Adt::Union(s) => s.module(db),
diff --git a/crates/ra_hir/src/code_model/docs.rs b/crates/ra_hir/src/code_model/docs.rs
index 99edc5814..9675e397f 100644
--- a/crates/ra_hir/src/code_model/docs.rs
+++ b/crates/ra_hir/src/code_model/docs.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::sync::Arc;
 
 use ra_syntax::ast;
diff --git a/crates/ra_hir/src/code_model/src.rs b/crates/ra_hir/src/code_model/src.rs
index c0cb27b47..fdae26906 100644
--- a/crates/ra_hir/src/code_model/src.rs
+++ b/crates/ra_hir/src/code_model/src.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use ra_syntax::{
     ast::{self, AstNode},
     SyntaxNode,
@@ -119,7 +121,7 @@ impl HasSource for TypeAlias {
 impl HasSource for MacroDef {
     type Ast = ast::MacroCall;
     fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::MacroCall> {
-        Source { file_id: self.id.0.file_id(), ast: self.id.0.to_node(db) }
+        Source { file_id: self.id.ast_id.file_id(), ast: self.id.ast_id.to_node(db) }
     }
 }
 
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index deed1c62f..73d7d6fb6 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::sync::Arc;
 
 use ra_db::{salsa, SourceDatabase};
diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index 60da33695..9acdaf8ed 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::{any::Any, fmt};
 
 use ra_syntax::{ast, AstNode, AstPtr, SyntaxNode, SyntaxNodePtr, TextRange};
diff --git a/crates/ra_hir/src/either.rs b/crates/ra_hir/src/either.rs
index 439e6ec87..83583ef8b 100644
--- a/crates/ra_hir/src/either.rs
+++ b/crates/ra_hir/src/either.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum Either<A, B> {
     A(A),
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index b1bec2a68..d238741ba 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 pub(crate) mod lower;
 pub(crate) mod scope;
 pub(crate) mod validation;
diff --git a/crates/ra_hir/src/expr/lower.rs b/crates/ra_hir/src/expr/lower.rs
index 61535d24f..50ea429ea 100644
--- a/crates/ra_hir/src/expr/lower.rs
+++ b/crates/ra_hir/src/expr/lower.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use ra_arena::Arena;
 use ra_syntax::{
     ast::{
@@ -272,8 +274,11 @@ where
                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
             }
             ast::Expr::PathExpr(e) => {
-                let path =
-                    e.path().and_then(Path::from_ast).map(Expr::Path).unwrap_or(Expr::Missing);
+                let path = e
+                    .path()
+                    .and_then(|path| self.parse_path(path))
+                    .map(Expr::Path)
+                    .unwrap_or(Expr::Missing);
                 self.alloc_expr(path, syntax_ptr)
             }
             ast::Expr::ContinueExpr(_e) => {
@@ -295,7 +300,7 @@ where
                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
             }
             ast::Expr::RecordLit(e) => {
-                let path = e.path().and_then(Path::from_ast);
+                let path = e.path().and_then(|path| self.parse_path(path));
                 let mut field_ptrs = Vec::new();
                 let record_lit = if let Some(nfl) = e.record_field_list() {
                     let fields = nfl
@@ -459,7 +464,7 @@ where
                     .ast_id(&e)
                     .with_file_id(self.current_file_id);
 
-                if let Some(path) = e.path().and_then(Path::from_ast) {
+                if let Some(path) = e.path().and_then(|path| self.parse_path(path)) {
                     if let Some(def) = self.resolver.resolve_path_as_macro(self.db, &path) {
                         let call_id = MacroCallLoc { def: def.id, ast_id }.id(self.db);
                         let file_id = call_id.as_file(MacroFileKind::Expr);
@@ -529,7 +534,7 @@ where
                 Pat::Bind { name, mode: annotation, subpat }
             }
             ast::Pat::TupleStructPat(p) => {
-                let path = p.path().and_then(Path::from_ast);
+                let path = p.path().and_then(|path| self.parse_path(path));
                 let args = p.args().map(|p| self.collect_pat(p)).collect();
                 Pat::TupleStruct { path, args }
             }
@@ -539,7 +544,7 @@ where
                 Pat::Ref { pat, mutability }
             }
             ast::Pat::PathPat(p) => {
-                let path = p.path().and_then(Path::from_ast);
+                let path = p.path().and_then(|path| self.parse_path(path));
                 path.map(Pat::Path).unwrap_or(Pat::Missing)
             }
             ast::Pat::TuplePat(p) => {
@@ -548,7 +553,7 @@ where
             }
             ast::Pat::PlaceholderPat(_) => Pat::Wild,
             ast::Pat::RecordPat(p) => {
-                let path = p.path().and_then(Path::from_ast);
+                let path = p.path().and_then(|path| self.parse_path(path));
                 let record_field_pat_list =
                     p.record_field_pat_list().expect("every struct should have a field list");
                 let mut fields: Vec<_> = record_field_pat_list
@@ -589,6 +594,10 @@ where
             self.missing_pat()
         }
     }
+
+    fn parse_path(&mut self, path: ast::Path) -> Option<Path> {
+        Path::from_src(Source { ast: path, file_id: self.current_file_id }, self.db)
+    }
 }
 
 impl From<ast::BinOp> for BinaryOp {
diff --git a/crates/ra_hir/src/expr/scope.rs b/crates/ra_hir/src/expr/scope.rs
index de0983a7e..5496822e7 100644
--- a/crates/ra_hir/src/expr/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::sync::Arc;
 
 use ra_arena::{impl_arena_id, Arena, RawId};
diff --git a/crates/ra_hir/src/expr/validation.rs b/crates/ra_hir/src/expr/validation.rs
index f06e5ec07..1aa853c3e 100644
--- a/crates/ra_hir/src/expr/validation.rs
+++ b/crates/ra_hir/src/expr/validation.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::sync::Arc;
 
 use ra_syntax::ast;
diff --git a/crates/ra_hir/src/from_source.rs b/crates/ra_hir/src/from_source.rs
index 7b6d9b240..a012f33f7 100644
--- a/crates/ra_hir/src/from_source.rs
+++ b/crates/ra_hir/src/from_source.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use ra_db::{FileId, FilePosition};
 use ra_syntax::{
     algo::find_node_at_offset,
diff --git a/crates/ra_hir/src/generics.rs b/crates/ra_hir/src/generics.rs
index 6865d34ba..4ce7551c3 100644
--- a/crates/ra_hir/src/generics.rs
+++ b/crates/ra_hir/src/generics.rs
@@ -132,6 +132,7 @@ impl GenericParams {
     fn fill_params(&mut self, params: ast::TypeParamList, start: u32) {
         for (idx, type_param) in params.type_params().enumerate() {
             let name = type_param.name().map_or_else(Name::missing, |it| it.as_name());
+            // FIXME: Use `Path::from_src`
             let default = type_param.default_type().and_then(|t| t.path()).and_then(Path::from_ast);
 
             let param = GenericParam { idx: idx as u32 + start, name: name.clone(), default };
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index 9ea4e695d..a3b65cc79 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::{
     hash::{Hash, Hasher},
     sync::Arc,
@@ -10,7 +12,7 @@ use ra_syntax::{ast, AstNode, Parse, SyntaxNode};
 
 use crate::{
     db::{AstDatabase, DefDatabase, InternDatabase},
-    AstId, FileAstId, Module, Source,
+    AstId, Crate, FileAstId, Module, Source,
 };
 
 /// hir makes heavy use of ids: integer (u32) handlers to various things. You
@@ -58,6 +60,17 @@ impl HirFileId {
         }
     }
 
+    /// Get the crate which the macro lives in, if it is a macro file.
+    pub(crate) fn macro_crate(self, db: &impl AstDatabase) -> Option<Crate> {
+        match self.0 {
+            HirFileIdRepr::File(_) => None,
+            HirFileIdRepr::Macro(macro_file) => {
+                let loc = macro_file.macro_call_id.loc(db);
+                Some(loc.def.krate)
+            }
+        }
+    }
+
     pub(crate) fn parse_or_expand_query(
         db: &impl AstDatabase,
         file_id: HirFileId,
@@ -121,10 +134,13 @@ impl From<FileId> for HirFileId {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct MacroDefId(pub(crate) AstId<ast::MacroCall>);
+pub struct MacroDefId {
+    pub(crate) ast_id: AstId<ast::MacroCall>,
+    pub(crate) krate: Crate,
+}
 
 pub(crate) fn macro_def_query(db: &impl AstDatabase, id: MacroDefId) -> Option<Arc<MacroRules>> {
-    let macro_call = id.0.to_node(db);
+    let macro_call = id.ast_id.to_node(db);
     let arg = macro_call.token_tree()?;
     let (tt, _) = mbe::ast_to_token_tree(&arg).or_else(|| {
         log::warn!("fail on macro_def to token tree: {:#?}", arg);
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index d830202bd..55dfc393b 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -1,13 +1,17 @@
+//! FIXME: write short doc here
+
 use rustc_hash::FxHashMap;
 use std::sync::Arc;
 
 use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
+use ra_cfg::CfgOptions;
 use ra_syntax::{
     ast::{self, AstNode},
     AstPtr,
 };
 
 use crate::{
+    attr::Attr,
     code_model::{Module, ModuleSource},
     db::{AstDatabase, DefDatabase, HirDatabase},
     generics::HasGenericParams,
@@ -174,6 +178,7 @@ pub struct ModuleImplBlocks {
 impl ModuleImplBlocks {
     fn collect(
         db: &(impl DefDatabase + AstDatabase),
+        cfg_options: &CfgOptions,
         module: Module,
         source_map: &mut ImplSourceMap,
     ) -> Self {
@@ -186,11 +191,11 @@ impl ModuleImplBlocks {
         let src = m.module.definition_source(db);
         match &src.ast {
             ModuleSource::SourceFile(node) => {
-                m.collect_from_item_owner(db, source_map, node, src.file_id)
+                m.collect_from_item_owner(db, cfg_options, source_map, node, src.file_id)
             }
             ModuleSource::Module(node) => {
                 let item_list = node.item_list().expect("inline module should have item list");
-                m.collect_from_item_owner(db, source_map, &item_list, src.file_id)
+                m.collect_from_item_owner(db, cfg_options, source_map, &item_list, src.file_id)
             }
         };
         m
@@ -199,6 +204,7 @@ impl ModuleImplBlocks {
     fn collect_from_item_owner(
         &mut self,
         db: &(impl DefDatabase + AstDatabase),
+        cfg_options: &CfgOptions,
         source_map: &mut ImplSourceMap,
         owner: &dyn ast::ModuleItemOwner,
         file_id: HirFileId,
@@ -206,6 +212,13 @@ impl ModuleImplBlocks {
         for item in owner.items_with_macros() {
             match item {
                 ast::ItemOrMacro::Item(ast::ModuleItem::ImplBlock(impl_block_ast)) => {
+                    let attrs = Attr::from_attrs_owner(file_id, &impl_block_ast, db);
+                    if attrs.map_or(false, |attrs| {
+                        attrs.iter().any(|attr| attr.is_cfg_enabled(cfg_options) == Some(false))
+                    }) {
+                        continue;
+                    }
+
                     let impl_block = ImplData::from_ast(db, file_id, self.module, &impl_block_ast);
                     let id = self.impls.alloc(impl_block);
                     for &impl_item in &self.impls[id].items {
@@ -216,9 +229,19 @@ impl ModuleImplBlocks {
                 }
                 ast::ItemOrMacro::Item(_) => (),
                 ast::ItemOrMacro::Macro(macro_call) => {
+                    let attrs = Attr::from_attrs_owner(file_id, &macro_call, db);
+                    if attrs.map_or(false, |attrs| {
+                        attrs.iter().any(|attr| attr.is_cfg_enabled(cfg_options) == Some(false))
+                    }) {
+                        continue;
+                    }
+
                     //FIXME: we should really cut down on the boilerplate required to process a macro
                     let ast_id = db.ast_id_map(file_id).ast_id(&macro_call).with_file_id(file_id);
-                    if let Some(path) = macro_call.path().and_then(Path::from_ast) {
+                    if let Some(path) = macro_call
+                        .path()
+                        .and_then(|path| Path::from_src(Source { ast: path, file_id }, db))
+                    {
                         if let Some(def) = self.module.resolver(db).resolve_path_as_macro(db, &path)
                         {
                             let call_id = MacroCallLoc { def: def.id, ast_id }.id(db);
@@ -226,7 +249,13 @@ impl ModuleImplBlocks {
                             if let Some(item_list) =
                                 db.parse_or_expand(file_id).and_then(ast::MacroItems::cast)
                             {
-                                self.collect_from_item_owner(db, source_map, &item_list, file_id)
+                                self.collect_from_item_owner(
+                                    db,
+                                    cfg_options,
+                                    source_map,
+                                    &item_list,
+                                    file_id,
+                                )
                             }
                         }
                     }
@@ -241,8 +270,10 @@ pub(crate) fn impls_in_module_with_source_map_query(
     module: Module,
 ) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>) {
     let mut source_map = ImplSourceMap::default();
+    let crate_graph = db.crate_graph();
+    let cfg_options = crate_graph.cfg_options(module.krate.crate_id());
 
-    let result = ModuleImplBlocks::collect(db, module, &mut source_map);
+    let result = ModuleImplBlocks::collect(db, cfg_options, module, &mut source_map);
     (Arc::new(result), Arc::new(source_map))
 }
 
diff --git a/crates/ra_hir/src/lang_item.rs b/crates/ra_hir/src/lang_item.rs
index bcce314d8..6c4e8ffbd 100644
--- a/crates/ra_hir/src/lang_item.rs
+++ b/crates/ra_hir/src/lang_item.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use rustc_hash::FxHashMap;
 use std::sync::Arc;
 
@@ -151,7 +153,7 @@ impl LangItems {
 
 fn lang_item_name<T: AttrsOwner>(node: &T) -> Option<SmolStr> {
     node.attrs()
-        .filter_map(|a| a.as_key_value())
+        .filter_map(|a| a.as_simple_key_value())
         .filter(|(key, _)| key == "lang")
         .map(|(_, val)| val)
         .nth(0)
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index a9de9fb6b..4340e9d34 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -1,5 +1,3 @@
-#![recursion_limit = "512"]
-
 //! HIR (previously known as descriptors) provides a high-level object oriented
 //! access to Rust code.
 //!
@@ -7,6 +5,8 @@
 //! to a particular crate instance. That is, it has cfg flags and features
 //! applied. So, the relation between syntax and HIR is many-to-one.
 
+#![recursion_limit = "512"]
+
 macro_rules! impl_froms {
     ($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
         $(
@@ -44,6 +44,7 @@ mod traits;
 mod type_alias;
 mod type_ref;
 mod ty;
+mod attr;
 mod impl_block;
 mod expr;
 mod lang_item;
diff --git a/crates/ra_hir/src/marks.rs b/crates/ra_hir/src/marks.rs
index b2111be05..79af24b20 100644
--- a/crates/ra_hir/src/marks.rs
+++ b/crates/ra_hir/src/marks.rs
@@ -1,3 +1,5 @@
+//! See test_utils/src/marks.rs
+
 test_utils::marks!(
     bogus_paths
     name_res_works_for_broken_modules
@@ -9,9 +11,10 @@ test_utils::marks!(
     glob_across_crates
     std_prelude
     match_ergonomics_ref
-    trait_resolution_on_fn_type
     infer_while_let
     macro_rules_from_other_crates_are_visible_with_macro_use
     prelude_is_macro_use
     coerce_merge_fail_fallback
+    macro_dollar_crate_self
+    macro_dollar_crate_other
 );
diff --git a/crates/ra_hir/src/mock.rs b/crates/ra_hir/src/mock.rs
index cb405091e..f750986b8 100644
--- a/crates/ra_hir/src/mock.rs
+++ b/crates/ra_hir/src/mock.rs
@@ -1,6 +1,9 @@
+//! FIXME: write short doc here
+
 use std::{panic, sync::Arc};
 
 use parking_lot::Mutex;
+use ra_cfg::CfgOptions;
 use ra_db::{
     salsa, CrateGraph, CrateId, Edition, FileId, FilePosition, SourceDatabase, SourceRoot,
     SourceRootId,
@@ -72,13 +75,13 @@ impl MockDatabase {
     pub fn set_crate_graph_from_fixture(&mut self, graph: CrateGraphFixture) {
         let mut ids = FxHashMap::default();
         let mut crate_graph = CrateGraph::default();
-        for (crate_name, (crate_root, edition, _)) in graph.0.iter() {
+        for (crate_name, (crate_root, edition, cfg_options, _)) in graph.0.iter() {
             let crate_root = self.file_id_of(&crate_root);
-            let crate_id = crate_graph.add_crate_root(crate_root, *edition);
+            let crate_id = crate_graph.add_crate_root(crate_root, *edition, cfg_options.clone());
             Arc::make_mut(&mut self.crate_names).insert(crate_id, crate_name.clone());
             ids.insert(crate_name, crate_id);
         }
-        for (crate_name, (_, _, deps)) in graph.0.iter() {
+        for (crate_name, (_, _, _, deps)) in graph.0.iter() {
             let from = ids[crate_name];
             for dep in deps {
                 let to = ids[dep];
@@ -182,7 +185,7 @@ impl MockDatabase {
 
         if is_crate_root {
             let mut crate_graph = CrateGraph::default();
-            crate_graph.add_crate_root(file_id, Edition::Edition2018);
+            crate_graph.add_crate_root(file_id, Edition::Edition2018, CfgOptions::default());
             self.set_crate_graph(Arc::new(crate_graph));
         }
         file_id
@@ -266,19 +269,27 @@ impl MockDatabase {
 }
 
 #[derive(Default)]
-pub struct CrateGraphFixture(pub Vec<(String, (String, Edition, Vec<String>))>);
+pub struct CrateGraphFixture(pub Vec<(String, (String, Edition, CfgOptions, Vec<String>))>);
 
 #[macro_export]
 macro_rules! crate_graph {
-    ($($crate_name:literal: ($crate_path:literal, $($edition:literal,)? [$($dep:literal),*]),)*) => {{
+    ($(
+        $crate_name:literal: (
+            $crate_path:literal,
+            $($edition:literal,)?
+            [$($dep:literal),*]
+            $(,$cfg:expr)?
+        ),
+    )*) => {{
         let mut res = $crate::mock::CrateGraphFixture::default();
         $(
             #[allow(unused_mut, unused_assignments)]
             let mut edition = ra_db::Edition::Edition2018;
             $(edition = ra_db::Edition::from_string($edition);)?
+            let cfg_options = { ::ra_cfg::CfgOptions::default() $(; $cfg)? };
             res.0.push((
                 $crate_name.to_string(),
-                ($crate_path.to_string(), edition, vec![$($dep.to_string()),*])
+                ($crate_path.to_string(), edition, cfg_options, vec![$($dep.to_string()),*])
             ));
         )*
         res
diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
index 1bf993ffb..1e0b8c350 100644
--- a/crates/ra_hir/src/name.rs
+++ b/crates/ra_hir/src/name.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::fmt;
 
 use ra_syntax::{ast, SmolStr};
@@ -5,20 +7,21 @@ use ra_syntax::{ast, SmolStr};
 /// `Name` is a wrapper around string, which is used in hir for both references
 /// and declarations. In theory, names should also carry hygiene info, but we are
 /// not there yet!
-#[derive(Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-pub struct Name {
-    text: SmolStr,
-}
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct Name(Repr);
 
-impl fmt::Display for Name {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Display::fmt(&self.text, f)
-    }
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+enum Repr {
+    Text(SmolStr),
+    TupleField(usize),
 }
 
-impl fmt::Debug for Name {
+impl fmt::Display for Name {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Debug::fmt(&self.text, f)
+        match &self.0 {
+            Repr::Text(text) => fmt::Display::fmt(&text, f),
+            Repr::TupleField(idx) => fmt::Display::fmt(&idx, f),
+        }
     }
 }
 
@@ -26,29 +29,38 @@ impl Name {
     /// Note: this is private to make creating name from random string hard.
     /// Hopefully, this should allow us to integrate hygiene cleaner in the
     /// future, and to switch to interned representation of names.
-    const fn new(text: SmolStr) -> Name {
-        Name { text }
+    const fn new_text(text: SmolStr) -> Name {
+        Name(Repr::Text(text))
     }
 
-    pub(crate) fn missing() -> Name {
-        Name::new("[missing name]".into())
+    pub(crate) fn new_tuple_field(idx: usize) -> Name {
+        Name(Repr::TupleField(idx))
+    }
+
+    /// Shortcut to create inline plain text name
+    const fn new_inline_ascii(len: usize, text: &[u8]) -> Name {
+        Name::new_text(SmolStr::new_inline_from_ascii(len, text))
     }
 
-    pub(crate) fn tuple_field_name(idx: usize) -> Name {
-        Name::new(idx.to_string().into())
+    /// Resolve a name from the text of token.
+    fn resolve(raw_text: &SmolStr) -> Name {
+        let raw_start = "r#";
+        if raw_text.as_str().starts_with(raw_start) {
+            Name::new_text(SmolStr::new(&raw_text[raw_start.len()..]))
+        } else {
+            Name::new_text(raw_text.clone())
+        }
     }
 
-    // There's should be no way to extract a string out of `Name`: `Name` in the
-    // future, `Name` will include hygiene information, and you can't encode
-    // hygiene into a String.
-    //
-    // If you need to compare something with `Name`, compare `Name`s directly.
-    //
-    // If you need to render `Name` for the user, use the `Display` impl, but be
-    // aware that it strips hygiene info.
-    #[deprecated(note = "use to_string instead")]
-    pub fn as_smolstr(&self) -> &SmolStr {
-        &self.text
+    pub(crate) fn missing() -> Name {
+        Name::new_text("[missing name]".into())
+    }
+
+    pub(crate) fn as_tuple_index(&self) -> Option<usize> {
+        match self.0 {
+            Repr::TupleField(idx) => Some(idx),
+            _ => None,
+        }
     }
 }
 
@@ -58,15 +70,16 @@ pub(crate) trait AsName {
 
 impl AsName for ast::NameRef {
     fn as_name(&self) -> Name {
-        let name = resolve_name(self.text());
-        Name::new(name)
+        match self.as_tuple_field() {
+            Some(idx) => Name::new_tuple_field(idx),
+            None => Name::resolve(self.text()),
+        }
     }
 }
 
 impl AsName for ast::Name {
     fn as_name(&self) -> Name {
-        let name = resolve_name(self.text());
-        Name::new(name)
+        Name::resolve(self.text())
     }
 }
 
@@ -74,66 +87,56 @@ impl AsName for ast::FieldKind {
     fn as_name(&self) -> Name {
         match self {
             ast::FieldKind::Name(nr) => nr.as_name(),
-            ast::FieldKind::Index(idx) => Name::new(idx.text().clone()),
+            ast::FieldKind::Index(idx) => Name::new_tuple_field(idx.text().parse().unwrap()),
         }
     }
 }
 
 impl AsName for ra_db::Dependency {
     fn as_name(&self) -> Name {
-        Name::new(self.name.clone())
+        Name::new_text(self.name.clone())
     }
 }
 
 // Primitives
-pub(crate) const ISIZE: Name = Name::new(SmolStr::new_inline_from_ascii(5, b"isize"));
-pub(crate) const I8: Name = Name::new(SmolStr::new_inline_from_ascii(2, b"i8"));
-pub(crate) const I16: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"i16"));
-pub(crate) const I32: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"i32"));
-pub(crate) const I64: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"i64"));
-pub(crate) const I128: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"i128"));
-pub(crate) const USIZE: Name = Name::new(SmolStr::new_inline_from_ascii(5, b"usize"));
-pub(crate) const U8: Name = Name::new(SmolStr::new_inline_from_ascii(2, b"u8"));
-pub(crate) const U16: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"u16"));
-pub(crate) const U32: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"u32"));
-pub(crate) const U64: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"u64"));
-pub(crate) const U128: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"u128"));
-pub(crate) const F32: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"f32"));
-pub(crate) const F64: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"f64"));
-pub(crate) const BOOL: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"bool"));
-pub(crate) const CHAR: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"char"));
-pub(crate) const STR: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"str"));
+pub(crate) const ISIZE: Name = Name::new_inline_ascii(5, b"isize");
+pub(crate) const I8: Name = Name::new_inline_ascii(2, b"i8");
+pub(crate) const I16: Name = Name::new_inline_ascii(3, b"i16");
+pub(crate) const I32: Name = Name::new_inline_ascii(3, b"i32");
+pub(crate) const I64: Name = Name::new_inline_ascii(3, b"i64");
+pub(crate) const I128: Name = Name::new_inline_ascii(4, b"i128");
+pub(crate) const USIZE: Name = Name::new_inline_ascii(5, b"usize");
+pub(crate) const U8: Name = Name::new_inline_ascii(2, b"u8");
+pub(crate) const U16: Name = Name::new_inline_ascii(3, b"u16");
+pub(crate) const U32: Name = Name::new_inline_ascii(3, b"u32");
+pub(crate) const U64: Name = Name::new_inline_ascii(3, b"u64");
+pub(crate) const U128: Name = Name::new_inline_ascii(4, b"u128");
+pub(crate) const F32: Name = Name::new_inline_ascii(3, b"f32");
+pub(crate) const F64: Name = Name::new_inline_ascii(3, b"f64");
+pub(crate) const BOOL: Name = Name::new_inline_ascii(4, b"bool");
+pub(crate) const CHAR: Name = Name::new_inline_ascii(4, b"char");
+pub(crate) const STR: Name = Name::new_inline_ascii(3, b"str");
 
 // Special names
-pub(crate) const SELF_PARAM: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"self"));
-pub(crate) const SELF_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"Self"));
-pub(crate) const MACRO_RULES: Name = Name::new(SmolStr::new_inline_from_ascii(11, b"macro_rules"));
+pub(crate) const SELF_PARAM: Name = Name::new_inline_ascii(4, b"self");
+pub(crate) const SELF_TYPE: Name = Name::new_inline_ascii(4, b"Self");
+pub(crate) const MACRO_RULES: Name = Name::new_inline_ascii(11, b"macro_rules");
 
 // Components of known path (value or mod name)
-pub(crate) const STD: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"std"));
-pub(crate) const ITER: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"iter"));
-pub(crate) const OPS: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"ops"));
-pub(crate) const FUTURE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"future"));
-pub(crate) const RESULT: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"result"));
-pub(crate) const BOXED: Name = Name::new(SmolStr::new_inline_from_ascii(5, b"boxed"));
+pub(crate) const STD: Name = Name::new_inline_ascii(3, b"std");
+pub(crate) const ITER: Name = Name::new_inline_ascii(4, b"iter");
+pub(crate) const OPS: Name = Name::new_inline_ascii(3, b"ops");
+pub(crate) const FUTURE: Name = Name::new_inline_ascii(6, b"future");
+pub(crate) const RESULT: Name = Name::new_inline_ascii(6, b"result");
+pub(crate) const BOXED: Name = Name::new_inline_ascii(5, b"boxed");
 
 // Components of known path (type name)
-pub(crate) const INTO_ITERATOR_TYPE: Name =
-    Name::new(SmolStr::new_inline_from_ascii(12, b"IntoIterator"));
-pub(crate) const ITEM_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"Item"));
-pub(crate) const TRY_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"Try"));
-pub(crate) const OK_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(2, b"Ok"));
-pub(crate) const FUTURE_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"Future"));
-pub(crate) const RESULT_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"Result"));
-pub(crate) const OUTPUT_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"Output"));
-pub(crate) const TARGET_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"Target"));
-pub(crate) const BOX_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"Box"));
-
-fn resolve_name(text: &SmolStr) -> SmolStr {
-    let raw_start = "r#";
-    if text.as_str().starts_with(raw_start) {
-        SmolStr::new(&text[raw_start.len()..])
-    } else {
-        text.clone()
-    }
-}
+pub(crate) const INTO_ITERATOR_TYPE: Name = Name::new_inline_ascii(12, b"IntoIterator");
+pub(crate) const ITEM_TYPE: Name = Name::new_inline_ascii(4, b"Item");
+pub(crate) const TRY_TYPE: Name = Name::new_inline_ascii(3, b"Try");
+pub(crate) const OK_TYPE: Name = Name::new_inline_ascii(2, b"Ok");
+pub(crate) const FUTURE_TYPE: Name = Name::new_inline_ascii(6, b"Future");
+pub(crate) const RESULT_TYPE: Name = Name::new_inline_ascii(6, b"Result");
+pub(crate) const OUTPUT_TYPE: Name = Name::new_inline_ascii(6, b"Output");
+pub(crate) const TARGET_TYPE: Name = Name::new_inline_ascii(6, b"Target");
+pub(crate) const BOX_TYPE: Name = Name::new_inline_ascii(3, b"Box");
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index b808a0c36..67adcfa28 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -332,6 +332,20 @@ impl CrateDefMap {
     ) -> ResolvePathResult {
         let mut segments = path.segments.iter().enumerate();
         let mut curr_per_ns: PerNs = match path.kind {
+            PathKind::DollarCrate(krate) => {
+                if krate == self.krate {
+                    tested_by!(macro_dollar_crate_self);
+                    PerNs::types(Module { krate: self.krate, module_id: self.root }.into())
+                } else {
+                    match krate.root_module(db) {
+                        Some(module) => {
+                            tested_by!(macro_dollar_crate_other);
+                            PerNs::types(module.into())
+                        }
+                        None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
+                    }
+                }
+            }
             PathKind::Crate => {
                 PerNs::types(Module { krate: self.krate, module_id: self.root }.into())
             }
diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
index ef7dc6ebe..cef2dc9d2 100644
--- a/crates/ra_hir/src/nameres/collector.rs
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -1,3 +1,6 @@
+//! FIXME: write short doc here
+
+use ra_cfg::CfgOptions;
 use ra_db::FileId;
 use ra_syntax::{ast, SmolStr};
 use rustc_hash::FxHashMap;
@@ -33,6 +36,9 @@ pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> C
         }
     }
 
+    let crate_graph = db.crate_graph();
+    let cfg_options = crate_graph.cfg_options(def_map.krate().crate_id());
+
     let mut collector = DefCollector {
         db,
         def_map,
@@ -40,6 +46,7 @@ pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> C
         unresolved_imports: Vec::new(),
         unexpanded_macros: Vec::new(),
         macro_stack_monitor: MacroStackMonitor::default(),
+        cfg_options,
     };
     collector.collect();
     collector.finish()
@@ -74,8 +81,8 @@ impl MacroStackMonitor {
 }
 
 /// Walks the tree of module recursively
-struct DefCollector<DB> {
-    db: DB,
+struct DefCollector<'a, DB> {
+    db: &'a DB,
     def_map: CrateDefMap,
     glob_imports: FxHashMap<CrateModuleId, Vec<(CrateModuleId, raw::ImportId)>>,
     unresolved_imports: Vec<(CrateModuleId, raw::ImportId, raw::ImportData)>,
@@ -84,9 +91,11 @@ struct DefCollector<DB> {
     /// Some macro use `$tt:tt which mean we have to handle the macro perfectly
     /// To prevent stack overflow, we add a deep counter here for prevent that.
     macro_stack_monitor: MacroStackMonitor,
+
+    cfg_options: &'a CfgOptions,
 }
 
-impl<'a, DB> DefCollector<&'a DB>
+impl<DB> DefCollector<'_, DB>
 where
     DB: DefDatabase,
 {
@@ -504,7 +513,7 @@ struct ModCollector<'a, D> {
     parent_module: Option<ParentModule<'a>>,
 }
 
-impl<DB> ModCollector<'_, &'_ mut DefCollector<&'_ DB>>
+impl<DB> ModCollector<'_, &'_ mut DefCollector<'_, DB>>
 where
     DB: DefDatabase,
 {
@@ -521,24 +530,27 @@ where
         // `#[macro_use] extern crate` is hoisted to imports macros before collecting
         // any other items.
         for item in items {
-            if let raw::RawItem::Import(import_id) = *item {
-                let import = self.raw_items[import_id].clone();
-                if import.is_extern_crate && import.is_macro_use {
-                    self.def_collector.import_macros_from_extern_crate(self.module_id, &import);
+            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 {
+                        self.def_collector.import_macros_from_extern_crate(self.module_id, &import);
+                    }
                 }
             }
         }
 
         for item in items {
-            match *item {
-                raw::RawItem::Module(m) => self.collect_module(&self.raw_items[m]),
-                raw::RawItem::Import(import_id) => self.def_collector.unresolved_imports.push((
-                    self.module_id,
-                    import_id,
-                    self.raw_items[import_id].clone(),
-                )),
-                raw::RawItem::Def(def) => self.define_def(&self.raw_items[def]),
-                raw::RawItem::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
+            if self.is_cfg_enabled(&item.attrs) {
+                match item.kind {
+                    raw::RawItemKind::Module(m) => self.collect_module(&self.raw_items[m]),
+                    raw::RawItemKind::Import(import_id) => self
+                        .def_collector
+                        .unresolved_imports
+                        .push((self.module_id, import_id, self.raw_items[import_id].clone())),
+                    raw::RawItemKind::Def(def) => self.define_def(&self.raw_items[def]),
+                    raw::RawItemKind::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
+                }
             }
         }
     }
@@ -662,7 +674,10 @@ where
         // Case 1: macro rules, define a macro in crate-global mutable scope
         if is_macro_rules(&mac.path) {
             if let Some(name) = &mac.name {
-                let macro_id = MacroDefId(mac.ast_id.with_file_id(self.file_id));
+                let macro_id = MacroDefId {
+                    ast_id: mac.ast_id.with_file_id(self.file_id),
+                    krate: self.def_collector.def_map.krate,
+                };
                 let macro_ = MacroDef { id: macro_id };
                 self.def_collector.define_macro(self.module_id, name.clone(), macro_, mac.export);
             }
@@ -698,6 +713,14 @@ where
             self.def_collector.define_legacy_macro(self.module_id, name.clone(), macro_);
         }
     }
+
+    fn is_cfg_enabled(&self, attrs: &raw::Attrs) -> bool {
+        attrs.as_ref().map_or(true, |attrs| {
+            attrs
+                .iter()
+                .all(|attr| attr.is_cfg_enabled(&self.def_collector.cfg_options) != Some(false))
+        })
+    }
 }
 
 fn is_macro_rules(path: &Path) -> bool {
@@ -725,6 +748,7 @@ mod tests {
             unresolved_imports: Vec::new(),
             unexpanded_macros: Vec::new(),
             macro_stack_monitor: monitor,
+            cfg_options: &CfgOptions::default(),
         };
         collector.collect();
         collector.finish()
diff --git a/crates/ra_hir/src/nameres/per_ns.rs b/crates/ra_hir/src/nameres/per_ns.rs
index 964da2794..0da6789de 100644
--- a/crates/ra_hir/src/nameres/per_ns.rs
+++ b/crates/ra_hir/src/nameres/per_ns.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use crate::{MacroDef, ModuleDef};
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
diff --git a/crates/ra_hir/src/nameres/raw.rs b/crates/ra_hir/src/nameres/raw.rs
index 29aaddbf1..623b343c4 100644
--- a/crates/ra_hir/src/nameres/raw.rs
+++ b/crates/ra_hir/src/nameres/raw.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::{ops::Index, sync::Arc};
 
 use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
@@ -8,8 +10,9 @@ use ra_syntax::{
 use test_utils::tested_by;
 
 use crate::{
+    attr::Attr,
     db::{AstDatabase, DefDatabase},
-    AsName, AstIdMap, Either, FileAstId, HirFileId, ModuleSource, Name, Path,
+    AsName, AstIdMap, Either, FileAstId, HirFileId, ModuleSource, Name, Path, Source,
 };
 
 /// `RawItems` is a set of top-level items in a file (except for impls).
@@ -71,6 +74,8 @@ impl RawItems {
             raw_items: RawItems::default(),
             source_ast_id_map: db.ast_id_map(file_id),
             source_map: ImportSourceMap::default(),
+            file_id,
+            db,
         };
         if let Some(node) = db.parse_or_expand(file_id) {
             if let Some(source_file) = ast::SourceFile::cast(node.clone()) {
@@ -115,8 +120,17 @@ impl Index<Macro> for RawItems {
     }
 }
 
+// Avoid heap allocation on items without attributes.
+pub(super) type Attrs = Option<Arc<[Attr]>>;
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub(super) struct RawItem {
+    pub(super) attrs: Attrs,
+    pub(super) kind: RawItemKind,
+}
+
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub(super) enum RawItem {
+pub(super) enum RawItemKind {
     Module(Module),
     Import(ImportId),
     Def(Def),
@@ -192,13 +206,15 @@ pub(super) struct MacroData {
     pub(super) export: bool,
 }
 
-struct RawItemsCollector {
+struct RawItemsCollector<DB> {
     raw_items: RawItems,
     source_ast_id_map: Arc<AstIdMap>,
     source_map: ImportSourceMap,
+    file_id: HirFileId,
+    db: DB,
 }
 
-impl RawItemsCollector {
+impl<DB: AstDatabase> RawItemsCollector<&DB> {
     fn process_module(&mut self, current_module: Option<Module>, body: impl ast::ModuleItemOwner) {
         for item_or_macro in body.items_with_macros() {
             match item_or_macro {
@@ -209,6 +225,7 @@ impl RawItemsCollector {
     }
 
     fn add_item(&mut self, current_module: Option<Module>, item: ast::ModuleItem) {
+        let attrs = self.parse_attrs(&item);
         let (kind, name) = match item {
             ast::ModuleItem::Module(module) => {
                 self.add_module(current_module, module);
@@ -257,7 +274,7 @@ impl RawItemsCollector {
         if let Some(name) = name {
             let name = name.as_name();
             let def = self.raw_items.defs.alloc(DefData { name, kind });
-            self.push_item(current_module, RawItem::Def(def))
+            self.push_item(current_module, attrs, RawItemKind::Def(def));
         }
     }
 
@@ -266,8 +283,10 @@ impl RawItemsCollector {
             Some(it) => it.as_name(),
             None => return,
         };
+        let attrs = self.parse_attrs(&module);
 
         let ast_id = self.source_ast_id_map.ast_id(&module);
+        // FIXME: cfg_attr
         let is_macro_use = module.has_atom_attr("macro_use");
         if module.has_semi() {
             let attr_path = extract_mod_path_attribute(&module);
@@ -277,7 +296,7 @@ impl RawItemsCollector {
                 attr_path,
                 is_macro_use,
             });
-            self.push_item(current_module, RawItem::Module(item));
+            self.push_item(current_module, attrs, RawItemKind::Module(item));
             return;
         }
 
@@ -291,26 +310,37 @@ impl RawItemsCollector {
                 is_macro_use,
             });
             self.process_module(Some(item), item_list);
-            self.push_item(current_module, RawItem::Module(item));
+            self.push_item(current_module, attrs, RawItemKind::Module(item));
             return;
         }
         tested_by!(name_res_works_for_broken_modules);
     }
 
     fn add_use_item(&mut self, current_module: Option<Module>, use_item: ast::UseItem) {
+        // FIXME: cfg_attr
         let is_prelude = use_item.has_atom_attr("prelude_import");
-
-        Path::expand_use_item(&use_item, |path, use_tree, is_glob, alias| {
-            let import_data = ImportData {
-                path,
-                alias,
-                is_glob,
-                is_prelude,
-                is_extern_crate: false,
-                is_macro_use: false,
-            };
-            self.push_import(current_module, import_data, Either::A(AstPtr::new(use_tree)));
-        })
+        let attrs = self.parse_attrs(&use_item);
+
+        Path::expand_use_item(
+            Source { ast: use_item, file_id: self.file_id },
+            self.db,
+            |path, use_tree, is_glob, alias| {
+                let import_data = ImportData {
+                    path,
+                    alias,
+                    is_glob,
+                    is_prelude,
+                    is_extern_crate: false,
+                    is_macro_use: false,
+                };
+                self.push_import(
+                    current_module,
+                    attrs.clone(),
+                    import_data,
+                    Either::A(AstPtr::new(use_tree)),
+                );
+            },
+        )
     }
 
     fn add_extern_crate_item(
@@ -321,6 +351,8 @@ impl RawItemsCollector {
         if let Some(name_ref) = extern_crate.name_ref() {
             let path = Path::from_name_ref(&name_ref);
             let alias = extern_crate.alias().and_then(|a| a.name()).map(|it| it.as_name());
+            let attrs = self.parse_attrs(&extern_crate);
+            // FIXME: cfg_attr
             let is_macro_use = extern_crate.has_atom_attr("macro_use");
             let import_data = ImportData {
                 path,
@@ -330,37 +362,47 @@ impl RawItemsCollector {
                 is_extern_crate: true,
                 is_macro_use,
             };
-            self.push_import(current_module, import_data, Either::B(AstPtr::new(&extern_crate)));
+            self.push_import(
+                current_module,
+                attrs,
+                import_data,
+                Either::B(AstPtr::new(&extern_crate)),
+            );
         }
     }
 
     fn add_macro(&mut self, current_module: Option<Module>, m: ast::MacroCall) {
-        let path = match m.path().and_then(Path::from_ast) {
+        let attrs = self.parse_attrs(&m);
+        let path = match m
+            .path()
+            .and_then(|path| Path::from_src(Source { ast: path, file_id: self.file_id }, self.db))
+        {
             Some(it) => it,
             _ => return,
         };
 
         let name = m.name().map(|it| it.as_name());
         let ast_id = self.source_ast_id_map.ast_id(&m);
-        let export = m.has_atom_attr("macro_export")
-            || m.attrs().filter_map(|x| x.as_call()).any(|(name, _)| name == "macro_export");
+        // FIXME: cfg_attr
+        let export = m.attrs().filter_map(|x| x.simple_name()).any(|name| name == "macro_export");
 
         let m = self.raw_items.macros.alloc(MacroData { ast_id, path, name, export });
-        self.push_item(current_module, RawItem::Macro(m));
+        self.push_item(current_module, attrs, RawItemKind::Macro(m));
     }
 
     fn push_import(
         &mut self,
         current_module: Option<Module>,
+        attrs: Attrs,
         data: ImportData,
         source: ImportSourcePtr,
     ) {
         let import = self.raw_items.imports.alloc(data);
         self.source_map.insert(import, source);
-        self.push_item(current_module, RawItem::Import(import))
+        self.push_item(current_module, attrs, RawItemKind::Import(import))
     }
 
-    fn push_item(&mut self, current_module: Option<Module>, item: RawItem) {
+    fn push_item(&mut self, current_module: Option<Module>, attrs: Attrs, kind: RawItemKind) {
         match current_module {
             Some(module) => match &mut self.raw_items.modules[module] {
                 ModuleData::Definition { items, .. } => items,
@@ -368,13 +410,17 @@ impl RawItemsCollector {
             },
             None => &mut self.raw_items.items,
         }
-        .push(item)
+        .push(RawItem { attrs, kind })
+    }
+
+    fn parse_attrs(&self, item: &impl ast::AttrsOwner) -> Attrs {
+        Attr::from_attrs_owner(self.file_id, item, self.db)
     }
 }
 
 fn extract_mod_path_attribute(module: &ast::Module) -> Option<SmolStr> {
     module.attrs().into_iter().find_map(|attr| {
-        attr.as_key_value().and_then(|(name, value)| {
+        attr.as_simple_key_value().and_then(|(name, value)| {
             let is_path = name == "path";
             if is_path {
                 Some(value)
diff --git a/crates/ra_hir/src/nameres/tests.rs b/crates/ra_hir/src/nameres/tests.rs
index bc4b47b70..34dd79574 100644
--- a/crates/ra_hir/src/nameres/tests.rs
+++ b/crates/ra_hir/src/nameres/tests.rs
@@ -7,6 +7,7 @@ mod mod_resolution;
 use std::sync::Arc;
 
 use insta::assert_snapshot;
+use ra_cfg::CfgOptions;
 use ra_db::SourceDatabase;
 use test_utils::covers;
 
@@ -507,3 +508,72 @@ fn values_dont_shadow_extern_crates() {
         ⋮foo: v
     "###);
 }
+
+#[test]
+fn cfg_not_test() {
+    let map = def_map_with_crate_graph(
+        r#"
+        //- /main.rs
+        use {Foo, Bar, Baz};
+        //- /lib.rs
+        #[prelude_import]
+        pub use self::prelude::*;
+        mod prelude {
+            #[cfg(test)]
+            pub struct Foo;
+            #[cfg(not(test))]
+            pub struct Bar;
+            #[cfg(all(not(any()), feature = "foo", feature = "bar", opt = "42"))]
+            pub struct Baz;
+        }
+        "#,
+        crate_graph! {
+            "main": ("/main.rs", ["std"]),
+            "std": ("/lib.rs", []),
+        },
+    );
+
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮Bar: t v
+        ⋮Baz: _
+        ⋮Foo: _
+    "###);
+}
+
+#[test]
+fn cfg_test() {
+    let map = def_map_with_crate_graph(
+        r#"
+        //- /main.rs
+        use {Foo, Bar, Baz};
+        //- /lib.rs
+        #[prelude_import]
+        pub use self::prelude::*;
+        mod prelude {
+            #[cfg(test)]
+            pub struct Foo;
+            #[cfg(not(test))]
+            pub struct Bar;
+            #[cfg(all(not(any()), feature = "foo", feature = "bar", opt = "42"))]
+            pub struct Baz;
+        }
+        "#,
+        crate_graph! {
+            "main": ("/main.rs", ["std"]),
+            "std": ("/lib.rs", [], CfgOptions::default()
+                .atom("test".into())
+                .key_value("feature".into(), "foo".into())
+                .key_value("feature".into(), "bar".into())
+                .key_value("opt".into(), "42".into())
+            ),
+        },
+    );
+
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮Bar: _
+        ⋮Baz: t v
+        ⋮Foo: t v
+    "###);
+}
diff --git a/crates/ra_hir/src/nameres/tests/macros.rs b/crates/ra_hir/src/nameres/tests/macros.rs
index bd60f4258..e4b408394 100644
--- a/crates/ra_hir/src/nameres/tests/macros.rs
+++ b/crates/ra_hir/src/nameres/tests/macros.rs
@@ -515,3 +515,108 @@ fn path_qualified_macros() {
         ⋮not_found: _
     "###);
 }
+
+#[test]
+fn macro_dollar_crate_is_correct_in_item() {
+    covers!(macro_dollar_crate_self);
+    covers!(macro_dollar_crate_other);
+    let map = def_map_with_crate_graph(
+        "
+        //- /main.rs
+        #[macro_use]
+        extern crate foo;
+
+        #[macro_use]
+        mod m {
+            macro_rules! current {
+                () => {
+                    use $crate::Foo as FooSelf;
+                }
+            }
+        }
+
+        struct Foo;
+
+        current!();
+        not_current1!();
+        foo::not_current2!();
+
+        //- /lib.rs
+        mod m {
+            #[macro_export]
+            macro_rules! not_current1 {
+                () => {
+                    use $crate::Bar;
+                }
+            }
+        }
+
+        #[macro_export]
+        macro_rules! not_current2 {
+            () => {
+                use $crate::Baz;
+            }
+        }
+
+        struct Bar;
+        struct Baz;
+        ",
+        crate_graph! {
+            "main": ("/main.rs", ["foo"]),
+            "foo": ("/lib.rs", []),
+        },
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮Bar: t v
+        ⋮Baz: t v
+        ⋮Foo: t v
+        ⋮FooSelf: t v
+        ⋮foo: t
+        ⋮m: t
+        ⋮
+        ⋮crate::m
+    "###);
+}
+
+#[test]
+fn macro_dollar_crate_is_correct_in_indirect_deps() {
+    covers!(macro_dollar_crate_other);
+    // From std
+    let map = def_map_with_crate_graph(
+        r#"
+        //- /main.rs
+        foo!();
+
+        //- /std.rs
+        #[prelude_import]
+        use self::prelude::*;
+
+        pub use core::foo;
+
+        mod prelude {}
+
+        #[macro_use]
+        mod std_macros;
+
+        //- /core.rs
+        #[macro_export]
+        macro_rules! foo {
+            () => {
+                use $crate::bar;
+            }
+        }
+
+        pub struct bar;
+        "#,
+        crate_graph! {
+            "main": ("/main.rs", ["std"]),
+            "std": ("/std.rs", ["core"]),
+            "core": ("/core.rs", []),
+        },
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮bar: t v
+    "###);
+}
diff --git a/crates/ra_hir/src/path.rs b/crates/ra_hir/src/path.rs
index 39d1b7e46..394617e1a 100644
--- a/crates/ra_hir/src/path.rs
+++ b/crates/ra_hir/src/path.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
+
 use std::{iter, sync::Arc};
 
 use ra_syntax::{
@@ -5,7 +7,7 @@ use ra_syntax::{
     AstNode,
 };
 
-use crate::{name, type_ref::TypeRef, AsName, Name};
+use crate::{db::AstDatabase, name, type_ref::TypeRef, AsName, Crate, Name, Source};
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Path {
@@ -52,16 +54,19 @@ pub enum PathKind {
     Abs,
     // Type based path like `<T>::foo`
     Type(Box<TypeRef>),
+    // `$crate` from macro expansion
+    DollarCrate(Crate),
 }
 
 impl Path {
     /// Calls `cb` with all paths, represented by this use item.
     pub fn expand_use_item(
-        item: &ast::UseItem,
+        item_src: Source<ast::UseItem>,
+        db: &impl AstDatabase,
         mut cb: impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
     ) {
-        if let Some(tree) = item.use_tree() {
+        if let Some