11 files changed, 837 insertions, 289 deletions

diff --git a/crates/ra_hir_expand/Cargo.toml b/crates/ra_hir_expand/Cargo.toml
index c60152a79..3ae4376dc 100644
--- a/crates/ra_hir_expand/Cargo.toml
+++ b/crates/ra_hir_expand/Cargo.toml
@@ -9,6 +9,7 @@ doctest = false
 
 [dependencies]
 log = "0.4.5"
+either = "1.5"
 
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
diff --git a/crates/ra_hir_expand/src/ast_id_map.rs b/crates/ra_hir_expand/src/ast_id_map.rs
index cb464c3ff..a764bdf24 100644
--- a/crates/ra_hir_expand/src/ast_id_map.rs
+++ b/crates/ra_hir_expand/src/ast_id_map.rs
@@ -39,6 +39,16 @@ impl<N: AstNode> Hash for FileAstId<N> {
     }
 }
 
+impl<N: AstNode> FileAstId<N> {
+    // Can't make this a From implementation because of coherence
+    pub fn upcast<M: AstNode>(self) -> FileAstId<M>
+    where
+        M: From<N>,
+    {
+        FileAstId { raw: self.raw, _ty: PhantomData }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 struct ErasedFileAstId(RawId);
 impl_arena_id!(ErasedFileAstId);
@@ -53,7 +63,7 @@ impl AstIdMap {
     pub(crate) fn from_source(node: &SyntaxNode) -> AstIdMap {
         assert!(node.parent().is_none());
         let mut res = AstIdMap { arena: Arena::default() };
-        // By walking the tree in bread-first order we make sure that parents
+        // By walking the tree in breadth-first order we make sure that parents
         // get lower ids then children. That is, adding a new child does not
         // change parent's id. This means that, say, adding a new function to a
         // trait does not change ids of top-level items, which helps caching.
diff --git a/crates/ra_hir_expand/src/builtin_derive.rs b/crates/ra_hir_expand/src/builtin_derive.rs
new file mode 100644
index 000000000..62c60e336
--- /dev/null
+++ b/crates/ra_hir_expand/src/builtin_derive.rs
@@ -0,0 +1,321 @@
+//! Builtin derives.
+
+use log::debug;
+
+use ra_parser::FragmentKind;
+use ra_syntax::{
+    ast::{self, AstNode, ModuleItemOwner, NameOwner, TypeParamsOwner},
+    match_ast,
+};
+
+use crate::db::AstDatabase;
+use crate::{name, quote, MacroCallId, MacroDefId, MacroDefKind};
+
+macro_rules! register_builtin {
+    ( $($trait:ident => $expand:ident),* ) => {
+        #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+        pub enum BuiltinDeriveExpander {
+            $($trait),*
+        }
+
+        impl BuiltinDeriveExpander {
+            pub fn expand(
+                &self,
+                db: &dyn AstDatabase,
+                id: MacroCallId,
+                tt: &tt::Subtree,
+            ) -> Result<tt::Subtree, mbe::ExpandError> {
+                let expander = match *self {
+                    $( BuiltinDeriveExpander::$trait => $expand, )*
+                };
+                expander(db, id, tt)
+            }
+        }
+
+        pub fn find_builtin_derive(ident: &name::Name) -> Option<MacroDefId> {
+            let kind = match ident {
+                $( id if id == &name::name![$trait] => BuiltinDeriveExpander::$trait, )*
+                 _ => return None,
+            };
+
+            Some(MacroDefId { krate: None, ast_id: None, kind: MacroDefKind::BuiltInDerive(kind) })
+        }
+    };
+}
+
+register_builtin! {
+    Copy => copy_expand,
+    Clone => clone_expand,
+    Default => default_expand,
+    Debug => debug_expand,
+    Hash => hash_expand,
+    Ord => ord_expand,
+    PartialOrd => partial_ord_expand,
+    Eq => eq_expand,
+    PartialEq => partial_eq_expand
+}
+
+struct BasicAdtInfo {
+    name: tt::Ident,
+    type_params: usize,
+}
+
+fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, mbe::ExpandError> {
+    let (parsed, token_map) = mbe::token_tree_to_syntax_node(tt, FragmentKind::Items)?; // FragmentKind::Items doesn't parse attrs?
+    let macro_items = ast::MacroItems::cast(parsed.syntax_node()).ok_or_else(|| {
+        debug!("derive node didn't parse");
+        mbe::ExpandError::UnexpectedToken
+    })?;
+    let item = macro_items.items().next().ok_or_else(|| {
+        debug!("no module item parsed");
+        mbe::ExpandError::NoMatchingRule
+    })?;
+    let node = item.syntax();
+    let (name, params) = match_ast! {
+        match node {
+            ast::StructDef(it) => { (it.name(), it.type_param_list()) },
+            ast::EnumDef(it) => { (it.name(), it.type_param_list()) },
+            ast::UnionDef(it) => { (it.name(), it.type_param_list()) },
+            _ => {
+                debug!("unexpected node is {:?}", node);
+                return Err(mbe::ExpandError::ConversionError)
+            },
+        }
+    };
+    let name = name.ok_or_else(|| {
+        debug!("parsed item has no name");
+        mbe::ExpandError::NoMatchingRule
+    })?;
+    let name_token_id = token_map.token_by_range(name.syntax().text_range()).ok_or_else(|| {
+        debug!("name token not found");
+        mbe::ExpandError::ConversionError
+    })?;
+    let name_token = tt::Ident { id: name_token_id, text: name.text().clone() };
+    let type_params = params.map_or(0, |type_param_list| type_param_list.type_params().count());
+    Ok(BasicAdtInfo { name: name_token, type_params })
+}
+
+fn make_type_args(n: usize, bound: Vec<tt::TokenTree>) -> Vec<tt::TokenTree> {
+    let mut result = Vec::<tt::TokenTree>::new();
+    result.push(
+        tt::Leaf::Punct(tt::Punct {
+            char: '<',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        })
+        .into(),
+    );
+    for i in 0..n {
+        if i > 0 {
+            result.push(
+                tt::Leaf::Punct(tt::Punct {
+                    char: ',',
+                    spacing: tt::Spacing::Alone,
+                    id: tt::TokenId::unspecified(),
+                })
+                .into(),
+            );
+        }
+        result.push(
+            tt::Leaf::Ident(tt::Ident {
+                id: tt::TokenId::unspecified(),
+                text: format!("T{}", i).into(),
+            })
+            .into(),
+        );
+        result.extend(bound.iter().cloned());
+    }
+    result.push(
+        tt::Leaf::Punct(tt::Punct {
+            char: '>',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        })
+        .into(),
+    );
+    result
+}
+
+fn expand_simple_derive(
+    tt: &tt::Subtree,
+    trait_path: tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    let info = parse_adt(tt)?;
+    let name = info.name;
+    let trait_path_clone = trait_path.token_trees.clone();
+    let bound = (quote! { : ##trait_path_clone }).token_trees;
+    let type_params = make_type_args(info.type_params, bound);
+    let type_args = make_type_args(info.type_params, Vec::new());
+    let trait_path = trait_path.token_trees;
+    let expanded = quote! {
+        impl ##type_params ##trait_path for #name ##type_args {}
+    };
+    Ok(expanded)
+}
+
+fn copy_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::marker::Copy })
+}
+
+fn clone_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::clone::Clone })
+}
+
+fn default_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::default::Default })
+}
+
+fn debug_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::fmt::Debug })
+}
+
+fn hash_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::hash::Hash })
+}
+
+fn eq_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::cmp::Eq })
+}
+
+fn partial_eq_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::cmp::PartialEq })
+}
+
+fn ord_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::cmp::Ord })
+}
+
+fn partial_ord_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::cmp::PartialOrd })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{test_db::TestDB, AstId, MacroCallKind, MacroCallLoc};
+    use ra_db::{fixture::WithFixture, SourceDatabase};
+
+    fn expand_builtin_derive(s: &str, expander: BuiltinDeriveExpander) -> String {
+        let (db, file_id) = TestDB::with_single_file(&s);
+        let parsed = db.parse(file_id);
+        let items: Vec<_> =
+            parsed.syntax_node().descendants().filter_map(|it| ast::ModuleItem::cast(it)).collect();
+
+        let ast_id_map = db.ast_id_map(file_id.into());
+
+        // the first one should be a macro_rules
+        let def =
+            MacroDefId { krate: None, ast_id: None, kind: MacroDefKind::BuiltInDerive(expander) };
+
+        let loc = MacroCallLoc {
+            def,
+            kind: MacroCallKind::Attr(AstId::new(file_id.into(), ast_id_map.ast_id(&items[0]))),
+        };
+
+        let id = db.intern_macro(loc);
+        let parsed = db.parse_or_expand(id.as_file()).unwrap();
+
+        // FIXME text() for syntax nodes parsed from token tree looks weird
+        // because there's no whitespace, see below
+        parsed.text().to_string()
+    }
+
+    #[test]
+    fn test_copy_expand_simple() {
+        let expanded = expand_builtin_derive(
+            r#"
+        #[derive(Copy)]
+        struct Foo;
+"#,
+            BuiltinDeriveExpander::Copy,
+        );
+
+        assert_eq!(expanded, "impl <>std::marker::CopyforFoo <>{}");
+    }
+
+    #[test]
+    fn test_copy_expand_with_type_params() {
+        let expanded = expand_builtin_derive(
+            r#"
+        #[derive(Copy)]
+        struct Foo<A, B>;
+"#,
+            BuiltinDeriveExpander::Copy,
+        );
+
+        assert_eq!(
+            expanded,
+            "impl<T0:std::marker::Copy,T1:std::marker::Copy>std::marker::CopyforFoo<T0,T1>{}"
+        );
+    }
+
+    #[test]
+    fn test_copy_expand_with_lifetimes() {
+        let expanded = expand_builtin_derive(
+            r#"
+        #[derive(Copy)]
+        struct Foo<A, B, 'a, 'b>;
+"#,
+            BuiltinDeriveExpander::Copy,
+        );
+
+        // We currently just ignore lifetimes
+
+        assert_eq!(
+            expanded,
+            "impl<T0:std::marker::Copy,T1:std::marker::Copy>std::marker::CopyforFoo<T0,T1>{}"
+        );
+    }
+
+    #[test]
+    fn test_clone_expand() {
+        let expanded = expand_builtin_derive(
+            r#"
+        #[derive(Clone)]
+        struct Foo<A, B>;
+"#,
+            BuiltinDeriveExpander::Clone,
+        );
+
+        assert_eq!(
+            expanded,
+            "impl<T0:std::clone::Clone,T1:std::clone::Clone>std::clone::CloneforFoo<T0,T1>{}"
+        );
+    }
+}
diff --git a/crates/ra_hir_expand/src/builtin_macro.rs b/crates/ra_hir_expand/src/builtin_macro.rs
index d370dfb34..2c119269c 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -2,8 +2,7 @@
 use crate::db::AstDatabase;
 use crate::{
     ast::{self, AstNode},
-    name, AstId, CrateId, HirFileId, MacroCallId, MacroDefId, MacroDefKind, MacroFileKind,
-    TextUnit,
+    name, AstId, CrateId, HirFileId, MacroCallId, MacroDefId, MacroDefKind, TextUnit,
 };
 
 use crate::quote;
@@ -27,6 +26,13 @@ macro_rules! register_builtin {
                 };
                 expander(db, id, tt)
             }
+
+            fn by_name(ident: &name::Name) -> Option<BuiltinFnLikeExpander> {
+                match ident {
+                    $( id if id == &name::name![$name] => Some(BuiltinFnLikeExpander::$kind), )*
+                    _ => return None,
+                }
+            }
         }
 
         pub fn find_builtin_macro(
@@ -34,22 +40,25 @@ macro_rules! register_builtin {
             krate: CrateId,
             ast_id: AstId<ast::MacroCall>,
         ) -> Option<MacroDefId> {
-            let kind = match ident {
-                 $( id if id == &name::$name => BuiltinFnLikeExpander::$kind, )*
-                 _ => return None,
-            };
+            let kind = BuiltinFnLikeExpander::by_name(ident)?;
 
-            Some(MacroDefId { krate, ast_id, kind: MacroDefKind::BuiltIn(kind) })
+            Some(MacroDefId { krate: Some(krate), ast_id: Some(ast_id), kind: MacroDefKind::BuiltIn(kind) })
         }
     };
 }
 
 register_builtin! {
-    (COLUMN_MACRO, Column) => column_expand,
-    (COMPILE_ERROR_MACRO, CompileError) => compile_error_expand,
-    (FILE_MACRO, File) => file_expand,
-    (LINE_MACRO, Line) => line_expand,
-    (STRINGIFY_MACRO, Stringify) => stringify_expand
+    (column, Column) => column_expand,
+    (compile_error, CompileError) => compile_error_expand,
+    (file, File) => file_expand,
+    (line, Line) => line_expand,
+    (stringify, Stringify) => stringify_expand,
+    (format_args, FormatArgs) => format_args_expand,
+    (env, Env) => env_expand,
+    (option_env, OptionEnv) => option_env_expand,
+    // format_args_nl only differs in that it adds a newline in the end,
+    // so we use the same stub expansion for now
+    (format_args_nl, FormatArgsNl) => format_args_expand
 }
 
 fn to_line_number(db: &dyn AstDatabase, file: HirFileId, pos: TextUnit) -> usize {
@@ -82,12 +91,11 @@ fn line_expand(
     _tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
     let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
 
-    let arg = macro_call.token_tree().ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
-    let arg_start = arg.syntax().text_range().start();
+    let arg = loc.kind.arg(db).ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
+    let arg_start = arg.text_range().start();
 
-    let file = id.as_file(MacroFileKind::Expr);
+    let file = id.as_file();
     let line_num = to_line_number(db, file, arg_start);
 
     let expanded = quote! {
@@ -103,11 +111,10 @@ fn stringify_expand(
     _tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
     let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
 
     let macro_content = {
-        let arg = macro_call.token_tree().ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
-        let macro_args = arg.syntax().clone();
+        let arg = loc.kind.arg(db).ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
+        let macro_args = arg;
         let text = macro_args.text();
         let without_parens = TextUnit::of_char('(')..text.len() - TextUnit::of_char(')');
         text.slice(without_parens).to_string()
@@ -120,6 +127,28 @@ fn stringify_expand(
     Ok(expanded)
 }
 
+fn env_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    _tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    // dummy implementation for type-checking purposes
+    let expanded = quote! { "" };
+
+    Ok(expanded)
+}
+
+fn option_env_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    _tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    // dummy implementation for type-checking purposes
+    let expanded = quote! { std::option::Option::None::<&str> };
+
+    Ok(expanded)
+}
+
 fn to_col_number(db: &dyn AstDatabase, file: HirFileId, pos: TextUnit) -> usize {
     // FIXME: Use expansion info
     let file_id = file.original_file(db);
@@ -137,7 +166,7 @@ fn to_col_number(db: &dyn AstDatabase, file: HirFileId, pos: TextUnit) -> usize
         if c == '\n' {
             break;
         }
-        col_num = col_num + 1;
+        col_num += 1;
     }
     col_num
 }
@@ -148,12 +177,15 @@ fn column_expand(
     _tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
     let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
+    let macro_call = match loc.kind {
+        crate::MacroCallKind::FnLike(ast_id) => ast_id.to_node(db),
+        _ => panic!("column macro called as attr"),
+    };
 
     let _arg = macro_call.token_tree().ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
     let col_start = macro_call.syntax().text_range().start();
 
-    let file = id.as_file(MacroFileKind::Expr);
+    let file = id.as_file();
     let col_num = to_col_number(db, file, col_start);
 
     let expanded = quote! {
@@ -164,15 +196,10 @@ fn column_expand(
 }
 
 fn file_expand(
-    db: &dyn AstDatabase,
-    id: MacroCallId,
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
     _tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
-
-    let _ = macro_call.token_tree().ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
-
     // FIXME: RA purposefully lacks knowledge of absolute file names
     // so just return "".
     let file_name = "";
@@ -204,13 +231,56 @@ fn compile_error_expand(
     Err(mbe::ExpandError::BindingError("Must be a string".into()))
 }
 
+fn format_args_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    // We expand `format_args!("", a1, a2)` to
+    // ```
+    // std::fmt::Arguments::new_v1(&[], &[
+    //   std::fmt::ArgumentV1::new(&arg1,std::fmt::Display::fmt),
+    //   std::fmt::ArgumentV1::new(&arg2,std::fmt::Display::fmt),
+    // ])
+    // ```,
+    // which is still not really correct, but close enough for now
+    let mut args = Vec::new();
+    let mut current = Vec::new();
+    for tt in tt.token_trees.iter().cloned() {
+        match tt {
+            tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ',' => {
+                args.push(current);
+                current = Vec::new();
+            }
+            _ => {
+                current.push(tt);
+            }
+        }
+    }
+    if !current.is_empty() {
+        args.push(current);
+    }
+    if args.is_empty() {
+        return Err(mbe::ExpandError::NoMatchingRule);
+    }
+    let _format_string = args.remove(0);
+    let arg_tts = args.into_iter().flat_map(|arg| {
+        quote! { std::fmt::ArgumentV1::new(&(##arg), std::fmt::Display::fmt), }
+    }.token_trees).collect::<Vec<_>>();
+    let expanded = quote! {
+        std::fmt::Arguments::new_v1(&[], &[##arg_tts])
+    };
+    Ok(expanded)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::{test_db::TestDB, MacroCallLoc};
+    use crate::{name::AsName, test_db::TestDB, MacroCallKind, MacroCallLoc};
     use ra_db::{fixture::WithFixture, SourceDatabase};
+    use ra_syntax::ast::NameOwner;
 
-    fn expand_builtin_macro(s: &str, expander: BuiltinFnLikeExpander) -> String {
+    fn expand_builtin_macro(s: &str) -> String {
         let (db, file_id) = TestDB::with_single_file(&s);
         let parsed = db.parse(file_id);
         let macro_calls: Vec<_> =
@@ -218,20 +288,26 @@ mod tests {
 
         let ast_id_map = db.ast_id_map(file_id.into());
 
+        let expander =
+            BuiltinFnLikeExpander::by_name(&macro_calls[0].name().unwrap().as_name()).unwrap();
+
         // the first one should be a macro_rules
         let def = MacroDefId {
-            krate: CrateId(0),
-            ast_id: AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[0])),
+            krate: Some(CrateId(0)),
+            ast_id: Some(AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[0]))),
             kind: MacroDefKind::BuiltIn(expander),
         };
 
         let loc = MacroCallLoc {
             def,
-            ast_id: AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[1])),
+            kind: MacroCallKind::FnLike(AstId::new(
+                file_id.into(),
+                ast_id_map.ast_id(&macro_calls[1]),
+            )),
         };
 
         let id = db.intern_macro(loc);
-        let parsed = db.parse_or_expand(id.as_file(MacroFileKind::Expr)).unwrap();
+        let parsed = db.parse_or_expand(id.as_file()).unwrap();
 
         parsed.text().to_string()
     }
@@ -240,25 +316,23 @@ mod tests {
     fn test_column_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! column {() => {}}
-        column!()
-"#,
-            BuiltinFnLikeExpander::Column,
+            #[rustc_builtin_macro]
+            macro_rules! column {() => {}}
+            column!()
+            "#,
         );
 
-        assert_eq!(expanded, "9");
+        assert_eq!(expanded, "13");
     }
 
     #[test]
     fn test_line_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! line {() => {}}
-        line!()
-"#,
-            BuiltinFnLikeExpander::Line,
+            #[rustc_builtin_macro]
+            macro_rules! line {() => {}}
+            line!()
+            "#,
         );
 
         assert_eq!(expanded, "4");
@@ -268,25 +342,49 @@ mod tests {
     fn test_stringify_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! stringify {() => {}}
-        stringify!(a b c)
-"#,
-            BuiltinFnLikeExpander::Stringify,
+            #[rustc_builtin_macro]
+            macro_rules! stringify {() => {}}
+            stringify!(a b c)
+            "#,
         );
 
         assert_eq!(expanded, "\"a b c\"");
     }
 
     #[test]
+    fn test_env_expand() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! env {() => {}}
+            env!("TEST_ENV_VAR")
+            "#,
+        );
+
+        assert_eq!(expanded, "\"\"");
+    }
+
+    #[test]
+    fn test_option_env_expand() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! option_env {() => {}}
+            option_env!("TEST_ENV_VAR")
+            "#,
+        );
+
+        assert_eq!(expanded, "std::option::Option::None:: <&str>");
+    }
+
+    #[test]
     fn test_file_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! file {() => {}}
-        file!()
-"#,
-            BuiltinFnLikeExpander::File,
+            #[rustc_builtin_macro]
+            macro_rules! file {() => {}}
+            file!()
+            "#,
         );
 
         assert_eq!(expanded, "\"\"");
@@ -296,16 +394,34 @@ mod tests {
     fn test_compile_error_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! compile_error {
-            ($msg:expr) => ({ /* compiler built-in */ });
-            ($msg:expr,) => ({ /* compiler built-in */ })
-        }
-        compile_error!("error!");
-"#,
-            BuiltinFnLikeExpander::CompileError,
+            #[rustc_builtin_macro]
+            macro_rules! compile_error {
+                ($msg:expr) => ({ /* compiler built-in */ });
+                ($msg:expr,) => ({ /* compiler built-in */ })
+            }
+            compile_error!("error!");
+            "#,
         );
 
         assert_eq!(expanded, r#"loop{"error!"}"#);
     }
+
+    #[test]
+    fn test_format_args_expand() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! format_args {
+                ($fmt:expr) => ({ /* compiler built-in */ });
+                ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ })
+            }
+            format_args!("{} {:?}", arg1(a, b, c), arg2);
+            "#,
+        );
+
+        assert_eq!(
+            expanded,
+            r#"std::fmt::Arguments::new_v1(&[] ,&[std::fmt::ArgumentV1::new(&(arg1(a,b,c)),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(arg2),std::fmt::Display::fmt),])"#
+        );
+    }
 }
diff --git a/crates/ra_hir_expand/src/db.rs b/crates/ra_hir_expand/src/db.rs
index 8e46fa177..2e12e126f 100644
--- a/crates/ra_hir_expand/src/db.rs
+++ b/crates/ra_hir_expand/src/db.rs
@@ -6,17 +6,18 @@ use mbe::MacroRules;
 use ra_db::{salsa, SourceDatabase};
 use ra_parser::FragmentKind;
 use ra_prof::profile;
-use ra_syntax::{AstNode, Parse, SyntaxNode};
+use ra_syntax::{AstNode, Parse, SyntaxKind::*, SyntaxNode};
 
 use crate::{
-    ast_id_map::AstIdMap, BuiltinFnLikeExpander, HirFileId, HirFileIdRepr, MacroCallId,
-    MacroCallLoc, MacroDefId, MacroDefKind, MacroFile, MacroFileKind,
+    ast_id_map::AstIdMap, BuiltinDeriveExpander, BuiltinFnLikeExpander, HirFileId, HirFileIdRepr,
+    MacroCallId, MacroCallLoc, MacroDefId, MacroDefKind, MacroFile,
 };
 
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub enum TokenExpander {
     MacroRules(mbe::MacroRules),
     Builtin(BuiltinFnLikeExpander),
+    BuiltinDerive(BuiltinDeriveExpander),
 }
 
 impl TokenExpander {
@@ -29,6 +30,7 @@ impl TokenExpander {
         match self {
             TokenExpander::MacroRules(it) => it.expand(tt),
             TokenExpander::Builtin(it) => it.expand(db, id, tt),
+            TokenExpander::BuiltinDerive(it) => it.expand(db, id, tt),
         }
     }
 
@@ -36,13 +38,15 @@ impl TokenExpander {
         match self {
             TokenExpander::MacroRules(it) => it.map_id_down(id),
             TokenExpander::Builtin(..) => id,
+            TokenExpander::BuiltinDerive(..) => id,
         }
     }
 
     pub fn map_id_up(&self, id: tt::TokenId) -> (tt::TokenId, mbe::Origin) {
         match self {
             TokenExpander::MacroRules(it) => it.map_id_up(id),
-            TokenExpander::Builtin(..) => (id, mbe::Origin::Def),
+            TokenExpander::Builtin(..) => (id, mbe::Origin::Call),
+            TokenExpander::BuiltinDerive(..) => (id, mbe::Origin::Call),
         }
     }
 }
@@ -76,7 +80,7 @@ pub(crate) fn macro_def(
 ) -> Option<Arc<(TokenExpander, mbe::TokenMap)>> {
     match id.kind {
         MacroDefKind::Declarative => {
-            let macro_call = id.ast_id.to_node(db);
+            let macro_call = id.ast_id?.to_node(db);
             let arg = macro_call.token_tree()?;
             let (tt, tmap) = mbe::ast_to_token_tree(&arg).or_else(|| {
                 log::warn!("fail on macro_def to token tree: {:#?}", arg);
@@ -89,7 +93,10 @@ pub(crate) fn macro_def(
             Some(Arc::new((TokenExpander::MacroRules(rules), tmap)))
         }
         MacroDefKind::BuiltIn(expander) => {
-            Some(Arc::new((TokenExpander::Builtin(expander.clone()), mbe::TokenMap::default())))
+            Some(Arc::new((TokenExpander::Builtin(expander), mbe::TokenMap::default())))
+        }
+        MacroDefKind::BuiltInDerive(expander) => {
+            Some(Arc::new((TokenExpander::BuiltinDerive(expander), mbe::TokenMap::default())))
         }
     }
 }
@@ -99,9 +106,8 @@ pub(crate) fn macro_arg(
     id: MacroCallId,
 ) -> Option<Arc<(tt::Subtree, mbe::TokenMap)>> {
     let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
-    let arg = macro_call.token_tree()?;
-    let (tt, tmap) = mbe::ast_to_token_tree(&arg)?;
+    let arg = loc.kind.arg(db)?;
+    let (tt, tmap) = mbe::syntax_node_to_token_tree(&arg)?;
     Some(Arc::new((tt, tmap)))
 }
 
@@ -148,11 +154,43 @@ pub(crate) fn parse_macro(
         })
         .ok()?;
 
-    let fragment_kind = match macro_file.macro_file_kind {
-        MacroFileKind::Items => FragmentKind::Items,
-        MacroFileKind::Expr => FragmentKind::Expr,
-        MacroFileKind::Statements => FragmentKind::Statements,
-    };
+    let fragment_kind = to_fragment_kind(db, macro_call_id);
+
     let (parse, rev_token_map) = mbe::token_tree_to_syntax_node(&tt, fragment_kind).ok()?;
     Some((parse, Arc::new(rev_token_map)))
 }
+
+/// Given a `MacroCallId`, return what `FragmentKind` it belongs to.
+/// FIXME: Not completed
+fn to_fragment_kind(db: &dyn AstDatabase, macro_call_id: MacroCallId) -> FragmentKind {
+    let syn = db.lookup_intern_macro(macro_call_id).kind.node(db).value;
+
+    let parent = match syn.parent() {
+        Some(it) => it,
+        None => {
+            // FIXME:
+            // If it is root, which means the parent HirFile
+            // MacroKindFile must be non-items
+            // return expr now.
+            return FragmentKind::Expr;
+        }
+    };
+
+    match parent.kind() {
+        MACRO_ITEMS | SOURCE_FILE => FragmentKind::Items,
+        LET_STMT => {
+            // FIXME: Handle Pattern
+            FragmentKind::Expr
+        }
+        // FIXME: Expand to statements in appropriate positions; HIR lowering needs to handle that
+        EXPR_STMT | BLOCK => FragmentKind::Expr,
+        ARG_LIST => FragmentKind::Expr,
+        TRY_EXPR => FragmentKind::Expr,
+        TUPLE_EXPR => FragmentKind::Expr,
+        ITEM_LIST => FragmentKind::Items,
+        _ => {
+            // Unknown , Just guess it is `Items`
+            FragmentKind::Items
+        }
+    }
+}
diff --git a/crates/ra_hir_expand/src/diagnostics.rs b/crates/ra_hir_expand/src/diagnostics.rs
index 3d37e9335..108c1e38c 100644
--- a/crates/ra_hir_expand/src/diagnostics.rs
+++ b/crates/ra_hir_expand/src/diagnostics.rs
@@ -18,11 +18,11 @@ use std::{any::Any, fmt};
 
 use ra_syntax::{SyntaxNode, SyntaxNodePtr, TextRange};
 
-use crate::{db::AstDatabase, Source};
+use crate::{db::AstDatabase, InFile};
 
 pub trait Diagnostic: Any + Send + Sync + fmt::Debug + 'static {
     fn message(&self) -> String;
-    fn source(&self) -> Source<SyntaxNodePtr>;
+    fn source(&self) -> InFile<SyntaxNodePtr>;
     fn highlight_range(&self) -> TextRange {
         self.source().value.range()
     }
diff --git a/crates/ra_hir_expand/src/either.rs b/crates/ra_hir_expand/src/either.rs
deleted file mode 100644
index 83583ef8b..000000000
--- a/crates/ra_hir_expand/src/either.rs
+++ /dev/null
@@ -1,54 +0,0 @@
-//! FIXME: write short doc here
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum Either<A, B> {
-    A(A),
-    B(B),
-}
-
-impl<A, B> Either<A, B> {
-    pub fn either<R, F1, F2>(self, f1: F1, f2: F2) -> R
-    where
-        F1: FnOnce(A) -> R,
-        F2: FnOnce(B) -> R,
-    {
-        match self {
-            Either::A(a) => f1(a),
-            Either::B(b) => f2(b),
-        }
-    }
-    pub fn map<U, V, F1, F2>(self, f1: F1, f2: F2) -> Either<U, V>
-    where
-        F1: FnOnce(A) -> U,
-        F2: FnOnce(B) -> V,
-    {
-        match self {
-            Either::A(a) => Either::A(f1(a)),
-            Either::B(b) => Either::B(f2(b)),
-        }
-    }
-    pub fn map_a<U, F>(self, f: F) -> Either<U, B>
-    where
-        F: FnOnce(A) -> U,
-    {
-        self.map(f, |it| it)
-    }
-    pub fn a(self) -> Option<A> {
-        match self {
-            Either::A(it) => Some(it),
-            Either::B(_) => None,
-        }
-    }
-    pub fn b(self) -> Option<B> {
-        match self {
-            Either::A(_) => None,
-            Either::B(it) => Some(it),
-        }
-    }
-    pub fn as_ref(&self) -> Either<&A, &B> {
-        match self {
-            Either::A(it) => Either::A(it),
-            Either::B(it) => Either::B(it),
-        }
-    }
-}
diff --git a/crates/ra_hir_expand/src/hygiene.rs b/crates/ra_hir_expand/src/hygiene.rs
index 379562a2c..2e8a533f7 100644
--- a/crates/ra_hir_expand/src/hygiene.rs
+++ b/crates/ra_hir_expand/src/hygiene.rs
@@ -2,12 +2,12 @@
 //!
 //! Specifically, `ast` + `Hygiene` allows you to create a `Name`. Note that, at
 //! this moment, this is horribly incomplete and handles only `$crate`.
+use either::Either;
 use ra_db::CrateId;
 use ra_syntax::ast;
 
 use crate::{
     db::AstDatabase,
-    either::Either,
     name::{AsName, Name},
     HirFileId, HirFileIdRepr, MacroDefKind,
 };
@@ -25,8 +25,9 @@ impl Hygiene {
             HirFileIdRepr::MacroFile(macro_file) => {
                 let loc = db.lookup_intern_macro(macro_file.macro_call_id);
                 match loc.def.kind {
-                    MacroDefKind::Declarative => Some(loc.def.krate),
+                    MacroDefKind::Declarative => loc.def.krate,
                     MacroDefKind::BuiltIn(_) => None,
+                    MacroDefKind::BuiltInDerive(_) => None,
                 }
             }
         };
@@ -41,9 +42,9 @@ impl Hygiene {
     pub fn name_ref_to_name(&self, name_ref: ast::NameRef) -> Either<Name, CrateId> {
         if let Some(def_crate) = self.def_crate {
             if name_ref.text() == "$crate" {
-                return Either::B(def_crate);
+                return Either::Right(def_crate);
             }
         }
-        Either::A(name_ref.as_name())
+        Either::Left(name_ref.as_name())
     }
 }
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index b6a739cda..2fa5d5140 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -6,14 +6,14 @@
 
 pub mod db;
 pub mod ast_id_map;
-pub mod either;
 pub mod name;
 pub mod hygiene;
 pub mod diagnostics;
+pub mod builtin_derive;
 pub mod builtin_macro;
 pub mod quote;
 
-use std::hash::{Hash, Hasher};
+use std::hash::Hash;
 use std::sync::Arc;
 
 use ra_db::{salsa, CrateId, FileId};
@@ -24,6 +24,7 @@ use ra_syntax::{
 };
 
 use crate::ast_id_map::FileAstId;
+use crate::builtin_derive::BuiltinDeriveExpander;
 use crate::builtin_macro::BuiltinFnLikeExpander;
 
 #[cfg(test)]
@@ -70,7 +71,18 @@ impl HirFileId {
             HirFileIdRepr::FileId(file_id) => file_id,
             HirFileIdRepr::MacroFile(macro_file) => {
                 let loc = db.lookup_intern_macro(macro_file.macro_call_id);
-                loc.ast_id.file_id().original_file(db)
+                loc.kind.file_id().original_file(db)
+            }
+        }
+    }
+
+    /// If this is a macro call, returns the syntax node of the call.
+    pub fn call_node(self, db: &dyn db::AstDatabase) -> Option<InFile<SyntaxNode>> {
+        match self.0 {
+            HirFileIdRepr::FileId(_) => None,
+            HirFileIdRepr::MacroFile(macro_file) => {
+                let loc = db.lookup_intern_macro(macro_file.macro_call_id);
+                Some(loc.kind.node(db))
             }
         }
     }
@@ -82,17 +94,17 @@ impl HirFileId {
             HirFileIdRepr::MacroFile(macro_file) => {
                 let loc: MacroCallLoc = db.lookup_intern_macro(macro_file.macro_call_id);
 
-                let arg_tt = loc.ast_id.to_node(db).token_tree()?;
-                let def_tt = loc.def.ast_id.to_node(db).token_tree()?;
+                let arg_tt = loc.kind.arg(db)?;
+                let def_tt = loc.def.ast_id?.to_node(db).token_tree()?;
 
                 let macro_def = db.macro_def(loc.def)?;
                 let (parse, exp_map) = db.parse_macro(macro_file)?;
                 let macro_arg = db.macro_arg(macro_file.macro_call_id)?;
 
                 Some(ExpansionInfo {
-                    expanded: Source::new(self, parse.syntax_node()),
-                    arg: Source::new(loc.ast_id.file_id, arg_tt),
-                    def: Source::new(loc.ast_id.file_id, def_tt),
+                    expanded: InFile::new(self, parse.syntax_node()),
+                    arg: InFile::new(loc.kind.file_id(), arg_tt),
+                    def: InFile::new(loc.def.ast_id?.file_id, def_tt),
                     macro_arg,
                     macro_def,
                     exp_map,
@@ -105,14 +117,6 @@ impl HirFileId {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct MacroFile {
     macro_call_id: MacroCallId,
-    macro_file_kind: MacroFileKind,
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum MacroFileKind {
-    Items,
-    Expr,
-    Statements,
 }
 
 /// `MacroCallId` identifies a particular macro invocation, like
@@ -130,18 +134,20 @@ impl salsa::InternKey for MacroCallId {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct MacroDefId {
-    pub krate: CrateId,
-    pub ast_id: AstId<ast::MacroCall>,
+    // FIXME: krate and ast_id are currently optional because we don't have a
+    // definition location for built-in derives. There is one, though: the
+    // standard library defines them. The problem is that it uses the new
+    // `macro` syntax for this, which we don't support yet. As soon as we do
+    // (which will probably require touching this code), we can instead use
+    // that (and also remove the hacks for resolving built-in derives).
+    pub krate: Option<CrateId>,
+    pub ast_id: Option<AstId<ast::MacroCall>>,
     pub kind: MacroDefKind,
 }
 
 impl MacroDefId {
-    pub fn as_call_id(
-        self,
-        db: &dyn db::AstDatabase,
-        ast_id: AstId<ast::MacroCall>,
-    ) -> MacroCallId {
-        db.intern_macro(MacroCallLoc { def: self, ast_id })
+    pub fn as_call_id(self, db: &dyn db::AstDatabase, kind: MacroCallKind) -> MacroCallId {
+        db.intern_macro(MacroCallLoc { def: self, kind })
     }
 }
 
@@ -149,64 +155,103 @@ impl MacroDefId {
 pub enum MacroDefKind {
     Declarative,
     BuiltIn(BuiltinFnLikeExpander),
+    // FIXME: maybe just Builtin and rename BuiltinFnLikeExpander to BuiltinExpander
+    BuiltInDerive(BuiltinDeriveExpander),
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct MacroCallLoc {
     pub(crate) def: MacroDefId,
-    pub(crate) ast_id: AstId<ast::MacroCall>,
+    pub(crate) kind: MacroCallKind,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum MacroCallKind {
+    FnLike(AstId<ast::MacroCall>),
+    Attr(AstId<ast::ModuleItem>),
+}
+
+impl MacroCallKind {
+    pub fn file_id(&self) -> HirFileId {
+        match self {
+            MacroCallKind::FnLike(ast_id) => ast_id.file_id,
+            MacroCallKind::Attr(ast_id) => ast_id.file_id,
+        }
+    }
+
+    pub fn node(&self, db: &dyn db::AstDatabase) -> InFile<SyntaxNode> {
+        match self {
+            MacroCallKind::FnLike(ast_id) => ast_id.with_value(ast_id.to_node(db).syntax().clone()),
+            MacroCallKind::Attr(ast_id) => ast_id.with_value(ast_id.to_node(db).syntax().clone()),
+        }
+    }
+
+    pub fn arg(&self, db: &dyn db::AstDatabase) -> Option<SyntaxNode> {
+        match self {
+            MacroCallKind::FnLike(ast_id) => {
+                Some(ast_id.to_node(db).token_tree()?.syntax().clone())
+            }
+            MacroCallKind::Attr(ast_id) => Some(ast_id.to_node(db).syntax().clone()),
+        }
+    }
 }
 
 impl MacroCallId {
-    pub fn as_file(self, kind: MacroFileKind) -> HirFileId {
-        let macro_file = MacroFile { macro_call_id: self, macro_file_kind: kind };
-        macro_file.into()
+    pub fn as_file(self) -> HirFileId {
+        MacroFile { macro_call_id: self }.into()
     }
 }
 
 /// ExpansionInfo mainly describes how to map text range between src and expanded macro
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ExpansionInfo {
-    expanded: Source<SyntaxNode>,
-    arg: Source<ast::TokenTree>,
-    def: Source<ast::TokenTree>,
+    expanded: InFile<SyntaxNode>,
+    arg: InFile<SyntaxNode>,
+    def: InFile<ast::TokenTree>,
 
     macro_def: Arc<(db::TokenExpander, mbe::TokenMap)>,
     macro_arg: Arc<(tt::Subtree, mbe::TokenMap)>,
     exp_map: Arc<mbe::TokenMap>,
 }
 
+pub use mbe::Origin;
+
 impl ExpansionInfo {
-    pub fn map_token_down(&self, token: Source<&SyntaxToken>) -> Option<Source<SyntaxToken>> {
+    pub fn call_node(&self) -> Option<InFile<SyntaxNode>> {
+        Some(self.arg.with_value(self.arg.value.parent()?))
+    }
+
+    pub fn map_token_down(&self, token: InFile<&SyntaxToken>) -> Option<InFile<SyntaxToken>> {
         assert_eq!(token.file_id, self.arg.file_id);
-        let range =
-            token.value.text_range().checked_sub(self.arg.value.syntax().text_range().start())?;
+        let range = token.value.text_range().checked_sub(self.arg.value.text_range().start())?;
         let token_id = self.macro_arg.1.token_by_range(range)?;
         let token_id = self.macro_def.0.map_id_down(token_id);
 
-        let range = self.exp_map.range_by_token(token_id)?;
+        let range = self.exp_map.range_by_token(token_id)?.by_kind(token.value.kind())?;
 
         let token = algo::find_covering_element(&self.expanded.value, range).into_token()?;
 
         Some(self.expanded.with_value(token))
     }
 
-    pub fn map_token_up(&self, token: Source<&SyntaxToken>) -> Option<Source<SyntaxToken>> {
+    pub fn map_token_up(
+        &self,
+        token: InFile<&SyntaxToken>,
+    ) -> Option<(InFile<SyntaxToken>, Origin)> {
         let token_id = self.exp_map.token_by_range(token.value.text_range())?;
 
         let (token_id, origin) = self.macro_def.0.map_id_up(token_id);
         let (token_map, tt) = match origin {
-            mbe::Origin::Call => (&self.macro_arg.1, &self.arg),
-            mbe::Origin::Def => (&self.macro_def.1, &self.def),
+            mbe::Origin::Call => (&self.macro_arg.1, self.arg.clone()),
+            mbe::Origin::Def => {
+                (&self.macro_def.1, self.def.as_ref().map(|tt| tt.syntax().clone()))
+            }
         };
 
-        let range = token_map.range_by_token(token_id)?;
-        let token = algo::find_covering_element(
-            tt.value.syntax(),
-            range + tt.value.syntax().text_range().start(),
-        )
-        .into_token()?;
-        Some(tt.with_value(token))
+        let range = token_map.range_by_token(token_id)?.by_kind(token.value.kind())?;
+        let token = algo::find_covering_element(&tt.value, range + tt.value.text_range().start())
+            .into_token()?;
+        Some((tt.with_value(token), origin))
     }
 }
 
@@ -214,76 +259,66 @@ impl ExpansionInfo {
 ///
 /// It is stable across reparses, and can be used as salsa key/value.
 // FIXME: isn't this just a `Source<FileAstId<N>>` ?
-#[derive(Debug)]
-pub struct AstId<N: AstNode> {
-    file_id: HirFileId,
-    file_ast_id: FileAstId<N>,
-}
-
-impl<N: AstNode> Clone for AstId<N> {
-    fn clone(&self) -> AstId<N> {
-        *self
-    }
-}
-impl<N: AstNode> Copy for AstId<N> {}
-
-impl<N: AstNode> PartialEq for AstId<N> {
-    fn eq(&self, other: &Self) -> bool {
-        (self.file_id, self.file_ast_id) == (other.file_id, other.file_ast_id)
-    }
-}
-impl<N: AstNode> Eq for AstId<N> {}
-impl<N: AstNode> Hash for AstId<N> {
-    fn hash<H: Hasher>(&self, hasher: &mut H) {
-        (self.file_id, self.file_ast_id).hash(hasher);
-    }
-}
+pub type AstId<N> = InFile<FileAstId<N>>;
 
 impl<N: AstNode> AstId<N> {
-    pub fn new(file_id: HirFileId, file_ast_id: FileAstId<N>) -> AstId<N> {
-        AstId { file_id, file_ast_id }
-    }
-
-    pub fn file_id(&self) -> HirFileId {
-        self.file_id
-    }
-
     pub fn to_node(&self, db: &dyn db::AstDatabase) -> N {
         let root = db.parse_or_expand(self.file_id).unwrap();
-        db.ast_id_map(self.file_id).get(self.file_ast_id).to_node(&root)
+        db.ast_id_map(self.file_id).get(self.value).to_node(&root)
     }
 }
 
-/// `Source<T>` stores a value of `T` inside a particular file/syntax tree.
+/// `InFile<T>` stores a value of `T` inside a particular file/syntax tree.
 ///
 /// Typical usages are:
 ///
-/// * `Source<SyntaxNode>` -- syntax node in a file
-/// * `Source<ast::FnDef>` -- ast node in a file
-/// * `Source<TextUnit>` -- offset in a file
+/// * `InFile<SyntaxNode>` -- syntax node in a file
+/// * `InFile<ast::FnDef>` -- ast node in a file
+/// * `InFile<TextUnit>` -- offset in a file
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Hash)]
-pub struct Source<T> {
+pub struct InFile<T> {
     pub file_id: HirFileId,
     pub value: T,
 }
 
-impl<T> Source<T> {
-    pub fn new(file_id: HirFileId, value: T) -> Source<T> {
-        Source { file_id, value }
+impl<T> InFile<T> {
+    pub fn new(file_id: HirFileId, value: T) -> InFile<T> {
+        InFile { file_id, value }
     }
 
     // Similarly, naming here is stupid...
-    pub fn with_value<U>(&self, value: U) -> Source<U> {
-        Source::new(self.file_id, value)
+    pub fn with_value<U>(&self, value: U) -> InFile<U> {
+        InFile::new(self.file_id, value)
     }
 
-    pub fn map<F: FnOnce(T) -> U, U>(self, f: F) -> Source<U> {
-        Source::new(self.file_id, f(self.value))
+    pub fn map<F: FnOnce(T) -> U, U>(self, f: F) -> InFile<U> {
+        InFile::new(self.file_id, f(self.value))
     }
-    pub fn as_ref(&self) -> Source<&T> {
+    pub fn as_ref(&self) -> InFile<&T> {
         self.with_value(&self.value)
     }
     pub fn file_syntax(&self, db: &impl db::AstDatabase) -> SyntaxNode {
         db.parse_or_expand(self.file_id).expect("source created from invalid file")
     }
 }
+
+impl<T: Clone> InFile<&T> {
+    pub fn cloned(&self) -> InFile<T> {
+        self.with_value(self.value.clone())
+    }
+}
+
+impl InFile<SyntaxNode> {
+    pub fn ancestors_with_macros<'a>(
+        self,
+        db: &'a impl crate::db::AstDatabase,
+    ) -> impl Iterator<Item = InFile<SyntaxNode>> + 'a {
+        std::iter::successors(Some(self), move |node| match node.value.parent() {
+            Some(parent) => Some(node.with_value(parent)),
+            None => {
+                let parent_node = node.file_id.call_node(db)?;
+                Some(parent_node)
+            }
+        })
+    }
+}
diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs
index 7824489d7..e62693b68 100644
--- a/crates/ra_hir_expand/src/name.rs
+++ b/crates/ra_hir_expand/src/name.rs
@@ -38,8 +38,8 @@ impl Name {
     }
 
     /// 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))
+    const fn new_inline_ascii(text: &[u8]) -> Name {
+        Name::new_text(SmolStr::new_inline_from_ascii(text.len(), text))
     }
 
     /// Resolve a name from the text of token.
@@ -83,6 +83,12 @@ impl AsName for ast::Name {
     }
 }
 
+impl AsName for tt::Ident {
+    fn as_name(&self) -> Name {
+        Name::resolve(&self.text)
+    }
+}
+
 impl AsName for ast::FieldKind {
     fn as_name(&self) -> Name {
         match self {
@@ -98,52 +104,102 @@ impl AsName for ra_db::Dependency {
     }
 }
 
-// Primitives
-pub const ISIZE: Name = Name::new_inline_ascii(5, b"isize");
-pub const I8: Name = Name::new_inline_ascii(2, b"i8");
-pub const I16: Name = Name::new_inline_ascii(3, b"i16");
-pub const I32: Name = Name::new_inline_ascii(3, b"i32");
-pub const I64: Name = Name::new_inline_ascii(3, b"i64");
-pub const I128: Name = Name::new_inline_ascii(4, b"i128");
-pub const USIZE: Name = Name::new_inline_ascii(5, b"usize");
-pub const U8: Name = Name::new_inline_ascii(2, b"u8");
-pub const U16: Name = Name::new_inline_ascii(3, b"u16");
-pub const U32: Name = Name::new_inline_ascii(3, b"u32");
-pub const U64: Name = Name::new_inline_ascii(3, b"u64");
-pub const U128: Name = Name::new_inline_ascii(4, b"u128");
-pub const F32: Name = Name::new_inline_ascii(3, b"f32");
-pub const F64: Name = Name::new_inline_ascii(3, b"f64");
-pub const BOOL: Name = Name::new_inline_ascii(4, b"bool");
-pub const CHAR: Name = Name::new_inline_ascii(4, b"char");
-pub const STR: Name = Name::new_inline_ascii(3, b"str");
-
-// Special names
-pub const SELF_PARAM: Name = Name::new_inline_ascii(4, b"self");
-pub const SELF_TYPE: Name = Name::new_inline_ascii(4, b"Self");
-pub const MACRO_RULES: Name = Name::new_inline_ascii(11, b"macro_rules");
-
-// Components of known path (value or mod name)
-pub const STD: Name = Name::new_inline_ascii(3, b"std");
-pub const ITER: Name = Name::new_inline_ascii(4, b"iter");
-pub const OPS: Name = Name::new_inline_ascii(3, b"ops");
-pub const FUTURE: Name = Name::new_inline_ascii(6, b"future");
-pub const RESULT: Name = Name::new_inline_ascii(6, b"result");
-pub const BOXED: Name = Name::new_inline_ascii(5, b"boxed");
-
-// Components of known path (type name)
-pub const INTO_ITERATOR_TYPE: Name = Name::new_inline_ascii(12, b"IntoIterator");
-pub const ITEM_TYPE: Name = Name::new_inline_ascii(4, b"Item");
-pub const TRY_TYPE: Name = Name::new_inline_ascii(3, b"Try");
-pub const OK_TYPE: Name = Name::new_inline_ascii(2, b"Ok");
-pub const FUTURE_TYPE: Name = Name::new_inline_ascii(6, b"Future");
-pub const RESULT_TYPE: Name = Name::new_inline_ascii(6, b"Result");
-pub const OUTPUT_TYPE: Name = Name::new_inline_ascii(6, b"Output");
-pub const TARGET_TYPE: Name = Name::new_inline_ascii(6, b"Target");
-pub const BOX_TYPE: Name = Name::new_inline_ascii(3, b"Box");
-
-// Builtin Macros
-pub const FILE_MACRO: Name = Name::new_inline_ascii(4, b"file");
-pub const COLUMN_MACRO: Name = Name::new_inline_ascii(6, b"column");
-pub const COMPILE_ERROR_MACRO: Name = Name::new_inline_ascii(13, b"compile_error");
-pub const LINE_MACRO: Name = Name::new_inline_ascii(4, b"line");
-pub const STRINGIFY_MACRO: Name = Name::new_inline_ascii(9, b"stringify");
+pub mod known {
+    macro_rules! known_names {
+        ($($ident:ident),* $(,)?) => {
+            $(
+                #[allow(bad_style)]
+                pub const $ident: super::Name =
+                    super::Name::new_inline_ascii(stringify!($ident).as_bytes());
+            )*
+        };
+    }
+
+    known_names!(
+        // Primitives
+        isize,
+        i8,
+        i16,
+        i32,
+        i64,
+        i128,
+        usize,
+        u8,
+        u16,
+        u32,
+        u64,
+        u128,
+        f32,
+        f64,
+        bool,
+        char,
+        str,
+        // Special names
+        macro_rules,
+        // Components of known path (value or mod name)
+        std,
+        iter,
+        ops,
+        future,
+        result,
+        boxed,
+        // Components of known path (type name)
+        IntoIterator,
+        Item,
+        Try,
+        Ok,
+        Future,
+        Result,
+        Output,
+        Target,
+        Box,
+        RangeFrom,
+        RangeFull,
+        RangeInclusive,
+        RangeToInclusive,
+        RangeTo,
+        Range,
+        Neg,
+        Not,
+        Index,
+        // Builtin macros
+        file,
+        column,
+        compile_error,
+        line,
+        stringify,
+        format_args,
+        format_args_nl,
+        env,
+        option_env,
+        // Builtin derives
+        Copy,
+        Clone,
+        Default,
+        Debug,
+        Hash,
+        Ord,
+        PartialOrd,
+        Eq,
+        PartialEq,
+    );
+
+    // self/Self cannot be used as an identifier
+    pub const SELF_PARAM: super::Name = super::Name::new_inline_ascii(b"self");
+    pub const SELF_TYPE: super::Name = super::Name::new_inline_ascii(b"Self");
+
+    #[macro_export]
+    macro_rules! name {
+        (self) => {
+            $crate::name::known::SELF_PARAM
+        };
+        (Self) => {
+            $crate::name::known::SELF_TYPE
+        };
+        ($ident:ident) => {
+            $crate::name::known::$ident
+        };
+    }
+}
+
+pub use crate::name;
diff --git a/crates/ra_hir_expand/src/quote.rs b/crates/ra_hir_expand/src/quote.rs
index 65a35e52f..4de219ce4 100644
--- a/crates/ra_hir_expand/src/quote.rs
+++ b/crates/ra_hir_expand/src/quote.rs
@@ -16,7 +16,10 @@ macro_rules! __quote {
         {
             let children = $crate::__quote!($($tt)*);
             let subtree = tt::Subtree {
-                delimiter: tt::Delimiter::$delim,
+                delimiter: Some(tt::Delimiter {
+                    kind: tt::DelimiterKind::$delim,
+                    id: tt::TokenId::unspecified(),
+                }),
                 token_trees: $crate::quote::IntoTt::to_tokens(children),
             };
             subtree
@@ -29,6 +32,7 @@ macro_rules! __quote {
                 tt::Leaf::Punct(tt::Punct {
                     char: $first,
                     spacing: tt::Spacing::Alone,
+                    id: tt::TokenId::unspecified(),
                 }).into()
             ]
         }
@@ -40,10 +44,12 @@ macro_rules! __quote {
                 tt::Leaf::Punct(tt::Punct {
                     char: $first,
                     spacing: tt::Spacing::Joint,
+                    id: tt::TokenId::unspecified(),
                 }).into(),
                 tt::Leaf::Punct(tt::Punct {
                     char: $sec,
                     spacing: tt::Spacing::Alone,
+                    id: tt::TokenId::unspecified(),
                 }).into()
             ]
         }
@@ -60,6 +66,15 @@ macro_rules! __quote {
         }
     };
 
+    ( ## $first:ident $($tail:tt)* ) => {
+        {
+            let mut tokens = $first.into_iter().map($crate::quote::ToTokenTree::to_token).collect::<Vec<tt::TokenTree>>();
+            let mut tail_tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($($tail)*));
+            tokens.append(&mut tail_tokens);
+            tokens
+        }
+    };
+
     // Brace
     ( { $($tt:tt)* } ) => { $crate::__quote!(@SUBTREE Brace $($tt)*) };
     // Bracket
@@ -85,7 +100,10 @@ macro_rules! __quote {
     ( & ) => {$crate::__quote!(@PUNCT '&')};
     ( , ) => {$crate::__quote!(@PUNCT ',')};
     ( : ) => {$crate::__quote!(@PUNCT ':')};
+    ( :: ) => {$crate::__quote!(@PUNCT ':', ':')};
     ( . ) => {$crate::__quote!(@PUNCT '.')};
+    ( < ) => {$crate::__quote!(@PUNCT '<')};
+    ( > ) => {$crate::__quote!(@PUNCT '>')};
 
     ( $first:tt $($tail:tt)+ ) => {
         {
@@ -114,7 +132,7 @@ pub(crate) trait IntoTt {
 
 impl IntoTt for Vec<tt::TokenTree> {
     fn to_subtree(self) -> tt::Subtree {
-        tt::Subtree { delimiter: tt::Delimiter::None, token_trees: self }
+        tt::Subtree { delimiter: None, token_trees: self }
     }
 
     fn to_tokens(self) -> Vec<tt::TokenTree> {
@@ -169,15 +187,15 @@ macro_rules! impl_to_to_tokentrees {
 }
 
 impl_to_to_tokentrees! {
-    u32 => self { tt::Literal{text: self.to_string().into()} };
-    usize => self { tt::Literal{text: self.to_string().into()}};
-    i32 => self { tt::Literal{text: self.to_string().into()}};
+    u32 => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()} };
+    usize => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()}};
+    i32 => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()}};
     tt::Leaf => self { self };
     tt::Literal => self { self };
     tt::Ident => self { self };
     tt::Punct => self { self };
-    &str => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into()}};
-    String => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into()}}
+    &str => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into(), id: tt::TokenId::unspecified()}};
+    String => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into(), id: tt::TokenId::unspecified()}}
 }
 
 #[cfg(test)]
@@ -244,7 +262,13 @@ mod tests {
         let fields =
             fields.iter().map(|it| quote!(#it: self.#it.clone(), ).token_trees.clone()).flatten();
 
-        let list = tt::Subtree { delimiter: tt::Delimiter::Brace, token_trees: fields.collect() };
+        let list = tt::Subtree {
+            delimiter: Some(tt::Delimiter {
+                kind: tt::DelimiterKind::Brace,
+                id: tt::TokenId::unspecified(),
+            }),
+            token_trees: fields.collect(),
+        };
 
         let quoted = quote! {
             impl Clone for #struct_name {