5 files changed, 110 insertions, 47 deletions

diff --git a/crates/ra_hir_expand/src/builtin_derive.rs b/crates/ra_hir_expand/src/builtin_derive.rs
index bb45b0f1d..1dc9cac66 100644
--- a/crates/ra_hir_expand/src/builtin_derive.rs
+++ b/crates/ra_hir_expand/src/builtin_derive.rs
@@ -9,7 +9,7 @@ use ra_syntax::{
 };
 
 use crate::db::AstDatabase;
-use crate::{name, quote, LazyMacroId, MacroDefId, MacroDefKind};
+use crate::{name, quote, LazyMacroId, MacroCallId, MacroDefId, MacroDefKind};
 
 macro_rules! register_builtin {
     ( $($trait:ident => $expand:ident),* ) => {
@@ -38,7 +38,7 @@ macro_rules! register_builtin {
                  _ => return None,
             };
 
-            Some(MacroDefId { krate: None, ast_id: None, kind: MacroDefKind::BuiltInDerive(kind) })
+            Some(MacroDefId { krate: None, ast_id: None, kind: MacroDefKind::BuiltInDerive(kind), local_inner: false })
         }
     };
 }
@@ -153,76 +153,113 @@ fn expand_simple_derive(
     Ok(expanded)
 }
 
+fn find_builtin_crate(db: &dyn AstDatabase, id: LazyMacroId) -> tt::TokenTree {
+    // FIXME: make hygiene works for builtin derive macro
+    // such that $crate can be used here.
+
+    let m: MacroCallId = id.into();
+    let file_id = m.as_file().original_file(db);
+    let cg = db.crate_graph();
+    let krates = db.relevant_crates(file_id);
+    let krate = match krates.get(0) {
+        Some(krate) => krate,
+        None => {
+            let tt = quote! { core };
+            return tt.token_trees[0].clone();
+        }
+    };
+
+    // XXX
+    //  All crates except core itself should have a dependency on core,
+    //  We detect `core` by seeing whether it doesn't have such a dependency.
+    let tt = if cg[*krate].dependencies.iter().any(|dep| dep.name == "core") {
+        quote! { core }
+    } else {
+        quote! { crate }
+    };
+
+    tt.token_trees[0].clone()
+}
+
 fn copy_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::marker::Copy })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::marker::Copy })
 }
 
 fn clone_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::clone::Clone })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::clone::Clone })
 }
 
 fn default_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::default::Default })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::default::Default })
 }
 
 fn debug_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::fmt::Debug })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::fmt::Debug })
 }
 
 fn hash_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::hash::Hash })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::hash::Hash })
 }
 
 fn eq_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::cmp::Eq })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::cmp::Eq })
 }
 
 fn partial_eq_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::cmp::PartialEq })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::cmp::PartialEq })
 }
 
 fn ord_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::cmp::Ord })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::cmp::Ord })
 }
 
 fn partial_ord_expand(
-    _db: &dyn AstDatabase,
-    _id: LazyMacroId,
+    db: &dyn AstDatabase,
+    id: LazyMacroId,
     tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    expand_simple_derive(tt, quote! { std::cmp::PartialOrd })
+    let krate = find_builtin_crate(db, id);
+    expand_simple_derive(tt, quote! { #krate::cmp::PartialOrd })
 }
 
 #[cfg(test)]
@@ -234,8 +271,18 @@ mod tests {
 
     fn expand_builtin_derive(s: &str, name: Name) -> String {
         let def = find_builtin_derive(&name).unwrap();
+        let fixture = format!(
+            r#"//- /main.rs crate:main deps:core
+<|>
+{}
+//- /lib.rs crate:core
+// empty
+"#,
+            s
+        );
 
-        let (db, file_id) = TestDB::with_single_file(&s);
+        let (db, file_pos) = TestDB::with_position(&fixture);
+        let file_id = file_pos.file_id;
         let parsed = db.parse(file_id);
         let items: Vec<_> =
             parsed.syntax_node().descendants().filter_map(ast::ModuleItem::cast).collect();
@@ -264,7 +311,7 @@ mod tests {
             known::Copy,
         );
 
-        assert_eq!(expanded, "impl< >std::marker::CopyforFoo< >{}");
+        assert_eq!(expanded, "impl< >core::marker::CopyforFoo< >{}");
     }
 
     #[test]
@@ -279,7 +326,7 @@ mod tests {
 
         assert_eq!(
             expanded,
-            "impl<T0:std::marker::Copy,T1:std::marker::Copy>std::marker::CopyforFoo<T0,T1>{}"
+            "impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"
         );
     }
 
@@ -297,7 +344,7 @@ mod tests {
 
         assert_eq!(
             expanded,
-            "impl<T0:std::marker::Copy,T1:std::marker::Copy>std::marker::CopyforFoo<T0,T1>{}"
+            "impl<T0:core::marker::Copy,T1:core::marker::Copy>core::marker::CopyforFoo<T0,T1>{}"
         );
     }
 
@@ -313,7 +360,7 @@ mod tests {
 
         assert_eq!(
             expanded,
-            "impl<T0:std::clone::Clone,T1:std::clone::Clone>std::clone::CloneforFoo<T0,T1>{}"
+            "impl<T0:core::clone::Clone,T1:core::clone::Clone>core::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 e0fef613d..d8b3d342c 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -73,11 +73,13 @@ pub fn find_builtin_macro(
             krate: Some(krate),
             ast_id: Some(ast_id),
             kind: MacroDefKind::BuiltIn(kind),
+            local_inner: false,
         }),
         Either::Right(kind) => Some(MacroDefId {
             krate: Some(krate),
             ast_id: Some(ast_id),
             kind: MacroDefKind::BuiltInEager(kind),
+            local_inner: false,
         }),
     }
 }
@@ -406,6 +408,7 @@ mod tests {
                     krate: Some(CrateId(0)),
                     ast_id: Some(AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[0]))),
                     kind: MacroDefKind::BuiltIn(expander),
+                    local_inner: false,
                 };
 
                 let loc = MacroCallLoc {
@@ -425,6 +428,7 @@ mod tests {
                     krate: Some(CrateId(0)),
                     ast_id: Some(AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[0]))),
                     kind: MacroDefKind::BuiltInEager(expander),
+                    local_inner: false,
                 };
 
                 let args = macro_calls[1].token_tree().unwrap();
diff --git a/crates/ra_hir_expand/src/db.rs b/crates/ra_hir_expand/src/db.rs
index 047452306..4c12d0a15 100644
--- a/crates/ra_hir_expand/src/db.rs
+++ b/crates/ra_hir_expand/src/db.rs
@@ -330,7 +330,7 @@ fn to_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
             FragmentKind::Expr
         }
         // FIXME: Expand to statements in appropriate positions; HIR lowering needs to handle that
-        EXPR_STMT | BLOCK => FragmentKind::Expr,
+        EXPR_STMT | BLOCK_EXPR => FragmentKind::Expr,
         ARG_LIST => FragmentKind::Expr,
         TRY_EXPR => FragmentKind::Expr,
         TUPLE_EXPR => FragmentKind::Expr,
@@ -342,7 +342,6 @@ fn to_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
         CONDITION => FragmentKind::Expr,
         BREAK_EXPR => FragmentKind::Expr,
         RETURN_EXPR => FragmentKind::Expr,
-        BLOCK_EXPR => FragmentKind::Expr,
         MATCH_EXPR => FragmentKind::Expr,
         MATCH_ARM => FragmentKind::Expr,
         MATCH_GUARD => FragmentKind::Expr,
diff --git a/crates/ra_hir_expand/src/hygiene.rs b/crates/ra_hir_expand/src/hygiene.rs
index 0b41d0e95..6b482a60c 100644
--- a/crates/ra_hir_expand/src/hygiene.rs
+++ b/crates/ra_hir_expand/src/hygiene.rs
@@ -12,35 +12,38 @@ use crate::{
     HirFileId, HirFileIdRepr, MacroCallId, MacroDefKind,
 };
 
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct Hygiene {
     // This is what `$crate` expands to
     def_crate: Option<CrateId>,
+
+    // Indiciate this is a local inner macro
+    local_inner: bool,
 }
 
 impl Hygiene {
     pub fn new(db: &dyn AstDatabase, file_id: HirFileId) -> Hygiene {
-        let def_crate = match file_id.0 {
-            HirFileIdRepr::FileId(_) => None,
+        let (def_crate, local_inner) = match file_id.0 {
+            HirFileIdRepr::FileId(_) => (None, false),
             HirFileIdRepr::MacroFile(macro_file) => match macro_file.macro_call_id {
                 MacroCallId::LazyMacro(id) => {
                     let loc = db.lookup_intern_macro(id);
                     match loc.def.kind {
-                        MacroDefKind::Declarative => loc.def.krate,
-                        MacroDefKind::BuiltIn(_) => None,
-                        MacroDefKind::BuiltInDerive(_) => None,
-                        MacroDefKind::BuiltInEager(_) => None,
-                        MacroDefKind::CustomDerive(_) => None,
+                        MacroDefKind::Declarative => (loc.def.krate, loc.def.local_inner),
+                        MacroDefKind::BuiltIn(_) => (None, false),
+                        MacroDefKind::BuiltInDerive(_) => (None, false),
+                        MacroDefKind::BuiltInEager(_) => (None, false),
+                        MacroDefKind::CustomDerive(_) => (None, false),
                     }
                 }
-                MacroCallId::EagerMacro(_id) => None,
+                MacroCallId::EagerMacro(_id) => (None, false),
             },
         };
-        Hygiene { def_crate }
+        Hygiene { def_crate, local_inner }
     }
 
     pub fn new_unhygienic() -> Hygiene {
-        Hygiene { def_crate: None }
+        Hygiene { def_crate: None, local_inner: false }
     }
 
     // FIXME: this should just return name
@@ -52,4 +55,12 @@ impl Hygiene {
         }
         Either::Left(name_ref.as_name())
     }
+
+    pub fn local_inner_macros(&self) -> Option<CrateId> {
+        if self.local_inner {
+            self.def_crate
+        } else {
+            None
+        }
+    }
 }
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index 754a0f005..f440c073b 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -204,6 +204,8 @@ pub struct MacroDefId {
     pub krate: Option<CrateId>,
     pub ast_id: Option<AstId<ast::MacroCall>>,
     pub kind: MacroDefKind,
+
+    pub local_inner: bool,
 }
 
 impl MacroDefId {