9 files changed, 95 insertions, 160 deletions

diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index 41abd8f83..b9ecf22fa 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -46,7 +46,7 @@ pub(crate) struct CfgExpander {
 
 pub(crate) struct Expander {
     cfg_expander: CfgExpander,
-    def_map: Arc<DefMap>,
+    crate_def_map: Arc<DefMap>,
     current_file_id: HirFileId,
     ast_id_map: Arc<AstIdMap>,
     module: ModuleId,
@@ -91,7 +91,7 @@ impl Expander {
         let ast_id_map = db.ast_id_map(current_file_id);
         Expander {
             cfg_expander,
-            def_map: crate_def_map,
+            crate_def_map,
             current_file_id,
             ast_id_map,
             module,
@@ -102,6 +102,7 @@ impl Expander {
     pub(crate) fn enter_expand<T: ast::AstNode>(
         &mut self,
         db: &dyn DefDatabase,
+        local_scope: Option<&ItemScope>,
         macro_call: ast::MacroCall,
     ) -> ExpandResult<Option<(Mark, T)>> {
         if self.recursion_limit + 1 > EXPANSION_RECURSION_LIMIT {
@@ -111,12 +112,18 @@ impl Expander {
 
         let macro_call = InFile::new(self.current_file_id, &macro_call);
 
-        let resolver =
-            |path: ModPath| -> Option<MacroDefId> { self.resolve_path_as_macro(db, &path) };
+        let resolver = |path: ModPath| -> Option<MacroDefId> {
+            if let Some(local_scope) = local_scope {
+                if let Some(def) = path.as_ident().and_then(|n| local_scope.get_legacy_macro(n)) {
+                    return Some(def);
+                }
+            }
+            self.resolve_path_as_macro(db, &path)
+        };
 
         let mut err = None;
         let call_id =
-            macro_call.as_call_id_with_errors(db, self.def_map.krate(), resolver, &mut |e| {
+            macro_call.as_call_id_with_errors(db, self.crate_def_map.krate(), resolver, &mut |e| {
                 err.get_or_insert(e);
             });
         let call_id = match call_id {
@@ -197,7 +204,7 @@ impl Expander {
     }
 
     fn resolve_path_as_macro(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<MacroDefId> {
-        self.def_map
+        self.crate_def_map
             .resolve_path(db, self.module.local_id, path, BuiltinShadowMode::Other)
             .0
             .take_macros()
diff --git a/crates/hir_def/src/body/lower.rs b/crates/hir_def/src/body/lower.rs
index bc61730a7..209965fca 100644
--- a/crates/hir_def/src/body/lower.rs
+++ b/crates/hir_def/src/body/lower.rs
@@ -1,7 +1,7 @@
 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
 //! representation.
 
-use std::{any::type_name, mem, sync::Arc};
+use std::{any::type_name, sync::Arc};
 
 use either::Either;
 use hir_expand::{
@@ -36,8 +36,8 @@ use crate::{
     item_tree::{ItemTree, ItemTreeId, ItemTreeNode},
     path::{GenericArgs, Path},
     type_ref::{Mutability, Rawness, TypeRef},
-    AdtId, BlockLoc, ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, Intern,
-    ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
+    AdtId, ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, Intern, ModuleDefId,
+    StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
 };
 
 use super::{diagnostics::BodyDiagnostic, ExprSource, PatSource};
@@ -152,8 +152,8 @@ impl ExprCollector<'_> {
     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
         self.make_expr(expr, Err(SyntheticSyntax))
     }
-    fn unit(&mut self) -> ExprId {
-        self.alloc_expr_desugared(Expr::Tuple { exprs: Vec::new() })
+    fn empty_block(&mut self) -> ExprId {
+        self.alloc_expr_desugared(Expr::Block { statements: Vec::new(), tail: None, label: None })
     }
     fn missing_expr(&mut self) -> ExprId {
         self.alloc_expr_desugared(Expr::Missing)
@@ -222,7 +222,7 @@ impl ExprCollector<'_> {
                                 MatchArm { pat, expr: then_branch, guard: None },
                                 MatchArm {
                                     pat: placeholder_pat,
-                                    expr: else_branch.unwrap_or_else(|| self.unit()),
+                                    expr: else_branch.unwrap_or_else(|| self.empty_block()),
                                     guard: None,
                                 },
                             ];
@@ -561,7 +561,7 @@ impl ExprCollector<'_> {
         let outer_file = self.expander.current_file_id;
 
         let macro_call = self.expander.to_source(AstPtr::new(&e));
-        let res = self.expander.enter_expand(self.db, e);
+        let res = self.expander.enter_expand(self.db, Some(&self.body.item_scope), e);
 
         match &res.err {
             Some(ExpandError::UnresolvedProcMacro) => {
@@ -697,27 +697,12 @@ impl ExprCollector<'_> {
     }
 
     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
-        let ast_id = self.expander.ast_id(&block);
-        let block_loc = BlockLoc { ast_id, module: self.expander.module };
-        let block_id = self.db.intern_block(block_loc);
-        let def_map = self.db.block_def_map(block_id);
-        let root = def_map.module_id(def_map.root());
-        let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
-        let prev_module = mem::replace(&mut self.expander.module, root);
-
+        let syntax_node_ptr = AstPtr::new(&block.clone().into());
         self.collect_stmts_items(block.statements());
         let statements =
             block.statements().filter_map(|s| self.collect_stmt(s)).flatten().collect();
         let tail = block.tail_expr().map(|e| self.collect_expr(e));
-        let syntax_node_ptr = AstPtr::new(&block.clone().into());
-        let expr_id = self.alloc_expr(
-            Expr::Block { id: block_id, statements, tail, label: None },
-            syntax_node_ptr,
-        );
-
-        self.expander.def_map = prev_def_map;
-        self.expander.module = prev_module;
-        expr_id
+        self.alloc_expr(Expr::Block { statements, tail, label: None }, syntax_node_ptr)
     }
 
     fn collect_stmts_items(&mut self, stmts: ast::AstChildren<ast::Stmt>) {
@@ -847,7 +832,7 @@ impl ExprCollector<'_> {
                 if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
                     // This could also be a single-segment path pattern. To
                     // decide that, we need to try resolving the name.
-                    let (resolved, _) = self.expander.def_map.resolve_path(
+                    let (resolved, _) = self.expander.crate_def_map.resolve_path(
                         self.db,
                         self.expander.module.local_id,
                         &name.clone().into(),
diff --git a/crates/hir_def/src/body/tests.rs b/crates/hir_def/src/body/tests.rs
index da60072ce..2e5d0a01e 100644
--- a/crates/hir_def/src/body/tests.rs
+++ b/crates/hir_def/src/body/tests.rs
@@ -1,10 +1,7 @@
-mod block;
-
-use base_db::{fixture::WithFixture, FilePosition, SourceDatabase};
-use expect_test::Expect;
+use base_db::{fixture::WithFixture, SourceDatabase};
 use test_utils::mark;
 
-use crate::{test_db::TestDB, BlockId, ModuleDefId};
+use crate::{test_db::TestDB, ModuleDefId};
 
 use super::*;
 
@@ -34,115 +31,6 @@ fn check_diagnostics(ra_fixture: &str) {
     db.check_diagnostics();
 }
 
-fn block_def_map_at(ra_fixture: &str) -> Arc<DefMap> {
-    let (db, position) = crate::test_db::TestDB::with_position(ra_fixture);
-
-    let krate = db.crate_graph().iter().next().unwrap();
-    let def_map = db.crate_def_map(krate);
-
-    let mut block =
-        block_at_pos(&db, &def_map, position).expect("couldn't find enclosing function or block");
-    loop {
-        let def_map = db.block_def_map(block);
-        let new_block = block_at_pos(&db, &def_map, position);
-        match new_block {
-            Some(new_block) => {
-                assert_ne!(block, new_block);
-                block = new_block;
-            }
-            None => {
-                return def_map;
-            }
-        }
-    }
-}
-
-fn block_at_pos(db: &dyn DefDatabase, def_map: &DefMap, position: FilePosition) -> Option<BlockId> {
-    let mut size = None;
-    let mut fn_def = None;
-    for (_, module) in def_map.modules() {
-        let file_id = module.definition_source(db).file_id;
-        if file_id != position.file_id.into() {
-            continue;
-        }
-        let root = db.parse_or_expand(file_id).unwrap();
-        let ast_map = db.ast_id_map(file_id);
-        let item_tree = db.item_tree(file_id);
-        for decl in module.scope.declarations() {
-            if let ModuleDefId::FunctionId(it) = decl {
-                let ast = ast_map.get(item_tree[it.lookup(db).id.value].ast_id).to_node(&root);
-                let range = ast.syntax().text_range();
-
-                // Find the smallest (innermost) function containing the cursor.
-                if !range.contains(position.offset) {
-                    continue;
-                }
-
-                let new_size = match size {
-                    None => range.len(),
-                    Some(size) => {
-                        if range.len() < size {
-                            range.len()
-                        } else {
-                            size
-                        }
-                    }
-                };
-                if size != Some(new_size) {
-                    size = Some(new_size);
-                    fn_def = Some(it);
-                }
-            }
-        }
-    }
-
-    let (body, source_map) = db.body_with_source_map(fn_def?.into());
-
-    // Now find the smallest encompassing block expression in the function body.
-    let mut size = None;
-    let mut block_id = None;
-    for (expr_id, expr) in body.exprs.iter() {
-        if let Expr::Block { id, .. } = expr {
-            if let Ok(ast) = source_map.expr_syntax(expr_id) {
-                if ast.file_id != position.file_id.into() {
-                    continue;
-                }
-
-                let root = db.parse_or_expand(ast.file_id).unwrap();
-                let ast = ast.value.to_node(&root);
-                let range = ast.syntax().text_range();
-
-                if !range.contains(position.offset) {
-                    continue;
-                }
-
-                let new_size = match size {
-                    None => range.len(),
-                    Some(size) => {
-                        if range.len() < size {
-                            range.len()
-                        } else {
-                            size
-                        }
-                    }
-                };
-                if size != Some(new_size) {
-                    size = Some(new_size);
-                    block_id = Some(*id);
-                }
-            }
-        }
-    }
-
-    Some(block_id.expect("can't find block containing cursor"))
-}
-
-fn check_at(ra_fixture: &str, expect: Expect) {
-    let def_map = block_def_map_at(ra_fixture);
-    let actual = def_map.dump();
-    expect.assert_eq(&actual);
-}
-
 #[test]
 fn your_stack_belongs_to_me() {
     mark::check!(your_stack_belongs_to_me);
diff --git a/crates/hir_def/src/data.rs b/crates/hir_def/src/data.rs
index c2b0dc007..e7b7724f7 100644
--- a/crates/hir_def/src/data.rs
+++ b/crates/hir_def/src/data.rs
@@ -262,7 +262,7 @@ fn collect_items(
                 let root = db.parse_or_expand(file_id).unwrap();
                 let call = ast_id_map.get(call.ast_id).to_node(&root);
 
-                if let Some((mark, mac)) = expander.enter_expand(db, call).value {
+                if let Some((mark, mac)) = expander.enter_expand(db, None, call).value {
                     let src: InFile<ast::MacroItems> = expander.to_source(mac);
                     let item_tree = db.item_tree(src.file_id);
                     let iter =
diff --git a/crates/hir_def/src/expr.rs b/crates/hir_def/src/expr.rs
index 4d72eaeaf..5be838f4a 100644
--- a/crates/hir_def/src/expr.rs
+++ b/crates/hir_def/src/expr.rs
@@ -20,7 +20,6 @@ use crate::{
     builtin_type::{BuiltinFloat, BuiltinInt},
     path::{GenericArgs, Path},
     type_ref::{Mutability, Rawness, TypeRef},
-    BlockId,
 };
 
 pub type ExprId = Idx<Expr>;
@@ -57,7 +56,6 @@ pub enum Expr {
         else_branch: Option<ExprId>,
     },
     Block {
-        id: BlockId,
         statements: Vec<Statement>,
         tail: Option<ExprId>,
         label: Option<LabelId>,
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 4bde67649..42d9f0947 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -24,7 +24,7 @@ use la_arena::{Arena, Idx, RawIdx};
 use profile::Count;
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
-use syntax::{ast, match_ast, SyntaxKind};
+use syntax::{ast, match_ast};
 use test_utils::mark;
 
 use crate::{
@@ -80,10 +80,6 @@ impl ItemTree {
     pub(crate) fn item_tree_query(db: &dyn DefDatabase, file_id: HirFileId) -> Arc<ItemTree> {
         let _p = profile::span("item_tree_query").detail(|| format!("{:?}", file_id));
         let syntax = if let Some(node) = db.parse_or_expand(file_id) {
-            if node.kind() == SyntaxKind::ERROR {
-                // FIXME: not 100% sure why these crop up, but return an empty tree to avoid a panic
-                return Default::default();
-            }
             node
         } else {
             return Default::default();
diff --git a/crates/hir_def/src/nameres.rs b/crates/hir_def/src/nameres.rs
index 9839761d1..6169b3bbc 100644
--- a/crates/hir_def/src/nameres.rs
+++ b/crates/hir_def/src/nameres.rs
@@ -201,10 +201,8 @@ impl DefMap {
         let block: BlockLoc = db.lookup_intern_block(block_id);
         let parent = block.module.def_map(db);
 
-        let item_tree = db.item_tree(block.ast_id.file_id);
-        if item_tree.inner_items_of_block(block.ast_id.value).is_empty() {
-            return parent.clone();
-        }
+        // FIXME: It would be good to just return the parent map when the block has no items, but
+        // we rely on `def_map.block` in a few places, which is `Some` for the inner `DefMap`.
 
         let block_info =
             BlockInfo { block: block_id, parent, parent_module: block.module.local_id };
diff --git a/crates/hir_def/src/nameres/tests.rs b/crates/hir_def/src/nameres/tests.rs
index 723481c36..b36d0b59b 100644
--- a/crates/hir_def/src/nameres/tests.rs
+++ b/crates/hir_def/src/nameres/tests.rs
@@ -4,14 +4,16 @@ mod macros;
 mod mod_resolution;
 mod diagnostics;
 mod primitives;
+mod block;
 
 use std::sync::Arc;
 
-use base_db::{fixture::WithFixture, SourceDatabase};
+use base_db::{fixture::WithFixture, FilePosition, SourceDatabase};
 use expect_test::{expect, Expect};
+use syntax::AstNode;
 use test_utils::mark;
 
-use crate::{db::DefDatabase, nameres::*, test_db::TestDB};
+use crate::{db::DefDatabase, nameres::*, test_db::TestDB, Lookup};
 
 fn compute_crate_def_map(ra_fixture: &str) -> Arc<DefMap> {
     let db = TestDB::with_files(ra_fixture);
@@ -19,12 +21,74 @@ fn compute_crate_def_map(ra_fixture: &str) -> Arc<DefMap> {
     db.crate_def_map(krate)
 }
 
+fn compute_block_def_map(ra_fixture: &str) -> Arc<DefMap> {
+    let (db, position) = TestDB::with_position(ra_fixture);
+
+    // FIXME: perhaps we should make this use body lowering tests instead?
+
+    let module = db.module_for_file(position.file_id);
+    let mut def_map = db.crate_def_map(module.krate);
+    while let Some(new_def_map) = descend_def_map_at_position(&db, position, def_map.clone()) {
+        def_map = new_def_map;
+    }
+
+    // FIXME: select the right module, not the root
+
+    def_map
+}
+
+fn descend_def_map_at_position(
+    db: &dyn DefDatabase,
+    position: FilePosition,
+    def_map: Arc<DefMap>,
+) -> Option<Arc<DefMap>> {
+    for (local_id, module_data) in def_map.modules() {
+        let mod_def = module_data.origin.definition_source(db);
+        let ast_map = db.ast_id_map(mod_def.file_id);
+        let item_tree = db.item_tree(mod_def.file_id);
+        let root = db.parse_or_expand(mod_def.file_id).unwrap();
+        for item in module_data.scope.declarations() {
+            match item {
+                ModuleDefId::FunctionId(it) => {
+                    // Technically blocks can be inside any type (due to arrays and const generics),
+                    // and also in const/static initializers. For tests we only really care about
+                    // functions though.
+
+                    let ast = ast_map.get(item_tree[it.lookup(db).id.value].ast_id).to_node(&root);
+
+                    if ast.syntax().text_range().contains(position.offset) {
+                        // Cursor inside function, descend into its body's DefMap.
+                        // Note that we don't handle block *expressions* inside function bodies.
+                        let ast_map = db.ast_id_map(position.file_id.into());
+                        let ast_id = ast_map.ast_id(&ast.body().unwrap());
+                        let block = BlockLoc {
+                            ast_id: InFile::new(position.file_id.into(), ast_id),
+                            module: def_map.module_id(local_id),
+                        };
+                        let block_id = db.intern_block(block);
+                        return Some(db.block_def_map(block_id));
+                    }
+                }
+                _ => continue,
+            }
+        }
+    }
+
+    None
+}
+
 fn check(ra_fixture: &str, expect: Expect) {
     let def_map = compute_crate_def_map(ra_fixture);
     let actual = def_map.dump();
     expect.assert_eq(&actual);
 }
 
+fn check_at(ra_fixture: &str, expect: Expect) {
+    let def_map = compute_block_def_map(ra_fixture);
+    let actual = def_map.dump();
+    expect.assert_eq(&actual);
+}
+
 #[test]
 fn crate_def_map_smoke_test() {
     check(
diff --git a/crates/hir_def/src/body/tests/block.rs b/crates/hir_def/src/nameres/tests/block.rs
index 6b1ed2555..6cc659513 100644
--- a/crates/hir_def/src/body/tests/block.rs
+++ b/crates/hir_def/src/nameres/tests/block.rs
@@ -1,5 +1,4 @@
 use super::*;
-use expect_test::expect;
 
 #[test]
 fn inner_item_smoke() {