Remove file id from item tree

It's not needed, and `source` is only used by tests anyways

crates/ra_hir_def/src/item_tree.rs

@@ -67,7 +67,6 @@ enum AttrOwner {
 /// The item tree of a source file.
 #[derive(Debug, Eq, PartialEq)]
 pub struct ItemTree {
-    file_id: HirFileId,
     top_level: SmallVec<[ModItem; 1]>,
     attrs: FxHashMap<AttrOwner, Attrs>,
     inner_items: FxHashMap<FileAstId<ast::ModuleItem>, SmallVec<[ModItem; 1]>>,
@@ -81,7 +80,7 @@ impl ItemTree {
         let syntax = if let Some(node) = db.parse_or_expand(file_id) {
             node
         } else {
-            return Arc::new(Self::empty(file_id));
+            return Arc::new(Self::empty());
         };
 
         let hygiene = Hygiene::new(db.upcast(), file_id);
@@ -113,9 +112,8 @@ impl ItemTree {
         Arc::new(item_tree)
     }
 
-    fn empty(file_id: HirFileId) -> Self {
+    fn empty() -> Self {
         Self {
-            file_id,
             top_level: Default::default(),
             attrs: Default::default(),
             inner_items: Default::default(),
@@ -150,19 +148,14 @@ impl ItemTree {
         self.inner_items.values().flatten().copied()
     }
 
-    pub fn source<S: ItemTreeNode>(
+    pub fn source<S: ItemTreeNode>(&self, db: &dyn DefDatabase, of: ItemTreeId<S>) -> S::Source {
-        &self,
-        db: &dyn DefDatabase,
-        of: FileItemTreeId<S>,
-    ) -> S::Source {
         // This unwrap cannot fail, since it has either succeeded above, or resulted in an empty
         // ItemTree (in which case there is no valid `FileItemTreeId` to call this method with).
-        let root = db
+        let root =
-            .parse_or_expand(self.file_id)
+            db.parse_or_expand(of.file_id).expect("parse_or_expand failed on constructed ItemTree");
-            .expect("parse_or_expand failed on constructed ItemTree");
 
-        let id = self[of].ast_id();
+        let id = self[of.value].ast_id();
-        let map = db.ast_id_map(self.file_id);
+        let map = db.ast_id_map(of.file_id);
         let ptr = map.get(id);
         ptr.to_node(&root)
     }

crates/ra_hir_def/src/item_tree/lower.rs

@@ -42,7 +42,7 @@ pub(super) struct Ctx {
 impl Ctx {
     pub(super) fn new(db: &dyn DefDatabase, hygiene: Hygiene, file: HirFileId) -> Self {
         Self {
-            tree: ItemTree::empty(file),
+            tree: ItemTree::empty(),
             hygiene,
             file,
             source_ast_id_map: db.ast_id_map(file),

crates/ra_hir_def/src/item_tree/tests.rs

@@ -1,6 +1,6 @@
 use super::{ItemTree, ModItem, ModKind};
 use crate::{db::DefDatabase, test_db::TestDB};
-use hir_expand::db::AstDatabase;
+use hir_expand::{db::AstDatabase, HirFileId, InFile};
 use insta::assert_snapshot;
 use ra_db::fixture::WithFixture;
 use ra_syntax::{ast, AstNode};
@@ -10,37 +10,38 @@ use stdx::format_to;
 
 fn test_inner_items(ra_fixture: &str) {
     let (db, file_id) = TestDB::with_single_file(ra_fixture);
-    let tree = db.item_tree(file_id.into());
+    let file_id = HirFileId::from(file_id);
-    let root = db.parse_or_expand(file_id.into()).unwrap();
+    let tree = db.item_tree(file_id);
-    let ast_id_map = db.ast_id_map(file_id.into());
+    let root = db.parse_or_expand(file_id).unwrap();
+    let ast_id_map = db.ast_id_map(file_id);
 
     // Traverse the item tree and collect all module/impl/trait-level items as AST nodes.
     let mut outer_items = FxHashSet::default();
     let mut worklist = tree.top_level_items().to_vec();
     while let Some(item) = worklist.pop() {
         let node: ast::ModuleItem = match item {
-            ModItem::Import(it) => tree.source(&db, it).into(),
+            ModItem::Import(it) => tree.source(&db, InFile::new(file_id, it)).into(),
-            ModItem::ExternCrate(it) => tree.source(&db, it).into(),
+            ModItem::ExternCrate(it) => tree.source(&db, InFile::new(file_id, it)).into(),
-            ModItem::Function(it) => tree.source(&db, it).into(),
+            ModItem::Function(it) => tree.source(&db, InFile::new(file_id, it)).into(),
-            ModItem::Struct(it) => tree.source(&db, it).into(),
+            ModItem::Struct(it) => tree.source(&db, InFile::new(file_id, it)).into(),
-            ModItem::Union(it) => tree.source(&db, it).into(),
+            ModItem::Union(it) => tree.source(&db, InFile::new(file_id, it)).into(),
-            ModItem::Enum(it) => tree.source(&db, it).into(),
+            ModItem::Enum(it) => tree.source(&db, InFile::new(file_id, it)).into(),
-            ModItem::Const(it) => tree.source(&db, it).into(),
+            ModItem::Const(it) => tree.source(&db, InFile::new(file_id, it)).into(),
-            ModItem::Static(it) => tree.source(&db, it).into(),
+            ModItem::Static(it) => tree.source(&db, InFile::new(file_id, it)).into(),
-            ModItem::TypeAlias(it) => tree.source(&db, it).into(),
+            ModItem::TypeAlias(it) => tree.source(&db, InFile::new(file_id, it)).into(),
             ModItem::Mod(it) => {
                 if let ModKind::Inline { items } = &tree[it].kind {
                     worklist.extend(items);
                 }
-                tree.source(&db, it).into()
+                tree.source(&db, InFile::new(file_id, it)).into()
             }
             ModItem::Trait(it) => {
                 worklist.extend(tree[it].items.iter().map(|item| ModItem::from(*item)));
-                tree.source(&db, it).into()
+                tree.source(&db, InFile::new(file_id, it)).into()
             }
             ModItem::Impl(it) => {
                 worklist.extend(tree[it].items.iter().map(|item| ModItem::from(*item)));
-                tree.source(&db, it).into()
+                tree.source(&db, InFile::new(file_id, it)).into()
             }
             ModItem::MacroCall(_) => continue,
         };

crates/ra_hir_ty/src/tests.rs

@@ -166,17 +166,17 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
         DefWithBodyId::FunctionId(it) => {
             let loc = it.lookup(&db);
             let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id.value).syntax().text_range().start()
+            tree.source(&db, loc.id).syntax().text_range().start()
         }
         DefWithBodyId::ConstId(it) => {
             let loc = it.lookup(&db);
             let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id.value).syntax().text_range().start()
+            tree.source(&db, loc.id).syntax().text_range().start()
         }
         DefWithBodyId::StaticId(it) => {
             let loc = it.lookup(&db);
             let tree = db.item_tree(loc.id.file_id);
-            tree.source(&db, loc.id.value).syntax().text_range().start()
+            tree.source(&db, loc.id).syntax().text_range().start()
         }
     });
     for def in defs {