Slightly shrink DefMap

Author: Veykril

crates/hir-def/src/body/lower.rs

@@ -1073,7 +1073,7 @@ impl ExprCollector<'_> {
             match block_id.map(|block_id| (self.db.block_def_map(block_id), block_id)) {
                 Some((def_map, block_id)) => {
                     self.body.block_scopes.push(block_id);
-                    (def_map.module_id(def_map.root()), def_map)
+                    (def_map.module_id(DefMap::ROOT), def_map)
                 }
                 None => (self.expander.module, self.def_map.clone()),
             };

crates/hir-def/src/child_by_source.rs

@@ -12,6 +12,7 @@ use crate::{
     db::DefDatabase,
     dyn_map::{keys, DynMap},
     item_scope::ItemScope,
+    nameres::DefMap,
     src::{HasChildSource, HasSource},
     AdtId, AssocItemId, DefWithBodyId, EnumId, EnumVariantId, FieldId, ImplId, Lookup, MacroId,
     ModuleDefId, ModuleId, TraitId, VariantId,
@@ -205,7 +206,7 @@ impl ChildBySource for DefWithBodyId {
         for (_, def_map) in body.blocks(db) {
             // All block expressions are merged into the same map, because they logically all add
             // inner items to the containing `DefWithBodyId`.
-            def_map[def_map.root()].scope.child_by_source_to(db, res, file_id);
+            def_map[DefMap::ROOT].scope.child_by_source_to(db, res, file_id);
         }
     }
 }

crates/hir-def/src/db.rs

@@ -198,15 +198,14 @@ pub trait DefDatabase: InternDatabase + ExpandDatabase + Upcast<dyn ExpandDataba
 
     // endregion:attrs
 
-    #[salsa::invoke(LangItems::crate_lang_items_query)]
-    fn crate_lang_items(&self, krate: CrateId) -> Arc<LangItems>;
-
     #[salsa::invoke(LangItems::lang_item_query)]
     fn lang_item(&self, start_crate: CrateId, item: LangItem) -> Option<LangItemTarget>;
 
     #[salsa::invoke(ImportMap::import_map_query)]
     fn import_map(&self, krate: CrateId) -> Arc<ImportMap>;
 
+    // region:visibilities
+
     #[salsa::invoke(visibility::field_visibilities_query)]
     fn field_visibilities(&self, var: VariantId) -> Arc<ArenaMap<LocalFieldId, Visibility>>;
 
@@ -217,8 +216,14 @@ pub trait DefDatabase: InternDatabase + ExpandDatabase + Upcast<dyn ExpandDataba
     #[salsa::invoke(visibility::const_visibility_query)]
     fn const_visibility(&self, def: ConstId) -> Visibility;
 
+    // endregion:visibilities
+
+    #[salsa::invoke(LangItems::crate_lang_items_query)]
+    fn crate_lang_items(&self, krate: CrateId) -> Arc<LangItems>;
+
     #[salsa::transparent]
     fn crate_limits(&self, crate_id: CrateId) -> CrateLimits;
+
     #[salsa::transparent]
     fn recursion_limit(&self, crate_id: CrateId) -> u32;
 

crates/hir-def/src/import_map.rs

@@ -11,8 +11,8 @@ use rustc_hash::{FxHashSet, FxHasher};
 use triomphe::Arc;
 
 use crate::{
-    db::DefDatabase, item_scope::ItemInNs, visibility::Visibility, AssocItemId, ModuleDefId,
-    ModuleId, TraitId,
+    db::DefDatabase, item_scope::ItemInNs, nameres::DefMap, visibility::Visibility, AssocItemId,
+    ModuleDefId, ModuleId, TraitId,
 };
 
 type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<FxHasher>>;
@@ -183,7 +183,7 @@ fn collect_import_map(db: &dyn DefDatabase, krate: CrateId) -> ImportMap {
 
     // We look only into modules that are public(ly reexported), starting with the crate root.
     let empty = ImportPath { segments: vec![] };
-    let root = def_map.module_id(def_map.root());
+    let root = def_map.module_id(DefMap::ROOT);
     let mut worklist = vec![(root, empty)];
     while let Some((module, mod_path)) = worklist.pop() {
         let ext_def_map;

crates/hir-def/src/macro_expansion_tests/mod.rs

@@ -35,7 +35,7 @@ use tt::token_id::{Subtree, TokenId};
 use crate::{
     db::DefDatabase,
     macro_id_to_def_id,
-    nameres::{MacroSubNs, ModuleSource},
+    nameres::{DefMap, MacroSubNs, ModuleSource},
     resolver::HasResolver,
     src::HasSource,
     test_db::TestDB,
@@ -61,7 +61,7 @@ pub fn identity_when_valid(_attr: TokenStream, item: TokenStream) -> TokenStream
     let db = TestDB::with_files_extra_proc_macros(ra_fixture, extra_proc_macros);
     let krate = db.crate_graph().iter().next().unwrap();
     let def_map = db.crate_def_map(krate);
-    let local_id = def_map.root();
+    let local_id = DefMap::ROOT;
     let module = def_map.module_id(local_id);
     let resolver = module.resolver(&db);
     let source = def_map[local_id].definition_source(&db);

crates/hir-def/src/nameres.rs

@@ -94,7 +94,6 @@ use crate::{
 pub struct DefMap {
     _c: Count<Self>,
     block: Option<BlockInfo>,
-    root: LocalModuleId,
     modules: Arena<ModuleData>,
     krate: CrateId,
     /// The prelude module for this crate. This either comes from an import
@@ -141,7 +140,19 @@ struct BlockInfo {
     /// The `BlockId` this `DefMap` was created from.
     block: BlockId,
     /// The containing module.
-    parent: ModuleId,
+    parent: BlockRelativeModuleId,
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+struct BlockRelativeModuleId {
+    block: Option<BlockId>,
+    local_id: LocalModuleId,
+}
+
+impl BlockRelativeModuleId {
+    fn def_map(self, db: &dyn DefDatabase, krate: CrateId) -> Arc<DefMap> {
+        ModuleId { krate, block: self.block, local_id: self.local_id }.def_map(db)
+    }
 }
 
 impl std::ops::Index<LocalModuleId> for DefMap {
@@ -231,6 +242,8 @@ pub struct ModuleData {
 }
 
 impl DefMap {
+    pub const ROOT: LocalModuleId = LocalModuleId::from_raw(la_arena::RawIdx::from_u32(0));
+
     pub(crate) fn crate_def_map_query(db: &dyn DefDatabase, krate: CrateId) -> Arc<DefMap> {
         let _p = profile::span("crate_def_map_query").detail(|| {
             db.crate_graph()[krate].display_name.as_deref().unwrap_or_default().to_string()
@@ -266,7 +279,13 @@ impl DefMap {
             ModuleData::new(ModuleOrigin::BlockExpr { block: block.ast_id }, visibility);
 
         let mut def_map = DefMap::empty(krate, parent_map.edition, module_data);
-        def_map.block = Some(BlockInfo { block: block_id, parent: block.module });
+        def_map.block = Some(BlockInfo {
+            block: block_id,
+            parent: BlockRelativeModuleId {
+                block: block.module.block,
+                local_id: block.module.local_id,
+            },
+        });
 
         let def_map = collector::collect_defs(db, def_map, tree_id);
         Arc::new(def_map)
@@ -275,6 +294,7 @@ impl DefMap {
     fn empty(krate: CrateId, edition: Edition, module_data: ModuleData) -> DefMap {
         let mut modules: Arena<ModuleData> = Arena::default();
         let root = modules.alloc(module_data);
+        assert_eq!(root, Self::ROOT);
 
         DefMap {
             _c: Count::new(),
@@ -289,7 +309,6 @@ impl DefMap {
             proc_macro_loading_error: None,
             derive_helpers_in_scope: FxHashMap::default(),
             prelude: None,
-            root,
             modules,
             registered_attrs: Vec::new(),
             registered_tools: Vec::new(),
@@ -339,10 +358,6 @@ impl DefMap {
         self.no_std || self.no_core
     }
 
-    pub fn root(&self) -> LocalModuleId {
-        self.root
-    }
-
     pub fn fn_as_proc_macro(&self, id: FunctionId) -> Option<ProcMacroId> {
         self.fn_proc_macro_mapping.get(&id).copied()
     }
@@ -377,9 +392,9 @@ impl DefMap {
     }
 
     pub(crate) fn crate_root(&self, db: &dyn DefDatabase) -> ModuleId {
-        self.with_ancestor_maps(db, self.root, &mut |def_map, _module| {
+        self.with_ancestor_maps(db, Self::ROOT, &mut |def_map, _module| {
             if def_map.block.is_none() {
-                Some(def_map.module_id(def_map.root))
+                Some(def_map.module_id(Self::ROOT))
             } else {
                 None
             }
@@ -439,7 +454,7 @@ impl DefMap {
         }
         let mut block = self.block;
         while let Some(block_info) = block {
-            let parent = block_info.parent.def_map(db);
+            let parent = block_info.parent.def_map(db, self.krate);
             if let Some(it) = f(&parent, block_info.parent.local_id) {
                 return Some(it);
             }
@@ -452,15 +467,22 @@ impl DefMap {
     /// If this `DefMap` is for a block expression, returns the module containing the block (which
     /// might again be a block, or a module inside a block).
     pub fn parent(&self) -> Option<ModuleId> {
-        Some(self.block?.parent)
+        let BlockRelativeModuleId { block, local_id } = self.block?.parent;
+        Some(ModuleId { krate: self.krate, block, local_id })
     }
 
     /// Returns the module containing `local_mod`, either the parent `mod`, or the module (or block) containing
     /// the block, if `self` corresponds to a block expression.
     pub fn containing_module(&self, local_mod: LocalModuleId) -> Option<ModuleId> {
         match self[local_mod].parent {
             Some(parent) => Some(self.module_id(parent)),
-            None => self.block.map(|block| block.parent),
+            None => {
+                self.block.map(
+                    |BlockInfo { parent: BlockRelativeModuleId { block, local_id }, .. }| {
+                        ModuleId { krate: self.krate, block, local_id }
+                    },
+                )
+            }
         }
     }
 
@@ -471,12 +493,12 @@ impl DefMap {
         let mut arc;
         let mut current_map = self;
         while let Some(block) = current_map.block {
-            go(&mut buf, db, current_map, "block scope", current_map.root);
+            go(&mut buf, db, current_map, "block scope", Self::ROOT);
             buf.push('\n');
-            arc = block.parent.def_map(db);
+            arc = block.parent.def_map(db, self.krate);
             current_map = &arc;
         }
-        go(&mut buf, db, current_map, "crate", current_map.root);
+        go(&mut buf, db, current_map, "crate", Self::ROOT);
         return buf;
 
         fn go(
@@ -506,7 +528,7 @@ impl DefMap {
         let mut current_map = self;
         while let Some(block) = current_map.block {
             format_to!(buf, "{:?} in {:?}\n", block.block, block.parent);
-            arc = block.parent.def_map(db);
+            arc = block.parent.def_map(db, self.krate);
             current_map = &arc;
         }
 
@@ -534,7 +556,6 @@ impl DefMap {
             recursion_limit: _,
             krate: _,
             prelude: _,
-            root: _,
             rustc_coherence_is_core: _,
             no_core: _,
             no_std: _,

crates/hir-def/src/nameres/collector.rs

@@ -71,7 +71,7 @@ pub(super) fn collect_defs(db: &dyn DefDatabase, mut def_map: DefMap, tree_id: T
     for dep in &krate.dependencies {
         tracing::debug!("crate dep {:?} -> {:?}", dep.name, dep.crate_id);
         let dep_def_map = db.crate_def_map(dep.crate_id);
-        let dep_root = dep_def_map.module_id(dep_def_map.root);
+        let dep_root = dep_def_map.module_id(DefMap::ROOT);
 
         deps.insert(dep.as_name(), dep_root);
 
@@ -287,7 +287,7 @@ impl DefCollector<'_> {
 
         let file_id = self.db.crate_graph()[self.def_map.krate].root_file_id;
         let item_tree = self.db.file_item_tree(file_id.into());
-        let module_id = self.def_map.root;
+        let module_id = DefMap::ROOT;
 
         let attrs = item_tree.top_level_attrs(self.db, self.def_map.krate);
 
@@ -382,7 +382,7 @@ impl DefCollector<'_> {
 
     fn seed_with_inner(&mut self, tree_id: TreeId) {
         let item_tree = tree_id.item_tree(self.db);
-        let module_id = self.def_map.root;
+        let module_id = DefMap::ROOT;
 
         let is_cfg_enabled = item_tree
             .top_level_attrs(self.db, self.def_map.krate)
@@ -464,7 +464,7 @@ impl DefCollector<'_> {
             // Additionally, while the proc macro entry points must be `pub`, they are not publicly
             // exported in type/value namespace. This function reduces the visibility of all items
             // in the crate root that aren't proc macros.
-            let root = self.def_map.root;
+            let root = DefMap::ROOT;
             let module_id = self.def_map.module_id(root);
             let root = &mut self.def_map.modules[root];
             root.scope.censor_non_proc_macros(module_id);
@@ -560,13 +560,8 @@ impl DefCollector<'_> {
         };
         let path = ModPath::from_segments(path_kind, [krate, name![prelude], edition]);
 
-        let (per_ns, _) = self.def_map.resolve_path(
-            self.db,
-            self.def_map.root,
-            &path,
-            BuiltinShadowMode::Other,
-            None,
-        );
+        let (per_ns, _) =
+            self.def_map.resolve_path(self.db, DefMap::ROOT, &path, BuiltinShadowMode::Other, None);
 
         match per_ns.types {
             Some((ModuleDefId::ModuleId(m), _)) => {
@@ -661,7 +656,7 @@ impl DefCollector<'_> {
         // In Rust, `#[macro_export]` macros are unconditionally visible at the
         // crate root, even if the parent modules is **not** visible.
         if export {
-            let module_id = self.def_map.root;
+            let module_id = DefMap::ROOT;
             self.def_map.modules[module_id].scope.declare(macro_.into());
             self.update(
                 module_id,
@@ -712,7 +707,7 @@ impl DefCollector<'_> {
     /// A proc macro is similar to normal macro scope, but it would not visible in legacy textual scoped.
     /// And unconditionally exported.
     fn define_proc_macro(&mut self, name: Name, macro_: ProcMacroId) {
-        let module_id = self.def_map.root;
+        let module_id = DefMap::ROOT;
         self.def_map.modules[module_id].scope.declare(macro_.into());
         self.update(
             module_id,
@@ -732,7 +727,7 @@ impl DefCollector<'_> {
         let def_map = self.db.crate_def_map(krate);
         // `#[macro_use]` brings macros into macro_use prelude. Yes, even non-`macro_rules!`
         // macros.
-        let root_scope = &def_map[def_map.root].scope;
+        let root_scope = &def_map[DefMap::ROOT].scope;
         if let Some(names) = names {
             for name in names {
                 // FIXME: Report diagnostic on 404.
@@ -834,9 +829,9 @@ impl DefCollector<'_> {
             let root = match self.def_map.block {
                 Some(_) => {
                     let def_map = self.def_map.crate_root(self.db).def_map(self.db);
-                    def_map.module_id(def_map.root())
+                    def_map.module_id(DefMap::ROOT)
                 }
-                None => self.def_map.module_id(self.def_map.root()),
+                None => self.def_map.module_id(DefMap::ROOT),
             };
             Some(root)
         } else {
@@ -879,7 +874,7 @@ impl DefCollector<'_> {
                 // extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658
                 if import.is_extern_crate
                     && self.def_map.block.is_none()
-                    && module_id == self.def_map.root
+                    && module_id == DefMap::ROOT
                 {
                     if let (Some(ModuleDefId::ModuleId(def)), Some(name)) = (def.take_types(), name)
                     {
@@ -1525,7 +1520,7 @@ impl ModCollector<'_, '_> {
 
     fn collect(&mut self, items: &[ModItem], container: ItemContainerId) {
         let krate = self.def_collector.def_map.krate;
-        let is_crate_root = self.module_id == self.def_collector.def_map.root;
+        let is_crate_root = self.module_id == DefMap::ROOT;
 
         // Note: don't assert that inserted value is fresh: it's simply not true
         // for macros.
@@ -1641,9 +1636,9 @@ impl ModCollector<'_, '_> {
                         FunctionLoc { container, id: ItemTreeId::new(self.tree_id, id) }.intern(db);
 
                     let vis = resolve_vis(def_map, &self.item_tree[it.visibility]);
-                    if self.def_collector.is_proc_macro && self.module_id == def_map.root {
+                    if self.def_collector.is_proc_macro && self.module_id == DefMap::ROOT {
                         if let Some(proc_macro) = attrs.parse_proc_macro_decl(&it.name) {
-                            let crate_root = def_map.module_id(def_map.root);
+                            let crate_root = def_map.module_id(DefMap::ROOT);
                             self.def_collector.export_proc_macro(
                                 proc_macro,
                                 ItemTreeId::new(self.tree_id, id),