Auto merge of rust-lang#18206 - ShoyuVanilla:issue-18187, r=Veykril

Fix: Handle block exprs as modules when finding their parents

Fixes rust-lang#18187

Author: bors

src/tools/rust-analyzer/crates/hir/src/lib.rs

@@ -497,10 +497,9 @@ impl Module {
 
     /// Finds a parent module.
     pub fn parent(self, db: &dyn HirDatabase) -> Option<Module> {
-        // FIXME: handle block expressions as modules (their parent is in a different DefMap)
         let def_map = self.id.def_map(db.upcast());
-        let parent_id = def_map[self.id.local_id].parent?;
-        Some(Module { id: def_map.module_id(parent_id) })
+        let parent_id = def_map.containing_module(self.id.local_id)?;
+        Some(Module { id: parent_id })
     }
 
     /// Finds nearest non-block ancestor `Module` (`self` included).

src/tools/rust-analyzer/crates/ide-completion/src/context.rs

@@ -7,7 +7,8 @@ mod tests;
 use std::{iter, ops::ControlFlow};
 
 use hir::{
-    HasAttrs, Local, Name, PathResolution, ScopeDef, Semantics, SemanticsScope, Type, TypeInfo,
+    HasAttrs, Local, ModuleSource, Name, PathResolution, ScopeDef, Semantics, SemanticsScope, Type,
+    TypeInfo,
 };
 use ide_db::{
     base_db::SourceDatabase, famous_defs::FamousDefs, helpers::is_editable_crate, FilePosition,
@@ -743,7 +744,12 @@ impl<'a> CompletionContext<'a> {
             }
         });
 
-        let depth_from_crate_root = iter::successors(module.parent(db), |m| m.parent(db)).count();
+        let depth_from_crate_root = iter::successors(Some(module), |m| m.parent(db))
+            // `BlockExpr` modules are not count as module depth
+            .filter(|m| !matches!(m.definition_source(db).value, ModuleSource::BlockExpr(_)))
+            .count()
+            // exclude `m` itself
+            .saturating_sub(1);
 
         let complete_semicolon = if config.add_semicolon_to_unit {
             let inside_closure_ret = token.parent_ancestors().try_for_each(|ancestor| {

src/tools/rust-analyzer/crates/ide/src/hover/render.rs

@@ -3,7 +3,7 @@ use std::{mem, ops::Not};
 
 use either::Either;
 use hir::{
-    db::ExpandDatabase, Adt, AsAssocItem, AsExternAssocItem, CaptureKind,
+    db::ExpandDatabase, Adt, AsAssocItem, AsExternAssocItem, AssocItemContainer, CaptureKind,
     DynCompatibilityViolation, HasCrate, HasSource, HirDisplay, Layout, LayoutError,
     MethodViolationCode, Name, Semantics, Trait, Type, TypeInfo,
 };
@@ -813,7 +813,15 @@ fn definition_mod_path(db: &RootDatabase, def: &Definition, edition: Edition) ->
     if matches!(def, Definition::GenericParam(_) | Definition::Local(_) | Definition::Label(_)) {
         return None;
     }
-    def.module(db).map(|module| path(db, module, definition_owner_name(db, def, edition), edition))
+    let container: Option<Definition> =
+        def.as_assoc_item(db).and_then(|assoc| match assoc.container(db) {
+            AssocItemContainer::Trait(trait_) => Some(trait_.into()),
+            AssocItemContainer::Impl(impl_) => impl_.self_ty(db).as_adt().map(|adt| adt.into()),
+        });
+    container
+        .unwrap_or(*def)
+        .module(db)
+        .map(|module| path(db, module, definition_owner_name(db, def, edition), edition))
 }
 
 fn markup(docs: Option<String>, desc: String, mod_path: Option<String>) -> Markup {

src/tools/rust-analyzer/crates/ide/src/hover/tests.rs

@@ -8962,3 +8962,29 @@ fn test_hover_function_with_pat_param() {
         "#]],
     );
 }
+
+#[test]
+fn hover_path_inside_block_scope() {
+    check(
+        r#"
+mod m {
+    const _: () = {
+        mod m2 {
+            const C$0: () = ();
+        }
+    };
+}
+"#,
+        expect![[r#"
+            *C*
+
+            ```rust
+            test::m::m2
+            ```
+
+            ```rust
+            const C: () = ()
+            ```
+        "#]],
+    );
+}