Fix prettify_macro_expansion() when the node isn't the whole file

src/tools/rust-analyzer/crates/hir-expand/src/prettify_macro_expansion_.rs

@@ -15,11 +15,14 @@ pub fn prettify_macro_expansion(
     span_map: &ExpansionSpanMap,
     target_crate_id: CrateId,
 ) -> SyntaxNode {
+    // Because `syntax_bridge::prettify_macro_expansion::prettify_macro_expansion()` clones subtree for `syn`,
+    // that means it will be offsetted to the beginning.
+    let span_offset = syn.text_range().start();
     let crate_graph = db.crate_graph();
     let target_crate = &crate_graph[target_crate_id];
     let mut syntax_ctx_id_to_dollar_crate_replacement = FxHashMap::default();
     syntax_bridge::prettify_macro_expansion::prettify_macro_expansion(syn, &mut |dollar_crate| {
-        let ctx = span_map.span_at(dollar_crate.text_range().start()).ctx;
+        let ctx = span_map.span_at(dollar_crate.text_range().start() + span_offset).ctx;
         let replacement =
             syntax_ctx_id_to_dollar_crate_replacement.entry(ctx).or_insert_with(|| {
                 let ctx_data = db.lookup_intern_syntax_context(ctx);

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

@@ -8988,3 +8988,33 @@ mod m {
         "#]],
     );
 }
+
+#[test]
+fn regression_18238() {
+    check(
+        r#"
+macro_rules! foo {
+    ($name:ident) => {
+        pub static $name = Foo::new(|| {
+            $crate;
+        });
+    };
+}
+
+foo!(BAR_$0);
+"#,
+        expect![[r#"
+        *BAR_*
+
+        ```rust
+        test
+        ```
+
+        ```rust
+        pub static BAR_: {error} = Foo::new(||{
+            crate;
+        })
+        ```
+        "#]],
+    );
+}