Merge #8910

8910: Don't lower extern block in the ItemTree r=jonas-schievink a=jonas-schievink

The ItemTree lowering code used to attach attributes on an `extern {}` block to all the children. This is wrong and causes problems with attribute resolution that manifested as a hang.

This PR treats extern blocks as first-class items in the ItemTree and lowers its contents in the `ModCollector` instead.

Fixes https://github.com/rust-analyzer/rust-analyzer/issues/8414#issuecomment-845607923
Fixes https://github.com/rust-analyzer/rust-analyzer/issues/8905
Fixes https://github.com/rust-analyzer/rust-analyzer/issues/8909

bors r+

Co-authored-by: Jonas Schievink <[email protected]>

1 files changed, 36 insertions, 0 deletions

diff --git a/crates/hir_def/src/nameres/tests/macros.rs b/crates/hir_def/src/nameres/tests/macros.rs
index 04de107f5..133b2d818 100644
--- a/crates/hir_def/src/nameres/tests/macros.rs
+++ b/crates/hir_def/src/nameres/tests/macros.rs
@@ -736,6 +736,42 @@ fn unresolved_attributes_fall_back_track_per_file_moditems() {
 }
 
 #[test]
+fn unresolved_attrs_extern_block_hang() {
+    check(
+        r#"
+#[unresolved]
+extern "C" {
+    #[unresolved]
+    fn f();
+}
+    "#,
+        expect![[r#"
+        crate
+        f: v
+    "#]],
+    );
+}
+
+#[test]
+fn macros_in_extern_block() {
+    check(
+        r#"
+macro_rules! m {
+    () => { static S: u8; };
+}
+
+extern {
+    m!();
+}
+    "#,
+        expect![[r#"
+            crate
+            S: v
+        "#]],
+    );
+}
+
+#[test]
 fn resolves_derive_helper() {
     cov_mark::check!(resolved_derive_helper);
     check(