1 files changed, 19 insertions, 0 deletions
diff --git a/compiler/rustc_metadata/src/foreign_modules.rs b/compiler/rustc_metadata/src/foreign_modules.rs
new file mode 100644
index 000000000..2ca4cd17f
--- /dev/null
+++ b/compiler/rustc_metadata/src/foreign_modules.rs
@@ -0,0 +1,19 @@
+use rustc_hir as hir;
+use rustc_hir::def::DefKind;
+use rustc_middle::ty::TyCtxt;
+use rustc_session::cstore::ForeignModule;
+
+pub(crate) fn collect(tcx: TyCtxt<'_>) -> Vec<ForeignModule> {
+    let mut modules = Vec::new();
+    for id in tcx.hir().items() {
+        if !matches!(tcx.def_kind(id.def_id), DefKind::ForeignMod) {
+            continue;
+        }
+        let item = tcx.hir().item(id);
+        if let hir::ItemKind::ForeignMod { items, .. } = item.kind {
+            let foreign_items = items.iter().map(|it| it.id.def_id.to_def_id()).collect();
+            modules.push(ForeignModule { foreign_items, def_id: id.def_id.to_def_id() });
+        }
+    }
+    modules
+}