commit d4678de68ab00e3b4b7e9236d0d2057353e768b8
author Marcel Hlopko <hlopko@google.com> Wed May 25 01:38:13 2022 -0700
committer Copybara-Service <copybara-worker@google.com> Wed May 25 01:38:37 2022 -0700
tree 97e2a85858d309c1eb33bcf520d59e182a32ca91
parent c21d92fb35d1f68d22a3644959a26db906410141

Import decls in LinkageSpecDecl

We don't need an explicit Item for this decl, so in this CL we're changing
importer.cc to iterate decls inside LinkageSpecDecl right away.

PiperOrigin-RevId: 450869812

rs_bindings_from_cc/BUILD

diff --git a/rs_bindings_from_cc/BUILD b/rs_bindings_from_cc/BUILD
index 2c373f0..0e1be69 100644
--- a/rs_bindings_from_cc/BUILD
+++ b/rs_bindings_from_cc/BUILD
@@ -335,6 +335,7 @@
         "//common:rust_allocator_shims",
         "@crate_index//:anyhow",
         "@crate_index//:itertools",
+        "@crate_index//:proc-macro2",
         "@crate_index//:quote",
     ],
 )

rs_bindings_from_cc/importer.cc

diff --git a/rs_bindings_from_cc/importer.cc b/rs_bindings_from_cc/importer.cc
index 4fdd514..b785291 100644
--- a/rs_bindings_from_cc/importer.cc
+++ b/rs_bindings_from_cc/importer.cc
@@ -298,10 +298,21 @@
   }
 
   absl::flat_hash_set<ItemId> visited_item_ids;
-  for (auto child : decl_context->decls()) {
+  std::vector<clang::Decl*> decls_to_visit;
+  llvm::copy(decl_context->decls(), std::back_inserter(decls_to_visit));
+
+  while (!decls_to_visit.empty()) {
+    clang::Decl* child = decls_to_visit.back();
+    decls_to_visit.pop_back();
     auto decl = child->getCanonicalDecl();
     if (!IsFromCurrentTarget(decl)) continue;
 
+    if (const auto* linkage_spec_decl =
+            llvm::dyn_cast<clang::LinkageSpecDecl>(decl)) {
+      absl::c_copy(linkage_spec_decl->decls(),
+                   std::back_inserter(decls_to_visit));
+    }
+
     // We remove comments attached to a child decl or that are within a child
     // decl.
     if (auto raw_comment = ctx_.getRawCommentForDeclNoCache(decl)) {
@@ -413,9 +424,14 @@
 void Importer::ImportDeclsFromDeclContext(
     const clang::DeclContext* decl_context) {
   for (auto decl : decl_context->decls()) {
-    // TODO(rosica): We don't always want the canonical decl here (especially
-    // not in namespaces).
-    GetDeclItem(decl->getCanonicalDecl());
+    if (const auto* linkage_spec_decl =
+            llvm::dyn_cast<clang::LinkageSpecDecl>(decl)) {
+      ImportDeclsFromDeclContext(linkage_spec_decl);
+    } else {
+      // TODO(rosica): We don't always want the canonical decl here (especially
+      // not in namespaces).
+      GetDeclItem(decl->getCanonicalDecl());
+    }
   }
 }
 

rs_bindings_from_cc/ir_from_cc_test.rs

diff --git a/rs_bindings_from_cc/ir_from_cc_test.rs b/rs_bindings_from_cc/ir_from_cc_test.rs
index 375e2f5..46eafca 100644
--- a/rs_bindings_from_cc/ir_from_cc_test.rs
+++ b/rs_bindings_from_cc/ir_from_cc_test.rs
@@ -2856,3 +2856,44 @@
     // assert_eq!(namespaces[0].canonical_namespace_id,
     // namespaces[1].canonical_namespace_id);
 }
+
+#[test]
+fn test_items_inside_linkage_spec_decl_are_imported() {
+    let ir = ir_from_cc(
+        r#"
+          extern "C" {
+            struct MyStruct {};
+          }
+      "#,
+    )
+    .unwrap();
+    assert_ir_matches!(ir, quote! { Record { ... cc_name: "MyStruct" ... } })
+}
+
+#[test]
+fn test_items_inside_linkage_spec_decl_are_considered_toplevel() {
+    // The test below assumes the first top_level_item_ids element is the one added
+    // by the the source code under test. Let's double check that assumption here.
+    assert!(ir_from_cc("").unwrap().top_level_item_ids().next().is_none());
+
+    let ir = ir_from_cc(
+        r#"
+    extern "C" {
+      struct MyStruct {};
+    }"#,
+    )
+    .unwrap();
+    let item_id = proc_macro2::Literal::usize_unsuffixed(ir.top_level_item_ids().next().unwrap().0);
+
+    assert_ir_matches!(
+        ir,
+        quote! {
+          ...
+          Record {
+            ... cc_name: "MyStruct" ...
+            ... id: ItemId(#item_id) ...
+          }
+          ...
+        }
+    );
+}