1 files changed, 10 insertions, 0 deletions
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 1e26f0f9c0d..e2b03ba98ee 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -1541,6 +1541,16 @@ void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
 }
 
 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
+  /// \brief Is this a local declaration (that is, one that will be written to
+  /// our AST file)? This is the case for declarations that are neither imported
+  /// from another AST file nor predefined.
+  auto IsLocalDecl = [&](const Decl *D) -> bool {
+    if (D->isFromASTFile())
+      return false;
+    auto I = DeclIDs.find(D);
+    return (I == DeclIDs.end() || I->second >= NUM_PREDEF_DECL_IDS);
+  };
+
   assert(IsLocalDecl(D) && "expected a local declaration");
 
   const Decl *Canon = D->getCanonicalDecl();