1 files changed, 15 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Serialization/ASTReaderDecl.cpp b/contrib/llvm/tools/clang/lib/Serialization/ASTReaderDecl.cpp
index 8fb110e..5bf95f8 100644
--- a/contrib/llvm/tools/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/contrib/llvm/tools/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -3626,6 +3626,21 @@ void ASTDeclReader::UpdateDecl(Decl *D, ModuleFile &ModuleFile,
           Reader.ReadSourceLocation(ModuleFile, Record, Idx));
       break;
 
+    case UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT: {
+      auto Param = cast<ParmVarDecl>(D);
+
+      // We have to read the default argument regardless of whether we use it
+      // so that hypothetical further update records aren't messed up.
+      // TODO: Add a function to skip over the next expr record.
+      auto DefaultArg = Reader.ReadExpr(F);
+
+      // Only apply the update if the parameter still has an uninstantiated
+      // default argument.
+      if (Param->hasUninstantiatedDefaultArg())
+        Param->setDefaultArg(DefaultArg);
+      break;
+    }
+
     case UPD_CXX_ADDED_FUNCTION_DEFINITION: {
       FunctionDecl *FD = cast<FunctionDecl>(D);
       if (Reader.PendingBodies[FD]) {