Make sure we correctly zero-initialize unions containing a pointer to data member as the first field. PR11487.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146009 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp
index 383452c79a..106ce10f51 100644
--- a/lib/CodeGen/CGRecordLayoutBuilder.cpp
+++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -531,6 +531,7 @@ void CGRecordLayoutBuilder::LayoutUnion(const RecordDecl *D) {
   CharUnits unionAlign = CharUnits::Zero();
 
   bool hasOnlyZeroSizedBitFields = true;
+  bool checkedFirstFieldZeroInit = false;
 
   unsigned fieldNo = 0;
   for (RecordDecl::field_iterator field = D->field_begin(),
@@ -542,6 +543,11 @@ void CGRecordLayoutBuilder::LayoutUnion(const RecordDecl *D) {
     if (!fieldType)
       continue;
 
+    if (field->getDeclName() && !checkedFirstFieldZeroInit) {
+      CheckZeroInitializable(field->getType());
+      checkedFirstFieldZeroInit = true;
+    }
+
     hasOnlyZeroSizedBitFields = false;
 
     CharUnits fieldAlign = CharUnits::fromQuantity(