Add a missing check in CodeGen of packed classes with vtables. <rdar://problem/11324125>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@155689 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 1 deletions

diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp
index 1193e974e1..7f69d6dc8a 100644
--- a/lib/CodeGen/CGRecordLayoutBuilder.cpp
+++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -721,7 +721,13 @@ CGRecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD,
       llvm::FunctionType::get(llvm::Type::getInt32Ty(Types.getLLVMContext()),
                               /*isVarArg=*/true);
     llvm::Type *VTableTy = FunctionType->getPointerTo();
-    
+
+    if (getTypeAlignment(VTableTy) > Alignment) {
+      // FIXME: Should we allow this to happen in Sema?
+      assert(!Packed && "Alignment is wrong even with packed struct!");
+      return false;
+    }
+
     assert(NextFieldOffset.isZero() &&
            "VTable pointer must come first!");
     AppendField(CharUnits::Zero(), VTableTy->getPointerTo());