1 files changed, 32 insertions, 1 deletions

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 3001be23cf..7f00981d34 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -6083,7 +6083,7 @@ Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo,
         ILE->setInit(i, ConstantExpr::Create(Context, Init));
       }
 
-  Expr *E = new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType,
+  auto *E = new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType,
                                               VK, LiteralExpr, isFileScope);
   if (isFileScope) {
     if (!LiteralExpr->isTypeDependent() &&
@@ -6101,6 +6101,19 @@ Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo,
     return ExprError();
   }
 
+  // Compound literals that have automatic storage duration are destroyed at
+  // the end of the scope. Emit diagnostics if it is or contains a C union type
+  // that is non-trivial to destruct.
+  if (!isFileScope)
+    if (E->getType().hasNonTrivialToPrimitiveDestructCUnion())
+      checkNonTrivialCUnion(E->getType(), E->getExprLoc(),
+                            NTCUC_CompoundLiteral, NTCUK_Destruct);
+
+  if (E->getType().hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
+      E->getType().hasNonTrivialToPrimitiveCopyCUnion())
+    checkNonTrivialCUnionInInitializer(E->getInitializer(),
+                                       E->getInitializer()->getExprLoc());
+
   return MaybeBindToTemporary(E);
 }
 
@@ -12782,6 +12795,10 @@ ExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc,
           if (auto *VD = dyn_cast<VarDecl>(DRE->getDecl()))
             if (VD->hasLocalStorage() && getCurScope()->isDeclScope(VD))
               BE->getBlockDecl()->setCanAvoidCopyToHeap();
+
+      if (LHS.get()->getType().hasNonTrivialToPrimitiveCopyCUnion())
+        checkNonTrivialCUnion(LHS.get()->getType(), LHS.get()->getExprLoc(),
+                              NTCUC_Assignment, NTCUK_Copy);
     }
     RecordModifiableNonNullParam(*this, LHS.get());
     break;
@@ -14194,6 +14211,11 @@ ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc,
       !BD->isDependentContext())
     computeNRVO(Body, BSI);
 
+  if (RetTy.hasNonTrivialToPrimitiveDestructCUnion() ||
+      RetTy.hasNonTrivialToPrimitiveCopyCUnion())
+    checkNonTrivialCUnion(RetTy, BD->getCaretLocation(), NTCUC_FunctionReturn,
+                          NTCUK_Destruct|NTCUK_Copy);
+
   PopDeclContext();
 
   // Pop the block scope now but keep it alive to the end of this function.
@@ -16464,6 +16486,15 @@ static ExprResult rebuildPotentialResultsAsNonOdrUsed(Sema &S, Expr *E,
 }
 
 ExprResult Sema::CheckLValueToRValueConversionOperand(Expr *E) {
+  // Check whether the operand is or contains an object of non-trivial C union
+  // type.
+  if (E->getType().isVolatileQualified() &&
+      (E->getType().hasNonTrivialToPrimitiveDestructCUnion() ||
+       E->getType().hasNonTrivialToPrimitiveCopyCUnion()))
+    checkNonTrivialCUnion(E->getType(), E->getExprLoc(),
+                          Sema::NTCUC_LValueToRValueVolatile,
+                          NTCUK_Destruct|NTCUK_Copy);
+
   // C++2a [basic.def.odr]p4:
   //   [...] an expression of non-volatile-qualified non-class type to which
   //   the lvalue-to-rvalue conversion is applied [...]