Fix __builtin_va_arg assertion failure in ARM AAPCS.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166369 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index a71da15322..6a6fe897c5 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -9643,6 +9643,16 @@ ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc,
     if (Result.isInvalid())
       return ExprError();
     E = Result.take();
+  } else if (VaListType->isRecordType() && getLangOpts().CPlusPlus) {
+    // If va_list is a record type and we are compiling in C++ mode,
+    // check the argument using reference binding.
+    InitializedEntity Entity
+      = InitializedEntity::InitializeParameter(Context,
+          Context.getLValueReferenceType(VaListType), false);
+    ExprResult Init = PerformCopyInitialization(Entity, SourceLocation(), E);
+    if (Init.isInvalid())
+      return ExprError();
+    E = Init.takeAs<Expr>();
   } else {
     // Otherwise, the va_list argument must be an l-value because
     // it is modified by va_arg.