+/// isValidReturnType - Return true if the specified type is valid as a return
+/// type.
+bool FunctionType::isValidReturnType(const Type *RetTy) {
+ if (RetTy->isFirstClassType())
+ return true;
+ if (RetTy == Type::VoidTy || isa<OpaqueType>(RetTy))
+ return true;
+
+ // If this is a multiple return case, verify that each return is a first class
+ // value and that there is at least one value.
+ const StructType *SRetTy = dyn_cast<StructType>(RetTy);
+ if (SRetTy == 0 || SRetTy->getNumElements() == 0)
+ return false;
+
+ for (unsigned i = 0, e = SRetTy->getNumElements(); i != e; ++i)
+ if (!SRetTy->getElementType(i)->isFirstClassType())
+ return false;
+ return true;
+}
+