/usr/include/llvm/ADT/SCCIterator.h: In instantiation of ‘class llvm::scc_iterator<tree_node*>’:
/data/project/xiangzhai/dragonegg/src/TypeConversion.cpp:1696:27: required from here
/usr/include/llvm/ADT/SCCIterator.h:40:7: error: no type named ‘NodeRef’ in ‘struct llvm::GraphTraits<tree_node*>’
class scc_iterator : public iterator_facade_base<