#ifndef cg_dfn_h#define cg_dfn_h/** Flags which mark a symbol as topologically ``busy'' or as* topologically ``not_numbered'':*/#define DFN_BUSY -1#define DFN_NAN 0/** Depth-first numbering of a call-graph.*/extern void cg_dfn (Sym * root);#endif /* cg_dfn_h */