代码函数调用关系图

代码函数调用关系

1. Graphviz + CodeViz
   http://www.linuxidc.com/Linux/2015-01/111501.htm
2. Callgraph ：静态分析 C 程序函数调用关系图cflow+graphviz +tree2dotx
   http://www.tinylab.org/callgraph-draw-the-calltree-of-c-functions/