foo.c:16:1: warning: return type defaults to 'int' [-Wimplicit-int]
 fb(int a,int b,int c)
 ^~
foo.c: In function 'fb':
foo.c:22:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

自豪的采用jd5进行评测(github.com/masnn/jd5)