/in/foo.c: In function 'main':
/in/foo.c:7:9: warning: zero-length gnu_printf format string [-Wformat-zero-length]
  printf("");
         ^~
/in/foo.c:19:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(c)
  ^~
/in/foo.c:21:5: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
     c=1;
     ^