在OS X上编译简单C程序时出现clang链接器错误

Question

我正在从这篇文章构建此代码

我正在使用建议的命令来构建它: gcc -Wall -o keyboard_leds keyboard_leds.c -framework IOKit -framework CoreFoundation

$ curl -O http://osxbook.com/book/bonus/chapter10/kbdleds/download/keyboard_leds.c
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 11542  100 11542    0     0   139k      0 --:--:-- --:--:-- --:--:--  140k

$ clang -Wall -o keyboard_leds keyboard_leds.c -framework IOKit -framework CoreFoundation
Undefined symbols for architecture x86_64:
  "_print_errmsg_if_err", referenced from:
      _create_hid_interface in keyboard_leds-d14ed5.o
  "_print_errmsg_if_io_err", referenced from:
      _create_hid_interface in keyboard_leds-d14ed5.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

$

如果有点过时(6年),代码非常简单.我看不到任何以下划线开头的符号.我可能遗漏了一些简单的东西,但我完全不知道这些符号的来源.

是什么赋予了？我可以注释掉调用它来编译.