1. 首先要配置emacs文件：
(global-linum-mode t)
(show-paren-mode t)
(global-set-key (kbd "C-s") 'save-buffer)
(global-set-key (kbd "RET") 'newline-and-indent)
(global-set-key [f9] 'compile)
(global-set-key [C-f7] 'gud-gdb)
(global-set-key (kbd "C-z") 'undo)
(global-set-key (kbd "C-c") 'kill-ring-save)
(global-set-key (kbd "C-v") 'yank)
(global-set-key (kbd "C-a") 'mark-whole-buffer)
(global-set-key (kbd "C-y") 'kill-whole-line)
(custom-set-variables
;; custom-set-variables was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.
'(inhibit-startup-screen t)
'(show-paren-mode t))
(custom-set-faces
;; custom-set-faces was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.
'(default ((t (:inherit nil :stipple nil :background "white" :foreground "black" :inverse-video nil :box nil :strike-through nil :overline nil :underline nil :slant normal :weight normal :height 113 :width normal :foundry "bitstream" :family "Courier 10 Pitch")))))
就是C-c, C-v, C-a, C-s, C-z, C-F7 和 F9的快捷键设置
2. 程序编译
先F9，输入 g++ -o xxx xxx.cpp -g -Wall (-Wl,-stack=1000000) 编译
C-F7调出gdb
3. gdb调试命令
先打：
b main
r
进入调试，各种调试命令：
单步执行：
n 表示next执行下一行，会跳过函数
s 同理，但不会跳过，而且会进入系统函数= =
fin 表示跳出当前函数，且返回函数值 ex："Value returned is $1 = (const int &) @0x8058cfc: 1"
b x if xxx 调到x行，并且满足xxx
查看变量：
p x 查看当前变量x的值（同时可以查看数组，显示就和P的一样。。）
disp x 永久查看变量x的值
und 一次性去除所有查看信息
断点：
b x 在line x设置一个断点
c 跳到下一个断点
d 去掉所有断点
其他：
k 杀死进程
q 退出gdb
两次C-c 死循环时退出程序
set print pretty on/off 调试的时候看变量的格式修改
(p.s. 这里的C代表Ctrl键)