Some problems of Emacs on my OS X 10.8.5

[Haomin Long]

Hello!
Recently I use Emacs 24.3 on my OS X 10.8.5.
To debug, I installed GNU GDB 7.7  from homebrew.
But in Emacs I can't use M-x gdb. It just showed "No such file or
directory, gdb" in the minibuffer.
I typed "M-! echo $PATH" and it did show the directory that containing the
GDB program.
So I typed "M-! gdb ***". After that it did execute GDB , but the first
line of it is "(gdb) quit"!!
I searched a lot at Google but I'm not able to solve it.
Is it some kind of Bug?
THANKS!

-- 

*Houman Lung*

*Department of Computer Science and Technology, Tsinghua University,
Beijing China*

*Mobile: (+86)18688148073*
*E-mail: cherudim9@gmail.com <cherudim9@gmail.com>*