Re: GDB on Mac is Broken

[YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>]

>>>>> On Sat, 13 Mar 2010 09:51:36 +0200, Eli Zaretskii <eliz@gnu.org> said:

>> Date: Sat, 13 Mar 2010 15:58:11 +0900 From: YAMAMOTO Mitsuharu
>> <mituharu@math.s.chiba-u.ac.jp>
>> 
>> The related difference between Emacs 22, on which the completion
>> works, and Emacs 23 seems to be:
>> 
>> 1. The default value of default-process-coding-system.  2. A change
>> in comint-exec-1.
>> 
>> For the first one, the value is (mule-utf-8 . mule-utf-8) in Emacs
>> 22, and (utf-8-unix . utf-8-unix) in Emacs 23 on Mac OS X 10.6.

> And what is wrong with the Emacs 23 default, exactly?  Doesn't OS X
> use LF as the end-of-line character, when communicating with
> subprocesses in general and with GDB in particular?

I've never said it's `wrong'; just different from Emacs 22, and that
leads to the different behavior for completion in GUD between Emacs 22
and 23.  It might be the case that what should be changed is at the
GUD or gdb side, but I don't know.

>> At least, the above differences explain why completion in *gdb*
>> buffer behaves differently between Emacs 22 and 23.

> Could you please explain how these two differences explain the bug?
> I'm afraid I don't see the immediate connection.

I should have been explained more why the difference in EOL conversion
affects this issue.  The hang in Emacs 23 on Mac OS X is caused by
unexpected ^M at EOL when processing gdb output.  Gdb actually outputs
^M, but GUD in Emacs 22 did not see ^M because it used dos (CRLF) EOL
conversion due to the comint code I showed in my previous mail.

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp