Re: Debugging Emacs

[phillip.lord@russet.org.uk (Phillip Lord)]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: phillip.lord@russet.org.uk (Phillip Lord)
>> Date: Fri, 27 Nov 2015 17:23:11 +0000
>> 
>> I debugged Emacs core the other day for the first time. As I have no
>> experience with C, GDB or any of the Emacs tooling, I found this an
>> uphill struggle, so I have written up a short "how-to-debug" Emacs file.
>
> Thanks.  Some of this is already in etc/DEBUG, other parts belong to
> basic GDB operation, so I'm not sure we should describe that in
> Emacs.  I suggest that you read etc/DEBUG, if you didn't already, and
> suggest changes to that file where you think it leaves something
> important uncovered.

With etc/DEBUG, I am worried not about what it does not say, but what it
does say. It's really very dense. For example, it starts with a
description of what src/.gdbinit does (at which point I still don't know
how to launch the debugger). Then has a very heavy section on compiler
flags which includes a section on DWARF.


> More specifically, how about a preamble section at the beginning of
> etc/DEBUG, named something like "If you are new to debugging Emacs",
> and describing the preliminaries you think are important?  You can
> refer to later sections instead of repeating what they say.

Yes, that was sort of the idea. Personally, I'd not be too worried about
repeating things. I realise that this adds to the maintainance burden,
but references to later sections make for harder reading.

I'll try and simplify what I wrote a bit further. Basically, I am after
the debugging hello world -- make a breakpoint, get the value of a
LispObject.

Phil