Re: [PATCH 4/5] Support 'info proc files' on live FreeBSD processes.

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2018-09-10 19:30, John Baldwin wrote:
> On 9/8/18 4:00 PM, Simon Marchi wrote:
>> On 2018-09-08 01:36 AM, John Baldwin wrote:
>>> This walks the list of struct kinfo_file objects returned by a call 
>>> to
>>> kinfo_getfile outputting a description of each open file descriptor.
>> 
>> LGTM.
>> 
>> It would be nice to share the printing of the information between core
>> and live process, so that we can't forget to change one if we change 
>> the
>> other.  But if there are some subtle differences between both loops 
>> that
>> would make sharing more annoying than anything, I don't mind.
> 
> I've followed the same approach I used for 'info proc mappings' which 
> is
> to use shared helper routines as much as possible.
> 
> What I could perhaps do to share code is add new TARGET_FREEBSD_<foo>
> target objects, but this would entail reworking the code quite a bit I
> think.  It would mean that I would need a way to let a gdbarch hook 
> into
> the core target's xfer_partial method more generically (right now there 
> is
> a hook just for siginfo, but I think we'd want a hook for arbitrary
> objects).  I would then rewrite the info proc bits in fbsd-tdep.c in 
> terms
> of fetching target objects and always parsing them in the core dump
> format.  I think there were a few things in some of the other 'info 
> proc'
> methods that weren't quite as straightforward as for the 'files' and
> 'mappings' case though.

I was thinking more about how to share the code that formats and print 
one entry.  Let's say you realize later that a column needs to be wider, 
you have to remember to update both the live and core versions.  Not 
really a big deal though.

Simon