gdb objc regressions

gdb objc regressions

[Matt Rice]

Hi,

there is some issues with debugging objc

GNU gdb Fedora (6.7.50.20080227-2.fc9)
GNU gdb 6.8.50.20080309-cvs

the 6.7.1 release doesn't seem to have these issues...

we can set a breakpoint on a method, so thats good.

Breakpoint 1, -[EOEntity attributes] (self=0x8937df0, _cmd=0x6e9210)

you cannot naively print an instance variable

(gdb) po isa
No symbol "isa" in current context.

though po in general works,
(gdb) po self.isa
EOEntity

also sending messages to an object doesn't work,

(gdb) p [self class]
A syntax error in expression, near `[self class]'.

it appears these are covered by failures in the testsuite but i
anticipate not alot of gdb developers have the objc compiler
installed,

I don't mind looking into this but it may take me a while to get up to speed,
so any pointers in where to start looking would be appreciated

matt

Re: gdb objc regressions

[David Ayers]

Hello Matt

Matt Rice schrieb:

> there is some issues with debugging objc
[snip]
> 
> it appears these are covered by failures in the testsuite but i
> anticipate not a lot of gdb developers have the objc compiler
> installed,
> 
> I don't mind looking into this but it may take me a while to get up to speed,
> so any pointers in where to start looking would be appreciated

I noticed this also.  It seem to be an issue with GDB not being able to
parse GCC's debug info and it seems like regression in GCC rather than GDB.

See: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=462882

A current workaround would be to:

set language objective-c

explicitly, as suggested by Daniel.

I haven't had the resources to investigate the exact commit that caused
the regression yet.

Cheers,
David

Re: gdb objc regressions

[Matt Rice]

On Mon, Mar 10, 2008 at 12:07 AM, David Ayers <ayers@fsfe.org> wrote:
> Hello Matt
>
>  Matt Rice schrieb:
>
>
>  > there is some issues with debugging objc
>  [snip]

>  A current workaround would be to:
>
>  set language objective-c
>
>  explicitly, as suggested by Daniel.
>
>  I haven't had the resources to investigate the exact commit that caused
>  the regression yet.
>

I just figured out why and will send a patch to the correct list,
an omission from dwarf2read.c:set_cu_language.

Re: gdb objc regressions

[Richard Frith-Macdonald]

On 10 Mar 2008, at 07:36, Matt Rice wrote:

> On Mon, Mar 10, 2008 at 12:07 AM, David Ayers <ayers@fsfe.org> wrote:
>> Hello Matt
>>
>> Matt Rice schrieb:
>>
>>
>>> there is some issues with debugging objc
>> [snip]
>
>> A current workaround would be to:
>>
>> set language objective-c
>>
>> explicitly, as suggested by Daniel.
>>
>> I haven't had the resources to investigate the exact commit that  
>> caused
>> the regression yet.
>>
>
> I just figured out why and will send a patch to the correct list,
> an omission from dwarf2read.c:set_cu_language.

Thanks very much ... I'd been very irritated by that bug myself, but  
just haven't had time to get round to looking at gdb to figure out  
what was causing it.