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Re: [LUG] GDB

 

Simon Williams wrote:
> 
> Firstly, gdb always says this when starting the program:
> Failed to read a valid object file image from memory.
> 
> I think that is a bug with gdb that's related to newer kernels, but if 
> anyone has any more info on that that would be good.

The Ubuntu forums claim it is sorted in 2.6.20-6 (was introduced at
2.6.19 by the sounds of it).

> The last line is driving me nuts- why won't it tell me where the 
> segfault is?

Segfault in gdb can also be a symptom of the gdb problem. I think "first
fix your tools" is the order of the day.

> I have no idea about multi-threaded programs, which isn't really helping.

They make your head hurt.

> The main question at the moment is: can I tell gdb to "run", but give 
> output like I was saying "step" each time? That would probably give me 
> the answer. I starting manually stepping, but wxwidgets seems to have a 
> lot of code that it goes through, and I'm not convinced that I'm not 
> going round in circles.

You can step per instruction, or you can step over a whole routine,
probably best to step over whole routines in the set-up till you get
closer to the error.

The trouble with stepping is you realize how big modern programs can be.

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