Re: [RFA] Dwarf2 fix

[Andreas Jaeger <aj@suse.de>]

Michal Ludvig <mludvig@suse.cz> writes:

> Andreas Jaeger wrote:
>> Michal Ludvig <mludvig@suse.cz> writes:
>
>>>   context_cpy (struct context *dst, struct context *src)
>>>   {
>>>     int regs_size = sizeof (struct context_reg) * NUM_REGS;
>>>+   struct context_reg *dreg;
>>>
>>>+   dreg = dst->reg;
>>>     *dst = *src;
>>>+   dst->reg = dreg;
>>>+
>>>     memcpy (dst->reg, src->reg, regs_size);
>>>   }
>
>  > Can you add a comment here, why this is needed?
>
> Structure dst contains a pointer to an array of registers of a given
> frame as well as src does. This array was already allocated before dst
> was passed to context_cpy but the pointer to it was overriden by
> '*dst = *src' and the array was lost. This led to the situation, that
> I've had a copy of src placed in dst, but both of them pointed to the
> same regs array and thus I've sometimes blindly rewritten it.
> Now I save the pointer before I copy src to dst, return it back after
> that and copy the registers into their new place finally.

thanks for the explanation.  I wanted to see a comment in the code...

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
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