Re: Add gdb.read_memory, gdb.write_memory and gdb.Membuf.

[Thiago Jung Bauermann <bauerman at br dot ibm dot com>]

El lun, 05-01-2009 a las 16:43 -0700, Tom Tromey escribiÃ:
> >>>>> "Thiago" == Thiago Jung Bauermann <bauerman@br.ibm.com> writes:
> Thiago> It's very simple: gdb.read_memory takes an address and a
> Thiago> length and reads the bytes from the inferior, placing them in
> Thiago> a Python buffer object. gdb.write_memory takes an address and
> Thiago> a Python object supporting the buffer protocol[0] (i.e., the
> Thiago> object from read_memory, an array or a string) and writes it
> Thiago> to the inferior memory.
> 
> I was wondering whether we should have a buffer object be the access
> method.  That is, provide a new class, implementing the buffer
> protocol, which provides "direct" access to inferior memory; it
> could have a constructor accepting an address and a size.  Then,
> explicit read/write calls would not be needed.q
> 
> Is this feasible?  Would it perform well enough?

You mean a way to make GDB write to inferior memory when, for instance,
"b[6] = 'a'" is executed? No, the buffer protocol doesn't allow that. It
just allows the object to return a pointer to some memory region.
Individual accesses to that memory region happen independently of the
buffer object.

We could do this by implementing some __magic__ Python method to
override the default implementation of [], but that would have nothing
to do with the buffer protocol, and would not work with the struct
module or other python facilities which use that protocol.
-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center