Re: Question Regarding Int Cast Error in GDB Python

Hi,

We chose this particular cast just to stay aligned with the
existing method of testing in QEMU which also uses this cast
but for 64bit integers.

qemu/tests/tcg/aarch64/gdbstub/test-sve.py at
b86307ecef9222c335ebd0ed4da2b243e86f779e · qemu/qemu
<https://github.com/qemu/qemu/blob/b86307ecef9222c335ebd0ed4da2b243e86f779e/tests/tcg/aarch64/gdbstub/test-sve.py>
https://lists.gnu.org/archive/html/qemu-devel/2025-08/msg01815.html


However, since we have seen that this issue only occurs with the
specific indiciated version of gdb, and does not fail for example with
gdb16.3, we have implemented a workaround to avoid the
casting in the case of gdb-multiarch 15.0.50.20240403-0ubuntu1.

Thank you for confirming this is a known issue!


Thanks,
Vacha

On Tue, Aug 26, 2025 at 4:49 PM Luis <[email protected]> wrote:

> Hi,
>
> On 8/25/25 14:29, Vacha Bhavsar wrote:
> > Hi,
> >
> > Apologies, it seems I pasted the wrong snippet in the original email.
> > The code in my reply just prior to this is the correct code. The snippet
> > that
> > should have been included in the first email, which causes the error, is
> > the one below:
> >
> > v = gdb.parse_and_eval(reg)
> > report(str(v.type) == "uint128_t", "size of %s" % (reg))
>
> Right, so gdb doesn't like casting integers to/from 8+ bytes. That's a
> limitation currently. But why are you considering this particular cast?
> To optimize the checks instead of using the byte vectors?
>