Re: [RFC PATCH 0/3] Remove some of the old libopcode based disassemblers

[Philippe Mathieu-Daudé]

On 9/5/22 15:18, Thomas Huth wrote:
> On 09/05/2022 14.20, Philippe Mathieu-Daudé wrote:
> > On 12/4/22 18:58, Thomas Huth wrote:
> > > Many of the disassemblers in the disas folder are based on old
> > > versions from the GNU tools (libopcode, GDB, ...) that were still
> > > licensed under the GPL v2. The GNU tools switched to GPL v3 at one
> > > point in time, so QEMU is stuck with the old versions, i.e. these
> > > files did not see much updates for new processors anymore. But
> > > for most architectures, we're preferring the Capstone disassembler
> > > now anyway, so the old libopcode disassemblers are also hardly
> > > used anymore.
> > >
> > > I'm not 100% sure (thus this is marked as RFC), but I think we could
> > > simply drop the old disassemblers nowadays, and hardly anybody would
> > > miss them, since we now always embed capstone as a submodule anyway.
> > > Or is there still an advantage in keeping these old files around?
> > >
> > > This RFC series tackles with s390, arm (32-bit) and i386 ... I wanted
> > > to get some feedback first, but if we agree that these can be removed,
> > > the sparc, mips and ppc disassemblers likely can be removed, too.
> > > (I think we should keep m68k.c since Capstone does not have support
> > > for Coldfire CPUs yet).
> > >
> > > Thomas Huth (3):
> > >    disas: Remove old libopcode s390 disassembler
> > >    disas: Remove old libopcode arm disassembler
> > >    disas: Remove old libopcode i386 disassembler
> >
> > >   disas/arm.c             | 4012 -----------------------
> > >   disas/i386.c            | 6771 ---------------------------------------
> > >   disas/s390.c            | 1892 -----------
> >
> > >   10 files changed, 12700 deletions(-)
> >
> > o_O Nice!
> >
> > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>
> Thanks, just a little bit too late - it's in my current pull request 
> already :-)

NP, trying to catch up.

> By the way, what about MIPS? Could MIPS be switched to Capstone, too, so 
> that we could finally remove disas/mips.c ? (We're not using capstone 
> there yet, and MIPS has so many flavours, big and little endian, 32- and 
> 64-bit ... so that I'm unsure whether there was a reason for not using 
> Capstone there, or whether it just hasn't been tried out yet?)

Last I remember is Richard saying "the capstone backend for mips is not
in terribly good shape":
https://lore.kernel.org/qemu-devel/0c7827df-c9d4-8dad-a38c-4881ce7dd22b@linaro.org/

My long-term hope is to switch to decodetree.