Re: [PATCH 3/3] capstone: Remove the capstone submodule

[Richard Henderson]

On 5/23/22 05:15, Thomas Huth wrote:
> On 19/05/2022 13.41, Peter Maydell wrote:
> > On Mon, 16 May 2022 at 16:22, Thomas Huth <thuth@redhat.com> wrote:
> > > Now that we allow compiling with Capstone v3.05 again, all our supported
> > > build hosts should provide at least this version of the disassembler
> > > library, so we do not need to ship this as a submodule anymore.
> >
> > When this eventually goes in, please remember to update the
> > wiki changelog page's 'Build Information' section to let
> > users know.
>
> Done: https://wiki.qemu.org/ChangeLog/7.1#Build_Dependencies

Ho hum.  So... the first time I try to do any actual debugging after this has gone in, and 
I am reminded exactly how terrible capstone 4.0.1 is for anything except x86.  There was a 
reason I had chosen a development branch snapshot, and that's because it was usable.

Here, for instance, is how ubuntu 20.04 capstone disassembles
tests/tcg/aarch64/system/boot.S:

0x00000000400027b0:  10ffc280      adr x0, #-0x7b0 (addr 0x40002000)

0x00000000400027b4:  d518c000      msr (unknown), x0


0x00000000400027b8:  d0000fe0      adrp x0, #+0x1fe000 (addr 0x40200000)

0x00000000400027bc:  91000000      add x0, x0, #0x0 (0)

0x00000000400027c0:  d5182000      msr (unknown), x0

...
0x0000000040002850:  d5381040      mrs x0, (unknown)

0x0000000040002854:  b26c0400      orr x0, x0, #0x300000

0x0000000040002858:  d5181040      msr (unknown), x0


And this is the extremely simple case of ARMv8.0 with no extensions.

I am very much tempted to re-instate the capstone submodule, or update disas/vixl and 
disable use of capstone for arm.

Would the ppc folk please have a look at how capstone is or is not handling ppc64? 
Because I strongly suspect that 333f944c15e7 ("disas: Remove old libopcode ppc 
disassembler") is also going to turn out to be a regression when combined with the removal 
of the capstone submodule.


r~


PS: While there are tags in upstream capstone hinting at a 5.0 release, there's no 
timeline for when we might see such a thing.  Anyway, it wouldn't help anyone with an LTS 
distro for the next half decade.