Re: [PATCH] arc: Select CPU model properly before disassembling

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2017-06-06 15:51, Anton Kolesov wrote:
>> Could gdb_disassembler set the section field of disassemble_info 
>> itself?
>>   What you are doing to set the section field here is not 
>> ARC-specific,
>> it looks like it could potentially help other architectures to have 
>> that
>> field set.
>> 
>> Other places that use the disassembler would have to set it too, for
>> example in the object prepared by the arc_disassemble_info function.
> 
> I think this info->section initialization code can be moved to
> arch-utils.c:default_print_insn, however I'm not sure if that wouldn't 
> cause
> any troubles with other architectures.

I don't see why setting the section would cause a problem.  If it does, 
I'd say it's more likely a bug in these other architectures code.  You 
could argue that for architectures that don't have disassembler options, 
it would be some wasted cycles though...

> Doing initialization in gdb_disassembler
> constructor is complicated, because we don't really know what would be 
> the
> disassembled address at this stage, hence what would be the section.
> Gdb_dissassembler construction can use .text section as a default, but 
> then
> might now work with some multi-arch ELFs, I presume (unlikely to be a
> problem for ARC, though).

That might be a good default behavior, to be overridden by the few 
architectures that have some more corner cases.

> Another option is, of course, to partially revert [2] for ARC - make
> arc_delayed_print_insn a printer for ARC, but change it, so it will 
> only
> set info->section and then call default_print_insn. I believe that same 
> change
> is needed in mep-tdep.c. At least for ARC we would need to use 
> print_insn
> anyway to disassemble, because opcodes/arc-dis.c:arc_insn_decode relies 
> on it.

That's fine with me.

Simon