RE: [PATCH 2/6] disasm: add struct disas_insn to describe to-be-disassembled instruction

Metzger, Markus T
2015-10-12T08:44:23Z

> -----Original Message-----
> From: gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] On Behalf Of Pedro Alves
> Sent: Friday, October 9, 2015 2:51 PM
> To: Metzger, Markus T; dje@google.com
> Cc: gdb-patches@sourceware.org
> Subject: Re: [PATCH 2/6] disasm: add struct disas_insn to describe to-be-
> disassembled instruction

> I think the log would be much clearer if the rationale was specified in
> terms of why this is necessary, and if we saw a before/after example.

I added the following to the beginning of the commit message to motivate
the patch:

The "record instruction-history" command prints for each instruction, in
addition to the instruction's disassembly:

- the instruction number in the recorded execution trace
- a '?' before the instruction if it was executed speculatively

To allow the "record instruction-history" command to use GDB's disassembly
infrastructure, we extend dump_insn to optionally print those additional
fields.

> Also, being a user/frontend visible change, shouldn't these new
> fields be documented and mentioned in NEWS?

There is no UI change and thus also no before/after example.

The new optional fields are currently not used. They will be used by the
"record instruction-history" command in the last patch of this series.
Even then, there is no UI change. Both the "record instruction-history"
and the "disassemble" command behave as they did before.

There is a change to the MI output of "record instruction-history".
As I didn't do any conscious MI support for record btrace, I don't expect
it to be working. I'm using the ui_out_* functions so there might be some
form of MI support. AFAIK it is not being used.

Regards,
Markus.
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