Re: [PATCH 1/2] [GDBserver] Fix compiling conditional expressions accessing registers

["Ulrich Weigand" <uweigand@de.ibm.com>]

Yao Qi wrote:
> Pierre Langlois <pierre.langlois@arm.com> writes:
> 
> > This patch fixes this issue by replacing `gdb_agent_get_raw_reg' with a
> > `gdb_agent_get_reg' function which takes the tracepoint context object
> > as argument instead of a raw buffer.  Additionally, this patch makes
> > this function architecture independent by initializing the context's
> > regcache early and making `gdb_agent_get_reg' use `collect_register'.
> > As a result, the fast tracepoint context object does not need to
> > contain the raw register buffer.
> 
> The fix looks reasonable to me as it makes no sense to keep two copies
> of registers.  I go through this patch, and it looks good to me.

It seems to me this was intended as performance optimization to avoid
having to do the full regcache setup every time a tracepoint is hit,
in case we're not actually tracing registers ...

Not sure whether this is a real performance concern for actual use
cases though.  I don't have any actual measurements ...
 
> This patch invalidates Wei-cheng's patch here
> <https://sourceware.org/ml/gdb-patches/2015-06/msg00587.html> which is
> already approved but not committed.
> 
> If Ulirch/Wei-cheng have no objections, this patch can go in.

Except for the performance question above, I have no objections.

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com