Re: [PATCH v3 08/12] btrace: Replace struct btrace_thread_info::up.

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2017-05-09 02:55, Tim Wiederhake wrote:
> This used to hold a function segment pointer.  Change it to hold an 
> index into
> the vector of function segments instead.
>
> 2017-05-09  Tim Wiederhake  <tim.wiederhake@intel.com>
>
> gdb/ChangeLog:
>
> 	* btrace.c (ftrace_find_call_by_number): New function.
> 	(ftrace_update_caller, ftrace_new_call, ftrace_new_tailcall,
> 	ftrace_get_caller, ftrace_find_call, ftrace_new_return,
> 	ftrace_match_backtrace, ftrace_connect_bfun, ftrace_connect_backtrace,
> 	ftrace_bridge_gap, btrace_bridge_gaps): Use btrace_function::up as an
> 	index.
> 	* btrace.h (struct btrace_function): Turn UP into an index.
> 	* python/py-record-btrace.c (btpy_call_up): Use btrace_function::up
> 	as an index.
> 	* record-btrace.c (record_btrace_frame_unwind_stop_reason,
> 	record_btrace_frame_prev_register, record_btrace_frame_sniffer,
> 	record_btrace_tailcall_frame_sniffe): Same.

LGTM, just a question below.

> @@ -1629,11 +1629,12 @@ record_btrace_frame_prev_register (struct
> frame_info *this_frame,
>    bfun = cache->bfun;
>    gdb_assert (bfun != NULL);
>
> -  caller = bfun->up;
> -  if (caller == NULL)
> +  if (bfun->up == 0)
>      throw_error (NOT_AVAILABLE_ERROR,
>  		 _("No caller in btrace record history"));
>
> +  caller = cache->tp->btrace.functions[bfun->up - 1];
> +

Would it be good to export ftrace_find_call_by_number so it can be used 
at a few places in this file?

Thanks,

Simon