Re: [PATCH 3/7] Force to insert software single step breakpoint

[Pedro Alves <palves at redhat dot com>]

Looks OK to me now.  A couple nits below.

On 04/20/2016 08:49 AM, Yao Qi wrote:

> 
> 2016-04-20  Yao Qi  <yao.qi@linaro.org>
> 
> 	* breakpoint.c (should_be_inserted): Return 0 if the location's
> 	owner is not single step breakpoint or single step brekapoint's

type "brekapoint".

> 	owner isn't the thread we are stepping over.
> 	* gdbarch.sh (software_single_step): Update comments.
> 	* gdbarch.h: Regenerated.
> 	* infrun.c (struct step_over_info) <thread>: New field.
> 	(set_step_over_info): New argument 'thread'.  Callers updated.
> 	(clear_step_over_info): Set field thread to -1.
> 	(thread_is_being_stepped_over_p): New function.

We don't step over threads, but rather threads step over breakpoints.

I'd suggest:

 thread_is_stepping_over_breakpoint_p

(Personally. I don't see the need for a _p / predicate suffix
when the function is clearly a predicate, due to use of the
"is".  thread_being_stepped_over_p / thread_is_being_stepped_over).

> 	* infrun.h (thread_is_being_stepped_over_p): Declaration.
> 
> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
> index f99a7ab..64e97c6 100644
> --- a/gdb/breakpoint.c
> +++ b/gdb/breakpoint.c
> @@ -2219,11 +2219,22 @@ should_be_inserted (struct bp_location *bl)
>      return 0;
>  
>    /* Don't insert a breakpoint if we're trying to step past its
> -     location.  */
> +     location except that the breakpoint is single-step breakpoint
> +     and the single-step breakpoint's owner is the thread we're
> +     stepping over.  */

"breakpoint's owner" is kind of possible confusing
with "bp location owner", which is itself a breakpoint.

I'd find it clearer to copy&edit it to say:

   /* Don't insert a breakpoint if we're trying to step past its
      location, except if the breakpoint is a single-step breakpoint,
      and the breakpoint's thread is the thread that is stepping past
      a breakpoint.  */

>  /* See infrun.h.  */
> @@ -1365,6 +1371,15 @@ stepping_past_instruction_at (struct address_space *aspace,
>  /* See infrun.h.  */
>  
>  int
> +thread_is_being_stepped_over_p (int thread)
> +{
> +  return (step_over_info.aspace != NULL
> +	  && thread == step_over_info.thread);

Wouldn't:

  return (step_over_info.thread != -1
	  && thread == step_over_info.thread);

be a bit more to the point?  Using the aspace field makes me wonder whether
we're caring for a case where step_over_info.thread is set to some
thread, but aspace is NULL.

Thanks,
Pedro Alves