Re: [PATCH v2 2/2] Only leave dprintf inserted if it is marked as persistent (PR breakpoints/17012)

[Pedro Alves <palves@redhat.com>]

On 07/07/2014 08:17 PM, Simon Marchi wrote:
> On Linux native, if dprintf are inserted when detaching, they are left
> in the inferior which causes it to crash from a SIGTRAP. It also happens
> with dprintfs on remote targets, when set disconnected-dprintf is off.
> 
> I believe that the rationale of the line I modified was to leave dprinfs
> inserted in order to support disconnected dprintfs. This adds a check to
> see if the dprintf should actually stay inserted or not.
> 
> bl->target_info.persist will be 1 only if disconnected-dprintf is on and
> we are debugging a remote target. On native, it will always be 0,
> regardless of the value of disconnected-dprintf. This makes sense, since
> disconnected dprintfs are not supported by the native target.
> 
> gdb/Changelog:
> 
> 2014-07-07  Simon Marchi  <simon.marchi@ericsson.com>
> 
> 	PR breakpoints/17012
> 	* breakpoint.c (remove_breakpoints_pid): Only skip removing
> 	dprintf if it is marked as persistent.
> 
> ---
>  gdb/breakpoint.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
> index 908a1ea..fb833d0 100644
> --- a/gdb/breakpoint.c
> +++ b/gdb/breakpoint.c
> @@ -3112,7 +3112,7 @@ remove_breakpoints_pid (int pid)
>      if (bl->pspace != inf->pspace)
>        continue;
>  
> -    if (bl->owner->type == bp_dprintf)
> +    if (bl->owner->type == bp_dprintf && bl->target_info.persist == 1)
>        continue;

I think that we don't really need the "bl->owner->type == bp_dprintf"
check anymore.  persist" carries all the semantics we need here.

Also, this is a boolean, so best write:

    if (bl->target_info.persist)
        continue;

without the "== 1" part.

But ... most importantly.  How do we end up with 'persist' set
on a call-style dprintf, given:

static void
build_target_command_list (struct bp_location *bl)
{
...
  /* For now, limit to agent-style dprintf breakpoints.  */
  if (dprintf_style != dprintf_style_agent)
    return;

I'm confused, as you say the test fails now, but nowhere in the
test are you setting the style to agent.  I think I'm missing
something.  :-)

-- 
Pedro Alves