Re: generic_prepare_to_proceed vs. Ctrl-C

[Michael Snyder <msnyder@cygnus.com>]

Jonathan Larmour wrote:
> 
> David S's recently added generic_prepare_to_proceed() only takes account of
> stopping at a breakpoint and switching threads. It does not deal with
> stopping due to a Ctrl-C and switching threads. The below patch fixes this.
> 
> Okay to check in?

I think it looks good, but this is such a hairy area that
I'd like to hear some more opinions...  


> 
> 2001-05-22  Jonathan Larmour  <jlarmour@redhat.com>
> 
>         * arch-utils.c (generic_prepare_to_proceed): Allow for having
>         stopped due to a Ctrl-C as well as breakpoints.
> 
> Jifl
> 
> Index: arch-utils.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/arch-utils.c,v
> retrieving revision 1.27
> diff -u -5 -p -r1.27 arch-utils.c
> --- arch-utils.c        2001/05/10 18:36:26     1.27
> +++ arch-utils.c        2001/05/22 22:19:29
> @@ -256,26 +256,26 @@ generic_prepare_to_proceed (int select_i
>    struct target_waitstatus wait_status;
> 
>    /* Get the last target status returned by target_wait().  */
>    get_last_target_status (&wait_ptid, &wait_status);
> 
> -  /* Make sure we were stopped at a breakpoint.  */
> +  /* Make sure we were stopped either at a breakpoint, or because
> +     of a Ctrl-C.  */
>    if (wait_status.kind != TARGET_WAITKIND_STOPPED
> -      || wait_status.value.sig != TARGET_SIGNAL_TRAP)
> +      || (wait_status.value.sig != TARGET_SIGNAL_TRAP &&
> +          wait_status.value.sig != TARGET_SIGNAL_INT))
>      {
>        return 0;
>      }
> 
>    if (!ptid_equal (wait_ptid, minus_one_ptid)
>        && !ptid_equal (inferior_ptid, wait_ptid))
>      {
>        /* Switched over from WAIT_PID.  */
>        CORE_ADDR wait_pc = read_pc_pid (wait_ptid);
> 
> -      /* Avoid switching where it wouldn't do any good, i.e. if both
> -         threads are at the same breakpoint.  */
> -      if (wait_pc != read_pc () && breakpoint_here_p (wait_pc))
> +      if (wait_pc != read_pc ())
>         {
>           if (select_it)
>             {
>               /* User hasn't deleted the breakpoint.  Switch back to
>                  WAIT_PID and return non-zero.  */
> @@ -286,12 +286,15 @@ generic_prepare_to_proceed (int select_i
>               flush_cached_frames ();
>               registers_changed ();
>               stop_pc = wait_pc;
>               select_frame (get_current_frame (), 0);
>             }
> -
> -         return 1;
> +          /* Step over the breakpoint if there is one here. */
> +          if (breakpoint_here_p (wait_pc))
> +            {
> +             return 1;
> +            }
>         }
>      }
>    return 0;
> 
>  }
> 
> --
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> Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine