Re: STEP_SKIPS_DELAY question, sort of

[Orjan Friberg <orjan.friberg@axis.com>]

Orjan Friberg wrote:
> 
> Gah.  Please ignore the previous patch (and sorry); what I posted only 
> works when doing a continue when stopped at the branch instruction. 
> Doing a step (which leaves us in the delay slot) followed by another 
> step (or continue for that matter) prematurely inserts the breakpoint.

Ok, second try (still concept patch though): the change in proceed is needed for 
when we resume from the delay slot - in that case we need to single-step again 
before re-inserting the breakpoint (similar to the MIPS case).  The change in 
handle_inferior_event (and I'll happily agree it's far more questionable) is 
needed for when we resume at the branch instruction itself.  Comments?

Index: infrun.c
===================================================================
RCS file: /cvs/src/src/gdb/infrun.c,v
retrieving revision 1.156
diff -u -p -r1.156 infrun.c
--- infrun.c    11 May 2004 23:30:31 -0000      1.156
+++ infrun.c    7 Jun 2004 12:59:10 -0000
@@ -748,6 +748,14 @@ proceed (CORE_ADDR addr, enum target_sig
           && breakpoint_here_p (read_pc () + 4)
           && STEP_SKIPS_DELAY (read_pc ()))
         oneproc = 1;
+
+      /* If we stepped into a delay slot, and the preceding instruction
+        will be re-executed when resuming, step again before re-inserting
+        the breakpoint.  */
+      if (STEP_SKIPS_IN_DELAY_P
+         && breakpoint_here_p (read_pc () - 2)
+         && STEP_SKIPS_IN_DELAY (read_pc ()))
+       oneproc = 1;
      }
    else
      {
@@ -1975,7 +1983,17 @@ handle_inferior_event (struct execution_
        /* Don't even think about breakpoints if just proceeded over a
           breakpoint.  */
        if (stop_signal == TARGET_SIGNAL_TRAP && trap_expected)
-       bpstat_clear (&stop_bpstat);
+       {
+         bpstat_clear (&stop_bpstat);
+
+         /* If we stepped into a delay slot, and the preceding instruction
+            will be re-executed when resuming, step again before re-inserting
+            the breakpoint.  */
+         if (STEP_SKIPS_IN_DELAY_P
+             && breakpoint_here_p (read_pc () - 2)
+             && STEP_SKIPS_IN_DELAY (read_pc ()))
+           ecs->another_trap = 1;
+       }
        else
         {
           /* See if there is a breakpoint at the current PC.  */

-- 
Orjan Friberg
Axis Communications