Re: [RFC] Remove need_step_over from struct lwp_info

[Yao Qi <qiyaoltc@gmail.com>]

Pedro Alves <palves@redhat.com> writes:

> In any case, looks like this never worked upstream, so I'm super
> fine with removing the field and cleaning this all up.

OK, patch is pushed in.

-- 
Yao (齐尧)

From f166f943f30a91792e8754cbca9d7652fc400aae Mon Sep 17 00:00:00 2001
From: Yao Qi <yao.qi@linaro.org>
Date: Thu, 28 Apr 2016 11:52:23 +0100
Subject: [PATCH] Remove need_step_over from struct lwp_info

Hi,
I happen to see that field need_step_over in struct lwp_info is only
used to print a debug info.  need_step_over is set in linux_wait_1
when breakpoint_here is true, however, we check breakpoint_here too in
need_step_over_p and do the step over.  I think we don't need field
need_step_over, and check breakpoint_here directly in need_step_over_p.

This field was added in this patch
https://sourceware.org/ml/gdb-patches/2010-03/msg00605.html and the code
wasn't changed much since then.

This patch is to remove it.

gdb/gdbserver:

2016-04-28  Yao Qi  <yao.qi@linaro.org>

	* linux-low.h (struct lwp_info) <need_step_over>: Remove.
	* linux-low.c (linux_wait_1): Update.
	(need_step_over_p): Likewise.

diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index efa0774..8e1e2fc 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -3267,14 +3267,8 @@ linux_wait_1 (ptid_t ptid,
 
       if (bp_explains_trap)
 	{
-	  /* If we stepped or ran into an internal breakpoint, we've
-	     already handled it.  So next time we resume (from this
-	     PC), we should step over it.  */
 	  if (debug_threads)
 	    debug_printf ("Hit a gdbserver breakpoint.\n");
-
-	  if (breakpoint_here (event_child->stop_pc))
-	    event_child->need_step_over = 1;
 	}
     }
   else
@@ -4540,12 +4534,6 @@ need_step_over_p (struct inferior_list_entry *entry, void *dummy)
       return 0;
     }
 
-  if (!lwp->need_step_over)
-    {
-      if (debug_threads)
-	debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread));
-    }
-
   if (lwp->status_pending_p)
     {
       if (debug_threads)
@@ -4571,8 +4559,6 @@ need_step_over_p (struct inferior_list_entry *entry, void *dummy)
 		      "Old stop_pc was 0x%s, PC is now 0x%s\n",
 		      lwpid_of (thread),
 		      paddress (lwp->stop_pc), paddress (pc));
-
-      lwp->need_step_over = 0;
       return 0;
     }
 
@@ -4622,8 +4608,6 @@ need_step_over_p (struct inferior_list_entry *entry, void *dummy)
 	     that find_inferior stops looking.  */
 	  current_thread = saved_thread;
 
-	  /* If the step over is cancelled, this is set again.  */
-	  lwp->need_step_over = 0;
 	  return 1;
 	}
     }
diff --git a/gdb/gdbserver/linux-low.h b/gdb/gdbserver/linux-low.h
index d4946c1..6e7ddbd 100644
--- a/gdb/gdbserver/linux-low.h
+++ b/gdb/gdbserver/linux-low.h
@@ -365,10 +365,6 @@ struct lwp_info
      a exit-jump-pad-quickly breakpoint.  This is it.  */
   struct breakpoint *exit_jump_pad_bkpt;
 
-  /* True if the LWP was seen stop at an internal breakpoint and needs
-     stepping over later when it is resumed.  */
-  int need_step_over;
-
 #ifdef USE_THREAD_DB
   int thread_known;
   /* The thread handle, used for e.g. TLS access.  Only valid if