[PATCH 4/7] range stepping: gdb

Yao Qi
2013-03-11T12:53:02Z

This patch teaches GDB to send 'vCont;r' packet when appropriate.
GDB has to check whether the target understands 'r' action of 'vCont'
packet. We also make use of fields 'step_range_start' and
'step_range_end' of 'struct thread_control_state' to compose the range
of the stepping.

gdb:

2013-03-11 Yao Qi <yao@codesourcery.com>

* remote.c (struct support_v_cont) <r>: New field.
(remote_vcont_probe): Handle 'r' action of 'vCont' packet.
(append_resumption): Send 'vCont;r' for range stepping.
---
gdb/remote.c | 36 +++++++++++++++++++++++++++++++++++-
1 files changed, 35 insertions(+), 1 deletions(-)

diff --git a/gdb/remote.c b/gdb/remote.c
index ae0ae7e..84e09b0 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -253,6 +253,8 @@ struct support_v_cont
{
/* True if the stub reports support for vCont;t. */
int t;
+ /* True if the stub reports support for vCont;r. */
+ int r;
};

/* Description of the remote protocol state for the currently
@@ -4644,6 +4646,7 @@ remote_vcont_probe (struct remote_state *rs)
support_c = 0;
support_C = 0;
rs->support_vCont.t = 0;
+ rs->support_vCont.r = 0;
while (p && *p == ';')
{
p++;
@@ -4657,6 +4660,8 @@ remote_vcont_probe (struct remote_state *rs)
support_C = 1;
else if (*p == 't' && (*(p + 1) == ';' || *(p + 1) == 0))
rs->support_vCont.t = 1;
+ else if (*p == 'r' && (*(p + 1) == ';' || *(p + 1) == 0))
+ rs->support_vCont.r = 1;

p = strchr (p, ';');
}
@@ -4689,7 +4694,36 @@ append_resumption (char *p, char *endp,
if (step && siggnal != GDB_SIGNAL_0)
p += xsnprintf (p, endp - p, ";S%02x", siggnal);
else if (step)
- p += xsnprintf (p, endp - p, ";s");
+ {
+ struct thread_info *tp = NULL;
+ CORE_ADDR pc;
+
+ gdb_assert (!ptid_equal (ptid, minus_one_ptid));
+
+ if (ptid_is_pid (ptid))
+ tp = find_thread_ptid (inferior_ptid);
+ else
+ tp = find_thread_ptid (ptid);
+ gdb_assert (tp != NULL);
+
+ pc = regcache_read_pc (get_thread_regcache (ptid));
+ if (rs->support_vCont.r /* Target supports step range. */
+ /* Can't do range stepping for all threads of a process
+ 'pPID.-1'. */
+ && !(remote_multi_process_p (rs) && ptid_is_pid (ptid))
+ /* Not step over a breakpoint. */
+ && !tp->control.trap_expected
+ /* We have a range to single step. */
+ && THREAD_WITHIN_SINGLE_STEP_RANGE (tp, pc))
+ {
+ p += xsnprintf (p, endp - p, ";r");
+ p += hexnumstr (p, tp->control.step_range_start);
+ p += xsnprintf (p, endp - p, ",");
+ p += hexnumstr (p, tp->control.step_range_end);
+ }
+ else
+ p += xsnprintf (p, endp - p, ";s");
+ }
else if (siggnal != GDB_SIGNAL_0)
p += xsnprintf (p, endp - p, ";C%02x", siggnal);
else
--
1.7.7.6