[PATCH 5/7] range stepping: New command 'maint set range stepping'

Yao Qi
2013-03-11T12:53:14Z

gdb:

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

* remote.c (use_range_stepping): New.
(remote_vcont_probe): Set 'use_range_stepping' if the remote
target supports range stepping.
(append_resumption): Use 'vCont;r' packet if 'use_range_stepping'
is true.
(maint_show_range_stepping): New.
(maint_set_range_stepping): New.
(_initialize_remote): Call add_setshow_boolean_cmd to register
commands 'maint set range-stepping' and
'maint show range-stepping'.

gdb/doc:

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

* gdb.texinfo (Maintenance Commands): Document commands
'maint set range-stepping' and 'maint show range-stepping'.
---
gdb/doc/gdb.texinfo | 7 +++++
gdb/remote.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 70 insertions(+), 1 deletions(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index a607166..7c06120 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -35547,6 +35547,13 @@ data in a @file{gmon.out} file, be sure to move it to a safe location.
Configuring with @samp{--enable-profiling} arranges for @value{GDBN} to be
compiled with the @samp{-pg} compiler option.

+@kindex maint set range-stepping
+@kindex maint show range-stepping
+@cindex range-stepping
+@item maint set range-stepping
+@itemx maint show range-stepping
+Control whether to do stepping in an address range.
+
@kindex maint set show-debug-regs
@kindex maint show show-debug-regs
@cindex hardware debug registers
diff --git a/gdb/remote.c b/gdb/remote.c
index 84e09b0..de7391f 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -257,6 +257,10 @@ struct support_v_cont
int r;
};

+/* A flag on GDB is willing to use range-stepping or not. */
+
+static int use_range_stepping = 0;
+
/* Description of the remote protocol state for the currently
connected target. This is per-target state, and independent of the
selected architecture. */
@@ -4647,6 +4651,7 @@ remote_vcont_probe (struct remote_state *rs)
support_C = 0;
rs->support_vCont.t = 0;
rs->support_vCont.r = 0;
+ use_range_stepping = 0;
while (p && *p == ';')
{
p++;
@@ -4661,7 +4666,10 @@ remote_vcont_probe (struct remote_state *rs)
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;
+ {
+ rs->support_vCont.r = 1;
+ use_range_stepping = 1;
+ }

p = strchr (p, ';');
}
@@ -4708,6 +4716,8 @@ append_resumption (char *p, char *endp,

pc = regcache_read_pc (get_thread_regcache (ptid));
if (rs->support_vCont.r /* Target supports step range. */
+ /* GDB is willing to do range stepping. */
+ && use_range_stepping
/* Can't do range stepping for all threads of a process
'pPID.-1'. */
&& !(remote_multi_process_p (rs) && ptid_is_pid (ptid))
@@ -11488,6 +11498,45 @@ remote_upload_trace_state_variables (struct uploaded_tsv **utsvp)
return 0;
}

+static void
+maint_show_range_stepping (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c,
+ const char *value)
+{
+ fprintf_filtered (file,
+ _("Debugger's willingness to do range-stepping "
+ "is %s.\n"), value);
+}
+
+static void
+maint_set_range_stepping (char *ignore_args, int from_tty,
+ struct cmd_list_element *c)
+{
+ /* Check range stepping is supported when turns it on. */
+ if (use_range_stepping)
+ {
+ if (remote_desc != NULL)
+ {
+ struct remote_state *rs = get_remote_state ();
+
+ if (remote_protocol_packets[PACKET_vCont].support == PACKET_SUPPORT_UNKNOWN)
+ remote_vcont_probe (rs);
+
+ if (remote_protocol_packets[PACKET_vCont].support == PACKET_DISABLE
+ || !rs->support_vCont.r)
+ {
+ use_range_stepping = 0;
+ error (_("Range stepping is not supported"));
+ }
+ }
+ else
+ {
+ use_range_stepping = 0;
+ error (_("Range stepping is not supported"));
+ }
+ }
+}
+
void
_initialize_remote (void)
{
@@ -11873,6 +11922,19 @@ Set the remote pathname for \"run\""), _("\
Show the remote pathname for \"run\""), NULL, NULL, NULL,
&remote_set_cmdlist, &remote_show_cmdlist);

+ add_setshow_boolean_cmd ("range-stepping", class_maintenance,
+ &use_range_stepping, _("\
+Enable or disable range-stepping."), _("\
+Show whether range-stepping is enabled."), _("\
+If On, GDB will tell the target to do stepping a range of address.\n\
+This will speed up stepping a line of source file.\n\
+If off, GDB will not use it, even if such is supported by the \n\
+target"),
+ maint_set_range_stepping,
+ maint_show_range_stepping,
+ &maintenance_set_cmdlist,
+ &maintenance_show_cmdlist);
+
/* Eventually initialize fileio. See fileio.c */
initialize_remote_fileio (remote_set_cmdlist, remote_show_cmdlist);

--
1.7.7.6