2015-03-04 Pedro Alves <palves@redhat.com>
+ * NEWS: Mention the new "swbreak" and "hwbreak" stop reasons.
+ * remote.c (struct remote_state) <remote_stopped_by_watchpoint_p>:
+ Delete field.
+ <stop_reason>: New field.
+ (PACKET_swbreak_feature, PACKET_hwbreak_feature): New enum values.
+ (packet_set_cmd_state): New function.
+ (remote_protocol_features): Register the "swbreak" and "hwbreak"
+ features.
+ (remote_query_supported): If not disabled with the corresponding
+ "set remote foo-packet" command, report support for the swbreak
+ and hwbreak features.
+ (struct stop_reply) <remote_stopped_by_watchpoint_p>: Delete
+ field.
+ <stop_reason>: New field.
+ (remote_parse_stop_reply): Handle "swbreak" and "hwbreak".
+ (remote_wait_as): Adjust.
+ (remote_stopped_by_sw_breakpoint)
+ (remote_supports_stopped_by_sw_breakpoint)
+ (remote_stopped_by_hw_breakpoint)
+ (remote_supports_stopped_by_hw_breakpoint): New functions.
+ (remote_stopped_by_watchpoint): New function.
+ (init_remote_ops): Install them.
+ (_initialize_remote): Register new "set/show remote
+ swbreak-feature-packet" and "set/show remote
+ swbreak-feature-packet" commands.
+
+2015-03-04 Pedro Alves <palves@redhat.com>
+
* btrace.h: Include target/waitstatus.h.
(struct btrace_thread_info) <stop_reason>: New field.
* record-btrace.c (record_btrace_step_thread): Use
@item @code{conditional-breakpoints-packet}
@tab @code{Z0 and Z1}
@tab @code{Support for target-side breakpoint condition evaluation}
+
+@item @code{swbreak-feature}
+@tab @code{swbreak stop reason}
+@tab @code{break}
+
+@item @code{hwbreak-feature}
+@tab @code{hwbreak stop reason}
+@tab @code{hbreak}
+
@end multitable
@node Remote Stub
conditions that should be taken into consideration when deciding if
the breakpoint trigger should be reported back to @var{GDBN}.
+See also the @samp{swbreak} stop reason (@pxref{swbreak stop reason})
+for how to best report a memory breakpoint event to @value{GDBN}.
+
The @var{cond_list} parameter is comprised of a series of expressions,
concatenated without separators. Each expression has the following form:
beginning when executing backward) of the log. The value of @var{r}
will be either @samp{begin} or @samp{end}. @xref{Reverse Execution},
for more information.
+
+@item swbreak
+@anchor{swbreak stop reason}
+The packet indicates a memory breakpoint instruction was executed,
+irrespective of whether it was @value{GDBN} that planted the
+breakpoint or the breakpoint is hardcoded in the program. The @var{r}
+part must be left empty.
+
+On some architectures, such as x86, at the architecture level, when a
+breakpoint instruction executes the program counter points at the
+breakpoint address plus an offset. On such targets, the stub is
+responsible for adjusting the PC to point back at the breakpoint
+address.
+
+This packet should not be sent by default; older @value{GDBN} versions
+did not support it. @value{GDBN} requests it, by supplying an
+appropriate @samp{qSupported} feature (@pxref{qSupported}). The
+remote stub must also supply the appropriate @samp{qSupported} feature
+indicating support.
+
+This packet is required for correct non-stop mode operation.
+
+@item hwbreak
+The packet indicates the target stopped for a hardware breakpoint.
+The @var{r} part must be left empty.
+
+The same remarks about @samp{qSupported} and non-stop mode above
+apply.
@end table
@item W @var{AA}
This feature indicates whether @value{GDBN} supports the
@samp{qRelocInsn} packet (@pxref{Tracepoint Packets,,Relocate
instruction reply packet}).
+
+@item swbreak
+This feature indicates whether @value{GDBN} supports the swbreak stop
+reason in stop replies. @xref{swbreak stop reason}, for details.
+
+@item hwbreak
+This feature indicates whether @value{GDBN} supports the hwbreak stop
+reason in stop replies. @xref{swbreak stop reason}, for details.
@end table
Stubs should ignore any unknown values for
@tab @samp{-}
@tab No
+@item @samp{swbreak}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{hwbreak}
+@tab No
+@tab @samp{-}
+@tab No
+
@end multitable
These are the currently defined stub features, in more detail:
@item Qbtrace-conf:bts:size
The remote stub understands the @samp{Qbtrace-conf:bts:size} packet.
+@item swbreak
+The remote stub reports the @samp{swbreak} stop reason for memory
+breakpoints.
+
+@item hwbreak
+The remote stub reports the @samp{hwbreak} stop reason for hardware
+breakpoints.
+
@end table
@item qSymbol::
or if the target is not attached to any process, it shall respond
@samp{OK}.
+If the stub supports non-stop mode, it should also support the
+@samp{swbreak} stop reason if software breakpoints are supported, and
+the @samp{hwbreak} stop reason if hardware breakpoints are supported
+(@pxref{swbreak stop reason}). This is because given the asynchronous
+nature of non-stop mode, between the time a thread hits a breakpoint
+and the time the event is finally processed by @value{GDBN}, the
+breakpoint may have already been removed from the target. Due to
+this, @value{GDBN} needs to be able to tell whether a trap stop was
+caused by a delayed breakpoint event, which should be ignored, as
+opposed to a random trap signal, which should be reported to the user.
+Note the @samp{swbreak} feature implies that the target is responsible
+for adjusting the PC when a software breakpoint triggers, if
+necessary, such as on the x86 architecture.
+
@node Packet Acknowledgment
@section Packet Acknowledgment
to stop for a watchpoint. */
CORE_ADDR remote_watch_data_address;
- /* This is non-zero if target stopped for a watchpoint. */
- int remote_stopped_by_watchpoint_p;
+ /* Whether the target stopped for a breakpoint/watchpoint. */
+ enum target_stop_reason stop_reason;
threadref echo_nextthread;
threadref nextthread;
/* Support for the Qbtrace-conf:bts:size packet. */
PACKET_Qbtrace_conf_bts_size,
+ /* Support for swbreak+ feature. */
+ PACKET_swbreak_feature,
+
+ /* Support for hwbreak+ feature. */
+ PACKET_hwbreak_feature,
+
PACKET_MAX
};
static struct packet_config remote_protocol_packets[PACKET_MAX];
+/* Returns the packet's corresponding "set remote foo-packet" command
+ state. See struct packet_config for more details. */
+
+static enum auto_boolean
+packet_set_cmd_state (int packet)
+{
+ return remote_protocol_packets[packet].detect;
+}
+
/* Returns whether a given packet or feature is supported. This takes
into account the state of the corresponding "set remote foo-packet"
command, which may be used to bypass auto-detection. */
{ "qXfer:btrace-conf:read", PACKET_DISABLE, remote_supported_packet,
PACKET_qXfer_btrace_conf },
{ "Qbtrace-conf:bts:size", PACKET_DISABLE, remote_supported_packet,
- PACKET_Qbtrace_conf_bts_size }
+ PACKET_Qbtrace_conf_bts_size },
+ { "swbreak", PACKET_DISABLE, remote_supported_packet, PACKET_swbreak_feature },
+ { "hwbreak", PACKET_DISABLE, remote_supported_packet, PACKET_hwbreak_feature }
};
static char *remote_support_xml;
q = remote_query_supported_append (q, "multiprocess+");
+ if (packet_set_cmd_state (PACKET_swbreak_feature) != AUTO_BOOLEAN_FALSE)
+ q = remote_query_supported_append (q, "swbreak+");
+ if (packet_set_cmd_state (PACKET_hwbreak_feature) != AUTO_BOOLEAN_FALSE)
+ q = remote_query_supported_append (q, "hwbreak+");
+
if (remote_support_xml)
q = remote_query_supported_append (q, remote_support_xml);
fetch them is avoided). */
VEC(cached_reg_t) *regcache;
- int stopped_by_watchpoint_p;
+ enum target_stop_reason stop_reason;
+
CORE_ADDR watch_data_address;
int core;
event->rs = get_remote_state ();
event->ws.kind = TARGET_WAITKIND_IGNORE;
event->ws.value.integer = 0;
- event->stopped_by_watchpoint_p = 0;
+ event->stop_reason = TARGET_STOPPED_BY_NO_REASON;
event->regcache = NULL;
event->core = -1;
|| (strncmp (p, "rwatch", p1 - p) == 0)
|| (strncmp (p, "awatch", p1 - p) == 0))
{
- event->stopped_by_watchpoint_p = 1;
+ event->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
p = unpack_varlen_hex (++p1, &addr);
event->watch_data_address = (CORE_ADDR) addr;
}
+ else if (strncmp (p, "swbreak", p1 - p) == 0)
+ {
+ event->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
+
+ /* Make sure the stub doesn't forget to indicate support
+ with qSupported. */
+ if (packet_support (PACKET_swbreak_feature) != PACKET_ENABLE)
+ error (_("Unexpected swbreak stop reason"));
+
+ /* The value part is documented as "must be empty",
+ though we ignore it, in case we ever decide to make
+ use of it in a backward compatible way. */
+ p = skip_to_semicolon (p1 + 1);
+ }
+ else if (strncmp (p, "hwbreak", p1 - p) == 0)
+ {
+ event->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
+
+ /* Make sure the stub doesn't forget to indicate support
+ with qSupported. */
+ if (packet_support (PACKET_hwbreak_feature) != PACKET_ENABLE)
+ error (_("Unexpected hwbreak stop reason"));
+
+ /* See above. */
+ p = skip_to_semicolon (p1 + 1);
+ }
else if (strncmp (p, "library", p1 - p) == 0)
{
event->ws.kind = TARGET_WAITKIND_LOADED;
VEC_free (cached_reg_t, stop_reply->regcache);
}
- rs->remote_stopped_by_watchpoint_p = stop_reply->stopped_by_watchpoint_p;
+ rs->stop_reason = stop_reply->stop_reason;
rs->remote_watch_data_address = stop_reply->watch_data_address;
remote_notice_new_inferior (ptid, 0);
buf = rs->buf;
- rs->remote_stopped_by_watchpoint_p = 0;
+ rs->stop_reason = TARGET_STOPPED_BY_NO_REASON;
/* We got something. */
rs->waiting_for_stop_reply = 0;
return -1;
}
+/* The to_stopped_by_sw_breakpoint method of target remote. */
+
+static int
+remote_stopped_by_sw_breakpoint (struct target_ops *ops)
+{
+ struct remote_state *rs = get_remote_state ();
+
+ return rs->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
+}
+
+/* The to_supports_stopped_by_sw_breakpoint method of target
+ remote. */
+
+static int
+remote_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
+{
+ struct remote_state *rs = get_remote_state ();
+
+ return (packet_support (PACKET_swbreak_feature) == PACKET_ENABLE);
+}
+
+/* The to_stopped_by_hw_breakpoint method of target remote. */
+
+static int
+remote_stopped_by_hw_breakpoint (struct target_ops *ops)
+{
+ struct remote_state *rs = get_remote_state ();
+
+ return rs->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
+}
+
+/* The to_supports_stopped_by_hw_breakpoint method of target
+ remote. */
+
+static int
+remote_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
+{
+ struct remote_state *rs = get_remote_state ();
+
+ return (packet_support (PACKET_hwbreak_feature) == PACKET_ENABLE);
+}
+
static int
remote_stopped_by_watchpoint (struct target_ops *ops)
{
struct remote_state *rs = get_remote_state ();
- return rs->remote_stopped_by_watchpoint_p;
+ return rs->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
}
static int
remote_ops.to_files_info = remote_files_info;
remote_ops.to_insert_breakpoint = remote_insert_breakpoint;
remote_ops.to_remove_breakpoint = remote_remove_breakpoint;
+ remote_ops.to_stopped_by_sw_breakpoint = remote_stopped_by_sw_breakpoint;
+ remote_ops.to_supports_stopped_by_sw_breakpoint = remote_supports_stopped_by_sw_breakpoint;
+ remote_ops.to_stopped_by_hw_breakpoint = remote_stopped_by_hw_breakpoint;
+ remote_ops.to_supports_stopped_by_hw_breakpoint = remote_supports_stopped_by_hw_breakpoint;
remote_ops.to_stopped_by_watchpoint = remote_stopped_by_watchpoint;
remote_ops.to_stopped_data_address = remote_stopped_data_address;
remote_ops.to_watchpoint_addr_within_range =
add_packet_config_cmd (&remote_protocol_packets[PACKET_Qbtrace_conf_bts_size],
"Qbtrace-conf:bts:size", "btrace-conf-bts-size", 0);
+ add_packet_config_cmd (&remote_protocol_packets[PACKET_swbreak_feature],
+ "swbreak-feature", "swbreak-feature", 0);
+
+ add_packet_config_cmd (&remote_protocol_packets[PACKET_hwbreak_feature],
+ "hwbreak-feature", "hwbreak-feature", 0);
+
/* Assert that we've registered commands for all packet configs. */
{
int i;