+/* Fetch the possible triggered data watchpoint info and store it in
+ LP.
+
+ On some archs, like x86, that use debug registers to set
+ watchpoints, it's possible that the way to know which watched
+ address trapped, is to check the register that is used to select
+ which address to watch. Problem is, between setting the watchpoint
+ and reading back which data address trapped, the user may change
+ the set of watchpoints, and, as a consequence, GDB changes the
+ debug registers in the inferior. To avoid reading back a stale
+ stopped-data-address when that happens, we cache in LP the fact
+ that a watchpoint trapped, and the corresponding data address, as
+ soon as we see LP stop with a SIGTRAP. If GDB changes the debug
+ registers meanwhile, we have the cached data we can rely on. */
+
+static void
+save_sigtrap (struct lwp_info *lp)
+{
+ struct cleanup *old_chain;
+
+ if (linux_ops->to_stopped_by_watchpoint == NULL)
+ {
+ lp->stopped_by_watchpoint = 0;
+ return;
+ }
+
+ old_chain = save_inferior_ptid ();
+ inferior_ptid = lp->ptid;
+
+ lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint ();
+
+ if (lp->stopped_by_watchpoint)
+ {
+ if (linux_ops->to_stopped_data_address != NULL)
+ lp->stopped_data_address_p =
+ linux_ops->to_stopped_data_address (¤t_target,
+ &lp->stopped_data_address);
+ else
+ lp->stopped_data_address_p = 0;
+ }
+
+ do_cleanups (old_chain);
+}
+
+/* See save_sigtrap. */
+
+static int
+linux_nat_stopped_by_watchpoint (void)
+{
+ struct lwp_info *lp = find_lwp_pid (inferior_ptid);
+
+ gdb_assert (lp != NULL);
+
+ return lp->stopped_by_watchpoint;
+}
+
+static int
+linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
+{
+ struct lwp_info *lp = find_lwp_pid (inferior_ptid);
+
+ gdb_assert (lp != NULL);
+
+ *addr_p = lp->stopped_data_address;
+
+ return lp->stopped_data_address_p;
+}
+
+/* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
+
+static int
+sigtrap_is_event (int status)
+{
+ return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
+}
+
+/* SIGTRAP-like events recognizer. */
+
+static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
+
+/* Check for SIGTRAP-like events in LP. */
+
+static int
+linux_nat_lp_status_is_event (struct lwp_info *lp)
+{
+ /* We check for lp->waitstatus in addition to lp->status, because we can
+ have pending process exits recorded in lp->status
+ and W_EXITCODE(0,0) == 0. We should probably have an additional
+ lp->status_p flag. */
+
+ return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE
+ && linux_nat_status_is_event (lp->status));
+}
+
+/* Set alternative SIGTRAP-like events recognizer. If
+ breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
+ applied. */
+
+void
+linux_nat_set_status_is_event (struct target_ops *t,
+ int (*status_is_event) (int status))
+{
+ linux_nat_status_is_event = status_is_event;
+}
+