+ /* Compute the btrace thread flag for the requested move. */
+ if (step == 0)
+ flag = execution_direction == EXEC_REVERSE ? BTHR_RCONT : BTHR_CONT;
+ else
+ flag = execution_direction == EXEC_REVERSE ? BTHR_RSTEP : BTHR_STEP;
+
+ /* At the moment, we only move a single thread. We could also move
+ all threads in parallel by single-stepping each resumed thread
+ until the first runs into an event.
+ When we do that, we would want to continue all other threads.
+ For now, just resume one thread to not confuse to_wait. */
+ record_btrace_resume_thread (tp, flag);
+
+ /* We just indicate the resume intent here. The actual stepping happens in
+ record_btrace_wait below. */
+}
+
+/* Find a thread to move. */
+
+static struct thread_info *
+record_btrace_find_thread_to_move (ptid_t ptid)
+{
+ struct thread_info *tp;
+
+ /* First check the parameter thread. */
+ tp = find_thread_ptid (ptid);
+ if (tp != NULL && (tp->btrace.flags & BTHR_MOVE) != 0)
+ return tp;
+
+ /* Otherwise, find one other thread that has been resumed. */
+ ALL_THREADS (tp)
+ if ((tp->btrace.flags & BTHR_MOVE) != 0)
+ return tp;
+
+ return NULL;
+}
+
+/* Return a target_waitstatus indicating that we ran out of history. */
+
+static struct target_waitstatus
+btrace_step_no_history (void)
+{
+ struct target_waitstatus status;
+
+ status.kind = TARGET_WAITKIND_NO_HISTORY;
+
+ return status;
+}
+
+/* Return a target_waitstatus indicating that a step finished. */
+
+static struct target_waitstatus
+btrace_step_stopped (void)
+{
+ struct target_waitstatus status;
+
+ status.kind = TARGET_WAITKIND_STOPPED;
+ status.value.sig = GDB_SIGNAL_TRAP;
+
+ return status;
+}
+
+/* Clear the record histories. */
+
+static void
+record_btrace_clear_histories (struct btrace_thread_info *btinfo)
+{
+ xfree (btinfo->insn_history);
+ xfree (btinfo->call_history);
+
+ btinfo->insn_history = NULL;
+ btinfo->call_history = NULL;
+}
+
+/* Step a single thread. */
+
+static struct target_waitstatus
+record_btrace_step_thread (struct thread_info *tp)
+{
+ struct btrace_insn_iterator *replay, end;
+ struct btrace_thread_info *btinfo;
+ struct address_space *aspace;
+ struct inferior *inf;
+ enum btrace_thread_flag flags;
+ unsigned int steps;
+
+ btinfo = &tp->btrace;
+ replay = btinfo->replay;
+
+ flags = btinfo->flags & BTHR_MOVE;
+ btinfo->flags &= ~BTHR_MOVE;
+
+ DEBUG ("stepping %d (%s): %u", tp->num, target_pid_to_str (tp->ptid), flags);
+
+ switch (flags)
+ {
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid stepping type."));
+
+ case BTHR_STEP:
+ /* We're done if we're not replaying. */
+ if (replay == NULL)
+ return btrace_step_no_history ();
+
+ /* We are always able to step at least once. */
+ steps = btrace_insn_next (replay, 1);
+ gdb_assert (steps == 1);
+
+ /* Determine the end of the instruction trace. */
+ btrace_insn_end (&end, btinfo);
+
+ /* We stop replaying if we reached the end of the trace. */
+ if (btrace_insn_cmp (replay, &end) == 0)
+ record_btrace_stop_replaying (tp);
+
+ return btrace_step_stopped ();
+
+ case BTHR_RSTEP:
+ /* Start replaying if we're not already doing so. */
+ if (replay == NULL)
+ replay = record_btrace_start_replaying (tp);
+
+ /* If we can't step any further, we reached the end of the history. */
+ steps = btrace_insn_prev (replay, 1);
+ if (steps == 0)
+ return btrace_step_no_history ();
+
+ return btrace_step_stopped ();
+
+ case BTHR_CONT:
+ /* We're done if we're not replaying. */
+ if (replay == NULL)
+ return btrace_step_no_history ();
+
+ inf = find_inferior_pid (ptid_get_pid (tp->ptid));
+ aspace = inf->aspace;
+
+ /* Determine the end of the instruction trace. */
+ btrace_insn_end (&end, btinfo);
+
+ for (;;)
+ {
+ const struct btrace_insn *insn;
+
+ /* We are always able to step at least once. */
+ steps = btrace_insn_next (replay, 1);
+ gdb_assert (steps == 1);
+
+ /* We stop replaying if we reached the end of the trace. */
+ if (btrace_insn_cmp (replay, &end) == 0)
+ {
+ record_btrace_stop_replaying (tp);
+ return btrace_step_no_history ();
+ }
+
+ insn = btrace_insn_get (replay);
+ gdb_assert (insn);
+
+ DEBUG ("stepping %d (%s) ... %s", tp->num,
+ target_pid_to_str (tp->ptid),
+ core_addr_to_string_nz (insn->pc));
+
+ if (breakpoint_here_p (aspace, insn->pc))
+ return btrace_step_stopped ();
+ }
+
+ case BTHR_RCONT:
+ /* Start replaying if we're not already doing so. */
+ if (replay == NULL)
+ replay = record_btrace_start_replaying (tp);
+
+ inf = find_inferior_pid (ptid_get_pid (tp->ptid));
+ aspace = inf->aspace;
+
+ for (;;)
+ {
+ const struct btrace_insn *insn;
+
+ /* If we can't step any further, we're done. */
+ steps = btrace_insn_prev (replay, 1);
+ if (steps == 0)
+ return btrace_step_no_history ();
+
+ insn = btrace_insn_get (replay);
+ gdb_assert (insn);
+
+ DEBUG ("reverse-stepping %d (%s) ... %s", tp->num,
+ target_pid_to_str (tp->ptid),
+ core_addr_to_string_nz (insn->pc));
+
+ if (breakpoint_here_p (aspace, insn->pc))
+ return btrace_step_stopped ();
+ }
+ }
projects / external / binutils.git / commitdiff