Expose per-step pre_step/post_step callbacks

c_emulator/riscv_callbacks.cpp

@@ -18,6 +18,22 @@ void remove_callback(callbacks_if *cb)
                   callbacks.end());
 }
 
+// Invoke pre_step_callback on all registered callbacks before each step.
+void call_pre_step_callbacks(bool is_waiting)
+{
+  for (auto c : callbacks) {
+    c->pre_step_callback(is_waiting);
+  }
+}
+
+// Invoke post_step_callback on all registered callbacks after each step.
+void call_post_step_callbacks(bool is_waiting)
+{
+  for (auto c : callbacks) {
+    c->post_step_callback(is_waiting);
+  }
+}
+
 unit fetch_callback(sbits opcode)
 {
   for (auto c : callbacks) {

c_emulator/riscv_callbacks_if.h

@@ -8,6 +8,13 @@
 class callbacks_if {
 public:
   virtual ~callbacks_if() = default;
+
+  // Callback invoked before each step
+  virtual void pre_step_callback([[maybe_unused]] bool is_waiting) { }
+
+  // Callback invoked after each step
+  virtual void post_step_callback([[maybe_unused]] bool is_waiting) { }
+
   // TODO: finding ways to improve the format
   virtual void fetch_callback([[maybe_unused]] sbits opcode) { }
   virtual void mem_write_callback([[maybe_unused]] const char *type,
@@ -63,3 +70,5 @@ class callbacks_if {
 
 void register_callback(callbacks_if *cb);
 void remove_callback(callbacks_if *cb);
+void call_pre_step_callbacks(bool is_waiting);
+void call_post_step_callbacks(bool is_waiting);

c_emulator/riscv_sim.cpp

@@ -384,7 +384,7 @@ void flush_logs(void)
 
 void run_sail(void)
 {
-  bool is_waiting;
+  bool is_waiting = false;
   bool exit_wait = true;
 
   /* initialize the step number */
@@ -414,6 +414,9 @@ void run_sail(void)
         break;
       }
     }
+
+    call_pre_step_callbacks(is_waiting);
+
     { /* run a Sail step */
       sail_int sail_step;
       CREATE(sail_int)(&sail_step);
@@ -428,6 +431,9 @@ void run_sail(void)
         rvfi->send_trace(config_print_rvfi);
       }
     }
+
+    call_post_step_callbacks(is_waiting);
+
     if (!is_waiting) {
       if (config_print_step) {
         fprintf(trace_log, "\n");