maintain virtual machine status

2 files changed, 57 insertions, 24 deletions

diff --git a/mixlib/mix_vm.c b/mixlib/mix_vm.c
index 692f84d..4bbc976 100644
--- a/mixlib/mix_vm.c
+++ b/mixlib/mix_vm.c
@@ -28,6 +28,7 @@ static void
 vm_reset_reload_ (mix_vm_t *vm, gboolean is_reload)
 {
   guint k;
+  set_status_ (vm, MIX_VM_EMPTY);
   set_rA_ (vm, MIX_WORD_ZERO);
   set_rX_ (vm, MIX_WORD_ZERO);
   set_rJ_ (vm, MIX_WORD_ZERO);
@@ -38,7 +39,6 @@ vm_reset_reload_ (mix_vm_t *vm, gboolean is_reload)
   set_loc_ (vm, MIX_WORD_ZERO);
   for ( k = 0; k < MEM_CELLS_NO_; ++k)
     set_cell_ (vm, k, MIX_WORD_ZERO);
-  halt_ (vm, FALSE);
   if (vm->symbol_table != NULL )
     {
       mix_symbol_table_delete (vm->symbol_table);
@@ -318,7 +318,11 @@ mix_vm_load_file (mix_vm_t *vm, const gchar *name)
   
   g_return_val_if_fail (vm != NULL, FALSE);
   file = mix_code_file_new_read (name);
-  if (file == NULL) return FALSE;
+  if (file == NULL)
+    {
+      set_status_ (vm, MIX_VM_ERROR);
+      return FALSE;
+    }
   sp = mix_code_file_get_source_path (file);
 
   if (sp != NULL)
@@ -357,6 +361,7 @@ mix_vm_load_file (mix_vm_t *vm, const gchar *name)
   set_start_ (vm, get_loc_ (vm));
   mix_code_file_delete (file);
   
+  set_status_ (vm, MIX_VM_LOADED);
   return TRUE;
 }
 
@@ -428,7 +433,7 @@ mix_vm_get_lineno_address (const mix_vm_t *vm, guint lineno)
 
 
 /* continue execution of instructions in memory */
-int
+mix_vm_status_t
 mix_vm_run (mix_vm_t *vm)
 {
   mix_ins_t ins;
@@ -441,39 +446,47 @@ mix_vm_run (mix_vm_t *vm)
 	g_slist_prepend (vm->address_list,
 			 GINT_TO_POINTER ((gint)get_loc_ (vm)));
       if ( !(*ins_handlers_[ins.opcode]) (vm,&ins) ) 
-	return MIX_VM_ERROR;
+	return set_status_ (vm, MIX_VM_ERROR);
       else
 	update_time_ (vm, &ins);
       if (bp_is_set_ (vm, get_loc_ (vm)))
-	return MIX_VM_BREAK;
+	return set_status_ (vm, MIX_VM_BREAK);
       if (mix_predicate_list_eval (get_pred_list_ (vm)))
-	return MIX_VM_COND_BREAK;
+	return set_status_ (vm, MIX_VM_COND_BREAK);
       if (get_loc_ (vm) >= MIX_VM_CELL_NO) halt_ (vm, TRUE);
     }
-  return MIX_VM_HALT;
+  return set_status_ (vm, MIX_VM_HALT);
 }
 
 /* execute next memory instruction */
-int
+mix_vm_status_t
 mix_vm_exec_next (mix_vm_t *vm)
 {
   mix_ins_t ins;
   g_return_val_if_fail (vm != NULL, MIX_VM_ERROR);
   if (get_loc_ (vm) >= MIX_VM_CELL_NO) halt_ (vm, TRUE);
-  if (is_halted_ (vm)) return MIX_VM_HALT;
+  if (is_halted_ (vm)) return set_status_ (vm, MIX_VM_HALT);
   vm->address_list =
     g_slist_prepend (vm->address_list,
 		     GINT_TO_POINTER ((gint)get_loc_ (vm)));
   mix_word_to_ins_uncheck (get_cell_ (vm, get_loc_ (vm)), ins);
   if (!(*ins_handlers_[ins.opcode]) (vm, &ins))
-    return MIX_VM_ERROR;
+    return set_status_ (vm, MIX_VM_ERROR);
   else
     update_time_ (vm, &ins);
-  if (is_halted_ (vm)) return MIX_VM_HALT;
-  if (bp_is_set_ (vm, get_loc_ (vm))) return MIX_VM_BREAK;
+  if (is_halted_ (vm)) return set_status_ (vm, MIX_VM_HALT);
+  if (bp_is_set_ (vm, get_loc_ (vm))) return set_status_ (vm, MIX_VM_BREAK);
   if (mix_predicate_list_eval (get_pred_list_ (vm)))
-    return MIX_VM_COND_BREAK;
-  return MIX_VM_OK;
+    return set_status_ (vm, MIX_VM_COND_BREAK);
+  return set_status_ (vm, MIX_VM_RUNNING);
+}
+
+/* get the current execution status */
+mix_vm_status_t
+mix_vm_get_run_status (const mix_vm_t *vm)
+{
+  g_return_val_if_fail (vm != NULL, MIX_VM_ERROR);
+  return get_status_ (vm);
 }
 
 /* Breakpoints */
@@ -624,6 +637,15 @@ mix_vm_get_last_breakpoint_message (const mix_vm_t *vm)
   return NULL;
 }
 
+mix_predicate_type_t
+mix_vm_get_last_conditional_breakpoint_type (const mix_vm_t *vm)
+{
+  const mix_predicate_t *last = NULL;
+  g_return_val_if_fail (vm != NULL, MIX_PRED_INVALID);
+  last = mix_predicate_list_last_true_eval (get_pred_list_ (vm));
+  return last? mix_predicate_get_type (last) : MIX_PRED_INVALID;
+}
+
 /* Get the vm uptime, defined as the time spent executing instructions */
 mix_time_t
 mix_vm_get_uptime (const mix_vm_t *vm)
diff --git a/mixlib/mix_vm.h b/mixlib/mix_vm.h
index d3f4e3f..b7412bf 100644
--- a/mixlib/mix_vm.h
+++ b/mixlib/mix_vm.h
@@ -153,25 +153,33 @@ mix_vm_get_lineno_address (const mix_vm_t *vm, guint lineno);
 
 /* continue execution of instructions in memory */
 /* Possible outcomes */
-enum {
-  MIX_VM_ERROR,		/* error executing instructions */
-  MIX_VM_BREAK,		/* breakpoint found */
-  MIX_VM_COND_BREAK,    /* conditional breakpoint found */
-  MIX_VM_HALT,		/* end of execution */
-  MIX_VM_OK		/* successful instruction execution */
-};
-
-extern int
+typedef enum {
+  MIX_VM_ERROR,			/* error executing instructions */
+  MIX_VM_BREAK,			/* breakpoint found */
+  MIX_VM_COND_BREAK,		/* conditional breakpoint found */
+  MIX_VM_HALT,			/* end of execution */
+  MIX_VM_RUNNING,		/* successful instruction execution */
+  MIX_VM_LOADED,		/* program loaded */
+  MIX_VM_EMPTY			/* no program loaded */
+} mix_vm_status_t;
+
+/* run until next breakpoint or end of execution */
+extern mix_vm_status_t
 mix_vm_run (mix_vm_t *vm);
 
 /* execute next memory instruction */
-extern int
+extern mix_vm_status_t
 mix_vm_exec_next (mix_vm_t *vm);
 
+/* get the current execution status */
+extern mix_vm_status_t
+mix_vm_get_run_status (const mix_vm_t *vm);
+
 /* get the line no. of the last break or 0 if not found */
 extern gulong
 mix_vm_get_break_lineno (const mix_vm_t *vm);
 
+
 /* Breakpoints */
 /* possible error outcomes */
 enum {
@@ -210,6 +218,9 @@ mix_vm_clear_conditional_breakpoint (mix_vm_t *vm, mix_predicate_t *pred);
 extern const gchar *
 mix_vm_get_last_breakpoint_message (const mix_vm_t *vm);
 
+extern mix_predicate_type_t
+mix_vm_get_last_conditional_breakpoint_type (const mix_vm_t *vm);
+
 /* Get the vm uptime, defined as the time spent executing instructions */
 extern mix_time_t
 mix_vm_get_uptime (const mix_vm_t *vm);