Add: is_read_only()

nml/expression/array.py

@@ -31,3 +31,9 @@ def __str__(self):
 
     def reduce(self, id_dicts = [], unknown_id_fatal = True):
         return Array([val.reduce(id_dicts, unknown_id_fatal) for val in self.values], self.pos)
+
+    def is_read_only(self):
+        ret = True
+        for v in self.values:
+            ret = ret and v.is_read_only()
+        return ret

nml/expression/base_expression.py

@@ -101,6 +101,14 @@ def supported_by_actionD(self, raise_error):
         if raise_error: raise generic.ScriptError("This expression can not be assigned to a parameter", self.pos)
         return False
 
+    def is_read_only(self):
+        """
+        Check if this expression store values.
+
+        @return: True if the expression doesn't store values.
+        """
+        return True
+
     def is_boolean(self):
         """
         Check if this expression is limited to 0 or 1 as value.

nml/expression/bin_not.py

@@ -41,6 +41,9 @@ def supported_by_action2(self, raise_error):
     def supported_by_actionD(self, raise_error):
         return self.expr.supported_by_actionD(raise_error)
 
+    def is_read_only(self):
+        return self.expr.is_read_only()
+
     def __str__(self):
         return "~" + str(self.expr)
 
@@ -76,6 +79,9 @@ def supported_by_action2(self, raise_error):
     def supported_by_actionD(self, raise_error):
         return self.expr.supported_by_actionD(raise_error)
 
+    def is_read_only(self):
+        return self.expr.is_read_only()
+
     def is_boolean(self):
         return True
 

nml/expression/binop.py

@@ -178,6 +178,9 @@ def supported_by_actionD(self, raise_error):
             return False
         return self.expr1.supported_by_actionD(raise_error) and self.expr2.supported_by_actionD(raise_error)
 
+    def is_read_only(self):
+        return self.expr1.is_read_only() and self.expr2.is_read_only()
+
     def is_boolean(self):
         if self.op in (nmlop.AND, nmlop.OR, nmlop.XOR):
             return self.expr1.is_boolean() and self.expr2.is_boolean()

nml/expression/bitmask.py

@@ -39,5 +39,11 @@ def reduce(self, id_dicts = [], unknown_id_fatal = True):
             ret = BinOp(nmlop.OR, ret, val, self.pos)
         return ret.reduce()
 
+    def is_read_only(self):
+        ret = True
+        for v in self.values:
+            ret = ret and v.is_read_only()
+        return ret
+
     def __str__(self):
         return "bitmask(" + ", ".join(str(e) for e in self.values) + ")"

nml/expression/boolean.py

@@ -44,6 +44,9 @@ def supported_by_action2(self, raise_error):
     def supported_by_actionD(self, raise_error):
         return self.expr.supported_by_actionD(raise_error)
 
+    def is_read_only(self):
+        return self.expr.is_read_only()
+
     def is_boolean(self):
         return True
 

nml/expression/storage_op.py

@@ -121,3 +121,6 @@ def supported_by_actionD(self, raise_error):
         if raise_error:
             raise generic.ScriptError("{}() may only be used inside switch-blocks".format(self.name), self.pos)
         return False
+
+    def is_read_only(self):
+        return (not self.info['store']) and self.register.is_read_only() and (self.value.is_read_only() if self.value is not None else True)

nml/expression/ternaryop.py

@@ -51,6 +51,9 @@ def supported_by_action2(self, raise_error):
     def supported_by_actionD(self, raise_error):
         return self.guard.supported_by_actionD(raise_error) and self.expr1.supported_by_actionD(raise_error) and self.expr2.supported_by_actionD(raise_error)
 
+    def is_read_only(self):
+        return self.expr1.is_read_only() and self.expr2.is_read_only()
+
     def is_boolean(self):
         return self.expr1.is_boolean() and self.expr2.is_boolean()