nitvm: The interpreter and the vm have each their own specialized frames

[nit.git] / src / variables_numbering.nit

diff --git a/src/variables_numbering.nit b/src/variables_numbering.nit
index 7698ad2..1190fab 100644 (file)
--- a/src/variables_numbering.nit
+++ b/src/variables_numbering.nit
@@ -21,6 +21,9 @@ import vm
 
 redef class VirtualMachine
 
+       # The frames of the VirtualMachine are specialized
+       redef type FRAME: VmFrame
+
        # Number the variables in `n`.
        # Do nothing if `n` is null
        fun numbering(n: nullable AExpr, position: Int): Int
@@ -30,6 +33,46 @@ redef class VirtualMachine
                var pos = n.numbering(self, position)
                return pos
        end
+
+       # Redef to add the numbering of variables and arguments
+       redef fun new_frame(node, mpropdef, args)
+       do
+               var f = new VmFrame(node, mpropdef, args)
+
+               # If this Frame is for a method then number variables into the body of the method
+               if node isa AMethPropdef then
+                       # Number the variables
+                       if not node.is_numbering then node.numbering_variables(self, mpropdef.as(MMethodDef))
+
+                       # Create an empty environment
+                       f.variables = new Array[Instance].filled_with(initialization_value, node.environment_size)
+               end
+
+               # If this Frame is for an attribute with a block then number the block
+               if node isa AAttrPropdef then
+                       # Number the variables
+                       if not node.is_numbering then node.numbering_variables(self)
+
+                       # Create an empty environment
+                       f.variables = new Array[Instance].filled_with(initialization_value, node.environment_size)
+               end
+
+               # Putting self at the beginning of the environment
+               f.variables[0] = args[0]
+               return f
+       end
+
+       # Read a `Variable` from a frame by using its position
+       redef fun read_variable(v: Variable): Instance
+       do
+               return frame.variables[v.position]
+       end
+
+       # Assign the value of the `Variable` in an environment
+       redef fun write_variable(v: Variable, value: Instance)
+       do
+               frame.variables[v.position] = value
+       end
 end
 
 redef class Variable
@@ -37,6 +80,14 @@ redef class Variable
        var position: Int
 end
 
+# Implementation of a Frame with numbered variables
+class VmFrame
+       super Frame
+
+       # Contains the value of Variables (which are numbered)
+       var variables: Array[Instance] = new Array[Instance]
+end
+
 redef class AExpr
        # Give a position to each variable declared in the node.
        # NOTE: Do not call this method directly, but use `v.numbering`