[Wip] Implement simple subroutine opcodes

Author: Peppece

eth/vm/computation.py

@@ -71,6 +71,9 @@
 from eth.vm.stack import (
     Stack,
 )
+from eth.vm.rstack import (
+    RStack,
+)
 
 
 def NO_RESULT(computation: ComputationAPI) -> None:
@@ -140,6 +143,7 @@ def __init__(self,
 
         self._memory = Memory()
         self._stack = Stack()
+        self._rstack = RStack()
         self._gas_meter = self.get_gas_meter()
 
         self.children = []

eth/vm/logic/flow.py

@@ -79,10 +79,6 @@ def jumpsub(computation: BaseComputation) -> None:
 
     else:
         computation.code.program_counter += 1
-
-    if computation.rstack.length >= 1023:
-        #TODO: abort execution
-        pass
 
     computation.rstack_push_int(temp + 1)