[WIP] Implement subroutine opcodes

Author: Peppece

eth/abc.py

@@ -1598,7 +1598,7 @@ def rstack_push_int(self) -> Callable[[int], None]:
         """
         Push integer onto the return stack.
         """
-    
+
     @abstractmethod
     def rstack_pop1_int(self) -> Callable[[int], None]:
         """

eth/vm/computation.py

@@ -324,7 +324,7 @@ def stack_push_int(self) -> Callable[[int], None]:
     @cached_property
     def stack_push_bytes(self) -> Callable[[bytes], None]:
         return self._stack.push_bytes
-    
+
     #
     # Return Stack Management
     #

eth/vm/forks/__init__.py

@@ -25,6 +25,6 @@
 from .muir_glacier import (  # noqa: F401
     MuirGlacierVM,
 )
-from .berlin import (
+from .berlin import (  # noqa: F401
     BerlinVM,
 )

eth/vm/forks/berlin/opcodes.py

@@ -14,25 +14,24 @@
 from eth.vm.logic import flow
 
 UPDATED_OPCODES = {
-	opcode_values.BEGINSUB: as_opcode(
-		logic_fn = flow.beginsub,
-		mnemonic = mnemonics.BEGINSUB,
-		gas_cost = constants.GAS_BASE,
-	),
-	opcode_values.JUMPSUB: as_opcode(
-		logic_fn = flow.jumpsub,
-		mnemonic = mnemonics.JUMPSUB,
-		gas_cost = constants.GAS_HIGH,
-	),
-	opcode_values.RETURNSUB: as_opcode(
-		logic_fn = flow.returnsub,
-		mnemonic = mnemonics.RETURNSUB,
-		gas_cost = constants.GAS_LOW,
-	),
+    opcode_values.BEGINSUB: as_opcode(
+        logic_fn=flow.beginsub,
+        mnemonic=mnemonics.BEGINSUB,
+        gas_cost=constants.GAS_BASE,
+    ),
+    opcode_values.JUMPSUB: as_opcode(
+        logic_fn=flow.jumpsub,
+        mnemonic=mnemonics.JUMPSUB,
+        gas_cost=constants.GAS_HIGH,
+    ),
+    opcode_values.RETURNSUB: as_opcode(
+        logic_fn=flow.returnsub,
+        mnemonic=mnemonics.RETURNSUB,
+        gas_cost=constants.GAS_LOW,
+    ),
 }
 
-
 BERLIN_OPCODES = merge(
-	copy.deepcopy(MUIR_GLACIER_OPCODES),
-	UPDATED_OPCODES,
+    copy.deepcopy(MUIR_GLACIER_OPCODES),
+    UPDATED_OPCODES,
 )

eth/vm/logic/flow.py

@@ -71,7 +71,8 @@ def jumpsub(computation: BaseComputation) -> None:
     code_range_length = computation.code._length_cache
 
     if sub_loc >= code_range_length:
-        raise InvalidJumpDestination("Error: at pc={}, op=JUMPSUB: invalid jump destination".format(computation.code.program_counter))
+        raise InvalidJumpDestination(
+            "Error: at pc={}, op=JUMPSUB: invalid jump destination".format(computation.code.program_counter))
 
     if computation.code.is_valid_opcode(sub_loc):
 
@@ -87,8 +88,7 @@ def returnsub(computation: BaseComputation) -> None:
     try:
         ret_loc = computation.rstack_pop1_int()
     except InsufficientStack:
-        raise InsufficientStack("Error: at pc={}, op=RETURNSUB: invalid retsub".format(computation.code.program_counter))
-        
-    
-    computation.code.program_counter = ret_loc
+        raise InsufficientStack(
+            "Error: at pc={}, op=RETURNSUB: invalid retsub".format(computation.code.program_counter))
 
+    computation.code.program_counter = ret_loc

eth/vm/rstack.py

@@ -18,11 +18,14 @@
 
 """
 This module simply implements for the return stack the exact same design used for the data stack.
-As this stack must simply push_int or pop1_int any time a subroutine is accessed or left, only those two functions are provided.
-For the same reason, the class RStack doesn't inherit from the abc StackAPI, as it would require to implement all the abstract methods defined.
+As this stack must simply push_int or pop1_int any time a subroutine is accessed or left, only those two functions are 
+provided.
+For the same reason, the class RStack doesn't inherit from the abc StackAPI, as it would require to implement all the
+abstract methods defined.
 """
 
-class RStack():
+
+class RStack:
     """
     VM Return Stack
     """
@@ -44,8 +47,7 @@ def push_int(self, value) -> int:
 
         self._append((int, value))
 
-
-    def pop1_int(self) -> int:
+    def pop1_int(self, value) -> int:
         #
         # Note: This function is optimized for speed over readability.
         #
@@ -59,6 +61,6 @@ def pop1_int(self) -> int:
                 return big_endian_to_int(popped)  # type: ignore
             else:
                 raise ValidationError(
-                "Stack must always be bytes or int, "
-                f"got {item_type!r} type, val {value!r}"
+                   "Stack must always be bytes or int, "
+                   f"got {item_type!r} type, val {value!r}"
                 )

tests/core/opcodes/test_opcodes.py

@@ -1127,6 +1127,7 @@ def test_blake2b_f_compression(vm_class, input_hex, output_hex, expect_exception
         result = comp.output
         assert result.hex() == output_hex
 
+
 @pytest.mark.parametrize(
     'vm_class, code, expect_gas_used',
     (
@@ -1157,6 +1158,7 @@ def test_jumpsub(vm_class, code, expect_gas_used):
     assert comp.is_success
     assert comp.get_gas_used() == expect_gas_used
 
+
 @pytest.mark.xfail(reason="invalid subroutines")
 @pytest.mark.parametrize(
     'vm_class, code',
@@ -1183,4 +1185,3 @@ def test_jumpsub(vm_class, code):
         computation.transaction_context,
     )
     assert comp.is_success
-