eip-3541: reserve '0xEF' byte in contract code + related tests

Author: fselmo

eth/exceptions.py

@@ -195,3 +195,11 @@ class OutOfBoundsRead(VMError):
     boundaries of the buffer (such as with RETURNDATACOPY)
     """
     pass
+
+
+class ReservedBytesInCode(VMError):
+    """
+    Raised when bytes for the code to be deployed are reserved
+    for a particular reason.
+    """
+    pass

eth/vm/forks/frontier/constants.py

@@ -1,24 +1,2 @@
-from eth_typing import (
-    Address
-)
-
-CREATE_CONTRACT_ADDRESS = Address(b'')
-
-
-#
-# Difficulty
-#
 FRONTIER_DIFFICULTY_ADJUSTMENT_CUTOFF = 13
-
-
-#
-# Stack Limit
-#
-STACK_DEPTH_LIMIT = 1024
-
-
-#
-# Gas Costs and Refunds
-#
 REFUND_SELFDESTRUCT = 24000
-GAS_CODEDEPOSIT = 200

eth/vm/forks/homestead/constants.py

@@ -2,9 +2,3 @@
 # Difficulty
 #
 HOMESTEAD_DIFFICULTY_ADJUSTMENT_CUTOFF = 10
-
-
-#
-# Gas Costs and Refunds
-#
-GAS_CODEDEPOSIT = 200

eth/vm/forks/london/computation.py

@@ -1,8 +1,15 @@
+from eth_utils import encode_hex, keccak
+
+from eth import constants
+from eth.abc import ComputationAPI, MessageAPI, StateAPI, TransactionContextAPI
+from eth.exceptions import OutOfGas, ReservedBytesInCode
 from eth.vm.forks.berlin.computation import (
     BerlinComputation,
 )
 
 from .opcodes import LONDON_OPCODES
+from ..london.constants import EIP3541_RESERVED_STARTING_BYTE
+from ..spurious_dragon.constants import EIP170_CODE_SIZE_LIMIT
 
 
 class LondonComputation(BerlinComputation):
@@ -11,3 +18,62 @@ class LondonComputation(BerlinComputation):
     Inherits from :class:`~eth.vm.forks.berlin.BerlinComputation`
     """
     opcodes = LONDON_OPCODES
+
+    @classmethod
+    def apply_create_message(
+        cls,
+        state: StateAPI,
+        message: MessageAPI,
+        transaction_context: TransactionContextAPI
+    ) -> ComputationAPI:
+
+        snapshot = state.snapshot()
+
+        # EIP161 nonce incrementation
+        state.increment_nonce(message.storage_address)
+
+        computation = cls.apply_message(state, message, transaction_context)
+
+        if computation.is_error:
+            state.revert(snapshot)
+            return computation
+        else:
+            contract_code = computation.output
+
+            if contract_code and len(contract_code) >= EIP170_CODE_SIZE_LIMIT:
+                computation.error = OutOfGas(
+                    f"Contract code size exceeds EIP170 limit of {EIP170_CODE_SIZE_LIMIT}."
+                    f" Got code of size: {len(contract_code)}"
+                )
+                state.revert(snapshot)
+            elif contract_code:
+                contract_code_gas_cost = len(contract_code) * constants.GAS_CODEDEPOSIT
+                try:
+                    computation.consume_gas(
+                        contract_code_gas_cost,
+                        reason="Write contract code for CREATE / CREATE2",
+                    )
+                except OutOfGas as err:
+                    computation.error = err
+                    state.revert(snapshot)
+                else:
+                    if contract_code[:1] == EIP3541_RESERVED_STARTING_BYTE:
+                        # As per EIP-3541, gas is still consumed on a revert of this nature
+                        state.revert(snapshot)
+                        raise ReservedBytesInCode(
+                            "Contract code begins with EIP3541 reserved byte '0xEF'."
+                        )
+                    else:
+                        if cls.logger:
+                            cls.logger.debug2(
+                                "SETTING CODE: %s -> length: %s | hash: %s",
+                                encode_hex(message.storage_address),
+                                len(contract_code),
+                                encode_hex(keccak(contract_code))
+                            )
+
+                        state.set_code(message.storage_address, contract_code)
+                        state.commit(snapshot)
+            else:
+                state.commit(snapshot)
+            return computation

eth/vm/forks/london/constants.py

@@ -11,3 +11,5 @@
 BASE_FEE_MAX_CHANGE_DENOMINATOR = 8
 INITIAL_BASE_FEE = 1000000000
 ELASTICITY_MULTIPLIER = 2
+
+EIP3541_RESERVED_STARTING_BYTE = b'\xef'

eth/vm/forks/spurious_dragon/constants.py

@@ -1,9 +1,3 @@
-#
-# Gas Costs and Refunds
-#
-GAS_CODEDEPOSIT = 200
-
-
 # https://github.com/ethereum/EIPs/issues/160
 GAS_EXP_EIP160 = 10
 GAS_EXPBYTE_EIP160 = 50

newsfragments/2018.feature.rst

@@ -0,0 +1,3 @@
+Implement `EIP-3554 <https://eips.ethereum.org/EIPS/eip-3554>`_ for London support.
+
+Implement `EIP-3541 <https://eips.ethereum.org/EIPS/eip-3541>`_ for London support.

tests/core/vm/conftest.py

@@ -0,0 +1,20 @@
+import pytest
+from eth_utils import to_canonical_address
+
+from eth.vm.transaction_context import BaseTransactionContext
+
+
+NORMALIZED_ADDRESS_A = "0x0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6"
+NORMALIZED_ADDRESS_B = "0xcd1722f3947def4cf144679da39c4c32bdc35681"
+CANONICAL_ADDRESS_A = to_canonical_address("0x0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6")
+CANONICAL_ADDRESS_B = to_canonical_address("0xcd1722f3947def4cf144679da39c4c32bdc35681")
+
+
+@pytest.fixture
+def transaction_context():
+    tx_context = BaseTransactionContext(
+        gas_price=1,
+        origin=CANONICAL_ADDRESS_B,
+    )
+    return tx_context
+

tests/core/vm/test_base_computation.py

@@ -1,7 +1,6 @@
 import pytest
 
 from eth_utils import (
-    to_canonical_address,
     ValidationError,
 )
 
@@ -18,12 +17,7 @@
 from eth.vm.transaction_context import (
     BaseTransactionContext,
 )
-
-
-NORMALIZED_ADDRESS_A = "0x0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6"
-NORMALIZED_ADDRESS_B = "0xcd1722f3947def4cf144679da39c4c32bdc35681"
-CANONICAL_ADDRESS_A = to_canonical_address("0x0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6")
-CANONICAL_ADDRESS_B = to_canonical_address("0xcd1722f3947def4cf144679da39c4c32bdc35681")
+from tests.core.vm.conftest import CANONICAL_ADDRESS_A, CANONICAL_ADDRESS_B, NORMALIZED_ADDRESS_A
 
 
 class DummyComputation(BaseComputation):
@@ -41,15 +35,6 @@ def get_intrinsic_gas(self):
         return 0
 
 
-@pytest.fixture
-def transaction_context():
-    tx_context = DummyTransactionContext(
-        gas_price=1,
-        origin=CANONICAL_ADDRESS_B,
-    )
-    return tx_context
-
-
 @pytest.fixture
 def message():
     message = Message(

tests/core/vm/test_frontier_computation.py

@@ -1,24 +1,12 @@
 import pytest
 
-from eth_utils import (
-    to_canonical_address,
-)
-
 from eth.vm.message import (
     Message,
 )
 from eth.vm.forks.frontier.computation import (
     FrontierComputation,
 )
-from eth.vm.transaction_context import (
-    BaseTransactionContext,
-)
-
-
-NORMALIZED_ADDRESS_A = "0x0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6"
-NORMALIZED_ADDRESS_B = "0xcd1722f3947def4cf144679da39c4c32bdc35681"
-CANONICAL_ADDRESS_A = to_canonical_address("0x0f572e5295c57f15886f9b263e2f6d2d6c7b5ec6")
-CANONICAL_ADDRESS_B = to_canonical_address("0xcd1722f3947def4cf144679da39c4c32bdc35681")
+from tests.core.vm.conftest import CANONICAL_ADDRESS_A, CANONICAL_ADDRESS_B
 
 
 @pytest.fixture
@@ -28,15 +16,6 @@ def state(chain_without_block_validation):
     return state
 
 
-@pytest.fixture
-def transaction_context():
-    tx_context = BaseTransactionContext(
-        gas_price=1,
-        origin=CANONICAL_ADDRESS_B,
-    )
-    return tx_context
-
-
 @pytest.fixture
 def message():
     message = Message(