[DRAFT] Implement EIP-7708

src/ethereum/cancun/vm/__init__.py

@@ -19,8 +19,9 @@
 from ethereum_types.bytes import Bytes, Bytes0, Bytes32
 from ethereum_types.numeric import U64, U256, Uint
 
-from ethereum.crypto.hash import Hash32
+from ethereum.crypto.hash import Hash32, keccak256
 from ethereum.exceptions import EthereumException
+from ethereum.utils.byte import left_pad_zero_bytes
 
 from ..blocks import Log
 from ..fork_types import Address, VersionedHash
@@ -150,3 +151,32 @@ def incorporate_child_on_error(evm: Evm, child_evm: Evm) -> None:
         ):
             evm.touched_accounts.add(RIPEMD160_ADDRESS)
     evm.gas_left += child_evm.gas_left
+
+def eth_transfer_log(sender: Address, recipient: Address, amount: U256) -> Log:
+    """
+    EIP-7708 style logs for all kinds of ETH transfers
+
+    Parameters
+    ----------
+    sender :
+        The address of the sender
+    recipient :
+        The address of the recipient
+    amount :
+        The amount transferred
+    Returns
+    -------
+    log_entry:
+        A log entry that can be appended to the current evm context
+    """
+    magic_signature = "MAGIC_00"
+    topic1 = keccak256(magic_signature.encode()) # Magic Signature
+    topic2 = Hash32(left_pad_zero_bytes(sender, 32))
+    topic3 = Hash32(left_pad_zero_bytes(recipient, 32))
+    amount_bytes = amount.to_bytes(32, byteorder='big')
+
+    return Log(
+        address=sender,
+        topics=(topic1, topic2, topic3),
+        data=amount_bytes,
+    )

src/ethereum/cancun/vm/instructions/system.py

@@ -37,6 +37,7 @@
     Message,
     incorporate_child_on_error,
     incorporate_child_on_success,
+    eth_transfer_log
 )
 from ..exceptions import OutOfGasError, Revert, WriteInStaticContext
 from ..gas import (
@@ -321,6 +322,7 @@ def generic_call(
         evm.return_data = child_evm.output
         push(evm.stack, U256(0))
     else:
+        # child CALL logs would be appended to parent logs
         incorporate_child_on_success(evm, child_evm)
         evm.return_data = child_evm.output
         push(evm.stack, U256(1))
@@ -384,7 +386,7 @@ def call(evm: Evm) -> None:
         raise WriteInStaticContext
     evm.memory += b"\x00" * extend_memory.expand_by
     sender_balance = get_account(
-        evm.env.state, evm.message.current_target
+        evm.env.state, evm.message.current_target # current_target is the contract that is calling the call opcode
     ).balance
     if sender_balance < value:
         push(evm.stack, U256(0))
@@ -522,6 +524,11 @@ def selfdestruct(evm: Evm) -> None:
         originator_balance,
     )
 
+    # check if amount was non zero, then update evm logs with the new log
+    if originator_balance > 0:
+        log_entry = eth_transfer_log(originator, beneficiary, originator_balance)
+        evm.logs = evm.logs + (log_entry,)
+
     # register account for deletion only if it was created
     # in the same transaction
     if originator in evm.env.state.created_accounts:

src/ethereum/cancun/vm/interpreter.py

@@ -49,7 +49,7 @@
 from ..vm import Message
 from ..vm.gas import GAS_CODE_DEPOSIT, charge_gas
 from ..vm.precompiled_contracts.mapping import PRE_COMPILED_CONTRACTS
-from . import Environment, Evm
+from . import Environment, Evm, eth_transfer_log
 from .exceptions import (
     AddressCollision,
     ExceptionalHalt,
@@ -89,6 +89,7 @@ class MessageCallOutput:
     error: Optional[EthereumException]
 
 
+## This is where a general transfer tx would start from
 def process_message_call(
     message: Message, env: Environment
 ) -> MessageCallOutput:
@@ -121,6 +122,7 @@ def process_message_call(
             evm = process_create_message(message, env)
     else:
         evm = process_message(message, env)
+        ## can append to logs here
         if account_exists_and_is_empty(env.state, Address(message.target)):
             evm.touched_accounts.add(Address(message.target))
 
@@ -232,12 +234,18 @@ def process_message(message: Message, env: Environment) -> Evm:
 
     touch_account(env.state, message.current_target)
 
+    log_entry = ()
     if message.should_transfer_value and message.value != 0:
         move_ether(
             env.state, message.caller, message.current_target, message.value
         )
+        ## add log here for transfer CALL (child evm calls) and normal ETH value transfers
+        log_entry = eth_transfer_log(message.caller, message.current_target, message.value)
+
+    # this ensures value transfer tx logs are before the child evm logs
+    # both eth value transfers and CALL opcode invocations reach this execution phase
+    evm = execute_code(message, env, log_entry)
 
-    evm = execute_code(message, env)
     if evm.error:
         # revert state to the last saved checkpoint
         # since the message call resulted in an error
@@ -247,7 +255,7 @@ def process_message(message: Message, env: Environment) -> Evm:
     return evm
 
 
-def execute_code(message: Message, env: Environment) -> Evm:
+def execute_code(message: Message, env: Environment, log_entry: Log) -> Evm:
     """
     Executes bytecode present in the `message`.
 
@@ -274,7 +282,7 @@ def execute_code(message: Message, env: Environment) -> Evm:
         gas_left=message.gas,
         env=env,
         valid_jump_destinations=valid_jump_destinations,
-        logs=(),
+        logs=(log_entry,) if log_entry != () else (),
         refund_counter=0,
         running=True,
         message=message,
@@ -286,6 +294,7 @@ def execute_code(message: Message, env: Environment) -> Evm:
         accessed_addresses=message.accessed_addresses,
         accessed_storage_keys=message.accessed_storage_keys,
     )
+
     try:
         if evm.message.code_address in PRE_COMPILED_CONTRACTS:
             evm_trace(evm, PrecompileStart(evm.message.code_address))