implement EIP-1153

src/ethereum/cancun/state.py

@@ -46,6 +46,19 @@ class State:
     _created_accounts: Set[Address] = field(default_factory=set)
 
 
+@dataclass
+class TransientStorage:
+    """
+    Contains all information that is preserved between message calls
+    within a transaction.
+    """
+
+    _tries: Dict[Address, Trie[Bytes, U256]] = field(default_factory=dict)
+    _snapshots: List[Dict[Address, Trie[Bytes, U256]]] = field(
+        default_factory=list
+    )
+
+
 def close_state(state: State) -> None:
     """
     Free resources held by the state. Used by optimized implementations to
@@ -57,7 +70,9 @@ def close_state(state: State) -> None:
     del state._created_accounts
 
 
-def begin_transaction(state: State) -> None:
+def begin_transaction(
+    state: State, transient_storage: Optional[TransientStorage] = None
+) -> None:
     """
     Start a state transaction.
 
@@ -68,6 +83,8 @@ def begin_transaction(state: State) -> None:
     ----------
     state : State
         The state.
+    transient_storage : TransientStorage
+        The transient storage of the transaction.
     """
     state._snapshots.append(
         (
@@ -76,6 +93,11 @@ def begin_transaction(state: State) -> None:
         )
     )
 
+    if transient_storage is not None:
+        transient_storage._snapshots.append(
+            {k: copy_trie(t) for (k, t) in transient_storage._tries.items()}
+        )
+
 
 def commit_transaction(state: State) -> None:
     """
@@ -91,7 +113,9 @@ def commit_transaction(state: State) -> None:
         state._created_accounts.clear()
 
 
-def rollback_transaction(state: State) -> None:
+def rollback_transaction(
+    state: State, transient_storage: Optional[TransientStorage] = None
+) -> None:
     """
     Rollback a state transaction, resetting the state to the point when the
     corresponding `start_transaction()` call was made.
@@ -100,11 +124,16 @@ def rollback_transaction(state: State) -> None:
     ----------
     state : State
         The state.
+    transient_storage : TransientStorage
+        The transient storage of the transaction.
     """
     state._main_trie, state._storage_tries = state._snapshots.pop()
     if not state._snapshots:
         state._created_accounts.clear()
 
+    if transient_storage:
+        transient_storage._tries = transient_storage._snapshots.pop()
+
 
 def get_account(state: State, address: Address) -> Account:
     """
@@ -603,3 +632,64 @@ def get_storage_original(state: State, address: Address, key: Bytes) -> U256:
     assert isinstance(original_value, U256)
 
     return original_value
+
+
+def get_transient_storage(
+    transient_storage: TransientStorage, address: Address, key: Bytes
+) -> U256:
+    """
+    Get a value at a storage key on an account from transient storage.
+    Returns `U256(0)` if the storage key has not been set previously.
+
+    Parameters
+    ----------
+    transient_storage: `TransientStorage`
+        The transient storage
+    address : `Address`
+        Address of the account.
+    key : `Bytes`
+        Key to lookup.
+
+    Returns
+    -------
+    value : `U256`
+        Value at the key.
+    """
+    trie = transient_storage._tries.get(address)
+    if trie is None:
+        return U256(0)
+
+    value = trie_get(trie, key)
+
+    assert isinstance(value, U256)
+    return value
+
+
+def set_transient_storage(
+    transient_storage: TransientStorage,
+    address: Address,
+    key: Bytes,
+    value: U256,
+) -> None:
+    """
+    Set a value at a storage key on an account. Setting to `U256(0)` deletes
+    the key.
+
+    Parameters
+    ----------
+    transient_storage: `TransientStorage`
+        The transient storage
+    address : `Address`
+        Address of the account.
+    key : `Bytes`
+        Key to set.
+    value : `U256`
+        Value to set at the key.
+    """
+    trie = transient_storage._tries.get(address)
+    if trie is None:
+        trie = Trie(secured=True, default=U256(0))
+        transient_storage._tries[address] = trie
+    trie_set(trie, key, value)
+    if trie._data == {}:
+        del transient_storage._tries[address]

src/ethereum/cancun/vm/__init__.py

@@ -20,7 +20,7 @@
 from ethereum.crypto.hash import Hash32
 
 from ..fork_types import Address, Log
-from ..state import State, account_exists_and_is_empty
+from ..state import State, TransientStorage, account_exists_and_is_empty
 from .precompiled_contracts import RIPEMD160_ADDRESS
 
 __all__ = ("Environment", "Evm", "Message")
@@ -91,6 +91,7 @@ class Evm:
     error: Optional[Exception]
     accessed_addresses: Set[Address]
     accessed_storage_keys: Set[Tuple[Address, Bytes32]]
+    transient_storage: TransientStorage
 
 
 def incorporate_child_on_success(evm: Evm, child_evm: Evm) -> None:

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

@@ -109,6 +109,8 @@ class Ops(enum.Enum):
     # Storage Ops
     SLOAD = 0x54
     SSTORE = 0x55
+    TLOAD = 0x5C
+    TSTORE = 0x5D
 
     # Pop Operation
     POP = 0x50
@@ -268,6 +270,8 @@ class Ops(enum.Enum):
     Ops.SELFBALANCE: environment_instructions.self_balance,
     Ops.BASEFEE: environment_instructions.base_fee,
     Ops.SSTORE: storage_instructions.sstore,
+    Ops.TLOAD: storage_instructions.tload,
+    Ops.TSTORE: storage_instructions.tstore,
     Ops.JUMP: control_flow_instructions.jump,
     Ops.JUMPI: control_flow_instructions.jumpi,
     Ops.PC: control_flow_instructions.pc,

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

@@ -14,7 +14,13 @@
 from ethereum.base_types import Uint
 from ethereum.utils.ensure import ensure
 
-from ...state import get_storage, get_storage_original, set_storage
+from ...state import (
+    get_storage,
+    get_storage_original,
+    get_transient_storage,
+    set_storage,
+    set_transient_storage,
+)
 from .. import Evm
 from ..exceptions import OutOfGasError, WriteInStaticContext
 from ..gas import (
@@ -124,3 +130,57 @@ def sstore(evm: Evm) -> None:
 
     # PROGRAM COUNTER
     evm.pc += 1
+
+
+def tload(evm: Evm) -> None:
+    """
+    Loads to the stack, the value corresponding to a certain key from the
+    transient storage of the current account.
+
+    Parameters
+    ----------
+    evm :
+        The current EVM frame.
+
+    """
+    # STACK
+    key = pop(evm.stack).to_be_bytes32()
+
+    # GAS
+    charge_gas(evm, GAS_WARM_ACCESS)
+
+    # OPERATION
+    value = get_transient_storage(
+        evm.transient_storage, evm.message.current_target, key
+    )
+    push(evm.stack, value)
+
+    # PROGRAM COUNTER
+    evm.pc += 1
+
+
+def tstore(evm: Evm) -> None:
+    """
+    Stores a value at a certain key in the current context's transient storage.
+
+    Parameters
+    ----------
+    evm :
+        The current EVM frame.
+
+    """
+    # STACK
+    key = pop(evm.stack).to_be_bytes32()
+    new_value = pop(evm.stack)
+
+    # GAS
+    charge_gas(evm, GAS_WARM_ACCESS)
+
+    # OPERATION
+    ensure(not evm.message.is_static, WriteInStaticContext)
+    set_transient_storage(
+        evm.transient_storage, evm.message.current_target, key, new_value
+    )
+
+    # PROGRAM COUNTER
+    evm.pc += 1

src/ethereum/cancun/vm/interpreter.py

@@ -29,6 +29,7 @@
 
 from ..fork_types import Address, Log
 from ..state import (
+    TransientStorage,
     account_exists_and_is_empty,
     account_has_code_or_nonce,
     begin_transaction,
@@ -219,7 +220,10 @@ def process_message(message: Message, env: Environment) -> Evm:
         raise StackDepthLimitError("Stack depth limit reached")
 
     # take snapshot of state before processing the message
-    begin_transaction(env.state)
+    transient_storage = (
+        message.parent_evm.transient_storage if message.parent_evm else None
+    )
+    begin_transaction(env.state, transient_storage)
 
     touch_account(env.state, message.current_target)
 
@@ -232,7 +236,7 @@ def process_message(message: Message, env: Environment) -> Evm:
     if evm.error:
         # revert state to the last saved checkpoint
         # since the message call resulted in an error
-        rollback_transaction(env.state)
+        rollback_transaction(env.state, evm.transient_storage)
     else:
         commit_transaction(env.state)
     return evm
@@ -257,6 +261,11 @@ def execute_code(message: Message, env: Environment) -> Evm:
     code = message.code
     valid_jump_destinations = get_valid_jump_destinations(code)
 
+    if message.parent_evm and message.parent_evm.transient_storage:
+        transient_storage = message.parent_evm.transient_storage
+    else:
+        transient_storage = TransientStorage()
+
     evm = Evm(
         pc=Uint(0),
         stack=[],
@@ -276,6 +285,7 @@ def execute_code(message: Message, env: Environment) -> Evm:
         error=None,
         accessed_addresses=message.accessed_addresses,
         accessed_storage_keys=message.accessed_storage_keys,
+        transient_storage=transient_storage,
     )
     try:
 

whitelist.txt

@@ -389,4 +389,7 @@ rlps
 jsons
 mem
 
-checkable
+checkable
+
+tload
+tstore