Replace ensure with if-statements (Prague)

src/ethereum/prague/fork.py

@@ -19,7 +19,6 @@
 from ethereum.crypto.elliptic_curve import SECP256K1N, secp256k1_recover
 from ethereum.crypto.hash import Hash32, keccak256
 from ethereum.exceptions import InvalidBlock
-from ethereum.utils.ensure import ensure
 
 from .. import rlp
 from ..base_types import U64, U256, Bytes, Uint
@@ -178,10 +177,12 @@ def state_transition(chain: BlockChain, block: Block) -> None:
     """
     parent_header = chain.blocks[-1].header
     excess_blob_gas = calculate_excess_blob_gas(parent_header)
-    ensure(block.header.excess_blob_gas == excess_blob_gas, InvalidBlock)
+    if block.header.excess_blob_gas != excess_blob_gas:
+        raise InvalidBlock
 
     validate_header(block.header, parent_header)
-    ensure(block.ommers == (), InvalidBlock)
+    if block.ommers != ():
+        raise InvalidBlock
     apply_body_output = apply_body(
         chain.state,
         get_last_256_block_hashes(chain),
@@ -197,31 +198,20 @@ def state_transition(chain: BlockChain, block: Block) -> None:
         block.header.parent_beacon_block_root,
         excess_blob_gas,
     )
-    ensure(
-        apply_body_output.block_gas_used == block.header.gas_used, InvalidBlock
-    )
-    ensure(
-        apply_body_output.transactions_root == block.header.transactions_root,
-        InvalidBlock,
-    )
-    ensure(
-        apply_body_output.state_root == block.header.state_root, InvalidBlock
-    )
-    ensure(
-        apply_body_output.receipt_root == block.header.receipt_root,
-        InvalidBlock,
-    )
-    ensure(
-        apply_body_output.block_logs_bloom == block.header.bloom, InvalidBlock
-    )
-    ensure(
-        apply_body_output.withdrawals_root == block.header.withdrawals_root,
-        InvalidBlock,
-    )
-    ensure(
-        apply_body_output.blob_gas_used == block.header.blob_gas_used,
-        InvalidBlock,
-    )
+    if apply_body_output.block_gas_used != block.header.gas_used:
+        raise InvalidBlock
+    if apply_body_output.transactions_root != block.header.transactions_root:
+        raise InvalidBlock
+    if apply_body_output.state_root != block.header.state_root:
+        raise InvalidBlock
+    if apply_body_output.receipt_root != block.header.receipt_root:
+        raise InvalidBlock
+    if apply_body_output.block_logs_bloom != block.header.bloom:
+        raise InvalidBlock
+    if apply_body_output.withdrawals_root != block.header.withdrawals_root:
+        raise InvalidBlock
+    if apply_body_output.blob_gas_used != block.header.blob_gas_used:
+        raise InvalidBlock
 
     chain.blocks.append(block)
     if len(chain.blocks) > 255:
@@ -256,11 +246,8 @@ def calculate_base_fee_per_gas(
         Base fee per gas for the block.
     """
     parent_gas_target = parent_gas_limit // ELASTICITY_MULTIPLIER
-
-    ensure(
-        check_gas_limit(block_gas_limit, parent_gas_limit),
-        InvalidBlock,
-    )
+    if not check_gas_limit(block_gas_limit, parent_gas_limit):
+        raise InvalidBlock
 
     if parent_gas_used == parent_gas_target:
         expected_base_fee_per_gas = parent_base_fee_per_gas
@@ -313,27 +300,33 @@ def validate_header(header: Header, parent_header: Header) -> None:
     parent_header :
         Parent Header of the header to check for correctness
     """
-    ensure(header.gas_used <= header.gas_limit, InvalidBlock)
+    if header.gas_used > header.gas_limit:
+        raise InvalidBlock
 
     expected_base_fee_per_gas = calculate_base_fee_per_gas(
         header.gas_limit,
         parent_header.gas_limit,
         parent_header.gas_used,
         parent_header.base_fee_per_gas,
     )
-
-    ensure(expected_base_fee_per_gas == header.base_fee_per_gas, InvalidBlock)
-
-    ensure(header.timestamp > parent_header.timestamp, InvalidBlock)
-    ensure(header.number == parent_header.number + 1, InvalidBlock)
-    ensure(len(header.extra_data) <= 32, InvalidBlock)
-
-    ensure(header.difficulty == 0, InvalidBlock)
-    ensure(header.nonce == b"\x00\x00\x00\x00\x00\x00\x00\x00", InvalidBlock)
-    ensure(header.ommers_hash == EMPTY_OMMER_HASH, InvalidBlock)
+    if expected_base_fee_per_gas != header.base_fee_per_gas:
+        raise InvalidBlock
+    if header.timestamp <= parent_header.timestamp:
+        raise InvalidBlock
+    if header.number != parent_header.number + 1:
+        raise InvalidBlock
+    if len(header.extra_data) > 32:
+        raise InvalidBlock
+    if header.difficulty != 0:
+        raise InvalidBlock
+    if header.nonce != b"\x00\x00\x00\x00\x00\x00\x00\x00":
+        raise InvalidBlock
+    if header.ommers_hash != EMPTY_OMMER_HASH:
+        raise InvalidBlock
 
     block_parent_hash = keccak256(rlp.encode(parent_header))
-    ensure(header.parent_hash == block_parent_hash, InvalidBlock)
+    if header.parent_hash != block_parent_hash:
+        raise InvalidBlock
 
 
 def check_transaction(
@@ -423,10 +416,12 @@ def check_transaction(
         blob_versioned_hashes = tx.blob_versioned_hashes
     else:
         blob_versioned_hashes = ()
-
-    ensure(sender_account.nonce == tx.nonce, InvalidBlock)
-    ensure(sender_account.balance >= max_gas_fee + tx.value, InvalidBlock)
-    ensure(sender_account.code == bytearray(), InvalidBlock)
+    if sender_account.nonce != tx.nonce:
+        raise InvalidBlock
+    if sender_account.balance < max_gas_fee + tx.value:
+        raise InvalidBlock
+    if sender_account.code != bytearray():
+        raise InvalidBlock
 
     return sender, effective_gas_price, blob_versioned_hashes
 
@@ -681,8 +676,8 @@ def apply_body(
 
         block_logs += logs
         blob_gas_used += calculate_total_blob_gas(tx)
-
-    ensure(blob_gas_used <= MAX_BLOB_GAS_PER_BLOCK, InvalidBlock)
+    if blob_gas_used > MAX_BLOB_GAS_PER_BLOCK:
+        raise InvalidBlock
     block_gas_used = block_gas_limit - gas_available
 
     block_logs_bloom = logs_bloom(block_logs)
@@ -884,9 +879,10 @@ def recover_sender(chain_id: U64, tx: Transaction) -> Address:
         The address of the account that signed the transaction.
     """
     r, s = tx.r, tx.s
-
-    ensure(0 < r and r < SECP256K1N, InvalidBlock)
-    ensure(0 < s and s <= SECP256K1N // 2, InvalidBlock)
+    if 0 >= r or r >= SECP256K1N:
+        raise InvalidBlock
+    if 0 >= s or s > SECP256K1N // 2:
+        raise InvalidBlock
 
     if isinstance(tx, LegacyTransaction):
         v = tx.v
@@ -895,9 +891,8 @@ def recover_sender(chain_id: U64, tx: Transaction) -> Address:
                 r, s, v - 27, signing_hash_pre155(tx)
             )
         else:
-            ensure(
-                v == 35 + chain_id * 2 or v == 36 + chain_id * 2, InvalidBlock
-            )
+            if v != 35 + chain_id * 2 and v != 36 + chain_id * 2:
+                raise InvalidBlock
             public_key = secp256k1_recover(
                 r, s, v - 35 - chain_id * 2, signing_hash_155(tx, chain_id)
             )

src/ethereum/prague/state.py

@@ -20,7 +20,6 @@
 from typing import Callable, Dict, Iterable, List, Optional, Set, Tuple
 
 from ethereum.base_types import U256, Bytes, Uint, modify
-from ethereum.utils.ensure import ensure
 
 from .blocks import Withdrawal
 from .fork_types import EMPTY_ACCOUNT, Account, Address, Root
@@ -502,7 +501,8 @@ def move_ether(
     """
 
     def reduce_sender_balance(sender: Account) -> None:
-        ensure(sender.balance >= amount, AssertionError)
+        if sender.balance < amount:
+            raise AssertionError
         sender.balance -= amount
 
     def increase_recipient_balance(recipient: Account) -> None:

src/ethereum/prague/trie.py

@@ -31,7 +31,6 @@
 
 from ethereum.cancun import trie as previous_trie
 from ethereum.crypto.hash import keccak256
-from ethereum.utils.ensure import ensure
 from ethereum.utils.hexadecimal import hex_to_bytes
 
 from .. import rlp
@@ -349,8 +348,8 @@ def _prepare_trie(
             encoded_value = encode_node(value, get_storage_root(address))
         else:
             encoded_value = encode_node(value)
-        # Empty values are represented by their absence
-        ensure(encoded_value != b"", AssertionError)
+        if encoded_value == b"":
+            raise AssertionError
         key: Bytes
         if trie.secured:
             # "secure" tries hash keys once before construction

src/ethereum/prague/vm/instructions/environment.py

@@ -14,7 +14,6 @@
 
 from ethereum.base_types import U256, Bytes32, Uint
 from ethereum.crypto.hash import keccak256
-from ethereum.utils.ensure import ensure
 from ethereum.utils.numeric import ceil32
 
 from ...fork_types import EMPTY_ACCOUNT
@@ -441,12 +440,8 @@ def returndatacopy(evm: Evm) -> None:
         evm.memory, [(memory_start_index, size)]
     )
     charge_gas(evm, GAS_VERY_LOW + copy_gas_cost + extend_memory.cost)
-
-    # OPERATION
-    ensure(
-        Uint(return_data_start_position) + Uint(size) <= len(evm.return_data),
-        OutOfBoundsRead,
-    )
+    if Uint(return_data_start_position) + Uint(size) > len(evm.return_data):
+        raise OutOfBoundsRead
 
     evm.memory += b"\x00" * extend_memory.expand_by
     value = evm.return_data[

src/ethereum/prague/vm/instructions/log.py

@@ -14,7 +14,6 @@
 from functools import partial
 
 from ethereum.base_types import U256
-from ethereum.utils.ensure import ensure
 
 from ...blocks import Log
 from .. import Evm
@@ -68,7 +67,8 @@ def log_n(evm: Evm, num_topics: U256) -> None:
 
     # OPERATION
     evm.memory += b"\x00" * extend_memory.expand_by
-    ensure(not evm.message.is_static, WriteInStaticContext)
+    if evm.message.is_static:
+        raise WriteInStaticContext
     log_entry = Log(
         address=evm.message.current_target,
         topics=tuple(topics),

src/ethereum/prague/vm/instructions/stack.py

@@ -15,7 +15,6 @@
 from functools import partial
 
 from ethereum.base_types import U256
-from ethereum.utils.ensure import ensure
 
 from .. import Evm, stack
 from ..exceptions import StackUnderflowError
@@ -98,9 +97,8 @@ def dup_n(evm: Evm, item_number: int) -> None:
 
     # GAS
     charge_gas(evm, GAS_VERY_LOW)
-
-    # OPERATION
-    ensure(item_number < len(evm.stack), StackUnderflowError)
+    if item_number >= len(evm.stack):
+        raise StackUnderflowError
     data_to_duplicate = evm.stack[len(evm.stack) - 1 - item_number]
     stack.push(evm.stack, data_to_duplicate)
 
@@ -131,9 +129,8 @@ def swap_n(evm: Evm, item_number: int) -> None:
 
     # GAS
     charge_gas(evm, GAS_VERY_LOW)
-
-    # OPERATION
-    ensure(item_number < len(evm.stack), StackUnderflowError)
+    if item_number >= len(evm.stack):
+        raise StackUnderflowError
     evm.stack[-1], evm.stack[-1 - item_number] = (
         evm.stack[-1 - item_number],
         evm.stack[-1],

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

@@ -12,7 +12,6 @@
 Implementations of the EVM storage related instructions.
 """
 from ethereum.base_types import Uint
-from ethereum.utils.ensure import ensure
 
 from ...state import (
     get_storage,
@@ -78,9 +77,8 @@ def sstore(evm: Evm) -> None:
     # STACK
     key = pop(evm.stack).to_be_bytes32()
     new_value = pop(evm.stack)
-
-    # GAS
-    ensure(evm.gas_left > GAS_CALL_STIPEND, OutOfGasError)
+    if evm.gas_left <= GAS_CALL_STIPEND:
+        raise OutOfGasError
 
     original_value = get_storage_original(
         evm.env.state, evm.message.current_target, key
@@ -123,9 +121,8 @@ def sstore(evm: Evm) -> None:
                 )
 
     charge_gas(evm, gas_cost)
-
-    # OPERATION
-    ensure(not evm.message.is_static, WriteInStaticContext)
+    if evm.message.is_static:
+        raise WriteInStaticContext
     set_storage(evm.env.state, evm.message.current_target, key, new_value)
 
     # PROGRAM COUNTER
@@ -171,9 +168,8 @@ def tstore(evm: Evm) -> None:
 
     # GAS
     charge_gas(evm, GAS_WARM_ACCESS)
-
-    # OPERATION
-    ensure(not evm.message.is_static, WriteInStaticContext)
+    if evm.message.is_static:
+        raise WriteInStaticContext
     set_transient_storage(
         evm.env.transient_storage, evm.message.current_target, key, new_value
     )

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

@@ -12,7 +12,6 @@
 Implementations of the EVM system related instructions.
 """
 from ethereum.base_types import U256, Bytes0, Uint
-from ethereum.utils.ensure import ensure
 from ethereum.utils.numeric import ceil32
 
 from ...fork_types import Address
@@ -79,15 +78,15 @@ def generic_create(
     call_data = memory_read_bytes(
         evm.memory, memory_start_position, memory_size
     )
-
-    ensure(len(call_data) <= 2 * MAX_CODE_SIZE, OutOfGasError)
+    if len(call_data) > 2 * MAX_CODE_SIZE:
+        raise OutOfGasError
 
     evm.accessed_addresses.add(contract_address)
 
     create_message_gas = max_message_call_gas(Uint(evm.gas_left))
     evm.gas_left -= create_message_gas
-
-    ensure(not evm.message.is_static, WriteInStaticContext)
+    if evm.message.is_static:
+        raise WriteInStaticContext
     evm.return_data = b""
 
     sender_address = evm.message.current_target
@@ -376,9 +375,8 @@ def call(evm: Evm) -> None:
         access_gas_cost + create_gas_cost + transfer_gas_cost,
     )
     charge_gas(evm, message_call_gas.cost + extend_memory.cost)
-
-    # OPERATION
-    ensure(not evm.message.is_static or value == U256(0), WriteInStaticContext)
+    if evm.message.is_static and value != U256(0):
+        raise WriteInStaticContext
     evm.memory += b"\x00" * extend_memory.expand_by
     sender_balance = get_account(
         evm.env.state, evm.message.current_target
@@ -506,9 +504,8 @@ def selfdestruct(evm: Evm) -> None:
         gas_cost += GAS_SELF_DESTRUCT_NEW_ACCOUNT
 
     charge_gas(evm, gas_cost)
-
-    # OPERATION
-    ensure(not evm.message.is_static, WriteInStaticContext)
+    if evm.message.is_static:
+        raise WriteInStaticContext
 
     originator = evm.message.current_target
     originator_balance = get_account(evm.env.state, originator).balance