new(tests): EOF - EIP-7069: Call Gas Testing for EXT*CALL (#713)

* new(tests) Call Gas Testing for EXT*CALL

Test call gas for EXT*CALL, using a legacy harness.

Signed-off-by: Danno Ferrin <[email protected]>

* lint fixes

Signed-off-by: Danno Ferrin <[email protected]>

* review comments

Signed-off-by: Danno Ferrin <[email protected]>

* fix: tox (imports)

---------

Signed-off-by: Danno Ferrin <[email protected]>
Co-authored-by: Mario Vega <[email protected]>

tests/prague/eip7692_eof_v1/eip7069_extcall/helpers.py

@@ -16,6 +16,8 @@
 slot_call_status = next(_slot)
 slot_calldata_1 = next(_slot)
 slot_calldata_2 = next(_slot)
+slot_cold_gas = next(_slot)
+slot_warm_gas = next(_slot)
 
 slot_last_slot = next(_slot)
 

tests/prague/eip7692_eof_v1/eip7069_extcall/test_gas.py

@@ -0,0 +1,139 @@
+"""
+abstract: Tests [EIP-7069: Revamped CALL instructions](https://eips.ethereum.org/EIPS/eip-7069)
+    Tests gas comsumption
+"""  # noqa: E501
+
+import pytest
+
+from ethereum_test_tools import Account, Alloc, Environment, StateTestFiller, Transaction
+from ethereum_test_tools.eof.v1 import Container, Section
+from ethereum_test_tools.vm.opcode import Opcodes as Op
+from ethereum_test_vm import Bytecode, EVMCodeType
+
+from .. import EOF_FORK_NAME
+from . import REFERENCE_SPEC_GIT_PATH, REFERENCE_SPEC_VERSION
+from .helpers import slot_cold_gas, slot_warm_gas
+
+REFERENCE_SPEC_GIT_PATH = REFERENCE_SPEC_GIT_PATH
+REFERENCE_SPEC_VERSION = REFERENCE_SPEC_VERSION
+
+pytestmark = pytest.mark.valid_from(EOF_FORK_NAME)
+
+
+@pytest.fixture
+def state_env() -> Environment:
+    """
+    Prepare the environment for all state test cases.
+
+    Main difference is that the excess blob gas is not increased by the target, as
+    there is no genesis block -> block 1 transition, and therefore the excess blob gas
+    is not decreased by the target.
+    """
+    return Environment()
+
+
+def gas_test(
+    state_test: StateTestFiller,
+    env: Environment,
+    pre: Alloc,
+    setup_code: Bytecode,
+    subject_code: Bytecode,
+    tear_down_code: Bytecode,
+    cold_gas: int,
+    warm_gas: int | None = None,
+):
+    """Creates a State Test to check the gas cost of a sequence of EOF code."""
+    if cold_gas <= 0:
+        raise ValueError(f"Target gas allocations (warm_gas) must be > 0, got {cold_gas}")
+    if warm_gas is None:
+        warm_gas = cold_gas
+
+    sender = pre.fund_eoa(10**18)
+
+    address_baseline = pre.deploy_contract(setup_code + tear_down_code)
+    address_subject = pre.deploy_contract(setup_code + subject_code + tear_down_code)
+    address_legacy_harness = pre.deploy_contract(
+        code=(
+            # warm subject and baseline without executing
+            (Op.BALANCE(address_subject) + Op.POP + Op.BALANCE(address_baseline) + Op.POP)
+            # cold gas run
+            + (
+                Op.GAS
+                + Op.CALL(address=address_subject, gas=500_000)
+                + Op.POP
+                + Op.GAS
+                + Op.SWAP1
+                + Op.SUB
+            )
+            # Baseline gas run
+            + (
+                Op.GAS
+                + Op.CALL(address=address_baseline, gas=500_000)
+                + Op.POP
+                + Op.GAS
+                + Op.SWAP1
+                + Op.SUB
+            )
+            # warm gas run
+            + (
+                Op.GAS
+                + Op.CALL(address=address_subject, gas=500_000)
+                + Op.POP
+                + Op.GAS
+                + Op.SWAP1
+                + Op.SUB
+            )
+            # Store warm gas
+            + (Op.DUP2 + Op.SWAP1 + Op.SUB + Op.PUSH2(slot_warm_gas) + Op.SSTORE)
+            # store cold gas
+            + (Op.SWAP1 + Op.SUB + Op.PUSH2(slot_cold_gas) + Op.SSTORE)
+            + Op.STOP
+        ),
+        evm_code_type=EVMCodeType.LEGACY,  # Needs to be legacy to use GAS opcode
+    )
+
+    post = {
+        address_legacy_harness: Account(
+            storage={
+                slot_warm_gas: warm_gas,
+                slot_cold_gas: cold_gas,
+            },
+        ),
+    }
+
+    tx = Transaction(to=address_legacy_harness, gas_limit=2_000_000, sender=sender)
+
+    state_test(env=env, pre=pre, tx=tx, post=post)
+
+
+@pytest.mark.parametrize(
+    ["opcode", "pre_setup", "cold_gas", "warm_gas"],
+    [
+        pytest.param(Op.EXTCALL, Op.PUSH0, 2600, 100, id="EXTCALL"),
+        pytest.param(Op.EXTCALL, Op.PUSH1(1), 2600 + 9000, 100 + 9000, id="EXTCALL_with_value"),
+        pytest.param(Op.EXTDELEGATECALL, Op.NOOP, 2600, 100, id="EXTSTATICCALL"),
+        pytest.param(Op.EXTSTATICCALL, Op.NOOP, 2600, 100, id="EXTDELEGATECALL"),
+    ],
+)
+def test_ext_calls_gas(
+    state_test: StateTestFiller,
+    pre: Alloc,
+    state_env: Environment,
+    opcode: Op,
+    pre_setup: Op,
+    cold_gas: int,
+    warm_gas: int | None,
+):
+    """Tests 4 variations of EXT*CALL gas, both warm and cold"""
+    address_target = pre.deploy_contract(Container(sections=[Section.Code(code=Op.STOP)]))
+
+    gas_test(
+        state_test,
+        state_env,
+        pre,
+        setup_code=pre_setup + Op.PUSH0 + Op.PUSH0 + Op.PUSH20(address_target),
+        subject_code=opcode,
+        tear_down_code=Op.STOP,
+        cold_gas=cold_gas,
+        warm_gas=warm_gas,
+    )