test_max_code_size_high_jumpdest()

Documentation for tests/amsterdam/eip7954_increase_max_contract_size/test_max_code_size.py::test_max_code_size_high_jumpdest@c74f1a67.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip7954_increase_max_contract_size/test_max_code_size.py::test_max_code_size_high_jumpdest --fork Amsterdam

Ensure jump destination validity is enforced past the old size limits.

Deploy a MAX_CODE_SIZE contract that stores a sentinel and then jumps near the new limit, far beyond the old 24 KiB code and 48 KiB initcode limits, then call it through a caller that records the call's success:

• valid_high_jumpdest: the target byte is a real JUMPDEST, so the jump succeeds, the frame returns, and the sentinel store is kept.
• invalid_high_dest: the target byte is a STOP (not a JUMPDEST), so the jump is rejected, the frame reverts, and the sentinel store is discarded.

A client whose jumpdest analysis or code execution does not cover the full new code range fails one of the two cases. No existing test executes a contract at a program counter beyond the old limit.

Source code in tests/amsterdam/eip7954_increase_max_contract_size/test_max_code_size.py

@pytest.mark.parametrize(
    "valid_jumpdest",
    [
        pytest.param(True, id="valid_high_jumpdest"),
        pytest.param(False, id="invalid_high_dest"),
    ],
)
def test_max_code_size_high_jumpdest(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
    valid_jumpdest: bool,
) -> None:
    """
    Ensure jump destination validity is enforced past the old size limits.

    Deploy a `MAX_CODE_SIZE` contract that stores a sentinel and then jumps
    near the new limit, far beyond the old 24 KiB code and 48 KiB initcode
    limits, then call it through a caller that records the call's success:

    - ``valid_high_jumpdest``: the target byte is a real ``JUMPDEST``, so the
      jump succeeds, the frame returns, and the sentinel store is kept.
    - ``invalid_high_dest``: the target byte is a ``STOP`` (not a
      ``JUMPDEST``), so the jump is rejected, the frame reverts, and the
      sentinel store is discarded.

    A client whose jumpdest analysis or code execution does not cover the
    full new code range fails one of the two cases. No existing test
    executes a contract at a program counter beyond the old limit.
    """
    if valid_jumpdest:
        tail = Op.JUMPDEST
    else:
        # A bare STOP, not a JUMPDEST: jumping here is invalid. A client that
        # wrongly accepts it halts normally and keeps the prefix store (1).
        tail = Op.STOP

    dest = fork.max_code_size() - len(tail)
    push_size = (dest.bit_length() + 7) // 8
    push_op = getattr(Op, f"PUSH{push_size}")
    prefix = Op.SSTORE(0, 1) + push_op(dest) + Op.JUMP
    target_code = prefix + Op.INVALID * (dest - len(prefix)) + tail
    assert len(target_code) == fork.max_code_size()

    target = pre.deploy_contract(target_code)
    caller = pre.deploy_contract(
        Op.SSTORE(0, Op.CALL(gas=Op.GAS, address=target)) + Op.STOP
    )

    tx = Transaction(sender=pre.fund_eoa(), to=caller)

    # Valid: jump completes, call succeeds (1), and the store is kept.
    # Invalid: jump reverts, call fails (0), and nothing is stored.
    stored = 1 if valid_jumpdest else 0
    post = {
        caller: Account(storage={0: stored}),
        target: Account(storage={0: stored}),
    }

    state_test(pre=pre, tx=tx, post=post)

Parametrized Test Cases

This test generates 2 parametrized test cases across 1 fork.