[gurukamath]

Description

Implements EIP-8272 on Bogota, at the text that landed with ethereum/EIPs#12443 (blob 0acc21ad8359): the recent root contract is an ordinary contract deployed by a pre-signed creation transaction, and a VERIFY frame targeting it is the recent root verifier frame.

Under that text the EIP changes nothing in the EVM, in transaction validity, or in block validity. The contract's write and validation operations are ordinary execution of its runtime code; the frame-shape, position, and gas-budget rules are public mempool policy, which the executable spec does not model; activation makes no state change. Everything the EIP relies on is already here from EIP-8141 and EIP-7843: static VERIFY frames, SLOTNUM, and the default VERIFY code failing a zero-flag frame against an empty target.

• specs: name the EIP in the Bogota fork docstring and add the RECENT_ROOT_VERIFIER address constant beside EXPIRY_VERIFIER.
• test-forks: an EIP8272 mixin pre-allocating the canonical runtime at the deployment address for state and blockchain tests, mirroring the expiry verifier.
• tests: tests/bogota/eip8272_recent_roots/, 185 fixtures at --fork Bogota:
  • reference vector from the EIP, with the pre-allocated code and its keccak pinned;
  • validation: distinct and repeated references, every invalid-reference shape including a stale occupant of the same ring index, the age window at 8191 and 8192 slots, calldata lengths, frame-shape variants that stay block-valid, exact and one-short execution gas across cold and warm reads, frame position, a failing tuple anywhere in a batch, full-width slots;
  • write: publish then verify with block access list pins, last write in a slot wins, ring overwrite, a contract as source, DELEGATECALL/CALLCODE/EIP-7702 writes landing in the caller's storage, value, wrong lengths, the static-context halt;
  • deployment via generate_system_contract_deploy_test with the EIP's deployment transaction, publishing in the deployment block and verifying in the next; a verifier frame before deployment failing under the default code;
  • fork transition: deployment and a plain write in the last Amsterdam block, verified by a frame in the first Bogota block.

The verifier frame's execution gas is pinned from a cost model derived twice against the canonical runtime, by measurement and by counting the sys-asm assembly, which agree.

The test corpus and helpers borrow from spencer-tb/execution-specs#71, which targeted the earlier activation-install text; its activation machinery and candidate bytecode do not apply here.

Related Issues or PRs

N/A.

Checklist

• Ran fast static checks to avoid CI fails, see Code Standards & Verifying Changes: just static
• PR title has the form <type>(<area>): <title>, where <type> and <area> come from an appropriate C-<type>, respectively A-<area>, label. The title should match the target squash commit message.

Cute Animal Picture

[codecov]

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Additional details and impacted files

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[spencer-tb]

Small nits :)

[spencer-tb]

Should we name this RECENT_ROOT_ADDRESS to match the EIP?

Suggested change

	RECENT_ROOT_VERIFIER: Final[Address] = Address(
	RECENT_ROOT_ADDRESS: Final[Address] = Address(

[spencer-tb]

Suggested change

	RECENT_ROOT_VERIFIER,
	RECENT_ROOT_ADDRESS,

[spencer-tb]

Suggested change

	RECENT_ROOT_VERIFIER
	RECENT_ROOT_ADDRESS

[spencer-tb]

The old root is never referenced here, and at later_slot + 1 it would be 8193 slots old, so it would fail on age rather than on the overwrite. The storage post check already covers the replacement.

Suggested change

	A write `RECENT_ROOT_LENGTH` slots after an earlier one lands on the
	same ring buffer key and replaces the earlier entry; the new root
	verifies in the following slot and the old root does not.
	A write `RECENT_ROOT_LENGTH` slots after an earlier one lands on the
	same ring buffer key and replaces the earlier entry. The new root
	verifies in the following slot.

[spencer-tb]

Could this come from Op.SSTORE(0, 1).state_cost(fork) like the 8141 tests?

[spencer-tb]

Some extra tests, feel free to use: gurukamath#25