foundry_evm_core/

utils.rs

use crate::{EvmEnv, FoundryBlock, hardfork::FoundryHardfork};
use alloy_chains::Chain;
use alloy_consensus::{BlockHeader, private::alloy_eips::eip7840::BlobParams};
use alloy_hardforks::EthereumHardfork;
use alloy_json_abi::{Function, JsonAbi};
use alloy_primitives::{B256, ChainId, Selector, U256};
use alloy_provider::{Network, network::BlockResponse};
use foundry_config::NamedChain;
use foundry_evm_networks::NetworkConfigs;
use revm::primitives::hardfork::SpecId;
pub use revm::state::EvmState as StateChangeset;

/// Hints to the compiler that this is a cold path, i.e. unlikely to be taken.
#[cold]
#[inline(always)]
pub const fn cold_path() {
    // TODO: remove `#[cold]` and call `std::hint::cold_path` once stable.
}

/// Constructs a generic [`FoundryBlock`] from a block header.
pub fn block_env_from_header<BLOCK: FoundryBlock + Default>(header: &impl BlockHeader) -> BLOCK {
    let mut block = BLOCK::default();
    block.set_number(U256::from(header.number()));
    block.set_slot_num(header.slot_number().unwrap_or_default());
    block.set_beneficiary(header.beneficiary());
    block.set_timestamp(U256::from(header.timestamp()));
    block.set_difficulty(header.difficulty());
    block.set_prevrandao(header.mix_hash());
    block.set_basefee(header.base_fee_per_gas().unwrap_or_default());
    block.set_gas_limit(header.gas_limit());
    block
}

/// Applies chain-specific changes required to replay transactions accepted on-chain.
pub fn apply_chain_specific_tx_replay_env_changes<SPEC, BLOCK>(evm_env: &mut EvmEnv<SPEC, BLOCK>) {
    let chain_id = evm_env.cfg_env.chain_id;
    apply_chain_specific_tx_replay_env_changes_for_chain(evm_env, chain_id);
}

/// Applies replay normalization for the provided source chain.
///
/// This keeps fork-specific transaction validation independent from an execution `CHAINID`
/// override.
pub fn apply_chain_specific_tx_replay_env_changes_for_chain<SPEC, BLOCK>(
    evm_env: &mut EvmEnv<SPEC, BLOCK>,
    source_chain_id: ChainId,
) {
    if NamedChain::try_from(source_chain_id).is_ok_and(|chain| chain.is_arbitrum()) {
        // Arbitrum does not enforce the EIP-1559 priority fee ordering constraint.
        evm_env.cfg_env.disable_priority_fee_check = true;
    }
}

/// Depending on the configured chain id and block number this should apply any specific changes
///
/// - checks for prevrandao mixhash after merge
/// - applies chain specifics: on Arbitrum `block.number` is the L1 block
///
/// Should be called with proper chain id (retrieved from provider if not provided), works with any
/// [`FoundryBlock`] type.
pub fn apply_chain_and_block_specific_env_changes<
    N: Network,
    SPEC: Into<SpecId> + Copy,
    BLOCK: FoundryBlock,
>(
    evm_env: &mut EvmEnv<SPEC, BLOCK>,
    block: &N::BlockResponse,
    configs: NetworkConfigs,
) {
    let chain_id = evm_env.cfg_env.chain_id;
    apply_chain_and_block_specific_env_changes_for_chain::<N, _, _>(
        evm_env, block, chain_id, configs,
    );
}

/// Applies block normalization for the provided source chain.
///
/// This keeps fork-specific header handling independent from an execution `CHAINID` override.
pub fn apply_chain_and_block_specific_env_changes_for_chain<
    N: Network,
    SPEC: Into<SpecId> + Copy,
    BLOCK: FoundryBlock,
>(
    evm_env: &mut EvmEnv<SPEC, BLOCK>,
    block: &N::BlockResponse,
    source_chain_id: ChainId,
    configs: NetworkConfigs,
) {
    use NamedChain::{
        Avalanche, AvalancheFuji, BinanceSmartChain, BinanceSmartChainTestnet, Mainnet, Polygon,
        PolygonAmoy,
    };

    // The blob fee market is priced from the header's excess blob gas and the source chain's
    // blob schedule at the block timestamp. Headers without the field (pre-Cancun blocks and
    // chains without EIP-4844) keep the default blob environment.
    if let Some(excess_blob_gas) = block.header().excess_blob_gas() {
        evm_env.block_env.set_blob_excess_gas_and_price(
            excess_blob_gas,
            get_blob_base_fee_update_fraction(source_chain_id, block.header().timestamp()),
        );
    }

    if let Ok(chain) = NamedChain::try_from(source_chain_id) {
        let block_number = block.header().number();

        match chain {
            Mainnet => {
                // after merge difficulty is supplanted with prevrandao EIP-4399
                if block_number >= 15_537_351u64 {
                    evm_env
                        .block_env
                        .set_difficulty(evm_env.block_env.prevrandao().unwrap_or_default().into());
                }

                return;
            }
            BinanceSmartChain
            | BinanceSmartChainTestnet
            | Polygon
            | PolygonAmoy
            | Avalanche
            | AvalancheFuji => {
                // https://github.com/foundry-rs/foundry/issues/9942
                // As far as observed from the source code of bnb-chain/bsc, the `difficulty` field
                // is still in use and returned by the corresponding opcode but `prevrandao`
                // (`mixHash`) is always zero, even though bsc adopts the newer EVM
                // specification. This will confuse revm and causes emulation
                // failure. Polygon and Avalanche behave the same way.
                evm_env.block_env.set_prevrandao(Some(evm_env.block_env.difficulty().into()));
                return;
            }
            c if c.is_arbitrum() => {
                // on arbitrum `block.number` is the L1 block which is included in the
                // `l1BlockNumber` field
                if let Some(l1_block_number) = block
                    .other_fields()
                    .and_then(|other| other.get("l1BlockNumber").cloned())
                    .and_then(|l1_block_number| {
                        serde_json::from_value::<U256>(l1_block_number).ok()
                    })
                {
                    evm_env.block_env.set_number(l1_block_number);
                }

                // `mixHash` carries L1 metadata rather than randomness here, while the
                // `PREVRANDAO` opcode returns `difficulty` like it does on the chains above.
                evm_env.block_env.set_prevrandao(Some(evm_env.block_env.difficulty().into()));
            }
            _ => {}
        }
    }

    if configs.bypass_prevrandao(source_chain_id) && evm_env.block_env.prevrandao().is_none() {
        // <https://github.com/foundry-rs/foundry/issues/4232>
        evm_env.block_env.set_prevrandao(Some(B256::random()));
    }

    // if difficulty is `0` we assume it's past merge
    if block.header().difficulty().is_zero() {
        evm_env.block_env.set_difficulty(evm_env.block_env.prevrandao().unwrap_or_default().into());
    }
}

/// Derives the active [`BlobParams`] based on the given timestamp.
///
/// This falls back to regular ethereum blob params if no hardforks for the given chain id are
/// detected.
pub fn get_blob_params(chain_id: ChainId, timestamp: u64) -> BlobParams {
    let hardfork = EthereumHardfork::from_chain_and_timestamp(Chain::from_id(chain_id), timestamp)
        .unwrap_or_default();

    match hardfork {
        EthereumHardfork::Prague => BlobParams::prague(),
        EthereumHardfork::Osaka => BlobParams::osaka(),
        EthereumHardfork::Bpo1 => BlobParams::bpo1(),
        EthereumHardfork::Bpo2 => BlobParams::bpo2(),

        // future hardforks/unknown settings: update once decided
        EthereumHardfork::Bpo3 => BlobParams::bpo2(),
        EthereumHardfork::Bpo4 => BlobParams::bpo2(),
        EthereumHardfork::Bpo5 => BlobParams::bpo2(),
        EthereumHardfork::Amsterdam => BlobParams::bpo2(),

        // fallback
        _ => BlobParams::cancun(),
    }
}

/// Derive the blob base fee update fraction based on the chain and timestamp by checking the
/// hardfork.
pub fn get_blob_base_fee_update_fraction(chain_id: ChainId, timestamp: u64) -> u64 {
    get_blob_params(chain_id, timestamp).update_fraction as u64
}

/// Returns the blob params based on the spec id.
pub fn get_blob_params_by_spec_id(spec: SpecId) -> BlobParams {
    if spec >= SpecId::AMSTERDAM {
        BlobParams::bpo2()
    } else if spec >= SpecId::OSAKA {
        BlobParams::osaka()
    } else if spec >= SpecId::PRAGUE {
        BlobParams::prague()
    } else {
        BlobParams::cancun()
    }
}

/// Returns the blob parameters selected by an explicit Foundry hardfork.
pub fn get_blob_params_by_hardfork(hardfork: FoundryHardfork) -> BlobParams {
    match hardfork {
        FoundryHardfork::Ethereum(EthereumHardfork::Prague) => BlobParams::prague(),
        FoundryHardfork::Ethereum(EthereumHardfork::Osaka) => BlobParams::osaka(),
        FoundryHardfork::Ethereum(EthereumHardfork::Bpo1) => BlobParams::bpo1(),
        FoundryHardfork::Ethereum(EthereumHardfork::Bpo2) => BlobParams::bpo2(),
        FoundryHardfork::Ethereum(
            EthereumHardfork::Bpo3
            | EthereumHardfork::Bpo4
            | EthereumHardfork::Bpo5
            | EthereumHardfork::Amsterdam,
        ) => BlobParams::bpo2(),
        _ => get_blob_params_by_spec_id(hardfork.into()),
    }
}

/// Returns the blob base fee update fraction based on the spec id.
pub fn get_blob_base_fee_update_fraction_by_spec_id(spec: SpecId) -> u64 {
    get_blob_params_by_spec_id(spec).update_fraction as u64
}

/// Given an ABI and selector, it tries to find the respective function.
pub fn get_function<'a>(
    contract_name: &str,
    selector: Selector,
    abi: &'a JsonAbi,
) -> eyre::Result<&'a Function> {
    abi.functions()
        .find(|func| func.selector() == selector)
        .ok_or_else(|| eyre::eyre!("{contract_name} does not have the selector {selector}"))
}

#[cfg(test)]
mod tests {
    use super::*;
    use alloy_network::{AnyHeader, AnyNetwork, AnyRpcBlock, AnyRpcHeader};
    use alloy_rpc_types::{Block, BlockTransactions};
    use revm::context::{BlockEnv, CfgEnv};

    #[test]
    fn block_env_preserves_slot_number() {
        for slot_number in [None, Some(0), Some(42), Some(u64::MAX)] {
            let header = AnyHeader { slot_number, ..Default::default() };
            let block = block_env_from_header::<BlockEnv>(&header);
            assert_eq!(block.slot_num, slot_number.unwrap_or_default());
        }
    }

    #[test]
    fn block_normalization_uses_source_chain() {
        let header = AnyHeader { number: 500, ..Default::default() };
        let mut block = AnyRpcBlock::new(
            Block::new(
                AnyRpcHeader::from_sealed(header.seal(B256::ZERO)),
                BlockTransactions::Full(Vec::new()),
            )
            .into(),
        );
        block.other.insert("l1BlockNumber".to_string(), serde_json::json!("0x64"));

        let mut cfg_env = CfgEnv::<SpecId>::default();
        cfg_env.chain_id = NamedChain::Mainnet as u64;
        let mut evm_env = EvmEnv {
            cfg_env,
            block_env: BlockEnv { number: U256::from(500), ..Default::default() },
        };

        apply_chain_and_block_specific_env_changes_for_chain::<AnyNetwork, _, _>(
            &mut evm_env,
            &block,
            NamedChain::Arbitrum as u64,
            NetworkConfigs::default(),
        );

        assert_eq!(evm_env.cfg_env.chain_id, NamedChain::Mainnet as u64);
        assert_eq!(evm_env.block_env.number, U256::from(100));
    }

    #[test]
    fn block_normalization_sets_blob_excess_gas_from_header() {
        // Mainnet block 22_000_000 (Cancun): 22_151_168 excess blob gas prices blobs at 761 wei.
        let header = AnyHeader {
            timestamp: 1_741_410_875,
            excess_blob_gas: Some(22_151_168),
            ..Default::default()
        };
        let block = AnyRpcBlock::new(
            Block::new(
                AnyRpcHeader::from_sealed(header.seal(B256::ZERO)),
                BlockTransactions::Full(Vec::new()),
            )
            .into(),
        );
        let mut evm_env = EvmEnv::new(CfgEnv::<SpecId>::default(), BlockEnv::default());
        // The execution chain id can be overridden; the blob schedule follows the source chain.
        evm_env.cfg_env.chain_id = 1337;

        apply_chain_and_block_specific_env_changes_for_chain::<AnyNetwork, _, _>(
            &mut evm_env,
            &block,
            NamedChain::Mainnet as u64,
            NetworkConfigs::default(),
        );

        let blob = evm_env.block_env.blob_excess_gas_and_price.unwrap();
        assert_eq!(blob.excess_blob_gas, 22_151_168);
        assert_eq!(blob.blob_gasprice, 761);
    }

    #[test]
    fn block_normalization_keeps_default_blob_env_without_header_field() {
        let header = AnyHeader { excess_blob_gas: None, ..Default::default() };
        let block = AnyRpcBlock::new(
            Block::new(
                AnyRpcHeader::from_sealed(header.seal(B256::ZERO)),
                BlockTransactions::Full(Vec::new()),
            )
            .into(),
        );
        let mut evm_env = EvmEnv::new(CfgEnv::<SpecId>::default(), BlockEnv::default());

        apply_chain_and_block_specific_env_changes_for_chain::<AnyNetwork, _, _>(
            &mut evm_env,
            &block,
            NamedChain::Mainnet as u64,
            NetworkConfigs::default(),
        );

        assert_eq!(
            evm_env.block_env.blob_excess_gas_and_price,
            BlockEnv::default().blob_excess_gas_and_price
        );
    }

    #[test]
    fn block_normalization_sets_prevrandao_for_moonbeam() {
        let header = AnyHeader { difficulty: U256::from(1), ..Default::default() };
        let block = AnyRpcBlock::new(
            Block::new(
                AnyRpcHeader::from_sealed(header.seal(B256::ZERO)),
                BlockTransactions::Full(Vec::new()),
            )
            .into(),
        );
        let mut evm_env = EvmEnv::new(
            CfgEnv::<SpecId>::default(),
            BlockEnv { prevrandao: None, ..Default::default() },
        );

        apply_chain_and_block_specific_env_changes_for_chain::<AnyNetwork, _, _>(
            &mut evm_env,
            &block,
            NamedChain::Moonbeam as u64,
            NetworkConfigs::default(),
        );

        assert!(evm_env.block_env.prevrandao.is_some());
    }

    #[test]
    fn block_normalization_uses_difficulty_as_prevrandao() {
        // These chains keep using `difficulty` and return it from `PREVRANDAO`, so a header
        // `mixHash` of zero (or, on Arbitrum, packed L1 metadata) must not reach the block env.
        for (chain, mix_hash) in [
            (NamedChain::BinanceSmartChain, B256::ZERO),
            (NamedChain::Polygon, B256::ZERO),
            (NamedChain::PolygonAmoy, B256::ZERO),
            (NamedChain::Avalanche, B256::ZERO),
            (NamedChain::AvalancheFuji, B256::ZERO),
            (NamedChain::Arbitrum, B256::repeat_byte(0xab)),
            (NamedChain::ArbitrumNova, B256::repeat_byte(0xab)),
            (NamedChain::ArbitrumSepolia, B256::repeat_byte(0xab)),
        ] {
            let header = AnyHeader {
                difficulty: U256::from(1),
                mix_hash: Some(mix_hash),
                ..Default::default()
            };
            let block = AnyRpcBlock::new(
                Block::new(
                    AnyRpcHeader::from_sealed(header.seal(B256::ZERO)),
                    BlockTransactions::Full(Vec::new()),
                )
                .into(),
            );
            let mut evm_env = EvmEnv::new(
                CfgEnv::<SpecId>::default(),
                BlockEnv {
                    difficulty: U256::from(1),
                    prevrandao: Some(mix_hash),
                    ..Default::default()
                },
            );

            apply_chain_and_block_specific_env_changes_for_chain::<AnyNetwork, _, _>(
                &mut evm_env,
                &block,
                chain as u64,
                NetworkConfigs::default(),
            );

            assert_eq!(
                evm_env.block_env.prevrandao,
                Some(B256::from(U256::from(1))),
                "{chain:?} should expose `difficulty` as `PREVRANDAO`"
            );
        }
    }

    #[test]
    fn tx_replay_env_changes_disable_priority_fee_check_only_for_arbitrum() {
        let mut evm_env = EvmEnv::new(
            revm::context::CfgEnv::<SpecId>::default(),
            revm::context::BlockEnv::default(),
        );
        evm_env.cfg_env.chain_id = NamedChain::Arbitrum as u64;

        apply_chain_specific_tx_replay_env_changes(&mut evm_env);
        assert!(evm_env.cfg_env.disable_priority_fee_check);

        evm_env.cfg_env.chain_id = NamedChain::Mainnet as u64;
        evm_env.cfg_env.disable_priority_fee_check = false;

        apply_chain_specific_tx_replay_env_changes(&mut evm_env);
        assert!(!evm_env.cfg_env.disable_priority_fee_check);
    }

    #[test]
    fn tx_replay_env_changes_use_source_chain() {
        let mut evm_env = EvmEnv::new(
            revm::context::CfgEnv::<SpecId>::default(),
            revm::context::BlockEnv::default(),
        );
        evm_env.cfg_env.chain_id = NamedChain::Mainnet as u64;

        apply_chain_specific_tx_replay_env_changes_for_chain(
            &mut evm_env,
            NamedChain::Arbitrum as u64,
        );

        assert_eq!(evm_env.cfg_env.chain_id, NamedChain::Mainnet as u64);
        assert!(evm_env.cfg_env.disable_priority_fee_check);
    }

    #[test]
    fn blob_params_by_spec_id_tracks_latest_known_blob_schedule() {
        assert_eq!(get_blob_params_by_spec_id(SpecId::CANCUN), BlobParams::cancun());
        assert_eq!(get_blob_params_by_spec_id(SpecId::PRAGUE), BlobParams::prague());
        assert_eq!(get_blob_params_by_spec_id(SpecId::OSAKA), BlobParams::osaka());
        assert_eq!(get_blob_params_by_spec_id(SpecId::AMSTERDAM), BlobParams::bpo2());
        assert_eq!(
            get_blob_base_fee_update_fraction_by_spec_id(SpecId::AMSTERDAM),
            BlobParams::bpo2().update_fraction as u64
        );
    }

    #[test]
    fn blob_params_by_explicit_hardfork() {
        for (hardfork, expected) in [
            (EthereumHardfork::Cancun, BlobParams::cancun()),
            (EthereumHardfork::Prague, BlobParams::prague()),
            (EthereumHardfork::Osaka, BlobParams::osaka()),
            (EthereumHardfork::Bpo1, BlobParams::bpo1()),
            (EthereumHardfork::Bpo2, BlobParams::bpo2()),
            (EthereumHardfork::Amsterdam, BlobParams::bpo2()),
        ] {
            assert_eq!(get_blob_params_by_hardfork(hardfork.into()), expected);
        }
    }
}