foundry_evm_core/backend/mod.rs
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//! Foundry's main executor backend abstraction and implementation.
use crate::{
constants::{CALLER, CHEATCODE_ADDRESS, DEFAULT_CREATE2_DEPLOYER, TEST_CONTRACT_ADDRESS},
fork::{CreateFork, ForkId, MultiFork},
state_snapshot::StateSnapshots,
utils::{configure_tx_env, configure_tx_req_env, new_evm_with_inspector},
InspectorExt,
};
use alloy_genesis::GenesisAccount;
use alloy_network::{AnyRpcBlock, AnyTxEnvelope, TransactionResponse};
use alloy_primitives::{keccak256, uint, Address, TxKind, B256, U256};
use alloy_rpc_types::{BlockNumberOrTag, Transaction, TransactionRequest};
use eyre::Context;
use foundry_common::{is_known_system_sender, SYSTEM_TRANSACTION_TYPE};
pub use foundry_fork_db::{cache::BlockchainDbMeta, BlockchainDb, SharedBackend};
use revm::{
db::{CacheDB, DatabaseRef},
inspectors::NoOpInspector,
precompile::{PrecompileSpecId, Precompiles},
primitives::{
Account, AccountInfo, BlobExcessGasAndPrice, Bytecode, Env, EnvWithHandlerCfg, EvmState,
EvmStorageSlot, HashMap as Map, Log, ResultAndState, SpecId, KECCAK_EMPTY,
},
Database, DatabaseCommit, JournaledState,
};
use std::{
collections::{BTreeMap, HashMap, HashSet},
time::Instant,
};
mod diagnostic;
pub use diagnostic::RevertDiagnostic;
mod error;
pub use error::{BackendError, BackendResult, DatabaseError, DatabaseResult};
mod cow;
pub use cow::CowBackend;
mod in_memory_db;
pub use in_memory_db::{EmptyDBWrapper, FoundryEvmInMemoryDB, MemDb};
mod snapshot;
pub use snapshot::{BackendStateSnapshot, RevertStateSnapshotAction, StateSnapshot};
// A `revm::Database` that is used in forking mode
type ForkDB = CacheDB<SharedBackend>;
/// Represents a numeric `ForkId` valid only for the existence of the `Backend`.
///
/// The difference between `ForkId` and `LocalForkId` is that `ForkId` tracks pairs of `endpoint +
/// block` which can be reused by multiple tests, whereas the `LocalForkId` is unique within a test
pub type LocalForkId = U256;
/// Represents the index of a fork in the created forks vector
/// This is used for fast lookup
type ForkLookupIndex = usize;
/// All accounts that will have persistent storage across fork swaps.
const DEFAULT_PERSISTENT_ACCOUNTS: [Address; 3] =
[CHEATCODE_ADDRESS, DEFAULT_CREATE2_DEPLOYER, CALLER];
/// `bytes32("failed")`, as a storage slot key into [`CHEATCODE_ADDRESS`].
///
/// Used by all `forge-std` test contracts and newer `DSTest` test contracts as a global marker for
/// a failed test.
pub const GLOBAL_FAIL_SLOT: U256 =
uint!(0x6661696c65640000000000000000000000000000000000000000000000000000_U256);
/// An extension trait that allows us to easily extend the `revm::Inspector` capabilities
#[auto_impl::auto_impl(&mut)]
pub trait DatabaseExt: Database<Error = DatabaseError> + DatabaseCommit {
/// Creates a new state snapshot at the current point of execution.
///
/// A state snapshot is associated with a new unique id that's created for the snapshot.
/// State snapshots can be reverted: [DatabaseExt::revert_state], however, depending on the
/// [RevertStateSnapshotAction], it will keep the snapshot alive or delete it.
fn snapshot_state(&mut self, journaled_state: &JournaledState, env: &Env) -> U256;
/// Reverts the snapshot if it exists
///
/// Returns `true` if the snapshot was successfully reverted, `false` if no snapshot for that id
/// exists.
///
/// **N.B.** While this reverts the state of the evm to the snapshot, it keeps new logs made
/// since the snapshots was created. This way we can show logs that were emitted between
/// snapshot and its revert.
/// This will also revert any changes in the `Env` and replace it with the captured `Env` of
/// `Self::snapshot_state`.
///
/// Depending on [RevertStateSnapshotAction] it will keep the snapshot alive or delete it.
fn revert_state(
&mut self,
id: U256,
journaled_state: &JournaledState,
env: &mut Env,
action: RevertStateSnapshotAction,
) -> Option<JournaledState>;
/// Deletes the state snapshot with the given `id`
///
/// Returns `true` if the snapshot was successfully deleted, `false` if no snapshot for that id
/// exists.
fn delete_state_snapshot(&mut self, id: U256) -> bool;
/// Deletes all state snapshots.
fn delete_state_snapshots(&mut self);
/// Creates and also selects a new fork
///
/// This is basically `create_fork` + `select_fork`
fn create_select_fork(
&mut self,
fork: CreateFork,
env: &mut Env,
journaled_state: &mut JournaledState,
) -> eyre::Result<LocalForkId> {
let id = self.create_fork(fork)?;
self.select_fork(id, env, journaled_state)?;
Ok(id)
}
/// Creates and also selects a new fork
///
/// This is basically `create_fork` + `select_fork`
fn create_select_fork_at_transaction(
&mut self,
fork: CreateFork,
env: &mut Env,
journaled_state: &mut JournaledState,
transaction: B256,
) -> eyre::Result<LocalForkId> {
let id = self.create_fork_at_transaction(fork, transaction)?;
self.select_fork(id, env, journaled_state)?;
Ok(id)
}
/// Creates a new fork but does _not_ select it
fn create_fork(&mut self, fork: CreateFork) -> eyre::Result<LocalForkId>;
/// Creates a new fork but does _not_ select it
fn create_fork_at_transaction(
&mut self,
fork: CreateFork,
transaction: B256,
) -> eyre::Result<LocalForkId>;
/// Selects the fork's state
///
/// This will also modify the current `Env`.
///
/// **Note**: this does not change the local state, but swaps the remote state
///
/// # Errors
///
/// Returns an error if no fork with the given `id` exists
fn select_fork(
&mut self,
id: LocalForkId,
env: &mut Env,
journaled_state: &mut JournaledState,
) -> eyre::Result<()>;
/// Updates the fork to given block number.
///
/// This will essentially create a new fork at the given block height.
///
/// # Errors
///
/// Returns an error if not matching fork was found.
fn roll_fork(
&mut self,
id: Option<LocalForkId>,
block_number: u64,
env: &mut Env,
journaled_state: &mut JournaledState,
) -> eyre::Result<()>;
/// Updates the fork to given transaction hash
///
/// This will essentially create a new fork at the block this transaction was mined and replays
/// all transactions up until the given transaction.
///
/// # Errors
///
/// Returns an error if not matching fork was found.
fn roll_fork_to_transaction(
&mut self,
id: Option<LocalForkId>,
transaction: B256,
env: &mut Env,
journaled_state: &mut JournaledState,
) -> eyre::Result<()>;
/// Fetches the given transaction for the fork and executes it, committing the state in the DB
fn transact(
&mut self,
id: Option<LocalForkId>,
transaction: B256,
env: Env,
journaled_state: &mut JournaledState,
inspector: &mut dyn InspectorExt,
) -> eyre::Result<()>;
/// Executes a given TransactionRequest, commits the new state to the DB
fn transact_from_tx(
&mut self,
transaction: &TransactionRequest,
env: Env,
journaled_state: &mut JournaledState,
inspector: &mut dyn InspectorExt,
) -> eyre::Result<()>;
/// Returns the `ForkId` that's currently used in the database, if fork mode is on
fn active_fork_id(&self) -> Option<LocalForkId>;
/// Returns the Fork url that's currently used in the database, if fork mode is on
fn active_fork_url(&self) -> Option<String>;
/// Whether the database is currently in forked mode.
fn is_forked_mode(&self) -> bool {
self.active_fork_id().is_some()
}
/// Ensures that an appropriate fork exists
///
/// If `id` contains a requested `Fork` this will ensure it exists.
/// Otherwise, this returns the currently active fork.
///
/// # Errors
///
/// Returns an error if the given `id` does not match any forks
///
/// Returns an error if no fork exists
fn ensure_fork(&self, id: Option<LocalForkId>) -> eyre::Result<LocalForkId>;
/// Ensures that a corresponding `ForkId` exists for the given local `id`
fn ensure_fork_id(&self, id: LocalForkId) -> eyre::Result<&ForkId>;
/// Handling multiple accounts/new contracts in a multifork environment can be challenging since
/// every fork has its own standalone storage section. So this can be a common error to run
/// into:
///
/// ```solidity
/// function testCanDeploy() public {
/// vm.selectFork(mainnetFork);
/// // contract created while on `mainnetFork`
/// DummyContract dummy = new DummyContract();
/// // this will succeed
/// dummy.hello();
///
/// vm.selectFork(optimismFork);
///
/// vm.expectRevert();
/// // this will revert since `dummy` contract only exists on `mainnetFork`
/// dummy.hello();
/// }
/// ```
///
/// If this happens (`dummy.hello()`), or more general, a call on an address that's not a
/// contract, revm will revert without useful context. This call will check in this context if
/// `address(dummy)` belongs to an existing contract and if not will check all other forks if
/// the contract is deployed there.
///
/// Returns a more useful error message if that's the case
fn diagnose_revert(
&self,
callee: Address,
journaled_state: &JournaledState,
) -> Option<RevertDiagnostic>;
/// Loads the account allocs from the given `allocs` map into the passed [JournaledState].
///
/// Returns [Ok] if all accounts were successfully inserted into the journal, [Err] otherwise.
fn load_allocs(
&mut self,
allocs: &BTreeMap<Address, GenesisAccount>,
journaled_state: &mut JournaledState,
) -> Result<(), BackendError>;
/// Copies bytecode, storage, nonce and balance from the given genesis account to the target
/// address.
///
/// Returns [Ok] if data was successfully inserted into the journal, [Err] otherwise.
fn clone_account(
&mut self,
source: &GenesisAccount,
target: &Address,
journaled_state: &mut JournaledState,
) -> Result<(), BackendError>;
/// Returns true if the given account is currently marked as persistent.
fn is_persistent(&self, acc: &Address) -> bool;
/// Revokes persistent status from the given account.
fn remove_persistent_account(&mut self, account: &Address) -> bool;
/// Marks the given account as persistent.
fn add_persistent_account(&mut self, account: Address) -> bool;
/// Removes persistent status from all given accounts.
#[auto_impl(keep_default_for(&, &mut, Rc, Arc, Box))]
fn remove_persistent_accounts(&mut self, accounts: impl IntoIterator<Item = Address>)
where
Self: Sized,
{
for acc in accounts {
self.remove_persistent_account(&acc);
}
}
/// Extends the persistent accounts with the accounts the iterator yields.
#[auto_impl(keep_default_for(&, &mut, Rc, Arc, Box))]
fn extend_persistent_accounts(&mut self, accounts: impl IntoIterator<Item = Address>)
where
Self: Sized,
{
for acc in accounts {
self.add_persistent_account(acc);
}
}
/// Grants cheatcode access for the given `account`
///
/// Returns true if the `account` already has access
fn allow_cheatcode_access(&mut self, account: Address) -> bool;
/// Revokes cheatcode access for the given account
///
/// Returns true if the `account` was previously allowed cheatcode access
fn revoke_cheatcode_access(&mut self, account: &Address) -> bool;
/// Returns `true` if the given account is allowed to execute cheatcodes
fn has_cheatcode_access(&self, account: &Address) -> bool;
/// Ensures that `account` is allowed to execute cheatcodes
///
/// Returns an error if [`Self::has_cheatcode_access`] returns `false`
fn ensure_cheatcode_access(&self, account: &Address) -> Result<(), BackendError> {
if !self.has_cheatcode_access(account) {
return Err(BackendError::NoCheats(*account));
}
Ok(())
}
/// Same as [`Self::ensure_cheatcode_access()`] but only enforces it if the backend is currently
/// in forking mode
fn ensure_cheatcode_access_forking_mode(&self, account: &Address) -> Result<(), BackendError> {
if self.is_forked_mode() {
return self.ensure_cheatcode_access(account);
}
Ok(())
}
/// Set the blockhash for a given block number.
///
/// # Arguments
///
/// * `number` - The block number to set the blockhash for
/// * `hash` - The blockhash to set
///
/// # Note
///
/// This function mimics the EVM limits of the `blockhash` operation:
/// - It sets the blockhash for blocks where `block.number - 256 <= number < block.number`
/// - Setting a blockhash for the current block (number == block.number) has no effect
/// - Setting a blockhash for future blocks (number > block.number) has no effect
/// - Setting a blockhash for blocks older than `block.number - 256` has no effect
fn set_blockhash(&mut self, block_number: U256, block_hash: B256);
}
struct _ObjectSafe(dyn DatabaseExt);
/// Provides the underlying `revm::Database` implementation.
///
/// A `Backend` can be initialised in two forms:
///
/// # 1. Empty in-memory Database
/// This is the default variant: an empty `revm::Database`
///
/// # 2. Forked Database
/// A `revm::Database` that forks off a remote client
///
///
/// In addition to that we support forking manually on the fly.
/// Additional forks can be created. Each unique fork is identified by its unique `ForkId`. We treat
/// forks as unique if they have the same `(endpoint, block number)` pair.
///
/// When it comes to testing, it's intended that each contract will use its own `Backend`
/// (`Backend::clone`). This way each contract uses its own encapsulated evm state. For in-memory
/// testing, the database is just an owned `revm::InMemoryDB`.
///
/// Each `Fork`, identified by a unique id, uses completely separate storage, write operations are
/// performed only in the fork's own database, `ForkDB`.
///
/// A `ForkDB` consists of 2 halves:
/// - everything fetched from the remote is readonly
/// - all local changes (instructed by the contract) are written to the backend's `db` and don't
/// alter the state of the remote client.
///
/// # Fork swapping
///
/// Multiple "forks" can be created `Backend::create_fork()`, however only 1 can be used by the
/// `db`. However, their state can be hot-swapped by swapping the read half of `db` from one fork to
/// another.
/// When swapping forks (`Backend::select_fork()`) we also update the current `Env` of the `EVM`
/// accordingly, so that all `block.*` config values match
///
/// When another for is selected [`DatabaseExt::select_fork()`] the entire storage, including
/// `JournaledState` is swapped, but the storage of the caller's and the test contract account is
/// _always_ cloned. This way a fork has entirely separate storage but data can still be shared
/// across fork boundaries via stack and contract variables.
///
/// # Snapshotting
///
/// A snapshot of the current overall state can be taken at any point in time. A snapshot is
/// identified by a unique id that's returned when a snapshot is created. A snapshot can only be
/// reverted _once_. After a successful revert, the same snapshot id cannot be used again. Reverting
/// a snapshot replaces the current active state with the snapshot state, the snapshot is deleted
/// afterwards, as well as any snapshots taken after the reverted snapshot, (e.g.: reverting to id
/// 0x1 will delete snapshots with ids 0x1, 0x2, etc.)
///
/// **Note:** State snapshots work across fork-swaps, e.g. if fork `A` is currently active, then a
/// snapshot is created before fork `B` is selected, then fork `A` will be the active fork again
/// after reverting the snapshot.
#[derive(Clone, Debug)]
#[must_use]
pub struct Backend {
/// The access point for managing forks
forks: MultiFork,
// The default in memory db
mem_db: FoundryEvmInMemoryDB,
/// The journaled_state to use to initialize new forks with
///
/// The way [`revm::JournaledState`] works is, that it holds the "hot" accounts loaded from the
/// underlying `Database` that feeds the Account and State data to the journaled_state so it
/// can apply changes to the state while the EVM executes.
///
/// In a way the `JournaledState` is something like a cache that
/// 1. check if account is already loaded (hot)
/// 2. if not load from the `Database` (this will then retrieve the account via RPC in forking
/// mode)
///
/// To properly initialize we store the `JournaledState` before the first fork is selected
/// ([`DatabaseExt::select_fork`]).
///
/// This will be an empty `JournaledState`, which will be populated with persistent accounts,
/// See [`Self::update_fork_db()`].
fork_init_journaled_state: JournaledState,
/// The currently active fork database
///
/// If this is set, then the Backend is currently in forking mode
active_fork_ids: Option<(LocalForkId, ForkLookupIndex)>,
/// holds additional Backend data
inner: BackendInner,
}
impl Backend {
/// Creates a new Backend with a spawned multi fork thread.
///
/// If `fork` is `Some` this will use a `fork` database, otherwise with an in-memory
/// database.
pub fn spawn(fork: Option<CreateFork>) -> Self {
Self::new(MultiFork::spawn(), fork)
}
/// Creates a new instance of `Backend`
///
/// If `fork` is `Some` this will use a `fork` database, otherwise with an in-memory
/// database.
///
/// Prefer using [`spawn`](Self::spawn) instead.
pub fn new(forks: MultiFork, fork: Option<CreateFork>) -> Self {
trace!(target: "backend", forking_mode=?fork.is_some(), "creating executor backend");
// Note: this will take of registering the `fork`
let inner = BackendInner {
persistent_accounts: HashSet::from(DEFAULT_PERSISTENT_ACCOUNTS),
..Default::default()
};
let mut backend = Self {
forks,
mem_db: CacheDB::new(Default::default()),
fork_init_journaled_state: inner.new_journaled_state(),
active_fork_ids: None,
inner,
};
if let Some(fork) = fork {
let (fork_id, fork, _) =
backend.forks.create_fork(fork).expect("Unable to create fork");
let fork_db = ForkDB::new(fork);
let fork_ids = backend.inner.insert_new_fork(
fork_id.clone(),
fork_db,
backend.inner.new_journaled_state(),
);
backend.inner.launched_with_fork = Some((fork_id, fork_ids.0, fork_ids.1));
backend.active_fork_ids = Some(fork_ids);
}
trace!(target: "backend", forking_mode=? backend.active_fork_ids.is_some(), "created executor backend");
backend
}
/// Creates a new instance of `Backend` with fork added to the fork database and sets the fork
/// as active
pub(crate) fn new_with_fork(id: &ForkId, fork: Fork, journaled_state: JournaledState) -> Self {
let mut backend = Self::spawn(None);
let fork_ids = backend.inner.insert_new_fork(id.clone(), fork.db, journaled_state);
backend.inner.launched_with_fork = Some((id.clone(), fork_ids.0, fork_ids.1));
backend.active_fork_ids = Some(fork_ids);
backend
}
/// Creates a new instance with a `BackendDatabase::InMemory` cache layer for the `CacheDB`
pub fn clone_empty(&self) -> Self {
Self {
forks: self.forks.clone(),
mem_db: CacheDB::new(Default::default()),
fork_init_journaled_state: self.inner.new_journaled_state(),
active_fork_ids: None,
inner: Default::default(),
}
}
pub fn insert_account_info(&mut self, address: Address, account: AccountInfo) {
if let Some(db) = self.active_fork_db_mut() {
db.insert_account_info(address, account)
} else {
self.mem_db.insert_account_info(address, account)
}
}
/// Inserts a value on an account's storage without overriding account info
pub fn insert_account_storage(
&mut self,
address: Address,
slot: U256,
value: U256,
) -> Result<(), DatabaseError> {
if let Some(db) = self.active_fork_db_mut() {
db.insert_account_storage(address, slot, value)
} else {
self.mem_db.insert_account_storage(address, slot, value)
}
}
/// Completely replace an account's storage without overriding account info.
///
/// When forking, this causes the backend to assume a `0` value for all
/// unset storage slots instead of trying to fetch it.
pub fn replace_account_storage(
&mut self,
address: Address,
storage: Map<U256, U256>,
) -> Result<(), DatabaseError> {
if let Some(db) = self.active_fork_db_mut() {
db.replace_account_storage(address, storage)
} else {
self.mem_db.replace_account_storage(address, storage)
}
}
/// Returns all snapshots created in this backend
pub fn state_snapshots(
&self,
) -> &StateSnapshots<BackendStateSnapshot<BackendDatabaseSnapshot>> {
&self.inner.state_snapshots
}
/// Sets the address of the `DSTest` contract that is being executed
///
/// This will also mark the caller as persistent and remove the persistent status from the
/// previous test contract address
///
/// This will also grant cheatcode access to the test account
pub fn set_test_contract(&mut self, acc: Address) -> &mut Self {
trace!(?acc, "setting test account");
self.add_persistent_account(acc);
self.allow_cheatcode_access(acc);
self
}
/// Sets the caller address
pub fn set_caller(&mut self, acc: Address) -> &mut Self {
trace!(?acc, "setting caller account");
self.inner.caller = Some(acc);
self.allow_cheatcode_access(acc);
self
}
/// Sets the current spec id
pub fn set_spec_id(&mut self, spec_id: SpecId) -> &mut Self {
trace!(?spec_id, "setting spec ID");
self.inner.spec_id = spec_id;
self
}
/// Returns the set caller address
pub fn caller_address(&self) -> Option<Address> {
self.inner.caller
}
/// Failures occurred in state snapshots are tracked when the state snapshot is reverted.
///
/// If an error occurs in a restored state snapshot, the test is considered failed.
///
/// This returns whether there was a reverted state snapshot that recorded an error.
pub fn has_state_snapshot_failure(&self) -> bool {
self.inner.has_state_snapshot_failure
}
/// Sets the state snapshot failure flag.
pub fn set_state_snapshot_failure(&mut self, has_state_snapshot_failure: bool) {
self.inner.has_state_snapshot_failure = has_state_snapshot_failure
}
/// When creating or switching forks, we update the AccountInfo of the contract
pub(crate) fn update_fork_db(
&self,
active_journaled_state: &mut JournaledState,
target_fork: &mut Fork,
) {
self.update_fork_db_contracts(
self.inner.persistent_accounts.iter().copied(),
active_journaled_state,
target_fork,
)
}
/// Merges the state of all `accounts` from the currently active db into the given `fork`
pub(crate) fn update_fork_db_contracts(
&self,
accounts: impl IntoIterator<Item = Address>,
active_journaled_state: &mut JournaledState,
target_fork: &mut Fork,
) {
if let Some(db) = self.active_fork_db() {
merge_account_data(accounts, db, active_journaled_state, target_fork)
} else {
merge_account_data(accounts, &self.mem_db, active_journaled_state, target_fork)
}
}
/// Returns the memory db used if not in forking mode
pub fn mem_db(&self) -> &FoundryEvmInMemoryDB {
&self.mem_db
}
/// Returns true if the `id` is currently active
pub fn is_active_fork(&self, id: LocalForkId) -> bool {
self.active_fork_ids.map(|(i, _)| i == id).unwrap_or_default()
}
/// Returns `true` if the `Backend` is currently in forking mode
pub fn is_in_forking_mode(&self) -> bool {
self.active_fork().is_some()
}
/// Returns the currently active `Fork`, if any
pub fn active_fork(&self) -> Option<&Fork> {
self.active_fork_ids.map(|(_, idx)| self.inner.get_fork(idx))
}
/// Returns the currently active `Fork`, if any
pub fn active_fork_mut(&mut self) -> Option<&mut Fork> {
self.active_fork_ids.map(|(_, idx)| self.inner.get_fork_mut(idx))
}
/// Returns the currently active `ForkDB`, if any
pub fn active_fork_db(&self) -> Option<&ForkDB> {
self.active_fork().map(|f| &f.db)
}
/// Returns the currently active `ForkDB`, if any
pub fn active_fork_db_mut(&mut self) -> Option<&mut ForkDB> {
self.active_fork_mut().map(|f| &mut f.db)
}
/// Returns the current database implementation as a `&dyn` value.
#[inline(always)]
pub fn db(&self) -> &dyn Database<Error = DatabaseError> {
match self.active_fork_db() {
Some(fork_db) => fork_db,
None => &self.mem_db,
}
}
/// Returns the current database implementation as a `&mut dyn` value.
#[inline(always)]
pub fn db_mut(&mut self) -> &mut dyn Database<Error = DatabaseError> {
match self.active_fork_ids.map(|(_, idx)| &mut self.inner.get_fork_mut(idx).db) {
Some(fork_db) => fork_db,
None => &mut self.mem_db,
}
}
/// Creates a snapshot of the currently active database
pub(crate) fn create_db_snapshot(&self) -> BackendDatabaseSnapshot {
if let Some((id, idx)) = self.active_fork_ids {
let fork = self.inner.get_fork(idx).clone();
let fork_id = self.inner.ensure_fork_id(id).cloned().expect("Exists; qed");
BackendDatabaseSnapshot::Forked(id, fork_id, idx, Box::new(fork))
} else {
BackendDatabaseSnapshot::InMemory(self.mem_db.clone())
}
}
/// Since each `Fork` tracks logs separately, we need to merge them to get _all_ of them
pub fn merged_logs(&self, mut logs: Vec<Log>) -> Vec<Log> {
if let Some((_, active)) = self.active_fork_ids {
let mut all_logs = Vec::with_capacity(logs.len());
self.inner
.forks
.iter()
.enumerate()
.filter_map(|(idx, f)| f.as_ref().map(|f| (idx, f)))
.for_each(|(idx, f)| {
if idx == active {
all_logs.append(&mut logs);
} else {
all_logs.extend(f.journaled_state.logs.clone())
}
});
return all_logs;
}
logs
}
/// Initializes settings we need to keep track of.
///
/// We need to track these mainly to prevent issues when switching between different evms
pub(crate) fn initialize(&mut self, env: &EnvWithHandlerCfg) {
self.set_caller(env.tx.caller);
self.set_spec_id(env.handler_cfg.spec_id);
let test_contract = match env.tx.transact_to {
TxKind::Call(to) => to,
TxKind::Create => {
let nonce = self
.basic_ref(env.tx.caller)
.map(|b| b.unwrap_or_default().nonce)
.unwrap_or_default();
env.tx.caller.create(nonce)
}
};
self.set_test_contract(test_contract);
}
/// Returns the `EnvWithHandlerCfg` with the current `spec_id` set.
fn env_with_handler_cfg(&self, env: Env) -> EnvWithHandlerCfg {
EnvWithHandlerCfg::new_with_spec_id(Box::new(env), self.inner.spec_id)
}
/// Executes the configured test call of the `env` without committing state changes.
///
/// Note: in case there are any cheatcodes executed that modify the environment, this will
/// update the given `env` with the new values.
#[instrument(name = "inspect", level = "debug", skip_all)]
pub fn inspect<I: InspectorExt>(
&mut self,
env: &mut EnvWithHandlerCfg,
inspector: &mut I,
) -> eyre::Result<ResultAndState> {
self.initialize(env);
let mut evm = crate::utils::new_evm_with_inspector(self, env.clone(), inspector);
let res = evm.transact().wrap_err("EVM error")?;
env.env = evm.context.evm.inner.env;
Ok(res)
}
/// Returns true if the address is a precompile
pub fn is_existing_precompile(&self, addr: &Address) -> bool {
self.inner.precompiles().contains(addr)
}
/// Sets the initial journaled state to use when initializing forks
#[inline]
fn set_init_journaled_state(&mut self, journaled_state: JournaledState) {
trace!("recording fork init journaled_state");
self.fork_init_journaled_state = journaled_state;
}
/// Cleans up already loaded accounts that would be initialized without the correct data from
/// the fork.
///
/// It can happen that an account is loaded before the first fork is selected, like
/// `getNonce(addr)`, which will load an empty account by default.
///
/// This account data then would not match the account data of a fork if it exists.
/// So when the first fork is initialized we replace these accounts with the actual account as
/// it exists on the fork.
fn prepare_init_journal_state(&mut self) -> Result<(), BackendError> {
let loaded_accounts = self
.fork_init_journaled_state
.state
.iter()
.filter(|(addr, _)| !self.is_existing_precompile(addr) && !self.is_persistent(addr))
.map(|(addr, _)| addr)
.copied()
.collect::<Vec<_>>();
for fork in self.inner.forks_iter_mut() {
let mut journaled_state = self.fork_init_journaled_state.clone();
for loaded_account in loaded_accounts.iter().copied() {
trace!(?loaded_account, "replacing account on init");
let init_account =
journaled_state.state.get_mut(&loaded_account).expect("exists; qed");
// here's an edge case where we need to check if this account has been created, in
// which case we don't need to replace it with the account from the fork because the
// created account takes precedence: for example contract creation in setups
if init_account.is_created() {
trace!(?loaded_account, "skipping created account");
continue
}
// otherwise we need to replace the account's info with the one from the fork's
// database
let fork_account = Database::basic(&mut fork.db, loaded_account)?
.ok_or(BackendError::MissingAccount(loaded_account))?;
init_account.info = fork_account;
}
fork.journaled_state = journaled_state;
}
Ok(())
}
/// Returns the block numbers required for replaying a transaction
fn get_block_number_and_block_for_transaction(
&self,
id: LocalForkId,
transaction: B256,
) -> eyre::Result<(u64, AnyRpcBlock)> {
let fork = self.inner.get_fork_by_id(id)?;
let tx = fork.db.db.get_transaction(transaction)?;
// get the block number we need to fork
if let Some(tx_block) = tx.block_number {
let block = fork.db.db.get_full_block(tx_block)?;
// we need to subtract 1 here because we want the state before the transaction
// was mined
let fork_block = tx_block - 1;
Ok((fork_block, block))
} else {
let block = fork.db.db.get_full_block(BlockNumberOrTag::Latest)?;
let number = block.header.number;
Ok((number, block))
}
}
/// Replays all the transactions at the forks current block that were mined before the `tx`
///
/// Returns the _unmined_ transaction that corresponds to the given `tx_hash`
pub fn replay_until(
&mut self,
id: LocalForkId,
env: Env,
tx_hash: B256,
journaled_state: &mut JournaledState,
) -> eyre::Result<Option<Transaction<AnyTxEnvelope>>> {
trace!(?id, ?tx_hash, "replay until transaction");
let persistent_accounts = self.inner.persistent_accounts.clone();
let fork_id = self.ensure_fork_id(id)?.clone();
let env = self.env_with_handler_cfg(env);
let fork = self.inner.get_fork_by_id_mut(id)?;
let full_block = fork.db.db.get_full_block(env.block.number.to::<u64>())?;
for tx in full_block.inner.transactions.into_transactions() {
// System transactions such as on L2s don't contain any pricing info so we skip them
// otherwise this would cause reverts
if is_known_system_sender(tx.from) ||
tx.transaction_type() == Some(SYSTEM_TRANSACTION_TYPE)
{
trace!(tx=?tx.tx_hash(), "skipping system transaction");
continue;
}
if tx.tx_hash() == tx_hash {
// found the target transaction
return Ok(Some(tx.inner))
}
trace!(tx=?tx.tx_hash(), "committing transaction");
commit_transaction(
&tx.inner,
env.clone(),
journaled_state,
fork,
&fork_id,
&persistent_accounts,
&mut NoOpInspector,
)?;
}
Ok(None)
}
}
impl DatabaseExt for Backend {
fn snapshot_state(&mut self, journaled_state: &JournaledState, env: &Env) -> U256 {
trace!("create snapshot");
let id = self.inner.state_snapshots.insert(BackendStateSnapshot::new(
self.create_db_snapshot(),
journaled_state.clone(),
env.clone(),
));
trace!(target: "backend", "Created new snapshot {}", id);
id
}
fn revert_state(
&mut self,
id: U256,
current_state: &JournaledState,
current: &mut Env,
action: RevertStateSnapshotAction,
) -> Option<JournaledState> {
trace!(?id, "revert snapshot");
if let Some(mut snapshot) = self.inner.state_snapshots.remove_at(id) {
// Re-insert snapshot to persist it
if action.is_keep() {
self.inner.state_snapshots.insert_at(snapshot.clone(), id);
}
// https://github.com/foundry-rs/foundry/issues/3055
// Check if an error occurred either during or before the snapshot.
// DSTest contracts don't have snapshot functionality, so this slot is enough to check
// for failure here.
if let Some(account) = current_state.state.get(&CHEATCODE_ADDRESS) {
if let Some(slot) = account.storage.get(&GLOBAL_FAIL_SLOT) {
if !slot.present_value.is_zero() {
self.set_state_snapshot_failure(true);
}
}
}
// merge additional logs
snapshot.merge(current_state);
let BackendStateSnapshot { db, mut journaled_state, env } = snapshot;
match db {
BackendDatabaseSnapshot::InMemory(mem_db) => {
self.mem_db = mem_db;
}
BackendDatabaseSnapshot::Forked(id, fork_id, idx, mut fork) => {
// there might be the case where the snapshot was created during `setUp` with
// another caller, so we need to ensure the caller account is present in the
// journaled state and database
let caller = current.tx.caller;
journaled_state.state.entry(caller).or_insert_with(|| {
let caller_account = current_state
.state
.get(&caller)
.map(|acc| acc.info.clone())
.unwrap_or_default();
if !fork.db.accounts.contains_key(&caller) {
// update the caller account which is required by the evm
fork.db.insert_account_info(caller, caller_account.clone());
}
caller_account.into()
});
self.inner.revert_state_snapshot(id, fork_id, idx, *fork);
self.active_fork_ids = Some((id, idx))
}
}
update_current_env_with_fork_env(current, env);
trace!(target: "backend", "Reverted snapshot {}", id);
Some(journaled_state)
} else {
warn!(target: "backend", "No snapshot to revert for {}", id);
None
}
}
fn delete_state_snapshot(&mut self, id: U256) -> bool {
self.inner.state_snapshots.remove_at(id).is_some()
}
fn delete_state_snapshots(&mut self) {
self.inner.state_snapshots.clear()
}
fn create_fork(&mut self, create_fork: CreateFork) -> eyre::Result<LocalForkId> {
trace!("create fork");
let (fork_id, fork, _) = self.forks.create_fork(create_fork)?;
let fork_db = ForkDB::new(fork);
let (id, _) =
self.inner.insert_new_fork(fork_id, fork_db, self.fork_init_journaled_state.clone());
Ok(id)
}
fn create_fork_at_transaction(
&mut self,
fork: CreateFork,
transaction: B256,
) -> eyre::Result<LocalForkId> {
trace!(?transaction, "create fork at transaction");
let id = self.create_fork(fork)?;
let fork_id = self.ensure_fork_id(id).cloned()?;
let mut env = self
.forks
.get_env(fork_id)?
.ok_or_else(|| eyre::eyre!("Requested fork `{}` does not exit", id))?;
// we still need to roll to the transaction, but we only need an empty dummy state since we
// don't need to update the active journaled state yet
self.roll_fork_to_transaction(
Some(id),
transaction,
&mut env,
&mut self.inner.new_journaled_state(),
)?;
Ok(id)
}
/// Select an existing fork by id.
/// When switching forks we copy the shared state
fn select_fork(
&mut self,
id: LocalForkId,
env: &mut Env,
active_journaled_state: &mut JournaledState,
) -> eyre::Result<()> {
trace!(?id, "select fork");
if self.is_active_fork(id) {
// nothing to do
return Ok(());
}
// Update block number and timestamp of active fork (if any) with current env values,
// in order to preserve values changed by using `roll` and `warp` cheatcodes.
if let Some(active_fork_id) = self.active_fork_id() {
self.forks.update_block(
self.ensure_fork_id(active_fork_id).cloned()?,
env.block.number,
env.block.timestamp,
)?;
}
let fork_id = self.ensure_fork_id(id).cloned()?;
let idx = self.inner.ensure_fork_index(&fork_id)?;
let fork_env = self
.forks
.get_env(fork_id)?
.ok_or_else(|| eyre::eyre!("Requested fork `{}` does not exit", id))?;
// If we're currently in forking mode we need to update the journaled_state to this point,
// this ensures the changes performed while the fork was active are recorded
if let Some(active) = self.active_fork_mut() {
active.journaled_state = active_journaled_state.clone();
let caller = env.tx.caller;
let caller_account = active.journaled_state.state.get(&env.tx.caller).cloned();
let target_fork = self.inner.get_fork_mut(idx);
// depth 0 will be the default value when the fork was created
if target_fork.journaled_state.depth == 0 {
// Initialize caller with its fork info
if let Some(mut acc) = caller_account {
let fork_account = Database::basic(&mut target_fork.db, caller)?
.ok_or(BackendError::MissingAccount(caller))?;
acc.info = fork_account;
target_fork.journaled_state.state.insert(caller, acc);
}
}
} else {
// this is the first time a fork is selected. This means up to this point all changes
// are made in a single `JournaledState`, for example after a `setup` that only created
// different forks. Since the `JournaledState` is valid for all forks until the
// first fork is selected, we need to update it for all forks and use it as init state
// for all future forks
self.set_init_journaled_state(active_journaled_state.clone());
self.prepare_init_journal_state()?;
// Make sure that the next created fork has a depth of 0.
self.fork_init_journaled_state.depth = 0;
}
{
// update the shared state and track
let mut fork = self.inner.take_fork(idx);
// since all forks handle their state separately, the depth can drift
// this is a handover where the target fork starts at the same depth where it was
// selected. This ensures that there are no gaps in depth which would
// otherwise cause issues with the tracer
fork.journaled_state.depth = active_journaled_state.depth;
// another edge case where a fork is created and selected during setup with not
// necessarily the same caller as for the test, however we must always
// ensure that fork's state contains the current sender
let caller = env.tx.caller;
fork.journaled_state.state.entry(caller).or_insert_with(|| {
let caller_account = active_journaled_state
.state
.get(&env.tx.caller)
.map(|acc| acc.info.clone())
.unwrap_or_default();
if !fork.db.accounts.contains_key(&caller) {
// update the caller account which is required by the evm
fork.db.insert_account_info(caller, caller_account.clone());
}
caller_account.into()
});
self.update_fork_db(active_journaled_state, &mut fork);
// insert the fork back
self.inner.set_fork(idx, fork);
}
self.active_fork_ids = Some((id, idx));
// Update current environment with environment of newly selected fork.
update_current_env_with_fork_env(env, fork_env);
Ok(())
}
/// This is effectively the same as [`Self::create_select_fork()`] but updating an existing
/// [ForkId] that is mapped to the [LocalForkId]
fn roll_fork(
&mut self,
id: Option<LocalForkId>,
block_number: u64,
env: &mut Env,
journaled_state: &mut JournaledState,
) -> eyre::Result<()> {
trace!(?id, ?block_number, "roll fork");
let id = self.ensure_fork(id)?;
let (fork_id, backend, fork_env) =
self.forks.roll_fork(self.inner.ensure_fork_id(id).cloned()?, block_number)?;
// this will update the local mapping
self.inner.roll_fork(id, fork_id, backend)?;
if let Some((active_id, active_idx)) = self.active_fork_ids {
// the currently active fork is the targeted fork of this call
if active_id == id {
// need to update the block's env settings right away, which is otherwise set when
// forks are selected `select_fork`
update_current_env_with_fork_env(env, fork_env);
// we also need to update the journaled_state right away, this has essentially the
// same effect as selecting (`select_fork`) by discarding
// non-persistent storage from the journaled_state. This which will
// reset cached state from the previous block
let mut persistent_addrs = self.inner.persistent_accounts.clone();
// we also want to copy the caller state here
persistent_addrs.extend(self.caller_address());
let active = self.inner.get_fork_mut(active_idx);
active.journaled_state = self.fork_init_journaled_state.clone();
active.journaled_state.depth = journaled_state.depth;
for addr in persistent_addrs {
merge_journaled_state_data(addr, journaled_state, &mut active.journaled_state);
}
// Ensure all previously loaded accounts are present in the journaled state to
// prevent issues in the new journalstate, e.g. assumptions that accounts are loaded
// if the account is not touched, we reload it, if it's touched we clone it.
//
// Special case for accounts that are not created: we don't merge their state but
// load it in order to reflect their state at the new block (they should explicitly
// be marked as persistent if it is desired to keep state between fork rolls).
for (addr, acc) in journaled_state.state.iter() {
if acc.is_created() {
if acc.is_touched() {
merge_journaled_state_data(
*addr,
journaled_state,
&mut active.journaled_state,
);
}
} else {
let _ = active.journaled_state.load_account(*addr, &mut active.db);
}
}
*journaled_state = active.journaled_state.clone();
}
}
Ok(())
}
fn roll_fork_to_transaction(
&mut self,
id: Option<LocalForkId>,
transaction: B256,
env: &mut Env,
journaled_state: &mut JournaledState,
) -> eyre::Result<()> {
trace!(?id, ?transaction, "roll fork to transaction");
let id = self.ensure_fork(id)?;
let (fork_block, block) =
self.get_block_number_and_block_for_transaction(id, transaction)?;
// roll the fork to the transaction's block or latest if it's pending
self.roll_fork(Some(id), fork_block, env, journaled_state)?;
update_env_block(env, &block);
// replay all transactions that came before
let env = env.clone();
self.replay_until(id, env, transaction, journaled_state)?;
Ok(())
}
fn transact(
&mut self,
maybe_id: Option<LocalForkId>,
transaction: B256,
mut env: Env,
journaled_state: &mut JournaledState,
inspector: &mut dyn InspectorExt,
) -> eyre::Result<()> {
trace!(?maybe_id, ?transaction, "execute transaction");
let persistent_accounts = self.inner.persistent_accounts.clone();
let id = self.ensure_fork(maybe_id)?;
let fork_id = self.ensure_fork_id(id).cloned()?;
let tx = {
let fork = self.inner.get_fork_by_id_mut(id)?;
fork.db.db.get_transaction(transaction)?
};
// This is a bit ambiguous because the user wants to transact an arbitrary transaction in
// the current context, but we're assuming the user wants to transact the transaction as it
// was mined. Usually this is used in a combination of a fork at the transaction's parent
// transaction in the block and then the transaction is transacted:
// <https://github.com/foundry-rs/foundry/issues/6538>
// So we modify the env to match the transaction's block.
let (_fork_block, block) =
self.get_block_number_and_block_for_transaction(id, transaction)?;
update_env_block(&mut env, &block);
let env = self.env_with_handler_cfg(env);
let fork = self.inner.get_fork_by_id_mut(id)?;
commit_transaction(
&tx,
env,
journaled_state,
fork,
&fork_id,
&persistent_accounts,
inspector,
)
}
fn transact_from_tx(
&mut self,
tx: &TransactionRequest,
mut env: Env,
journaled_state: &mut JournaledState,
inspector: &mut dyn InspectorExt,
) -> eyre::Result<()> {
trace!(?tx, "execute signed transaction");
self.commit(journaled_state.state.clone());
let res = {
configure_tx_req_env(&mut env, tx, None)?;
let env = self.env_with_handler_cfg(env);
let mut db = self.clone();
let mut evm = new_evm_with_inspector(&mut db, env, inspector);
evm.context.evm.journaled_state.depth = journaled_state.depth + 1;
evm.transact()?
};
self.commit(res.state);
update_state(&mut journaled_state.state, self, None)?;
Ok(())
}
fn active_fork_id(&self) -> Option<LocalForkId> {
self.active_fork_ids.map(|(id, _)| id)
}
fn active_fork_url(&self) -> Option<String> {
let fork = self.inner.issued_local_fork_ids.get(&self.active_fork_id()?)?;
self.forks.get_fork_url(fork.clone()).ok()?
}
fn ensure_fork(&self, id: Option<LocalForkId>) -> eyre::Result<LocalForkId> {
if let Some(id) = id {
if self.inner.issued_local_fork_ids.contains_key(&id) {
return Ok(id);
}
eyre::bail!("Requested fork `{}` does not exit", id)
}
if let Some(id) = self.active_fork_id() {
Ok(id)
} else {
eyre::bail!("No fork active")
}
}
fn ensure_fork_id(&self, id: LocalForkId) -> eyre::Result<&ForkId> {
self.inner.ensure_fork_id(id)
}
fn diagnose_revert(
&self,
callee: Address,
journaled_state: &JournaledState,
) -> Option<RevertDiagnostic> {
let active_id = self.active_fork_id()?;
let active_fork = self.active_fork()?;
if self.inner.forks.len() == 1 {
// we only want to provide additional diagnostics here when in multifork mode with > 1
// forks
return None;
}
if !active_fork.is_contract(callee) && !is_contract_in_state(journaled_state, callee) {
// no contract for `callee` available on current fork, check if available on other forks
let mut available_on = Vec::new();
for (id, fork) in self.inner.forks_iter().filter(|(id, _)| *id != active_id) {
trace!(?id, address=?callee, "checking if account exists");
if fork.is_contract(callee) {
available_on.push(id);
}
}
return if available_on.is_empty() {
Some(RevertDiagnostic::ContractDoesNotExist {
contract: callee,
active: active_id,
persistent: self.is_persistent(&callee),
})
} else {
// likely user error: called a contract that's not available on active fork but is
// present other forks
Some(RevertDiagnostic::ContractExistsOnOtherForks {
contract: callee,
active: active_id,
available_on,
})
};
}
None
}
/// Loads the account allocs from the given `allocs` map into the passed [JournaledState].
///
/// Returns [Ok] if all accounts were successfully inserted into the journal, [Err] otherwise.
fn load_allocs(
&mut self,
allocs: &BTreeMap<Address, GenesisAccount>,
journaled_state: &mut JournaledState,
) -> Result<(), BackendError> {
// Loop through all of the allocs defined in the map and commit them to the journal.
for (addr, acc) in allocs.iter() {
self.clone_account(acc, addr, journaled_state)?;
}
Ok(())
}
/// Copies bytecode, storage, nonce and balance from the given genesis account to the target
/// address.
///
/// Returns [Ok] if data was successfully inserted into the journal, [Err] otherwise.
fn clone_account(
&mut self,
source: &GenesisAccount,
target: &Address,
journaled_state: &mut JournaledState,
) -> Result<(), BackendError> {
// Fetch the account from the journaled state. Will create a new account if it does
// not already exist.
let mut state_acc = journaled_state.load_account(*target, self)?;
// Set the account's bytecode and code hash, if the `bytecode` field is present.
if let Some(bytecode) = source.code.as_ref() {
state_acc.info.code_hash = keccak256(bytecode);
let bytecode = Bytecode::new_raw(bytecode.0.clone().into());
state_acc.info.code = Some(bytecode);
}
// Set the account's storage, if the `storage` field is present.
if let Some(storage) = source.storage.as_ref() {
state_acc.storage = storage
.iter()
.map(|(slot, value)| {
let slot = U256::from_be_bytes(slot.0);
(
slot,
EvmStorageSlot::new_changed(
state_acc
.storage
.get(&slot)
.map(|s| s.present_value)
.unwrap_or_default(),
U256::from_be_bytes(value.0),
),
)
})
.collect();
}
// Set the account's nonce and balance.
state_acc.info.nonce = source.nonce.unwrap_or_default();
state_acc.info.balance = source.balance;
// Touch the account to ensure the loaded information persists if called in `setUp`.
journaled_state.touch(target);
Ok(())
}
fn add_persistent_account(&mut self, account: Address) -> bool {
trace!(?account, "add persistent account");
self.inner.persistent_accounts.insert(account)
}
fn remove_persistent_account(&mut self, account: &Address) -> bool {
trace!(?account, "remove persistent account");
self.inner.persistent_accounts.remove(account)
}
fn is_persistent(&self, acc: &Address) -> bool {
self.inner.persistent_accounts.contains(acc)
}
fn allow_cheatcode_access(&mut self, account: Address) -> bool {
trace!(?account, "allow cheatcode access");
self.inner.cheatcode_access_accounts.insert(account)
}
fn revoke_cheatcode_access(&mut self, account: &Address) -> bool {
trace!(?account, "revoke cheatcode access");
self.inner.cheatcode_access_accounts.remove(account)
}
fn has_cheatcode_access(&self, account: &Address) -> bool {
self.inner.cheatcode_access_accounts.contains(account)
}
fn set_blockhash(&mut self, block_number: U256, block_hash: B256) {
if let Some(db) = self.active_fork_db_mut() {
db.block_hashes.insert(block_number, block_hash);
} else {
self.mem_db.block_hashes.insert(block_number, block_hash);
}
}
}
impl DatabaseRef for Backend {
type Error = DatabaseError;
fn basic_ref(&self, address: Address) -> Result<Option<AccountInfo>, Self::Error> {
if let Some(db) = self.active_fork_db() {
db.basic_ref(address)
} else {
Ok(self.mem_db.basic_ref(address)?)
}
}
fn code_by_hash_ref(&self, code_hash: B256) -> Result<Bytecode, Self::Error> {
if let Some(db) = self.active_fork_db() {
db.code_by_hash_ref(code_hash)
} else {
Ok(self.mem_db.code_by_hash_ref(code_hash)?)
}
}
fn storage_ref(&self, address: Address, index: U256) -> Result<U256, Self::Error> {
if let Some(db) = self.active_fork_db() {
DatabaseRef::storage_ref(db, address, index)
} else {
Ok(DatabaseRef::storage_ref(&self.mem_db, address, index)?)
}
}
fn block_hash_ref(&self, number: u64) -> Result<B256, Self::Error> {
if let Some(db) = self.active_fork_db() {
db.block_hash_ref(number)
} else {
Ok(self.mem_db.block_hash_ref(number)?)
}
}
}
impl DatabaseCommit for Backend {
fn commit(&mut self, changes: Map<Address, Account>) {
if let Some(db) = self.active_fork_db_mut() {
db.commit(changes)
} else {
self.mem_db.commit(changes)
}
}
}
impl Database for Backend {
type Error = DatabaseError;
fn basic(&mut self, address: Address) -> Result<Option<AccountInfo>, Self::Error> {
if let Some(db) = self.active_fork_db_mut() {
Ok(db.basic(address)?)
} else {
Ok(self.mem_db.basic(address)?)
}
}
fn code_by_hash(&mut self, code_hash: B256) -> Result<Bytecode, Self::Error> {
if let Some(db) = self.active_fork_db_mut() {
Ok(db.code_by_hash(code_hash)?)
} else {
Ok(self.mem_db.code_by_hash(code_hash)?)
}
}
fn storage(&mut self, address: Address, index: U256) -> Result<U256, Self::Error> {
if let Some(db) = self.active_fork_db_mut() {
Ok(Database::storage(db, address, index)?)
} else {
Ok(Database::storage(&mut self.mem_db, address, index)?)
}
}
fn block_hash(&mut self, number: u64) -> Result<B256, Self::Error> {
if let Some(db) = self.active_fork_db_mut() {
Ok(db.block_hash(number)?)
} else {
Ok(self.mem_db.block_hash(number)?)
}
}
}
/// Variants of a [revm::Database]
#[derive(Clone, Debug)]
pub enum BackendDatabaseSnapshot {
/// Simple in-memory [revm::Database]
InMemory(FoundryEvmInMemoryDB),
/// Contains the entire forking mode database
Forked(LocalForkId, ForkId, ForkLookupIndex, Box<Fork>),
}
/// Represents a fork
#[derive(Clone, Debug)]
pub struct Fork {
db: ForkDB,
journaled_state: JournaledState,
}
impl Fork {
/// Returns true if the account is a contract
pub fn is_contract(&self, acc: Address) -> bool {
if let Ok(Some(acc)) = self.db.basic_ref(acc) {
if acc.code_hash != KECCAK_EMPTY {
return true;
}
}
is_contract_in_state(&self.journaled_state, acc)
}
}
/// Container type for various Backend related data
#[derive(Clone, Debug)]
pub struct BackendInner {
/// Stores the `ForkId` of the fork the `Backend` launched with from the start.
///
/// In other words if [`Backend::spawn()`] was called with a `CreateFork` command, to launch
/// directly in fork mode, this holds the corresponding fork identifier of this fork.
pub launched_with_fork: Option<(ForkId, LocalForkId, ForkLookupIndex)>,
/// This tracks numeric fork ids and the `ForkId` used by the handler.
///
/// This is necessary, because there can be multiple `Backends` associated with a single
/// `ForkId` which is only a pair of endpoint + block. Since an existing fork can be
/// modified (e.g. `roll_fork`), but this should only affect the fork that's unique for the
/// test and not the `ForkId`
///
/// This ensures we can treat forks as unique from the context of a test, so rolling to another
/// is basically creating(or reusing) another `ForkId` that's then mapped to the previous
/// issued _local_ numeric identifier, that remains constant, even if the underlying fork
/// backend changes.
pub issued_local_fork_ids: HashMap<LocalForkId, ForkId>,
/// tracks all the created forks
/// Contains the index of the corresponding `ForkDB` in the `forks` vec
pub created_forks: HashMap<ForkId, ForkLookupIndex>,
/// Holds all created fork databases
// Note: data is stored in an `Option` so we can remove it without reshuffling
pub forks: Vec<Option<Fork>>,
/// Contains state snapshots made at a certain point
pub state_snapshots: StateSnapshots<BackendStateSnapshot<BackendDatabaseSnapshot>>,
/// Tracks whether there was a failure in a snapshot that was reverted
///
/// The Test contract contains a bool variable that is set to true when an `assert` function
/// failed. When a snapshot is reverted, it reverts the state of the evm, but we still want
/// to know if there was an `assert` that failed after the snapshot was taken so that we can
/// check if the test function passed all asserts even across snapshots. When a snapshot is
/// reverted we get the _current_ `revm::JournaledState` which contains the state that we can
/// check if the `_failed` variable is set,
/// additionally
pub has_state_snapshot_failure: bool,
/// Tracks the caller of the test function
pub caller: Option<Address>,
/// Tracks numeric identifiers for forks
pub next_fork_id: LocalForkId,
/// All accounts that should be kept persistent when switching forks.
/// This means all accounts stored here _don't_ use a separate storage section on each fork
/// instead the use only one that's persistent across fork swaps.
pub persistent_accounts: HashSet<Address>,
/// The configured spec id
pub spec_id: SpecId,
/// All accounts that are allowed to execute cheatcodes
pub cheatcode_access_accounts: HashSet<Address>,
}
impl BackendInner {
pub fn ensure_fork_id(&self, id: LocalForkId) -> eyre::Result<&ForkId> {
self.issued_local_fork_ids
.get(&id)
.ok_or_else(|| eyre::eyre!("No matching fork found for {}", id))
}
pub fn ensure_fork_index(&self, id: &ForkId) -> eyre::Result<ForkLookupIndex> {
self.created_forks
.get(id)
.copied()
.ok_or_else(|| eyre::eyre!("No matching fork found for {}", id))
}
pub fn ensure_fork_index_by_local_id(&self, id: LocalForkId) -> eyre::Result<ForkLookupIndex> {
self.ensure_fork_index(self.ensure_fork_id(id)?)
}
/// Returns the underlying fork mapped to the index
#[track_caller]
fn get_fork(&self, idx: ForkLookupIndex) -> &Fork {
debug_assert!(idx < self.forks.len(), "fork lookup index must exist");
self.forks[idx].as_ref().unwrap()
}
/// Returns the underlying fork mapped to the index
#[track_caller]
fn get_fork_mut(&mut self, idx: ForkLookupIndex) -> &mut Fork {
debug_assert!(idx < self.forks.len(), "fork lookup index must exist");
self.forks[idx].as_mut().unwrap()
}
/// Returns the underlying fork corresponding to the id
#[track_caller]
fn get_fork_by_id_mut(&mut self, id: LocalForkId) -> eyre::Result<&mut Fork> {
let idx = self.ensure_fork_index_by_local_id(id)?;
Ok(self.get_fork_mut(idx))
}
/// Returns the underlying fork corresponding to the id
#[track_caller]
fn get_fork_by_id(&self, id: LocalForkId) -> eyre::Result<&Fork> {
let idx = self.ensure_fork_index_by_local_id(id)?;
Ok(self.get_fork(idx))
}
/// Removes the fork
fn take_fork(&mut self, idx: ForkLookupIndex) -> Fork {
debug_assert!(idx < self.forks.len(), "fork lookup index must exist");
self.forks[idx].take().unwrap()
}
fn set_fork(&mut self, idx: ForkLookupIndex, fork: Fork) {
self.forks[idx] = Some(fork)
}
/// Returns an iterator over Forks
pub fn forks_iter(&self) -> impl Iterator<Item = (LocalForkId, &Fork)> + '_ {
self.issued_local_fork_ids
.iter()
.map(|(id, fork_id)| (*id, self.get_fork(self.created_forks[fork_id])))
}
/// Returns a mutable iterator over all Forks
pub fn forks_iter_mut(&mut self) -> impl Iterator<Item = &mut Fork> + '_ {
self.forks.iter_mut().filter_map(|f| f.as_mut())
}
/// Reverts the entire fork database
pub fn revert_state_snapshot(
&mut self,
id: LocalForkId,
fork_id: ForkId,
idx: ForkLookupIndex,
fork: Fork,
) {
self.created_forks.insert(fork_id.clone(), idx);
self.issued_local_fork_ids.insert(id, fork_id);
self.set_fork(idx, fork)
}
/// Updates the fork and the local mapping and returns the new index for the `fork_db`
pub fn update_fork_mapping(
&mut self,
id: LocalForkId,
fork_id: ForkId,
db: ForkDB,
journaled_state: JournaledState,
) -> ForkLookupIndex {
let idx = self.forks.len();
self.issued_local_fork_ids.insert(id, fork_id.clone());
self.created_forks.insert(fork_id, idx);
let fork = Fork { db, journaled_state };
self.forks.push(Some(fork));
idx
}
pub fn roll_fork(
&mut self,
id: LocalForkId,
new_fork_id: ForkId,
backend: SharedBackend,
) -> eyre::Result<ForkLookupIndex> {
let fork_id = self.ensure_fork_id(id)?;
let idx = self.ensure_fork_index(fork_id)?;
if let Some(active) = self.forks[idx].as_mut() {
// we initialize a _new_ `ForkDB` but keep the state of persistent accounts
let mut new_db = ForkDB::new(backend);
for addr in self.persistent_accounts.iter().copied() {
merge_db_account_data(addr, &active.db, &mut new_db);
}
active.db = new_db;
}
// update mappings
self.issued_local_fork_ids.insert(id, new_fork_id.clone());
self.created_forks.insert(new_fork_id, idx);
Ok(idx)
}
/// Inserts a _new_ `ForkDB` and issues a new local fork identifier
///
/// Also returns the index where the `ForDB` is stored
pub fn insert_new_fork(
&mut self,
fork_id: ForkId,
db: ForkDB,
journaled_state: JournaledState,
) -> (LocalForkId, ForkLookupIndex) {
let idx = self.forks.len();
self.created_forks.insert(fork_id.clone(), idx);
let id = self.next_id();
self.issued_local_fork_ids.insert(id, fork_id);
let fork = Fork { db, journaled_state };
self.forks.push(Some(fork));
(id, idx)
}
fn next_id(&mut self) -> U256 {
let id = self.next_fork_id;
self.next_fork_id += U256::from(1);
id
}
/// Returns the number of issued ids
pub fn len(&self) -> usize {
self.issued_local_fork_ids.len()
}
/// Returns true if no forks are issued
pub fn is_empty(&self) -> bool {
self.issued_local_fork_ids.is_empty()
}
pub fn precompiles(&self) -> &'static Precompiles {
Precompiles::new(PrecompileSpecId::from_spec_id(self.spec_id))
}
/// Returns a new, empty, `JournaledState` with set precompiles
pub fn new_journaled_state(&self) -> JournaledState {
JournaledState::new(self.spec_id, self.precompiles().addresses().copied().collect())
}
}
impl Default for BackendInner {
fn default() -> Self {
Self {
launched_with_fork: None,
issued_local_fork_ids: Default::default(),
created_forks: Default::default(),
forks: vec![],
state_snapshots: Default::default(),
has_state_snapshot_failure: false,
caller: None,
next_fork_id: Default::default(),
persistent_accounts: Default::default(),
spec_id: SpecId::LATEST,
// grant the cheatcode,default test and caller address access to execute cheatcodes
// itself
cheatcode_access_accounts: HashSet::from([
CHEATCODE_ADDRESS,
TEST_CONTRACT_ADDRESS,
CALLER,
]),
}
}
}
/// This updates the currently used env with the fork's environment
pub(crate) fn update_current_env_with_fork_env(current: &mut Env, fork: Env) {
current.block = fork.block;
current.cfg = fork.cfg;
current.tx.chain_id = fork.tx.chain_id;
}
/// Clones the data of the given `accounts` from the `active` database into the `fork_db`
/// This includes the data held in storage (`CacheDB`) and kept in the `JournaledState`.
pub(crate) fn merge_account_data<ExtDB: DatabaseRef>(
accounts: impl IntoIterator<Item = Address>,
active: &CacheDB<ExtDB>,
active_journaled_state: &mut JournaledState,
target_fork: &mut Fork,
) {
for addr in accounts.into_iter() {
merge_db_account_data(addr, active, &mut target_fork.db);
merge_journaled_state_data(addr, active_journaled_state, &mut target_fork.journaled_state);
}
// need to mock empty journal entries in case the current checkpoint is higher than the existing
// journal entries
while active_journaled_state.journal.len() > target_fork.journaled_state.journal.len() {
target_fork.journaled_state.journal.push(Default::default());
}
*active_journaled_state = target_fork.journaled_state.clone();
}
/// Clones the account data from the `active_journaled_state` into the `fork_journaled_state`
fn merge_journaled_state_data(
addr: Address,
active_journaled_state: &JournaledState,
fork_journaled_state: &mut JournaledState,
) {
if let Some(mut acc) = active_journaled_state.state.get(&addr).cloned() {
trace!(?addr, "updating journaled_state account data");
if let Some(fork_account) = fork_journaled_state.state.get_mut(&addr) {
// This will merge the fork's tracked storage with active storage and update values
fork_account.storage.extend(std::mem::take(&mut acc.storage));
// swap them so we can insert the account as whole in the next step
std::mem::swap(&mut fork_account.storage, &mut acc.storage);
}
fork_journaled_state.state.insert(addr, acc);
}
}
/// Clones the account data from the `active` db into the `ForkDB`
fn merge_db_account_data<ExtDB: DatabaseRef>(
addr: Address,
active: &CacheDB<ExtDB>,
fork_db: &mut ForkDB,
) {
trace!(?addr, "merging database data");
let Some(acc) = active.accounts.get(&addr) else { return };
// port contract cache over
if let Some(code) = active.contracts.get(&acc.info.code_hash) {
trace!("merging contract cache");
fork_db.contracts.insert(acc.info.code_hash, code.clone());
}
// port account storage over
use std::collections::hash_map::Entry;
match fork_db.accounts.entry(addr) {
Entry::Vacant(vacant) => {
trace!("target account not present - inserting from active");
// if the fork_db doesn't have the target account
// insert the entire thing
vacant.insert(acc.clone());
}
Entry::Occupied(mut occupied) => {
trace!("target account present - merging storage slots");
// if the fork_db does have the system,
// extend the existing storage (overriding)
let fork_account = occupied.get_mut();
fork_account.storage.extend(&acc.storage);
}
}
}
/// Returns true of the address is a contract
fn is_contract_in_state(journaled_state: &JournaledState, acc: Address) -> bool {
journaled_state
.state
.get(&acc)
.map(|acc| acc.info.code_hash != KECCAK_EMPTY)
.unwrap_or_default()
}
/// Updates the env's block with the block's data
fn update_env_block(env: &mut Env, block: &AnyRpcBlock) {
env.block.timestamp = U256::from(block.header.timestamp);
env.block.coinbase = block.header.beneficiary;
env.block.difficulty = block.header.difficulty;
env.block.prevrandao = Some(block.header.mix_hash.unwrap_or_default());
env.block.basefee = U256::from(block.header.base_fee_per_gas.unwrap_or_default());
env.block.gas_limit = U256::from(block.header.gas_limit);
env.block.number = U256::from(block.header.number);
if let Some(excess_blob_gas) = block.header.excess_blob_gas {
env.block.blob_excess_gas_and_price = Some(BlobExcessGasAndPrice::new(excess_blob_gas));
}
}
/// Executes the given transaction and commits state changes to the database _and_ the journaled
/// state, with an inspector.
fn commit_transaction(
tx: &Transaction<AnyTxEnvelope>,
mut env: EnvWithHandlerCfg,
journaled_state: &mut JournaledState,
fork: &mut Fork,
fork_id: &ForkId,
persistent_accounts: &HashSet<Address>,
inspector: &mut dyn InspectorExt,
) -> eyre::Result<()> {
configure_tx_env(&mut env.env, tx);
let now = Instant::now();
let res = {
let fork = fork.clone();
let journaled_state = journaled_state.clone();
let depth = journaled_state.depth;
let mut db = Backend::new_with_fork(fork_id, fork, journaled_state);
let mut evm = crate::utils::new_evm_with_inspector(&mut db as _, env, inspector);
// Adjust inner EVM depth to ensure that inspectors receive accurate data.
evm.context.evm.inner.journaled_state.depth = depth + 1;
evm.transact().wrap_err("backend: failed committing transaction")?
};
trace!(elapsed = ?now.elapsed(), "transacted transaction");
apply_state_changeset(res.state, journaled_state, fork, persistent_accounts)?;
Ok(())
}
/// Helper method which updates data in the state with the data from the database.
/// Does not change state for persistent accounts (for roll fork to transaction and transact).
pub fn update_state<DB: Database>(
state: &mut EvmState,
db: &mut DB,
persistent_accounts: Option<&HashSet<Address>>,
) -> Result<(), DB::Error> {
for (addr, acc) in state.iter_mut() {
if !persistent_accounts.is_some_and(|accounts| accounts.contains(addr)) {
acc.info = db.basic(*addr)?.unwrap_or_default();
for (key, val) in acc.storage.iter_mut() {
val.present_value = db.storage(*addr, *key)?;
}
}
}
Ok(())
}
/// Applies the changeset of a transaction to the active journaled state and also commits it in the
/// forked db
fn apply_state_changeset(
state: Map<revm::primitives::Address, Account>,
journaled_state: &mut JournaledState,
fork: &mut Fork,
persistent_accounts: &HashSet<Address>,
) -> Result<(), BackendError> {
// commit the state and update the loaded accounts
fork.db.commit(state);
update_state(&mut journaled_state.state, &mut fork.db, Some(persistent_accounts))?;
update_state(&mut fork.journaled_state.state, &mut fork.db, Some(persistent_accounts))?;
Ok(())
}
#[cfg(test)]
#[allow(clippy::needless_return)]
mod tests {
use crate::{backend::Backend, fork::CreateFork, opts::EvmOpts};
use alloy_primitives::{Address, U256};
use alloy_provider::Provider;
use foundry_common::provider::get_http_provider;
use foundry_config::{Config, NamedChain};
use foundry_fork_db::cache::{BlockchainDb, BlockchainDbMeta};
use revm::DatabaseRef;
const ENDPOINT: Option<&str> = option_env!("ETH_RPC_URL");
#[tokio::test(flavor = "multi_thread")]
async fn can_read_write_cache() {
let Some(endpoint) = ENDPOINT else { return };
let provider = get_http_provider(endpoint);
let block_num = provider.get_block_number().await.unwrap();
let config = Config::figment();
let mut evm_opts = config.extract::<EvmOpts>().unwrap();
evm_opts.fork_block_number = Some(block_num);
let (env, _block) = evm_opts.fork_evm_env(endpoint).await.unwrap();
let fork = CreateFork {
enable_caching: true,
url: endpoint.to_string(),
env: env.clone(),
evm_opts,
};
let backend = Backend::spawn(Some(fork));
// some rng contract from etherscan
let address: Address = "63091244180ae240c87d1f528f5f269134cb07b3".parse().unwrap();
let idx = U256::from(0u64);
let _value = backend.storage_ref(address, idx);
let _account = backend.basic_ref(address);
// fill some slots
let num_slots = 10u64;
for idx in 1..num_slots {
let _ = backend.storage_ref(address, U256::from(idx));
}
drop(backend);
let meta =
BlockchainDbMeta { cfg_env: env.cfg, block_env: env.block, hosts: Default::default() };
let db = BlockchainDb::new(
meta,
Some(Config::foundry_block_cache_dir(NamedChain::Mainnet, block_num).unwrap()),
);
assert!(db.accounts().read().contains_key(&address));
assert!(db.storage().read().contains_key(&address));
assert_eq!(db.storage().read().get(&address).unwrap().len(), num_slots as usize);
}
}