Feature gate withdrawals (#3684)

* start feature gating

* feature gate withdrawals

consensus/state_processing/Cargo.toml

@@ -43,3 +43,5 @@ arbitrary-fuzz = [
   "eth2_ssz_types/arbitrary",
   "tree_hash/arbitrary",
 ]
+withdrawals = ["types/withdrawals"]
+withdrawals-processing = []

consensus/state_processing/src/common/mod.rs

@@ -15,6 +15,7 @@ pub use get_attesting_indices::{get_attesting_indices, get_attesting_indices_fro
 pub use get_indexed_attestation::get_indexed_attestation;
 pub use initiate_validator_exit::initiate_validator_exit;
 pub use slash_validator::slash_validator;
+#[cfg(feature = "withdrawals")]
 pub use withdraw_balance::withdraw_balance;
 
 use safe_arith::SafeArith;

consensus/state_processing/src/common/withdraw_balance.rs

@@ -2,6 +2,7 @@ use crate::common::decrease_balance;
 use safe_arith::SafeArith;
 use types::{BeaconStateError as Error, *};
 
+#[cfg(feature = "withdrawals")]
 pub fn withdraw_balance<T: EthSpec>(
     state: &mut BeaconState<T>,
     validator_index: usize,

consensus/state_processing/src/per_epoch_processing/capella.rs

@@ -5,11 +5,15 @@ use crate::per_epoch_processing::{
     historical_roots_update::process_historical_roots_update,
     resets::{process_eth1_data_reset, process_randao_mixes_reset, process_slashings_reset},
 };
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub use full_withdrawals::process_full_withdrawals;
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub use partial_withdrawals::process_partial_withdrawals;
 use types::{BeaconState, ChainSpec, EthSpec, RelativeEpoch};
 
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub mod full_withdrawals;
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub mod partial_withdrawals;
 
 pub fn process_epoch<T: EthSpec>(
@@ -66,8 +70,10 @@ pub fn process_epoch<T: EthSpec>(
     altair::process_sync_committee_updates(state, spec)?;
 
     // Withdrawals
+    #[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
     process_full_withdrawals(state, spec)?;
 
+    #[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
     process_partial_withdrawals(state, spec)?;
 
     // Rotate the epoch caches to suit the epoch transition.

consensus/state_processing/src/per_epoch_processing/capella/full_withdrawals.rs

@@ -1,7 +1,9 @@
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 use crate::common::withdraw_balance;
 use crate::EpochProcessingError;
 use types::{beacon_state::BeaconState, eth_spec::EthSpec, ChainSpec};
 
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub fn process_full_withdrawals<T: EthSpec>(
     state: &mut BeaconState<T>,
     spec: &ChainSpec,

consensus/state_processing/src/per_epoch_processing/capella/partial_withdrawals.rs

@@ -1,8 +1,10 @@
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 use crate::common::withdraw_balance;
 use crate::EpochProcessingError;
 use safe_arith::SafeArith;
 use types::{beacon_state::BeaconState, eth_spec::EthSpec, ChainSpec};
 
+#[cfg(all(feature = "withdrawals", feature = "withdrawals-processing"))]
 pub fn process_partial_withdrawals<T: EthSpec>(
     state: &mut BeaconState<T>,
     spec: &ChainSpec,

consensus/state_processing/src/upgrade/capella.rs

@@ -57,8 +57,11 @@ pub fn upgrade_to_capella<E: EthSpec>(
         // Execution
         latest_execution_payload_header: pre.latest_execution_payload_header.upgrade_to_capella(),
         // Withdrawals
+        #[cfg(feature = "withdrawals")]
         withdrawal_queue: VariableList::empty(),
+        #[cfg(feature = "withdrawals")]
         next_withdrawal_index: 0,
+        #[cfg(feature = "withdrawals")]
         next_partial_withdrawal_validator_index: 0,
         // Caches
         total_active_balance: pre.total_active_balance,

consensus/state_processing/src/upgrade/eip4844.rs

@@ -9,6 +9,14 @@ pub fn upgrade_to_eip4844<E: EthSpec>(
     let epoch = pre_state.current_epoch();
     let pre = pre_state.as_capella_mut()?;
 
+    // FIXME(sean) This is a hack to let us participate in testnets where capella doesn't exist.
+    // if we are disabling withdrawals, assume we should fork off of bellatrix.
+    let previous_fork_version = if cfg!(feature ="withdrawals") {
+        pre.fork.current_version
+    } else {
+        spec.bellatrix_fork_epoch
+    };
+
     // Where possible, use something like `mem::take` to move fields from behind the &mut
     // reference. For other fields that don't have a good default value, use `clone`.
     //
@@ -20,7 +28,7 @@ pub fn upgrade_to_eip4844<E: EthSpec>(
         genesis_validators_root: pre.genesis_validators_root,
         slot: pre.slot,
         fork: Fork {
-            previous_version: pre.fork.current_version,
+            previous_version: previous_fork_version,
             current_version: spec.eip4844_fork_version,
             epoch,
         },
@@ -56,8 +64,11 @@ pub fn upgrade_to_eip4844<E: EthSpec>(
         // Execution
         latest_execution_payload_header: pre.latest_execution_payload_header.upgrade_to_eip4844(),
         // Withdrawals
+        #[cfg(feature = "withdrawals")]
         withdrawal_queue: mem::take(&mut pre.withdrawal_queue),
+        #[cfg(feature = "withdrawals")]
         next_withdrawal_index: pre.next_withdrawal_index,
+        #[cfg(feature = "withdrawals")]
         next_partial_withdrawal_validator_index: pre.next_partial_withdrawal_validator_index,
         // Caches
         total_active_balance: pre.total_active_balance,

consensus/types/Cargo.toml

@@ -71,3 +71,4 @@ arbitrary-fuzz = [
   "swap_or_not_shuffle/arbitrary",
   "tree_hash/arbitrary",
 ]
+withdrawals = []

consensus/types/src/beacon_state.rs

@@ -295,10 +295,13 @@ where
     pub latest_execution_payload_header: ExecutionPayloadHeaderEip4844<T>,
 
     // Withdrawals
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub withdrawal_queue: VariableList<Withdrawal, T::WithdrawalQueueLimit>,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub next_withdrawal_index: u64,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub next_partial_withdrawal_validator_index: u64,
 

consensus/types/src/execution_payload.rs

@@ -80,6 +80,7 @@ pub struct ExecutionPayload<T: EthSpec> {
     pub block_hash: ExecutionBlockHash,
     #[serde(with = "ssz_types::serde_utils::list_of_hex_var_list")]
     pub transactions: Transactions<T>,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     pub withdrawals: VariableList<Withdrawal, T::MaxWithdrawalsPerPayload>,
 }

consensus/types/src/execution_payload_header.rs

@@ -74,6 +74,7 @@ pub struct ExecutionPayloadHeader<T: EthSpec> {
     pub block_hash: ExecutionBlockHash,
     #[superstruct(getter(copy))]
     pub transactions_root: Hash256,
+    #[cfg(feature = "withdrawals")]
     #[superstruct(only(Capella, Eip4844))]
     #[superstruct(getter(copy))]
     pub withdrawals_root: Hash256,
@@ -104,6 +105,7 @@ impl<'a, T: EthSpec> ExecutionPayloadHeaderRef<'a, T> {
 
 impl<T: EthSpec> ExecutionPayloadHeaderMerge<T> {
     pub fn upgrade_to_capella(&self) -> ExecutionPayloadHeaderCapella<T> {
+        #[cfg(feature = "withdrawals")]
         // TODO: if this is correct we should calculate and hardcode this..
         let empty_withdrawals_root =
             VariableList::<Withdrawal, T::MaxWithdrawalsPerPayload>::empty().tree_hash_root();
@@ -122,6 +124,7 @@ impl<T: EthSpec> ExecutionPayloadHeaderMerge<T> {
             base_fee_per_gas: self.base_fee_per_gas,
             block_hash: self.block_hash,
             transactions_root: self.transactions_root,
+            #[cfg(feature = "withdrawals")]
             // FIXME: the spec doesn't seem to define what to do here..
             withdrawals_root: empty_withdrawals_root,
         }
@@ -147,6 +150,7 @@ impl<T: EthSpec> ExecutionPayloadHeaderCapella<T> {
             excess_blobs: 0,
             block_hash: self.block_hash,
             transactions_root: self.transactions_root,
+            #[cfg(feature = "withdrawals")]
             withdrawals_root: self.withdrawals_root,
         }
     }
@@ -189,6 +193,7 @@ impl<T: EthSpec> From<ExecutionPayloadCapella<T>> for ExecutionPayloadHeaderCape
             base_fee_per_gas: payload.base_fee_per_gas,
             block_hash: payload.block_hash,
             transactions_root: payload.transactions.tree_hash_root(),
+            #[cfg(feature = "withdrawals")]
             withdrawals_root: payload.withdrawals.tree_hash_root(),
         }
     }
@@ -211,6 +216,7 @@ impl<T: EthSpec> From<ExecutionPayloadEip4844<T>> for ExecutionPayloadHeaderEip4
             excess_blobs: payload.excess_blobs,
             block_hash: payload.block_hash,
             transactions_root: payload.transactions.tree_hash_root(),
+            #[cfg(feature = "withdrawals")]
             withdrawals_root: payload.withdrawals.tree_hash_root(),
         }
     }