feat(revm): Add prevrandao field to EnvBlock

bins/revme/Cargo.toml

@@ -17,7 +17,7 @@ hex = "0.4"
 indicatif = "0.17"
 plain_hasher = "0.2"
 primitive-types = { version = "0.11", features = ["rlp", "serde"] }
-revm = { path = "../../crates/revm", version = "2.1", default-features = false, features = ["web3db","std","secp256k1"] }
+revm = { path = "../../crates/revm", version = "2.2", default-features = false, features = ["web3db","std","secp256k1"] }
 rlp = { version = "0.5", default-features = false }
 ruint = { version = "1.6.0", features = ["rlp", "serde"] }
 serde = "1.0"

bins/revme/src/statetest/runner.rs

@@ -156,6 +156,8 @@ pub fn execute_test_suit(path: &Path, elapsed: &Arc<Mutex<Duration>>) -> Result<
         env.block.gas_limit = unit.env.current_gas_limit;
         env.block.basefee = unit.env.current_base_fee.unwrap_or_default();
         env.block.difficulty = unit.env.current_difficulty;
+        // after the Merge prevrandao replaces mix_hash field in block and replaced difficulty opcode in EVM.
+        env.block.prevrandao = Some(unit.env.current_difficulty.to_be_bytes().into());
 
         //tx env
         env.tx.caller =

crates/revm/src/evm_impl.rs

@@ -49,6 +49,10 @@ impl<'a, GSPEC: Spec, DB: Database, const INSPECT: bool> Transact
         let gas_limit = self.data.env.tx.gas_limit;
         let exit = |reason: Return| (ExecutionResult::new_with_reason(reason), State::new());
 
+        if GSPEC::enabled(MERGE) && self.data.env.block.prevrandao.is_none() {
+            return exit(Return::PrevrandaoNotSet);
+        }
+
         if GSPEC::enabled(LONDON) {
             if let Some(priority_fee) = self.data.env.tx.gas_priority_fee {
                 if priority_fee > self.data.env.tx.gas_price {

crates/revm/src/instructions.rs

@@ -59,6 +59,7 @@ pub enum Return {
     OutOfOffset,
     FatalExternalError,
     GasMaxFeeGreaterThanPriorityFee,
+    PrevrandaoNotSet,
     GasPriceLessThenBasefee,
     CallerGasLimitMoreThenBlock,
     /// EIP-3607 Reject transactions from senders with deployed code
@@ -225,7 +226,7 @@ pub fn eval<H: Host, S: Spec>(opcode: u8, interp: &mut Interpreter, host: &mut H
         opcode::COINBASE => host_env::coinbase(interp, host),
         opcode::TIMESTAMP => host_env::timestamp(interp, host),
         opcode::NUMBER => host_env::number(interp, host),
-        opcode::DIFFICULTY => host_env::difficulty(interp, host),
+        opcode::DIFFICULTY => host_env::difficulty::<H, S>(interp, host),
         opcode::GASLIMIT => host_env::gaslimit(interp, host),
         opcode::SLOAD => host::sload::<H, S>(interp, host),
         opcode::SSTORE => host::sstore::<H, S>(interp, host),

crates/revm/src/instructions/host_env.rs

@@ -27,9 +27,13 @@ pub fn number<H: Host>(interp: &mut Interpreter, host: &mut H) -> Return {
     Return::Continue
 }
 
-pub fn difficulty<H: Host>(interp: &mut Interpreter, host: &mut H) -> Return {
+pub fn difficulty<H: Host, SPEC: Spec>(interp: &mut Interpreter, host: &mut H) -> Return {
     // gas!(interp, gas::BASE);
-    push!(interp, host.env().block.difficulty);
+    if SPEC::enabled(MERGE) {
+        push_h256!(interp, host.env().block.prevrandao.unwrap());
+    } else {
+        push!(interp, host.env().block.difficulty);
+    }
     Return::Continue
 }
 

crates/revm/src/models.rs

@@ -195,7 +195,11 @@ pub struct BlockEnv {
     /// Address where we are going to send gas spend
     pub coinbase: H160,
     pub timestamp: U256,
+    /// Difficulty is removed and not used after Paris (aka TheMerge). Value is replaced with prevrandao.
     pub difficulty: U256,
+    /// Prevrandao is used after Paris (aka TheMerge) instead of the difficulty value.
+    /// NOTE: prevrandao can be found in block in place of mix_hash.
+    pub prevrandao: Option<H256>,
     /// basefee is added in EIP1559 London upgrade
     pub basefee: U256,
     pub gas_limit: U256,
@@ -288,6 +292,7 @@ impl Default for BlockEnv {
             coinbase: H160::zero(),
             timestamp: U256::from(1),
             difficulty: U256::ZERO,
+            prevrandao: Some(H256::zero()),
             basefee: U256::ZERO,
         }
     }