persist precompiles in evm

core/vm/contracts.go

@@ -40,9 +40,12 @@ type PrecompiledContract interface {
 	Run(input []byte) ([]byte, error) // Run runs the precompiled contract
 }
 
+// PrecompiledContractByName contains the precompiled contracts supported at the given fork.
+type PrecompiledContracts map[common.Address]PrecompiledContract
+
 // PrecompiledContractsHomestead contains the default set of pre-compiled Ethereum
 // contracts used in the Frontier and Homestead releases.
-var PrecompiledContractsHomestead = map[common.Address]PrecompiledContract{
+var PrecompiledContractsHomestead = PrecompiledContracts{
 	common.BytesToAddress([]byte{1}): &ecrecover{},
 	common.BytesToAddress([]byte{2}): &sha256hash{},
 	common.BytesToAddress([]byte{3}): &ripemd160hash{},
@@ -51,7 +54,7 @@ var PrecompiledContractsHomestead = map[common.Address]PrecompiledContract{
 
 // PrecompiledContractsByzantium contains the default set of pre-compiled Ethereum
 // contracts used in the Byzantium release.
-var PrecompiledContractsByzantium = map[common.Address]PrecompiledContract{
+var PrecompiledContractsByzantium = PrecompiledContracts{
 	common.BytesToAddress([]byte{1}): &ecrecover{},
 	common.BytesToAddress([]byte{2}): &sha256hash{},
 	common.BytesToAddress([]byte{3}): &ripemd160hash{},
@@ -64,7 +67,7 @@ var PrecompiledContractsByzantium = map[common.Address]PrecompiledContract{
 
 // PrecompiledContractsIstanbul contains the default set of pre-compiled Ethereum
 // contracts used in the Istanbul release.
-var PrecompiledContractsIstanbul = map[common.Address]PrecompiledContract{
+var PrecompiledContractsIstanbul = PrecompiledContracts{
 	common.BytesToAddress([]byte{1}): &ecrecover{},
 	common.BytesToAddress([]byte{2}): &sha256hash{},
 	common.BytesToAddress([]byte{3}): &ripemd160hash{},
@@ -78,7 +81,7 @@ var PrecompiledContractsIstanbul = map[common.Address]PrecompiledContract{
 
 // PrecompiledContractsBerlin contains the default set of pre-compiled Ethereum
 // contracts used in the Berlin release.
-var PrecompiledContractsBerlin = map[common.Address]PrecompiledContract{
+var PrecompiledContractsBerlin = PrecompiledContracts{
 	common.BytesToAddress([]byte{1}): &ecrecover{},
 	common.BytesToAddress([]byte{2}): &sha256hash{},
 	common.BytesToAddress([]byte{3}): &ripemd160hash{},
@@ -92,7 +95,7 @@ var PrecompiledContractsBerlin = map[common.Address]PrecompiledContract{
 
 // PrecompiledContractsBLS contains the set of pre-compiled Ethereum
 // contracts specified in EIP-2537. These are exported for testing purposes.
-var PrecompiledContractsBLS = map[common.Address]PrecompiledContract{
+var PrecompiledContractsBLS = PrecompiledContracts{
 	common.BytesToAddress([]byte{10}): &bls12381G1Add{},
 	common.BytesToAddress([]byte{11}): &bls12381G1Mul{},
 	common.BytesToAddress([]byte{12}): &bls12381G1MultiExp{},
@@ -126,6 +129,15 @@ func init() {
 	}
 }
 
+// Copy returns a copy of the precompiled contracts.
+func (p PrecompiledContracts) Copy() PrecompiledContracts {
+	c := make(PrecompiledContracts)
+	for k, v := range p {
+		c[k] = v
+	}
+	return c
+}
+
 // ActivePrecompiles returns the precompiles enabled with the current configuration.
 func ActivePrecompiles(rules params.Rules) []common.Address {
 	switch {

core/vm/evm.go

@@ -41,24 +41,7 @@ type (
 )
 
 func (evm *EVM) precompile(addr common.Address) (PrecompiledContract, bool) {
-	var precompiles map[common.Address]PrecompiledContract
+	p, ok := evm.precompiles[addr]
-	switch {
-	case evm.chainRules.IsBerlin:
-		precompiles = PrecompiledContractsBerlin
-	case evm.chainRules.IsIstanbul:
-		precompiles = PrecompiledContractsIstanbul
-	case evm.chainRules.IsByzantium:
-		precompiles = PrecompiledContractsByzantium
-	default:
-		precompiles = PrecompiledContractsHomestead
-	}
-	// ECRecoverCode can be set only through RPC calls
-	if evm.Config.DisableECRecover {
-		if addr == common.BytesToAddress([]byte{1}) {
-			return nil, false
-		}
-	}
-	p, ok := precompiles[addr]
 	return p, ok
 }
 
@@ -125,6 +108,8 @@ type EVM struct {
 	// available gas is calculated in gasCall* according to the 63/64 rule and later
 	// applied in opCall*.
 	callGasTemp uint64
+	// precompiles holds the precompiled contracts for the current epoch
+	precompiles map[common.Address]PrecompiledContract
 }
 
 // NewEVM returns a new EVM. The returned EVM is not thread safe and should
@@ -138,6 +123,20 @@ func NewEVM(blockCtx BlockContext, txCtx TxContext, statedb StateDB, chainConfig
 		chainConfig: chainConfig,
 		chainRules:  chainConfig.Rules(blockCtx.BlockNumber, blockCtx.Random != nil, blockCtx.Time),
 	}
+	switch {
+	case evm.chainRules.IsBerlin:
+		evm.precompiles = PrecompiledContractsBerlin.Copy()
+	case evm.chainRules.IsIstanbul:
+		evm.precompiles = PrecompiledContractsIstanbul.Copy()
+	case evm.chainRules.IsByzantium:
+		evm.precompiles = PrecompiledContractsByzantium.Copy()
+	default:
+		evm.precompiles = PrecompiledContractsHomestead.Copy()
+	}
+	// ECRecoverCode can be set only through RPC calls
+	if config.DisableECRecover {
+		delete(evm.precompiles, common.BytesToAddress([]byte{1}))
+	}
 	evm.interpreter = NewEVMInterpreter(evm)
 	return evm
 }