Merge pull request #242 from ethereum-optimism/inphi/kzg-oracle

core/vm: Allow precompiles to be overriden

core/vm/evm.go

@@ -53,6 +53,13 @@ func (evm *EVM) precompile(addr common.Address) (PrecompiledContract, bool) {
 		precompiles = PrecompiledContractsHomestead
 	}
 	p, ok := precompiles[addr]
+	// Restrict overrides to known precompiles
+	if ok && evm.chainConfig.IsOptimism() && evm.Config.OptimismPrecompileOverrides != nil {
+		override, ok := evm.Config.OptimismPrecompileOverrides(evm.chainRules, addr)
+		if ok {
+			return override, ok
+		}
+	}
 	return p, ok
 }
 

core/vm/interpreter.go

@@ -21,14 +21,19 @@ import (
 	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
 )
 
+// PrecompileOverrides is a function that can be used to override the default precompiled contracts
+type PrecompileOverrides func(params.Rules, common.Address) (PrecompiledContract, bool)
+
 // Config are the configuration options for the Interpreter
 type Config struct {
-	Tracer                  EVMLogger // Opcode logger
-	NoBaseFee               bool      // Forces the EIP-1559 baseFee to 0 (needed for 0 price calls)
-	EnablePreimageRecording bool      // Enables recording of SHA3/keccak preimages
-	ExtraEips               []int     // Additional EIPS that are to be enabled
+	Tracer                      EVMLogger           // Opcode logger
+	NoBaseFee                   bool                // Forces the EIP-1559 baseFee to 0 (needed for 0 price calls)
+	EnablePreimageRecording     bool                // Enables recording of SHA3/keccak preimages
+	ExtraEips                   []int               // Additional EIPS that are to be enabled
+	OptimismPrecompileOverrides PrecompileOverrides // Precompile overrides for Optimism
 }
 
 // ScopeContext contains the things that are per-call, such as stack and memory,