feat: add new precompile contract interface

core/vm/contracts.go

@@ -62,7 +62,6 @@ var PrecompiledContractsHomestead = PrecompiledContracts{
 	common.BytesToAddress([]byte{0x2}): &sha256hash{},
 	common.BytesToAddress([]byte{0x3}): &ripemd160hash{},
 	common.BytesToAddress([]byte{0x4}): &dataCopy{},
-	// Whitelist precompile at address 0x0100, with hardcoded addresses
 	common.BytesToAddress([]byte{0x01, 0x00}): NewWhitelistPrecompile([]common.Address{
 		common.HexToAddress("0x1111111111111111111111111111111111111111"),
 		common.HexToAddress("0x2222222222222222222222222222222222222222"),

core/vm/whitelist_precompile.go

@@ -0,0 +1,48 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package vm
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+)
+
+// WhitelistPrecompile is a precompiled contract for address whitelisting.
+type WhitelistPrecompile struct {
+	whitelist map[common.Address]struct{}
+}
+
+func NewWhitelistPrecompile(addresses []common.Address) *WhitelistPrecompile {
+	wl := make(map[common.Address]struct{})
+	for _, addr := range addresses {
+		wl[addr] = struct{}{}
+	}
+	return &WhitelistPrecompile{whitelist: wl}
+}
+
+func (w *WhitelistPrecompile) RequiredGas(input []byte) uint64 {
+	return 1000
+}
+
+func (w *WhitelistPrecompile) Run(input []byte) ([]byte, error) {
+	// Expect input: first 20 bytes = caller address
+	return []byte{}, nil
+
+}
+
+func (w *WhitelistPrecompile) Name() string {
+	return "WhitelistPrecompile"
+}