feat: add preDeployedContract hardfork (bnb-chain#5)

* feat: add preDeployedContract hardfork to modify WBNB contract name/symbol and remove GovernanceToken

* fix: remove useless IsPreContractBlock

cmd/evm/internal/t8ntool/execution.go

@@ -162,6 +162,10 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 		misc.ApplyDAOHardFork(statedb)
 	}
 
+	if chainConfig.PreContractForkBlock != nil && chainConfig.PreContractForkBlock.Cmp(new(big.Int).SetUint64(pre.Env.Number)) == 0 {
+		misc.ApplyPreContractHardFork(statedb)
+	}
+
 	for i, tx := range txs {
 		msg, err := core.TransactionToMessage(tx, signer, pre.Env.BaseFee)
 		if err != nil {

consensus/misc/precontract.go

@@ -0,0 +1,42 @@
+// Copyright 2016 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 misc
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/state"
+)
+
+var (
+	// WBNBContract WBNB preDeploy contract address
+	WBNBContract = common.HexToAddress("0x4200000000000000000000000000000000000006")
+	// GovernanceToken contract address
+	governanceToken = common.HexToAddress("4200000000000000000000000000000000000042")
+	nameSlot        = common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000000")
+	symbolSlot      = common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000001")
+	// Wrapped BNB
+	nameValue = common.HexToHash("0x5772617070656420424e42000000000000000000000000000000000000000016")
+	// WBNB
+	symbolValue = common.HexToHash("0x57424e4200000000000000000000000000000000000000000000000000000008")
+)
+
+// ApplyPreContractHardFork modifies the state database according to the hard-fork rules
+func ApplyPreContractHardFork(statedb *state.StateDB) {
+	statedb.SetState(WBNBContract, nameSlot, nameValue)
+	statedb.SetState(WBNBContract, symbolSlot, symbolValue)
+	statedb.Suicide(governanceToken)
+}

core/chain_makers.go

@@ -310,6 +310,9 @@ func GenerateChain(config *params.ChainConfig, parent *types.Block, engine conse
 		if config.DAOForkSupport && config.DAOForkBlock != nil && config.DAOForkBlock.Cmp(b.header.Number) == 0 {
 			misc.ApplyDAOHardFork(statedb)
 		}
+		if config.PreContractForkBlock != nil && config.PreContractForkBlock.Cmp(b.header.Number) == 0 {
+			misc.ApplyPreContractHardFork(statedb)
+		}
 		// Execute any user modifications to the block
 		if gen != nil {
 			gen(i, b)

core/state_processor.go

@@ -70,6 +70,9 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 	if p.config.DAOForkSupport && p.config.DAOForkBlock != nil && p.config.DAOForkBlock.Cmp(block.Number()) == 0 {
 		misc.ApplyDAOHardFork(statedb)
 	}
+	if p.config.PreContractForkBlock != nil && p.config.PreContractForkBlock.Cmp(block.Number()) == 0 {
+		misc.ApplyPreContractHardFork(statedb)
+	}
 	blockContext := NewEVMBlockContext(header, p.bc, nil, p.config, statedb)
 	vmenv := vm.NewEVM(blockContext, vm.TxContext{}, statedb, p.config, cfg)
 	// Iterate over and process the individual transactions

miner/worker.go

@@ -1176,6 +1176,10 @@ func (w *worker) generateWork(genParams *generateParams) (*types.Block, *big.Int
 		return nil, nil, nil, err
 	}
 	defer work.discard()
+
+	if w.chainConfig.PreContractForkBlock != nil && work.header.Number.Cmp(w.chainConfig.PreContractForkBlock) == 0 {
+		misc.ApplyPreContractHardFork(work.state)
+	}
 	if work.gasPool == nil {
 		work.gasPool = new(core.GasPool).AddGas(work.header.GasLimit)
 	}

params/config.go

@@ -476,6 +476,8 @@ type ChainConfig struct {
 
 	// Optimism config, nil if not active
 	Optimism *OptimismConfig `json:"optimism,omitempty"`
+	// PreContractForkBlock hard-fork switch block (nil = no fork, 0 = already on preContractForkBlock)
+	PreContractForkBlock *big.Int `json:"preContractForkBlock,omitempty"`
 }
 
 // EthashConfig is the consensus engine configs for proof-of-work based sealing.
@@ -599,6 +601,9 @@ func (c *ChainConfig) Description() string {
 	if c.RegolithTime != nil {
 		banner += fmt.Sprintf(" - Regolith:                    @%-10v\n", *c.RegolithTime)
 	}
+	if c.PreContractForkBlock != nil {
+		banner += fmt.Sprintf(" - PreContractForkBlock:        @%-10v\n", *c.PreContractForkBlock)
+	}
 	return banner
 }