cmd/geth: add support for --dev flag in dumpgenesis (#28463)

Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: lightclient <lightclient@protonmail.com>

cmd/geth/chaincmd.go

@@ -224,14 +224,21 @@ func initGenesis(ctx *cli.Context) error {
 }
 
 func dumpGenesis(ctx *cli.Context) error {
-	// if there is a testnet preset enabled, dump that
+	// check if there is a testnet preset enabled
+	var genesis *core.Genesis
 	if utils.IsNetworkPreset(ctx) {
-		genesis := utils.MakeGenesis(ctx)
+		genesis = utils.MakeGenesis(ctx)
+	} else if ctx.IsSet(utils.DeveloperFlag.Name) && !ctx.IsSet(utils.DataDirFlag.Name) {
+		genesis = core.DeveloperGenesisBlock(11_500_000, nil)
+	}
+
+	if genesis != nil {
 		if err := json.NewEncoder(os.Stdout).Encode(genesis); err != nil {
 			utils.Fatalf("could not encode genesis: %s", err)
 		}
 		return nil
 	}
+
 	// dump whatever already exists in the datadir
 	stack, _ := makeConfigNode(ctx)
 	for _, name := range []string{"chaindata", "lightchaindata"} {
@@ -256,7 +263,7 @@ func dumpGenesis(ctx *cli.Context) error {
 	if ctx.IsSet(utils.DataDirFlag.Name) {
 		utils.Fatalf("no existing datadir at %s", stack.Config().DataDir)
 	}
-	utils.Fatalf("no network preset provided, no existing genesis in the default datadir")
+	utils.Fatalf("no network preset provided, and no genesis exists in the default datadir")
 	return nil
 }
 

cmd/utils/flags.go

@@ -1865,7 +1865,7 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 		log.Info("Using developer account", "address", developer.Address)
 
 		// Create a new developer genesis block or reuse existing one
-		cfg.Genesis = core.DeveloperGenesisBlock(ctx.Uint64(DeveloperGasLimitFlag.Name), developer.Address)
+		cfg.Genesis = core.DeveloperGenesisBlock(ctx.Uint64(DeveloperGasLimitFlag.Name), &developer.Address)
 		if ctx.IsSet(DataDirFlag.Name) {
 			chaindb := tryMakeReadOnlyDatabase(ctx, stack)
 			if rawdb.ReadCanonicalHash(chaindb, 0) != (common.Hash{}) {

console/console_test.go

@@ -94,7 +94,7 @@ func newTester(t *testing.T, confOverride func(*ethconfig.Config)) *tester {
 		t.Fatalf("failed to create node: %v", err)
 	}
 	ethConf := &ethconfig.Config{
-		Genesis: core.DeveloperGenesisBlock(11_500_000, common.Address{}),
+		Genesis: core.DeveloperGenesisBlock(11_500_000, nil),
 		Miner: miner.Config{
 			Etherbase: common.HexToAddress(testAddress),
 		},

core/genesis.go

@@ -580,12 +580,12 @@ func DefaultHoleskyGenesisBlock() *Genesis {
 }
 
 // DeveloperGenesisBlock returns the 'geth --dev' genesis block.
-func DeveloperGenesisBlock(gasLimit uint64, faucet common.Address) *Genesis {
+func DeveloperGenesisBlock(gasLimit uint64, faucet *common.Address) *Genesis {
 	// Override the default period to the user requested one
 	config := *params.AllDevChainProtocolChanges
 
 	// Assemble and return the genesis with the precompiles and faucet pre-funded
-	return &Genesis{
+	genesis := &Genesis{
 		Config:     &config,
 		GasLimit:   gasLimit,
 		BaseFee:    big.NewInt(params.InitialBaseFee),
@@ -600,9 +600,12 @@ func DeveloperGenesisBlock(gasLimit uint64, faucet common.Address) *Genesis {
 			common.BytesToAddress([]byte{7}): {Balance: big.NewInt(1)}, // ECScalarMul
 			common.BytesToAddress([]byte{8}): {Balance: big.NewInt(1)}, // ECPairing
 			common.BytesToAddress([]byte{9}): {Balance: big.NewInt(1)}, // BLAKE2b
-			faucet:                           {Balance: new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(9))},
 		},
 	}
+	if faucet != nil {
+		genesis.Alloc[*faucet] = GenesisAccount{Balance: new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(9))}
+	}
+	return genesis
 }
 
 func decodePrealloc(data string) GenesisAlloc {

eth/catalyst/simulated_beacon_test.go

@@ -85,7 +85,7 @@ func TestSimulatedBeaconSendWithdrawals(t *testing.T) {
 
 	// short period (1 second) for testing purposes
 	var gasLimit uint64 = 10_000_000
-	genesis := core.DeveloperGenesisBlock(gasLimit, testAddr)
+	genesis := core.DeveloperGenesisBlock(gasLimit, &testAddr)
 	node, ethService, mock := startSimulatedBeaconEthService(t, genesis)
 	_ = mock
 	defer node.Close()