From 9894b45b21ef9176a92f9fc8162b6b7297e8b209 Mon Sep 17 00:00:00 2001
From: evgeniy-scherbina <evgeniy.shcherbina.es@gmail.com>
Date: Mon, 6 May 2024 14:04:06 -0400
Subject: [PATCH] Initialize precompiles in InitGenesis

---
 x/evm/genesis.go      | 24 ++++++++++++++++++++++++
 x/evm/genesis_test.go | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/x/evm/genesis.go b/x/evm/genesis.go
index 992d53c9fd..4eb9b1c3cf 100644
--- a/x/evm/genesis.go
+++ b/x/evm/genesis.go
@@ -27,9 +27,14 @@ import (
 	precompile_modules "github.com/ethereum/go-ethereum/precompile/modules"
 	ethermint "github.com/evmos/ethermint/types"
 	"github.com/evmos/ethermint/x/evm/keeper"
+	"github.com/evmos/ethermint/x/evm/statedb"
 	"github.com/evmos/ethermint/x/evm/types"
 )
 
+const PrecompileNonce uint64 = 1
+
+var PrecompileCode = []byte{0x1}
+
 // InitGenesis initializes genesis state based on exported genesis
 func InitGenesis(
 	ctx sdk.Context,
@@ -48,6 +53,25 @@ func InitGenesis(
 		panic(err)
 	}
 
+	txConfig := statedb.NewEmptyTxConfig(common.BytesToHash(ctx.HeaderHash().Bytes()))
+	stateDB := statedb.New(ctx, k, txConfig)
+
+	for _, hexAddr := range data.Params.EnabledPrecompiles {
+		addr := common.HexToAddress(hexAddr)
+
+		// Set the nonce of the precompile's address (as is done when a contract is created) to ensure
+		// that it is marked as non-empty and will not be cleaned up when the statedb is finalized.
+		stateDB.SetNonce(addr, PrecompileNonce)
+		// Set the code of the precompile's address to a non-zero length byte slice to ensure that the precompile
+		// can be called from within Solidity contracts. Solidity adds a check before invoking a contract to ensure
+		// that it does not attempt to invoke a non-existent contract.
+		stateDB.SetCode(addr, PrecompileCode)
+	}
+
+	if err := stateDB.Commit(); err != nil {
+		panic(err)
+	}
+
 	err = k.SetParams(ctx, data.Params)
 	if err != nil {
 		panic(fmt.Errorf("error setting params %s", err))
diff --git a/x/evm/genesis_test.go b/x/evm/genesis_test.go
index 0359a29664..44e57d4892 100644
--- a/x/evm/genesis_test.go
+++ b/x/evm/genesis_test.go
@@ -231,3 +231,35 @@ func (suite *EvmTestSuite) TestInitGenesis() {
 		})
 	}
 }
+
+func (suite *EvmTestSuite) TestInitPrecompiles() {
+	hexAddr1 := "0x1000000000000000000000000000000000000000"
+	hexAddr2 := "0x2000000000000000000000000000000000000000"
+
+	genState := types.DefaultGenesisState()
+	genState.Params.EnabledPrecompiles = []string{hexAddr1, hexAddr2}
+	registeredModules := []precompile_modules.Module{
+		{Address: common.HexToAddress(hexAddr1)},
+		{Address: common.HexToAddress(hexAddr2)},
+	}
+
+	vmdb := suite.StateDB()
+
+	// check that enabled precompile are uninitialized
+	for _, hexAddr := range genState.Params.EnabledPrecompiles {
+		addr := common.HexToAddress(hexAddr)
+
+		suite.Require().Equal(uint64(0), vmdb.GetNonce(addr))
+		suite.Require().Equal([]byte(nil), vmdb.GetCode(addr))
+	}
+
+	evm.InitGenesis(suite.ctx, suite.app.EvmKeeper, suite.app.AccountKeeper, *genState, registeredModules)
+
+	// check that enabled precompile are initialized
+	for _, hexAddr := range genState.Params.EnabledPrecompiles {
+		addr := common.HexToAddress(hexAddr)
+
+		suite.Require().Equal(evm.PrecompileNonce, vmdb.GetNonce(addr))
+		suite.Require().Equal(evm.PrecompileCode, vmdb.GetCode(addr))
+	}
+}