Problem: can't support prevrando opcode (backport #443) (#444)

* Problem: can't support prevrando opcode (#443)

* Problem: no proper error msg for unsupported opcode

* panic specific

* fix test

* update deps

* Apply suggestions from code review

* Apply suggestions from code review

* keep default nil

* clean doc

CHANGELOG.md

@@ -39,12 +39,14 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Bug Fixes
 
-
 * (rpc) [#434](https://github.com/crypto-org-chain/ethermint/pull/434) No need gasPrice when patch gasUsed for `eth_getTransactionReceipt`.
 * (feemarket) [#433](https://github.com/crypto-org-chain/ethermint/pull/433) Fix sdk int conversion panic with baseFee.
 * (rpc) [#439](https://github.com/crypto-org-chain/ethermint/pull/439), [#441](https://github.com/crypto-org-chain/ethermint/pull/441) Align trace response for failed tx with go-ethereum.
 
-### Features
+### State Machine Breaking
+
+* (rpc) [#443](https://github.com/crypto-org-chain/ethermint/pull/443) Keep behavior of random opcode as before.
+
 
 ## v0.21.x-cronos
 

app/app.go

@@ -482,6 +482,7 @@ func NewEthermintApp(
 		tracer,
 		evmSs, nil,
 		allKeys,
+		nil,
 	)
 
 	// Create IBC Keeper

tests/integration_tests/hardhat/contracts/Random.sol

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.15;
+
+contract Random {
+    function randomTokenId() public returns (uint256) {
+        return uint256(keccak256(abi.encodePacked(block.prevrandao)));
+    }
+}

tests/integration_tests/hardhat/hardhat.config.ts

@@ -6,6 +6,15 @@ import "@nomiclabs/hardhat-ethers";
 const config: HardhatUserConfig = {
   solidity: {
     compilers: [
+      {
+        version: "0.8.21",
+        settings: {
+          optimizer: {
+            enabled: true
+          },
+          evmVersion: "shanghai"
+        }
+      },
       {
         version: "0.8.10",
         settings: {

tests/integration_tests/test_call.py

@@ -1,5 +1,6 @@
 import json
 
+import pytest
 from hexbytes import HexBytes
 from web3 import Web3
 from web3._utils.contracts import encode_transaction_data
@@ -95,3 +96,13 @@ def test_override_state(ethermint):
         },
     )
     assert ("",) == w3.codec.decode(("string",), result)
+
+
+def test_opcode(ethermint):
+    contract, _ = deploy_contract(
+        ethermint.w3,
+        CONTRACTS["Random"],
+    )
+    with pytest.raises(ValueError) as e_info:
+        contract.caller.randomTokenId()
+    assert "invalid memory address or nil pointer dereference" in str(e_info.value)

tests/integration_tests/utils.py

@@ -40,6 +40,7 @@
     "TestMessageCall": "TestMessageCall.sol",
     "Calculator": "Calculator.sol",
     "Caller": "Caller.sol",
+    "Random": "Random.sol",
 }
 
 

x/evm/keeper/keeper.go

@@ -79,6 +79,8 @@ type Keeper struct {
 	// a set of store keys that should cover all the precompile use cases,
 	// or ideally just pass the application's all stores.
 	keys map[string]storetypes.StoreKey
+
+	forkEnabledFunc func(sdk.Context) bool
 }
 
 // NewKeeper generates new evm module keeper
@@ -94,6 +96,7 @@ func NewKeeper(
 	ss paramstypes.Subspace,
 	customContractFns []CustomContractFn,
 	keys map[string]storetypes.StoreKey,
+	forkEnabledFunc func(sdk.Context) bool,
 ) *Keeper {
 	// ensure evm module account is set
 	if addr := ak.GetModuleAddress(types.ModuleName); addr == nil {
@@ -105,6 +108,12 @@ func NewKeeper(
 		panic(err)
 	}
 
+	if forkEnabledFunc == nil {
+		forkEnabledFunc = func(sdk.Context) bool {
+			return false
+		}
+	}
+
 	// NOTE: we pass in the parameter space to the CommitStateDB in order to use custom denominations for the EVM operations
 	return &Keeper{
 		cdc:               cdc,
@@ -119,6 +128,7 @@ func NewKeeper(
 		ss:                ss,
 		customContractFns: customContractFns,
 		keys:              keys,
+		forkEnabledFunc:   forkEnabledFunc,
 	}
 }
 

x/evm/keeper/state_transition.go

@@ -51,6 +51,7 @@ func (k *Keeper) NewEVM(
 	msg core.Message,
 	cfg *EVMConfig,
 	stateDB vm.StateDB,
+	random *common.Hash,
 ) *vm.EVM {
 	blockCtx := vm.BlockContext{
 		CanTransfer: core.CanTransfer,
@@ -62,7 +63,7 @@ func (k *Keeper) NewEVM(
 		Time:        uint64(ctx.BlockHeader().Time.Unix()),
 		Difficulty:  big.NewInt(0), // unused. Only required in PoW context
 		BaseFee:     cfg.BaseFee,
-		Random:      nil, // not supported
+		Random:      random, // not supported
 	}
 	if cfg.BlockOverrides != nil {
 		cfg.BlockOverrides.Apply(&blockCtx)
@@ -361,7 +362,12 @@ func (k *Keeper) ApplyMessageWithConfig(
 			return nil, errorsmod.Wrap(err, "failed to apply state override")
 		}
 	}
-	evm = k.NewEVM(ctx, msg, cfg, stateDB)
+	var random *common.Hash
+	if k.forkEnabledFunc(ctx) {
+		zero := common.BigToHash(big.NewInt(0))
+		random = &zero
+	}
+	evm = k.NewEVM(ctx, msg, cfg, stateDB, random)
 	leftoverGas := msg.GasLimit
 	sender := vm.AccountRef(msg.From)
 	// Allow the tracer captures the tx level events, mainly the gas consumption.

x/evm/statedb/statedb_test.go

@@ -825,6 +825,7 @@ func newTestKeeper(t *testing.T, cms sdk.MultiStore) (sdk.Context, *evmkeeper.Ke
 		"",
 		paramstypes.Subspace{}, nil,
 		allKeys,
+		nil,
 	)
 
 	ctx := sdk.NewContext(cms, tmproto.Header{}, false, log.NewNopLogger())