sae: Implement Tx.TransferNonAVAX

vms/saevm/cchain/tx/BUILD.bazel

@@ -19,6 +19,7 @@ go_library(
         "//chains/atomic",
         "//codec",
         "//codec/linearcodec",
+        "//graft/coreth/core/extstate",
         "//graft/coreth/plugin/evm/atomic",
         "//graft/coreth/plugin/evm/upgrade/ap5",
         "//ids",
@@ -44,6 +45,8 @@ go_test(
     embed = [":tx"],
     deps = [
         "//chains/atomic",
+        "//graft/coreth/core/extstate",
+        "//graft/coreth/plugin/evm",
         "//graft/coreth/plugin/evm/atomic",
         "//graft/coreth/plugin/evm/atomic/vm",
         "//ids",
@@ -57,6 +60,9 @@ go_test(
         "//vms/saevm/hook",
         "//vms/secp256k1fx",
         "@com_github_ava_labs_libevm//common",
+        "@com_github_ava_labs_libevm//core/rawdb",
+        "@com_github_ava_labs_libevm//core/state",
+        "@com_github_ava_labs_libevm//core/types",
         "@com_github_google_go_cmp//cmp",
         "@com_github_google_go_cmp//cmp/cmpopts",
         "@com_github_holiman_uint256//:uint256",

vms/saevm/cchain/tx/compatibility_test.go

@@ -5,6 +5,7 @@
 
 import (
 	"encoding/json"
+	"math"
 	"math/big"
 	"testing"
 
@@ -15,7 +16,9 @@
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
+	"github.com/ava-labs/avalanchego/graft/coreth/core/extstate"
 	"github.com/ava-labs/avalanchego/graft/coreth/plugin/evm/atomic"
+	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/snow"
 	"github.com/ava-labs/avalanchego/vms/components/gas"
 	"github.com/ava-labs/avalanchego/vms/saevm/cchain/tx/txtest"
@@ -24,10 +27,17 @@
 	. "github.com/ava-labs/avalanchego/vms/saevm/cchain/tx"
 )
 
-// fuzz seeds f with [NewTxs] and fuzzes the test.
+// fuzz seeds f with [NewTxs], specifies simple alphabets used to bias the
+// fuzzer, and fuzzes the test.
 func fuzz(f *testing.F, ff func(t *testing.T, tx *Tx)) {
 	fuzzer := &txtest.F{
 		F: f,
+		Addresses: []common.Address{
+			{1},
+		},
+		AssetIDs: []ids.ID{
+			AVAXAssetID,
+		},
 	}
 	for _, tx := range NewTxs {
 		fuzzer.Add(tx)
@@ -128,17 +138,15 @@
 }
 
 func (*asOpStateDB) GetBalance(common.Address) *uint256.Int {
-	// Large enough to never underflow, but small enough to never overflow.
-	return new(uint256.Int).Lsh(uint256.NewInt(1), 128)
+	return largeUint256()
 }
 
 func (*asOpStateDB) AddBalanceMultiCoin(common.Address, common.Hash, *big.Int) {}
 
 func (*asOpStateDB) SubBalanceMultiCoin(common.Address, common.Hash, *big.Int) {}
 
 func (*asOpStateDB) GetBalanceMultiCoin(common.Address, common.Hash) *big.Int {
-	// Large enough to never underflow, but small enough to never overflow.
-	return new(big.Int).Lsh(big.NewInt(1), 128)
+	return largeBigInt()
 }
 
 func (s *asOpStateDB) SetNonce(addr common.Address, nonce uint64) {
@@ -165,3 +173,50 @@
 		assert.Equal(t, wantRequests, gotRequests, "requests")
 	})
 }
+
+func FuzzTransferNonAVAXCompatibility(f *testing.F) {
+	fuzz(f, func(t *testing.T, newTx *Tx) {
+		op, err := newTx.AsOp(AVAXAssetID)
+		if err != nil {
+			t.Skip("invalid tx")
+		}
+
+		oldState := NewEmptyStateDB(t)
+		newState := NewEmptyStateDB(t)
+		states := []*extstate.StateDB{oldState, newState}
+
+		if tx, ok := newTx.Unsigned.(*Export); ok {
+			for _, in := range tx.Ins {
+				// Coreth silently overflows the nonce, whereas SAE will leave
+				// the nonce unmodified. This difference doesn't matter on live
+				// networks.
+				if in.Nonce == math.MaxUint64 {
+					t.Skip("nonce overflow")
+				}
+
+				for _, state := range states {
+					state.AddBalance(in.Address, largeUint256())
+					state.SetNonce(in.Address, in.Nonce)
+					state.AddBalanceMultiCoin(in.Address, common.Hash(in.AssetID), largeBigInt())
+				}
+			}
+		}
+
+		var (
+			oldTx = ToOldTx(t, newTx)
+			ctx   = &snow.Context{AVAXAssetID: AVAXAssetID}
+		)
+		require.NoErrorf(t, oldTx.EVMStateTransfer(ctx, oldState), "%T.EVMStateTransfer()", oldTx)
+		require.NoErrorf(t, newTx.TransferNonAVAX(AVAXAssetID, newState), "%T.TransferNonAVAX()", newTx)
+		require.NoErrorf(t, op.ApplyTo(newState.StateDB), "%T.ApplyTo(%T)", op, newState.StateDB)
+
+		if diff := CompareStateDBs(oldState, newState); diff != "" {
+			t.Errorf("%T.TransferNonAVAX() diff (-want +got):\n%s", newTx, diff)
+		}
+	})
+}
+
+// largeUint256 and largeBigInt return a balance large enough to never underflow
+// but small enough to never overflow during test arithmetic.
+func largeUint256() *uint256.Int { return new(uint256.Int).Lsh(uint256.NewInt(1), 128) }
+func largeBigInt() *big.Int      { return new(big.Int).Lsh(big.NewInt(1), 128) }

vms/saevm/cchain/tx/export.go

@@ -6,12 +6,14 @@ package tx
 import (
 	"errors"
 	"fmt"
+	"math/big"
 
 	"github.com/ava-labs/libevm/common"
 
 	// Imported for [atomic.UnsignedExportTx.Burned] comment resolution.
 	_ "github.com/ava-labs/avalanchego/graft/coreth/plugin/evm/atomic"
 
+	"github.com/ava-labs/avalanchego/graft/coreth/core/extstate"
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/utils/math"
 	"github.com/ava-labs/avalanchego/vms/components/avax"
@@ -136,3 +138,22 @@ func (e *Export) atomicRequests(txID ids.ID) (ids.ID, *chainsatomic.Requests, er
 	}
 	return e.DestinationChain, &chainsatomic.Requests{PutRequests: elems}, nil
 }
+
+var errInsufficientFunds = errors.New("insufficient funds")
+
+// TransferNonAVAX subtracts the non-AVAX balances from the statedb.
+func (e *Export) TransferNonAVAX(avaxAssetID ids.ID, statedb *extstate.StateDB) error {
+	for _, in := range e.Ins {
+		if in.AssetID == avaxAssetID {
+			continue
+		}
+
+		coinID := common.Hash(in.AssetID)
+		amount := new(big.Int).SetUint64(in.Amount)
+		if balance := statedb.GetBalanceMultiCoin(in.Address, coinID); balance.Cmp(amount) < 0 {
+			return fmt.Errorf("%w: address %s asset %s has %d want %d", errInsufficientFunds, in.Address, coinID, balance, amount)
+		}
+		statedb.SubBalanceMultiCoin(in.Address, coinID, amount)
+	}
+	return nil
+}

vms/saevm/cchain/tx/import.go

@@ -6,13 +6,15 @@ package tx
 import (
 	"errors"
 	"fmt"
+	"math/big"
 
 	"github.com/ava-labs/libevm/common"
 	"github.com/holiman/uint256"
 
 	// Imported for [atomic.UnsignedImportTx.Burned] comment resolution.
 	_ "github.com/ava-labs/avalanchego/graft/coreth/plugin/evm/atomic"
 
+	"github.com/ava-labs/avalanchego/graft/coreth/core/extstate"
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/utils/math"
 	"github.com/ava-labs/avalanchego/vms/components/avax"
@@ -121,3 +123,17 @@ func (i *Import) atomicRequests(ids.ID) (ids.ID, *chainsatomic.Requests, error)
 	}
 	return i.SourceChain, &chainsatomic.Requests{RemoveRequests: utxoIDs}, nil
 }
+
+// TransferNonAVAX adds the non-AVAX balances to the statedb.
+func (i *Import) TransferNonAVAX(avaxAssetID ids.ID, statedb *extstate.StateDB) error {
+	for _, out := range i.Outs {
+		if out.AssetID == avaxAssetID {
+			continue
+		}
+
+		coinID := common.Hash(out.AssetID)
+		amount := new(big.Int).SetUint64(out.Amount)
+		statedb.AddBalanceMultiCoin(out.Address, coinID, amount)
+	}
+	return nil
+}

vms/saevm/cchain/tx/tx.go

@@ -15,6 +15,7 @@ import (
 	// Imported for [atomic.TxBytesGas] comment resolution.
 	_ "github.com/ava-labs/avalanchego/graft/coreth/plugin/evm/atomic"
 
+	"github.com/ava-labs/avalanchego/graft/coreth/core/extstate"
 	"github.com/ava-labs/avalanchego/graft/coreth/plugin/evm/upgrade/ap5"
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/utils/hashing"
@@ -36,9 +37,15 @@ type Tx struct {
 
 // Unsigned is a common interface implemented by [Import] and [Export].
 //
-// TODO(StephenButtolph): Expand this interface to include UTXO handling,
-// verification, and state execution.
+// TODO(StephenButtolph): Expand this interface to include UTXO handling and
+// verification.
 type Unsigned interface {
+	// TransferNonAVAX transfers the non-AVAX balances requested by this
+	// transaction.
+	//
+	// Non-AVAX transfers were only allowed prior to the Banff upgrade.
+	TransferNonAVAX(avaxAssetID ids.ID, statedb *extstate.StateDB) error
+
 	// burned returns the amount of assetID that is consumed but not produced by
 	// this transaction.
 	burned(assetID ids.ID) (uint64, error)
@@ -47,8 +54,8 @@ type Unsigned interface {
 	// transaction.
 	numSigs() (uint64, error)
 
-	// asOp returns the operation that this transaction performs on the EVM
-	// state.
+	// asOp returns the operation that this transaction performs on the
+	// EVM-native state. Ops do not include any non-AVAX balance changes.
 	asOp(avaxAssetID ids.ID) (op, error)
 
 	// atomicRequests returns the operations that should be applied to shared