feat: eth: parse revert data (#10295)

We don't really want to do this in the FVM because it's Ethereum
specific, but this makes sense to do in the Ethereum API.

See:

See https://docs.soliditylang.org/en/latest/control-structures.html#panic-via-assert-and-error-via-require

chain/types/ethtypes/eth_types.go

@@ -66,6 +66,18 @@ func EthUint64FromHex(s string) (EthUint64, error) {
 	return EthUint64(parsedInt), nil
 }
 
+// Parse a uint64 from big-endian encoded bytes.
+func EthUint64FromBytes(b []byte) (EthUint64, error) {
+	if len(b) != 32 {
+		return 0, xerrors.Errorf("eth int must be 32 bytes long")
+	}
+	var zeros [32 - 8]byte
+	if !bytes.Equal(b[:len(zeros)], zeros[:]) {
+		return 0, xerrors.Errorf("eth int overflows 64 bits")
+	}
+	return EthUint64(binary.BigEndian.Uint64(b[len(zeros):])), nil
+}
+
 func (e EthUint64) Hex() string {
 	if e == 0 {
 		return "0x0"
@@ -78,11 +90,15 @@ type EthBigInt big.Int
 
 var EthBigIntZero = EthBigInt{Int: big.Zero().Int}
 
-func (e EthBigInt) MarshalJSON() ([]byte, error) {
+func (e EthBigInt) String() string {
 	if e.Int == nil || e.Int.BitLen() == 0 {
-		return json.Marshal("0x0")
+		return "0x0"
 	}
-	return json.Marshal(fmt.Sprintf("0x%x", e.Int))
+	return fmt.Sprintf("0x%x", e.Int)
+}
+
+func (e EthBigInt) MarshalJSON() ([]byte, error) {
+	return json.Marshal(e.String())
 }
 
 func (e *EthBigInt) UnmarshalJSON(b []byte) error {
@@ -106,12 +122,15 @@ func (e *EthBigInt) UnmarshalJSON(b []byte) error {
 // EthBytes represent arbitrary bytes. A nil or empty slice serializes to "0x".
 type EthBytes []byte
 
-func (e EthBytes) MarshalJSON() ([]byte, error) {
+func (e EthBytes) String() string {
 	if len(e) == 0 {
-		return json.Marshal("0x")
+		return "0x"
 	}
-	s := hex.EncodeToString(e)
-	return json.Marshal("0x" + s)
+	return "0x" + hex.EncodeToString(e)
+}
+
+func (e EthBytes) MarshalJSON() ([]byte, error) {
+	return json.Marshal(e.String())
 }
 
 func (e *EthBytes) UnmarshalJSON(b []byte) error {

itests/contracts/Errors.hex

@@ -0,0 +1 @@
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

itests/contracts/Errors.sol

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.17;
+
+contract Errors {
+    error CustomError();
+
+    function failRevertEmpty() public  {
+        revert();
+    }
+    function failRevertReason() public  {
+        revert("my reason");
+    }
+    function failAssert() public  {
+        assert(false);
+    }
+    function failDivZero() public  {
+        int a = 1;
+        int b = 0;
+        a / b;
+    }
+    function failCustom() public  {
+        revert CustomError();
+    }
+}

itests/fevm_test.go

@@ -882,3 +882,33 @@ func TestFEVMGetBlockDifficulty(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, len(ret), 32)
 }
+
+func TestFEVMErrorParsing(t *testing.T) {
+	ctx, cancel, client := kit.SetupFEVMTest(t)
+	defer cancel()
+
+	e := client.EVM()
+
+	_, contractAddr := e.DeployContractFromFilename(ctx, "contracts/Errors.hex")
+	contractAddrEth, err := ethtypes.EthAddressFromFilecoinAddress(contractAddr)
+	require.NoError(t, err)
+	customError := ethtypes.EthBytes(kit.CalcFuncSignature("CustomError()")).String()
+	for sig, expected := range map[string]string{
+		"failRevertEmpty()":  "none",
+		"failRevertReason()": "Error(my reason)",
+		"failAssert()":       "Assert()",
+		"failDivZero()":      "DivideByZero()",
+		"failCustom()":       customError,
+	} {
+		sig := sig
+		expected := expected
+		t.Run(sig, func(t *testing.T) {
+			entryPoint := kit.CalcFuncSignature(sig)
+			_, err := e.EthCall(ctx, ethtypes.EthCall{
+				To:   &contractAddrEth,
+				Data: entryPoint,
+			}, "latest")
+			require.ErrorContains(t, err, fmt.Sprintf("exit 33, revert reason: %s, vm error", expected))
+		})
+	}
+}

node/impl/full/eth.go

@@ -871,7 +871,8 @@ func (a *EthModule) applyMessage(ctx context.Context, msg *types.Message, tsk ty
 		return nil, xerrors.Errorf("CallWithGas failed: %w", err)
 	}
 	if res.MsgRct.ExitCode.IsError() {
-		return nil, xerrors.Errorf("message execution failed: exit %s, msg receipt: %s, reason: %s", res.MsgRct.ExitCode, res.MsgRct.Return, res.Error)
+		reason := parseEthRevert(res.MsgRct.Return)
+		return nil, xerrors.Errorf("message execution failed: exit %s, revert reason: %s, vm error: %s", res.MsgRct.ExitCode, reason, res.Error)
 	}
 	return res, nil
 }
@@ -1032,7 +1033,7 @@ func (a *EthModule) EthCall(ctx context.Context, tx ethtypes.EthCall, blkParam s
 
 	invokeResult, err := a.applyMessage(ctx, msg, ts.Key())
 	if err != nil {
-		return nil, xerrors.Errorf("failed to apply message: %w", err)
+		return nil, err
 	}
 
 	if msg.To == builtintypes.EthereumAddressManagerActorAddr {
@@ -2211,6 +2212,85 @@ func parseEthTopics(topics ethtypes.EthTopicSpec) (map[string][][]byte, error) {
 	return keys, nil
 }
 
+const errorFunctionSelector = "\x08\xc3\x79\xa0" // Error(string)
+const panicFunctionSelector = "\x4e\x48\x7b\x71" // Panic(uint256)
+// Eth ABI (solidity) panic codes.
+var panicErrorCodes map[uint64]string = map[uint64]string{
+	0x00: "Panic()",
+	0x01: "Assert()",
+	0x11: "ArithmeticOverflow()",
+	0x12: "DivideByZero()",
+	0x21: "InvalidEnumVariant()",
+	0x22: "InvalidStorageArray()",
+	0x31: "PopEmptyArray()",
+	0x32: "ArrayIndexOutOfBounds()",
+	0x41: "OutOfMemory()",
+	0x51: "CalledUninitializedFunction()",
+}
+
+// Parse an ABI encoded revert reason. This reason should be encoded as if it were the parameters to
+// an `Error(string)` function call.
+//
+// See https://docs.soliditylang.org/en/latest/control-structures.html#panic-via-assert-and-error-via-require
+func parseEthRevert(ret []byte) string {
+	if len(ret) == 0 {
+		return "none"
+	}
+	var cbytes abi.CborBytes
+	if err := cbytes.UnmarshalCBOR(bytes.NewReader(ret)); err != nil {
+		return "ERROR: revert reason is not cbor encoded bytes"
+	}
+	if len(cbytes) == 0 {
+		return "none"
+	}
+	// If it's not long enough to contain an ABI encoded response, return immediately.
+	if len(cbytes) < 4+32 {
+		return ethtypes.EthBytes(cbytes).String()
+	}
+	switch string(cbytes[:4]) {
+	case panicFunctionSelector:
+		cbytes := cbytes[4 : 4+32]
+		// Read the and check the code.
+		code, err := ethtypes.EthUint64FromBytes(cbytes)
+		if err != nil {
+			// If it's too big, just return the raw value.
+			codeInt := big.PositiveFromUnsignedBytes(cbytes)
+			return fmt.Sprintf("Panic(%s)", ethtypes.EthBigInt(codeInt).String())
+		}
+		if s, ok := panicErrorCodes[uint64(code)]; ok {
+			return s
+		}
+		return fmt.Sprintf("Panic(0x%x)", code)
+	case errorFunctionSelector:
+		cbytes := cbytes[4:]
+		cbytesLen := ethtypes.EthUint64(len(cbytes))
+		// Read the and check the offset.
+		offset, err := ethtypes.EthUint64FromBytes(cbytes[:32])
+		if err != nil {
+			break
+		}
+		if cbytesLen < offset {
+			break
+		}
+
+		// Read and check the length.
+		if cbytesLen-offset < 32 {
+			break
+		}
+		start := offset + 32
+		length, err := ethtypes.EthUint64FromBytes(cbytes[offset : offset+32])
+		if err != nil {
+			break
+		}
+		if cbytesLen-start < length {
+			break
+		}
+		// Slice the error message.
+		return fmt.Sprintf("Error(%s)", cbytes[start:start+length])
+	}
+	return ethtypes.EthBytes(cbytes).String()
+}
+
 func calculateRewardsAndGasUsed(rewardPercentiles []float64, txGasRewards gasRewardSorter) ([]ethtypes.EthBigInt, uint64) {
 	var totalGasUsed uint64
 	for _, tx := range txGasRewards {