internal/ethapi: EstimateGas and Call handle revert error(#173)

accounts/abi/abi.go

@@ -19,8 +19,11 @@ package abi
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
+
+	"github.com/XinFinOrg/XDPoSChain/crypto"
 )
 
 // The ABI holds information about a contract's context and available
@@ -144,3 +147,26 @@ func (abi *ABI) MethodById(sigdata []byte) (*Method, error) {
 	}
 	return nil, fmt.Errorf("no method with id: %#x", sigdata[:4])
 }
+
+
+// revertSelector is a special function selector for revert reason unpacking.
+var revertSelector = crypto.Keccak256([]byte("Error(string)"))[:4]
+
+// UnpackRevert resolves the abi-encoded revert reason. According to the solidity
+// spec https://solidity.readthedocs.io/en/latest/control-structures.html#revert,
+// the provided revert reason is abi-encoded as if it were a call to a function
+// `Error(string)`. So it's a special tool for it.
+func UnpackRevert(data []byte) (string, error) {
+	if len(data) < 4 {
+		return "", errors.New("invalid data for unpacking")
+	}
+	if !bytes.Equal(data[:4], revertSelector) {
+		return "", errors.New("invalid data for unpacking")
+	}
+	typ, _ := NewType("string")
+	unpacked, err := (Arguments{{Type: typ}}).Unpack2(data[4:])
+	if err != nil {
+		return "", err
+	}
+	return unpacked[0].(string), nil
+}

accounts/abi/argument.go

@@ -18,6 +18,7 @@ package abi
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"reflect"
 	"strings"
@@ -100,6 +101,17 @@ func (arguments Arguments) Unpack(v interface{}, data []byte) error {
 	return arguments.unpackAtomic(v, marshalledValues)
 }
 
+// Unpack2 performs the operation hexdata -> Go format.
+func (arguments Arguments) Unpack2(data []byte) ([]interface{}, error) {
+	if len(data) == 0 {
+		if len(arguments.NonIndexed()) != 0 {
+			return nil, errors.New("abi: attempting to unmarshall an empty string while arguments are expected")
+		}
+		return make([]interface{}, 0), nil
+	}
+	return arguments.UnpackValues(data)
+}
+
 func (arguments Arguments) unpackTuple(v interface{}, marshalledValues []interface{}) error {
 
 	var (

accounts/abi/bind/backends/simulated.go

@@ -325,7 +325,7 @@ func (b *SimulatedBackend) EstimateGas(ctx context.Context, call XDPoSChain.Call
 
 // callContract implements common code between normal and pending contract calls.
 // state is modified during execution, make sure to copy it if necessary.
-func (b *SimulatedBackend) callContract(ctx context.Context, call XDPoSChain.CallMsg, block *types.Block, statedb *state.StateDB) ([]byte, uint64, bool, error) {
+func (b *SimulatedBackend) callContract(ctx context.Context, call XDPoSChain.CallMsg, block *types.Block, statedb *state.StateDB) (ret []byte, usedGas uint64, failed bool, err error) {
 	// Ensure message is initialized properly.
 	if call.GasPrice == nil {
 		call.GasPrice = big.NewInt(1)
@@ -353,7 +353,8 @@ func (b *SimulatedBackend) callContract(ctx context.Context, call XDPoSChain.Cal
 	vmenv := vm.NewEVM(evmContext, statedb, nil, b.config, vm.Config{})
 	gaspool := new(core.GasPool).AddGas(math.MaxUint64)
 	owner := common.Address{}
-	return core.NewStateTransition(vmenv, msg, gaspool).TransitionDb(owner)
+	ret, usedGas, failed, err, _ = core.NewStateTransition(vmenv, msg, gaspool).TransitionDb(owner)
+	return
 }
 
 // SendTransaction updates the pending block to include the given transaction.

core/state_processor.go

@@ -409,7 +409,7 @@ func ApplyTransaction(config *params.ChainConfig, tokensFee map[common.Address]*
 	// End Bypass blacklist address
 
 	// Apply the transaction to the current state (included in the env)
-	_, gas, failed, err := ApplyMessage(vmenv, msg, gp, coinbaseOwner)
+	_, gas, failed, err, _ := ApplyMessage(vmenv, msg, gp, coinbaseOwner)
 
 	if err != nil {
 		return nil, 0, err, false

core/state_transition.go

@@ -129,7 +129,7 @@ func NewStateTransition(evm *vm.EVM, msg Message, gp *GasPool) *StateTransition
 // the gas used (which includes gas refunds) and an error if it failed. An error always
 // indicates a core error meaning that the message would always fail for that particular
 // state and would never be accepted within a block.
-func ApplyMessage(evm *vm.EVM, msg Message, gp *GasPool, owner common.Address) ([]byte, uint64, bool, error) {
+func ApplyMessage(evm *vm.EVM, msg Message, gp *GasPool, owner common.Address) ([]byte, uint64, bool, error, error) {
 	return NewStateTransition(evm, msg, gp).TransitionDb(owner)
 }
 
@@ -215,7 +215,7 @@ func (st *StateTransition) preCheck() error {
 // TransitionDb will transition the state by applying the current message and
 // returning the result including the the used gas. It returns an error if it
 // failed. An error indicates a consensus issue.
-func (st *StateTransition) TransitionDb(owner common.Address) (ret []byte, usedGas uint64, failed bool, err error) {
+func (st *StateTransition) TransitionDb(owner common.Address) (ret []byte, usedGas uint64, failed bool, err error, vmErr error) {
 	if err = st.preCheck(); err != nil {
 		return
 	}
@@ -228,10 +228,10 @@ func (st *StateTransition) TransitionDb(owner common.Address) (ret []byte, usedG
 	// Pay intrinsic gas
 	gas, err := IntrinsicGas(st.data, contractCreation, homestead)
 	if err != nil {
-		return nil, 0, false, err
+		return nil, 0, false, err, nil
 	}
 	if err = st.useGas(gas); err != nil {
-		return nil, 0, false, err
+		return nil, 0, false, err, nil
 	}
 
 	var (
@@ -261,7 +261,7 @@ func (st *StateTransition) TransitionDb(owner common.Address) (ret []byte, usedG
 		// sufficient balance to make the transfer happen. The first
 		// balance transfer may never fail.
 		if vmerr == vm.ErrInsufficientBalance {
-			return nil, 0, false, vmerr
+			return nil, 0, false, vmerr, nil
 		}
 	}
 	st.refundGas()
@@ -274,7 +274,7 @@ func (st *StateTransition) TransitionDb(owner common.Address) (ret []byte, usedG
 		st.state.AddBalance(st.evm.Coinbase, new(big.Int).Mul(new(big.Int).SetUint64(st.gasUsed()), st.gasPrice))
 	}
 
-	return ret, st.gasUsed(), vmerr != nil, err
+	return ret, st.gasUsed(), vmerr != nil, err, vmerr
 }
 
 func (st *StateTransition) refundGas() {

core/token_validator.go

@@ -112,7 +112,7 @@ func CallContractWithState(call ethereum.CallMsg, chain consensus.ChainContext,
 	vmenv := vm.NewEVM(evmContext, statedb, nil, chain.Config(), vm.Config{})
 	gaspool := new(GasPool).AddGas(1000000)
 	owner := common.Address{}
-	rval, _, _, err := NewStateTransition(vmenv, msg, gaspool).TransitionDb(owner)
+	rval, _, _, err, _ := NewStateTransition(vmenv, msg, gaspool).TransitionDb(owner)
 	if err != nil {
 		return nil, err
 	}

eth/api_tracer.go

@@ -475,7 +475,7 @@ func (api *PrivateDebugAPI) traceBlock(ctx context.Context, block *types.Block,
 
 		vmenv := vm.NewEVM(vmctx, statedb, XDCxState, api.config, vm.Config{})
 		owner := common.Address{}
-		if _, _, _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(msg.Gas()), owner); err != nil {
+		if _, _, _, err, _ := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(msg.Gas()), owner); err != nil {
 			failed = err
 			break
 		}
@@ -631,7 +631,7 @@ func (api *PrivateDebugAPI) traceTx(ctx context.Context, message core.Message, v
 	vmenv := vm.NewEVM(vmctx, statedb, nil, api.config, vm.Config{Debug: true, Tracer: tracer})
 
 	owner := common.Address{}
-	ret, gas, failed, err := core.ApplyMessage(vmenv, message, new(core.GasPool).AddGas(message.Gas()), owner)
+	ret, gas, failed, err, _ := core.ApplyMessage(vmenv, message, new(core.GasPool).AddGas(message.Gas()), owner)
 	if err != nil {
 		return nil, fmt.Errorf("tracing failed: %v", err)
 	}

eth/tracers/tracers_test.go

@@ -20,6 +20,13 @@ import (
 	"crypto/ecdsa"
 	"crypto/rand"
 	"encoding/json"
+	"io/ioutil"
+	"math/big"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+
 	"github.com/XinFinOrg/XDPoSChain/common"
 	"github.com/XinFinOrg/XDPoSChain/common/hexutil"
 	"github.com/XinFinOrg/XDPoSChain/common/math"
@@ -31,12 +38,6 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/params"
 	"github.com/XinFinOrg/XDPoSChain/rlp"
 	"github.com/XinFinOrg/XDPoSChain/tests"
-	"io/ioutil"
-	"math/big"
-	"path/filepath"
-	"reflect"
-	"strings"
-	"testing"
 )
 
 // To generate a new callTracer test, copy paste the makeTest method below into
@@ -183,7 +184,7 @@ func TestPrestateTracerCreate2(t *testing.T) {
 		t.Fatalf("failed to prepare transaction for tracing: %v", err)
 	}
 	st := core.NewStateTransition(evm, msg, new(core.GasPool).AddGas(tx.Gas()))
-	if _, _, _, err = st.TransitionDb(common.Address{}); err != nil {
+	if _, _, _, err, _ = st.TransitionDb(common.Address{}); err != nil {
 		t.Fatalf("failed to execute transaction: %v", err)
 	}
 	// Retrieve the trace result and compare against the etalon
@@ -258,7 +259,7 @@ func TestCallTracer(t *testing.T) {
 				t.Fatalf("failed to prepare transaction for tracing: %v", err)
 			}
 			st := core.NewStateTransition(evm, msg, new(core.GasPool).AddGas(tx.Gas()))
-			if _, _, _, err = st.TransitionDb(common.Address{}); err != nil {
+			if _, _, _, err, _ = st.TransitionDb(common.Address{}); err != nil {
 				t.Fatalf("failed to execute transaction: %v", err)
 			}
 			// Retrieve the trace result and compare against the etalon