github.com/ethw3/go-ethereuma@v0.0.0-20221013053120-c14602a4c23c/eth/tracers/native/revertreason.go (about)

     1  // Copyright 2022 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package native
    18  
    19  import (
    20  	"bytes"
    21  	"encoding/json"
    22  	"math/big"
    23  	"sync/atomic"
    24  	"time"
    25  
    26  	"github.com/ethw3/go-ethereuma/accounts/abi"
    27  	"github.com/ethw3/go-ethereuma/common"
    28  	"github.com/ethw3/go-ethereuma/core/vm"
    29  	"github.com/ethw3/go-ethereuma/crypto"
    30  	"github.com/ethw3/go-ethereuma/eth/tracers"
    31  )
    32  
    33  func init() {
    34  	register("revertReasonTracer", newRevertReasonTracer)
    35  }
    36  
    37  var revertSelector = crypto.Keccak256([]byte("Error(string)"))[:4]
    38  
    39  // revertReasonTracer is a go implementation of the Tracer interface which
    40  // track the error message or revert reason return by the contract.
    41  type revertReasonTracer struct {
    42  	env          *vm.EVM
    43  	revertReason string // The revert reason return from the tx, if tx success, empty string return
    44  	interrupt    uint32 // Atomic flag to signal execution interruption
    45  	reason       error  // Textual reason for the interruption
    46  }
    47  
    48  // newRevertReasonTracer returns a new revert reason tracer.
    49  func newRevertReasonTracer(_ *tracers.Context, _ json.RawMessage) (tracers.Tracer, error) {
    50  	return &revertReasonTracer{}, nil
    51  }
    52  
    53  // CaptureStart implements the EVMLogger interface to initialize the tracing operation.
    54  func (t *revertReasonTracer) CaptureStart(env *vm.EVM, _ common.Address, _ common.Address, _ bool, _ []byte, _ uint64, _ *big.Int) {
    55  	t.env = env
    56  }
    57  
    58  // CaptureEnd is called after the call finishes to finalize the tracing.
    59  func (t *revertReasonTracer) CaptureEnd(output []byte, _ uint64, _ time.Duration, err error) {
    60  	if err != nil {
    61  		if err == vm.ErrExecutionReverted && len(output) > 4 && bytes.Equal(output[:4], revertSelector) {
    62  			errMsg, _ := abi.UnpackRevert(output)
    63  			t.revertReason = err.Error() + ": " + errMsg
    64  		} else {
    65  			t.revertReason = err.Error()
    66  		}
    67  	}
    68  }
    69  
    70  // CaptureState implements the EVMLogger interface to trace a single step of VM execution.
    71  func (t *revertReasonTracer) CaptureState(_ uint64, _ vm.OpCode, _, _ uint64, _ *vm.ScopeContext, _ []byte, _ int, _ error) {
    72  }
    73  
    74  // CaptureFault implements the EVMLogger interface to trace an execution fault.
    75  func (t *revertReasonTracer) CaptureFault(_ uint64, _ vm.OpCode, _, _ uint64, _ *vm.ScopeContext, _ int, _ error) {
    76  }
    77  
    78  // CaptureEnter is called when EVM enters a new scope (via call, create or selfdestruct).
    79  func (t *revertReasonTracer) CaptureEnter(_ vm.OpCode, _ common.Address, _ common.Address, _ []byte, _ uint64, _ *big.Int) {
    80  	// Skip if tracing was interrupted
    81  	if atomic.LoadUint32(&t.interrupt) > 0 {
    82  		t.env.Cancel()
    83  		return
    84  	}
    85  }
    86  
    87  // CaptureExit is called when EVM exits a scope, even if the scope didn't
    88  // execute any code.
    89  func (t *revertReasonTracer) CaptureExit(_ []byte, _ uint64, _ error) {}
    90  
    91  func (t *revertReasonTracer) CaptureTxStart(_ uint64) {}
    92  
    93  func (t *revertReasonTracer) CaptureTxEnd(_ uint64) {}
    94  
    95  // GetResult returns an error message json object.
    96  func (t *revertReasonTracer) GetResult() (json.RawMessage, error) {
    97  	res, err := json.Marshal(t.revertReason)
    98  	if err != nil {
    99  		return nil, err
   100  	}
   101  	return res, t.reason
   102  }
   103  
   104  // Stop terminates execution of the tracer at the first opportune moment.
   105  func (t *revertReasonTracer) Stop(err error) {
   106  	t.reason = err
   107  	atomic.StoreUint32(&t.interrupt, 1)
   108  }