core/vm, eth: Add support for javascript trace functions

This commit is contained in:
Nick Johnson 2016-08-22 15:03:30 +01:00
parent d8cec35b10
commit 2f99720901
6 changed files with 551 additions and 18 deletions

View File

@ -85,7 +85,7 @@ func TestCompiling(t *testing.T) {
func TestResetInput(t *testing.T) {
var sender account
env := NewEnv(false, true)
env := NewEnv(&Config{EnableJit: true, ForceJit: true})
contract := NewContract(sender, sender, big.NewInt(100), big.NewInt(10000), big.NewInt(0))
contract.CodeAddr = &common.Address{}
@ -144,7 +144,7 @@ func runVmBench(test vmBench, b *testing.B) {
if test.precompile && !test.forcejit {
NewProgram(test.code)
}
env := NewEnv(test.nojit, test.forcejit)
env := NewEnv(&Config{EnableJit: !test.nojit, ForceJit: test.forcejit})
b.ResetTimer()
@ -166,12 +166,9 @@ type Env struct {
evm *EVM
}
func NewEnv(noJit, forceJit bool) *Env {
func NewEnv(config *Config) *Env {
env := &Env{gasLimit: big.NewInt(10000), depth: 0}
env.evm = New(env, Config{
EnableJit: !noJit,
ForceJit: forceJit,
})
env.evm = New(env, *config)
return env
}

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@ -47,7 +47,7 @@ type dummyEnv struct {
func newDummyEnv(ref *dummyContractRef) *dummyEnv {
return &dummyEnv{
Env: NewEnv(true, false),
Env: NewEnv(&Config{EnableJit: false, ForceJit: false}),
ref: ref,
}
}
@ -57,7 +57,7 @@ func (d dummyEnv) GetAccount(common.Address) Account {
func TestStoreCapture(t *testing.T) {
var (
env = NewEnv(true, false)
env = NewEnv(&Config{EnableJit: false, ForceJit: false})
logger = NewStructLogger(nil)
mem = NewMemory()
stack = newstack()

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@ -25,6 +25,7 @@ import (
"math/big"
"os"
"runtime"
"time"
"github.com/ethereum/ethash"
"github.com/ethereum/go-ethereum/common"
@ -38,8 +39,11 @@ import (
"github.com/ethereum/go-ethereum/miner"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/rpc"
"golang.org/x/net/context"
)
const defaultTraceTimeout = 5 * time.Second
// PublicEthereumAPI provides an API to access Ethereum full node-related
// information.
type PublicEthereumAPI struct {
@ -317,6 +321,13 @@ type BlockTraceResult struct {
Error string `json:"error"`
}
// TraceArgs holds extra parameters to trace functions
type TraceArgs struct {
*vm.LogConfig
Tracer *string
Timeout *string
}
// TraceBlock processes the given block's RLP but does not import the block in to
// the chain.
func (api *PrivateDebugAPI) TraceBlock(blockRlp []byte, config *vm.LogConfig) BlockTraceResult {
@ -439,10 +450,42 @@ func formatError(err error) string {
return err.Error()
}
type timeoutError struct{}
func (t *timeoutError) Error() string {
return "Execution time exceeded"
}
// TraceTransaction returns the structured logs created during the execution of EVM
// and returns them as a JSON object.
func (api *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logConfig *vm.LogConfig) (*ethapi.ExecutionResult, error) {
logger := vm.NewStructLogger(logConfig)
func (api *PrivateDebugAPI) TraceTransaction(ctx context.Context, txHash common.Hash, config *TraceArgs) (interface{}, error) {
var tracer vm.Tracer
if config != nil && config.Tracer != nil {
timeout := defaultTraceTimeout
if config.Timeout != nil {
var err error
if timeout, err = time.ParseDuration(*config.Timeout); err != nil {
return nil, err
}
}
var err error
if tracer, err = ethapi.NewJavascriptTracer(*config.Tracer); err != nil {
return nil, err
}
// Handle timeouts and RPC cancellations
deadlineCtx, cancel := context.WithTimeout(ctx, timeout)
go func() {
<-deadlineCtx.Done()
tracer.(*ethapi.JavascriptTracer).Stop(&timeoutError{})
}()
defer cancel()
} else if config == nil {
tracer = vm.NewStructLogger(nil)
} else {
tracer = vm.NewStructLogger(config.LogConfig)
}
// Retrieve the tx from the chain and the containing block
tx, blockHash, _, txIndex := core.GetTransaction(api.eth.ChainDb(), txHash)
@ -488,16 +531,22 @@ func (api *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logConfig *vm.L
continue
}
// Otherwise trace the transaction and return
vmenv := core.NewEnv(stateDb, api.config, api.eth.BlockChain(), msg, block.Header(), vm.Config{Debug: true, Tracer: logger})
vmenv := core.NewEnv(stateDb, api.config, api.eth.BlockChain(), msg, block.Header(), vm.Config{Debug: true, Tracer: tracer})
ret, gas, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
if err != nil {
return nil, fmt.Errorf("tracing failed: %v", err)
}
return &ethapi.ExecutionResult{
Gas: gas,
ReturnValue: fmt.Sprintf("%x", ret),
StructLogs: ethapi.FormatLogs(logger.StructLogs()),
}, nil
switch tracer := tracer.(type) {
case *vm.StructLogger:
return &ethapi.ExecutionResult{
Gas: gas,
ReturnValue: fmt.Sprintf("%x", ret),
StructLogs: ethapi.FormatLogs(tracer.StructLogs()),
}, nil
case *ethapi.JavascriptTracer:
return tracer.GetResult()
}
}
return nil, errors.New("database inconsistency")
}

300
internal/ethapi/tracer.go Normal file
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@ -0,0 +1,300 @@
// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package ethapi
import (
"errors"
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/robertkrimen/otto"
)
// fakeBig is used to provide an interface to Javascript for 'big.NewInt'
type fakeBig struct{}
// NewInt creates a new big.Int with the specified int64 value.
func (fb *fakeBig) NewInt(x int64) *big.Int {
return big.NewInt(x)
}
// OpCodeWrapper provides a JavaScript-friendly wrapper around OpCode, to convince Otto to treat it
// as an object, instead of a number.
type opCodeWrapper struct {
op vm.OpCode
}
// toNumber returns the ID of this opcode as an integer
func (ocw *opCodeWrapper) toNumber() int {
return int(ocw.op)
}
// toString returns the string representation of the opcode
func (ocw *opCodeWrapper) toString() string {
return ocw.op.String()
}
// isPush returns true if the op is a Push
func (ocw *opCodeWrapper) isPush() bool {
return ocw.op.IsPush()
}
// toValue returns an otto.Value for the opCodeWrapper
func (ocw *opCodeWrapper) toValue(vm *otto.Otto) otto.Value {
value, _ := vm.ToValue(ocw)
obj := value.Object()
obj.Set("toNumber", ocw.toNumber)
obj.Set("toString", ocw.toString)
obj.Set("isPush", ocw.isPush)
return value
}
// memoryWrapper provides a JS wrapper around vm.Memory
type memoryWrapper struct {
memory *vm.Memory
}
// slice returns the requested range of memory as a byte slice
func (mw *memoryWrapper) slice(begin, end int64) []byte {
return mw.memory.Get(begin, end-begin)
}
// getUint returns the 32 bytes at the specified address interpreted
// as an unsigned integer
func (mw *memoryWrapper) getUint(addr int64) *big.Int {
ret := big.NewInt(0)
ret.SetBytes(mw.memory.GetPtr(addr, 32))
return ret
}
// toValue returns an otto.Value for the memoryWrapper
func (mw *memoryWrapper) toValue(vm *otto.Otto) otto.Value {
value, _ := vm.ToValue(mw)
obj := value.Object()
obj.Set("slice", mw.slice)
obj.Set("getUint", mw.getUint)
return value
}
// stackWrapper provides a JS wrapper around vm.Stack
type stackWrapper struct {
stack *vm.Stack
}
// peek returns the nth-from-the-top element of the stack.
func (sw *stackWrapper) peek(idx int) *big.Int {
return sw.stack.Data()[len(sw.stack.Data())-idx-1]
}
// length returns the length of the stack
func (sw *stackWrapper) length() int {
return len(sw.stack.Data())
}
// toValue returns an otto.Value for the stackWrapper
func (sw *stackWrapper) toValue(vm *otto.Otto) otto.Value {
value, _ := vm.ToValue(sw)
obj := value.Object()
obj.Set("peek", sw.peek)
obj.Set("length", sw.length)
return value
}
// dbWrapper provides a JS wrapper around vm.Database
type dbWrapper struct {
db vm.Database
}
// getBalance retrieves an account's balance
func (dw *dbWrapper) getBalance(addr common.Address) *big.Int {
return dw.db.GetBalance(addr)
}
// getNonce retrieves an account's nonce
func (dw *dbWrapper) getNonce(addr common.Address) uint64 {
return dw.db.GetNonce(addr)
}
// getCode retrieves an account's code
func (dw *dbWrapper) getCode(addr common.Address) []byte {
return dw.db.GetCode(addr)
}
// getState retrieves an account's state data for the given hash
func (dw *dbWrapper) getState(addr common.Address, hash common.Hash) common.Hash {
return dw.db.GetState(addr, hash)
}
// exists returns true iff the account exists
func (dw *dbWrapper) exists(addr common.Address) bool {
return dw.db.Exist(addr)
}
// toValue returns an otto.Value for the dbWrapper
func (dw *dbWrapper) toValue(vm *otto.Otto) otto.Value {
value, _ := vm.ToValue(dw)
obj := value.Object()
obj.Set("getBalance", dw.getBalance)
obj.Set("getNonce", dw.getNonce)
obj.Set("getCode", dw.getCode)
obj.Set("getState", dw.getState)
obj.Set("exists", dw.exists)
return value
}
// JavascriptTracer provides an implementation of Tracer that evaluates a
// Javascript function for each VM execution step.
type JavascriptTracer struct {
vm *otto.Otto // Javascript VM instance
traceobj *otto.Object // User-supplied object to call
log map[string]interface{} // (Reusable) map for the `log` arg to `step`
logvalue otto.Value // JS view of `log`
opcode *opCodeWrapper // Wrapper around the opcode
opcodevalue otto.Value // JS view of 'opcode'
memory *memoryWrapper // Wrapper around the VM memory
memvalue otto.Value // JS view of `memory`
stack *stackWrapper // Wrapper around the VM stack
stackvalue otto.Value // JS view of `stack`
db *dbWrapper // Wrapper around the VM environment
dbvalue otto.Value // JS view of `db`
err error // Error, if one has occurred
}
// NewJavascriptTracer instantiates a new JavascriptTracer instance.
// code specifies a Javascript snippet, which must evaluate to an expression
// returning an object with 'step' and 'result' functions.
func NewJavascriptTracer(code string) (*JavascriptTracer, error) {
vm := otto.New()
vm.Interrupt = make(chan func(), 1)
// Set up builtins for this environment
vm.Set("big", &fakeBig{})
jstracer, err := vm.Object("(" + code + ")")
if err != nil {
return nil, err
}
// Check the required functions exist
step, err := jstracer.Get("step")
if err != nil {
return nil, err
}
if !step.IsFunction() {
return nil, fmt.Errorf("Trace object must expose a function step()")
}
result, err := jstracer.Get("result")
if err != nil {
return nil, err
}
if !result.IsFunction() {
return nil, fmt.Errorf("Trace object must expose a function result()")
}
// Create the persistent log object
log := make(map[string]interface{})
logvalue, _ := vm.ToValue(log)
// Create persistent wrappers for memory and stack
opcode := &opCodeWrapper{}
mem := &memoryWrapper{}
stack := &stackWrapper{}
db := &dbWrapper{}
return &JavascriptTracer{
vm: vm,
traceobj: jstracer,
log: log,
logvalue: logvalue,
opcode: opcode,
opcodevalue: opcode.toValue(vm),
memory: mem,
memvalue: mem.toValue(vm),
stack: stack,
stackvalue: stack.toValue(vm),
db: db,
dbvalue: db.toValue(vm),
err: nil,
}, nil
}
// Stop terminates execution of any JavaScript
func (jst *JavascriptTracer) Stop(err error) {
jst.vm.Interrupt <- func() {
panic(err)
}
}
// callSafely executes a method on a JS object, catching any panics and
// returning them as error objects.
func (jst *JavascriptTracer) callSafely(method string, argumentList ...interface{}) (ret interface{}, err error) {
defer func() {
if caught := recover(); caught != nil {
switch caught := caught.(type) {
case error:
err = caught
case string:
err = errors.New(caught)
case fmt.Stringer:
err = errors.New(caught.String())
default:
panic(caught)
}
}
}()
value, err := jst.traceobj.Call(method, argumentList...)
ret, _ = value.Export()
return ret, err
}
// CaptureState implements the Tracer interface to trace a single step of VM execution
func (jst *JavascriptTracer) CaptureState(env vm.Environment, pc uint64, op vm.OpCode, gas, cost *big.Int, memory *vm.Memory, stack *vm.Stack, contract *vm.Contract, depth int, err error) {
if jst.err == nil {
jst.opcode.op = op
jst.memory.memory = memory
jst.stack.stack = stack
jst.db.db = env.Db()
jst.log["pc"] = pc
jst.log["op"] = jst.opcodevalue
jst.log["gas"] = gas.Int64()
jst.log["gasPrice"] = cost.Int64()
jst.log["memory"] = jst.memvalue
jst.log["stack"] = jst.stackvalue
jst.log["depth"] = depth
jst.log["account"] = contract.Address()
jst.log["err"] = err
_, err := jst.callSafely("step", jst.logvalue, jst.dbvalue)
if err != nil {
jst.err = err
}
}
}
// GetResult calls the Javascript 'result' function and returns its value, or any accumulated error
func (jst *JavascriptTracer) GetResult() (result interface{}, err error) {
if jst.err != nil {
return nil, jst.err
}
return jst.callSafely("result")
}

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@ -0,0 +1,186 @@
// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package ethapi
import (
"errors"
"math/big"
"testing"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/crypto"
)
type ruleSet struct{}
func (self *ruleSet) IsHomestead(*big.Int) bool { return true }
type Env struct {
gasLimit *big.Int
depth int
evm *vm.EVM
}
func NewEnv(config *vm.Config) *Env {
env := &Env{gasLimit: big.NewInt(10000), depth: 0}
env.evm = vm.New(env, *config)
return env
}
func (self *Env) RuleSet() vm.RuleSet { return &ruleSet{} }
func (self *Env) Vm() vm.Vm { return self.evm }
func (self *Env) Origin() common.Address { return common.Address{} }
func (self *Env) BlockNumber() *big.Int { return big.NewInt(0) }
//func (self *Env) PrevHash() []byte { return self.parent }
func (self *Env) Coinbase() common.Address { return common.Address{} }
func (self *Env) MakeSnapshot() vm.Database { return nil }
func (self *Env) SetSnapshot(vm.Database) {}
func (self *Env) Time() *big.Int { return big.NewInt(time.Now().Unix()) }
func (self *Env) Difficulty() *big.Int { return big.NewInt(0) }
func (self *Env) Db() vm.Database { return nil }
func (self *Env) GasLimit() *big.Int { return self.gasLimit }
func (self *Env) VmType() vm.Type { return vm.StdVmTy }
func (self *Env) GetHash(n uint64) common.Hash {
return common.BytesToHash(crypto.Keccak256([]byte(big.NewInt(int64(n)).String())))
}
func (self *Env) AddLog(log *vm.Log) {
}
func (self *Env) Depth() int { return self.depth }
func (self *Env) SetDepth(i int) { self.depth = i }
func (self *Env) CanTransfer(from common.Address, balance *big.Int) bool {
return true
}
func (self *Env) Transfer(from, to vm.Account, amount *big.Int) {}
func (self *Env) Call(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
return nil, nil
}
func (self *Env) CallCode(caller vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
return nil, nil
}
func (self *Env) Create(caller vm.ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error) {
return nil, common.Address{}, nil
}
func (self *Env) DelegateCall(me vm.ContractRef, addr common.Address, data []byte, gas, price *big.Int) ([]byte, error) {
return nil, nil
}
type account struct{}
func (account) SubBalance(amount *big.Int) {}
func (account) AddBalance(amount *big.Int) {}
func (account) SetAddress(common.Address) {}
func (account) Value() *big.Int { return nil }
func (account) SetBalance(*big.Int) {}
func (account) SetNonce(uint64) {}
func (account) Balance() *big.Int { return nil }
func (account) Address() common.Address { return common.Address{} }
func (account) ReturnGas(*big.Int, *big.Int) {}
func (account) SetCode([]byte) {}
func (account) ForEachStorage(cb func(key, value common.Hash) bool) {}
func runTrace(tracer *JavascriptTracer) (interface{}, error) {
env := NewEnv(&vm.Config{Debug: true, Tracer: tracer})
contract := vm.NewContract(account{}, account{}, big.NewInt(0), env.GasLimit(), big.NewInt(1))
contract.Code = []byte{byte(vm.PUSH1), 0x1, byte(vm.PUSH1), 0x1, 0x0}
_, err := env.Vm().Run(contract, []byte{})
if err != nil {
return nil, err
}
return tracer.GetResult()
}
func TestTracing(t *testing.T) {
tracer, err := NewJavascriptTracer("{count: 0, step: function() { this.count += 1; }, result: function() { return this.count; }}")
if err != nil {
t.Fatal(err)
}
ret, err := runTrace(tracer)
if err != nil {
t.Fatal(err)
}
value, ok := ret.(float64)
if !ok {
t.Errorf("Expected return value to be float64, was %T", ret)
}
if value != 3 {
t.Errorf("Expected return value to be 3, got %v", value)
}
}
func TestStack(t *testing.T) {
tracer, err := NewJavascriptTracer("{depths: [], step: function(log) { this.depths.push(log.stack.length()); }, result: function() { return this.depths; }}")
if err != nil {
t.Fatal(err)
}
ret, err := runTrace(tracer)
if err != nil {
t.Fatal(err)
}
value, ok := ret.([]int)
if !ok {
t.Errorf("Expected return value to be []int, was %T", ret)
}
if len(value) != 3 || value[0] != 0 || value[1] != 1 || value[2] != 2 {
t.Errorf("Expected return value to be [0 1 2], got %v", value)
}
}
func TestHalt(t *testing.T) {
timeout := errors.New("stahp")
tracer, err := NewJavascriptTracer("{step: function() { while(1); }, result: function() { return null; }}")
if err != nil {
t.Fatal(err)
}
go func() {
time.Sleep(1 * time.Second)
tracer.Stop(timeout)
}()
if _, err = runTrace(tracer); err != timeout {
t.Errorf("Expected timeout error, got %v", err)
}
}
func TestHaltBetweenSteps(t *testing.T) {
tracer, err := NewJavascriptTracer("{step: function() {}, result: function() { return null; }}")
if err != nil {
t.Fatal(err)
}
env := NewEnv(&vm.Config{Debug: true, Tracer: tracer})
contract := vm.NewContract(&account{}, &account{}, big.NewInt(0), big.NewInt(0), big.NewInt(0))
tracer.CaptureState(env, 0, 0, big.NewInt(0), big.NewInt(0), nil, nil, contract, 0, nil)
timeout := errors.New("stahp")
tracer.Stop(timeout)
tracer.CaptureState(env, 0, 0, big.NewInt(0), big.NewInt(0), nil, nil, contract, 0, nil)
if _, err := tracer.GetResult(); err != timeout {
t.Errorf("Expected timeout error, got %v", err)
}
}

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@ -284,7 +284,8 @@ web3._extend({
new web3._extend.Method({
name: 'traceTransaction',
call: 'debug_traceTransaction',
params: 1
params: 2,
inputFormatter: [null, null]
})
],
properties: []