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

1 files changed, 186 insertions, 0 deletions

diff --git a/internal/ethapi/tracer_test.go b/internal/ethapi/tracer_test.go
new file mode 100644
index 000000000..2f1dfa0be
--- /dev/null
+++ b/internal/ethapi/tracer_test.go
@@ -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)
+	}
+}