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-rw-r--r--internal/ethapi/tracer.go300
1 files changed, 300 insertions, 0 deletions
diff --git a/internal/ethapi/tracer.go b/internal/ethapi/tracer.go
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+++ b/internal/ethapi/tracer.go
@@ -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")
+}
generated by cgit (git 2.34.1) at 2024-10-12 08:28:36 +0800