neoneo-go/pkg/vm/stack_item.go
Evgenii Stratonikov dfc59129c7 vm: implement EQUAL opcode properly
When comparing elements of different types, conversions
should be performed. This commit implement custom equality
predicate for each stack item type.
2020-03-11 17:19:10 +03:00

584 lines
13 KiB
Go

package vm
import (
"bytes"
"encoding/binary"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"math/big"
"reflect"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/vm/emit"
)
// A StackItem represents the "real" value that is pushed on the stack.
type StackItem interface {
fmt.Stringer
Value() interface{}
// Dup duplicates current StackItem.
Dup() StackItem
// TryBytes converts StackItem to a byte slice.
TryBytes() ([]byte, error)
// Equals checks if 2 StackItems are equal.
Equals(s StackItem) bool
// ToContractParameter converts StackItem to smartcontract.Parameter
ToContractParameter(map[StackItem]bool) smartcontract.Parameter
}
func makeStackItem(v interface{}) StackItem {
switch val := v.(type) {
case int:
return &BigIntegerItem{
value: big.NewInt(int64(val)),
}
case int64:
return &BigIntegerItem{
value: big.NewInt(val),
}
case uint8:
return &BigIntegerItem{
value: big.NewInt(int64(val)),
}
case uint16:
return &BigIntegerItem{
value: big.NewInt(int64(val)),
}
case uint32:
return &BigIntegerItem{
value: big.NewInt(int64(val)),
}
case uint64:
b := make([]byte, 8)
binary.BigEndian.PutUint64(b, val)
bigInt := big.NewInt(0)
bigInt.SetBytes(b)
return &BigIntegerItem{
value: bigInt,
}
case []byte:
return &ByteArrayItem{
value: val,
}
case string:
return &ByteArrayItem{
value: []byte(val),
}
case bool:
return &BoolItem{
value: val,
}
case []StackItem:
return &ArrayItem{
value: val,
}
case *big.Int:
return &BigIntegerItem{
value: val,
}
case StackItem:
return val
case []int:
var a []StackItem
for _, i := range val {
a = append(a, makeStackItem(i))
}
return makeStackItem(a)
default:
panic(
fmt.Sprintf(
"invalid stack item type: %v (%v)",
val,
reflect.TypeOf(val),
),
)
}
}
// StructItem represents a struct on the stack.
type StructItem struct {
value []StackItem
}
// NewStructItem returns an new StructItem object.
func NewStructItem(items []StackItem) *StructItem {
return &StructItem{
value: items,
}
}
// Value implements StackItem interface.
func (i *StructItem) Value() interface{} {
return i.value
}
func (i *StructItem) String() string {
return "Struct"
}
// Dup implements StackItem interface.
func (i *StructItem) Dup() StackItem {
// it's a reference type, so no copying here.
return i
}
// TryBytes implements StackItem interface.
func (i *StructItem) TryBytes() ([]byte, error) {
return nil, errors.New("can't convert Struct to ByteArray")
}
// Equals implements StackItem interface.
func (i *StructItem) Equals(s StackItem) bool {
if i == s {
return true
} else if s == nil {
return false
}
val, ok := s.(*StructItem)
if !ok || len(i.value) != len(val.value) {
return false
}
for j := range i.value {
if !i.value[j].Equals(val.value[j]) {
return false
}
}
return true
}
// ToContractParameter implements StackItem interface.
func (i *StructItem) ToContractParameter(seen map[StackItem]bool) smartcontract.Parameter {
var value []smartcontract.Parameter
if !seen[i] {
seen[i] = true
for _, stackItem := range i.value {
parameter := stackItem.ToContractParameter(seen)
value = append(value, parameter)
}
}
return smartcontract.Parameter{
Type: smartcontract.ArrayType,
Value: value,
}
}
// Clone returns a Struct with all Struct fields copied by value.
// Array fields are still copied by reference.
func (i *StructItem) Clone() *StructItem {
ret := &StructItem{make([]StackItem, len(i.value))}
for j := range i.value {
switch t := i.value[j].(type) {
case *StructItem:
ret.value[j] = t.Clone()
default:
ret.value[j] = t
}
}
return ret
}
// BigIntegerItem represents a big integer on the stack.
type BigIntegerItem struct {
value *big.Int
}
// NewBigIntegerItem returns an new BigIntegerItem object.
func NewBigIntegerItem(value int) *BigIntegerItem {
return &BigIntegerItem{
value: big.NewInt(int64(value)),
}
}
// Bytes converts i to a slice of bytes.
func (i *BigIntegerItem) Bytes() []byte {
return emit.IntToBytes(i.value)
}
// TryBytes implements StackItem interface.
func (i *BigIntegerItem) TryBytes() ([]byte, error) {
return i.Bytes(), nil
}
// Equals implements StackItem interface.
func (i *BigIntegerItem) Equals(s StackItem) bool {
if i == s {
return true
} else if s == nil {
return false
}
val, ok := s.(*BigIntegerItem)
if ok {
return i.value.Cmp(val.value) == 0
}
bs, err := s.TryBytes()
return err == nil && bytes.Equal(i.Bytes(), bs)
}
// Value implements StackItem interface.
func (i *BigIntegerItem) Value() interface{} {
return i.value
}
func (i *BigIntegerItem) String() string {
return "BigInteger"
}
// Dup implements StackItem interface.
func (i *BigIntegerItem) Dup() StackItem {
n := new(big.Int)
return &BigIntegerItem{n.Set(i.value)}
}
// ToContractParameter implements StackItem interface.
func (i *BigIntegerItem) ToContractParameter(map[StackItem]bool) smartcontract.Parameter {
return smartcontract.Parameter{
Type: smartcontract.IntegerType,
Value: i.value.Int64(),
}
}
// MarshalJSON implements the json.Marshaler interface.
func (i *BigIntegerItem) MarshalJSON() ([]byte, error) {
return json.Marshal(i.value)
}
// BoolItem represents a boolean StackItem.
type BoolItem struct {
value bool
}
// NewBoolItem returns an new BoolItem object.
func NewBoolItem(val bool) *BoolItem {
return &BoolItem{
value: val,
}
}
// Value implements StackItem interface.
func (i *BoolItem) Value() interface{} {
return i.value
}
// MarshalJSON implements the json.Marshaler interface.
func (i *BoolItem) MarshalJSON() ([]byte, error) {
return json.Marshal(i.value)
}
func (i *BoolItem) String() string {
return "Boolean"
}
// Dup implements StackItem interface.
func (i *BoolItem) Dup() StackItem {
return &BoolItem{i.value}
}
// Bytes converts BoolItem to bytes.
func (i *BoolItem) Bytes() []byte {
if i.value {
return []byte{1}
}
// return []byte{0}
// FIXME revert when NEO 3.0 https://github.com/nspcc-dev/neo-go/issues/477
return []byte{}
}
// TryBytes implements StackItem interface.
func (i *BoolItem) TryBytes() ([]byte, error) {
return i.Bytes(), nil
}
// Equals implements StackItem interface.
func (i *BoolItem) Equals(s StackItem) bool {
if i == s {
return true
} else if s == nil {
return false
}
val, ok := s.(*BoolItem)
if ok {
return i.value == val.value
}
bs, err := s.TryBytes()
return err == nil && bytes.Equal(i.Bytes(), bs)
}
// ToContractParameter implements StackItem interface.
func (i *BoolItem) ToContractParameter(map[StackItem]bool) smartcontract.Parameter {
return smartcontract.Parameter{
Type: smartcontract.BoolType,
Value: i.value,
}
}
// ByteArrayItem represents a byte array on the stack.
type ByteArrayItem struct {
value []byte
}
// NewByteArrayItem returns an new ByteArrayItem object.
func NewByteArrayItem(b []byte) *ByteArrayItem {
return &ByteArrayItem{
value: b,
}
}
// Value implements StackItem interface.
func (i *ByteArrayItem) Value() interface{} {
return i.value
}
// MarshalJSON implements the json.Marshaler interface.
func (i *ByteArrayItem) MarshalJSON() ([]byte, error) {
return json.Marshal(hex.EncodeToString(i.value))
}
func (i *ByteArrayItem) String() string {
return "ByteArray"
}
// TryBytes implements StackItem interface.
func (i *ByteArrayItem) TryBytes() ([]byte, error) {
return i.value, nil
}
// Equals implements StackItem interface.
func (i *ByteArrayItem) Equals(s StackItem) bool {
if i == s {
return true
} else if s == nil {
return false
}
bs, err := s.TryBytes()
return err == nil && bytes.Equal(i.value, bs)
}
// Dup implements StackItem interface.
func (i *ByteArrayItem) Dup() StackItem {
a := make([]byte, len(i.value))
copy(a, i.value)
return &ByteArrayItem{a}
}
// ToContractParameter implements StackItem interface.
func (i *ByteArrayItem) ToContractParameter(map[StackItem]bool) smartcontract.Parameter {
return smartcontract.Parameter{
Type: smartcontract.ByteArrayType,
Value: i.value,
}
}
// ArrayItem represents a new ArrayItem object.
type ArrayItem struct {
value []StackItem
}
// NewArrayItem returns a new ArrayItem object.
func NewArrayItem(items []StackItem) *ArrayItem {
return &ArrayItem{
value: items,
}
}
// Value implements StackItem interface.
func (i *ArrayItem) Value() interface{} {
return i.value
}
// MarshalJSON implements the json.Marshaler interface.
func (i *ArrayItem) MarshalJSON() ([]byte, error) {
return json.Marshal(i.value)
}
func (i *ArrayItem) String() string {
return "Array"
}
// TryBytes implements StackItem interface.
func (i *ArrayItem) TryBytes() ([]byte, error) {
return nil, errors.New("can't convert Array to ByteArray")
}
// Equals implements StackItem interface.
func (i *ArrayItem) Equals(s StackItem) bool {
return i == s
}
// Dup implements StackItem interface.
func (i *ArrayItem) Dup() StackItem {
// reference type
return i
}
// ToContractParameter implements StackItem interface.
func (i *ArrayItem) ToContractParameter(seen map[StackItem]bool) smartcontract.Parameter {
var value []smartcontract.Parameter
if !seen[i] {
seen[i] = true
for _, stackItem := range i.value {
parameter := stackItem.ToContractParameter(seen)
value = append(value, parameter)
}
}
return smartcontract.Parameter{
Type: smartcontract.ArrayType,
Value: value,
}
}
// MapItem represents Map object.
type MapItem struct {
value map[interface{}]StackItem
}
// NewMapItem returns new MapItem object.
func NewMapItem() *MapItem {
return &MapItem{
value: make(map[interface{}]StackItem),
}
}
// Value implements StackItem interface.
func (i *MapItem) Value() interface{} {
return i.value
}
// TryBytes implements StackItem interface.
func (i *MapItem) TryBytes() ([]byte, error) {
return nil, errors.New("can't convert Map to ByteArray")
}
// Equals implements StackItem interface.
func (i *MapItem) Equals(s StackItem) bool {
return i == s
}
func (i *MapItem) String() string {
return "Map"
}
// Has checks if map has specified key.
func (i *MapItem) Has(key StackItem) (ok bool) {
_, ok = i.value[toMapKey(key)]
return
}
// Dup implements StackItem interface.
func (i *MapItem) Dup() StackItem {
// reference type
return i
}
// ToContractParameter implements StackItem interface.
func (i *MapItem) ToContractParameter(seen map[StackItem]bool) smartcontract.Parameter {
value := make(map[smartcontract.Parameter]smartcontract.Parameter)
if !seen[i] {
seen[i] = true
for key, val := range i.value {
pValue := val.ToContractParameter(seen)
pKey := fromMapKey(key).ToContractParameter(seen)
if pKey.Type == smartcontract.ByteArrayType {
pKey.Value = string(pKey.Value.([]byte))
}
value[pKey] = pValue
}
}
return smartcontract.Parameter{
Type: smartcontract.MapType,
Value: value,
}
}
// Add adds key-value pair to the map.
func (i *MapItem) Add(key, value StackItem) {
i.value[toMapKey(key)] = value
}
// toMapKey converts StackItem so that it can be used as a map key.
func toMapKey(key StackItem) interface{} {
switch t := key.(type) {
case *BoolItem:
return t.value
case *BigIntegerItem:
return t.value.Int64()
case *ByteArrayItem:
return string(t.value)
default:
panic("wrong key type")
}
}
// fromMapKey converts map key to StackItem
func fromMapKey(key interface{}) StackItem {
switch t := key.(type) {
case bool:
return &BoolItem{value: t}
case int64:
return &BigIntegerItem{value: big.NewInt(t)}
case string:
return &ByteArrayItem{value: []byte(t)}
default:
panic("wrong key type")
}
}
// InteropItem represents interop data on the stack.
type InteropItem struct {
value interface{}
}
// NewInteropItem returns new InteropItem object.
func NewInteropItem(value interface{}) *InteropItem {
return &InteropItem{
value: value,
}
}
// Value implements StackItem interface.
func (i *InteropItem) Value() interface{} {
return i.value
}
// String implements stringer interface.
func (i *InteropItem) String() string {
return "InteropItem"
}
// Dup implements StackItem interface.
func (i *InteropItem) Dup() StackItem {
// reference type
return i
}
// TryBytes implements StackItem interface.
func (i *InteropItem) TryBytes() ([]byte, error) {
return nil, errors.New("can't convert Interop to ByteArray")
}
// Equals implements StackItem interface.
func (i *InteropItem) Equals(s StackItem) bool {
if i == s {
return true
} else if s == nil {
return false
}
val, ok := s.(*InteropItem)
return ok && i.value == val.value
}
// ToContractParameter implements StackItem interface.
func (i *InteropItem) ToContractParameter(map[StackItem]bool) smartcontract.Parameter {
return smartcontract.Parameter{
Type: smartcontract.InteropInterfaceType,
Value: nil,
}
}
// MarshalJSON implements the json.Marshaler interface.
func (i *InteropItem) MarshalJSON() ([]byte, error) {
return json.Marshal(i.value)
}