package vm import ( "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) // 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") } // 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 } // 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 } // 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 } // 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") } // 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") } 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") } // 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) }