Merge pull request #382 from nspcc-dev/feature/implicit-stackitem-conversion

VM: implement stack item conversion

Fixes #372.

Also added tests for NOT and SIGN to check new behavior.
Also fixed a bug with Bool casting: it should be != 0 instead of == 1.

pkg/vm/stack.go

@@ -63,6 +63,11 @@ func (e *Element) BigInt() *big.Int {
 	switch t := e.value.(type) {
 	case *BigIntegerItem:
 		return t.value
+	case *BoolItem:
+		if t.value {
+			return big.NewInt(1)
+		}
+		return big.NewInt(0)
 	default:
 		b := t.Value().([]uint8)
 		return new(big.Int).SetBytes(util.ArrayReverse(b))
@@ -72,16 +77,41 @@ func (e *Element) BigInt() *big.Int {
 // Bool attempts to get the underlying value of the element as a boolean.
 // Will panic if the assertion failed which will be caught by the VM.
 func (e *Element) Bool() bool {
-	if v, ok := e.value.Value().(*big.Int); ok {
-		return v.Int64() == 1
+	switch t := e.value.(type) {
+	case *BigIntegerItem:
+		return t.value.Int64() != 0
+	case *BoolItem:
+		return t.value
+	case *ArrayItem, *StructItem:
+		return true
+	case *ByteArrayItem:
+		for _, b := range t.value {
+			if b != 0 {
+				return true
+			}
+		}
+		return false
+	default:
+		panic("can't convert to bool: " + t.String())
 	}
-	return e.value.Value().(bool)
 }
 
 // Bytes attempts to get the underlying value of the element as a byte array.
 // Will panic if the assertion failed which will be caught by the VM.
 func (e *Element) Bytes() []byte {
-	return e.value.Value().([]byte)
+	switch t := e.value.(type) {
+	case *ByteArrayItem:
+		return t.value
+	case *BigIntegerItem:
+		return util.ArrayReverse(t.value.Bytes()) // neoVM returns in LE
+	case *BoolItem:
+		if t.value {
+			return []byte{1}
+		}
+		return []byte{0}
+	default:
+		panic("can't convert to []byte: " + t.String())
+	}
 }
 
 // Array attempts to get the underlying value of the element as an array of

pkg/vm/vm_test.go

@@ -111,6 +111,67 @@ func TestPushData4(t *testing.T) {
 
 }
 
+func TestNOTNoArgument(t *testing.T) {
+	prog := makeProgram(NOT)
+	vm := load(prog)
+	vm.Run()
+	assert.Equal(t, true, vm.state.HasFlag(faultState))
+}
+
+func TestNOTBool(t *testing.T) {
+	prog := makeProgram(NOT)
+	vm := load(prog)
+	vm.estack.PushVal(false)
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, &BoolItem{true}, vm.estack.Pop().value)
+}
+
+func TestNOTNonZeroInt(t *testing.T) {
+	prog := makeProgram(NOT)
+	vm := load(prog)
+	vm.estack.PushVal(3)
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, &BoolItem{false}, vm.estack.Pop().value)
+}
+
+func TestNOTArray(t *testing.T) {
+	prog := makeProgram(NOT)
+	vm := load(prog)
+	vm.estack.PushVal([]StackItem{})
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, &BoolItem{false}, vm.estack.Pop().value)
+}
+
+func TestNOTStruct(t *testing.T) {
+	prog := makeProgram(NOT)
+	vm := load(prog)
+	vm.estack.Push(NewElement(&StructItem{[]StackItem{}}))
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, &BoolItem{false}, vm.estack.Pop().value)
+}
+
+func TestNOTByteArray0(t *testing.T) {
+	prog := makeProgram(NOT)
+	vm := load(prog)
+	vm.estack.PushVal([]byte{0, 0})
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, &BoolItem{true}, vm.estack.Pop().value)
+}
+
+func TestNOTByteArray1(t *testing.T) {
+	prog := makeProgram(NOT)
+	vm := load(prog)
+	vm.estack.PushVal([]byte{0, 1})
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, &BoolItem{false}, vm.estack.Pop().value)
+}
+
 func TestAdd(t *testing.T) {
 	prog := makeProgram(ADD)
 	vm := load(prog)
@@ -312,6 +373,71 @@ func TestNEWSTRUCTWrongType(t *testing.T) {
 	assert.Equal(t, true, vm.state.HasFlag(faultState))
 }
 
+func TestSIGNNoArgument(t *testing.T) {
+	prog := makeProgram(SIGN)
+	vm := load(prog)
+	vm.Run()
+	assert.Equal(t, true, vm.state.HasFlag(faultState))
+}
+
+func TestSIGNWrongType(t *testing.T) {
+	prog := makeProgram(SIGN)
+	vm := load(prog)
+	vm.estack.PushVal([]StackItem{})
+	vm.Run()
+	assert.Equal(t, true, vm.state.HasFlag(faultState))
+}
+
+func TestSIGNBool(t *testing.T) {
+	prog := makeProgram(SIGN)
+	vm := load(prog)
+	vm.estack.PushVal(false)
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, 1, vm.estack.Len())
+	assert.Equal(t, &BigIntegerItem{big.NewInt(0)}, vm.estack.Pop().value)
+}
+
+func TestSIGNPositiveInt(t *testing.T) {
+	prog := makeProgram(SIGN)
+	vm := load(prog)
+	vm.estack.PushVal(1)
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, 1, vm.estack.Len())
+	assert.Equal(t, &BigIntegerItem{big.NewInt(1)}, vm.estack.Pop().value)
+}
+
+func TestSIGNNegativeInt(t *testing.T) {
+	prog := makeProgram(SIGN)
+	vm := load(prog)
+	vm.estack.PushVal(-1)
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, 1, vm.estack.Len())
+	assert.Equal(t, &BigIntegerItem{big.NewInt(-1)}, vm.estack.Pop().value)
+}
+
+func TestSIGNZero(t *testing.T) {
+	prog := makeProgram(SIGN)
+	vm := load(prog)
+	vm.estack.PushVal(0)
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, 1, vm.estack.Len())
+	assert.Equal(t, &BigIntegerItem{big.NewInt(0)}, vm.estack.Pop().value)
+}
+
+func TestSIGNByteArray(t *testing.T) {
+	prog := makeProgram(SIGN)
+	vm := load(prog)
+	vm.estack.PushVal([]byte{0, 1})
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, 1, vm.estack.Len())
+	assert.Equal(t, &BigIntegerItem{big.NewInt(1)}, vm.estack.Pop().value)
+}
+
 func TestAppCall(t *testing.T) {
 	prog := []byte{byte(APPCALL)}
 	hash := util.Uint160{}
@@ -603,6 +729,28 @@ func TestCATGood(t *testing.T) {
 	assert.Equal(t, []byte("abcdef"), vm.estack.Peek(0).Bytes())
 }
 
+func TestCATInt0ByteArray(t *testing.T) {
+	prog := makeProgram(CAT)
+	vm := load(prog)
+	vm.estack.PushVal(0)
+	vm.estack.PushVal([]byte{})
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, 1, vm.estack.Len())
+	assert.Equal(t, &ByteArrayItem{[]byte{}}, vm.estack.Pop().value)
+}
+
+func TestCATByteArrayInt1(t *testing.T) {
+	prog := makeProgram(CAT)
+	vm := load(prog)
+	vm.estack.PushVal([]byte{})
+	vm.estack.PushVal(1)
+	vm.Run()
+	assert.Equal(t, false, vm.state.HasFlag(faultState))
+	assert.Equal(t, 1, vm.estack.Len())
+	assert.Equal(t, &ByteArrayItem{[]byte{1}}, vm.estack.Pop().value)
+}
+
 func TestSUBSTRBadNoArgs(t *testing.T) {
 	prog := makeProgram(SUBSTR)
 	vm := load(prog)