Implemented following opcodes:

1) XSWAP
2) XTUCK
3) DEPTH
4) DROP
This commit is contained in:
DauTT 2019-04-12 00:38:57 +02:00
parent 045db09af2
commit aa67e98726
4 changed files with 264 additions and 0 deletions

View file

@ -127,6 +127,21 @@ func (ras *RandomAccess) CopyTo(stack *RandomAccess) error {
return nil return nil
} }
// Set sets the n-item from the stack
// starting from the top of the stack with the new item.
// the n-item to replace is located at the position "len(stack)-index-1".
func (ras *RandomAccess) Set(index uint16, item Item) error {
stackSize := uint16(len(ras.vals))
if ok := index >= stackSize; ok {
return errors.New("index out of range")
}
n := stackSize - index - 1
ras.vals[n] = item
return nil
}
// Convenience Functions // Convenience Functions
// PopInt will remove the last stack item that was added // PopInt will remove the last stack item that was added

View file

@ -5,6 +5,10 @@ import "github.com/CityOfZion/neo-go/pkg/vm/stack"
type stackInfo func(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) type stackInfo func(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error)
var opFunc = map[stack.Instruction]stackInfo{ var opFunc = map[stack.Instruction]stackInfo{
stack.DROP: DROP,
stack.DEPTH: DEPTH,
stack.XTUCK: XTUCK,
stack.XSWAP: XSWAP,
stack.NUMEQUAL: NumEqual, stack.NUMEQUAL: NumEqual,
stack.NUMNOTEQUAL: NumNotEqual, stack.NUMNOTEQUAL: NumNotEqual,
stack.BOOLAND: BoolAnd, stack.BOOLAND: BoolAnd,

View file

@ -1,6 +1,8 @@
package vm package vm
import ( import (
"math/big"
"github.com/CityOfZion/neo-go/pkg/vm/stack" "github.com/CityOfZion/neo-go/pkg/vm/stack"
) )
@ -17,3 +19,84 @@ func PushNBytes(op stack.Instruction, ctx *stack.Context, istack *stack.Invocati
ctx.Estack.Push(ba) ctx.Estack.Push(ba)
return NONE, nil return NONE, nil
} }
// XSWAP pops an integer n off of the stack and
// swaps the n-item from the stack starting from
// the top of the stack with the top stack item.
func XSWAP(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
n, err := ctx.Estack.PopInt()
if err != nil {
return FAULT, err
}
nItem, err := ctx.Estack.Peek(uint16(n.Value().Int64()))
if err != nil {
return FAULT, err
}
item, err := ctx.Estack.Peek(0)
if err != nil {
return FAULT, err
}
if err := ctx.Estack.Set(uint16(n.Value().Int64()), item); err != nil {
return FAULT, err
}
if err := ctx.Estack.Set(0, nItem); err != nil {
return FAULT, err
}
return NONE, nil
}
// XTUCK pops an integer n off of the stack and
// inserts the top stack item to the position len(stack)-n in the evaluation stack.
func XTUCK(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
n, err := ctx.Estack.PopInt()
if err != nil || n.Value().Int64() < 0 {
return FAULT, err
}
item, err := ctx.Estack.Peek(0)
if err != nil {
return FAULT, err
}
ras, err := ctx.Estack.Insert(uint16(n.Value().Int64()), item)
if err != nil {
return FAULT, err
}
ctx.Estack = *ras
return NONE, nil
}
// DEPTH puts the number of stack items onto the stack.
func DEPTH(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
l := ctx.Estack.Len()
length, err := stack.NewInt(big.NewInt(int64(l)))
if err != nil {
return FAULT, err
}
ctx.Estack.Push(length)
return NONE, nil
}
// DROP removes the the top stack item.
// Returns error if the operation Pop cannot
// be performed.
func DROP(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
_, err := ctx.Estack.Pop()
if err != nil {
return FAULT, err
}
return NONE, nil
}

View file

@ -0,0 +1,162 @@
package vm
import (
"math/big"
"testing"
"github.com/CityOfZion/neo-go/pkg/vm/stack"
"github.com/stretchr/testify/assert"
)
func TestXswapOp(t *testing.T) {
v := VM{}
a, err := stack.NewInt(big.NewInt(3))
assert.Nil(t, err)
b, err := stack.NewInt(big.NewInt(6))
assert.Nil(t, err)
c, err := stack.NewInt(big.NewInt(9))
assert.Nil(t, err)
d, err := stack.NewInt(big.NewInt(2))
assert.Nil(t, err)
ctx := stack.NewContext([]byte{})
ctx.Estack.Push(a).Push(b).Push(c).Push(d)
// pop n (= d = 2) from the stack.
// we will swap the n-item which
// is located in position len(stack)-n-1 (= 3-2-1= 0)
// with the top stack item.
// The final stack will be [c,b,a]
v.executeOp(stack.XSWAP, ctx)
// Stack should have three items
assert.Equal(t, 3, ctx.Estack.Len())
itemA, err := ctx.Estack.PopInt()
assert.Nil(t, err)
itemB, err := ctx.Estack.PopInt()
assert.Nil(t, err)
itemC, err := ctx.Estack.PopInt()
assert.Nil(t, err)
assert.Equal(t, int64(3), itemA.Value().Int64())
assert.Equal(t, int64(6), itemB.Value().Int64())
assert.Equal(t, int64(9), itemC.Value().Int64())
}
func TestXTuckOp(t *testing.T) {
v := VM{}
a, err := stack.NewInt(big.NewInt(3))
assert.Nil(t, err)
b, err := stack.NewInt(big.NewInt(6))
assert.Nil(t, err)
c, err := stack.NewInt(big.NewInt(9))
assert.Nil(t, err)
d, err := stack.NewInt(big.NewInt(2))
assert.Nil(t, err)
ctx := stack.NewContext([]byte{})
ctx.Estack.Push(a).Push(b).Push(c).Push(d)
// pop n (= d = 2) from the stack
// and insert the top stack item c
// to the position len(stack)-n (= 3-2 = 1)
// of the stack.The final stack will be [a,c,b,c]
v.executeOp(stack.XTUCK, ctx)
// Stack should have four items
assert.Equal(t, 4, ctx.Estack.Len())
// c
item0, err := ctx.Estack.PopInt()
assert.Nil(t, err)
// b
item1, err := ctx.Estack.PopInt()
assert.Nil(t, err)
// c
item2, err := ctx.Estack.PopInt()
assert.Nil(t, err)
// a
item3, err := ctx.Estack.PopInt()
assert.Nil(t, err)
assert.Equal(t, int64(9), item0.Value().Int64())
assert.Equal(t, int64(6), item1.Value().Int64())
assert.Equal(t, int64(9), item2.Value().Int64())
assert.Equal(t, int64(3), item3.Value().Int64())
}
func TestXDepthOp(t *testing.T) {
v := VM{}
a, err := stack.NewInt(big.NewInt(3))
assert.Nil(t, err)
b, err := stack.NewInt(big.NewInt(6))
assert.Nil(t, err)
ctx := stack.NewContext([]byte{})
ctx.Estack.Push(a).Push(b)
// push integer whose value is len(stack) (2)
// on top of the stack
v.executeOp(stack.DEPTH, ctx)
// Stack should have three items
assert.Equal(t, 3, ctx.Estack.Len())
// len(stack)
item0, err := ctx.Estack.PopInt()
assert.Nil(t, err)
// b
item1, err := ctx.Estack.PopInt()
assert.Nil(t, err)
// a
item2, err := ctx.Estack.PopInt()
assert.Nil(t, err)
assert.Equal(t, int64(2), item0.Value().Int64())
assert.Equal(t, int64(6), item1.Value().Int64())
assert.Equal(t, int64(3), item2.Value().Int64())
}
func TestXDropOp(t *testing.T) {
v := VM{}
a, err := stack.NewInt(big.NewInt(3))
assert.Nil(t, err)
b, err := stack.NewInt(big.NewInt(6))
assert.Nil(t, err)
ctx := stack.NewContext([]byte{})
ctx.Estack.Push(a).Push(b)
// Remove the top stack item from the stack.
// The remaining stack is [a]
v.executeOp(stack.DROP, ctx)
// Stack should have 2 items
assert.Equal(t, 1, ctx.Estack.Len())
itemA, err := ctx.Estack.PopInt()
assert.Nil(t, err)
assert.Equal(t, int64(3), itemA.Value().Int64())
}