89 lines
2.2 KiB
Go
89 lines
2.2 KiB
Go
// Copyright 2014 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 vm
|
|
|
|
import (
|
|
"fmt"
|
|
"math/big"
|
|
)
|
|
|
|
// stack is an object for basic stack operations. Items popped to the stack are
|
|
// expected to be changed and modified. stack does not take care of adding newly
|
|
// initialised objects.
|
|
type stack struct {
|
|
data []*big.Int
|
|
}
|
|
|
|
func newstack() *stack {
|
|
return &stack{}
|
|
}
|
|
|
|
func (st *stack) Data() []*big.Int {
|
|
return st.data
|
|
}
|
|
|
|
func (st *stack) push(d *big.Int) {
|
|
// NOTE push limit (1024) is checked in baseCheck
|
|
//stackItem := new(big.Int).Set(d)
|
|
//st.data = append(st.data, stackItem)
|
|
st.data = append(st.data, d)
|
|
}
|
|
func (st *stack) pushN(ds ...*big.Int) {
|
|
st.data = append(st.data, ds...)
|
|
}
|
|
|
|
func (st *stack) pop() (ret *big.Int) {
|
|
ret = st.data[len(st.data)-1]
|
|
st.data = st.data[:len(st.data)-1]
|
|
return
|
|
}
|
|
|
|
func (st *stack) len() int {
|
|
return len(st.data)
|
|
}
|
|
|
|
func (st *stack) swap(n int) {
|
|
st.data[st.len()-n], st.data[st.len()-1] = st.data[st.len()-1], st.data[st.len()-n]
|
|
}
|
|
|
|
func (st *stack) dup(n int) {
|
|
st.push(new(big.Int).Set(st.data[st.len()-n]))
|
|
}
|
|
|
|
func (st *stack) peek() *big.Int {
|
|
return st.data[st.len()-1]
|
|
}
|
|
|
|
func (st *stack) require(n int) error {
|
|
if st.len() < n {
|
|
return fmt.Errorf("stack underflow (%d <=> %d)", len(st.data), n)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (st *stack) Print() {
|
|
fmt.Println("### stack ###")
|
|
if len(st.data) > 0 {
|
|
for i, val := range st.data {
|
|
fmt.Printf("%-3d %v\n", i, val)
|
|
}
|
|
} else {
|
|
fmt.Println("-- empty --")
|
|
}
|
|
fmt.Println("#############")
|
|
}
|