go-pulse/vm/analysis.go
2014-11-05 00:34:59 +01:00

36 lines
808 B
Go

package vm
import (
"math/big"
"github.com/ethereum/go-ethereum/ethutil"
)
func analyseJumpDests(code []byte) (dests map[int64]*big.Int) {
dests = make(map[int64]*big.Int)
lp := false
var lpv *big.Int
for pc := int64(0); pc < int64(len(code)); pc++ {
var op OpCode = OpCode(code[pc])
switch op {
case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
a := int64(op) - int64(PUSH1) + 1
if int64(len(code)) > pc+1+a {
lpv = ethutil.BigD(code[pc+1 : pc+1+a])
}
pc += a
lp = true
case JUMP, JUMPI:
if lp {
dests[pc] = lpv
}
default:
lp = false
}
}
return
}