1 files changed, 44 insertions, 0 deletions
diff --git a/ethvm/asm.go b/ethvm/asm.go
new file mode 100644
index 000000000..fd559d1dc
--- /dev/null
+++ b/ethvm/asm.go
@@ -0,0 +1,44 @@
+package ethvm
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethutil"
+	"math/big"
+)
+
+func Disassemble(script []byte) (asm []string) {
+	pc := new(big.Int)
+	for {
+		if pc.Cmp(big.NewInt(int64(len(script)))) >= 0 {
+			return
+		}
+
+		// Get the memory location of pc
+		val := script[pc.Int64()]
+		// Get the opcode (it must be an opcode!)
+		op := OpCode(val)
+
+		asm = append(asm, fmt.Sprintf("%04v: %v", pc, op))
+
+		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:
+			pc.Add(pc, ethutil.Big1)
+			a := int64(op) - int64(PUSH1) + 1
+			if int(pc.Int64()+a) > len(script) {
+				return nil
+			}
+
+			data := script[pc.Int64() : pc.Int64()+a]
+			if len(data) == 0 {
+				data = []byte{0}
+			}
+			asm = append(asm, fmt.Sprintf("%04v: 0x%x", pc, data))
+
+			pc.Add(pc, big.NewInt(a-1))
+		}
+
+		pc.Add(pc, ethutil.Big1)
+	}
+
+	return
+}