Merge pull request #150 from fjl/develop

Merge eth-go repo into go-ethereum

1 files changed, 45 insertions, 0 deletions

diff --git a/vm/asm.go b/vm/asm.go
new file mode 100644
index 000000000..a94f01d3d
--- /dev/null
+++ b/vm/asm.go
@@ -0,0 +1,45 @@
+package vm
+
+import (
+	"fmt"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/ethutil"
+)
+
+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("%v", 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("0x%x", data))
+
+			pc.Add(pc, big.NewInt(a-1))
+		}
+
+		pc.Add(pc, ethutil.Big1)
+	}
+
+	return
+}