package cli import ( "bytes" "encoding/hex" "errors" "fmt" "io/ioutil" "math/big" "os" "strconv" "strings" "github.com/nspcc-dev/neo-go/pkg/compiler" "github.com/nspcc-dev/neo-go/pkg/vm" "gopkg.in/abiosoft/ishell.v2" ) const ( vmKey = "vm" boolType = "bool" boolFalse = "false" boolTrue = "true" intType = "int" stringType = "string" ) var commands = []*ishell.Cmd{ { Name: "exit", Help: "Exit the VM prompt", LongHelp: "Exit the VM prompt", Func: handleExit, }, { Name: "ip", Help: "Show current instruction", LongHelp: "Show current instruction", Func: handleIP, }, { Name: "break", Help: "Place a breakpoint", LongHelp: `Usage: break is mandatory parameter, example: > break 12`, Func: handleBreak, }, { Name: "estack", Help: "Show evaluation stack contents", LongHelp: "Show evaluation stack contents", Func: handleXStack, }, { Name: "astack", Help: "Show alt stack contents", LongHelp: "Show alt stack contents", Func: handleXStack, }, { Name: "istack", Help: "Show invocation stack contents", LongHelp: "Show invocation stack contents", Func: handleXStack, }, { Name: "loadavm", Help: "Load an avm script into the VM", LongHelp: `Usage: loadavm is mandatory parameter, example: > load /path/to/script.avm`, Func: handleLoadAVM, }, { Name: "loadhex", Help: "Load a hex-encoded script string into the VM", LongHelp: `Usage: loadhex is mandatory parameter, example: > load 006166`, Func: handleLoadHex, }, { Name: "loadgo", Help: "Compile and load a Go file into the VM", LongHelp: `Usage: loadhex is mandatory parameter, example: > load /path/to/file.go`, Func: handleLoadGo, }, { Name: "run", Help: "Execute the current loaded script", LongHelp: `Usage: run [ [...]] is an operation name, passed as a first parameter to Main() (and it can't be 'help' at the moment) is a parameter (can be repeated multiple times) that can be specified as :, where type can be: '` + boolType + `': supports '` + boolFalse + `' and '` + boolTrue + `' values '` + intType + `': supports integers as values '` + stringType + `': supports strings as values (that are pushed as a byte array values to the stack) or can be just , for which the type will be detected automatically following these rules: '` + boolTrue + `' and '` + boolFalse + `' are treated as respective boolean values, everything that can be converted to integer is treated as integer and everything else is treated like a string. Passing parameters without operation is not supported. Parameters are packed into array before they're passed to the script, so effectively 'run' only supports contracts with signatures like this: func Main(operation string, args []interface{}) interface{} Example: > run put ` + stringType + `:"Something to put"`, Func: handleRun, }, { Name: "cont", Help: "Continue execution of the current loaded script", LongHelp: "Continue execution of the current loaded script", Func: handleCont, }, { Name: "step", Help: "Step (n) instruction in the program", LongHelp: `Usage: step [] is optional parameter to specify number of instructions to run, example: > step 10`, Func: handleStep, }, { Name: "stepinto", Help: "Stepinto instruction to take in the debugger", LongHelp: `Usage: stepInto example: > stepinto`, Func: handleStepInto, }, { Name: "stepout", Help: "Stepout instruction to take in the debugger", LongHelp: `Usage: stepOut example: > stepout`, Func: handleStepOut, }, { Name: "stepover", Help: "Stepover instruction to take in the debugger", LongHelp: `Usage: stepOver example: > stepover`, Func: handleStepOver, }, { Name: "ops", Help: "Dump opcodes of the current loaded program", LongHelp: "Dump opcodes of the current loaded program", Func: handleOps, }, } // VMCLI object for interacting with the VM. type VMCLI struct { vm *vm.VM shell *ishell.Shell } // New returns a new VMCLI object. func New() *VMCLI { vmcli := VMCLI{ vm: vm.New(), shell: ishell.New(), } vmcli.shell.Set(vmKey, vmcli.vm) for _, c := range commands { vmcli.shell.AddCmd(c) } changePrompt(vmcli.shell, vmcli.vm) return &vmcli } func getVMFromContext(c *ishell.Context) *vm.VM { return c.Get(vmKey).(*vm.VM) } func checkVMIsReady(c *ishell.Context) bool { v := getVMFromContext(c) if v == nil || !v.Ready() { c.Err(errors.New("VM is not ready: no program loaded")) return false } return true } func handleExit(c *ishell.Context) { c.Println("Bye!") os.Exit(0) } func handleIP(c *ishell.Context) { if !checkVMIsReady(c) { return } v := getVMFromContext(c) ip, opcode := v.Context().CurrInstr() c.Printf("instruction pointer at %d (%s)\n", ip, opcode) } func handleBreak(c *ishell.Context) { if !checkVMIsReady(c) { return } v := getVMFromContext(c) if len(c.Args) != 1 { c.Err(errors.New("missing parameter ")) } n, err := strconv.Atoi(c.Args[0]) if err != nil { c.Err(fmt.Errorf("argument conversion error: %s", err)) return } v.AddBreakPoint(n) c.Printf("breakpoint added at instruction %d\n", n) } func handleXStack(c *ishell.Context) { v := getVMFromContext(c) c.Println(v.Stack(c.Cmd.Name)) } func handleLoadAVM(c *ishell.Context) { v := getVMFromContext(c) if err := v.LoadFile(c.Args[0]); err != nil { c.Err(err) } else { c.Printf("READY: loaded %d instructions\n", v.Context().LenInstr()) } changePrompt(c, v) } func handleLoadHex(c *ishell.Context) { v := getVMFromContext(c) b, err := hex.DecodeString(c.Args[0]) if err != nil { c.Err(err) return } v.Load(b) c.Printf("READY: loaded %d instructions\n", v.Context().LenInstr()) changePrompt(c, v) } func handleLoadGo(c *ishell.Context) { v := getVMFromContext(c) fb, err := ioutil.ReadFile(c.Args[0]) if err != nil { c.Err(err) return } b, err := compiler.Compile(bytes.NewReader(fb)) if err != nil { c.Err(err) return } v.Load(b) c.Printf("READY: loaded %d instructions\n", v.Context().LenInstr()) changePrompt(c, v) } func handleRun(c *ishell.Context) { v := getVMFromContext(c) if len(c.Args) != 0 { var ( method []byte params []vm.StackItem err error ) method = []byte(c.Args[0]) params, err = parseArgs(c.Args[1:]) if err != nil { c.Err(err) return } v.LoadArgs(method, params) } runVMWithHandling(c, v) changePrompt(c, v) } // runVMWithHandling runs VM with handling errors and additional state messages. func runVMWithHandling(c *ishell.Context, v *vm.VM) { err := v.Run() if err != nil { c.Err(err) return } var message string switch { case v.HasFailed(): message = "FAILED" case v.HasHalted(): message = v.Stack("estack") case v.AtBreakpoint(): ctx := v.Context() i, op := ctx.CurrInstr() message = fmt.Sprintf("at breakpoint %d (%s)\n", i, op.String()) } if message != "" { c.Printf(message) } } func handleCont(c *ishell.Context) { if !checkVMIsReady(c) { return } v := getVMFromContext(c) runVMWithHandling(c, v) changePrompt(c, v) } func handleStep(c *ishell.Context) { var ( n = 1 err error ) if !checkVMIsReady(c) { return } v := getVMFromContext(c) if len(c.Args) > 0 { n, err = strconv.Atoi(c.Args[0]) if err != nil { c.Err(fmt.Errorf("argument conversion error: %s", err)) return } } v.AddBreakPointRel(n) runVMWithHandling(c, v) changePrompt(c, v) } func handleStepInto(c *ishell.Context) { handleStepType(c, "into") } func handleStepOut(c *ishell.Context) { handleStepType(c, "out") } func handleStepOver(c *ishell.Context) { handleStepType(c, "over") } func handleStepType(c *ishell.Context, stepType string) { if !checkVMIsReady(c) { return } v := getVMFromContext(c) var err error switch stepType { case "into": err = v.StepInto() case "out": err = v.StepOut() case "over": err = v.StepOver() } if err != nil { c.Err(err) } handleIP(c) changePrompt(c, v) } func handleOps(c *ishell.Context) { if !checkVMIsReady(c) { return } v := getVMFromContext(c) v.PrintOps() } func changePrompt(c ishell.Actions, v *vm.VM) { if v.Ready() && v.Context().IP()-1 >= 0 { c.SetPrompt(fmt.Sprintf("NEO-GO-VM %d > ", v.Context().IP()-1)) } else { c.SetPrompt("NEO-GO-VM > ") } } // Run waits for user input from Stdin and executes the passed command. func (c *VMCLI) Run() error { printLogo(c.shell) c.shell.Run() return nil } func isMethodArg(s string) bool { return len(strings.Split(s, ":")) == 1 } func parseArgs(args []string) ([]vm.StackItem, error) { items := make([]vm.StackItem, len(args)) for i, arg := range args { var typ, value string typeAndVal := strings.Split(arg, ":") if len(typeAndVal) < 2 { if typeAndVal[0] == boolFalse || typeAndVal[0] == boolTrue { typ = boolType } else if _, err := strconv.Atoi(typeAndVal[0]); err == nil { typ = intType } else { typ = stringType } value = typeAndVal[0] } else { typ = typeAndVal[0] value = typeAndVal[1] } switch typ { case boolType: if value == boolFalse { items[i] = vm.NewBoolItem(false) } else if value == boolTrue { items[i] = vm.NewBoolItem(true) } else { return nil, errors.New("failed to parse bool parameter") } case intType: val, err := strconv.ParseInt(value, 10, 64) if err != nil { return nil, err } items[i] = vm.NewBigIntegerItem(big.NewInt(val)) case stringType: items[i] = vm.NewByteArrayItem([]byte(value)) } } return items, nil } func printLogo(c *ishell.Shell) { logo := ` _ ____________ __________ _ ____ ___ / | / / ____/ __ \ / ____/ __ \ | | / / |/ / / |/ / __/ / / / /_____/ / __/ / / /____| | / / /|_/ / / /| / /___/ /_/ /_____/ /_/ / /_/ /_____/ |/ / / / / /_/ |_/_____/\____/ \____/\____/ |___/_/ /_/ ` c.Print(logo) c.Println() c.Println() }