Add support for command-line editing to ddbg.

tools/ddbg.dart

Index: tools/ddbg.dart
===================================================================
--- tools/ddbg.dart	(revision 30481)
+++ tools/ddbg.dart	(working copy)
@@ -1,650 +0,0 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// Simple interactive debugger shell that connects to the Dart VM's debugger
-// connection port.
-
-import "dart:convert";
-import "dart:io";
-import "dart:async";
-
-
-Map<int, Completer> outstandingCommands;
-
-Socket vmSock;
-String vmData;
-var stdinSubscription;
-var vmSubscription;
-int seqNum = 0;
-int isolate_id = -1;
-
-final verbose = false;
-final printMessages = false;
-
-// The location of the last paused event.
-Map pausedLocation = null;
-
-
-void printHelp() {
-  print("""
-  q   Quit debugger shell
-  bt  Show backtrace
-  r   Resume execution
-  s   Single step
-  so  Step over
-  si  Step into
-  sbp [<file>] <line> Set breakpoint
-  rbp <id> Remove breakpoint with given id
-  po <id> Print object info for given id
-  eval obj <id> <expr> Evaluate expr on object id
-  eval cls <id> <expr> Evaluate expr on class id
-  eval lib <id> <expr> Evaluate expr in toplevel of library id
-  pl <id> <idx> [<len>] Print list element/slice
-  pc <id> Print class info for given id
-  ll  List loaded libraries
-  plib <id> Print library info for given library id
-  slib <id> <true|false> Set library id debuggable
-  pg <id> Print all global variables visible within given library id
-  ls <lib_id> List loaded scripts in library
-  gs <lib_id> <script_url> Get source text of script in library
-  tok <lib_id> <script_url> Get line and token table of script in library
-  epi <none|all|unhandled>  Set exception pause info
-  li List ids of all isolates in the VM
-  i <id> Interrupt execution of given isolate id
-  h   Print help
-""");
-}
-
-
-void quitShell() {
-  vmSubscription.cancel();
-  vmSock.close();
-  stdinSubscription.cancel();
-}
-
-
-Future sendCmd(Map<String, dynamic> cmd) {
-  var completer = new Completer();
-  int id = cmd["id"];
-  outstandingCommands[id] = completer;
-  if (verbose) {
-    print("sending: '${JSON.encode(cmd)}'");
-  }
-  vmSock.write(JSON.encode(cmd));
-  return completer.future;
-}
-
-void processCommand(String cmdLine) {
-  
-  void huh() {
-    print("'$cmdLine' not understood, try h for help");
-  }
-
-  seqNum++;
-  var args = cmdLine.split(' ');
-  if (args.length == 0) {
-    return;
-  }
-  var command = args[0];
-  var simple_commands =
-      { 'r':'resume', 's':'stepOver', 'si':'stepInto', 'so':'stepOut'};
-  if (simple_commands[command] != null) {
-    var cmd = { "id": seqNum,
-                "command": simple_commands[command],
-                "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
-  } else if (command == "bt") {
-    var cmd = { "id": seqNum,
-                "command": "getStackTrace",
-                "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleStackTraceResponse(result));
-  } else if (command == "ll") {
-    var cmd = { "id": seqNum,
-                "command": "getLibraries",
-                "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleGetLibraryResponse(result));
-  } else if (command == "sbp" && args.length >= 2) {
-    var url, line;
-    if (args.length == 2 && pausedLocation != null) {
-      url = pausedLocation["url"];
-      assert(url != null);
-      line = int.parse(args[1]);
-    } else {
-      url = args[1];
-      line = int.parse(args[2]);
-    }
-    var cmd = { "id": seqNum,
-                "command": "setBreakpoint",
-                "params": { "isolateId" : isolate_id,
-                            "url": url,
-                            "line": line }};
-    sendCmd(cmd).then((result) => handleSetBpResponse(result));
-  } else if (command == "rbp" && args.length == 2) {
-    var cmd = { "id": seqNum,
-                "command": "removeBreakpoint",
-                "params": { "isolateId" : isolate_id,
-                            "breakpointId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
-  } else if (command == "ls" && args.length == 2) {
-    var cmd = { "id": seqNum,
-                "command": "getScriptURLs",
-                "params": { "isolateId" : isolate_id,
-                            "libraryId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetScriptsResponse(result));
-  } else if (command == "eval" && args.length > 3) {
-    var expr = args.getRange(3, args.length).join(" ");
-    var target = args[1];
-    if (target == "obj") {
-      target = "objectId";
-    } else if (target == "cls") {
-      target = "classId";
-    } else if (target == "lib") {
-      target = "libraryId";
-    } else {
-      huh();
-      return;
-    }
-    var cmd = { "id": seqNum,
-                "command": "evaluateExpr",
-                "params": { "isolateId": isolate_id,
-                            target: int.parse(args[2]),
-                            "expression": expr } };
-    sendCmd(cmd).then((result) => handleEvalResponse(result));
-  } else if (command == "po" && args.length == 2) {
-    var cmd = { "id": seqNum,
-                "command": "getObjectProperties",
-                "params": { "isolateId" : isolate_id,
-                            "objectId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetObjPropsResponse(result));
-  } else if (command == "pl" && args.length >= 3) {
-     var cmd;
-     if (args.length == 3) {
-       cmd = { "id": seqNum,
-               "command": "getListElements",
-               "params": { "isolateId" : isolate_id,
-                           "objectId": int.parse(args[1]),
-                           "index": int.parse(args[2]) } };
-    } else {
-       cmd = { "id": seqNum,
-               "command": "getListElements",
-               "params": { "isolateId" : isolate_id,
-                           "objectId": int.parse(args[1]),
-                           "index": int.parse(args[2]),
-                           "length": int.parse(args[3]) } };
-    }
-    sendCmd(cmd).then((result) => handleGetListResponse(result));
-  } else if (command == "pc" && args.length == 2) {
-    var cmd = { "id": seqNum,
-                "command": "getClassProperties",
-                "params": { "isolateId" : isolate_id,
-                            "classId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetClassPropsResponse(result));
-  } else if (command == "plib" && args.length == 2) {
-    var cmd = { "id": seqNum,
-                "command": "getLibraryProperties",
-                "params": {"isolateId" : isolate_id,
-                           "libraryId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetLibraryPropsResponse(result));
-  } else if (command == "slib" && args.length == 3) {
-    var cmd = { "id": seqNum,
-                "command": "setLibraryProperties",
-                "params": {"isolateId" : isolate_id,
-                           "libraryId": int.parse(args[1]),
-                           "debuggingEnabled": args[2] } };
-    sendCmd(cmd).then((result) => handleSetLibraryPropsResponse(result));
-  } else if (command == "pg" && args.length == 2) {
-    var cmd = { "id": seqNum,
-                "command": "getGlobalVariables",
-                "params": { "isolateId" : isolate_id,
-                            "libraryId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGetGlobalVarsResponse(result));
-  } else if (command == "gs" && args.length == 3) {
-    var cmd = { "id": seqNum,
-                "command":  "getScriptSource",
-                "params": { "isolateId" : isolate_id,
-                            "libraryId": int.parse(args[1]),
-                            "url": args[2] } };
-    sendCmd(cmd).then((result) => handleGetSourceResponse(result));
-  } else if (command == "tok" && args.length == 3) {
-    var cmd = { "id": seqNum,
-                "command":  "getLineNumberTable",
-                "params": { "isolateId" : isolate_id,
-                            "libraryId": int.parse(args[1]),
-                            "url": args[2] } };
-    sendCmd(cmd).then((result) => handleGetLineTableResponse(result));
-  } else if (command == "epi" && args.length == 2) {
-    var cmd = { "id": seqNum,
-                "command":  "setPauseOnException",
-                "params": { "isolateId" : isolate_id,
-                            "exceptions": args[1] } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
-  } else if (command == "li") {
-    var cmd = { "id": seqNum, "command": "getIsolateIds" };
-    sendCmd(cmd).then((result) => handleGetIsolatesResponse(result));
-  } else if (command == "i" && args.length == 2) {
-    var cmd = { "id": seqNum,
-                "command": "interrupt",
-                "params": { "isolateId": int.parse(args[1]) } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
-  } else if (command == "q") {
-    quitShell();
-  } else if (command == "h") {
-    printHelp();
-  } else {
-    huh();
-  }
-}
-
-
-String remoteObject(value) {
-  var kind = value["kind"];
-  var text = value["text"];
-  var id = value["objectId"];
-  if (kind == "string") {
-    return "(string, id $id) '$text'";
-  } else if (kind == "list") {
-    var len = value["length"];
-    return "(list, id $id, len $len) $text";
-  } else if (kind == "object") {
-    return "(obj, id $id) $text";
-  } else if (kind == "function") {
-    var location = value['location'] != null
-        ? ", file '${value['location']['url']}'"
-          ", token pos ${value['location']['tokenOffset']}"
-        : "";
-    var name = value['name'];
-    var signature = value['signature'];
-    return "(closure ${name}${signature} $location)";
-  } else {
-    return "$text";
-  }
-}
-
-
-printNamedObject(obj) {
-  var name = obj["name"];
-  var value = obj["value"];
-  print("  $name = ${remoteObject(value)}");
-}
-
-
-handleGetObjPropsResponse(response) {
-  Map props = response["result"];
-  int class_id = props["classId"];
-  if (class_id == -1) {
-    print("  null");
-    return;
-  }
-  List fields = props["fields"];
-  print("  class id: $class_id");
-  for (int i = 0; i < fields.length; i++) {
-    printNamedObject(fields[i]);
-  }
-}
-
-handleGetListResponse(response) {
-  Map result = response["result"];
-  if (result["elements"] != null) {
-    // List slice.
-    var index = result["index"];
-    var length = result["length"];
-    List elements = result["elements"];
-    assert(length == elements.length);
-    for (int i = 0; i < length; i++) {
-      var kind = elements[i]["kind"];
-      var text = elements[i]["text"];
-      print("  ${index + i}: ($kind) $text");
-    }
-  } else {
-    // One element, a remote object.
-    print(result);
-    print("  ${remoteObject(result)}");
-  }
-}
-
-
-handleGetClassPropsResponse(response) {
-  Map props = response["result"];
-  assert(props["name"] != null);
-  int libId = props["libraryId"];
-  assert(libId != null);
-  print("  class ${props["name"]} (library id: $libId)");
-  List fields = props["fields"];
-  if (fields.length > 0) {
-    print("  static fields:");
-    for (int i = 0; i < fields.length; i++) {
-      printNamedObject(fields[i]);
-    }
-  }
-}
-
-
-handleGetLibraryPropsResponse(response) {
-  Map props = response["result"];
-  assert(props["url"] != null);
-  print("  library url: ${props["url"]}");
-  assert(props["debuggingEnabled"] != null);
-  print("  debugging enabled: ${props["debuggingEnabled"]}");
-  List imports = props["imports"];
-  assert(imports != null);
-  if (imports.length > 0) {
-    print("  imports:");
-    for (int i = 0; i < imports.length; i++) {
-      print("    id ${imports[i]["libraryId"]} prefix ${imports[i]["prefix"]}");
-    }
-  }
-  List globals = props["globals"];
-  assert(globals != null);
-  if (globals.length > 0) {
-    print("  global variables:");
-    for (int i = 0; i < globals.length; i++) {
-      printNamedObject(globals[i]);
-    }
-  }
-}
-
-
-handleSetLibraryPropsResponse(response) {
-  Map props = response["result"];
-  assert(props["debuggingEnabled"] != null);
-  print("  debugging enabled: ${props["debuggingEnabled"]}");
-}
-
-
-handleGetGlobalVarsResponse(response) {
-  List globals = response["result"]["globals"];
-  for (int i = 0; i < globals.length; i++) {
-    printNamedObject(globals[i]);
-  }
-}
-
-
-handleGetSourceResponse(response) {
-  Map result = response["result"];
-  String source = result["text"];
-  print("Source text:\n$source\n--------");
-}
-
-
-handleGetLineTableResponse(response) {
-  Map result = response["result"];
-  var info = result["lines"];
-  print("Line info table:\n$info");
-}
-
-
-handleGetIsolatesResponse(response) {
-  Map result = response["result"];
-  print("Isolates: ${result["isolateIds"]}");
-}
-
-
-void handleGetLibraryResponse(response) {
-  Map result = response["result"];
-  List libs = result["libraries"];
-  print("Loaded libraries:");
-  print(libs);
-  for (int i = 0; i < libs.length; i++) {
-    print("  ${libs[i]["id"]} ${libs[i]["url"]}");
-  }
-}
-
-
-void handleGetScriptsResponse(response) {
-  Map result = response["result"];
-  List urls = result["urls"];
-  print("Loaded scripts:");
-  for (int i = 0; i < urls.length; i++) {
-    print("  $i ${urls[i]}");
-  }
-}
-
-
-void handleEvalResponse(response) {
-  Map result = response["result"];
-  print(remoteObject(result));
-}
-
-
-void handleSetBpResponse(response) {
-  Map result = response["result"];
-  var id = result["breakpointId"];
-  assert(id != null);
-  print("Set BP $id");
-}
-
-
-void handleGenericResponse(response) {
-  if (response["error"] != null) {
-    print("Error: ${response["error"]}");
-  }
-}
-
-
-void handleStackTraceResponse(response) {
-  Map result = response["result"];
-  List callFrames = result["callFrames"];
-  assert(callFrames != null);
-  printStackTrace(callFrames);
-}
-
-
-void printStackFrame(frame_num, Map frame) {
-  var fname = frame["functionName"];
-  var libId = frame["location"]["libraryId"];
-  var url = frame["location"]["url"];
-  var toff = frame["location"]["tokenOffset"];
-  print("$frame_num  $fname (url: $url token: $toff lib: $libId)");
-  List locals = frame["locals"];
-  for (int i = 0; i < locals.length; i++) {
-    printNamedObject(locals[i]);
-  }
-}
-
-
-void printStackTrace(List frames) {
-  for (int i = 0; i < frames.length; i++) {
-    printStackFrame(i, frames[i]);
-  }
-}
-
-
-void handlePausedEvent(msg) {
-  assert(msg["params"] != null);
-  var reason = msg["params"]["reason"];
-  isolate_id = msg["params"]["isolateId"];
-  assert(isolate_id != null);
-  pausedLocation = msg["params"]["location"];
-  assert(pausedLocation != null);
-  if (reason == "breakpoint") {
-    print("Isolate $isolate_id paused on breakpoint");
-    print("location: $pausedLocation");
-  } else if (reason == "interrupted") {
-    print("Isolate $isolate_id paused due to an interrupt");
-  } else {
-    assert(reason == "exception");
-    var excObj = msg["params"]["exception"];
-    print("Isolate $isolate_id paused on exception");
-    print(remoteObject(excObj));
-  }
-}
-
-
-void processVmMessage(String jsonString) {
-  var msg = JSON.decode(jsonString);
-  if (msg == null) {
-    return;
-  }
-  var event = msg["event"];
-  if (event == "paused") {
-    handlePausedEvent(msg);
-    return;
-  }
-  if (event == "breakpointResolved") {
-    Map params = msg["params"];
-    assert(params != null);
-    print("BP ${params["breakpointId"]} resolved and "
-          "set at line ${params["line"]}.");
-    return;
-  }
-  if (event == "isolate") {
-    Map params = msg["params"];
-    assert(params != null);
-    print("Isolate ${params["id"]} has been ${params["reason"]}.");
-    return;
-  }
-  if (msg["id"] != null) {
-    var id = msg["id"];
-    if (outstandingCommands.containsKey(id)) {
-      if (msg["error"] != null) {
-        print("VM says: ${msg["error"]}");
-      } else {
-        var completer = outstandingCommands[id];
-        completer.complete(msg);
-      }
-      outstandingCommands.remove(id);
-    }
-  }
-}
-
-bool haveGarbageVmData() {
-  if (vmData == null || vmData.length == 0) return false;
-  var i = 0, char = " ";
-  while (i < vmData.length) {
-    char = vmData[i];
-    if (char != " " && char != "\n" && char != "\r" && char != "\t") break;
-    i++;
-  }
-  if (i >= vmData.length) {
-    return false;
-  } else { 
-    return char != "{";
-  }
-}
-
-
-void processVmData(String data) {
-  if (vmData == null || vmData.length == 0) {
-    vmData = data;
-  } else {
-    vmData = vmData + data;
-  }
-  if (haveGarbageVmData()) {
-    print("Error: have garbage data from VM: '$vmData'");
-    return;
-  }
-  int msg_len = jsonObjectLength(vmData);
-  if (printMessages && msg_len == 0) {
-    print("have partial or illegal json message"
-          " of ${vmData.length} chars:\n'$vmData'");
-    return;
-  }
-  while (msg_len > 0 && msg_len <= vmData.length) {
-    if (msg_len == vmData.length) {
-      if (printMessages) { print("have one full message:\n$vmData"); }
-      processVmMessage(vmData);
-      vmData = null;
-      return;
-    }
-    if (printMessages) { print("at least one message: '$vmData'"); }
-    var msg = vmData.substring(0, msg_len);
-    if (printMessages) { print("first message: $msg"); }
-    vmData = vmData.substring(msg_len);
-    if (haveGarbageVmData()) {
-      print("Error: garbage data after previous message: '$vmData'");
-      print("Previous message was: '$msg'");
-      return;
-    }
-    processVmMessage(msg);
-    msg_len = jsonObjectLength(vmData);
-  }
-  if (printMessages) { print("leftover vm data '$vmData'"); }
-}
-
-/**
- * Skip past a JSON object value.
- * The object value must start with '{' and continues to the
- * matching '}'. No attempt is made to otherwise validate the contents
- * as JSON. If it is invalid, a later [parseJson] will fail.
- */
-int jsonObjectLength(String string) {
-  int skipWhitespace(int index) {
-    while (index < string.length) {
-      String char = string[index];
-      if (char != " " && char != "\n" && char != "\r" && char != "\t") break;
-      index++;
-    }
-    return index;
-  }
-  int skipString(int index) {
-    assert(string[index - 1] == '"');
-    while (index < string.length) {
-      String char = string[index];
-      if (char == '"') return index + 1;
-      if (char == r'\') index++;
-      if (index == string.length) return index;
-      index++;
-    }
-    return index;
-  }
-  int index = 0;
-  index = skipWhitespace(index);
-  // Bail out if the first non-whitespace character isn't '{'.
-  if (index == string.length || string[index] != '{') return 0;
-  int nesting = 0;
-  while (index < string.length) {
-    String char = string[index++];
-    if (char == '{') {
-      nesting++;
-    } else if (char == '}') {
-      nesting--;
-      if (nesting == 0) return index;
-    } else if (char == '"') {
-      // Strings can contain braces. Skip their content.
-      index = skipString(index);
-    }
-  }
-  return 0;
-}
-
-
-void debuggerMain() {
-  outstandingCommands = new Map<int, Completer>();
-  Socket.connect("127.0.0.1", 5858).then((s) {
-    vmSock = s;
-    vmSock.setOption(SocketOption.TCP_NODELAY, true);
-    var stringStream = vmSock.transform(UTF8.decoder);
-    vmSubscription = stringStream.listen(
-        (String data) {
-          processVmData(data);
-        },
-        onDone: () {
-          print("VM debugger connection closed");
-          quitShell();
-        },
-        onError: (err) {
-          print("Error in debug connection: $err");
-          // TODO(floitsch): do we want to print the stack trace?
-          quitShell();
-        });
-    stdinSubscription = stdin.transform(UTF8.decoder)
-                             .transform(new LineSplitter())
-                             .listen((String line) => processCommand(line));
-  });
-}
-
-void main(List<String> arguments) {
-  if (arguments.length > 0) {
-    arguments = <String>['--debug', '--verbose_debug']..addAll(arguments);
-    Process.start(Platform.executable, arguments).then((Process process) {
-      process.stdin.close();
-      process.exitCode.then((int exitCode) {
-        print('${arguments.join(" ")} exited with $exitCode');
-      });
-      debuggerMain();
-    });
-  } else {
-    debuggerMain();
-  }
-}