Add support for command-line editing to ddbg.

tools/ddbg/bin/ddbg.dart

Index: tools/ddbg/bin/ddbg.dart
===================================================================
--- tools/ddbg/bin/ddbg.dart	(revision 0)
+++ tools/ddbg/bin/ddbg.dart	(working copy)
@@ -9,16 +9,20 @@
 import "dart:io";
 import "dart:async";
 
+import "../lib/commando.dart";
 
+
 Map<int, Completer> outstandingCommands;
 
 Socket vmSock;
 String vmData;
-var stdinSubscription;
+Commando cmdo;
 var vmSubscription;
 int seqNum = 0;
 int isolate_id = -1;
 
+Process targetProcess;
+
 final verbose = false;
 final printMessages = false;
 
@@ -60,7 +64,7 @@
 void quitShell() {
   vmSubscription.cancel();
   vmSock.close();
-  stdinSubscription.cancel();
+  cmdo.done();
 }
 
 
@@ -75,6 +79,19 @@
   return completer.future;
 }
 
+
+typedef void HandlerType(response);

[hausner, 2013/11/21 22:30:02]

Would help to have a type on the parameter. Is it Map?

[turnidge, 2013/11/22 19:59:59]

The actual handlers did not have types, so I was copying them.  Will go add
types to the response params below...

+
+HandlerType hidePrompt(void handler(response)) {
+  // Hide the command prompt immediately.
+  cmdo.hide();
+  return (response) {
+    handler(response);
+    cmdo.show();
+  };
+}
+
+
 void processCommand(String cmdLine) {
   
   void huh() {
@@ -82,6 +99,7 @@
   }
 
   seqNum++;
+  cmdLine = cmdLine.trim();
   var args = cmdLine.split(' ');
   if (args.length == 0) {
     return;
@@ -93,17 +111,17 @@
     var cmd = { "id": seqNum,
                 "command": simple_commands[command],
                 "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleGenericResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGenericResponse));

[hausner, 2013/11/21 22:30:02]

I find it confusing that the "hidePrompt" function is a parameter to the closure
that is supposed to be executed when the future completes. It's difficult enough
to follow the control flow when futures are used. This makes it even harder I
think. Why not

cmdo.hide();
sendCmd(cmd).then(showPrompt(handleGenericResponse));

Or even put the cmdo.show() into the handleXXXX functions?

[turnidge, 2013/11/22 19:59:59]

Yeah, I didn't think this was exactly perfect either.

For now I went with your first suggestion -- cmdo.hide() explicitly.  I actually
renamed hidePrompt to "showPromptAfter" which reads a little better.

Longer term:

To make command completion work nicely, I would like to make command
dispatch/completion/help driven by data (basically a map from command to
dispatchers/handlers/completers/helpers).  Once this rewrite is done, I
anticipate that the hide/show will happen in just one place, which can be
well-documented.

   } else if (command == "bt") {
     var cmd = { "id": seqNum,
                 "command": "getStackTrace",
                 "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleStackTraceResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleStackTraceResponse));
   } else if (command == "ll") {
     var cmd = { "id": seqNum,
                 "command": "getLibraries",
                 "params": { "isolateId" : isolate_id } };
-    sendCmd(cmd).then((result) => handleGetLibraryResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetLibraryResponse));
   } else if (command == "sbp" && args.length >= 2) {
     var url, line;
     if (args.length == 2 && pausedLocation != null) {
@@ -119,19 +137,19 @@
                 "params": { "isolateId" : isolate_id,
                             "url": url,
                             "line": line }};
-    sendCmd(cmd).then((result) => handleSetBpResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleSetBpResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGenericResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGetScriptsResponse));
   } else if (command == "eval" && args.length > 3) {
     var expr = args.getRange(3, args.length).join(" ");
     var target = args[1];
@@ -150,83 +168,83 @@
                 "params": { "isolateId": isolate_id,
                             target: int.parse(args[2]),
                             "expression": expr } };
-    sendCmd(cmd).then((result) => handleEvalResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleEvalResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGetObjPropsResponse));
   } 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]) } };
+    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]) } };
+      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));
+    sendCmd(cmd).then(hidePrompt(handleGetListResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGetClassPropsResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGetLibraryPropsResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleSetLibraryPropsResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGetGlobalVarsResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGetSourceResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGetLineTableResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGenericResponse));
   } else if (command == "li") {
     var cmd = { "id": seqNum, "command": "getIsolateIds" };
-    sendCmd(cmd).then((result) => handleGetIsolatesResponse(result));
+    sendCmd(cmd).then(hidePrompt(handleGetIsolatesResponse));
   } 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));
+    sendCmd(cmd).then(hidePrompt(handleGenericResponse));
   } else if (command == "q") {
     quitShell();
   } else if (command == "h") {
@@ -366,7 +384,7 @@
 }
 
 
-handleGetIsolatesResponse(response) {
+void handleGetIsolatesResponse(response) {

[hausner, 2013/11/21 22:30:02]

Remove the void annotation?

[turnidge, 2013/11/22 19:59:59]

I wanted it to be a match for HandlerType, above.

Also, it makes it consistent with e.g. handleGetLibraryResponse.

   Map result = response["result"];
   print("Isolates: ${result["isolateIds"]}");
 }
@@ -470,32 +488,39 @@
   }
   var event = msg["event"];
   if (event == "paused") {
+    cmdo.hide();
     handlePausedEvent(msg);
+    cmdo.show();
     return;
   }
   if (event == "breakpointResolved") {
     Map params = msg["params"];
     assert(params != null);
+    cmdo.hide();
     print("BP ${params["breakpointId"]} resolved and "
           "set at line ${params["line"]}.");
+    cmdo.show();
     return;
   }
   if (event == "isolate") {
     Map params = msg["params"];
     assert(params != null);
+    cmdo.hide();
     print("Isolate ${params["id"]} has been ${params["reason"]}.");
+    cmdo.show();
     return;
   }
   if (msg["id"] != null) {
     var id = msg["id"];
     if (outstandingCommands.containsKey(id)) {
+      var completer = outstandingCommands.remove(id);
       if (msg["error"] != null) {
         print("VM says: ${msg["error"]}");
+        // TODO(turnidge): Rework how hide/show happen.  For now
+        cmdo.show();
       } else {
-        var completer = outstandingCommands[id];
         completer.complete(msg);
       }
-      outstandingCommands.remove(id);
     }
   }
 }
@@ -600,7 +625,31 @@
   return 0;
 }
 
+List<String> debuggerCommandCompleter(List<String> commandParts) {
+  List<String> completions = new List<String>();
 
+  // TODO(turnidge): Have a global command table and use it to for
+  // help messages, command completion, and command dispatching.  For now
+  // we hardcode the list here.
+  //
+  // TODO(turnidge): Implement completion for arguments as well.
+  List<String> allCommands = ['q', 'bt', 'r', 's', 'so', 'si', 'sbp', 'rbp',
+                              'po', 'eval', 'pl', 'pc', 'll', 'plib', 'slib',
+                              'pg', 'ls', 'gs', 'tok', 'epi', 'li', 'i', 'h'];
+
+  // Completion of first word in the command.
+  if (commandParts.length == 1) {
+    String prefix = commandParts.last;
+    for (String command in allCommands) {
+      if (command.startsWith(prefix)) {
+        completions.add(command);
+      }
+    } 
+  }
+
+  return completions;
+}
+
 void debuggerMain() {
   outstandingCommands = new Map<int, Completer>();
   Socket.connect("127.0.0.1", 5858).then((s) {
@@ -620,20 +669,46 @@
           // TODO(floitsch): do we want to print the stack trace?
           quitShell();
         });
-    stdinSubscription = stdin.transform(UTF8.decoder)
-                             .transform(new LineSplitter())
-                             .listen((String line) => processCommand(line));
+    cmdo = new Commando(stdin, stdout, processCommand,
+                        completer:debuggerCommandCompleter);

[hausner, 2013/11/21 22:30:02]

Spaces around :

[turnidge, 2013/11/22 19:59:59]

Done.

   });
 }
 
-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 $exitCode');
-      });
+void main(List<String> args) {
+  if (args.length > 0) {
+    if (verbose) {
+      args = <String>['--debug', '--verbose_debug']..addAll(args);
+    } else {
+      args = <String>['--debug']..addAll(args);
+    }
+    Process.start(Platform.executable, args).then((Process process) {
+        targetProcess = process;
+        process.stdin.close();
+
+        // TODO(turnidge): For now we only show full lines of output
+        // from the debugged process.  Should show each character.
+        process.stdout
+            .transform(UTF8.decoder)
+            .transform(new LineSplitter())
+            .listen((String line) {
+                // Hide/show command prompt across asynchronous output.
+                if (cmdo != null) {
+                  cmdo.hide();
+                }
+                print("$line");
+                if (cmdo != null) {
+                  cmdo.show();
+                }
+              });
+
+        process.exitCode.then((int exitCode) {
+            if (exitCode == 0) {
+              print('Program exited normally.');
+            } else {
+              print('Program exited with code $exitCode.');
+            }
+          });
+
       debuggerMain();
     });
   } else {