Implement generator mirror

src/mirror-debugger.js

 // Copyright 2006-2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Handle id counters.
 var next_handle_ = 0;
 var next_transient_handle_ = -1;
 
 // Mirror cache.
 var mirror_cache_ = [];
@@ skipping 69 matching lines @@
   } else if (IS_ERROR(value)) {
     mirror = new ErrorMirror(value);
   } else if (IS_SCRIPT(value)) {
     mirror = new ScriptMirror(value);
   } else if (IS_MAP(value) || IS_WEAKMAP(value)) {
     mirror = new MapMirror(value);
   } else if (IS_SET(value) || IS_WEAKSET(value)) {
     mirror = new SetMirror(value);
   } else if (ObjectIsPromise(value)) {
     mirror = new PromiseMirror(value);
+  } else if (IS_GENERATOR(value)) {
+    mirror = new GeneratorMirror(value);
   } else {
     mirror = new ObjectMirror(value, OBJECT_TYPE, opt_transient);
   }
 
   if (mirror_cache_enabled_) mirror_cache_[mirror.handle()] = mirror;
   return mirror;
 }
 
 
 /**
@@ skipping 54 matching lines @@
 var ERROR_TYPE = 'error';
 var PROPERTY_TYPE = 'property';
 var INTERNAL_PROPERTY_TYPE = 'internalProperty';
 var FRAME_TYPE = 'frame';
 var SCRIPT_TYPE = 'script';
 var CONTEXT_TYPE = 'context';
 var SCOPE_TYPE = 'scope';
 var PROMISE_TYPE = 'promise';
 var MAP_TYPE = 'map';
 var SET_TYPE = 'set';
+var GENERATOR_TYPE = 'generator';
 
 // Maximum length when sending strings through the JSON protocol.
 var kMaxProtocolStringLength = 80;
 
 // Different kind of properties.
 var PropertyKind = {};
 PropertyKind.Named   = 1;
 PropertyKind.Indexed = 2;
 
 
@@ skipping 33 matching lines @@
 //       - ObjectMirror
 //         - FunctionMirror
 //           - UnresolvedFunctionMirror
 //         - ArrayMirror
 //         - DateMirror
 //         - RegExpMirror
 //         - ErrorMirror
 //         - PromiseMirror
 //         - MapMirror
 //         - SetMirror
+//         - GeneratorMirror
 //     - PropertyMirror
 //     - InternalPropertyMirror
 //     - FrameMirror
 //     - ScriptMirror
 
 
 /**
  * Base class for all mirror objects.
  * @param {string} type The type of the mirror
  * @constructor
@@ skipping 137 matching lines @@
 /**
  * Check whether the mirror reflects a promise.
  * @returns {boolean} True if the mirror reflects a promise
  */
 Mirror.prototype.isPromise = function() {
   return this instanceof PromiseMirror;
 };
 
 
 /**
+ * Check whether the mirror reflects a generator object.
+ * @returns {boolean} True if the mirror reflects a generator object
+ */
+Mirror.prototype.isGenerator = function() {
+  return this instanceof GeneratorMirror;
+};
+
+
+/**
  * Check whether the mirror reflects a property.
  * @returns {boolean} True if the mirror reflects a property
  */
 Mirror.prototype.isProperty = function() {
   return this instanceof PropertyMirror;
 };
 
 
 /**
  * Check whether the mirror reflects an internal property.
@@ skipping 595 matching lines @@
   }
 };
 
 
 /**
  * Returns the script source position for the function. Only makes sense
  * for functions which has a script defined.
  * @return {Number or undefined} in-script position for the function
  */
 FunctionMirror.prototype.sourcePosition_ = function() {
-  // Return script if function is resolved. Otherwise just fall through
-  // to return undefined.
+  // Return position if function is resolved. Otherwise just fall
+  // through to return undefined.
   if (this.resolved()) {
     return %FunctionGetScriptSourcePosition(this.value_);
   }
 };
 
 
 /**
  * Returns the script source location object for the function. Only makes sense
  * for functions which has a script defined.
  * @return {Location or undefined} in-script location for the function begin
@@ skipping 344 matching lines @@
   var iter = %_CallFunction(this.value_, builtins.SetValues);
   var next;
   while (!(next = iter.next()).done) {
     result.push(next.value);
   }
   return result;
 };
 
 
 /**
+ * Mirror object for a Generator object.
+ * @param {Object} data The Generator object
+ * @constructor
+ * @extends Mirror
+ */
+function GeneratorMirror(value) {
+  %_CallFunction(this, value, GENERATOR_TYPE, ObjectMirror);
+}
+inherits(GeneratorMirror, ObjectMirror);
+
+
+GeneratorMirror.prototype.status = function() {
+  var continuation = %GeneratorGetContinuation(this.value_);
+  if (continuation < 0) return "running";

[aandrey, 2014/09/17 13:21:29]

is it possible to test this status?

[wingo, 2014/09/17 13:54:30]

Done.

+  if (continuation == 0) return "closed";
+  return "suspended";
+};
+
+
+GeneratorMirror.prototype.sourcePosition_ = function() {
+  return %GeneratorGetSourcePosition(this.value_);
+};
+
+
+GeneratorMirror.prototype.sourceLocation = function() {
+  var pos = this.sourcePosition_();
+  if (!IS_UNDEFINED(pos)) {
+    var script = this.func().script();
+    if (script) {
+      return script.locationFromPosition(pos, true);
+    }
+  }
+};
+
+
+GeneratorMirror.prototype.func = function() {
+  if (!this.func_) {
+    this.func_ = MakeMirror(%GeneratorGetFunction(this.value_));
+  }
+  return this.func_;
+};
+
+
+GeneratorMirror.prototype.context = function() {

[aandrey, 2014/09/17 13:21:30]

Is this the same as this.func().script().context() ?

[wingo, 2014/09/17 13:54:30]

Hum, I realized that it isn't -- it's one of the other 30 things in V8 that are
named "context" :/

This thing is the scope chain.  In generator functions, all locals are reified
on the scope chain ("context-allocated").  You can get the set of local
variables from a generator activation by looking at the set of properties of a
node on the scope chain, stopping when you find a node that is on the scope
chain of the function itself.  However I revised the patch not to expose this
any more, as I don't know the right way to expose a scope chain.

+  if (!this.context_) {
+    this.context_ = new ContextMirror(%GeneratorGetContext(this.value_));
+  }
+  return this.context_;
+};
+
+
+GeneratorMirror.prototype.receiver = function() {
+  if (!this.receiver_) {
+    this.receiver_ = MakeMirror(%GeneratorGetReceiver(this.value_));
+  }
+  return this.receiver_;
+};
+
+
+/**
  * Base mirror object for properties.
  * @param {ObjectMirror} mirror The mirror object having this property
  * @param {string} name The name of the property
  * @param {Array} details Details about the property
  * @constructor
  * @extends Mirror
  */
 function PropertyMirror(mirror, name, details) {
   %_CallFunction(this, PROPERTY_TYPE, Mirror);
   this.mirror_ = mirror;
@@ skipping 1167 matching lines @@
 
     case SYMBOL_TYPE:
       content.description = mirror.description();
       break;
 
     case OBJECT_TYPE:
     case FUNCTION_TYPE:
     case ERROR_TYPE:
     case REGEXP_TYPE:
     case PROMISE_TYPE:
+    case GENERATOR_TYPE:
       // Add object representation.
       this.serializeObject_(mirror, content, details);
       break;
 
     case PROPERTY_TYPE:
     case INTERNAL_PROPERTY_TYPE:
       throw new Error('PropertyMirror cannot be serialized independently');
       break;
 
     case FRAME_TYPE:
@@ skipping 325 matching lines @@
   }
   if (!NUMBER_IS_FINITE(value)) {
     if (value > 0) {
       return 'Infinity';
     } else {
       return '-Infinity';
     }
   }
   return value;
 }