Allow access to scopes of suspended generator objects

src/debug/mirrors.js

Index: src/debug/mirrors.js
diff --git a/src/debug/mirrors.js b/src/debug/mirrors.js
index fbe6da5d8605408bd0bad86467e5cdfa30ff3c19..165e1724492f106896475d3153227c9a1a4bf748 100644
--- a/src/debug/mirrors.js
+++ b/src/debug/mirrors.js
@@ -1022,7 +1022,7 @@ FunctionMirror.prototype.scopeCount = function() {
 
 FunctionMirror.prototype.scope = function(index) {
   if (this.resolved()) {
-    return new ScopeMirror(UNDEFINED, this, index);
+    return new ScopeMirror(UNDEFINED, this, UNDEFINED, index);
   }
 };
 
@@ -1451,6 +1451,27 @@ GeneratorMirror.prototype.receiver = function() {
 };
 
 
+GeneratorMirror.prototype.scopeCount = function() {
+  // This value can change over time as the underlying generator is suspended
+  // at different locations.
+  return %GetGeneratorScopeCount(this.value());
+};
+
+
+GeneratorMirror.prototype.scope = function(index) {
+  return new ScopeMirror(UNDEFINED, UNDEFINED, this, index);
+};
+
+
+GeneratorMirror.prototype.allScopes = function() {
+  var scopes = [];
+  for (let i = 0; i < this.scopeCount(); i++) {
+    scopes.push(this.scope(i));
+  }
+  return scopes;
+};
+
+
 /**
  * Base mirror object for properties.
  * @param {ObjectMirror} mirror The mirror object having this property
@@ -1973,7 +1994,7 @@ FrameMirror.prototype.scopeCount = function() {
 
 
 FrameMirror.prototype.scope = function(index) {
-  return new ScopeMirror(this, UNDEFINED, index);
+  return new ScopeMirror(this, UNDEFINED, UNDEFINED, index);
 };
 
 
@@ -1984,7 +2005,8 @@ FrameMirror.prototype.allScopes = function(opt_ignore_nested_scopes) {
                                           !!opt_ignore_nested_scopes);
   var result = [];
   for (var i = 0; i < scopeDetails.length; ++i) {
-    result.push(new ScopeMirror(this, UNDEFINED, i, scopeDetails[i]));
+    result.push(new ScopeMirror(this, UNDEFINED, UNDEFINED, i,
+                                scopeDetails[i]));
   }
   return result;
 };
@@ -2163,7 +2185,7 @@ var kScopeDetailsStartPositionIndex = 3;
 var kScopeDetailsEndPositionIndex = 4;
 var kScopeDetailsFunctionIndex = 5;
 
-function ScopeDetails(frame, fun, index, opt_details) {
+function ScopeDetails(frame, fun, gen, index, opt_details) {
   if (frame) {
     this.break_id_ = frame.break_id_;
     this.details_ = opt_details ||
@@ -2173,10 +2195,15 @@ function ScopeDetails(frame, fun, index, opt_details) {
                                      index);
     this.frame_id_ = frame.details_.frameId();
     this.inlined_frame_id_ = frame.details_.inlinedFrameIndex();
-  } else {
+  } else if (fun) {
     this.details_ = opt_details || %GetFunctionScopeDetails(fun.value(), index);
     this.fun_value_ = fun.value();
     this.break_id_ = UNDEFINED;
+  } else {
+    this.details_ =
+      opt_details || %GetGeneratorScopeDetails(gen.value(), index);
+    this.gen_value_ = gen.value();
+    this.break_id_ = UNDEFINED;
   }
   this.index_ = index;
 }
@@ -2235,9 +2262,12 @@ ScopeDetails.prototype.setVariableValueImpl = function(name, new_value) {
     %CheckExecutionState(this.break_id_);
     raw_res = %SetScopeVariableValue(this.break_id_, this.frame_id_,
         this.inlined_frame_id_, this.index_, name, new_value);
-  } else {
+  } else if (!IS_UNDEFINED(this.fun_value_)) {
     raw_res = %SetScopeVariableValue(this.fun_value_, null, null, this.index_,
         name, new_value);
+  } else {
+    raw_res = %SetScopeVariableValue(this.gen_value_, null, null, this.index_,
+        name, new_value);
   }
   if (!raw_res) throw %make_error(kDebugger, "Failed to set variable value");
 };
@@ -2248,12 +2278,13 @@ ScopeDetails.prototype.setVariableValueImpl = function(name, new_value) {
  * be specified.
  * @param {FrameMirror} frame The frame this scope is a part of
  * @param {FunctionMirror} function The function this scope is a part of
+ * @param {GeneratorMirror} gen The generator this scope is a part of
  * @param {number} index The scope index in the frame
  * @param {Array=} opt_details Raw scope details data
  * @constructor
  * @extends Mirror
  */
-function ScopeMirror(frame, fun, index, opt_details) {
+function ScopeMirror(frame, fun, gen, index, opt_details) {
   %_Call(Mirror, this, MirrorType.SCOPE_TYPE);
   if (frame) {
     this.frame_index_ = frame.index_;
@@ -2261,7 +2292,7 @@ function ScopeMirror(frame, fun, index, opt_details) {
     this.frame_index_ = UNDEFINED;
   }
   this.scope_index_ = index;
-  this.details_ = new ScopeDetails(frame, fun, index, opt_details);
+  this.details_ = new ScopeDetails(frame, fun, gen, index, opt_details);
 }
 inherits(ScopeMirror, Mirror);