Add 'address' vm service message that finds heap objects.

runtime/vm/service.cc

 // Copyright (c) 2013, 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.
 
 #include "vm/service.h"
 
 #include "include/dart_api.h"
+#include "platform/globals.h"
 
 #include "vm/compiler.h"
 #include "vm/coverage.h"
 #include "vm/cpu.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/isolate.h"
 #include "vm/message.h"
 #include "vm/message_handler.h"
@@ skipping 1425 matching lines @@
   return true;
 }
 
 
 static bool HandleHeapMap(Isolate* isolate, JSONStream* js) {
   isolate->heap()->PrintHeapMapToJSONStream(js);
   return true;
 }
 
 
+class ContainsAddressVisitor : public FindObjectVisitor {
+ public:
+  ContainsAddressVisitor(Isolate* isolate, uword addr)
+      : FindObjectVisitor(isolate), addr_(addr) { }
+  virtual ~ContainsAddressVisitor() { }
+
+  virtual uword filter_addr() const { return addr_; }
+
+  virtual bool FindObject(RawObject* obj) const {
+    uword obj_begin = RawObject::ToAddr(obj);
+    uword obj_end = obj_begin + obj->Size();
+    return obj_begin <= addr_ && addr_ < obj_end;
+  }
+ private:
+  uword addr_;
+};
+
+
+static bool HandleAddress(Isolate* isolate, JSONStream* js) {
+  uword addr = 0;
+  if (js->num_arguments() != 2 ||
+      !GetUnsignedIntegerId(js->GetArgument(1), &addr, 16)) {
+    static const uword kExampleAddr = static_cast<uword>(kIntptrMax / 7);
+    PrintError(js, "Must specify address: address/" Px ".", kExampleAddr);
+    return true;
+  }
+  Object& object = Object::Handle(isolate);
+  {
+    NoGCScope no_gc;
+    ContainsAddressVisitor visitor(isolate, addr);
+    object = isolate->heap()->FindObject(&visitor);
+  }
+  object.PrintToJSONStream(js, true);
+  return true;
+}
+
+
 static IsolateMessageHandlerEntry isolate_handlers[] = {
   { "_echo", HandleIsolateEcho },
   { "", HandleIsolate },
+  { "address", HandleAddress },
   { "allocationprofile", HandleAllocationProfile },
   { "classes", HandleClasses },
   { "code", HandleCode },
   { "coverage", HandleCoverage },
   { "cpu", HandleCpu },
   { "debug", HandleDebug },
   { "heapmap", HandleHeapMap },
   { "libraries", HandleLibraries },
   { "objects", HandleObjects },
   { "profile", HandleProfile },
@@ skipping 212 matching lines @@
   while (current != NULL) {
     if (strcmp(name, current->name()) == 0) {
       return current;
     }
     current = current->next();
   }
   return NULL;
 }
 
 }  // namespace dart