Add basic C++ implementation of CPU profiler.

src/handles.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 496 matching lines @@
     if ((Smi::cast(line_ends_array->get(left + half)))->value() > code_pos) {
       right -= half;
     } else {
       left += half;
     }
   }
   return right + script->line_offset()->value();
 }
 
 
+int GetScriptLineNumberSafe(Handle<Script> script, int code_pos) {
+  AssertNoAllocation no_allocation;
+  if (!script->line_ends()->IsUndefined()) {
+    return GetScriptLineNumber(script, code_pos);
+  }
+  // Slow mode: we do not have line_ends. We have to iterate through source.
+  if (!script->source()->IsString()) {
+    return -1;
+  }
+  String* source = String::cast(script->source());
+  int line = 0;
+  int len = source->length();
+  for (int pos = 0; pos < len; pos++) {
+    if (pos == code_pos) {
+      break;
+    }
+    if (source->Get(pos) == '\n') {
+      line++;
+    }
+  }
+  return line;
+}
+
+
 void CustomArguments::IterateInstance(ObjectVisitor* v) {
   v->VisitPointers(values_, values_ + 4);
 }
 
 
 // Compute the property keys from the interceptor.
 v8::Handle<v8::Array> GetKeysForNamedInterceptor(Handle<JSObject> receiver,
                                                  Handle<JSObject> object) {
   Handle<InterceptorInfo> interceptor(object->GetNamedInterceptor());
   CustomArguments args(interceptor->data(), *receiver, *object);
@@ skipping 311 matching lines @@
   Handle<Map> new_map = Factory::CopyMapDropTransitions(old_map);
   obj->set_map(*new_map);
   new_map->set_needs_loading(true);
   // Store the lazy loading info in the constructor field.  We'll
   // reestablish the constructor from the fixed array after loading.
   new_map->set_constructor(*arr);
   ASSERT(!obj->IsLoaded());
 }
 
 } }  // namespace v8::internal