Fix compilation when disabling debugger support.

src/runtime.cc

 // Copyright 2012 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 4874 matching lines @@
     FixedArray* object_array = FixedArray::cast(object->elements());
     object_array->set(store_index, *value);
   }
   return *object;
 }
 
 
 // Check whether debugger and is about to step into the callback that is passed
 // to a built-in function such as Array.forEach.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugCallbackSupportsStepping) {
+#ifdef ENABLE_DEBUGGER_SUPPORT
   if (!isolate->IsDebuggerActive()) return isolate->heap()->false_value();
   CONVERT_ARG_CHECKED(Object, callback, 0);
   // We do not step into the callback if it's a builtin or not even a function.
   if (!callback->IsJSFunction() || JSFunction::cast(callback)->IsBuiltin()) {
     return isolate->heap()->false_value();
   }
   return isolate->heap()->true_value();
+#else
+  return isolate->heap()->false_value();
+#endif  // ENABLE_DEBUGGER_SUPPORT
 }
 
 
 // Set one shot breakpoints for the callback function that is passed to a
 // built-in function such as Array.forEach to enable stepping into the callback.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugPrepareStepInIfStepping) {
+#ifdef ENABLE_DEBUGGER_SUPPORT
   Debug* debug = isolate->debug();
   if (!debug->IsStepping()) return NULL;
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, callback, 0);
   HandleScope scope(isolate);
   // When leaving the callback, step out has been activated, but not performed
   // if we do not leave the builtin.  To be able to step into the callback
   // again, we need to clear the step out at this point.
   debug->ClearStepOut();
   debug->FloodWithOneShot(callback);
-  return NULL;
+#endif  // ENABLE_DEBUGGER_SUPPORT
+  return isolate->heap()->undefined_value();
 }
 
 
 // Set a local property, even if it is READ_ONLY.  If the property does not
 // exist, it will be added with attributes NONE.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_IgnoreAttributesAndSetProperty) {
   NoHandleAllocation ha;
   RUNTIME_ASSERT(args.length() == 3 || args.length() == 4);
   CONVERT_ARG_CHECKED(JSObject, object, 0);
   CONVERT_ARG_CHECKED(String, name, 1);
@@ skipping 8777 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal