Merged: [runtime stats] Fix crash after r41001

src/counters.cc

 // Copyright 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.
 
 #include "src/counters.h"
 
 #include <iomanip>
 
 #include "src/base/platform/platform.h"
 #include "src/isolate.h"
@@ skipping 295 matching lines @@
 #undef CALL_BUILTIN_COUNTER
 #define CALL_BUILTIN_COUNTER(name) &RuntimeCallStats::Handler_##name,
     FOR_EACH_HANDLER_COUNTER(CALL_BUILTIN_COUNTER)
 #undef CALL_BUILTIN_COUNTER
 };
 
 // static
 void RuntimeCallStats::Enter(RuntimeCallStats* stats, RuntimeCallTimer* timer,
                              CounterId counter_id) {
   RuntimeCallCounter* counter = &(stats->*counter_id);
-  DCHECK(counter->name != NULL);
+  DCHECK(counter->name != nullptr);
   timer->Start(counter, stats->current_timer_.Value());
   stats->current_timer_.SetValue(timer);
 }
 
 // static
 void RuntimeCallStats::Leave(RuntimeCallStats* stats, RuntimeCallTimer* timer) {
   if (stats->current_timer_.Value() == timer) {
     stats->current_timer_.SetValue(timer->Stop());
   } else {
     // Must be a Threading cctest. Walk the chain of Timers to find the
     // buried one that's leaving. We don't care about keeping nested timings
     // accurate, just avoid crashing by keeping the chain intact.
     RuntimeCallTimer* next = stats->current_timer_.Value();
-    while (next->parent() != timer) next = next->parent();
+    while (next && next->parent() != timer) next = next->parent();
+    if (next == nullptr) return;
     next->parent_.SetValue(timer->Stop());
   }
 }
 
 void RuntimeCallStats::Add(RuntimeCallStats* other) {
   for (const RuntimeCallStats::CounterId counter_id :
        RuntimeCallStats::counters) {
     RuntimeCallCounter* counter = &(this->*counter_id);
     RuntimeCallCounter* other_counter = &(other->*counter_id);
     counter->Add(other_counter);
@@ skipping 47 matching lines @@
        RuntimeCallStats::counters) {
     RuntimeCallCounter* counter = &(this->*counter_id);
     if (counter->count > 0) counter->Dump(value);
   }
 
   in_use_ = false;
 }
 
 }  // namespace internal
 }  // namespace v8