Fix printf formats

src/heap/gc-tracer.h

 // Copyright 2014 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.
 
 #ifndef V8_HEAP_GC_TRACER_H_
 #define V8_HEAP_GC_TRACER_H_
 
+#include "src/base/compiler-specific.h"
 #include "src/base/platform/platform.h"
 #include "src/counters.h"
 #include "src/globals.h"
 
 namespace v8 {
 namespace internal {
 
 template <typename T>
 class RingBuffer {
  public:
@@ skipping 358 matching lines @@
   // Print one detailed trace line in name=value format.
   // TODO(ernstm): Move to Heap.
   void PrintNVP() const;
 
   // Print one trace line.
   // TODO(ernstm): Move to Heap.
   void Print() const;
 
   // Prints a line and also adds it to the heap's ring buffer so that
   // it can be included in later crash dumps.
-  void Output(const char* format, ...) const;
+  void PRINTF_FORMAT(2, 3) Output(const char* format, ...) const;
 
   void ClearMarkCompactStatistics() {
     cumulative_incremental_marking_steps_ = 0;
     cumulative_incremental_marking_bytes_ = 0;
     cumulative_incremental_marking_duration_ = 0;
     cumulative_pure_incremental_marking_duration_ = 0;
     longest_incremental_marking_step_ = 0;
     cumulative_incremental_marking_finalization_steps_ = 0;
     cumulative_incremental_marking_finalization_duration_ = 0;
     longest_incremental_marking_finalization_step_ = 0;
@@ skipping 93 matching lines @@
   RingBuffer<BytesAndDuration> recorded_old_generation_allocations_;
   RingBuffer<double> recorded_context_disposal_times_;
   RingBuffer<double> recorded_survival_ratios_;
 
   DISALLOW_COPY_AND_ASSIGN(GCTracer);
 };
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_GC_TRACER_H_