Fix printf formats

src/heap/gc-tracer.h

Index: src/heap/gc-tracer.h
diff --git a/src/heap/gc-tracer.h b/src/heap/gc-tracer.h
index 9ea3cce8fa0fb126bf1cd14cab39a022193bea86..9a2fab91e3a39ca5b757f3b65d7226445108fd1f 100644
--- a/src/heap/gc-tracer.h
+++ b/src/heap/gc-tracer.h
@@ -5,6 +5,7 @@
 #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"
@@ -383,7 +384,7 @@ class GCTracer {
 
   // 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;