Add attributions so printf like functions can have their arguments checked.

runtime/vm/il_printer.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_IL_PRINTER_H_
 #define VM_IL_PRINTER_H_
 
 #include "vm/flow_graph.h"
 #include "vm/intermediate_language.h"
 
 namespace dart {
 
 class BufferFormatter : public ValueObject {
  public:
   BufferFormatter(char* buffer, intptr_t size)
     : position_(0),
       buffer_(buffer),
       size_(size) { }
 
   void VPrint(const char* format, va_list args);
-  void Print(const char* format, ...);
+  void Print(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
 
  private:
   intptr_t position_;
   char* buffer_;
   const intptr_t size_;
 
   DISALLOW_COPY_AND_ASSIGN(BufferFormatter);
 };
 
 
@@ skipping 33 matching lines @@
   explicit FlowGraphVisualizer(const FlowGraph& flow_graph)
       : function_(flow_graph.parsed_function().function()),
         block_order_(flow_graph.reverse_postorder()),
         indent_(0) { }
 
   void PrintFunction();
 
  private:
   // Helpers for printing.
   void PrintInstruction(Instruction* instr);
-  void Print(const char* format, ...);
+  void Print(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
 
   const Function& function_;
   const GrowableArray<BlockEntryInstr*>& block_order_;
   intptr_t indent_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisualizer);
 };
 
 }  // namespace dart
 
 #endif  // VM_IL_PRINTER_H_