Add support for javascript incompatibility warnings.

runtime/vm/exceptions.h

 // Copyright (c) 2011, 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_EXCEPTIONS_H_
 #define VM_EXCEPTIONS_H_
 
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
 
 namespace dart {
 
 // Forward declarations.
 class Class;
 class DartFrameIterator;
 class Error;
 class Instance;
 class Object;
 class RawInstance;
 class RawScript;
 class RawStacktrace;
 class RawObject;
 class Script;
+class StackFrame;
 class String;
 
 class Exceptions : AllStatic {
  public:
   static const char* kCastErrorDstName;
 
   static void Throw(const Instance& exception);
   static void ReThrow(const Instance& exception, const Instance& stacktrace);
   static void PropagateError(const Error& error);
+
+  // Report a Javascript compatibility warning at the call site given by
+  // caller_frame. Note that a JavascriptCompatibilityError is thrown
+  // if --warning_as_error is specified.
+  static void JSWarning(StackFrame* caller_frame, const char* format, ...)
+      PRINTF_ATTRIBUTE(2, 3);
+
   static RawStacktrace* CurrentStacktrace();
 
   // Helpers to create and throw errors.
   static RawScript* GetCallerScript(DartFrameIterator* iterator);
   static RawInstance* NewInstance(const char* class_name);
   static void CreateAndThrowTypeError(intptr_t location,
                                       const String& src_type_name,
                                       const String& dst_type_name,
                                       const String& dst_name,
                                       const String& error_msg);
 
   enum ExceptionType {
     kNone,
     kRange,
     kArgument,
     kNoSuchMethod,
     kFormat,
     kUnsupported,
     kStackOverflow,
     kOutOfMemory,
     kInternalError,
     kNullThrown,
     kIsolateSpawn,
     kIsolateUnhandledException,
     kJavascriptIntegerOverflowError,
+    kJavascriptCompatibilityError,
     kAssertion,
     kCast,
     kType,
     kFallThrough,
     kAbstractClassInstantiation,
     kMirroredCompilationError,
   };
 
   static void ThrowByType(ExceptionType type, const Array& arguments);
   static void ThrowOOM();
   static void ThrowStackOverflow();
   static void ThrowArgumentError(const Instance& arg);
 
   // Returns a RawInstance if the exception is successfully created,
   // otherwise returns a RawError.
   static RawObject* Create(ExceptionType type, const Array& arguments);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Exceptions);
 };
 
 }  // namespace dart
 
 #endif  // VM_EXCEPTIONS_H_