Force checking of result on all functions in elements.h that return MaybeObject*.

src/elements.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 42 matching lines @@
   virtual bool HasElement(Object* receiver,
                           JSObject* holder,
                           uint32_t key,
                           FixedArrayBase* backing_store = NULL) = 0;
 
   // Returns the element with the specified key or undefined if there is no such
   // element. This method doesn't iterate up the prototype chain.  The caller
   // can optionally pass in the backing store to use for the check, which must
   // be compatible with the ElementsKind of the ElementsAccessor. If
   // backing_store is NULL, the holder->elements() is used as the backing store.
-  virtual MaybeObject* Get(Object* receiver,
-                           JSObject* holder,
-                           uint32_t key,
-                           FixedArrayBase* backing_store = NULL) = 0;
+  MUST_USE_RESULT virtual MaybeObject* Get(
+      Object* receiver,
+      JSObject* holder,
+      uint32_t key,
+      FixedArrayBase* backing_store = NULL) = 0;
 
   // Modifies the length data property as specified for JSArrays and resizes the
   // underlying backing store accordingly. The method honors the semantics of
   // changing array sizes as defined in EcmaScript 5.1 15.4.5.2, i.e. array that
   // have non-deletable elements can only be shrunk to the size of highest
   // element that is non-deletable.
-  virtual MaybeObject* SetLength(JSArray* holder,
-                                 Object* new_length) = 0;
+  MUST_USE_RESULT virtual MaybeObject* SetLength(JSArray* holder,
+                                                 Object* new_length) = 0;
 
   // Modifies both the length and capacity of a JSArray, resizing the underlying
   // backing store as necessary. This method does NOT honor the semantics of
   // EcmaScript 5.1 15.4.5.2, arrays can be shrunk beyond non-deletable
   // elements. This method should only be called for array expansion OR by
   // runtime JavaScript code that use InternalArrays and don't care about
   // EcmaScript 5.1 semantics.
-  virtual MaybeObject* SetCapacityAndLength(JSArray* array,
-                                            int capacity,
-                                            int length) = 0;
+  MUST_USE_RESULT virtual MaybeObject* SetCapacityAndLength(JSArray* array,
+                                                            int capacity,
+                                                            int length) = 0;
 
   // Deletes an element in an object, returning a new elements backing store.
-  virtual MaybeObject* Delete(JSObject* holder,
-                              uint32_t key,
-                              JSReceiver::DeleteMode mode) = 0;
+  MUST_USE_RESULT virtual MaybeObject* Delete(JSObject* holder,
+                                              uint32_t key,
+                                              JSReceiver::DeleteMode mode) = 0;
 
   // If kCopyToEnd is specified as the copy_size to CopyElements, it copies all
   // of elements from source after source_start to the destination array.
   static const int kCopyToEnd = -1;
   // If kCopyToEndAndInitializeToHole is specified as the copy_size to
   // CopyElements, it copies all of elements from source after source_start to
   // destination array, padding any remaining uninitialized elements in the
   // destination array with the hole.
   static const int kCopyToEndAndInitializeToHole = -2;
 
   // Copy elements from one backing store to another. Typically, callers specify
   // the source JSObject or JSArray in source_holder. If the holder's backing
   // store is available, it can be passed in source and source_holder is
   // ignored.
-  virtual MaybeObject* CopyElements(JSObject* source_holder,
-                                    uint32_t source_start,
-                                    FixedArrayBase* destination,
-                                    ElementsKind destination_kind,
-                                    uint32_t destination_start,
-                                    int copy_size,
-                                    FixedArrayBase* source = NULL) = 0;
+  MUST_USE_RESULT virtual MaybeObject* CopyElements(
+      JSObject* source_holder,
+      uint32_t source_start,
+      FixedArrayBase* destination,
+      ElementsKind destination_kind,
+      uint32_t destination_start,
+      int copy_size,
+      FixedArrayBase* source = NULL) = 0;
 
-  MaybeObject* CopyElements(JSObject* from_holder,
-                            FixedArrayBase* to,
-                            ElementsKind to_kind,
-                            FixedArrayBase* from = NULL) {
+  MUST_USE_RESULT MaybeObject* CopyElements(JSObject* from_holder,
+                                            FixedArrayBase* to,
+                                            ElementsKind to_kind,
+                                            FixedArrayBase* from = NULL) {
     return CopyElements(from_holder, 0, to, to_kind, 0,
                         kCopyToEndAndInitializeToHole, from);
   }
 
-  virtual MaybeObject* AddElementsToFixedArray(Object* receiver,
-                                               JSObject* holder,
-                                               FixedArray* to,
-                                               FixedArrayBase* from = NULL) = 0;
+  MUST_USE_RESULT virtual MaybeObject* AddElementsToFixedArray(
+      Object* receiver,
+      JSObject* holder,
+      FixedArray* to,
+      FixedArrayBase* from = NULL) = 0;
 
   // Returns a shared ElementsAccessor for the specified ElementsKind.
   static ElementsAccessor* ForKind(ElementsKind elements_kind) {
     ASSERT(elements_kind < kElementsKindCount);
     return elements_accessors_[elements_kind];
   }
 
   static ElementsAccessor* ForArray(FixedArrayBase* array);
 
   static void InitializeOncePerProcess();
@@ skipping 28 matching lines @@
                                 uint32_t from_start,
                                 FixedArray* to_obj,
                                 ElementsKind to_kind,
                                 uint32_t to_start,
                                 int copy_size);
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ELEMENTS_H_