Replaced empty handle checks with MaybeHandles

src/jsregexp.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 58 matching lines @@
   // generic data and choice of implementation - as well as what
   // the implementation wants to store in the data field.
   // Returns false if compilation fails.
   MUST_USE_RESULT static MaybeHandle<Object> Compile(
       Handle<JSRegExp> re,
       Handle<String> pattern,
       Handle<String> flags);
 
   // See ECMA-262 section 15.10.6.2.
   // This function calls the garbage collector if necessary.
-  static Handle<Object> Exec(Handle<JSRegExp> regexp,
-                             Handle<String> subject,
-                             int index,
-                             Handle<JSArray> lastMatchInfo);
+  MUST_USE_RESULT static MaybeHandle<Object> Exec(
+      Handle<JSRegExp> regexp,
+      Handle<String> subject,
+      int index,
+      Handle<JSArray> lastMatchInfo);
 
   // Prepares a JSRegExp object with Irregexp-specific data.
   static void IrregexpInitialize(Handle<JSRegExp> re,
                                  Handle<String> pattern,
                                  JSRegExp::Flags flags,
                                  int capture_register_count);
 
 
   static void AtomCompile(Handle<JSRegExp> re,
                           Handle<String> pattern,
@@ skipping 34 matching lines @@
   static int IrregexpExecRaw(Handle<JSRegExp> regexp,
                              Handle<String> subject,
                              int index,
                              int32_t* output,
                              int output_size);
 
   // Execute an Irregexp bytecode pattern.
   // On a successful match, the result is a JSArray containing
   // captured positions.  On a failure, the result is the null value.
   // Returns an empty handle in case of an exception.
-  static Handle<Object> IrregexpExec(Handle<JSRegExp> regexp,
-                                     Handle<String> subject,
-                                     int index,
-                                     Handle<JSArray> lastMatchInfo);
+  MUST_USE_RESULT static MaybeHandle<Object> IrregexpExec(
+      Handle<JSRegExp> regexp,
+      Handle<String> subject,
+      int index,
+      Handle<JSArray> lastMatchInfo);
 
   // Set last match info.  If match is NULL, then setting captures is omitted.
   static Handle<JSArray> SetLastMatchInfo(Handle<JSArray> last_match_info,
                                           Handle<String> subject,
                                           int capture_count,
                                           int32_t* match);
 
 
   class GlobalCache {
    public:
@@ skipping 1486 matching lines @@
                                    Handle<String> sample_subject,
                                    bool is_ascii, Zone* zone);
 
   static void DotPrint(const char* label, RegExpNode* node, bool ignore_case);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSREGEXP_H_