Add basic infrastructure for protecting V8's heap when leaving the VM...

src/platform-freebsd.cc

 // Copyright 2006-2008 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 242 matching lines @@
   return mbase;
 }
 
 
 void OS::Free(void* buf, const size_t length) {
   // TODO(1240712): munmap has a return value which is ignored here.
   munmap(buf, length);
 }
 
 
+#ifdef ENABLE_HEAP_PROTECTION
+
+void OS::Protect(void* address, size_t size) {
+  UNIMPLEMENTED();
+}
+
+
+void OS::Unprotect(void* address, size_t size, bool is_executable) {
+  UNIMPLEMENTED();
+}
+
+#endif
+
+
 void OS::Sleep(int milliseconds) {
   unsigned int ms = static_cast<unsigned int>(milliseconds);
   usleep(1000 * ms);
 }
 
 
 void OS::Abort() {
   // Redirect to std abort to signal abnormal program termination.
   abort();
 }
@@ skipping 628 matching lines @@
   }
 
   // This sampler is no longer the active sampler.
   active_sampler_ = NULL;
   active_ = false;
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal