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

src/flag-definitions.h

 // Copyright 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 319 matching lines @@
 DEFINE_bool(log_state_changes, false, "Log state changes.")
 DEFINE_bool(log_suspect, false, "Log suspect operations.")
 DEFINE_bool(prof, false,
             "Log statistical profiling information (implies --log-code).")
 DEFINE_bool(prof_auto, true,
             "Used with --prof, starts profiling automatically")
 DEFINE_bool(log_regexp, false, "Log regular expression execution.")
 DEFINE_bool(sliding_state_window, false,
             "Update sliding state window counters.")
 DEFINE_string(logfile, "v8.log", "Specify the name of the log file.")
-DEFINE_bool(oprofile, false,
-            "Enable JIT agent for OProfile.")
+DEFINE_bool(oprofile, false, "Enable JIT agent for OProfile.")
+
+//
+// Heap protection flags
+// Using heap protection requires ENABLE_LOGGING_AND_PROFILING as well.
+//
+#ifdef ENABLE_HEAP_PROTECTION
+#undef FLAG
+#define FLAG FLAG_FULL
+
+DEFINE_bool(protect_heap, false,
+            "Protect/unprotect V8's heap when leaving/entring the VM.")
+
+#endif
 
 //
 // Disassembler only flags
 //
 #undef FLAG
 #ifdef ENABLE_DISASSEMBLER
 #define FLAG FLAG_FULL
 #else
 #define FLAG FLAG_READONLY
 #endif
@@ skipping 11 matching lines @@
 #undef FLAG
 
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META