Introduce --zap-cpp-pointers (off by default)

src/type-info.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/type-info.h"
 
 #include "src/assembler-inl.h"
 #include "src/ast/ast.h"
 #include "src/code-stubs.h"
 #include "src/ic/ic.h"
@@ skipping 472 matching lines @@
                                        ZoneList<RelocInfo>* infos) {
   int mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET_WITH_ID);
   for (RelocIterator it(*code, mask); !it.done(); it.next()) {
     infos->Add(*it.rinfo(), zone());
   }
 }
 
 
 void TypeFeedbackOracle::CreateDictionary(Handle<Code> code,
                                           ZoneList<RelocInfo>* infos) {
-  AllowHeapAllocation allocation_allowed;
-  Code* old_code = *code;
+  AllowHeapAllocation will_relocate_manually;
+  // Store an (aligned) Address, so this doesn't look like a raw heap pointer
+  // to verification tools scanning the stack.
+  Address old_code_address = code->address();
   dictionary_ = UnseededNumberDictionary::New(isolate(), infos->length());
-  RelocateRelocInfos(infos, old_code, *code);
+  RelocateRelocInfos(infos, old_code_address, code->address());
 }
 
-
 void TypeFeedbackOracle::RelocateRelocInfos(ZoneList<RelocInfo>* infos,
-                                            Code* old_code,
-                                            Code* new_code) {
+                                            Address old_code_address,
+                                            Address new_code_address) {
+  intptr_t delta = new_code_address - old_code_address;
+  if (delta == 0) return;
+  Code* new_code = Code::cast(HeapObject::FromAddress(new_code_address));
   for (int i = 0; i < infos->length(); i++) {
     RelocInfo* info = &(*infos)[i];
     info->set_host(new_code);
-    info->set_pc(new_code->instruction_start() +
-                 (info->pc() - old_code->instruction_start()));
+    info->set_pc(info->pc() + delta);
   }
 }
 
 
 void TypeFeedbackOracle::ProcessRelocInfos(ZoneList<RelocInfo>* infos) {
   for (int i = 0; i < infos->length(); i++) {
     RelocInfo reloc_entry = (*infos)[i];
     Address target_address = reloc_entry.target_address();
     TypeFeedbackId ast_id =
         TypeFeedbackId(static_cast<unsigned>((*infos)[i].data()));
@@ skipping 22 matching lines @@
   // Dictionary has been allocated with sufficient size for all elements.
   DisallowHeapAllocation no_need_to_resize_dictionary;
   HandleScope scope(isolate());
   USE(UnseededNumberDictionary::AtNumberPut(
       dictionary_, IdToKey(ast_id), handle(target, isolate())));
 }
 
 
 }  // namespace internal
 }  // namespace v8