[WIP] TrapHandler 2014/11/27.

src/isolate.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 <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/v8.h"
@@ skipping 2514 matching lines @@
   if (FLAG_trace_turbo_cfg_file == NULL) {
     std::ostringstream os;
     os << "turbo-" << base::OS::GetCurrentProcessId() << "-" << id() << ".cfg";
     return os.str();
   } else {
     return FLAG_trace_turbo_cfg_file;
   }
 }
 
 
+void Isolate::AddGuardArea(void const* address, size_t const length) {
+  DCHECK(address != nullptr);
+  DCHECK(length != 0);
+  DCHECK((bit_cast<uintptr_t>(address) % base::OS::CommitPageSize()) == 0);
+  DCHECK((length % base::OS::CommitPageSize()) == 0);
+  DCHECK(!IsInGuardArea(address));
+  base::OS::Guard(const_cast<void*>(address), length);
+  guard_areas_.push_back(
+      std::make_pair(address, static_cast<uint8_t const*>(address) + length));
+}
+
+
+void Isolate::RemoveGuardArea(void const* address, size_t const length) {
+  DCHECK(address != nullptr);
+  DCHECK(length != 0);
+  DCHECK((bit_cast<uintptr_t>(address) % base::OS::CommitPageSize()) == 0);
+  DCHECK((length % base::OS::CommitPageSize()) == 0);
+  base::OS::Unguard(const_cast<void*>(address), length);
+  for (auto i = guard_areas_.begin(); ; ++i) {
+    DCHECK(i != guard_areas_.end());
+    if (i->first == address) {
+      guard_areas_.erase(i);
+      break;
+    }
+  }
+}
+
+
+bool Isolate::IsInGuardArea(void const* address) const {
+  for (auto i = guard_areas_.begin(); i != guard_areas_.end(); ++i) {
+    if (i->first <= address && address < i->second) {
+      return true;
+    }
+  }
+  return false;
+}
+
+
 bool StackLimitCheck::JsHasOverflowed() const {
   StackGuard* stack_guard = isolate_->stack_guard();
 #ifdef USE_SIMULATOR
   // The simulator uses a separate JS stack.
   Address jssp_address = Simulator::current(isolate_)->get_sp();
   uintptr_t jssp = reinterpret_cast<uintptr_t>(jssp_address);
   if (jssp < stack_guard->real_jslimit()) return true;
 #endif  // USE_SIMULATOR
   return GetCurrentStackPosition() < stack_guard->real_climit();
 }
 
 
 bool PostponeInterruptsScope::Intercept(StackGuard::InterruptFlag flag) {
   // First check whether the previous scope intercepts.
   if (prev_ && prev_->Intercept(flag)) return true;
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 } }  // namespace v8::internal