Enforce ScriptForbiddenScope and make it non-fatal.

Source/bindings/core/v8/V8RecursionScope.h

 /*
  * Copyright (C) 2011 Google Inc. 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
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef V8RecursionScope_h
 #define V8RecursionScope_h
 
 #include "bindings/core/v8/V8PerIsolateData.h"
 #include "core/dom/ExecutionContext.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "wtf/Noncopyable.h"
+#include "wtf/PassOwnPtr.h"
 #include <v8.h>
 
 namespace blink {
 
 // C++ calls into script contexts which are "owned" by WebKit (created in a
 // process where WebKit.cpp initializes v8) must declare their type:
 //
 //   1. Calls into page/author script from a frame
 //   2. Calls into page/author script from a worker
 //   3. Calls into internal script (typically setup/teardown work)
 //
 // Debug-time checking of this is enforced via this class.
 //
 // Calls of type (1) should generally go through ScriptController, as inspector
 // instrumentation is needed. ScriptController allocates V8RecursionScope for you.
 // Calls of type (2) should always stack-allocate a V8RecursionScope in the same
 // block as the call into script. Calls of type (3) should stack allocate a
 // V8RecursionScope::MicrotaskSuppression -- this skips work that is spec'd to
 // happen at the end of the outer-most script stack frame of calls into page script:
 //
 // http://www.whatwg.org/specs/web-apps/current-work/#perform-a-microtask-checkpoint
 class V8RecursionScope {
     WTF_MAKE_NONCOPYABLE(V8RecursionScope);
 public:
-    explicit V8RecursionScope(v8::Isolate* isolate)
-        : m_isolate(isolate)
+    static PassOwnPtr<V8RecursionScope> create(v8::Isolate* isolate)

[haraken, 2014/10/14 01:04:29]

Shall we rename create => createIfScriptAllowed ?

     {
-        V8PerIsolateData::from(m_isolate)->incrementRecursionLevel();
-        RELEASE_ASSERT(!ScriptForbiddenScope::isScriptForbidden());
-        // If you want V8 to autorun microtasks, this class needs to have a
-        // v8::Isolate::SuppressMicrotaskExecutionScope member.
-        ASSERT(!isolate->WillAutorunMicrotasks());
+        return !ScriptForbiddenScope::isScriptForbidden()
+            ? adoptPtr(new V8RecursionScope(isolate))
+            : nullptr;
     }
 
     ~V8RecursionScope()
     {
         if (!V8PerIsolateData::from(m_isolate)->decrementRecursionLevel())
             didLeaveScriptContext();
     }
 
     static int recursionLevel(v8::Isolate* isolate)
     {
         return V8PerIsolateData::from(isolate)->recursionLevel();
     }
 
 #if ENABLE(ASSERT)
     static bool properlyUsed(v8::Isolate* isolate)
     {
         return recursionLevel(isolate) > 0 || V8PerIsolateData::from(isolate)->internalScriptRecursionLevel() > 0;
     }
 #endif
 
     class MicrotaskSuppression {

[haraken, 2014/10/14 01:04:30]

You need to take care of MicrotaskSuppression as well.

     public:
         MicrotaskSuppression(v8::Isolate* isolate)
 #if ENABLE(ASSERT)
             : m_isolate(isolate)
 #endif
         {
             ASSERT(!ScriptForbiddenScope::isScriptForbidden());
 #if ENABLE(ASSERT)
             V8PerIsolateData::from(m_isolate)->incrementInternalScriptRecursionLevel();
 #endif
         }
 
         ~MicrotaskSuppression()
         {
 #if ENABLE(ASSERT)
             V8PerIsolateData::from(m_isolate)->decrementInternalScriptRecursionLevel();
 #endif
         }
 
     private:
 #if ENABLE(ASSERT)
         v8::Isolate* m_isolate;
 #endif
     };
 
 private:
+    explicit V8RecursionScope(v8::Isolate* isolate)
+        : m_isolate(isolate)
+    {
+        V8PerIsolateData::from(m_isolate)->incrementRecursionLevel();
+        // If you want V8 to autorun microtasks, this class needs to have a
+        // v8::Isolate::SuppressMicrotaskExecutionScope member.
+        ASSERT(!isolate->WillAutorunMicrotasks());
+    }
+
     void didLeaveScriptContext();
 
     v8::Isolate* m_isolate;
 };
 
 } // namespace blink
 
 #endif // V8RecursionScope_h