Implement better JS exception handling by abstracting KJS::ExecState into an ...

webkit/pending/ExceptionContext.h

+// Copyright 2008, 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
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Javascript exception abstraction
+
+#ifndef ExceptionContext_h
+#define ExceptionContext_h
+
+#include <wtf/Noncopyable.h>
+#include "ScriptController.h"
+
+namespace WebCore {
+
+class Node;
+
+// Provides context of an exception. This class is an abstraction of JSC's
+// ExecState. In V8, its purpose is to carry along the exceptions captured
+// by the ExceptionCatcher.
+class ExceptionContext : Noncopyable {
+public:
+    ExceptionContext();
+    ~ExceptionContext();
+
+    bool hadException();
+    JSException exception() const { return m_exception; }
+
+    static ExceptionContext* createFromNode(Node*);
+
+    // Returns a non-exception code object.
+    static JSException NoException();
+
+private:
+    void setException(JSException exception) { m_exception = exception; }
+
+    JSException m_exception;
+
+#if USE(V8)
+    friend class ExceptionCatcher;
+    void setExceptionCatcher(ExceptionCatcher*);
+    ExceptionCatcher* m_exceptionCatcher;
+#endif
+};
+
+#if USE(V8)
+// A wrapper around v8::TryCatch helper in order to facilitate updating
+// ExceptionContext with the latest exceptions that may have occurred.
+class ExceptionCatcher {
+public:
+    ExceptionCatcher(ExceptionContext*);
+    ~ExceptionCatcher();
+    void updateContext();
+    void detachContext();
+
+private:
+    ExceptionContext* m_context;
+    v8::TryCatch m_catcher;
+};
+#endif
+
+}  // namespace WebCore
+
+#endif  // !defined(ExceptionContext_h)