1  /*
 2   * Copyright (C) 2015-2019 Apple Inc. All rights reserved.
 3   *
 4   * Redistribution and use in source and binary forms, with or without
 5   * modification, are permitted provided that the following conditions
 6   * are met:
 7   * 1. Redistributions of source code must retain the above copyright
 8   *    notice, this list of conditions and the following disclaimer.
 9   * 2. Redistributions in binary form must reproduce the above copyright
10   *    notice, this list of conditions and the following disclaimer in the
11   *    documentation and/or other materials provided with the distribution.
12   *
13   * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24   */
25  
26  #pragma once
27  
28  #include "JSDestructibleObject.h"
29  #include "StackFrame.h"
30  #include <wtf/Vector.h>
31  
32  namespace JSC {
33      
34  class Exception final : public JSCell {
35  public:
36      using Base = JSCell;
37      static constexpr unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
38      static constexpr bool needsDestruction = true;
39  
40      template<typename CellType, SubspaceAccess mode>
41      static IsoSubspace* subspaceFor(VM& vm)
42      {
43          return &vm.exceptionSpace;
44      }
45  
46      enum StackCaptureAction {
47          CaptureStack,
48          DoNotCaptureStack
49      };
50      JS_EXPORT_PRIVATE static Exception* create(VM&, JSValue thrownValue, StackCaptureAction = CaptureStack);
51  
52      static Structure* createStructure(VM&, JSGlobalObject*, JSValue prototype);
53  
54      static void visitChildren(JSCell*, SlotVisitor&);
55  
56      DECLARE_EXPORT_INFO;
57  
58      static ptrdiff_t valueOffset()
59      {
60          return OBJECT_OFFSETOF(Exception, m_value);
61      }
62  
63      JSValue value() const { return m_value.get(); }
64      const Vector<StackFrame>& stack() const { return m_stack; }
65  
66      bool didNotifyInspectorOfThrow() const { return m_didNotifyInspectorOfThrow; }
67      void setDidNotifyInspectorOfThrow() { m_didNotifyInspectorOfThrow = true; }
68  
69      ~Exception();
70  
71  private:
72      Exception(VM&);
73      void finishCreation(VM&, JSValue thrownValue, StackCaptureAction);
74      static void destroy(JSCell*);
75  
76      WriteBarrier<Unknown> m_value;
77      Vector<StackFrame> m_stack;
78      bool m_didNotifyInspectorOfThrow { false };
79  
80      friend class LLIntOffsetsExtractor;
81  };
82  
83  } // namespace JSC