1  /*
 2   * Copyright (C) 2012-2019 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 "UnlinkedGlobalCodeBlock.h"
29  
30  namespace JSC {
31  
32  class CachedEvalCodeBlock;
33  
34  class UnlinkedEvalCodeBlock final : public UnlinkedGlobalCodeBlock {
35  public:
36      typedef UnlinkedGlobalCodeBlock Base;
37      static constexpr unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
38  
39      template<typename CellType, SubspaceAccess mode>
40      static IsoSubspace* subspaceFor(VM& vm)
41      {
42          return vm.unlinkedEvalCodeBlockSpace<mode>();
43      }
44  
45      static UnlinkedEvalCodeBlock* create(VM& vm, const ExecutableInfo& info, OptionSet<CodeGenerationMode> codeGenerationMode)
46      {
47          UnlinkedEvalCodeBlock* instance = new (NotNull, allocateCell<UnlinkedEvalCodeBlock>(vm.heap)) UnlinkedEvalCodeBlock(vm, vm.unlinkedEvalCodeBlockStructure.get(), info, codeGenerationMode);
48          instance->finishCreation(vm);
49          return instance;
50      }
51  
52      static void destroy(JSCell*);
53  
54      const Identifier& variable(unsigned index) { return m_variables[index]; }
55      unsigned numVariables() { return m_variables.size(); }
56      void adoptVariables(Vector<Identifier, 0, UnsafeVectorOverflow>& variables)
57      {
58          ASSERT(m_variables.isEmpty());
59          m_variables.swap(variables);
60      }
61  
62      const Identifier& functionHoistingCandidate(unsigned index) { return m_functionHoistingCandidates[index]; }
63      unsigned numFunctionHoistingCandidates() { return m_functionHoistingCandidates.size(); }
64      void adoptFunctionHoistingCandidates(Vector<Identifier, 0, UnsafeVectorOverflow>&& functionHoistingCandidates)
65      {
66          ASSERT(m_functionHoistingCandidates.isEmpty());
67          m_functionHoistingCandidates = WTFMove(functionHoistingCandidates);
68      }
69  private:
70      friend CachedEvalCodeBlock;
71  
72      UnlinkedEvalCodeBlock(VM& vm, Structure* structure, const ExecutableInfo& info, OptionSet<CodeGenerationMode> codeGenerationMode)
73          : Base(vm, structure, EvalCode, info, codeGenerationMode)
74      {
75      }
76  
77      UnlinkedEvalCodeBlock(Decoder&, const CachedEvalCodeBlock&);
78  
79      Vector<Identifier, 0, UnsafeVectorOverflow> m_variables;
80      Vector<Identifier, 0, UnsafeVectorOverflow> m_functionHoistingCandidates;
81  
82  public:
83      static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue proto)
84      {
85          return Structure::create(vm, globalObject, proto, TypeInfo(UnlinkedEvalCodeBlockType, StructureFlags), info());
86      }
87  
88      DECLARE_INFO;
89  };
90  
91  }