1  /*
 2   * Copyright (C) 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  #include "config.h"
27  #include "WideningNumberPredictionFuzzerAgent.h"
28  
29  #include "CodeBlock.h"
30  
31  namespace JSC {
32  
33  WideningNumberPredictionFuzzerAgent::WideningNumberPredictionFuzzerAgent(VM& vm)
34      : NumberPredictionFuzzerAgent(vm)
35  {
36  }
37  
38  SpeculatedType WideningNumberPredictionFuzzerAgent::getPrediction(CodeBlock* codeBlock, const CodeOrigin& codeOrigin, SpeculatedType original)
39  {
40      auto locker = holdLock(m_lock);
41  
42      if (!(original && speculationChecked(original, SpecBytecodeNumber)))
43          return original;
44  
45      if (original == SpecBytecodeNumber)
46          return original;
47  
48      Vector<SpeculatedType> numberTypesNotIncludedInSpeculation;
49      for (auto numberType : bytecodeNumberTypes()) {
50          if (!(numberType & original))
51              numberTypesNotIncludedInSpeculation.append(numberType);
52      }
53  
54      unsigned numberOfTypesToAdd = m_random.getUint32(numberTypesNotIncludedInSpeculation.size() + 1);
55      if (!numberOfTypesToAdd)
56          return original;
57  
58      SpeculatedType generated = original;
59      for (unsigned i = 0; i < numberOfTypesToAdd; i++) {
60          unsigned indexOfNewType = m_random.getUint32(numberTypesNotIncludedInSpeculation.size());
61          mergeSpeculation(generated, numberTypesNotIncludedInSpeculation[indexOfNewType]);
62          numberTypesNotIncludedInSpeculation.remove(indexOfNewType);
63      }
64  
65      if (Options::dumpFuzzerAgentPredictions())
66          dataLogLn("WideningNumberPredictionFuzzerAgent::getPrediction name:(", codeBlock->inferredName(), "#", codeBlock->hashAsStringIfPossible(), "),bytecodeIndex:(", codeOrigin.bytecodeIndex(), "),original:(", SpeculationDump(original), "),generated:(", SpeculationDump(generated), ")");
67  
68      return generated;
69  }
70  
71  } // namespace JSC