dfg/DFGAnalysis.h

   1 /*
   2  * Copyright (C) 2013, 2014 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 #ifndef DFGAnalysis_h
  27 #define DFGAnalysis_h
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 namespace JSC { namespace DFG {
  32
  33 class Graph;
  34
  35 // Use this as a mixin for DFG analyses. The analysis itself implements a public
  36 // compute(Graph&) method. Clients call computeIfNecessary() when they want
  37 // results.
  38
  39 template<typename T>
  40 class Analysis {
  41 public:
  42     Analysis()
  43         : m_valid(false)
  44     {
  45     }
  46
  47     void invalidate()
  48     {
  49         m_valid = false;
  50     }
  51
  52     void computeIfNecessary(Graph& graph)
  53     {
  54         if (m_valid)
  55             return;
  56         // It's best to run dependent analyses from this method.
  57         static_cast<T*>(this)->computeDependencies(graph);
  58         // Set to true early, since the analysis may choose to call its own methods in
  59         // compute() and it may want to ASSERT() validity in those methods.
  60         m_valid = true;
  61         static_cast<T*>(this)->compute(graph);
  62     }
  63
  64     bool isValid() const { return m_valid; }
  65
  66     // Override this to compute any dependent analyses. See
  67     // NaturalLoops::computeDependencies(Graph&) for an example. This isn't strictly necessary but
  68     // it makes debug dumps in cases of error work a bit better because this analysis wouldn't yet
  69     // be pretending to be valid.
  70     void computeDependencies(Graph&) { }
  71
  72 private:
  73     bool m_valid;
  74 };
  75
  76 } } // namespace JSC::DFG
  77
  78 #endif // ENABLE(DFG_JIT)
  79
  80 #endif // DFGAnalysis_h
  81