mcs/class/Mono.CodeContracts/Mono.CodeContracts.Static.Analysis.ExpressionAnalysis/AssumeDecoder.cs

   1 //
   2 // AssumeDecoder.cs
   3 //
   4 // Authors:
   5 //      Alexander Chebaturkin (chebaturkin@gmail.com)
   6 //
   7 // Copyright (C) 2011 Alexander Chebaturkin
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using Mono.CodeContracts.Static.AST;
  31 using Mono.CodeContracts.Static.AST.Visitors;
  32 using Mono.CodeContracts.Static.Analysis.ExpressionAnalysis.Expressions;
  33 using Mono.CodeContracts.Static.ControlFlow;
  34 using Mono.CodeContracts.Static.Lattices;
  35
  36 namespace Mono.CodeContracts.Static.Analysis.ExpressionAnalysis {
  37         struct AssumeDecoder<SymbolicValue> : IExpressionILVisitor<APC, SymbolicValue, SymbolicValue, ExprDomain<SymbolicValue>, ExprDomain<SymbolicValue>>
  38                 where SymbolicValue : IEquatable<SymbolicValue> {
  39                 private readonly bool truth;
  40
  41                 public AssumeDecoder (bool truth)
  42                 {
  43                         this.truth = truth;
  44                 }
  45
  46                 #region IExpressionILVisitor<APC,SymbolicValue,SymbolicValue,ExprDomain<SymbolicValue>,ExprDomain<SymbolicValue>> Members
  47                 public ExprDomain<SymbolicValue> Binary (APC pc, BinaryOperator op, SymbolicValue dest, SymbolicValue s1, SymbolicValue s2, ExprDomain<SymbolicValue> data)
  48                 {
  49                         if (this.truth && op.IsEqualityOperator ()) {
  50                                 if (!data.HasRefinement (s1)) {
  51                                         FlatDomain<Expr<SymbolicValue>> expression2 = data [s2];
  52                                         if (expression2.IsNormal && !data.IsReachableFrom (s2, s1))
  53                                                 return data.Add (s1, expression2.Concrete);
  54                                 } else if (!data.HasRefinement (s2)) {
  55                                         FlatDomain<Expr<SymbolicValue>> expression1 = data [s1];
  56                                         if (expression1.IsNormal && !data.IsReachableFrom (s1, s2))
  57                                                 return data.Add (s2, expression1.Concrete);
  58                                 }
  59                         }
  60                         if (!this.truth && op == BinaryOperator.Cne_Un) {
  61                                 if (!data.HasRefinement (s1)) {
  62                                         FlatDomain<Expr<SymbolicValue>> expression2 = data [s2];
  63                                         if (expression2.IsNormal && !data.IsReachableFrom (s2, s1))
  64                                                 return data.Add (s1, expression2.Concrete);
  65                                 } else if (!data.HasRefinement (s2)) {
  66                                         FlatDomain<Expr<SymbolicValue>> expression1 = data [s1];
  67                                         if (expression1.IsNormal && !data.IsReachableFrom (s1, s2))
  68                                                 return data.Add (s2, expression1.Concrete);
  69                                 }
  70                         }
  71                         return data;
  72                 }
  73
  74                 public ExprDomain<SymbolicValue> Isinst (APC pc, TypeNode type, SymbolicValue dest, SymbolicValue obj, ExprDomain<SymbolicValue> data)
  75                 {
  76                         return data;
  77                 }
  78
  79                 public ExprDomain<SymbolicValue> LoadNull (APC pc, SymbolicValue dest, ExprDomain<SymbolicValue> polarity)
  80                 {
  81                         return polarity;
  82                 }
  83
  84                 public ExprDomain<SymbolicValue> LoadConst (APC pc, TypeNode type, object constant, SymbolicValue dest, ExprDomain<SymbolicValue> data)
  85                 {
  86                         return data;
  87                 }
  88
  89                 public ExprDomain<SymbolicValue> Sizeof (APC pc, TypeNode type, SymbolicValue dest, ExprDomain<SymbolicValue> data)
  90                 {
  91                         return data;
  92                 }
  93
  94                 public ExprDomain<SymbolicValue> Unary (APC pc, UnaryOperator op, bool unsigned, SymbolicValue dest, SymbolicValue source, ExprDomain<SymbolicValue> data)
  95                 {
  96                         return data;
  97                 }
  98                 #endregion
  99         }
 100 }