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

   1 //
   2 // ExprDomain.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 System.Collections.Generic;
  31 using System.IO;
  32 using Mono.CodeContracts.Static.Analysis.ExpressionAnalysis.Expressions;
  33 using Mono.CodeContracts.Static.DataStructures;
  34 using Mono.CodeContracts.Static.Lattices;
  35
  36 namespace Mono.CodeContracts.Static.Analysis.ExpressionAnalysis {
  37         class ExprDomain<TSymValue> : IGraph<TSymValue, Dummy>
  38                 where TSymValue : IEquatable<TSymValue> {
  39                 private readonly EnvironmentDomain<TSymValue, FlatDomain<Expr<TSymValue>>> expressions;
  40
  41                 private ExprDomain (EnvironmentDomain<TSymValue, FlatDomain<Expr<TSymValue>>> expressions)
  42                 {
  43                         this.expressions = expressions;
  44                 }
  45
  46                 #region Implementation of IGraph<SymbolicValue,Dummy>
  47                 public IEnumerable<TSymValue> Keys
  48                 {
  49                         get { return this.expressions.Keys; }
  50                 }
  51
  52                 public bool IsBottom
  53                 {
  54                         get { return this.expressions.IsBottom; }
  55                 }
  56
  57                 IEnumerable<TSymValue> IGraph<TSymValue, Dummy>.Nodes
  58                 {
  59                         get { return this.expressions.Keys; }
  60                 }
  61
  62                 public IEnumerable<Pair<Dummy, TSymValue>> Successors(TSymValue node)
  63                 {
  64                         FlatDomain<Expr<TSymValue>> expr = this.expressions[node];
  65                         if (expr.IsNormal())
  66                 foreach (TSymValue sv in expr.Value.Variables)
  67                     yield return new Pair<Dummy, TSymValue> (Dummy.Value, sv);
  68                 }
  69                 #endregion
  70
  71                 public FlatDomain<Expr<TSymValue>> this[TSymValue sv]
  72                 {
  73                         get { return this.expressions[sv]; }
  74                 }
  75
  76                 public ExprDomain<TSymValue> Join(ExprDomain<TSymValue> that, bool widening, out bool weaker)
  77                 {
  78                         return new ExprDomain<TSymValue> (this.expressions.Join (that.expressions, widening, out weaker));
  79                 }
  80
  81                 public static ExprDomain<TSymValue> TopValue(Func<TSymValue, int> keyConverter)
  82                 {
  83                         return new ExprDomain<TSymValue> (EnvironmentDomain<TSymValue, FlatDomain<Expr<TSymValue>>>.TopValue (keyConverter));
  84                 }
  85
  86                 public ExprDomain<TSymValue> Add (TSymValue sv, Expr<TSymValue> expr)
  87                 {
  88                         return new ExprDomain<TSymValue> (this.expressions.With (sv, expr));
  89                 }
  90
  91                 public ExprDomain<TSymValue> Remove(TSymValue sv)
  92                 {
  93                         return new ExprDomain<TSymValue> (this.expressions.Without (sv));
  94                 }
  95
  96                 public ExprDomain<TSymValue> Empty()
  97                 {
  98                         return new ExprDomain<TSymValue> (this.expressions.Empty ());
  99                 }
 100
 101                 public bool HasRefinement(TSymValue sv)
 102                 {
 103                         return this.expressions.Contains (sv);
 104                 }
 105
 106                 public bool IsReachableFrom(TSymValue source, TSymValue target)
 107                 {
 108                         bool reachable = false;
 109                         DepthFirst.Visit (this, source, sv => {
 110                                                                 if (sv.Equals (target))
 111                                                                         reachable = true;
 112
 113                                                                 return !reachable; // break if reachable
 114                                                         }, null);
 115                         return reachable;
 116                 }
 117
 118                 public void Dump(TextWriter tw)
 119                 {
 120                         this.expressions.Dump (tw);
 121                 }
 122         }
 123 }