mcs/class/Mono.CodeContracts/Mono.CodeContracts.Static.Analysis.HeapAnalysis/ValueContextProvider.cs

   1 //
   2 // ValueContextProvider.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 using System;
  29 using System.Collections.Generic;
  30 using System.Linq;
  31 using Mono.CodeContracts.Static.AST;
  32 using Mono.CodeContracts.Static.Analysis.HeapAnalysis.Paths;
  33 using Mono.CodeContracts.Static.ControlFlow;
  34 using Mono.CodeContracts.Static.DataStructures;
  35 using Mono.CodeContracts.Static.Lattices;
  36
  37 namespace Mono.CodeContracts.Static.Analysis.HeapAnalysis {
  38         class ValueContextProvider<TContext> : IValueContextProvider<SymbolicValue>, IValueContext<SymbolicValue>
  39                 where TContext : IStackContextProvider {
  40                 private readonly HeapAnalysis parent;
  41                 private readonly TContext underlying;
  42
  43                 public ValueContextProvider (HeapAnalysis parent, TContext underlying)
  44                 {
  45                         this.parent = parent;
  46                         this.underlying = underlying;
  47                 }
  48
  49                 #region Implementation of IMethodContextProvider
  50                 public IMethodContext MethodContext
  51                 {
  52                         get { return this.underlying.MethodContext; }
  53                 }
  54                 #endregion
  55
  56                 #region Implementation of IStackContextProvider
  57                 public IStackContext StackContext
  58                 {
  59                         get { return this.underlying.StackContext; }
  60                 }
  61                 #endregion
  62
  63                 #region Implementation of IValueContextProvider<SymbolicValue>
  64                 IValueContext<SymbolicValue> IValueContextProvider<SymbolicValue>.ValueContext
  65                 {
  66                         get { return this; }
  67                 }
  68                 #endregion
  69
  70                 #region Implementation of IValueContext<SymbolicValue>
  71                 public FlatDomain<TypeNode> GetType (APC pc, SymbolicValue value)
  72                 {
  73                         Domain domain;
  74                         if (!this.parent.PreStateLookup (pc, out domain) || domain.IsBottom)
  75                                 return FlatDomain<TypeNode>.TopValue;
  76
  77                         return domain.GetType (value.Symbol).Type;
  78                 }
  79
  80                 public bool IsZero (APC at, SymbolicValue value)
  81                 {
  82                         Domain domain;
  83                         if (!this.parent.PreStateLookup (at, out domain))
  84                                 return true;
  85
  86                         return domain.IsZero (value.Symbol);
  87                 }
  88
  89                 public bool TryLocalValue (APC at, Local local, out SymbolicValue sv)
  90                 {
  91                         Domain domain;
  92                         if (this.parent.PreStateLookup (at, out domain))
  93                                 return domain.TryGetCorrespondingValueAbstraction (local, out sv);
  94
  95                         sv = new SymbolicValue ();
  96                         return false;
  97                 }
  98
  99                 public bool TryParameterValue (APC at, Parameter p, out SymbolicValue sv)
 100                 {
 101                         Domain domain;
 102                         if (this.parent.PreStateLookup (at, out domain))
 103                                 return domain.TryGetCorrespondingValueAbstraction (p, out sv);
 104
 105                         sv = new SymbolicValue ();
 106                         return false;
 107                 }
 108
 109                 public bool TryGetArrayLength (APC at, SymbolicValue array, out SymbolicValue length)
 110                 {
 111                         Domain domain;
 112                         if (!this.parent.PreStateLookup (at, out domain))
 113                                 throw new ArgumentException ("pc wasn't visited");
 114                         SymValue lengthValue;
 115                         bool arrayLength = domain.TryGetArrayLength (array.Symbol, out lengthValue);
 116
 117                         length = new SymbolicValue (lengthValue);
 118                         return arrayLength;
 119                 }
 120
 121                 public LispList<PathElement> AccessPathList (APC at, SymbolicValue sv, bool allowLocal, bool preferLocal)
 122                 {
 123                         Domain domain;
 124                         if (!this.parent.PreStateLookup (at, out domain))
 125                                 throw new ArgumentException ("pc wasn't visited");
 126
 127                         AccessPathFilter<Method> filter = AccessPathFilter<Method>.IsVisibleFrom (MethodContext.CurrentMethod);
 128                         return domain.GetAccessPathList (sv.Symbol, filter, allowLocal, preferLocal);
 129                 }
 130
 131                 public bool IsConstant (APC at, SymbolicValue symbol, out TypeNode type, out object constant)
 132                 {
 133                         Domain domain;
 134                         if (!this.parent.PreStateLookup (at, out domain))
 135                                 throw new ArgumentException ("pc wasn't visited");
 136
 137                         return domain.IsConstant (symbol.Symbol, out type, out constant);
 138                 }
 139
 140                 public bool TryStackValue (APC at, int stackIndex, out SymbolicValue sv)
 141                 {
 142                         Domain domain;
 143                         if (this.parent.PreStateLookup (at, out domain))
 144                                 return domain.TryGetCorrespondingValueAbstraction (stackIndex, out sv);
 145
 146                         sv = new SymbolicValue ();
 147                         return false;
 148                 }
 149
 150                 public bool IsValid (SymbolicValue sv)
 151                 {
 152                         return sv.Symbol != null;
 153                 }
 154
 155                 public string AccessPath (APC at, SymbolicValue sv)
 156                 {
 157                         Domain domain;
 158                         if (!this.parent.PreStateLookup (at, out domain))
 159                                 throw new ArgumentException ("pc wasn't visited");
 160
 161                         return domain.GetAccessPath (sv.Symbol);
 162                 }
 163
 164                 public IEnumerable<LispList<PathElement>> AccessPaths (APC at, SymValue value, AccessPathFilter<Method> filter)
 165                 {
 166                         Domain domain;
 167                         if (!this.parent.PreStateLookup (at, out domain))
 168                                 throw new ArgumentException ("pc wasn't visited");
 169
 170                         return domain.GetAccessPathsFiltered (value, filter, true).Select (path => path.Coerce<PathElementBase, PathElement> ());
 171                 }
 172
 173                 public LispList<PathElement> VisibleAccessPathList (APC at, SymbolicValue value)
 174                 {
 175                         Domain domain;
 176                         if (!this.parent.PreStateLookup (at, out domain))
 177                                 throw new ArgumentException ("pc wasn't visited");
 178
 179                         AccessPathFilter<Method> filter = AccessPathFilter<Method>.FromPrecondition (MethodContext.CurrentMethod);
 180                         return domain.GetAccessPathList (value.Symbol, filter, false, false);
 181                 }
 182                 #endregion
 183         }
 184 }