mcs/class/Mono.CodeContracts/Mono.CodeContracts.Rewrite/TransformContractsVisitor.cs

   1 //
   2 // TransformContractsVisitor.cs
   3 //
   4 // Authors:
   5 //      Chris Bacon (chrisbacon76@gmail.com)
   6 //
   7 // Copyright (C) 2010 Chris Bacon
   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.Linq;
  32 using System.Text;
  33 using Mono.CodeContracts.Rewrite;
  34 using Mono.CodeContracts.Rewrite.Ast;
  35 using System.Diagnostics.Contracts;
  36 using Mono.Cecil;
  37 using Mono.CodeContracts.Rewrite.AstVisitors;
  38 using Mono.Cecil.Cil;
  39
  40 namespace Mono.CodeContracts.Rewrite {
  41         class TransformContractsVisitor : ExprVisitor {
  42
  43                 public TransformContractsVisitor (ModuleDefinition module, MethodDefinition method, Dictionary<Expr, Instruction> instructionLookup, ContractsRuntime contractsRuntime)
  44                 {
  45                         //this.module = method.Module;
  46                         this.instructionLookup = instructionLookup;
  47                         this.contractsRuntime = contractsRuntime;
  48                         this.methodInfo = new MethodInfo (module, method);
  49                 }
  50
  51                 //private ModuleDefinition module;
  52                 private Dictionary<Expr, Instruction> instructionLookup;
  53                 private ContractsRuntime contractsRuntime;
  54                 private MethodInfo methodInfo;
  55
  56                 private List<ContractRequiresInfo> contractRequiresInfo = new List<ContractRequiresInfo> ();
  57
  58                 public IEnumerable<ContractRequiresInfo> ContractRequiresInfo {
  59                         get { return this.contractRequiresInfo; }
  60                 }
  61
  62                 protected override Expr VisitCall (ExprCall e)
  63                 {
  64                         var call = (ExprCall)base.VisitCall (e);
  65
  66                         var method = e.Method;
  67                         if (method.DeclaringType.FullName == "System.Diagnostics.Contracts.Contract") {
  68                                 switch (method.Name) {
  69                                 case "Requires":
  70                                         if (!method.HasGenericParameters) {
  71                                                 switch (method.Parameters.Count) {
  72                                                 case 1:
  73                                                         return this.ProcessRequires1 (call);
  74                                                 case 2:
  75                                                         return this.ProcessRequires2 (call);
  76                                                 default:
  77                                                         throw new NotSupportedException ("Invalid number of parameters to Contract.Requires()");
  78                                                 }
  79                                         } else {
  80                                                 goto default;
  81                                         }
  82                                 default:
  83                                         throw new NotSupportedException ("Cannot handle Contract." + e.Method.Name + "()");
  84                                 }
  85                         }
  86
  87                         return call;
  88                 }
  89
  90                 private string GetConditionString (Expr e)
  91                 {
  92                         var vSource = new SourcePositionVisitor (this.instructionLookup);
  93                         vSource.Visit (e);
  94                         var extractor = new ConditionTextExtractor (vSource.SourceCodeFileName, vSource.StartPosition, vSource.EndPosition);
  95                         return extractor.GetConditionText ();
  96                 }
  97
  98                 private Expr ProcessRequires1 (ExprCall e)
  99                 {
 100                         MethodDefinition mRequires = this.contractsRuntime.GetRequires ();
 101                         Expr conditionExpr = e.Parameters.First ();
 102                         Expr nullArgExpr = new ExprLoadConstant (this.methodInfo, null);
 103                         string conditionText = this.GetConditionString (e);
 104                         Expr conditionStringExpr = new ExprLoadConstant (this.methodInfo, conditionText);
 105                         var call = new ExprCall (this.methodInfo, mRequires, new Expr [] { conditionExpr, nullArgExpr, conditionStringExpr });
 106
 107                         this.contractRequiresInfo.Add (new ContractRequiresInfo (e, call));
 108
 109                         return call;
 110                 }
 111
 112                 private Expr ProcessRequires2 (ExprCall e)
 113                 {
 114                         MethodDefinition mRequires = this.contractsRuntime.GetRequires ();
 115                         Expr conditionExpr = e.Parameters.First ();
 116                         Expr msgExpr = e.Parameters.ElementAt (1);
 117                         string conditionText = this.GetConditionString (e);
 118                         Expr conditionStringExpr = new ExprLoadConstant (this.methodInfo, conditionText);
 119                         var call = new ExprCall (this.methodInfo, mRequires, new Expr [] { conditionExpr, msgExpr, conditionStringExpr });
 120
 121                         this.contractRequiresInfo.Add (new ContractRequiresInfo (e, call));
 122
 123                         return call;
 124                 }
 125
 126         }
 127 }