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

   1 //\r
   2 // TransformContractsVisitor.cs\r
   3 //\r
   4 // Authors:\r
   5 //      Chris Bacon (chrisbacon76@gmail.com)\r
   6 //\r
   7 // Copyright (C) 2010 Novell, Inc (http://www.novell.com)\r
   8 //\r
   9 // Permission is hereby granted, free of charge, to any person obtaining\r
  10 // a copy of this software and associated documentation files (the\r
  11 // "Software"), to deal in the Software without restriction, including\r
  12 // without limitation the rights to use, copy, modify, merge, publish,\r
  13 // distribute, sublicense, and/or sell copies of the Software, and to\r
  14 // permit persons to whom the Software is furnished to do so, subject to\r
  15 // the following conditions:\r
  16 // \r
  17 // The above copyright notice and this permission notice shall be\r
  18 // included in all copies or substantial portions of the Software.\r
  19 // \r
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,\r
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\r
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND\r
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE\r
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION\r
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION\r
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  27 //\r
  28 \r
  29 using System;\r
  30 using System.Collections.Generic;\r
  31 using System.Linq;\r
  32 using System.Text;\r
  33 using Mono.CodeContracts.Rewrite;\r
  34 using Mono.CodeContracts.Rewrite.Ast;\r
  35 using System.Diagnostics.Contracts;\r
  36 using Mono.Cecil;\r
  37 using Mono.CodeContracts.Rewrite.AstVisitors;\r
  38 using Mono.Cecil.Cil;\r
  39 \r
  40 namespace Mono.CodeContracts.Rewrite {\r
  41         class TransformContractsVisitor : ExprVisitor {\r
  42 \r
  43                 public TransformContractsVisitor (ModuleDefinition module, MethodDefinition method, Dictionary<Expr, Instruction> instructionLookup, ContractsRuntime contractsRuntime)\r
  44                 {\r
  45                         //this.module = method.Module;\r
  46                         this.instructionLookup = instructionLookup;\r
  47                         this.contractsRuntime = contractsRuntime;\r
  48                         this.methodInfo = new MethodInfo (module, method);\r
  49                 }\r
  50 \r
  51                 //private ModuleDefinition module;\r
  52                 private Dictionary<Expr, Instruction> instructionLookup;\r
  53                 private ContractsRuntime contractsRuntime;\r
  54                 private MethodInfo methodInfo;\r
  55 \r
  56                 private List<ContractRequiresInfo> contractRequiresInfo = new List<ContractRequiresInfo> ();\r
  57 \r
  58                 public IEnumerable<ContractRequiresInfo> ContractRequiresInfo {\r
  59                         get { return this.contractRequiresInfo; }\r
  60                 }\r
  61 \r
  62                 protected override Expr VisitCall (ExprCall e)\r
  63                 {\r
  64                         var call = (ExprCall)base.VisitCall (e);\r
  65 \r
  66                         var method = e.Method;\r
  67                         if (method.DeclaringType.FullName == "System.Diagnostics.Contracts.Contract") {\r
  68                                 switch (method.Name) {\r
  69                                 case "Requires":\r
  70                                         if (!method.HasGenericParameters) {\r
  71                                                 switch (method.Parameters.Count) {\r
  72                                                 case 1:\r
  73                                                         return this.ProcessRequires1 (call);\r
  74                                                 case 2:\r
  75                                                         return this.ProcessRequires2 (call);\r
  76                                                 default:\r
  77                                                         throw new NotSupportedException ("Invalid number of parameters to Contract.Requires()");\r
  78                                                 }\r
  79                                         } else {\r
  80                                                 goto default;\r
  81                                         }\r
  82                                 default:\r
  83                                         throw new NotSupportedException ("Cannot handle Contract." + e.Method.Name + "()");\r
  84                                 }\r
  85                         }\r
  86 \r
  87                         return call;\r
  88                 }\r
  89 \r
  90                 private string GetConditionString (Expr e)\r
  91                 {\r
  92                         var vSource = new SourcePositionVisitor (this.instructionLookup);\r
  93                         vSource.Visit (e);\r
  94                         var extractor = new ConditionTextExtractor (vSource.SourceCodeFileName, vSource.StartPosition, vSource.EndPosition);\r
  95                         return extractor.GetConditionText ();\r
  96                 }\r
  97 \r
  98                 private Expr ProcessRequires1 (ExprCall e)\r
  99                 {\r
 100                         MethodDefinition mRequires = this.contractsRuntime.GetRequires ();\r
 101                         Expr conditionExpr = e.Parameters.First ();\r
 102                         Expr nullArgExpr = new ExprLoadConstant (this.methodInfo, null);\r
 103                         string conditionText = this.GetConditionString (e);\r
 104                         Expr conditionStringExpr = new ExprLoadConstant (this.methodInfo, conditionText);\r
 105                         var call = new ExprCall (this.methodInfo, mRequires, new Expr [] { conditionExpr, nullArgExpr, conditionStringExpr });\r
 106 \r
 107                         this.contractRequiresInfo.Add (new ContractRequiresInfo (e, call));\r
 108 \r
 109                         return call;\r
 110                 }\r
 111 \r
 112                 private Expr ProcessRequires2 (ExprCall e)\r
 113                 {\r
 114                         MethodDefinition mRequires = this.contractsRuntime.GetRequires ();\r
 115                         Expr conditionExpr = e.Parameters.First ();\r
 116                         Expr msgExpr = e.Parameters.ElementAt (1);\r
 117                         string conditionText = this.GetConditionString (e);\r
 118                         Expr conditionStringExpr = new ExprLoadConstant (this.methodInfo, conditionText);\r
 119                         var call = new ExprCall (this.methodInfo, mRequires, new Expr [] { conditionExpr, msgExpr, conditionStringExpr });\r
 120 \r
 121                         this.contractRequiresInfo.Add (new ContractRequiresInfo (e, call));\r
 122 \r
 123                         return call;\r
 124                 }\r
 125 \r
 126         }\r
 127 }\r