mcs/class/Mono.CodeContracts/Mono.CodeContracts.Rewrite.AstVisitors/ExprVisitor.cs

   1 //
   2 // ExprVisitor.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.Ast;
  34
  35 namespace Mono.CodeContracts.Rewrite.AstVisitors {
  36         abstract class ExprVisitor {
  37
  38                 public virtual Expr Visit (Expr e)
  39                 {
  40                         switch (e.ExprType) {
  41                         case ExprType.Block:
  42                                 return this.VisitBlock ((ExprBlock) e);
  43                         case ExprType.Nop:
  44                                 return this.VisitNop ((ExprNop) e);
  45                         case ExprType.Call:
  46                                 return this.VisitCall ((ExprCall) e);
  47                         case ExprType.CompareEqual:
  48                                 return this.VisitCompareEqual ((ExprCompareEqual) e);
  49                         case ExprType.CompareLessThan:
  50                                 return this.VisitCompareLessThan ((ExprCompareLessThan) e);
  51                         case ExprType.CompareGreaterThan:
  52                                 return this.VisitCompareGreaterThan ((ExprCompareGreaterThan) e);
  53                         case ExprType.Add:
  54                                 return this.VisitAdd ((ExprAdd) e);
  55                         case ExprType.Sub:
  56                                 return this.VisitSub ((ExprSub) e);
  57                         case ExprType.LoadArg:
  58                                 return this.VisitLoadArg ((ExprLoadArg) e);
  59                         case ExprType.LoadConstant:
  60                                 return this.VisitLoadConstant ((ExprLoadConstant) e);
  61                         case ExprType.Return:
  62                                 return this.VisitReturn ((ExprReturn) e);
  63                         case ExprType.Box:
  64                                 return this.VisitBox ((ExprBox) e);
  65                         case ExprType.Conv:
  66                                 return this.VisitConv ((ExprConv) e);
  67                         default:
  68                                 throw new NotSupportedException ("Cannot handle: " + e.ExprType);
  69                         }
  70                 }
  71
  72                 protected virtual Expr VisitCollection (IEnumerable<Expr> collection, Expr e, Func<IEnumerable<Expr>, Expr> fnCreateNew)
  73                 {
  74                         int index = 0;
  75                         List<Expr> exprs = null;
  76                         foreach (var expr in collection) {
  77                                 Expr exprVisited = this.Visit (expr);
  78                                 if (exprs != null || exprVisited != expr) {
  79                                         if (exprs == null) {
  80                                                 exprs = new List<Expr> (collection.Take (index));
  81                                         }
  82                                         exprs.Add (exprVisited);
  83                                 }
  84                                 index++;
  85                         }
  86                         if (exprs == null) {
  87                                 return e;
  88                         } else {
  89                                 return fnCreateNew(exprs);
  90                         }
  91                 }
  92
  93                 protected Expr VisitCollection (Expr e, Func<IEnumerable<Expr>, Expr> fnCreateNew, params Expr [] collection)
  94                 {
  95                         return this.VisitCollection (collection, e, fnCreateNew);
  96                 }
  97
  98                 protected virtual Expr VisitBlock (ExprBlock e)
  99                 {
 100                         return this.VisitCollection (e.Exprs, e, exprs => new ExprBlock (e.MethodInfo, exprs));
 101                 }
 102
 103                 protected virtual Expr VisitNop (ExprNop e)
 104                 {
 105                         return e;
 106                 }
 107
 108                 protected virtual Expr VisitLoadArg (ExprLoadArg e)
 109                 {
 110                         return e;
 111                 }
 112
 113                 protected virtual Expr VisitLoadConstant (ExprLoadConstant e)
 114                 {
 115                         return e;
 116                 }
 117
 118                 protected virtual Expr VisitCompareLessThan (ExprCompareLessThan e)
 119                 {
 120                         return this.VisitCollection (e, exprs => new ExprCompareLessThan (e.MethodInfo, exprs.First (), exprs.ElementAt (1), e.Signage), e.Left, e.Right);
 121                 }
 122
 123                 protected virtual Expr VisitCompareGreaterThan (ExprCompareGreaterThan e)
 124                 {
 125                         return this.VisitCollection (e, exprs => new ExprCompareGreaterThan (e.MethodInfo, exprs.First (), exprs.ElementAt (1), e.Signage), e.Left, e.Right);
 126                 }
 127
 128                 protected virtual Expr VisitCompareEqual (ExprCompareEqual e)
 129                 {
 130                         return this.VisitCollection (e, exprs => new ExprCompareEqual (e.MethodInfo, exprs.First (), exprs.ElementAt (1)), e.Left, e.Right);
 131                 }
 132
 133                 protected virtual Expr VisitAdd (ExprAdd e)
 134                 {
 135                         return this.VisitCollection (e, exprs => new ExprAdd (e.MethodInfo, exprs.First (), exprs.ElementAt (1), e.Signage, e.Overflow), e.Left, e.Right);
 136                 }
 137
 138                 protected virtual Expr VisitSub (ExprSub e)
 139                 {
 140                         return this.VisitCollection (e, exprs => new ExprSub (e.MethodInfo, exprs.First (), exprs.ElementAt (1), e.Signage, e.Overflow), e.Left, e.Right);
 141                 }
 142
 143                 protected virtual Expr VisitCall (ExprCall e)
 144                 {
 145                         return this.VisitCollection (e.Parameters, e, exprs => new ExprCall (e.MethodInfo, e.Method, exprs));
 146                 }
 147
 148                 protected virtual Expr VisitReturn (ExprReturn e)
 149                 {
 150                         return e;
 151                 }
 152
 153                 protected virtual Expr VisitBox (ExprBox e)
 154                 {
 155                         return this.VisitCollection (e, exprs => new ExprBox (e.MethodInfo, exprs.First ()), e.ExprToBox);
 156                 }
 157
 158                 protected virtual Expr VisitConv (ExprConv e)
 159                 {
 160                         return this.VisitCollection (e, exprs => new ExprConv (e.MethodInfo, exprs.First (), e.ConvToType), e.ExprToConvert);
 161                 }
 162         }
 163 }