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

   1 //
   2 // ConditionTextExtractor.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.AstVisitors;
  34 using System.IO;
  35
  36 namespace Mono.CodeContracts.Rewrite {
  37         class ConditionTextExtractor {
  38
  39                 public ConditionTextExtractor (string filename, SourcePositionVisitor.CodePosition start, SourcePositionVisitor.CodePosition end)
  40                 {
  41                         this.filename = filename;
  42                         this.start = start;
  43                         this.end = end;
  44                 }
  45
  46                 private string filename;
  47                 private SourcePositionVisitor.CodePosition start, end;
  48
  49                 enum State {
  50                         FunctionName,
  51                         Parameters,
  52                 };
  53
  54                 private State state;
  55
  56                 public string GetConditionText ()
  57                 {
  58                         if (this.filename == null || this.start.IsEmpty || this.end.IsEmpty){
  59                                 return "<unknown source code position>";
  60                         }
  61                         string[] lines;
  62                         try {
  63                                 lines = File.ReadAllLines (this.filename);
  64                         } catch {
  65                                 return "<cannot access source code>";
  66                         }
  67                         try {
  68                                 StringBuilder sb = new StringBuilder ();
  69                                 for (int i = this.start.Line; i <= this.end.Line; i++) {
  70                                         string line = lines [i - 1];
  71                                         if (i == this.end.Line && this.end.Column != 0) {
  72                                                 line = line.Substring (0, this.end.Column - 1);
  73                                         }
  74                                         if (i == this.start.Line && this.start.Column != 0) {
  75                                                 line = line.Substring (this.start.Column - 1);
  76                                         }
  77                                         sb.Append (line.Trim());
  78                                 }
  79                                 string cndStr = sb.ToString ();
  80
  81                                 this.state = State.FunctionName;
  82
  83                                 var cnd = this.RunStateMachine (cndStr);
  84
  85                                 return cnd.ToString ().Trim ();
  86                         } catch {
  87                                 return "<source-code parse error>";
  88                         }
  89                 }
  90
  91                 private StringBuilder RunStateMachine (string line)
  92                 {
  93                         StringBuilder cnd = new StringBuilder ();
  94                         int inBrackets = 0;
  95                         bool inDoubleQuotes = false;
  96                         bool inSingleQuotes = false;
  97                         bool inEscape = false;
  98                         foreach (char c in line) {
  99                                 switch (this.state) {
 100                                 case State.FunctionName:
 101                                         if (c == '(') {
 102                                                 this.state = State.Parameters;
 103                                         }
 104                                         break;
 105                                 case State.Parameters:
 106                                         switch (c) {
 107                                         case ',':
 108                                                 if (inBrackets == 0 && !inDoubleQuotes && !inSingleQuotes) {
 109                                                         return cnd;
 110                                                 }
 111                                                 break;
 112                                         case '(':
 113                                                 if (!inDoubleQuotes && !inSingleQuotes) {
 114                                                         inBrackets++;
 115                                                 }
 116                                                 break;
 117                                         case ')':
 118                                                 if (!inDoubleQuotes && !inSingleQuotes) {
 119                                                         if (inBrackets == 0) {
 120                                                                 return cnd;
 121                                                         }
 122                                                         inBrackets--;
 123                                                 }
 124                                                 break;
 125                                         case '"':
 126                                                 if (!inEscape) {
 127                                                         inDoubleQuotes = !inDoubleQuotes;
 128                                                 }
 129                                                 break;
 130                                         case '\'':
 131                                                 if (!inEscape) {
 132                                                         inSingleQuotes = !inSingleQuotes;
 133                                                 }
 134                                                 break;
 135                                         case '\\':
 136                                                 inEscape = true;
 137                                                 goto forceEscape;
 138                                         }
 139                                         inEscape = false;
 140                                 forceEscape:
 141                                         cnd.Append (c);
 142                                         break;
 143                                 default:
 144                                         throw new NotSupportedException ("Cannot handle state: " + this.state);
 145                                 }
 146                         }
 147
 148                         return new StringBuilder ("<bad source code>");
 149                 }
 150
 151         }
 152 }