mcs/mbas/location.cs

   1 //\r
   2 // location.cs: Keeps track of the location of source code entity\r
   3 //\r
   4 // Author:\r
   5 //   Miguel de Icaza\r
   6 //\r
   7 // (C) 2001 Ximian, Inc.\r
   8 //\r
   9 \r
  10 using System;\r
  11 using System.Collections;\r
  12 \r
  13 namespace Mono.CSharp {\r
  14         /// <summary>\r
  15         ///   Keeps track of the location in the program\r
  16         /// </summary>\r
  17         ///\r
  18         /// <remarks>\r
  19         ///   This uses a compact representation and a couple of auxiliary\r
  20         ///   structures to keep track of tokens to (file,line) mappings.\r
  21         ///\r
  22         ///   We could probably also keep track of columns by storing those\r
  23         ///   in 8 bits (and say, map anything after char 255 to be `255+').\r
  24         /// </remarks>\r
  25         public struct Location {\r
  26                 public int token; \r
  27 \r
  28                 static Hashtable map;\r
  29                 static ArrayList list;\r
  30                 static int global_count;\r
  31                 static int module_base;\r
  32 \r
  33                 static Location ()\r
  34                 {\r
  35                         map = new Hashtable ();\r
  36                         list = new ArrayList ();\r
  37                         global_count = 0;\r
  38                         module_base = 0;\r
  39                 }\r
  40         \r
  41                 static public void Push (string name)\r
  42                 {\r
  43                         map.Remove (global_count);\r
  44                         map.Add (global_count, name);\r
  45                         list.Add (global_count);\r
  46                         module_base = global_count;\r
  47                 }\r
  48                 \r
  49                 public Location (int row)\r
  50                 {\r
  51                         if (row < 0)\r
  52                                 token = -1;\r
  53                         else {\r
  54                                 token = module_base + row;\r
  55                                 if (global_count < token)\r
  56                                         global_count = token;\r
  57                         }\r
  58                 }\r
  59 \r
  60                 public override string ToString ()\r
  61                 {\r
  62                         return Name + ": (" + Row + ")";\r
  63                 }\r
  64                 \r
  65                 /// <summary>\r
  66                 ///   Whether the Location is Null\r
  67                 /// </summary>\r
  68                 static public bool IsNull (Location l)\r
  69                 {\r
  70                         return l.token == -1;\r
  71                 }\r
  72 \r
  73                 static public Location Null {\r
  74                         get {\r
  75                                 return new Location (-1);\r
  76                         }\r
  77                 }\r
  78 \r
  79                 public string Name {\r
  80                         get {\r
  81                                 int best = 0;\r
  82                                 \r
  83                                 if (token < 0)\r
  84                                         return "Internal";\r
  85 \r
  86                                 foreach (int b in list){\r
  87                                         if (token > b)\r
  88                                                 best = b;\r
  89                                 }\r
  90                                 return (string) map [best];\r
  91                         }\r
  92                 }\r
  93 \r
  94                 public int Row {\r
  95                         get {\r
  96                                 int best = 0;\r
  97                                 \r
  98                                 if (token < 0)\r
  99                                         return 1;\r
 100                                 \r
 101                                 foreach (int b in list){\r
 102                                         if (token > b)\r
 103                                                 best = b;\r
 104                                 }\r
 105                                 return token - best;\r
 106                         }\r
 107                 }\r
 108         }\r
 109 }\r