mcs/mcs/location.cs

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