mcs/mbas/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.IO;
  12 using System.Collections;
  13 using System.Diagnostics.SymbolStore;
  14
  15 namespace Mono.CSharp {
  16         /// <summary>
  17         ///   Keeps track of the location in the program
  18         /// </summary>
  19         ///
  20         /// <remarks>
  21         ///   This uses a compact representation and a couple of auxiliary
  22         ///   structures to keep track of tokens to (file,line) mappings.
  23         ///
  24         ///   We could probably also keep track of columns by storing those
  25         ///   in 8 bits (and say, map anything after char 255 to be `255+').
  26         /// </remarks>
  27         public struct Location {
  28                 public int token;
  29
  30                 static Hashtable map;
  31                 static Hashtable sym_docs;
  32                 static ArrayList list;
  33                 static int global_count;
  34                 static int module_base;
  35
  36                 public readonly static Location Null;
  37
  38                 static Location ()
  39                 {
  40                         map = new Hashtable ();
  41                         list = new ArrayList ();
  42                         sym_docs = new Hashtable ();
  43                         global_count = 0;
  44                         module_base = 0;
  45                         Null.token = -1;
  46                 }
  47
  48                 static public void Push (string name)
  49                 {
  50                         map.Remove (global_count);
  51                         map.Add (global_count, name);
  52                         list.Add (global_count);
  53                         module_base = global_count;
  54                 }
  55
  56                 public Location (int row, int col)
  57                 {
  58                         if (row < 0 || col <  0)
  59                                 token = -1;
  60                         else {
  61                                 if (col > 255)
  62                                         col = 255;
  63                                 token = module_base + (row << 8) + col;
  64                                 if (global_count < token)
  65                                         global_count = token;
  66                         }
  67                 }
  68
  69                 public override string ToString ()
  70                 {
  71                         return Name + ": (" + Row + ")";
  72                 }
  73
  74                 /// <summary>
  75                 ///   Whether the Location is Null
  76                 /// </summary>
  77                 static public bool IsNull (Location l)
  78                 {
  79                         return l.token == -1;
  80                 }
  81
  82                 public string Name {
  83                         get {
  84                                 int best = 0;
  85
  86                                 if (token < 0)
  87                                         return "Internal";
  88
  89                                 foreach (int b in list){
  90                                         if (token > b)
  91                                                 best = b;
  92                                 }
  93                                 return (string) map [best];
  94                         }
  95                 }
  96
  97                 public int Row {
  98                         get {
  99                                 int best = 0;
 100
 101                                 if (token < 0)
 102                                         return 1;
 103
 104                                 foreach (int b in list){
 105                                         if (token > b)
 106                                                 best = b;
 107                                 }
 108                                 return (token - best) >> 8;
 109                         }
 110                 }
 111
 112                 public int Col {
 113                         get {
 114                                 int best = 0;
 115
 116                                 if (token < 0)
 117                                         return 1;
 118
 119                                 foreach (int b in list){
 120                                         if (token > b)
 121                                                 best = b;
 122                                 }
 123                                 return (token - best) & 0xFF;
 124                         }
 125                 }
 126
 127                 // The ISymbolDocumentWriter interface is used by the symbol writer to
 128                 // describe a single source file - for each source file there's exactly
 129                 // one corresponding ISymbolDocumentWriter instance.
 130                 //
 131                 // This class has an internal hash table mapping source document names
 132                 // to such ISymbolDocumentWriter instances - so there's exactly one
 133                 // instance per document.
 134                 //
 135                 // This property returns the ISymbolDocumentWriter instance which belongs
 136                 // to the location's source file.
 137                 //
 138                 // If we don't have a symbol writer, this property is always null.
 139                 public ISymbolDocumentWriter SymbolDocument {
 140                         get {
 141                                 ISymbolWriter sw = CodeGen.SymbolWriter;
 142                                 ISymbolDocumentWriter doc;
 143
 144                                 if (token < 0)
 145                                         return null;
 146
 147                                 // If we don't have a symbol writer, return null.
 148                                 if (sw == null)
 149                                         return null;
 150
 151                                 string path = Path.GetFullPath (Name);
 152
 153                                 if (sym_docs.Contains (path))
 154                                         // If we already created an ISymbolDocumentWriter
 155                                         // instance for this document, return it.
 156                                         doc = (ISymbolDocumentWriter) sym_docs [path];
 157                                 else {
 158                                         // Create a new ISymbolDocumentWriter instance and
 159                                         // store it in the hash table.
 160                                         doc = sw.DefineDocument (path, SymLanguageType.CSharp,
 161                                                                  SymLanguageVendor.Microsoft,
 162                                                                  SymDocumentType.Text);
 163
 164                                         sym_docs.Add (path, doc);
 165                                 }
 166
 167                                 return doc;
 168                         }
 169                 }
 170         }
 171 }