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