mcs/gmcs/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 Mono.CompilerServices.SymbolWriter;
  14
  15 namespace Mono.CSharp {
  16         /// <summary>
  17         ///   This is one single source file.
  18         /// </summary>
  19         /// <remarks>
  20         ///   This is intentionally a class and not a struct since we need
  21         ///   to pass this by reference.
  22         /// </remarks>
  23         public sealed class SourceFile : ISourceFile {
  24                 public readonly string Name;
  25                 public readonly string Path;
  26                 public readonly int Index;
  27                 public SourceFileEntry SourceFileEntry;
  28                 public bool HasLineDirective;
  29
  30                 public SourceFile (string name, string path, int index)
  31                 {
  32                         this.Index = index;
  33                         this.Name = name;
  34                         this.Path = path;
  35                 }
  36
  37                 SourceFileEntry ISourceFile.Entry {
  38                         get { return SourceFileEntry; }
  39                 }
  40
  41                 public override string ToString ()
  42                 {
  43                         return String.Format ("SourceFile ({0}:{1}:{2}:{3})",
  44                                               Name, Path, Index, SourceFileEntry);
  45                 }
  46         }
  47
  48         /// <summary>
  49         ///   Keeps track of the location in the program
  50         /// </summary>
  51         ///
  52         /// <remarks>
  53         ///   This uses a compact representation and a couple of auxiliary
  54         ///   structures to keep track of tokens to (file,line) mappings.
  55         ///
  56         ///   We could probably also keep track of columns by storing those
  57         ///   in 8 bits (and say, map anything after char 255 to be `255+').
  58         /// </remarks>
  59         public struct Location {
  60                 public int token;
  61
  62                 static ArrayList source_list;
  63                 static Hashtable source_files;
  64                 static int source_bits;
  65                 static int source_mask;
  66                 static int source_count;
  67                 static int current_source;
  68
  69                 public readonly static Location Null;
  70
  71                 static Location ()
  72                 {
  73                         source_files = new Hashtable ();
  74                         source_list = new ArrayList ();
  75                         current_source = 0;
  76                         Null.token = 0;
  77                 }
  78
  79                 // <summary>
  80                 //   This must be called before parsing/tokenizing any files.
  81                 // </summary>
  82                 static public void AddFile (string name)
  83                 {
  84                         string path = Path.GetFullPath (name);
  85
  86                         if (source_files.Contains (path)){
  87                                 Report.Warning (2002, name, "Source file '{0}' specified multiple times");
  88                                 return;
  89                         }
  90
  91                         source_files.Add (path, ++source_count);
  92                         source_list.Add (new SourceFile (name, path, source_count));
  93                 }
  94
  95                 static public SourceFile[] SourceFiles {
  96                         get {
  97                                 SourceFile[] retval = new SourceFile [source_list.Count];
  98                                 source_list.CopyTo (retval, 0);
  99                                 return retval;
 100                         }
 101                 }
 102
 103                 static int log2 (int number)
 104                 {
 105                         int bits = 0;
 106                         while (number > 0) {
 107                                 bits++;
 108                                 number /= 2;
 109                         }
 110
 111                         return bits;
 112                 }
 113
 114                 // <summary>
 115                 //   After adding all source files we want to compile with AddFile(), this method
 116                 //   must be called to `reserve' an appropriate number of bits in the token for the
 117                 //   source file.  We reserve some extra space for files we encounter via #line
 118                 //   directives while parsing.
 119                 // </summary>
 120                 static public void Initialize ()
 121                 {
 122                         source_bits = log2 (source_list.Count) + 2;
 123                         source_mask = (1 << source_bits) - 1;
 124                 }
 125
 126                 // <remarks>
 127                 //   This is used when we encounter a #line preprocessing directive.
 128                 // </remarks>
 129                 static public SourceFile LookupFile (string name)
 130                 {
 131                         string path = name == "" ? "" : Path.GetFullPath (name);
 132
 133                         if (!source_files.Contains (path)) {
 134                                 if (source_count >= (1 << source_bits))
 135                                         return new SourceFile (name, path, 0);
 136
 137                                 source_files.Add (path, ++source_count);
 138                                 SourceFile retval = new SourceFile (name, path, source_count);
 139                                 source_list.Add (retval);
 140                                 return retval;
 141                         }
 142
 143                         int index = (int) source_files [path];
 144                         return (SourceFile) source_list [index - 1];
 145                 }
 146
 147                 static public void Push (SourceFile file)
 148                 {
 149                         current_source = file.Index;
 150                 }
 151
 152                 // <remarks>
 153                 //   If we're compiling with debugging support, this is called between parsing
 154                 //   and code generation to register all the source files with the
 155                 //   symbol writer.
 156                 // </remarks>
 157                 static public void DefineSymbolDocuments (SymbolWriter symwriter)
 158                 {
 159                         foreach (SourceFile file in source_list) {
 160                                 file.SourceFileEntry = symwriter.DefineDocument (file.Path);
 161                         }
 162                 }
 163
 164                 public Location (int row)
 165                 {
 166                         if (row < 0)
 167                                 token = 0;
 168                         else
 169                                 token = current_source + (row << source_bits);
 170                 }
 171
 172                 public override string ToString ()
 173                 {
 174                         return Name + ": (" + Row + ")";
 175                 }
 176
 177                 /// <summary>
 178                 ///   Whether the Location is Null
 179                 /// </summary>
 180                 static public bool IsNull (Location l)
 181                 {
 182                         return l.token == 0;
 183                 }
 184
 185                 public string Name {
 186                         get {
 187                                 int index = token & source_mask;
 188                                 if ((token == 0) || (index == 0))
 189                                         return "Internal";
 190
 191                                 SourceFile file = (SourceFile) source_list [index - 1];
 192                                 return file.Name;
 193                         }
 194                 }
 195
 196                 public int Row {
 197                         get {
 198                                 if (token == 0)
 199                                         return 1;
 200
 201                                 return token >> source_bits;
 202                         }
 203                 }
 204
 205                 public int File {
 206                         get {
 207                                 return token & source_mask;
 208                         }
 209                 }
 210
 211                 // The ISymbolDocumentWriter interface is used by the symbol writer to
 212                 // describe a single source file - for each source file there's exactly
 213                 // one corresponding ISymbolDocumentWriter instance.
 214                 //
 215                 // This class has an internal hash table mapping source document names
 216                 // to such ISymbolDocumentWriter instances - so there's exactly one
 217                 // instance per document.
 218                 //
 219                 // This property returns the ISymbolDocumentWriter instance which belongs
 220                 // to the location's source file.
 221                 //
 222                 // If we don't have a symbol writer, this property is always null.
 223                 public SourceFile SourceFile {
 224                         get {
 225                                 int index = token & source_mask;
 226                                 if (index == 0)
 227                                         return null;
 228                                 return (SourceFile) source_list [index - 1];
 229                         }
 230                 }
 231         }
 232 }