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 //   Atsushi Enomoto  <atsushi@ximian.com>
   7 //
   8 // (C) 2001 Ximian, Inc.
   9 // (C) 2005 Novell, Inc.
  10 //
  11
  12 using System;
  13 using System.IO;
  14 using System.Collections;
  15 using Mono.CompilerServices.SymbolWriter;
  16
  17 namespace Mono.CSharp {
  18         /// <summary>
  19         ///   This is one single source file.
  20         /// </summary>
  21         /// <remarks>
  22         ///   This is intentionally a class and not a struct since we need
  23         ///   to pass this by reference.
  24         /// </remarks>
  25         public sealed class SourceFile : ISourceFile {
  26                 public readonly string Name;
  27                 public readonly string Path;
  28                 public readonly int Index;
  29                 public SourceFileEntry SourceFileEntry;
  30                 public bool HasLineDirective;
  31
  32                 public SourceFile (string name, string path, int index)
  33                 {
  34                         this.Index = index;
  35                         this.Name = name;
  36                         this.Path = path;
  37                 }
  38
  39                 SourceFileEntry ISourceFile.Entry {
  40                         get { return SourceFileEntry; }
  41                 }
  42
  43                 public override string ToString ()
  44                 {
  45                         return String.Format ("SourceFile ({0}:{1}:{2}:{3})",
  46                                               Name, Path, Index, SourceFileEntry);
  47                 }
  48         }
  49
  50         /// <summary>
  51         ///   Keeps track of the location in the program
  52         /// </summary>
  53         ///
  54         /// <remarks>
  55         ///   This uses a compact representation and a couple of auxiliary
  56         ///   structures to keep track of tokens to (file,line and column)
  57         ///   mappings. The usage of the bits is:
  58         ///
  59         ///     - 16 bits for "checkpoint" which is a mixed concept of
  60         ///       file and "line segment"
  61         ///     - 8 bits for line delta (offset) from the line segment
  62         ///     - 8 bits for column number.
  63         ///
  64         ///   http://lists.ximian.com/pipermail/mono-devel-list/2004-December/009508.html
  65         /// </remarks>
  66         public struct Location {
  67                 int token;
  68
  69                 struct Checkpoint {
  70                         public readonly int LineOffset;
  71                         public readonly int File;
  72
  73                         public Checkpoint (int file, int line)
  74                         {
  75                                 File = file;
  76                                 LineOffset = line - (int) (line % (1 << line_delta_bits));
  77                         }
  78                 }
  79
  80                 static ArrayList source_list;
  81                 static Hashtable source_files;
  82                 static int checkpoint_bits;
  83                 static int source_count;
  84                 static int current_source;
  85                 static int line_delta_bits;
  86                 static int line_delta_mask;
  87                 static int column_bits;
  88                 static int column_mask;
  89                 static Checkpoint [] checkpoints;
  90                 static int checkpoint_index;
  91
  92                 public readonly static Location Null = new Location (-1);
  93                 public static bool InEmacs;
  94
  95                 static Location ()
  96                 {
  97                         source_files = new Hashtable ();
  98                         source_list = new ArrayList ();
  99                         current_source = 0;
 100                         checkpoints = new Checkpoint [10];
 101                 }
 102
 103                 public static void Reset ()
 104                 {
 105                         source_files = new Hashtable ();
 106                         source_list = new ArrayList ();
 107                         current_source = 0;
 108                         source_count = 0;
 109                 }
 110
 111                 // <summary>
 112                 //   This must be called before parsing/tokenizing any files.
 113                 // </summary>
 114                 static public void AddFile (string name)
 115                 {
 116                         string path = Path.GetFullPath (name);
 117
 118                         if (source_files.Contains (path)){
 119                                 int id = (int) source_files [path];
 120                                 string other_name = ((SourceFile) source_list [id - 1]).Name;
 121                                 if (name.Equals (other_name))
 122                                         Report.Warning (2002, 1, "Source file `{0}' specified multiple times", other_name);
 123                                 else
 124                                         Report.Warning (2002, 1, "Source filenames `{0}' and `{1}' both refer to the same file: {2}", name, other_name, path);
 125                                 return;
 126                         }
 127
 128                         source_files.Add (path, ++source_count);
 129                         source_list.Add (new SourceFile (name, path, source_count));
 130                 }
 131
 132                 static public SourceFile[] SourceFiles {
 133                         get {
 134                                 SourceFile[] retval = new SourceFile [source_list.Count];
 135                                 source_list.CopyTo (retval, 0);
 136                                 return retval;
 137                         }
 138                 }
 139
 140                 // <summary>
 141                 //   After adding all source files we want to compile with AddFile(), this method
 142                 //   must be called to `reserve' an appropriate number of bits in the token for the
 143                 //   source file.  We reserve some extra space for files we encounter via #line
 144                 //   directives while parsing.
 145                 // </summary>
 146                 static public void Initialize ()
 147                 {
 148                         checkpoints = new Checkpoint [source_list.Count * 2];
 149                         if (checkpoints.Length > 0)
 150                                 checkpoints [0] = new Checkpoint (0, 0);
 151
 152                         column_bits = 8;
 153                         column_mask = 0xFF;
 154                         line_delta_bits = 8;
 155                         line_delta_mask = 0xFF00;
 156                         checkpoint_index = 0;
 157                         checkpoint_bits = 16;
 158                 }
 159
 160                 // <remarks>
 161                 //   This is used when we encounter a #line preprocessing directive.
 162                 // </remarks>
 163                 static public SourceFile LookupFile (string name)
 164                 {
 165                         string path = name.Length == 0 ? "" : Path.GetFullPath (name);
 166
 167                         if (!source_files.Contains (path)) {
 168                                 if (source_count >= (1 << checkpoint_bits))
 169                                         return new SourceFile (name, path, 0);
 170
 171                                 source_files.Add (path, ++source_count);
 172                                 SourceFile retval = new SourceFile (name, path, source_count);
 173                                 source_list.Add (retval);
 174                                 return retval;
 175                         }
 176
 177                         int index = (int) source_files [path];
 178                         return (SourceFile) source_list [index - 1];
 179                 }
 180
 181                 static public void Push (SourceFile file)
 182                 {
 183                         current_source = file.Index;
 184                         // File is always pushed before being changed.
 185                 }
 186
 187                 // <remarks>
 188                 //   If we're compiling with debugging support, this is called between parsing
 189                 //   and code generation to register all the source files with the
 190                 //   symbol writer.
 191                 // </remarks>
 192                 static public void DefineSymbolDocuments (MonoSymbolWriter symwriter)
 193                 {
 194                         foreach (SourceFile file in source_list) {
 195                                 file.SourceFileEntry = symwriter.DefineDocument (file.Path);
 196                         }
 197                 }
 198
 199                 public Location (int row)
 200                         : this (row, 0)
 201                 {
 202                 }
 203
 204                 public Location (int row, int column)
 205                 {
 206                         if (row <= 0)
 207                                 token = 0;
 208                         else {
 209                                 if (column > 255)
 210                                         column = 255;
 211                                 int target = -1;
 212                                 int delta = 0;
 213                                 int max = checkpoint_index < 10 ?
 214                                         checkpoint_index : 10;
 215                                 for (int i = 0; i < max; i++) {
 216                                         int offset = checkpoints [checkpoint_index - i].LineOffset;
 217                                         delta = row - offset;
 218                                         if (delta >= 0 &&
 219                                                 delta < (1 << line_delta_bits) &&
 220                                                 checkpoints [checkpoint_index - i].File == current_source) {
 221                                                 target = checkpoint_index - i;
 222                                                 break;
 223                                         }
 224                                 }
 225                                 if (target == -1) {
 226                                         AddCheckpoint (current_source, row);
 227                                         target = checkpoint_index;
 228                                         delta = row % (1 << line_delta_bits);
 229                                 }
 230                                 long l = column +
 231                                         (long) (delta << column_bits) +
 232                                         (long) (target << (line_delta_bits + column_bits));
 233                                 token = l > 0xFFFFFFFF ? 0 : (int) l;
 234                         }
 235                 }
 236
 237                 static void AddCheckpoint (int file, int row)
 238                 {
 239                         if (checkpoints.Length == ++checkpoint_index) {
 240                                 Checkpoint [] tmp = new Checkpoint [checkpoint_index * 2];
 241                                 Array.Copy (checkpoints, tmp, checkpoints.Length);
 242                                 checkpoints = tmp;
 243                         }
 244                         checkpoints [checkpoint_index] = new Checkpoint (file, row);
 245                 }
 246
 247                 public override string ToString ()
 248                 {
 249                         if (column_bits == 0 || InEmacs)
 250                                 return Name + "(" + Row.ToString () + "):";
 251                         else
 252                                 return Name + "(" + Row.ToString () + "," + Column.ToString () +
 253                                         (Column == column_mask ? "+):" : "):");
 254                 }
 255
 256                 /// <summary>
 257                 ///   Whether the Location is Null
 258                 /// </summary>
 259                 public bool IsNull {
 260                         get { return token == 0; }
 261                 }
 262
 263                 public string Name {
 264                         get {
 265                                 int index = File;
 266                                 if (token == 0 || index == 0)
 267                                         return "Internal";
 268
 269                                 SourceFile file = (SourceFile) source_list [index - 1];
 270                                 return file.Name;
 271                         }
 272                 }
 273
 274                 int CheckpointIndex {
 275                         get { return (int) ((token & 0xFFFF0000) >> (line_delta_bits + column_bits)); }
 276                 }
 277
 278                 public int Row {
 279                         get {
 280                                 if (token == 0)
 281                                         return 1;
 282                                 return checkpoints [CheckpointIndex].LineOffset + ((token & line_delta_mask) >> column_bits);
 283                         }
 284                 }
 285
 286                 public int Column {
 287                         get {
 288                                 if (token == 0)
 289                                         return 1;
 290                                 return (int) (token & column_mask);
 291                         }
 292                 }
 293
 294                 public int File {
 295                         get {
 296                                 if (token == 0)
 297                                         return 0;
 298 if (checkpoints.Length <= CheckpointIndex) throw new Exception (String.Format ("Should not happen. Token is {0:X04}, checkpoints are {1}, index is {2}", token, checkpoints.Length, CheckpointIndex));
 299                                 return checkpoints [CheckpointIndex].File;
 300                         }
 301                 }
 302
 303                 // The ISymbolDocumentWriter interface is used by the symbol writer to
 304                 // describe a single source file - for each source file there's exactly
 305                 // one corresponding ISymbolDocumentWriter instance.
 306                 //
 307                 // This class has an internal hash table mapping source document names
 308                 // to such ISymbolDocumentWriter instances - so there's exactly one
 309                 // instance per document.
 310                 //
 311                 // This property returns the ISymbolDocumentWriter instance which belongs
 312                 // to the location's source file.
 313                 //
 314                 // If we don't have a symbol writer, this property is always null.
 315                 public SourceFile SourceFile {
 316                         get {
 317                                 int index = File;
 318                                 if (index == 0)
 319                                         return null;
 320                                 return (SourceFile) source_list [index - 1];
 321                         }
 322                 }
 323         }
 324
 325         public class LocatedToken
 326         {
 327                 public readonly Location Location;
 328                 public readonly string Value;
 329
 330                 public LocatedToken (Location loc, string value)
 331                 {
 332                         Location = loc;
 333                         Value = value;
 334                 }
 335
 336                 public override string ToString ()
 337                 {
 338                         return Location.ToString () + Value;
 339                 }
 340         }
 341 }