mcs/mcs/support.cs

   1 //
   2 // support.cs: Support routines to work around the fact that System.Reflection.Emit
   3 // can not introspect types that are being constructed
   4 //
   5 // Author:
   6 //   Miguel de Icaza (miguel@ximian.com)
   7 //
   8 // (C) 2001 Ximian, Inc (http://www.ximian.com)
   9 //
  10
  11 using System;
  12 using System.IO;
  13 using System.Text;
  14 using System.Reflection;
  15 using System.Collections;
  16 using System.Reflection.Emit;
  17 using System.Globalization;
  18
  19 namespace Mono.CSharp {
  20
  21         public interface ParameterData {
  22                 Type ParameterType (int pos);
  23                 int  Count { get; }
  24                 string ParameterName (int pos);
  25                 string ParameterDesc (int pos);
  26                 Parameter.Modifier ParameterModifier (int pos);
  27         }
  28
  29         public class ReflectionParameters : ParameterData {
  30                 ParameterInfo [] pi;
  31                 bool last_arg_is_params = false;
  32
  33                 public ReflectionParameters (ParameterInfo [] pi)
  34                 {
  35                         object [] attrs;
  36
  37                         this.pi = pi;
  38                         int count = pi.Length-1;
  39
  40                         if (count >= 0) {
  41                                 attrs = pi [count].GetCustomAttributes (TypeManager.param_array_type, true);
  42
  43                                 if (attrs == null)
  44                                         return;
  45
  46                                 if (attrs.Length == 0)
  47                                         return;
  48
  49                                 last_arg_is_params = true;
  50                         }
  51                 }
  52
  53                 public Type ParameterType (int pos)
  54                 {
  55                         if (last_arg_is_params && pos >= pi.Length - 1)
  56                                 return pi [pi.Length - 1].ParameterType;
  57                         else {
  58                                 Type t = pi [pos].ParameterType;
  59
  60                                 return t;
  61                         }
  62                 }
  63
  64                 public string ParameterName (int pos)
  65                 {
  66                         if (last_arg_is_params && pos >= pi.Length - 1)
  67                                 return pi [pi.Length - 1].Name;
  68                         else
  69                                 return pi [pos].Name;
  70                 }
  71
  72                 public string ParameterDesc (int pos)
  73                 {
  74                         StringBuilder sb = new StringBuilder ();
  75
  76                         if (pi [pos].IsIn)
  77                                 sb.Append ("in ");
  78
  79                         Type partype = ParameterType (pos);
  80                         if (partype.IsByRef){
  81                                 partype = TypeManager.GetElementType (partype);
  82                                 if (pi [pos].IsOut)
  83                                         sb.Append ("out ");
  84                                 else
  85                                         sb.Append ("ref ");
  86                         }
  87
  88                         if (pos >= pi.Length - 1 && last_arg_is_params)
  89                                 sb.Append ("params ");
  90
  91                         sb.Append (TypeManager.CSharpName (partype));
  92
  93                         return sb.ToString ();
  94
  95                 }
  96
  97                 public Parameter.Modifier ParameterModifier (int pos)
  98                 {
  99                         int len = pi.Length;
 100
 101                         if (pos >= len - 1)
 102                                 if (last_arg_is_params)
 103                                         return Parameter.Modifier.PARAMS;
 104
 105                         Type t = pi [pos].ParameterType;
 106                         if (t.IsByRef){
 107                                 if ((pi [pos].Attributes & ParameterAttributes.Out) != 0)
 108                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.OUT;
 109                                 else
 110                                         return Parameter.Modifier.ISBYREF | Parameter.Modifier.REF;
 111                         }
 112
 113                         return Parameter.Modifier.NONE;
 114                 }
 115
 116                 public int Count {
 117                         get {
 118                                 return pi.Length;
 119                         }
 120                 }
 121
 122         }
 123
 124         public class InternalParameters : ParameterData {
 125                 Type [] param_types;
 126
 127                 public readonly Parameters Parameters;
 128
 129                 public InternalParameters (Type [] param_types, Parameters parameters)
 130                 {
 131                         this.param_types = param_types;
 132                         this.Parameters = parameters;
 133                 }
 134
 135                 public InternalParameters (DeclSpace ds, Parameters parameters)
 136                         : this (parameters.GetParameterInfo (ds), parameters)
 137                 {
 138                 }
 139
 140                 public int Count {
 141                         get {
 142                                 if (param_types == null)
 143                                         return 0;
 144
 145                                 return param_types.Length;
 146                         }
 147                 }
 148
 149                 Parameter GetParameter (int pos)
 150                 {
 151                         Parameter [] fixed_pars = Parameters.FixedParameters;
 152                         if (fixed_pars != null){
 153                                 int len = fixed_pars.Length;
 154                                 if (pos < len)
 155                                         return Parameters.FixedParameters [pos];
 156                         }
 157
 158                         return Parameters.ArrayParameter;
 159                 }
 160
 161                 public Type ParameterType (int pos)
 162                 {
 163                         if (param_types == null)
 164                                 return null;
 165
 166                         return GetParameter (pos).ExternalType ();
 167                 }
 168
 169
 170                 public string ParameterName (int pos)
 171                 {
 172                         return GetParameter (pos).Name;
 173                 }
 174
 175                 public string ParameterDesc (int pos)
 176                 {
 177                         string tmp = String.Empty;
 178                         Parameter p = GetParameter (pos);
 179
 180                         //
 181                         // We need to and for REF/OUT, because if either is set the
 182                         // extra flag ISBYREF will be set as well
 183                         //
 184                         if ((p.ModFlags & Parameter.Modifier.REF) != 0)
 185                                 tmp = "ref ";
 186                         else if ((p.ModFlags & Parameter.Modifier.OUT) != 0)
 187                                 tmp = "out ";
 188                         else if (p.ModFlags == Parameter.Modifier.PARAMS)
 189                                 tmp = "params ";
 190
 191                         Type t = ParameterType (pos);
 192
 193                         return tmp + TypeManager.CSharpName (t);
 194                 }
 195
 196                 public Parameter.Modifier ParameterModifier (int pos)
 197                 {
 198                         Parameter.Modifier mod = GetParameter (pos).ModFlags;
 199
 200                         if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0)
 201                                 mod |= Parameter.Modifier.ISBYREF;
 202
 203                         return mod;
 204                 }
 205
 206         }
 207
 208         class PtrHashtable : Hashtable {
 209                 class PtrComparer : IComparer {
 210                         public int Compare (object x, object y)
 211                         {
 212                                 if (x == y)
 213                                         return 0;
 214                                 else
 215                                         return 1;
 216                         }
 217                 }
 218
 219                 public PtrHashtable ()
 220                 {
 221                         comparer = new PtrComparer ();
 222                 }
 223         }
 224
 225         //
 226         // Compares member infos based on their name and
 227         // also allows one argument to be a string
 228         //
 229         class MemberInfoCompare : IComparer {
 230
 231                 public int Compare (object a, object b)
 232                 {
 233                         if (a == null || b == null){
 234                                 Console.WriteLine ("Invalid information passed");
 235                                 throw new Exception ();
 236                         }
 237
 238                         if (a is string)
 239                                 return String.Compare ((string) a, ((MemberInfo)b).Name);
 240
 241                         if (b is string)
 242                                 return String.Compare (((MemberInfo)a).Name, (string) b);
 243
 244                         return String.Compare (((MemberInfo)a).Name, ((MemberInfo)b).Name);
 245                 }
 246         }
 247
 248         struct Pair {
 249                 public object First;
 250                 public object Second;
 251
 252                 public Pair (object f, object s)
 253                 {
 254                         First = f;
 255                         Second = s;
 256                 }
 257         }
 258
 259         /// <summary>
 260         ///   This is a wrapper around StreamReader which is seekable.
 261         /// </summary>
 262         public class SeekableStreamReader
 263         {
 264                 public SeekableStreamReader (StreamReader reader)
 265                 {
 266                         this.reader = reader;
 267                         this.buffer = new char [DefaultCacheSize];
 268                 }
 269
 270                 public SeekableStreamReader (Stream stream, Encoding encoding, bool detect_encoding_from_bytemarks)
 271                         : this (new StreamReader (stream, encoding, detect_encoding_from_bytemarks))
 272                 { }
 273
 274                 StreamReader reader;
 275
 276                 private const int DefaultCacheSize = 1024;
 277
 278                 char[] buffer;
 279                 int buffer_start;
 280                 int buffer_size;
 281                 int pos;
 282
 283                 /// <remarks>
 284                 ///   The difference to the StreamReader's BaseStream.Position is that this one is reliable; ie. it
 285                 //    always reports the correct position and if it's modified, it also takes care of the buffered data.
 286                 /// </remarks>
 287                 public int Position {
 288                         get {
 289                                 return buffer_start + pos;
 290                         }
 291
 292                         set {
 293                                 // This one is easy: we're modifying the position within our current
 294                                 // buffer.
 295                                 if ((value >= buffer_start) && (value < buffer_start + buffer_size)) {
 296                                         pos = value - buffer_start;
 297                                         return;
 298                                 }
 299
 300                                 // Ok, now we need to seek.
 301                                 reader.DiscardBufferedData ();
 302                                 reader.BaseStream.Position = buffer_start = value;
 303                                 buffer_size = pos = 0;
 304                         }
 305                 }
 306
 307                 private bool ReadBuffer ()
 308                 {
 309                         pos = 0;
 310                         buffer_start += buffer_size;
 311                         buffer_size = reader.Read (buffer, 0, buffer.Length);
 312                         return buffer_size > 0;
 313                 }
 314
 315                 public int Peek ()
 316                 {
 317                         if ((pos >= buffer_size) && !ReadBuffer ())
 318                                 return -1;
 319
 320                         return buffer [pos];
 321                 }
 322
 323                 public int Read ()
 324                 {
 325                         if ((pos >= buffer_size) && !ReadBuffer ())
 326                                 return -1;
 327
 328                         return buffer [pos++];
 329                 }
 330         }
 331
 332         public class DoubleHash {
 333                 Hashtable l = new Hashtable ();
 334
 335                 public DoubleHash ()
 336                 {
 337                 }
 338
 339                 public bool Lookup (object a, object b, out object res)
 340                 {
 341                         object r = l [a];
 342                         if (r == null){
 343                                 res = null;
 344                                 return false;
 345                         }
 346                         Hashtable ht = (Hashtable) r;
 347                         if (ht.Contains (b)){
 348                                 res = ht [b];
 349                                 return true;
 350                         }
 351                         res = null;
 352                         return false;
 353                 }
 354
 355                 public void Insert (object a, object b, object value)
 356                 {
 357                         Hashtable ht;
 358                         object r = l [a];
 359                         if (r == null){
 360                                 ht = new Hashtable ();
 361                                 l [a] = ht;
 362                                 ht [b] = value;
 363                                 return;
 364                         }
 365                         ht = (Hashtable) r;
 366                         ht [b] = value;
 367                 }
 368         }
 369 }