mcs/class/corlib/System/MonoCustomAttrs.cs

   1 // System.MonoCustomAttrs.cs
   2 // Hooks into the runtime to get custom attributes for reflection handles
   3 //
   4 // Authors:
   5 //      Paolo Molaro (lupus@ximian.com)
   6 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   7 //
   8 // (c) 2002,2003 Ximian, Inc. (http://www.ximian.com)
   9 //
  10
  11 //
  12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 using System;
  35 using System.Reflection;
  36 using System.Collections;
  37 using System.Runtime.CompilerServices;
  38 #if !FULL_AOT_RUNTIME
  39 using System.Reflection.Emit;
  40 #endif
  41
  42 using System.Collections.Generic;
  43
  44 namespace System
  45 {
  46         internal class MonoCustomAttrs
  47         {
  48                 static Assembly corlib;
  49
  50                 /* Treat as user types all corlib types extending System.Type that are not MonoType and TypeBuilder */
  51                 static bool IsUserCattrProvider (object obj)
  52                 {
  53                         Type type = obj as Type;
  54 #if !FULL_AOT_RUNTIME
  55                         if ((type is MonoType) || (type is TypeBuilder))
  56 #else
  57                         if (type is MonoType)
  58 #endif
  59                                 return false;
  60                         if ((obj is Type))
  61                                 return true;
  62                         if (corlib == null)
  63                                  corlib = typeof (int).Assembly;
  64                         return obj.GetType ().Assembly != corlib;
  65                 }
  66
  67                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
  68                 internal static extern object[] GetCustomAttributesInternal (ICustomAttributeProvider obj, Type attributeType, bool pseudoAttrs);
  69
  70                 internal static object[] GetPseudoCustomAttributes (ICustomAttributeProvider obj, Type attributeType) {
  71                         object[] pseudoAttrs = null;
  72
  73                         /* FIXME: Add other types */
  74                         if (obj is MonoMethod)
  75                                 pseudoAttrs = ((MonoMethod)obj).GetPseudoCustomAttributes ();
  76                         else if (obj is FieldInfo)
  77                                 pseudoAttrs = ((FieldInfo)obj).GetPseudoCustomAttributes ();
  78                         else if (obj is ParameterInfo)
  79                                 pseudoAttrs = ((ParameterInfo)obj).GetPseudoCustomAttributes ();
  80                         else if (obj is Type)
  81                                 pseudoAttrs = ((Type)obj).GetPseudoCustomAttributes ();
  82
  83                         if ((attributeType != null) && (pseudoAttrs != null)) {
  84                                 for (int i = 0; i < pseudoAttrs.Length; ++i)
  85                                         if (attributeType.IsAssignableFrom (pseudoAttrs [i].GetType ()))
  86                                                 if (pseudoAttrs.Length == 1)
  87                                                         return pseudoAttrs;
  88                                                 else
  89                                                         return new object [] { pseudoAttrs [i] };
  90                                 return new object [0];
  91                         }
  92                         else
  93                                 return pseudoAttrs;
  94                 }
  95
  96                 internal static object[] GetCustomAttributesBase (ICustomAttributeProvider obj, Type attributeType)
  97                 {
  98                         object[] attrs;
  99                         if (IsUserCattrProvider (obj))
 100                                 attrs = obj.GetCustomAttributes (attributeType, true);
 101                         else
 102                                 attrs = GetCustomAttributesInternal (obj, attributeType, false);
 103
 104                         object[] pseudoAttrs = GetPseudoCustomAttributes (obj, attributeType);
 105                         if (pseudoAttrs != null) {
 106                                 object[] res = new object [attrs.Length + pseudoAttrs.Length];
 107                                 System.Array.Copy (attrs, res, attrs.Length);
 108                                 System.Array.Copy (pseudoAttrs, 0, res, attrs.Length, pseudoAttrs.Length);
 109                                 return res;
 110                         }
 111                         else
 112                                 return attrs;
 113                 }
 114
 115                 internal static Attribute GetCustomAttribute (ICustomAttributeProvider obj,
 116                                                                 Type attributeType,
 117                                                                 bool inherit)
 118                 {
 119                         object[] res = GetCustomAttributes (obj, attributeType, inherit);
 120                         if (res.Length == 0)
 121                         {
 122                                 return null;
 123                         }
 124                         else if (res.Length > 1)
 125                         {
 126                                 string msg = "'{0}' has more than one attribute of type '{1}";
 127                                 msg = String.Format (msg, obj, attributeType);
 128                                 throw new AmbiguousMatchException (msg);
 129                         }
 130
 131                         return (Attribute) res[0];
 132                 }
 133
 134                 internal static object[] GetCustomAttributes (ICustomAttributeProvider obj, Type attributeType, bool inherit)
 135                 {
 136                         if (obj == null)
 137                                 throw new ArgumentNullException ("obj");
 138                         if (attributeType == null)
 139                                 throw new ArgumentNullException ("attributeType");
 140
 141                         if (attributeType == typeof (MonoCustomAttrs))
 142                                 attributeType = null;
 143
 144                         object[] r;
 145                         object[] res = GetCustomAttributesBase (obj, attributeType);
 146                         // shortcut
 147                         if (!inherit && res.Length == 1)
 148                         {
 149                                 if (res [0] == null)
 150                                         throw new CustomAttributeFormatException ("Invalid custom attribute format");
 151
 152                                 if (attributeType != null)
 153                                 {
 154                                         if (attributeType.IsAssignableFrom (res[0].GetType ()))
 155                                         {
 156                                                 r = (object[]) Array.CreateInstance (attributeType, 1);
 157                                                 r[0] = res[0];
 158                                         }
 159                                         else
 160                                         {
 161                                                 r = (object[]) Array.CreateInstance (attributeType, 0);
 162                                         }
 163                                 }
 164                                 else
 165                                 {
 166                                         r = (object[]) Array.CreateInstance (res[0].GetType (), 1);
 167                                         r[0] = res[0];
 168                                 }
 169                                 return r;
 170                         }
 171
 172                         // if AttributeType is sealed, and Inherited is set to false, then
 173                         // there's no use in scanning base types
 174                         if ((attributeType != null && attributeType.IsSealed) && inherit)
 175                         {
 176                                 AttributeUsageAttribute usageAttribute = RetrieveAttributeUsage (
 177                                         attributeType);
 178                                 if (!usageAttribute.Inherited)
 179                                 {
 180                                         inherit = false;
 181                                 }
 182                         }
 183
 184                         int initialSize = res.Length < 16 ? res.Length : 16;
 185
 186                         Hashtable attributeInfos = new Hashtable (initialSize);
 187                         ArrayList a = new ArrayList (initialSize);
 188                         ICustomAttributeProvider btype = obj;
 189
 190                         int inheritanceLevel = 0;
 191
 192                         do
 193                         {
 194                                 foreach (object attr in res)
 195                                 {
 196                                         AttributeUsageAttribute usage;
 197                                         if (attr == null)
 198                                                 throw new CustomAttributeFormatException ("Invalid custom attribute format");
 199
 200                                         Type attrType = attr.GetType ();
 201                                         if (attributeType != null)
 202                                         {
 203                                                 if (!attributeType.IsAssignableFrom (attrType))
 204                                                 {
 205                                                         continue;
 206                                                 }
 207                                         }
 208
 209                                         AttributeInfo firstAttribute = (AttributeInfo) attributeInfos[attrType];
 210                                         if (firstAttribute != null)
 211                                         {
 212                                                 usage = firstAttribute.Usage;
 213                                         }
 214                                         else
 215                                         {
 216                                                 usage = RetrieveAttributeUsage (attrType);
 217                                         }
 218
 219                                         // only add attribute to the list of attributes if
 220                                         // - we are on the first inheritance level, or the attribute can be inherited anyway
 221                                         // and (
 222                                         // - multiple attributes of the type are allowed
 223                                         // or (
 224                                         // - this is the first attribute we've discovered
 225                                         // or
 226                                         // - the attribute is on same inheritance level than the first
 227                                         //   attribute that was discovered for this attribute type ))
 228                                         if ((inheritanceLevel == 0 || usage.Inherited) && (usage.AllowMultiple ||
 229                                                 (firstAttribute == null || (firstAttribute != null
 230                                                         && firstAttribute.InheritanceLevel == inheritanceLevel))))
 231                                         {
 232                                                 a.Add (attr);
 233                                         }
 234
 235                                         if (firstAttribute == null)
 236                                         {
 237                                                 attributeInfos.Add (attrType, new AttributeInfo (usage, inheritanceLevel));
 238                                         }
 239                                 }
 240
 241                                 if ((btype = GetBase (btype)) != null)
 242                                 {
 243                                         inheritanceLevel++;
 244                                         res = GetCustomAttributesBase (btype, attributeType);
 245                                 }
 246                         } while (inherit && btype != null);
 247
 248                         object[] array = null;
 249                         if (attributeType == null || attributeType.IsValueType)
 250                         {
 251                                 array = (object[]) Array.CreateInstance (typeof(Attribute), a.Count);
 252                         }
 253                         else
 254                         {
 255                                 array = Array.CreateInstance (attributeType, a.Count) as object[];
 256                         }
 257
 258                         // copy attributes to array
 259                         a.CopyTo (array, 0);
 260
 261                         return array;
 262                 }
 263
 264                 internal static object[] GetCustomAttributes (ICustomAttributeProvider obj, bool inherit)
 265                 {
 266                         if (obj == null)
 267                                 throw new ArgumentNullException ("obj");
 268
 269                         if (!inherit)
 270                                 return (object[]) GetCustomAttributesBase (obj, null).Clone ();
 271
 272                         return GetCustomAttributes (obj, typeof (MonoCustomAttrs), inherit);
 273                 }
 274
 275                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 276                 static extern CustomAttributeData [] GetCustomAttributesDataInternal (ICustomAttributeProvider obj);
 277
 278                 internal static IList<CustomAttributeData> GetCustomAttributesData (ICustomAttributeProvider obj)
 279                 {
 280                         if (obj == null)
 281                                 throw new ArgumentNullException ("obj");
 282
 283                         CustomAttributeData [] attrs = GetCustomAttributesDataInternal (obj);
 284                         return Array.AsReadOnly<CustomAttributeData> (attrs);
 285                 }
 286
 287                 internal static bool IsDefined (ICustomAttributeProvider obj, Type attributeType, bool inherit)
 288                 {
 289                         if (attributeType == null)
 290                                 throw new ArgumentNullException ("attributeType");
 291
 292                         AttributeUsageAttribute usage = null;
 293                         do {
 294                                 if (IsUserCattrProvider (obj))
 295                                         return obj.IsDefined (attributeType, inherit);
 296
 297                                 if (IsDefinedInternal (obj, attributeType))
 298                                         return true;
 299
 300                                 object[] pseudoAttrs = GetPseudoCustomAttributes (obj, attributeType);
 301                                 if (pseudoAttrs != null) {
 302                                         for (int i = 0; i < pseudoAttrs.Length; ++i)
 303                                                 if (attributeType.IsAssignableFrom (pseudoAttrs[i].GetType ()))
 304                                                         return true;
 305                                 }
 306
 307                                 if (usage == null) {
 308                                         if (!inherit)
 309                                                 return false;
 310
 311                                         usage = RetrieveAttributeUsage (attributeType);
 312                                         if (!usage.Inherited)
 313                                                 return false;
 314                                 }
 315
 316                                 obj = GetBase (obj);
 317                         } while (obj != null);
 318
 319                         return false;
 320                 }
 321
 322                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 323                 internal static extern bool IsDefinedInternal (ICustomAttributeProvider obj, Type AttributeType);
 324
 325                 static PropertyInfo GetBasePropertyDefinition (PropertyInfo property)
 326                 {
 327                         MethodInfo method = property.GetGetMethod (true);
 328                         if (method == null || !method.IsVirtual)
 329                                 method = property.GetSetMethod (true);
 330                         if (method == null || !method.IsVirtual)
 331                                 return null;
 332
 333                         MethodInfo baseMethod = method.GetBaseMethod ();
 334                         if (baseMethod != null && baseMethod != method) {
 335                                 ParameterInfo[] parameters = property.GetIndexParameters ();
 336                                 if (parameters != null && parameters.Length > 0) {
 337                                         Type[] paramTypes = new Type[parameters.Length];
 338                                         for (int i=0; i < paramTypes.Length; i++)
 339                                                 paramTypes[i] = parameters[i].ParameterType;
 340                                         return baseMethod.DeclaringType.GetProperty (property.Name, property.PropertyType,
 341                                                                                      paramTypes);
 342                                 } else {
 343                                         return baseMethod.DeclaringType.GetProperty (property.Name, property.PropertyType);
 344                                 }
 345                         }
 346                         return null;
 347
 348                 }
 349
 350                 static EventInfo GetBaseEventDefinition (EventInfo evt)
 351                 {
 352                         MethodInfo method = evt.GetAddMethod (true);
 353                         if (method == null || !method.IsVirtual)
 354                                 method = evt.GetRaiseMethod (true);
 355                         if (method == null || !method.IsVirtual)
 356                                 method = evt.GetRemoveMethod (true);
 357                         if (method == null || !method.IsVirtual)
 358                                 return null;
 359
 360                         MethodInfo baseMethod = method.GetBaseMethod ();
 361                         if (baseMethod != null && baseMethod != method) {
 362                                 BindingFlags flags = method.IsPublic ? BindingFlags.Public : BindingFlags.NonPublic;
 363                                 flags |= method.IsStatic ? BindingFlags.Static : BindingFlags.Instance;
 364
 365                                 return baseMethod.DeclaringType.GetEvent (evt.Name, flags);
 366                         }
 367                         return null;
 368                 }
 369
 370                 // Handles Type, MonoProperty and MonoMethod.
 371                 // The runtime has also cases for MonoEvent, MonoField, Assembly and ParameterInfo,
 372                 // but for those we return null here.
 373                 static ICustomAttributeProvider GetBase (ICustomAttributeProvider obj)
 374                 {
 375                         if (obj == null)
 376                                 return null;
 377
 378                         if (obj is Type)
 379                                 return ((Type) obj).BaseType;
 380
 381                         MethodInfo method = null;
 382                         if (obj is MonoProperty)
 383                                 return GetBasePropertyDefinition ((MonoProperty) obj);
 384                         else if (obj is MonoEvent)
 385                                 return GetBaseEventDefinition ((MonoEvent)obj);
 386                         else if (obj is MonoMethod)
 387                                 method = (MethodInfo) obj;
 388
 389                         /**
 390                          * ParameterInfo -> null
 391                          * Assembly -> null
 392                          * MonoEvent -> null
 393                          * MonoField -> null
 394                          */
 395                         if (method == null || !method.IsVirtual)
 396                                 return null;
 397
 398                         MethodInfo baseMethod = method.GetBaseMethod ();
 399                         if (baseMethod == method)
 400                                 return null;
 401
 402                         return baseMethod;
 403                 }
 404
 405                 private static AttributeUsageAttribute RetrieveAttributeUsage (Type attributeType)
 406                 {
 407                         if (attributeType == typeof (AttributeUsageAttribute))
 408                                 /* Avoid endless recursion */
 409                                 return new AttributeUsageAttribute (AttributeTargets.Class);
 410
 411                         AttributeUsageAttribute usageAttribute = null;
 412                         object[] attribs = GetCustomAttributes (attributeType, typeof(AttributeUsageAttribute), false);
 413                         if (attribs.Length == 0)
 414                         {
 415                                 // if no AttributeUsage was defined on the attribute level, then
 416                                 // try to retrieve if from its base type
 417                                 if (attributeType.BaseType != null)
 418                                 {
 419                                         usageAttribute = RetrieveAttributeUsage (attributeType.BaseType);
 420
 421                                 }
 422                                 if (usageAttribute != null)
 423                                 {
 424                                         // return AttributeUsage of base class
 425                                         return usageAttribute;
 426
 427                                 }
 428                                 // return default AttributeUsageAttribute if no AttributeUsage
 429                                 // was defined on attribute, or its base class
 430                                 return DefaultAttributeUsage;
 431                         }
 432                         // check if more than one AttributeUsageAttribute has been specified
 433                         // on the type
 434                         // NOTE: compilers should prevent this, but that doesn't prevent
 435                         // anyone from using IL ofcourse
 436                         if (attribs.Length > 1)
 437                         {
 438                                 throw new FormatException ("Duplicate AttributeUsageAttribute cannot be specified on an attribute type.");
 439                         }
 440
 441                         return ((AttributeUsageAttribute) attribs[0]);
 442                 }
 443
 444                 private static readonly AttributeUsageAttribute DefaultAttributeUsage =
 445                         new AttributeUsageAttribute (AttributeTargets.All);
 446
 447                 private class AttributeInfo
 448                 {
 449                         private AttributeUsageAttribute _usage;
 450                         private int _inheritanceLevel;
 451
 452                         public AttributeInfo (AttributeUsageAttribute usage, int inheritanceLevel)
 453                         {
 454                                 _usage = usage;
 455                                 _inheritanceLevel = inheritanceLevel;
 456                         }
 457
 458                         public AttributeUsageAttribute Usage
 459                         {
 460                                 get
 461                                 {
 462                                         return _usage;
 463                                 }
 464                         }
 465
 466                         public int InheritanceLevel
 467                         {
 468                                 get
 469                                 {
 470                                         return _inheritanceLevel;
 471                                 }
 472                         }
 473                 }
 474         }
 475 }
 476