1 // System.Reflection.Binder
4 // Sean MacIsaac (macisaac@ximian.com)
5 // Paolo Molaro (lupus@ximian.com)
6 // Gonzalo Paniagua Javier (gonzalo@ximian.com)
8 // (C) Ximian, Inc. 2001 - 2003
9 // (c) Copyright 2004 Novell, Inc. (http://www.novell.com)
12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
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:
22 // The above copyright notice and this permission notice shall be
23 // included in all copies or substantial portions of the Software.
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.
34 using System.Globalization;
35 using System.Runtime.InteropServices;
37 namespace System.Reflection
43 [ClassInterface(ClassInterfaceType.AutoDual)]
44 public abstract class Binder
46 protected Binder () {}
48 public abstract FieldInfo BindToField (BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture);
49 public abstract MethodBase BindToMethod (BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state);
50 public abstract object ChangeType (object value, Type type, CultureInfo culture);
51 public abstract void ReorderArgumentArray( ref object[] args, object state);
52 public abstract MethodBase SelectMethod (BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers);
53 public abstract PropertyInfo SelectProperty( BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers);
55 static Binder default_binder = new Default ();
57 internal static Binder DefaultBinder {
59 return default_binder;
63 internal static bool ConvertArgs (Binder binder, object[] args, ParameterInfo[] pinfo, CultureInfo culture) {
65 if ( pinfo.Length == 0)
68 throw new TargetParameterCountException ();
70 if (pinfo.Length != args.Length)
71 throw new TargetParameterCountException ();
72 for (int i = 0; i < args.Length; ++i) {
73 object v = binder.ChangeType (args [i], pinfo[i].ParameterType, culture);
74 if ((v == null) && (args [i] != null))
81 internal static int GetDerivedLevel (Type type)
83 Type searchType = type;
86 while (searchType.BaseType != null)
89 searchType = searchType.BaseType;
95 internal static MethodBase FindMostDerivedMatch (MethodBase [] match)
99 int count = match.Length;
101 for (int current = 0; current < count; current++)
103 int level = GetDerivedLevel (match[current].DeclaringType);
104 if (level == highLevel)
105 throw new AmbiguousMatchException ();
107 if (level > highLevel)
114 return match[matchId];
117 internal sealed class Default : Binder {
118 public override FieldInfo BindToField (BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture)
121 throw new ArgumentNullException ("match");
122 foreach (FieldInfo f in match) {
123 if (check_type (value.GetType (), f.FieldType))
130 public override MethodBase BindToMethod (BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state)
134 types = Type.EmptyTypes;
136 types = new Type [args.Length];
137 for (int i = 0; i < args.Length; ++i) {
138 if (args [i] != null)
139 types [i] = args [i].GetType ();
142 MethodBase selected = SelectMethod (bindingAttr, match, types, modifiers);
145 ReorderParameters (names, ref args, selected);
149 void ReorderParameters (string [] names, ref object [] args, MethodBase selected)
151 object [] newArgs = new object [args.Length];
152 Array.Copy (args, newArgs, args.Length);
153 ParameterInfo [] plist = selected.GetParameters ();
154 for (int n = 0; n < names.Length; n++)
155 for (int p = 0; p < plist.Length; p++) {
156 if (names [n] == plist [p].Name) {
157 newArgs [p] = args [n];
161 Array.Copy (newArgs, args, args.Length);
164 static bool IsArrayAssignable (Type object_type, Type target_type)
166 if (object_type.IsArray && target_type.IsArray)
167 return IsArrayAssignable (object_type.GetElementType (), target_type.GetElementType ());
169 if (target_type.IsAssignableFrom (object_type))
175 public override object ChangeType (object value, Type type, CultureInfo culture)
179 Type vtype = value.GetType ();
181 type = type.GetElementType ();
182 if (vtype == type || type.IsInstanceOfType (value))
184 if (vtype.IsArray && type.IsArray){
185 if (IsArrayAssignable (vtype.GetElementType (), type.GetElementType ()))
189 if (check_type (vtype, type))
190 return Convert.ChangeType (value, type);
195 public override void ReorderArgumentArray (ref object[] args, object state)
197 //do nothing until we support named arguments
198 //throw new NotImplementedException ();
201 private static bool check_type (Type from, Type to) {
208 TypeCode fromt = Type.GetTypeCode (from);
209 TypeCode tot = Type.GetTypeCode (to);
211 if (to.IsByRef != from.IsByRef)
215 return to.IsAssignableFrom (from);
220 case TypeCode.UInt16:
221 case TypeCode.UInt32:
223 case TypeCode.UInt64:
225 case TypeCode.Single:
226 case TypeCode.Double:
229 return to == typeof (object);
233 case TypeCode.UInt16:
235 case TypeCode.UInt32:
237 case TypeCode.UInt64:
239 case TypeCode.Single:
240 case TypeCode.Double:
243 return to == typeof (object) || (from.IsEnum && to == typeof (Enum));
249 case TypeCode.Single:
250 case TypeCode.Double:
253 return to == typeof (object) || (from.IsEnum && to == typeof (Enum));
254 case TypeCode.UInt16:
256 case TypeCode.UInt32:
258 case TypeCode.UInt64:
260 case TypeCode.Single:
261 case TypeCode.Double:
264 return to == typeof (object) || (from.IsEnum && to == typeof (Enum));
269 case TypeCode.Single:
270 case TypeCode.Double:
273 return to == typeof (object) || (from.IsEnum && to == typeof (Enum));
274 case TypeCode.UInt32:
276 case TypeCode.UInt64:
278 case TypeCode.Single:
279 case TypeCode.Double:
282 return to == typeof (object) || (from.IsEnum && to == typeof (Enum));
286 case TypeCode.Single:
287 case TypeCode.Double:
290 return to == typeof (object) || (from.IsEnum && to == typeof (Enum));
291 case TypeCode.UInt64:
294 case TypeCode.Single:
295 case TypeCode.Double:
298 return to == typeof (object) || (from.IsEnum && to == typeof (Enum));
299 case TypeCode.Single:
300 return tot == TypeCode.Double || to == typeof (object);
302 /* TODO: handle valuetype -> byref */
303 if (to == typeof (object) && from.IsValueType)
306 return to.IsAssignableFrom (from);
310 private static bool check_arguments (Type[] types, ParameterInfo[] args) {
311 for (int i = 0; i < types.Length; ++i) {
312 if (!check_type (types [i], args [i].ParameterType))
318 public override MethodBase SelectMethod (BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers)
324 throw new ArgumentNullException ("match");
326 /* first look for an exact match... */
327 for (i = 0; i < match.Length; ++i) {
329 ParameterInfo[] args = m.GetParameters ();
330 if (args.Length != types.Length)
332 for (j = 0; j < types.Length; ++j) {
333 if (types [j] != args [j].ParameterType)
336 if (j == types.Length)
340 if ((int)(bindingAttr & BindingFlags.ExactBinding) != 0)
343 MethodBase result = null;
344 for (i = 0; i < match.Length; ++i) {
346 ParameterInfo[] args = m.GetParameters ();
347 if (args.Length != types.Length)
349 if (!check_arguments (types, args))
353 result = GetBetterMethod (result, m, types);
361 MethodBase GetBetterMethod (MethodBase m1, MethodBase m2, Type [] types)
364 if (m1.IsGenericMethodDefinition &&
365 !m2.IsGenericMethodDefinition)
367 if (m2.IsGenericMethodDefinition &&
368 !m1.IsGenericMethodDefinition)
372 ParameterInfo [] pl1 = m1.GetParameters ();
373 ParameterInfo [] pl2 = m2.GetParameters ();
375 for (int i = 0; i < pl1.Length; i++) {
376 int cmp = CompareCloserType (pl1 [i].ParameterType, pl2 [i].ParameterType);
377 if (cmp != 0 && prev != 0 && prev != cmp)
378 throw new AmbiguousMatchException ();
383 return prev > 0 ? m2 : m1;
385 bool va1 = (m1.CallingConvention & CallingConventions.VarArgs) != 0;
386 bool va2 = (m1.CallingConvention & CallingConventions.VarArgs) != 0;
392 throw new AmbiguousMatchException ();
395 int CompareCloserType (Type t1, Type t2)
400 if (t1.IsGenericParameter && !t2.IsGenericParameter)
402 if (!t1.IsGenericParameter && t2.IsGenericParameter)
405 if (t1.HasElementType && t2.HasElementType)
406 return CompareCloserType (
407 t1.GetElementType (),
408 t2.GetElementType ());
410 if (t1.IsSubclassOf (t2))
412 if (t2.IsSubclassOf (t1))
415 if (t1.IsInterface && Array.IndexOf (t2.GetInterfaces (), t1) >= 0)
417 if (t2.IsInterface && Array.IndexOf (t1.GetInterfaces (), t2) >= 0)
420 // What kind of cases could reach here?
424 public override PropertyInfo SelectProperty (BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers)
426 if (match == null || match.Length == 0)
427 throw new ArgumentException ("No properties provided", "match");
429 bool haveRet = (returnType != null);
430 int idxlen = (indexes != null) ? indexes.Length : -1;
431 PropertyInfo result = null;
433 int best_score = Int32.MaxValue - 1;
434 int fail_score = Int32.MaxValue;
437 for (i = match.Length - 1; i >= 0; i--) {
438 PropertyInfo p = match [i];
439 ParameterInfo[] args = p.GetIndexParameters ();
440 if (idxlen >= 0 && idxlen != args.Length)
443 if (haveRet && !check_type (p.PropertyType, returnType))
446 int score = Int32.MaxValue - 1;
448 score = check_arguments_with_score (indexes, args);
453 int new_level = GetDerivedLevel (p.DeclaringType);
454 if (result != null) {
455 if (best_score < score)
458 if (best_score == score) {
459 if (level == new_level) {
460 // Keep searching. May be there's something
466 if (level > new_level)
476 if (fail_score <= best_score)
477 throw new AmbiguousMatchException ();
482 static int check_arguments_with_score (Type [] types, ParameterInfo [] args)
486 for (int i = 0; i < types.Length; ++i) {
487 int res = check_type_with_score (types [i], args [i].ParameterType);
498 // 0 -> same type or null and !valuetype
500 // 2 -> value type that don't lose data
501 // 3 -> to == IsAssignableFrom
503 static int check_type_with_score (Type from, Type to)
506 return to.IsValueType ? -1 : 0;
511 if (to == typeof (object))
514 TypeCode fromt = Type.GetTypeCode (from);
515 TypeCode tot = Type.GetTypeCode (to);
520 case TypeCode.UInt16:
523 case TypeCode.UInt32:
525 case TypeCode.UInt64:
527 case TypeCode.Single:
528 case TypeCode.Double:
535 case TypeCode.UInt16:
537 case TypeCode.UInt32:
539 case TypeCode.UInt64:
541 case TypeCode.Single:
542 case TypeCode.Double:
545 return (from.IsEnum && to == typeof (Enum)) ? 1 : -1;
551 case TypeCode.Single:
552 case TypeCode.Double:
555 return (from.IsEnum && to == typeof (Enum)) ? 1 : -1;
556 case TypeCode.UInt16:
558 case TypeCode.UInt32:
560 case TypeCode.UInt64:
562 case TypeCode.Single:
563 case TypeCode.Double:
566 return (from.IsEnum && to == typeof (Enum)) ? 1 : -1;
571 case TypeCode.Single:
572 case TypeCode.Double:
575 return (from.IsEnum && to == typeof (Enum)) ? 1 : -1;
576 case TypeCode.UInt32:
578 case TypeCode.UInt64:
580 case TypeCode.Single:
581 case TypeCode.Double:
584 return (from.IsEnum && to == typeof (Enum)) ? 1 : -1;
588 case TypeCode.Single:
589 case TypeCode.Double:
592 return (from.IsEnum && to == typeof (Enum)) ? 1 : -1;
593 case TypeCode.UInt64:
596 case TypeCode.Single:
597 case TypeCode.Double:
600 return (from.IsEnum && to == typeof (Enum)) ? 1 : -1;
601 case TypeCode.Single:
602 return tot == TypeCode.Double ? 2 : -1;
604 return (to.IsAssignableFrom (from)) ? 3 : -1;