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*
* Copyright (c) Microsoft Corporation.
*
* This source code is subject to terms and conditions of the Microsoft Public License. A
* copy of the license can be found in the License.html file at the root of this distribution. If
* you cannot locate the Microsoft Public License, please send an email to
* dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound
* by the terms of the Microsoft Public License.
*
* You must not remove this notice, or any other, from this software.
*
*
* ***************************************************************************/
using System.Diagnostics;
using System.Reflection;
using System.Reflection.Emit;
using System.Text;
namespace System.Dynamic.Utils{
// Extensions on System.Type and friends
internal static class TypeExtensions {
/// <summary>
/// Creates an open delegate for the given (dynamic)method.
/// </summary>
internal static Delegate CreateDelegate(this MethodInfo methodInfo, Type delegateType) {
Debug.Assert(methodInfo != null && delegateType != null);
var dm = methodInfo as DynamicMethod;
if (dm != null) {
return dm.CreateDelegate(delegateType);
} else {
return Delegate.CreateDelegate(delegateType, methodInfo);
}
}
/// <summary>
/// Creates a closed delegate for the given (dynamic)method.
/// </summary>
internal static Delegate CreateDelegate(this MethodInfo methodInfo, Type delegateType, object target) {
Debug.Assert(methodInfo != null && delegateType != null);
var dm = methodInfo as DynamicMethod;
if (dm != null) {
return dm.CreateDelegate(delegateType, target);
} else {
return Delegate.CreateDelegate(delegateType, target, methodInfo);
}
}
internal static Type GetReturnType(this MethodBase mi) {
return (mi.IsConstructor) ? mi.DeclaringType : ((MethodInfo)mi).ReturnType;
}
private static readonly CacheDict<MethodBase, ParameterInfo[]> _ParamInfoCache = new CacheDict<MethodBase, ParameterInfo[]>(75);
internal static ParameterInfo[] GetParametersCached(this MethodBase method) {
ParameterInfo[] pis;
lock (_ParamInfoCache) {
if (!_ParamInfoCache.TryGetValue(method, out pis)) {
pis = method.GetParameters();
Type t = method.DeclaringType;
if (t != null && TypeUtils.CanCache(t)) {
_ParamInfoCache[method] = pis;
}
}
}
return pis;
}
// Expression trees/compiler just use IsByRef, why do we need this?
// (see LambdaCompiler.EmitArguments for usage in the compiler)
internal static bool IsByRefParameter(this ParameterInfo pi) {
// not using IsIn/IsOut properties as they are not available in Silverlight:
if (pi.ParameterType.IsByRef) return true;
return (pi.Attributes & (ParameterAttributes.Out)) == ParameterAttributes.Out;
}
// Returns the matching method if the parameter types are reference
// assignable from the provided type arguments, otherwise null.
internal static MethodInfo GetMethodValidated(
this Type type,
string name,
BindingFlags bindingAttr,
Binder binder,
Type[] types,
ParameterModifier[] modifiers) {
var method = type.GetMethod(name, bindingAttr, binder, types, modifiers);
return method.MatchesArgumentTypes(types) ? method : null;
}
/// <summary>
/// Returns true if the method's parameter types are reference assignable from
/// the argument types, otherwise false.
///
/// An example that can make the method return false is that
/// typeof(double).GetMethod("op_Equality", ..., new[] { typeof(double), typeof(int) })
/// returns a method with two double parameters, which doesn't match the provided
/// argument types.
/// </summary>
/// <returns></returns>
private static bool MatchesArgumentTypes(this MethodInfo mi, Type[] argTypes) {
if (mi == null || argTypes == null) {
return false;
}
var ps = mi.GetParameters();
if (ps.Length != argTypes.Length) {
return false;
}
for (int i = 0; i < ps.Length; i++) {
if (!TypeUtils.AreReferenceAssignable(ps[i].ParameterType, argTypes[i])) {
return false;
}
}
return true;
}
}
}
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