File size: 5,244 Bytes
8c763fb | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | // Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
#pragma warning disable 618 // CurrencyWrapper is obsolete
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Dynamic;
using System.Globalization;
using System.Linq.Expressions;
using System.Management.Automation.Language;
using System.Runtime.InteropServices;
namespace System.Management.Automation.ComInterop
{
internal static class ComBinderHelpers
{
internal static bool PreferPut(Type type, bool holdsNull)
{
Debug.Assert(type != null);
if (type.IsValueType
|| type.IsArray
|| type == typeof(string)
|| type == typeof(DBNull)
|| holdsNull
|| type == typeof(System.Reflection.Missing)
|| type == typeof(CurrencyWrapper))
{
return true;
}
return false;
}
internal static bool IsByRef(DynamicMetaObject mo)
{
return mo.Expression is ParameterExpression pe && pe.IsByRef;
}
internal static bool IsPSReferenceArg(DynamicMetaObject o)
{
Type t = o.LimitType;
return t.IsGenericType && t.GetGenericTypeDefinition() == typeof(PSReference<>);
}
// This helper prepares arguments for COM binding by transforming ByVal StrongBox arguments
// into ByRef expressions that represent the argument's Value fields.
internal static bool[] ProcessArgumentsForCom(ComMethodDesc method, ref DynamicMetaObject[] args,
List<ParameterExpression> temps, List<Expression> initTemps)
{
Debug.Assert(args != null);
DynamicMetaObject[] newArgs = new DynamicMetaObject[args.Length];
bool[] isByRefArg = new bool[args.Length];
for (int i = 0; i < args.Length; i++)
{
DynamicMetaObject curArgument = args[i];
// set new arg infos to their original values or set default ones
// we will do this fixup early so that we can assume we always have
// arginfos in COM binder.
if (IsByRef(curArgument))
{
newArgs[i] = curArgument;
isByRefArg[i] = true;
}
else
{
if (IsPSReferenceArg(curArgument))
{
var restrictions = curArgument.Restrictions.Merge(
GetTypeRestrictionForDynamicMetaObject(curArgument)
);
// we have restricted this argument to LimitType so we can convert and conversion will be trivial cast.
Expression boxedValueAccessor = Expression.Property(
Helpers.Convert(
curArgument.Expression,
curArgument.LimitType
),
curArgument.LimitType.GetProperty("Value")
);
PSReference value = curArgument.Value as PSReference;
object boxedValue = value?.Value;
newArgs[i] = new DynamicMetaObject(
boxedValueAccessor,
restrictions,
boxedValue
);
isByRefArg[i] = true;
}
else
{
if ((method.ParameterInformation != null) && (i < method.ParameterInformation.Length))
{
newArgs[i] = new DynamicMetaObject(
curArgument.CastOrConvertMethodArgument(
method.ParameterInformation[i].parameterType,
i.ToString(CultureInfo.InvariantCulture),
method.Name,
allowCastingToByRefLikeType: false,
temps,
initTemps),
curArgument.Restrictions);
}
else
{
newArgs[i] = curArgument;
}
isByRefArg[i] = false;
}
}
}
args = newArgs;
return isByRefArg;
}
internal static BindingRestrictions GetTypeRestrictionForDynamicMetaObject(DynamicMetaObject obj)
{
if (obj.Value == null && obj.HasValue)
{
//If the meta object holds a null value, create an instance restriction for checking null
return BindingRestrictions.GetInstanceRestriction(obj.Expression, null);
}
return BindingRestrictions.GetTypeRestriction(obj.Expression, obj.LimitType);
}
}
}
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