/* ****************************************************************************
*
* 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; using Microsoft;
#if !SILVERLIGHT // ComObject
using System.Collections.Generic;
#if CODEPLEX_40
using System.Linq.Expressions;
#else
using Microsoft.Linq.Expressions;
#endif
using System.Runtime.InteropServices;
using System.Diagnostics;
#if CODEPLEX_40
using System.Dynamic.Utils;
#else
using Microsoft.Scripting.Utils;
#endif
#if CODEPLEX_40
namespace System.Dynamic{
#else
namespace Microsoft.Scripting {
#endif
internal class StringArgBuilder : SimpleArgBuilder {
private readonly bool _isWrapper;
internal StringArgBuilder(Type parameterType)
: base(parameterType) {
Debug.Assert(parameterType == typeof(string) ||
parameterType == typeof(BStrWrapper));
_isWrapper = parameterType == typeof(BStrWrapper);
}
internal override Expression Marshal(Expression parameter) {
parameter = base.Marshal(parameter);
// parameter.WrappedObject
if (_isWrapper) {
parameter = Expression.Property(
Helpers.Convert(parameter, typeof(BStrWrapper)),
typeof(BStrWrapper).GetProperty("WrappedObject")
);
};
return parameter;
}
internal override Expression MarshalToRef(Expression parameter) {
parameter = Marshal(parameter);
// Marshal.StringToBSTR(parameter)
return Expression.Call(
typeof(Marshal).GetMethod("StringToBSTR"),
parameter
);
}
internal override Expression UnmarshalFromRef(Expression value) {
// value == IntPtr.Zero ? null : Marshal.PtrToStringBSTR(value);
Expression unmarshal = Expression.Condition(
Expression.Equal(value, Expression.Constant(IntPtr.Zero)),
Expression.Constant(null, typeof(string)), // default value
Expression.Call(
typeof(Marshal).GetMethod("PtrToStringBSTR"),
value
)
);
if (_isWrapper) {
unmarshal = Expression.New(
typeof(BStrWrapper).GetConstructor(new Type[] { typeof(string) }),
unmarshal
);
};
return base.UnmarshalFromRef(unmarshal);
}
}
}
#endif
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