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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System;
using System.Diagnostics.CodeAnalysis;
using System.Dynamic;
using System.Linq.Expressions;
namespace Microsoft.CSharp.RuntimeBinder.ComInterop
{
[RequiresUnreferencedCode(Binder.TrimmerWarning)]
[RequiresDynamicCode(Binder.DynamicCodeWarning)]
internal sealed class IDispatchMetaObject : ComFallbackMetaObject
{
private readonly IDispatchComObject _self;
private static readonly bool[] s_false = new bool[] { false };
internal IDispatchMetaObject(Expression expression, IDispatchComObject self)
: base(expression, BindingRestrictions.Empty, self)
{
_self = self;
}
public override DynamicMetaObject BindInvokeMember(InvokeMemberBinder binder, DynamicMetaObject[] args)
{
Requires.NotNull(binder);
if (_self.TryGetMemberMethod(binder.Name, out ComMethodDesc method) ||
_self.TryGetMemberMethodExplicit(binder.Name, out method))
{
bool[] isByRef = ComBinderHelpers.ProcessArgumentsForCom(ref args);
return BindComInvoke(args, method, binder.CallInfo, isByRef);
}
return base.BindInvokeMember(binder, args);
}
public override DynamicMetaObject BindInvoke(InvokeBinder binder, DynamicMetaObject[] args)
{
Requires.NotNull(binder);
if (_self.TryGetGetItem(out ComMethodDesc method))
{
bool[] isByRef = ComBinderHelpers.ProcessArgumentsForCom(ref args);
return BindComInvoke(args, method, binder.CallInfo, isByRef);
}
return base.BindInvoke(binder, args);
}
private DynamicMetaObject BindComInvoke(DynamicMetaObject[] args, ComMethodDesc method, CallInfo callInfo, bool[] isByRef)
{
return new ComInvokeBinder(
callInfo,
args,
isByRef,
IDispatchRestriction(),
Expression.Constant(method),
Expression.Property(
Helpers.Convert(Expression, typeof(IDispatchComObject)),
typeof(IDispatchComObject).GetProperty(nameof(IDispatchComObject.DispatchObject))
),
method
).Invoke();
}
public override DynamicMetaObject BindGetMember(GetMemberBinder binder)
{
ComBinder.ComGetMemberBinder comBinder = binder as ComBinder.ComGetMemberBinder;
bool canReturnCallables = comBinder?._canReturnCallables ?? false;
Requires.NotNull(binder);
// 1. Try methods
if (_self.TryGetMemberMethod(binder.Name, out ComMethodDesc method))
{
return BindGetMember(method, canReturnCallables);
}
// 2. Try events
if (_self.TryGetMemberEvent(binder.Name, out ComEventDesc @event))
{
return BindEvent(@event);
}
// 3. Try methods explicitly by name
if (_self.TryGetMemberMethodExplicit(binder.Name, out method))
{
return BindGetMember(method, canReturnCallables);
}
// 4. Fallback
return base.BindGetMember(binder);
}
private DynamicMetaObject BindGetMember(ComMethodDesc method, bool canReturnCallables)
{
if (method.IsDataMember)
{
if (method.ParamCount == 0)
{
return BindComInvoke(DynamicMetaObject.EmptyMetaObjects, method, new CallInfo(0), Array.Empty<bool>());
}
}
// ComGetMemberBinder does not expect callables. Try to call always.
if (!canReturnCallables)
{
return BindComInvoke(DynamicMetaObject.EmptyMetaObjects, method, new CallInfo(0), Array.Empty<bool>());
}
return new DynamicMetaObject(
Expression.Call(
typeof(ComRuntimeHelpers).GetMethod(nameof(ComRuntimeHelpers.CreateDispCallable)),
Helpers.Convert(Expression, typeof(IDispatchComObject)),
Expression.Constant(method)
),
IDispatchRestriction()
);
}
private DynamicMetaObject BindEvent(ComEventDesc eventDesc)
{
// BoundDispEvent CreateComEvent(object rcw, Guid sourceIid, int dispid)
Expression result =
Expression.Call(
typeof(ComRuntimeHelpers).GetMethod(nameof(ComRuntimeHelpers.CreateComEvent)),
ComObject.RcwFromComObject(Expression),
Expression.Constant(eventDesc.SourceIID),
Expression.Constant(eventDesc.Dispid)
);
return new DynamicMetaObject(
result,
IDispatchRestriction()
);
}
public override DynamicMetaObject BindGetIndex(GetIndexBinder binder, DynamicMetaObject[] indexes)
{
Requires.NotNull(binder);
if (_self.TryGetGetItem(out ComMethodDesc getItem))
{
bool[] isByRef = ComBinderHelpers.ProcessArgumentsForCom(ref indexes);
return BindComInvoke(indexes, getItem, binder.CallInfo, isByRef);
}
return base.BindGetIndex(binder, indexes);
}
public override DynamicMetaObject BindSetIndex(SetIndexBinder binder, DynamicMetaObject[] indexes, DynamicMetaObject value)
{
Requires.NotNull(binder);
if (_self.TryGetSetItem(out ComMethodDesc setItem))
{
bool[] isByRef = ComBinderHelpers.ProcessArgumentsForCom(ref indexes);
isByRef = isByRef.AddLast(false);
DynamicMetaObject result = BindComInvoke(indexes.AddLast(value), setItem, binder.CallInfo, isByRef);
// Make sure to return the value; some languages need it.
return new DynamicMetaObject(
Expression.Block(result.Expression, Expression.Convert(value.Expression, typeof(object))),
result.Restrictions
);
}
return base.BindSetIndex(binder, indexes, value);
}
public override DynamicMetaObject BindSetMember(SetMemberBinder binder, DynamicMetaObject value)
{
Requires.NotNull(binder);
return
// 1. Check for simple property put
TryPropertyPut(binder, value) ??
// 2. Check for event handler hookup where the put is dropped
TryEventHandlerNoop(binder, value) ??
// 3. Fallback
base.BindSetMember(binder, value);
}
private DynamicMetaObject TryPropertyPut(SetMemberBinder binder, DynamicMetaObject value)
{
bool holdsNull = value.Value == null && value.HasValue;
if (_self.TryGetPropertySetter(binder.Name, out ComMethodDesc method, value.LimitType, holdsNull) ||
_self.TryGetPropertySetterExplicit(binder.Name, out method, value.LimitType, holdsNull))
{
BindingRestrictions restrictions = IDispatchRestriction();
Expression dispatch =
Expression.Property(
Helpers.Convert(Expression, typeof(IDispatchComObject)),
typeof(IDispatchComObject).GetProperty(nameof(IDispatchComObject.DispatchObject))
);
DynamicMetaObject result = new ComInvokeBinder(
new CallInfo(1),
new[] { value },
s_false,
restrictions,
Expression.Constant(method),
dispatch,
method
).Invoke();
// Make sure to return the value; some languages need it.
return new DynamicMetaObject(
Expression.Block(result.Expression, Expression.Convert(value.Expression, typeof(object))),
result.Restrictions
);
}
return null;
}
private DynamicMetaObject TryEventHandlerNoop(SetMemberBinder binder, DynamicMetaObject value)
{
if (_self.TryGetMemberEvent(binder.Name, out _) && value.LimitType == typeof(BoundDispEvent))
{
// Drop the event property set.
return new DynamicMetaObject(
Expression.Constant(null),
value.Restrictions.Merge(IDispatchRestriction()).Merge(BindingRestrictions.GetTypeRestriction(value.Expression, typeof(BoundDispEvent)))
);
}
return null;
}
private BindingRestrictions IDispatchRestriction()
{
return IDispatchRestriction(Expression, _self.ComTypeDesc);
}
internal static BindingRestrictions IDispatchRestriction(Expression expr, ComTypeDesc typeDesc)
{
return BindingRestrictions.GetTypeRestriction(
expr, typeof(IDispatchComObject)
).Merge(
BindingRestrictions.GetExpressionRestriction(
Expression.Equal(
Expression.Property(
Helpers.Convert(expr, typeof(IDispatchComObject)),
typeof(IDispatchComObject).GetProperty(nameof(IDispatchComObject.ComTypeDesc))
),
Expression.Constant(typeDesc)
)
)
);
}
protected override ComUnwrappedMetaObject UnwrapSelf()
{
return new ComUnwrappedMetaObject(
ComObject.RcwFromComObject(Expression),
IDispatchRestriction(),
_self.RuntimeCallableWrapper
);
}
}
}
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