OverloadResolutionErrors IsUnambiguousCall(ExpectedTargetDetails expectedTargetDetails, IMethod method,
TranslatedExpression target, IType[] typeArguments, IList <TranslatedExpression> arguments)
{
var lookup = new MemberLookup(resolver.CurrentTypeDefinition, resolver.CurrentTypeDefinition.ParentAssembly);
var or = new OverloadResolution(resolver.Compilation, arguments.SelectArray(a => a.ResolveResult), typeArguments: typeArguments);
if (expectedTargetDetails.CallOpCode == OpCode.NewObj)
{
foreach (IMethod ctor in method.DeclaringType.GetConstructors())
{
if (lookup.IsAccessible(ctor, allowProtectedAccess: resolver.CurrentTypeDefinition == method.DeclaringTypeDefinition))
{
or.AddCandidate(ctor);
}
}
}
else
{
var result = lookup.Lookup(target.ResolveResult, method.Name, EmptyList <IType> .Instance, true) as MethodGroupResolveResult;
if (result == null)
{
return(OverloadResolutionErrors.AmbiguousMatch);
}
or.AddMethodLists(result.MethodsGroupedByDeclaringType.ToArray());
}
if (or.BestCandidateErrors != OverloadResolutionErrors.None)
{
return(or.BestCandidateErrors);
}
if (!IsAppropriateCallTarget(expectedTargetDetails, method, or.GetBestCandidateWithSubstitutedTypeArguments()))
{
return(OverloadResolutionErrors.AmbiguousMatch);
}
return(OverloadResolutionErrors.None);
}
TranslatedExpression HandleAccessorCall(ILInstruction inst, TranslatedExpression target, IMethod method, IList <TranslatedExpression> arguments)
{
var lookup = new MemberLookup(resolver.CurrentTypeDefinition, resolver.CurrentTypeDefinition.ParentAssembly);
var result = lookup.Lookup(target.ResolveResult, method.AccessorOwner.Name, EmptyList <IType> .Instance, isInvocation: false);
if (result.IsError || (result is MemberResolveResult && !IsAppropriateCallTarget(method.AccessorOwner, ((MemberResolveResult)result).Member, inst.OpCode == OpCode.CallVirt)))
{
target = target.ConvertTo(method.AccessorOwner.DeclaringType, expressionBuilder);
}
var rr = new MemberResolveResult(target.ResolveResult, method.AccessorOwner);
if (method.ReturnType.IsKnownType(KnownTypeCode.Void))
{
var value = arguments.Last();
arguments.Remove(value);
TranslatedExpression expr;
if (arguments.Count == 0)
{
expr = new MemberReferenceExpression(target.Expression, method.AccessorOwner.Name)
.WithoutILInstruction().WithRR(rr);
}
else
{
expr = new IndexerExpression(target.Expression, arguments.Select(a => a.Expression))
.WithoutILInstruction().WithRR(rr);
}
var op = AssignmentOperatorType.Assign;
var parentEvent = method.AccessorOwner as IEvent;
if (parentEvent != null)
{
if (method.Equals(parentEvent.AddAccessor))
{
op = AssignmentOperatorType.Add;
}
if (method.Equals(parentEvent.RemoveAccessor))
{
op = AssignmentOperatorType.Subtract;
}
}
return(new AssignmentExpression(expr, op, value.Expression).WithILInstruction(inst).WithRR(new TypeResolveResult(method.AccessorOwner.ReturnType)));
}
else
{
if (arguments.Count == 0)
{
return(new MemberReferenceExpression(target.Expression, method.AccessorOwner.Name).WithILInstruction(inst).WithRR(rr));
}
else
{
return(new IndexerExpression(target.Expression, arguments.Select(a => a.Expression)).WithILInstruction(inst).WithRR(rr));
}
}
}
private ExpressionWithResolveResult HandleImplicitConversion(IMethod method, TranslatedExpression argument)
{
var conversions = CSharpConversions.Get(expressionBuilder.compilation);
IType targetType = method.ReturnType;
var conv = conversions.ImplicitConversion(argument.Type, targetType);
if (!(conv.IsUserDefined && conv.Method.Equals(method)))
{
// implicit conversion to targetType isn't directly possible, so first insert a cast to the argument type
argument = argument.ConvertTo(method.Parameters[0].Type, expressionBuilder);
conv = conversions.ImplicitConversion(argument.Type, targetType);
}
return(new CastExpression(expressionBuilder.ConvertType(targetType), argument.Expression)
.WithRR(new ConversionResolveResult(targetType, argument.ResolveResult, conv)));
}
internal static TranslatedExpression WithILInstruction(this TranslatedExpression expression, ILInstruction instruction)
{
expression.Expression.AddAnnotation(instruction);
return(expression);
}
public ExpressionWithResolveResult Build(OpCode callOpCode, IMethod method, IReadOnlyList <ILInstruction> callArguments,
IType constrainedTo = null)
{
// Used for Call, CallVirt and NewObj
var expectedTargetDetails = new ExpectedTargetDetails {
CallOpCode = callOpCode
};
TranslatedExpression target;
if (callOpCode == OpCode.NewObj)
{
target = default(TranslatedExpression); // no target
}
else
{
target = expressionBuilder.TranslateTarget(method, callArguments.FirstOrDefault(), callOpCode == OpCode.Call, constrainedTo);
if (callOpCode == OpCode.CallVirt &&
constrainedTo == null &&
target.Expression is CastExpression cast &&
target.ResolveResult is ConversionResolveResult conversion &&
target.Type.IsKnownType(KnownTypeCode.Object) &&
conversion.Conversion.IsBoxingConversion)
{
// boxing conversion on call target?
// let's see if we can make that implicit:
target = target.UnwrapChild(cast.Expression);
// we'll need to make sure the boxing effect is preserved
expectedTargetDetails.NeedsBoxingConversion = true;
}
}
int firstParamIndex = (method.IsStatic || callOpCode == OpCode.NewObj) ? 0 : 1;
// Translate arguments to the expected parameter types
var arguments = new List <TranslatedExpression>(method.Parameters.Count);
Debug.Assert(callArguments.Count == firstParamIndex + method.Parameters.Count);
var expectedParameters = method.Parameters.ToList();
bool isExpandedForm = false;
for (int i = 0; i < method.Parameters.Count; i++)
{
var parameter = expectedParameters[i];
var arg = expressionBuilder.Translate(callArguments[firstParamIndex + i], parameter.Type);
if (parameter.IsParams && i + 1 == method.Parameters.Count)
{
// Parameter is marked params
// If the argument is an array creation, inline all elements into the call and add missing default values.
// Otherwise handle it normally.
if (arg.ResolveResult is ArrayCreateResolveResult acrr &&
acrr.SizeArguments.Count == 1 &&
acrr.SizeArguments[0].IsCompileTimeConstant &&
acrr.SizeArguments[0].ConstantValue is int length)
{
var expandedParameters = expectedParameters.Take(expectedParameters.Count - 1).ToList();
var expandedArguments = new List <TranslatedExpression>(arguments);
if (length > 0)
{
var arrayElements = ((ArrayCreateExpression)arg.Expression).Initializer.Elements.ToArray();
var elementType = ((ArrayType)acrr.Type).ElementType;
for (int j = 0; j < length; j++)
{
expandedParameters.Add(new DefaultParameter(elementType, parameter.Name + j));
if (j < arrayElements.Length)
{
expandedArguments.Add(new TranslatedExpression(arrayElements[j]));
}
else
{
expandedArguments.Add(expressionBuilder.GetDefaultValueExpression(elementType).WithoutILInstruction());
}
}
}
if (IsUnambiguousCall(expectedTargetDetails, method, target.ResolveResult, Empty <IType> .Array, expandedArguments) == OverloadResolutionErrors.None)
{
isExpandedForm = true;
expectedParameters = expandedParameters;
arguments = expandedArguments.SelectList(a => new TranslatedExpression(a.Expression.Detach()));
continue;
}
}
}
arguments.Add(arg.ConvertTo(parameter.Type, expressionBuilder, allowImplicitConversion: true));
if (parameter.IsOut && arguments[i].Expression is DirectionExpression dirExpr && arguments[i].ResolveResult is ByReferenceResolveResult brrr)
{
dirExpr.FieldDirection = FieldDirection.Out;
dirExpr.RemoveAnnotations <ByReferenceResolveResult>();
if (brrr.ElementResult == null)
{
brrr = new ByReferenceResolveResult(brrr.ElementType, isOut: true);
}
else
{
brrr = new ByReferenceResolveResult(brrr.ElementResult, isOut: true);
}
dirExpr.AddAnnotation(brrr);
arguments[i] = new TranslatedExpression(dirExpr);
}
}
if (method is VarArgInstanceMethod)
{
int regularParameterCount = ((VarArgInstanceMethod)method).RegularParameterCount;
var argListArg = new UndocumentedExpression();
argListArg.UndocumentedExpressionType = UndocumentedExpressionType.ArgList;
int paramIndex = regularParameterCount;
var builder = expressionBuilder;
argListArg.Arguments.AddRange(arguments.Skip(regularParameterCount).Select(arg => arg.ConvertTo(expectedParameters[paramIndex++].Type, builder).Expression));
var argListRR = new ResolveResult(SpecialType.ArgList);
arguments = arguments.Take(regularParameterCount)
.Concat(new[] { argListArg.WithoutILInstruction().WithRR(argListRR) }).ToList();
method = (IMethod)method.MemberDefinition;
expectedParameters = method.Parameters.ToList();
}
var argumentResolveResults = arguments.Select(arg => arg.ResolveResult).ToList();
ResolveResult rr = new CSharpInvocationResolveResult(target.ResolveResult, method, argumentResolveResults, isExpandedForm: isExpandedForm);
if (callOpCode == OpCode.NewObj)
{
if (settings.AnonymousTypes && method.DeclaringType.IsAnonymousType())
{
var argumentExpressions = arguments.SelectArray(arg => arg.Expression);
AnonymousTypeCreateExpression atce = new AnonymousTypeCreateExpression();
if (CanInferAnonymousTypePropertyNamesFromArguments(argumentExpressions, expectedParameters))
{
atce.Initializers.AddRange(argumentExpressions);
}
else
{
for (int i = 0; i < argumentExpressions.Length; i++)
{
atce.Initializers.Add(
new NamedExpression {
Name = expectedParameters[i].Name,
Expression = arguments[i].ConvertTo(expectedParameters[i].Type, expressionBuilder)
});
}
}
return(atce
.WithRR(rr));
}
else
{
if (IsUnambiguousCall(expectedTargetDetails, method, null, Empty <IType> .Array, arguments) != OverloadResolutionErrors.None)
{
for (int i = 0; i < arguments.Count; i++)
{
if (settings.AnonymousTypes && expectedParameters[i].Type.ContainsAnonymousType())
{
if (arguments[i].Expression is LambdaExpression lambda)
{
ModifyReturnTypeOfLambda(lambda);
}
}
else
{
arguments[i] = arguments[i].ConvertTo(expectedParameters[i].Type, expressionBuilder);
}
}
}
return(new ObjectCreateExpression(expressionBuilder.ConvertType(method.DeclaringType), arguments.SelectArray(arg => arg.Expression))
.WithRR(rr));
}
}
else
{
int allowedParamCount = (method.ReturnType.IsKnownType(KnownTypeCode.Void) ? 1 : 0);
if (method.IsAccessor && (method.AccessorOwner.SymbolKind == SymbolKind.Indexer || expectedParameters.Count == allowedParamCount))
{
return(HandleAccessorCall(expectedTargetDetails, method, target, arguments.ToList()));
}
else if (method.Name == "Invoke" && method.DeclaringType.Kind == TypeKind.Delegate && !IsNullConditional(target))
{
return(new InvocationExpression(target, arguments.Select(arg => arg.Expression)).WithRR(rr));
}
else if (IsDelegateEqualityComparison(method, arguments))
{
return(HandleDelegateEqualityComparison(method, arguments)
.WithRR(rr));
}
else if (method.IsOperator && method.Name == "op_Implicit" && arguments.Count == 1)
{
return(HandleImplicitConversion(method, arguments[0]));
}
else
{
bool requireTypeArguments = false;
bool requireTarget;
if (expressionBuilder.HidesVariableWithName(method.Name))
{
requireTarget = true;
}
else
{
if (method.IsStatic)
{
requireTarget = !expressionBuilder.IsCurrentOrContainingType(method.DeclaringTypeDefinition) || method.Name == ".cctor";
}
else
{
requireTarget = !(target.Expression is ThisReferenceExpression || target.Expression is BaseReferenceExpression) || method.Name == ".ctor";
}
}
bool targetCasted = false;
bool argumentsCasted = false;
IType[] typeArguments = Empty <IType> .Array;
var targetResolveResult = requireTarget ? target.ResolveResult : null;
OverloadResolutionErrors errors;
while ((errors = IsUnambiguousCall(expectedTargetDetails, method, targetResolveResult, typeArguments, arguments)) != OverloadResolutionErrors.None)
{
switch (errors)
{
case OverloadResolutionErrors.TypeInferenceFailed:
case OverloadResolutionErrors.WrongNumberOfTypeArguments:
if (requireTypeArguments)
{
goto default;
}
requireTypeArguments = true;
typeArguments = method.TypeArguments.ToArray();
continue;
default:
// TODO : implement some more intelligent algorithm that decides which of these fixes (cast args, add target, cast target, add type args)
// is best in this case. Additionally we should not cast all arguments at once, but step-by-step try to add only a minimal number of casts.
if (!argumentsCasted)
{
argumentsCasted = true;
for (int i = 0; i < arguments.Count; i++)
{
if (settings.AnonymousTypes && expectedParameters[i].Type.ContainsAnonymousType())
{
if (arguments[i].Expression is LambdaExpression lambda)
{
ModifyReturnTypeOfLambda(lambda);
}
}
else
{
arguments[i] = arguments[i].ConvertTo(expectedParameters[i].Type, expressionBuilder);
}
}
}
else if (!requireTarget)
{
requireTarget = true;
targetResolveResult = target.ResolveResult;
}
else if (!targetCasted)
{
targetCasted = true;
target = target.ConvertTo(method.DeclaringType, expressionBuilder);
targetResolveResult = target.ResolveResult;
}
else if (!requireTypeArguments)
{
requireTypeArguments = true;
typeArguments = method.TypeArguments.ToArray();
}
else
{
break;
}
continue;
}
break;
}
Expression targetExpr;
string methodName = method.Name;
AstNodeCollection <AstType> typeArgumentList;
if (requireTarget)
{
targetExpr = new MemberReferenceExpression(target.Expression, methodName);
typeArgumentList = ((MemberReferenceExpression)targetExpr).TypeArguments;
// HACK : convert this.Dispose() to ((IDisposable)this).Dispose(), if Dispose is an explicitly implemented interface method.
if (method.IsExplicitInterfaceImplementation && target.Expression is ThisReferenceExpression)
{
var castExpression = new CastExpression(expressionBuilder.ConvertType(method.ImplementedInterfaceMembers[0].DeclaringType), target.Expression);
methodName = method.ImplementedInterfaceMembers[0].Name;
targetExpr = new MemberReferenceExpression(castExpression, methodName);
typeArgumentList = ((MemberReferenceExpression)targetExpr).TypeArguments;
}
}
else
{
targetExpr = new IdentifierExpression(methodName);
typeArgumentList = ((IdentifierExpression)targetExpr).TypeArguments;
}
if (requireTypeArguments && (!settings.AnonymousTypes || !method.TypeArguments.Any(a => a.ContainsAnonymousType())))
{
typeArgumentList.AddRange(method.TypeArguments.Select(expressionBuilder.ConvertType));
}
var argumentExpressions = arguments.Select(arg => arg.Expression);
return(new InvocationExpression(targetExpr, argumentExpressions).WithRR(rr));
}
}
}
ExpressionWithResolveResult HandleAccessorCall(ExpectedTargetDetails expectedTargetDetails, IMethod method, TranslatedExpression target, IList <TranslatedExpression> arguments)
{
bool requireTarget = expressionBuilder.HidesVariableWithName(method.AccessorOwner.Name) ||
(method.IsStatic ? !expressionBuilder.IsCurrentOrContainingType(method.DeclaringTypeDefinition) : !(target.Expression is ThisReferenceExpression));
bool targetCasted = false;
var targetResolveResult = requireTarget ? target.ResolveResult : null;
while (!IsUnambiguousAccess(expectedTargetDetails, targetResolveResult, method))
{
if (!requireTarget)
{
requireTarget = true;
targetResolveResult = target.ResolveResult;
}
else if (!targetCasted)
{
targetCasted = true;
target = target.ConvertTo(method.AccessorOwner.DeclaringType, expressionBuilder);
targetResolveResult = target.ResolveResult;
}
else
{
break;
}
}
var rr = new MemberResolveResult(target.ResolveResult, method.AccessorOwner);
if (method.ReturnType.IsKnownType(KnownTypeCode.Void))
{
var value = arguments.Last();
arguments.Remove(value);
TranslatedExpression expr;
if (arguments.Count != 0)
{
expr = new IndexerExpression(target.Expression, arguments.Select(a => a.Expression))
.WithoutILInstruction().WithRR(rr);
}
else if (requireTarget)
{
expr = new MemberReferenceExpression(target.Expression, method.AccessorOwner.Name)
.WithoutILInstruction().WithRR(rr);
}
else
{
expr = new IdentifierExpression(method.AccessorOwner.Name)
.WithoutILInstruction().WithRR(rr);
}
var op = AssignmentOperatorType.Assign;
var parentEvent = method.AccessorOwner as IEvent;
if (parentEvent != null)
{
if (method.Equals(parentEvent.AddAccessor))
{
op = AssignmentOperatorType.Add;
}
if (method.Equals(parentEvent.RemoveAccessor))
{
op = AssignmentOperatorType.Subtract;
}
}
return(new AssignmentExpression(expr, op, value.Expression).WithRR(new TypeResolveResult(method.AccessorOwner.ReturnType)));
}
else
{
if (arguments.Count != 0)
{
return(new IndexerExpression(target.Expression, arguments.Select(a => a.Expression))
.WithoutILInstruction().WithRR(rr));
}
else if (requireTarget)
{
return(new MemberReferenceExpression(target.Expression, method.AccessorOwner.Name)
.WithoutILInstruction().WithRR(rr));
}
else
{
return(new IdentifierExpression(method.AccessorOwner.Name)
.WithoutILInstruction().WithRR(rr));
}
}
}
