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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.
// See the LICENSE file in the project root for more information.
#nullable disable
using System;
using System.Collections.Immutable;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.PooledObjects;
using Roslyn.Utilities;
namespace Microsoft.CodeAnalysis.CSharp.Symbols
{
/// <summary>
/// A source parameter, potentially with a default value, attributes, etc.
/// </summary>
internal abstract class SourceComplexParameterSymbolBase : SourceParameterSymbol, IAttributeTargetSymbol
{
[Flags]
private enum ParameterFlags : byte
{
None = 0,
HasParamsModifier = 0x1,
ParamsParameter = 0x02, // Value of this flag is either derived from HasParamsModifier, or inherited from overridden member
ExtensionThisParameter = 0x04,
DefaultParameter = 0x08,
}
private readonly SyntaxReference _syntaxRef;
private readonly ParameterFlags _parameterSyntaxKind;
private ThreeState _lazyHasOptionalAttribute;
private CustomAttributesBag<CSharpAttributeData> _lazyCustomAttributesBag;
protected ConstantValue _lazyDefaultSyntaxValue;
protected SourceComplexParameterSymbolBase(
Symbol owner,
int ordinal,
RefKind refKind,
string name,
Location location,
SyntaxReference syntaxRef,
bool hasParamsModifier,
bool isParams,
bool isExtensionMethodThis,
ScopedKind scope)
: base(owner, ordinal, refKind, scope, name, location)
{
Debug.Assert((syntaxRef == null) || (syntaxRef.GetSyntax().IsKind(SyntaxKind.Parameter)));
_lazyHasOptionalAttribute = ThreeState.Unknown;
_syntaxRef = syntaxRef;
if (hasParamsModifier)
{
_parameterSyntaxKind |= ParameterFlags.HasParamsModifier;
}
if (isParams)
{
_parameterSyntaxKind |= ParameterFlags.ParamsParameter;
}
if (isExtensionMethodThis)
{
_parameterSyntaxKind |= ParameterFlags.ExtensionThisParameter;
}
var parameterSyntax = this.ParameterSyntax;
if (parameterSyntax != null && parameterSyntax.Default != null)
{
_parameterSyntaxKind |= ParameterFlags.DefaultParameter;
}
_lazyDefaultSyntaxValue = ConstantValue.Unset;
}
private Binder WithTypeParametersBinderOpt => (ContainingSymbol as SourceMethodSymbolWithAttributes)?.WithTypeParametersBinder;
internal sealed override SyntaxReference SyntaxReference => _syntaxRef;
private ParameterSyntax ParameterSyntax => (ParameterSyntax)_syntaxRef?.GetSyntax();
public override bool IsDiscard => false;
internal sealed override ConstantValue ExplicitDefaultConstantValue
{
get
{
// Parameter has either default argument syntax or DefaultParameterValue attribute, but not both.
// We separate these since in some scenarios (delegate Invoke methods) we need to suppress syntactic
// default value but use value from pseudo-custom attribute.
//
// For example:
// public delegate void D([Optional, DefaultParameterValue(1)]int a, int b = 2);
//
// Dev11 emits the first parameter as option with default value and the second as regular parameter.
// The syntactic default value is suppressed since additional synthesized parameters are added at the end of the signature.
return DefaultSyntaxValue ?? DefaultValueFromAttributes;
}
}
internal sealed override ConstantValue DefaultValueFromAttributes
{
get
{
ParameterEarlyWellKnownAttributeData data = GetEarlyDecodedWellKnownAttributeData();
return (data != null && data.DefaultParameterValue != ConstantValue.Unset) ? data.DefaultParameterValue : ConstantValue.NotAvailable;
}
}
internal sealed override bool IsIDispatchConstant
=> GetDecodedWellKnownAttributeData()?.HasIDispatchConstantAttribute == true;
internal override bool IsIUnknownConstant
=> GetDecodedWellKnownAttributeData()?.HasIUnknownConstantAttribute == true;
internal override bool IsCallerLineNumber => GetEarlyDecodedWellKnownAttributeData()?.HasCallerLineNumberAttribute == true;
internal override bool IsCallerFilePath => GetEarlyDecodedWellKnownAttributeData()?.HasCallerFilePathAttribute == true;
internal override bool IsCallerMemberName => GetEarlyDecodedWellKnownAttributeData()?.HasCallerMemberNameAttribute == true;
internal override int CallerArgumentExpressionParameterIndex
{
get
{
return GetEarlyDecodedWellKnownAttributeData()?.CallerArgumentExpressionParameterIndex ?? -1;
}
}
internal override ImmutableArray<int> InterpolatedStringHandlerArgumentIndexes
=> (GetDecodedWellKnownAttributeData()?.InterpolatedStringHandlerArguments).NullToEmpty();
internal override bool HasInterpolatedStringHandlerArgumentError
=> GetDecodedWellKnownAttributeData()?.InterpolatedStringHandlerArguments.IsDefault ?? false;
internal override FlowAnalysisAnnotations FlowAnalysisAnnotations
{
get
{
return DecodeFlowAnalysisAttributes(GetDecodedWellKnownAttributeData());
}
}
private static FlowAnalysisAnnotations DecodeFlowAnalysisAttributes(ParameterWellKnownAttributeData attributeData)
{
if (attributeData == null)
{
return FlowAnalysisAnnotations.None;
}
FlowAnalysisAnnotations annotations = FlowAnalysisAnnotations.None;
if (attributeData.HasAllowNullAttribute) annotations |= FlowAnalysisAnnotations.AllowNull;
if (attributeData.HasDisallowNullAttribute) annotations |= FlowAnalysisAnnotations.DisallowNull;
if (attributeData.HasMaybeNullAttribute)
{
annotations |= FlowAnalysisAnnotations.MaybeNull;
}
else
{
if (attributeData.MaybeNullWhenAttribute is bool when)
{
annotations |= (when ? FlowAnalysisAnnotations.MaybeNullWhenTrue : FlowAnalysisAnnotations.MaybeNullWhenFalse);
}
}
if (attributeData.HasNotNullAttribute)
{
annotations |= FlowAnalysisAnnotations.NotNull;
}
else
{
if (attributeData.NotNullWhenAttribute is bool when)
{
annotations |= (when ? FlowAnalysisAnnotations.NotNullWhenTrue : FlowAnalysisAnnotations.NotNullWhenFalse);
}
}
if (attributeData.DoesNotReturnIfAttribute is bool condition)
{
annotations |= (condition ? FlowAnalysisAnnotations.DoesNotReturnIfTrue : FlowAnalysisAnnotations.DoesNotReturnIfFalse);
}
return annotations;
}
internal override ImmutableHashSet<string> NotNullIfParameterNotNull
=> GetDecodedWellKnownAttributeData()?.NotNullIfParameterNotNull ?? ImmutableHashSet<string>.Empty;
internal bool HasEnumeratorCancellationAttribute
{
get
{
ParameterWellKnownAttributeData attributeData = GetDecodedWellKnownAttributeData();
return attributeData?.HasEnumeratorCancellationAttribute == true;
}
}
#nullable enable
internal sealed override ScopedKind EffectiveScope
{
get
{
var scope = CalculateEffectiveScopeIgnoringAttributes();
if (scope != ScopedKind.None &&
HasUnscopedRefAttribute)
{
return ScopedKind.None;
}
return scope;
}
}
internal override bool HasUnscopedRefAttribute => GetEarlyDecodedWellKnownAttributeData()?.HasUnscopedRefAttribute == true;
internal static SyntaxNode? GetDefaultValueSyntaxForIsNullableAnalysisEnabled(ParameterSyntax? parameterSyntax) =>
parameterSyntax?.Default?.Value;
/// <summary>
/// Returns the bound default value syntax from the parameter, if it exists.
/// Note that this method will only return a non-null value if the
/// default value was supplied in syntax. If the value is supplied through the DefaultParameterValue
/// attribute, then ExplicitDefaultValue will be non-null but this method will return null.
/// However, if ExplicitDefaultValue is null, this method should always return null.
/// </summary>
public BoundParameterEqualsValue? BindParameterEqualsValue()
{
// Rebind default value expression, ignoring any diagnostics, in order to produce
// a bound node that can be used for passes such as definite assignment.
MakeDefaultExpression(BindingDiagnosticBag.Discarded, out var _, out var parameterEqualsValue);
return parameterEqualsValue;
}
private ConstantValue DefaultSyntaxValue
{
get
{
if (state.NotePartComplete(CompletionPart.StartDefaultSyntaxValue))
{
var diagnostics = BindingDiagnosticBag.GetInstance();
Debug.Assert(diagnostics.DiagnosticBag != null);
var previousValue = Interlocked.CompareExchange(
ref _lazyDefaultSyntaxValue,
MakeDefaultExpression(diagnostics, out var binder, out var parameterEqualsValue),
ConstantValue.Unset);
Debug.Assert(previousValue == ConstantValue.Unset);
var completedOnThisThread = state.NotePartComplete(CompletionPart.EndDefaultSyntaxValue);
Debug.Assert(completedOnThisThread);
if (parameterEqualsValue is not null)
{
if (binder is not null &&
GetDefaultValueSyntaxForIsNullableAnalysisEnabled(ParameterSyntax) is { } valueSyntax)
{
NullableWalker.AnalyzeIfNeeded(binder, parameterEqualsValue, valueSyntax, diagnostics.DiagnosticBag);
}
if (!_lazyDefaultSyntaxValue.IsBad)
{
VerifyParamDefaultValueMatchesAttributeIfAny(_lazyDefaultSyntaxValue, parameterEqualsValue.Value.Syntax, diagnostics);
// Ensure availability of `DecimalConstantAttribute`.
if (_lazyDefaultSyntaxValue.IsDecimal &&
DefaultValueFromAttributes == ConstantValue.NotAvailable)
{
Binder.ReportUseSiteDiagnosticForSynthesizedAttribute(DeclaringCompilation,
WellKnownMember.System_Runtime_CompilerServices_DecimalConstantAttribute__ctor,
diagnostics,
parameterEqualsValue.Value.Syntax.Location);
}
}
}
AddDeclarationDiagnostics(diagnostics);
diagnostics.Free();
completedOnThisThread = state.NotePartComplete(CompletionPart.EndDefaultSyntaxValueDiagnostics);
Debug.Assert(completedOnThisThread);
}
state.SpinWaitComplete(CompletionPart.EndDefaultSyntaxValue, default(CancellationToken));
return _lazyDefaultSyntaxValue;
}
}
private Binder GetDefaultParameterValueBinder(SyntaxNode syntax)
{
var binder = WithTypeParametersBinderOpt;
// If binder is null, then get it from the compilation. Otherwise use the provided binder.
// Don't always get it from the compilation because we might be in a speculative context (local function parameter),
// in which case the declaring compilation is the wrong one.
if (binder == null)
{
var compilation = this.DeclaringCompilation;
var binderFactory = compilation.GetBinderFactory(syntax.SyntaxTree);
binder = binderFactory.GetBinder(syntax);
}
Debug.Assert(binder.GetBinder(syntax) == null);
return binder;
}
private void NullableAnalyzeParameterDefaultValueFromAttributes()
{
var parameterSyntax = this.ParameterSyntax;
if (parameterSyntax == null)
{
// If there is no syntax at all for the parameter, it means we are in a situation like
// a property setter whose 'value' parameter has a default value from attributes.
// There isn't a sensible use for this in the language, so we just bail in such scenarios.
return;
}
// The syntax span used to determine whether the attribute value is in a nullable-enabled
// context is larger than necessary - it includes the entire attribute list rather than the specific
// default value attribute which is used in AttributeSemanticModel.IsNullableAnalysisEnabled().
var attributes = parameterSyntax.AttributeLists.Node;
if (attributes is null || !NullableWalker.NeedsAnalysis(DeclaringCompilation, attributes))
{
return;
}
var defaultValue = DefaultValueFromAttributes;
if (defaultValue == null || defaultValue.IsBad)
{
return;
}
var binder = GetDefaultParameterValueBinder(parameterSyntax);
// Nullable warnings *within* the attribute argument (such as a W-warning for `(string)null`)
// are reported when we nullable-analyze attribute arguments separately from here.
// However, this analysis of the constant value's compatibility with the parameter
// needs to wait until the attributes are populated on the parameter symbol.
var parameterEqualsValue = new BoundParameterEqualsValue(
parameterSyntax,
this,
ImmutableArray<LocalSymbol>.Empty,
// note that if the parameter type conflicts with the default value from attributes,
// we will just get a bad constant value above and return early.
new BoundLiteral(parameterSyntax, defaultValue, Type));
var diagnostics = BindingDiagnosticBag.GetInstance(withDiagnostics: true, withDependencies: false);
Debug.Assert(diagnostics.DiagnosticBag != null);
NullableWalker.AnalyzeIfNeeded(binder, parameterEqualsValue, parameterSyntax, diagnostics.DiagnosticBag);
AddDeclarationDiagnostics(diagnostics);
diagnostics.Free();
}
// This method *must not* depend on attributes on the parameter symbol.
// Otherwise we will have cycles when binding usage of attributes whose constructors have optional parameters
private ConstantValue MakeDefaultExpression(BindingDiagnosticBag diagnostics, out Binder? binder, out BoundParameterEqualsValue? parameterEqualsValue)
{
binder = null;
parameterEqualsValue = null;
var parameterSyntax = this.ParameterSyntax;
if (parameterSyntax == null)
{
return ConstantValue.NotAvailable;
}
var defaultSyntax = parameterSyntax.Default;
if (defaultSyntax == null)
{
return ConstantValue.NotAvailable;
}
MessageID.IDS_FeatureOptionalParameter.CheckFeatureAvailability(diagnostics, defaultSyntax.EqualsToken);
binder = GetDefaultParameterValueBinder(defaultSyntax);
binder = binder.CreateBinderForParameterDefaultValue(this, defaultSyntax);
Debug.Assert(binder.InParameterDefaultValue);
Debug.Assert(binder.ContainingMemberOrLambda == ContainingSymbol);
parameterEqualsValue = binder.BindParameterDefaultValue(defaultSyntax, this, diagnostics, out var valueBeforeConversion);
if (valueBeforeConversion.HasErrors)
{
return ConstantValue.Bad;
}
BoundExpression convertedExpression = parameterEqualsValue.Value;
bool hasErrors = ParameterHelpers.ReportDefaultParameterErrors(binder, ContainingSymbol, parameterSyntax, this, valueBeforeConversion, convertedExpression, diagnostics);
if (hasErrors)
{
return ConstantValue.Bad;
}
// If we have something like M(double? x = 1) then the expression we'll get is (double?)1, which
// does not have a constant value. The constant value we want is (double)1.
// The default literal conversion is an exception: (double)default would give the wrong value for M(double? x = default).
if (convertedExpression.ConstantValueOpt == null && convertedExpression.Kind == BoundKind.Conversion &&
((BoundConversion)convertedExpression).ConversionKind != ConversionKind.DefaultLiteral)
{
if (Type.IsNullableType())
{
convertedExpression = binder.GenerateConversionForAssignment(Type.GetNullableUnderlyingType(),
valueBeforeConversion, diagnostics, Binder.ConversionForAssignmentFlags.DefaultParameter);
}
}
// represent default(struct) by a Null constant:
var value = convertedExpression.ConstantValueOpt ?? ConstantValue.Null;
return value;
}
#nullable disable
public override string MetadataName
{
get
{
// The metadata parameter name should be the name used in the partial definition.
var sourceMethod = this.ContainingSymbol as SourceOrdinaryMethodSymbol;
if ((object)sourceMethod == null)
{
return base.MetadataName;
}
var definition = sourceMethod.SourcePartialDefinition;
if ((object)definition == null)
{
return base.MetadataName;
}
return definition.Parameters[this.Ordinal].MetadataName;
}
}
protected virtual IAttributeTargetSymbol AttributeOwner => this;
IAttributeTargetSymbol IAttributeTargetSymbol.AttributesOwner => AttributeOwner;
AttributeLocation IAttributeTargetSymbol.DefaultAttributeLocation => AttributeLocation.Parameter;
AttributeLocation IAttributeTargetSymbol.AllowedAttributeLocations
{
get
{
if (SynthesizedRecordPropertySymbol.HaveCorrespondingSynthesizedRecordPropertySymbol(this))
{
return AttributeLocation.Parameter | AttributeLocation.Property | AttributeLocation.Field;
}
return AttributeLocation.Parameter;
}
}
#nullable enable
/// <summary>
/// Symbol to copy bound attributes from, or null if the attributes are not shared among multiple source parameter symbols.
/// </summary>
/// <remarks>
/// This is inconsistent with analogous 'BoundAttributesSource' on other symbols.
/// Usually the definition part is the source, but for parameters the implementation part is the source.
/// This affects the location of diagnostics among other things.
/// </remarks>
private SourceParameterSymbol? BoundAttributesSource
=> PartialImplementationPart;
protected SourceParameterSymbol? PartialImplementationPart
{
get
{
ImmutableArray<ParameterSymbol> implParameters = this.ContainingSymbol switch
{
SourceMemberMethodSymbol { PartialImplementationPart.Parameters: { } parameters } => parameters,
SourcePropertySymbol { PartialImplementationPart.Parameters: { } parameters } => parameters,
_ => default
};
if (implParameters.IsDefault)
{
return null;
}
Debug.Assert(!this.ContainingSymbol.IsPartialImplementation());
return (SourceParameterSymbol)implParameters[this.Ordinal];
}
}
protected SourceParameterSymbol? PartialDefinitionPart
{
get
{
ImmutableArray<ParameterSymbol> defParameters = this.ContainingSymbol switch
{
SourceMemberMethodSymbol { PartialDefinitionPart.Parameters: { } parameters } => parameters,
SourcePropertySymbol { PartialDefinitionPart.Parameters: { } parameters } => parameters,
_ => default
};
if (defParameters.IsDefault)
{
return null;
}
Debug.Assert(!this.ContainingSymbol.IsPartialDefinition());
return (SourceParameterSymbol)defParameters[this.Ordinal];
}
}
internal sealed override SyntaxList<AttributeListSyntax> AttributeDeclarationList
{
get
{
var syntax = this.ParameterSyntax;
return (syntax != null) ? syntax.AttributeLists : default(SyntaxList<AttributeListSyntax>);
}
}
/// <summary>
/// Gets the syntax list of custom attributes that declares attributes for this parameter symbol.
/// </summary>
internal virtual OneOrMany<SyntaxList<AttributeListSyntax>> GetAttributeDeclarations()
{
// Attributes on parameters in partial members are owned by the parameter in the implementation part.
// If this symbol has a non-null PartialImplementationPart, we should have accessed this method through that implementation symbol.
Debug.Assert(PartialImplementationPart is null);
if (PartialDefinitionPart is { } definitionPart)
{
return OneOrMany.Create(
AttributeDeclarationList,
definitionPart.AttributeDeclarationList);
}
else
{
return OneOrMany.Create(AttributeDeclarationList);
}
}
#nullable disable
/// <summary>
/// Returns data decoded from well-known attributes applied to the symbol or null if there are no applied attributes.
/// </summary>
/// <remarks>
/// Forces binding and decoding of attributes.
/// </remarks>
internal ParameterWellKnownAttributeData GetDecodedWellKnownAttributeData()
{
var attributesBag = _lazyCustomAttributesBag;
if (attributesBag == null || !attributesBag.IsDecodedWellKnownAttributeDataComputed)
{
attributesBag = this.GetAttributesBag();
}
return (ParameterWellKnownAttributeData)attributesBag.DecodedWellKnownAttributeData;
}
/// <summary>
/// Returns data decoded from special early bound well-known attributes applied to the symbol or null if there are no applied attributes.
/// </summary>
/// <remarks>
/// Forces binding and decoding of attributes.
/// </remarks>
internal ParameterEarlyWellKnownAttributeData GetEarlyDecodedWellKnownAttributeData()
{
var attributesBag = _lazyCustomAttributesBag;
if (attributesBag == null || !attributesBag.IsEarlyDecodedWellKnownAttributeDataComputed)
{
attributesBag = this.GetAttributesBag();
}
return (ParameterEarlyWellKnownAttributeData)attributesBag.EarlyDecodedWellKnownAttributeData;
}
/// <summary>
/// Returns a bag of applied custom attributes and data decoded from well-known attributes. Returns null if there are no attributes applied on the symbol.
/// </summary>
/// <remarks>
/// Forces binding and decoding of attributes.
/// </remarks>
internal sealed override CustomAttributesBag<CSharpAttributeData> GetAttributesBag()
{
if (_lazyCustomAttributesBag == null || !_lazyCustomAttributesBag.IsSealed)
{
SourceParameterSymbol copyFrom = this.BoundAttributesSource;
// prevent infinite recursion:
Debug.Assert(!ReferenceEquals(copyFrom, this));
bool bagCreatedOnThisThread;
if ((object)copyFrom != null)
{
var attributesBag = copyFrom.GetAttributesBag();
bagCreatedOnThisThread = Interlocked.CompareExchange(ref _lazyCustomAttributesBag, attributesBag, null) == null;
}
else
{
var attributeSyntax = this.GetAttributeDeclarations();
bagCreatedOnThisThread = LoadAndValidateAttributes(attributeSyntax, ref _lazyCustomAttributesBag, binderOpt: WithTypeParametersBinderOpt);
}
if (bagCreatedOnThisThread)
{
NullableAnalyzeParameterDefaultValueFromAttributes();
state.NotePartComplete(CompletionPart.Attributes);
}
}
return _lazyCustomAttributesBag;
}
/// <summary>
/// Binds attributes applied to this parameter.
/// </summary>
public ImmutableArray<(CSharpAttributeData, BoundAttribute)> BindParameterAttributes()
{
return BindAttributes(GetAttributeDeclarations(), WithTypeParametersBinderOpt);
}
internal override void EarlyDecodeWellKnownAttributeType(NamedTypeSymbol attributeType, AttributeSyntax attributeSyntax)
{
Debug.Assert(!attributeType.IsErrorType());
// NOTE: OptionalAttribute is decoded specially before any of the other attributes and stored in the parameter
// symbol (rather than in the EarlyWellKnownAttributeData) because it is needed during overload resolution.
if (CSharpAttributeData.IsTargetEarlyAttribute(attributeType, attributeSyntax, AttributeDescription.OptionalAttribute))
{
_lazyHasOptionalAttribute = ThreeState.True;
}
}
internal override void PostEarlyDecodeWellKnownAttributeTypes()
{
if (_lazyHasOptionalAttribute == ThreeState.Unknown)
{
_lazyHasOptionalAttribute = ThreeState.False;
}
base.PostEarlyDecodeWellKnownAttributeTypes();
}
#nullable enable
internal override (CSharpAttributeData?, BoundAttribute?) EarlyDecodeWellKnownAttribute(ref EarlyDecodeWellKnownAttributeArguments<EarlyWellKnownAttributeBinder, NamedTypeSymbol, AttributeSyntax, AttributeLocation> arguments)
{
if (CSharpAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.DefaultParameterValueAttribute))
{
return EarlyDecodeAttributeForDefaultParameterValue(AttributeDescription.DefaultParameterValueAttribute, ref arguments);
}
else if (CSharpAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.DecimalConstantAttribute))
{
return EarlyDecodeAttributeForDefaultParameterValue(AttributeDescription.DecimalConstantAttribute, ref arguments);
}
else if (CSharpAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.DateTimeConstantAttribute))
{
return EarlyDecodeAttributeForDefaultParameterValue(AttributeDescription.DateTimeConstantAttribute, ref arguments);
}
else if (CSharpAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.UnscopedRefAttribute))
{
// We can't bind the attribute here because that might lead to a cycle.
// Instead, simply record that the attribute exists and bind later.
arguments.GetOrCreateData<ParameterEarlyWellKnownAttributeData>().HasUnscopedRefAttribute = true;
return (null, null);
}
else if (!IsOnPartialImplementation(arguments.AttributeSyntax))
{
if (CSharpAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.CallerLineNumberAttribute))
{
arguments.GetOrCreateData<ParameterEarlyWellKnownAttributeData>().HasCallerLineNumberAttribute = true;
}
else if (CSharpAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.CallerFilePathAttribute))
{
arguments.GetOrCreateData<ParameterEarlyWellKnownAttributeData>().HasCallerFilePathAttribute = true;
}
else if (CSharpAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.CallerMemberNameAttribute))
{
arguments.GetOrCreateData<ParameterEarlyWellKnownAttributeData>().HasCallerMemberNameAttribute = true;
}
else if (CSharpAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.CallerArgumentExpressionAttribute))
{
var index = -1;
var (attributeData, _) = arguments.Binder.GetAttribute(arguments.AttributeSyntax, arguments.AttributeType, beforeAttributePartBound: null, afterAttributePartBound: null, out _);
if (!attributeData.HasErrors)
{
var constructorArguments = attributeData.CommonConstructorArguments;
Debug.Assert(constructorArguments.Length == 1);
if (constructorArguments[0].TryDecodeValue(SpecialType.System_String, out string? parameterName))
{
var parameters = ContainingSymbol.GetParameters();
for (int i = 0; i < parameters.Length; i++)
{
if (parameters[i].Name.Equals(parameterName, StringComparison.Ordinal))
{
index = i;
break;
}
}
}
}
arguments.GetOrCreateData<ParameterEarlyWellKnownAttributeData>().CallerArgumentExpressionParameterIndex = index;
}
}
return base.EarlyDecodeWellKnownAttribute(ref arguments);
}
private (CSharpAttributeData?, BoundAttribute?) EarlyDecodeAttributeForDefaultParameterValue(AttributeDescription description, ref EarlyDecodeWellKnownAttributeArguments<EarlyWellKnownAttributeBinder, NamedTypeSymbol, AttributeSyntax, AttributeLocation> arguments)
{
Debug.Assert(description.Equals(AttributeDescription.DefaultParameterValueAttribute) ||
description.Equals(AttributeDescription.DecimalConstantAttribute) ||
description.Equals(AttributeDescription.DateTimeConstantAttribute));
bool hasAnyDiagnostics;
var (attributeData, boundAttribute) = arguments.Binder.GetAttribute(arguments.AttributeSyntax, arguments.AttributeType, beforeAttributePartBound: null, afterAttributePartBound: null, out hasAnyDiagnostics);
ConstantValue value;
if (attributeData.HasErrors)
{
value = ConstantValue.Bad;
hasAnyDiagnostics = true;
}
else
{
value = DecodeDefaultParameterValueAttribute(description, attributeData, arguments.AttributeSyntax, diagnose: false, diagnosticsOpt: null);
}
var paramData = arguments.GetOrCreateData<ParameterEarlyWellKnownAttributeData>();
if (paramData.DefaultParameterValue == ConstantValue.Unset)
{
paramData.DefaultParameterValue = value;
}
return !hasAnyDiagnostics ? (attributeData, boundAttribute) : (null, null);
}
#nullable disable
protected override void DecodeWellKnownAttributeImpl(ref DecodeWellKnownAttributeArguments<AttributeSyntax, CSharpAttributeData, AttributeLocation> arguments)
{
Debug.Assert((object)arguments.AttributeSyntaxOpt != null);
var attribute = arguments.Attribute;
Debug.Assert(!attribute.HasErrors);
Debug.Assert(arguments.SymbolPart == AttributeLocation.None);
Debug.Assert(AttributeDescription.InterpolatedStringHandlerArgumentAttribute.Signatures.Length == 2);
var diagnostics = (BindingDiagnosticBag)arguments.Diagnostics;
if (attribute.IsTargetAttribute(AttributeDescription.DefaultParameterValueAttribute))
{
// Attribute decoded and constant value stored during EarlyDecodeWellKnownAttribute.
DecodeDefaultParameterValueAttribute(AttributeDescription.DefaultParameterValueAttribute, ref arguments);
}
else if (attribute.IsTargetAttribute(AttributeDescription.DecimalConstantAttribute))
{
// Attribute decoded and constant value stored during EarlyDecodeWellKnownAttribute.
DecodeDefaultParameterValueAttribute(AttributeDescription.DecimalConstantAttribute, ref arguments);
}
else if (attribute.IsTargetAttribute(AttributeDescription.DateTimeConstantAttribute))
{
// Attribute decoded and constant value stored during EarlyDecodeWellKnownAttribute.
DecodeDefaultParameterValueAttribute(AttributeDescription.DateTimeConstantAttribute, ref arguments);
}
else if (attribute.IsTargetAttribute(AttributeDescription.OptionalAttribute))
{
Debug.Assert(_lazyHasOptionalAttribute == ThreeState.True);
if (HasDefaultArgumentSyntax)
{
// error CS1745: Cannot specify default parameter value in conjunction with DefaultParameterAttribute or OptionalAttribute
diagnostics.Add(ErrorCode.ERR_DefaultValueUsedWithAttributes, arguments.AttributeSyntaxOpt.Name.Location);
}
}
else if (attribute.IsTargetAttribute(AttributeDescription.ParamArrayAttribute) || attribute.IsTargetAttribute(AttributeDescription.ParamCollectionAttribute))
{
// error CS0674: Do not use 'System.ParamArrayAttribute'/'System.Runtime.CompilerServices.ParamCollectionAttribute'. Use the 'params' keyword instead.
diagnostics.Add(ErrorCode.ERR_ExplicitParamArrayOrCollection, arguments.AttributeSyntaxOpt.Name.Location);
}
else if (attribute.IsTargetAttribute(AttributeDescription.InAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasInAttribute = true;
}
else if (attribute.IsTargetAttribute(AttributeDescription.OutAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasOutAttribute = true;
}
else if (attribute.IsTargetAttribute(AttributeDescription.MarshalAsAttribute))
{
MarshalAsAttributeDecoder<ParameterWellKnownAttributeData, AttributeSyntax, CSharpAttributeData, AttributeLocation>.Decode(ref arguments, AttributeTargets.Parameter, MessageProvider.Instance);
}
else if (attribute.IsTargetAttribute(AttributeDescription.IDispatchConstantAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasIDispatchConstantAttribute = true;
}
else if (attribute.IsTargetAttribute(AttributeDescription.IUnknownConstantAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasIUnknownConstantAttribute = true;
}
else if (attribute.IsTargetAttribute(AttributeDescription.CallerLineNumberAttribute))
{
ValidateCallerLineNumberAttribute(arguments.AttributeSyntaxOpt, diagnostics);
}
else if (attribute.IsTargetAttribute(AttributeDescription.CallerFilePathAttribute))
{
ValidateCallerFilePathAttribute(arguments.AttributeSyntaxOpt, diagnostics);
}
else if (attribute.IsTargetAttribute(AttributeDescription.CallerMemberNameAttribute))
{
ValidateCallerMemberNameAttribute(arguments.AttributeSyntaxOpt, diagnostics);
}
else if (attribute.IsTargetAttribute(AttributeDescription.CallerArgumentExpressionAttribute))
{
ValidateCallerArgumentExpressionAttribute(arguments.AttributeSyntaxOpt, attribute, diagnostics);
}
else if (ReportExplicitUseOfReservedAttributes(in arguments,
ReservedAttributes.DynamicAttribute |
ReservedAttributes.IsReadOnlyAttribute |
ReservedAttributes.RequiresLocationAttribute |
ReservedAttributes.IsUnmanagedAttribute |
ReservedAttributes.IsByRefLikeAttribute |
ReservedAttributes.TupleElementNamesAttribute |
ReservedAttributes.NullableAttribute |
ReservedAttributes.NativeIntegerAttribute |
ReservedAttributes.ScopedRefAttribute))
{
}
else if (attribute.IsTargetAttribute(AttributeDescription.AllowNullAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasAllowNullAttribute = true;
}
else if (attribute.IsTargetAttribute(AttributeDescription.DisallowNullAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasDisallowNullAttribute = true;
}
else if (attribute.IsTargetAttribute(AttributeDescription.MaybeNullAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasMaybeNullAttribute = true;
}
else if (attribute.IsTargetAttribute(AttributeDescription.MaybeNullWhenAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().MaybeNullWhenAttribute = DecodeMaybeNullWhenOrNotNullWhenOrDoesNotReturnIfAttribute(attribute);
}
else if (attribute.IsTargetAttribute(AttributeDescription.NotNullAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasNotNullAttribute = true;
}
else if (attribute.IsTargetAttribute(AttributeDescription.NotNullWhenAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().NotNullWhenAttribute = DecodeMaybeNullWhenOrNotNullWhenOrDoesNotReturnIfAttribute(attribute);
}
else if (attribute.IsTargetAttribute(AttributeDescription.DoesNotReturnIfAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().DoesNotReturnIfAttribute = DecodeMaybeNullWhenOrNotNullWhenOrDoesNotReturnIfAttribute(attribute);
}
else if (attribute.IsTargetAttribute(AttributeDescription.NotNullIfNotNullAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().AddNotNullIfParameterNotNull(attribute.DecodeNotNullIfNotNullAttribute());
}
else if (attribute.IsTargetAttribute(AttributeDescription.EnumeratorCancellationAttribute))
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().HasEnumeratorCancellationAttribute = true;
ValidateCancellationTokenAttribute(arguments.AttributeSyntaxOpt, (BindingDiagnosticBag)arguments.Diagnostics);
}
else if (attribute.GetTargetAttributeSignatureIndex(AttributeDescription.InterpolatedStringHandlerArgumentAttribute) is (0 or 1) and var index)
{
DecodeInterpolatedStringHandlerArgumentAttribute(ref arguments, diagnostics, index);
}
else if (attribute.IsTargetAttribute(AttributeDescription.UnscopedRefAttribute))
{
if (!this.IsValidUnscopedRefAttributeTarget())
{
diagnostics.Add(ErrorCode.ERR_UnscopedRefAttributeUnsupportedTarget, arguments.AttributeSyntaxOpt.Location);
}
else if (DeclaredScope != ScopedKind.None)
{
diagnostics.Add(ErrorCode.ERR_UnscopedScoped, arguments.AttributeSyntaxOpt.Location);
}
}
}
private bool IsValidUnscopedRefAttributeTarget()
{
return UseUpdatedEscapeRules && (RefKind != RefKind.None || (HasParamsModifier && Type.IsRefLikeOrAllowsRefLikeType()));
}
private static bool? DecodeMaybeNullWhenOrNotNullWhenOrDoesNotReturnIfAttribute(CSharpAttributeData attribute)
{
var arguments = attribute.CommonConstructorArguments;
return arguments.Length == 1 && arguments[0].TryDecodeValue(SpecialType.System_Boolean, out bool value) ?
(bool?)value :
null;
}
private void DecodeDefaultParameterValueAttribute(AttributeDescription description, ref DecodeWellKnownAttributeArguments<AttributeSyntax, CSharpAttributeData, AttributeLocation> arguments)
{
var attribute = arguments.Attribute;
var syntax = arguments.AttributeSyntaxOpt;
var diagnostics = (BindingDiagnosticBag)arguments.Diagnostics;
Debug.Assert(syntax != null);
Debug.Assert(diagnostics != null);
var value = DecodeDefaultParameterValueAttribute(description, attribute, syntax, diagnose: true, diagnosticsOpt: diagnostics);
if (!value.IsBad)
{
VerifyParamDefaultValueMatchesAttributeIfAny(value, syntax, diagnostics);
if (this.RefKind == RefKind.RefReadOnlyParameter && this.IsOptional && this.ParameterSyntax.Default is null)
{
// A default value is specified for 'ref readonly' parameter '{0}', but 'ref readonly' should be used only for references. Consider declaring the parameter as 'in'.
diagnostics.Add(ErrorCode.WRN_RefReadonlyParameterDefaultValue, syntax, this.Name);
}
}
}
/// <summary>
/// Verify the default value matches the default value from any earlier attribute
/// (DefaultParameterValueAttribute, DateTimeConstantAttribute or DecimalConstantAttribute).
/// If not, report ERR_ParamDefaultValueDiffersFromAttribute.
/// </summary>
private void VerifyParamDefaultValueMatchesAttributeIfAny(ConstantValue value, SyntaxNode syntax, BindingDiagnosticBag diagnostics)
{
var data = GetEarlyDecodedWellKnownAttributeData();
if (data != null)
{
var attrValue = data.DefaultParameterValue;
if ((attrValue != ConstantValue.Unset) &&
(value != attrValue))
{
// CS8017: The parameter has multiple distinct default values.
diagnostics.Add(ErrorCode.ERR_ParamDefaultValueDiffersFromAttribute, syntax.Location);
}
}
}
private ConstantValue DecodeDefaultParameterValueAttribute(AttributeDescription description, CSharpAttributeData attribute, AttributeSyntax node, bool diagnose, BindingDiagnosticBag diagnosticsOpt)
{
Debug.Assert(!attribute.HasErrors);
if (description.Equals(AttributeDescription.DefaultParameterValueAttribute))
{
return DecodeDefaultParameterValueAttribute(attribute, node, diagnose, diagnosticsOpt);
}
else if (description.Equals(AttributeDescription.DecimalConstantAttribute))
{
return attribute.DecodeDecimalConstantValue();
}
else
{
Debug.Assert(description.Equals(AttributeDescription.DateTimeConstantAttribute));
return attribute.DecodeDateTimeConstantValue();
}
}
private ConstantValue DecodeDefaultParameterValueAttribute(CSharpAttributeData attribute, AttributeSyntax node, bool diagnose, BindingDiagnosticBag diagnosticsOpt)
{
Debug.Assert(!diagnose || diagnosticsOpt != null);
if (HasDefaultArgumentSyntax)
{
// error CS1745: Cannot specify default parameter value in conjunction with DefaultParameterAttribute or OptionalAttribute
if (diagnose)
{
diagnosticsOpt.Add(ErrorCode.ERR_DefaultValueUsedWithAttributes, node.Name.Location);
}
return ConstantValue.Bad;
}
// BREAK: In dev10, DefaultParameterValueAttribute could not be applied to System.Type or array parameters.
// When this was attempted, dev10 produced CS1909, ERR_DefaultValueBadParamType. Roslyn takes a different
// approach: instead of looking at the parameter type, we look at the argument type. There's nothing wrong
// with providing a default value for a System.Type or array parameter, as long as the default parameter
// is not a System.Type or an array (i.e. null is fine). Since we are no longer interested in the type of
// the parameter, all occurrences of CS1909 have been replaced with CS1910, ERR_DefaultValueBadValueType,
// to indicate that the argument type, rather than the parameter type, is the source of the problem.
Debug.Assert(attribute.CommonConstructorArguments.Length == 1);
// the type of the value is the type of the expression in the attribute:
var arg = attribute.CommonConstructorArguments[0];
SpecialType specialType = arg.Kind == TypedConstantKind.Enum ?
((NamedTypeSymbol)arg.TypeInternal).EnumUnderlyingType.SpecialType :
arg.TypeInternal.SpecialType;
var compilation = this.DeclaringCompilation;
var constantValueDiscriminator = ConstantValue.GetDiscriminator(specialType);
var useSiteInfo = new CompoundUseSiteInfo<AssemblySymbol>(diagnosticsOpt, ContainingAssembly);
if (constantValueDiscriminator == ConstantValueTypeDiscriminator.Bad)
{
if (arg.Kind != TypedConstantKind.Array && arg.ValueInternal == null)
{
if (this.Type.IsReferenceType)
{
constantValueDiscriminator = ConstantValueTypeDiscriminator.Null;
}
else
{
// error CS1908: The type of the argument to the DefaultParameterValue attribute must match the parameter type
if (diagnose)
{
diagnosticsOpt.Add(ErrorCode.ERR_DefaultValueTypeMustMatch, node.Name.Location);
}
return ConstantValue.Bad;
}
}
else
{
// error CS1910: Argument of type '{0}' is not applicable for the DefaultParameterValue attribute
if (diagnose)
{
diagnosticsOpt.Add(ErrorCode.ERR_DefaultValueBadValueType, node.Name.Location, arg.TypeInternal);
}
return ConstantValue.Bad;
}
}
else if (!compilation.Conversions.ClassifyConversionFromType((TypeSymbol)arg.TypeInternal, this.Type, isChecked: false, ref useSiteInfo).Kind.IsImplicitConversion())
{
// error CS1908: The type of the argument to the DefaultParameterValue attribute must match the parameter type
if (diagnose)
{
diagnosticsOpt.Add(ErrorCode.ERR_DefaultValueTypeMustMatch, node.Name.Location);
diagnosticsOpt.Add(node.Name, useSiteInfo);
}
return ConstantValue.Bad;
}
if (diagnose)
{
diagnosticsOpt.Add(node.Name, useSiteInfo);
}
return ConstantValue.Create(arg.ValueInternal, constantValueDiscriminator);
}
private bool IsValidCallerInfoContext(AttributeSyntax node) => !ContainingSymbol.IsExplicitInterfaceImplementation()
&& !ContainingSymbol.IsOperator()
&& !IsOnPartialImplementation(node);
#nullable enable
/// <summary>
/// Is the attribute syntax appearing on a parameter of a partial method implementation part?
/// Since attributes are merged between the parts of a partial, we need to look at the syntax where the
/// attribute appeared in the source to see if it corresponds to a partial method implementation part.
/// </summary>
private bool IsOnPartialImplementation(AttributeSyntax node)
{
// If we are asking this, the candidate attribute had better be contained in *some* attribute associated with this parameter syntactically
Debug.Assert(this.GetAttributeDeclarations().Any(attrLists => attrLists.Any(attrList => attrList.Contains(node))));
var implParameter = this.ContainingSymbol.IsPartialImplementation() ? this : PartialImplementationPart;
if (implParameter?.AttributeDeclarationList is not { } implParameterAttributeList)
{
return false;
}
return implParameterAttributeList.Any(attrList => attrList.Attributes.Contains(node));
}
#nullable disable
private void ValidateCallerLineNumberAttribute(AttributeSyntax node, BindingDiagnosticBag diagnostics)
{
CSharpCompilation compilation = this.DeclaringCompilation;
var useSiteInfo = new CompoundUseSiteInfo<AssemblySymbol>(diagnostics, ContainingAssembly);
if (!IsValidCallerInfoContext(node))
{
// CS4024: The CallerLineNumberAttribute applied to parameter '{0}' will have no effect because it applies to a
// member that is used in contexts that do not allow optional arguments
diagnostics.Add(ErrorCode.WRN_CallerLineNumberParamForUnconsumedLocation, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (!compilation.Conversions.HasCallerLineNumberConversion(TypeWithAnnotations.Type, ref useSiteInfo))
{
// CS4017: CallerLineNumberAttribute cannot be applied because there are no standard conversions from type '{0}' to type '{1}'
TypeSymbol intType = compilation.GetSpecialType(SpecialType.System_Int32);
diagnostics.Add(ErrorCode.ERR_NoConversionForCallerLineNumberParam, node.Name.Location, intType, TypeWithAnnotations.Type);
}
else if (!HasExplicitDefaultValue && !ContainingSymbol.IsPartialImplementation()) // attribute applied to parameter without default
{
// Unconsumed location checks happen first, so we require a default value.
// CS4020: The CallerLineNumberAttribute may only be applied to parameters with default values
diagnostics.Add(ErrorCode.ERR_BadCallerLineNumberParamWithoutDefaultValue, node.Name.Location);
}
diagnostics.Add(node.Name, useSiteInfo);
}
private void ValidateCallerFilePathAttribute(AttributeSyntax node, BindingDiagnosticBag diagnostics)
{
CSharpCompilation compilation = this.DeclaringCompilation;
var useSiteInfo = new CompoundUseSiteInfo<AssemblySymbol>(diagnostics, ContainingAssembly);
if (!IsValidCallerInfoContext(node))
{
// CS4025: The CallerFilePathAttribute applied to parameter '{0}' will have no effect because it applies to a
// member that is used in contexts that do not allow optional arguments
diagnostics.Add(ErrorCode.WRN_CallerFilePathParamForUnconsumedLocation, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (!compilation.Conversions.HasCallerInfoStringConversion(TypeWithAnnotations.Type, ref useSiteInfo))
{
// CS4018: CallerFilePathAttribute cannot be applied because there are no standard conversions from type '{0}' to type '{1}'
TypeSymbol stringType = compilation.GetSpecialType(SpecialType.System_String);
diagnostics.Add(ErrorCode.ERR_NoConversionForCallerFilePathParam, node.Name.Location, stringType, TypeWithAnnotations.Type);
}
else if (!HasExplicitDefaultValue && !ContainingSymbol.IsPartialImplementation()) // attribute applied to parameter without default
{
// Unconsumed location checks happen first, so we require a default value.
// CS4021: The CallerFilePathAttribute may only be applied to parameters with default values
diagnostics.Add(ErrorCode.ERR_BadCallerFilePathParamWithoutDefaultValue, node.Name.Location);
}
else if (IsCallerLineNumber)
{
// CS7082: The CallerFilePathAttribute applied to parameter '{0}' will have no effect. It is overridden by the CallerLineNumberAttribute.
diagnostics.Add(ErrorCode.WRN_CallerLineNumberPreferredOverCallerFilePath, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
diagnostics.Add(node.Name, useSiteInfo);
}
private void ValidateCallerMemberNameAttribute(AttributeSyntax node, BindingDiagnosticBag diagnostics)
{
CSharpCompilation compilation = this.DeclaringCompilation;
var useSiteInfo = new CompoundUseSiteInfo<AssemblySymbol>(diagnostics, ContainingAssembly);
if (!IsValidCallerInfoContext(node))
{
// CS4026: The CallerMemberNameAttribute applied to parameter '{0}' will have no effect because it applies to a
// member that is used in contexts that do not allow optional arguments
diagnostics.Add(ErrorCode.WRN_CallerMemberNameParamForUnconsumedLocation, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (!compilation.Conversions.HasCallerInfoStringConversion(TypeWithAnnotations.Type, ref useSiteInfo))
{
// CS4019: CallerMemberNameAttribute cannot be applied because there are no standard conversions from type '{0}' to type '{1}'
TypeSymbol stringType = compilation.GetSpecialType(SpecialType.System_String);
diagnostics.Add(ErrorCode.ERR_NoConversionForCallerMemberNameParam, node.Name.Location, stringType, TypeWithAnnotations.Type);
}
else if (!HasExplicitDefaultValue && !ContainingSymbol.IsPartialImplementation()) // attribute applied to parameter without default
{
// Unconsumed location checks happen first, so we require a default value.
// CS4022: The CallerMemberNameAttribute may only be applied to parameters with default values
diagnostics.Add(ErrorCode.ERR_BadCallerMemberNameParamWithoutDefaultValue, node.Name.Location);
}
else if (IsCallerLineNumber)
{
// CS7081: The CallerMemberNameAttribute applied to parameter '{0}' will have no effect. It is overridden by the CallerLineNumberAttribute.
diagnostics.Add(ErrorCode.WRN_CallerLineNumberPreferredOverCallerMemberName, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (IsCallerFilePath)
{
// CS7080: The CallerMemberNameAttribute applied to parameter '{0}' will have no effect. It is overridden by the CallerFilePathAttribute.
diagnostics.Add(ErrorCode.WRN_CallerFilePathPreferredOverCallerMemberName, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
diagnostics.Add(node.Name, useSiteInfo);
}
private void ValidateCallerArgumentExpressionAttribute(AttributeSyntax node, CSharpAttributeData attribute, BindingDiagnosticBag diagnostics)
{
// We intentionally don't report an error for earlier language versions here. The attribute already existed
// before the feature was developed. The error is only reported when the binder supplies a value
// based on the attribute.
CSharpCompilation compilation = this.DeclaringCompilation;
var useSiteInfo = new CompoundUseSiteInfo<AssemblySymbol>(diagnostics, ContainingAssembly);
if (!IsValidCallerInfoContext(node))
{
// CS8966: The CallerArgumentExpressionAttribute applied to parameter '{0}' will have no effect because it applies to a
// member that is used in contexts that do not allow optional arguments
diagnostics.Add(ErrorCode.WRN_CallerArgumentExpressionParamForUnconsumedLocation, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (!compilation.Conversions.HasCallerInfoStringConversion(TypeWithAnnotations.Type, ref useSiteInfo))
{
// CS8959: CallerArgumentExpressionAttribute cannot be applied because there are no standard conversions from type '{0}' to type '{1}'
TypeSymbol stringType = compilation.GetSpecialType(SpecialType.System_String);
diagnostics.Add(ErrorCode.ERR_NoConversionForCallerArgumentExpressionParam, node.Name.Location, stringType, TypeWithAnnotations.Type);
}
else if (!HasExplicitDefaultValue && !ContainingSymbol.IsPartialImplementation()) // attribute applied to parameter without default
{
// Unconsumed location checks happen first, so we require a default value.
// CS8964: The CallerArgumentExpressionAttribute may only be applied to parameters with default values
diagnostics.Add(ErrorCode.ERR_BadCallerArgumentExpressionParamWithoutDefaultValue, node.Name.Location);
}
else if (IsCallerLineNumber)
{
// CS8960: The CallerArgumentExpressionAttribute applied to parameter '{0}' will have no effect. It is overridden by the CallerLineNumberAttribute.
diagnostics.Add(ErrorCode.WRN_CallerLineNumberPreferredOverCallerArgumentExpression, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (IsCallerFilePath)
{
// CS8961: The CallerArgumentExpressionAttribute applied to parameter '{0}' will have no effect. It is overridden by the CallerFilePathAttribute.
diagnostics.Add(ErrorCode.WRN_CallerFilePathPreferredOverCallerArgumentExpression, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (IsCallerMemberName)
{
// CS8962: The CallerArgumentExpressionAttribute applied to parameter '{0}' will have no effect. It is overridden by the CallerMemberNameAttribute.
diagnostics.Add(ErrorCode.WRN_CallerMemberNamePreferredOverCallerArgumentExpression, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (attribute.CommonConstructorArguments.Length == 1 &&
GetEarlyDecodedWellKnownAttributeData()?.CallerArgumentExpressionParameterIndex == -1)
{
// CS8963: The CallerArgumentExpressionAttribute applied to parameter '{0}' will have no effect. It is applied with an invalid parameter name.
diagnostics.Add(ErrorCode.WRN_CallerArgumentExpressionAttributeHasInvalidParameterName, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
else if (GetEarlyDecodedWellKnownAttributeData()?.CallerArgumentExpressionParameterIndex == Ordinal)
{
// CS8965: The CallerArgumentExpressionAttribute applied to parameter '{0}' will have no effect because it's self-referential.
diagnostics.Add(ErrorCode.WRN_CallerArgumentExpressionAttributeSelfReferential, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
diagnostics.Add(node.Name, useSiteInfo);
}
private void ValidateCancellationTokenAttribute(AttributeSyntax node, BindingDiagnosticBag diagnostics)
{
if (needsReporting())
{
diagnostics.Add(ErrorCode.WRN_UnconsumedEnumeratorCancellationAttributeUsage, node.Name.Location, ParameterSyntax.Identifier.ValueText);
}
bool needsReporting()
{
if (!Type.Equals(this.DeclaringCompilation.GetWellKnownType(WellKnownType.System_Threading_CancellationToken)))
{
return true;
}
else if (this.ContainingSymbol is MethodSymbol method &&
method.IsAsync &&
method.ReturnType.OriginalDefinition.Equals(this.DeclaringCompilation.GetWellKnownType(WellKnownType.System_Collections_Generic_IAsyncEnumerable_T)))
{
// Note: async methods that return this type must be iterators. This is enforced elsewhere
return false;
}
return true;
}
}
#nullable enable
private void DecodeInterpolatedStringHandlerArgumentAttribute(ref DecodeWellKnownAttributeArguments<AttributeSyntax, CSharpAttributeData, AttributeLocation> arguments, BindingDiagnosticBag diagnostics, int attributeIndex)
{
Debug.Assert(attributeIndex is 0 or 1);
Debug.Assert(arguments.Attribute.IsTargetAttribute(AttributeDescription.InterpolatedStringHandlerArgumentAttribute) && arguments.Attribute.CommonConstructorArguments.Length == 1);
Debug.Assert(arguments.AttributeSyntaxOpt is not null);
if (Type is not NamedTypeSymbol { IsInterpolatedStringHandlerType: true } handlerType)
{
// '{0}' is not an interpolated string handler type.
diagnostics.Add(ErrorCode.ERR_TypeIsNotAnInterpolatedStringHandlerType, arguments.AttributeSyntaxOpt.Location, Type);
setInterpolatedStringHandlerAttributeError(ref arguments);
return;
}
if (this is LambdaParameterSymbol)
{
// Lambda parameters will ignore this attribute at usage
diagnostics.Add(ErrorCode.WRN_InterpolatedStringHandlerArgumentAttributeIgnoredOnLambdaParameters, arguments.AttributeSyntaxOpt.Location);
}
TypedConstant constructorArgument = arguments.Attribute.CommonConstructorArguments[0];
ImmutableArray<ParameterSymbol> containingSymbolParameters = ContainingSymbol.GetParameters();
ImmutableArray<int> parameterOrdinals;
ArrayBuilder<ParameterSymbol?> parameters;
if (attributeIndex == 0)
{
if (decodeName(constructorArgument, ref arguments) is not (int ordinal, var parameter))
{
// If an error needs to be reported, it will already have been reported by another step.
setInterpolatedStringHandlerAttributeError(ref arguments);
return;
}
parameterOrdinals = ImmutableArray.Create(ordinal);
parameters = ArrayBuilder<ParameterSymbol?>.GetInstance(1);
parameters.Add(parameter);
}
else if (attributeIndex == 1)
{
if (constructorArgument.IsNull)
{
setInterpolatedStringHandlerAttributeError(ref arguments);
// null is not a valid parameter name. To get access to the receiver of an instance method, use the empty string as the parameter name.
diagnostics.Add(ErrorCode.ERR_NullInvalidInterpolatedStringHandlerArgumentName, arguments.AttributeSyntaxOpt!.Location);
return;
}
bool hadError = false;
parameters = ArrayBuilder<ParameterSymbol?>.GetInstance(constructorArgument.Values.Length);
var ordinalsBuilder = ArrayBuilder<int>.GetInstance(constructorArgument.Values.Length);
foreach (var nestedArgument in constructorArgument.Values)
{
if (decodeName(nestedArgument, ref arguments) is (int ordinal, var parameter) && !hadError)
{
parameters.Add(parameter);
ordinalsBuilder.Add(ordinal);
}
else
{
hadError = true;
}
}
if (hadError)
{
parameters.Free();
ordinalsBuilder.Free();
setInterpolatedStringHandlerAttributeError(ref arguments);
return;
}
parameterOrdinals = ordinalsBuilder.ToImmutableAndFree();
}
else
{
throw ExceptionUtilities.Unreachable();
}
var parameterWellKnownAttributeData = arguments.GetOrCreateData<ParameterWellKnownAttributeData>();
parameterWellKnownAttributeData.InterpolatedStringHandlerArguments = parameterOrdinals;
(int Ordinal, ParameterSymbol? Parameter)? decodeName(TypedConstant constant, ref DecodeWellKnownAttributeArguments<AttributeSyntax, CSharpAttributeData, AttributeLocation> arguments)
{
Debug.Assert(arguments.AttributeSyntaxOpt is not null);
if (constant.IsNull)
{
// null is not a valid parameter name. To get access to the receiver of an instance method, use the empty string as the parameter name.
diagnostics.Add(ErrorCode.ERR_NullInvalidInterpolatedStringHandlerArgumentName, arguments.AttributeSyntaxOpt.Location);
return null;
}
if (constant.TypeInternal is not { SpecialType: SpecialType.System_String })
{
// There has already been an error reported. Just return null.
return null;
}
var name = constant.DecodeValue<string>(SpecialType.System_String);
Debug.Assert(name != null);
if (name == "")
{
// Name refers to the "this" instance parameter.
if (!ContainingSymbol.RequiresInstanceReceiver() || ContainingSymbol is MethodSymbol { MethodKind: MethodKind.Constructor or MethodKind.DelegateInvoke or MethodKind.LambdaMethod })
{
// '{0}' is not an instance method, the receiver cannot be an interpolated string handler argument.
diagnostics.Add(ErrorCode.ERR_NotInstanceInvalidInterpolatedStringHandlerArgumentName, arguments.AttributeSyntaxOpt.Location, ContainingSymbol);
return null;
}
return (BoundInterpolatedStringArgumentPlaceholder.InstanceParameter, null);
}
var parameter = containingSymbolParameters.FirstOrDefault(static (param, name) => string.Equals(param.Name, name, StringComparison.Ordinal), name);
if (parameter is null)
{
// '{0}' is not a valid parameter name from '{1}'.
diagnostics.Add(ErrorCode.ERR_InvalidInterpolatedStringHandlerArgumentName, arguments.AttributeSyntaxOpt.Location, name, ContainingSymbol);
return null;
}
if ((object)parameter == this)
{
// InterpolatedStringHandlerArgumentAttribute arguments cannot refer to the parameter the attribute is used on.
diagnostics.Add(ErrorCode.ERR_CannotUseSelfAsInterpolatedStringHandlerArgument, arguments.AttributeSyntaxOpt.Location);
return null;
}
if (parameter.Ordinal > Ordinal)
{
// Parameter '{0}' occurs after '{1}' in the parameter list, but is used as an argument for interpolated string handler conversions.
// This will require the caller to reorder parameters with named arguments at the call site. Consider putting the interpolated
// string handler parameter after all arguments involved.
diagnostics.Add(ErrorCode.WRN_ParameterOccursAfterInterpolatedStringHandlerParameter, arguments.AttributeSyntaxOpt.Location, parameter.Name, this.Name);
}
return (parameter.Ordinal, parameter);
}
static void setInterpolatedStringHandlerAttributeError(ref DecodeWellKnownAttributeArguments<AttributeSyntax, CSharpAttributeData, AttributeLocation> arguments)
{
arguments.GetOrCreateData<ParameterWellKnownAttributeData>().InterpolatedStringHandlerArguments = default;
}
}
#nullable disable
internal override void PostDecodeWellKnownAttributes(ImmutableArray<CSharpAttributeData> boundAttributes, ImmutableArray<AttributeSyntax> allAttributeSyntaxNodes, BindingDiagnosticBag diagnostics, AttributeLocation symbolPart, WellKnownAttributeData decodedData)
{
Debug.Assert(!boundAttributes.IsDefault);
Debug.Assert(!allAttributeSyntaxNodes.IsDefault);
Debug.Assert(boundAttributes.Length == allAttributeSyntaxNodes.Length);
Debug.Assert(_lazyCustomAttributesBag != null);
Debug.Assert(_lazyCustomAttributesBag.IsDecodedWellKnownAttributeDataComputed);
Debug.Assert(symbolPart == AttributeLocation.None);
var data = (ParameterWellKnownAttributeData)decodedData;
if (data != null)
{
switch (RefKind)
{
case RefKind.Ref:
if (data.HasOutAttribute && !data.HasInAttribute)
{
// error CS0662: Cannot specify the Out attribute on a ref parameter without also specifying the In attribute.
diagnostics.Add(ErrorCode.ERR_OutAttrOnRefParam, this.GetFirstLocation());
}
break;
case RefKind.Out:
if (data.HasInAttribute)
{
// error CS0036: An out parameter cannot have the In attribute.
diagnostics.Add(ErrorCode.ERR_InAttrOnOutParam, this.GetFirstLocation());
}
break;
case RefKind.In:
if (data.HasOutAttribute)
{
// error CS8355: An in parameter cannot have the Out attribute.
diagnostics.Add(ErrorCode.ERR_OutAttrOnInParam, this.GetFirstLocation());
}
break;
case RefKind.RefReadOnlyParameter:
if (data.HasOutAttribute)
{
// error: A ref readonly parameter cannot have the Out attribute.
diagnostics.Add(ErrorCode.ERR_OutAttrOnRefReadonlyParam, this.GetFirstLocation());
}
break;
}
}
base.PostDecodeWellKnownAttributes(boundAttributes, allAttributeSyntaxNodes, diagnostics, symbolPart, decodedData);
}
/// <summary>
/// True if the parameter has default argument syntax.
/// </summary>
internal override bool HasDefaultArgumentSyntax
{
get
{
return (_parameterSyntaxKind & ParameterFlags.DefaultParameter) != 0;
}
}
/// <summary>
/// True if the parameter is marked by <see cref="System.Runtime.InteropServices.OptionalAttribute"/>.
/// </summary>
internal sealed override bool HasOptionalAttribute
{
get
{
if (_lazyHasOptionalAttribute == ThreeState.Unknown)
{
SourceParameterSymbol copyFrom = this.BoundAttributesSource;
// prevent infinite recursion:
Debug.Assert(!ReferenceEquals(copyFrom, this));
if ((object)copyFrom != null)
{
// Parameter of partial implementation.
// We bind the attributes only on the definition part and copy them over to the implementation.
_lazyHasOptionalAttribute = copyFrom.HasOptionalAttribute.ToThreeState();
}
else
{
// lazyHasOptionalAttribute is decoded early, hence we cannot reach here when binding attributes for this symbol.
// So it is fine to force complete attributes here.
var attributes = GetAttributes();
if (!attributes.Any())
{
_lazyHasOptionalAttribute = ThreeState.False;
}
}
}
Debug.Assert(_lazyHasOptionalAttribute.HasValue());
return _lazyHasOptionalAttribute.Value();
}
}
internal override bool IsMetadataOptional
{
get
{
// NOTE: IsMetadataOptional property can be invoked during overload resolution.
// NOTE: Optional attribute is decoded very early in attribute binding phase, see method EarlyDecodeOptionalAttribute
// NOTE: If you update the below check to look for any more attributes, make sure that they are decoded early.
return HasDefaultArgumentSyntax || HasOptionalAttribute;
}
}
internal sealed override bool IsMetadataIn
=> base.IsMetadataIn || GetDecodedWellKnownAttributeData()?.HasInAttribute == true;
internal sealed override bool IsMetadataOut
=> base.IsMetadataOut || GetDecodedWellKnownAttributeData()?.HasOutAttribute == true;
internal sealed override MarshalPseudoCustomAttributeData MarshallingInformation
=> GetDecodedWellKnownAttributeData()?.MarshallingInformation;
protected sealed override bool HasParamsModifier => (_parameterSyntaxKind & ParameterFlags.HasParamsModifier) != 0;
public sealed override bool IsParamsArray => (_parameterSyntaxKind & ParameterFlags.ParamsParameter) != 0 && this.Type.IsSZArray();
public sealed override bool IsParamsCollection => (_parameterSyntaxKind & ParameterFlags.ParamsParameter) != 0 && !this.Type.IsSZArray();
internal override bool IsExtensionMethodThis => (_parameterSyntaxKind & ParameterFlags.ExtensionThisParameter) != 0;
public abstract override ImmutableArray<CustomModifier> RefCustomModifiers { get; }
internal override void ForceComplete(SourceLocation locationOpt, Predicate<Symbol> filter, CancellationToken cancellationToken)
{
Debug.Assert(filter == null);
_ = this.GetAttributes();
_ = this.ExplicitDefaultConstantValue;
DoMiscValidation();
state.SpinWaitComplete(CompletionPart.ComplexParameterSymbolAll, cancellationToken);
}
#nullable enable
private void DoMiscValidation()
{
if (state.NotePartComplete(CompletionPart.StartMiscValidation))
{
var diagnostics = BindingDiagnosticBag.GetInstance();
if (IsParams && ParameterSyntax?.Modifiers.Any(SyntaxKind.ParamsKeyword) == true)
{
validateParamsType(diagnostics);
}
if (DeclaredScope == ScopedKind.ScopedValue && !Type.IsErrorOrRefLikeOrAllowsRefLikeType())
{
Debug.Assert(ParameterSyntax is not null);
diagnostics.Add(ErrorCode.ERR_ScopedRefAndRefStructOnly, ParameterSyntax);
}
AddDeclarationDiagnostics(diagnostics);
diagnostics.Free();
bool completedOnThisThread = state.NotePartComplete(CompletionPart.EndMiscValidation);
Debug.Assert(completedOnThisThread);
}
state.SpinWaitComplete(CompletionPart.EndMiscValidation, default(CancellationToken));
void validateParamsType(BindingDiagnosticBag diagnostics)
{
var collectionTypeKind = ConversionsBase.GetCollectionExpressionTypeKind(DeclaringCompilation, Type, out TypeWithAnnotations elementTypeWithAnnotations);
var elementType = elementTypeWithAnnotations.Type;
switch (collectionTypeKind)
{
case CollectionExpressionTypeKind.None:
reportInvalidParams(diagnostics);
return;
case CollectionExpressionTypeKind.ImplementsIEnumerable:
{
var syntax = ParameterSyntax;
var binder = GetDefaultParameterValueBinder(syntax).WithContainingMemberOrLambda(ContainingSymbol); // this binder is good for our purpose
binder.TryGetCollectionIterationType(syntax, Type, out elementTypeWithAnnotations);
elementType = elementTypeWithAnnotations.Type;
if (elementType is null)
{
reportInvalidParams(diagnostics);
return;
}
if (!binder.HasCollectionExpressionApplicableConstructor(syntax, Type, out MethodSymbol? constructor, isExpanded: out _, diagnostics, isParamsModifierValidation: true))
{
return;
}
if (constructor is not null)
{
checkIsAtLeastAsVisible(syntax, binder, constructor, diagnostics);
}
if (!binder.HasCollectionExpressionApplicableAddMethod(syntax, Type, out ImmutableArray<MethodSymbol> addMethods, diagnostics))
{
return;
}
Debug.Assert(!addMethods.IsDefaultOrEmpty);
if (addMethods[0].IsStatic) // No need to check other methods, extensions are never mixed with instance methods
{
Debug.Assert(addMethods[0].IsExtensionMethod);
diagnostics.Add(ErrorCode.ERR_ParamsCollectionExtensionAddMethod, syntax, Type);
return;
}
MethodSymbol? reportAsLessVisible = null;
foreach (var addMethod in addMethods)
{
if (isAtLeastAsVisible(syntax, binder, addMethod, diagnostics))
{
reportAsLessVisible = null;
break;
}
else
{
reportAsLessVisible ??= addMethod;
}
}
if (reportAsLessVisible is not null)
{
diagnostics.Add(ErrorCode.ERR_ParamsMemberCannotBeLessVisibleThanDeclaringMember, syntax, reportAsLessVisible, ContainingSymbol);
}
}
break;
case CollectionExpressionTypeKind.CollectionBuilder:
{
var syntax = ParameterSyntax;
var binder = GetDefaultParameterValueBinder(syntax).WithContainingMemberOrLambda(ContainingSymbol); // this binder is good for our purpose
binder.TryGetCollectionIterationType(syntax, Type, out elementTypeWithAnnotations);
elementType = elementTypeWithAnnotations.Type;
if (elementType is null)
{
reportInvalidParams(diagnostics);
return;
}
MethodSymbol? collectionBuilderMethod = binder.GetAndValidateCollectionBuilderMethod(syntax, (NamedTypeSymbol)Type, diagnostics, elementType: out _);
if (collectionBuilderMethod is null)
{
return;
}
if (ContainingSymbol.ContainingSymbol is NamedTypeSymbol) // No need to check for lambdas or local function
{
checkIsAtLeastAsVisible(syntax, binder, collectionBuilderMethod, diagnostics);
}
}
break;
}
Debug.Assert(elementType is { });
if (collectionTypeKind != CollectionExpressionTypeKind.Array)
{
MessageID.IDS_FeatureParamsCollections.CheckFeatureAvailability(diagnostics, ParameterSyntax);
}
}
bool isAtLeastAsVisible(ParameterSyntax syntax, Binder binder, MethodSymbol method, BindingDiagnosticBag diagnostics)
{
var useSiteInfo = binder.GetNewCompoundUseSiteInfo(diagnostics);
bool result = method.IsAsRestrictive(ContainingSymbol, ref useSiteInfo) &&
method.ContainingType.IsAtLeastAsVisibleAs(ContainingSymbol, ref useSiteInfo);
diagnostics.Add(syntax.Location, useSiteInfo);
return result;
}
void checkIsAtLeastAsVisible(ParameterSyntax syntax, Binder binder, MethodSymbol method, BindingDiagnosticBag diagnostics)
{
if (!isAtLeastAsVisible(syntax, binder, method, diagnostics))
{
diagnostics.Add(ErrorCode.ERR_ParamsMemberCannotBeLessVisibleThanDeclaringMember, syntax, method, ContainingSymbol);
}
}
void reportInvalidParams(BindingDiagnosticBag diagnostics)
{
diagnostics.Add(ErrorCode.ERR_ParamsMustBeCollection, ParameterSyntax.Modifiers.First(static m => m.IsKind(SyntaxKind.ParamsKeyword)).GetLocation());
}
}
#nullable disable
}
internal sealed class SourceComplexParameterSymbol : SourceComplexParameterSymbolBase
{
private readonly TypeWithAnnotations _parameterType;
internal SourceComplexParameterSymbol(
Symbol owner,
int ordinal,
TypeWithAnnotations parameterType,
RefKind refKind,
string name,
Location location,
SyntaxReference syntaxRef,
bool hasParamsModifier,
bool isParams,
bool isExtensionMethodThis,
ScopedKind scope)
: base(owner, ordinal, refKind, name, location, syntaxRef, hasParamsModifier: hasParamsModifier, isParams: isParams, isExtensionMethodThis, scope)
{
_parameterType = parameterType;
}
public override TypeWithAnnotations TypeWithAnnotations => _parameterType;
public override ImmutableArray<CustomModifier> RefCustomModifiers => ImmutableArray<CustomModifier>.Empty;
}
internal sealed class SourceComplexParameterSymbolWithCustomModifiersPrecedingRef : SourceComplexParameterSymbolBase
{
private readonly ImmutableArray<CustomModifier> _refCustomModifiers;
private readonly TypeWithAnnotations _parameterType;
internal SourceComplexParameterSymbolWithCustomModifiersPrecedingRef(
Symbol owner,
int ordinal,
TypeWithAnnotations parameterType,
RefKind refKind,
ImmutableArray<CustomModifier> refCustomModifiers,
string name,
Location location,
SyntaxReference syntaxRef,
bool hasParamsModifier,
bool isParams,
bool isExtensionMethodThis,
ScopedKind scope)
: base(owner, ordinal, refKind, name, location, syntaxRef, hasParamsModifier: hasParamsModifier, isParams: isParams, isExtensionMethodThis, scope)
{
Debug.Assert(!refCustomModifiers.IsEmpty);
_parameterType = parameterType;
_refCustomModifiers = refCustomModifiers;
Debug.Assert(refKind != RefKind.None || _refCustomModifiers.IsEmpty);
}
public override TypeWithAnnotations TypeWithAnnotations => _parameterType;
public override ImmutableArray<CustomModifier> RefCustomModifiers => _refCustomModifiers;
}
}
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