public static void InListOfTAdd(string expression)
{
var code = @"
namespace N
{
using System;
using System.Collections.Generic;
internal class C
{
private List<IDisposable> disposables = new List<IDisposable>();
internal C(IDisposable disposable)
{
this.disposables.Add(disposable);
}
}
}".AssertReplace("Add(disposable)", expression);
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("IDisposable disposable");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(true, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out var container));
Assert.AreEqual("N.C.disposables", container.ToString());
}
public static void Recursive()
{
var code = @"
namespace N
{
using System.IO;
public class C
{
public C(Stream stream)
{
this.disposable = GetReader(stream);
}
private static StreamReader GetReader(Stream arg) => GetReader(arg);
}
}";
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("Stream stream");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(false, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out _));
}
public static void InLeaveOpen(string expression, bool stores)
{
var code = @"
namespace N
{
using System;
using System.IO;
using System.IO.Compression;
using System.Security.Cryptography;
using System.Text;
public class C
{
private readonly IDisposable disposable;
public C(Stream stream)
{
this.disposable = new BinaryReader(stream);
}
}
}".AssertReplace("new BinaryReader(stream)", expression);
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("stream");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(stores, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out var container));
Assert.AreEqual(stores, Disposable.DisposedByReturnValue(syntaxTree.FindArgument("stream"), semanticModel, CancellationToken.None, out _));
if (stores)
{
Assert.AreEqual("N.C.disposable", container.ToString());
}
}
private static void Handle(SyntaxNodeAnalysisContext context)
{
if (!context.IsExcludedFromAnalysis() &&
context.Node is ArgumentSyntax argument &&
argument.Parent is ArgumentListSyntax argumentList &&
argumentList.Parent is InvocationExpressionSyntax invocation &&
argument.RefOrOutKeyword.IsEither(SyntaxKind.RefKeyword, SyntaxKind.OutKeyword) &&
context.SemanticModel.TryGetSymbol(invocation, context.CancellationToken, out var method) &&
method.TrySingleDeclaration(context.CancellationToken, out BaseMethodDeclarationSyntax declaration) &&
method.TryFindParameter(argument, out var parameter) &&
Disposable.IsPotentiallyAssignableFrom(parameter.Type, context.Compilation))
{
if (Disposable.IsCreation(argument, context.SemanticModel, context.CancellationToken).IsEither(Result.Yes, Result.AssumeYes) &&
!Disposable.IsAddedToFieldOrProperty(parameter, declaration, context.SemanticModel, context.CancellationToken) &&
context.SemanticModel.TryGetSymbol(argument.Expression, context.CancellationToken, out ISymbol symbol))
{
if (LocalOrParameter.TryCreate(symbol, out var localOrParameter) &&
Disposable.ShouldDispose(localOrParameter, argument.Expression, context.SemanticModel, context.CancellationToken))
{
context.ReportDiagnostic(Diagnostic.Create(IDISP001DisposeCreated.Descriptor, argument.GetLocation()));
}
if (Disposable.IsAssignedWithCreated(symbol, invocation, context.SemanticModel, context.CancellationToken).IsEither(Result.Yes, Result.AssumeYes) &&
!Disposable.IsDisposedBefore(symbol, invocation, context.SemanticModel, context.CancellationToken))
{
context.ReportDiagnostic(Diagnostic.Create(IDISP003DisposeBeforeReassigning.Descriptor, argument.GetLocation()));
}
}
}
}
public static void ArrayFieldAssignedInCtor()
{
var code = @"
namespace N
{
using System;
internal class C
{
private IDisposable[] disposables = new IDisposable[1];
internal C(IDisposable disposable)
{
this.disposables[0] = disposable;
}
}
}";
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("IDisposable disposable");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(true, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out var container));
Assert.AreEqual("N.C.disposables", container.ToString());
}
public static void WhenNotUsed(string type, string expression)
{
var code = @"
namespace N
{
using System;
internal class C
{
private readonly bool value;
internal C(IDisposable disposable)
{
this.value = Equals(disposable, null);
}
}
}".AssertReplace("bool", type)
.AssertReplace("Equals(disposable, null)", expression);
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("IDisposable disposable");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(false, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out _));
}
public static void DisposableMixinsDisposeWith()
{
var code = @"
namespace N
{
using System;
using System.IO;
using System.Reactive.Disposables;
sealed class C : IDisposable
{
private readonly CompositeDisposable compositeDisposable = new CompositeDisposable();
public DisposeWith(Stream stream)
{
this.disposable = stream.DisposeWith(this.compositeDisposable);
}
public void Dispose()
{
this.compositeDisposable.Dispose();
}
}
}";
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("Stream stream");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(true, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out _));
}
public static void ListOfTAddInInitializeParameter(string call)
{
var code = @"
namespace N
{
using System;
using System.Collections.Generic;
internal class C
{
internal C(List<IDisposable> disposables, IDisposable disposable)
{
this.Initialize(disposables, disposable);
}
private void Initialize(List<IDisposable> disposables, IDisposable disposable)
{
disposables.Add(disposable);
}
}
}".AssertReplace("this.Initialize(disposables, disposable)", call);
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("IDisposable disposable");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(true, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out var container));
Assert.AreEqual(SymbolKind.Parameter, container.Kind);
Assert.AreEqual("disposables", container.Name);
}
public static void FieldAssignedViaCalledMethodParameter()
{
var code = @"
namespace N
{
using System;
internal class C
{
private IDisposable disposable;
internal C(IDisposable disposable)
{
this.M(disposable);
}
private void M(IDisposable disposable)
{
this.disposable = disposable;
}
}
}";
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("IDisposable disposable");
var symbol = semanticModel.GetDeclaredSymbol(value, CancellationToken.None);
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(true, Disposable.Assigns(localOrParameter, semanticModel, CancellationToken.None, out var field));
Assert.AreEqual("N.C.disposable", field.Symbol.ToString());
}
private static void Handle(SyntaxNodeAnalysisContext context)
{
if (!context.IsExcludedFromAnalysis() &&
context.Node is AssignmentExpressionSyntax {
Left : { } left, Right : { } right
} assignment&&
!left.IsKind(SyntaxKind.ElementAccessExpression) &&
context.SemanticModel.TryGetSymbol(left, context.CancellationToken, out var assignedSymbol))
{
if (LocalOrParameter.TryCreate(assignedSymbol, out var localOrParameter) &&
Disposable.IsCreation(right, context.SemanticModel, context.CancellationToken).IsEither(Result.Yes, Result.AssumeYes) &&
Disposable.ShouldDispose(localOrParameter, context.SemanticModel, context.CancellationToken))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.IDISP001DisposeCreated, assignment.GetLocation()));
}
if (IsReassignedWithCreated(assignment, context))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.IDISP003DisposeBeforeReassigning, assignment.GetLocation()));
}
if (assignedSymbol is IParameterSymbol {
RefKind : RefKind.Ref
} refParameter&&
refParameter.ContainingSymbol.DeclaredAccessibility != Accessibility.Private &&
context.SemanticModel.TryGetType(right, context.CancellationToken, out var type) &&
Disposable.IsAssignableFrom(type, context.Compilation))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.IDISP008DoNotMixInjectedAndCreatedForMember, context.Node.GetLocation()));
}
}
}
private static void Handle(SyntaxNodeAnalysisContext context)
{
if (!context.IsExcludedFromAnalysis() &&
context.Node is ArgumentSyntax {
Parent : ArgumentListSyntax {
Parent : InvocationExpressionSyntax invocation
}
} argument&&
argument.RefOrOutKeyword.IsEither(SyntaxKind.RefKeyword, SyntaxKind.OutKeyword) &&
IsCreation(argument, context.SemanticModel, context.CancellationToken) &&
context.SemanticModel.TryGetSymbol(argument.Expression, context.CancellationToken, out var symbol))
{
if (symbol.Kind == SymbolKind.Discard ||
(LocalOrParameter.TryCreate(symbol, out var localOrParameter) &&
Disposable.ShouldDispose(localOrParameter, context.SemanticModel, context.CancellationToken)))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.IDISP001DisposeCreated, argument.GetLocation()));
}
if (Disposable.IsAssignedWithCreated(symbol, invocation, context.SemanticModel, context.CancellationToken).IsEither(Result.Yes, Result.AssumeYes) &&
!Disposable.IsDisposedBefore(symbol, invocation, context.SemanticModel, context.CancellationToken))
{
context.ReportDiagnostic(Diagnostic.Create(Descriptors.IDISP003DisposeBeforeReassigning, argument.GetLocation()));
}
}
}
public static void InHttpClient(string expression, bool stores)
{
var code = @"
namespace N
{
using System.Net.Http;
public class C
{
private readonly IDisposable disposable;
public C(HttpClientHandler handler)
{
this.disposable = new HttpClient(handler);
}
}
}".AssertReplace("new HttpClient(handler)", expression);
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("handler");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(stores, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out var container));
Assert.AreEqual(stores, Disposable.DisposedByReturnValue(syntaxTree.FindArgument("handler"), semanticModel, CancellationToken.None, out _));
if (stores)
{
Assert.AreEqual("N.C.disposable", container.ToString());
}
}
public static void InDiscardedTuple(string expression)
{
var code = @"
namespace N
{
using System;
using System.Collections.Generic;
internal class C
{
internal C(IDisposable disposable)
{
_ = Tuple.Create(disposable, 1);
}
}
}".AssertReplace("Tuple.Create(disposable, 1)", expression);
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("IDisposable disposable");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(false, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out _));
}
internal static bool ShouldDispose(LocalOrParameter localOrParameter, ExpressionSyntax location, SemanticModel semanticModel, CancellationToken cancellationToken)
{
switch (localOrParameter.Symbol)
{
case ILocalSymbol local:
return(ShouldDispose(local, location, semanticModel, cancellationToken));
case IParameterSymbol parameter:
return(ShouldDispose(parameter, location, semanticModel, cancellationToken));
}
throw new InvalidOperationException("Should never get here.");
}
public static void CompositeDisposableExtAddAndReturn(string expression)
{
var code = @"
namespace N
{
using System;
using System.IO;
using System.Reactive.Disposables;
public static class CompositeDisposableExt
{
public static T AddAndReturn<T>(this CompositeDisposable disposable, T item)
where T : IDisposable
{
if (item != null)
{
disposable.Add(item);
}
return item;
}
}
public sealed class C : IDisposable
{
private readonly CompositeDisposable disposable = new CompositeDisposable();
public void Dispose()
{
this.disposable.Dispose();
}
internal object M(Stream stream)
{
return this.disposable.AddAndReturn(stream);
}
}
}".AssertReplace("disposable.AddAndReturn(stream)", expression);
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("Stream stream");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(true, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out var container));
Assert.AreEqual("disposable", container.Name);
Assert.AreEqual(SymbolKind.Parameter, container.Kind);
}
internal static bool Returns(LocalOrParameter localOrParameter, SemanticModel semanticModel, CancellationToken cancellationToken)
{
using var recursion = Recursion.Borrow(localOrParameter.Symbol.ContainingType, semanticModel, cancellationToken);
using var walker = UsagesWalker.Borrow(localOrParameter, recursion.SemanticModel, recursion.CancellationToken);
foreach (var usage in walker.Usages)
{
if (Returns(usage, recursion))
{
return(true);
}
}
return(false);
}
internal static bool Stores(LocalOrParameter localOrParameter, SemanticModel semanticModel, CancellationToken cancellationToken, [NotNullWhen(true)] out ISymbol?container)
{
using var recursion = Recursion.Borrow(localOrParameter.Symbol.ContainingType, semanticModel, cancellationToken);
using var walker = UsagesWalker.Borrow(localOrParameter, semanticModel, cancellationToken);
foreach (var usage in walker.Usages)
{
if (Stores(usage, recursion, out container))
{
return(true);
}
}
container = null;
return(false);
}
public static void InDisposingPairWhenFactoryMethod(string parameter)
{
var code = @"
namespace N
{
using System;
internal class C
{
private readonly Pair<IDisposable> pair;
internal C(IDisposable disposable1, IDisposable disposable2)
{
this.pair = Create<IDisposable>(disposable1, disposable2);
}
private static Pair<T> Create<T>(T x, T y) where T : IDisposable => new Pair<T>(x, y);
private class Pair<T> : IDisposable
where T : IDisposable
{
private readonly T item1;
private readonly T item2;
public Pair(T item1, T item2)
{
this.item1 = item1;
this.item2 = item2;
}
public void Dispose()
{
this.item1.Dispose();
(this.item2 as IDisposable)?.Dispose();
}
}
}
}";
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter(parameter);
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(true, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out var container));
Assert.AreEqual("N.C.pair", container.ToString());
}
public static void InPairWhenNew(string parameter)
{
var code = @"
namespace N
{
using System;
using System.Collections.Generic;
internal class C
{
private readonly Pair<IDisposable> pair;
internal C(IDisposable disposable1, IDisposable disposable2)
{
this.pair = new Pair<IDisposable>(disposable1, disposable2);
}
public class Pair<T>
{
public Pair(T item1, T item2)
{
this.Item1 = item1;
this.Item2 = item2;
}
public T Item1 { get; }
public T Item2 { get; }
}
}
}";
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter(parameter);
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(true, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out var container));
Assert.AreEqual("N.C.pair", container.ToString());
}
internal static bool ShouldDispose(LocalOrParameter localOrParameter, SemanticModel semanticModel, CancellationToken cancellationToken)
{
if (localOrParameter.Symbol is IParameterSymbol parameter &&
parameter.RefKind != RefKind.None)
{
return(false);
}
using var recursion = Recursion.Borrow(localOrParameter.Symbol.ContainingType, semanticModel, cancellationToken);
using var walker = UsagesWalker.Borrow(localOrParameter, semanticModel, cancellationToken);
foreach (var usage in walker.Usages)
{
if (Returns(usage, recursion))
{
return(false);
}
if (Assigns(usage, recursion, out _))
{
return(false);
}
if (Stores(usage, recursion, out _))
{
return(false);
}
if (Disposes(usage, recursion))
{
return(false);
}
if (DisposedByReturnValue(usage, recursion, out _))
{
return(false);
}
}
return(true);
}
public static void WhenNotUsed()
{
var code = @"
namespace N
{
using System;
internal class C
{
internal C(IDisposable disposable)
{
}
}
}";
var syntaxTree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test", new[] { syntaxTree }, MetadataReferences.FromAttributes());
var semanticModel = compilation.GetSemanticModel(syntaxTree);
var value = syntaxTree.FindParameter("IDisposable disposable");
Assert.AreEqual(true, semanticModel.TryGetSymbol(value, CancellationToken.None, out var symbol));
Assert.AreEqual(true, LocalOrParameter.TryCreate(symbol, out var localOrParameter));
Assert.AreEqual(false, Disposable.Stores(localOrParameter, semanticModel, CancellationToken.None, out _));
}
internal static bool Assigns(LocalOrParameter localOrParameter, SemanticModel semanticModel, CancellationToken cancellationToken, out FieldOrProperty first)
{
if (localOrParameter.TryGetScope(cancellationToken, out var scope) &&
localOrParameter is { ContainingSymbol : { ContainingType : { } containingType } })
