[Gh-12] detect reentrant calls

src/NSubstitute.Analyzers.CSharp/DiagnosticAnalyzers/ReEntrantCallFinder.cs

@@ -0,0 +1,68 @@
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using NSubstitute.Analyzers.Shared.DiagnosticAnalyzers;
+
+namespace NSubstitute.Analyzers.CSharp.DiagnosticAnalyzers
+{
+    internal class ReEntrantCallFinder : AbstractReEntrantCallFinder
+    {
+        protected override ImmutableList<ISymbol> GetReEntrantSymbols(SemanticModel semanticModel, SyntaxNode rootNode)
+        {
+            var visitor = new ReEntrantCallVisitor(this, semanticModel);
+            visitor.Visit(rootNode);
+            return visitor.InvocationSymbols;
+        }
+
+        private class ReEntrantCallVisitor : CSharpSyntaxWalker
+        {
+            private readonly ReEntrantCallFinder _reEntrantCallFinder;
+            private readonly SemanticModel _semanticModel;
+            private readonly HashSet<SyntaxNode> _visitedNodes = new HashSet<SyntaxNode>();
+            private readonly List<ISymbol> _invocationSymbols = new List<ISymbol>();
+
+            public ImmutableList<ISymbol> InvocationSymbols => _invocationSymbols.ToImmutableList();
+
+            public ReEntrantCallVisitor(ReEntrantCallFinder reEntrantCallFinder, SemanticModel semanticModel)
+            {
+                _reEntrantCallFinder = reEntrantCallFinder;
+                _semanticModel = semanticModel;
+            }
+
+            public override void VisitInvocationExpression(InvocationExpressionSyntax node)
+            {
+                var symbolInfo = _semanticModel.GetSymbolInfo(node);
+                if (_reEntrantCallFinder.IsReturnsLikeMethod(_semanticModel, symbolInfo.Symbol))
+                {
+                    _invocationSymbols.Add(symbolInfo.Symbol);
+                }
+
+                base.VisitInvocationExpression(node);
+            }
+
+            public override void DefaultVisit(SyntaxNode node)
+            {
+                VisitRelatedSymbols(node);
+                base.DefaultVisit(node);
+            }
+
+            private void VisitRelatedSymbols(SyntaxNode syntaxNode)
+            {
+                if (_visitedNodes.Contains(syntaxNode) == false &&
+                    (syntaxNode.IsKind(SyntaxKind.IdentifierName) ||
+                    syntaxNode.IsKind(SyntaxKind.ElementAccessExpression) ||
+                    syntaxNode.IsKind(SyntaxKind.SimpleMemberAccessExpression)))
+                {
+                    _visitedNodes.Add(syntaxNode);
+                    foreach (var relatedNode in _reEntrantCallFinder.GetRelatedNodes(_semanticModel, syntaxNode))
+                    {
+                        Visit(relatedNode);
+                    }
+                }
+            }
+        }
+    }
+}

src/NSubstitute.Analyzers.CSharp/DiagnosticAnalyzers/ReEntrantSetupAnalyzer.cs

@@ -0,0 +1,32 @@
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using NSubstitute.Analyzers.Shared.DiagnosticAnalyzers;
+
+namespace NSubstitute.Analyzers.CSharp.DiagnosticAnalyzers
+{
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    internal class ReEntrantSetupAnalyzer : AbstractReEntrantSetupAnalyzer<SyntaxKind, InvocationExpressionSyntax>
+    {
+        public ReEntrantSetupAnalyzer()
+            : base(new DiagnosticDescriptorsProvider())
+        {
+        }
+
+        protected override AbstractReEntrantCallFinder GetReEntrantCallFinder()
+        {
+            return new ReEntrantCallFinder();
+        }
+
+        protected override SyntaxKind InvocationExpressionKind { get; } = SyntaxKind.InvocationExpression;
+
+        protected override IEnumerable<SyntaxNode> ExtractArguments(InvocationExpressionSyntax invocationExpressionSyntax)
+        {
+            return invocationExpressionSyntax.ArgumentList.Arguments.Select(arg => arg.Expression);
+        }
+    }
+}

src/NSubstitute.Analyzers.CSharp/Resources.resx

@@ -273,4 +273,16 @@
     <value>Non-virtual setup specification.</value>
     <comment>The title of the diagnostic.</comment>
   </data>
+    <data name="ReEntrantSubstituteCallDescription" xml:space="preserve">
+    <value>Re-entrant substitute call.</value>
+    <comment>An optional longer localizable description of the diagnostic.</comment>
+  </data>
+  <data name="ReEntrantSubstituteCallMessageFormat" xml:space="preserve">
+    <value>{0}() is set with a method that itself calls {1}. This can cause problems with NSubstitute. Consider replacing with a lambda: {0}(x => {2}).</value>
+    <comment>The format-able message the diagnostic displays.</comment>
+  </data>
+  <data name="ReEntrantSubstituteCallTitle" xml:space="preserve">
+    <value>Re-entrant substitute call.</value>
+    <comment>The title of the diagnostic.</comment>
+  </data>
 </root>

src/NSubstitute.Analyzers.Shared/AbstractDiagnosticDescriptorsProvider.cs

@@ -29,5 +29,7 @@ internal class AbstractDiagnosticDescriptorsProvider<T> : IDiagnosticDescriptors
         public DiagnosticDescriptor NonVirtualReceivedSetupSpecification { get; } = DiagnosticDescriptors<T>.NonVirtualReceivedSetupSpecification;
 
         public DiagnosticDescriptor NonVirtualWhenSetupSpecification { get; } = DiagnosticDescriptors<T>.NonVirtualWhenSetupSpecification;
+
+        public DiagnosticDescriptor ReEntrantSubstituteCall { get; } = DiagnosticDescriptors<T>.ReEntrantSubstituteCall;
     }
 }

src/NSubstitute.Analyzers.Shared/DiagnosticAnalyzers/AbstractReEntrantCallFinder.cs

@@ -0,0 +1,78 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+
+namespace NSubstitute.Analyzers.Shared.DiagnosticAnalyzers
+{
+    internal abstract class AbstractReEntrantCallFinder
+    {
+        private static readonly ImmutableDictionary<string, string> MethodNames = new Dictionary<string, string>()
+        {
+            [MetadataNames.NSubstituteReturnsMethod] = MetadataNames.NSubstituteSubstituteExtensionsFullTypeName,
+            [MetadataNames.NSubstituteReturnsForAnyArgsMethod] = MetadataNames.NSubstituteSubstituteExtensionsFullTypeName,
+            [MetadataNames.NSubstituteDoMethod] = MetadataNames.NSubstituteWhenCalledType
+        }.ToImmutableDictionary();
+
+        public ImmutableList<ISymbol> GetReEntrantCalls(SemanticModel semanticModel, SyntaxNode rootNode)
+        {
+            var typeInfo = semanticModel.GetTypeInfo(rootNode);
+            if (IsCalledViaDelegate(semanticModel, typeInfo))
+            {
+                return ImmutableList<ISymbol>.Empty;
+            }
+
+            return GetReEntrantSymbols(semanticModel, rootNode);
+        }
+
+        protected abstract ImmutableList<ISymbol> GetReEntrantSymbols(SemanticModel semanticModel, SyntaxNode rootNode);
+
+        protected IEnumerable<SyntaxNode> GetRelatedNodes(SemanticModel semanticModel, SyntaxNode syntaxNode)
+        {
+            var symbol = semanticModel.GetSymbolInfo(syntaxNode);
+            if (symbol.Symbol != null && symbol.Symbol.Locations.Any())
+            {
+                foreach (var symbolLocation in symbol.Symbol.Locations.Where(location => location.SourceTree != null))
+                {
+                    var root = symbolLocation.SourceTree.GetRoot();
+                    var relatedNode = root.FindNode(symbolLocation.SourceSpan);
+                    if (relatedNode != null)
+                    {
+                        yield return relatedNode;
+                    }
+                }
+            }
+        }
+
+        protected bool IsReturnsLikeMethod(SemanticModel semanticModel, ISymbol symbol)
+        {
+            if (symbol == null || MethodNames.TryGetValue(symbol.Name, out var containingType) == false)
+            {
+                return false;
+            }
+
+            return symbol.ContainingAssembly?.Name.Equals(MetadataNames.NSubstituteAssemblyName, StringComparison.OrdinalIgnoreCase) == true &&
+                   (symbol.ContainingType?.ToString().Equals(containingType, StringComparison.OrdinalIgnoreCase) == true ||
+                    (symbol.ContainingType?.ConstructedFrom.Name)?.Equals(containingType, StringComparison.OrdinalIgnoreCase) == true);
+        }
+
+        private static bool IsCalledViaDelegate(SemanticModel semanticModel, TypeInfo typeInfo)
+        {
+            var typeSymbol = typeInfo.Type ?? typeInfo.ConvertedType;
+            var isCalledViaDelegate = typeSymbol != null &&
+                                      typeSymbol.TypeKind == TypeKind.Delegate &&
+                                      typeSymbol is INamedTypeSymbol namedTypeSymbol &&
+                                      namedTypeSymbol.ConstructedFrom.Equals(semanticModel.Compilation.GetTypeByMetadataName("System.Func`2")) &&
+                                      IsCallInfoParameter(namedTypeSymbol.TypeArguments.First());
+
+            return isCalledViaDelegate;
+        }
+
+        private static bool IsCallInfoParameter(ITypeSymbol symbol)
+        {
+            return symbol.ContainingAssembly?.Name.Equals(MetadataNames.NSubstituteAssemblyName, StringComparison.OrdinalIgnoreCase) == true &&
+                   symbol.ToString().Equals(MetadataNames.NSubstituteCoreFullTypeName, StringComparison.OrdinalIgnoreCase) == true;
+        }
+    }
+}

src/NSubstitute.Analyzers.Shared/DiagnosticAnalyzers/AbstractReEntrantSetupAnalyzer.cs

@@ -0,0 +1,92 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+namespace NSubstitute.Analyzers.Shared.DiagnosticAnalyzers
+{
+    internal abstract class AbstractReEntrantSetupAnalyzer<TSyntaxKind, TInvocationExpressionSyntax> : AbstractDiagnosticAnalyzer
+        where TInvocationExpressionSyntax : SyntaxNode
+        where TSyntaxKind : struct
+    {
+        private static readonly ImmutableHashSet<string> MethodNames = ImmutableHashSet.Create(
+            MetadataNames.NSubstituteReturnsMethod,
+            MetadataNames.NSubstituteReturnsForAnyArgsMethod);
+
+        private AbstractReEntrantCallFinder ReEntrantCallFinder => _reEntrantCallFinderProxy.Value;
+
+        private readonly Lazy<AbstractReEntrantCallFinder> _reEntrantCallFinderProxy;
+
+        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics =>
+            ImmutableArray.Create(DiagnosticDescriptorsProvider.ReEntrantSubstituteCall);
+
+        protected AbstractReEntrantSetupAnalyzer(IDiagnosticDescriptorsProvider diagnosticDescriptorsProvider)
+            : base(diagnosticDescriptorsProvider)
+        {
+            _reEntrantCallFinderProxy = new Lazy<AbstractReEntrantCallFinder>(GetReEntrantCallFinder);
+        }
+
+        protected abstract AbstractReEntrantCallFinder GetReEntrantCallFinder();
+
+        protected abstract TSyntaxKind InvocationExpressionKind { get; }
+
+        public override void Initialize(AnalysisContext context)
+        {
+            context.RegisterSyntaxNodeAction(AnalyzeInvocation, InvocationExpressionKind);
+        }
+
+        protected abstract IEnumerable<SyntaxNode> ExtractArguments(TInvocationExpressionSyntax invocationExpressionSyntax);
+
+        private void AnalyzeInvocation(SyntaxNodeAnalysisContext syntaxNodeContext)
+        {
+            var invocationExpression = (TInvocationExpressionSyntax)syntaxNodeContext.Node;
+            var methodSymbolInfo = syntaxNodeContext.SemanticModel.GetSymbolInfo(invocationExpression);
+
+            if (methodSymbolInfo.Symbol?.Kind != SymbolKind.Method)
+            {
+                return;
+            }
+
+            var methodSymbol = (IMethodSymbol)methodSymbolInfo.Symbol;
+
+            if (IsReturnsLikeMethod(syntaxNodeContext, invocationExpression, methodSymbol.Name) == false)
+            {
+                return;
+            }
+
+            var allArguments = ExtractArguments(invocationExpression);
+            var argumentsForAnalysis = methodSymbol.MethodKind == MethodKind.ReducedExtension ? allArguments : allArguments.Skip(1);
+
+            foreach (var argument in argumentsForAnalysis)
+            {
+                var reentrantSymbol = ReEntrantCallFinder.GetReEntrantCalls(syntaxNodeContext.SemanticModel, argument).FirstOrDefault();
+                if (reentrantSymbol != null)
+                {
+                    var diagnostic = Diagnostic.Create(
+                        DiagnosticDescriptorsProvider.ReEntrantSubstituteCall,
+                        argument.GetLocation(),
+                        methodSymbol.Name,
+                        reentrantSymbol.Name,
+                        argument.ToString());
+
+                    syntaxNodeContext.ReportDiagnostic(diagnostic);
+                }
+            }
+        }
+
+        private bool IsReturnsLikeMethod(SyntaxNodeAnalysisContext syntaxNodeContext, SyntaxNode syntax, string memberName)
+        {
+            if (MethodNames.Contains(memberName) == false)
+            {
+                return false;
+            }
+
+            var symbol = syntaxNodeContext.SemanticModel.GetSymbolInfo(syntax);
+
+            return symbol.Symbol?.ContainingAssembly?.Name.Equals(MetadataNames.NSubstituteAssemblyName, StringComparison.OrdinalIgnoreCase) == true &&
+                   symbol.Symbol?.ContainingType?.ToString().Equals(MetadataNames.NSubstituteSubstituteExtensionsFullTypeName, StringComparison.OrdinalIgnoreCase) == true;
+        }
+    }
+}

src/NSubstitute.Analyzers.Shared/DiagnosticDescriptors.cs

@@ -115,6 +115,14 @@ internal class DiagnosticDescriptors<T>
                 defaultSeverity: DiagnosticSeverity.Warning,
                 isEnabledByDefault: true);
 
+        public static DiagnosticDescriptor ReEntrantSubstituteCall { get; } =
+            CreateDiagnosticDescriptor(
+                name: nameof(ReEntrantSubstituteCall),
+                id: DiagnosticIdentifiers.ReEntrantSubstituteCall,
+                category: DiagnosticCategories.Usage,
+                defaultSeverity: DiagnosticSeverity.Warning,
+                isEnabledByDefault: true);
+
         private static DiagnosticDescriptor CreateDiagnosticDescriptor(
             string name, string id, string category, DiagnosticSeverity defaultSeverity, bool isEnabledByDefault)
         {

src/NSubstitute.Analyzers.Shared/DiagnosticIdentifiers.cs

@@ -14,5 +14,6 @@ internal class DiagnosticIdentifiers
         public static readonly string SubstituteConstructorArgumentsForDelegate = "NS010";
         public static readonly string NonVirtualReceivedSetupSpecification = "NS011";
         public static readonly string NonVirtualWhenSetupSpecification = "NS012";
+        public static readonly string ReEntrantSubstituteCall = "NS013";
     }
 }

src/NSubstitute.Analyzers.Shared/IDiagnosticDescriptorsProvider.cs

@@ -29,5 +29,7 @@ internal interface IDiagnosticDescriptorsProvider
         DiagnosticDescriptor NonVirtualReceivedSetupSpecification { get; }
 
         DiagnosticDescriptor NonVirtualWhenSetupSpecification { get; }
+
+        DiagnosticDescriptor ReEntrantSubstituteCall { get; }
     }
 }

src/NSubstitute.Analyzers.Shared/MetadataNames.cs

@@ -4,9 +4,11 @@ internal class MetadataNames
     {
         public const string NSubstituteAssemblyName = "NSubstitute";
         public const string NSubstituteSubstituteExtensionsFullTypeName = "NSubstitute.SubstituteExtensions";
+        public const string NSubstituteCoreFullTypeName = "NSubstitute.Core.CallInfo";
         public const string NSubstituteSubstituteFullTypeName = "NSubstitute.Substitute";
         public const string NSubstituteReturnsMethod = "Returns";
         public const string NSubstituteReturnsForAnyArgsMethod = "ReturnsForAnyArgs";
+        public const string NSubstituteDoMethod = "Do";
         public const string NSubstituteReceivedMethod = "Received";
         public const string NSubstituteReceivedWithAnyArgsMethod = "ReceivedWithAnyArgs";
         public const string NSubstituteDidNotReceiveMethod = "DidNotReceive";
@@ -17,5 +19,6 @@ internal class MetadataNames
         public const string CastleDynamicProxyGenAssembly2Name = "DynamicProxyGenAssembly2";
         public const string NSubstituteWhenMethod = "When";
         public const string NSubstituteWhenForAnyArgsMethod = "WhenForAnyArgs";
+        public const string NSubstituteWhenCalledType = "WhenCalled";
     }
 }