public void ExplodedGraph_BothBranchesVisited_NonCondition() { string testInput = "var str = this?.ToString();"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var countConditionEvaluated = 0; explodedGraph.ConditionEvaluated += (sender, args) => { countConditionEvaluated++; }; var visitedBlocks = new HashSet <Block>(); explodedGraph.InstructionProcessed += (sender, args) => { visitedBlocks.Add(args.ProgramPoint.Block); }; explodedGraph.Walk(); Assert.IsTrue(explorationEnded); Assert.AreEqual(cfg.Blocks.Count() - 1 /* Exit block */, visitedBlocks.Count); Assert.AreEqual(0, countConditionEvaluated); }
public void ExplodedGraph_LoopExploration() { string testInput = "var i = 0; while (i < 1) { i = i + 1; }"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var exceeded = 0; explodedGraph.ProgramPointVisitCountExceedLimit += (sender, args) => { exceeded++; args.ProgramPoint.Block.Instructions.Where(i => i.ToString() == "i < 1").Should().NotBeEmpty(); }; explodedGraph.Walk(); Assert.IsTrue(explorationEnded); Assert.AreEqual(1, exceeded); }
public void ExplodedGraph_SequentialInput_Max() { var inputBuilder = new StringBuilder(); for (int i = 0; i < ExplodedGraph.MaxStepCount / 2 + 1; i++) { inputBuilder.AppendLine($"var x{i} = true;"); } string testInput = inputBuilder.ToString(); SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var maxStepCountReached = false; explodedGraph.MaxStepCountReached += (sender, args) => { maxStepCountReached = true; }; var numberOfExitBlockReached = 0; explodedGraph.ExitBlockReached += (sender, args) => { numberOfExitBlockReached++; }; explodedGraph.Walk(); Assert.IsFalse(explorationEnded); Assert.IsTrue(maxStepCountReached); Assert.AreEqual(0, numberOfExitBlockReached); }
public void ExplodedGraph_SingleBranchVisited_If() { string testInput = "var a = false; bool b; if (a) { b = true; } else { b = false; } a = b;"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var varDeclarators = method.DescendantNodes().OfType <VariableDeclaratorSyntax>(); var aSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "a")); var bSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "b")); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var numberOfExitBlockReached = 0; explodedGraph.ExitBlockReached += (sender, args) => { numberOfExitBlockReached++; }; var numberOfLastInstructionVisits = 0; var numberOfProcessedInstructions = 0; explodedGraph.InstructionProcessed += (sender, args) => { numberOfProcessedInstructions++; if (args.Instruction.ToString() == "a = false") { Assert.IsTrue(args.ProgramState.GetSymbolValue(aSymbol) == SymbolicValue.False); } if (args.Instruction.ToString() == "b = true") { Assert.Fail("We should never get into this branch"); } if (args.Instruction.ToString() == "b = false") { Assert.IsTrue(args.ProgramState.GetSymbolValue(bSymbol) == SymbolicValue.False); Assert.IsNull(args.ProgramState.GetSymbolValue(aSymbol), "a is dead, so there should be no associated value to it."); } if (args.Instruction.ToString() == "a = b") { numberOfLastInstructionVisits++; } }; explodedGraph.Walk(); Assert.IsTrue(explorationEnded); Assert.AreEqual(10, numberOfProcessedInstructions); Assert.AreEqual(1, numberOfExitBlockReached); Assert.AreEqual(1, numberOfLastInstructionVisits); }
public void ExplodedGraph_SequentialInput() { string testInput = "var a = true; var b = false; b = !b; a = (b);"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var varDeclarators = method.DescendantNodes().OfType <VariableDeclaratorSyntax>(); var aSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "a")); var bSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "b")); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var numberOfExitBlockReached = 0; explodedGraph.ExitBlockReached += (sender, args) => { numberOfExitBlockReached++; }; var numberOfProcessedInstructions = 0; explodedGraph.InstructionProcessed += (sender, args) => { numberOfProcessedInstructions++; if (args.Instruction.ToString() == "a = true") { Assert.IsTrue(args.ProgramState.GetSymbolValue(aSymbol) == SymbolicValue.True); } if (args.Instruction.ToString() == "b = false") { Assert.IsTrue(args.ProgramState.GetSymbolValue(bSymbol) == SymbolicValue.False); } if (args.Instruction.ToString() == "b = !b") { Assert.IsFalse(args.ProgramState.GetSymbolValue(bSymbol) == SymbolicValue.False); Assert.IsFalse(args.ProgramState.GetSymbolValue(bSymbol) == SymbolicValue.True); } if (args.Instruction.ToString() == "a = (b)") { Assert.AreEqual( args.ProgramState.GetSymbolValue(bSymbol), args.ProgramState.GetSymbolValue(aSymbol)); } }; explodedGraph.Walk(); Assert.IsTrue(explorationEnded); Assert.AreEqual(11, numberOfProcessedInstructions); Assert.AreEqual(1, numberOfExitBlockReached); }
private static void CheckForDeadStores(CSharpSyntaxNode node, ISymbol declaration, SyntaxNodeAnalysisContext context) { IControlFlowGraph cfg; if (!ControlFlowGraph.TryGet(node, context.SemanticModel, out cfg)) { return; } var lva = LiveVariableAnalysis.Analyze(cfg, declaration, context.SemanticModel); foreach (var block in cfg.Blocks) { CheckCfgBlockForDeadStores(block, lva.GetLiveOut(block), lva.CapturedVariables, node, declaration, context); } }
public void ExplodedGraph_AllBranchesVisited() { string testInput = "int i = 1; switch (i) { case 1: default: cw1(); break; case 2: cw2(); break; }"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var numberOfExitBlockReached = 0; explodedGraph.ExitBlockReached += (sender, args) => { numberOfExitBlockReached++; }; var numberOfCw1InstructionVisits = 0; var numberOfCw2InstructionVisits = 0; var numberOfProcessedInstructions = 0; explodedGraph.InstructionProcessed += (sender, args) => { numberOfProcessedInstructions++; if (args.Instruction.ToString() == "cw1()") { numberOfCw1InstructionVisits++; } if (args.Instruction.ToString() == "cw2()") { numberOfCw2InstructionVisits++; } }; explodedGraph.Walk(); Assert.IsTrue(explorationEnded); Assert.AreEqual(1, numberOfExitBlockReached); Assert.AreEqual(1, numberOfCw1InstructionVisits); Assert.AreEqual(1, numberOfCw2InstructionVisits); }
public void ExplodedGraph_SingleBranchVisited_And() { string testInput = "var a = false; if (a && !a) { a = true; }"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var varDeclarators = method.DescendantNodes().OfType <VariableDeclaratorSyntax>(); var aSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "a")); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var numberOfExitBlockReached = 0; explodedGraph.ExitBlockReached += (sender, args) => { numberOfExitBlockReached++; }; var numberOfProcessedInstructions = 0; explodedGraph.InstructionProcessed += (sender, args) => { numberOfProcessedInstructions++; if (args.Instruction.ToString() == "a = !true") { Assert.IsTrue(args.ProgramState.GetSymbolValue(aSymbol) == SymbolicValue.False); // Roslyn is clever !true has const value. } if (args.Instruction.ToString() == "!a") { Assert.Fail("We should never get into this branch"); } }; explodedGraph.Walk(); Assert.IsTrue(explorationEnded); Assert.AreEqual(1, numberOfExitBlockReached); }
public void ExplodedGraph_NonLocalSymbolBranching() { string testInput = "if (field) { cw(); }"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var fieldSymbol = semanticModel.GetSymbolInfo( method.DescendantNodes().OfType <IdentifierNameSyntax>().First(d => d.Identifier.ToString() == "field")).Symbol; Assert.IsNotNull(fieldSymbol); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var numberOfExitBlockReached = 0; explodedGraph.ExitBlockReached += (sender, args) => { numberOfExitBlockReached++; }; var numberOfProcessedInstructions = 0; explodedGraph.InstructionProcessed += (sender, args) => { numberOfProcessedInstructions++; if (args.Instruction.ToString() == "field") { Assert.IsNull(args.ProgramState.GetSymbolValue(fieldSymbol)); } }; explodedGraph.Walk(); Assert.IsTrue(explorationEnded); Assert.AreEqual(1, numberOfExitBlockReached); }
private static void ReportOnDeadParametersAtEntry(BaseMethodDeclarationSyntax declaration, IMethodSymbol methodSymbol, IImmutableList <IParameterSymbol> noReportOnParameters, SyntaxNodeAnalysisContext context) { if (!declaration.IsKind(SyntaxKind.MethodDeclaration) || declaration.Body == null) { return; } var excludedParameters = noReportOnParameters; if (methodSymbol.IsExtensionMethod) { excludedParameters = excludedParameters.Add(methodSymbol.Parameters.First()); } excludedParameters = excludedParameters.AddRange(methodSymbol.Parameters.Where(p => p.RefKind != RefKind.None)); var candidateParameters = methodSymbol.Parameters.Except(excludedParameters); if (!candidateParameters.Any()) { return; } IControlFlowGraph cfg; if (!ControlFlowGraph.TryGet(declaration.Body, context.SemanticModel, out cfg)) { return; } var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, context.SemanticModel); var liveParameters = lva.GetLiveIn(cfg.EntryBlock).OfType <IParameterSymbol>(); ReportOnUnusedParameters(declaration, candidateParameters.Except(liveParameters).Except(lva.CapturedVariables), MessageDead, context, isRemovable: false); }
public void ExplodedGraph_NonDecisionMakingAssignments() { string testInput = "var a = true; a |= false; var b = 42; b++; ++b;"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var varDeclarators = method.DescendantNodes().OfType <VariableDeclaratorSyntax>(); var aSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "a")); var bSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "b")); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); SymbolicValue sv = null; var numberOfProcessedInstructions = 0; var branchesVisited = 0; explodedGraph.InstructionProcessed += (sender, args) => { numberOfProcessedInstructions++; if (args.Instruction.ToString() == "a = true") { branchesVisited++; Assert.IsTrue(args.ProgramState.GetSymbolValue(aSymbol) == SymbolicValue.True); } if (args.Instruction.ToString() == "a |= false") { branchesVisited++; Assert.IsNotNull(args.ProgramState.GetSymbolValue(aSymbol)); Assert.IsFalse(args.ProgramState.GetSymbolValue(aSymbol) == SymbolicValue.False); Assert.IsFalse(args.ProgramState.GetSymbolValue(aSymbol) == SymbolicValue.True); } if (args.Instruction.ToString() == "b = 42") { branchesVisited++; sv = args.ProgramState.GetSymbolValue(bSymbol); Assert.IsNotNull(sv); } if (args.Instruction.ToString() == "b++") { branchesVisited++; var svNew = args.ProgramState.GetSymbolValue(bSymbol); Assert.IsNotNull(svNew); Assert.AreNotEqual(sv, svNew); } if (args.Instruction.ToString() == "++b") { branchesVisited++; var svNew = args.ProgramState.GetSymbolValue(bSymbol); Assert.IsNotNull(svNew); Assert.AreNotEqual(sv, svNew); } }; explodedGraph.Walk(); Assert.AreEqual(11, numberOfProcessedInstructions); Assert.AreEqual(5, branchesVisited); }
public void ExplodedGraph_BothBranchesVisited() { string testInput = "var a = false; bool b; if (inParameter) { b = inParameter; } else { b = !inParameter; } a = b;"; SemanticModel semanticModel; var method = ControlFlowGraphTest.Compile(string.Format(TestInput, testInput), "Bar", out semanticModel); var methodSymbol = semanticModel.GetDeclaredSymbol(method); var varDeclarators = method.DescendantNodes().OfType <VariableDeclaratorSyntax>(); var aSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "a")); var bSymbol = semanticModel.GetDeclaredSymbol(varDeclarators.First(d => d.Identifier.ToString() == "b")); var parameters = method.DescendantNodes().OfType <ParameterSyntax>(); var inParameterSymbol = semanticModel.GetDeclaredSymbol(parameters.First(d => d.Identifier.ToString() == "inParameter")); var cfg = ControlFlowGraph.Create(method.Body, semanticModel); var lva = LiveVariableAnalysis.Analyze(cfg, methodSymbol, semanticModel); var explodedGraph = new ExplodedGraph(cfg, methodSymbol, semanticModel, lva); var explorationEnded = false; explodedGraph.ExplorationEnded += (sender, args) => { explorationEnded = true; }; var numberOfExitBlockReached = 0; explodedGraph.ExitBlockReached += (sender, args) => { numberOfExitBlockReached++; }; var numberOfLastInstructionVisits = 0; var numberOfProcessedInstructions = 0; var visitedBlocks = new HashSet <Block>(); var branchesVisited = 0; explodedGraph.InstructionProcessed += (sender, args) => { visitedBlocks.Add(args.ProgramPoint.Block); numberOfProcessedInstructions++; if (args.Instruction.ToString() == "a = false") { branchesVisited++; Assert.IsTrue(args.ProgramState.GetSymbolValue(aSymbol) == SymbolicValue.False); // Roslyn is clever !true has const value. } if (args.Instruction.ToString() == "b = inParameter") { branchesVisited++; Assert.IsTrue(bSymbol.HasConstraint(BoolConstraint.True, args.ProgramState)); Assert.IsTrue(inParameterSymbol.HasConstraint(BoolConstraint.True, args.ProgramState)); } if (args.Instruction.ToString() == "b = !inParameter") { branchesVisited++; // b has value, but not true or false Assert.IsNotNull(args.ProgramState.GetSymbolValue(bSymbol)); Assert.IsFalse(bSymbol.HasConstraint(BoolConstraint.False, args.ProgramState)); Assert.IsFalse(bSymbol.HasConstraint(BoolConstraint.True, args.ProgramState)); Assert.IsTrue(inParameterSymbol.HasConstraint(BoolConstraint.False, args.ProgramState)); } if (args.Instruction.ToString() == "a = b") { branchesVisited++; Assert.IsNull(args.ProgramState.GetSymbolValue(inParameterSymbol)); // not out/ref parameter and LVA says dead numberOfLastInstructionVisits++; } }; explodedGraph.Walk(); Assert.IsTrue(explorationEnded); Assert.AreEqual(4 + 1, branchesVisited); Assert.AreEqual(1, numberOfExitBlockReached, "All variables are dead at the ExitBlock, so whenever we get there, the ExplodedGraph nodes should be the same, " + "and thus should be processed only once."); Assert.AreEqual(2, numberOfLastInstructionVisits); Assert.AreEqual(cfg.Blocks.Count() - 1 /* Exit block */, visitedBlocks.Count); }