internal static bool IsFixableRecursively(IfStatementSyntax ifStatement, SyntaxKind jumpKind)
        {
            if (!(ifStatement.Statement is BlockSyntax block))
            {
                return(false);
            }

            SyntaxList <StatementSyntax> statements = block.Statements;

            if (!statements.Any())
            {
                return(false);
            }

            StatementSyntax statement = statements.Last();

            if (statement is IfStatementSyntax ifStatement2)
            {
                return(IsFixable(ifStatement2));
            }

            return(jumpKind == GetJumpKind(statement) &&
                   (statements.LastButOneOrDefault() is IfStatementSyntax ifStatement3) &&
                   IsFixable(ifStatement3));
        }
        private static ReduceIfNestingAnalysisResult AnalyzeCore(
            IfStatementSyntax ifStatement,
            SemanticModel semanticModel,
            SyntaxKind jumpKind,
            ReduceIfNestingOptions options,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            StatementListInfo statementsInfo = SyntaxInfo.StatementListInfo(ifStatement);

            if (!statementsInfo.Success)
            {
                return(Fail(ifStatement));
            }

            SyntaxNode node       = statementsInfo.Parent;
            SyntaxNode parent     = node.Parent;
            SyntaxKind parentKind = parent.Kind();

            SyntaxList <StatementSyntax> statements = statementsInfo.Statements;

            if (statementsInfo.IsParentSwitchSection ||
                parentKind == SyntaxKind.SwitchSection)
            {
                SyntaxNode switchSection = (statementsInfo.IsParentSwitchSection) ? node : parent;

                if (!options.AllowSwitchSection())
                {
                    return(Fail(switchSection));
                }

                if (ifStatement != statements.LastButOneOrDefault())
                {
                    return(Fail(switchSection));
                }

                if (!IsFixableJumpStatement(statements.Last(), ref jumpKind))
                {
                    return(Fail(switchSection));
                }

                if (!options.AllowNestedFix() &&
                    IsNestedFix(switchSection.Parent, semanticModel, options, cancellationToken))
                {
                    return(Fail(switchSection));
                }

                return(Success(jumpKind, switchSection));
            }

            if (parentKind.Is(
                    SyntaxKind.ForStatement,
                    SyntaxKind.ForEachStatement,
                    SyntaxKind.DoStatement,
                    SyntaxKind.WhileStatement))
            {
                if (!options.AllowLoop())
                {
                    return(Fail(parent));
                }

                StatementSyntax lastStatement = statements.Last();

                if (ifStatement == lastStatement)
                {
                    jumpKind = SyntaxKind.ContinueStatement;
                }
                else
                {
                    if (ifStatement != statements.LastButOneOrDefault())
                    {
                        return(Fail(parent));
                    }

                    if (!IsFixableJumpStatement(lastStatement, ref jumpKind))
                    {
                        return(Fail(parent));
                    }
                }

                if (!options.AllowNestedFix() &&
                    IsNestedFix(parent.Parent, semanticModel, options, cancellationToken))
                {
                    return(Fail(parent));
                }

                return(Success(jumpKind, parent));
            }

            if (!IsFixable(ifStatement, statements, ref jumpKind))
            {
                return(Fail(node));
            }

            switch (parentKind)
            {
            case SyntaxKind.ConstructorDeclaration:
            case SyntaxKind.DestructorDeclaration:
            case SyntaxKind.SetAccessorDeclaration:
            case SyntaxKind.AddAccessorDeclaration:
            case SyntaxKind.RemoveAccessorDeclaration:
            {
                if (jumpKind == SyntaxKind.None)
                {
                    jumpKind = SyntaxKind.ReturnStatement;
                }
                else if (jumpKind != SyntaxKind.ReturnStatement)
                {
                    return(Fail(parent));
                }

                return(Success(jumpKind, parent));
            }

            case SyntaxKind.OperatorDeclaration:
            case SyntaxKind.ConversionOperatorDeclaration:
            case SyntaxKind.GetAccessorDeclaration:
            {
                if (jumpKind == SyntaxKind.None)
                {
                    return(Fail(parent));
                }

                return(Success(jumpKind, parent));
            }

            case SyntaxKind.MethodDeclaration:
            {
                var methodDeclaration = (MethodDeclarationSyntax)parent;

                if (jumpKind != SyntaxKind.None)
                {
                    return(Success(jumpKind, parent));
                }

                if (methodDeclaration.ReturnsVoid())
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (methodDeclaration.Modifiers.Contains(SyntaxKind.AsyncKeyword) &&
                    semanticModel
                    .GetDeclaredSymbol(methodDeclaration, cancellationToken)?
                    .ReturnType
                    .HasMetadataName(MetadataNames.System_Threading_Tasks_Task) == true)
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (semanticModel
                    .GetDeclaredSymbol(methodDeclaration, cancellationToken)?
                    .ReturnType
                    .OriginalDefinition
                    .IsIEnumerableOrIEnumerableOfT() == true &&
                    methodDeclaration.ContainsYield())
                {
                    return(Success(SyntaxKind.YieldBreakStatement, parent));
                }

                break;
            }

            case SyntaxKind.LocalFunctionStatement:
            {
                var localFunction = (LocalFunctionStatementSyntax)parent;

                if (jumpKind != SyntaxKind.None)
                {
                    return(Success(jumpKind, parent));
                }

                if (localFunction.ReturnsVoid())
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (localFunction.Modifiers.Contains(SyntaxKind.AsyncKeyword) &&
                    semanticModel.GetDeclaredSymbol(localFunction, cancellationToken)?
                    .ReturnType
                    .HasMetadataName(MetadataNames.System_Threading_Tasks_Task) == true)
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (semanticModel.GetDeclaredSymbol(localFunction, cancellationToken)?
                    .ReturnType
                    .OriginalDefinition
                    .IsIEnumerableOrIEnumerableOfT() == true &&
                    localFunction.ContainsYield())
                {
                    return(Success(SyntaxKind.YieldBreakStatement, parent));
                }

                break;
            }

            case SyntaxKind.AnonymousMethodExpression:
            case SyntaxKind.SimpleLambdaExpression:
            case SyntaxKind.ParenthesizedLambdaExpression:
            {
                var anonymousFunction = (AnonymousFunctionExpressionSyntax)parent;

                if (jumpKind != SyntaxKind.None)
                {
                    return(Success(jumpKind, parent));
                }

                if (!(semanticModel.GetSymbol(anonymousFunction, cancellationToken) is IMethodSymbol methodSymbol))
                {
                    return(Fail(parent));
                }

                if (methodSymbol.ReturnsVoid)
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (anonymousFunction.AsyncKeyword.Kind() == SyntaxKind.AsyncKeyword &&
                    methodSymbol.ReturnType.HasMetadataName(MetadataNames.System_Threading_Tasks_Task))
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                break;
            }

            case SyntaxKind.IfStatement:
            {
                ifStatement = (IfStatementSyntax)parent;

                if (ifStatement.Parent is ElseClauseSyntax elseClause)
                {
                    if (ifStatement.Else != null)
                    {
                        return(Fail(parent));
                    }

                    if (!options.AllowIfInsideIfElse())
                    {
                        return(Fail(parent));
                    }

                    return(AnalyzeCore(ifStatement.GetTopmostIf(), semanticModel, jumpKind, options, cancellationToken));
                }
                else
                {
                    if (!IsFixable(ifStatement))
                    {
                        return(Fail(parent));
                    }

                    if (!options.AllowNestedFix())
                    {
                        return(Fail(parent));
                    }

                    return(AnalyzeCore(ifStatement, semanticModel, jumpKind, options, cancellationToken));
                }
            }

            case SyntaxKind.ElseClause:
            {
                if (!options.AllowIfInsideIfElse())
                {
                    return(Fail(parent));
                }

                var elseClause = (ElseClauseSyntax)parent;

                return(AnalyzeCore(elseClause.GetTopmostIf(), semanticModel, jumpKind, options, cancellationToken));
            }
            }

            return(Fail(parent));
        }
Esempio n. 3
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        private static ReduceIfNestingAnalysis AnalyzeCore(
            IfStatementSyntax ifStatement,
            SemanticModel semanticModel,
            SyntaxKind jumpKind,
            ReduceIfNestingOptions options,
            INamedTypeSymbol taskSymbol         = null,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            if (!StatementContainer.TryCreate(ifStatement, out StatementContainer container))
            {
                return(Fail(ifStatement));
            }

            CSharpSyntaxNode node       = container.Node;
            SyntaxNode       parent     = node.Parent;
            SyntaxKind       parentKind = parent.Kind();

            SyntaxList <StatementSyntax> statements = container.Statements;

            if (container.IsSwitchSection ||
                parentKind == SyntaxKind.SwitchSection)
            {
                SyntaxNode switchSection = (container.IsSwitchSection) ? node : parent;

                if (!options.AllowSwitchSection())
                {
                    return(Fail(switchSection));
                }

                if (ifStatement != statements.LastButOneOrDefault())
                {
                    return(Fail(switchSection));
                }

                if (!IsFixableJumpStatement(statements.Last(), ref jumpKind))
                {
                    return(Fail(switchSection));
                }

                if (!options.AllowNestedFix() &&
                    IsNestedFix(switchSection.Parent, semanticModel, options, taskSymbol, cancellationToken))
                {
                    return(Fail(switchSection));
                }

                return(Success(jumpKind, switchSection));
            }

            if (parentKind.Is(
                    SyntaxKind.ForStatement,
                    SyntaxKind.ForEachStatement,
                    SyntaxKind.DoStatement,
                    SyntaxKind.WhileStatement))
            {
                if (!options.AllowLoop())
                {
                    return(Fail(parent));
                }

                StatementSyntax lastStatement = statements.Last();

                if (ifStatement == lastStatement)
                {
                    jumpKind = SyntaxKind.ContinueStatement;
                }
                else
                {
                    if (ifStatement != statements.LastButOneOrDefault())
                    {
                        return(Fail(parent));
                    }

                    if (!IsFixableJumpStatement(lastStatement, ref jumpKind))
                    {
                        return(Fail(parent));
                    }
                }

                if (!options.AllowNestedFix() &&
                    IsNestedFix(parent.Parent, semanticModel, options, taskSymbol, cancellationToken))
                {
                    return(Fail(parent));
                }

                return(Success(jumpKind, parent));
            }

            if (!IsFixable(ifStatement, statements, ref jumpKind))
            {
                return(Fail(node));
            }

            switch (parentKind)
            {
            case SyntaxKind.ConstructorDeclaration:
            case SyntaxKind.DestructorDeclaration:
            case SyntaxKind.SetAccessorDeclaration:
            case SyntaxKind.AddAccessorDeclaration:
            case SyntaxKind.RemoveAccessorDeclaration:
            {
                if (jumpKind == SyntaxKind.None)
                {
                    jumpKind = SyntaxKind.ReturnStatement;
                }
                else if (jumpKind != SyntaxKind.ReturnStatement)
                {
                    return(Fail(parent));
                }

                return(Success(jumpKind, parent));
            }

            case SyntaxKind.OperatorDeclaration:
            case SyntaxKind.ConversionOperatorDeclaration:
            case SyntaxKind.GetAccessorDeclaration:
            {
                if (jumpKind == SyntaxKind.None)
                {
                    return(Fail(parent));
                }

                return(Success(jumpKind, parent));
            }

            case SyntaxKind.MethodDeclaration:
            {
                var methodDeclaration = (MethodDeclarationSyntax)parent;

                if (jumpKind != SyntaxKind.None)
                {
                    return(Success(jumpKind, parent));
                }

                if (methodDeclaration.ReturnsVoid())
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (methodDeclaration.Modifiers.Contains(SyntaxKind.AsyncKeyword) &&
                    taskSymbol != null &&
                    semanticModel
                    .GetDeclaredSymbol(methodDeclaration, cancellationToken)?
                    .ReturnType
                    .Equals(taskSymbol) == true)
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (semanticModel
                    .GetDeclaredSymbol(methodDeclaration, cancellationToken)?
                    .ReturnType
                    .IsIEnumerableOrConstructedFromIEnumerableOfT() == true &&
                    methodDeclaration.ContainsYield())
                {
                    return(Success(SyntaxKind.YieldBreakStatement, parent));
                }

                break;
            }

            case SyntaxKind.LocalFunctionStatement:
            {
                var localFunction = (LocalFunctionStatementSyntax)parent;

                if (jumpKind != SyntaxKind.None)
                {
                    return(Success(jumpKind, parent));
                }

                if (localFunction.ReturnsVoid())
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (localFunction.Modifiers.Contains(SyntaxKind.AsyncKeyword) &&
                    taskSymbol != null &&
                    ((IMethodSymbol)semanticModel.GetDeclaredSymbol(localFunction, cancellationToken))?
                    .ReturnType
                    .Equals(taskSymbol) == true)
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (((IMethodSymbol)semanticModel.GetDeclaredSymbol(localFunction, cancellationToken))?
                    .ReturnType
                    .IsIEnumerableOrConstructedFromIEnumerableOfT() == true &&
                    localFunction.ContainsYield())
                {
                    return(Success(SyntaxKind.YieldBreakStatement, parent));
                }

                break;
            }

            case SyntaxKind.AnonymousMethodExpression:
            case SyntaxKind.SimpleLambdaExpression:
            case SyntaxKind.ParenthesizedLambdaExpression:
            {
                var anonymousFunction = (AnonymousFunctionExpressionSyntax)parent;

                if (jumpKind != SyntaxKind.None)
                {
                    return(Success(jumpKind, parent));
                }

                var methodSymbol = semanticModel.GetSymbol(anonymousFunction, cancellationToken) as IMethodSymbol;

                if (methodSymbol == null)
                {
                    return(Fail(parent));
                }

                if (methodSymbol.ReturnsVoid)
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                if (anonymousFunction.AsyncKeyword.IsKind(SyntaxKind.AsyncKeyword) &&
                    methodSymbol.ReturnType.Equals(taskSymbol))
                {
                    return(Success(SyntaxKind.ReturnStatement, parent));
                }

                break;
            }

            case SyntaxKind.IfStatement:
            {
                ifStatement = (IfStatementSyntax)parent;

                if (ifStatement.Parent is ElseClauseSyntax elseClause)
                {
                    if (ifStatement.Else != null)
                    {
                        return(Fail(parent));
                    }

                    if (!options.AllowIfInsideIfElse())
                    {
                        return(Fail(parent));
                    }

                    return(AnalyzeCore(ifStatement.GetTopmostIf(), semanticModel, jumpKind, options, taskSymbol, cancellationToken));
                }
                else
                {
                    if (!IsFixable(ifStatement))
                    {
                        return(Fail(parent));
                    }

                    if (!options.AllowNestedFix())
                    {
                        return(Fail(parent));
                    }

                    return(AnalyzeCore(ifStatement, semanticModel, jumpKind, options, taskSymbol, cancellationToken));
                }
            }

            case SyntaxKind.ElseClause:
            {
                if (!options.AllowIfInsideIfElse())
                {
                    return(Fail(parent));
                }

                var elseClause = (ElseClauseSyntax)parent;

                return(AnalyzeCore(elseClause.GetTopmostIf(), semanticModel, jumpKind, options, taskSymbol, cancellationToken));
            }
            }

            return(Fail(parent));
        }