public static ReduceIfNestingAnalysisResult Analyze(
IfStatementSyntax ifStatement,
SemanticModel semanticModel,
ReduceIfNestingOptions options,
CancellationToken cancellationToken = default(CancellationToken))
{
if (!IsFixable(ifStatement))
{
return(Fail(ifStatement));
}
return(AnalyzeCore(ifStatement, semanticModel, SyntaxKind.None, options, cancellationToken));
}
public static ReduceIfNestingAnalysis Analyze(
IfStatementSyntax ifStatement,
SemanticModel semanticModel,
ReduceIfNestingOptions options,
INamedTypeSymbol taskSymbol = null,
CancellationToken cancellationToken = default(CancellationToken))
{
if (!IsFixable(ifStatement))
{
return(Fail(ifStatement));
}
return(AnalyzeCore(ifStatement, semanticModel, SyntaxKind.None, options, taskSymbol, cancellationToken));
}
public static bool AllowNestedFix(this ReduceIfNestingOptions options)
{
return((options & ReduceIfNestingOptions.AllowNestedFix) != 0);
}
public static bool AllowIfInsideIfElse(this ReduceIfNestingOptions options)
{
return((options & ReduceIfNestingOptions.AllowIfInsideIfElse) != 0);
}
public static bool AllowSwitchSection(this ReduceIfNestingOptions options)
{
return((options & ReduceIfNestingOptions.AllowSwitchSection) != 0);
}
public static bool AllowLoop(this ReduceIfNestingOptions options)
{
return((options & ReduceIfNestingOptions.AllowLoop) != 0);
}
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));
}
private static bool IsNestedFix(SyntaxNode node, SemanticModel semanticModel, ReduceIfNestingOptions options, CancellationToken cancellationToken)
{
options |= ReduceIfNestingOptions.AllowNestedFix;
while (node != null)
{
if (node is IfStatementSyntax ifStatement)
{
ReduceIfNestingAnalysisResult analysis = Analyze(ifStatement, semanticModel, options, cancellationToken);
if (analysis.Success)
{
return(true);
}
node = analysis.TopNode;
}
if (node is MemberDeclarationSyntax)
{
return(false);
}
if (node is AccessorDeclarationSyntax)
{
return(false);
}
node = node.Parent;
}
Debug.Fail("");
return(false);
}
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));
}