public static ContainsContinueStatementWalker GetInstance()
{
ContainsContinueStatementWalker walker = _cachedInstance;
if (walker != null)
{
_cachedInstance = null;
return(walker);
}
return(new ContainsContinueStatementWalker());
}
private static void AnalyzeWhileStatement(SyntaxNodeAnalysisContext context)
{
var whileStatement = (WhileStatementSyntax)context.Node;
ExpressionSyntax condition = whileStatement.Condition;
if (condition.IsMissing)
{
return;
}
if (!condition.IsSingleLine())
{
return;
}
StatementSyntax statement = whileStatement.Statement;
if (!(statement is BlockSyntax block))
{
return;
}
SyntaxList <StatementSyntax> innerStatements = block.Statements;
if (innerStatements.Count <= 1)
{
return;
}
ExpressionSyntax incrementedExpression = GetIncrementedExpression(innerStatements.Last());
if (!incrementedExpression.IsKind(SyntaxKind.IdentifierName))
{
return;
}
SyntaxList <StatementSyntax> outerStatements = SyntaxInfo.StatementListInfo(whileStatement).Statements;
int index = outerStatements.IndexOf(whileStatement);
if (index <= 0)
{
return;
}
SingleLocalDeclarationStatementInfo localInfo = GetLocalInfo(outerStatements[index - 1]);
if (!localInfo.Success)
{
return;
}
if (index > 1)
{
SingleLocalDeclarationStatementInfo localInfo2 = GetLocalInfo(outerStatements[index - 2]);
if (localInfo2.Success)
{
ExpressionSyntax incrementedExpression2 = GetIncrementedExpression(innerStatements[innerStatements.Count - 2]);
if (incrementedExpression2 is IdentifierNameSyntax identifierName2 &&
string.Equals(localInfo2.Identifier.ValueText, identifierName2.Identifier.ValueText, StringComparison.Ordinal))
{
return;
}
}
}
var identifierName = (IdentifierNameSyntax)incrementedExpression;
if (!string.Equals(localInfo.Identifier.ValueText, identifierName.Identifier.ValueText, StringComparison.Ordinal))
{
return;
}
if (ContainsContinueStatement())
{
return;
}
SemanticModel semanticModel = context.SemanticModel;
CancellationToken cancellationToken = context.CancellationToken;
ISymbol symbol = semanticModel.GetDeclaredSymbol(localInfo.Declarator, cancellationToken);
if (symbol?.Kind != SymbolKind.Local)
{
return;
}
if (IsLocalVariableReferencedAfterWhileStatement())
{
return;
}
DiagnosticHelpers.ReportDiagnostic(context, DiagnosticDescriptors.UseForStatementInsteadOfWhileStatement, whileStatement.WhileKeyword);
bool ContainsContinueStatement()
{
ContainsContinueStatementWalker walker = ContainsContinueStatementWalker.GetInstance();
walker.ContainsContinueStatement = false;
bool containsContinueStatement = false;
foreach (StatementSyntax innerStatement in innerStatements)
{
walker.Visit(innerStatement);
if (walker.ContainsContinueStatement)
{
containsContinueStatement = true;
break;
}
}
ContainsContinueStatementWalker.Free(walker);
return(containsContinueStatement);
}
bool IsLocalVariableReferencedAfterWhileStatement()
{
ContainsLocalOrParameterReferenceWalker walker = ContainsLocalOrParameterReferenceWalker.GetInstance(symbol, semanticModel, cancellationToken);
walker.VisitList(outerStatements, index + 1);
return(ContainsLocalOrParameterReferenceWalker.GetResultAndFree(walker));
}
}
public static void Free(ContainsContinueStatementWalker walker)
{
_cachedInstance = walker;
}