public static UnnecessaryUsageOfEnumeratorWalker GetInstance()
{
UnnecessaryUsageOfEnumeratorWalker walker = _cachedInstance;
if (walker != null)
{
_cachedInstance = null;
return(walker);
}
return(new UnnecessaryUsageOfEnumeratorWalker());
}
public static UnnecessaryUsageOfEnumeratorWalker GetInstance()
{
UnnecessaryUsageOfEnumeratorWalker walker = _cachedInstance;
if (walker != null)
{
Debug.Assert(walker._symbol == null);
Debug.Assert(walker._variableDeclarator == null);
Debug.Assert(walker._semanticModel == null);
Debug.Assert(walker._cancellationToken == default);
_cachedInstance = null;
return(walker);
}
return(new UnnecessaryUsageOfEnumeratorWalker());
}
public static void Free(UnnecessaryUsageOfEnumeratorWalker walker)
{
walker.SetValues(default(VariableDeclaratorSyntax), default(SemanticModel), default(CancellationToken));
_cachedInstance = walker;
}
private static void AnalyzeUsingStatement(SyntaxNodeAnalysisContext context)
{
var usingStatement = (UsingStatementSyntax)context.Node;
VariableDeclaratorSyntax declarator = usingStatement.Declaration?.Variables.SingleOrDefault(shouldThrow: false);
if (declarator == null)
{
return;
}
if (!(usingStatement.Statement?.SingleNonBlockStatementOrDefault() is WhileStatementSyntax whileStatement))
{
return;
}
SimpleMemberInvocationExpressionInfo invocationInfo = SyntaxInfo.SimpleMemberInvocationExpressionInfo(whileStatement.Condition);
if (!invocationInfo.Success)
{
return;
}
if (invocationInfo.Arguments.Any())
{
return;
}
if (!string.Equals(invocationInfo.NameText, WellKnownMemberNames.MoveNextMethodName, StringComparison.Ordinal))
{
return;
}
if (!string.Equals((invocationInfo.Expression as IdentifierNameSyntax)?.Identifier.ValueText, declarator.Identifier.ValueText, StringComparison.Ordinal))
{
return;
}
SimpleMemberInvocationExpressionInfo invocationInfo2 = SyntaxInfo.SimpleMemberInvocationExpressionInfo(declarator.Initializer.Value);
if (!invocationInfo2.Success)
{
return;
}
if (invocationInfo2.Arguments.Any())
{
return;
}
if (!string.Equals(invocationInfo2.NameText, WellKnownMemberNames.GetEnumeratorMethodName, StringComparison.Ordinal))
{
return;
}
UnnecessaryUsageOfEnumeratorWalker walker = UnnecessaryUsageOfEnumeratorWalker.GetInstance();
walker.SetValues(declarator, context.SemanticModel, context.CancellationToken);
walker.Visit(whileStatement.Statement);
bool?isFixable = walker.IsFixable;
UnnecessaryUsageOfEnumeratorWalker.Free(walker);
if (isFixable == true)
{
DiagnosticHelpers.ReportDiagnostic(context, DiagnosticDescriptors.UnnecessaryExplicitUseOfEnumerator, usingStatement.UsingKeyword);
}
}
public static void Free(UnnecessaryUsageOfEnumeratorWalker walker)
{
_cachedInstance = walker;
}
