private static void OnCompilationStart(CompilationStartAnalysisContext context)
{
if (!RequiredSymbols.TryGetSymbols(context.Compilation, out var symbols))
{
return;
}
context.RegisterOperationAction(AnalyzeOperation, OperationKind.Binary);
return;
// Local functions
void AnalyzeOperation(OperationAnalysisContext context)
{
var operation = (IBinaryOperation)context.Operation;
foreach (var selector in CaseSelectors)
{
if (selector(operation, symbols))
{
context.ReportDiagnostic(operation.CreateDiagnostic(Rule));
return;
}
}
}
}
private static void OnCompilationStart(CompilationStartAnalysisContext context)
{
if (!RequiredSymbols.TryGetSymbols(context.Compilation, out RequiredSymbols symbols))
{
return;
}
context.RegisterOperationBlockStartAction(OnOperationBlockStart);
return;
// Local functions
void OnOperationBlockStart(OperationBlockStartAnalysisContext context)
{
var invocations = PooledConcurrentSet <IInvocationOperation> .GetInstance();
context.RegisterOperationAction(context =>
{
var argument = (IArgumentOperation)context.Operation;
if (symbols.IsAnySubstringInvocation(argument.Value.WalkDownConversion(c => c.IsImplicit)) && argument.Parent is IInvocationOperation invocation)
{
invocations.Add(invocation);
}
}, OperationKind.Argument);
context.RegisterOperationBlockEndAction(context =>
{
foreach (var invocation in invocations)
{
// We search for an overload of the invoked member whose signature matches the signature of
// the invoked member, except with ReadOnlySpan<char> substituted in for some of the
// arguments that are Substring invocations.
if (!GetBestSpanBasedOverloads(symbols, invocation, context.CancellationToken).IsEmpty)
{
Diagnostic diagnostic = invocation.CreateDiagnostic(Rule);
context.ReportDiagnostic(diagnostic);
}
}
invocations.Free(context.CancellationToken);
});
}
}
private static void OnCompilationStart(CompilationStartAnalysisContext context)
{
if (!RequiredSymbols.TryGetSymbols(context.Compilation, out var symbols))
{
return;
}
context.RegisterOperationAction(AnalyzeOperation, OperationKind.Conditional);
return;
void AnalyzeOperation(OperationAnalysisContext context)
{
var conditional = (IConditionalOperation)context.Operation;
if (symbols.IsSimpleAffirmativeCheck(conditional, out _) || symbols.IsNegatedCheckWithThrowingElseClause(conditional, out _))
{
context.ReportDiagnostic(conditional.CreateDiagnostic(Rule));
}
}
}
private void OnCompilationStart(CompilationStartAnalysisContext context)
{
if (!RequiredSymbols.TryGetSymbols(context.Compilation, out RequiredSymbols symbols))
{
return;
}
context.RegisterOperationBlockStartAction(OnOperationBlockStart);
return;
// Local functions
void OnOperationBlockStart(OperationBlockStartAnalysisContext context)
{
// Maintain set of all top-most concat operations so we don't report sub-expressions of an
// already-reported violation.
// We also don't report any diagnostic if the concat operation has too many operands for the span-based
// Concat overloads to handle.
var topMostConcatOperations = PooledConcurrentSet <IBinaryOperation> .GetInstance();
context.RegisterOperationAction(PopulateTopMostConcatOperations, OperationKind.Binary);
context.RegisterOperationBlockEndAction(ReportDiagnosticsOnRootConcatOperationsWithSubstringCalls);
void PopulateTopMostConcatOperations(OperationAnalysisContext context)
{
// If the current operation is a string-concatenation operation, walk up to the top-most concat
// operation and add it to the set.
var binary = (IBinaryOperation)context.Operation;
if (!TryGetTopMostConcatOperation(binary, out var topMostConcatOperation))
{
return;
}
topMostConcatOperations.Add(topMostConcatOperation);
}
void ReportDiagnosticsOnRootConcatOperationsWithSubstringCalls(OperationBlockAnalysisContext context)
{
// We report diagnostics for all top-most concat operations that contain
// direct or conditional substring invocations when there is an applicable span-based overload of
// the string.Concat method.
// We don't report when the concatenation contains anything other than strings or character literals.
foreach (var operation in topMostConcatOperations)
{
if (ShouldBeReported(operation))
{
context.ReportDiagnostic(operation.CreateDiagnostic(Rule));
}
}
topMostConcatOperations.Free(context.CancellationToken);
}
}
bool ShouldBeReported(IBinaryOperation topMostConcatOperation)
{
var concatOperands = FlattenBinaryOperation(topMostConcatOperation);
// Bail if no suitable overload of 'string.Concat' exists.
if (!symbols.TryGetRoscharConcatMethodWithArity(concatOperands.Length, out _))
{
return(false);
}
bool anySubstringInvocations = false;
foreach (var operand in concatOperands)
{
var value = WalkDownBuiltInImplicitConversionOnConcatOperand(operand);
switch (value.Type?.SpecialType)
{
// Report diagnostics only when operands are exclusively strings and character literals.
case SpecialType.System_String:
case SpecialType.System_Char when value is ILiteralOperation:
if (IsAnyDirectOrConditionalSubstringInvocation(value))
{
anySubstringInvocations = true;
}
break;
default:
return(false);
}
}
return(anySubstringInvocations);
}
bool IsAnyDirectOrConditionalSubstringInvocation(IOperation operation)
{
if (operation is IConditionalAccessOperation conditionallAccessOperation)
{
operation = conditionallAccessOperation.WhenNotNull;
}
return(operation is IInvocationOperation invocation && symbols.IsAnySubstringMethod(invocation.TargetMethod));
}
}