S3236 — Caller information arguments should not be provided explicitly

Why is this an issue?

Caller information attributes: CallerFilePathAttribute, CallerLineNumberAttribute, and CallerArgumentExpressionAttribute provide a way to get information about the caller of a method through optional parameters. But the arguments for these optional parameters are only generated if they are not explicitly defined in the call. Thus, specifying the argument values defeats the purpose of the attributes.

Noncompliant code example

void TraceMessage(string message,
  [CallerFilePath] string filePath = null,
  [CallerLineNumber] int lineNumber = 0)
{
  /* ... */
}

void MyMethod()
{
  TraceMessage("my message", "A.B.C.Foo.cs", 42); // Noncompliant
}

Compliant solution

void TraceMessage(string message,
  [CallerFilePath] string filePath = "",
  [CallerLineNumber] int lineNumber = 0)
{
  /* ... */
}

void MyMethod()
{
  TraceMessage("my message");
}

Exceptions

• CallerMemberName is not checked to avoid False-Positives with WPF/UWP applications.
• System.Diagnostics.Debug.Assert is excluded as a custom message from the developer is sometimes preferred as an explanation of the failed assertion.