Examples of errors detected by the V3137 diagnostic

V3137. The variable is assigned but is not used by the end of the function.

Roslyn Analyzers

V3137 The 'sourceOrigins' variable is assigned but is not used by the end of the function. TaintedDataAnalysis.TaintedDataOperationVisitor.cs 328

public override TaintedDataAbstractValue VisitArrayInitializer(
  IArrayInitializerOperation operation,
  object argument)
{
  HashSet<SymbolAccess> sourceOrigins = null;
  ....
  if (baseAbstractValue.Kind == TaintedDataAbstractValueKind.Tainted)
  {
     sourceOrigins = new HashSet<SymbolAccess>(....);
  }
  ....
}

Azure PowerShell

V3137 The 'apiVersionSetId' variable is assigned but is not used by the end of the function. GetAzureApiManagementApiVersionSet.cs 69

public String ApiVersionSetId { get; set; }
....
public override void ExecuteApiManagementCmdlet()
{
  ....
  string apiVersionSetId;

  if (ParameterSetName.Equals(ContextParameterSet))
  {
    ....
    apiVersionSetId = ApiVersionSetId;
  }
  else
  {
    apiVersionSetId = ....;
  }

  if (string.IsNullOrEmpty(ApiVersionSetId))  // <=
  {
    WriteObject(....);
  }
  else
  {
    WriteObject(Client.GetApiVersionSet(...., ApiVersionSetId))  // <=
  }
}

Similar errors can be found in some other places:

• V3137 The 'cacheId' variable is assigned but is not used by the end of the function. RemoveAzureApiManagementCache.cs 94

Telerik UI for UWP

V3137 The 'leftMargin' variable is assigned but is not used by the end of the function. DragDrop.cs 87

internal static void StartDrag(....)
{
  ....
  if (frameworkElementSource != null)
  {
    leftMargin = frameworkElementSource.Margin.Left;    // <=
    topMargin = frameworkElementSource.Margin.Top;      // <=
  }
  if (dragDropElement == null ||
     !dragDropElement.CanStartDrag(trigger, initializeContext))
  {
    return;
  }

  var context = dragDropElement
               .DragStarting(trigger, initializeContext);

  if (context == null)
  {
    return;
  }

  var startDragPosition = e.GetCurrentPoint(context.DragSurface.RootElement)
                           .Position;
  var relativeStartDragPosition = e.GetCurrentPoint(uiDragDropElement)
                                   .Position;
  var dragPositionMode = DragDrop.GetDragPositionMode(uiDragDropElement);

  AddOperation(new DragDropOperation(context,
                                     dragDropElement,
                                     dragPositionMode,
                                     e.Pointer,
                                     startDragPosition,
                                     relativeStartDragPosition));
}

Similar errors can be found in some other places:

• V3137 The 'topMargin' variable is assigned but is not used by the end of the function. DragDrop.cs 88
• V3137 The 'currentColumnLength' variable is assigned but is not used by the end of the function. WrapLayout.cs 824

LINQ to DB

V3137 The 'version' variable is assigned but is not used by the end of the function. Query.cs 408

public void TryAdd(IDataContext dataContext, Query<T> query, QueryFlags flags)
{
  QueryCacheEntry[] cache;
  int version;
  lock (_syncCache)
  {
    cache   = _cache;
    version = _version;
  }
  ....
  lock(_syncCash)
  {
    ....
    var versionsDiff = _version - version;
    ....
    _cache   = newCache;
    _indexes = newPriorities;
    version  = _version;
  }
}

Similar errors can be found in some other places:

• V3137 The 'leftContext' variable is assigned but is not used by the end of the function. ExpressionBuilder.SqlBuilder.cs 1989

Umbraco

V3137 The 'username' variable is assigned but is not used by the end of the function. MemberManager.cs 87

public async Task<bool> IsMemberAuthorizedAsync(....)
{
  ....
  if (IsLoggedIn() == false)
  {
    allowAction = false;
  }
  else
  {
    string username;
    ....
    username = currentMember.UserName;
    IList<string> allowTypesList = allowTypes as IList<string> ??
                                              allowTypes.ToList();
    if (allowTypesList.Any(allowType => allowType != string.Empty))
    {
      allowAction = allowTypesList.Select(x => x.ToLowerInvariant())
                                                .Contains(currentMember
                                                .MemberTypeAlias
                                                .ToLowerInvariant());
    }

    if (allowAction && allowMembers.Any())
    {
      allowAction = allowMembers.Contains(memberId);
    }
    ....
  }
  return allowAction;
}

MonoGame

V3137 The 'relativeVelocity' variable is assigned but is not used by the end of the function. MonoGame.Framework.DesktopGL(netstandard2.0) Cue.cs 266

public void Apply3D(AudioListener listener, AudioEmitter emitter)

{
  ....
  lock (_engine.UpdateLock)
  {
    ....
    // Calculate doppler effect.
    var relativeVelocity = emitter.Velocity - listener.Velocity;
    relativeVelocity *= emitter.DopplerScale;
  }
}

MonoGame

V3137 The 'len' variable is assigned but is not used by the end of the function. MonoGame.Framework.DesktopGL(netstandard2.0) ConstantBuffer.cs 91

private void SetData(int offset, int rows, int columns, object data)
{
  ....
  if(....)
  {
    ....
  }
  else if (rows == 1 || (rows == 4 && columns == 4))
  {
    // take care of shader compiler optimization
    int len = rows * columns * elementSize;
    if (_buffer.Length - offset > len)
      len = _buffer.Length - offset;    //  <=
    Buffer.BlockCopy(data as Array,
                     0,
                     _buffer,
                     offset,
                     rows*columns*elementSize);
  }
  ....
}

Unity C# reference source code

V3137 The 'maxDist' variable is assigned but is not used by the end of the function. TreeAOImporter.cs 142

static int CountIntersections(....)
{
  ....
  int hitLength = s_RayCastHits.Length;
  float maxDist = 0;
  if (hitLength > 0)
    maxDist = s_RayCastHits[s_RayCastHits.Length - 1].distance;

  physicsScene.Raycast(....);
  if (s_RayCastHits.Length > 0)
  {
    float len = length - s_RayCastHits[0].distance;
    if (len > maxDist)
    {
      maxDist = len;                                 // <=
    }
  }

  return hitLength + s_RayCastHits.Length;
}

AWS SDK for .NET

V3137 The 'platform' variable is assigned but is not used by the end of the function. InternalSDKUtils.netstandard.cs 70

private static string GetXamarinInformation()
{
  var xamarinDevice = Type.GetType("Xamarin.Forms.Device, Xamarin.Forms.Core");
  if (xamarinDevice == null)
  {
    return null;
  }

  var runtime = xamarinDevice.GetProperty("RuntimePlatform")
                            ?.GetValue(null)
                            ?.ToString() ?? "";

  var idiom = xamarinDevice.GetProperty("Idiom")
                          ?.GetValue(null)
                          ?.ToString() ?? "";

  var platform = runtime + idiom;                    // <=

  if (string.IsNullOrEmpty(platform))
  {
    platform = UnknownPlatform;
  }

  return string.Format(CultureInfo.InvariantCulture,
                       "Xamarin_{0}",
                       "Xamarin");                   // <=
}

Power-Fx

V3137 [CWE-563] The 'fullType' variable is assigned but is not used by the end of the function. DType.cs 1350

public DType Add(DName name, DType type)
{
    AssertValid();
    Contracts.Assert(IsAggregate);
    Contracts.Assert(name.IsValid);
    type.AssertValid();

    var fullType = this;
    if (IsLazyType)
    {
        fullType = LazyTypeProvider.GetExpandedType(IsTable);
    }

    Contracts.Assert(!TypeTree.Contains(name));
    var tree = TypeTree.SetItem(name, type);
    var newType = new DType(Kind, tree, AssociatedDataSources,
                                        DisplayNameProvider);

    return newType;
}