misc: Tweak NullReferenceException fixes

src/Ryujinx.Common/Collections/IntervalTree.cs

@@ -327,17 +327,14 @@ namespace Ryujinx.Common.Collections
             {
                 Root = newNode;
             }
-            else if (parent != null && start.CompareTo(parent.Start) < 0)
+            else if (start.CompareTo(parent!.Start) < 0)
             {
                 parent.Left = newNode;
             }
             else
-            {
-                if (parent != null)
             {
                 parent.Right = newNode;
             }
-            }
 
             PropagateIncrease(newNode);
             Count++;

src/Ryujinx.Common/Collections/TreeDictionary.cs

@@ -278,17 +278,14 @@ namespace Ryujinx.Common.Collections
             {
                 Root = newNode;
             }
-            else if (parent != null && key.CompareTo(parent.Key) < 0)
+            else if (key.CompareTo(parent.Key) < 0)
             {
                 parent.Left = newNode;
             }
             else
-            {
-                if (parent != null)
             {
                 parent.Right = newNode;
             }
-            }
             Count++;
             return newNode;
         }

src/Ryujinx.Cpu/Jit/HostTracked/AddressSpacePartition.cs

@@ -388,12 +388,7 @@ namespace Ryujinx.Cpu.Jit.HostTracked
                 _treeLock.ExitReadLock();
             }
 
-            if (_firstPagePa != null)
+            return _firstPagePa != null ? (_backingMemory, _firstPagePa.Value) : (null, 0);
-            {
-                return (_backingMemory, _firstPagePa.Value);
-            }
-
-            return (null, 0);
         }
 
         public PrivateRange GetPrivateAllocation(ulong va)

src/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs

@@ -391,7 +391,7 @@ namespace Ryujinx.Graphics.Gpu.Memory
             // Range list must be consistent for this operation
             if (_migrationTarget != null)
             {
-                _migrationTarget!.WaitForAndFlushRanges(address, size);
+                _migrationTarget.WaitForAndFlushRanges(address, size);
 
                 return;
             }

src/Ryujinx.Graphics.OpenGL/Effects/SmaaPostProcessingEffect.cs

@@ -210,7 +210,7 @@ namespace Ryujinx.Graphics.OpenGL.Effects.Smaa
             var dispatchY = BitUtils.DivRoundUp(view.Height, IPostProcessingEffect.LocalGroupSize);
 
             int previousProgram = GL.GetInteger(GetPName.CurrentProgram);
-            GL.BindImageTexture(0, edgeOutput.Handle, 0, false, 0, TextureAccess.ReadWrite, SizedInternalFormat.Rgba8);
+            GL.BindImageTexture(0, edgeOutput!.Handle, 0, false, 0, TextureAccess.ReadWrite, SizedInternalFormat.Rgba8);
             GL.UseProgram(_edgeShaderPrograms[Quality]);
             view.Bind(0);
             GL.Uniform1(_inputUniform, 0);
@@ -219,7 +219,7 @@ namespace Ryujinx.Graphics.OpenGL.Effects.Smaa
             GL.DispatchCompute(dispatchX, dispatchY, 1);
             GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
 
-            GL.BindImageTexture(0, blendOutput.Handle, 0, false, 0, TextureAccess.ReadWrite, SizedInternalFormat.Rgba8);
+            GL.BindImageTexture(0, blendOutput!.Handle, 0, false, 0, TextureAccess.ReadWrite, SizedInternalFormat.Rgba8);
             GL.UseProgram(_blendShaderPrograms[Quality]);
             edgeOutput.Bind(0);
             areaTexture?.Bind(1);
@@ -232,7 +232,7 @@ namespace Ryujinx.Graphics.OpenGL.Effects.Smaa
             GL.DispatchCompute(dispatchX, dispatchY, 1);
             GL.MemoryBarrier(MemoryBarrierFlags.ShaderImageAccessBarrierBit);
 
-            GL.BindImageTexture(0, textureView.Handle, 0, false, 0, TextureAccess.ReadWrite, SizedInternalFormat.Rgba8);
+            GL.BindImageTexture(0, textureView!.Handle, 0, false, 0, TextureAccess.ReadWrite, SizedInternalFormat.Rgba8);
             GL.UseProgram(_neighbourShaderPrograms[Quality]);
             view.Bind(0);
             blendOutput.Bind(1);

src/Ryujinx.Graphics.Shader/IntermediateRepresentation/BasicBlock.cs

@@ -63,13 +63,10 @@ namespace Ryujinx.Graphics.Shader.IntermediateRepresentation
         {
             INode lastOp = GetLastOp();
 
-            if (lastOp is Operation operation && IsControlFlowInst(operation.Inst))
+            if (lastOp is Operation operation && IsControlFlowInst(operation.Inst) && Operations.Last != null)
-            {
-                if (Operations.Last != null)
             {
                 Operations.AddBefore(Operations.Last, node);
             }
-            }
             else
             {
                 Operations.AddLast(node);

src/Ryujinx.Graphics.Vulkan/PipelineBase.cs

@@ -1693,7 +1693,7 @@ namespace Ryujinx.Graphics.Vulkan
 
                 var pipeline = pbp == PipelineBindPoint.Compute
                     ? _newState.CreateComputePipeline(Gd, Device, _program, PipelineCache)
-                    : _newState.CreateGraphicsPipeline(Gd, Device, _program, PipelineCache, _renderPass.Get(Cbs).Value);
+                    : _newState.CreateGraphicsPipeline(Gd, Device, _program, PipelineCache, _renderPass!.Get(Cbs).Value);
 
                 if (pipeline == null)
                 {

src/Ryujinx.Graphics.Vulkan/RenderPassHolder.cs

@@ -134,7 +134,7 @@ namespace Ryujinx.Graphics.Vulkan
 
             // Register this render pass with all render target views.
 
-            if (fb != null)
+            if (hasFramebuffer)
             {
                 var textures = fb.GetAttachmentViews();
 

src/Ryujinx.HLE.Generators/IpcServiceGenerator.cs

@@ -19,29 +19,41 @@ namespace Ryujinx.HLE.Generators
             generator.EnterScope($"partial class IUserInterface");
 
             generator.EnterScope($"public IpcService? GetServiceInstance(Type type, ServiceCtx context, object? parameter = null)");
+            if (syntaxReceiver != null)
+            {
                 foreach (var className in syntaxReceiver.Types)
                 {
-                if (className.Modifiers.Any(SyntaxKind.AbstractKeyword) || className.Modifiers.Any(SyntaxKind.PrivateKeyword) || !className.AttributeLists.Any(x => x.Attributes.Any(y => y.ToString().StartsWith("Service"))))
+                    if (className.Modifiers.Any(SyntaxKind.AbstractKeyword) ||
+                        className.Modifiers.Any(SyntaxKind.PrivateKeyword) ||
+                        !className.AttributeLists.Any(x => x.Attributes.Any(y => y.ToString().StartsWith("Service"))))
                         continue;
                     var name = GetFullName(className, context).Replace("global::", "");
                     if (!name.StartsWith("Ryujinx.HLE.HOS.Services"))
                         continue;
-                var constructors = className.ChildNodes().Where(x => x.IsKind(SyntaxKind.ConstructorDeclaration)).Select(y => y as ConstructorDeclarationSyntax);
+                    var constructors = className.ChildNodes().Where(x => x.IsKind(SyntaxKind.ConstructorDeclaration))
+                        .Select(y => y as ConstructorDeclarationSyntax);
 
-                if (!constructors.Any(x => x != null && x.ParameterList.Parameters.Count >= 1))
+                    if (!constructors.Any(x => x?.ParameterList.Parameters.Count >= 1))
                         continue;
 
-                if (constructors.FirstOrDefault(x => x != null && x.ParameterList.Parameters.Count >= 1).ParameterList.Parameters[0].Type.ToString() == "ServiceCtx")
+                    if (constructors.FirstOrDefault(x => x?.ParameterList.Parameters.Count >= 1)
+                            .ParameterList.Parameters[0].Type.ToString() == "ServiceCtx")
                     {
                         generator.EnterScope($"if (type == typeof({GetFullName(className, context)}))");
-                    if (constructors.Any(x => x != null && x.ParameterList.Parameters.Count == 2))
+                        if (constructors.Any(x => x?.ParameterList.Parameters.Count == 2))
+                        {
+                            var type = constructors
+                                .FirstOrDefault(x => x?.ParameterList.Parameters.Count == 2).ParameterList
+                                .Parameters[1].Type;
+                            if (type?.SyntaxTree != null)
                             {
-                        var type = constructors.FirstOrDefault(x => x != null && x.ParameterList.Parameters.Count == 2).ParameterList.Parameters[1].Type;
                                 var model = context.Compilation.GetSemanticModel(type.SyntaxTree);
                                 var typeSymbol = model.GetSymbolInfo(type).Symbol as INamedTypeSymbol;
                                 var fullName = typeSymbol?.ToString();
                                 generator.EnterScope("if (parameter != null)");
                                 generator.AppendLine($"return new {GetFullName(className, context)}(context, ({fullName})parameter);");
+                            }
+
                             generator.LeaveScope();
                         }
 
@@ -53,6 +65,7 @@ namespace Ryujinx.HLE.Generators
                         generator.LeaveScope();
                     }
                 }
+            }
 
             generator.AppendLine("return null;");
             generator.LeaveScope();

src/Ryujinx.HLE/HOS/Kernel/Ipc/KServerPort.cs

@@ -60,12 +60,9 @@ namespace Ryujinx.HLE.HOS.Kernel.Ipc
 
             KernelContext.CriticalSection.Enter();
 
-            if (list.Count != 0)
+            if (list.Count != 0 && list.First != null)
-            {
-                if (list.First != null)
             {
                 session = list.First.Value;
-                }
 
                 list.RemoveFirst();
             }

src/Ryujinx.HLE/HOS/Kernel/Memory/SharedMemoryStorage.cs

@@ -32,14 +32,11 @@ namespace Ryujinx.HLE.HOS.Kernel.Memory
 
         public ref T GetRef<T>(ulong offset) where T : unmanaged
         {
-            if (_pageList.Nodes.Count == 1)
+            if (_pageList.Nodes.Count == 1 && _pageList.Nodes.First != null)
-            {
-                if (_pageList.Nodes.First != null)
             {
                 ulong address = _pageList.Nodes.First.Value.Address - DramMemoryMap.DramBase;
                 return ref _context.Memory.GetRef<T>(address + offset);
             }
-            }
 
             throw new NotImplementedException("Non-contiguous shared memory is not yet supported.");
         }

src/Ryujinx.HLE/HOS/Services/Nv/NvMemoryAllocator.cs

@@ -164,11 +164,14 @@ namespace Ryujinx.HLE.HOS.Services.Nv
                     Logger.Debug?.Print(LogClass.ServiceNv, $"Deallocation resulted in new free range from 0x{expandedStart:X} to 0x{expandedEnd:X}.");
 
                     _tree.Add(expandedStart, expandedEnd);
+                    if (node != null)
+                    {
                         LinkedListNode<ulong> nodePtr = _list.AddAfter(node, expandedStart);
                         _dictionary[expandedStart] = nodePtr;
                     }
                 }
             }
+        }
 
         /// <summary>
         /// Gets the address of an unused (free) region of the specified size.
@@ -196,12 +199,15 @@ namespace Ryujinx.HLE.HOS.Services.Nv
                 if (address < AddressSpaceSize)
                 {
                     bool reachedEndOfAddresses = false;
-                    ulong targetAddress;
+                    ulong targetAddress = 0;
                     if (start == DefaultStart)
+                    {
+                        if (_list.Last != null)
                         {
                             Logger.Debug?.Print(LogClass.ServiceNv, $"Target address set to start of the last available range: 0x{_list.Last.Value:X}.");
                             targetAddress = _list.Last.Value;
                         }
+                    }
                     else
                     {
                         targetAddress = _tree.Floor(address);

src/Ryujinx.HLE/HOS/Services/Sm/IUserInterface.cs

@@ -97,8 +97,8 @@ namespace Ryujinx.HLE.HOS.Services.Sm
 
                     IpcService service = GetServiceInstance(type, context, serviceAttribute.Parameter);
 
-                    service.TrySetServer(_commonServer);
+                    service?.TrySetServer(_commonServer);
-                    service.Server.AddSessionObj(session.ServerSession, service);
+                    service?.Server.AddSessionObj(session.ServerSession, service);
                 }
                 else
                 {

src/Ryujinx.Horizon.Generators/Hipc/HipcGenerator.cs

@@ -61,7 +61,7 @@ namespace Ryujinx.Horizon.Generators.Hipc
         {
             HipcSyntaxReceiver syntaxReceiver = (HipcSyntaxReceiver)context.SyntaxReceiver;
 
-            if (syntaxReceiver?.CommandInterfaces != null)
+            if (syntaxReceiver != null)
             {
                 foreach (var commandInterface in syntaxReceiver.CommandInterfaces)
                 {
@@ -98,7 +98,8 @@ namespace Ryujinx.Horizon.Generators.Hipc
                     generator.LeaveScope();
                     generator.LeaveScope();
 
-                    context.AddSource($"{GetNamespaceName(commandInterface.ClassDeclarationSyntax)}.{className}.g.cs", generator.ToString());
+                    context.AddSource($"{GetNamespaceName(commandInterface.ClassDeclarationSyntax)}.{className}.g.cs",
+                        generator.ToString());
                 }
             }
         }
@@ -244,7 +245,7 @@ namespace Ryujinx.Horizon.Generators.Hipc
                 "ReadOnlySpan<byte> inRawData, " +
                 "ref Span<CmifOutHeader> outHeader)");
 
-            bool returnsResult = method.ReturnType != null && GetCanonicalTypeName(compilation, method.ReturnType) == TypeResult;
+            bool returnsResult = GetCanonicalTypeName(compilation, method.ReturnType) == TypeResult;
 
             if (returnsResult || buffersCount != 0 || inObjectsCount != 0)
             {
@@ -567,16 +568,11 @@ namespace Ryujinx.Horizon.Generators.Hipc
 
             if (symbol != null)
             {
-                foreach (var attribute in symbol.GetAttributes())
+                return (from attribute in symbol.GetAttributes()
-                {
+                    where attribute.AttributeClass?.ToDisplayString() == attributeName
-                    if (attribute.AttributeClass?.ToDisplayString() == attributeName)
+                    from kv in attribute.NamedArguments
-                    {
+                    where kv.Key == argName
-                        foreach (var kv in attribute.NamedArguments.Where(kv => kv.Key == argName))
+                    select kv.Value.ToCSharpString()).FirstOrDefault();
-                        {
-                            return kv.Value.ToCSharpString();
-                        }
-                    }
-                }
             }
 
             return null;
@@ -717,13 +713,18 @@ namespace Ryujinx.Horizon.Generators.Hipc
         private static bool IsObject(Compilation compilation, ParameterSyntax parameter)
         {
             SyntaxNode syntaxNode = parameter.Type;
-            TypeInfo typeInfo = compilation.GetSemanticModel(syntaxNode!.SyntaxTree).GetTypeInfo(syntaxNode);
+            if (syntaxNode != null)
+            {
+                TypeInfo typeInfo = compilation.GetSemanticModel(syntaxNode.SyntaxTree).GetTypeInfo(syntaxNode);
 
                 return typeInfo.Type != null &&
                        (typeInfo.Type.ToDisplayString() == TypeIServiceObject ||
                         typeInfo.Type.AllInterfaces.Any(x => x.ToDisplayString() == TypeIServiceObject));
             }
 
+            return false;
+        }
+
         private static bool IsProcessId(Compilation compilation, ParameterSyntax parameter)
         {
             return HasAttribute(compilation, parameter, TypeClientProcessIdAttribute) &&

src/Ryujinx.Horizon.Kernel.Generators/SyscallGenerator.cs

@@ -164,7 +164,9 @@ namespace Ryujinx.Horizon.Kernel.Generators
                                 where attributeArg.Expression.Kind() == SyntaxKind.NumericLiteralExpression
                                 select (LiteralExpressionSyntax)attributeArg.Expression
                                 into numericLiteral
-                                select new SyscallIdAndName((int)numericLiteral.Token.Value, method.Identifier.Text));
+                                let tokenValue = numericLiteral.Token.Value
+                                where tokenValue != null
+                                select new SyscallIdAndName((int)tokenValue, method.Identifier.Text));
                         }
                     }
                 }

src/Ryujinx/UI/Models/UserProfile.cs

@@ -88,7 +88,8 @@ namespace Ryujinx.Ava.UI.Models
         private void UpdateBackground()
         {
             var currentApplication = Avalonia.Application.Current;
-            currentApplication!.Styles.TryGetResource("ControlFillColorSecondary", currentApplication.ActualThemeVariant, out object color);
+            object color = null;
+            currentApplication?.Styles.TryGetResource("ControlFillColorSecondary", currentApplication.ActualThemeVariant, out color);
 
             if (color is not null)
             {

src/Ryujinx/UI/ViewModels/Input/InputViewModel.cs

@@ -525,16 +525,16 @@ namespace Ryujinx.Ava.UI.ViewModels.Input
         {
             ProfilesList.Clear();
 
-            string basePath = GetProfileBasePath() ?? string.Empty;
+            string basePath = GetProfileBasePath();
 
             if (!Directory.Exists(basePath))
             {
-                Directory.CreateDirectory(basePath);
+                Directory.CreateDirectory(basePath ?? string.Empty);
             }
 
             ProfilesList.Add((LocaleManager.Instance[LocaleKeys.ControllerSettingsProfileDefault]));
 
-            foreach (string profile in Directory.GetFiles(basePath, "*.json", SearchOption.AllDirectories))
+            foreach (string profile in Directory.GetFiles(basePath ?? string.Empty, "*.json", SearchOption.AllDirectories))
             {
                 ProfilesList.Add(Path.GetFileNameWithoutExtension(profile));
             }

src/Ryujinx/UI/ViewModels/MainWindowViewModel.cs

@@ -1555,11 +1555,11 @@ namespace Ryujinx.Ava.UI.ViewModels
 
         private void Update_StatusBar(object sender, StatusUpdatedEventArgs args)
         {
-            if (ShowMenuAndStatusBar && !ShowLoadProgress)
+            if (ShowMenuAndStatusBar && !ShowLoadProgress && Application.Current != null)
             {
                 Dispatcher.UIThread.InvokeAsync(() =>
                 {
-                    Application.Current!.Styles.TryGetResource(args.VSyncMode,
+                    Application.Current.Styles.TryGetResource(args.VSyncMode,
                         Application.Current.ActualThemeVariant,
                         out object color);
 

src/Ryujinx/UI/Views/Input/ControllerInputView.axaml.cs

@@ -9,6 +9,7 @@ using Ryujinx.Ava.UI.ViewModels.Input;
 using Ryujinx.Common.Configuration.Hid.Controller;
 using Ryujinx.Input;
 using Ryujinx.Input.Assigner;
+using System;
 using StickInputId = Ryujinx.Common.Configuration.Hid.Controller.StickInputId;
 
 namespace Ryujinx.Ava.UI.Views.Input
@@ -68,9 +69,7 @@ namespace Ryujinx.Ava.UI.Views.Input
 
                 if (_changeSlider != -1.0f && _changeSlider != (float)check.Value)
                 {
-
+                    if (DataContext is ControllerInputViewModel viewModel)
-                     var viewModel = (DataContext as ControllerInputViewModel);
-                     if (viewModel != null)
                     {
                         viewModel.ParentModel.IsModified = true;
                     }
@@ -119,7 +118,10 @@ namespace Ryujinx.Ava.UI.Views.Input
 
                         PointerPressed += MouseClick;
 
-                        var viewModel = (DataContext as ControllerInputViewModel);
+                        if (DataContext is not ControllerInputViewModel viewModel)
+                        {
+                            return;
+                        }
 
                         IKeyboard keyboard = (IKeyboard)viewModel.ParentModel.AvaloniaKeyboardDriver.GetGamepad("0"); // Open Avalonia keyboard for cancel operations.
                         IButtonAssigner assigner = CreateButtonAssigner(isStick);
@@ -234,13 +236,14 @@ namespace Ryujinx.Ava.UI.Views.Input
 
         private IButtonAssigner CreateButtonAssigner(bool forStick)
         {
-            IButtonAssigner assigner;
+            if (DataContext is not ControllerInputViewModel controllerInputViewModel)
+            {
+                return null;
+            }
 
-            var controllerInputViewModel = DataContext as ControllerInputViewModel;
+            IButtonAssigner assigner = new GamepadButtonAssigner(
-
+                controllerInputViewModel.ParentModel.SelectedGamepad,
-            assigner = new GamepadButtonAssigner(
+                ((StandardControllerInputConfig)controllerInputViewModel.ParentModel.Config).TriggerThreshold,
-                controllerInputViewModel?.ParentModel.SelectedGamepad,
-                (controllerInputViewModel.ParentModel.Config as StandardControllerInputConfig).TriggerThreshold,
                 forStick);
 
             return assigner;

src/Ryujinx/UI/Views/Settings/SettingsHotkeysView.axaml.cs

@@ -36,7 +36,7 @@ namespace Ryujinx.Ava.UI.Views.Settings
         {
             base.OnPointerReleased(e);
 
-            if (!_currentAssigner?.ToggledButton?.IsPointerOver ?? false)
+            if (!_currentAssigner?.ToggledButton.IsPointerOver ?? false)
             {
                 _currentAssigner.Cancel();
             }

src/Ryujinx/UI/Views/User/UserProfileImageSelectorView.axaml.cs

@@ -63,8 +63,9 @@ namespace Ryujinx.Ava.UI.Views.User
 
         private async void Import_OnClick(object sender, RoutedEventArgs e)
         {
-            var window = this.GetVisualRoot() as Window;
+            if (this.GetVisualRoot() is Window window)
-            var result = await window?.StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
+            {
+                var result = await window.StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
                 {
                     AllowMultiple = false,
                     FileTypeFilter = new List<FilePickerFileType>
@@ -84,6 +85,7 @@ namespace Ryujinx.Ava.UI.Views.User
                     _parent.GoBack();
                 }
             }
+        }
 
         private void GoBack(object sender, RoutedEventArgs e)
         {

src/Ryujinx/UI/Views/User/UserSelectorView.axaml.cs

@@ -41,9 +41,12 @@ namespace Ryujinx.Ava.UI.Views.User
                 }
 
                 if (arg.NavigationMode == NavigationMode.Back)
+                {
+                    if (_parent.Parent != null)
                     {
                         ((ContentDialog)_parent.Parent).Title = LocaleManager.Instance[LocaleKeys.UserProfileWindowTitle];
                     }
+                }
 
                 DataContext = ViewModel;
             }

src/Ryujinx/UI/Windows/MainWindow.axaml.cs

@@ -516,12 +516,16 @@ namespace Ryujinx.Ava.UI.Windows
 
             ApplicationLibrary.ApplicationCountUpdated += ApplicationLibrary_ApplicationCountUpdated;
             _appLibraryAppsSubscription?.Dispose();
+            if (SynchronizationContext.Current != null)
+            {
                 _appLibraryAppsSubscription = ApplicationLibrary.Applications
                     .Connect()
                     .ObserveOn(SynchronizationContext.Current)
                     .Bind(ViewModel.Applications)
                     .OnItemAdded(UpdateApplicationWithLdnData)
                     .Subscribe();
+            }
+
             ApplicationLibrary.LdnGameDataReceived += ApplicationLibrary_LdnGameDataReceived;
 
             ConfigurationState.Instance.Multiplayer.Mode.Event += (sender, evt) =>
@@ -581,7 +585,7 @@ namespace Ryujinx.Ava.UI.Windows
             var volumeSplitButton = sender as ToggleSplitButton;
             if (ViewModel.IsGameRunning)
             {
-                if (volumeSplitButton is not { IsChecked: true })
+                if (volumeSplitButton is { IsChecked: false })
                 {
                     ViewModel.AppHost.Device.SetVolume(ViewModel.VolumeBeforeMute);
                 }