chore: enable nullable annotation for Disassembler related code (#2939)

Author: filzrev

src/BenchmarkDotNet/Diagnosers/DiagnoserActionParameters.cs

@@ -1,7 +1,10 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 using BenchmarkDotNet.Configs;
 using BenchmarkDotNet.Running;
 
+#nullable enable
+
 namespace BenchmarkDotNet.Diagnosers
 {
     public class DiagnoserActionParameters
@@ -13,7 +16,9 @@ public DiagnoserActionParameters(Process? process, BenchmarkCase benchmarkCase,
             BenchmarkId = benchmarkId;
         }
 
-        public Process Process { get; }
+        public Process? Process { get; }
+
+        public int ProcessId => Process?.Id ?? throw new InvalidOperationException("The process instance is not set.");
 
         public BenchmarkCase BenchmarkCase { get; }
 

src/BenchmarkDotNet/Diagnosers/EventPipeProfiler.cs

@@ -74,7 +74,7 @@ public void Handle(HostSignal signal, DiagnoserActionParameters parameters)
             if (signal != HostSignal.BeforeAnythingElse)
                 return;
 
-            var diagnosticsClient = new DiagnosticsClient(parameters.Process.Id);
+            var diagnosticsClient = new DiagnosticsClient(parameters.ProcessId);
 
             EventPipeSession session = diagnosticsClient.StartEventPipeSession(eventPipeProviders, true);
 

src/BenchmarkDotNet/Diagnosers/SnapshotProfilerBase.cs

@@ -13,6 +13,8 @@
 using BenchmarkDotNet.Running;
 using BenchmarkDotNet.Validators;
 
+#nullable enable
+
 namespace BenchmarkDotNet.Diagnosers;
 
 public abstract class SnapshotProfilerBase : IProfiler
@@ -162,7 +164,7 @@ private void Stop(ILogger logger)
 
     private void Attach(DiagnoserActionParameters parameters, string snapshotFile)
     {
-        int pid = parameters.Process.Id;
+        int pid = parameters.ProcessId;
         int currentPid = Process.GetCurrentProcess().Id;
         if (pid != currentPid)
             AttachToProcessByPid(pid, snapshotFile);

src/BenchmarkDotNet/Disassemblers/Arm64Disassembler.cs

@@ -6,6 +6,8 @@
 using System.Collections.Generic;
 using System.Linq;
 
+#nullable enable
+
 namespace BenchmarkDotNet.Disassemblers
 {
     internal struct RegisterValueAccumulator
@@ -193,7 +195,7 @@ internal RuntimeSpecificData(State state)
 
         protected override IEnumerable<Asm> Decode(byte[] code, ulong startAddress, State state, int depth, ClrMethod currentMethod, DisassemblySyntax syntax)
         {
-            if (!runtimeSpecificData.TryGetValue(state.RuntimeVersion, out RuntimeSpecificData data))
+            if (!runtimeSpecificData.TryGetValue(state.RuntimeVersion, out var data))
             {
                 runtimeSpecificData.Add(state.RuntimeVersion, data = new RuntimeSpecificData(state));
             }

src/BenchmarkDotNet/Disassemblers/Arm64InstructionFormatter.cs

@@ -3,6 +3,8 @@
 using System.Collections.Generic;
 using System.Text;
 
+#nullable enable
+
 namespace BenchmarkDotNet.Disassemblers
 {
     internal static class Arm64InstructionFormatter
@@ -12,8 +14,11 @@ internal static class Arm64InstructionFormatter
         internal static string Format(Arm64Asm asm, FormatterOptions formatterOptions,
             bool printInstructionAddresses, uint pointerSize, IReadOnlyDictionary<ulong, string> symbols)
         {
+            var instruction = asm.Instruction;
+            if (instruction == null)
+                return "";
+
             StringBuilder output = new();
-            Arm64Instruction instruction = asm.Instruction;
 
             if (printInstructionAddresses)
             {
@@ -22,7 +27,7 @@ internal static string Format(Arm64Asm asm, FormatterOptions formatterOptions,
 
             output.Append(instruction.Mnemonic.ToString().PadRight(formatterOptions.FirstOperandCharIndex));
 
-            if (asm.ReferencedAddress.HasValue && !asm.IsReferencedAddressIndirect && symbols.TryGetValue(asm.ReferencedAddress.Value, out string name))
+            if (asm.ReferencedAddress.HasValue && !asm.IsReferencedAddressIndirect && symbols.TryGetValue(asm.ReferencedAddress.Value, out var name))
             {
                 string partToReplace = $"#0x{asm.ReferencedAddress.Value:x}";
                 output.Append(instruction.Operand.Replace(partToReplace, name));

src/BenchmarkDotNet/Disassemblers/ClrMdArgs.cs

@@ -2,9 +2,11 @@
 using System.Linq;
 using SimpleJson;
 
+#nullable enable
+
 namespace BenchmarkDotNet.Disassemblers
 {
-    internal struct ClrMdArgs(int processId, string typeName, string methodName, bool printSource, int maxDepth, string syntax, string tfm, string[] filters, string resultsPath = null)
+    internal struct ClrMdArgs(int processId, string typeName, string methodName, bool printSource, int maxDepth, string syntax, string tfm, string[] filters, string resultsPath = "")
     {
         internal int ProcessId = processId;
         internal string TypeName = typeName;
@@ -50,11 +52,14 @@ internal readonly string Serialize()
             return jsonObject.ToString();
         }
 
-        internal void Deserialize(string json)
+        internal void Deserialize(string? json)
         {
             var jsonObject = SimpleJsonSerializer.DeserializeObject<JsonObject>(json);
-            MethodName = (string) jsonObject[nameof(MethodName)];
-            PrintSource = (bool) jsonObject[nameof(PrintSource)];
+            if (jsonObject == null)
+                return;
+
+            MethodName = (string)jsonObject[nameof(MethodName)];
+            PrintSource = (bool)jsonObject[nameof(PrintSource)];
             MaxDepth = Convert.ToInt32(jsonObject[nameof(MaxDepth)]);
             Syntax = (string) jsonObject[nameof(Syntax)];
             TargetFrameworkMoniker = (string) jsonObject[nameof(TargetFrameworkMoniker)];

src/BenchmarkDotNet/Disassemblers/ClrMdDisassembler.cs

@@ -11,6 +11,8 @@
 using Microsoft.Diagnostics.NETCore.Client;
 using BenchmarkDotNet.Extensions;
 
+#nullable enable
+
 namespace BenchmarkDotNet.Disassemblers
 {
     internal abstract class ClrMdDisassembler
@@ -100,7 +102,7 @@ internal DisassemblyResult AttachAndDisassemble(ClrMdArgs args)
             }
             else
             {
-                ClrType typeWithBenchmark = state.Runtime.EnumerateModules().Select(module => module.GetTypeByName(args.TypeName)).First(type => type != null);
+                var typeWithBenchmark = state.Runtime.EnumerateModules().Select(module => module.GetTypeByName(args.TypeName)).WhereNotNull().First();
 
                 state.Todo.Enqueue(
                     new MethodInfo(
@@ -135,22 +137,22 @@ private static void FilterAndEnqueue(State state, ClrMdArgs args)
             Regex[] filters = GlobFilter.ToRegex(args.Filters);
 
             foreach (ClrModule module in state.Runtime.EnumerateModules())
-                foreach (ClrType type in module.EnumerateTypeDefToMethodTableMap().Select(map => state.Runtime.GetTypeByMethodTable(map.MethodTable)).Where(type => type is not null))
-                    foreach (ClrMethod method in type.Methods.Where(method => method.Signature != null))
+                foreach (ClrType type in module.EnumerateTypeDefToMethodTableMap().Select(map => state.Runtime.GetTypeByMethodTable(map.MethodTable)).WhereNotNull())
+                    foreach (ClrMethod method in type.Methods.Where(method => method.Signature.IsNotBlank()))
                     {
                         if (method.NativeCode > 0)
                         {
                             if (!state.AddressToNameMapping.TryGetValue(method.NativeCode, out _))
                             {
-                                state.AddressToNameMapping.Add(method.NativeCode, method.Signature);
+                                state.AddressToNameMapping.Add(method.NativeCode, method.Signature!);
                             }
                         }
 
                         if (CanBeDisassembled(method))
                         {
                             foreach (Regex filter in filters)
                             {
-                                if (filter.IsMatch(method.Signature))
+                                if (filter.IsMatch(method.Signature!))
                                 {
                                     state.Todo.Enqueue(new MethodInfo(method,
                                         depth: args.MaxDepth)); // don't allow for recursive disassembling
@@ -225,7 +227,7 @@ private DisassembledMethod DisassembleMethod(MethodInfo methodInfo, State state,
             return new DisassembledMethod
             {
                 Maps = maps,
-                Name = method.Signature,
+                Name = method.Signature ?? "",
                 NativeCode = method.NativeCode
             };
         }
@@ -277,7 +279,7 @@ private static ILToNativeMap[] GetCompleteNativeMap(ClrMethod method, ClrRuntime
         }
 
         private static DisassembledMethod CreateEmpty(ClrMethod method, string reason)
-            => DisassembledMethod.Empty(method.Signature, method.NativeCode, reason);
+            => DisassembledMethod.Empty(method.Signature ?? "", method.NativeCode, reason);
 
         protected void TryTranslateAddressToName(ulong address, bool isAddressPrecodeMD, State state, int depth, ClrMethod currentMethod)
         {
@@ -289,7 +291,7 @@ protected void TryTranslateAddressToName(ulong address, bool isAddressPrecodeMD,
             var jitHelperFunctionName = runtime.GetJitHelperFunctionName(address);
             if (jitHelperFunctionName.IsNotBlank())
             {
-                state.AddressToNameMapping.Add(address, jitHelperFunctionName);
+                state.AddressToNameMapping.Add(address, jitHelperFunctionName!);
                 return;
             }
 
@@ -330,7 +332,7 @@ protected void TryTranslateAddressToName(ulong address, bool isAddressPrecodeMD,
             if (!state.HandledMethods.Contains(method))
                 state.Todo.Enqueue(new MethodInfo(method, depth + 1));
 
-            var methodName = method.Signature;
+            var methodName = method.Signature!;
             if (!methodName.Any(c => c == '.')) // the method name does not contain namespace and type name
                 methodName = $"{method.Type.Name}.{method.Signature}";
             state.AddressToNameMapping.Add(address, methodName);
@@ -354,8 +356,13 @@ protected void FlushCachedDataIfNeeded(IDataReader dataTargetDataReader, ulong a
 
         private class SharpComparer : IEqualityComparer<Sharp>
         {
-            public bool Equals(Sharp x, Sharp y)
+            public bool Equals(Sharp? x, Sharp? y)
             {
+                if (ReferenceEquals(x, y))
+                    return true;
+                if (x is null || y is null)
+                    return false;
+
                 // sometimes some C# code lines are duplicated because the same line is the best match for multiple ILToNativeMaps
                 // we don't want to confuse the users, so this must also be removed
                 return x.FilePath == y.FilePath && x.LineNumber == y.LineNumber;

src/BenchmarkDotNet/Disassemblers/DataContracts.cs

@@ -5,10 +5,15 @@
 using SimpleJson;
 using System;
 using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Xml.Serialization;
 
+#if NET6_0_OR_GREATER
+using System.Diagnostics.CodeAnalysis;
+#endif
+
+#nullable enable
+
 namespace BenchmarkDotNet.Disassemblers;
 
 public abstract class SourceCode
@@ -38,8 +43,8 @@ internal virtual void Deserialize(JsonObject json)
 
 public sealed class Sharp : SourceCode
 {
-    public string Text { get; set; }
-    public string FilePath { get; set; }
+    public string Text { get; set; } = default!;
+    public string FilePath { get; set; } = default!;
     public int LineNumber { get; set; }
 
     private protected override void Serialize(JsonObject json)
@@ -134,7 +139,7 @@ internal override void Deserialize(JsonObject json)
         foreach (var kvp in (JsonObject) json[nameof(Instruction)])
         {
             object value = kvp.Value;
-            var property = typeof(Instruction).GetProperty(kvp.Key);
+            var property = typeof(Instruction).GetProperty(kvp.Key)!;
             var propertyType = property.PropertyType;
             if (propertyType == typeof(ulong))
             {
@@ -154,7 +159,7 @@ internal override void Deserialize(JsonObject json)
             }
             property.SetValue(instruction, value);
         }
-        Instruction = (Instruction) instruction;
+        Instruction = (Instruction)instruction;
     }
 }
 
@@ -164,10 +169,10 @@ public sealed class Arm64Asm : Asm
     private const string BytesKey = "Arm64Bytes";
     private const string SyntaxKey = "Arm64Syntax";
 
-    public Arm64Instruction Instruction { get; set; }
+    public Arm64Instruction? Instruction { get; set; }
     internal DisassembleSyntax DisassembleSyntax { get; set; }
 
-    public override string ToString() => Instruction.ToString();
+    public override string ToString() => Instruction?.ToString() ?? "";
 
     private protected override void Serialize(JsonObject json)
     {
@@ -178,7 +183,7 @@ private protected override void Serialize(JsonObject json)
         {
             json[AddressKey] = Instruction.Address.ToString();
             json[BytesKey] = Convert.ToBase64String(Instruction.Bytes);
-            json[SyntaxKey] = (int) DisassembleSyntax;
+            json[SyntaxKey] = (int)DisassembleSyntax;
         }
     }
 
@@ -191,16 +196,16 @@ internal override void Deserialize(JsonObject json)
             // Use the Capstone disassembler to recreate the instruction from the bytes.
             using var disassembler = CapstoneDisassembler.CreateArm64Disassembler(Arm64DisassembleMode.Arm);
             disassembler.EnableInstructionDetails = true;
-            disassembler.DisassembleSyntax = (DisassembleSyntax) Convert.ToInt32(json[SyntaxKey]);
-            byte[] bytes = Convert.FromBase64String((string) bytes64);
-            Instruction = disassembler.Disassemble(bytes, long.Parse((string) json[AddressKey])).Single();
+            disassembler.DisassembleSyntax = (DisassembleSyntax)Convert.ToInt32(json[SyntaxKey]);
+            byte[] bytes = Convert.FromBase64String((string)bytes64);
+            Instruction = disassembler.Disassemble(bytes, long.Parse((string)json[AddressKey])).Single();
         }
     }
 }
 
 public sealed class MonoCode : SourceCode
 {
-    public string Text { get; set; }
+    public string Text { get; set; } = "";
 
     private protected override void Serialize(JsonObject json)
     {
@@ -223,7 +228,7 @@ public sealed class Map
     [XmlArrayItem(nameof(SourceCode), typeof(SourceCode))]
     [XmlArrayItem(nameof(Sharp), typeof(Sharp))]
     [XmlArrayItem(nameof(IntelAsm), typeof(IntelAsm))]
-    public SourceCode[] SourceCodes { get; set; }
+    public SourceCode[] SourceCodes { get; set; } = [];
 
     internal JsonObject Serialize()
     {
@@ -260,15 +265,15 @@ internal void Deserialize(JsonObject json)
 
 public sealed class DisassembledMethod
 {
-    public string Name { get; set; }
+    public string Name { get; set; } = "";
 
     public ulong NativeCode { get; set; }
 
-    public string Problem { get; set; }
+    public string Problem { get; set; } = "";
 
     public Map[] Maps { get; set; } = [];
 
-    public string CommandLine { get; set; }
+    public string CommandLine { get; set; } = "";
 
     public static DisassembledMethod Empty(string fullSignature, ulong nativeCode, string problem)
         => new()
@@ -325,7 +330,7 @@ public Dictionary<ulong, string> AddressToNameMapping
         =>  _addressToNameMapping ??= SerializedAddressToNameMapping.ToDictionary(x => x.Key, x => x.Value);
 
     [XmlIgnore]
-    private Dictionary<ulong, string> _addressToNameMapping;
+    private Dictionary<ulong, string>? _addressToNameMapping = null;
 
     // KeyValuePair is not serializable, because it has read-only properties
     // so we need to define our own...
@@ -411,7 +416,6 @@ internal State(ClrRuntime runtime, string targetFrameworkMoniker)
     }
 
     internal ClrRuntime Runtime { get; }
-    internal string TargetFrameworkMoniker { get; }
     internal Queue<MethodInfo> Todo { get; }
     internal HashSet<ClrMethod> HandledMethods { get; }
     internal Dictionary<ulong, string> AddressToNameMapping { get; }
@@ -444,7 +448,16 @@ internal static Version ParseVersion(string targetFrameworkMoniker)
 
     private sealed class ClrMethodComparer : IEqualityComparer<ClrMethod>
     {
-        public bool Equals(ClrMethod x, ClrMethod y) => x.NativeCode == y.NativeCode;
+        public bool Equals(ClrMethod? x, ClrMethod? y)
+        {
+            if (ReferenceEquals(x, y))
+                return true;
+
+            if (x is null || y is null)
+                return false;
+
+            return x.NativeCode == y.NativeCode;
+        }
 
         public int GetHashCode(ClrMethod obj) => (int) obj.NativeCode;
     }