Merge pull request #40484 from jaredpar/nullable2.1

Remove null from Diagnostic.Arguments

.vscode/tasks.json

@@ -21,6 +21,18 @@
         ],
         "problemMatcher": "$msCompile",
         "group": "build"
+    },
+    {
+        "label": "build csc skip analyzers",
+        "command": "dotnet",
+        "type": "shell",
+        "args": [
+          "msbuild",
+          "src/Compilers/CSharp/csc/csc.csproj",
+          "-p:UseRoslynAnalyzers=false"
+        ],
+        "problemMatcher": "$msCompile",
+        "group": "build"
     }
   ]
 }

src/Compilers/Core/Portable/Diagnostic/Diagnostic.DiagnosticWithProgrammaticSuppression.cs

@@ -43,7 +43,7 @@ public override string Id
             public override string GetMessage(IFormatProvider? formatProvider = null)
                 => _originalUnsuppressedDiagnostic.GetMessage(formatProvider);
 
-            internal override IReadOnlyList<object?>? Arguments
+            internal override IReadOnlyList<object?> Arguments
             {
                 get { return _originalUnsuppressedDiagnostic.Arguments; }
             }

src/Compilers/Core/Portable/Diagnostic/Diagnostic.cs

@@ -466,7 +466,7 @@ internal Diagnostic WithProgrammaticSuppression(ProgrammaticSuppressionInfo prog
         // compatibility
         internal virtual int Code { get { return 0; } }
 
-        internal virtual IReadOnlyList<object?>? Arguments
+        internal virtual IReadOnlyList<object?> Arguments
         {
             get { return SpecializedCollections.EmptyReadOnlyList<object?>(); }
         }

src/Compilers/Core/Portable/Diagnostic/DiagnosticInfo.cs

@@ -28,7 +28,7 @@ internal class DiagnosticInfo : IFormattable, IObjectWritable
         private readonly int _errorCode;
         private readonly DiagnosticSeverity _defaultSeverity;
         private readonly DiagnosticSeverity _effectiveSeverity;
-        private readonly object[]? _arguments;
+        private readonly object[] _arguments;
 
         private static ImmutableDictionary<int, DiagnosticDescriptor> s_errorCodeToDescriptorMap = ImmutableDictionary<int, DiagnosticDescriptor>.Empty;
 
@@ -48,6 +48,7 @@ internal DiagnosticInfo(CommonMessageProvider messageProvider, int errorCode)
             _errorCode = errorCode;
             _defaultSeverity = messageProvider.GetSeverity(errorCode);
             _effectiveSeverity = _defaultSeverity;
+            _arguments = Array.Empty<object>();
         }
 
         // Only the compiler creates instances.
@@ -155,12 +156,12 @@ protected virtual void WriteTo(ObjectWriter writer)
             writer.WriteInt32((int)_effectiveSeverity);
             writer.WriteInt32((int)_defaultSeverity);
 
-            int count = _arguments?.Length ?? 0;
+            int count = _arguments.Length;
             writer.WriteUInt32((uint)count);
 
             if (count > 0)
             {
-                foreach (var arg in _arguments!)
+                foreach (var arg in _arguments)
                 {
                     writer.WriteString(arg.ToString());
                 }
@@ -175,11 +176,7 @@ protected DiagnosticInfo(ObjectReader reader)
             _defaultSeverity = (DiagnosticSeverity)reader.ReadInt32();
 
             var count = (int)reader.ReadUInt32();
-            if (count == 0)
-            {
-                _arguments = Array.Empty<object>();
-            }
-            else if (count > 0)
+            if (count > 0)
             {
                 _arguments = new string[count];
                 for (int i = 0; i < count; i++)
@@ -187,6 +184,10 @@ protected DiagnosticInfo(ObjectReader reader)
                     _arguments[i] = reader.ReadString();
                 }
             }
+            else
+            {
+                _arguments = Array.Empty<object>();
+            }
         }
 
         #endregion
@@ -331,7 +332,7 @@ public virtual string GetMessage(IFormatProvider? formatProvider = null)
                 return string.Empty;
             }
 
-            if (_arguments == null || _arguments.Length == 0)
+            if (_arguments.Length == 0)
             {
                 return message;
             }
@@ -341,7 +342,6 @@ public virtual string GetMessage(IFormatProvider? formatProvider = null)
 
         protected object[] GetArgumentsToUse(IFormatProvider? formatProvider)
         {
-            RoslynDebug.Assert(_arguments is object);
             object[]? argumentsToUse = null;
             for (int i = 0; i < _arguments.Length; i++)
             {
@@ -371,14 +371,13 @@ private object[] InitializeArgumentListIfNeeded(object[]? argumentsToUse)
                 return argumentsToUse;
             }
 
-            RoslynDebug.Assert(_arguments != null);
             var newArguments = new object[_arguments.Length];
             Array.Copy(_arguments, newArguments, newArguments.Length);
 
             return newArguments;
         }
 
-        internal object[]? Arguments
+        internal object[] Arguments
         {
             get { return _arguments; }
         }
@@ -409,12 +408,9 @@ string IFormattable.ToString(string format, IFormatProvider? formatProvider)
         public sealed override int GetHashCode()
         {
             int hashCode = _errorCode;
-            if (_arguments != null)
+            for (int i = 0; i < _arguments.Length; i++)
             {
-                for (int i = 0; i < _arguments.Length; i++)
-                {
-                    hashCode = Hash.Combine(_arguments[i], hashCode);
-                }
+                hashCode = Hash.Combine(_arguments[i], hashCode);
             }
 
             return hashCode;
@@ -430,11 +426,7 @@ public sealed override bool Equals(object? obj)
                 other._errorCode == _errorCode &&
                 other.GetType() == this.GetType())
             {
-                if (_arguments == null && other._arguments == null)
-                {
-                    result = true;
-                }
-                else if (_arguments != null && other._arguments != null && _arguments.Length == other._arguments.Length)
+                if (_arguments.Length == other._arguments.Length)
                 {
                     result = true;
                     for (int i = 0; i < _arguments.Length; i++)

src/Compilers/Core/Portable/Diagnostic/DiagnosticWithInfo.cs

@@ -102,7 +102,7 @@ public override string GetMessage(IFormatProvider? formatProvider = null)
             return this.Info.GetMessage(formatProvider);
         }
 
-        internal override IReadOnlyList<object>? Arguments
+        internal override IReadOnlyList<object> Arguments
         {
             get { return this.Info.Arguments; }
         }