New constant expected analyzer

src/NetAnalyzers/CSharp/Microsoft.NetCore.Analyzers/Performance/CSharpConstantExpectedAnalyzer.cs

@@ -0,0 +1,64 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the MIT license.  See License.txt in the project root for license information.
+
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.NetCore.Analyzers.Performance;
+
+namespace Microsoft.NetCore.CSharp.Analyzers.Performance
+{
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public sealed class CSharpConstantExpectedAnalyzer : ConstantExpectedAnalyzer
+    {
+        private static readonly CSharpDiagnosticHelper s_diagnosticHelper = new();
+        private static readonly IdentifierNameSyntax s_constantExpectedIdentifier = (IdentifierNameSyntax)SyntaxFactory.ParseName(ConstantExpected);
+        private static readonly IdentifierNameSyntax s_constantExpectedAttributeIdentifier = (IdentifierNameSyntax)SyntaxFactory.ParseName(ConstantExpectedAttribute);
+
+        protected override DiagnosticHelper Helper => s_diagnosticHelper;
+
+        protected override void RegisterAttributeSyntax(CompilationStartAnalysisContext context, ConstantExpectedContext constantExpectedContext)
+        {
+            context.RegisterSyntaxNodeAction(context => OnAttributeNode(context, constantExpectedContext), SyntaxKind.Attribute);
+        }
+
+        private void OnAttributeNode(SyntaxNodeAnalysisContext context, ConstantExpectedContext constantExpectedContext)
+        {
+            var attributeSyntax = (AttributeSyntax)context.Node;
+            var attributeName = attributeSyntax.Name;
+            if (!attributeName.IsEquivalentTo(s_constantExpectedIdentifier) && !attributeName.IsEquivalentTo(s_constantExpectedAttributeIdentifier))
+            {
+                return;
+            }
+
+            if (attributeSyntax.Parent.Parent is ParameterSyntax parameter)
+            {
+                var parameterSymbol = context.SemanticModel.GetDeclaredSymbol(parameter);
+                OnParameterWithConstantExpectedAttribute(parameterSymbol, constantExpectedContext, context.ReportDiagnostic);
+            }
+        }
+
+        private sealed class CSharpDiagnosticHelper : DiagnosticHelper
+        {
+            private readonly IdentifierNameSyntax _constantExpectedMinIdentifier = (IdentifierNameSyntax)SyntaxFactory.ParseName(ConstantExpectedMin);
+            private readonly IdentifierNameSyntax _constantExpectedMaxIdentifier = (IdentifierNameSyntax)SyntaxFactory.ParseName(ConstantExpectedMax);
+
+            public override Location? GetMaxLocation(SyntaxNode attributeNode) => GetArgumentLocation(attributeNode, _constantExpectedMaxIdentifier);
+
+            public override Location? GetMinLocation(SyntaxNode attributeNode) => GetArgumentLocation(attributeNode, _constantExpectedMinIdentifier);
+
+            private static Location? GetArgumentLocation(SyntaxNode attributeNode, IdentifierNameSyntax targetNameSyntax)
+            {
+                var attributeSyntax = (AttributeSyntax)attributeNode;
+                if (attributeSyntax.ArgumentList is null)
+                {
+                    return null;
+                }
+                var targetArg = attributeSyntax.ArgumentList.Arguments.FirstOrDefault(arg => arg.NameEquals.Name.IsEquivalentTo(targetNameSyntax, true));
+                return targetArg?.GetLocation();
+            }
+        }
+    }
+}
+;

src/NetAnalyzers/Core/AnalyzerReleases.Unshipped.md

@@ -1 +1,8 @@
 ; Please do not edit this file manually, it should only be updated through code fix application.
+
+### New Rules
+
+Rule ID | Category | Severity | Notes
+--------|----------|----------|-------
+CA1856 | Performance | Error | ConstantExpectedAnalyzer, [Documentation](https://docs.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1856)
+CA1857 | Performance | Warning | ConstantExpectedAnalyzer, [Documentation](https://docs.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1857)

src/NetAnalyzers/Core/Microsoft.NetCore.Analyzers/MicrosoftNetCoreAnalyzersResources.resx

@@ -1864,6 +1864,42 @@
   <data name="UsesPreviewTypeParameterMessage" xml:space="preserve">
     <value>'{0}' uses the preview type '{1}' and needs to opt into preview features. See {2} for more information.</value>
   </data>
+  <data name="ConstantExpectedApplicationTitle" xml:space="preserve">
+    <value>Incorrect usage of ConstantExpected attribute</value>
+  </data>
+  <data name="ConstantExpectedApplicationDescription" xml:space="preserve">
+    <value>ConstantExpected attribute is not applied correctly on the parameter.</value>
+  </data>
+  <data name="ConstantExpectedUsageTitle" xml:space="preserve">
+    <value>A constant is expected for the parameter</value>
+  </data>
+  <data name="ConstantExpectedUsageDescription" xml:space="preserve">
+    <value>The parameter expects a constant for optimal performance.</value>
+  </data>
+  <data name="ConstantExpectedNotSupportedMessage" xml:space="preserve">
+    <value>The '{0}' type is not supported for ConstantExpected attribute</value>
+  </data>
+  <data name="ConstantExpectedIncompatibleConstantTypeMessage" xml:space="preserve">
+    <value>The '{0}' value is not compatible with parameter type of '{1}'</value>
+  </data>
+  <data name="ConstantExpectedInvalidBoundsMessage" xml:space="preserve">
+    <value>The '{0}' value does not fit within the parameter value bounds of '{1}' to '{2}'</value>
+  </data>
+  <data name="ConstantExpectedInvertedRangeMessage" xml:space="preserve">
+    <value>The Min and Max values are inverted</value>
+  </data>
+  <data name="ConstantExpectedOutOfBoundsMessage" xml:space="preserve">
+    <value>The constant does not fit within the value bounds of '{0}' to '{1}'</value>
+  </data>
+  <data name="ConstantExpectedInvalidMessage" xml:space="preserve">
+    <value>The constant is not of the same '{0}' type as the parameter</value>
+  </data>
+  <data name="ConstantExpectedNotConstantMessage" xml:space="preserve">
+    <value>The argument should be a constant for optimal performance</value>
+  </data>
+  <data name="ConstantExpectedAttributExpectedMessage" xml:space="preserve">
+    <value>The ConstantExpected attribute is required for the parameter due to the parent method annotation</value>
+  </data>
   <data name="SpecifyCultureForToLowerAndToUpperTitle" xml:space="preserve">
     <value>Specify a culture or use an invariant version</value>
   </data>