Fix analyzer RCS1096 (#1558)

dotnet · Oct 11, 2024 · 05477ca · 05477ca
1 parent ca8d20f
commit 05477ca
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diff --git a/ChangeLog.md b/ChangeLog.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix analyzer [RCS0053](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0053) ([PR](https://github.com/dotnet/roslynator/pull/1547))
 - Fix analyzer [RCS1223](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1223) ([PR](https://github.com/dotnet/roslynator/pull/1552))
 - Fix analyzer [RCS1140](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1140) ([PR](https://github.com/dotnet/roslynator/pull/1554))
+- Fix analyzer [RCS1096](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1096) ([PR](https://github.com/dotnet/roslynator/pull/1558))
 - [CLI] Improve removing of unused symbols ([PR](https://github.com/dotnet/roslynator/pull/1550))
 
 ## [4.12.7] - 2024-10-01

diff --git a/src/Analyzers/CSharp/Analysis/UseHasFlagMethodOrBitwiseOperatorAnalyzer.cs b/src/Analyzers/CSharp/Analysis/UseHasFlagMethodOrBitwiseOperatorAnalyzer.cs
@@ -79,8 +79,20 @@ private static void AnalyzeBitwiseAndExpression(SyntaxNodeAnalysisContext contex
 
  if (otherExpression.IsNumericLiteralExpression("0"))
  {
- if (SyntaxUtility.IsCompositeEnumValue(right, semanticModel, cancellationToken))
- return;
+ var enumTypeSymbol = (INamedTypeSymbol)semanticModel.GetTypeSymbol(right, cancellationToken);
+
+ if (enumTypeSymbol?.EnumUnderlyingType is not null)
+ {
+ Optional<object> constantValue = semanticModel.GetConstantValue(right, cancellationToken);
+
+ if (!constantValue.HasValue)
+ return;
+
+ ulong value = SymbolUtility.GetEnumValueAsUInt64(constantValue.Value!, enumTypeSymbol);
+
+ if (FlagsUtility<ulong>.Instance.IsComposite(value))
+ return;
+ }
  }
  else if (!CSharpFactory.AreEquivalent(right, otherExpression))
  {

diff --git a/src/Tests/Analyzers.Tests/RCS1096UseHasFlagMethodOrBitwiseOperatorTests.cs b/src/Tests/Analyzers.Tests/RCS1096UseHasFlagMethodOrBitwiseOperatorTests.cs
@@ -267,6 +267,28 @@ bool M(int value)
  return (value & (value - 1)) == 0;
  }
 }
+");
+ }
+
+ [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.UseHasFlagMethodOrBitwiseOperator)]
+ public async Task TestNoDiagnostic_NotConstant()
+ {
+ await VerifyNoDiagnosticAsync(@"
+using System.IO;
+
+class P
+{
+ private FileAttributes _flags = FileAttributes.Device | FileAttributes.Offline;
+
+ void M()
+ {
+ var flag = FileAttributes.Device;
+
+ if ((flag & _flags) != 0)
+ {
+ }
+ }
+}
 ");
  }
 }