Suppress an assert when an indexer is declared, but DefaultMemberName…

…Attribute is missing. Fixes dotnet#75032.
AlekseyTs · Sep 12, 2024 · 1c90a61 · 1c90a61
1 parent 64ba034
commit 1c90a61
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Showing 2 changed files with 17 additions and 1 deletion.
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamedTypeSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamedTypeSymbol.cs
@@ -1713,7 +1713,7 @@ internal override void AddSynthesizedAttributes(PEModuleBuilder moduleBuilder, r
 
                 AddSynthesizedAttribute(ref attributes, compilation.TrySynthesizeAttribute(
                     WellKnownMember.System_Reflection_DefaultMemberAttribute__ctor,
-                    ImmutableArray.Create(defaultMemberNameConstant)));
+                    ImmutableArray.Create(defaultMemberNameConstant), isOptionalUse: true));
             }
 
             if (this.declaration.Declarations.All(d => d.IsSimpleProgram))

diff --git a/src/Compilers/CSharp/Test/Emit/CodeGen/IndexerTests.cs b/src/Compilers/CSharp/Test/Emit/CodeGen/IndexerTests.cs
@@ -1185,5 +1185,21 @@ static void Main()
         }
 
         #endregion Lowering
+
+        [Fact]
+        [WorkItem("https://github.com/dotnet/roslyn/issues/75032")]
+        public void MissingDefaultMemberAttribute()
+        {
+            var text = @"
+interface I1
+{
+    I1 this[I1 args] { get; }
+}
+";
+            var comp = CreateCompilation(text);
+            comp.MakeMemberMissing(WellKnownMember.System_Reflection_DefaultMemberAttribute__ctor);
+
+            CompileAndVerify(comp).VerifyDiagnostics();
+        }
     }
 }