From f209eed91c2ca4dd4a28466db12ddb37c65202ea Mon Sep 17 00:00:00 2001
From: Michael Nebel <michaelnebel@github.com>
Date: Mon, 27 Feb 2023 14:00:56 +0100
Subject: [PATCH] C#: Extractor- and library support for explicit interface
 implementations for operators.

---
 .../extractor/Semmle.Extraction.CSharp/Entities/Conversion.cs | 2 ++
 csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs  | 4 +++-
 .../Semmle.Extraction.CSharp/Entities/UserOperator.cs         | 3 +++
 csharp/ql/lib/semmle/code/csharp/Callable.qll                 | 2 +-
 4 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Conversion.cs b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Conversion.cs
index c3d59f94de7..c081f43e24f 100644
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Conversion.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Conversion.cs
@@ -10,6 +10,8 @@ namespace Semmle.Extraction.CSharp.Entities
         private Conversion(Context cx, IMethodSymbol init)
             : base(cx, init) { }
 
+        protected override MethodKind ExplicitlyImplementsKind => MethodKind.Conversion;
+
         public static new Conversion Create(Context cx, IMethodSymbol symbol) =>
             ConversionFactory.Instance.CreateEntityFromSymbol(cx, symbol);
 
diff --git a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs
index cd765159769..22bf9f69670 100644
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs
@@ -83,10 +83,12 @@ namespace Semmle.Extraction.CSharp.Entities
             }
         }
 
+        protected virtual MethodKind ExplicitlyImplementsKind => MethodKind.Ordinary;
+
         public void Overrides(TextWriter trapFile)
         {
             foreach (var explicitInterface in Symbol.ExplicitInterfaceImplementations
-                .Where(sym => sym.MethodKind == MethodKind.Ordinary)
+                .Where(sym => sym.MethodKind == ExplicitlyImplementsKind)
                 .Select(impl => Type.Create(Context, impl.ContainingType)))
             {
                 trapFile.explicitly_implements(this, explicitInterface.TypeRef);
diff --git a/csharp/extractor/Semmle.Extraction.CSharp/Entities/UserOperator.cs b/csharp/extractor/Semmle.Extraction.CSharp/Entities/UserOperator.cs
index f478d991919..c6e03f86a29 100644
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/UserOperator.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/UserOperator.cs
@@ -11,6 +11,8 @@ namespace Semmle.Extraction.CSharp.Entities
         protected UserOperator(Context cx, IMethodSymbol init)
             : base(cx, init) { }
 
+        protected override MethodKind ExplicitlyImplementsKind => MethodKind.UserDefinedOperator;
+
         public override void Populate(TextWriter trapFile)
         {
             PopulateMethod(trapFile);
@@ -37,6 +39,7 @@ namespace Semmle.Extraction.CSharp.Entities
             }
 
             ContainingType.PopulateGenerics();
+            Overrides(trapFile);
         }
 
         public override bool NeedsPopulation => Context.Defines(Symbol) || IsImplicitOperator(out _);
diff --git a/csharp/ql/lib/semmle/code/csharp/Callable.qll b/csharp/ql/lib/semmle/code/csharp/Callable.qll
index 82ffbfa6a06..00091f66ddc 100644
--- a/csharp/ql/lib/semmle/code/csharp/Callable.qll
+++ b/csharp/ql/lib/semmle/code/csharp/Callable.qll
@@ -434,7 +434,7 @@ class Destructor extends DotNet::Destructor, Callable, Member, Attributable, @de
  * Either a unary operator (`UnaryOperator`), a binary operator
  * (`BinaryOperator`), or a conversion operator (`ConversionOperator`).
  */
-class Operator extends Callable, Member, Attributable, @operator {
+class Operator extends Callable, Member, Attributable, Overridable, @operator {
   /**
    * DEPRECATED: use `getFunctionName()` instead.
    *