Merge pull request #21220 from michaelnebel/csharp14/extension

C# 14: Support `extension` types.
2026-02-12 05:01:06 +01:00 · 2026-02-10 14:15:57 +01:00
parent f2d3bc03aa 25b836b1b5
commit c15ad31b07
49 changed files with 8623 additions and 126 deletions
--- a/csharp/downgrades/178a7e6cf335486d33d4e49543148e3f57f04a9a/old.dbscheme
+++ b/csharp/downgrades/178a7e6cf335486d33d4e49543148e3f57f04a9a/old.dbscheme
--- a/csharp/downgrades/178a7e6cf335486d33d4e49543148e3f57f04a9a/semmlecode.csharp.dbscheme
+++ b/csharp/downgrades/178a7e6cf335486d33d4e49543148e3f57f04a9a/semmlecode.csharp.dbscheme
--- a/csharp/downgrades/178a7e6cf335486d33d4e49543148e3f57f04a9a/upgrade.properties
+++ b/csharp/downgrades/178a7e6cf335486d33d4e49543148e3f57f04a9a/upgrade.properties
@@ -0,0 +1,3 @@
+description: Remove the relation `extension_receiver_type` and remove the `extension_type` type kind.
+compatibility: backwards
+extension_receiver_type.rel: delete
--- a/csharp/extractor/Semmle.Extraction.CSharp/CodeAnalysisExtensions/SymbolExtensions.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/CodeAnalysisExtensions/SymbolExtensions.cs
@@ -4,6 +4,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using Microsoft.CodeAnalysis;
+using Semmle.Util;
 using Semmle.Extraction.CSharp.Entities;

 namespace Semmle.Extraction.CSharp
@@ -164,6 +165,7 @@ namespace Semmle.Extraction.CSharp
                    case TypeKind.Enum:
                    case TypeKind.Delegate:
                    case TypeKind.Error:
+                    case TypeKind.Extension:
                        var named = (INamedTypeSymbol)type;
                        named.BuildNamedTypeId(cx, trapFile, symbolBeingDefined, constructUnderlyingTupleType);
                        return;
@@ -275,6 +277,20 @@ namespace Semmle.Extraction.CSharp
        public static IEnumerable<IFieldSymbol?> GetTupleElementsMaybeNull(this INamedTypeSymbol type) =>
            type.TupleElements;

+        private static void BuildExtensionTypeId(this INamedTypeSymbol named, Context cx, EscapingTextWriter trapFile)
+        {
+            trapFile.Write("extension(");
+            if (named.ExtensionMarkerName is not null)
+            {
+                trapFile.Write(named.ExtensionMarkerName);
+            }
+            else
+            {
+                trapFile.Write("unknown");
+            }
+            trapFile.Write(")");
+        }
+
        private static void BuildQualifierAndName(INamedTypeSymbol named, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined)
        {
            if (named.ContainingType is not null)
@@ -289,8 +305,18 @@ namespace Semmle.Extraction.CSharp
                named.ContainingNamespace.BuildNamespace(cx, trapFile);
            }

-            var name = named.IsFileLocal ? named.MetadataName : named.Name;
-            trapFile.Write(name);
+            if (named.IsFileLocal)
+            {
+                trapFile.Write(named.MetadataName);
+            }
+            else if (named.IsExtension)
+            {
+                named.BuildExtensionTypeId(cx, trapFile);
+            }
+            else
+            {
+                trapFile.Write(named.Name);
+            }
        }

        private static void BuildTupleId(INamedTypeSymbol named, Context cx, EscapingTextWriter trapFile, ISymbol symbolBeingDefined)
@@ -391,6 +417,7 @@ namespace Semmle.Extraction.CSharp
                    case TypeKind.Enum:
                    case TypeKind.Delegate:
                    case TypeKind.Error:
+                    case TypeKind.Extension:
                        var named = (INamedTypeSymbol)type;
                        named.BuildNamedTypeDisplayName(cx, trapFile, constructUnderlyingTupleType);
                        return;
@@ -465,6 +492,20 @@ namespace Semmle.Extraction.CSharp
        private static void BuildFunctionPointerTypeDisplayName(this IFunctionPointerTypeSymbol funptr, Context cx, TextWriter trapFile) =>
            BuildFunctionPointerSignature(funptr, trapFile, s => s.BuildDisplayName(cx, trapFile));

+        private static void BuildExtensionTypeDisplayName(this INamedTypeSymbol named, Context cx, TextWriter trapFile)
+        {
+            trapFile.Write("extension(");
+            if (named.ExtensionParameter?.Type is ITypeSymbol type)
+            {
+                type.BuildDisplayName(cx, trapFile);
+            }
+            else
+            {
+                trapFile.Write("unknown");
+            }
+            trapFile.Write(")");
+        }
+
        private static void BuildNamedTypeDisplayName(this INamedTypeSymbol namedType, Context cx, TextWriter trapFile, bool constructUnderlyingTupleType)
        {
            if (!constructUnderlyingTupleType && namedType.IsTupleType)
@@ -484,6 +525,12 @@ namespace Semmle.Extraction.CSharp
                return;
            }

+            if (namedType.IsExtension)
+            {
+                namedType.BuildExtensionTypeDisplayName(cx, trapFile);
+                return;
+            }
+
            if (namedType.IsAnonymousType)
            {
                namedType.BuildAnonymousName(cx, trapFile);
@@ -596,6 +643,84 @@ namespace Semmle.Extraction.CSharp
            return true;
        }

+        /// <summary>
+        /// Return true if this method is a compiler-generated extension method.
+        /// </summary>
+        public static bool IsCompilerGeneratedExtensionMethod(this IMethodSymbol method) =>
+            method.TryGetExtensionMethod() is not null;
+
+        /// <summary>
+        /// Returns the extension method corresponding to this compiler-generated extension method, if it exists.
+        /// </summary>
+        public static IMethodSymbol? TryGetExtensionMethod(this IMethodSymbol method)
+        {
+            if (method.IsImplicitlyDeclared && method.ContainingSymbol is INamedTypeSymbol containingType)
+            {
+                // Extension types are declared within the same type as the generated
+                // extension method implementation.
+                var extensions = containingType.GetMembers()
+                    .OfType<INamedTypeSymbol>()
+                    .Where(t => t.IsExtension);
+                // Find the (possibly unbound) original extension method that maps to this implementation (if any).
+                var unboundDeclaration = extensions.SelectMany(e => e.GetMembers())
+                    .OfType<IMethodSymbol>()
+                    .FirstOrDefault(m => SymbolEqualityComparer.Default.Equals(m.AssociatedExtensionImplementation, method.ConstructedFrom));
+
+                var isFullyConstructed = method.IsBoundGenericMethod();
+                if (isFullyConstructed && unboundDeclaration?.ContainingType is INamedTypeSymbol extensionType)
+                {
+                    try
+                    {
+                        // Use the type arguments from the constructed extension method to construct the extension type.
+                        var arguments = method.TypeArguments.ToArray();
+                        var (extensionTypeArguments, extensionMethodArguments) = arguments.SplitAt(extensionType.TypeParameters.Length);
+
+                        // Construct the extension type.
+                        var boundExtensionType = extensionType.IsUnboundGenericType()
+                            ? extensionType.Construct(extensionTypeArguments.ToArray())
+                            : extensionType;
+
+                        // Find the extension method declaration within the constructed extension type.
+                        var extensionDeclaration = boundExtensionType.GetMembers()
+                            .OfType<IMethodSymbol>()
+                            .First(c => SymbolEqualityComparer.Default.Equals(c.OriginalDefinition, unboundDeclaration));
+
+                        // If the extension declaration is unbound apply the remaning type arguments and construct it.
+                        return extensionDeclaration.IsUnboundGenericMethod()
+                            ? extensionDeclaration.Construct(extensionMethodArguments.ToArray())
+                            : extensionDeclaration;
+                    }
+                    catch
+                    {
+                        // If anything goes wrong, fall back to the unbound declaration.
+                        return unboundDeclaration;
+                    }
+                }
+                else
+                {
+                    return unboundDeclaration;
+                }
+            }
+            return null;
+        }
+
+        /// <summary>
+        /// Returns true if this method is an unbound generic method.
+        /// </summary>
+        public static bool IsUnboundGenericMethod(this IMethodSymbol method) =>
+            method.IsGenericMethod && SymbolEqualityComparer.Default.Equals(method.ConstructedFrom, method);
+
+        /// <summary>
+        /// Returns true if this method is a bound generic method.
+        /// </summary>
+        public static bool IsBoundGenericMethod(this IMethodSymbol method) => method.IsGenericMethod && !method.IsUnboundGenericMethod();
+
+        /// <summary>
+        /// Returns true if this type is an unbound generic type.
+        /// </summary>
+        public static bool IsUnboundGenericType(this INamedTypeSymbol type) =>
+            type.IsGenericType && SymbolEqualityComparer.Default.Equals(type.ConstructedFrom, type);
+
        /// <summary>
        /// Gets the base type of `symbol`. Unlike `symbol.BaseType`, this excludes effective base
        /// types of type parameters as well as `object` base types.
@@ -692,5 +817,35 @@ namespace Semmle.Extraction.CSharp
        /// </summary>
        public static IEnumerable<T> ExtractionCandidates<T>(this IEnumerable<T> symbols) where T : ISymbol =>
            symbols.Where(symbol => symbol.ShouldExtractSymbol());
+
+        /// <summary>
+        /// Returns the parameter kind for this parameter symbol, e.g. `ref`, `out`, `params`, etc.
+        /// </summary>
+        public static Parameter.Kind GetParameterKind(this IParameterSymbol parameter)
+        {
+            switch (parameter.RefKind)
+            {
+                case RefKind.Out:
+                    return Parameter.Kind.Out;
+                case RefKind.Ref:
+                    return Parameter.Kind.Ref;
+                case RefKind.In:
+                    return Parameter.Kind.In;
+                case RefKind.RefReadOnlyParameter:
+                    return Parameter.Kind.RefReadOnly;
+                default:
+                    if (parameter.IsParams)
+                        return Parameter.Kind.Params;
+
+                    if (parameter.Ordinal == 0)
+                    {
+                        if (parameter.ContainingSymbol is IMethodSymbol method && method.IsExtensionMethod)
+                        {
+                            return Parameter.Kind.This;
+                        }
+                    }
+                    return Parameter.Kind.None;
+            }
+        }
    }
 }
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Base/CachedEntity.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Base/CachedEntity.cs
@@ -54,22 +54,6 @@ namespace Semmle.Extraction.CSharp.Entities
            }
        }

-        protected static void WriteLocationToTrap<T1>(Action<T1, Location> writeAction, T1 entity, Location l)
-        {
-            if (l is not EmptyLocation)
-            {
-                writeAction(entity, l);
-            }
-        }
-
-        protected static void WriteLocationsToTrap<T1>(Action<T1, Location> writeAction, T1 entity, IEnumerable<Location> locations)
-        {
-            foreach (var loc in locations)
-            {
-                WriteLocationToTrap(writeAction, entity, loc);
-            }
-        }
-
        public override bool NeedsPopulation { get; }

        public override int GetHashCode() => Symbol is null ? 0 : Symbol.GetHashCode();
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Base/CachedSymbol.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Base/CachedSymbol.cs
@@ -32,32 +32,6 @@ namespace Semmle.Extraction.CSharp.Entities
                Attribute.ExtractAttributes(Context, Symbol, this);
        }

-        protected void PopulateNullability(TextWriter trapFile, AnnotatedTypeSymbol type)
-        {
-            var n = NullabilityEntity.Create(Context, Nullability.Create(type));
-            if (!type.HasObliviousNullability())
-            {
-                trapFile.type_nullability(this, n);
-            }
-        }
-
-        protected void PopulateRefKind(TextWriter trapFile, RefKind kind)
-        {
-            switch (kind)
-            {
-                case RefKind.Out:
-                    trapFile.type_annotation(this, Kinds.TypeAnnotation.Out);
-                    break;
-                case RefKind.Ref:
-                    trapFile.type_annotation(this, Kinds.TypeAnnotation.Ref);
-                    break;
-                case RefKind.RefReadOnly:
-                case RefKind.RefReadOnlyParameter:
-                    trapFile.type_annotation(this, Kinds.TypeAnnotation.ReadonlyRef);
-                    break;
-            }
-        }
-
        protected void PopulateScopedKind(TextWriter trapFile, ScopedKind kind)
        {
            switch (kind)
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Base/Entity.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Base/Entity.cs
@@ -1,6 +1,8 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using Microsoft.CodeAnalysis;
+using Semmle.Extraction.CSharp.Entities;

 namespace Semmle.Extraction.CSharp
 {
@@ -24,7 +26,7 @@ namespace Semmle.Extraction.CSharp
            trapFile.WriteUnescaped('\"');
        }

-        public abstract Location? ReportingLocation { get; }
+        public abstract Microsoft.CodeAnalysis.Location? ReportingLocation { get; }

        public abstract TrapStackBehaviour TrapStackBehaviour { get; }

@@ -65,6 +67,48 @@ namespace Semmle.Extraction.CSharp
        }
 #endif

+        protected void PopulateRefKind(TextWriter trapFile, RefKind kind)
+        {
+            switch (kind)
+            {
+                case RefKind.Out:
+                    trapFile.type_annotation(this, Kinds.TypeAnnotation.Out);
+                    break;
+                case RefKind.Ref:
+                    trapFile.type_annotation(this, Kinds.TypeAnnotation.Ref);
+                    break;
+                case RefKind.RefReadOnly:
+                case RefKind.RefReadOnlyParameter:
+                    trapFile.type_annotation(this, Kinds.TypeAnnotation.ReadonlyRef);
+                    break;
+            }
+        }
+
+        protected void PopulateNullability(TextWriter trapFile, AnnotatedTypeSymbol type)
+        {
+            var n = NullabilityEntity.Create(Context, Nullability.Create(type));
+            if (!type.HasObliviousNullability())
+            {
+                trapFile.type_nullability(this, n);
+            }
+        }
+
+        protected static void WriteLocationToTrap<T1>(Action<T1, Entities.Location> writeAction, T1 entity, Entities.Location l)
+        {
+            if (l is not EmptyLocation)
+            {
+                writeAction(entity, l);
+            }
+        }
+
+        protected static void WriteLocationsToTrap<T1>(Action<T1, Entities.Location> writeAction, T1 entity, IEnumerable<Entities.Location> locations)
+        {
+            foreach (var loc in locations)
+            {
+                WriteLocationToTrap(writeAction, entity, loc);
+            }
+        }
+
        public override string ToString() => Label.ToString();
    }
 }
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Invocation.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Invocation.cs
@@ -24,6 +24,16 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions

        private bool IsExplicitDelegateInvokeCall() => Kind == ExprKind.DELEGATE_INVOCATION && Context.GetModel(Syntax.Expression).GetSymbolInfo(Syntax.Expression).Symbol is IMethodSymbol m && m.MethodKind == MethodKind.DelegateInvoke;

+        private bool IsOperatorCall() => Kind == ExprKind.OPERATOR_INVOCATION;
+
+        private bool IsValidMemberAccessKind()
+        {
+            return Kind == ExprKind.METHOD_INVOCATION ||
+                IsEventDelegateCall() ||
+                IsExplicitDelegateInvokeCall() ||
+                IsOperatorCall();
+        }
+
        protected override void PopulateExpression(TextWriter trapFile)
        {
            if (IsNameof(Syntax))
@@ -37,7 +47,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
            var target = TargetSymbol;
            switch (Syntax.Expression)
            {
-                case MemberAccessExpressionSyntax memberAccess when Kind == ExprKind.METHOD_INVOCATION || IsEventDelegateCall() || IsExplicitDelegateInvokeCall():
+                case MemberAccessExpressionSyntax memberAccess when IsValidMemberAccessKind():
                    memberName = memberAccess.Name.Identifier.Text;
                    if (Syntax.Expression.Kind() == SyntaxKind.SimpleMemberAccessExpression)
                        // Qualified method call; `x.M()`
@@ -113,14 +123,24 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions

        public SymbolInfo SymbolInfo => info.SymbolInfo;

+        private static bool IsOperatorLikeCall(ExpressionNodeInfo info)
+        {
+            return info.SymbolInfo.Symbol is IMethodSymbol method &&
+                method.TryGetExtensionMethod()?.MethodKind == MethodKind.UserDefinedOperator;
+        }
+
        public IMethodSymbol? TargetSymbol
        {
            get
            {
                var si = SymbolInfo;

-                if (si.Symbol is not null)
-                    return si.Symbol as IMethodSymbol;
+                if (si.Symbol is ISymbol symbol)
+                {
+                    var method = symbol as IMethodSymbol;
+                    // Case for compiler-generated extension methods.
+                    return method?.TryGetExtensionMethod() ?? method;
+                }

                if (si.CandidateReason == CandidateReason.OverloadResolutionFailure)
                {
@@ -196,15 +216,25 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions

        private static ExprKind GetKind(ExpressionNodeInfo info)
        {
-            return IsNameof((InvocationExpressionSyntax)info.Node)
-                ? ExprKind.NAMEOF
-                : IsDelegateLikeCall(info)
-                    ? IsDelegateInvokeCall(info)
-                        ? ExprKind.DELEGATE_INVOCATION
-                        : ExprKind.FUNCTION_POINTER_INVOCATION
-                    : IsLocalFunctionInvocation(info)
-                        ? ExprKind.LOCAL_FUNCTION_INVOCATION
-                        : ExprKind.METHOD_INVOCATION;
+            if (IsNameof((InvocationExpressionSyntax)info.Node))
+            {
+                return ExprKind.NAMEOF;
+            }
+            if (IsDelegateLikeCall(info))
+            {
+                return IsDelegateInvokeCall(info)
+                    ? ExprKind.DELEGATE_INVOCATION
+                    : ExprKind.FUNCTION_POINTER_INVOCATION;
+            }
+            if (IsLocalFunctionInvocation(info))
+            {
+                return ExprKind.LOCAL_FUNCTION_INVOCATION;
+            }
+            if (IsOperatorLikeCall(info))
+            {
+                return ExprKind.OPERATOR_INVOCATION;
+            }
+            return ExprKind.METHOD_INVOCATION;
        }

        private static bool IsNameof(InvocationExpressionSyntax syntax)
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/IParameter.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/IParameter.cs
@@ -0,0 +1,9 @@
+namespace Semmle.Extraction.CSharp.Entities
+{
+    /// <summary>
+    /// Marker interface for parameter entities.
+    /// </summary>
+    internal interface IParameter : IEntity
+    {
+    }
+}
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs
@@ -14,9 +14,28 @@ namespace Semmle.Extraction.CSharp.Entities
        protected Method(Context cx, IMethodSymbol init)
            : base(cx, init) { }

+        private SyntheticExtensionParameter? SyntheticParameter { get; set; }
+
+        private int SynthesizeExtensionParameter()
+        {
+            // Synthesize implicit parameter for extension methods declared using extension(...) syntax.
+            if (Symbol.ContainingSymbol is INamedTypeSymbol type &&
+                type.IsExtension && type.ExtensionParameter is IParameterSymbol parameter &&
+                !string.IsNullOrEmpty(parameter.Name) && !Symbol.IsStatic)
+            {
+                var originalSyntheticParam = OriginalDefinition.SyntheticParameter;
+                SyntheticParameter = SyntheticExtensionParameter.Create(Context, this, parameter, originalSyntheticParam);
+                return 1;
+            }
+
+            return 0;
+        }
+
        protected void PopulateParameters()
        {
            var originalMethod = OriginalDefinition;
+            var positionOffset = SynthesizeExtensionParameter();
+
            IEnumerable<IParameterSymbol> parameters = Symbol.Parameters;
            IEnumerable<IParameterSymbol> originalParameters = originalMethod.Symbol.Parameters;

@@ -24,8 +43,8 @@ namespace Semmle.Extraction.CSharp.Entities
            {
                var original = SymbolEqualityComparer.Default.Equals(p.paramSymbol, p.originalParam)
                    ? null
-                    : Parameter.Create(Context, p.originalParam, originalMethod);
-                Parameter.Create(Context, p.paramSymbol, this, original);
+                    : Parameter.Create(Context, p.originalParam, originalMethod, null, positionOffset);
+                Parameter.Create(Context, p.paramSymbol, this, original, positionOffset);
            }

            if (Symbol.IsVararg)
@@ -302,9 +321,9 @@ namespace Semmle.Extraction.CSharp.Entities
        /// <summary>
        /// Whether this method has unbound type parameters.
        /// </summary>
-        public bool IsUnboundGeneric => IsGeneric && SymbolEqualityComparer.Default.Equals(Symbol.ConstructedFrom, Symbol);
+        public bool IsUnboundGeneric => Symbol.IsUnboundGenericMethod();

-        public bool IsBoundGeneric => IsGeneric && !IsUnboundGeneric;
+        public bool IsBoundGeneric => Symbol.IsBoundGenericMethod();

        protected IMethodSymbol ConstructedFromSymbol => Symbol.ConstructedFrom;

--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/OrdinaryMethod.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/OrdinaryMethod.cs
@@ -23,7 +23,11 @@ namespace Semmle.Extraction.CSharp.Entities
                ? Symbol.ContainingType.GetSymbolLocation()
                : BodyDeclaringSymbol.GetSymbolLocation();

-        public override bool NeedsPopulation => base.NeedsPopulation || IsCompilerGeneratedDelegate();
+        public override bool NeedsPopulation =>
+            (base.NeedsPopulation || IsCompilerGeneratedDelegate()) &&
+            // Exclude compiler-generated extension methods. A call to such a method
+            // is replaced by a call to the defining extension method.
+            !Symbol.IsCompilerGeneratedExtensionMethod();

        public override void Populate(TextWriter trapFile)
        {
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Parameter.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Parameter.cs
@@ -7,16 +7,23 @@ using Semmle.Extraction.CSharp.Populators;

 namespace Semmle.Extraction.CSharp.Entities
 {
-    internal class Parameter : CachedSymbol<IParameterSymbol>, IExpressionParentEntity
+    internal class Parameter : CachedSymbol<IParameterSymbol>, IExpressionParentEntity, IParameter
    {
        protected IEntity? Parent { get; set; }
        protected Parameter Original { get; }
+        private int PositionOffset { get; set; }

-        protected Parameter(Context cx, IParameterSymbol init, IEntity? parent, Parameter? original)
+        private Parameter(Context cx, IParameterSymbol init, IEntity? parent, Parameter? original, int positionOffset)
            : base(cx, init)
        {
            Parent = parent;
            Original = original ?? this;
+            PositionOffset = positionOffset;
+        }
+
+        protected Parameter(Context cx, IParameterSymbol init, IEntity? parent, Parameter? original)
+            : this(cx, init, parent, original, 0)
+        {
        }

        public override Microsoft.CodeAnalysis.Location ReportingLocation => Symbol.GetSymbolLocation();
@@ -32,46 +39,18 @@ namespace Semmle.Extraction.CSharp.Entities
            RefReadOnly = 6
        }

-        protected virtual int Ordinal => Symbol.Ordinal;
+        protected virtual int Ordinal => Symbol.Ordinal + PositionOffset;

-        private Kind ParamKind
-        {
-            get
-            {
-                switch (Symbol.RefKind)
-                {
-                    case RefKind.Out:
-                        return Kind.Out;
-                    case RefKind.Ref:
-                        return Kind.Ref;
-                    case RefKind.In:
-                        return Kind.In;
-                    case RefKind.RefReadOnlyParameter:
-                        return Kind.RefReadOnly;
-                    default:
-                        if (Symbol.IsParams)
-                            return Kind.Params;
-
-                        if (Ordinal == 0)
-                        {
-                            if (Symbol.ContainingSymbol is IMethodSymbol method && method.IsExtensionMethod)
-                                return Kind.This;
-                        }
-                        return Kind.None;
-                }
-            }
-        }
-
-        public static Parameter Create(Context cx, IParameterSymbol param, IEntity parent, Parameter? original = null)
+        public static Parameter Create(Context cx, IParameterSymbol param, IEntity parent, Parameter? original = null, int positionOffset = 0)
        {
            var cachedSymbol = cx.GetPossiblyCachedParameterSymbol(param);
-            return ParameterFactory.Instance.CreateEntity(cx, cachedSymbol, (cachedSymbol, parent, original));
+            return ParameterFactory.Instance.CreateEntity(cx, cachedSymbol, (cachedSymbol, parent, original, positionOffset));
        }

        public static Parameter Create(Context cx, IParameterSymbol param)
        {
            var cachedSymbol = cx.GetPossiblyCachedParameterSymbol(param);
-            return ParameterFactory.Instance.CreateEntity(cx, cachedSymbol, (cachedSymbol, null, null));
+            return ParameterFactory.Instance.CreateEntity(cx, cachedSymbol, (cachedSymbol, null, null, 0));
        }

        public override void WriteId(EscapingTextWriter trapFile)
@@ -79,6 +58,9 @@ namespace Semmle.Extraction.CSharp.Entities
            if (Parent is null)
                Parent = Method.Create(Context, Symbol.ContainingSymbol as IMethodSymbol);

+            if (Parent is null && Symbol.ContainingSymbol is INamedTypeSymbol type && type.IsExtension)
+                Parent = Type.Create(Context, type);
+
            if (Parent is null)
                throw new InternalError(Symbol, "Couldn't get parent of symbol.");

@@ -113,7 +95,8 @@ namespace Semmle.Extraction.CSharp.Entities
                Context.ModelError(Symbol, "Inconsistent parameter declaration");

            var type = Type.Create(Context, Symbol.Type);
-            trapFile.@params(this, Name, type.TypeRef, Ordinal, ParamKind, Parent!, Original);
+            var kind = Symbol.GetParameterKind();
+            trapFile.@params(this, Name, type.TypeRef, Ordinal, kind, Parent!, Original);

            if (Context.OnlyScaffold)
            {
@@ -194,11 +177,11 @@ namespace Semmle.Extraction.CSharp.Entities
            return syntax?.Default;
        }

-        private class ParameterFactory : CachedEntityFactory<(IParameterSymbol, IEntity?, Parameter?), Parameter>
+        private class ParameterFactory : CachedEntityFactory<(IParameterSymbol, IEntity?, Parameter?, int), Parameter>
        {
            public static ParameterFactory Instance { get; } = new ParameterFactory();

-            public override Parameter Create(Context cx, (IParameterSymbol, IEntity?, Parameter?) init) => new Parameter(cx, init.Item1, init.Item2, init.Item3);
+            public override Parameter Create(Context cx, (IParameterSymbol, IEntity?, Parameter?, int) init) => new Parameter(cx, init.Item1, init.Item2, init.Item3, init.Item4);
        }

        public override TrapStackBehaviour TrapStackBehaviour => TrapStackBehaviour.OptionalLabel;
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/SyntheticExtensionParameter.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/SyntheticExtensionParameter.cs
@@ -0,0 +1,77 @@
+using System.IO;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace Semmle.Extraction.CSharp.Entities
+{
+    /// <summary>
+    /// Synthetic parameter for extension methods declared using the extension syntax.
+    /// That is, we add a synthetic parameter `s` to `IsValid` in the following example:
+    /// extension(string s) {
+    ///   public bool IsValid() { ... }
+    /// }
+    ///
+    /// Note, that we use the characteristics of the parameter of the extension type
+    /// to populate the database.
+    /// </summary>
+    internal class SyntheticExtensionParameter : FreshEntity, IParameter
+    {
+        private Method ExtensionMethod { get; }
+        private IParameterSymbol ExtensionParameter { get; }
+        private SyntheticExtensionParameter Original { get; }
+
+        private SyntheticExtensionParameter(Context cx, Method method, IParameterSymbol parameter, SyntheticExtensionParameter? original) : base(cx)
+        {
+            ExtensionMethod = method;
+            ExtensionParameter = parameter;
+            Original = original ?? this;
+        }
+
+        private static int Ordinal => 0;
+
+        private string Name => ExtensionParameter.Name;
+
+        private bool IsSourceDeclaration => ExtensionMethod.Symbol.IsSourceDeclaration();
+
+        protected override void Populate(TextWriter trapFile)
+        {
+            PopulateNullability(trapFile, ExtensionParameter.GetAnnotatedType());
+            PopulateRefKind(trapFile, ExtensionParameter.RefKind);
+
+            var type = Type.Create(Context, ExtensionParameter.Type);
+            var kind = ExtensionParameter.GetParameterKind();
+            trapFile.@params(this, Name, type.TypeRef, Ordinal, kind, ExtensionMethod, Original);
+
+            if (Context.OnlyScaffold)
+            {
+                return;
+            }
+
+            if (Context.ExtractLocation(ExtensionParameter))
+            {
+                var locations = Context.GetLocations(ExtensionParameter);
+                WriteLocationsToTrap(trapFile.param_location, this, locations);
+            }
+
+            if (IsSourceDeclaration)
+            {
+                foreach (var syntax in ExtensionParameter.DeclaringSyntaxReferences
+                    .Select(d => d.GetSyntax())
+                    .OfType<ParameterSyntax>()
+                    .Where(s => s.Type is not null))
+                {
+                    TypeMention.Create(Context, syntax.Type!, this, type);
+                }
+            }
+        }
+
+        public static SyntheticExtensionParameter Create(Context cx, Method method, IParameterSymbol parameter, SyntheticExtensionParameter? original)
+        {
+            var p = new SyntheticExtensionParameter(cx, method, parameter, original);
+            p.TryPopulate();
+            return p;
+        }
+    }
+
+}
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/NamedType.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/NamedType.cs
@@ -20,6 +20,8 @@ namespace Semmle.Extraction.CSharp.Entities
        public static NamedType Create(Context cx, INamedTypeSymbol type) =>
            NamedTypeFactory.Instance.CreateEntityFromSymbol(cx, type);

+        public NamedType OriginalDefinition => Create(Context, Symbol.OriginalDefinition);
+
        /// <summary>
        /// Creates a named type entity from a tuple type. Unlike <see cref="Create"/>, this
        /// will create an entity for the underlying `System.ValueTuple` struct.
@@ -90,6 +92,25 @@ namespace Semmle.Extraction.CSharp.Entities
            {
                trapFile.anonymous_types(this);
            }
+
+            if (Symbol.IsExtension && Symbol.ExtensionParameter is IParameterSymbol parameter)
+            {
+                // For some reason an extension type has a receiver parameter with an empty name
+                // even when there is no parameter.
+                if (!string.IsNullOrEmpty(parameter.Name))
+                {
+                    var originalType = OriginalDefinition;
+                    // In case this is a constructed generic, we also need to create the unbound parameter.
+                    var originalParameter = SymbolEqualityComparer.Default.Equals(Symbol, originalType.Symbol.ExtensionParameter) || originalType.Symbol.ExtensionParameter is null
+                        ? null
+                        : Parameter.Create(Context, originalType.Symbol.ExtensionParameter, originalType);
+                    Parameter.Create(Context, parameter, this, originalParameter);
+                }
+
+                // Use the parameter type as the receiver type.
+                var receiverType = Type.Create(Context, parameter.Type).TypeRef;
+                trapFile.extension_receiver_type(this, receiverType);
+            }
        }

        private readonly Lazy<Type[]> typeArgumentsLazy;
--- a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/Type.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/Type.cs
@@ -105,6 +105,7 @@ namespace Semmle.Extraction.CSharp.Entities
                        case TypeKind.Pointer: return Kinds.TypeKind.POINTER;
                        case TypeKind.FunctionPointer: return Kinds.TypeKind.FUNCTION_POINTER;
                        case TypeKind.Error: return Kinds.TypeKind.UNKNOWN;
+                        case TypeKind.Extension: return Kinds.TypeKind.EXTENSION;
                        default:
                            cx.ModelError(Symbol, $"Unhandled type kind '{Symbol.TypeKind}'");
                            return Kinds.TypeKind.UNKNOWN;
@@ -366,7 +367,7 @@ namespace Semmle.Extraction.CSharp.Entities
            private DelegateTypeParameter(Context cx, IParameterSymbol init, IEntity parent, Parameter? original)
                : base(cx, init, parent, original) { }

-            public static new DelegateTypeParameter Create(Context cx, IParameterSymbol param, IEntity parent, Parameter? original = null) =>
+            public static DelegateTypeParameter Create(Context cx, IParameterSymbol param, IEntity parent, Parameter? original = null) =>
               // We need to use a different cache key than `param` to avoid mixing up
               // `DelegateTypeParameter`s and `Parameter`s
               DelegateTypeParameterFactory.Instance.CreateEntity(cx, (typeof(DelegateTypeParameter), new SymbolEqualityWrapper(param)), (param, parent, original));
--- a/csharp/extractor/Semmle.Extraction.CSharp/Kinds/TypeKind.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Kinds/TypeKind.cs
@@ -38,5 +38,6 @@ namespace Semmle.Extraction.Kinds
        TUPLE = 32,
        FUNCTION_POINTER = 33,
        INLINE_ARRAY = 34,
+        EXTENSION = 35
    }
 }
--- a/csharp/extractor/Semmle.Extraction.CSharp/Trap/Tuples.cs
+++ b/csharp/extractor/Semmle.Extraction.CSharp/Trap/Tuples.cs
@@ -202,6 +202,9 @@ namespace Semmle.Extraction.CSharp
        internal static void extend(this TextWriter trapFile, Type type, Type super) =>
            trapFile.WriteTuple("extend", type, super);

+        internal static void extension_receiver_type(this TextWriter trapFile, Type @extension, Type receiverType) =>
+            trapFile.WriteTuple("extension_receiver_type", extension, receiverType);
+
        internal static void anonymous_types(this TextWriter trapFile, Type type) =>
            trapFile.WriteTuple("anonymous_types", type);

@@ -292,10 +295,10 @@ namespace Semmle.Extraction.CSharp
        internal static void overrides(this TextWriter trapFile, Method overriding, Method overridden) =>
            trapFile.WriteTuple("overrides", overriding, overridden);

-        internal static void param_location(this TextWriter trapFile, Parameter param, Location location) =>
+        internal static void param_location(this TextWriter trapFile, IParameter param, Location location) =>
            trapFile.WriteTuple("param_location", param, location);

-        internal static void @params(this TextWriter trapFile, Parameter param, string name, Type type, int child, Parameter.Kind mode, IEntity method, Parameter originalDefinition) =>
+        internal static void @params(this TextWriter trapFile, IParameter param, string name, Type type, int child, Parameter.Kind mode, IEntity method, IParameter originalDefinition) =>
            trapFile.WriteTuple("params", param, name, type, child, (int)mode, method, originalDefinition);

        internal static void parent_namespace(this TextWriter trapFile, IEntity type, Namespace parent) =>
--- a/csharp/extractor/Semmle.Util/IEnumerableExtensions.cs
+++ b/csharp/extractor/Semmle.Util/IEnumerableExtensions.cs
@@ -119,5 +119,28 @@ namespace Semmle.Util
        /// </summary>
        public static IEnumerable<T> WhereNotNull<T>(this IEnumerable<T?> items) where T : class =>
            items.Where(i => i is not null)!;
+
+        /// <summary>
+        /// Splits the sequence at the given index.
+        /// </summary>
+        public static (IEnumerable<T>, IEnumerable<T>) SplitAt<T>(this IEnumerable<T> items, int index)
+        {
+            var left = new List<T>();
+            var right = new List<T>();
+            var i = 0;
+            foreach (var item in items)
+            {
+                if (i < index)
+                {
+                    left.Add(item);
+                }
+                else
+                {
+                    right.Add(item);
+                }
+                i++;
+            }
+            return (left, right);
+        }
    }
 }
--- a/csharp/ql/lib/change-notes/2026-02-05-extension-types.md
+++ b/csharp/ql/lib/change-notes/2026-02-05-extension-types.md
@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* C# 14: Added support for `extension` members in the extractor, QL library, data flow, and Models as Data, covering extension methods, properties, and operators.
--- a/csharp/ql/lib/semmle/code/csharp/Callable.qll
+++ b/csharp/ql/lib/semmle/code/csharp/Callable.qll
@@ -10,6 +10,7 @@ import exprs.Call
 private import commons.QualifiedName
 private import commons.Collections
 private import semmle.code.csharp.ExprOrStmtParent
+private import semmle.code.csharp.internal.Callable
 private import semmle.code.csharp.metrics.Complexity
 private import TypeRef

@@ -223,6 +224,8 @@ class Callable extends Parameterizable, ExprOrStmtParent, @callable {
  Call getACall() { this = result.getTarget() }
 }

+final class ExtensionCallable = ExtensionCallableImpl;
+
 /**
 * A method, for example
 *
@@ -267,8 +270,11 @@ class Method extends Callable, Virtualizable, Attributable, @method {

  override Location getALocation() { method_location(this.getUnboundDeclaration(), result) }

+  /** Holds if this method is a classic extension method. */
+  predicate isClassicExtensionMethod() { this.getParameter(0).hasExtensionMethodModifier() }
+
  /** Holds if this method is an extension method. */
-  predicate isExtensionMethod() { this.getParameter(0).hasExtensionMethodModifier() }
+  predicate isExtensionMethod() { this.isClassicExtensionMethod() or this.isInExtension() }

  /** Gets the type of the `params` parameter of this method, if any. */
  Type getParamsType() {
@@ -295,8 +301,10 @@ class Method extends Callable, Virtualizable, Attributable, @method {
  override string getAPrimaryQlClass() { result = "Method" }
 }

+final class ExtensionMethod = ExtensionMethodImpl;
+
 /**
- * An extension method, for example
+ *  An extension method, for example
 *
 * ```csharp
 * static bool IsDefined(this Widget w) {
@@ -304,16 +312,28 @@ class Method extends Callable, Virtualizable, Attributable, @method {
 * }
 * ```
 */
-class ExtensionMethod extends Method {
-  ExtensionMethod() { this.isExtensionMethod() }
+class ClassicExtensionMethod extends ExtensionMethodImpl {
+  ClassicExtensionMethod() { this.isClassicExtensionMethod() }
+
+  pragma[noinline]
+  override Type getExtendedType() { result = this.getParameter(0).getType() }

  override predicate isStatic() { any() }
+}

-  /** Gets the type being extended by this method. */
-  pragma[noinline]
-  Type getExtendedType() { result = this.getParameter(0).getType() }
-
-  override string getAPrimaryQlClass() { result = "ExtensionMethod" }
+/**
+ * An extension method declared in an extension type, for example `IsNullOrEmpty` in
+ *
+ * ```csharp
+ * static class MyExtensions {
+ *   extension(string s) {
+ *     public bool IsNullOrEmpty() { ... }
+ *   }
+ * }
+ * ```
+ */
+class ExtensionTypeExtensionMethod extends ExtensionMethodImpl {
+  ExtensionTypeExtensionMethod() { this.isInExtension() }
 }

 /**
@@ -536,6 +556,21 @@ class RecordCloneMethod extends Method {
  }
 }

+/**
+ * An extension operator, for example `*` in
+ *
+ * ```csharp
+ * static class MyExtensions {
+ *   extension(string s) {
+ *     public static string operator *(int s1, string s2) { ... }
+ *   }
+ * }
+ * ```
+ */
+class ExtensionOperator extends ExtensionCallableImpl, Operator {
+  ExtensionOperator() { this.isInExtension() }
+}
+
 /**
 * A user-defined unary operator - an operator taking one operand.
 *
--- a/csharp/ql/lib/semmle/code/csharp/Member.qll
+++ b/csharp/ql/lib/semmle/code/csharp/Member.qll
@@ -102,6 +102,9 @@ class Declaration extends NamedElement, @declaration {
   * implicit constructors or accessors.
   */
  predicate isCompilerGenerated() { compiler_generated(this) }
+
+  /** Holds if this declaration is in an extension type. */
+  predicate isInExtension() { this.getDeclaringType() instanceof ExtensionType }
 }

 /** A declaration that can have a modifier. */
@@ -469,7 +472,7 @@ class Virtualizable extends Overridable, Member, @virtualizable {

 /**
 * A parameterizable declaration. Either a callable (`Callable`), a delegate
- * type (`DelegateType`), or an indexer (`Indexer`).
+ * type (`DelegateType`), an indexer (`Indexer`), or an extension (`ExtensionType`).
 */
 class Parameterizable extends Declaration, @parameterizable {
  /** Gets raw parameter `i`, including the `this` parameter at index 0. */
--- a/csharp/ql/lib/semmle/code/csharp/Property.qll
+++ b/csharp/ql/lib/semmle/code/csharp/Property.qll
@@ -6,6 +6,7 @@ import Member
 import Stmt
 import Type
 private import semmle.code.csharp.ExprOrStmtParent
+private import semmle.code.csharp.internal.Callable
 private import TypeRef

 /**
@@ -260,6 +261,21 @@ class Property extends DeclarationWithGetSetAccessors, @property {
  override string getAPrimaryQlClass() { result = "Property" }
 }

+/**
+ * An extension property, for example `FirstChar` in
+ *
+ * ```csharp
+ * static class MyExtensions {
+ *   extension(string s) {
+ *     public char FirstChar { get { ... } }
+ *   }
+ * }
+ * ```
+ */
+class ExtensionProperty extends Property {
+  ExtensionProperty() { this.isInExtension() }
+}
+
 /**
 * An indexer, for example `string this[int i]` on line 2 in
 *
@@ -413,6 +429,22 @@ class Accessor extends Callable, Modifiable, Attributable, Overridable, @callabl
  override string toString() { result = this.getName() }
 }

+/**
+ *  An extension accessor. Either a getter (`Getter`) or a setter (`Setter`) of an
+ *  extension property, for example `get` in
+ *
+ * ```csharp
+ * static class MyExtensions {
+ *   extension(string s) {
+ *     public char FirstChar { get { ... } }
+ *   }
+ * }
+ * ```
+ */
+class ExtensionAccessor extends ExtensionCallableImpl, Accessor {
+  ExtensionAccessor() { this.isInExtension() }
+}
+
 /**
 * A `get` accessor, for example `get { return p; }` in
 *
--- a/csharp/ql/lib/semmle/code/csharp/Type.qll
+++ b/csharp/ql/lib/semmle/code/csharp/Type.qll
@@ -17,7 +17,8 @@ private import semmle.code.csharp.frameworks.system.runtime.CompilerServices
 *
 * Either a value or reference type (`ValueOrRefType`), the `void` type (`VoidType`),
 * a pointer type (`PointerType`), the arglist type (`ArglistType`), an unknown
- * type (`UnknownType`), or a type parameter (`TypeParameter`).
+ * type (`UnknownType`), a type parameter (`TypeParameter`) or
+ * an extension type (`ExtensionType`).
 */
 class Type extends Member, TypeContainer, @type {
  /** Gets the name of this type without additional syntax such as `[]` or `*`. */
@@ -1326,3 +1327,35 @@ class TypeMention extends @type_mention {
  /** Gets the location of this type mention. */
  Location getLocation() { type_mention_location(this, result) }
 }
+
+/**
+ * A type extension declaration, for example `extension(string s) { ... }` in
+ *
+ * ```csharp
+ * static class MyExtensions {
+ *   extension(string s) { ... }
+ * ```
+ */
+class ExtensionType extends Parameterizable, @extension_type {
+  /**
+   * Gets the receiver parameter of this extension type, if any.
+   */
+  Parameter getReceiverParameter() { result = this.getParameter(0) }
+
+  /**
+   * Holds if this extension type has a receiver parameter.
+   */
+  predicate hasReceiverParameter() { exists(this.getReceiverParameter()) }
+
+  /**
+   * Gets the type being extended by this extension type.
+   */
+  Type getExtendedType() {
+    extension_receiver_type(this, result)
+    or
+    not extension_receiver_type(this, any(Type t)) and
+    extension_receiver_type(this, getTypeRef(result))
+  }
+
+  override string getAPrimaryQlClass() { result = "ExtensionType" }
+}
--- a/csharp/ql/lib/semmle/code/csharp/commons/QualifiedName.qll
+++ b/csharp/ql/lib/semmle/code/csharp/commons/QualifiedName.qll
@@ -67,6 +67,12 @@ module QualifiedName<QualifiedNameInputSig Input> {
      )
  }

+  private string getName(ValueOrRefType t) {
+    not t instanceof ExtensionType and result = t.getUndecoratedName()
+    or
+    result = "extension(" + getFullName(t.(ExtensionType).getExtendedType()) + ")"
+  }
+
  /** Holds if declaration `d` has the qualified name `qualifier`.`name`. */
  predicate hasQualifiedName(Declaration d, string qualifier, string name) {
    d =
@@ -86,12 +92,12 @@ module QualifiedName<QualifiedNameInputSig Input> {
            exists(string name0 | name = name0 + Input::getUnboundGenericSuffix(ugt) |
              exists(string enclosing |
                hasQualifiedName(ugt.getDeclaringType(), qualifier, enclosing) and
-                name0 = enclosing + "+" + ugt.getUndecoratedName()
+                name0 = enclosing + "+" + getName(ugt)
              )
              or
              not exists(ugt.getDeclaringType()) and
              qualifier = ugt.getNamespace().getFullName() and
-              name0 = ugt.getUndecoratedName()
+              name0 = getName(ugt)
            )
          )
        or
@@ -100,12 +106,12 @@ module QualifiedName<QualifiedNameInputSig Input> {
            exists(string name0 | name = name0 + "<" + getTypeArgumentsQualifiedNames(ct) + ">" |
              exists(string enclosing |
                hasQualifiedName(ct.getDeclaringType(), qualifier, enclosing) and
-                name0 = enclosing + "+" + ct.getUndecoratedName()
+                name0 = enclosing + "+" + getName(ct)
              )
              or
              not exists(ct.getDeclaringType()) and
              qualifier = ct.getNamespace().getFullName() and
-              name0 = ct.getUndecoratedName()
+              name0 = getName(ct)
            )
          )
        or
@@ -116,12 +122,12 @@ module QualifiedName<QualifiedNameInputSig Input> {
        (
          exists(string enclosing |
            hasQualifiedName(vort.getDeclaringType(), qualifier, enclosing) and
-            name = enclosing + "+" + vort.getUndecoratedName()
+            name = enclosing + "+" + getName(vort)
          )
          or
          not exists(vort.getDeclaringType()) and
          qualifier = vort.getNamespace().getFullName() and
-          name = vort.getUndecoratedName()
+          name = getName(vort)
        )
      )
    or
--- a/csharp/ql/lib/semmle/code/csharp/dataflow/internal/ExternalFlow.qll
+++ b/csharp/ql/lib/semmle/code/csharp/dataflow/internal/ExternalFlow.qll
@@ -214,7 +214,7 @@ module ModelValidation {
      not namespace.regexpMatch("[a-zA-Z0-9_\\.]+") and
      result = "Dubious namespace \"" + namespace + "\" in " + pred + " model."
      or
-      not type.regexpMatch("[a-zA-Z0-9_<>,\\+]+") and
+      not type.regexpMatch("[a-zA-Z0-9_<>,\\(\\)\\+\\.]+") and
      result = "Dubious type \"" + type + "\" in " + pred + " model."
      or
      not name.regexpMatch("[a-zA-Z0-9_<>,\\.]*") and
--- a/csharp/ql/lib/semmle/code/csharp/dispatch/Dispatch.qll
+++ b/csharp/ql/lib/semmle/code/csharp/dispatch/Dispatch.qll
@@ -87,7 +87,8 @@ private module Internal {
    newtype TDispatchCall =
      TDispatchMethodCall(MethodCall mc) {
        not isReflectionCall(mc, _, _, _, _) and
-        not mc.isLateBound()
+        not mc.isLateBound() and
+        not isExtensionAccessorCall(mc)
      } or
      TDispatchAccessorCall(AccessorCall ac) or
      TDispatchOperatorCall(OperatorCall oc) { not oc.isLateBound() } or
@@ -110,7 +111,8 @@ private module Internal {
        c instanceof ConstructorInitializer
        or
        c instanceof LocalFunctionCall
-      }
+      } or
+      TDispatchExtensionAccessorCall(MethodCall mc) { isExtensionAccessorCall(mc) }

    cached
    Expr getCall(DispatchCall dc) { result = dc.(DispatchCallImpl).getCall() }
@@ -142,6 +144,8 @@ private module Internal {

  import Cached

+  private predicate isExtensionAccessorCall(MethodCall mc) { exists(mc.getTargetAccessor()) }
+
  /**
   * Holds if `mc` is a reflection call to a method named `name`, where
   * `object` is the object on which to invoke the method (`null` if a
@@ -819,6 +823,33 @@ private module Internal {
    override Method getAStaticTarget() { result = this.getCall().getTarget() }
  }

+  /**
+   * A call to an extension accessor method.
+   */
+  private class DispatchExtensionAccessorCall extends DispatchCallImpl,
+    TDispatchExtensionAccessorCall
+  {
+    override MethodCall getCall() { this = TDispatchExtensionAccessorCall(result) }
+
+    private Expr getArgumentForParameter(Parameter p) {
+      this.getCall().getTargetAccessor().getAParameter() = p and
+      result = this.getCall().getArgument(p.getPosition())
+    }
+
+    override Expr getArgument(int i) {
+      exists(MethodCall call, Parameter p | call = this.getCall() |
+        p = call.getTargetAccessor().getParameter(i) and
+        result = this.getArgumentForParameter(p)
+      )
+    }
+
+    override Expr getQualifier() { result = this.getCall().getQualifier() }
+
+    override Accessor getAStaticTarget() { result = this.getCall().getTargetAccessor() }
+
+    override RuntimeCallable getADynamicTarget() { result = this.getAStaticTarget() }
+  }
+
  /**
   * An ordinary operator call.
   *
--- a/csharp/ql/lib/semmle/code/csharp/exprs/Access.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/Access.qll
@@ -223,6 +223,40 @@ class ParameterAccess extends LocalScopeVariableAccess, @parameter_access_expr {
  override string getAPrimaryQlClass() { result = "ParameterAccess" }
 }

+/**
+ * An access to a synthetic parameter for an extension method, for example the
+ * access to `s` on line 3 in
+ *
+ * ```csharp
+ * static class MyExtensions {
+ *   extension(string s) {
+ *     public bool IsEmpty() { return s == string.Empty; }
+ *   }
+ * }
+ * ```
+ */
+class SyntheticExtensionParameterAccess extends ParameterAccess {
+  SyntheticExtensionParameterAccess() {
+    exists(ExtensionType et, Parameter p |
+      p = et.getReceiverParameter() and
+      expr_access(this, p)
+    )
+  }
+
+  override Parameter getTarget() {
+    exists(ExtensionCallable c |
+      this.getEnclosingCallable+() = c and
+      result = c.getParameter(0)
+    )
+  }
+
+  override string toString() {
+    result = "access to extension synthetic parameter " + this.getTarget().getName()
+  }
+
+  override string getAPrimaryQlClass() { result = "SyntheticExtensionParameterAccess" }
+}
+
 /**
 * An access to a parameter that reads the underlying value, for example
 * the access to `p` on line 2 in
--- a/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll
+++ b/csharp/ql/lib/semmle/code/csharp/exprs/Call.qll
@@ -267,9 +267,33 @@ class Call extends Expr, @call {
 class MethodCall extends Call, QualifiableExpr, LateBindableExpr, @method_invocation_expr {
  override Method getTarget() { expr_call(this, result) }

+  /**
+   * Gets the accessor that was used to generate this method, if any. For example, the
+   * method call `MyExtensions.get_FirstChar(s)` on line 9 is generated from the property
+   * accessor `get_FirstChar` on line 3 in
+   *
+   * ```csharp
+   * static class MyExtensions {
+   *   extension(string s) {
+   *     public char FirstChar { get { ... } }
+   *   }
+   * }
+   *
+   * class A {
+   *   char M(string s) {
+   *     return MyExtensions.get_FirstChar(s);
+   *   }
+   * }
+   */
+  Accessor getTargetAccessor() { expr_call(this, result) }
+
  override Method getQualifiedDeclaration() { result = this.getTarget() }

-  override string toString() { result = "call to method " + concat(this.getTarget().getName()) }
+  override string toString() {
+    if exists(this.getTargetAccessor())
+    then result = "call to extension accessor " + concat(this.getTargetAccessor().getName())
+    else result = "call to method " + concat(this.getTarget().getName())
+  }

  override string getAPrimaryQlClass() { result = "MethodCall" }

@@ -479,6 +503,30 @@ class OperatorCall extends Call, LateBindableExpr, @operator_invocation_expr {
  override string getAPrimaryQlClass() { result = "OperatorCall" }
 }

+/**
+ * A call to an extension operator, for example `3 * s` on
+ * line 9 in
+ *
+ * ```csharp
+ * static class MyExtensions {
+ *   extension(string s) {
+ *     public static string operator *(int i, string s) { ... }
+ *   }
+ * }
+ *
+ * class A {
+ *   string M(string s) {
+ *     return 3 * s;
+ *   }
+ * }
+ * ```
+ */
+class ExtensionOperatorCall extends OperatorCall {
+  ExtensionOperatorCall() { this.getTarget() instanceof ExtensionOperator }
+
+  override string getAPrimaryQlClass() { result = "ExtensionOperatorCall" }
+}
+
 /**
 * A call to a user-defined mutator operator, for example `a++` on
 * line 7 in
@@ -658,6 +706,44 @@ class IndexerCall extends AccessorCall, IndexerAccessExpr {
  override string getAPrimaryQlClass() { result = "IndexerCall" }
 }

+/**
+ * A call to an extension property accessor (via the property), for example
+ * `s.FirstChar` on line 9 in
+ *
+ * ```csharp
+ * static class MyExtensions {
+ *   extension(string s) {
+ *     public char FirstChar { get { ... } }
+ *   }
+ * }
+ *
+ * class A {
+ *   char M(string s) {
+ *     return s.FirstChar;
+ *   }
+ * }
+ * ```
+ */
+class ExtensionPropertyCall extends PropertyCall {
+  private ExtensionProperty prop;
+
+  ExtensionPropertyCall() { this.getProperty() = prop }
+
+  override Expr getArgument(int i) {
+    if prop.isStatic()
+    then result = super.getArgument(i)
+    else (
+      // Shift arguments as the qualifier is an explicit argument in the getter/setter.
+      i = 0 and
+      result = this.getQualifier()
+      or
+      result = super.getArgument(i - 1)
+    )
+  }
+
+  override string getAPrimaryQlClass() { result = "ExtensionPropertyCall" }
+}
+
 /**
 * A call to an event accessor, for example the call to `add_Click`
 * (defined on line 5) on line 12 in
--- a/csharp/ql/lib/semmle/code/csharp/internal/Callable.qll
+++ b/csharp/ql/lib/semmle/code/csharp/internal/Callable.qll
@@ -0,0 +1,33 @@
+/**
+ * INTERNAL: Do not use.
+ *
+ * Provides `Callable` classes, which are things that can be called
+ * such as methods and operators.
+ */
+
+private import semmle.code.csharp.Callable
+private import semmle.code.csharp.Property
+
+/**
+ * A callable that is declared as an extension.
+ *
+ * Either an extension method (`ExtensionMethod`), an extension operator
+ * (`ExtensionOperator`) or an extension accessor (`ExtensionAccessor`).
+ */
+abstract class ExtensionCallableImpl extends Callable {
+  /** Gets the type being extended by this method. */
+  pragma[noinline]
+  Type getExtendedType() { result = this.getDeclaringType().(ExtensionType).getExtendedType() }
+
+  override string getAPrimaryQlClass() { result = "ExtensionCallable" }
+}
+
+/**
+ * An extension method.
+ *
+ * Either a classic extension method (`ClassicExtensionMethod`) or an extension
+ * type extension method (`ExtensionTypeExtensionMethod`).
+ */
+abstract class ExtensionMethodImpl extends ExtensionCallableImpl, Method {
+  override string getAPrimaryQlClass() { result = "ExtensionMethod" }
+}
--- a/csharp/ql/lib/semmlecode.csharp.dbscheme
+++ b/csharp/ql/lib/semmlecode.csharp.dbscheme
@@ -492,6 +492,7 @@ case @type.kind of
 | 32 = @tuple_type
 | 33 = @function_pointer_type
 | 34 = @inline_array_type
+| 35 = @extension_type
  ;

@simple_type = @bool_type | @char_type | @integral_type | @floating_point_type | @decimal_type;
@@ -502,7 +503,7 @@ case @type.kind of
@value_type = @simple_type | @enum_type | @struct_type | @nullable_type | @int_ptr_type
            | @uint_ptr_type | @tuple_type | @void_type | @inline_array_type;
@ref_type = @class_type | @interface_type | @array_type | @delegate_type | @null_type
-          | @dynamic_type;
+          | @dynamic_type | @extension_type;
@value_or_ref_type = @value_type | @ref_type;

 typerefs(
@@ -541,6 +542,10 @@ function_pointer_return_type(
    unique int function_pointer_id: @function_pointer_type ref,
    int return_type_id: @type_or_ref ref);

+extension_receiver_type(
+  unique int extension: @extension_type ref,
+  int receiver_type_id: @type_or_ref ref);
+
 extend(
  int sub: @type ref,
  int super: @type_or_ref ref);
@@ -903,7 +908,7 @@ localvar_location(
  unique int id: @local_variable ref,
  int loc: @location ref);

-@parameterizable = @callable | @delegate_type | @indexer | @function_pointer_type;
+@parameterizable = @callable | @delegate_type | @indexer | @function_pointer_type | @extension_type;

 #keyset[name, parent_id]
 #keyset[index, parent_id]
--- a/csharp/ql/lib/upgrades/68b5aec54e50fe7e375df3777b756a746ca3a37c/old.dbscheme
+++ b/csharp/ql/lib/upgrades/68b5aec54e50fe7e375df3777b756a746ca3a37c/old.dbscheme
--- a/csharp/ql/lib/upgrades/68b5aec54e50fe7e375df3777b756a746ca3a37c/semmlecode.csharp.dbscheme
+++ b/csharp/ql/lib/upgrades/68b5aec54e50fe7e375df3777b756a746ca3a37c/semmlecode.csharp.dbscheme
--- a/csharp/ql/lib/upgrades/68b5aec54e50fe7e375df3777b756a746ca3a37c/upgrade.properties
+++ b/csharp/ql/lib/upgrades/68b5aec54e50fe7e375df3777b756a746ca3a37c/upgrade.properties
@@ -0,0 +1,2 @@
+description: Add the relation `extension_receiver_type` and add the `extension_type` type kind.
+compatibility: full
--- a/csharp/ql/test/library-tests/dataflow/extensions/ExtensionFlow.expected
+++ b/csharp/ql/test/library-tests/dataflow/extensions/ExtensionFlow.expected
@@ -0,0 +1,502 @@
+models
+edges
+| extensions.cs:5:22:5:24 | obj : B | extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | provenance |  |
+| extensions.cs:5:22:5:24 | obj : B | extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | provenance |  |
+| extensions.cs:5:22:5:24 | obj : B | extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | provenance |  |
+| extensions.cs:5:22:5:24 | obj : B | extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | provenance |  |
+| extensions.cs:5:22:5:24 | obj : B | extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | provenance |  |
+| extensions.cs:5:22:5:24 | obj : B | extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | provenance |  |
+| extensions.cs:11:24:11:37 | call to method Source<B> : B | extensions.cs:108:18:108:26 | access to property Prop1 : B | provenance |  |
+| extensions.cs:11:24:11:37 | call to method Source<B> : B | extensions.cs:108:18:108:26 | access to property Prop1 : B | provenance |  |
+| extensions.cs:11:24:11:37 | call to method Source<B> : B | extensions.cs:111:18:111:44 | call to extension accessor get_Prop1 : B | provenance |  |
+| extensions.cs:11:24:11:37 | call to method Source<B> : B | extensions.cs:111:18:111:44 | call to extension accessor get_Prop1 : B | provenance |  |
+| extensions.cs:13:13:13:15 | value : B | extensions.cs:15:24:15:28 | access to parameter value | provenance |  |
+| extensions.cs:13:13:13:15 | value : B | extensions.cs:15:24:15:28 | access to parameter value | provenance |  |
+| extensions.cs:36:24:36:38 | call to method Source<B> : B | extensions.cs:194:18:194:35 | access to property StaticProp1 : B | provenance |  |
+| extensions.cs:36:24:36:38 | call to method Source<B> : B | extensions.cs:194:18:194:35 | access to property StaticProp1 : B | provenance |  |
+| extensions.cs:36:24:36:38 | call to method Source<B> : B | extensions.cs:197:18:197:47 | call to extension accessor get_StaticProp1 : B | provenance |  |
+| extensions.cs:36:24:36:38 | call to method Source<B> : B | extensions.cs:197:18:197:47 | call to extension accessor get_StaticProp1 : B | provenance |  |
+| extensions.cs:38:13:38:15 | value : B | extensions.cs:40:24:40:28 | access to parameter value | provenance |  |
+| extensions.cs:38:13:38:15 | value : B | extensions.cs:40:24:40:28 | access to parameter value | provenance |  |
+| extensions.cs:46:20:46:33 | call to method Source<B> : B | extensions.cs:127:18:127:25 | call to method M1 : B | provenance |  |
+| extensions.cs:46:20:46:33 | call to method Source<B> : B | extensions.cs:127:18:127:25 | call to method M1 : B | provenance |  |
+| extensions.cs:46:20:46:33 | call to method Source<B> : B | extensions.cs:130:18:130:37 | call to method M1 : B | provenance |  |
+| extensions.cs:46:20:46:33 | call to method Source<B> : B | extensions.cs:130:18:130:37 | call to method M1 : B | provenance |  |
+| extensions.cs:59:48:59:48 | a : B | extensions.cs:61:20:61:20 | access to parameter a | provenance |  |
+| extensions.cs:59:48:59:48 | a : B | extensions.cs:61:20:61:20 | access to parameter a | provenance |  |
+| extensions.cs:67:20:67:33 | call to method Source<B> : B | extensions.cs:185:18:185:24 | call to operator - : B | provenance |  |
+| extensions.cs:67:20:67:33 | call to method Source<B> : B | extensions.cs:185:18:185:24 | call to operator - : B | provenance |  |
+| extensions.cs:67:20:67:33 | call to method Source<B> : B | extensions.cs:188:18:188:52 | call to operator - : B | provenance |  |
+| extensions.cs:67:20:67:33 | call to method Source<B> : B | extensions.cs:188:18:188:52 | call to operator - : B | provenance |  |
+| extensions.cs:76:17:76:17 | b : B | extensions.cs:80:20:80:20 | access to extension synthetic parameter b : B | provenance |  |
+| extensions.cs:76:17:76:17 | b : B | extensions.cs:80:20:80:20 | access to extension synthetic parameter b : B | provenance |  |
+| extensions.cs:76:17:76:17 | b : B | extensions.cs:85:20:85:20 | access to extension synthetic parameter b | provenance |  |
+| extensions.cs:76:17:76:17 | b : B | extensions.cs:85:20:85:20 | access to extension synthetic parameter b | provenance |  |
+| extensions.cs:89:20:89:20 | t : B | extensions.cs:93:20:93:20 | access to extension synthetic parameter t | provenance |  |
+| extensions.cs:89:20:89:20 | t : B | extensions.cs:93:20:93:20 | access to extension synthetic parameter t | provenance |  |
+| extensions.cs:96:33:96:37 | other : B | extensions.cs:98:20:98:24 | access to parameter other : B | provenance |  |
+| extensions.cs:96:33:96:37 | other : B | extensions.cs:98:20:98:24 | access to parameter other : B | provenance |  |
+| extensions.cs:108:13:108:14 | access to local variable b1 : B | extensions.cs:109:14:109:15 | access to local variable b1 | provenance |  |
+| extensions.cs:108:13:108:14 | access to local variable b1 : B | extensions.cs:109:14:109:15 | access to local variable b1 | provenance |  |
+| extensions.cs:108:18:108:26 | access to property Prop1 : B | extensions.cs:108:13:108:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:108:18:108:26 | access to property Prop1 : B | extensions.cs:108:13:108:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:111:13:111:14 | access to local variable b2 : B | extensions.cs:112:14:112:15 | access to local variable b2 | provenance |  |
+| extensions.cs:111:13:111:14 | access to local variable b2 : B | extensions.cs:112:14:112:15 | access to local variable b2 | provenance |  |
+| extensions.cs:111:18:111:44 | call to extension accessor get_Prop1 : B | extensions.cs:111:13:111:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:111:18:111:44 | call to extension accessor get_Prop1 : B | extensions.cs:111:13:111:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:118:21:118:32 | call to method Source<B> : B | extensions.cs:13:13:13:15 | value : B | provenance |  |
+| extensions.cs:118:21:118:32 | call to method Source<B> : B | extensions.cs:13:13:13:15 | value : B | provenance |  |
+| extensions.cs:120:13:120:13 | access to local variable b : B | extensions.cs:121:37:121:37 | access to local variable b : B | provenance |  |
+| extensions.cs:120:13:120:13 | access to local variable b : B | extensions.cs:121:37:121:37 | access to local variable b : B | provenance |  |
+| extensions.cs:120:17:120:30 | call to method Source<B> : B | extensions.cs:120:13:120:13 | access to local variable b : B | provenance |  |
+| extensions.cs:120:17:120:30 | call to method Source<B> : B | extensions.cs:120:13:120:13 | access to local variable b : B | provenance |  |
+| extensions.cs:121:37:121:37 | access to local variable b : B | extensions.cs:13:13:13:15 | value : B | provenance |  |
+| extensions.cs:121:37:121:37 | access to local variable b : B | extensions.cs:13:13:13:15 | value : B | provenance |  |
+| extensions.cs:127:13:127:14 | access to local variable b1 : B | extensions.cs:128:14:128:15 | access to local variable b1 | provenance |  |
+| extensions.cs:127:13:127:14 | access to local variable b1 : B | extensions.cs:128:14:128:15 | access to local variable b1 | provenance |  |
+| extensions.cs:127:18:127:25 | call to method M1 : B | extensions.cs:127:13:127:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:127:18:127:25 | call to method M1 : B | extensions.cs:127:13:127:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:130:13:130:14 | access to local variable b2 : B | extensions.cs:131:14:131:15 | access to local variable b2 | provenance |  |
+| extensions.cs:130:13:130:14 | access to local variable b2 : B | extensions.cs:131:14:131:15 | access to local variable b2 | provenance |  |
+| extensions.cs:130:18:130:37 | call to method M1 : B | extensions.cs:130:13:130:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:130:18:130:37 | call to method M1 : B | extensions.cs:130:13:130:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:136:13:136:14 | access to local variable b1 : B | extensions.cs:137:9:137:10 | access to local variable b1 : B | provenance |  |
+| extensions.cs:136:13:136:14 | access to local variable b1 : B | extensions.cs:137:9:137:10 | access to local variable b1 : B | provenance |  |
+| extensions.cs:136:18:136:29 | call to method Source<B> : B | extensions.cs:136:13:136:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:136:18:136:29 | call to method Source<B> : B | extensions.cs:136:13:136:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:137:9:137:10 | access to local variable b1 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:137:9:137:10 | access to local variable b1 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:139:13:139:14 | access to local variable b2 : B | extensions.cs:140:25:140:26 | access to local variable b2 : B | provenance |  |
+| extensions.cs:139:13:139:14 | access to local variable b2 : B | extensions.cs:140:25:140:26 | access to local variable b2 : B | provenance |  |
+| extensions.cs:139:18:139:31 | call to method Source<B> : B | extensions.cs:139:13:139:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:139:18:139:31 | call to method Source<B> : B | extensions.cs:139:13:139:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:140:25:140:26 | access to local variable b2 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:140:25:140:26 | access to local variable b2 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:145:13:145:14 | access to local variable b1 : B | extensions.cs:146:18:146:19 | access to local variable b1 : B | provenance |  |
+| extensions.cs:145:13:145:14 | access to local variable b1 : B | extensions.cs:146:18:146:19 | access to local variable b1 : B | provenance |  |
+| extensions.cs:145:13:145:14 | access to local variable b1 : B | extensions.cs:149:34:149:35 | access to local variable b1 : B | provenance |  |
+| extensions.cs:145:13:145:14 | access to local variable b1 : B | extensions.cs:149:34:149:35 | access to local variable b1 : B | provenance |  |
+| extensions.cs:145:18:145:29 | call to method Source<B> : B | extensions.cs:145:13:145:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:145:18:145:29 | call to method Source<B> : B | extensions.cs:145:13:145:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:146:13:146:14 | access to local variable b2 : B | extensions.cs:147:14:147:15 | access to local variable b2 | provenance |  |
+| extensions.cs:146:13:146:14 | access to local variable b2 : B | extensions.cs:147:14:147:15 | access to local variable b2 | provenance |  |
+| extensions.cs:146:18:146:19 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | provenance |  |
+| extensions.cs:146:18:146:19 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | provenance |  |
+| extensions.cs:146:18:146:19 | access to local variable b1 : B | extensions.cs:146:18:146:24 | call to method B1 : B | provenance |  |
+| extensions.cs:146:18:146:19 | access to local variable b1 : B | extensions.cs:146:18:146:24 | call to method B1 : B | provenance |  |
+| extensions.cs:146:18:146:24 | call to method B1 : B | extensions.cs:146:13:146:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:146:18:146:24 | call to method B1 : B | extensions.cs:146:13:146:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:149:13:149:14 | access to local variable b3 : B | extensions.cs:150:14:150:15 | access to local variable b3 | provenance |  |
+| extensions.cs:149:13:149:14 | access to local variable b3 : B | extensions.cs:150:14:150:15 | access to local variable b3 | provenance |  |
+| extensions.cs:149:18:149:36 | call to method B1 : B | extensions.cs:149:13:149:14 | access to local variable b3 : B | provenance |  |
+| extensions.cs:149:18:149:36 | call to method B1 : B | extensions.cs:149:13:149:14 | access to local variable b3 : B | provenance |  |
+| extensions.cs:149:34:149:35 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | provenance |  |
+| extensions.cs:149:34:149:35 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | provenance |  |
+| extensions.cs:149:34:149:35 | access to local variable b1 : B | extensions.cs:149:18:149:36 | call to method B1 : B | provenance |  |
+| extensions.cs:149:34:149:35 | access to local variable b1 : B | extensions.cs:149:18:149:36 | call to method B1 : B | provenance |  |
+| extensions.cs:155:13:155:14 | access to local variable b1 : B | extensions.cs:156:18:156:19 | access to local variable b1 : B | provenance |  |
+| extensions.cs:155:13:155:14 | access to local variable b1 : B | extensions.cs:156:18:156:19 | access to local variable b1 : B | provenance |  |
+| extensions.cs:155:18:155:29 | call to method Source<B> : B | extensions.cs:155:13:155:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:155:18:155:29 | call to method Source<B> : B | extensions.cs:155:13:155:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:156:18:156:19 | access to local variable b1 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:156:18:156:19 | access to local variable b1 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:158:13:158:14 | access to local variable b3 : B | extensions.cs:159:41:159:42 | access to local variable b3 : B | provenance |  |
+| extensions.cs:158:13:158:14 | access to local variable b3 : B | extensions.cs:159:41:159:42 | access to local variable b3 : B | provenance |  |
+| extensions.cs:158:18:158:31 | call to method Source<B> : B | extensions.cs:158:13:158:14 | access to local variable b3 : B | provenance |  |
+| extensions.cs:158:18:158:31 | call to method Source<B> : B | extensions.cs:158:13:158:14 | access to local variable b3 : B | provenance |  |
+| extensions.cs:159:41:159:42 | access to local variable b3 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:159:41:159:42 | access to local variable b3 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:164:13:164:14 | access to local variable b1 : B | extensions.cs:165:9:165:10 | access to local variable b1 : B | provenance |  |
+| extensions.cs:164:13:164:14 | access to local variable b1 : B | extensions.cs:165:9:165:10 | access to local variable b1 : B | provenance |  |
+| extensions.cs:164:18:164:29 | call to method Source<B> : B | extensions.cs:164:13:164:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:164:18:164:29 | call to method Source<B> : B | extensions.cs:164:13:164:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:165:9:165:10 | access to local variable b1 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:165:9:165:10 | access to local variable b1 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:167:13:167:14 | access to local variable b2 : B | extensions.cs:168:32:168:33 | access to local variable b2 : B | provenance |  |
+| extensions.cs:167:13:167:14 | access to local variable b2 : B | extensions.cs:168:32:168:33 | access to local variable b2 : B | provenance |  |
+| extensions.cs:167:18:167:31 | call to method Source<B> : B | extensions.cs:167:13:167:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:167:18:167:31 | call to method Source<B> : B | extensions.cs:167:13:167:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:168:32:168:33 | access to local variable b2 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:168:32:168:33 | access to local variable b2 : B | extensions.cs:5:22:5:24 | obj : B | provenance |  |
+| extensions.cs:173:13:173:14 | access to local variable b1 : B | extensions.cs:175:18:175:19 | access to local variable b1 : B | provenance |  |
+| extensions.cs:173:13:173:14 | access to local variable b1 : B | extensions.cs:175:18:175:19 | access to local variable b1 : B | provenance |  |
+| extensions.cs:173:18:173:29 | call to method Source<B> : B | extensions.cs:173:13:173:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:173:18:173:29 | call to method Source<B> : B | extensions.cs:173:13:173:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:175:18:175:19 | access to local variable b1 : B | extensions.cs:59:48:59:48 | a : B | provenance |  |
+| extensions.cs:175:18:175:19 | access to local variable b1 : B | extensions.cs:59:48:59:48 | a : B | provenance |  |
+| extensions.cs:177:13:177:14 | access to local variable b4 : B | extensions.cs:178:43:178:44 | access to local variable b4 : B | provenance |  |
+| extensions.cs:177:13:177:14 | access to local variable b4 : B | extensions.cs:178:43:178:44 | access to local variable b4 : B | provenance |  |
+| extensions.cs:177:18:177:31 | call to method Source<B> : B | extensions.cs:177:13:177:14 | access to local variable b4 : B | provenance |  |
+| extensions.cs:177:18:177:31 | call to method Source<B> : B | extensions.cs:177:13:177:14 | access to local variable b4 : B | provenance |  |
+| extensions.cs:178:43:178:44 | access to local variable b4 : B | extensions.cs:59:48:59:48 | a : B | provenance |  |
+| extensions.cs:178:43:178:44 | access to local variable b4 : B | extensions.cs:59:48:59:48 | a : B | provenance |  |
+| extensions.cs:185:13:185:14 | access to local variable b3 : B | extensions.cs:186:14:186:15 | access to local variable b3 | provenance |  |
+| extensions.cs:185:13:185:14 | access to local variable b3 : B | extensions.cs:186:14:186:15 | access to local variable b3 | provenance |  |
+| extensions.cs:185:18:185:24 | call to operator - : B | extensions.cs:185:13:185:14 | access to local variable b3 : B | provenance |  |
+| extensions.cs:185:18:185:24 | call to operator - : B | extensions.cs:185:13:185:14 | access to local variable b3 : B | provenance |  |
+| extensions.cs:188:13:188:14 | access to local variable b4 : B | extensions.cs:189:14:189:15 | access to local variable b4 | provenance |  |
+| extensions.cs:188:13:188:14 | access to local variable b4 : B | extensions.cs:189:14:189:15 | access to local variable b4 | provenance |  |
+| extensions.cs:188:18:188:52 | call to operator - : B | extensions.cs:188:13:188:14 | access to local variable b4 : B | provenance |  |
+| extensions.cs:188:18:188:52 | call to operator - : B | extensions.cs:188:13:188:14 | access to local variable b4 : B | provenance |  |
+| extensions.cs:194:13:194:14 | access to local variable b1 : B | extensions.cs:195:14:195:15 | access to local variable b1 | provenance |  |
+| extensions.cs:194:13:194:14 | access to local variable b1 : B | extensions.cs:195:14:195:15 | access to local variable b1 | provenance |  |
+| extensions.cs:194:18:194:35 | access to property StaticProp1 : B | extensions.cs:194:13:194:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:194:18:194:35 | access to property StaticProp1 : B | extensions.cs:194:13:194:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:197:13:197:14 | access to local variable b2 : B | extensions.cs:198:14:198:15 | access to local variable b2 | provenance |  |
+| extensions.cs:197:13:197:14 | access to local variable b2 : B | extensions.cs:198:14:198:15 | access to local variable b2 | provenance |  |
+| extensions.cs:197:18:197:47 | call to extension accessor get_StaticProp1 : B | extensions.cs:197:13:197:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:197:18:197:47 | call to extension accessor get_StaticProp1 : B | extensions.cs:197:13:197:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:203:13:203:14 | access to local variable b1 : B | extensions.cs:204:30:204:31 | access to local variable b1 : B | provenance |  |
+| extensions.cs:203:13:203:14 | access to local variable b1 : B | extensions.cs:204:30:204:31 | access to local variable b1 : B | provenance |  |
+| extensions.cs:203:18:203:30 | call to method Source<B> : B | extensions.cs:203:13:203:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:203:18:203:30 | call to method Source<B> : B | extensions.cs:203:13:203:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:204:30:204:31 | access to local variable b1 : B | extensions.cs:38:13:38:15 | value : B | provenance |  |
+| extensions.cs:204:30:204:31 | access to local variable b1 : B | extensions.cs:38:13:38:15 | value : B | provenance |  |
+| extensions.cs:206:13:206:14 | access to local variable b2 : B | extensions.cs:207:38:207:39 | access to local variable b2 : B | provenance |  |
+| extensions.cs:206:13:206:14 | access to local variable b2 : B | extensions.cs:207:38:207:39 | access to local variable b2 : B | provenance |  |
+| extensions.cs:206:18:206:31 | call to method Source<B> : B | extensions.cs:206:13:206:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:206:18:206:31 | call to method Source<B> : B | extensions.cs:206:13:206:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:207:38:207:39 | access to local variable b2 : B | extensions.cs:38:13:38:15 | value : B | provenance |  |
+| extensions.cs:207:38:207:39 | access to local variable b2 : B | extensions.cs:38:13:38:15 | value : B | provenance |  |
+| extensions.cs:212:13:212:14 | access to local variable b1 : B | extensions.cs:213:9:213:10 | access to local variable b1 : B | provenance |  |
+| extensions.cs:212:13:212:14 | access to local variable b1 : B | extensions.cs:213:9:213:10 | access to local variable b1 : B | provenance |  |
+| extensions.cs:212:18:212:30 | call to method Source<B> : B | extensions.cs:212:13:212:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:212:18:212:30 | call to method Source<B> : B | extensions.cs:212:13:212:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:213:9:213:10 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | provenance |  |
+| extensions.cs:213:9:213:10 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | provenance |  |
+| extensions.cs:215:13:215:14 | access to local variable b2 : B | extensions.cs:216:25:216:26 | access to local variable b2 : B | provenance |  |
+| extensions.cs:215:13:215:14 | access to local variable b2 : B | extensions.cs:216:25:216:26 | access to local variable b2 : B | provenance |  |
+| extensions.cs:215:18:215:31 | call to method Source<B> : B | extensions.cs:215:13:215:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:215:18:215:31 | call to method Source<B> : B | extensions.cs:215:13:215:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:216:25:216:26 | access to local variable b2 : B | extensions.cs:76:17:76:17 | b : B | provenance |  |
+| extensions.cs:216:25:216:26 | access to local variable b2 : B | extensions.cs:76:17:76:17 | b : B | provenance |  |
+| extensions.cs:221:13:221:14 | access to local variable b1 : B | extensions.cs:222:9:222:10 | access to local variable b1 : B | provenance |  |
+| extensions.cs:221:13:221:14 | access to local variable b1 : B | extensions.cs:222:9:222:10 | access to local variable b1 : B | provenance |  |
+| extensions.cs:221:18:221:30 | call to method Source<B> : B | extensions.cs:221:13:221:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:221:18:221:30 | call to method Source<B> : B | extensions.cs:221:13:221:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:222:9:222:10 | access to local variable b1 : B | extensions.cs:89:20:89:20 | t : B | provenance |  |
+| extensions.cs:222:9:222:10 | access to local variable b1 : B | extensions.cs:89:20:89:20 | t : B | provenance |  |
+| extensions.cs:224:13:224:14 | access to local variable b2 : B | extensions.cs:225:32:225:33 | access to local variable b2 : B | provenance |  |
+| extensions.cs:224:13:224:14 | access to local variable b2 : B | extensions.cs:225:32:225:33 | access to local variable b2 : B | provenance |  |
+| extensions.cs:224:18:224:31 | call to method Source<B> : B | extensions.cs:224:13:224:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:224:18:224:31 | call to method Source<B> : B | extensions.cs:224:13:224:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:225:32:225:33 | access to local variable b2 : B | extensions.cs:89:20:89:20 | t : B | provenance |  |
+| extensions.cs:225:32:225:33 | access to local variable b2 : B | extensions.cs:89:20:89:20 | t : B | provenance |  |
+| extensions.cs:231:13:231:14 | access to local variable b1 : B | extensions.cs:232:32:232:33 | access to local variable b1 : B | provenance |  |
+| extensions.cs:231:13:231:14 | access to local variable b1 : B | extensions.cs:232:32:232:33 | access to local variable b1 : B | provenance |  |
+| extensions.cs:231:13:231:14 | access to local variable b1 : B | extensions.cs:235:46:235:47 | access to local variable b1 : B | provenance |  |
+| extensions.cs:231:13:231:14 | access to local variable b1 : B | extensions.cs:235:46:235:47 | access to local variable b1 : B | provenance |  |
+| extensions.cs:231:18:231:30 | call to method Source<B> : B | extensions.cs:231:13:231:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:231:18:231:30 | call to method Source<B> : B | extensions.cs:231:13:231:14 | access to local variable b1 : B | provenance |  |
+| extensions.cs:232:13:232:14 | access to local variable b2 : B | extensions.cs:233:14:233:15 | access to local variable b2 | provenance |  |
+| extensions.cs:232:13:232:14 | access to local variable b2 : B | extensions.cs:233:14:233:15 | access to local variable b2 | provenance |  |
+| extensions.cs:232:18:232:34 | call to method GenericM2<B> : B | extensions.cs:232:13:232:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:232:18:232:34 | call to method GenericM2<B> : B | extensions.cs:232:13:232:14 | access to local variable b2 : B | provenance |  |
+| extensions.cs:232:32:232:33 | access to local variable b1 : B | extensions.cs:96:33:96:37 | other : B | provenance |  |
+| extensions.cs:232:32:232:33 | access to local variable b1 : B | extensions.cs:96:33:96:37 | other : B | provenance |  |
+| extensions.cs:232:32:232:33 | access to local variable b1 : B | extensions.cs:232:18:232:34 | call to method GenericM2<B> : B | provenance |  |
+| extensions.cs:232:32:232:33 | access to local variable b1 : B | extensions.cs:232:18:232:34 | call to method GenericM2<B> : B | provenance |  |
+| extensions.cs:235:13:235:14 | access to local variable b3 : B | extensions.cs:236:14:236:15 | access to local variable b3 | provenance |  |
+| extensions.cs:235:13:235:14 | access to local variable b3 : B | extensions.cs:236:14:236:15 | access to local variable b3 | provenance |  |
+| extensions.cs:235:18:235:48 | call to method GenericM2<B> : B | extensions.cs:235:13:235:14 | access to local variable b3 : B | provenance |  |
+| extensions.cs:235:18:235:48 | call to method GenericM2<B> : B | extensions.cs:235:13:235:14 | access to local variable b3 : B | provenance |  |
+| extensions.cs:235:46:235:47 | access to local variable b1 : B | extensions.cs:96:33:96:37 | other : B | provenance |  |
+| extensions.cs:235:46:235:47 | access to local variable b1 : B | extensions.cs:96:33:96:37 | other : B | provenance |  |
+| extensions.cs:235:46:235:47 | access to local variable b1 : B | extensions.cs:235:18:235:48 | call to method GenericM2<B> : B | provenance |  |
+| extensions.cs:235:46:235:47 | access to local variable b1 : B | extensions.cs:235:18:235:48 | call to method GenericM2<B> : B | provenance |  |
+nodes
+| extensions.cs:5:22:5:24 | obj : B | semmle.label | obj : B |
+| extensions.cs:5:22:5:24 | obj : B | semmle.label | obj : B |
+| extensions.cs:5:22:5:24 | obj : B | semmle.label | obj : B |
+| extensions.cs:5:22:5:24 | obj : B | semmle.label | obj : B |
+| extensions.cs:5:22:5:24 | obj : B | semmle.label | obj : B |
+| extensions.cs:5:22:5:24 | obj : B | semmle.label | obj : B |
+| extensions.cs:11:24:11:37 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:11:24:11:37 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:13:13:13:15 | value : B | semmle.label | value : B |
+| extensions.cs:13:13:13:15 | value : B | semmle.label | value : B |
+| extensions.cs:15:24:15:28 | access to parameter value | semmle.label | access to parameter value |
+| extensions.cs:15:24:15:28 | access to parameter value | semmle.label | access to parameter value |
+| extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | semmle.label | access to extension synthetic parameter obj |
+| extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | semmle.label | access to extension synthetic parameter obj |
+| extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | semmle.label | access to extension synthetic parameter obj |
+| extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | semmle.label | access to extension synthetic parameter obj |
+| extensions.cs:36:24:36:38 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:36:24:36:38 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:38:13:38:15 | value : B | semmle.label | value : B |
+| extensions.cs:38:13:38:15 | value : B | semmle.label | value : B |
+| extensions.cs:40:24:40:28 | access to parameter value | semmle.label | access to parameter value |
+| extensions.cs:40:24:40:28 | access to parameter value | semmle.label | access to parameter value |
+| extensions.cs:46:20:46:33 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:46:20:46:33 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | semmle.label | access to extension synthetic parameter obj |
+| extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | semmle.label | access to extension synthetic parameter obj |
+| extensions.cs:59:48:59:48 | a : B | semmle.label | a : B |
+| extensions.cs:59:48:59:48 | a : B | semmle.label | a : B |
+| extensions.cs:61:20:61:20 | access to parameter a | semmle.label | access to parameter a |
+| extensions.cs:61:20:61:20 | access to parameter a | semmle.label | access to parameter a |
+| extensions.cs:67:20:67:33 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:67:20:67:33 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:76:17:76:17 | b : B | semmle.label | b : B |
+| extensions.cs:76:17:76:17 | b : B | semmle.label | b : B |
+| extensions.cs:76:17:76:17 | b : B | semmle.label | b : B |
+| extensions.cs:76:17:76:17 | b : B | semmle.label | b : B |
+| extensions.cs:80:20:80:20 | access to extension synthetic parameter b : B | semmle.label | access to extension synthetic parameter b : B |
+| extensions.cs:80:20:80:20 | access to extension synthetic parameter b : B | semmle.label | access to extension synthetic parameter b : B |
+| extensions.cs:85:20:85:20 | access to extension synthetic parameter b | semmle.label | access to extension synthetic parameter b |
+| extensions.cs:85:20:85:20 | access to extension synthetic parameter b | semmle.label | access to extension synthetic parameter b |
+| extensions.cs:89:20:89:20 | t : B | semmle.label | t : B |
+| extensions.cs:89:20:89:20 | t : B | semmle.label | t : B |
+| extensions.cs:93:20:93:20 | access to extension synthetic parameter t | semmle.label | access to extension synthetic parameter t |
+| extensions.cs:93:20:93:20 | access to extension synthetic parameter t | semmle.label | access to extension synthetic parameter t |
+| extensions.cs:96:33:96:37 | other : B | semmle.label | other : B |
+| extensions.cs:96:33:96:37 | other : B | semmle.label | other : B |
+| extensions.cs:98:20:98:24 | access to parameter other : B | semmle.label | access to parameter other : B |
+| extensions.cs:98:20:98:24 | access to parameter other : B | semmle.label | access to parameter other : B |
+| extensions.cs:108:13:108:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:108:13:108:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:108:18:108:26 | access to property Prop1 : B | semmle.label | access to property Prop1 : B |
+| extensions.cs:108:18:108:26 | access to property Prop1 : B | semmle.label | access to property Prop1 : B |
+| extensions.cs:109:14:109:15 | access to local variable b1 | semmle.label | access to local variable b1 |
+| extensions.cs:109:14:109:15 | access to local variable b1 | semmle.label | access to local variable b1 |
+| extensions.cs:111:13:111:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:111:13:111:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:111:18:111:44 | call to extension accessor get_Prop1 : B | semmle.label | call to extension accessor get_Prop1 : B |
+| extensions.cs:111:18:111:44 | call to extension accessor get_Prop1 : B | semmle.label | call to extension accessor get_Prop1 : B |
+| extensions.cs:112:14:112:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:112:14:112:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:118:21:118:32 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:118:21:118:32 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:120:13:120:13 | access to local variable b : B | semmle.label | access to local variable b : B |
+| extensions.cs:120:13:120:13 | access to local variable b : B | semmle.label | access to local variable b : B |
+| extensions.cs:120:17:120:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:120:17:120:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:121:37:121:37 | access to local variable b : B | semmle.label | access to local variable b : B |
+| extensions.cs:121:37:121:37 | access to local variable b : B | semmle.label | access to local variable b : B |
+| extensions.cs:127:13:127:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:127:13:127:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:127:18:127:25 | call to method M1 : B | semmle.label | call to method M1 : B |
+| extensions.cs:127:18:127:25 | call to method M1 : B | semmle.label | call to method M1 : B |
+| extensions.cs:128:14:128:15 | access to local variable b1 | semmle.label | access to local variable b1 |
+| extensions.cs:128:14:128:15 | access to local variable b1 | semmle.label | access to local variable b1 |
+| extensions.cs:130:13:130:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:130:13:130:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:130:18:130:37 | call to method M1 : B | semmle.label | call to method M1 : B |
+| extensions.cs:130:18:130:37 | call to method M1 : B | semmle.label | call to method M1 : B |
+| extensions.cs:131:14:131:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:131:14:131:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:136:13:136:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:136:13:136:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:136:18:136:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:136:18:136:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:137:9:137:10 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:137:9:137:10 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:139:13:139:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:139:13:139:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:139:18:139:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:139:18:139:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:140:25:140:26 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:140:25:140:26 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:145:13:145:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:145:13:145:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:145:18:145:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:145:18:145:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:146:13:146:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:146:13:146:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:146:18:146:19 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:146:18:146:19 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:146:18:146:24 | call to method B1 : B | semmle.label | call to method B1 : B |
+| extensions.cs:146:18:146:24 | call to method B1 : B | semmle.label | call to method B1 : B |
+| extensions.cs:147:14:147:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:147:14:147:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:149:13:149:14 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:149:13:149:14 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:149:18:149:36 | call to method B1 : B | semmle.label | call to method B1 : B |
+| extensions.cs:149:18:149:36 | call to method B1 : B | semmle.label | call to method B1 : B |
+| extensions.cs:149:34:149:35 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:149:34:149:35 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:150:14:150:15 | access to local variable b3 | semmle.label | access to local variable b3 |
+| extensions.cs:150:14:150:15 | access to local variable b3 | semmle.label | access to local variable b3 |
+| extensions.cs:155:13:155:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:155:13:155:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:155:18:155:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:155:18:155:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:156:18:156:19 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:156:18:156:19 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:158:13:158:14 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:158:13:158:14 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:158:18:158:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:158:18:158:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:159:41:159:42 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:159:41:159:42 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:164:13:164:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:164:13:164:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:164:18:164:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:164:18:164:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:165:9:165:10 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:165:9:165:10 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:167:13:167:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:167:13:167:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:167:18:167:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:167:18:167:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:168:32:168:33 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:168:32:168:33 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:173:13:173:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:173:13:173:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:173:18:173:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:173:18:173:29 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:175:18:175:19 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:175:18:175:19 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:177:13:177:14 | access to local variable b4 : B | semmle.label | access to local variable b4 : B |
+| extensions.cs:177:13:177:14 | access to local variable b4 : B | semmle.label | access to local variable b4 : B |
+| extensions.cs:177:18:177:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:177:18:177:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:178:43:178:44 | access to local variable b4 : B | semmle.label | access to local variable b4 : B |
+| extensions.cs:178:43:178:44 | access to local variable b4 : B | semmle.label | access to local variable b4 : B |
+| extensions.cs:185:13:185:14 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:185:13:185:14 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:185:18:185:24 | call to operator - : B | semmle.label | call to operator - : B |
+| extensions.cs:185:18:185:24 | call to operator - : B | semmle.label | call to operator - : B |
+| extensions.cs:186:14:186:15 | access to local variable b3 | semmle.label | access to local variable b3 |
+| extensions.cs:186:14:186:15 | access to local variable b3 | semmle.label | access to local variable b3 |
+| extensions.cs:188:13:188:14 | access to local variable b4 : B | semmle.label | access to local variable b4 : B |
+| extensions.cs:188:13:188:14 | access to local variable b4 : B | semmle.label | access to local variable b4 : B |
+| extensions.cs:188:18:188:52 | call to operator - : B | semmle.label | call to operator - : B |
+| extensions.cs:188:18:188:52 | call to operator - : B | semmle.label | call to operator - : B |
+| extensions.cs:189:14:189:15 | access to local variable b4 | semmle.label | access to local variable b4 |
+| extensions.cs:189:14:189:15 | access to local variable b4 | semmle.label | access to local variable b4 |
+| extensions.cs:194:13:194:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:194:13:194:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:194:18:194:35 | access to property StaticProp1 : B | semmle.label | access to property StaticProp1 : B |
+| extensions.cs:194:18:194:35 | access to property StaticProp1 : B | semmle.label | access to property StaticProp1 : B |
+| extensions.cs:195:14:195:15 | access to local variable b1 | semmle.label | access to local variable b1 |
+| extensions.cs:195:14:195:15 | access to local variable b1 | semmle.label | access to local variable b1 |
+| extensions.cs:197:13:197:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:197:13:197:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:197:18:197:47 | call to extension accessor get_StaticProp1 : B | semmle.label | call to extension accessor get_StaticProp1 : B |
+| extensions.cs:197:18:197:47 | call to extension accessor get_StaticProp1 : B | semmle.label | call to extension accessor get_StaticProp1 : B |
+| extensions.cs:198:14:198:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:198:14:198:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:203:13:203:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:203:13:203:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:203:18:203:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:203:18:203:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:204:30:204:31 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:204:30:204:31 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:206:13:206:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:206:13:206:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:206:18:206:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:206:18:206:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:207:38:207:39 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:207:38:207:39 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:212:13:212:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:212:13:212:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:212:18:212:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:212:18:212:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:213:9:213:10 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:213:9:213:10 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:215:13:215:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:215:13:215:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:215:18:215:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:215:18:215:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:216:25:216:26 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:216:25:216:26 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:221:13:221:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:221:13:221:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:221:18:221:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:221:18:221:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:222:9:222:10 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:222:9:222:10 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:224:13:224:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:224:13:224:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:224:18:224:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:224:18:224:31 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:225:32:225:33 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:225:32:225:33 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:231:13:231:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:231:13:231:14 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:231:18:231:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:231:18:231:30 | call to method Source<B> : B | semmle.label | call to method Source<B> : B |
+| extensions.cs:232:13:232:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:232:13:232:14 | access to local variable b2 : B | semmle.label | access to local variable b2 : B |
+| extensions.cs:232:18:232:34 | call to method GenericM2<B> : B | semmle.label | call to method GenericM2<B> : B |
+| extensions.cs:232:18:232:34 | call to method GenericM2<B> : B | semmle.label | call to method GenericM2<B> : B |
+| extensions.cs:232:32:232:33 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:232:32:232:33 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:233:14:233:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:233:14:233:15 | access to local variable b2 | semmle.label | access to local variable b2 |
+| extensions.cs:235:13:235:14 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:235:13:235:14 | access to local variable b3 : B | semmle.label | access to local variable b3 : B |
+| extensions.cs:235:18:235:48 | call to method GenericM2<B> : B | semmle.label | call to method GenericM2<B> : B |
+| extensions.cs:235:18:235:48 | call to method GenericM2<B> : B | semmle.label | call to method GenericM2<B> : B |
+| extensions.cs:235:46:235:47 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:235:46:235:47 | access to local variable b1 : B | semmle.label | access to local variable b1 : B |
+| extensions.cs:236:14:236:15 | access to local variable b3 | semmle.label | access to local variable b3 |
+| extensions.cs:236:14:236:15 | access to local variable b3 | semmle.label | access to local variable b3 |
+subpaths
+| extensions.cs:146:18:146:19 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | extensions.cs:80:20:80:20 | access to extension synthetic parameter b : B | extensions.cs:146:18:146:24 | call to method B1 : B |
+| extensions.cs:146:18:146:19 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | extensions.cs:80:20:80:20 | access to extension synthetic parameter b : B | extensions.cs:146:18:146:24 | call to method B1 : B |
+| extensions.cs:149:34:149:35 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | extensions.cs:80:20:80:20 | access to extension synthetic parameter b : B | extensions.cs:149:18:149:36 | call to method B1 : B |
+| extensions.cs:149:34:149:35 | access to local variable b1 : B | extensions.cs:76:17:76:17 | b : B | extensions.cs:80:20:80:20 | access to extension synthetic parameter b : B | extensions.cs:149:18:149:36 | call to method B1 : B |
+| extensions.cs:232:32:232:33 | access to local variable b1 : B | extensions.cs:96:33:96:37 | other : B | extensions.cs:98:20:98:24 | access to parameter other : B | extensions.cs:232:18:232:34 | call to method GenericM2<B> : B |
+| extensions.cs:232:32:232:33 | access to local variable b1 : B | extensions.cs:96:33:96:37 | other : B | extensions.cs:98:20:98:24 | access to parameter other : B | extensions.cs:232:18:232:34 | call to method GenericM2<B> : B |
+| extensions.cs:235:46:235:47 | access to local variable b1 : B | extensions.cs:96:33:96:37 | other : B | extensions.cs:98:20:98:24 | access to parameter other : B | extensions.cs:235:18:235:48 | call to method GenericM2<B> : B |
+| extensions.cs:235:46:235:47 | access to local variable b1 : B | extensions.cs:96:33:96:37 | other : B | extensions.cs:98:20:98:24 | access to parameter other : B | extensions.cs:235:18:235:48 | call to method GenericM2<B> : B |
+testFailures
+#select
+| extensions.cs:15:24:15:28 | access to parameter value | extensions.cs:118:21:118:32 | call to method Source<B> : B | extensions.cs:15:24:15:28 | access to parameter value | $@ | extensions.cs:118:21:118:32 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:15:24:15:28 | access to parameter value | extensions.cs:118:21:118:32 | call to method Source<B> : B | extensions.cs:15:24:15:28 | access to parameter value | $@ | extensions.cs:118:21:118:32 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:15:24:15:28 | access to parameter value | extensions.cs:120:17:120:30 | call to method Source<B> : B | extensions.cs:15:24:15:28 | access to parameter value | $@ | extensions.cs:120:17:120:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:15:24:15:28 | access to parameter value | extensions.cs:120:17:120:30 | call to method Source<B> : B | extensions.cs:15:24:15:28 | access to parameter value | $@ | extensions.cs:120:17:120:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | extensions.cs:155:18:155:29 | call to method Source<B> : B | extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | $@ | extensions.cs:155:18:155:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | extensions.cs:155:18:155:29 | call to method Source<B> : B | extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | $@ | extensions.cs:155:18:155:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | extensions.cs:158:18:158:31 | call to method Source<B> : B | extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | $@ | extensions.cs:158:18:158:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | extensions.cs:158:18:158:31 | call to method Source<B> : B | extensions.cs:23:24:23:26 | access to extension synthetic parameter obj | $@ | extensions.cs:158:18:158:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | extensions.cs:164:18:164:29 | call to method Source<B> : B | extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | $@ | extensions.cs:164:18:164:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | extensions.cs:164:18:164:29 | call to method Source<B> : B | extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | $@ | extensions.cs:164:18:164:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | extensions.cs:167:18:167:31 | call to method Source<B> : B | extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | $@ | extensions.cs:167:18:167:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | extensions.cs:167:18:167:31 | call to method Source<B> : B | extensions.cs:28:24:28:26 | access to extension synthetic parameter obj | $@ | extensions.cs:167:18:167:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:40:24:40:28 | access to parameter value | extensions.cs:203:18:203:30 | call to method Source<B> : B | extensions.cs:40:24:40:28 | access to parameter value | $@ | extensions.cs:203:18:203:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:40:24:40:28 | access to parameter value | extensions.cs:203:18:203:30 | call to method Source<B> : B | extensions.cs:40:24:40:28 | access to parameter value | $@ | extensions.cs:203:18:203:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:40:24:40:28 | access to parameter value | extensions.cs:206:18:206:31 | call to method Source<B> : B | extensions.cs:40:24:40:28 | access to parameter value | $@ | extensions.cs:206:18:206:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:40:24:40:28 | access to parameter value | extensions.cs:206:18:206:31 | call to method Source<B> : B | extensions.cs:40:24:40:28 | access to parameter value | $@ | extensions.cs:206:18:206:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | extensions.cs:136:18:136:29 | call to method Source<B> : B | extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | $@ | extensions.cs:136:18:136:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | extensions.cs:136:18:136:29 | call to method Source<B> : B | extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | $@ | extensions.cs:136:18:136:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | extensions.cs:139:18:139:31 | call to method Source<B> : B | extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | $@ | extensions.cs:139:18:139:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | extensions.cs:139:18:139:31 | call to method Source<B> : B | extensions.cs:51:20:51:22 | access to extension synthetic parameter obj | $@ | extensions.cs:139:18:139:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:61:20:61:20 | access to parameter a | extensions.cs:173:18:173:29 | call to method Source<B> : B | extensions.cs:61:20:61:20 | access to parameter a | $@ | extensions.cs:173:18:173:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:61:20:61:20 | access to parameter a | extensions.cs:173:18:173:29 | call to method Source<B> : B | extensions.cs:61:20:61:20 | access to parameter a | $@ | extensions.cs:173:18:173:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:61:20:61:20 | access to parameter a | extensions.cs:177:18:177:31 | call to method Source<B> : B | extensions.cs:61:20:61:20 | access to parameter a | $@ | extensions.cs:177:18:177:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:61:20:61:20 | access to parameter a | extensions.cs:177:18:177:31 | call to method Source<B> : B | extensions.cs:61:20:61:20 | access to parameter a | $@ | extensions.cs:177:18:177:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:85:20:85:20 | access to extension synthetic parameter b | extensions.cs:212:18:212:30 | call to method Source<B> : B | extensions.cs:85:20:85:20 | access to extension synthetic parameter b | $@ | extensions.cs:212:18:212:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:85:20:85:20 | access to extension synthetic parameter b | extensions.cs:212:18:212:30 | call to method Source<B> : B | extensions.cs:85:20:85:20 | access to extension synthetic parameter b | $@ | extensions.cs:212:18:212:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:85:20:85:20 | access to extension synthetic parameter b | extensions.cs:215:18:215:31 | call to method Source<B> : B | extensions.cs:85:20:85:20 | access to extension synthetic parameter b | $@ | extensions.cs:215:18:215:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:85:20:85:20 | access to extension synthetic parameter b | extensions.cs:215:18:215:31 | call to method Source<B> : B | extensions.cs:85:20:85:20 | access to extension synthetic parameter b | $@ | extensions.cs:215:18:215:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:93:20:93:20 | access to extension synthetic parameter t | extensions.cs:221:18:221:30 | call to method Source<B> : B | extensions.cs:93:20:93:20 | access to extension synthetic parameter t | $@ | extensions.cs:221:18:221:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:93:20:93:20 | access to extension synthetic parameter t | extensions.cs:221:18:221:30 | call to method Source<B> : B | extensions.cs:93:20:93:20 | access to extension synthetic parameter t | $@ | extensions.cs:221:18:221:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:93:20:93:20 | access to extension synthetic parameter t | extensions.cs:224:18:224:31 | call to method Source<B> : B | extensions.cs:93:20:93:20 | access to extension synthetic parameter t | $@ | extensions.cs:224:18:224:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:93:20:93:20 | access to extension synthetic parameter t | extensions.cs:224:18:224:31 | call to method Source<B> : B | extensions.cs:93:20:93:20 | access to extension synthetic parameter t | $@ | extensions.cs:224:18:224:31 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:109:14:109:15 | access to local variable b1 | extensions.cs:11:24:11:37 | call to method Source<B> : B | extensions.cs:109:14:109:15 | access to local variable b1 | $@ | extensions.cs:11:24:11:37 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:109:14:109:15 | access to local variable b1 | extensions.cs:11:24:11:37 | call to method Source<B> : B | extensions.cs:109:14:109:15 | access to local variable b1 | $@ | extensions.cs:11:24:11:37 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:112:14:112:15 | access to local variable b2 | extensions.cs:11:24:11:37 | call to method Source<B> : B | extensions.cs:112:14:112:15 | access to local variable b2 | $@ | extensions.cs:11:24:11:37 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:112:14:112:15 | access to local variable b2 | extensions.cs:11:24:11:37 | call to method Source<B> : B | extensions.cs:112:14:112:15 | access to local variable b2 | $@ | extensions.cs:11:24:11:37 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:128:14:128:15 | access to local variable b1 | extensions.cs:46:20:46:33 | call to method Source<B> : B | extensions.cs:128:14:128:15 | access to local variable b1 | $@ | extensions.cs:46:20:46:33 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:128:14:128:15 | access to local variable b1 | extensions.cs:46:20:46:33 | call to method Source<B> : B | extensions.cs:128:14:128:15 | access to local variable b1 | $@ | extensions.cs:46:20:46:33 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:131:14:131:15 | access to local variable b2 | extensions.cs:46:20:46:33 | call to method Source<B> : B | extensions.cs:131:14:131:15 | access to local variable b2 | $@ | extensions.cs:46:20:46:33 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:131:14:131:15 | access to local variable b2 | extensions.cs:46:20:46:33 | call to method Source<B> : B | extensions.cs:131:14:131:15 | access to local variable b2 | $@ | extensions.cs:46:20:46:33 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:147:14:147:15 | access to local variable b2 | extensions.cs:145:18:145:29 | call to method Source<B> : B | extensions.cs:147:14:147:15 | access to local variable b2 | $@ | extensions.cs:145:18:145:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:147:14:147:15 | access to local variable b2 | extensions.cs:145:18:145:29 | call to method Source<B> : B | extensions.cs:147:14:147:15 | access to local variable b2 | $@ | extensions.cs:145:18:145:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:150:14:150:15 | access to local variable b3 | extensions.cs:145:18:145:29 | call to method Source<B> : B | extensions.cs:150:14:150:15 | access to local variable b3 | $@ | extensions.cs:145:18:145:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:150:14:150:15 | access to local variable b3 | extensions.cs:145:18:145:29 | call to method Source<B> : B | extensions.cs:150:14:150:15 | access to local variable b3 | $@ | extensions.cs:145:18:145:29 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:186:14:186:15 | access to local variable b3 | extensions.cs:67:20:67:33 | call to method Source<B> : B | extensions.cs:186:14:186:15 | access to local variable b3 | $@ | extensions.cs:67:20:67:33 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:186:14:186:15 | access to local variable b3 | extensions.cs:67:20:67:33 | call to method Source<B> : B | extensions.cs:186:14:186:15 | access to local variable b3 | $@ | extensions.cs:67:20:67:33 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:189:14:189:15 | access to local variable b4 | extensions.cs:67:20:67:33 | call to method Source<B> : B | extensions.cs:189:14:189:15 | access to local variable b4 | $@ | extensions.cs:67:20:67:33 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:189:14:189:15 | access to local variable b4 | extensions.cs:67:20:67:33 | call to method Source<B> : B | extensions.cs:189:14:189:15 | access to local variable b4 | $@ | extensions.cs:67:20:67:33 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:195:14:195:15 | access to local variable b1 | extensions.cs:36:24:36:38 | call to method Source<B> : B | extensions.cs:195:14:195:15 | access to local variable b1 | $@ | extensions.cs:36:24:36:38 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:195:14:195:15 | access to local variable b1 | extensions.cs:36:24:36:38 | call to method Source<B> : B | extensions.cs:195:14:195:15 | access to local variable b1 | $@ | extensions.cs:36:24:36:38 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:198:14:198:15 | access to local variable b2 | extensions.cs:36:24:36:38 | call to method Source<B> : B | extensions.cs:198:14:198:15 | access to local variable b2 | $@ | extensions.cs:36:24:36:38 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:198:14:198:15 | access to local variable b2 | extensions.cs:36:24:36:38 | call to method Source<B> : B | extensions.cs:198:14:198:15 | access to local variable b2 | $@ | extensions.cs:36:24:36:38 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:233:14:233:15 | access to local variable b2 | extensions.cs:231:18:231:30 | call to method Source<B> : B | extensions.cs:233:14:233:15 | access to local variable b2 | $@ | extensions.cs:231:18:231:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:233:14:233:15 | access to local variable b2 | extensions.cs:231:18:231:30 | call to method Source<B> : B | extensions.cs:233:14:233:15 | access to local variable b2 | $@ | extensions.cs:231:18:231:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:236:14:236:15 | access to local variable b3 | extensions.cs:231:18:231:30 | call to method Source<B> : B | extensions.cs:236:14:236:15 | access to local variable b3 | $@ | extensions.cs:231:18:231:30 | call to method Source<B> : B | call to method Source<B> : B |
+| extensions.cs:236:14:236:15 | access to local variable b3 | extensions.cs:231:18:231:30 | call to method Source<B> : B | extensions.cs:236:14:236:15 | access to local variable b3 | $@ | extensions.cs:231:18:231:30 | call to method Source<B> : B | call to method Source<B> : B |
--- a/csharp/ql/test/library-tests/dataflow/extensions/ExtensionFlow.ql
+++ b/csharp/ql/test/library-tests/dataflow/extensions/ExtensionFlow.ql
@@ -0,0 +1,12 @@
+/**
+ * @kind path-problem
+ */
+
+import csharp
+import utils.test.InlineFlowTest
+import DefaultFlowTest
+import PathGraph
+
+from PathNode source, PathNode sink
+where flowPath(source, sink)
+select sink, source, sink, "$@", source, source.toString()
--- a/csharp/ql/test/library-tests/dataflow/extensions/extensions.cs
+++ b/csharp/ql/test/library-tests/dataflow/extensions/extensions.cs
@@ -0,0 +1,243 @@
+using System;
+
+public static class MyExtensions
+{
+    extension(object obj)
+    {
+        public B Prop1
+        {
+            get
+            {
+                return A.Source<B>(1);
+            }
+            set
+            {
+                A.Sink(value); // $ hasValueFlow=2 hasValueFlow=102
+            }
+        }
+
+        public B Prop2
+        {
+            get
+            {
+                A.Sink(obj); // $ hasValueFlow=6 hasValueFlow=106
+                return new B();
+            }
+            set
+            {
+                A.Sink(obj); // $ hasValueFlow=7 hasValueFlow=107
+            }
+        }
+
+        public static B StaticProp1
+        {
+            get
+            {
+                return A.Source<B>(10);
+            }
+            set
+            {
+                A.Sink(value); // $ hasValueFlow=11 hasValueFlow=111
+            }
+        }
+
+        public B M1()
+        {
+            return A.Source<B>(3);
+        }
+
+        public void M2()
+        {
+            A.Sink(obj); // $ hasValueFlow=4 hasValueFlow=104
+        }
+
+        public static B M3(B b)
+        {
+            return b;
+        }
+
+        public static object operator +(object a, object b)
+        {
+            A.Sink(a); // $ hasValueFlow=8 hasValueFlow=108
+            return new object();
+        }
+
+        public static object operator -(object a, object b)
+        {
+            return A.Source<B>(9);
+        }
+
+        public T GenericMethod<T>(T t)
+        {
+            return t;
+        }
+    }
+
+    extension(B b)
+    {
+        public B B1()
+        {
+            return b;
+        }
+
+        public void B2()
+        {
+            A.Sink(b); // $ hasValueFlow=12 hasValueFlow=112
+        }
+    }
+
+    extension<T>(T t) where T : class
+    {
+        public void GenericM1()
+        {
+            A.Sink(t); // $ hasValueFlow=13 hasValueFlow=113
+        }
+
+        public S GenericM2<S>(S other)
+        {
+            return other;
+        }
+    }
+}
+
+public class A
+{
+    public void Test1()
+    {
+        var obj = new object();
+        var b1 = obj.Prop1;
+        Sink(b1); // $ hasValueFlow=1
+
+        var b2 = MyExtensions.get_Prop1(obj);
+        Sink(b2); // $ hasValueFlow=1
+    }
+
+    public void Test2()
+    {
+        var obj = new object();
+        obj.Prop1 = Source<B>(2);
+
+        var b = Source<B>(102);
+        MyExtensions.set_Prop1(obj, b);
+    }
+
+    public void Test3()
+    {
+        var obj = new object();
+        var b1 = obj.M1();
+        Sink(b1); // $ hasValueFlow=3
+
+        var b2 = MyExtensions.M1(obj);
+        Sink(b2); // $ hasValueFlow=3
+    }
+
+    public void Test4()
+    {
+        var b1 = Source<B>(4);
+        b1.M2();
+
+        var b2 = Source<B>(104);
+        MyExtensions.M2(b2);
+    }
+
+    public void Test5()
+    {
+        var b1 = Source<B>(5);
+        var b2 = b1.B1();
+        Sink(b2); // $ hasValueFlow=5
+
+        var b3 = MyExtensions.B1(b1);
+        Sink(b3); // $ hasValueFlow=5
+    }
+
+    public void Test6()
+    {
+        var b1 = Source<B>(6);
+        var b2 = b1.Prop2;
+
+        var b3 = Source<B>(106);
+        var b4 = MyExtensions.get_Prop2(b3);
+    }
+
+    public void Test7()
+    {
+        var b1 = Source<B>(7);
+        b1.Prop2 = new B();
+
+        var b2 = Source<B>(107);
+        MyExtensions.set_Prop2(b2, new B());
+    }
+
+    public void Test8()
+    {
+        var b1 = Source<B>(8);
+        var b2 = Source<B>(1);
+        var b3 = b1 + b2;
+
+        var b4 = Source<B>(108);
+        var b5 = MyExtensions.op_Addition(b4, b2);
+    }
+
+    public void Test9()
+    {
+        var b1 = Source<B>(0);
+        var b2 = Source<B>(1);
+        var b3 = b1 - b2;
+        Sink(b3); // $ hasValueFlow=9
+
+        var b4 = MyExtensions.op_Subtraction(b1, b2);
+        Sink(b4); // $ hasValueFlow=9
+    }
+
+    public void Test10()
+    {
+        var b1 = object.StaticProp1;
+        Sink(b1); // $ hasValueFlow=10
+
+        var b2 = MyExtensions.get_StaticProp1();
+        Sink(b2); // $ hasValueFlow=10
+    }
+
+    public void Test11()
+    {
+        var b1 = Source<B>(11);
+        object.StaticProp1 = b1;
+
+        var b2 = Source<B>(111);
+        MyExtensions.set_StaticProp1(b2);
+    }
+
+    public void Test12()
+    {
+        var b1 = Source<B>(12);
+        b1.B2();
+
+        var b2 = Source<B>(112);
+        MyExtensions.B2(b2);
+    }
+
+    public void Test13()
+    {
+        var b1 = Source<B>(13);
+        b1.GenericM1();
+
+        var b2 = Source<B>(113);
+        MyExtensions.GenericM1(b2);
+    }
+
+    public void Test14()
+    {
+        var obj = new object();
+        var b1 = Source<B>(14);
+        var b2 = obj.GenericM2(b1);
+        Sink(b2); // $ hasValueFlow=14
+
+        var b3 = MyExtensions.GenericM2(obj, b1);
+        Sink(b3); // $ hasValueFlow=14
+    }
+
+    public static T Source<T>(object source) => throw null;
+    public static void Sink(object o) { }
+}
+
+public class B { }
--- a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.cs
+++ b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.cs
@@ -348,4 +348,98 @@ namespace My.Qltest
        static void Sink(object o) { }
    }

+    // Test extensions
+    public static class TestExtensions
+    {
+        extension(object o)
+        {
+            public object Method1() => throw null;
+            public static object StaticMethod1(object s) => throw null;
+            public object Property1 { get { throw null; } set { throw null; } }
+        }
+
+        extension<T>(T t) where T : class
+        {
+            public T GenericMethod1() => throw null;
+            public static T GenericStaticMethod1(T t0) => throw null;
+            public T GenericProperty1 { get { throw null; } set { throw null; } }
+        }
+    }
+
+    public class M
+    {
+        public void M1()
+        {
+            var obj = new object();
+            var o1 = obj.Method1();
+            Sink(o1);
+
+            var o2 = TestExtensions.Method1(obj);
+            Sink(o2);
+        }
+
+        public void M2()
+        {
+            var obj = new object();
+            var o1 = object.StaticMethod1(obj);
+            Sink(o1);
+
+            var o2 = TestExtensions.StaticMethod1(obj);
+            Sink(o2);
+        }
+
+        public void M3(object o)
+        {
+            var obj = new object();
+            o.Property1 = obj;
+            var o1 = o.Property1;
+            Sink(o1);
+        }
+
+        public void M4(object o)
+        {
+            var obj = new object();
+            TestExtensions.set_Property1(o, obj);
+            var o1 = TestExtensions.get_Property1(o);
+            Sink(o1);
+        }
+
+        public void M5()
+        {
+            var obj = new object();
+            var o1 = obj.GenericMethod1();
+            Sink(o1);
+
+            var o2 = TestExtensions.GenericMethod1(obj);
+            Sink(o2);
+        }
+
+        public void M6()
+        {
+            var obj = new object();
+            var o1 = object.GenericStaticMethod1(obj);
+            Sink(o1);
+
+            var o2 = TestExtensions.GenericStaticMethod1(obj);
+            Sink(o2);
+        }
+
+        public void M7(object o)
+        {
+            var obj = new object();
+            o.GenericProperty1 = obj;
+            var o1 = o.GenericProperty1;
+            Sink(o1);
+        }
+
+        public void M8(object o)
+        {
+            var obj = new object();
+            TestExtensions.set_GenericProperty1(o, obj);
+            var o1 = TestExtensions.get_GenericProperty1(o);
+            Sink(o1);
+        }
+
+        static void Sink(object o) { }
+    }
 }
--- a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.expected
+++ b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.expected
@@ -32,6 +32,14 @@ models
 | 31 | Summary: My.Qltest; Library; false; GetValue; (); ; Argument[this].SyntheticField[X]; ReturnValue; value; dfc-generated |
 | 32 | Summary: My.Qltest; Library; false; MixedFlowArgs; (System.Object,System.Object); ; Argument[1]; ReturnValue; value; manual |
 | 33 | Summary: My.Qltest; Library; false; SetValue; (System.Object); ; Argument[0]; Argument[this].SyntheticField[X]; value; dfc-generated |
+| 34 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; Method1; (System.Object); ; Argument[0]; ReturnValue; value; manual |
+| 35 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; StaticMethod1; (System.Object); ; Argument[0]; ReturnValue; value; manual |
+| 36 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; get_Property1; (System.Object); ; Argument[0].SyntheticField[TestExtensions.Property1]; ReturnValue; value; manual |
+| 37 | Summary: My.Qltest; TestExtensions+extension(System.Object); false; set_Property1; (System.Object,System.Object); ; Argument[1]; Argument[0].SyntheticField[TestExtensions.Property1]; value; manual |
+| 38 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; GenericMethod1; (T); ; Argument[0]; ReturnValue; value; manual |
+| 39 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; GenericStaticMethod1; (T); ; Argument[0]; ReturnValue; value; manual |
+| 40 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; get_GenericProperty1; (T); ; Argument[0].SyntheticField[TestExtensions.GenericProperty1]; ReturnValue; value; manual |
+| 41 | Summary: My.Qltest; TestExtensions+extension(T)<T>; false; set_GenericProperty1; (T,T); ; Argument[1]; Argument[0].SyntheticField[TestExtensions.GenericProperty1]; value; manual |
 edges
 | ExternalFlow.cs:9:20:9:23 | access to local variable arg1 : Object | ExternalFlow.cs:10:29:10:32 | access to local variable arg1 : Object | provenance |  |
 | ExternalFlow.cs:9:27:9:38 | object creation of type Object : Object | ExternalFlow.cs:9:20:9:23 | access to local variable arg1 : Object | provenance |  |
@@ -150,6 +158,73 @@ edges
 | ExternalFlow.cs:344:13:344:13 | [post] access to local variable l : Library [synthetic X] : Object | ExternalFlow.cs:345:18:345:18 | access to local variable l : Library [synthetic X] : Object | provenance |  |
 | ExternalFlow.cs:344:24:344:24 | access to local variable o : Object | ExternalFlow.cs:344:13:344:13 | [post] access to local variable l : Library [synthetic X] : Object | provenance | MaD:33 |
 | ExternalFlow.cs:345:18:345:18 | access to local variable l : Library [synthetic X] : Object | ExternalFlow.cs:345:18:345:29 | call to method GetValue | provenance | MaD:31 |
+| ExternalFlow.cs:373:17:373:19 | access to local variable obj : Object | ExternalFlow.cs:374:22:374:24 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:373:17:373:19 | access to local variable obj : Object | ExternalFlow.cs:377:45:377:47 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:373:23:373:34 | object creation of type Object : Object | ExternalFlow.cs:373:17:373:19 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:374:17:374:18 | access to local variable o1 : Object | ExternalFlow.cs:375:18:375:19 | access to local variable o1 | provenance |  |
+| ExternalFlow.cs:374:22:374:24 | access to local variable obj : Object | ExternalFlow.cs:374:22:374:34 | call to method Method1 : Object | provenance | MaD:34 |
+| ExternalFlow.cs:374:22:374:34 | call to method Method1 : Object | ExternalFlow.cs:374:17:374:18 | access to local variable o1 : Object | provenance |  |
+| ExternalFlow.cs:377:17:377:18 | access to local variable o2 : Object | ExternalFlow.cs:378:18:378:19 | access to local variable o2 | provenance |  |
+| ExternalFlow.cs:377:22:377:48 | call to method Method1 : Object | ExternalFlow.cs:377:17:377:18 | access to local variable o2 : Object | provenance |  |
+| ExternalFlow.cs:377:45:377:47 | access to local variable obj : Object | ExternalFlow.cs:377:22:377:48 | call to method Method1 : Object | provenance | MaD:34 |
+| ExternalFlow.cs:383:17:383:19 | access to local variable obj : Object | ExternalFlow.cs:384:43:384:45 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:383:17:383:19 | access to local variable obj : Object | ExternalFlow.cs:387:51:387:53 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:383:23:383:34 | object creation of type Object : Object | ExternalFlow.cs:383:17:383:19 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:384:17:384:18 | access to local variable o1 : Object | ExternalFlow.cs:385:18:385:19 | access to local variable o1 | provenance |  |
+| ExternalFlow.cs:384:22:384:46 | call to method StaticMethod1 : Object | ExternalFlow.cs:384:17:384:18 | access to local variable o1 : Object | provenance |  |
+| ExternalFlow.cs:384:43:384:45 | access to local variable obj : Object | ExternalFlow.cs:384:22:384:46 | call to method StaticMethod1 : Object | provenance | MaD:35 |
+| ExternalFlow.cs:387:17:387:18 | access to local variable o2 : Object | ExternalFlow.cs:388:18:388:19 | access to local variable o2 | provenance |  |
+| ExternalFlow.cs:387:22:387:54 | call to method StaticMethod1 : Object | ExternalFlow.cs:387:17:387:18 | access to local variable o2 : Object | provenance |  |
+| ExternalFlow.cs:387:51:387:53 | access to local variable obj : Object | ExternalFlow.cs:387:22:387:54 | call to method StaticMethod1 : Object | provenance | MaD:35 |
+| ExternalFlow.cs:393:17:393:19 | access to local variable obj : Object | ExternalFlow.cs:394:27:394:29 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:393:23:393:34 | object creation of type Object : Object | ExternalFlow.cs:393:17:393:19 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:394:13:394:13 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:395:22:395:22 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance |  |
+| ExternalFlow.cs:394:27:394:29 | access to local variable obj : Object | ExternalFlow.cs:394:13:394:13 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance | MaD:37 |
+| ExternalFlow.cs:395:17:395:18 | access to local variable o1 : Object | ExternalFlow.cs:396:18:396:19 | access to local variable o1 | provenance |  |
+| ExternalFlow.cs:395:22:395:22 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:395:22:395:32 | access to property Property1 : Object | provenance | MaD:36 |
+| ExternalFlow.cs:395:22:395:32 | access to property Property1 : Object | ExternalFlow.cs:395:17:395:18 | access to local variable o1 : Object | provenance |  |
+| ExternalFlow.cs:401:17:401:19 | access to local variable obj : Object | ExternalFlow.cs:402:45:402:47 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:401:23:401:34 | object creation of type Object : Object | ExternalFlow.cs:401:17:401:19 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:402:42:402:42 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:403:51:403:51 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance |  |
+| ExternalFlow.cs:402:45:402:47 | access to local variable obj : Object | ExternalFlow.cs:402:42:402:42 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | provenance | MaD:37 |
+| ExternalFlow.cs:403:17:403:18 | access to local variable o1 : Object | ExternalFlow.cs:404:18:404:19 | access to local variable o1 | provenance |  |
+| ExternalFlow.cs:403:22:403:52 | call to extension accessor get_Property1 : Object | ExternalFlow.cs:403:17:403:18 | access to local variable o1 : Object | provenance |  |
+| ExternalFlow.cs:403:51:403:51 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | ExternalFlow.cs:403:22:403:52 | call to extension accessor get_Property1 : Object | provenance | MaD:36 |
+| ExternalFlow.cs:409:17:409:19 | access to local variable obj : Object | ExternalFlow.cs:410:22:410:24 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:409:17:409:19 | access to local variable obj : Object | ExternalFlow.cs:413:52:413:54 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:409:23:409:34 | object creation of type Object : Object | ExternalFlow.cs:409:17:409:19 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:410:17:410:18 | access to local variable o1 : Object | ExternalFlow.cs:411:18:411:19 | access to local variable o1 | provenance |  |
+| ExternalFlow.cs:410:22:410:24 | access to local variable obj : Object | ExternalFlow.cs:410:22:410:41 | call to method GenericMethod1 : Object | provenance | MaD:38 |
+| ExternalFlow.cs:410:22:410:41 | call to method GenericMethod1 : Object | ExternalFlow.cs:410:17:410:18 | access to local variable o1 : Object | provenance |  |
+| ExternalFlow.cs:413:17:413:18 | access to local variable o2 : Object | ExternalFlow.cs:414:18:414:19 | access to local variable o2 | provenance |  |
+| ExternalFlow.cs:413:22:413:55 | call to method GenericMethod1 : Object | ExternalFlow.cs:413:17:413:18 | access to local variable o2 : Object | provenance |  |
+| ExternalFlow.cs:413:52:413:54 | access to local variable obj : Object | ExternalFlow.cs:413:22:413:55 | call to method GenericMethod1 : Object | provenance | MaD:38 |
+| ExternalFlow.cs:419:17:419:19 | access to local variable obj : Object | ExternalFlow.cs:420:50:420:52 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:419:17:419:19 | access to local variable obj : Object | ExternalFlow.cs:423:58:423:60 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | ExternalFlow.cs:419:17:419:19 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:420:17:420:18 | access to local variable o1 : Object | ExternalFlow.cs:421:18:421:19 | access to local variable o1 | provenance |  |
+| ExternalFlow.cs:420:22:420:53 | call to method GenericStaticMethod1 : Object | ExternalFlow.cs:420:17:420:18 | access to local variable o1 : Object | provenance |  |
+| ExternalFlow.cs:420:50:420:52 | access to local variable obj : Object | ExternalFlow.cs:420:22:420:53 | call to method GenericStaticMethod1 : Object | provenance | MaD:39 |
+| ExternalFlow.cs:423:17:423:18 | access to local variable o2 : Object | ExternalFlow.cs:424:18:424:19 | access to local variable o2 | provenance |  |
+| ExternalFlow.cs:423:22:423:61 | call to method GenericStaticMethod1 : Object | ExternalFlow.cs:423:17:423:18 | access to local variable o2 : Object | provenance |  |
+| ExternalFlow.cs:423:58:423:60 | access to local variable obj : Object | ExternalFlow.cs:423:22:423:61 | call to method GenericStaticMethod1 : Object | provenance | MaD:39 |
+| ExternalFlow.cs:429:17:429:19 | access to local variable obj : Object | ExternalFlow.cs:430:34:430:36 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:429:23:429:34 | object creation of type Object : Object | ExternalFlow.cs:429:17:429:19 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [property GenericProperty1] : Object | ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [property GenericProperty1] : Object | provenance |  |
+| ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance |  |
+| ExternalFlow.cs:430:34:430:36 | access to local variable obj : Object | ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [property GenericProperty1] : Object | provenance |  |
+| ExternalFlow.cs:430:34:430:36 | access to local variable obj : Object | ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance | MaD:41 |
+| ExternalFlow.cs:431:17:431:18 | access to local variable o1 : Object | ExternalFlow.cs:432:18:432:19 | access to local variable o1 | provenance |  |
+| ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [property GenericProperty1] : Object | ExternalFlow.cs:431:22:431:39 | access to property GenericProperty1 : Object | provenance |  |
+| ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:431:22:431:39 | access to property GenericProperty1 : Object | provenance | MaD:40 |
+| ExternalFlow.cs:431:22:431:39 | access to property GenericProperty1 : Object | ExternalFlow.cs:431:17:431:18 | access to local variable o1 : Object | provenance |  |
+| ExternalFlow.cs:437:17:437:19 | access to local variable obj : Object | ExternalFlow.cs:438:52:438:54 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:437:23:437:34 | object creation of type Object : Object | ExternalFlow.cs:437:17:437:19 | access to local variable obj : Object | provenance |  |
+| ExternalFlow.cs:438:49:438:49 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:439:58:439:58 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance |  |
+| ExternalFlow.cs:438:52:438:54 | access to local variable obj : Object | ExternalFlow.cs:438:49:438:49 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | provenance | MaD:41 |
+| ExternalFlow.cs:439:17:439:18 | access to local variable o1 : Object | ExternalFlow.cs:440:18:440:19 | access to local variable o1 | provenance |  |
+| ExternalFlow.cs:439:22:439:59 | call to extension accessor get_GenericProperty1 : Object | ExternalFlow.cs:439:17:439:18 | access to local variable o1 : Object | provenance |  |
+| ExternalFlow.cs:439:58:439:58 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | ExternalFlow.cs:439:22:439:59 | call to extension accessor get_GenericProperty1 : Object | provenance | MaD:40 |
 nodes
 | ExternalFlow.cs:9:20:9:23 | access to local variable arg1 : Object | semmle.label | access to local variable arg1 : Object |
 | ExternalFlow.cs:9:27:9:38 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
@@ -294,6 +369,80 @@ nodes
 | ExternalFlow.cs:344:24:344:24 | access to local variable o : Object | semmle.label | access to local variable o : Object |
 | ExternalFlow.cs:345:18:345:18 | access to local variable l : Library [synthetic X] : Object | semmle.label | access to local variable l : Library [synthetic X] : Object |
 | ExternalFlow.cs:345:18:345:29 | call to method GetValue | semmle.label | call to method GetValue |
+| ExternalFlow.cs:373:17:373:19 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:373:23:373:34 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
+| ExternalFlow.cs:374:17:374:18 | access to local variable o1 : Object | semmle.label | access to local variable o1 : Object |
+| ExternalFlow.cs:374:22:374:24 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:374:22:374:34 | call to method Method1 : Object | semmle.label | call to method Method1 : Object |
+| ExternalFlow.cs:375:18:375:19 | access to local variable o1 | semmle.label | access to local variable o1 |
+| ExternalFlow.cs:377:17:377:18 | access to local variable o2 : Object | semmle.label | access to local variable o2 : Object |
+| ExternalFlow.cs:377:22:377:48 | call to method Method1 : Object | semmle.label | call to method Method1 : Object |
+| ExternalFlow.cs:377:45:377:47 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:378:18:378:19 | access to local variable o2 | semmle.label | access to local variable o2 |
+| ExternalFlow.cs:383:17:383:19 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:383:23:383:34 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
+| ExternalFlow.cs:384:17:384:18 | access to local variable o1 : Object | semmle.label | access to local variable o1 : Object |
+| ExternalFlow.cs:384:22:384:46 | call to method StaticMethod1 : Object | semmle.label | call to method StaticMethod1 : Object |
+| ExternalFlow.cs:384:43:384:45 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:385:18:385:19 | access to local variable o1 | semmle.label | access to local variable o1 |
+| ExternalFlow.cs:387:17:387:18 | access to local variable o2 : Object | semmle.label | access to local variable o2 : Object |
+| ExternalFlow.cs:387:22:387:54 | call to method StaticMethod1 : Object | semmle.label | call to method StaticMethod1 : Object |
+| ExternalFlow.cs:387:51:387:53 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:388:18:388:19 | access to local variable o2 | semmle.label | access to local variable o2 |
+| ExternalFlow.cs:393:17:393:19 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:393:23:393:34 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
+| ExternalFlow.cs:394:13:394:13 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | semmle.label | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object |
+| ExternalFlow.cs:394:27:394:29 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:395:17:395:18 | access to local variable o1 : Object | semmle.label | access to local variable o1 : Object |
+| ExternalFlow.cs:395:22:395:22 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | semmle.label | access to parameter o : Object [synthetic TestExtensions.Property1] : Object |
+| ExternalFlow.cs:395:22:395:32 | access to property Property1 : Object | semmle.label | access to property Property1 : Object |
+| ExternalFlow.cs:396:18:396:19 | access to local variable o1 | semmle.label | access to local variable o1 |
+| ExternalFlow.cs:401:17:401:19 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:401:23:401:34 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
+| ExternalFlow.cs:402:42:402:42 | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object | semmle.label | [post] access to parameter o : Object [synthetic TestExtensions.Property1] : Object |
+| ExternalFlow.cs:402:45:402:47 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:403:17:403:18 | access to local variable o1 : Object | semmle.label | access to local variable o1 : Object |
+| ExternalFlow.cs:403:22:403:52 | call to extension accessor get_Property1 : Object | semmle.label | call to extension accessor get_Property1 : Object |
+| ExternalFlow.cs:403:51:403:51 | access to parameter o : Object [synthetic TestExtensions.Property1] : Object | semmle.label | access to parameter o : Object [synthetic TestExtensions.Property1] : Object |
+| ExternalFlow.cs:404:18:404:19 | access to local variable o1 | semmle.label | access to local variable o1 |
+| ExternalFlow.cs:409:17:409:19 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:409:23:409:34 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
+| ExternalFlow.cs:410:17:410:18 | access to local variable o1 : Object | semmle.label | access to local variable o1 : Object |
+| ExternalFlow.cs:410:22:410:24 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:410:22:410:41 | call to method GenericMethod1 : Object | semmle.label | call to method GenericMethod1 : Object |
+| ExternalFlow.cs:411:18:411:19 | access to local variable o1 | semmle.label | access to local variable o1 |
+| ExternalFlow.cs:413:17:413:18 | access to local variable o2 : Object | semmle.label | access to local variable o2 : Object |
+| ExternalFlow.cs:413:22:413:55 | call to method GenericMethod1 : Object | semmle.label | call to method GenericMethod1 : Object |
+| ExternalFlow.cs:413:52:413:54 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:414:18:414:19 | access to local variable o2 | semmle.label | access to local variable o2 |
+| ExternalFlow.cs:419:17:419:19 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
+| ExternalFlow.cs:420:17:420:18 | access to local variable o1 : Object | semmle.label | access to local variable o1 : Object |
+| ExternalFlow.cs:420:22:420:53 | call to method GenericStaticMethod1 : Object | semmle.label | call to method GenericStaticMethod1 : Object |
+| ExternalFlow.cs:420:50:420:52 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:421:18:421:19 | access to local variable o1 | semmle.label | access to local variable o1 |
+| ExternalFlow.cs:423:17:423:18 | access to local variable o2 : Object | semmle.label | access to local variable o2 : Object |
+| ExternalFlow.cs:423:22:423:61 | call to method GenericStaticMethod1 : Object | semmle.label | call to method GenericStaticMethod1 : Object |
+| ExternalFlow.cs:423:58:423:60 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:424:18:424:19 | access to local variable o2 | semmle.label | access to local variable o2 |
+| ExternalFlow.cs:429:17:429:19 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:429:23:429:34 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
+| ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [property GenericProperty1] : Object | semmle.label | [post] access to parameter o : Object [property GenericProperty1] : Object |
+| ExternalFlow.cs:430:13:430:13 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | semmle.label | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object |
+| ExternalFlow.cs:430:34:430:36 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:431:17:431:18 | access to local variable o1 : Object | semmle.label | access to local variable o1 : Object |
+| ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [property GenericProperty1] : Object | semmle.label | access to parameter o : Object [property GenericProperty1] : Object |
+| ExternalFlow.cs:431:22:431:22 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | semmle.label | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object |
+| ExternalFlow.cs:431:22:431:39 | access to property GenericProperty1 : Object | semmle.label | access to property GenericProperty1 : Object |
+| ExternalFlow.cs:432:18:432:19 | access to local variable o1 | semmle.label | access to local variable o1 |
+| ExternalFlow.cs:437:17:437:19 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:437:23:437:34 | object creation of type Object : Object | semmle.label | object creation of type Object : Object |
+| ExternalFlow.cs:438:49:438:49 | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | semmle.label | [post] access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object |
+| ExternalFlow.cs:438:52:438:54 | access to local variable obj : Object | semmle.label | access to local variable obj : Object |
+| ExternalFlow.cs:439:17:439:18 | access to local variable o1 : Object | semmle.label | access to local variable o1 : Object |
+| ExternalFlow.cs:439:22:439:59 | call to extension accessor get_GenericProperty1 : Object | semmle.label | call to extension accessor get_GenericProperty1 : Object |
+| ExternalFlow.cs:439:58:439:58 | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object | semmle.label | access to parameter o : Object [synthetic TestExtensions.GenericProperty1] : Object |
+| ExternalFlow.cs:440:18:440:19 | access to local variable o1 | semmle.label | access to local variable o1 |
 subpaths
 | ExternalFlow.cs:84:29:84:32 | access to local variable objs : null [element] : Object | ExternalFlow.cs:84:35:84:35 | o : Object | ExternalFlow.cs:84:40:84:40 | access to parameter o : Object | ExternalFlow.cs:84:25:84:41 | call to method Map<Object,Object> : T[] [element] : Object |
 invalidModelRow
@@ -328,3 +477,15 @@ invalidModelRow
 | ExternalFlow.cs:324:18:324:44 | call to method GetMyNestedSyntheticField | ExternalFlow.cs:322:21:322:32 | object creation of type Object : Object | ExternalFlow.cs:324:18:324:44 | call to method GetMyNestedSyntheticField | $@ | ExternalFlow.cs:322:21:322:32 | object creation of type Object : Object | object creation of type Object : Object |
 | ExternalFlow.cs:331:18:331:45 | call to method GetMyFieldOnSyntheticField | ExternalFlow.cs:329:21:329:32 | object creation of type Object : Object | ExternalFlow.cs:331:18:331:45 | call to method GetMyFieldOnSyntheticField | $@ | ExternalFlow.cs:329:21:329:32 | object creation of type Object : Object | object creation of type Object : Object |
 | ExternalFlow.cs:345:18:345:29 | call to method GetValue | ExternalFlow.cs:343:21:343:32 | object creation of type Object : Object | ExternalFlow.cs:345:18:345:29 | call to method GetValue | $@ | ExternalFlow.cs:343:21:343:32 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:375:18:375:19 | access to local variable o1 | ExternalFlow.cs:373:23:373:34 | object creation of type Object : Object | ExternalFlow.cs:375:18:375:19 | access to local variable o1 | $@ | ExternalFlow.cs:373:23:373:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:378:18:378:19 | access to local variable o2 | ExternalFlow.cs:373:23:373:34 | object creation of type Object : Object | ExternalFlow.cs:378:18:378:19 | access to local variable o2 | $@ | ExternalFlow.cs:373:23:373:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:385:18:385:19 | access to local variable o1 | ExternalFlow.cs:383:23:383:34 | object creation of type Object : Object | ExternalFlow.cs:385:18:385:19 | access to local variable o1 | $@ | ExternalFlow.cs:383:23:383:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:388:18:388:19 | access to local variable o2 | ExternalFlow.cs:383:23:383:34 | object creation of type Object : Object | ExternalFlow.cs:388:18:388:19 | access to local variable o2 | $@ | ExternalFlow.cs:383:23:383:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:396:18:396:19 | access to local variable o1 | ExternalFlow.cs:393:23:393:34 | object creation of type Object : Object | ExternalFlow.cs:396:18:396:19 | access to local variable o1 | $@ | ExternalFlow.cs:393:23:393:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:404:18:404:19 | access to local variable o1 | ExternalFlow.cs:401:23:401:34 | object creation of type Object : Object | ExternalFlow.cs:404:18:404:19 | access to local variable o1 | $@ | ExternalFlow.cs:401:23:401:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:411:18:411:19 | access to local variable o1 | ExternalFlow.cs:409:23:409:34 | object creation of type Object : Object | ExternalFlow.cs:411:18:411:19 | access to local variable o1 | $@ | ExternalFlow.cs:409:23:409:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:414:18:414:19 | access to local variable o2 | ExternalFlow.cs:409:23:409:34 | object creation of type Object : Object | ExternalFlow.cs:414:18:414:19 | access to local variable o2 | $@ | ExternalFlow.cs:409:23:409:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:421:18:421:19 | access to local variable o1 | ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | ExternalFlow.cs:421:18:421:19 | access to local variable o1 | $@ | ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:424:18:424:19 | access to local variable o2 | ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | ExternalFlow.cs:424:18:424:19 | access to local variable o2 | $@ | ExternalFlow.cs:419:23:419:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:432:18:432:19 | access to local variable o1 | ExternalFlow.cs:429:23:429:34 | object creation of type Object : Object | ExternalFlow.cs:432:18:432:19 | access to local variable o1 | $@ | ExternalFlow.cs:429:23:429:34 | object creation of type Object : Object | object creation of type Object : Object |
+| ExternalFlow.cs:440:18:440:19 | access to local variable o1 | ExternalFlow.cs:437:23:437:34 | object creation of type Object : Object | ExternalFlow.cs:440:18:440:19 | access to local variable o1 | $@ | ExternalFlow.cs:437:23:437:34 | object creation of type Object : Object | object creation of type Object : Object |
--- a/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.ext.yml
+++ b/csharp/ql/test/library-tests/dataflow/external-models/ExternalFlow.ext.yml
@@ -45,6 +45,14 @@ extensions:
      - ["My.Qltest", "K", false, "GetMyFieldOnSyntheticField", "()", "", "Argument[this].SyntheticField[My.Qltest.K.MySyntheticField2].Field[My.Qltest.K.MyField]", "ReturnValue", "value", "manual"]
      - ["My.Qltest", "Library", false, "SetValue", "(System.Object)", "", "Argument[0]", "Argument[this].SyntheticField[X]", "value", "dfc-generated"]
      - ["My.Qltest", "Library", false, "GetValue", "()", "", "Argument[this].SyntheticField[X]", "ReturnValue", "value", "dfc-generated"]
+      - ["My.Qltest", "TestExtensions+extension(System.Object)", false, "Method1", "(System.Object)", "", "Argument[0]", "ReturnValue", "value", "manual"]
+      - ["My.Qltest", "TestExtensions+extension(System.Object)", false, "StaticMethod1", "(System.Object)", "", "Argument[0]", "ReturnValue", "value", "manual"]
+      - ["My.Qltest", "TestExtensions+extension(System.Object)", false, "get_Property1", "(System.Object)", "", "Argument[0].SyntheticField[TestExtensions.Property1]", "ReturnValue", "value", "manual"]
+      - ["My.Qltest", "TestExtensions+extension(System.Object)", false, "set_Property1", "(System.Object,System.Object)", "", "Argument[1]", "Argument[0].SyntheticField[TestExtensions.Property1]", "value", "manual"]
+      - ["My.Qltest", "TestExtensions+extension(T)<T>", false, "GenericMethod1", "(T)", "", "Argument[0]", "ReturnValue", "value", "manual"]
+      - ["My.Qltest", "TestExtensions+extension(T)<T>", false, "GenericStaticMethod1", "(T)", "", "Argument[0]", "ReturnValue", "value", "manual"]
+      - ["My.Qltest", "TestExtensions+extension(T)<T>", false, "get_GenericProperty1", "(T)", "", "Argument[0].SyntheticField[TestExtensions.GenericProperty1]", "ReturnValue", "value", "manual"]
+      - ["My.Qltest", "TestExtensions+extension(T)<T>", false, "set_GenericProperty1", "(T,T)", "", "Argument[1]", "Argument[0].SyntheticField[TestExtensions.GenericProperty1]", "value", "manual"]

  - addsTo:
      pack: codeql/csharp-all
--- a/csharp/ql/test/library-tests/extension/PrintAst.expected
+++ b/csharp/ql/test/library-tests/extension/PrintAst.expected
@@ -0,0 +1,481 @@
+extensionTypes.cs:
+#    4| [Class] MyExtensionTypes
+#    6|   4: [ExtensionType] extension(String)
+#-----|     2: (Parameters)
+#    6|       0: [Parameter] s
+#    6|         -1: [TypeMention] string
+#-----|         0: (Attributes)
+#    6|           1: [DefaultAttribute] [NotNull(...)]
+#    6|             0: [TypeMention] NotNullAttribute
+#    8|     4: [ExtensionMethod] M11
+#    8|       -1: [TypeMention] Void
+#-----|       2: (Parameters)
+#    6|         0: [Parameter] s
+#    6|           -1: [TypeMention] string
+#    8|       4: [BlockStmt] {...}
+#   10|   5: [ExtensionType] extension(Int32)
+#-----|     2: (Parameters)
+#   10|       0: [Parameter] i1
+#   10|         -1: [TypeMention] int
+#   12|     4: [ExtensionMethod] M21
+#   12|       -1: [TypeMention] Void
+#-----|       2: (Parameters)
+#   10|         0: [Parameter] i1
+#   10|           -1: [TypeMention] int
+#   12|       4: [BlockStmt] {...}
+#   14|   6: [ExtensionType] extension(Int32)
+#-----|     2: (Parameters)
+#   14|       0: [Parameter] i2
+#   14|         -1: [TypeMention] int
+#   16|     4: [ExtensionMethod] M31
+#   16|       -1: [TypeMention] Void
+#-----|       2: (Parameters)
+#   14|         0: [Parameter] i2
+#   14|           -1: [TypeMention] int
+#   16|       4: [BlockStmt] {...}
+#   18|   7: [ExtensionType] extension(Int32)
+#-----|     2: (Parameters)
+#   18|       0: [Parameter] i3
+#   18|         -1: [TypeMention] int
+#   20|     4: [ExtensionMethod] M41
+#   20|       -1: [TypeMention] Void
+#-----|       2: (Parameters)
+#   18|         0: [Parameter] i3
+#   18|           -1: [TypeMention] int
+#   20|       4: [BlockStmt] {...}
+#   22|   8: [ExtensionType] extension(String)
+#-----|     2: (Parameters)
+#   22|       0: [Parameter] s
+#   22|         -1: [TypeMention] string
+#   24|     4: [ExtensionMethod] M51
+#   24|       -1: [TypeMention] Void
+#-----|       2: (Parameters)
+#   22|         0: [Parameter] s
+#   22|           -1: [TypeMention] string
+#   24|       4: [BlockStmt] {...}
+#   26|   9: [ExtensionType] extension(T1)`1
+#-----|     1: (Type parameters)
+#   26|       0: [TypeParameter] T1
+#-----|     2: (Parameters)
+#   26|       0: [Parameter] t1
+#   26|         -1: [TypeMention] T1
+#-----|         0: (Attributes)
+#   26|           1: [DefaultAttribute] [NotNullWhen(...)]
+#   26|             -1: [TypeMention] NotNullWhenAttribute
+#   26|             0: [BoolLiteral] true
+#   28|     4: [ExtensionMethod] M61`1
+#   28|       -1: [TypeMention] Void
+#-----|       1: (Type parameters)
+#   28|         0: [TypeParameter] T2
+#-----|       2: (Parameters)
+#   26|         0: [Parameter] t1
+#   26|           -1: [TypeMention] T1
+#   28|         1: [Parameter] o
+#   28|           -1: [TypeMention] object
+#   28|         2: [Parameter] t2
+#   28|           -1: [TypeMention] T2
+#   28|       4: [BlockStmt] {...}
+extensions.cs:
+#    4| [Class] MyExtensions
+#    6|   4: [ExtensionType] extension(String)
+#-----|     2: (Parameters)
+#    6|       0: [Parameter] s
+#    6|         -1: [TypeMention] string
+#    8|     4: [Property] Prop1
+#    8|       -1: [TypeMention] bool
+#    8|       3: [ExtensionCallable,Getter] get_Prop1
+#-----|         2: (Parameters)
+#    6|           0: [Parameter] s
+#    6|             -1: [TypeMention] string
+#    8|         4: [GTExpr] ... > ...
+#    8|           0: [PropertyCall] access to property Length
+#    8|             -1: [SyntheticExtensionParameterAccess] access to extension synthetic parameter s
+#    8|           1: [IntLiteral] 0
+#    9|     5: [Property] Prop2
+#    9|       -1: [TypeMention] bool
+#    9|       3: [ExtensionCallable,Getter] get_Prop2
+#-----|         2: (Parameters)
+#    6|           0: [Parameter] s
+#    6|             -1: [TypeMention] string
+#    9|         4: [BlockStmt] {...}
+#    9|           0: [ReturnStmt] return ...;
+#    9|             0: [BoolLiteral] true
+#    9|       4: [ExtensionCallable,Setter] set_Prop2
+#-----|         2: (Parameters)
+#    6|           0: [Parameter] s
+#    6|             -1: [TypeMention] string
+#    9|           1: [Parameter] value
+#    9|         4: [BlockStmt] {...}
+#   10|     6: [Property] StaticProp1
+#   10|       -1: [TypeMention] bool
+#   10|       3: [ExtensionCallable,Getter] get_StaticProp1
+#   10|         4: [BlockStmt] {...}
+#   10|           0: [ReturnStmt] return ...;
+#   10|             0: [BoolLiteral] false
+#   11|     7: [ExtensionMethod] M1
+#   11|       -1: [TypeMention] bool
+#-----|       2: (Parameters)
+#    6|         0: [Parameter] s
+#    6|           -1: [TypeMention] string
+#   11|       4: [IsExpr] ... is ...
+#   11|         0: [SyntheticExtensionParameterAccess] access to extension synthetic parameter s
+#   11|         1: [NotPatternExpr] not ...
+#   11|           0: [ConstantPatternExpr,NullLiteral] null
+#   12|     8: [ExtensionMethod] M2
+#   12|       -1: [TypeMention] string
+#-----|       2: (Parameters)
+#    6|         0: [Parameter] s
+#    6|           -1: [TypeMention] string
+#   12|         1: [Parameter] other
+#   12|           -1: [TypeMention] string
+#   12|       4: [BlockStmt] {...}
+#   12|         0: [ReturnStmt] return ...;
+#   12|           0: [AddExpr] ... + ...
+#   12|             0: [SyntheticExtensionParameterAccess] access to extension synthetic parameter s
+#   12|             1: [ParameterAccess] access to parameter other
+#   13|     9: [ExtensionMethod] StaticM1
+#   13|       -1: [TypeMention] int
+#   13|       4: [BlockStmt] {...}
+#   13|         0: [ReturnStmt] return ...;
+#   13|           0: [IntLiteral] 0
+#   14|     10: [ExtensionMethod] StaticM2
+#   14|       -1: [TypeMention] int
+#-----|       2: (Parameters)
+#   14|         0: [Parameter] x
+#   14|           -1: [TypeMention] string
+#   14|       4: [BlockStmt] {...}
+#   14|         0: [ReturnStmt] return ...;
+#   14|           0: [PropertyCall] access to property Length
+#   14|             -1: [ParameterAccess] access to parameter x
+#   15|     11: [ExtensionCallable,MulOperator] *
+#   15|       -1: [TypeMention] string
+#-----|       2: (Parameters)
+#   15|         0: [Parameter] a
+#   15|           -1: [TypeMention] int
+#   15|         1: [Parameter] b
+#   15|           -1: [TypeMention] string
+#   15|       4: [BlockStmt] {...}
+#   15|         0: [ReturnStmt] return ...;
+#   15|           0: [StringLiteralUtf16] ""
+#   16|     14: [ExtensionMethod] StringGenericM1`1
+#   16|       -1: [TypeMention] T
+#-----|       1: (Type parameters)
+#   16|         0: [TypeParameter] T
+#-----|       2: (Parameters)
+#    6|         0: [Parameter] s
+#    6|           -1: [TypeMention] string
+#   16|         1: [Parameter] t
+#   16|           -1: [TypeMention] T
+#   16|         2: [Parameter] o
+#   16|           -1: [TypeMention] object
+#   16|       4: [BlockStmt] {...}
+#   16|         0: [ReturnStmt] return ...;
+#   16|           0: [ParameterAccess] access to parameter t
+#   19|   5: [ExtensionType] extension(Object)
+#   21|     4: [ExtensionMethod] StaticObjectM1
+#   21|       -1: [TypeMention] int
+#   21|       4: [BlockStmt] {...}
+#   21|         0: [ReturnStmt] return ...;
+#   21|           0: [IntLiteral] 0
+#   22|     5: [ExtensionMethod] StaticObjectM2
+#   22|       -1: [TypeMention] int
+#-----|       2: (Parameters)
+#   22|         0: [Parameter] s
+#   22|           -1: [TypeMention] string
+#   22|       4: [BlockStmt] {...}
+#   22|         0: [ReturnStmt] return ...;
+#   22|           0: [PropertyCall] access to property Length
+#   22|             -1: [ParameterAccess] access to parameter s
+#   23|     6: [Property] StaticProp
+#   23|       -1: [TypeMention] bool
+#   23|       3: [ExtensionCallable,Getter] get_StaticProp
+#   23|         4: [BoolLiteral] true
+#   26|   8: [ExtensionType] extension(T)`1
+#-----|     1: (Type parameters)
+#   26|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#   26|       0: [Parameter] t
+#   26|         -1: [TypeMention] T
+#   28|     4: [Property] GenericProp1
+#   28|       -1: [TypeMention] bool
+#   28|       3: [ExtensionCallable,Getter] get_GenericProp1
+#-----|         2: (Parameters)
+#   26|           0: [Parameter] t
+#   26|             -1: [TypeMention] T
+#   28|         4: [IsExpr] ... is ...
+#   28|           0: [SyntheticExtensionParameterAccess] access to extension synthetic parameter t
+#   28|           1: [NotPatternExpr] not ...
+#   28|             0: [ConstantPatternExpr,NullLiteral] null
+#   29|     5: [Property] GenericProp2
+#   29|       -1: [TypeMention] bool
+#   29|       3: [ExtensionCallable,Getter] get_GenericProp2
+#-----|         2: (Parameters)
+#   26|           0: [Parameter] t
+#   26|             -1: [TypeMention] T
+#   29|         4: [BlockStmt] {...}
+#   29|           0: [ReturnStmt] return ...;
+#   29|             0: [BoolLiteral] true
+#   29|       4: [ExtensionCallable,Setter] set_GenericProp2
+#-----|         2: (Parameters)
+#   26|           0: [Parameter] t
+#   26|             -1: [TypeMention] T
+#   29|           1: [Parameter] value
+#   29|         4: [BlockStmt] {...}
+#   30|     6: [ExtensionMethod] GenericM1
+#   30|       -1: [TypeMention] bool
+#-----|       2: (Parameters)
+#   26|         0: [Parameter] t
+#   26|           -1: [TypeMention] T
+#   30|       4: [IsExpr] ... is ...
+#   30|         0: [SyntheticExtensionParameterAccess] access to extension synthetic parameter t
+#   30|         1: [NotPatternExpr] not ...
+#   30|           0: [ConstantPatternExpr,NullLiteral] null
+#   31|     7: [ExtensionMethod] GenericM2`1
+#   31|       -1: [TypeMention] Void
+#-----|       1: (Type parameters)
+#   31|         0: [TypeParameter] S
+#-----|       2: (Parameters)
+#   26|         0: [Parameter] t
+#   26|           -1: [TypeMention] T
+#   31|         1: [Parameter] other
+#   31|           -1: [TypeMention] S
+#   31|       4: [BlockStmt] {...}
+#   32|     8: [ExtensionMethod] GenericStaticM1
+#   32|       -1: [TypeMention] Void
+#-----|       2: (Parameters)
+#   26|         0: [Parameter] t
+#   26|           -1: [TypeMention] T
+#   32|       4: [BlockStmt] {...}
+#   33|     9: [ExtensionMethod] GenericStaticM2`1
+#   33|       -1: [TypeMention] Void
+#-----|       1: (Type parameters)
+#   33|         0: [TypeParameter] S
+#-----|       2: (Parameters)
+#   33|         0: [Parameter] other
+#   33|           -1: [TypeMention] S
+#   33|       4: [BlockStmt] {...}
+#   34|     10: [AddOperator,ExtensionCallable] +
+#   34|       -1: [TypeMention] T
+#-----|       2: (Parameters)
+#   34|         0: [Parameter] a
+#   34|           -1: [TypeMention] T
+#   34|         1: [Parameter] b
+#   34|           -1: [TypeMention] T
+#   34|       4: [BlockStmt] {...}
+#   34|         0: [ReturnStmt] return ...;
+#   34|           0: [NullLiteral] null
+#   38| [Class] ClassicExtensions
+#   40|   4: [ExtensionMethod] M3
+#   40|     -1: [TypeMention] bool
+#-----|     2: (Parameters)
+#   40|       0: [Parameter] s
+#   40|         -1: [TypeMention] string
+#   40|     4: [IsExpr] ... is ...
+#   40|       0: [ParameterAccess] access to parameter s
+#   40|       1: [NotPatternExpr] not ...
+#   40|         0: [ConstantPatternExpr,NullLiteral] null
+#   43| [Class] C
+#   45|   6: [Method] CallingExtensions
+#   45|     -1: [TypeMention] Void
+#   46|     4: [BlockStmt] {...}
+#   47|       0: [LocalVariableDeclStmt] ... ...;
+#   47|         0: [LocalVariableDeclAndInitExpr] String s = ...
+#   47|           -1: [TypeMention] string
+#   47|           0: [LocalVariableAccess] access to local variable s
+#   47|           1: [StringLiteralUtf16] "Hello World."
+#   50|       1: [LocalVariableDeclStmt] ... ...;
+#   50|         0: [LocalVariableDeclAndInitExpr] Boolean x11 = ...
+#   50|           -1: [TypeMention] bool
+#   50|           0: [LocalVariableAccess] access to local variable x11
+#   50|           1: [ExtensionPropertyCall] access to property Prop1
+#   50|             -1: [LocalVariableAccess] access to local variable s
+#   51|       2: [LocalVariableDeclStmt] ... ...;
+#   51|         0: [LocalVariableDeclAndInitExpr] Boolean x12 = ...
+#   51|           -1: [TypeMention] bool
+#   51|           0: [LocalVariableAccess] access to local variable x12
+#   51|           1: [ExtensionPropertyCall] access to property Prop2
+#   51|             -1: [LocalVariableAccess] access to local variable s
+#   52|       3: [ExprStmt] ...;
+#   52|         0: [AssignExpr] ... = ...
+#   52|           0: [ExtensionPropertyCall] access to property Prop2
+#   52|             -1: [LocalVariableAccess] access to local variable s
+#   52|           1: [BoolLiteral] true
+#   53|       4: [LocalVariableDeclStmt] ... ...;
+#   53|         0: [LocalVariableDeclAndInitExpr] Boolean x13 = ...
+#   53|           -1: [TypeMention] bool
+#   53|           0: [LocalVariableAccess] access to local variable x13
+#   53|           1: [ExtensionPropertyCall] access to property StaticProp1
+#   53|             -1: [TypeAccess] access to type String
+#   53|               0: [TypeMention] string
+#   54|       5: [LocalVariableDeclStmt] ... ...;
+#   54|         0: [LocalVariableDeclAndInitExpr] Boolean x14 = ...
+#   54|           -1: [TypeMention] bool
+#   54|           0: [LocalVariableAccess] access to local variable x14
+#   54|           1: [ExtensionPropertyCall] access to property StaticProp
+#   54|             -1: [TypeAccess] access to type Object
+#   54|               0: [TypeMention] object
+#   57|       6: [LocalVariableDeclStmt] ... ...;
+#   57|         0: [LocalVariableDeclAndInitExpr] Boolean x21 = ...
+#   57|           -1: [TypeMention] bool
+#   57|           0: [LocalVariableAccess] access to local variable x21
+#   57|           1: [MethodCall] call to method M1
+#   57|             -1: [LocalVariableAccess] access to local variable s
+#   58|       7: [LocalVariableDeclStmt] ... ...;
+#   58|         0: [LocalVariableDeclAndInitExpr] String x22 = ...
+#   58|           -1: [TypeMention] string
+#   58|           0: [LocalVariableAccess] access to local variable x22
+#   58|           1: [MethodCall] call to method M2
+#   58|             -1: [LocalVariableAccess] access to local variable s
+#   58|             0: [StringLiteralUtf16] "!!!"
+#   59|       8: [LocalVariableDeclStmt] ... ...;
+#   59|         0: [LocalVariableDeclAndInitExpr] Int32 x23 = ...
+#   59|           -1: [TypeMention] int
+#   59|           0: [LocalVariableAccess] access to local variable x23
+#   59|           1: [MethodCall] call to method StaticM1
+#   59|             -1: [TypeAccess] access to type String
+#   59|               0: [TypeMention] string
+#   60|       9: [LocalVariableDeclStmt] ... ...;
+#   60|         0: [LocalVariableDeclAndInitExpr] Int32 x24 = ...
+#   60|           -1: [TypeMention] int
+#   60|           0: [LocalVariableAccess] access to local variable x24
+#   60|           1: [MethodCall] call to method StaticM2
+#   60|             -1: [TypeAccess] access to type String
+#   60|               0: [TypeMention] string
+#   60|             0: [LocalVariableAccess] access to local variable s
+#   61|       10: [LocalVariableDeclStmt] ... ...;
+#   61|         0: [LocalVariableDeclAndInitExpr] Int32 x25 = ...
+#   61|           -1: [TypeMention] int
+#   61|           0: [LocalVariableAccess] access to local variable x25
+#   61|           1: [MethodCall] call to method StaticObjectM1
+#   61|             -1: [TypeAccess] access to type Object
+#   61|               0: [TypeMention] object
+#   62|       11: [LocalVariableDeclStmt] ... ...;
+#   62|         0: [LocalVariableDeclAndInitExpr] Int32 x26 = ...
+#   62|           -1: [TypeMention] int
+#   62|           0: [LocalVariableAccess] access to local variable x26
+#   62|           1: [MethodCall] call to method StaticObjectM2
+#   62|             -1: [TypeAccess] access to type Object
+#   62|               0: [TypeMention] object
+#   62|             0: [LocalVariableAccess] access to local variable s
+#   65|       12: [LocalVariableDeclStmt] ... ...;
+#   65|         0: [LocalVariableDeclAndInitExpr] String x30 = ...
+#   65|           -1: [TypeMention] string
+#   65|           0: [LocalVariableAccess] access to local variable x30
+#   65|           1: [ExtensionOperatorCall] call to operator *
+#   65|             0: [IntLiteral] 3
+#   65|             1: [LocalVariableAccess] access to local variable s
+#   68|       13: [LocalVariableDeclStmt] ... ...;
+#   68|         0: [LocalVariableDeclAndInitExpr] Boolean y = ...
+#   68|           -1: [TypeMention] bool
+#   68|           0: [LocalVariableAccess] access to local variable y
+#   68|           1: [MethodCall] call to method M3
+#   68|             -1: [LocalVariableAccess] access to local variable s
+#   71|       14: [ExprStmt] ...;
+#   71|         0: [MethodCall] call to method M1
+#   71|           -1: [TypeAccess] access to type MyExtensions
+#   71|             0: [TypeMention] MyExtensions
+#   71|           0: [LocalVariableAccess] access to local variable s
+#   72|       15: [ExprStmt] ...;
+#   72|         0: [MethodCall] call to method M2
+#   72|           -1: [TypeAccess] access to type MyExtensions
+#   72|             0: [TypeMention] MyExtensions
+#   72|           0: [LocalVariableAccess] access to local variable s
+#   72|           1: [StringLiteralUtf16] "!!!"
+#   73|       16: [ExprStmt] ...;
+#   73|         0: [MethodCall] call to method StaticM1
+#   73|           -1: [TypeAccess] access to type MyExtensions
+#   73|             0: [TypeMention] MyExtensions
+#   74|       17: [ExprStmt] ...;
+#   74|         0: [MethodCall] call to method StaticM2
+#   74|           -1: [TypeAccess] access to type MyExtensions
+#   74|             0: [TypeMention] MyExtensions
+#   74|           0: [LocalVariableAccess] access to local variable s
+#   75|       18: [ExprStmt] ...;
+#   75|         0: [MethodCall] call to method StaticObjectM1
+#   75|           -1: [TypeAccess] access to type MyExtensions
+#   75|             0: [TypeMention] MyExtensions
+#   76|       19: [ExprStmt] ...;
+#   76|         0: [MethodCall] call to method StaticObjectM2
+#   76|           -1: [TypeAccess] access to type MyExtensions
+#   76|             0: [TypeMention] MyExtensions
+#   76|           0: [LocalVariableAccess] access to local variable s
+#   79|       20: [ExprStmt] ...;
+#   79|         0: [ExtensionOperatorCall] call to operator *
+#   79|           -1: [TypeAccess] access to type MyExtensions
+#   79|             0: [TypeMention] MyExtensions
+#   79|           0: [IntLiteral] 3
+#   79|           1: [LocalVariableAccess] access to local variable s
+#   82|       21: [ExprStmt] ...;
+#   82|         0: [MethodCall] call to extension accessor get_Prop1
+#   82|           -1: [TypeAccess] access to type MyExtensions
+#   82|             0: [TypeMention] MyExtensions
+#   82|           0: [LocalVariableAccess] access to local variable s
+#   83|       22: [ExprStmt] ...;
+#   83|         0: [MethodCall] call to extension accessor get_Prop2
+#   83|           -1: [TypeAccess] access to type MyExtensions
+#   83|             0: [TypeMention] MyExtensions
+#   83|           0: [LocalVariableAccess] access to local variable s
+#   84|       23: [ExprStmt] ...;
+#   84|         0: [MethodCall] call to extension accessor set_Prop2
+#   84|           -1: [TypeAccess] access to type MyExtensions
+#   84|             0: [TypeMention] MyExtensions
+#   84|           0: [LocalVariableAccess] access to local variable s
+#   84|           1: [BoolLiteral] false
+#   85|       24: [ExprStmt] ...;
+#   85|         0: [MethodCall] call to extension accessor get_StaticProp
+#   85|           -1: [TypeAccess] access to type MyExtensions
+#   85|             0: [TypeMention] MyExtensions
+#   88|   7: [Method] CallingGenericExtensions
+#   88|     -1: [TypeMention] Void
+#   89|     4: [BlockStmt] {...}
+#   90|       0: [LocalVariableDeclStmt] ... ...;
+#   90|         0: [LocalVariableDeclAndInitExpr] String s = ...
+#   90|           -1: [TypeMention] string
+#   90|           0: [LocalVariableAccess] access to local variable s
+#   90|           1: [StringLiteralUtf16] "Hello Generic World."
+#   91|       1: [LocalVariableDeclStmt] ... ...;
+#   91|         0: [LocalVariableDeclAndInitExpr] Object o = ...
+#   91|           -1: [TypeMention] object
+#   91|           0: [LocalVariableAccess] access to local variable o
+#   91|           1: [ObjectCreation] object creation of type Object
+#   91|             0: [TypeMention] object
+#   94|       2: [ExprStmt] ...;
+#   94|         0: [MethodCall] call to method GenericM1
+#   94|           -1: [LocalVariableAccess] access to local variable o
+#   95|       3: [ExprStmt] ...;
+#   95|         0: [MethodCall] call to method GenericM1
+#   95|           -1: [LocalVariableAccess] access to local variable s
+#   98|       4: [ExprStmt] ...;
+#   98|         0: [MethodCall] call to method GenericM1
+#   98|           -1: [TypeAccess] access to type MyExtensions
+#   98|             0: [TypeMention] MyExtensions
+#   98|           0: [LocalVariableAccess] access to local variable o
+#   99|       5: [ExprStmt] ...;
+#   99|         0: [MethodCall] call to method GenericM1
+#   99|           -1: [TypeAccess] access to type MyExtensions
+#   99|             0: [TypeMention] MyExtensions
+#   99|           0: [LocalVariableAccess] access to local variable s
+#  101|       6: [ExprStmt] ...;
+#  101|         0: [MethodCall] call to method GenericM2<Int32>
+#  101|           -1: [LocalVariableAccess] access to local variable o
+#  101|           0: [IntLiteral] 42
+#  102|       7: [ExprStmt] ...;
+#  102|         0: [MethodCall] call to method GenericM2<Int32>
+#  102|           -1: [TypeAccess] access to type MyExtensions
+#  102|             0: [TypeMention] MyExtensions
+#  102|           0: [LocalVariableAccess] access to local variable o
+#  102|           1: [IntLiteral] 42
+#  104|       8: [ExprStmt] ...;
+#  104|         0: [MethodCall] call to method StringGenericM1<Int32>
+#  104|           -1: [LocalVariableAccess] access to local variable s
+#  104|           0: [IntLiteral] 7
+#  104|           1: [ObjectCreation] object creation of type Object
+#  104|             0: [TypeMention] object
+#  105|       9: [ExprStmt] ...;
+#  105|         0: [MethodCall] call to method StringGenericM1<String>
+#  105|           -1: [TypeAccess] access to type MyExtensions
+#  105|             0: [TypeMention] MyExtensions
+#  105|           0: [LocalVariableAccess] access to local variable s
+#  105|           1: [StringLiteralUtf16] "test"
+#  105|           2: [ObjectCreation] object creation of type Object
+#  105|             0: [TypeMention] object
--- a/csharp/ql/test/library-tests/extension/PrintAst.qlref
+++ b/csharp/ql/test/library-tests/extension/PrintAst.qlref
@@ -0,0 +1 @@
+shared/PrintAst.ql
--- a/csharp/ql/test/library-tests/extension/extensionTypes.cs
+++ b/csharp/ql/test/library-tests/extension/extensionTypes.cs
@@ -0,0 +1,30 @@
+using System;
+using System.Diagnostics.CodeAnalysis;
+
+public static class MyExtensionTypes
+{
+    extension([NotNull] string s)
+    {
+        public void M11() { }
+    }
+    extension(ref readonly int i1)
+    {
+        public void M21() { }
+    }
+    extension(in int i2)
+    {
+        public void M31() { }
+    }
+    extension(ref int i3)
+    {
+        public void M41() { }
+    }
+    extension(string? s)
+    {
+        public void M51() { }
+    }
+    extension<T1>([NotNullWhen(true)] T1 t1) where T1 : class
+    {
+        public void M61<T2>(object o, T2 t2) { }
+    }
+}
--- a/csharp/ql/test/library-tests/extension/extensionTypes.expected
+++ b/csharp/ql/test/library-tests/extension/extensionTypes.expected
@@ -0,0 +1,37 @@
+extensionTypeReceiverParameter
+| extensionTypes.cs:6:5:9:5 | extension(String) | extensionTypes.cs:6:32:6:32 | s |
+| extensionTypes.cs:10:5:13:5 | extension(Int32) | extensionTypes.cs:10:32:10:33 | i1 |
+| extensionTypes.cs:14:5:17:5 | extension(Int32) | extensionTypes.cs:14:22:14:23 | i2 |
+| extensionTypes.cs:18:5:21:5 | extension(Int32) | extensionTypes.cs:18:23:18:24 | i3 |
+| extensionTypes.cs:22:5:25:5 | extension(String) | extensionTypes.cs:22:23:22:23 | s |
+| extensionTypes.cs:26:5:29:5 | extension(T1)`1 | extensionTypes.cs:26:42:26:43 | t1 |
+| extensions.cs:6:5:17:5 | extension(String) | extensions.cs:6:22:6:22 | s |
+| extensions.cs:26:5:35:5 | extension(Object)<Object> | extensions.cs:26:20:26:20 | t |
+| extensions.cs:26:5:35:5 | extension(String)<String> | extensions.cs:26:20:26:20 | t |
+| extensions.cs:26:5:35:5 | extension(T)`1 | extensions.cs:26:20:26:20 | t |
+extensionTypeExtendedType
+| extensionTypes.cs:6:5:9:5 | extension(String) | string |
+| extensionTypes.cs:10:5:13:5 | extension(Int32) | int |
+| extensionTypes.cs:14:5:17:5 | extension(Int32) | int |
+| extensionTypes.cs:18:5:21:5 | extension(Int32) | int |
+| extensionTypes.cs:22:5:25:5 | extension(String) | string |
+| extensionTypes.cs:26:5:29:5 | extension(T1)`1 | T1 |
+| extensions.cs:6:5:17:5 | extension(String) | string |
+| extensions.cs:19:5:24:5 | extension(Object) | object |
+| extensions.cs:26:5:35:5 | extension(Object)<Object> | object |
+| extensions.cs:26:5:35:5 | extension(String)<String> | string |
+| extensions.cs:26:5:35:5 | extension(T)`1 | T |
+extensionTypeReceiverParameterAttribute
+| extensionTypes.cs:6:5:9:5 | extension(String) | extensionTypes.cs:6:32:6:32 | s | extensionTypes.cs:6:16:6:22 | [NotNull(...)] |
+| extensionTypes.cs:26:5:29:5 | extension(T1)`1 | extensionTypes.cs:26:42:26:43 | t1 | extensionTypes.cs:26:20:26:30 | [NotNullWhen(...)] |
+extensionTypeReceiverParameterModifier
+| extensionTypes.cs:10:5:13:5 | extension(Int32) | extensionTypes.cs:10:32:10:33 | i1 | ref readonly |
+| extensionTypes.cs:14:5:17:5 | extension(Int32) | extensionTypes.cs:14:22:14:23 | i2 | in |
+| extensionTypes.cs:18:5:21:5 | extension(Int32) | extensionTypes.cs:18:23:18:24 | i3 | ref |
+extensionTypeParameterConstraints
+| extensionTypes.cs:26:5:29:5 | extension(T1)`1 | extensionTypes.cs:26:15:26:16 | T1 | file://:0:0:0:0 | where T1: ... |
+| extensions.cs:26:5:35:5 | extension(T)`1 | extensions.cs:26:15:26:15 | T | file://:0:0:0:0 | where T: ... |
+syntheticParameterModifier
+| extensionTypes.cs:10:5:13:5 | extension(Int32) | extensionTypes.cs:12:21:12:23 | M21 | extensionTypes.cs:10:32:10:33 | i1 | ref readonly |
+| extensionTypes.cs:14:5:17:5 | extension(Int32) | extensionTypes.cs:16:21:16:23 | M31 | extensionTypes.cs:14:22:14:23 | i2 | in |
+| extensionTypes.cs:18:5:21:5 | extension(Int32) | extensionTypes.cs:20:21:20:23 | M41 | extensionTypes.cs:18:23:18:24 | i3 | ref |
--- a/csharp/ql/test/library-tests/extension/extensionTypes.ql
+++ b/csharp/ql/test/library-tests/extension/extensionTypes.ql
@@ -0,0 +1,56 @@
+import csharp
+
+private predicate inTestFile(ExtensionType et) {
+  et.getFile().getBaseName() = ["extensions.cs", "extensionTypes.cs"]
+}
+
+private string getModifier(Parameter p) {
+  p.isIn() and result = "in"
+  or
+  p.isRef() and result = "ref"
+  or
+  p.isReadonlyRef() and result = "ref readonly"
+}
+
+query predicate extensionTypeReceiverParameter(ExtensionType et, Parameter p) {
+  inTestFile(et) and
+  p = et.getReceiverParameter()
+}
+
+query predicate extensionTypeExtendedType(ExtensionType et, string t) {
+  inTestFile(et) and
+  t = et.getExtendedType().toStringWithTypes()
+}
+
+query predicate extensionTypeReceiverParameterAttribute(ExtensionType et, Parameter p, Attribute a) {
+  inTestFile(et) and
+  et.getReceiverParameter() = p and
+  p.getAnAttribute() = a
+}
+
+query predicate extensionTypeReceiverParameterModifier(
+  ExtensionType et, Parameter p, string modifier
+) {
+  inTestFile(et) and
+  et.getReceiverParameter() = p and
+  modifier = getModifier(p)
+}
+
+query predicate extensionTypeParameterConstraints(
+  UnboundGeneric ug, TypeParameter tp, TypeParameterConstraints c
+) {
+  inTestFile(ug) and
+  ug instanceof ExtensionType and
+  tp = ug.getATypeParameter() and
+  tp.getConstraints() = c
+}
+
+query predicate syntheticParameterModifier(
+  ExtensionType et, ExtensionMethod em, Parameter p, string modifier
+) {
+  inTestFile(et) and
+  em.getDeclaringType() = et and
+  p = em.getParameter(0) and
+  not em.isStatic() and
+  modifier = getModifier(p)
+}
--- a/csharp/ql/test/library-tests/extension/extensions.cs
+++ b/csharp/ql/test/library-tests/extension/extensions.cs
@@ -0,0 +1,107 @@
+using System;
+using System.Collections.Generic;
+
+public static class MyExtensions
+{
+    extension(string s)
+    {
+        public bool Prop1 => s.Length > 0;
+        public bool Prop2 { get { return true; } set { } }
+        public static bool StaticProp1 { get { return false; } }
+        public bool M1() => s is not null;
+        public string M2(string other) { return s + other; }
+        public static int StaticM1() { return 0; }
+        public static int StaticM2(string x) { return x.Length; }
+        public static string operator *(int a, string b) { return ""; }
+        public T StringGenericM1<T>(T t, object o) { return t; }
+    }
+
+    extension(object)
+    {
+        public static int StaticObjectM1() { return 0; }
+        public static int StaticObjectM2(string s) { return s.Length; }
+        public static bool StaticProp => true;
+    }
+
+    extension<T>(T t) where T : class
+    {
+        public bool GenericProp1 => t is not null;
+        public bool GenericProp2 { get { return true; } set { } }
+        public bool GenericM1() => t is not null;
+        public void GenericM2<S>(S other) { }
+        public void GenericStaticM1() { }
+        public static void GenericStaticM2<S>(S other) { }
+        public static T operator +(T a, T b) { return null; }
+    }
+}
+
+public static class ClassicExtensions
+{
+    public static bool M3(this string s) => s is not null;
+}
+
+public class C
+{
+    public static void CallingExtensions()
+    {
+        var s = "Hello World.";
+
+        // Calling the extensions properties
+        var x11 = s.Prop1;
+        var x12 = s.Prop2;
+        s.Prop2 = true;
+        var x13 = string.StaticProp1;
+        var x14 = object.StaticProp;
+
+        // Calling the extensions methods.
+        var x21 = s.M1();
+        var x22 = s.M2("!!!");
+        var x23 = string.StaticM1();
+        var x24 = string.StaticM2(s);
+        var x25 = object.StaticObjectM1();
+        var x26 = object.StaticObjectM2(s);
+
+        // Calling the extension operator.
+        var x30 = 3 * s;
+
+        // Calling the classic extension method.
+        var y = s.M3();
+
+        // Calling the compiler generated static extension methods.
+        MyExtensions.M1(s);
+        MyExtensions.M2(s, "!!!");
+        MyExtensions.StaticM1();
+        MyExtensions.StaticM2(s);
+        MyExtensions.StaticObjectM1();
+        MyExtensions.StaticObjectM2(s);
+
+        // Calling the compiler generated operator method.
+        MyExtensions.op_Multiply(3, s);
+
+        // Calling the compiler generated methods used by the extension property accessors.
+        MyExtensions.get_Prop1(s);
+        MyExtensions.get_Prop2(s);
+        MyExtensions.set_Prop2(s, false);
+        MyExtensions.get_StaticProp();
+    }
+
+    public static void CallingGenericExtensions()
+    {
+        var s = "Hello Generic World.";
+        var o = new object();
+
+        // Calling generic extension method
+        o.GenericM1();
+        s.GenericM1();
+
+        // Calling the compiler generated static extension methods.
+        MyExtensions.GenericM1(o);
+        MyExtensions.GenericM1(s);
+
+        o.GenericM2(42);
+        MyExtensions.GenericM2(o, 42);
+
+        s.StringGenericM1<int>(7, new object());
+        MyExtensions.StringGenericM1<string>(s, "test", new object());
+    }
+}
--- a/csharp/ql/test/library-tests/extension/extensions.expected
+++ b/csharp/ql/test/library-tests/extension/extensions.expected
@@ -0,0 +1,111 @@
+extensionMethodCallArgument
+| extensions.cs:57:19:57:24 | call to method M1 | extensions.cs:11:21:11:22 | M1 | extensions.cs:6:22:6:22 | s | 0 | extensions.cs:57:19:57:19 | access to local variable s |
+| extensions.cs:58:19:58:29 | call to method M2 | extensions.cs:12:23:12:24 | M2 | extensions.cs:6:22:6:22 | s | 0 | extensions.cs:58:19:58:19 | access to local variable s |
+| extensions.cs:58:19:58:29 | call to method M2 | extensions.cs:12:23:12:24 | M2 | extensions.cs:12:33:12:37 | other | 1 | extensions.cs:58:24:58:28 | "!!!" |
+| extensions.cs:60:19:60:36 | call to method StaticM2 | extensions.cs:14:27:14:34 | StaticM2 | extensions.cs:14:43:14:43 | x | 0 | extensions.cs:60:35:60:35 | access to local variable s |
+| extensions.cs:62:19:62:42 | call to method StaticObjectM2 | extensions.cs:22:27:22:40 | StaticObjectM2 | extensions.cs:22:49:22:49 | s | 0 | extensions.cs:62:41:62:41 | access to local variable s |
+| extensions.cs:68:17:68:22 | call to method M3 | extensions.cs:40:24:40:25 | M3 | extensions.cs:40:39:40:39 | s | 0 | extensions.cs:68:17:68:17 | access to local variable s |
+| extensions.cs:71:9:71:26 | call to method M1 | extensions.cs:11:21:11:22 | M1 | extensions.cs:6:22:6:22 | s | 0 | extensions.cs:71:25:71:25 | access to local variable s |
+| extensions.cs:72:9:72:33 | call to method M2 | extensions.cs:12:23:12:24 | M2 | extensions.cs:6:22:6:22 | s | 0 | extensions.cs:72:25:72:25 | access to local variable s |
+| extensions.cs:72:9:72:33 | call to method M2 | extensions.cs:12:23:12:24 | M2 | extensions.cs:12:33:12:37 | other | 1 | extensions.cs:72:28:72:32 | "!!!" |
+| extensions.cs:74:9:74:32 | call to method StaticM2 | extensions.cs:14:27:14:34 | StaticM2 | extensions.cs:14:43:14:43 | x | 0 | extensions.cs:74:31:74:31 | access to local variable s |
+| extensions.cs:76:9:76:38 | call to method StaticObjectM2 | extensions.cs:22:27:22:40 | StaticObjectM2 | extensions.cs:22:49:22:49 | s | 0 | extensions.cs:76:37:76:37 | access to local variable s |
+| extensions.cs:94:9:94:21 | call to method GenericM1 | extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:20:26:20 | t | 0 | extensions.cs:94:9:94:9 | access to local variable o |
+| extensions.cs:95:9:95:21 | call to method GenericM1 | extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:20:26:20 | t | 0 | extensions.cs:95:9:95:9 | access to local variable s |
+| extensions.cs:98:9:98:33 | call to method GenericM1 | extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:20:26:20 | t | 0 | extensions.cs:98:32:98:32 | access to local variable o |
+| extensions.cs:99:9:99:33 | call to method GenericM1 | extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:20:26:20 | t | 0 | extensions.cs:99:32:99:32 | access to local variable s |
+| extensions.cs:101:9:101:23 | call to method GenericM2<Int32> | extensions.cs:31:21:31:32 | GenericM2<Int32> | extensions.cs:26:20:26:20 | t | 0 | extensions.cs:101:9:101:9 | access to local variable o |
+| extensions.cs:101:9:101:23 | call to method GenericM2<Int32> | extensions.cs:31:21:31:32 | GenericM2<Int32> | extensions.cs:31:36:31:40 | other | 1 | extensions.cs:101:21:101:22 | 42 |
+| extensions.cs:102:9:102:37 | call to method GenericM2<Int32> | extensions.cs:31:21:31:32 | GenericM2<Int32> | extensions.cs:26:20:26:20 | t | 0 | extensions.cs:102:32:102:32 | access to local variable o |
+| extensions.cs:102:9:102:37 | call to method GenericM2<Int32> | extensions.cs:31:21:31:32 | GenericM2<Int32> | extensions.cs:31:36:31:40 | other | 1 | extensions.cs:102:35:102:36 | 42 |
+| extensions.cs:104:9:104:47 | call to method StringGenericM1<Int32> | extensions.cs:16:18:16:35 | StringGenericM1<Int32> | extensions.cs:6:22:6:22 | s | 0 | extensions.cs:104:9:104:9 | access to local variable s |
+| extensions.cs:104:9:104:47 | call to method StringGenericM1<Int32> | extensions.cs:16:18:16:35 | StringGenericM1<Int32> | extensions.cs:16:39:16:39 | t | 1 | extensions.cs:104:32:104:32 | 7 |
+| extensions.cs:104:9:104:47 | call to method StringGenericM1<Int32> | extensions.cs:16:18:16:35 | StringGenericM1<Int32> | extensions.cs:16:49:16:49 | o | 2 | extensions.cs:104:35:104:46 | object creation of type Object |
+| extensions.cs:105:9:105:69 | call to method StringGenericM1<String> | extensions.cs:16:18:16:35 | StringGenericM1<String> | extensions.cs:6:22:6:22 | s | 0 | extensions.cs:105:46:105:46 | access to local variable s |
+| extensions.cs:105:9:105:69 | call to method StringGenericM1<String> | extensions.cs:16:18:16:35 | StringGenericM1<String> | extensions.cs:16:39:16:39 | t | 1 | extensions.cs:105:49:105:54 | "test" |
+| extensions.cs:105:9:105:69 | call to method StringGenericM1<String> | extensions.cs:16:18:16:35 | StringGenericM1<String> | extensions.cs:16:49:16:49 | o | 2 | extensions.cs:105:57:105:68 | object creation of type Object |
+extensionMethodCalls
+| extensions.cs:57:19:57:24 | call to method M1 | extensions.cs:11:21:11:22 | M1 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).M1 |
+| extensions.cs:58:19:58:29 | call to method M2 | extensions.cs:12:23:12:24 | M2 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).M2 |
+| extensions.cs:59:19:59:35 | call to method StaticM1 | extensions.cs:13:27:13:34 | StaticM1 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).StaticM1 |
+| extensions.cs:60:19:60:36 | call to method StaticM2 | extensions.cs:14:27:14:34 | StaticM2 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).StaticM2 |
+| extensions.cs:61:19:61:41 | call to method StaticObjectM1 | extensions.cs:21:27:21:40 | StaticObjectM1 | extensions.cs:19:5:24:5 | extension(Object) | MyExtensions+extension(System.Object).StaticObjectM1 |
+| extensions.cs:62:19:62:42 | call to method StaticObjectM2 | extensions.cs:22:27:22:40 | StaticObjectM2 | extensions.cs:19:5:24:5 | extension(Object) | MyExtensions+extension(System.Object).StaticObjectM2 |
+| extensions.cs:68:17:68:22 | call to method M3 | extensions.cs:40:24:40:25 | M3 | extensions.cs:38:21:38:37 | ClassicExtensions | ClassicExtensions.M3 |
+| extensions.cs:71:9:71:26 | call to method M1 | extensions.cs:11:21:11:22 | M1 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).M1 |
+| extensions.cs:72:9:72:33 | call to method M2 | extensions.cs:12:23:12:24 | M2 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).M2 |
+| extensions.cs:73:9:73:31 | call to method StaticM1 | extensions.cs:13:27:13:34 | StaticM1 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).StaticM1 |
+| extensions.cs:74:9:74:32 | call to method StaticM2 | extensions.cs:14:27:14:34 | StaticM2 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).StaticM2 |
+| extensions.cs:75:9:75:37 | call to method StaticObjectM1 | extensions.cs:21:27:21:40 | StaticObjectM1 | extensions.cs:19:5:24:5 | extension(Object) | MyExtensions+extension(System.Object).StaticObjectM1 |
+| extensions.cs:76:9:76:38 | call to method StaticObjectM2 | extensions.cs:22:27:22:40 | StaticObjectM2 | extensions.cs:19:5:24:5 | extension(Object) | MyExtensions+extension(System.Object).StaticObjectM2 |
+| extensions.cs:94:9:94:21 | call to method GenericM1 | extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:5:35:5 | extension(Object)<Object> | MyExtensions+extension(System.Object)<System.Object>.GenericM1 |
+| extensions.cs:95:9:95:21 | call to method GenericM1 | extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:5:35:5 | extension(String)<String> | MyExtensions+extension(System.String)<System.String>.GenericM1 |
+| extensions.cs:98:9:98:33 | call to method GenericM1 | extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:5:35:5 | extension(Object)<Object> | MyExtensions+extension(System.Object)<System.Object>.GenericM1 |
+| extensions.cs:99:9:99:33 | call to method GenericM1 | extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:5:35:5 | extension(String)<String> | MyExtensions+extension(System.String)<System.String>.GenericM1 |
+| extensions.cs:101:9:101:23 | call to method GenericM2<Int32> | extensions.cs:31:21:31:32 | GenericM2<Int32> | extensions.cs:26:5:35:5 | extension(Object)<Object> | MyExtensions+extension(System.Object)<System.Object>.GenericM2<Int32> |
+| extensions.cs:102:9:102:37 | call to method GenericM2<Int32> | extensions.cs:31:21:31:32 | GenericM2<Int32> | extensions.cs:26:5:35:5 | extension(Object)<Object> | MyExtensions+extension(System.Object)<System.Object>.GenericM2<Int32> |
+| extensions.cs:104:9:104:47 | call to method StringGenericM1<Int32> | extensions.cs:16:18:16:35 | StringGenericM1<Int32> | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).StringGenericM1<Int32> |
+| extensions.cs:105:9:105:69 | call to method StringGenericM1<String> | extensions.cs:16:18:16:35 | StringGenericM1<String> | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).StringGenericM1<String> |
+extensionParameter
+| extensions.cs:11:21:11:22 | M1 | extensions.cs:6:22:6:22 | s | 0 | string | extensions.cs:6:22:6:22 | s |
+| extensions.cs:12:23:12:24 | M2 | extensions.cs:6:22:6:22 | s | 0 | string | extensions.cs:6:22:6:22 | s |
+| extensions.cs:12:23:12:24 | M2 | extensions.cs:12:33:12:37 | other | 1 | string | extensions.cs:12:33:12:37 | other |
+| extensions.cs:14:27:14:34 | StaticM2 | extensions.cs:14:43:14:43 | x | 0 | string | extensions.cs:14:43:14:43 | x |
+| extensions.cs:16:18:16:35 | StringGenericM1<Int32> | extensions.cs:6:22:6:22 | s | 0 | string | extensions.cs:6:22:6:22 | s |
+| extensions.cs:16:18:16:35 | StringGenericM1<Int32> | extensions.cs:16:39:16:39 | t | 1 | int | extensions.cs:16:39:16:39 | t |
+| extensions.cs:16:18:16:35 | StringGenericM1<Int32> | extensions.cs:16:49:16:49 | o | 2 | object | extensions.cs:16:49:16:49 | o |
+| extensions.cs:16:18:16:35 | StringGenericM1<String> | extensions.cs:6:22:6:22 | s | 0 | string | extensions.cs:6:22:6:22 | s |
+| extensions.cs:16:18:16:35 | StringGenericM1<String> | extensions.cs:16:39:16:39 | t | 1 | string | extensions.cs:16:39:16:39 | t |
+| extensions.cs:16:18:16:35 | StringGenericM1<String> | extensions.cs:16:49:16:49 | o | 2 | object | extensions.cs:16:49:16:49 | o |
+| extensions.cs:16:18:16:35 | StringGenericM1`1 | extensions.cs:6:22:6:22 | s | 0 | string | extensions.cs:6:22:6:22 | s |
+| extensions.cs:16:18:16:35 | StringGenericM1`1 | extensions.cs:16:39:16:39 | t | 1 | T | extensions.cs:16:39:16:39 | t |
+| extensions.cs:16:18:16:35 | StringGenericM1`1 | extensions.cs:16:49:16:49 | o | 2 | object | extensions.cs:16:49:16:49 | o |
+| extensions.cs:22:27:22:40 | StaticObjectM2 | extensions.cs:22:49:22:49 | s | 0 | string | extensions.cs:22:49:22:49 | s |
+| extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:20:26:20 | t | 0 | T | extensions.cs:26:20:26:20 | t |
+| extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:20:26:20 | t | 0 | object | extensions.cs:26:20:26:20 | t |
+| extensions.cs:30:21:30:29 | GenericM1 | extensions.cs:26:20:26:20 | t | 0 | string | extensions.cs:26:20:26:20 | t |
+| extensions.cs:31:21:31:32 | GenericM2<Int32> | extensions.cs:26:20:26:20 | t | 0 | object | extensions.cs:26:20:26:20 | t |
+| extensions.cs:31:21:31:32 | GenericM2<Int32> | extensions.cs:31:36:31:40 | other | 1 | int | extensions.cs:31:36:31:40 | other |
+| extensions.cs:31:21:31:32 | GenericM2`1 | extensions.cs:26:20:26:20 | t | 0 | T | extensions.cs:26:20:26:20 | t |
+| extensions.cs:31:21:31:32 | GenericM2`1 | extensions.cs:26:20:26:20 | t | 0 | object | extensions.cs:26:20:26:20 | t |
+| extensions.cs:31:21:31:32 | GenericM2`1 | extensions.cs:26:20:26:20 | t | 0 | string | extensions.cs:26:20:26:20 | t |
+| extensions.cs:31:21:31:32 | GenericM2`1 | extensions.cs:31:36:31:40 | other | 1 | S | extensions.cs:31:36:31:40 | other |
+| extensions.cs:31:21:31:32 | GenericM2`1 | extensions.cs:31:36:31:40 | other | 1 | S | extensions.cs:31:36:31:40 | other |
+| extensions.cs:31:21:31:32 | GenericM2`1 | extensions.cs:31:36:31:40 | other | 1 | S | extensions.cs:31:36:31:40 | other |
+| extensions.cs:32:21:32:35 | GenericStaticM1 | extensions.cs:26:20:26:20 | t | 0 | T | extensions.cs:26:20:26:20 | t |
+| extensions.cs:32:21:32:35 | GenericStaticM1 | extensions.cs:26:20:26:20 | t | 0 | object | extensions.cs:26:20:26:20 | t |
+| extensions.cs:32:21:32:35 | GenericStaticM1 | extensions.cs:26:20:26:20 | t | 0 | string | extensions.cs:26:20:26:20 | t |
+| extensions.cs:33:28:33:45 | GenericStaticM2`1 | extensions.cs:33:49:33:53 | other | 0 | S | extensions.cs:33:49:33:53 | other |
+| extensions.cs:33:28:33:45 | GenericStaticM2`1 | extensions.cs:33:49:33:53 | other | 0 | S | extensions.cs:33:49:33:53 | other |
+| extensions.cs:33:28:33:45 | GenericStaticM2`1 | extensions.cs:33:49:33:53 | other | 0 | S | extensions.cs:33:49:33:53 | other |
+| extensions.cs:40:24:40:25 | M3 | extensions.cs:40:39:40:39 | s | 0 | string | extensions.cs:40:39:40:39 | s |
+extensionOperatorCallArgument
+| extensions.cs:15:39:15:39 | * | extensions.cs:65:19:65:23 | call to operator * | extensions.cs:15:45:15:45 | a | 0 | extensions.cs:65:19:65:19 | 3 |
+| extensions.cs:15:39:15:39 | * | extensions.cs:65:19:65:23 | call to operator * | extensions.cs:15:55:15:55 | b | 1 | extensions.cs:65:23:65:23 | access to local variable s |
+| extensions.cs:15:39:15:39 | * | extensions.cs:79:9:79:38 | call to operator * | extensions.cs:15:45:15:45 | a | 0 | extensions.cs:79:34:79:34 | 3 |
+| extensions.cs:15:39:15:39 | * | extensions.cs:79:9:79:38 | call to operator * | extensions.cs:15:55:15:55 | b | 1 | extensions.cs:79:37:79:37 | access to local variable s |
+extensionOperatorCalls
+| extensions.cs:65:19:65:23 | call to operator * | extensions.cs:15:39:15:39 | * | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).op_Multiply |
+| extensions.cs:79:9:79:38 | call to operator * | extensions.cs:15:39:15:39 | * | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).op_Multiply |
+extensionProperty
+| extensions.cs:8:21:8:25 | Prop1 | extensions.cs:6:5:17:5 | extension(String) |
+| extensions.cs:9:21:9:25 | Prop2 | extensions.cs:6:5:17:5 | extension(String) |
+| extensions.cs:10:28:10:38 | StaticProp1 | extensions.cs:6:5:17:5 | extension(String) |
+| extensions.cs:23:28:23:37 | StaticProp | extensions.cs:19:5:24:5 | extension(Object) |
+| extensions.cs:28:21:28:32 | GenericProp1 | extensions.cs:26:5:35:5 | extension(Object)<Object> |
+| extensions.cs:28:21:28:32 | GenericProp1 | extensions.cs:26:5:35:5 | extension(String)<String> |
+| extensions.cs:28:21:28:32 | GenericProp1 | extensions.cs:26:5:35:5 | extension(T)`1 |
+| extensions.cs:29:21:29:32 | GenericProp2 | extensions.cs:26:5:35:5 | extension(Object)<Object> |
+| extensions.cs:29:21:29:32 | GenericProp2 | extensions.cs:26:5:35:5 | extension(String)<String> |
+| extensions.cs:29:21:29:32 | GenericProp2 | extensions.cs:26:5:35:5 | extension(T)`1 |
+extensionPropertyCall
+| extensions.cs:50:19:50:25 | access to property Prop1 | extensions.cs:8:21:8:25 | Prop1 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).Prop1 |
+| extensions.cs:51:19:51:25 | access to property Prop2 | extensions.cs:9:21:9:25 | Prop2 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).Prop2 |
+| extensions.cs:52:9:52:15 | access to property Prop2 | extensions.cs:9:21:9:25 | Prop2 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).Prop2 |
+| extensions.cs:53:19:53:36 | access to property StaticProp1 | extensions.cs:10:28:10:38 | StaticProp1 | extensions.cs:6:5:17:5 | extension(String) | MyExtensions+extension(System.String).StaticProp1 |
+| extensions.cs:54:19:54:35 | access to property StaticProp | extensions.cs:23:28:23:37 | StaticProp | extensions.cs:19:5:24:5 | extension(Object) | MyExtensions+extension(System.Object).StaticProp |
+extensionAccessorCall
+| extensions.cs:82:9:82:33 | call to extension accessor get_Prop1 | extensions.cs:8:30:8:41 | get_Prop1 | extensions.cs:8:21:8:25 | Prop1 | MyExtensions+extension(System.String).get_Prop1 |
+| extensions.cs:83:9:83:33 | call to extension accessor get_Prop2 | extensions.cs:9:29:9:31 | get_Prop2 | extensions.cs:9:21:9:25 | Prop2 | MyExtensions+extension(System.String).get_Prop2 |
+| extensions.cs:84:9:84:40 | call to extension accessor set_Prop2 | extensions.cs:9:50:9:52 | set_Prop2 | extensions.cs:9:21:9:25 | Prop2 | MyExtensions+extension(System.String).set_Prop2 |
+| extensions.cs:85:9:85:37 | call to extension accessor get_StaticProp | extensions.cs:23:42:23:45 | get_StaticProp | extensions.cs:23:28:23:37 | StaticProp | MyExtensions+extension(System.Object).get_StaticProp |
--- a/csharp/ql/test/library-tests/extension/extensions.ql
+++ b/csharp/ql/test/library-tests/extension/extensions.ql
@@ -0,0 +1,69 @@
+import csharp
+
+query predicate extensionMethodCallArgument(
+  ExtensionMethodCall emc, ExtensionMethod em, Parameter p, int i, Expr e
+) {
+  em.getFile().getBaseName() = "extensions.cs" and
+  emc.getTarget() = em and
+  em.getParameter(i) = p and
+  emc.getArgument(i) = e
+}
+
+query predicate extensionMethodCalls(
+  ExtensionMethodCall emc, ExtensionMethod em, Type t, string type
+) {
+  em.getFile().getBaseName() = "extensions.cs" and
+  emc.getTarget() = em and
+  em.getDeclaringType() = t and
+  em.getFullyQualifiedNameDebug() = type
+}
+
+query predicate extensionParameter(
+  ExtensionMethod em, Parameter p, int i, string type, Parameter unbound
+) {
+  em.getFile().getBaseName() = "extensions.cs" and
+  p = em.getParameter(i) and
+  type = p.getType().toStringWithTypes() and
+  unbound = p.getUnboundDeclaration()
+}
+
+query predicate extensionOperatorCallArgument(
+  ExtensionOperator op, ExtensionOperatorCall opc, Parameter p, int pos, Expr e
+) {
+  opc.getTarget() = op and
+  op.getFile().getBaseName() = "extensions.cs" and
+  p = op.getParameter(pos) and
+  e = opc.getArgument(pos)
+}
+
+query predicate extensionOperatorCalls(
+  ExtensionOperatorCall opc, ExtensionOperator op, Type t, string type
+) {
+  op.getFile().getBaseName() = "extensions.cs" and
+  opc.getTarget() = op and
+  op.getDeclaringType() = t and
+  op.getFullyQualifiedNameDebug() = type
+}
+
+query predicate extensionProperty(ExtensionProperty p, Type t) {
+  p.getFile().getBaseName() = "extensions.cs" and
+  p.getDeclaringType() = t
+}
+
+query predicate extensionPropertyCall(
+  ExtensionPropertyCall pc, ExtensionProperty p, Type t, string type
+) {
+  p.getFile().getBaseName() = "extensions.cs" and
+  pc.getProperty() = p and
+  p.getDeclaringType() = t and
+  p.getFullyQualifiedNameDebug() = type
+}
+
+query predicate extensionAccessorCall(
+  MethodCall m, ExtensionAccessor a, ExtensionProperty p, string type
+) {
+  p.getFile().getBaseName() = "extensions.cs" and
+  (a.(Getter).getDeclaration() = p or a.(Setter).getDeclaration() = p) and
+  m.getTargetAccessor() = a and
+  a.getFullyQualifiedNameDebug() = type
+}
--- a/csharp/ql/test/library-tests/extension/options
+++ b/csharp/ql/test/library-tests/extension/options
@@ -0,0 +1,2 @@
+semmle-extractor-options: /nostdlib /noconfig
+semmle-extractor-options: --load-sources-from-project:${testdir}/../../resources/stubs/_frameworks/Microsoft.NETCore.App/Microsoft.NETCore.App.csproj