C#: Add generated cast expression for nuint and nint parameter defaults.

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expression.cs

@@ -214,14 +214,19 @@ private static bool ContainsPattern(SyntaxNode node) =>
 
             if (type.SpecialType is SpecialType.None)
             {
-                return ImplicitCast.CreateGenerated(cx, parent, childIndex, type, defaultValue, location);
+                return ImplicitCast.CreateGeneratedConversion(cx, parent, childIndex, type, defaultValue, location);
             }
 
             if (type.SpecialType is SpecialType.System_DateTime)
             {
                 return DateTimeObjectCreation.CreateGenerated(cx, parent, childIndex, type, defaultValue, location);
             }
 
+            if (type.SpecialType is SpecialType.System_IntPtr || type.SpecialType is SpecialType.System_UIntPtr)
+            {
+                return ImplicitCast.CreateGenerated(cx, parent, childIndex, type, defaultValue, location);
+            }
+
             // const literal:
             return Literal.CreateGenerated(cx, parent, childIndex, type, defaultValue, location);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/ImplicitCast.cs

@@ -51,8 +51,10 @@ private void AddOperatorCall(IMethodSymbol method)
                 )
                 .FirstOrDefault();
 
-        // Creates a new generated expression with an implicit cast added, if needed.
-        public static Expression CreateGenerated(Context cx, IExpressionParentEntity parent, int childIndex, ITypeSymbol type, object value,
+        /// <summary>
+        /// Creates a new generated expression with an implicit conversion added.
+        /// </summary>
+        public static Expression CreateGeneratedConversion(Context cx, IExpressionParentEntity parent, int childIndex, ITypeSymbol type, object value,
             Extraction.Entities.Location location)
         {
             ExpressionInfo create(ExprKind kind, string? v) =>
@@ -79,7 +81,27 @@ ExpressionInfo create(ExprKind kind, string? v) =>
             }
         }
 
-        // Creates a new expression, adding casts as required.
+        /// <summary>
+        /// Creates a new generated cast expression.
+        /// </summary>
+        public static Expression CreateGenerated(Context cx, IExpressionParentEntity parent, int childIndex, ITypeSymbol type, object value,
+                    Extraction.Entities.Location location)
+        {
+            var info = new ExpressionInfo(cx,
+                    AnnotatedTypeSymbol.CreateNotAnnotated(type),
+                    location,
+                    ExprKind.CAST,
+                    parent,
+                    childIndex,
+                    true,
+                    ValueAsString(value));
+
+            return new Expression(info);
+        }
+
+        /// <summary>
+        /// Creates a new expression, adding casts as required.
+        /// </summary>
         public static Expression Create(ExpressionNodeInfo info)
         {
             var resolvedType = info.ResolvedType;