Merge pull request #4630 from tamasvajk/feature/csharp9-init-prop

C#: Add support for init only accessors

Author: tamasvajk

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

@@ -76,6 +76,11 @@ public override void Populate(TextWriter trapFile)
             {
                 trapFile.compiler_generated(this);
             }
+
+            if (symbol.IsInitOnly)
+            {
+                trapFile.init_only_accessors(this);
+            }
         }
 
         public static new Accessor Create(Context cx, IMethodSymbol symbol) =>

csharp/extractor/Semmle.Extraction.CSharp/Tuples.cs

@@ -26,6 +26,11 @@ internal static void accessors(this TextWriter trapFile, Accessor accessorKey, i
             trapFile.WriteTuple("accessors", accessorKey, kind, name, propKey, unboundAccessor);
         }
 
+        internal static void init_only_accessors(this TextWriter trapFile, Accessor accessorKey)
+        {
+            trapFile.WriteTuple("init_only_accessors", accessorKey);
+        }
+
         internal static void array_element_type(this TextWriter trapFile, ArrayType array, int dimension, int rank, Type elementType)
         {
             trapFile.WriteTuple("array_element_type", array, dimension, rank, elementType);

csharp/ql/src/semmle/code/csharp/Property.qll

@@ -472,6 +472,9 @@ class Setter extends Accessor, @setter {
     result = Accessor.super.getDeclaration()
   }
 
+  /** Holds if this setter is an `init`-only accessor. */
+  predicate isInitOnly() { init_only_accessors(this) }
+
   override string getAPrimaryQlClass() { result = "Setter" }
 }
 

csharp/ql/src/semmlecode.csharp.dbscheme

@@ -604,6 +604,9 @@ case @accessor.kind of
 | 2 = @setter
   ;
 
+init_only_accessors(
+  unique int id: @accessor ref);
+
 accessor_location(
   int id: @accessor ref,
   int loc: @location ref);