C#: Re-factor. Introduce variablekind enum.

Author: michaelnebel

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

@@ -33,7 +33,8 @@ public override void Populate(TextWriter trapFile)
             PopulateRefKind(trapFile, Symbol.RefKind);
 
             var unboundFieldKey = Field.Create(Context, Symbol.OriginalDefinition);
-            trapFile.fields(this, (Symbol.IsConst ? 2 : 1), Symbol.Name, ContainingType, Type.TypeRef, unboundFieldKey);
+            var kind = Symbol.IsConst ? VariableKind.Const : VariableKind.None;
+            trapFile.fields(this, kind, Symbol.Name, ContainingType, Type.TypeRef, unboundFieldKey);
 
             PopulateModifiers(trapFile);
 

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

@@ -27,17 +27,17 @@ public void PopulateManual(Expression parent, bool isVar)
 
             if (Symbol is ILocalSymbol local)
             {
-                var @const = local.IsRef ? 3 : local.IsConst ? 2 : 1;
+                var kind = local.IsRef ? Kinds.VariableKind.Ref : local.IsConst ? Kinds.VariableKind.Const : Kinds.VariableKind.None;
                 var type = local.GetAnnotatedType();
-                trapFile.localvars(this, @const, Symbol.Name, @var, Type.Create(Context, type).TypeRef, parent);
+                trapFile.localvars(this, kind, Symbol.Name, @var, Type.Create(Context, type).TypeRef, parent);
 
                 PopulateNullability(trapFile, local.GetAnnotatedType());
                 if (local.IsRef)
                     trapFile.type_annotation(this, Kinds.TypeAnnotation.Ref);
             }
             else
             {
-                trapFile.localvars(this, 1, Symbol.Name, @var, Type.Create(Context, parent.Type).TypeRef, parent);
+                trapFile.localvars(this, Kinds.VariableKind.None, Symbol.Name, @var, Type.Create(Context, parent.Type).TypeRef, parent);
             }
 
             trapFile.localvar_location(this, Location);

csharp/extractor/Semmle.Extraction.CSharp/Kinds/VariableKind.cs

@@ -0,0 +1,8 @@
+namespace Semmle.Extraction.Kinds;
+
+public enum VariableKind
+{
+    None = 1,
+    Const = 2,
+    Ref = 3
+}

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

@@ -191,8 +191,8 @@ internal static void anonymous_types(this TextWriter trapFile, Type type) =>
         internal static void field_location(this TextWriter trapFile, Field field, Location location) =>
             trapFile.WriteTuple("field_location", field, location);
 
-        internal static void fields(this TextWriter trapFile, Field field, int @const, string name, Type declaringType, Type fieldType, Field unboundKey) =>
-            trapFile.WriteTuple("fields", field, @const, name, declaringType, fieldType, unboundKey);
+        internal static void fields(this TextWriter trapFile, Field field, VariableKind kind, string name, Type declaringType, Type fieldType, Field unboundKey) =>
+            trapFile.WriteTuple("fields", field, (int)kind, name, declaringType, fieldType, unboundKey);
 
         internal static void general_type_parameter_constraints(this TextWriter trapFile, TypeParameterConstraints constraints, int hasKind) =>
             trapFile.WriteTuple("general_type_parameter_constraints", constraints, hasKind);
@@ -227,8 +227,8 @@ internal static void local_functions(this TextWriter trapFile, LocalFunction fn,
         internal static void localvar_location(this TextWriter trapFile, LocalVariable var, Location location) =>
             trapFile.WriteTuple("localvar_location", var, location);
 
-        internal static void localvars(this TextWriter trapFile, LocalVariable key, int @const, string name, int @var, Type type, Expression expr) =>
-            trapFile.WriteTuple("localvars", key, @const, name, @var, type, expr);
+        internal static void localvars(this TextWriter trapFile, LocalVariable key, VariableKind kind, string name, int @var, Type type, Expression expr) =>
+            trapFile.WriteTuple("localvars", key, (int)kind, name, @var, type, expr);
 
         public static void metadata_handle(this TextWriter trapFile, IEntity entity, Location assembly, int handleValue) =>
             trapFile.WriteTuple("metadata_handle", entity, assembly, handleValue);