Merge pull request #15328 from michaelnebel/csharp/inlinearrays

C# 12: Inline array support.

Author: michaelnebel

csharp/downgrades/f595d31422d7d462d2bee8c69b44341df8bdadb6/old.dbscheme

@@ -0,0 +1,9 @@
+class Type extends @type {
+  string toString() { none() }
+}
+
+from Type t, int k, int kind, string name
+where
+  types(t, k, name) and
+  if k = 34 then kind = 15 else kind = k
+select t, kind, name

csharp/downgrades/f595d31422d7d462d2bee8c69b44341df8bdadb6/semmlecode.csharp.dbscheme

@@ -0,0 +1,3 @@
+description: Remove support for inline arrays.
+compatibility: backwards
+types.rel: run types.qlo

csharp/downgrades/f595d31422d7d462d2bee8c69b44341df8bdadb6/types.ql

@@ -43,6 +43,9 @@ protected override void PopulateExpression(TextWriter trapFile)
 
         public sealed override Microsoft.CodeAnalysis.Location? ReportingLocation => base.ReportingLocation;
 
+        private static bool IsArray(ITypeSymbol symbol) =>
+            symbol.TypeKind == Microsoft.CodeAnalysis.TypeKind.Array || symbol.IsInlineArray();
+
         private static ExprKind GetKind(Context cx, ExpressionSyntax qualifier)
         {
             var qualifierType = cx.GetType(qualifier);
@@ -59,7 +62,7 @@ private static ExprKind GetKind(Context cx, ExpressionSyntax qualifier)
 
             return IsDynamic(cx, qualifier)
                 ? ExprKind.DYNAMIC_ELEMENT_ACCESS
-                : qualifierType.Symbol.TypeKind == Microsoft.CodeAnalysis.TypeKind.Array
+                : IsArray(qualifierType.Symbol)
                     ? ExprKind.ARRAY_ACCESS
                     : ExprKind.INDEXER_ACCESS;
         }

csharp/downgrades/f595d31422d7d462d2bee8c69b44341df8bdadb6/upgrade.properties

@@ -52,9 +52,15 @@ public Kinds.TypeKind GetTypeKind(Context cx, bool constructUnderlyingTupleType)
                     {
                         case TypeKind.Class: return Kinds.TypeKind.CLASS;
                         case TypeKind.Struct:
-                            return ((INamedTypeSymbol)Symbol).IsTupleType && !constructUnderlyingTupleType
-                                ? Kinds.TypeKind.TUPLE
-                                : Kinds.TypeKind.STRUCT;
+                            {
+                                if (((INamedTypeSymbol)Symbol).IsTupleType && !constructUnderlyingTupleType)
+                                {
+                                    return Kinds.TypeKind.TUPLE;
+                                }
+                                return Symbol.IsInlineArray() 
+                                    ? Kinds.TypeKind.INLINE_ARRAY
+                                    : Kinds.TypeKind.STRUCT;
+                            }
                         case TypeKind.Interface: return Kinds.TypeKind.INTERFACE;
                         case TypeKind.Array: return Kinds.TypeKind.ARRAY;
                         case TypeKind.Enum: return Kinds.TypeKind.ENUM;

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

@@ -1,7 +1,8 @@
-namespace Semmle.Extraction.Kinds  // lgtm[cs/similar-file]
+namespace Semmle.Extraction.Kinds
 {
     /// <summary>
     /// This enum has been auto-generated from the C# DB scheme - do not edit.
+    /// Auto-generate command: `genkindenum.pl type`
     /// </summary>
     public enum TypeKind
     {
@@ -35,6 +36,7 @@ public enum TypeKind
         ARGLIST = 30,
         UNKNOWN = 31,
         TUPLE = 32,
-        FUNCTION_POINTER = 33
+        FUNCTION_POINTER = 33,
+        INLINE_ARRAY = 34,
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/Type.cs

@@ -524,6 +524,17 @@ public static bool IsBoundSpan(this ITypeSymbol type) =>
         public static bool IsUnboundReadOnlySpan(this ITypeSymbol type) =>
             type.ToString() == "System.ReadOnlySpan<T>";
 
+        public static bool IsInlineArray(this ITypeSymbol type)
+        {
+            var attributes = type.GetAttributes();
+            var isInline = attributes.Any(attribute =>
+                    attribute.AttributeClass is INamedTypeSymbol nt &&
+                    nt.Name == "InlineArrayAttribute" &&
+                    nt.ContainingNamespace.ToString() == "System.Runtime.CompilerServices"
+            );
+            return isInline;
+        }
+
         /// <summary>
         /// Holds if this type is of the form <code>System.ReadOnlySpan<byte></code>.
         /// </summary>

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

@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* C# 12: Add extractor support and QL library support for inline arrays.