From 71de29790e83b97232b1ed085ca363092fd17143 Mon Sep 17 00:00:00 2001
From: triton <ripzonetriton@gmail.com>
Date: Thu, 31 Oct 2013 22:25:19 +0000
Subject: [PATCH] Added a new pass to check for duplicated vtable components.

This helps workaround some Clang's work-in-progress vftable layouting implementation.
---
 src/Generator/Driver.cs                       |  2 +
 .../Passes/CheckVTableComponentsPass.cs       | 38 +++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 src/Generator/Passes/CheckVTableComponentsPass.cs

diff --git a/src/Generator/Driver.cs b/src/Generator/Driver.cs
index 86d6cdfb..70a9cb85 100644
--- a/src/Generator/Driver.cs
+++ b/src/Generator/Driver.cs
@@ -213,6 +213,8 @@ namespace CppSharp
                 TranslationUnitPasses.AddPass(new MultipleInheritancePass());
                 TranslationUnitPasses.AddPass(new ParamTypeToInterfacePass());
             }
+            if (Options.GenerateVirtualTables)
+                TranslationUnitPasses.AddPass(new CheckVTableComponentsPass());
             if (Options.GenerateProperties)
                 TranslationUnitPasses.AddPass(new GetterSetterToPropertyAdvancedPass());
         }
diff --git a/src/Generator/Passes/CheckVTableComponentsPass.cs b/src/Generator/Passes/CheckVTableComponentsPass.cs
new file mode 100644
index 00000000..eac5278e
--- /dev/null
+++ b/src/Generator/Passes/CheckVTableComponentsPass.cs
@@ -0,0 +1,38 @@
+using System.Collections.Generic;
+using System.Linq;
+using CppSharp.AST;
+using CppSharp.Utils;
+
+namespace CppSharp.Passes
+{
+    /// <summary>
+    /// This pass checks for vftable entries with duplicated components.
+    /// This might happen because of bugs in Clang vftable layouting.
+    /// </summary>
+    public class CheckVTableComponentsPass : TranslationUnitPass
+    {
+        public override bool VisitClassDecl(AST.Class @class)
+        {
+            if (AlreadyVisited(@class))
+                return false;
+
+            foreach (var vfptr in @class.Layout.VFTables)
+            {
+                var uniqueEntries = new OrderedSet<VTableComponent>();
+                foreach (var entry in vfptr.Layout.Components)
+                    uniqueEntries.Add(entry);
+
+                // The vftable does not have duplicated components.
+                if (vfptr.Layout.Components.Count == uniqueEntries.Count)
+                    continue;
+
+                Driver.Diagnostics.EmitWarning(
+                    "Class '{0}' found with duplicated vftable components",
+                    @class.Name);
+                vfptr.Layout.Components = uniqueEntries.ToList();
+            }
+
+            return base.VisitClassDecl(@class);
+        }
+    }
+}