From daf5b828c9431b90dfccb7930b465adcd255898f Mon Sep 17 00:00:00 2001
From: Stefanos A <stapostol@gmail.com>
Date: Wed, 27 Nov 2013 01:40:12 +0100
Subject: [PATCH] Implemented string return types

---
 Source/OpenTK.Rewrite/Program.cs | 90 ++++++++++++++++++++++++++------
 1 file changed, 74 insertions(+), 16 deletions(-)

diff --git a/Source/OpenTK.Rewrite/Program.cs b/Source/OpenTK.Rewrite/Program.cs
index b04af180..22413a8f 100644
--- a/Source/OpenTK.Rewrite/Program.cs
+++ b/Source/OpenTK.Rewrite/Program.cs
@@ -44,6 +44,8 @@ namespace OpenTK.Rewrite
             program.Rewrite(file, key);
         }
 
+        static AssemblyDefinition mscorlib;
+
         void Rewrite(string file, string keyfile)
         {
             // Specify assembly read and write parameters
@@ -87,17 +89,27 @@ namespace OpenTK.Rewrite
             {
                 foreach (var module in assembly.Modules)
                 {
-                    if (rewritten == null)
+                    foreach (var reference in module.AssemblyReferences)
                     {
-                        foreach (var reference in module.AssemblyReferences)
+                        var resolved = module.AssemblyResolver.Resolve(reference);
+                        if (reference.Name == "mscorlib")
                         {
-                            module.AssemblyResolver.Resolve(reference);
+                            mscorlib = resolved;
                         }
+                    }
+                }
 
-                        foreach (var type in module.Types)
-                        {
-                            Rewrite(type);
-                        }
+                if (mscorlib == null)
+                {
+                    Console.Error.WriteLine("Falied to locate mscorlib");
+                    return;
+                }
+
+                foreach (var module in assembly.Modules)
+                {
+                    foreach (var type in module.Types)
+                    {
+                        Rewrite(type);
                     }
                 }
             }
@@ -138,8 +150,8 @@ namespace OpenTK.Rewrite
                     ProcessMethod(wrapper, signature, slot, entry_points);
                 }
 
-                //RemoveNativeSignatures();
-                //RemoveSupportingAttributes();
+                RemoveNativeSignatures(type, native_signatures);
+                RemoveSupportingAttributes(type);
             }
 
             if (type.Name == "RewrittenAttribute")
@@ -150,21 +162,41 @@ namespace OpenTK.Rewrite
             }
         }
 
+        void RemoveNativeSignatures(TypeDefinition type, List<MethodDefinition> methods)
+        {
+            while (methods.Count > 0)
+            {
+                type.Methods.Remove(methods.Last());
+                methods.RemoveAt(methods.Count - 1);
+            }
+        }
+
+        void RemoveSupportingAttributes(TypeDefinition type)
+        {
+            foreach (var method in type.Methods)
+            {
+                var attr = method.CustomAttributes;
+                for (int i = 0; i < attr.Count; i++)
+                {
+                    if (attr[i].AttributeType.Name == "AutoGeneratedAttribute")
+                    {
+                        attr.RemoveAt(i);
+                        i--;
+                    }
+                }
+            }
+        }
+
         // Create body for method
         static void ProcessMethod(MethodDefinition wrapper, MethodDefinition native, int slot, FieldDefinition entry_points)
         {
-            var nint = wrapper.DeclaringType.Module.Import(typeof(IntPtr));
+            var nint = wrapper.DeclaringType.Module.Import(mscorlib.MainModule.GetType("System.IntPtr"));
             //var nint = new TypeReference("System", "IntPtr", wrapper.DeclaringType.Module, null);
             var body = wrapper.Body;
             var il = body.GetILProcessor();
             var instructions = body.Instructions;
             instructions.Clear();
 
-            if (wrapper.ReturnType != native.ReturnType)
-            {
-                Console.Error.WriteLine("Return type wrappers not implemented yet ({0})", native.Name);
-            }
-
             // Declare pinned variables for every reference and array parameter
             // and push each parameter on the stack
             EmitParameters(wrapper, nint, body, il);
@@ -233,7 +265,33 @@ namespace OpenTK.Rewrite
                 }
                 else if (wrapper.ReturnType != native.ReturnType)
                 {
-                    Console.Error.WriteLine("Return wrappers not implemented yet ({0})", native.Name);
+                    if (wrapper.ReturnType.Name == "String")
+                    {
+                        // String return-type wrapper
+                        // return new string((sbyte*)((void*)GetString()));
+
+                        var intptr_to_voidpointer = wrapper.Module.Import(typeof(IntPtr).GetMethods()
+                            .First(m =>
+                            {
+                                return
+                                    m.Name == "op_Explicit" &&
+                                    m.ReturnType.Name == "Void*";
+                            }));
+
+                        var string_constructor = wrapper.Module.Import(typeof(string).GetConstructors()
+                            .First(m =>
+                                {
+                                    var p = m.GetParameters(); 
+                                    return p.Length > 0 && p[0].ParameterType.Name == "SByte*";
+                                }));
+
+                        il.Emit(OpCodes.Call, intptr_to_voidpointer);
+                        il.Emit(OpCodes.Newobj, string_constructor);
+                    }
+                    else
+                    {
+                        Console.Error.WriteLine("Return wrappers not implemented yet ({0})", native.Name);
+                    }
                 }
                 else
                 {