From c64efe70910271fc82ff4abcd9ac8f65559057d4 Mon Sep 17 00:00:00 2001
From: triton <ripzonetriton@gmail.com>
Date: Wed, 30 Jan 2013 15:42:17 +0000
Subject: [PATCH] Added a pass to convert functions to instance methods.

---
 .../Passes/FunctionToInstanceMethodPass.cs    | 87 +++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 src/Generator/Passes/FunctionToInstanceMethodPass.cs

diff --git a/src/Generator/Passes/FunctionToInstanceMethodPass.cs b/src/Generator/Passes/FunctionToInstanceMethodPass.cs
new file mode 100644
index 00000000..e1456082
--- /dev/null
+++ b/src/Generator/Passes/FunctionToInstanceMethodPass.cs
@@ -0,0 +1,87 @@
+using System;
+
+namespace Cxxi.Passes
+{
+    /// <summary>
+    /// This pass will try to hoist functions into classes so they
+    /// work just like instance methods.
+    /// </summary>
+    public class FunctionToInstanceMethodPass : TranslationUnitPass
+    {
+        /// <summary>
+        /// Processes a function declaration.
+        /// </summary>
+        public override bool ProcessFunction(Function function)
+        {
+            if (function.Ignore)
+                return false;
+
+            // Check if this function can be converted.
+            if (function.Parameters.Count == 0)
+                return false;
+
+            var classParam = function.Parameters[0];
+
+            Class @class;
+            if (!GetClassParameter(classParam, out @class))
+                return false;
+
+            // If we reach here, it means the first parameter is of class type.
+            // This means we can change the function to be an instance method.
+
+            // Clean up the name of the function now that it will be an instance method.
+            if (!function.Name.StartsWith(@class.Name))
+                return false;
+
+            function.Name = function.Name.Substring(@class.Name.Length);
+            function.ExplicityIgnored = true;
+
+            // Create a new fake method so it acts as an instance method.
+            var method = new Method()
+                {
+                    Namespace = @class.Namespace,
+                    Name = function.Name,
+                    OriginalName = function.OriginalName,
+                    Access = AccessSpecifier.Public,
+                    Kind = CXXMethodKind.Normal,
+                    ReturnType = function.ReturnType,
+                    Parameters = function.Parameters,
+                    CallingConvention = function.CallingConvention,
+                    IsVariadic = function.IsVariadic,
+                    IsInline = function.IsInline,
+                    Conversion = MethodConversionKind.FunctionToInstanceMethod
+                };
+
+            @class.Methods.Add(method);
+
+            Console.WriteLine("Instance method: {0}::{1}", @class.Name,
+                function.Name);
+
+            return true;
+        }
+
+        private static bool GetClassParameter(Parameter classParam, out Class @class)
+        {
+            TagType tag;
+            if (classParam.Type.IsPointerTo(out tag))
+            {
+                @class = tag.Declaration as Class;
+                return true;
+            }
+
+            if (classParam.Type.IsTagDecl(out @class))
+                return true;
+
+            return false;
+        }
+    }
+
+    public static class FunctionToInstanceMethodExtensions
+    {
+        public static void FunctionToInstanceMethod(this PassBuilder builder)
+        {
+            var pass = new FunctionToInstanceMethodPass();
+            builder.AddPass(pass);
+        }
+    }
+}