Opentk/Source/OpenTK.Rewrite/Program.cs
2013-11-25 00:19:54 +01:00

151 lines
5 KiB
C#

// OpenTK.Rewrite: IL rewriter for OpenTK.dll
// Copyright (C) 2013 Stefanos Apostolopoulos
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using Mono.Cecil;
using Mono.Cecil.Cil;
namespace OpenTK.Rewrite
{
// Replaces OpenTK.InteropHelper method instances
// with the s IL instructions.
class Program
{
static void Main(string[] args)
{
if (args.Length == 0)
{
Console.WriteLine("Usage: rewrite [file1] [file2] ...");
return;
}
var program = new Program();
foreach (var file in args)
{
program.Rewrite(file);
}
}
void Rewrite(string file)
{
var assembly = AssemblyDefinition.ReadAssembly(file);
foreach (var module in assembly.Modules)
{
foreach (var reference in module.AssemblyReferences)
{
module.AssemblyResolver.Resolve(reference);
}
foreach (var type in module.Types)
{
Rewrite(type);
}
}
var fs = new FileStream("../../../OpenTK.snk", FileMode.Open);
var keypair = new System.Reflection.StrongNameKeyPair(fs);
fs.Close();
assembly.Write(
file,
new WriterParameters
{
StrongNameKeyPair = keypair
});
}
void Rewrite(TypeDefinition type)
{
foreach (var method in type.Methods)
{
if (method.HasBody)
{
ProcessMethodBody(method.Body);
}
}
}
// Search the instruction stream for calls
// to methods we need to rewrite.
static void ProcessMethodBody(MethodBody body)
{
var instructions = body.Instructions;
var il = body.GetILProcessor();
Instruction inst1 = instructions[0];
Instruction inst2 = instructions[0];
for (int i = 1; i < instructions.Count; i++)
{
var inst = instructions[i];
if ((inst.OpCode == OpCodes.Call || inst.OpCode == OpCodes.Callvirt) &&
inst.Operand is MethodReference)
{
var reference = inst.Operand as MethodReference;
// Make sure we are rewriting OpenTK.InteropHelper methods
// and not random methods that happen to have similar names.
if (reference.DeclaringType.Name == "InteropHelper")
{
switch (reference.Name)
{
case "Call":
case "CallReturn":
RewriteCall(il, inst, reference);
break;
}
}
}
}
}
static void RewriteCall(ILProcessor il, Instruction inst, MethodReference reference)
{
var signature = new CallSite(reference.ReturnType)
{
CallingConvention = MethodCallingConvention.StdCall,
};
if (reference is GenericInstanceMethod)
{
var greference = reference as GenericInstanceMethod;
foreach (var ptype in greference.GenericArguments)
{
var p = new ParameterDefinition(ptype);
signature.Parameters.Add(p);
}
}
else
{
// The last parameter is the function address of this entry point.
// It is placed at the top of the stack (first parameter of calli)
// but is not actually part of the unmanaged signature, so we must
// not add it to the signature parameters.
foreach (var p in reference.Parameters.Take(reference.Parameters.Count - 1))
{
signature.Parameters.Add(p);
}
}
var call = il.Create(OpCodes.Calli, signature);
il.Replace(inst, call);
}
}
}