private static MethodDefinition CreateNativeMethod(MetadataImage image)
{
var nativeMethod = new MethodDefinition("MyNativeMethod",
MethodAttributes.Assembly | MethodAttributes.Static | MethodAttributes.PInvokeImpl,
new MethodSignature(image.TypeSystem.Int32));
nativeMethod.ImplAttributes = MethodImplAttributes.Native
| MethodImplAttributes.Unmanaged
| MethodImplAttributes.PreserveSig;
var nativeBody = new X86MethodBody();
nativeBody.Instructions.Add(new X86Instruction
{
Mnemonic = X86Mnemonic.Mov,
OpCode = X86OpCodes.Mov_Eax_Imm1632,
Operand1 = new X86Operand(X86Register.Eax),
Operand2 = new X86Operand(1337),
});
nativeBody.Instructions.Add(new X86Instruction
{
Mnemonic = X86Mnemonic.Retn,
OpCode = X86OpCodes.Retn,
});
nativeMethod.MethodBody = nativeBody;
return(nativeMethod);
}
public void PersistentNativeMethod()
{
var assembly = CreateTempAssembly();
assembly.NetDirectory.Flags &= ~ImageNetDirectoryFlags.IlOnly;
var image = assembly.NetDirectory.MetadataHeader.Image;
var importer = new ReferenceImporter(image);
var nativeMethod = new MethodDefinition("MyNativeMethod",
MethodAttributes.Assembly | MethodAttributes.Static | MethodAttributes.PInvokeImpl,
new MethodSignature(image.TypeSystem.Int32));
nativeMethod.ImplAttributes = MethodImplAttributes.Native
| MethodImplAttributes.Unmanaged
| MethodImplAttributes.PreserveSig;
var nativeBody = new X86MethodBody();
nativeBody.Instructions.Add(new X86Instruction
{
Mnemonic = X86Mnemonic.Mov,
OpCode = X86OpCodes.Mov_Eax_Imm1632,
Operand1 = new X86Operand(X86Register.Eax),
Operand2 = new X86Operand(1337),
});
nativeBody.Instructions.Add(new X86Instruction
{
Mnemonic = X86Mnemonic.Retn,
OpCode = X86OpCodes.Retn,
});
nativeMethod.MethodBody = nativeBody;
image.Assembly.Modules[0].TopLevelTypes[0].Methods.Add(nativeMethod);
var mainMethod = image.Assembly.Modules[0].TopLevelTypes.First(x => x.Name == TypeName).Methods.First(x => x.Name == MainMethodName);
var instructions = mainMethod.CilMethodBody.Instructions;
instructions.AddRange(new[]
{
CilInstruction.Create(CilOpCodes.Ldstr, "The secret number is: {0}"),
CilInstruction.Create(CilOpCodes.Call, nativeMethod),
CilInstruction.Create(CilOpCodes.Box, importer.ImportType(typeof(int))),
CilInstruction.Create(CilOpCodes.Call,
importer.ImportMethod(
typeof(Console).GetMethod("WriteLine", new[] { typeof(string), typeof(object) }))),
CilInstruction.Create(CilOpCodes.Ret)
});
assembly.NetDirectory.MetadataHeader.UnlockMetadata();
_context.VerifyOutput(assembly, "The secret number is: 1337");
}
