static Type createDelegate(TypeBuilder tbDelegates, MethodInfo method)
{
// Initially based on this: https://blogs.msdn.microsoft.com/joelpob/2004/02/15/creating-delegate-types-via-reflection-emit/
// Create the delegate type
TypeAttributes ta = TypeAttributes.AutoClass | TypeAttributes.AnsiClass | TypeAttributes.Sealed | TypeAttributes.NestedPublic;
TypeBuilder tb = tbDelegates.DefineNestedType(method.Name, ta, typeof(MulticastDelegate));
// Apply [UnmanagedFunctionPointer] using the value from RuntimeClass.defaultCallingConvention
CustomAttributeBuilder cab = new CustomAttributeBuilder(ciFPAttribute, new object[1] {
RuntimeClass.defaultCallingConvention
});
tb.SetCustomAttribute(cab);
// Create constructor for the delegate
MethodAttributes ma = MethodAttributes.SpecialName | MethodAttributes.RTSpecialName | MethodAttributes.HideBySig | MethodAttributes.Public;
ConstructorBuilder cb = tb.DefineConstructor(ma, CallingConventions.Standard, new Type[] { typeof(object), typeof(IntPtr) });
cb.SetImplementationFlags(MethodImplAttributes.Runtime | MethodImplAttributes.Managed);
cb.DefineParameter(1, ParameterAttributes.In, "object");
cb.DefineParameter(2, ParameterAttributes.In, "method");
// Create Invoke method for the delegate. Appending one more parameter to the start, `[in] IntPtr pThis`
ParameterInfo[] methodParams = method.GetParameters();
Type[] paramTypes = new Type[methodParams.Length + 1];
paramTypes[0] = typeof(IntPtr);
for (int i = 0; i < methodParams.Length; i++)
{
ParameterInfo pi = methodParams[i];
Type tp = pi.ParameterType;
iCustomMarshal cm = pi.customMarshaller();
if (null != cm)
{
tp = cm.getNativeType(pi);
}
paramTypes[i + 1] = tp;
}
var mb = tb.DefineMethod("Invoke", MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.NewSlot | MethodAttributes.Virtual, typeof(int), paramTypes);
mb.SetImplementationFlags(MethodImplAttributes.Runtime | MethodImplAttributes.Managed);
defineDelegateParameters(mb, methodParams);
// The method has no code, it's pure virtual.
return(tb.CreateType());
}
static Type createDelegate(DelegatesBuilder builder, MethodInfo method)
{
// Initially based on this: https://blogs.msdn.microsoft.com/joelpob/2004/02/15/creating-delegate-types-via-reflection-emit/
// Create the delegate type
TypeBuilder tb = builder.defineMulticastDelegate(method);
// Apply [UnmanagedFunctionPointer] using the value from RuntimeClass.defaultCallingConvention
CustomAttributeBuilder cab = new CustomAttributeBuilder(ciFPAttribute, new object[1] {
RuntimeClass.defaultCallingConvention
});
tb.SetCustomAttribute(cab);
// Create constructor for the delegate
MethodAttributes ma = MethodAttributes.SpecialName | MethodAttributes.RTSpecialName | MethodAttributes.HideBySig | MethodAttributes.Public;
ConstructorBuilder cb = tb.DefineConstructor(ma, CallingConventions.Standard, new Type[] { typeof(object), typeof(IntPtr) });
cb.SetImplementationFlags(MethodImplAttributes.Runtime | MethodImplAttributes.Managed);
cb.DefineParameter(1, ParameterAttributes.In, "object");
cb.DefineParameter(2, ParameterAttributes.In, "method");
// Create Invoke method for the delegate. Appending one more parameter to the start, `[in] IntPtr pThis`
ParameterInfo[] methodParams = method.GetParameters();
int nativeParamsCount = methodParams.Length + 1;
int retValIndex = -1;
RetValIndexAttribute rvi = method.GetCustomAttribute <RetValIndexAttribute>();
if (rvi != null)
{
retValIndex = rvi.index;
nativeParamsCount++;
}
Type[] paramTypes = new Type[nativeParamsCount];
paramTypes[0] = typeof(IntPtr);
int iNativeParam = 1;
for (int i = 0; i < methodParams.Length; i++, iNativeParam++)
{
if (i == retValIndex)
{
retValIndex = -1;
i--;
paramTypes[iNativeParam] = nativeRetValArgType(method);
continue;
}
ParameterInfo pi = methodParams[i];
Type tp = pi.ParameterType;
iCustomMarshal cm = pi.customMarshaller();
if (null != cm)
{
tp = cm.getNativeType(pi);
}
paramTypes[iNativeParam] = tp;
}
if (retValIndex >= 0)
{
// User has specified [RetValIndex] value after the rest of the parameters
paramTypes[iNativeParam] = nativeRetValArgType(method);
}
Type returnType;
if (method.ReturnType != typeof(IntPtr) || null != rvi)
{
returnType = typeof(int);
}
else
{
returnType = typeof(IntPtr);
}
var mb = tb.DefineMethod("Invoke", MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.NewSlot | MethodAttributes.Virtual, returnType, paramTypes);
mb.SetImplementationFlags(MethodImplAttributes.Runtime | MethodImplAttributes.Managed);
mb.DefineParameter(1, ParameterAttributes.In, "pThis");
iNativeParam = 2; // 2 because the first one is native this pointer, and MethodBuilder.DefineParameter API uses 1-based indices, the number 0 represents the return value of the method.
retValIndex = rvi?.index ?? -1;
for (int i = 0; i < methodParams.Length; i++, iNativeParam++)
{
if (i == retValIndex)
{
retValIndex = -1;
i--;
mb.DefineParameter(iNativeParam, ParameterAttributes.Out, "retVal");
continue;
}
ParameterInfo pi = methodParams[i];
ParameterBuilder pb = mb.DefineParameter(iNativeParam, pi.Attributes, pi.Name);
ParamsMarshalling.buildDelegateParam(pi, pb, rvi?.index);
}
if (retValIndex >= 0)
{
// User has specified [RetValIndex] value after the rest of the parameters
mb.DefineParameter(iNativeParam, ParameterAttributes.Out, "retVal");
}
// The method has no code, it's pure virtual.
return(tb.CreateType());
}