private MethodIL EmitIL()
{
if (!_importMetadata.Flags.PreserveSig)
{
throw new NotSupportedException();
}
if (MarshalHelpers.ShouldCheckForPendingException(_targetMethod.Context.Target, _importMetadata))
{
throw new NotSupportedException();
}
if (_targetMethod.IsUnmanagedCallersOnly)
{
throw new NotSupportedException();
}
if (_targetMethod.HasCustomAttribute("System.Runtime.InteropServices", "LCIDConversionAttribute"))
{
throw new NotSupportedException();
}
PInvokeILCodeStreams pInvokeILCodeStreams = new PInvokeILCodeStreams();
ILEmitter emitter = pInvokeILCodeStreams.Emitter;
ILCodeStream marshallingCodestream = pInvokeILCodeStreams.MarshallingCodeStream;
ILCodeStream unmarshallingCodestream = pInvokeILCodeStreams.UnmarshallingCodestream;
ILCodeStream cleanupCodestream = pInvokeILCodeStreams.CleanupCodeStream;
// Marshalling is wrapped in a finally block to guarantee cleanup
ILExceptionRegionBuilder tryFinally = emitter.NewFinallyRegion();
marshallingCodestream.BeginTry(tryFinally);
cleanupCodestream.BeginHandler(tryFinally);
// Marshal the arguments
for (int i = 0; i < _marshallers.Length; i++)
{
_marshallers[i].EmitMarshallingIL(pInvokeILCodeStreams);
}
EmitPInvokeCall(pInvokeILCodeStreams);
ILCodeLabel lReturn = emitter.NewCodeLabel();
unmarshallingCodestream.Emit(ILOpcode.leave, lReturn);
unmarshallingCodestream.EndTry(tryFinally);
cleanupCodestream.Emit(ILOpcode.endfinally);
cleanupCodestream.EndHandler(tryFinally);
cleanupCodestream.EmitLabel(lReturn);
_marshallers[0].LoadReturnValue(cleanupCodestream);
cleanupCodestream.Emit(ILOpcode.ret);
return(new PInvokeILStubMethodIL((ILStubMethodIL)emitter.Link(_targetMethod)));
}