private static void TryGetILOffsetInfo(IDiaSession session, int rva, out int ilOffset)
        {
            IDiaEnumLineNumbers lineNumbers;
            int hr = session.FindILOffsetsByRVA(rva, 1, out lineNumbers);

            if (hr == S_OK)
            {
                int numLineNumbers;
                hr = lineNumbers.Count(out numLineNumbers);
                if (hr == S_OK && numLineNumbers > 0)
                {
                    IDiaLineNumber ln;
                    hr = lineNumbers.Item(0, out ln);
                    if (hr == S_OK)
                    {
                        hr = ln.LineNumber(out ilOffset);
                        if (hr == S_OK)
                        {
                            return;
                        }
                    }
                }
            }
            ilOffset = StackFrame.OFFSET_UNKNOWN;
        }