1. © Copyright QinetiQ limited 2006 Objectives of Coding Standards & MISRA C++ Clive Pygott, Systems Assurance Group, QinetiQ Chris Tapp, Keylevel Consultants & MISRA C++ chair

2. © Copyright QinetiQ limited 2006 2 DARP Workshop April 2006 Conclusions Predictability: behaviour, time, memory usage A requirement for more precise definition of the language/subset to be used in a high integrity environment A requirement for a more structured and capable means of recording intent and invariants in source code Verification A requirement for a means of collecting data on the effectiveness of any high-integrity guidelines Participants at the last Defence Aerospace Research Partnership C++ workshop were asked: what do you want to see in a generic software vulnerabilities standard

3. © Copyright QinetiQ limited 2006 3 Reasons for coding standards To avoid undefined behaviour To avoid implementation defined behaviour To improve clarity for review and maintenance To provide a consistent style across a program or set of programs To avoid common programmer errors To incorporate good practice, particularly with regard to future proofing

4. © Copyright QinetiQ limited 2006 4 Who are MISRA? Motor Industry Software Reliability Association Started in 1990 Mission: to provide assistance to the automotive industry in the creation and application of safe and reliable software in vehicle systems The original project was part of the UK Governments SafeIT programme Now self-supported – and used far outside the automotive industry

5. © Copyright QinetiQ limited 2006 5 MISRA C++ Extension of MISRA-C No language feature totally barred (except goto – for a better reason than in MISRA-C) Target date for draft for peer review – January 2007 Being developed by a working group including –Software safety consultants/researchers –Tool vendors –Users

6. © Copyright QinetiQ limited 2006 6 MISRA C++ sources Identification of Issues –QinetiQ Vulnerabilities Report Evaluation of Existing Material –Other Coding Standards MISRA-C JSF++ Medical Systems Transportation Tool Vendors (real world experience). –Other Publications Scott Meyers Stephen Dewhurst Etc.

7. © Copyright QinetiQ limited 2006 7 MISRA C++ Aims Predictability – mostly functional Portability Clarity for review/maintenance Avoiding common errors Not systematically addressed Predictability – temporal, memory usage Not Consistency of style Good practice/future proofing

8. © Copyright QinetiQ limited 2006 8 MISRA C++ (&C) rule structure Rule Structure –Rule Number and category (Mandatory…) –Headline Text (should be) precise and testable –Issue and Existing Material References –Explanation of the issue(s) and rule justification. –Examples of non-conforming and, where appropriate, conforming code. –Expected deviations (if appropriate and may include none!)

9. © Copyright QinetiQ limited 2006 9 MISRA C++ relationship with OWGV? Would hope that this group sets the objectives for high integrity software MISRA C++ would then want to claim compliance