0

JPL Coding Standards for C

How do the folks at JPL write the code that will land a 2000-pound robot on Mars without a single glitch? Much of their success is no doubt due to their talent and dedication, but it doesn’t hurt that they have very strict coding standards (PDF). Among the requirements for C-language code at JPL:

  • Compile with all warnings enabled; use static source code analyzers.
  • Do not use direct or indirect recursion.
  • Do not use dynamic memory allocation after task initialization.
  • Declare data objects at smallest possible level of scope.
  • Check the validity of values passed to functions.
  • Make the order of evaluation in compound expressions explicit.
  • Do not use expressions with side effects.
  • Make only very limited use of the C pre-processor.
  • Use short functions with a limited number of parameters.
  • Do not cast function pointers into other types.

The JPL code standards are based on the 2004 MISRA-C coding standard. MISRA was originally designed for automotive applications, but was later adapted to other safety-critical systems where computer glitches can have dire consequences, like remote control locomotives. Some of the requirements parallel specifications of the language ADA, which was originally designed for safety-critical applications like missile guidance systems.

The 2009 version of the standard is available as a PDF from jpl.nasa.gov.


Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.

Join 7,500+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython in 2018 – Python on Microcontrollers is here!

Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/


Maker Business — Fewer startups, and other collateral damage from the 2018 tariffs

Wearables — Light as a Worbla feather

Electronics — How to make your own magnetic field probe!

Biohacking — The State of DNA Analysis in Three Mindmaps

Python for Microcontrollers — One year of CircuitPython weeklies!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



2 Comments

  1. i love this kind of stuff…

  2. I’ve been looking for a decent MISRA/JPL static analysis tool, but it seems most of them are internal and proprietary or linked to specific toolchains. I have a license for IAR for ARM, for example, which includes MISRA … but it’s hardly accessible to the general public. Seems like a pressing addition needed to complement the rest of the GCC ecosystem, but maybe I’m just not aware of some tool that exists.

    If you do any C++ development, there’s also a Joint Strike Fighter C++ Safety Coding Standards: http://www.jsf.mil/downloads/down_documentation.htm

    But the MISRA standard is definately a good investment for the price.

Sorry, the comment form is closed at this time.