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Comment by 0xff00ffee | Hacker News Reader

I downloaded the actual document and spent 10 minutes reading every 20th page. This is a staggering effort of technical writing.

I feel like I'm reading "The Pact" from the Silo series of sci-fi (Wool, Switch, Dust). Hopefully you get the reference.

This goes far beyond coding guidelines. It reads more like THINKING guidelines, fallacies to decision making to resource allocation.

Who is the target audience for this?

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> This goes far beyond coding guidelines. It reads more like THINKING guidelines

Well, yes. That's the "safety culture" influence, the idea that there is not really such a thing as an "accident". With careful thought all the possible outcomes should be forseeable, and mitigation should be in place for all risks. This includes what might be called affordances for the programmer - tools that are prone to misuse and mistakes should be avoided. Guardrails around thought.

This chafes if you got into programming for the freedom, but is a lot more reassuring for people driving the car.

(edit: my own personal benchmark for technical writing is the dully-named "App Note 47: High Speed Amplifier Techniques" by the legendary Jim Williams. From its own preface:

"This publication represents the largest LTC commitment to an application note to date. No other application note absorbed as much effort, took so long or cost so much. ... We intend to supply useful high speed products and the level of support necessary for their successful application(such high minded community spirit is, of course, capitalism’s deputy)."

It is 132 pages including photographs, illustrations, screenshots of osciliscopes, equations, and a few jokes.)

Safety critical systems aren't places that tolerate clever hacks for the sake of being clever. But meeting application requirements while staying within the safety guidelines can be an interesting challenge in its own right.

Thanks for the link. Looking forward to reading it. I first learned about Jim Williams when I bought a book called Analog Circuit Design from the EDN press. He edited most of the book, but it is a collection of beliefs, values and attitudes around Analog Design by like-minded folks. It's equal parts educational and humorous.

> Who is the target audience for this?

Systems programmers in the automotive industry, and their direct superiors.

That was the original motivation but it slowly mutated into general guidelines for safety-critical C in embedded systems.

Although not an official regulatory requirement it is often used as a guideline in low-resource targets for Medical embedded systems.

In aerospace for example the JPL guidelines are also influenced by the initial MISRA consortium effort. And at least in style and motivation the JSF for C++ ia also influenced by MISRA.

Also: Aerospace, I think.

Almost. Aerospace usually follows DO-178C, which has a many similarities with MISRA but is a separate standard.

RTCA/DO-178 is not a coding standard, but does mandate one be used, such as MISRA

Correct :-)

Which document?

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