RE: MISRA C (was: Industry support groups that foster secure/quality coding practices)

["David Crocker" <dcrocker () eschertech com>]

MISRA C is widely used in the automotive industry. I have been told (but not had
confirmation) that MISRA C was also the basis of the standard used for coding
new software for the Joint Strike Fighter.

The MISRA C standard comprises 127 rules banning various constructs and library
calls. Most of these are designed to avoid areas of C where the behaviour is
undefined, implementation-dependent, or liable to cause inadvertent errors. A
few of the rules are there because the authors believe they help to promote
"good style". Conformance with most (but not all) of the rules can be checked
statically.

A number of deficiencies have been identified in the original MISRA standard;
version 2 of the standard is being developed to address these.

Personally, I agree that C is not a good place to start from for reliable
applications (see my earlier rant about why C is a dreadful language). However,
for many embedded processors, there are few (if any) other languages supported.
Despite the limitations of MISRA C, I believe that coding in MISRA C and using a
good tool to check for conformance with the standard (as far as is possible) is
significantly better (from a safety & security point of view) than coding in
plain C.

What I would like to see is a widely-implemented, well-designed, type-safe
object-oriented language. Eiffel comes close but is not widely implemented or
used. The present version of Ada (95) is a poor choice for serious O-O
development. Maybe in future we will see a C++ subset based on extending the
MISRA standard.

Our own practice is to specify software using a custom O-O specification and
refinement language, prove that the specification meets the functional
requirements, then generate all the code in a MISRA-like C++ subset (or Java in
some cases). By using C++ as a sort of high-level assembler for our code
generators to target, we avoid the traps that humans encounter when writing in
it.

David Crocker
Escher Technologies Ltd.
www.eschertech.com

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of ljknews
Sent: 31 December 2003 16:37
To: [EMAIL PROTECTED]
Subject: Re: [SC-L] Industry support groups that foster secure/quality
coding practices


At 9:53 AM -0500 12/31/03, Kenneth R. van Wyk wrote:

> In any event, is anyone here aware of MISRA?

MISRA (the standard) has been widely discussed in comp.lang.ada lately.

There are various advocacy positions taken whether MISRA (the organization)
did admit that trying to use C for safety-critical work was a weak substitute
for using another language.