Re: Have the Itanium critics all been proven wrong?

[Brian Drummond <brian@shapes.demon.co.uk>]

On Wed, 22 Aug 2012 03:28:24 -0700, Ludovic Brenta wrote:

> Michael S a wrote on comp.lang.ada:
>> "not possible to clobber arbitrary memory locations" is probably good
>> enough definition of what I consider "safe" computer language.
> [...]
>> So let's do not call it "two languages". Let's talk about "full Ada"
>> and "checked Ada" where "checked Ada" is a subset in which "it is not
>> possible to clobber arbitrary memory locations". Hopefully  "checked
>> Ada" is still much closer in # features to the "full Ada" than to
>> SPARK.
> 
> Yes.  SPARK imposes a lot of restrictions which in turn exclude most of
> the standard run-time library.
> 
>>>> Q.
>>>> Do people actually use the "second" Ada language for really big and
>>>> really complex application programs?
 
> I work on such an application: 2 million lines of code, multiple
> processes running 24x7 on multiple machines, mission-critical, multiple
> GUIs.  
...
> Like I said we use almost every feature Ada has to offer, from high-
> level tasks and protected objects to the lowest level of bit
> manipulation ...  But these "scary" bits are few, far
> between and well isolated; they must represent less than 0.5% of our
> code base (still, 10 kSLOC or so...).  It is important to note that we
> could do without those low-level tricks; they exist only for performance
> reasons or to detect and diagnose rare errors.

Interesting and good to know. But dare I ask ... (if you have any such 
statistics to hand, or even a gut feel) ... what percentage of the bugs 
arise out of that 0.5% of the code?

- Brian