On (09/28/12 09:54), Chris Ferron wrote:
[..]
> Well to be fair, not that I agree any-more, but years ago it was
> common practice to disable exceptions (via the compiler) for C++ in
> very specialized "REAL" "Embedded Systems". This practice was
> problematic in that you needed to have a will defined Error handling
> design, but saved space. Honestly, its been a long time since I
> worked on anything that has a "REAL" size requirement, so I don't see
> the point. On the other hand in some Embedded system  The whole
> reason to using your own error handling design was that in a real
> embedded system, design considerations like, uptime, failure control
> and ability to eliminate undefined behaviour were KEY. So taking the
> time to design was already a given, and size was not a single point
> factor. (not arguing the C vs C++ point here BTW)  So for what ever
> reason the decision to use C++ happens for an embedded project.
> Problem was C++ exception were good for insure the program didn't
> fail, but detailed failure handling became problematic. Sure you
> could avoid general failures but often especially in an embedded
> system you found yourself with undefined behaviour that was nearly
> imposable to handle. OK in general history over :)
> 
> Unfortunately this practice has been inherited still today in
> segments of other then embedded. Most commonly you may see this
> practice in specialized segments like gaming consoles. Such practices
> are still in valid use in such device as switches,
> telecommunications, avionic systems, weapon systems, medical devices,
> ect.
> 
> So I have an understanding of the issues, "some" of its history, and
> valid uses. But in my opinion this is still a bad implementation for
> anyone distributing a general operating system.
> 
> 

Sure, I totally agree. Nowadays, with 4 CPU cores in a pocket, I simply don't buy 
"exceptions are slow" argument. If in some particular project exceptions are so 
common that they're able to sensibly slow down application, then the project most
probably is doing something terribly wrong and mis-concept exceptions.

The tragedy is that at this point in time I believe Google will never consider using
exceptions due to legacy reasons.


	-ss