Programming language failings [was Re: strangest systems I've sent email from]

[Diane Bruce]

On Sat, Apr 30, 2016 at 12:28:35PM -0700, Chris Hanson wrote:
> On Apr 30, 2016, at 11:43 AM, Diane Bruce <db at db.net> wrote:
> > 
> > We cannot use the same outdated ideas we used to use for 'C'
> > that we used 40 years ago today. Compilers have improved.
> > Know your tools. And that's all I have said. 
> 
> In support of this, I’d encourage everyone who works with C to read Chris Lattner’s “What Every C Programmer Should Know About Undefined Behavior” series from the LLVM blog:
> 
>     http://blog.llvm.org/2011/05/what-every-c-programmer-should-know.html
>     http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_14.html
>     http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_21.html

Yes, it's an excellent series. 

> 
> C has fairly well-defined semantics, they just aren’t necessarily what you think they are, and optimizers are taking advantage of them (under the “as if” rule) such that a developer’s idea of what assembly a specific section of C code should generate is not all that accurate these days.
> 

Indeed.

>   -- Chris
> 
> 

Diane
-- 
- db at FreeBSD.org db at db.net http://www.db.net/~db