Re: Ada and OpenMP

[Shark8 <onewingedshark@gmail.com>]

On Thursday, March 7, 2013 4:42:59 PM UTC-7, Randy Brukardt wrote:
> 
> Pragmas, IMHO, are the worst way to do anything. Compiler writers tend to 
> use them because they can do so without appearing to modify the language, 
> but it's all an illusion: the program probably won't work right without the 
> pragma, so you're still locked into that particular vendor. Might as well 
> have done it right in the first place (and make a proposal to the ARG, 
> backed with practice, so it can get done right in the next version of Ada).

I'm not sure I totally agree with your sentiment; IIRC, Pragmas in Ada were supposed to be parentheticals to the compiler that were not essential to program correctness -- such as Optimize or the source-printing pragma Page.

That sentiment was thwarted with the inclusion of representation pragmas. -- However, the Ada specification *does* allow for implementation-defined pragmas. It seems to me that such would be ideal for experimental or compiler-specific code-generation. The previous poster's "Pragma OMP(...)" is an excellent example (though I think the FOR_LOOP parameter is stupid, the feature [OMP] should be turned on/off as needed, letting the compiler determine the optimal technique to use. {A program written in such a way would be correct even if the code were ported to a non-OMP compiler, provided the underlying algorithm was correct.}