[m-rev.] the grade library is ready for review

[Zoltan Somogyi]

On Tue, 5 Apr 2016 13:15:31 +1000 (AEST), Julien Fischer <jfischer at opturion.com> wrote:
> That tool generates approx. 370,000 grades with the pregen component.
> While it's true that the code generator(s) can generate code for those,
> Mercury's build system only supports five of them (i.e. if you're using
> the pregen grade component for its intended purpose there are only five
> pregen grades -- the others won't work).

What does "won't work" mean in this case? What is the symptom,
and what part of the build system is responsible?

> Those grades are:
> 
>      none.gc.pregen
>      reg.gc.pregen
>      asm_fast.gc.pregen
>      hlc.gc.pregen
> 
> and (currently) asm_jump.gc.pregen.
> 
> Given that the configure script only selects asm_jump as the best LLDS
> base grade when something is amiss, I think it would probably be safer
> to fall back to reg or none in that case as well.  I'll make that change
> shortly.  I think the grade library should reject any grade with a
> pregen component that is not one of the four in the list above.

Two questions. First: reject how? Just impose requirements that have
pregen imply the absence of any grade component that isn't none/reg/.../hlc,
or just solve the existing set of constraints, and then print an error if the solution
contains pregen but is not one of the four privileged solution above?
Second: in the email exchange from feb 23, it was Peter and you, not me,
who were arguing for keeping pregen a grade component, allowing it
to be combined with other grade components. What has changed?

Zoltan.