[m-rev.] for review: add ll_debug GC grade

[Julien Fischer]

On Wed, 7 Dec 2011, Peter Ross wrote:

> On 6 December 2011 20:29, Ian MacLarty <maclarty at csse.unimelb.edu.au> wrote:
>> For review by Julien.
>>
>> Branches: main, 11.07
>>
>> Add a new GC grade for the .ll_debug Mercury grade.
>>
>> Previously the .ll_debug grade used the usual "gc" GC grade.  This was a
>> problem, because it meant that installing a .ll_debug grade would overwrite the
>> libgc library with the unoptimised .ll_debug version, resulting in a severe
>> performance loss for applications even if they weren't built in the .ll_debug
>> grade.
>>
>> compiler/compile_target_code.m:
>>    Link against the ll_debug GC library if low-level debugging
>>    is enabled.
>>
>> scripts/ml.in:
>>    Use the new ll_debug GC grade for the .ll_debug Mercury
>>    grades.
>>
> Maybe the ll_debug grade should imply the gcd grade?  Rather than
> installing a new version of the gc library.

I disagree.  I use the ll_debug grade quite a bit for debugging programs
written in the hlc grade that make heavy use of the C foreign code.
I have nver required the gcd grades for this; outside of debugging
interactions between the collector and the rest of the system I think
they are of too limited use.

Julien.