Mail Archives: djgpp/1995/03/17/15:56:02
>Mike Feldman said:
>
>Well, Dewar should know better than to project deadlines.:-)
>
>In any case, anyone working with a compiler like this really has to be
>willing to work with a "work in progress", reporting bugs, etc. I don;t
>know which version you had, but I'll bet it was _many_ months back, if
>Dewar was projecting March 95 for validation.
>>
>> I deleted all the GNAT modules on my DOS machine but I kept the DJGPP
>> support because I found I could do real work with C and C++.
>
>Well, that is because you are dealing there with mature compilers.
>There are folks who are willing to get in on the ground floor of
>a work-in-progress, and there are folks who are not.:-)
>
>I delete each old version of GNAT as I get the newest one, roughly
>once a month. How many months old was yours?
It was (1994) December ~15th release.
I give much credit to those working on GNAT, its just that my disappointment
was proportional to my expectations of performance from a compiler
just three months from validation. At that stage compilers should
pass 95% of validation tests with the remaining issues just a mop-up.
>>
>> >Also, GNAT is about 250k lines of (mostly) Ada 95, (a bit of C around
>> >the edges) so its writers get a lot of opportunity to test the compiler
>> >on itself! GNAT has been compiling itself since July 1993, and its own
>> >sources contain more and more of the Ada 95 extensions with each new
>> >release (new releases about once a month now).
>>
>> But the compiler isn't multitasking(?), so that feature will never
>> be self-tested. Not to mention representation_clause, etc, maybe 10%
>> of Ada95 will be tested.
>
>Excuse me? You're right that GNAT does not use tasking, but neither does
>_any_ compiler for _any_ language. My impression is that a good deal of
>rep-clause stuff is now implemented. GNAT is now passing well over 50%
>of validation tests, probably somewhere in the 70% range.
>
Right, so a self-compiling compiler would not test tasking. Also I
expect the compiler to be as free as possible from machine dependencies,
so the compiler would not _use_ rep-clauses and thus would not test
rep-clauses when compiling itself. Self-compilation was my issue. I
acknowledge that the compiler is being tested in other ways.
>I'm curious - why are people willing to deal with unvalidated C/C++
>compilers but get very cynical about Ada validation? How many C++
>compilers do you know that really handle templates properly (assuming
>anyone can define "properly" properly..:-))
The C/C++ compilers may be unvalidated, but they pass my test by producing
code that computes good numbers, which I double-check. And the code is
portable, which is of practical value. I have no language prejudice, I'd
use Basic if I could get results faster.
>Bottom line: GNAT is a lot of fun to work with, if you are willing to
>deal with encountering and reporting bugs. I lurk on NYU's internal
>mailing list and have gotten lots of insight into how responsive they
>are. _Of course_ it is immature - I'm surprised anyone expected
>otherwise...
Well, _He_ said it was ready :-).
I am used to dealing with "works in progress", and can scale my inputs
and deal with the outputs, especially when I'm told at the outset what
the situation is. Then I will not push the envelope with a production
type of Ada program.
Yes, I am cynical about Ada validation. Take the Vax compiler (and don't
bring it back.)
Happy computing,
Douglas Kubler
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