RFC: "Native -XCPP" Proposal

[Jan Stolarek]

> I want to emphasize that cpphs is actively maintained as it's pointed
> out in https://ghc.haskell.org/trac/ghc/wiki/Proposal/NativeCp. The
> Agda team has found some cpphs bugs which have been *quickly* fixed by
> cpphs's author, Malcolm Wallace.
Yes. It was not my intention to imply in any way that cpphs suffers from maintanance issues.

> Unfortunately I have not been able to track down the problem mentioned by Janek Stolarek.
Yes, and that's what gets me worried. I suppose the problem was somehow related to my locale 
settings although we were unable to track down the cause. I also recall someone else reported 
being affected by the same problem. So, until that problem is solved I would say it is a blocker 
as it would essentialy make development of GHC impossible for some people.

Janek


>
> On 6 May 2015 at 06:38, Jan Stolarek <jan.stolarek at p.lodz.pl> wrote:
> > One thing to keep in mind is that while cpphs will solve some problems of
> > system-cpp, it will also bring problems of its own. I, for one, have run
> > into problems with it when installing Agda. There is a very long thread
> > here:
> >
> > https://lists.chalmers.se/pipermail/agda/2014/006975.html
> >
> > and twice as more on my private inbox. We've reached no conclusion about
> > the cause and the only solution was to use system-cpp.
> >
> > Regarding licensing issues: perhaps we should simply ask Malcolm Wallace
> > if he would consider changing the license for the sake of GHC? Or perhaps
> > he could grant a custom-tailored license to the GHC project? After all,
> > the project page [1] says: " If that's a problem for you, contact me to
> > make other arrangements."
> >
> > Janek
> >
> > [1] http://projects.haskell.org/cpphs/
> >
> > Dnia środa, 6 maja 2015, Herbert Valerio Riedel napisał:
> >> Hello *,
> >>
> >> As you may be aware, GHC's `{-# LANGUAGE CPP #-}` language extension
> >> currently relies on the system's C-compiler bundled `cpp` program to
> >> provide a "traditional mode" c-preprocessor.
> >>
> >> This has caused several problems in the past, since parsing Haskell code
> >> with a preprocessor mode designed for use with C's tokenizer has caused
> >> already quite some problems[1] in the past. I'd like to see GHC 7.12
> >> adopt an implemntation of `-XCPP` that does not rely on the shaky
> >> system-`cpp` foundation. To this end I've created a wiki page
> >>
> >>   https://ghc.haskell.org/trac/ghc/wiki/Proposal/NativeCpp
> >>
> >> to describe the actual problems in more detail, and a couple of possible
> >> ways forward. Ideally, we'd simply integrate `cpphs` into GHC
> >> (i.e. "plan 2"). However, due to `cpp`s non-BSD3 license this should be
> >> discussed and debated since affects the overall-license of the GHC
> >> code-base, which may or may not be a problem to GHC's user-base (and
> >> that's what I hope this discussion will help to find out).
> >>
> >> So please go ahead and read the Wiki page... and then speak your mind!
> >>
> >>
> >> Thanks,
> >>   HVR
> >>
> >>
> >> [1]: ...does anybody remember the issues Haskell packages (& GHC)
> >>      encountered when Apple switched to the Clang tool-chain, thereby
> >>      causing code using `-XCPP` to suddenly break due to subtly
> >>      different `cpp`-semantics?
> >>
> >> _______________________________________________
> >> Glasgow-haskell-users mailing list
> >> Glasgow-haskell-users at haskell.org
> >> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
> >
> > ---
> > Politechnika Łódzka
> > Lodz University of Technology
> >
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---
Politechnika Łódzka
Lodz University of Technology

Treść tej wiadomości zawiera informacje przeznaczone tylko dla adresata.
Jeżeli nie jesteście Państwo jej adresatem, bądź otrzymaliście ją przez pomyłkę
prosimy o powiadomienie o tym nadawcy oraz trwałe jej usunięcie.

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If you are not the intended recipient or if you have received this message in error,
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