May 2015 - Glasgow-haskell-users

Re: [Haskell-cafe] RFC: "Native -XCPP" Proposal
by Brandon Allbery 06 May '15

06 May '15

On Wed, May 6, 2015 at 11:27 AM, Kosyrev Serge <_deepfire(a)feelingofgreen.ru> wrote: > Why *shouldn't* TH fill that role? What can be done about it? For one, it's difficult to make it available in cross compilers (granted, work is being done on this) and not available on some platforms (ARM has been a problem, dunno if it currently is). For another, I don't think you can currently control things like imports or LANGUAGE pragmas --- and as TH is currently constructed it's not clear that you could do so, or that you could do so in a way that is sane for users. This is not to say that I like cpp --- I'd like it a lot more if it weren't actually using a C preprocessor that is not actually under our control or guaranteed to be compatible with Haskell --- but it does provide a "meta" in a different dimension than TH does. -- brandon s allbery kf8nh sine nomine associates allbery.b(a)gmail.com ballbery(a)sinenomine.net unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net

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Re: [Haskell-cafe] RFC: "Native -XCPP" Proposal
by Brandon Allbery 06 May '15

06 May '15

On Wed, May 6, 2015 at 10:59 AM, Bardur Arantsson <spam(a)scientician.net> wrote: > (I'm not going to be doing any of the work, so this is just armchairing, > but this seems like an 80/20 solution would be warranted.) > Only if you're convinced it will remain 80/20 for the foreseeable future. I do not want to bet on Linux always being gcc (and dislike the One True Platform-ism that line of thought encourages). -- brandon s allbery kf8nh sine nomine associates allbery.b(a)gmail.com ballbery(a)sinenomine.net unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net

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Re: [Haskell-cafe] RFC: "Native -XCPP" Proposal
by Sven Panne 06 May '15

06 May '15

2015-05-06 16:21 GMT+02:00 Bardur Arantsson <spam(a)scientician.net>: > +1, I'll wager that the vast majority of usages are just for version > range checks. The OpenGL-related packages used macros to generate some binding magic (a "foreign import" plus some helper functions for each API entry), not just range checks. I had serious trouble when Apple switched to clang, so as a quick fix, the macro-expanded (via GCC's CPP) sources had been checked in. :-P Nowadays the binding is generated from the OpenGL XML registry file, so this is not an issue anymore. > If there are packages that require more, they could just keep using the > system-cpp or, I, guess cpphs if it gets baked into GHC. Like you, I'd > want to see real evidence that that's actually worth the > effort/complication. Simply relying on the system CPP doesn't work due to the various differences between GCC's CPP and the one from clang, see e.g. https://github.com/haskell-opengl/OpenGLRaw/issues/18#issuecomment-31428380. Ignoring the problem doesn't make it go away... ;-) Note that we still need CPP to handle the various calling conventions on the different platforms when the FFI is used, so it's not only range checks, see e.g. https://github.com/haskell-opengl/OpenGLRaw/blob/master/OpenGLRaw.cabal#L588.

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Increased memory usage with GHC 7.10.1
by Jan Stolarek 04 May '15

04 May '15

Forall hi, I just uprgaded both of my machines to use GHC 7.10.1. I keep sandboxed installations of GHC and this means I had to rebuild Agda and Idris because the binaries built with GHC 7.8.4 were stored inside deactivated 7.8.4 sandbox. Sadly, I had problems building both Agda and Idris due to GHC taking up all of available memory. With Idris the problematic module was Idris.ElabTerm (~2900LOC). The interesting part of the story is that when I do a clean build of Idris GHC consumes all of memory when compiling that module and I have to kill the build. But when I restart the build after killing GHC the module is compiled using a reasonable amount of memory and within reasonable time. With Agda the problematic module is Agda.TypeChecking.Serialise (~2000LOC). The trick with killing the build and restarting it didn't work in this case. I had to compile Agda with GHC 7.8.4 (which works without problems though the mentioned module still requires a lot of memory) and alter my setup so that Agda binary is not stored inside GHC sandbox. I wonder if any of you came across similar issues with GHC 7.10.1? Do we have any performance data that allows to compare memory usage and performance of GHC 7.10.1 with previous stable releases? All of the above happened on 64bit Debian Wheezy with 2GB of RAM. Janek --- 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. This email contains information intended solely for the use of the individual to whom it is addressed. If you are not the intended recipient or if you have received this message in error, please notify the sender and delete it from your system.

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