- Glasgow-haskell-users

RE: .hc files for building ghc-6.4 on amd64 ?
by Simon Marlow 17 Sep '05

17 Sep '05

On 12 September 2005 12:53, Wilhelm B. Kloke wrote: > Simon Marlow <simonmar(a)microsoft.com> schrieb: >> On 06 September 2005 15:33, Wilhelm B. Kloke wrote: >> >>> I have a FreeBSD box running FreeSD-amd64-6.0. Is there anybody who >>> can give me a set of .hc files (probably from linux x86_64) to build >>> GHC? I tried to follow the instructions to crossbuild from >>> FreeBSD-i386, but my attempts failed for reasons I don't understand. >> >> I have an account on a box, but haven't yet had time to do the port. >> >> If you let us know where your build got stuck, we might be able to >> help you out. > > Thank you for answering. This is more complicated to do it fast. > I tried to follow the building guide for a new port. IIRC there were > messages related to the difference in range for 64bit constants in the > header files for amd64 and the range which 32bit GHC could handle. > For now I have screwed up both build trees. I am going to restart the > process with fresh copies to give the exact information. > > I was just hoping that a set of Linux-64 .hc files would do > the job for FreeBSD, too. > > BTW, should I hold my breath for 6.4.1? You should certainly bootstrap using a 6.4.1 snapshot source tree, because there have been plenty of amd64-related fixes. There won't be a lot of change between now and the 6.4.1 release. Cheers, Simon

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upgrading glibc
by Gustavo Arroyo Delgado 16 Sep '05

16 Sep '05

Hi, I just want to know, whats the right version of ghc binaries for FC3 at Intel pentium 4 2.4 GHz. I tried it with: ghc-6.4-7.x86_64.rpm ghc-6.4-1.x86_64.rpm but they request the following: [root@mist ~]# rpm -Uvh ghc-6.4-1.x86_64.rpm warning: ghc-6.4-1.x86_64.rpm: V3 DSA signature: NOKEY, key ID aedf7ebb error: Failed dependencies: libc.so.6()(64bit) is needed by ghc-6.4-1.x86_64 libc.so.6(GLIBC_2.2.5)(64bit) is needed by ghc-6.4-1.x86_64 libc.so.6(GLIBC_2.3)(64bit) is needed by ghc-6.4-1.x86_64 libdl.so.2()(64bit) is needed by ghc-6.4-1.x86_64 libgmp.so.3()(64bit) is needed by ghc-6.4-1.x86_64 libm.so.6()(64bit) is needed by ghc-6.4-1.x86_64 libm.so.6(GLIBC_2.2.5)(64bit) is needed by ghc-6.4-1.x86_64 Can I Use #yum install glibc-2.3.5-10.3 with out problems? Thanks in advance. Gustavo Arroyo Delgado ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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Set.lookup?
by Serge D. Mechveliani 16 Sep '05

16 Sep '05

Dear GHC developers, How do you think, maybe, Data.Set also needs to provide `lookup' ? For example, I have data D = D Int String, with the instances Eq and Ord defined by the first coordinate. I do use Map Int String, and for a certain reason, also use Set D. Then, for example, the function check :: D -> Set D -> Bool check (D i name) s = case Set.lookup (D i name) s of Just (D _ nm) -> name == nm _ -> False looks natural, apart that there is no Set.lookup. ----------------- Serge Mechveliani mechvel(a)botik.ru

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RE: FFI: calling Haskell from C++?
by Simon Peyton-Jones 14 Sep '05

14 Sep '05

There's been a bit of traffic about calling Haskell from C++ recently, and I know that calling C++ from Haskell is a frequently asked question. (E.g. Koen Claessen was asking me about it this week.) It also seems to be somewhat platform dependent. (Esp on Windows, I think.) Would someone like to write up a description of how to successfully call out from Haskell to C++ and vice versa, using GHC? If you did, we'd gladly include the result in the user manual, and save others a lot of head scratching. Maybe there are simple things we could do to GHC to make the process simpler. But what it needs is someone who knows C++ well to write a coherent story. Please! Simon ________________________________ From: glasgow-haskell-users-bounces(a)haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] On Behalf Of Rich Neswold Sent: 13 September 2005 16:45 To: Felix Breuer Cc: glasgow-haskell-users(a)haskell.org Subject: Re: FFI: calling Haskell from C++? On 9/13/05, Felix Breuer <felix(a)fbreuer.de> wrote: $ ghc -fffi Foo.o Foo_stub.o main.cpp main.o(.text+0x22): In function `main': main.cpp: undefined reference to `__stginit_Foo()' main.o(.eh_frame+0x11): undefined reference to `__gxx_personality_v0' collect2: ld returned 1 exit status In main.cpp, you need to define __stginit_Foo(void) like this: extern "C" void __stginit_Foo(void); Specifying the "C" linkage with prevent the compiler from looking for a name-mangled version of the function. To fix the second problem, you need to shut off exception handling (specifying the -fno-exceptions option ought to do this. I don't know how to pass compiler option via ghc, though. -- Rich AIM : rnezzy ICQ : 174908475

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unsafePerformIO and NOINLINE Pragma
by Jan Christiansen 14 Sep '05

14 Sep '05

Hi! I want to analyse the laziness of a data structure. To check how many nodes are constructed I use a global counter. counter :: IORef Int counter = unsafePerformIO (newIORef 0) This counter is increased every time the constructor is called by redefining the constructor OBDD as follows. oBDD low var high = seq (unsafePerformIO (modifyIORef counter (+1))) (OBDD low var high) This works fine. When I compile with optimisations the counter is always set to one no matter how many nodes are constructed. I thought this would be caused by inlining. Therefore I have added two NOINLINE pragmata. {-# NOINLINE counter #-} {-# NOINLINE oBDD #-} Although the counter doesn't work. Is there another optimisation that can cause harm? Is there something wrong with the pragmata? best regards, Jan

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RE: CVS Repository
by Simon Marlow 14 Sep '05

14 Sep '05

On 14 September 2005 11:51, Peter Simons wrote: > I understand the GHC CVS repository has moved recently? It > appears that the document > > http://www.haskell.org/ghc/docs/latest/html/building/sec-cvs.html > > hasn't been updated accordingly; could someone with CVS > commit access please fix that? I've updated it in CVS, a new version will get uploaded with the 6.4.1 release. Cheers, Simon

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CVS Repository
by Peter Simons 14 Sep '05

14 Sep '05

Hi, I understand the GHC CVS repository has moved recently? It appears that the document http://www.haskell.org/ghc/docs/latest/html/building/sec-cvs.html hasn't been updated accordingly; could someone with CVS commit access please fix that? Thanks, Peter

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Strictness annotations question
by Adrian Hey 14 Sep '05

14 Sep '05

Hello, One thing I discovered a while ago when fiddling about with optimisting the AVL library was that making the AVL constructors strict in left and right sub-tree fields resulted in slower code than using no strictness annotation and explicit forcing of evaluation with `seq`. I hope it isn't too presumptious of me to hazard a guess as to what might cause this :-) My guess is that it's because the AVL code contains a lot of stuff like this.. -- With strictness annotations case blah of N l e r -> N l e (f r) -- l and r are left and right sub-trees or -- Without strictness annotations case blah of N l e r -> let r' = f r in r' `seq` N l e r' Now if the compiler wasn't smart enough to figure out that in the first example l was already reduced (because it's from a strict field) then it would get diverted trying to reduce it again (pointlessly accessing heap record it didn't need, disrupting the cache etc), so the net result would be slower code. But in truth I understand precious little about what analyses and optimisations ghc is capable of, so this could all be complete nonsense. So is this explanation plausible? Also (persuing this a little further) it occurs to me that the if this hypothesis is correct there could be other bad effects. For example, if in an expression I have a constructor with a strict field, but the constructor is used in a non-strict context. Presumably the compiler won't generate this constructor in it's "reduced form" (whatever that might be for ghc :-) because this would force evaluation of the field value. So it must construct some kind of thunk instead. But there's no reason it should be so inhibited if the constructor was non-strict (or if the compiler could figure out the field value was already reduced). Thanks -- Adrian Hey

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FFI: calling Haskell from C++?
by Felix Breuer 13 Sep '05

13 Sep '05

Hello everyone, we have tried long and hard to call Haskell functions from C++ using the FFI mechanism but without success. Our problem is as follows: We tried the C case first. Taking the example code from Chapter 8.2 of the GHC User Guide, we created files Foo.hs and main.c and then did $ ghc -fffi -c Foo.hs /tmp/ghc28407.hc: In function `__stginit_Foo_': /tmp/ghc28407.hc:278: warning: implicit declaration of function `getStablePtr' $ ghc -fffi Foo. Foo.hi Foo.hs Foo.o $ mv main.cpp main.c $ ghc -fffi Foo.o Foo_stub.o main.c $ ./a.out 2500 2500 2500 2500 2500 which worked fine. But when we simply rename main.c -> main.cpp, then $ ghc -fffi Foo.o Foo_stub.o main.cpp main.o(.text+0x22): In function `main': main.cpp: undefined reference to `__stginit_Foo()' main.o(.eh_frame+0x11): undefined reference to `__gxx_personality_v0' collect2: ld returned 1 exit status We tried many different options to ghc and also using g++ directly, all to no avail. It would be really great if someone could shed some light on this. For convenience, we have attached Foo.hs and main.cpp. Thanks, Felix

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6.4.1 update
by Simon Marlow 13 Sep '05

13 Sep '05

Hi Folks, I'm back, and it's high time we released 6.4.1. The bug reports keep on rolling in, but I think there are only a few blockers and the rest can be pushed back to 6.4.2 (long gone are the days when we used to be able to claim that all outstanding bugs have been fixed!). I'll set a tentative release date for next Monday (19 Sept). If there's anything still broken in the release candidate that is really holding you up, please let us know (unless I've already sent an email about it in the last couple of days in which case it'll be paged in). Things I hope to look into before the release: - building GHC with an upgraded Cabal (Duncan Coutts) - crashes when compiling Pugs (Gaal Yahas) - scavenge_stack crash (Jason Dagit) Cheers, Simon

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