- Glasgow-haskell-users

Linking and Including nonstandard paths
by Chris McCraw 08 Apr '07

08 Apr '07

Hi! We're fairly happy users of ghc in my department. We use it widely for instruction and to some degree for research. I'm the fellow tasked with maintaining the local installation, and I have a couple of simple and seemingly related problems that I'm sure have easy solutions, though I haven't been able to find them. 1) I'd like to embed an additional library search directory in ghc so that it does the equivalent of -L/path/to/extra/dir every time it's used to link something. Unfortunately, our libgmp resides in a nonstandard directory and so *every time* someone wants to compile they must ghc -L/lusr/gnu/lib ... to find -lgmp. I promise, we have thought about moving libgmp into the default search path, and setting $LD_LIBRARY_PATH, but those break a lot of other stuff in our setup, and are really not practical in our environment. We build all of our utilities from source (including ghc) so I would be happy & able to tweak some setting during configure or make or even hack the source--but I can't figure out where to change it. I figured it'd be in configure.mk(.in) but adding "-R /lusr/gnu/lib" to the LD command line did not do the trick in generating a ghc binary that calls ld/collect2 in the same way. 2) When building something, I often need to add an include directory. As an example, GSLHaskell: % runhaskell -I/lusr/gnu/include Setup.hs build [...] [16 of 17] Compiling GSL.Plot ( GSL/Plot.hs, dist/build/GSL/Plot.p_o ) [17 of 17] Compiling GSL ( GSL.hs, dist/build/GSL.p_o ) GSL/gslaux.c:2:26: gsl/gsl_blas.h: No such file or directory GSL/gslaux.c:3:28: gsl/gsl_linalg.h: No such file or directory gsl/gsl_blas.h and friends are indeed in /lusr/gnu/include and I'd like to do the equivalent of adding a $CFLAGS of -I/lusr/gnu/include to the build (or to every build--it'd be grand if that was included by default, though not as necessary as item #1 above) but can't figure out how. I'm working with ghc-6.6 on ubuntu linux, in case that matters. I'm not sure what else is relevant, but am happy to provide details as needed. Help? Thanks in advance!

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distributed compilation by GHC
by Bulat Ziganshin 05 Apr '07

05 Apr '07

Hello GHC, i'm interested to know how much people are interested in having support for distributed compilation by GHC? it's true that production GHC version doesn't support multi-threaded compilation, so such system will be of benefit even for local usage for users with multi-core chips? -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com

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Re: Failed to load interface for `Prelude'
by Joel Reymont 05 Apr '07

05 Apr '07

It's driving me nuts but I keep getting the same error with our without split objects! I did manage to build the quickest configuration, it's the performance one I cannot build. On Apr 5, 2007, at 3:02 PM, Pepe Iborra wrote: > The problem is not in the logs you attached, those are from stage2. > The real error shows up when compiling base, if I recall correctly, > but I never had the courage to find out why. -- http://wagerlabs.com/

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ghci doesn't run FFi'd code which works under ghc on WinXP
by Vivian McPhail 05 Apr '07

05 Apr '07

Hi All, I wrote a binding to matlab matrix.h and mat.h. My test program works when I compile a binary, but when I try to use the code in ghci nothing happens. There are no error messages, but all computations return a blank line. Does this fall into a known class of error? I can provide my source code, but because of licensing requirements I can't provide the .dll's against which the code is linked. TIA Vivian

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Login problems with trac
by Robin Green 03 Apr '07

03 Apr '07

I am having difficulty logging in to GHC's trac. The situation is this: 1. I'm pretty sure I used to log in with username "greenrd" to file bugs (at least, that's what Firefox's password manager tells me!). That no longer works. I get the message below. ------------------------------------------------------------------ Permission Denied To create tickets or edit the wiki, please login with username guest, password guest. TICKET_CREATE privileges are required to perform this operation TracGuide — The Trac User and Administration Guide ------------------------------------------------------------------ 2. I cannot log in with username "guest" using Firefox 1.5 on my office machine. I just get the same message, when I click "login". This occurs even after I have cleared my web browser's cache. Maybe I need to do something else other than clear the cache? 3. I have been able to log in once as a guest *and* create a ticket - but only on Firefox 2, on my office machine, which is not behind a proxy. 4. Strangest of all, I have not been able to log in as a guest using Firefox 2 on my dorm machine which is behind a proxy - even though Firefox is *not* automatically supplying a username and password! When I attempt to login as guest, I get redirected to http://hackage.haskell.org/trac/ghc and I don't seem to be logged in - a "login" link is still there, instead of a "logout" one. This is all rather confusing. I have not figured out what is going on here. -- Robin

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Re: More on FreeBSD/amd64
by Gregory Wright 03 Apr '07

03 Apr '07

Hi Ian, On Mar 29, 2007, at 8:36 PM, Ian Lynagh wrote: > > Hmm, oh well. > > OK, so we know that the wrong value is being passed to > newPinnedByteArray#, right? There aren't many calls to that: > > libraries/base/Foreign/Marshal/Alloc.hs > libraries/base/GHC/ForeignPtr.hs (4 calls) > libraries/base/GHC/Handle.hs > > so the easiest way forward is probably to print something unique, and > the size passed, in each one and try to work backwards towards the > source. e.g. > > mallocPlainForeignPtrBytes (I# size) = IO $ \s -> > case newPinnedByteArray# size s of { (# s, mbarr# #) -> > > => > > mallocPlainForeignPtrBytes i@(I# size) = do > print ('A', i) > IO $ \s -> > case newPinnedByteArray# size s of { (# s, mbarr# #) -> > > (it might be worth printing something after the existing IO action as > well, just to avoid confusion as to what is happening. > Is there a version of "print" I can use for debugging these libraries? Just adding "print" causes a cycle in module dependencies. I can now start gdb instruction stepping close to the crash and it looks as if the trouble comes from mallocForeignPtr. I'm trying to find out what calls that now. Best Wishes, Greg

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ghc development version (6.7) from MacPorts
by Gregory Wright 02 Apr '07

02 Apr '07

Hi, For those who live on the bleeding edge, I have made a port of the latest development version of ghc for OS X through MacPorts. (If you are not familiar with MacPorts, see http://macports.org.) The build is from the darcs repository, and installs its binaries as <bin_name>-6.7.<date_code> . This naming allows the development version to be installed alongside the released ghc-6.6 with no conflicts. The port should work with OS X 10.3 and later on Intel or PPC. The name of the port is "ghc-devel". Note that because this is really a _development_ version, it may be buggy or not build at all. For day to day use you want the released ghc-6.6. Have fun, Greg

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Re: [Haskell-cafe] ghc-6.7.20070330 on Mac OS X
by Pepe Iborra 02 Apr '07

02 Apr '07

(redirecting to glasgow-haskell-users) It is well known that the readline lib that comes with OS X is no good, and you need to use a replacement. A nice post from the blogosphere explaining all this: http://mult.ifario.us/articles/2006/10/17/ghc-6-6-and-mac-os-x- readline-quick-fix If that doesn't help, please post the errors that you get when building the readline package. Cheers pepe On 01/04/2007, at 16:33, Ruben Zilibowitz wrote: > I am trying to build this version of GHC on Mac OS X. I'm currently > using GHC 6.6. The build is failing with the following error: > > ghci/InteractiveUI.hs:69:7: > Could not find module `System.Console.Readline': > Use -v to see a list of the files searched for. > <<ghc: 310591992 bytes, 51 GCs, 4238510/9457140 avg/max bytes > residency (4 samples), 26M in use, 0.02 INIT (0.00 elapsed), 2.11 > MUT (15.73 elapsed), 0.31 GC (0.36 elapsed) :ghc>> > make[2]: *** [depend] Error 1 > make[1]: *** [stage2] Error 2 > make: *** [bootstrap2] Error 2 > > So it seems I need to install the Readline library. But building > the Readline library is also giving me errors on my system. > > Just wondering if someone else has managed to build ghc-6.7.x on > Mac OS X? If so, what did you need to do? > > Cheers, > > Ruben > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe

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Arrows and GHC rewrite rules
by Eric Cheng 31 Mar '07

31 Mar '07

In GHC's Control.Arrow implementation, there are several rewrite rules which exploit some properties of arrows. For example, > "compose/arr" forall f g . arr f >>> arr g = arr (f >>> g) > "first/arr" forall f . first (arr f) = arr (first f) > "second/arr" forall f . second (arr f) = arr (second f) ... and so forth. Now say I have a simple arrow instance: > newtype SF a b = SF ([a] -> [b]) > > instance Arrow SF where > arr f = SF (map f) > > first (SF f) = SF g > where g l = let (x, y) = unzip l > in zip (f x) y > > (SF f) >>> (SF g) = SF (g . f) and some arrow composition: > foo :: SF (Int,Int) (Int,Int) > foo = first (arr (+1)) >>> first (arr (+2) >>> arr (+3)) I was expecting that ghc would at least make use of compose/arr or even first/arr, but it didn't appear to be the case. I was using ghc-6.6, and -ddump-simpl-stats showed a bunch of list-specific rules were fired (map, mapFB, fold/build, etc), but I did not see any arrow-related rules being applied. Were the rewrite rules subsumed by inlining or beta-reduction? Am I missing something here? Thanks, Eric

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RULES and type classes
by Mike Hamburg 31 Mar '07

31 Mar '07

Is there any way to use RULES substitutions with type classes? I'm writing a reactive programming arrow (same idea as Yampa, different design goals), and it would help performance (and not just in the speed sense) to be able to tell when a value derived with arr hasn't changed. So I'd like to be able to specialize arr to functions whose result is an instance of Eq. I tried {-# RULES "reactiveArr/Eq" reactiveArr = reactiveArrEq #-} but got the message Control/Arrow/Reactive/Reactive.hs:89:41: No instance for (Eq b) arising from instantiating a type signature at Control/Arrow/Reactive/Reactive.hs:89:41-89 Possible fix: add (Eq b) to the tcRule When checking the transformation rule "reactiveArr/Eq" I tried adding various sorts of type signatures, but I couldn't find any way around this... is it a restriction in the RULES rewrite engine? Is there a workaround, or some mechanism other than RULES that I should be using? I could write a special "arrEq" function, but I'd like to minimize the number of extraneous operations outside the Arrow class. Thanks, Mike Hamburg

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