- Glasgow-haskell-users

RE: ghc-5.02.2 cannot parse string gaps
by Simon Marlow 06 Mar '02

06 Mar '02

> Section 2.6. of the Haskell report says: > > A string may include a "gap"---two backslants enclosing white > characters---which is ignored. This allows one to write long > strings on > more than one line by writing a backslant at the end of one > line and at > the start of the next. For example, > > "Here is a backslant \\ as well as \137, \ > \a numeric escape character, and \^X, a control character." > > > > ghc-5.02.2 cannot parse string gaps. > It accepts \ at the end of a line but not at the beginning of the > following line. It works ok here. There's a well-known problem with string gaps in conjunction with CPP; see http://www.haskell.org/ghc/docs/latest/set/options-phases.html#C-PRE-PROCES… If this isn't the problem, could you send us a complete module which fails to compile? Cheers, Simon

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filepath mangling under Windows?
by Malcolm Wallace 05 Mar '02

05 Mar '02

With ghc-5.02.2 running from a Makefile in a cygwin shell under Windows XP, the following behaviour occurs: ghc -package lang -package posix -c -o /d/haskell/hmake-3.00/targets/ix86-CYGWIN_NT-5.1/obj/hmake/QSort.o QSort.hs Assembler messages: FATAL: Can't create \d\haskell\hmake-3.00\targets\ix86-CYGWIN_NT-5.1\obj\hmake\QSort.o: No such file or directory It looks like ghc has reversed the slashes in the filepath given to the -o option, and this is the reason the assembler fails. The directory certainly exists, but we suspect cygwin only understands the forward-slash form not the backward-slash form. Is this a bug in ghc? Or is there some option we can give to persuade ghc not to reverse the slashes? Regards, Malcolm

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Double your monad in 30 days
by Albert Lai 05 Mar '02

05 Mar '02

Ashley Yakeley <ashley(a)semantic.org> writes: > Prelude> 0 * 2 > 0 We can generalize this. import Monad double_your_monad_in_30_days :: (MonadPlus M) => M a double_your_monad_in_30_days = mzero `mplus` mzero

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binding time in haskell
by Barbara Nostrand 05 Mar '02

05 Mar '02

We have sporadic network problems here and I may have missed an earlier reply. I need to know about binding time in Haskell especially with regard to type variables. Barbara Nostrand mailto:nostrand@acm.org

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RE: Raw Sockets
by Simon Marlow 04 Mar '02

04 Mar '02

> It looks like you want SOCK_RAW, not AF_RAW. GHC does support this, > with the 'Raw' socket type, something like this: > > proto <- getProtocolByName "icmp" > s <- socket AF_INT Raw proto should be: s <- socket AF_INET Raw (protoNumber proto) and of course you have to be root to send raw packets to the network. Cheers, Simon

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RE: Raw Sockets
by Simon Marlow 04 Mar '02

04 Mar '02

> Thanks for the reply. > > I wanted to send ICMP packets. Linux does support AF_RAW. > This compiles and > runs on my linux system. > > /* > * Create the socket. > */ > if ( (proto = getprotobyname("icmp")) == NULL) > err_quit("unknown protocol: icmp"); > if ( (sockfd = socket(AF_INET, SOCK_RAW, proto->p_proto)) < 0) > err_sys("can't create raw socket"); It looks like you want SOCK_RAW, not AF_RAW. GHC does support this, with the 'Raw' socket type, something like this: proto <- getProtocolByName "icmp" s <- socket AF_INT Raw proto Cheers, Simon

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RE: Raw Sockets
by dominic.j.steinitz＠britishairways.com 04 Mar '02

04 Mar '02

Simon, Thanks for the reply. I wanted to send ICMP packets. Linux does support AF_RAW. This compiles and runs on my linux system. /* * Create the socket. */ if ( (proto = getprotobyname("icmp")) == NULL) err_quit("unknown protocol: icmp"); if ( (sockfd = socket(AF_INET, SOCK_RAW, proto->p_proto)) < 0) err_sys("can't create raw socket"); Dominic. "Simon Marlow" <simonmar(a)microsoft.com>@haskell.org on 04/03/2002 12:00:33 Sent by: glasgow-haskell-users-admin(a)haskell.org To: "Dominic Steinitz" <dominic.j.steinitz <glasgow-haskell-users cc: bcc: Subject: RE: Raw Sockets > How do I use raw sockets? According to the documentation I > can use AF_RAW. > It also refers the user to the implementation in > fptools/hslibs/net/SocketPrim.lhs. Do I really need to do > this and if so > how do I get it? The SocketPrim library (aka Network.Socket) really only supports AF_INET and AF_UNIX. Many of the other AF_ things are quite system-dependent; eg. Linux doesn't have AF_RAW. The documentation is a bit slack, although it does mention at the top of the Family(..) definition that "your mileage may vary depending on the OS you use". Do you really want a raw socket, or will a datagram (UDP) socket do? If so, you can just pass Datagram as the SocketType argument to SocketPrim.socket. Cheers, Simon _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users(a)haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ------------------------------------------------------------------------------------------------- Save time by using an eTicket and our Self-Service Check-in Kiosks. For more information go to http://www.britishairways.com/eservice1

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RE: GHC on MacOS X
by Simon Marlow 04 Mar '02

04 Mar '02

> I've spent a day compiling ghc (5.03, checked out from CVS a > few days ago) on MacOS X 10.1. > The results: another unregistered build, a PowerPC implementation > of createAdjustor (foreign export dynamic now works!). Great stuff! You should coordinate with Sigbjorn Finne <sof(a)galois.com> who is also working on a MacOS X port, I believe. > I needed to modify a total of six files: > File: Adjustor.c Status: Locally Modified > File: ClosureFlags.c Status: Locally Modified > File: Main.c Status: Locally Modified > File: Storage.h Status: Locally Modified > File: Posix.hs Status: Locally Modified > File: Socket.hsc Status: Locally Modified If you post the patches to cvs-ghc(a)haskell.org, we'll take a look. > Socket.hsc refused to compile because on MacOS X, sigaddset() > is a macro > that chokes if its parameter is a void*. I added a wrapper > function in a > small C header file, but that's really ugly. What's the "proper" way? The right way is to add a wrapper, as you've done. With proper use of 'inline' you can eliminate any performance reduction too (it's probably not that big a deal, though). > I also got a compiler panic on one of my own modules I tried > to compile. > I'll post that to ghc-bugs, as I somehow don't think it has to do with > the PPC port. There are/were some problems due to rottage in the unregisterised code generation path, but I think Sigbjorn has mostly cleaned these up now. Try updating your CVS tree to get the fixes. > What I really need, of course, is a registered compiler... > I'm even prepared to learn some Perl to do that, but for now I > don't really have a clue what to > do - I don't know enough about Intel/Sparc assembly language > and runtime > conventions to find out from the code without a few hints - can anyone > give me a few pointers what the mangler is supposed to do _exactly_? Ok, the mangler really just does two things. It removes the C function prologues/epilogues to support tail-calls, and it brings info tables and entry code next to each other. You'll get most of the way there by just setting up a PPC machine-specific section at the start of mangler/ghc-asm.lprl (there's already a powerpc version for rs6000, I'm not sure how relevant this is, though). The other things you need to look at are: - rts/StgCRun.c, which is the tiny layer between C land and registerised Haskell land, which just saves a few registers and makes some space on the C stack. - includes/TailCalls.c (probably the defaults for FB_ FE_ and JMP_() will do). - includes/MachRegs.h, which defines the register mapping. There's one for PPC already, which again may or may not be relevant. Be sure to talk to Sigbjorn before diving in though, so as to avoid duplicating any effort. Cheers, Simon

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RE: Cross compilers
by Simon Marlow 04 Mar '02

04 Mar '02

> "Simon Marlow" <simonmar(a)microsoft.com> writes: > > > Cross compilation in GHC is usually done by taking .hc files > > generated on a machine with a working GHC and compiling them on the > > target machine using only gcc. This is how we bootstrap GHC on new > > machines. > > So then it reduces to getting a GCC cross compiler? (Which shouldn't > be insurmountable) Yes, you could do it this way. It may be less hassle to just take the .hc files to the target machine and compile them there, however. Setting up a real cross-compiling environment can be tricky - eg. making sure you're getting the right include files and so on. Cheers, Simon

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RE: Raw Sockets
by Simon Marlow 04 Mar '02

04 Mar '02

> How do I use raw sockets? According to the documentation I > can use AF_RAW. > It also refers the user to the implementation in > fptools/hslibs/net/SocketPrim.lhs. Do I really need to do > this and if so > how do I get it? The SocketPrim library (aka Network.Socket) really only supports AF_INET and AF_UNIX. Many of the other AF_ things are quite system-dependent; eg. Linux doesn't have AF_RAW. The documentation is a bit slack, although it does mention at the top of the Family(..) definition that "your mileage may vary depending on the OS you use". Do you really want a raw socket, or will a datagram (UDP) socket do? If so, you can just pass Datagram as the SocketType argument to SocketPrim.socket. Cheers, Simon

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