- Glasgow-haskell-users

C-- source highlighting using source-highlight
by Johan Tibell 15 Apr '11

15 Apr '11

Hi, I've thrown together a small source-highlight language file for C--. You can use it to e.g. highlight C-- code when piped through less. ### Installion ### # This works on Debian/Ubuntu $ sudo apt-get install source-highlight # Put this file anywhere $ cat $HOME/cmm.lang comment start "//" # multi-line comments comment delim "/*" "*/" multiline string delim "\"" "\"" escape "\\" keyword = "aborts|align|aligned|also|as|big|bits|byteorder|case|const", "continuation|cut|cuts|else|equal|export|foreign|goto|if|import|in", "invariant|invisible|jump|little|memsize|pragma|reads|register", "return|returns|section|semi|span|stackdata|switch|target|targets|to", "typedef|unicode|unwinds|writes" number = '\<[+-]?((0x[[:xdigit:]]+)|(([[:digit:]]*\.)? [[:digit:]]+([eE][+-]?[[:digit:]]+)?))u?((int(?:8|16|32|64))|L)?\>' ### Usage ### $ ghc <source> -ddump-cmm | source-highlight --lang-def=$HOME/cmm.lang -f esc -s cmm | less -R Johan

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Meaning of ghc-pkg package-conf flags
by C Rodrigues 15 Apr '11

15 Apr '11

Hello, I'd like to know how ghc-pkg searches package databases and how the command-line flags affect the search. My model of ghc-pkg was that it builds a list of package databases and then searches them starting from the head. I'd like to work with a sandboxed local package database. Looking at what ghc-pkg list prints, I can infer what database list it's using: ghc-pkg list: [user-db, global-db] ghc-pkg list --global: [global-db] ghc-pkg list --global --package-conf=$HOME/sandbox/package.conf.d: [sandbox-db, global-db] However, even though ghc-pkg doesn't show my user database, it still reports broken packages that are in my user database. So ghc-pkg isn't really scanning packages according to this database list. What is it doing?

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Rebuilding ghc changes interface hashes?
by Joachim Breitner 10 Apr '11

10 Apr '11

Dear ghc developers, I am currently rebuilding ghc-7.0.2 to upload some packaging changes. Unfortunately, this had the effect of changing the package id of "base", which would require rebuilding every Haskell library. In the times of ghc-6.12, rebuilding the compiler left the hashes intact. Is there anything new in ghc-7 that interferes here? Also, the initial upload was built using ghc-6.12.1, while the upload now is build with ghc-7.0.2. Given that it is a two-stage compiler, I assume that the output should be identical, but it seems not to be the case. Any idea what could be causing this? Greetings, Joachim -- Joachim "nomeata" Breitner Debian Developer nomeata(a)debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nomeata(a)joachim-breitner.de | http://people.debian.org/~nomeata

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Changing language options in ghci at runtime
by Simon Hengel 09 Apr '11

09 Apr '11

Hello, does anyone know whether you can somehow change the currently active language flags during a ghci session (say change what `:show languages' outputs)? If no, is this possible by using the GHC API? Cheers, Simon

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Strange performance effects with unsafePerformIO
by Björn Peemöller 08 Apr '11

08 Apr '11

Hello, we have a strange performance behaviour when we use unsafePerformIO, at least with GHC 6.12.3 and 7.0.1. Please consider the example program following at the end of this post. Running the original code the execution time is about 26 seconds, while uncommenting one (or both) of the comments shrinks it to about 0.01 seconds on our machine. Is there an explanation for this effect? Regards, Bjoern -- --------------- module Main where import System.IO.Unsafe traverse [] = return () -- traverse (_:xs) = traverse xs traverse (_:xs) = traverse xs >> return () makeList 0 = [] -- makeList n = () : (makeList (n - 1)) makeList n = () : (unsafePerformIO . return) (makeList (n - 1)) main = traverse $ makeList (10^5)

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dynamic loading with ghc api?
by Rob Nikander 08 Apr '11

08 Apr '11

Hi all, I'd like to load a value from a .o file. I've got... import ObjLink main = do initObjLinker loadObj "Thing.o" resolveObjs Just ptr <- lookupSymbol "Thing_value_closure" Is that the correct symbol to load for the name "value" in module "Thing"? And if so, how to I get the haskell value out of the Ptr that I get from lookupSymbol? I found some code to do it and it works value :: Int, but it seg faults if value :: Integer, or something more complex like a function. {-# LANGUAGE MagicHash #-} {-# LANGUAGE UnboxedTuples #-} ... let !(Ptr addr) = ptr in case addrToHValue# addr of (# hval #) -> hval Is there some documentation for this that I'm missing? I'm looking at haddock with just type signatures, like this: http://www.haskell.org/ghc/docs/7.0.3/html/libraries/ghc-7.0.3/ObjLink.html (I'm a haskell beginner.) thank you, Rob

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Re: Validate failures on the new codegen
by Edward Z. Yang 07 Apr '11

07 Apr '11

Excerpts from Karel Gardas's message of Thu Apr 07 13:14:46 -0400 2011: > OK! Thanks for the information. So this -fnew-codegen is this famous > codegen which is using hoopl for data-dependency tracking or something > like that if I understand correctly Yep. > And which is producing just C-- in order to be compatible with the current > infrastructure, i.e. NCG? Not quite. We have two C-- representations, in cmm/CmmNode.hs and cmm/OldCmm.hs respectively. Our backends consume OldCmm, and Hoopl consumes CmmNode, and then converts it to OldCmm using CmmCvt.hs. > If I also read correctly somewhere on GHC Trac Wiki, then this -fnew-codegen > should sometime in the future even replace NCG. May I ask you when such > replace is planed? That's the idea, but depends on how long it takes for us to get the new code generator generating as good (or better--that's the idea behind Hoopl) as the old code generator at a reasonable pace. The new codegen is already several years into the making. > I'm asking since I'm still poking with the idea of writing NCG for some GHC > not yet supported platform and since this will be my free time hobby project > it'll certainly take some time hence I do have doubts if to use current NCG > as a basis for it or wait and/or use your new planned infrastructure. It's certainly a question. Since we can convert from one to another, whichever one you pick, we should be able to support (some fiddling may be required if you use the new C-- representation, since none of our other backends use it right now--but this is certainly the way forward.) Edward

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T3738 allocation figures for 32-bit
by Daniel Fischer 07 Apr '11

07 Apr '11

Hit send too soon: > Apparently the allocation figures drastically vary by arch and OS, it > would probably be necessary to test on several such and be more > generous with the limits. The same holds for other tests, of course. I had unexpected failures due to allocation figures also for space_leak001, T4801 and T3064. space_leak001 failing with bytes allocated 9328745840 is more than maximum allowed 9100000000 (allocation figures slightly vary among the different ways) which is close enough to not worry about, considering the minimum allowed is 9050000000. T4801 with peak_megabytes_allocated 41 is less than minimum allowed 70 If this is because you have improved GHC, please update the test so that GHC doesn't regress again bytes allocated 358364424 is more than maximum allowed 80000000 max_bytes_used 17406288 is more than maximum allowed 4000000 and T3064 with peak_megabytes_allocated 9 is less than minimum allowed 14 If this is because you have improved GHC, please update the test so that GHC doesn't regress again bytes allocated 69984336 is less than minimum allowed 150000000 If this is because you have improved GHC, please update the test so that GHC doesn't regress again max_bytes_used 3368652 is less than minimum allowed 6000000 If this is because you have improved GHC, please update the test so that GHC doesn't regress again The figures in HEAD's testsuite are again close to what I get, while the 7.0.3 figures are way off. Cheers, Daniel

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Some tips for using git rebase and keeping your history clean
by Johan Tibell 06 Apr '11

06 Apr '11

Hi all, Since we've now switched to git I though I share Linus' notes on rebasing for those of you who haven't seen them: http://www.mail-archive.com/dri-devel@lists.sourceforge.net/msg39091.html The mail talks about when to use rebase and when not to. Johan

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-DDEBUG and testsuite
by Edward Z. Yang 06 Apr '11

06 Apr '11

Hello all, If I run 'make fast' in the testsuite, with a stage2 compiler that has been built with -DDEBUG, should I be getting extra failures? Edward

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