- ghc-devs - Haskell.org

Advice on replacing ghc-split
by Tamar Christina 09 Apr '15

09 Apr '15

Hi All, I have been working on creating a Haskell replacement for the perl script ghc-split. The issue I need some advice on is that the perl script is 280 SLOC primarily because of the use of RegExpr. The problem I have is that It seems i’m limited to only packages that are available already because GHC needs them (since it seems to compile using the in-place cabal and pkg list, am I correct here?). So I see my options as follows: Inline one of the regexp libraries, e.g. pcre-light Create my own string matching functions (possibly a simple DFA and encode the rexexpr into that) Use parsec (which I think is available as part of the ghc build no?) Does anyone have an idea on what the best approach would be? The regexpr don’t seem to use any perl extensions, so normal posix regex would be fine, I thought Base contained a regexp component. But it seems that’s now a separate library? Kind Regards, Tamar

2 1

Where are the HsTyVarBndrs collapsed in an explicit HsForAllTy?
by Alan & Kim Zimmerman 09 Apr '15

09 Apr '15

When parsing extremumNewton :: (Eq a, Fractional a) => (forall tag. forall tag1. Tower tag1 (Tower tag a) -> Tower tag1 (Tower tag a)) -> a -> [a] the nested `forall` declarations are parsed by ctypedoc :: { LHsType RdrName } : 'forall' tv_bndrs '.' ctypedoc {% hintExplicitForall (getLoc $1) >> ams (sLL $1 $> $ mkExplicitHsForAllTy $2 (noLoc []) $4) [mj AnnForall $1,mj AnnDot $3] } This generates a HsForAllTy for the first forall that simply wraps the second one, which is also a `ctypedoc`. But, when looking at the AST provided via ParsedSource, the two `forall`s are collapsed into a single one, containing both `tag` and `tag1` in the TyVarBndrs. In the process the annotation for the second forall loses its anchor, as that span is no longer in the AST. I cannot find where this collapsing takes place, can anyone point me at it? Thanks Alan

1 0

Flurry of late patches for 7.10.2
by Alan & Kim Zimmerman 08 Apr '15

08 Apr '15

You may have noticed that I have submitted a lot of patches for the 7.10.2 release at a very late stage. I apologise for this, but it has been triggered by an exciting test conducted by Matt Pickering using the new ghc-exactprint[1] based on the API Annotations in 7.10.1 He ran it in round-trip mode over all the source files in hackage, with the following results Total: 62,741 files. Parse fails: 6,611 CPP: 4,487 (not currently processed, coming soon) So the total succesfully processed was 51,643 files. Of these, 3,042 failed to reproduce the source exactly. The patches coming in are to bring the 3,042 count down even further. Regards Alan [1] https://github.com/alanz/ghc-exactprint

1 0

Toward better syntax errors
by Dan Aloni 08 Apr '15

08 Apr '15

Hello, Forwarded here is a link to a blog post I authored about improving GHC's syntax errors: http://blog.aloni.org/posts/toward-better-ghc-syntax-errors/ In fact, this came about after I started using Happy more extensively, and at one point thought that GHC could benefit too The gist of it, is that it was relatively easy to reach an improvement such as follows (notice 'possible tokens' below): input: -- test i = case i of 2 main = return () output: -- example1.hs:2:1: parse error (possibly incorrect indentation or mismatched brackets), possible tokens: '|' '->' It spawned a more extensive discussion regarding type errors here: https://www.reddit.com/r/haskell/comments/31m7pc/toward_better_ghc_syntax_e… Following to that, it was suggested that a further discussion in the GHC dev mailing list can continue about this direction (syntax errors, type errors and whatnot). -- Dan Aloni

2 2

Validate problems on Windows
by Simon Peyton Jones 07 Apr '15

07 Apr '15

Folks I'm getting this stuff at the end of a validate run. The test failures are at least understandable. But what's all this "traceback" stuff from Python? And "Warning:haddock-interfaces"? Simon Unexpected failures: ../../libraries/array/tests T9220 [bad stdout] (ghci) ../../libraries/base/tests/System Timeout001 [bad exit code] (normal) codeGen/should_compile debug [bad exit code] (normal) ghc-e/should_fail T9930fail [bad exit code] (normal) ghci/linking T1407 [bad stderr] (ghci) ghci/scripts T5975a [bad stderr] (ghci) ghci/scripts T9878b [bad exit code] (ghci) rts T7037 [bad stdout] (normal) stranal/should_run T10148 [bad stderr] (optasm) Unexpected stat failures: perf/compiler T5030 [stat too good] (normal) perf/compiler T5837 [stat too good] (normal) perf/compiler T783 [stat not good enough] (normal) perf/compiler T9872d [stat not good enough] (normal) perf/should_run T9203 [stat not good enough] (normal) Traceback (most recent call last): File "C:\code\HEAD\testsuite\driver\testlib.py", line 806, in do_test result = func(*[name,way] + args) File "C:\code\HEAD\testsuite\driver\testlib.py", line 1121, in stats return checkStats(name, way, stats_file, opts.stats_range_fields) File "C:\code\HEAD\testsuite\driver\testlib.py", line 1131, in checkStats f = open(in_testdir(stats_file)) IOError: [Errno 2] No such file or directory: './perf/haddock/../../../../libraries/base/dist-install/doc/html/base/base.haddock.t' Traceback (most recent call last): File "C:\code\HEAD\testsuite\driver\testlib.py", line 806, in do_test result = func(*[name,way] + args) File "C:\code\HEAD\testsuite\driver\testlib.py", line 1121, in stats return checkStats(name, way, stats_file, opts.stats_range_fields) File "C:\code\HEAD\testsuite\driver\testlib.py", line 1131, in checkStats f = open(in_testdir(stats_file)) IOError: [Errno 2] No such file or directory: './perf/haddock/../../../../libraries/Cabal/Cabal/dist-install/doc/html/Cabal/Cabal.haddock.t' Traceback (most recent call last): File "C:\code\HEAD\testsuite\driver\testlib.py", line 806, in do_test result = func(*[name,way] + args) File "C:\code\HEAD\testsuite\driver\testlib.py", line 1121, in stats return checkStats(name, way, stats_file, opts.stats_range_fields) File "C:\code\HEAD\testsuite\driver\testlib.py", line 1131, in checkStats f = open(in_testdir(stats_file)) IOError: [Errno 2] No such file or directory: './perf/haddock/../../../../compiler/stage2/doc/html/ghc/ghc.haddock.t' make[2]: Leaving directory '/cygdrive/c/code/HEAD/testsuite/tests' make[1]: Leaving directory '/cygdrive/c/code/HEAD/testsuite/tests' == Start post-testsuite package check Timestamp 2015-04-07 18:53:42 UTC for C:/code/HEAD/inplace\lib\package.conf.d\package.cache Timestamp 2015-04-07 18:53:42 UTC for C:/code/HEAD/inplace\lib\package.conf.d (same as cache) using cache: C:/code/HEAD/inplace\lib\package.conf.d\package.cache db stack: ["C:\\Users\\simonpj\\AppData\\Roaming\\ghc\\i386-mingw32-7.11.20150407\\package.conf.d","C:/code/HEAD/inplace\\lib\\package.conf.d"] modifying: Nothing flag db stack: ["C:\\Users\\simonpj\\AppData\\Roaming\\ghc\\i386-mingw32-7.11.20150407\\package.conf.d","C:/code/HEAD/inplace\\lib\\package.conf.d"] Warning: haddock-interfaces: C:\code\HEAD\libraries\stm\dist-install\doc\html\stm\stm.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\parallel\dist-install\doc\html\parallel\parallel.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\compiler\stage2\doc\html\ghc\ghc.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\haskeline\dist-install\doc\html\haskeline\haskeline.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\transformers\dist-install\doc\html\transformers\transformers.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\hoopl\dist-install\doc\html\hoopl\hoopl.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\bin-package-db\dist-install\doc\html\bin-package-db\bin-package-db.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\Cabal\Cabal\dist-install\doc\html\Cabal\Cabal.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\binary\dist-install\doc\html\binary\binary.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\template-haskell\dist-install\doc\html\template-haskell\template-haskell.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\pretty\dist-install\doc\html\pretty\pretty.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\hpc\dist-install\doc\html\hpc\hpc.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\process\dist-install\doc\html\process\process.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\directory\dist-install\doc\html\directory\directory.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\time\dist-install\doc\html\time\time.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\Win32\dist-install\doc\html\Win32\Win32.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\containers\dist-install\doc\html\containers\containers.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\bytestring\dist-install\doc\html\bytestring\bytestring.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\deepseq\dist-install\doc\html\deepseq\deepseq.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\array\dist-install\doc\html\array\array.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\filepath\dist-install\doc\html\filepath\filepath.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\base\dist-install\doc\html\base\base.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\integer-gmp\dist-install\doc\html\integer-gmp\integer-gmp.haddock doesn't exist or isn't a file Warning: haddock-interfaces: C:\code\HEAD\libraries\ghc-prim\dist-install\doc\html\ghc-prim\ghc-prim.haddock doesn't exist or isn't a file == End post-testsuite package check

1 0

[haskell.org Google Summer of Code] Call for Mentors
by Edward Kmett 07 Apr '15

07 Apr '15

We have had a rather large pool of potential students apply for this year's Google Summer of Code, but, ultimately, Google won't let us ask for a slot unless we have a potential mentor assigned in advance. On top of that, one thing we try to do with each project is wherever possible, assign both a primary and a backup mentor, so the available mentoring pool is drawn a little thin. Many hands make for light work, though: If you've mentored or thought about mentoring in years past, I'd encourage you to sign up on google-melange for the Google Summer of Code at: https://www.google-melange.com/gsoc/homepage/google/gsoc2015 and request a connection to haskell.org as a Mentor. Once you've done this you can help us vote on proposals, and should something seem appropriate to you, you can flag yourself as available as a potential mentor or backup mentor for one (or more) of the projects. We have a couple of weeks left to rate proposals and request slots, but it'd be good to make as much progress as we can this week. If you have any questions, feel free to reach out to me, or to Shachaf Ben-Kiki or Gershom Bazerman who have been helping out with organizational issues this year. We also have a #haskell-gsoc channel on irc.freenode.net if you have questions about what is involved. Thank you for your time and consideration, -Edward Kmett

1 0

Use of GHC in Open Embedded Environments
by dpquigl 06 Apr '15

06 Apr '15

Hello Everyone, I sent a couple of private messages to Simon and he suggested I post to the list instead to get more eyes on the problem. I have been working for the better part of 3 days on trying to get GHC to build within an Open Embedded environment. Open Embedded is used to set up embedded build environments that are completely isolated from the build platform. The problem I'm encountering is due to the way GHC builds its requiring the build and host platforms to be the same. I want to create a GHC build where the build and host are different so I can guarantee the isolation of the Haskell used to build our programs and libraries on target. I looked extensively through the cross compilation wiki page and even tried specifying paths into configure script to specify the tools from within my toolchain to build with and I am still running into problems. It seems that even if the top level makefile gets configured properly the build environment for the modules created with cabal under libraries do not retain any of that configuration information. The reason this is important is that I'm working on OpenXT which is a recently Open Sources version of a product Citrix use to have called Xen Client XT. The idea of OpenXT is that we use Xen to decompose what is traditionally a monolithic system into several VMs which serve specific purposes. For example we have the user interface for the platform which manages things like sound levels and bringing up and shutting down VMs into its own domain called the UI domain. We also separate out networking into its own domain as well where the network card is mapped exclusively into that domain and it manages creating and running virtual network adapters for other VMs on the platform. We use haskell in two different ways in this system. We personally want to use OpenXT as a research platform and we have special purpose mini domains for doing things like measurement and attestation and we have components of these written in Haskell to do formal verification of the domains. What OpenXT is using Haskell for directly is as part of its management engine for the platform. We have a haskell and ocaml(just for glue) based versions of metadata storage and platform management APIs. Now when we build the platform we want to remove the dependency on the host platform GHC version. We try to do this by building what would essentially be a stage 1 compiler which will then be used to build the runtime and tools used in the final platform VMs. The issue is that the GHC build does not recognize the use case of host and build machines being different. They expect host and build to be the same and target to be different. Because of this even if we specify each component individually on the configure line for the base GHC build when the build gets to the point of building the libraries it seems to have this information completely vanish. I think this is because it is using cabal to build the libraries and cabal isn't taking into account that GHC is built for a second platform and we want to build those libraries for that same platform. Dave

2 1

DPH tests
by Konstantine Rybnikov 06 Apr '15

06 Apr '15

Hi! There’s «Additional Packages» section [0] which lists packages that need to be installed in order to run full testsuite. But I couldn’t install dph-* ones, first errors I was getting were regular cabal-constraint ones. I wrote an author Ben Lippmeier, but he replied that dph-* packages were obsolete and not maintained anymore. I grepped and saw that all tests are under testsuite/dph folder. So: does GHC still run them at all? Should we edit wiki? Or edit test-suite? Thanks! [0]: https://ghc.haskell.org/trac/ghc/wiki/Building/RunningTests/Running#Additio…

4 3

DynFlags.hs
by Kazu Yamamoto 06 Apr '15

06 Apr '15

Hi, I cannot build GHC 7.10.1 on CentOS 6.5 whose memory is just 1G. This is because compiler/main/DynFlags.hs is huge. It would be nice if this file could be split. --Kazu

3 2

GHC 7.10.1 html docs all flat?
by Randy Polen 02 Apr '15

02 Apr '15

The HP build expects that the html docs for the ghc-bundled packages will be in heirarchical directories, based on the package name (e.g., GHC.Magic docs in libraries/ghc-prim-0.3.1.0/GHC-Magic.html) which is how it has been for many ghc releases. In 7.10.1, I thought it was an error but it seems the haskell.org docs reflect this new, flat way (e.g,. GHC.Magic docs in libraries/GHC-Magic.html). Just want to make sure this is what is expected, and then change the HP build code accordingly. Follow up question: should the HP-bundled docs do the same thing? Is the flat model the way to go for all the docs? Won't this cause collisions for updated packages? Randy

3 2