October 2013 - ghc-tickets

[GHC] #8115: GHC 64-bit build failures with LLVM
by GHC 28 Sep '14

28 Sep '14

#8115: GHC 64-bit build failures with LLVM ------------------------------------+--------------------------------- Reporter: schyler | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Windows Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+--------------------------------- When using LLVM 2.9, 3.1 or 3.4svn on Windows with the 64-bit GHC from the downloads page (http://www.haskell.org/ghc/download_ghc_7_6_3) to compile this simple program; {{{ main = print "Hello!" }}} I get these errors; {{{ Kyle@kyle-laptop /c/Users/Kyle/Desktop$ ghc -fllvm -fforce-recomp test.hs [1 of 1] Compiling Main ( test.hs, test.o ) C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s: Assembler messages: C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:2: Error: junk at end of line, first unrecognized character is `,' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:3: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:3: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:7: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:7: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:10: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:10: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:17: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:17: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:19: Error: junk at end of line, first unrecognized character is `,' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:20: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:20: Error: junk at end of line, first unrecognized character is `c' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:24: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:24: Error: junk at end of line, first unrecognized character is `c' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:26: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:26: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:31: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:31: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:34: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:34: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:41: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:41: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:43: Error: junk at end of line, first unrecognized character is `,' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:44: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:44: Error: junk at end of line, first unrecognized character is `M' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:50: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:50: Error: junk at end of line, first unrecognized character is `M' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:53: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:53: Error: junk at end of line, first unrecognized character is `M' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:61: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:61: Error: junk at end of line, first unrecognized character is `M' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:63: Error: junk at end of line, first unrecognized character is `,' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:64: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:64: Error: junk at end of line, first unrecognized character is `Z' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:69: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:69: Error: junk at end of line, first unrecognized character is `Z' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:72: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:72: Error: junk at end of line, first unrecognized character is `Z' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:80: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:80: Error: junk at end of line, first unrecognized character is `Z' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:82: Error: junk at end of line, first unrecognized character is `"' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:85: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:85: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:91: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:91: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:95: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:95: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:137: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:137: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:140: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:140: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:146: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:146: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:150: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:150: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:192: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:192: Error: junk at end of line, first unrecognized character is `s' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:195: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:195: Error: junk at end of line, first unrecognized character is `M' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:202: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:202: Error: junk at end of line, first unrecognized character is `M' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:207: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:207: Error: junk at end of line, first unrecognized character is `M' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:250: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:250: Error: junk at end of line, first unrecognized character is `M' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:253: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:253: Error: junk at end of line, first unrecognized character is `Z' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:260: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:260: Error: junk at end of line, first unrecognized character is `Z' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:266: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:266: Error: junk at end of line, first unrecognized character is `Z' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:308: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:308: Error: junk at end of line, first unrecognized character is `Z' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:310: Warning: .type pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:310: Error: junk at end of line, first unrecognized character is `_' C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:315: Warning: .size pseudo-op used outside of .def/.endef ignored. C:\Users\Kyle\AppData\Local\Temp\ghc6708_0\ghc6708_0.s:315: Error: junk at end of line, first unrecognized character is `_' }}} Invocation is `ghc -fllvm test.hs`. ghc --info: {{{ Kyle@kyle-laptop /c/Users/Kyle/Desktop$ ghc --info [("Project name","The Glorious Glasgow Haskell Compilation System") ,("GCC extra via C opts"," -fwrapv") ,("C compiler command","$topdir/../mingw/bin/gcc.exe") ,("C compiler flags"," -fno-stack-protector -Wl,--hash-size=31 -Wl ,--reduce-memory-overheads") ,("ar command","$topdir/../mingw/bin/ar.exe") ,("ar flags","q") ,("ar supports at file","YES") ,("touch command","$topdir/touchy.exe") ,("dllwrap command","$topdir/../mingw/bin/dllwrap.exe") ,("windres command","$topdir/../mingw/bin/windres.exe") ,("perl command","$topdir/../perl/perl.exe") ,("target os","OSMinGW32") ,("target arch","ArchX86_64") ,("target word size","8") ,("target has GNU nonexec stack","False") ,("target has .ident directive","True") ,("target has subsections via symbols","False") ,("LLVM llc command","llc") ,("LLVM opt command","opt") ,("Project version","7.6.3") ,("Booter version","7.6.1") ,("Stage","2") ,("Build platform","x86_64-unknown-mingw32") ,("Host platform","x86_64-unknown-mingw32") ,("Target platform","x86_64-unknown-mingw32") ,("Have interpreter","YES") ,("Object splitting supported","YES") ,("Have native code generator","YES") ,("Support SMP","YES") ,("Unregisterised","NO") ,("Tables next to code","YES") ,("RTS ways","l debug thr thr_debug thr_l thr_p dyn debug_dyn thr_dyn thr_debug_dyn") ,("Leading underscore","NO") ,("Debug on","False") ,("LibDir","C:\\Program Files\\Haskell Platform\\2013.2.0.0\\lib") ,("Global Package DB","C:\\Program Files\\Haskell Platform\\2013.2.0.0\\lib\\package.conf.d") ,("Gcc Linker flags","[\"-Wl,--hash-size=31\",\"-Wl,--reduce-memory- overheads\"]") ,("Ld Linker flags","[\"--hash-size=31\",\"--reduce-memory-overheads\"]") ] }}} No output binary is produced. Same llvm used with 32-bit ghc works smoothly to compile the same program. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8115> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8480: ghc 7.6.3 + clang-compatibility patches
by GHC 24 Sep '14

24 Sep '14

#8480: ghc 7.6.3 + clang-compatibility patches ----------------------------------------------+---------------------------- Reporter: darinmorrison | Owner: Type: task | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: Difficulty: Moderate (less than a day) | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: ----------------------------------------------+---------------------------- I did a first pass at back-porting Austin's clang-compatibility patches from HEAD to 7.6.3 in anticipating of a 7.6.4 release, or at least some sort of update for OS X 10.9 folks. The back-ported commits are on branches in my GHC GitHub repo: https://github.com/darinmorrison/ghc ghc-7.6.3-clang (just clang stuff) ghc-7.6.3-clang+mavericks (clang stuff + 10.9 fixes) I haven't tested this fully yet, or even compiled it yet with the latest changes, but I think I caught most of the stuff that might cause problems. (Actually I just tried now and there's another error further along I still need to track down.) There are a few other rough edges still: warnings, etc. Also, if you want to use the validate script, you'll need to turn off Werror. Anyway, I'll try to get remaining stuff sorted out and get some binaries up in the next couple of days. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8480> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8251: Validate submodule references during pre-receive hook
by GHC 24 Sep '14

24 Sep '14

#8251: Validate submodule references during pre-receive hook ------------------------------------+------------------------------------- Reporter: hvr | Owner: hvr Type: task | Status: new Priority: normal | Milestone: Component: None | Version: 7.6.3 Keywords: admin git | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Right now, you can push a commit introducing a not-yet existing Git submodule commit reference. However, such commits can be rejected for submodule repositories hosted at git.haskell.org, thus forcing the user to push the submodule first, and only after that push the submodule-affecting commit in ghc.git This kind of sanity checking ghc.git commits will become more important, if more repositories are converted into Git submodules. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8251> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8369: Small improvements to ./sync-all
by GHC 24 Sep '14

24 Sep '14

#8369: Small improvements to ./sync-all ------------------------------------+------------------------------------- Reporter: nwf | Owner: Type: bug | Status: new Priority: lowest | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- ./sync-all get in a local clone does not use local submodules. That is, if I {{{ git clone ghc ghc-tmp; cd ghc-tmp; ./sync-all get }}} the contained clones come over just fine from ghc/... into ghc-tmp/..., but the submodules are fetched over the network connection. I think the attached patch brings the "fetch from the clone source if possible" behavior over to submodules, though possibly not in an ideal way. Separately, I find that I want to run shell commands in each repository; adding a "shell" verb is trivial and a second patch is attached. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8369> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8070: Use a captcha for trac registrations
by GHC 24 Sep '14

24 Sep '14

#8070: Use a captcha for trac registrations ------------------------------------+------------------------------------- Reporter: igloo | Owner: Type: bug | Status: new Priority: high | Milestone: Component: None | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Use a captcha for trac registrations. These all seem to be 0.11-only: * http://trac-hacks.org/wiki/CaptchaAuthPlugin * http://trac-hacks.org/wiki/CaptchaAuthPlusPlugin * http://trac-hacks.org/wiki/SimpleCaptchaPlugin so the simplest answer might be recaptcha, although I believe that needs to be set up to be associated with a Google account: * http://trac-hacks.org/wiki/RecaptchaRegisterPlugin -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8070> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8097: internal error: getMBlock: mmap: Operation not permitted
by GHC 18 Sep '14

18 Sep '14

#8097: internal error: getMBlock: mmap: Operation not permitted ------------------------------+---------------------------------- Reporter: singpolyma | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.4.2 Keywords: | Operating System: Linux Architecture: x86 | Type of failure: Runtime crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------+---------------------------------- I get the following: {{{ <interactive>: internal error: getMBlock: mmap: Operation not permitted (GHC version 7.4.2 for i386_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Aborted (core dumped) }}} when running {{{parseOnly queryKeyParse (Data.Text.pack "hello")}}} where: {{{ queryKeyParse :: Attoparsec.Parser [T.Text] queryKeyParse = do top <- Attoparsec.takeTill (=='[') keys <- many key return (top:keys) where key = many (Attoparsec.char '[') *> Attoparsec.takeTill (==']') <* many (Attoparsec.char ']') }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8097> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8052: make ghci look for the files made by -dynamic-too
by GHC 03 Sep '14

03 Sep '14

#8052: make ghci look for the files made by -dynamic-too -----------------------------------+--------------------------------- Reporter: nfrisby | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.7 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -----------------------------------+--------------------------------- If I compile with `-dynamic-too`, ghci still re-interprets the source code instead of finding the `Test.dyn_o` file. {{{ $ inplace/bin/ghc-stage2 -O1 -dynamic-too -c Test.hs $ inplace/bin/ghc-stage2 --interactive Test GHCi, version 7.7.20130710: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. [1 of 1] Compiling Test ( Test.hs, interpreted ) Ok, modules loaded: Test. *Test> }}} I'm guessing that ghci sees the `.o` file isn't suitable for dynamic loading and then falls-back to the interpreter without first checking for the `.dyn_o` file. ghci loads `Test.o` as expected if I instead compile with `-dynamic`. I'm on OS X 64-bit, if that might matter. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8052> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8288: add idris style EDSL support for deep embedding lambdas
by GHC 27 Aug '14

27 Aug '14

#8288: add idris style EDSL support for deep embedding lambdas ----------------------------------------------+---------------------------- Reporter: carter | Owner: Type: feature request | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Project (more than a week) | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: ----------------------------------------------+---------------------------- I could be wrong, but I think this would actually make it much easier to write interesting EDSLs and have a native haskelly syntax. This would sort of be in the same vein as the recently requested applicative brackets idea, albeit a tad more going on . -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8288> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8331: GHC fails to apply {-# SPECIALIZE #-} for dubious reasons
by GHC 01 Aug '14

01 Aug '14

#8331: GHC fails to apply {-# SPECIALIZE #-} for dubious reasons -------------------------+------------------------------------------------- Reporter: | Owner: blitzcode | Status: new Type: bug | Milestone: Priority: | Version: 7.6.3 normal | Operating System: Unknown/Multiple Component: | Type of failure: Incorrect warning at Compiler | compile-time Keywords: | Test Case: Architecture: | Blocking: Unknown/Multiple | Difficulty: | Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- I encountered a 'RULE left-hand side too complicated to desugar' warning when trying to reduce some typeclass overhead through a SPECIALIZE pragma. The change I had to make to my program to make the warning go away seems rather strange, so I thought it might be worth reporting as a bug. This is the small test case I wrote to understand the problem better: {{{ {-# LANGUAGE FlexibleInstances, RankNTypes #-} module Main (main) where import Control.Monad import Control.Monad.Reader import Control.Monad.ST import Control.Applicative class (Applicative m, {- Functor m ,-} Monad m) => MonadAbstractIOST m where addstuff :: Int -> m Int type ReaderST s = ReaderT (Int) (ST s) instance MonadAbstractIOST (ReaderST s) where addstuff a = return . (a +) =<< ask runAbstractST :: (forall s. ReaderST s a) -> a runAbstractST f = runST $ runReaderT f 99 {-# SPECIALIZE INLINE useAbstractMonad :: ReaderST s Int #-} useAbstractMonad :: MonadAbstractIOST m => m Int useAbstractMonad = foldM (\a b -> a `seq` return . (a +) =<< (addstuff b)) 0 [1..50000000] -- useConcreteMonad :: ReaderST s Int -- useConcreteMonad = foldM (\a b -> a `seq` return . (a +) =<< (addstuff b)) 0 [1..50000000] main :: IO () main = do let st = runAbstractST useAbstractMonad putStrLn . show $ st }}} The use case here is simply having a library of functions which are abstracted from the underlying implementation of state (Reader / IO, Reader / ST, etc.) and operate on it with a small set of typeclass functions. This has very severe runtime overhead (~5x) compared to using the actual transformer stack directly, so a SPECIALIZE pragma seemed a good idea. The simple program above works as expected, but the warning appears as soon as the 'Functor' superclass is commented back in. It seems to me this should make no difference as Functor is already a superclass of Applicative. It was still there simply by oversight. I think SPECIALIZE should not fail in this case, and if it does, it would be really helpful to have a better error message. 'Too complicated' does not help in tracking down what needs to be changed for the specialization to happen, and given how harsh the overhead is otherwise, this is quite painful. In any case, once the specialization is applied in my actual program, the following error appears: {{{ ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for i386-apple-darwin): Simplifier ticks exhausted When trying UnfoldingDone a_saCf{v} [lid] To increase the limit, use -fsimpl-tick-factor=N (default 100) If you need to do this, let GHC HQ know, and what factor you needed To see detailed counts use -ddump-simpl-stats Total ticks: 66169 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} It seems like I need a -fsimpl-tick-factor of 450-500 for the compilation to succeed, resulting in a ~3x increase in binary size and a ~4x increase in compile time. The resulting code at least seems to benefit from the specialization as expected. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8331> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8407: Module re-exports at the package level
by GHC 26 Jul '14

26 Jul '14

#8407: Module re-exports at the package level ------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Package system | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- For various package reorganization purposes, especially for possibly turning `base` into a shim package that re-exports some modules from more specialized packages, good support for module re-exports would be nice. I wrote up a design spec at ModuleReexports; this bug is to track the progress. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8407> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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