June 2014 - ghc-tickets

[GHC] #9192: Add sameByteArray#
by GHC 15 Nov '14

15 Nov '14

#9192: Add sameByteArray# ------------------------------------+------------------------------------- Reporter: tibbe | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- We have `sameMutableByteArray#` so we ought to have `sameByteArray#` as well, allowing for cheap equality checks. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9192> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9197: FFI types should be usable in foreign import decls without revealing representations
by GHC 15 Nov '14

15 Nov '14

#9197: FFI types should be usable in foreign import decls without revealing representations ------------------------------------+------------------------------------- Reporter: duncan | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (FFI) | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- This is another go at #5529 but with, we hope, clearer and better arguments. The original FFI spec defined a whole bunch of FFI types that are acceptable in foreign import/export declarations, including lots of things defined in Foreign.C.*. The original spec defined these as abstract types. The original FFI spec also allowed for automatic newtype unwrapping in foreign declarations. In 2009 Simon PJ [pointed out http://www.haskell.org/pipermail/haskell-prime/2009-February/002726.html] that automatic newtype unwrapping breaks abstraction for user-defined types. In that same thread [I suggested http://www.haskell.org/pipermail /haskell-prime/2009-February/002727.html] that the breaking of abstraction for user types should be fixed, but that the intent of the FFI spec to have the FFI types as abstract should be kept. Manuel [argued http://www.haskell.org/pipermail/haskell-prime/2009-February/002729.html] that the C FFI types should actually not be abstract, and thus no special case for them was needed. On the basis of that thread the decision in #5529 was to only allow FFI decls to look through newtypes when the constructor is available, plus for a few types GHC uses to represent the C FFI types, like Int32 etc. Johan and I want to argue that it still makes sense as a user to not be forced into knowing the representation of the C FFI types to be able to use them. This is similar to but slightly weaker than the rationale of the FFI spec originally making those types abstract. Manuels argument is essentially that sometimes you need to know concrete types when those can change, e.g. CInt might be Int32 or Int64 and you should be free to depend on that difference. Manuel's argument is fine when the "concrete" representation exists as yet another portable type, as is the case for Int32. Of course we don't insist that the representation for Int or Int32 be exposed, in large part because they cannot have a Haskell implementation independent representation. The important point is Johan and I are defining/writing a portable low level ByteArray library that could be considered alongside the FFI's definition of some of the Foreign.* libraries: it defines and API for some low level types and functions but different Haskell implementations will implement them differently. For GHC we implement `data ByteArray = BA ByteArray#`. We want to make this an FFI type, in the same sense as the FFI spec defines the C types to be FFI types. (You could consider our library as a Haskell extension and implementations following this extension will support this type for FFI in a similar way to the FFI spec). Of course for this implementation of `ByteArray` the representation crosses the boundary into implementation dependent, unlike the case for `newtype CInt = CInt Int32` where both are still portable types. So, we think the right thing to do is to again be able to declare certain types (those defined in the FFI spec and its extensions) as being valid types to use in FFI decls, without their constructors being available. Thus users could choose to import `CInt` only (i.e. without its constructor) and use it. We are not arguing against Manuel's point that it's sometimes useful to not hide representations where that is possible (like for CInt being an Int32 or 64). So we are not asking that the C FFI types be made abstract again, just that it be possible to use them (and our new type) as FFI types without user access to the constrctor. For GHC, my suggestion for a reasonable way to do this is with a pragma. The pragma would say that this single-constrcutor single-field newtype or data is an FFI type, and that GHC may perform the usual newtype unwrapping even when the constructor is not in scope at the FFI decl site. We would then use this pragma on Int, Int32 and other core GHC (and FFI) types, and also on the various C FFI types. And finally, we would also do this on our ByteArray type. Note that it would have to cover data as well as newtype to be able to work for Int and other boxed wrappers of unboxed types. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9197> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8701: Update libffi-tarballs to latest libffi
by GHC 14 Nov '14

14 Nov '14

#8701: Update libffi-tarballs to latest libffi -------------------------------------+------------------------------------- Reporter: lukexi | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler (FFI) | Version: 7.8.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Building GHC Difficulty: Easy (less than 1 | failed hour) | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- libffi 3.0.14 contains fixes necessary for successful iOS (and probably ARM in general) cross-compilation. I've created a new archive that can be dropped in to replace the current libffi-tarballs archive here: https://github.com/ghc-ios/libffi- tarballs/blob/master/libffi-3.0.14.tar.gz?raw=true -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8701> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8750: Invalid identifier generated with Template Haskell not rejected
by GHC 13 Nov '14

13 Nov '14

#8750: Invalid identifier generated with Template Haskell not rejected --------------------------+------------------------------------------------ Reporter: | Owner: jstolarek | Status: new Type: bug | Milestone: Priority: normal | Version: 7.7 Component: | Operating System: Unknown/Multiple Template Haskell | Type of failure: GHC accepts invalid program Keywords: | Test Case: Architecture: | Blocking: Unknown/Multiple | Difficulty: | Unknown | Blocked By: | Related Tickets: | --------------------------+------------------------------------------------ I wrote Template Haskell code that generates this declaration: {{{ data (:+Sym1) (a:: Nat) (b :: TyFun Nat Nat) }}} `(:+Sym1)` is not a valid identifier and this declaration fails when I simply put it in a source file and try to compile it. However I get no errors when this definition is generated from Template Haskell. Not sure if this is intended behaviour or not. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8750> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9077: Forcing the type to be IO {} instead of IO() causes a "panic! The impossible has happened" output.
by GHC 11 Nov '14

11 Nov '14

#9077: Forcing the type to be IO {} instead of IO() causes a "panic! The impossible has happened" output. -------------------------+------------------------------------------------- Reporter: | Owner: Westycoot | Status: new Type: bug | Milestone: Priority: | Version: 7.8.2 normal | Operating System: Unknown/Multiple Component: | Type of failure: Compile-time performance bug Compiler | Test Case: Keywords: | Blocking: Architecture: x86 | Difficulty: | Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- Below is the source code in which the bug occurs. It is easily reproduce- able, by having the type be IO{} instead of IO(). When ran, this code will produce the "panic! The impossible has happened" output. Which told me to report the bug here. By changing IO() to IO{} (which I did by accident), no exception is thrown, it simply tells the user to panic! {{{ main :: IO {} main = do e1 <- getLine e2 <- getLine print ((read e1) + (read e2)) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9077> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8427: GHC accepts invalid program because of EPS poisoning
by GHC 10 Nov '14

10 Nov '14

#8427: GHC accepts invalid program because of EPS poisoning -------------------------------------+------------------------------------- Reporter: errge | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: GHC accepts Difficulty: Moderate (less | invalid program than a day) | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- Assume the following setup: - compiling in batch mode (`--make`), - package klassz, module Class contains the class "Class a" and the data "Data", - package klassz, module A contains an (orphan) instance "Class Data", - package main, module AImporter just imports A, - package main, module B imports only Class, but uses the instance (invalidly); then - if package main, module Main imports B, later imports AImporter; then it compiles; - if package main, module Main imports AImporter, later imports B, then it doesn't compile. The attached tgz contains this setup. `diff -u main-docompile main- nocompile` shows that the only difference between the two main directories is the order of import statements. The language definitely doesn't accept compilation success to depend on import ordering, therefore this is a bug. My current understanding is that the issue is that this code should never compile, both mains should be rejected, since module B imports only the class, but not the instance. The issue is that the EPS is only ever increased, never decreased between compilation of different modules in a single batch compilation. This naïve approach causes the instances to be loaded and then never unloaded, so it can be magically found when compiling the invalid B module. The current code can be found in [[GhcFile(compiler/iface/LoadIface.hs)]] line 280. I propose to instead of always loading ifaces into the EPS directly, introduce a proper cache for interfaces, that contains parsed up interface data in a `ModuleEnv`. Then we can start up with an empty EPS at the beginning of the compilation of every unit and quickly merge info from this cache. I guess the majority of time is the file reading IO and the parsing, not the merging of multiple interface files together. I also think that these kind of issues will get more and more prominent as people start to use parallel cabal and ghc, because if compilation of the attached example program is randomly parallelized, then in some cases it will build, some cases it won't. Any opinions, alternative fix ideas? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8427> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8672: :browse and roles on typefamilies
by GHC 10 Nov '14

10 Nov '14

#8672: :browse and roles on typefamilies -------------------------------------+------------------------------------- Reporter: monoidal | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler (Type | Version: 7.7 checker) | Operating System: Unknown/Multiple Keywords: | Type of failure: Incorrect Architecture: Unknown/Multiple | warning at compile-time Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- :browse on `ghci tests/ghci.debugger/scripts/T8557.hs` outputs a weird looking line: {{{ type role Sing nominal data family Sing (a :: k) type role T8557.R:Sing[]a nominal <-- data instance Sing a = SNil }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8672> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9073: small SPECIALIZE INLINE program taking gigabytes of memory to compile
by GHC 09 Nov '14

09 Nov '14

#9073: small SPECIALIZE INLINE program taking gigabytes of memory to compile -------------------------+------------------------------------------------- Reporter: dagit | Owner: Type: bug | Status: new Priority: | Milestone: normal | Version: 7.8.2 Component: | Operating System: Unknown/Multiple Compiler | Type of failure: Compile-time performance bug Keywords: | Test Case: Architecture: | Blocking: Unknown/Multiple | Difficulty: | Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- I have a small program that is taking 1+ GB of memory to compile. I've distilled the troublesome input down to the following: {{{ {-# LANGUAGE BangPatterns #-} import Data.Vector knot :: Vector Double -> Int -> Double knot vs k = vs ! idx0 where !idx0 = abs k `mod` 16 {-# SPECIALIZE INLINE knot :: Vector Double -> Int -> Double #-} noise :: Vector Double -> Int -> Double noise vs k = knot vs k + knot vs k + knot vs k + knot vs k + knot vs k + knot vs k + knot vs k + knot vs k }}} Compiled with `ghc -fprof-auto -prof -O2 -Wall`. As far as I can tell, prof-auto, prof, and optimizations of at least -O1 are required to trigger it. I'm using ghc-7.8.2 64bit for Windows. vector is version 0.10.9.1 (currently the latest on hackage). Same code worked fine on ghc 7.6.2. Also worth noting: Even though the `SPECIALIZE` isn't needed, if you remove the `SPECIALIZE` or the `INLINE` the problem goes away. If you remove even one of the duplicated calls to `knot vs k` in the body of `noise` then the amount of memory required drops dramatically. Add more to increase the requirements. I've been able to push it up around 10 GB, but I don't have enough memory to test beyond that! Thanks! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9073> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9053: make sdist fails with repeated /bin/sh[1]: lndir: not found [No such file or directory]
by GHC 09 Nov '14

09 Nov '14

#9053: make sdist fails with repeated /bin/sh[1]: lndir: not found [No such file or directory] -------------------------------------+------------------------------------- Reporter: AlainODea | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 7.8.2 Keywords: smartos illumos | Operating System: Solaris lndir sdist | Type of failure: Building GHC Architecture: Unknown/Multiple | failed Difficulty: Easy (less than 1 | Test Case: hour) | Blocking: Blocked By: | Related Tickets: | -------------------------------------+------------------------------------- It appears that source for lndir was intentionally included in utils and customized to handle .git directories: http://git.haskell.org/ghc.git/blobdiff/c629bd1539b1865cc28ce053234595e7aeb… This ignoring of .git directories has been in the upstream lndir.c since 2009: http://cgit.freedesktop.org/xorg/util/lndir/tree/lndir.c However, lndir is not installed by default (on Ubuntu or SmartOS) and is not listed in the tools required to build: https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation/Tools It does not appear to be built during the sync, boot, or make steps of a GHC build. Here is an excerpt: {{{ /bin/sh[1]: lndir: not found [No such file or directory] /bin/sh[1]: lndir: not found [No such file or directory] /bin/sh[1]: lndir: not found [No such file or directory] /bin/sh[1]: lndir: not found [No such file or directory] ghc.mk:1117: recipe for target 'sdist-ghc-prep' failed gmake[1]: *** [sdist-ghc-prep] Error 127 Makefile:64: recipe for target 'sdist' failed gmake: *** [sdist] Error 2 }}} Here is a detailed log: http://haskell.inf.elte.hu/builders/smartos-x86_64-head/19/16.html -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9053> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8699: Multiple test faliures on 32-bit Linux systems.
by GHC 07 Nov '14

07 Nov '14

#8699: Multiple test faliures on 32-bit Linux systems. ----------------------------+------------------------------------- Reporter: Fuuzetsu | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: x86 | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------+------------------------------------- I ran validate with HEAD (e01367ff8c3165b0dd1fb78bcb3a3ced1e4a5f19) on 3 different 32-bit Linux boxes and I'm seeing different failures on each one. I was advised on IRC to create a ticket with all the failures. The first and third box are using the binary of 7.6.3 provided on the GHC site. I had to link libgmp.so.3 to libgmp.so.10 on both of these in order to get it to install properly. Please ask about any info that I have not provided below! First box: {{{Linux misaki 3.12.3-gentoo #2 SMP Sat Dec 7 23:14:57 GMT 2013 i686 Intel(R) Core(TM)2 Duo CPU L7700 @ 1.80GHz GenuineIntel GNU/Linux}}} {{{Happy Version 1.19.0 Copyright (c) 1993-1996 Andy Gill, Simon Marlow (c) 1997-2005 Simon Marlow}}} {{{Alex version 3.1.0, (c) 2003 Chris Dornan and Simon Marlow}}} {{{ lrwxrwxrwx 1 root root 16 Oct 14 04:24 /usr/lib/libgmp.so.10 -> libgmp.so.10.1.3 lrwxrwxrwx 1 root root 12 May 31 2013 /usr/lib/libgmp.so.3 -> libgmp.so.10 }}} The full log is at [1]. Inlining the end of the log with the failures: {{{ Unexpected results from: TEST="T1969 haddock.Cabal haddock.base" OVERALL SUMMARY for test run started at Sun Jan 26 03:26:36 2014 GMT 0:19:58 spent to go through 3883 total tests, which gave rise to 15172 test cases, of which 11625 were skipped 28 had missing libraries 3458 expected passes 58 expected failures 3 caused framework failures 0 unexpected passes 3 unexpected failures Unexpected failures: perf/compiler T1969 [stat not good enough] (normal) perf/haddock haddock.Cabal [stat not good enough] (normal) perf/haddock haddock.base [stat not good enough] (normal) }}} As discussed on the mailing list, the Haddock numbers still need tweaking even after Austin updated them the other day. T1969 failure seems to come and go. ---- Second box: {{{Linux yuuki 3.11.4-gentoo #1 SMP Tue Oct 8 00:19:37 BST 2013 i686 Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz GenuineIntel GNU/Linux}}} {{{Happy Version 1.19.3 Copyright (c) 1993-1996 Andy Gill, Simon Marlow (c) 1997-2005 Simon Marlow}}} {{{Alex version 3.1.3, (c) 2003 Chris Dornan and Simon Marlow}}} I installed the bootstrapping compiler on this box from Gentoo's package manager so I'm not sure how gmp is linked here. I can retry by boostrapping from binary and linking libgmp.3 to libgmp.10 (like the other boxes did) for consistency. The version of this complier is 7.6.3-r1. The full log is at [2]. Inlining the end of the log with the failures: {{{ Unexpected results from: TEST="T1969 haddock.compiler T7859" OVERALL SUMMARY for test run started at Sun Jan 26 03:34:47 2014 GMT 0:12:04 spent to go through 3883 total tests, which gave rise to 12748 test cases, of which 9209 were skipped 26 had missing libraries 3453 expected passes 57 expected failures 3 caused framework failures 0 unexpected passes 3 unexpected failures Unexpected failures: perf/compiler T1969 [stat too good] (normal) perf/haddock haddock.compiler [stat not good enough] (normal) runghc T7859 [bad stderr] (normal) }}} A different Haddock perf failure, T1969 seems to have failed again and a totally new failure, T7859. ---- Third box: {{{Linux lenalee 3.11.4-gentoo #1 SMP Mon Oct 7 19:19:00 BST 2013 i686 Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz GenuineIntel GNU/Linux}}} {{{Happy Version 1.19.3 Copyright (c) 1993-1996 Andy Gill, Simon Marlow (c) 1997-2005 Simon Marlow}}} {{{Alex version 3.1.3, (c) 2003 Chris Dornan and Simon Marlow}}} {{{ lrwxrwxrwx 1 root root 9 Jan 26 02:42 /usr/lib/libgmp.so.3 -> libgmp.so lrwxrwxrwx 1 root root 16 Nov 20 11:54 /usr/lib/libgmp.so -> libgmp.so.10.1.3 }}} The full log is at [3]. Inlining the end of the log with the failures: {{{ Unexpected results from: TEST="hsc2hs004 T3837 haddock.compiler haddock.base T3307 environment001 T1969 gadt23 Capi_Ctype_001 Capi_Ctype_002" OVERALL SUMMARY for test run started at Sun Jan 26 03:28:47 2014 GMT 0:10:37 spent to go through 3883 total tests, which gave rise to 12748 test cases, of which 9209 were skipped 26 had missing libraries 3446 expected passes 57 expected failures 3 caused framework failures 0 unexpected passes 10 unexpected failures Unexpected failures: ../../libraries/base/tests/IO T3307 [bad stderr] (normal) ../../libraries/base/tests/IO environment001 [bad stderr] (normal) ffi/should_run Capi_Ctype_001 [bad stderr] (normal) ffi/should_run Capi_Ctype_002 [bad stderr] (normal) gadt gadt23 [bad stderr] (normal) hsc2hs T3837 [bad stderr] (normal) hsc2hs hsc2hs004 [bad stderr] (normal) perf/compiler T1969 [stat too good] (normal) perf/haddock haddock.base [stat not good enough] (normal) perf/haddock haddock.compiler [stat not good enough] (normal) }}} Whole plethora of failures! Haddock numbers again and a bunch of other stuff. Considering how close 7.8 is, I think these should be looked at (especially that last set doesn't look too good). I notice that over 2000 more tests were skipped on the first box (this is my day-to-day use computer). How are the tests to be skipped determined? [1]: http://fuuzetsu.co.uk/misc/validate-misaki- e01367ff8c3165b0dd1fb78bcb3a3ced1e4a5f19 [2]: http://fuuzetsu.co.uk/misc/validate-yuuki- e01367ff8c3165b0dd1fb78bcb3a3ced1e4a5f19 [3]: http://fuuzetsu.co.uk/misc/validate-lenalee- e01367ff8c3165b0dd1fb78bcb3a3ced1e4a5f19 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8699> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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