January 2014 - ghc-tickets

[GHC] #8197: telling people how to use GHC 7.6 correctly with Xcode 5/ OS X Mavericks
by GHC 24 May '14

24 May '14

#8197: telling people how to use GHC 7.6 correctly with Xcode 5/ OS X Mavericks ----------------------------------+--------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------- Are we going to make available directions so that people can use 7.6 correctly with xcode 5 and/or mavericks? eg: will we provide directions to either 1. use Luke Ianni's clang wrapper hack, and bundle that with a 7.6 release thats 7.6.3 + that extra binary to make a 10.8 friendly "stability" release 2. tell people to stick to xcode 4.6 and/or install a newer GCC (say, GCC 4.8) and adjust their ghc settings file to point to that other GCC? We need to provide this information in a clear way, because this WILL be a problem where we'll have a support load from it (whether we want to or not, until GHC 7.8 gets a haskell platform release, this WILL happen. We need to have a mitigation strategy so that we aren't dealing with it constantly) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8197> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8673: GHC could generate GADT record selectors in more cases
by GHC 17 May '14

17 May '14

#8673: GHC could generate GADT record selectors in more cases ------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | 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: | ------------------------------------+------------------------------------- Philip Holzenspies writes (in email to ghc-users): I was playing around with GADT-records again and ran into behaviour that I'm not sure is intentional. Given this program: {{{ {-#LANGUAGE GADTs #-} data FooBar x a where Foo :: { fooBar :: a } -> FooBar Char a Bar :: { fooBar :: a } -> FooBar Bool a }}} GHC tells me this: {{{ foo.hs:3:1: Constructors Foo and Bar have a common field `fooBar', but have different result types In the data declaration for `FooBar' Failed, modules loaded: none. }}} The user guide does say (section 7.4.7): "However, for GADTs there is the following additional constraint: every constructor that has a field f must have the same result type (modulo alpha conversion)." So this behaviour is documented in the user guide. However, it seems reasonable that in the case above, where all the relevant variables are exposed in the result type of both constructors, this should be perfectly typeable. In other words, shouldn't GHC be able to derive a type that is simply: {{{ fooBar :: FooBar x a -> a }}} ? Is this something that was simply never implemented, but could be, or is this not decidable or prohibitively computationally complex? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8673> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8121: Gitolite Migration
by GHC 28 Apr '14

28 Apr '14

#8121: Gitolite Migration ------------------------------------+------------------------------------- Reporter: hvr | Owner: hvr Type: task | Status: new Priority: normal | Milestone: Component: None | Version: Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- This ticket is for keeping track of the implementation of the [GitolitePlan Gitolite Migration Plan] See also the posting [http://permalink.gmane.org/gmane.comp.lang.haskell.ghc.devel/1618 "Proposal: Gitolite for repository management"] to ghc-devs(a)haskell.org -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8121> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8498: gcc hardcoded in build scripts! (ignores the --with-gcc= flag in configure)
by GHC 28 Apr '14

28 Apr '14

#8498: gcc hardcoded in build scripts! (ignores the --with-gcc= flag in configure) ------------------------------------+--------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.7 Keywords: | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+--------------------------------- NB: this may be a dupe of another issue, but reporting is separately for now i'm on OS X 10.8 (mountain lion) with xcode 5, ghc comit 23fb7f3b7987d7b3fa445e54680a8a00a37e714d, I've got a gcc-4.8 installed, though gcc in my path is actually clang (as is typical for xcode 5), so I configured as {{{ ./configure --with-gcc=gcc-4.8 }}} and then I noticed as i'm building, some warnings that mean clang is being called rather than gcc! heres a relevant snippet of the build transcript {{{ cp" utils/hsc2hs/template-hsc.h inplace/lib/template-hsc.h "/usr/bin/ghc" -hisuf hi -osuf o -hcsuf hc -static -H64m -O -fasm -package process -package containers -package-db libraries/bootstrapping.conf -i -iutils/deriveConstants/. -iutils/deriveConstants/dist/build -iutils/deriveConstants/dist/build/autogen -Iutils/deriveConstants/dist/build -Iutils/deriveConstants/dist/build/autogen -no-user-package-db -rtsopts -odir utils/deriveConstants/dist/build -hidir utils/deriveConstants/dist/build -stubdir utils/deriveConstants/dist/build -c utils/deriveConstants/./DeriveConstants.hs -o utils/deriveConstants/dist/build/DeriveConstants.o "inplace/bin/mkdirhier" utils/deriveConstants/dist/build/tmp//. "inplace/bin/mkdirhier" rts/dist/build//. gcc -E -m64 -undef -traditional -P -Iincludes -Iincludes/dist -Iincludes /dist-derivedconstants/header -Iincludes/dist-ghcconstants/header -Icompiler/stage1 -x c compiler/prelude/primops.txt.pp | grep -v '^#pragma GCC' > compiler/stage1/build/primops.txt compiler/prelude/primops.txt.pp:35:55: warning: missing terminating ' character [-Winvalid-pp-token] -- The default attribute values which apply if you don't specify ^ compiler/prelude/primops.txt.pp:1310:19: warning: missing terminating ' character [-Winvalid-pp-token] difference doesn't fit in an {\tt Int\#}.} ^ compiler/prelude/primops.txt.pp:1591:41: warning: missing terminating ' character [-Winvalid-pp-token] -- not really the right type, but we don't know about pairs here. The ^ compiler/prelude/primops.txt.pp:1620:15: warning: missing terminating ' character [-Winvalid-pp-token] -- but we don't want to tell the strictness ^ compiler/prelude/primops.txt.pp:1634:30: warning: missing terminating ' character [-Winvalid-pp-token] -- must be *precise* - we don't want the strictness analyser turning ^ compiler/prelude/primops.txt.pp:1690:14: warning: missing terminating ' character [-Winvalid-pp-token] -- NB: retry#'s strictness information specifies it to return bottom. ^ compiler/prelude/primops.txt.pp:1811:47: warning: missing terminating ' character [-Winvalid-pp-token] Otherwise, store value arg as {\tt MVar\#}'s new contents, and return with integer 1.} ^ compiler/prelude/primops.txt.pp:1906:21: warning: missing terminating ' character [-Winvalid-pp-token] {\tt RealWorld}; it's only used in the type system, to parameterise {\tt State\#}. } ^ compiler/prelude/primops.txt.pp:2084:67: warning: missing terminating ' character [-Winvalid-pp-token] -- why return the value? So that we can control sharing of seq'd ^ compiler/prelude/primops.txt.pp:2087:13: warning: missing terminating ' character [-Winvalid-pp-token] -- we don't want to inline x, so better to represent it as ^ compiler/prelude/primops.txt.pp:2108:48: warning: missing terminating ' character [-Winvalid-pp-token] -- `the processor containing the expression v'; it is not evaluated ^ compiler/prelude/primops.txt.pp:2206:20: warning: missing terminating ' character [-Winvalid-pp-token] {These aren't nearly as wired in as Etc...} ^ compiler/prelude/primops.txt.pp:2236:57: warning: missing terminating ' character [-Winvalid-pp-token] * It does not claim to be a {\it data} type, and that's important for ^ compiler/prelude/primops.txt.pp:2240:4: warning: missing terminating ' character [-Winvalid-pp-token] It's also used to instantiate un-constrained type variables after type ^ compiler/prelude/primops.txt.pp:2278:86: warning: missing terminating ' character [-Winvalid-pp-token] used when you want to write a program that you know is well-typed, but where Haskell's ^ compiler/prelude/primops.txt.pp:2301:28: warning: missing terminating ' character [-Winvalid-pp-token] have to do with GHC's internal representation details (for the congnoscenti, data values ^ compiler/prelude/primops.txt.pp:2307:76: warning: missing terminating ' character [-Winvalid-pp-token] -- NB. It is tempting to think that casting a value to a type that it doesn't have is safe ^ compiler/prelude/primops.txt.pp:2308:22: warning: missing terminating ' character [-Winvalid-pp-token] -- as long as you don't "do anything" with the value in its cast form, such as seq on it. This ^ compiler/prelude/primops.txt.pp:2309:7: warning: missing terminating ' character [-Winvalid-pp-token] -- isn't the case: the compiler can insert seqs itself, and if these happen at the wrong type, ^ compiler/prelude/primops.txt.pp:2344:17: warning: missing terminating ' character [-Winvalid-pp-token] the newtype's concrete type to the abstract type. But it also works in ^ compiler/prelude/primops.txt.pp:2367:67: warning: missing terminating ' character [-Winvalid-pp-token] {\tt instance Coercible b b' => Coercible (D a b c) (D a b' c')} ^ compiler/prelude/primops.txt.pp:2389:43: warning: missing terminating ' character [-Winvalid-pp-token] you need to set the role of {\tt Set}'s type parameter to Nominal. }}} notice the hard coded gcc call {{{ gcc -E -m64 -undef -traditional -P -Iincludes -Iincludes/dist -Iincludes/dist-derivedconstants/header -Iincludes/dist- ghcconstants/header -Icompiler/stage1 -x c compiler/prelude/primops.txt.pp | grep -v '^#pragma GCC' > compiler/stage1/build/primops.txt }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8498> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8303: defer StackOverflow exceptions (rather than dropping them) when exceptions are masked
by GHC 28 Apr '14

28 Apr '14

#8303: defer StackOverflow exceptions (rather than dropping them) when exceptions are masked ------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Runtime 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: | ------------------------------------+------------------------------------- See http://www.reddit.com/r/haskell/comments/1luan1/strange_io_sequence_behavio… for a very simple program (`main'`) that accidentally evades the stack size limit, running to completion even though it has allocated hundreds of megabytes of stack chunks, and [http://www.reddit.com/r/haskell/comments/1luan1/strange_io_sequence_behavio… my comment] for an explanation of this behavior. ryani suggested that when a thread exceeds its stack limit but it is currently blocking exceptions, the RTS shouldn't simply drop the `StackOverflow` exception, but rather deliver it when the `mask` operation completes. That sounds sensible to me and it would give a nice guarantee that when any individual `mask` operation uses a small amount of stack, the stack size limit is approximately enforced. (I know that the default stack size limit may go away or essentially go away, but it can still be nice when developing to use a small stack size limit, so that one's system isn't run into the ground by infinite recursion quickly gobbling up tons of memory.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8303> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8676: RTS headers don't compile as C++
by GHC 28 Apr '14

28 Apr '14

#8676: RTS headers don't compile as C++ ----------------------------------+---------------------------------------- Reporter: blitzcode | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Runtime System | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Building GHC failed Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | ----------------------------------+---------------------------------------- GHC's RTS headers can't be included from C++, as they contain constructs like this {{{ dbl_link_replace(bdescr *new, bdescr *old, bdescr **list) }}} (notice the 'new'). This is the case for the headers shipped with 7.6.3 and still seems to be in the HEAD version. Since the code has the usual {{{ #ifdef __cplusplus extern "C" { #endif }}} all over the place, I assume the C++ incompatibility is simply an oversight? In any case, it would seem highly unusual to have a C interface that can't be consumed from C++. It seems all the incompatibilities could be removed with at worst a small amount of inconvenience, and automatic checking for C++ compatibility on each build could be added. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8676> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8366: haskeline Posix backend needs #include <sys/termios.h> on Solaris
by GHC 28 Apr '14

28 Apr '14

#8366: haskeline Posix backend needs #include <sys/termios.h> on Solaris -------------------------------------+------------------------------------- Reporter: oddsignals | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: libraries (other) | Version: 7.7 Keywords: | Operating System: Solaris Architecture: Unknown/Multiple | Type of failure: Building GHC Difficulty: Easy (less than 1 | failed hour) | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- !System/Console/Haskeline/Backend/Posix.hsc needs an #include <sys/termios.h> to compile under Solaris. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8366> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8641: ghc with -odir and -prof cannot create the specified output directory
by GHC 22 Apr '14

22 Apr '14

#8641: ghc with -odir and -prof cannot create the specified output directory -----------------------------------+--------------------------------------- Reporter: wmarshall | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time crash Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- Calling ghc with -odir set to a non-existent directory causes ghc to create the directory. However, if the -prof option is also specified, ghc fails to create the directory and quits with an error. Steps to reproduce: {{{ $ echo 'main = print "Hello world"' > Main.hs $ ghc Main.hs -odir bin [1 of 1] Compiling Main ( Main.hs, bin\Main.o ) Linking Main.exe ... $ rm -Rvf bin removed `bin/Main.o' removed directory: `bin' $ ghc Main.hs -odir bin -prof [1 of 1] Compiling Main ( Main.hs, bin\Main.o ) C:/Program Files (x86)/Haskell Platform/2013.2.0.0/mingw/bin/ld.exe: cannot open output file bin\Main.o: No such file or directory collect2: ld returned 1 exit status }}} Expected result: The output directory is created regardless of whether -prof is specified. The above commands were executed from within Cygwin, but the error occurs in the Windows command shell as well. (I used Cygwin here because it is easier to give precise instructions to reproduce the error.) I have only tested this on Windows. I do not know if the issue exists on Linux or other platforms. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8641> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8458: T5435_dyn_asm fails on x86_64 Linux
by GHC 22 Apr '14

22 Apr '14

#8458: T5435_dyn_asm fails on x86_64 Linux --------------------------+------------------------------------------------ Reporter: | Owner: simonmar jstolarek | Status: new Type: bug | Milestone: Priority: normal | Version: 7.7 Component: | Operating System: Linux Runtime System | Type of failure: Incorrect result at runtime Keywords: | Test Case: Architecture: x86_64 | Blocking: (amd64) | Difficulty: | Unknown | Blocked By: | Related Tickets: | --------------------------+------------------------------------------------ I keep getting failure from `T5435_dyn_asm` test: {{{ make WAY=normal TEST=T5435_dyn_asm =====> T5435_dyn_asm(normal) 2622 of 3829 [0, 0, 0] cd ./rts && $MAKE -s --no-print-directory T5435_dyn_asm </dev/null >T5435_dyn_asm.run.stdout 2>T5435_dyn_asm.run.stderr Actual stdout output differs from expected: --- ./rts/T5435_dyn_asm.stdout 2013-10-16 09:49:22.236712001 +0200 +++ ./rts/T5435_dyn_asm.run.stdout 2013-10-18 19:26:11.076223002 +0200 @@ -1,5 +1,5 @@ -initArray1 -initArray2 ctors1 ctors2 +initArray1 +initArray2 success *** unexpected failure for T5435_dyn_asm(normal) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8458> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8141: Liberalising IncoherentInstances
by GHC 21 Apr '14

21 Apr '14

#8141: Liberalising IncoherentInstances ------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | 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: | ------------------------------------+------------------------------------- As [http://www.haskell.org/pipermail/glasgow-haskell- users/2013-July/022651.html|SPJ argued], -XIncoherentInstances could be even more liberal. This ticket is to give the proposal a number; I am currently preparing a patch for this. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8141> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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