February 2018 - ghc-tickets

[GHC] #13892: Add some benchmarks to nofib from Andras Kovac's Eff benchmarks
by GHC 19 Mar '18

19 Mar '18

#13892: Add some benchmarks to nofib from Andras Kovac's Eff benchmarks -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Andras has a bunch of different benchmarks for different effect handler code which stresses the optimiser in interesting ways. It would be good to add some of these benchmarks to nofib as they are likely quite different from a lot of the examples already in there. https://github.com/AndrasKovacs/misc-stuff/tree/master/haskell/Eff -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13892> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12193: Include target versions of unlit and hsc2hs when cross-compiling
by GHC 19 Mar '18

19 Mar '18

#12193: Include target versions of unlit and hsc2hs when cross-compiling -------------------------------------+------------------------------------- Reporter: glaubitz | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Hello! I have been working on getting ghc packaged on Debian for m68k and sh4. While ghc itself works without any major issues on these targets, the performance is a bit too low to just build ghc from sources on the machines itself. It works, but it may take up to three weeks or more. To workaround this problem, I am using a cross-compiled version of ghc on these platforms which works quite well. However, while using the cross- compiled Debian ghc packaged, I noticed that some packages fail to build from source because my cross-compiled version of ghc is missing the "unlit" utility. Looking at the result of the cross-compiled ghc for m68k, it's obvious why unlit is missing: {{{ glaubitz@ikarus:~/debian/ghc/ghc-8.0.1$ file ./inplace/lib/bin/* ./inplace/lib/bin/ghc-iserv: ELF 32-bit MSB executable, Motorola m68k, 68020, version 1 (SYSV), dynamically linked, interpreter /lib/ld.so.1, for GNU/Linux 3.2.0, BuildID[sha1]=39f595d60d0c596714aa0fedcc0bfa3a35921c41, not stripped ./inplace/lib/bin/ghc-iserv-prof: ELF 32-bit MSB executable, Motorola m68k, 68020, version 1 (SYSV), dynamically linked, interpreter /lib/ld.so.1, for GNU/Linux 3.2.0, BuildID[sha1]=f83f10fc7d925f54fb18816384ae91ae6c1b9ac8, not stripped ./inplace/lib/bin/ghc-pkg: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld- linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=41d534ca0e83df11274eade67477db1e9667fec5, not stripped ./inplace/lib/bin/ghc-stage1: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld- linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=089a2121e49e16ea7ba721c350b04a965b19dded, not stripped ./inplace/lib/bin/ghc-stage2: ELF 32-bit MSB executable, Motorola m68k, 68020, version 1 (SYSV), dynamically linked, interpreter /lib/ld.so.1, for GNU/Linux 3.2.0, BuildID[sha1]=589cdca9242bd132e1c80736a79ebf4209eb1c78, not stripped ./inplace/lib/bin/hpc: ELF 32-bit MSB executable, Motorola m68k, 68020, version 1 (SYSV), dynamically linked, interpreter /lib/ld.so.1, for GNU/Linux 3.2.0, BuildID[sha1]=f401ba499a4cf865def36a7dc6d7c3a32385c85f, not stripped ./inplace/lib/bin/hsc2hs: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld- linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=a532a7cc6f0c1e95e7c66aab2b4c53e1d0b58d88, not stripped ./inplace/lib/bin/unlit: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld- linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=30ab37170ddcb09bcb7885ae3c18a353f6d128b7, not stripped glaubitz@ikarus:~/debian/ghc/ghc-8.0.1$ }}} Thus, both "unlit" and "hsc2hs" are not built for the target architecture when cross-compiling. After a quick look at utils/unlit/ghc.mk, it becomes obvious why that's the case: {{{ $(eval $(call build-prog,utils/unlit,dist,0)) }}} Would it be possible to change the build configuration such that "unlit" and "hsc2hs" are built for the target as well when cross-compiling? That would be great :). Adrian [1] [https://buildd.debian.org/status/fetch.php?pkg=haskell- fmlist&arch=m68k&ver=0.9-4&stamp=1465990971] -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12193> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14282: tagToEnum# . dataToTag# not optimized away
by GHC 19 Mar '18

19 Mar '18

#14282: tagToEnum# . dataToTag# not optimized away -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 Keywords: datacon-tags | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Consider {{{#!hs foo :: Int# -> Int# foo x = dataToTag# (tagToEnum# x :: Bool) bar :: Bool -> Bool bar x = tagToEnum# (dataToTag# x) }}} These are both effectively identity functions. But while `foo` simplifies to one, `bar` does not! We might want to fix that. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14282> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14501: hp2ps and unlit are compiled by the stage0 compiler
by GHC 19 Mar '18

19 Mar '18

#14501: hp2ps and unlit are compiled by the stage0 compiler -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.1 Component: Build System | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- In looking at #14057 I noticed that the hp2ps and unlit binaries that we install are both produced by the stage0 compiler. This will almost certainly break during cross-compilation and it generally breaks release hygiene. We should fix this in Hadrian (assuming angerman hasn't fixed it already). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14501> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12038: Shutdown interacts badly with requestSync()
by GHC 19 Mar '18

19 Mar '18

#12038: Shutdown interacts badly with requestSync() -------------------------------------+------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Runtime | Version: 7.10.3 System | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12038> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12715: T3994 is intermittently broken on Windows
by GHC 19 Mar '18

19 Mar '18

#12715: T3994 is intermittently broken on Windows --------------------------------------+--------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Test Suite | Version: 8.1 Keywords: | Operating System: Windows Architecture: x86_64 (amd64) | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------------+--------------------------------- The `T3994` testcase sometimes appears to crash on Windows, {{{ +++ ../../libraries/process/tests/T3994.run/T3994.run.stderr.normalised 2016-10-16 03:11:54.601205700 +0000 @@ -0,0 +1,2 @@ + 1521 [main] sh 5272 child_copy: cygheap read copy failed, 0x1802FE408..0x180307A08, done 0, windows pid 5272, Win32 error 299 + 7952 [main] sh 5272 C:/msys64/usr/bin/sh: *** fatal error in forked process - ccalloc would have returned NULL }}} This very well may be an msys issue. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12715> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12737: T12227 is failing on ghc-8.0
by GHC 19 Mar '18

19 Mar '18

#12737: T12227 is failing on ghc-8.0 -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: Visual | Version: 8.0.1 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Runtime Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Fresh validate from 5eab189b329344630f76b8751c1289ce480ca46b on x86_64 Linux: {{{ =====> T12227(normal) 1 of 1 [0, 0, 0] cd ./perf/compiler && "/home/hs01/ezyang/ghc-validate/inplace/test spaces/ghc-stage2" -c T12227.hs -fforce-recomp -dno-debug-output -fshow- warning-groups -no-user-package-db -rtsopts -fno-warn-tabs -fno-warn- missed-specialisations -fno-ghci-history -O2 -ddump-hi -ddump-to-file +RTS -M1G +RTS -V0 -tT12227.comp.stats --machine-readable -RTS > T12227.comp.stderr 2>&1 bytes allocated value is too high: Expected T12227(normal) bytes allocated: 1822822016 +/-5% Lower bound T12227(normal) bytes allocated: 1731680915 Upper bound T12227(normal) bytes allocated: 1913963117 Actual T12227(normal) bytes allocated: 9256914200 Deviation T12227(normal) bytes allocated: 407.8 % *** unexpected stat test failure for T12227(normal) }}} That's a pretty awful regression, if it is real. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12737> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal
by GHC 19 Mar '18

19 Mar '18

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: #14236 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- When doing a default build of GHC HEAD (i.e. without `mk/build.mk`), GHC panics: {{{ $ make V=0 ===--- building phase 0 make --no-print-directory -f ghc.mk phase=0 phase_0_builds make[1]: Nothing to be done for 'phase_0_builds'. ===--- building phase 1 make --no-print-directory -f ghc.mk phase=1 phase_1_builds make[1]: Nothing to be done for 'phase_1_builds'. ===--- building final phase make --no-print-directory -f ghc.mk phase=final all HC [stage 1] libraries/base/dist-install/build/Data/Typeable/Internal.o ghc-stage1: panic! (the 'impossible' happened) (GHC version 8.3.20170922 for x86_64-unknown-linux): Template variable unbound in rewrite rule Variable: cobox_a3S9 Rule "SC:mkTrApp0" Rule bndrs: [k1_X4g7, b_X4gb, k1_a3RW, a_a3RX, k1_X426, b_X42a, b_a3RY, sc_s7Yv, sc_s7Yr, sc_s7Ys, sc_s7Yt, cobox_a3S9, cobox_a3RZ, cobox_X42x, cobox_a3S8] LHS args: [TYPE: TYPE (b_a3RY |> Nth:2 (Sym cobox_a3S8)), TYPE: TYPE (b_X42a |> Nth:2 (Sym cobox_X42x)) -> *, TYPE: (->), TYPE: (b_X4gb |> Sym (cobox_a3S9 (Coh (Sym (Coh <b_a3RY>_N (Nth:2 (Sym cobox_a3S8)))) (Nth:2 (Sym cobox_a3S8)) ; Coh <b_a3RY>_N (Nth:2 (Sym cobox_a3S8))) ; Sym cobox_a3RZ)), TrTyCon @ (TYPE (b_a3RY |> Nth:2 (Sym cobox_a3S8)) -> TYPE (b_X42a |> Nth:2 (Sym cobox_X42x)) -> *) @ (->) sc_s7Yr sc_s7Ys $tc(->) sc_s7Yt, sc_s7Yv] Actual args: [TYPE: TYPE (b_a3RY |> Nth:2 (Sym cobox_a3S8)), TYPE: TYPE (b_X42a |> Nth:2 (Sym cobox_X42x)) -> *, TYPE: (->), TYPE: (b_X4gb |> Sym (cobox_a3S9 (Coh (Sym (Coh <b_a3RY>_N (Nth:2 (Sym cobox_a3S8)))) (Nth:2 (Sym cobox_a3S8)) ; Coh <b_a3RY>_N (Nth:2 (Sym cobox_a3S8))) ; Sym cobox_a3RZ)), TrTyCon @ (TYPE (b_a3RY |> Nth:2 (Sym cobox_a3S8)) -> TYPE (b_X42a |> Nth:2 (Sym cobox_X42x)) -> *) @ (->) dt_a2Vb dt_a2Vc $tc(->) kind_vars_X37r, ... }}} You can see a more complete error in the build log at https://launchpadlibrarian.net/337888338/buildlog_ubuntu-trusty-amd64 .ghc-head_8.3.20170922+git.0.5a8b843-7~14.04_BUILDING.txt.gz This panic seems to be causally connected to cc6be3a2f23c9b2e04f9f491099149e1e1d4d20b (which addressed #14236) because reverting that commit allows me to avoid the panic. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14270> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12619: Allow users guide to be built independently from GHC
by GHC 19 Mar '18

19 Mar '18

#12619: Allow users guide to be built independently from GHC -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- At HIW 2016 it was suggested that this would greatly reduce the friction to contributing users guide fixes. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12619> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12389: Limit duplicate export warnings for datatypes
by GHC 19 Mar '18

19 Mar '18

#12389: Limit duplicate export warnings for datatypes -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: feature | Status: new request | Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 7.10.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect Unknown/Multiple | warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: #11959 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- `containers` sometimes exports data constructors/patterns conditionally (depending on GHC version and whether `TESTING` is defined). Presently, to avoid a duplicate export warning, it's necessary to write a separate export line for each combination of exported constructors, which is horrible: {{{#!hs module Foo ( #ifdef TESTING #ifdef USE_PATTERN_SYNONYMS Foo (Foo, Pat1, Pat2) #else Foo (Foo) #endif #elif USE_PATTERN_SYNONYMS Foo (Pat1, Pat2) #else Foo #endif }}} or to break up the lines with CPP, which is so horrible I can't even bring myself to write it. I'd much rather be able to write {{{#!hs module Foo ( Foo #ifdef TESTING ,Foo(Foo) #endif #ifdef USE_PATTERN_SYNONYMS ,Foo(Pat1, Pat2) #endif ) }}} The trouble here is that GHC warns about duplicate export of the type `Foo`. I think there's a pretty simple partial solution: only warn about a type export that is *completely* redundant, adding neither type constructor nor pattern. And offer a way to turn off the redundant export warning entirely for types and classes without turning it off for bindings. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12389> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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