July 2015 - ghc-tickets

[GHC] #10009: type inference regression when faking injective type families
by GHC 13 Jul '15

13 Jul '15

#10009: type inference regression when faking injective type families -------------------------------------+------------------------------------- Reporter: aavogt | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- ghc-7.10.0.20141222 does not accept the program unless I uncomment the type signature (a :: a). ghc-7.8 accepts it as-is. {{{#!hs {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE TypeFamilies #-} class (UnF (F a) ~ a, Show a) => C a where type F a f :: F a -> a type family UnF a g :: forall a. C a => a -> String g _ = show a where a = f (undefined :: F a) -- :: a }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10009> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10463: Wrong warning with PartialTypeSignatures
by GHC 13 Jul '15

13 Jul '15

#10463: Wrong warning with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: augustss | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- This program {{{#!hs {-# LANGUAGE ScopedTypeVariables, PartialTypeSignatures #-} f (x :: _) = x ++ "" }}} gives this warning {{{ Bug.hs:2:9: Warning: Found hole ‘_’ with type: [Char] Relevant bindings include f :: [Char] -> [Char] (bound at Bug.hs:2:1) In a pattern type signature: _ In the pattern: x :: _ In an equation for ‘f’: f (x :: _) = x ++ "" }}} But there is no hole, only an _ in a type. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10463> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10628: clang's cpp causes incorrect line numbers in type errors
by GHC 10 Jul '15

10 Jul '15

#10628: clang's cpp causes incorrect line numbers in type errors -------------------------------------+------------------------------------- Reporter: gridaphobe | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Keywords: | Operating System: MacOS X Architecture: | Type of failure: Incorrect Unknown/Multiple | warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- If I run GHC on {{{ {-# LANGUAGE CPP #-} module Foo where foo :: String foo = True }}} I get an error {{{ Foo.hs:7:7: Couldn't match type ‘Bool’ with ‘[Char]’ Expected type: String Actual type: Bool In the expression: True In an equation for ‘foo’: foo = True }}} but the type error is on line 6, not line 7. It seems to have something to do with the fact that line 2 starts with a `#` since the error is reported correctly if I make the language pragma a single line. GHC on linux reports the correct location, as does GHC on OS X if I use any other language pragma, so I'm pretty sure this is another instance of clang's `cpp` causing problems for us. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10628> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8709: `make 1` does not work (well)
by GHC 10 Jul '15

10 Jul '15

#8709: `make 1` does not work (well) ------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Build System | 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: | ------------------------------------+------------------------------------- Say I do a `sync-all pull` and then fix a bunch of merge errors. The changes mean that I need to recompile the stage-1 compiler. So, I dutifully `make distclean` and start rebuilding. I then find a bunch of compiler errors in my edited code. Now, I'd like to start the fix error/recompile loop. BUT, when I do `make 1` in the `compiler/` directory, I get errors: {{{ rae:13:49:29 ~/Documents/ghc/compiler> make 1 make -C .. stage=1 all_ghc_stage1 compiler_dist_NO_BUILD_DEPS=YES compiler_dist-boot_NO_BUILD_DEPS=YES compiler_dist- install_NO_BUILD_DEPS=YES NO_GENERATED_MAKEFILE_RULES=YES OMIT_PHASE_0=YES OMIT_PHASE_1=YES compiler_stage1_NO_BUILD_DEPS=YES compiler_stage2_NO_BUILD_DEPS=YES compiler_stage3_NO_BUILD_DEPS=YES ghc_stage1_NO_BUILD_DEPS=YES ghc_stage2_NO_BUILD_DEPS=YES ghc_stage3_NO_BUILD_DEPS=YES ONLY_DEPS_FOR="compiler_stage1 ghc_stage1" ===--- building final phase make -r --no-print-directory -f ghc.mk phase=final all_ghc_stage1 libraries/old-time/ghc.mk:5: libraries/old-time/dist-install/package- data.mk: No such file or directory libraries/haskell98/ghc.mk:5: libraries/haskell98/dist-install/package- data.mk: No such file or directory libraries/haskell2010/ghc.mk:5: libraries/haskell2010/dist-install /package-data.mk: No such file or directory libraries/random/ghc.mk:5: libraries/random/dist-install/package-data.mk: No such file or directory libraries/primitive/ghc.mk:5: libraries/primitive/dist-install/package- data.mk: No such file or directory libraries/vector/ghc.mk:5: libraries/vector/dist-install/package-data.mk: No such file or directory libraries/dph/dph-base/ghc.mk:5: libraries/dph/dph-base/dist-install /package-data.mk: No such file or directory libraries/dph/dph-prim-interface/ghc.mk:5: libraries/dph/dph-prim- interface/dist-install/package-data.mk: No such file or directory libraries/dph/dph-prim-seq/ghc.mk:5: libraries/dph/dph-prim-seq/dist- install/package-data.mk: No such file or directory libraries/dph/dph-prim-par/ghc.mk:5: libraries/dph/dph-prim-par/dist- install/package-data.mk: No such file or directory libraries/dph/dph-lifted-base/ghc.mk:5: libraries/dph/dph-lifted-base /dist-install/package-data.mk: No such file or directory libraries/dph/dph-lifted-boxed/ghc.mk:5: libraries/dph/dph-lifted-boxed /dist-install/package-data.mk: No such file or directory libraries/dph/dph-lifted-copy/ghc.mk:5: libraries/dph/dph-lifted-copy /dist-install/package-data.mk: No such file or directory libraries/dph/dph-lifted-vseg/ghc.mk:5: libraries/dph/dph-lifted-vseg /dist-install/package-data.mk: No such file or directory libraries/ghc-prim/ghc.mk:4: libraries/ghc-prim/dist-install/package- data.mk: No such file or directory libraries/integer-gmp/ghc.mk:4: libraries/integer-gmp/dist-install /package-data.mk: No such file or directory libraries/base/ghc.mk:4: libraries/base/dist-install/package-data.mk: No such file or directory libraries/filepath/ghc.mk:4: libraries/filepath/dist-install/package- data.mk: No such file or directory libraries/array/ghc.mk:4: libraries/array/dist-install/package-data.mk: No such file or directory libraries/deepseq/ghc.mk:4: libraries/deepseq/dist-install/package- data.mk: No such file or directory libraries/bytestring/ghc.mk:4: libraries/bytestring/dist-install/package- data.mk: No such file or directory libraries/containers/ghc.mk:4: libraries/containers/dist-install/package- data.mk: No such file or directory libraries/old-locale/ghc.mk:4: libraries/old-locale/dist-install/package- data.mk: No such file or directory libraries/time/ghc.mk:4: libraries/time/dist-install/package-data.mk: No such file or directory libraries/unix/ghc.mk:4: libraries/unix/dist-install/package-data.mk: No such file or directory libraries/directory/ghc.mk:4: libraries/directory/dist-install/package- data.mk: No such file or directory libraries/process/ghc.mk:4: libraries/process/dist-install/package- data.mk: No such file or directory libraries/hpc/ghc.mk:4: libraries/hpc/dist-install/package-data.mk: No such file or directory libraries/pretty/ghc.mk:4: libraries/pretty/dist-install/package-data.mk: No such file or directory libraries/template-haskell/ghc.mk:4: libraries/template-haskell/dist- install/package-data.mk: No such file or directory libraries/Cabal/Cabal/ghc.mk:4: libraries/Cabal/Cabal/dist-install /package-data.mk: No such file or directory libraries/binary/ghc.mk:4: libraries/binary/dist-install/package-data.mk: No such file or directory libraries/bin-package-db/ghc.mk:4: libraries/bin-package-db/dist-install /package-data.mk: No such file or directory libraries/hoopl/ghc.mk:4: libraries/hoopl/dist-install/package-data.mk: No such file or directory libraries/transformers/ghc.mk:4: libraries/transformers/dist-install /package-data.mk: No such file or directory libraries/xhtml/ghc.mk:4: libraries/xhtml/dist-install/package-data.mk: No such file or directory libraries/terminfo/ghc.mk:4: libraries/terminfo/dist-install/package- data.mk: No such file or directory libraries/haskeline/ghc.mk:4: libraries/haskeline/dist-install/package- data.mk: No such file or directory libraries/integer-gmp/gmp/ghc.mk:49: libraries/integer-gmp/gmp/config.mk: No such file or directory utils/hsc2hs/ghc.mk:16: utils/hsc2hs/dist-install/package-data.mk: No such file or directory utils/ghc-pkg/ghc.mk:66: utils/ghc-pkg/dist-install/package-data.mk: No such file or directory utils/dll-split/ghc.mk:18: utils/dll-split/dist-install/package-data.mk: No such file or directory utils/ghc-pwd/ghc.mk:8: utils/ghc-pwd/dist-install/package-data.mk: No such file or directory utils/ghc-cabal/ghc.mk:67: utils/ghc-cabal/dist-install/package-data.mk: No such file or directory utils/hpc/ghc.mk:18: utils/hpc/dist-install/package-data.mk: No such file or directory utils/runghc/ghc.mk:28: utils/runghc/dist-install/package-data.mk: No such file or directory utils/mkUserGuidePart/ghc.mk:18: utils/mkUserGuidePart/dist/package- data.mk: No such file or directory utils/compare_sizes/ghc.mk:8: utils/compare_sizes/dist-install/package- data.mk: No such file or directory make[2]: *** No rule to make target `libraries/integer-gmp/gmp/config.mk'. Stop. make[1]: *** [all_ghc_stage1] Error 2 make: *** [1] Error 2 }}} Using `make stage=1` works fine, but computing the dependencies each time is annoying. In past experience, I've seen that, once the stage-1 compiler builds to completion at least once, `make 1` works just fine -- it just fails after a `clean`. I don't recall having this problem with `make 2`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8709> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7810: make show VALUE=VAR depends on ghc-stage1
by GHC 10 Jul '15

10 Jul '15

#7810: make show VALUE=VAR depends on ghc-stage1 -------------------------------------+------------------------------------- Reporter: kgardas | Owner: thomie Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Build System | Version: 7.7 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: Phab:D1064 -------------------------------------+------------------------------------- Changes (by thomie): * owner: thoughtpolice => thomie * differential: => Phab:D1064 Comment: I have a patch that adds a `make show!` command. From the commit message: A normal `make show` starts a build of the ghc-stage1 compiler, to create package-data.mk files. This version doesn't read those, so it will work right after ./configure. Does that sound reasonable to add? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7810#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7695: Hang when locale-archive and gconv-modules are not there
by GHC 10 Jul '15

10 Jul '15

#7695: Hang when locale-archive and gconv-modules are not there -------------------------------------+------------------------------------- Reporter: hpd | Owner: Type: bug | Status: closed Priority: highest | Milestone: 7.10.2 Component: None | Version: 7.8.1 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime crash | Unknown/Multiple Blocked By: | Test Case: Related Tickets: #8977, #10298 | Blocking: | Differential Revisions: Phab:D898 -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"d69dfba4e27c4ec33459906fd87c9a56a371f510/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="d69dfba4e27c4ec33459906fd87c9a56a371f510" Fix self-contained handling of ASCII encoding D898 was primarily intended to fix hangs in the event that iconv was unavailable (namely #10298 and #7695). In addition to this fix, it also introduced self-contained handling of ANSI terminals to allow compiled executables to run in minimal environments lacking iconv. However, the behavior that the patch introduced is highly suspicious. Specifically, it gives the user a UTF-8 encoding even if they requested ASCII. This has the potential to break quite a lot of code. At very least it breaks GHC's Unicode terminal detection logic, which attempts to catch an invalid character when encoding a pair of smart-quotes. Of course, this exception will never be thrown if a UTF-8 encoder is used. Here we use the `char8` encoding to handle requests for ASCII encodings in the event that we find iconv to be non-functional. Fixes #10623. Test Plan: Validate with T8959a Reviewers: rwbarton, hvr, austin, hsyl20 Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1059 GHC Trac Issues: #10623 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7695#comment:23> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10298: Infinite loop when shared libraries are unavailable
by GHC 10 Jul '15

10 Jul '15

#10298: Infinite loop when shared libraries are unavailable -------------------------------------+------------------------------------- Reporter: snoyberg | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime | Version: 7.10.1 System | Operating System: Linux Keywords: | Type of failure: Runtime crash Architecture: x86_64 | Blocked By: (amd64) | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Originally discussed at: https://groups.google.com/d/msg/haskell- cafe/5ZTv5mCG_HI/hBJ-VkdpxdoJ. Note that this was originally discussed as a static linking and Docker issue, but in fact affects dynamically linked executables without any containerization. I've put together the following script that reproduces my problem: {{{ cat > hello.hs <<EOF main :: IO () main = putStrLn "Hello World" EOF ghc hello.hs rm -rf tmp mkdir tmp cp hello tmp mkdir -p tmp/usr/lib/x86_64-linux-gnu cp /usr/lib/x86_64-linux-gnu/libgmp.so.10 tmp/usr/lib/x86_64-linux-gnu mkdir -p tmp/lib/x86_64-linux-gnu cp \ /lib/x86_64-linux-gnu/libm.so.6 \ /lib/x86_64-linux-gnu/librt.so.1 \ /lib/x86_64-linux-gnu/libdl.so.2 \ /lib/x86_64-linux-gnu/libc.so.6 \ /lib/x86_64-linux-gnu/libpthread.so.0 \ tmp/lib/x86_64-linux-gnu mkdir -p tmp/lib64 cp /lib64/ld-linux-x86-64.so.2 tmp/lib64 #mkdir -p tmp/usr/lib/x86_64-linux-gnu/gconv/ #cp \ # /usr/lib/x86_64-linux-gnu/gconv/UTF-32.so \ # /usr/lib/x86_64-linux-gnu/gconv/gconv-modules \ # tmp/usr/lib/x86_64-linux-gnu/gconv sudo chroot tmp /hello }}} If I uncomment the block that copies the gconv files, the program runs as expected. However, without those files copied, the program burns CPU and consumes memory until killed by the OS. I ran strace on a similar executable, and got the results at: https://gist.github.com/snoyberg/095efb17e36acc1d6360 Note that this problem also occurs with statically linked executables when some of the other dynamically linked libraries are not available in the chroot environment. Expected behavior: ideal would be not to require the gconv files and other shared libraries be present, especially when statically linked. Barring that, it would be much better if the RTS could produce a meaningful error message about the missing file. Note that strace does demonstrate that a open system call is failing, e.g.: open("/usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache", O_RDONLY) = -1 ENOENT (No such file or directory) Reproduced on GHC 7.8.4 and 7.10.1, on Ubuntu 14.04 64-bit. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10298> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7782: flag to run the demand analysis a second time
by GHC 10 Jul '15

10 Jul '15

#7782: flag to run the demand analysis a second time -------------------------------------+------------------------------------- Reporter: nfrisby | Owner: Type: task | Status: new Priority: high | Milestone: 7.12.1 Component: Compiler | Version: 7.7 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: #4941, #5302, | Blocking: #6087, #4962 | Differential Revisions: -------------------------------------+------------------------------------- Description changed by simonpj: Old description: > There are some tickets documenting runtime bugs that can be cleaned up by > running the demand analyzer (followed by a simplifier run) a second time > at the end of the pipeline: #4941, #5302, #6087. #6070 ? Others? > > The -flate-dmd-anal flag has been committed to HEAD (cf comment:10 > below). > > The remaining task is to determine if `-O2` should imply `-flate-dmd- > anal`. It currently does not: late demand analysis is ''off'' by default. > > See LateDmd for more info. New description: There are some tickets documenting runtime bugs that can be cleaned up by running the demand analyzer (followed by a simplifier run) a second time at the end of the pipeline: #4941, #5302, #6087, #6070. #10626 ? Others? The -flate-dmd-anal flag has been committed to HEAD (cf comment:10 below). The remaining task is to determine if `-O2` should imply `-flate-dmd- anal`. It currently does not: late demand analysis is ''off'' by default. See LateDmd for more info. -- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7782#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4243: Make a proper options parser for the RTS
by GHC 09 Jul '15

09 Jul '15

#4243: Make a proper options parser for the RTS -------------------------------------+------------------------------------- Reporter: igloo | Owner: carlostome Type: task | Status: new Priority: normal | Milestone: 7.12.1 Component: Runtime System | Version: 6.13 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: #9839 | Blocking: 7535 | Differential Revisions: -------------------------------------+------------------------------------- Changes (by osa1): * cc: osa1 (added) Comment: What keeps us from implementing RTS arg parser in Haskell? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4243#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10608: Compile error regression from GHC 7.10 to 7.11
by GHC 09 Jul '15

09 Jul '15

#10608: Compile error regression from GHC 7.10 to 7.11 -------------------------------------+------------------------------------- Reporter: hvr | Owner: simonpj Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Other Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Consider the following program, {{{#!hs {-# LANGUAGE OverloadedStrings #-} -- {-# LANGUAGE FlexibleContexts #-} chunksOf :: Int -> String -> [String] chunksOf n = go where -- go :: String -> [String] go "" = [] go s@(_:_) = a : go b where (a,b) = splitAt n s }}} when compiled with GHC 7.8.4: {{{ GHCi, version 7.8.4: 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 Main ( chunksof.hs, interpreted ) chunksof.hs:8:5: Warning: Pattern match(es) are overlapped In an equation for ‘go’: go s@(_ : _) = ... Ok, modules loaded: Main. λ:2> }}} when compiled with GHC 7.10: {{{ GHCi, version 7.10.1.20150630: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( chunksof.hs, interpreted ) chunksof.hs:8:5: Non type-variable argument in the constraint: Data.String.IsString [t] (Use FlexibleContexts to permit this) When checking that ‘go’ has the inferred type go :: forall t. (Eq t, Data.String.IsString [t]) => [t] -> [[t]] In an equation for ‘chunksOf’: chunksOf n = go where go "" = [] go s@(_ : _) = a : go b where (a, b) = splitAt n s Failed, modules loaded: none. }}} NB: `FlexibleContexts` is rightly suggested! However, when compiled with GHC HEAD: {{{ GHCi, version 7.11.20150630: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( chunksof.hs, interpreted ) chunksof.hs:8:8: error: Could not deduce (IsString [t]) arising from the literal ‘""’ from the context: Eq t bound by the inferred type of go :: Eq t => [t] -> [[t]] at chunksof.hs:(8,5)-(11,27) In the pattern: "" In an equation for ‘go’: go "" = [] In an equation for ‘chunksOf’: chunksOf n = go where go "" = [] go s@(_ : _) = a : go b where (a, b) = splitAt n s Failed, modules loaded: none. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10608> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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