January 2019 - ghc-tickets

[GHC] #16222: PPC NCG: C calling convention violated for integers smaller than word size
by GHC 04 Mar '19

04 Mar '19

#16222: PPC NCG: C calling convention violated for integers smaller than word size -------------------------------------+------------------------------------- Reporter: trommler | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.10.1 Component: Compiler | Version: 8.7 (FFI) | Keywords: big endian | Operating System: Unknown/Multiple Architecture: powerpc64 | Type of failure: Incorrect result Test Case: | at runtime primops/should_run/PrimFFIInt8 | Blocked By: primops/should_run/PrimFFIInt16 | Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The C calling convention for powerpc64 and powerpc64le require simple integer types to be zero or sign extended to 64 bit. The PPC NCG assumes that all values have been promoted to word size but now we introduced integer operations on smaller than machine word size and in general we cannot assume that values have been promoted anymore. When a value is not promoted and passed to a foreign function on the stack that value will be in the wrong position within the stack slot on big endian systems and the function will deliver wrong results. On little endian systems we still get correct results as long as we stay in the smaller integer range. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16222> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #16219: Backpack - TH+indefinite module interface file error
by GHC 04 Mar '19

04 Mar '19

#16219: Backpack - TH+indefinite module interface file error -------------------------------------+------------------------------------- Reporter: lightandlight | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.7 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: -------------------------------------+------------------------------------- Repro: https://github.com/LightAndLight/backpack-test I've been stuck on this for a while now. There's a weird interaction between the Template Haskell pragma and indefinite modules. When Template Haskell is enabled in this particular file (but TH features aren't used) I get an interface error. When I remove the pragma, the project successfully compiles. I hope I haven't made some trivial .cabal blunder. Anyway, I'm interested in potentially trying to fix this, but I've been digging around in GHC for a couple of days and figured it was time to ask for help. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16219> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 13

[GHC] #16205: Printing a large (GMP) Integer in ghci-ext with LLVM causes a segfault
by GHC 04 Mar '19

04 Mar '19

#16205: Printing a large (GMP) Integer in ghci-ext with LLVM causes a segfault -------------------------------------+------------------------------------- Reporter: harpocrates | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 8.6.3 Keywords: llvm integer- | Operating System: Unknown/Multiple gmp | Architecture: | Type of failure: GHCi crash Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Although I haven't reproduced this locally yet, the `validate-x86_64 -linux-deb9-llvm` CI pipeline (which is allowed to fail) has continuously been failing for `print037(ghci-ext)`. Here's the relevant output: {{{ --- ghci.debugger/scripts/print037.run/print037.stdout.normalised 2019-01-19 11:37:48.698917882 +0000 +++ ghci.debugger/scripts/print037.run/print037.run.stdout.normalised 2019-01-19 11:37:48.698917882 +0000 @@ -1,5 +1,4 @@ smallNeg = -53 smallPos = 89 zero = 0 -largeNeg = -4123841823694876543987265438957349857349 -largePos = 5402398759384752938475029384750298347554 +ghc-stage2: ghc-iserv terminated (-11) *** unexpected failure for print037(ghci-ext) }}} Given that the crash happens only on large integers (i.e. not `S#`), something in the C FFI with the GMP code is probably to blame. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16205> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

[GHC] #16227: T15897 causes CI failures due to timing out
by GHC 04 Mar '19

04 Mar '19

#16227: T15897 causes CI failures due to timing out -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.6.3 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: -------------------------------------+------------------------------------- For example: https://gitlab.haskell.org/ghc/ghc/-/jobs/16084 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16227> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 2

[GHC] #16260: Use of plugins causes -XSafe to fail
by GHC 04 Mar '19

04 Mar '19

#16260: Use of plugins causes -XSafe to fail -------------------------------------+------------------------------------- Reporter: watashi | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.7 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Use of plugins will mark safe inference as failed, even when the plugin does not modify anything. This can result in compile error when -XSafe is used. For example: {{{ $ cat DefaultPlugin.hs module DefaultPlugin (plugin) where import GhcPlugins plugin = defaultPlugin $ cat B.hs {-# OPTIONS_GHC -fplugin DefaultPlugin #-} module B (answer) where answer = 42 $ cat A.hs {-# LANGUAGE Safe #-} module A (main) where import B main = print answer $ ... A.hs:4:1: error: B: Can't be safely imported! The module itself isn't safe. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16260> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 13

[GHC] #16001: hadrian doesn't support setting intree gmp configuration explicitly
by GHC 04 Mar '19

04 Mar '19

#16001: hadrian doesn't support setting intree gmp configuration explicitly -------------------------------------+------------------------------------- Reporter: carter | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: Build System | Version: 8.6.2 (Hadrian) | 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/16001> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 7

[GHC] #16214: Hadrian prof flavour doesn't build a compiler which you can profile
by GHC 04 Mar '19

04 Mar '19

#16214: Hadrian prof flavour doesn't build a compiler which you can profile -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 8.6.3 (Hadrian) | Keywords: newcomer | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- After building a compiler with the `prof` flavour. I tried to use it with the `-xc` option. {{{ ./hadrian/build.sh --flavour=prof _build/stage1/bin/ghc A.hs +RTS -xc }}} But apparently {{{ ghc: the flag -xc requires the program to be built with -prof }}} So it seems that the `prof` flavour is broken. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16214> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

[GHC] #16202: Hadrian install script doesn't update location of haddockHTMLs and haddockInterfaces
by GHC 04 Mar '19

04 Mar '19

#16202: Hadrian install script doesn't update location of haddockHTMLs and haddockInterfaces -------------------------------------+------------------------------------- Reporter: harpocrates | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 8.6.3 (Hadrian) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Installing GHC Unknown/Multiple | failed Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This is to track part two of the plan here: https://gitlab.haskell.org/ghc/ghc/merge_requests/50#note_1808. When installing a bindist, the make system runs `ghc-cabal` to reconfigure packages and regenerate the package DB. Hadrian, on the other hand, seems to just be copying the package DB as is to its install location. This is mostly OK since most paths only need to be relative to package root. However, it breaks down for the `haddock-interfaces` and `haddock-html` fields, (esp. since documentation can be installed in a completely different location). The following interaction demonstrates the problem. Note how `ghc-pkg` is pointing us to a directory that doesn't even exist! {{{ $ ./hadrian/build.sh -c -j binary-dist $ mv _build/bindist/ghc-8.7.20190117-x86_64-apple-darwin.tar.xz /Users/alec/scratch $ cd /Users/alec/scratch $ tar xpvf ghc-8.7.20190117-x86_64-apple-darwin.tar.xz $ ./configure --prefix=/Users/alec/scratch && make install $ ./bin/ghc-pkg field base haddock-html haddock-html: /Users/alec/scratch/lib/../../docs/html/libraries/base $ ls /Users/alec/scratch/lib/../../docs/html/libraries/base ls: /Users/alec/scratch/lib/../../docs/html/libraries/base: No such file or directory }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16202> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 7

[GHC] #16218: T16180 is broken on Darwin
by GHC 04 Mar '19

04 Mar '19

#16218: T16180 is broken on Darwin ----------------------------------------+--------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.8.1 Component: Compiler | Version: 8.6.3 Keywords: | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+--------------------------------- Unfortunately the test `T16180` snuck in to the tree in with commit f035504b, just before I had a chance to merge !137, making Darwin a mandatory-green platform. Consequently we didn't catch that this test is broken on Darwin. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16218> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 5

[GHC] #15593: QuantifiedConstraints: trouble with type family
by GHC 04 Mar '19

04 Mar '19

#15593: QuantifiedConstraints: trouble with type family -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.5 Keywords: | Operating System: Unknown/Multiple QuantifiedConstraints, | ConstraintKinds | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# Language KindSignatures, TypeFamilies, QuantifiedConstraints, FlexibleInstances #-} import Data.Kind data TreeF a b = T0 | T1 a | T2 b b -- from Data.Reify class MuRef (a :: Type) where type DeRef a :: Type -> Type class (forall xx. DeRef (tree xx) ~ TreeF xx) => MuRef1 tree instance (forall xx. DeRef (tree xx) ~ TreeF xx) => MuRef1 tree }}} fails with {{{ $ ~/code/qc-ghc/inplace/bin/ghc-stage2 --interactive -ignore-dot-ghci 351.hs GHCi, version 8.5.20180128: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( 351.hs, interpreted ) 351.hs:12:10: error: • Couldn't match type ‘DeRef (tree xx)’ with ‘TreeF xx’ arising from the superclasses of an instance declaration • In the instance declaration for ‘MuRef1 tree’ | 12 | instance (forall xx. DeRef (tree xx) ~ TreeF xx) => MuRef1 tree | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Failed, no modules loaded. Prelude> }}} ---- What I want to write: {{{#!hs {-# Language KindSignatures, TypeFamilies, QuantifiedConstraints, FlexibleInstances, DataKinds, TypeInType, MultiParamTypeClasses, UndecidableInstances, AllowAmbiguousTypes #-} import Data.Kind -- from Data.Reify class MuRef (a :: Type) where type DeRef a :: Type -> Type type T = Type type TT = T -> T type TTT = T -> TT class (forall xx. (MuRef (f xx), DeRef (f xx) ~ deRef1 f xx)) => MuRef1 (f :: TT) (deRef1 :: TT -> TTT) instance (forall xx. (MuRef (f xx), DeRef (f xx) ~ deRef1 f xx)) => MuRef1 (f :: TT) (deRef1 :: TT -> TTT) }}} where I am trying to capture [https://hackage.haskell.org/package/folds-0.7.4/docs/src/Data-Fold- Internal.html MuRef1 & DeRef1] {{{#!hs class MuRef1 (f :: TT) where type DeRef1 f :: TTT muRef1 :: proxy (f a) -> Dict (MuRef (f a), DeRef (f a) ~ DeRef1 f a) }}} ---- Workarounds: I think splitting the class alias & quantification does the job (I haven't tested it but it compiles), I want to know if the first two programs are meant to compile or not {{{#!hs {-# Language KindSignatures, TypeFamilies, QuantifiedConstraints, FlexibleInstances, DataKinds, TypeInType, MultiParamTypeClasses, UndecidableInstances, AllowAmbiguousTypes, FlexibleContexts #-} -- .. class (MuRef (f xx), DeRef (f xx) ~ deRef1 f xx) => MuRef1_ f deRef1 xx instance (MuRef (f xx), DeRef (f xx) ~ deRef1 f xx) => MuRef1_ f deRef1 xx class (forall xx. cls xx) => Forall cls instance (forall xx. cls xx) => Forall cls class Forall (MuRef1_ f deRef1) => MuRef1 f deRef1 instance Forall (MuRef1_ f deRef1) => MuRef1 f deRef1 }}} or as a regular type/constraint synonym (at the loss of partial application) {{{#!hs type MuRef1 f deRef1 = (forall xx. (MuRef (f xx), DeRef (f xx) ~ deRef1 f xx)) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15593> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4