#13055: Adding INLINABLE pragma causes GHC panic -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): The panic. I don't know what you mean with `idInfo`. It was trying to build `libraries/transformers/dist- install/build/Control/Applicative/Backwards.o`. {{{ ghc-stage1: panic! (the 'impossible' happened) (GHC version 8.1.20170102 for x86_64-unknown-linux): Iface Lint failure In interface for GHC.Base Unfolding of <**> <no location info>: warning: In the expression: $ @ a @ b Kinds don't match in type application: Type variable: r_1i :: RuntimeRep Arg type: a :: * xx * <no location info>: warning: In the expression: flip @ (a -> b) @ a @ b ($ @ a @ b) Argument value doesn't match argument type: Fun type: ((a -> b) -> a -> b) -> a -> (a -> b) -> b Arg type: forall (b :: TYPE a). (b -> b) -> b -> b Arg: $ @ a @ b <**> = \ (@ (f_a6mX :: * -> *)) (@ a_a6mY) (@ b_a6mZ) ($dApplicative_a6n0 :: Applicative f) -> liftA2 @ f @ a @ (a -> b) @ b $dApplicative_a6n0 (flip @ (a -> b) @ a @ b ($ @ a @ b)) Iface expr = \ @ f :: * -> * @ a @ b ($dApplicative :: Applicative f) -> liftA2 @ f @ a @ (a -> b) @ b $dApplicative (flip @ (a -> b) @ a @ b ($ @ a @ b)) }}} I'm not sure where `$ @ a @ b` came from but it seems to be treating `a` as the kind/representation argument when clearly it was intended to be the `a` in `(a -> b) -> a -> b`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13055#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13055: Adding INLINABLE pragma causes GHC panic -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): Ah I see. What does `./inplace/bin/ghc-stage2 --show-iface ./libraries/base/dist-install/build/GHC/Base.hi` have to say about `<**>`, for you? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13055#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13055: Adding INLINABLE pragma causes GHC panic -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari ): In [changeset:"683ed475964bbd90030deb8f738370ae90b48a22/ghc" 683ed47/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="683ed475964bbd90030deb8f738370ae90b48a22" Don't use $ in the definition of (<**>) in GHC.Base ($) is special as Richard explains in the note at the top of the page. However, when adding the note he didn't remove this usage. Normally it didn't cause any problems as the optimiser optimised it away. However if one had the propensity to stick one's fingers into the depths of the inliner, it caused horrible idInfo panics. Reviewers: rwbarton, hvr, austin, bgamari Reviewed By: bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2913 GHC Trac Issues: #13055 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13055#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13055: Adding INLINABLE pragma causes GHC panic -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: closed Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I'm very confused about this. The comment at the top of `GHC.Base` says {{{ NOTA BENE: Do NOT use ($) anywhere in this module! The type of ($) is slightly magical (it can return unlifted types), and it is wired in. But, it is also *defined* in this module, with a non-magical type. GHC gets terribly confused (and *hangs*) if you try to use ($) in this module, because it has different types in different scenarios. This is not a problem in general, because the type ($), being wired in, is not written out to the interface file, so importing files don't get confused. The problem is only if ($) is used here. So don't! }}} (It should jolly well have a `Note` heading so we can refer to it.) But I don't understand that. The wired-in definition should override the local one, even in the module it is defined in. I'd love a better understanding of what goes wrong. But life is short, I suppose. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13055#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler