Re: [GHC] #9718: Avoid TidyPgm predicting what CorePrep will do

#9718: Avoid TidyPgm predicting what CorePrep will do -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Resolution: | Keywords: CodeGen, CAFs 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 osa1): Another thing we need to figure out is how to update use sites of binders when we update CAFness info. For example, in the example in #15113: {{{ lvl2_r3y3 :: [Char] [GblId] lvl2_r3y3 = unpackCString# lvl1_r3y2 -- RHS size: {terms: 7, types: 6, coercions: 2, joins: 0/0} patError :: forall a. Addr# -> a [GblId, Arity=1, Str=x, Unf=OtherCon []] patError = \ (@ a_a2kh) (s_a1Pi :: Addr#) -> raise# @ SomeException @ 'LiftedRep @ a_a2kh (Control.Exception.Base.$fExceptionPatternMatchFail_$ctoException ((untangle s_a1Pi lvl2_r3y3) `cast` (Sym (Control.Exception.Base.N:PatternMatchFail[0]) :: (String :: *) ~R# (PatternMatchFail :: *)))) }}} We want to be able to make `lvl2_r3y3` re-entrant. When we do this `patError` won't have any CAF refs, but to actually realize this we need to update references to `lvl2_r3y3` to update the id info. Alternatively I think we could pass an environment of updated ids to `topStgBindHasCafRefs` and friends. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9718#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler