#12650: Too many warnings about consistentCafInfo -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: task | Status: new Priority: normal | 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: | -------------------------------------+------------------------------------- Description changed by mpickering: Old description:
Building GHC with debug on yiedls in many (97!) warnings of the form {{{ WARNING: file compiler/stgSyn/CoreToStg.hs, line 252 $fFunctorIOEnv True False }}}
The code in question is {{{ -- Assertion helper: this checks that the CafInfo on the Id matches -- what CoreToStg has figured out about the binding's SRT. The -- CafInfo will be exact in all cases except when CorePrep has -- floated out a binding, in which case it will be approximate. consistentCafInfo :: Id -> GenStgBinding Var Id -> Bool consistentCafInfo id bind = WARN( not (exact || is_sat_thing) , ppr id <+> ppr id_marked_caffy <+> ppr binding_is_caffy ) safe where safe = id_marked_caffy || not binding_is_caffy exact = id_marked_caffy == binding_is_caffy id_marked_caffy = mayHaveCafRefs (idCafInfo id) binding_is_caffy = topStgBindHasCafRefs bind is_sat_thing = occNameFS (nameOccName (idName id)) == fsLit "sat" }}}
It would be nice to have less warnings, to make them more useful. I don’t know if the warning is not right, or if there is something that can be fixed about the thing it is warning about.
New description: Building GHC with debug on yields in many (97!) warnings of the form {{{ WARNING: file compiler/stgSyn/CoreToStg.hs, line 252 $fFunctorIOEnv True False }}} The code in question is {{{ -- Assertion helper: this checks that the CafInfo on the Id matches -- what CoreToStg has figured out about the binding's SRT. The -- CafInfo will be exact in all cases except when CorePrep has -- floated out a binding, in which case it will be approximate. consistentCafInfo :: Id -> GenStgBinding Var Id -> Bool consistentCafInfo id bind = WARN( not (exact || is_sat_thing) , ppr id <+> ppr id_marked_caffy <+> ppr binding_is_caffy ) safe where safe = id_marked_caffy || not binding_is_caffy exact = id_marked_caffy == binding_is_caffy id_marked_caffy = mayHaveCafRefs (idCafInfo id) binding_is_caffy = topStgBindHasCafRefs bind is_sat_thing = occNameFS (nameOccName (idName id)) == fsLit "sat" }}} It would be nice to have less warnings, to make them more useful. I don’t know if the warning is not right, or if there is something that can be fixed about the thing it is warning about. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12650#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler