#13251: Must perform family consistency check on non-imported identifiers -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.1 checker) | Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): Not thoroughly thought out, but how about in `checkWiredInTyCon` (or something which wraps it) and in `tcLookupGlobal`, we check whether the thing lives in a module that was actually imported and, if not, add the relevant import information to `tcg_imports`, and either do the ensuing type family consistency checks immediately, or perhaps add them to `tcg_pending_fam_checks`? I mean, we also have this behavior: {{{#!hs {-# LANGUAGE TemplateHaskell #-} import Language.Haskell.TH.Syntax main = print $( return (VarE (Name (OccName "sigFPE") (NameG VarName (PkgName "unix-2.7.0.1") (ModName "System.Posix.Signals")))) ) }}} {{{ rwbarton@morphism:~/ghc2$ ghc x/TH -fforce-recomp [1 of 1] Compiling Main ( x/TH.hs, x/TH.o ) Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package array-0.5.0.0 ... linking ... done. Loading package deepseq-1.3.0.2 ... linking ... done. Loading package containers-0.5.5.1 ... linking ... done. Loading package pretty-1.1.1.1 ... linking ... done. Loading package template-haskell ... linking ... done. Linking x/TH ... x/TH.o:(.text+0x4b): undefined reference to `unixzm2zi7zi0zi1_SystemziPosixziSignals_sigFPE_closure' x/TH.o: In function `S4hM_srt': (.data+0x48): undefined reference to `unixzm2zi7zi0zi1_SystemziPosixziSignals_sigFPE_closure' collect2: error: ld returned 1 exit status }}} If we updated the `ImportAvails` when we type checked the spliced thing, wouldn't that also create a dependency on the `unix` package at link time? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13251#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler