#13237: Extend TH with addModCStub -------------------------------------+------------------------------------- Reporter: | Owner: facundo.dominguez | facundo.dominguez Type: feature request | Status: patch Priority: normal | Milestone: 8.2.1 Component: Template Haskell | Version: 8.0.1 Resolution: | Keywords: inline-c Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D3106 Wiki Page: | -------------------------------------+------------------------------------- Comment (by nh2): Replying to [comment:17 facundo.dominguez]:
I follow this far. Now that the hash is in the .hi file, how does GHC know to recompile `A.hs` the next time `header.h` changes?
Ah, now I get what you're thinking about. No, cannot notice when it has to recompile A.hs when includes change; it would have to be the CPP to notice that (or ask the CPP what files it read, or run the CPP unconditionally). I was suggesting (but you're right, I didn't actually state it) that *when* we recompile A.hs, and notice `mystring` is unchanged (which would usually result in further compilation being avoided), we can invalidate *downstream* modules of `A.hs` based on the includes, even when the unexpanded argument `mystring` of `addModCStub` doesn't change. Sorry for the confusion. The value this would add is that you can touch (or save the buffer) of the module that contains the Haskell string to force a proper non-avoided build when (you know that) includes changed, as opposed to e.g. having to stack/cabal clean the entire project. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13237#comment:18 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler