#10923: GHC should recompile if flags change -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.10.2 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: | -------------------------------------+------------------------------------- Changes (by thomie): * cc: simonmar (added) Comment: simonmar: you wrote in ticket:437#comment:18 (5 years ago):
It's not clear to me that changing optimisation settings should trigger recompilation: for example, you might have a large program compiled unoptimised, and then decide that you want to optimise just one or two modules, so you remove a few .o files, add -O and recompile.
Isn't stack supposed to rebuild a package when I specify a new set of ghc-options on the command line? As in e.g. 'stack build --ghc-
But these GHC users recently expressed their confusion about the current behavior: * #haskell user mtesseract: options=-O0'? It doesn't seem to rebuild anything here, irregardles of the ghc-options I specify. * reddit user [https://www.reddit.com/r/haskell/comments/4ro749/help_cabal_and_ghc_optimzat... winterland1989]:
when I change my own project's cabal from none to -O2, nothing will be recompiled, why?
Shall we add optimization flags to `fingerprintDynFlags` in `compiler/iface/FlagChecker.hs`? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10923#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler