#13392: ghc --show-options lists flags twice ---------------------------------+-------------------------------------- Reporter: ThreeFx | Owner: (none) Type: bug | Status: new Priority: low | Milestone: ⊥ Component: Compiler | Version: 8.0.1 Resolution: | Keywords: newcomer Operating System: Linux | Architecture: x86_64 (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | ---------------------------------+-------------------------------------- Comment (by bgamari): Replying to [comment:1 SantiM]:
Hello,
Welcome SantiM!
I'd be happy to take this issue as my first contribution to GHC.
Great; don't hesitate to ask me if you have any questions. Email (ben @well-typed.com) or IRC (bgamari on `#ghc`) are both fine.
I wanted to ask a few questions first though:
1) I didn't find tests on the 'ghc' command or the "showOptions" function[0]. Any suggestions on where to put the test for this change and how to go about it?
I think `testsuite/tests/driver/` is probably best. See [[Building/RunningTests/Adding]] for instructions on adding testcases to the testsuite.
2) We could fix this by just adding 'nub' to the showOptions, but I guess that is not good enough and we probably want to take a look at how flags are registered in DynFlags. Ideas?
I suspect the issue is that "O" is registered twice (as of 6c05b27e5bafe9f232e7014f4760335f5e3ba591), {{{#!hs ------ Optimisation flags ------------------------------------------ , make_ord_flag defGhcFlag "O" (noArgM (setOptLevel 1)) ... , make_ord_flag defGhcFlag "O" (optIntSuffixM (\mb_n -> setOptLevel (mb_n `orElse` 1))) -- If the number is missing, use 1 }}} However, I believe the former is actually redundant, being handled by the latter. Perhaps try just removing it and adding a test. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13392#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler