Mentoring for implementing #8004
Hey Devs, I haven't worked on GHC before, so I'm having trouble finding an entry point to implementing the AMP warnings (#8004). I only have a rough working knowledge of GHC's inner workings, but it would be a shame if the ticket wasn't resolved until the 7.8 deadline (which is somewhere in September if I remember it right). My last approach was grepping through the source for "DEPRECATED" and seeing whether there would be an appropriate place for these warnings there, but that wasn't very fruitful. Long story short: can anyone point me in the right direction? I assume the right place to look is somewhere in the typechecker where there's a type class environment, and that's as far as I've come. (It's hard to understand thousands of lines when you're not even sure you're in the right place ...) Greetings, David
I haven't played much with instances, but it looks to me like tcInstDecls1, in typecheck/TcInstDecls.lhs, is a good place. Toward the end of the body of that function is a bunch of checks in the style that you will need to write (such as for bogus Typeable instances). I hope this helps! Richard On 2013-07-31 13:56, David Luposchainsky wrote:
Hey Devs,
I haven't worked on GHC before, so I'm having trouble finding an entry point to implementing the AMP warnings (#8004). I only have a rough working knowledge of GHC's inner workings, but it would be a shame if the ticket wasn't resolved until the 7.8 deadline (which is somewhere in September if I remember it right). My last approach was grepping through the source for "DEPRECATED" and seeing whether there would be an appropriate place for these warnings there, but that wasn't very fruitful.
Long story short: can anyone point me in the right direction? I assume the right place to look is somewhere in the typechecker where there's a type class environment, and that's as far as I've come. (It's hard to understand thousands of lines when you're not even sure you're in the right place ...)
Greetings, David
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Rather than scatter these AMP checks here and there, I'd suggest adding checkAMPStuff tcg_env on line 206 or so of TcRnDriver, near the call to reportUnusedNames. This happens after typechecking is complete. The tcg_env includes all the newly-defined instances (in tcg_insts), what is in scope etc (tcg_rdr_env), so all the stuff you need is to hand. You can write checkAMPStuff in one place. Simon | -----Original Message----- | From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf Of David | Luposchainsky | Sent: 31 July 2013 13:57 | To: ghc-devs@haskell.org | Subject: Mentoring for implementing #8004 | | Hey Devs, | | I haven't worked on GHC before, so I'm having trouble finding an entry | point to implementing the AMP warnings (#8004). I only have a rough | working knowledge of GHC's inner workings, but it would be a shame if | the ticket wasn't resolved until the 7.8 deadline (which is somewhere in | September if I remember it right). | My last approach was grepping through the source for "DEPRECATED" and | seeing whether there would be an appropriate place for these warnings | there, but that wasn't very fruitful. | | Long story short: can anyone point me in the right direction? I assume | the right place to look is somewhere in the typechecker where there's a | type class environment, and that's as far as I've come. (It's hard to | understand thousands of lines when you're not even sure you're in the | right place ...) | | Greetings, | David | | _______________________________________________ | ghc-devs mailing list | ghc-devs@haskell.org | http://www.haskell.org/mailman/listinfo/ghc-devs
participants (3)
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David Luposchainsky -
Richard Eisenberg -
Simon Peyton-Jones