[GHC] #3813: Invalid warning from GHCi

[GHC]

#3813: Invalid warning from GHCi
---------------------------------+------------------------------------------
    Reporter:  NeilMitchell      |        Owner:  igloo                            
        Type:  bug               |       Status:  new                              
    Priority:  normal            |    Milestone:  6.12.2                           
   Component:  GHCi              |      Version:  6.10.4                           
    Keywords:                    |   Difficulty:                                   
          Os:  Unknown/Multiple  |     Testcase:                                   
Architecture:  Unknown/Multiple  |      Failure:  Incorrect warning at compile-time
---------------------------------+------------------------------------------
Changes (by simonpj):

  * owner:  simonpj => igloo


Comment:

 Thanks for the report.  Fixed by
 {{{
 Wed Jan 20 09:45:33 GMT 2010  simonpj at microsoft.com
   * Fix Trac #3813: unused variables in GHCi bindings

   In a GHCi stmt we don't want to report unused variables,
   because we don't know the scope of the binding, eg

         Prelude> x <- blah

   Fixing this needed a little more info about the context of the stmt,
   thus the new constructor GhciStmt in the HsStmtContext type.

     M ./compiler/deSugar/DsExpr.lhs +3
     M ./compiler/deSugar/DsMeta.hs -7 +13
     M ./compiler/hsSyn/HsExpr.lhs -1 +4
     M ./compiler/rename/RnEnv.lhs -1
     M ./compiler/rename/RnPat.lhs -5 +13
     M ./compiler/typecheck/TcMatches.lhs -2 +1
     M ./compiler/typecheck/TcRnDriver.lhs -3 +3
 }}}
 Ian is going to add a test, then close.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3813#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler