[GHC] #5439: Crash in TcEnv.lhs line 461

[GHC]

#5439: Crash in TcEnv.lhs line 461
-----------------------------------+----------------------------------------
    Reporter:  mikhail.vorozhtsov  |       Owner:                    
        Type:  bug                 |      Status:  new               
    Priority:  normal              |   Component:  Compiler          
     Version:  7.3                 |    Keywords:                    
    Testcase:                      |   Blockedby:                    
          Os:  Unknown/Multiple    |    Blocking:                    
Architecture:  Unknown/Multiple    |     Failure:  Compile-time crash
-----------------------------------+----------------------------------------

Comment(by simonpj@…):

 commit eb46e0de6eab60483f38ed2088d9de13d8e74e2f
 {{{
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Thu Sep 1 08:28:36 2011 +0100

     Fix the trimming of bind_fvs (fixes Trac #5439)

     For the bind_fvs field of FunBind/PatBind, we need to be careful to
     keep track of uses of all functions in this module (although not
     imported ones).  Moreover in TcBinds.decideGeneralisationPlan we
     need to take note of uses of lexically scoped type variables.

     These two buglets led to a (useful) assertion failure in TcEnv.

  compiler/hsSyn/HsBinds.lhs       |   52 ++++++++++++++++++++++++----
  compiler/rename/RnBinds.lhs      |   70
 +++++++++++++++++---------------------
  compiler/typecheck/TcBinds.lhs   |   12 +++++-
  compiler/typecheck/TcRnTypes.lhs |   36 +++++++++++++++++++-
  4 files changed, 121 insertions(+), 49 deletions(-)
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5439#comment:2>
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