[GHC] #5955: Renamer hangs when checking type family consistency

[GHC]

#5955: Renamer hangs when checking type family consistency
-------------------------------------------------+--------------------------
  Reporter:  gmainland                           |          Owner:                  
      Type:  bug                                 |         Status:  closed          
  Priority:  normal                              |      Milestone:                  
 Component:  Compiler                            |        Version:  7.5             
Resolution:  fixed                               |       Keywords:                  
        Os:  Unknown/Multiple                    |   Architecture:  Unknown/Multiple
   Failure:  None/Unknown                        |     Difficulty:  Unknown         
  Testcase:  indexed-types/should_compile/T5955  |      Blockedby:                  
  Blocking:                                      |        Related:                  
-------------------------------------------------+--------------------------
Changes (by simonpj):

  * status:  new => closed
  * difficulty:  => Unknown
  * resolution:  => fixed
  * testcase:  => indexed-types/should_compile/T5955


Comment:

 Fixed by
 {{{
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Wed Mar 28 09:56:14 2012 +0100

     Add a crucial forkM on the superclass context of IfaceClass in
 tcIfaceDecl

     The absence of this was causing a loop when typechecking an interface
     where the superclass context mentioned an associated type
        class C (T a) => D a where
          data T a

     Fixes Trac #5970

  compiler/iface/BuildTyCl.lhs   |    7 +++----
  compiler/iface/LoadIface.lhs   |    2 +-
  compiler/iface/TcIface.lhs     |   36
 +++++++++++++++++++++++++-----------
  compiler/typecheck/FamInst.lhs |    3 +++
  4 files changed, 32 insertions(+), 16 deletions(-)
 }}}
 The comment is wrong when it mentions #5970; the patch fixes this ticket
 #5955.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5955#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler