#7057: Simplifier infinite loop regression
---------------------------------+------------------------------------------
Reporter: ronwalf | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 7.4.2
Keywords: | Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time crash
Difficulty: Unknown | Testcase:
Blockedby: | Blocking:
Related: |
---------------------------------+------------------------------------------
Changes (by simonpj):
* difficulty: => Unknown
Comment:
Thanks. This yet another example of #5448, the Russell-paradox bug.
It is easily fixed by adding `{-# NOINLINE #-}` on the `pddlDocExpr`
definition in the instance declaration, and in general on every such
instance declaration. The threads attached to #5448 explain the
background. So that's a workaround, but not a satisfactory one.
Since the "live" examples of this bug all involve a class used
contravariantly in one of its methods, I'm beginning to think that an
effective counter-measure might be to NOINLINE such methods. It's a bit
disgusting, and does not solve the whole problem, but it would fix all the
real occurrences in the wild.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7057#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
Glasgow-haskell-bugs mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
