Segfault when using unboxed tuples in GHCi
If you put this module in a package:
{-# LANGUAGE MagicHash, UnboxedTuples #-}
module Bug ( box, wrap, proxy ) where
import GHC.Prim
box :: (# Proxy# a, b #) -> b
box (# x, y #) = y
wrap :: b -> Proxy# a -> (# Proxy# a, b #)
wrap x = \i# -> (# i#, x #)
proxy :: () -> Proxy# a
proxy () = proxy#Then in GHCi you can do:
GHCi, version 8.0.1: http://www.haskell.org/ghc/ :? for help
Prelude> import Bug
Prelude Bug> box (wrap "foo" (proxy ()))
"Segmentation fault (core dumped)Alternatively you can crash runhaskell if you put the above code in main.
It seems that GHCi fails to pickup usage of (# VoidRep, PtrLiftedRep #) tuples or something. The same trick works with State# in place of Proxy#, but not with Int#.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.0.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | GHCi |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |