`foo !f = id . f` becomes non-strict with -O2
The following program:
foo :: (a -> b) -> a -> b
foo !f = id . f
main :: IO ()
main = print (foo undefined `seq` "ok")Crashes with Prelude.undefined when compiled without -O2, but prints "ok" with it. As far as I can tell the optimizer shouldn't be allowed to do that.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.6.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |