`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 |