Code using seq has wrong strictness (too lazy) when optimised
Following program prints [1]
instead of crashing when compiled with -O -fno-full-laziness
. Note that it's neccessary to use the extra definition hiddenError
instead of calling error
directly. The problem might be related to #5557 (closed), which, however, has already been fixed and optimisation is needed to trigger the current bug.
hiddenError = error "hidden error"
main = do
print $ seq (head (map (\a -> \b -> hiddenError) (hiddenError::[] Bool))) id [1]
I used GHC 7.3.20111022 for triggering this problem.
Trac metadata
Trac field | Value |
---|---|
Version | 7.3 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | michal.palka@poczta.fm |
Operating system | |
Architecture |