recompilation bug with -O

Recompilation with -O should also rebuild Main.hs in the attached test application consisting of Main.hs and X.hs.

Test case:

1. build the app with GHC --make -O Main.hs

2. run Main (output = B)

3. change and save in X.hs

x = D { f = B }

to

x = D { f = A }

4. rebuild the app with GHC --make -O Main.hs (recompiles only X.hs)

5. run Main (unexpected output = B)

6. force recompilation of both X.hs and Main.hs

7. run Main (output = A)

The bug is in -O. A similar test with f :: String instead of f :: D2 runs without problems.

Problem is tested positive on WIN GHC 7.0.2, OpenSuse GHC 6.12.3, Mac OS X GHC 7.0.3 and GHC 7.2.1 (MAC?).

for more detail see http://sourceforge.net/apps/trac/ampersand/ticket/172.

the closed #1959 (closed) and #3166 (closed) describe similar problems.

Trac metadata

Trac field	Value
Version	7.2.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture