On Sat, Jun 01, 2002 at 11:01:57PM +1000, Andre Pang wrote:
It seems that the fromDynamic and fromDyn functions seem to work if you load your module into GHCI, but they don't work when you compile it into a stand-alone executable with GHC.
.. unless you compile it with -O2:
23:18(0) .../project/dynamic_types-bug% ghc --make -package lang -O2 DynamicTypesBug.hs
ghc-5.02.2: chasing modules from: DynamicTypesBug.hs
Compiling Main ( DynamicTypesBug.hs, ./DynamicTypesBug.o )
ghc: linking ...
23:18(0) .../project/dynamic_types-bug% ./a.out
Static type: FootnoteData [Char] Int
Coerced (dynamic) type: FootnoteData [Char] Int
Does dynamic type == static type? True
Attempting to run fromDynamic on the dynamic type ...
5. This be the footnote
Weird.
It also seems to work with -O1.
I should note that I observed the buggy GHC behaviour with
-fvia-c as well, regardless of whether gcc-2.95 or gcc-3.1 was
used.
Putting -O0 on the GHC commandline, or omitting the -O option
altogether, appears to trigger the bug. This doesn't happen with
GHCI (i.e. 'ghci -O0' seems to work).
--
#ozone/algorithm