Boost C++ Libraries: Ticket #1952: [saywhat] The operation static_cast(boost::python::extract(...)) crashes Python. Seems to create reference counting problem.

attachment set

Tue, 27 May 2008 14:50:04 GMT

attachment → VarSw2.zip

Tue, 27 May 2008 15:02:57 GMT

Less complicated inputs do not create immediate problem: p.set((1,2)) p.set('d')

are fine.

status changed

Dave Abrahams — Tue, 27 May 2008 18:37:18 GMT

status new → assigned

suppose you replace

static_cast<std::string>(boost::python::extract<std::string>(...))

with

boost::python::extract<std::string>(...)() // note extra parens

If the static_cast fails but my replacement works, I think you need to file a bug report with your compiler vendor.

Tue, 27 May 2008 19:42:04 GMT

Dave,

I tried all combinations, I do use extra perens in the submitted code. The code compiles, links, runs. It succeds for list,dicts,strings etc. It fails for embedded structures such as tuple of tuples.

For example: import vrsw2 p=vrsw2.VarSwapTest() p.set((1,2)) p.set('d')

are successful.

However, p.set(((1,2),(3,4))) crashes. I did some debugging, it appears that the crash occurs during heap deallocation. I was unable to find any version of the submitted code that would pass the tuple of tuples.

Tue, 27 May 2008 19:43:45 GMT

Please, see the newly submitted correction.

Replying to dave:

suppose you replace
static_cast<std::string>(boost::python::extract<std::string>(...))
with
boost::python::extract<std::string>(...)() // note extra parens
If the static_cast fails but my replacement works, I think you need to file a bug report with your compiler vendor.

Tue, 27 May 2008 20:28:09 GMT

... in addition to previous comments, I verified the below suggestion. It does not work.

Replying to dave:

suppose you replace
static_cast<std::string>(boost::python::extract<std::string>(...))
with
boost::python::extract<std::string>(...)() // note extra parens
If the static_cast fails but my replacement works, I think you need to file a bug report with your compiler vendor.

status, summary changed; cc, resolution set

troy d. straszheim — Thu, 22 Oct 2009 04:39:19 GMT

cc troy@… added
status assigned → closed
resolution → worksforme
summary The operation static_cast<std::string>(boost::python::extract<std::string>(...)) crashes Python. Seems to create reference counting problem. → [saywhat] The operation static_cast<std::string>(boost::python::extract<std::string>(...)) crashes Python. Seems to create reference counting problem.

unable to reproduce with recent gcc. Test case simplified and added to my branch in git, will test on vc9, if it doesn't pass there i'll reopen.

the test:

http://gitorious.org/~straszheim/boost/straszheim/commit/43829f0e3290b74aa88907a25698e30c573b1012