Bug 791280

Description of problem:
I've been writing an experimental static analysis tool to detect bugs commonly occurring within C Python extension modules:
  https://fedorahosted.org/gcc-python-plugin/
  http://gcc-python-plugin.readthedocs.org/en/latest/cpychecker.html
  http://fedoraproject.org/wiki/Features/StaticAnalysisOfPythonRefcounts

I ran the latest version of the tool (in git master; post 0.9) on
cmusphinx3-0.8-10.fc17.src.rpm, and it reports various errors.

You can see a list of errors here, triaged into categories (from most significant to least significant):
http://fedorapeople.org/~dmalcolm/gcc-python-plugin/2012-02-16/cmusphinx3-0.8-10.fc17/

The two reported reference leaks appear to be genuine bugs: in this code:
   231    return Py_BuildValue("(OO)", hypstr_obj, hypseg_obj);
both hypstr_obj and hypseg_obj are references owned by the function.

The "O" format codes to Py_BuildValue build the 2-tuple by adding additional references.  It should instead use the "N" format code to transfer ownership of the owned references to the new tuple.  See:
  http://docs.python.org/c-api/arg.html#Py_BuildValue

The reported "Segfaults within error-handling paths" appears to also be a genuine bug: there isn't any checking for the possibility that this call:
  206 	hypseg_obj = PyTuple_New(nhyps);
fails (e.g. under low-memory conditions), returning NULL, and this pointer is then written through at:
  228 		PyTuple_SET_ITEM(hypseg_obj, i, seg_obj);

There may of course be other bugs in my checker tool.

Hope this is helpful; let me know if you need help reading the logs that the tool generates - I know that it could use some improvement.

Version-Release number of selected component (if applicable):
cmusphinx3-0.8-10.fc17
gcc-python-plugin post-0.9 git 073d390de53ef52136bd90e5ac06f1ef833d047d running the checker in an *f16* chroot