'Bad return' profiler assertion error in python 2.2, worked in <=2.1

[Matthew Mueller]

I've written a profiler helper script a while ago,
(http://www.azstarnet.com/~donut/programs/index_s.html#pyprof)
and it doesn't fully work in python2.2.

The script has 2 methods of invocation: (assuming blah.py has #! for
python2.2)
standard: pyprof [opts] blah.py
env-var: PYPROF=[opts] blah.py

The first method works in 2.2 (not suprising, since it just boils down
to a standard Profile.run call).  But the second doesn't.  It does do
some "magic" in order to get the profiler call stack to the right
level so that everything works out when you try to print the stats on
atexit.

The main function for type 2 looks like:

def force_profile(argv):
	"""force profiling, do output at python exit
	
	Usually this function will not be called directly, but by pyprof_auto
	being imported while the PYPROF environment variable is set.
	
	argv -- parsed by parseargs to set which output options to use
	"""
	try: raise Exception
	except:
		fr=sys.exc_info()[2].tb_frame
		stacklevel=-1
		while fr!=None:
			stacklevel=stacklevel+1
			fr=fr.f_back

	# ... <registers atexit handler here, snipped to conserve space>
	
	args,_f_profkw=parseargs(argv)
	_f_prof=_f_profkw.get('Profiler',profile.Profile)()
	_f_prof.set_cmd('<force_profile>')
	for i in range(0,stacklevel):
		_f_prof.simulate_call('<force_profile>')
	sys.setprofile(_f_prof.dispatcher)

when run in python2.2, it generates:
Traceback (most recent call last):
  File "/usr/lib/python2.2/site.py", line 315, in ?
    import sitecustomize
  File "/usr/local/lib/python2.2/site-packages/sitecustomize.py", line 1, in ?
    import pyprof_auto #if PYPROF is set, profile automatically.
  File "/usr/local/lib/python2.2/site-packages/pyprof_auto.py", line 30, in ?
    pyprof.force_profile(os.environ['PYPROF'])
  File "/usr/local/lib/python2.2/site-packages/pyprof.py", line 291, in force_profile
    sys.setprofile(_f_prof.dispatcher)
  File "/usr/lib/python2.2/profile.py", line 214, in trace_dispatch_i
    if self.dispatch[event](self, frame,t):
  File "/usr/lib/python2.2/profile.py", line 280, in trace_dispatch_return
    assert frame is self.cur[-2].f_back, ("Bad return", self.cur[-3])
AssertionError: ('Bad return', ('profile', 0, '<force_profile>'))

I assume this has to do with how I'm stuffing the stack with
simulate_call, but it worked in older python and I don't see anything
obvious about how I should change it to work with 2.2..

-- 
Matthew Mueller
Remove S P A M to reply.