Inspecting whether a file handle is open in RPython

error.txt

[translation:info] Error:
[translation:info]    File "/home/wilfred/projects/trifle/src/pypy/rpython/translator/goal/translate.py", line 318, in main
[translation:info]     drv.proceed(goals)
[translation:info]    File "/home/wilfred/projects/trifle/src/pypy/rpython/translator/driver.py", line 534, in proceed
[translation:info]     return self._execute(goals, task_skip = self._maybe_skip())
[translation:info]    File "/home/wilfred/projects/trifle/src/pypy/rpython/translator/tool/taskengine.py", line 114, in _execute
[translation:info]     res = self._do(goal, taskcallable, *args, **kwds)
[translation:info]    File "/home/wilfred/projects/trifle/src/pypy/rpython/translator/driver.py", line 283, in _do
[translation:info]     res = func()
[translation:info]    File "/home/wilfred/projects/trifle/src/pypy/rpython/translator/driver.py", line 320, in task_annotate
[translation:info]     s = annotator.build_types(self.entry_point, self.inputtypes)
[translation:info]    File "/home/wilfred/projects/trifle/src/pypy/rpython/annotator/annrpython.py", line 91, in build_types
[translation:info]     return self.build_graph_types(flowgraph, inputcells, complete_now=complete_now)
[translation:info]    File "/home/wilfred/projects/trifle/src/pypy/rpython/annotator/annrpython.py", line 145, in build_graph_types
[translation:info]     self.complete()
[translation:info]    File "/home/wilfred/projects/trifle/src/pypy/rpython/annotator/annrpython.py", line 221, in complete
[translation:info]     raise annmodel.AnnotatorError(text)
[translation:ERROR] AnnotatorError:
[translation:ERROR]
[translation:ERROR] Blocked block -- operation cannot succeed
[translation:ERROR]
[translation:ERROR]     v1 = getattr(v0, ('closed'))
[translation:ERROR]
[translation:ERROR] In <FunctionGraph of (files:4)entry_point at 0x2823bd0>:
[translation:ERROR] Happened at file files.py line 6
[translation:ERROR]
[translation:ERROR]         f = open("/tmp/test.txt", 'w')
[translation:ERROR] ==>     print "f is closed: %s" % f.closed
[translation:ERROR]
[translation:ERROR] Known variable annotations:
[translation:ERROR]  v0 = SomeInstance(can_be_None=False, classdef=rpython.rlib.rfile.RFile)
[translation:ERROR]
[translation] start debugger...
> /home/wilfred/projects/trifle/src/pypy/rpython/annotator/annrpython.py(221)complete()
-> raise annmodel.AnnotatorError(text)

files.py

import sys


def entry_point(argv):
    f = open("/tmp/test.txt", 'w')
    print "f is closed: %s" % f.closed


def target(*args):
    return entry_point, None


if __name__ == '__main__':
    entry_point(sys.argv)