contrib/showstack.py

typing: make the localrepo classes known to pytype

9d4ad05bc91c and 1b17309cdaab both mentioned making `bundlerepository` and
`unionrepository` subclass `localrepository` during the type checking phase, but
that didn't apply to pytype in practice.  See bcaa5d408657 and friends for how
the zope interfaces confuse pytype, and end up converting the classes they
decorate into `Any`.

This commit is slightly more complex though, because `localrepository` has mixin
classes applied to it when it is instantiated.  Specifically, `RevlogFileStorage`
is added, which adds `def file(f)` (which isn't defined on `localrepository`).
Therefore a list of `localrepository` superclasses is provided during type
checking to account for the mixins.  Without this, the `bundlerepository` class
gets flagged when it attempts to call its superclass implementation of `file()`.
Note that pytype doesn't understand these mixin superclasses (it marks the
superclass of `localrepository` as `Any`, because they are zope interfaces it
doesn't understand), but that's enough to get it to not flag `bundlerepository`.
PyCharm also stops flagging it as a missing function, though it seems like it is
able to handle the zope interfaces.

# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)
r"""dump stack trace when receiving SIGQUIT (Ctrl-\) or SIGINFO (Ctrl-T on BSDs)
"""

import signal
import sys
import traceback


def sigshow(*args):
    sys.stderr.write("\n")
    traceback.print_stack(args[1], limit=10, file=sys.stderr)
    sys.stderr.write("----\n")


def sigexit(*args):
    sigshow(*args)
    print('alarm!')
    sys.exit(1)


def extsetup(ui):
    signal.signal(signal.SIGQUIT, sigshow)
    signal.signal(signal.SIGALRM, sigexit)
    try:
        signal.signal(signal.SIGINFO, sigshow)
    except AttributeError:
        pass