annotate contrib/showstack.py @ 40955:f6187e60f792

help: present boolean arguments as "--[no-]foo"

This should make it much more discoverable (we document it in `hg help
flags`, but most users don't think to look there).

Note that flags that default to None (and not False) will not get this
new presentation. We can change the defaults to False later for flags
where it makes sense (probably almost all boolean flags).

Differential Revision: https://phab.mercurial-scm.org/D5432

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

from __future__ import absolute_import, print_function
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