Tweak the script used for creating a new skeleton dissector, to allow it
to create the dissector in `plugins/epan/PROTOSHORTNAME` instead of in
`epan/dissectors`. Handles modifying the appropriate CMake file in the
appropriate way, and generates the plugin's `CMakeLists.txt` if needed.
PEP 394[1] says,
"In cases where the script is expected to be executed outside virtual
environments, developers will need to be aware of the following
discrepancies across platforms and installation methods:
* Older Linux distributions will provide a python command that refers
to Python 2, and will likely not provide a python2 command.
* Some newer Linux distributions will provide a python command that
refers to Python 3.
* Some Linux distributions will not provide a python command at all by
default, but will provide a python3 command by default."
Debian has forced the issue by choosing the third option[2]:
"NOTE: Debian testing (bullseye) has removed the "python" package and
the '/usr/bin/python' symlink due to the deprecation of Python 2."
Switch our shebang from "#!/usr/bin/env python" to "#!/usr/bin/env
python3" in some places. Remove some 2/3 version checks if we know we're
running under Python 3. Remove the "coding: utf-8" in a bunch of places
since that's the default in Python 3.
[1]https://www.python.org/dev/peps/pep-0394/#for-python-script-publishers
[2]https://wiki.debian.org/Python
Fix some issues discovered by common python linters including:
* switch `None` comparisons to use `is` rather than `==`. Identity !=
equality, and I've spent 40+ hours before tracking down a subtle bug
caused by exactly this issue. Note that this may introduce a problem if
one of the scripts is depending on this behavior, in which case the
comparison should be changed to `True`/`False` rather than `None`.
* Use `except Exception:` as bare `except:` statements have been
discouraged for years. Ideally for some of these we'd examine if there
were specific exceptions that should be caught, but for now I simply
caught all. Again, this could introduce very subtle behavioral changes
under Python 2, but IIUC, that was all fixed in Python 3, so safe to
move to `except Exception:`.
* Use more idiomatic `if not x in y`--> `if x not in y`
* Use more idiomatic 2 blank lines. I only did this at the beginning,
until I realized how overwhelming this was going to be to apply, then I
stopped.
* Add a TODO where an undefined function name is called, so will fail
whenever that code is run.
* Add more idiomatic spacing around `:`. This is also only partially
cleaned up, as I gave up when I saw how `asn2wrs.py` was clearly
infatuated with the construct.
* Various other small cleanups, removed some trailing whitespace and
improper indentation that wasn't a multiple of 4, etc.
There is still _much_ to do, but I haven't been heavily involved with
this project before, so thought this was a sufficient amount to put up
and see what the feedback is.
Linters that I have enabled which highlighted some of these issues
include:
* `pylint`
* `flake8`
* `pycodestyle`
Generate a dissector based on doc/packet-PROTOABBREV.c.
Change-Id: I9233c1212acb30f7166ba91e39d98bc3fb123731
Reviewed-on: https://code.wireshark.org/review/35062
Reviewed-by: Graham Bloice <graham.bloice@trihedral.com>
Reviewed-by: Dario Lombardo <lomato@gmail.com>
David Perry