closes 16162.

Avoid using file names and file paths for compatibility with
out-of-tree builds.

Note make and ccache don't track blacklist dependencies,
add workarounds.

Document use of coverity, clang static analyzer, and clang dynamic
undefined behavior and address sanitizers in doc/HACKING.

Add clang dynamic sanitizer blacklist in
contrib/clang/sanitizer_blacklist.txt to exempt known undefined
behavior. Include detailed usage instructions in this blacklist file.

Patch by "teor".

Fixes 16152.

This explains that if you change your torrc to do more, you might
need to change tor.service.in to allow it.  See #15195.

Tomasz Torcz authored 10 years ago and Nick Mathewson committed 10 years ago

  There were following problems:
  - configure.ac wrongly checked for defined HAVE_SYSTEMD; this
    wasn't working, so the watchdog code was not compiled in.
    Replace library search with explicit version check
  - sd_notify() watchdog call was unsetting NOTIFY_SOCKET from env;
    this means only first "watchdog ping" was delivered, each
    subsequent one did not have socket to be sent to and systemd
    was killing service
  - after those fixes, enable Watchdog in systemd unit with one
    minute intervals

Tomasz Torcz authored 10 years ago and Nick Mathewson committed 10 years ago

  If running under systemd, notify the supervisor about current PID
of Tor daemon.  This makes systemd unit simpler and more robust:
it will do the right thing regardless of RunAsDaemon settings.