meson: add options to disable polkit and libsystemd

[brad0]

No description provided.

[LudovicRousseau]

You can already build without polkit using: meson setup -Dpolkit=false.

What problem do you want to solve?

[ssauvin]

Hello!

I was about to send the same patch for PolKit on Debian's Salsa but my spider sense made me check GitHub first.

@LudovicRousseau, currently this build option will only make PolKit optional at compilation time and disable it only if polkit-gobject-1 is actually missing on the system. For example, if I have PolKit available and -Dpolkit=false, pcscd will still use PolKit because polkit_dep.found() will be true.

Disclaimer, I haven't tested it without libsystemd, only without polkit.

With the current Meson configuration (slightly redacted for readability):

❯ meson setup -Dpolkit=false build
The Meson build system
Version: 1.5.1
[...]
Library dl found: YES
Run-time dependency polkit-gobject-1 found: YES 124
Run-time dependency libsystemd found: YES 256
[...]
pcsc-lite 2.3.0

  User defined options
    polkit: false

Found ninja-1.12.1 at /usr/host/bin/ninja

❯ cd build && meson compile
INFO: autodetecting backend as ninja
INFO: calculating backend command to run: /usr/host/bin/ninja
[45/45] Linking target testpcsc

❯ ./pcscd -v | grep Enabled
Enabled features: USB serial filter_names libudev polkit systemd Linux x86_64 ipcdir=/run/pcscd usbdropdir=/usr/lib/pcsc/drivers serialconfdir=/etc/reader.conf.d

With this PR:

❯ curl -s https://github.com/LudovicRousseau/PCSC/commit/bde1526e879804bbcadf65cb8b532531dd0e56b8.patch | patch
patching file meson.build

❯ meson setup -Dpolkit=false build
[...]
Library dl found: YES
Run-time dependency libsystemd found: YES 256
[...]
pcsc-lite 2.3.0

  User defined options
    polkit: false

Found ninja-1.12.1 at /usr/host/bin/ninja

❯ cd build && meson compile
INFO: autodetecting backend as ninja
INFO: calculating backend command to run: /usr/host/bin/ninja
[45/45] Linking target libpcsclite_real.so.1

❯ ./pcscd -v | grep Enabled
Enabled features: USB serial filter_names libudev systemd Linux x86_64 ipcdir=/run/pcscd usbdropdir=/usr/lib/pcsc/drivers serialconfdir=/etc/reader.conf.d

Thank you!

[LudovicRousseau]

Merged in d688f7e

Thanks