Automake buildsystem?

[ndim]

Even though building with an Automake based buildsystem takes a lot more time, it is still convenient to follow standard conventions like having a configure script to run.

Not sure I really want to switch. The current GNUmakefile is quite neat with its installing only what actually is actually necessary and stuff.

[3x380V]

Using AC_LINK_IFELSE would be actually useful to find out whenever beep needs to be linked with -latomic. It's the case with at least armv5te target. Either that or move to event loop (your other draft) as it removes the use of volatile sig_atomic_t global_abort.

[3x380V]

Hmm, above is caused by address sanitizer which requires both -lubsan and -latomic. There is nothing to handle additional libraries currently, so I'll just provide local.mk to disable all that additional checks. However there are few nits to fix and I will open PR for them. You may disregard my comments now.

[ndim]

beep does not use any symbols regarding atomic stuff which might be supplied by a library. beep only uses the sig_atomic_t type at compile time, so I do not see how linking any library to beep would make sense.

Besides, what system using a armv5te target CPU can make use of beep? It cannot have classic PC speaker hardware, so beep would at least need to add a well known device name to look for.

[ndim]

So... if I understand you correctly, you basically want to have a local.mk containing

CFLAGS = -fsanitize=undefined
LDADD = -lubsan -latomic

but only add the LDADD part for architecture/compiler/libc environments where it is actually needed?

[3x380V]

You may see actual linking error and explanation here: https://lore.ptxdist.org/ptxdist/ZjNw3VmNCgGpJwsq@lenoch/T/#m080d02abdd4a8f7432d73fa5fedfc26f949cdcf4
Solved this way: https://git.pengutronix.de/cgit/ptxdist/commit/?id=0b9fb169815fdea1de4901ce0434a048affbff39
While GNUMakefile could certainly use something like Busybox' scripts/trylink I'm considering that an overkill, so no action needed on beep part :)

Also note kernel contains drivers/input/misc/gpio-beeper.c and drivers/input/misc/pwm-beeper.c both being perfectly useable with beep, so many thanks for still maintaining it!

[ndim]

Also note kernel contains drivers/input/misc/gpio-beeper.c and drivers/input/misc/pwm-beeper.c both being perfectly useable with beep, so many thanks for still maintaining it!

If you have an idea where to find the well-known device names for those hardware devices, please let me know so I can add them to beep.

At this time, beep only knows to look for the PC speaker device /dev/input/by-path/platform-pcspkr-event-spkr.

I will take a look at the build stuff later.