SUMMARY
The code is marked as invalid or warnings are listed.

STEPS TO REPRODUCE
1. Insert sample code.
2. Watch the errors
3. Compile code without warnings or errors

OBSERVED RESULT
Lots of errors and warining despite correct includes

EXPECTED RESULT
No warnings or errors

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux
KDE Plasma Version: 5.24.3
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.3

ADDITIONAL INFORMATION
Sample code used:
```c
#include <stdio.h>
#include <signal.h>
#include <stdlib.h>

#define SIGNAL SIGUSR1

void action_handler(int sig, siginfo_t *info, void *ucontext) {
    printf("received signal %d\n", sig);
    exit(0);
}

int main(int argc, char** argv) {

    struct sigaction sa;
    sigaction(SIGNAL, NULL, &sa);
    sa.sa_sigaction = action_handler;
    sigaction(SIGNAL, &sa, NULL);

    raise(SIGNAL);

    while(1);

    return 0;
}
```