On Sun, 8 Dec 2024 13:36:07 +0800
Chris Billington <cbillington@emulti.net> wrote:

> First steps, getting the program to build, having solved a few type errors I have run into the following issue:
> ...
> /home/chris/Downloads/build/ctune/src/datastructure/CircularBuffer.c:36:17: warning: call to undeclared function 'syscall'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>     long fd   = syscall( __NR_memfd_create, name, flags );
>                 ^
> /home/chris/Downloads/build/ctune/src/datastructure/CircularBuffer.c:36:26: error: use of undeclared identifier '__NR_memfd_create'
>     long fd   = syscall( __NR_memfd_create, name, flags );
>                          ^
> 1 warning and 1 error generated.

OpenBSD has neither the syscall(2) nor memfd_create(2) functions from
Linux.  I would try mkstemp(3) and unlink(2) to create a file
descriptor.  That might look like

#ifdef __OpenBSD__
    int fd;
    char buf [] = "/tmp/mem.XXXXXXXXXX";

    fd = mkstemp( buf );
    if( fd != -1 )
        unlink( buf );
    return fd;
#else
    long fd   = syscall( __NR_memfd_create, name, flags );
    ...
    return cast;
#endif

If mkstemp or unlink aren't declared, then #include <stdlib.h> or
<unistd.h>.

--gkoehler