Re: [PATCH v7 3/8] Use xml-syscall to compare syscall numbers in arm_linux_sigreturn_return-addr.

Pedro Alves
2015-12-11T11:59:18Z

On 12/11/2015 11:29 AM, Yao Qi wrote:
> Antoine Tremblay <antoine.tremblay@ericsson.com> writes:
>
>> It also adds a new function to xml-syscall.h/c to compare syscalls numbers
>> called is_syscall.
>
> Why don't we use existing get_syscall_by_name in
> arm_linux_sigreturn_return_addr rather than adding a new function is_syscall?
>

I wonder whether going through xml is really best. E.g., writing a syscall
call by name as a string is more typo prone than a macro constant. If you
typo the string, you get a runtime error. If you typo a macro you get a
compile time error. You could fix that by adding macros like:

#define ARM_SIGRETURN_NAME "sigreturn"

but then you might as well just do:

#define ARM_SIGRETURN 119

and avoid the xml look up. Syscall numbers are ABI, they can't ever change.

Thanks,
Pedro Alves