RE: [PATCH v2 4/4] tools/nolibc: sys.h: apply __syscall() helper

[David Laight <David.Laight@ACULAB.COM>]

From: Zhangjin Wu
> Sent: 07 June 2023 06:39
...
> As a summary, will use 'sysret()' and something like:
> 
>    static __attribute__((unused))
>    int chdir(const char *path)
>    {
>    	return sysret(chdir(path));
>    }
> 
> to renew the syscall helper patchset, Thanks you very much.

While I'm all for using 'cpp-magic' to abstract and (hopefully)
simplify things. Token-pasting the sys_ here doesn't seem to gain
anything.
Anyone grepping the code for 'sys_chdir' is also going to
wonder where it is used.

There might be scope for something like:
#define syscall_wrapper(func, type) \
	static __attribute__((unused)) \
	int func(type *arg) \
	{ \
		return sysret(sys_#func(arg)); \
	}
and then:
syscall_wrapper(chdir, const char *)
would expand to the code above.

I think you'd need separate defines for each number of arguments.

	David

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