> Hi Zhangjin,
>
> On 2023-06-06 16:17:38+0800, Zhangjin Wu wrote:
> > Use __syscall() helper to shrink 252 lines of code.
> >
> > $ git show HEAD^:tools/include/nolibc/sys.h | wc -l
> > 1425
> > $ git show HEAD:tools/include/nolibc/sys.h | wc -l
> > 1173
> > $ echo "1425-1173" | bc -l
> > 252
> >
> > Signed-off-by: Zhangjin Wu <falcon@xxxxxxxxxxx>
> > ---
> > tools/include/nolibc/sys.h | 336 +++++--------------------------------
> > 1 file changed, 42 insertions(+), 294 deletions(-)
> >
> > diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
> > index f6e3168b3e50..0cfc5157845a 100644
> > --- a/tools/include/nolibc/sys.h
> > +++ b/tools/include/nolibc/sys.h
> > @@ -108,13 +108,7 @@ int sys_chdir(const char *path)
> > static __attribute__((unused))
> > int chdir(const char *path)
> > {
> > - int ret = sys_chdir(path);
> > -
> > - if (ret < 0) {
> > - SET_ERRNO(-ret);
> > - ret = -1;
> > - }
> > - return ret;
> > + return __syscall(chdir, path);
>
> To be honest I'm still not a big fan of the __syscall macro.
> It's a bit too magic for too little gain.
>
> The commit message argues that the patches make the code shorter.
>
> However doing
>
> __sysret(sys_chdir(path));
>
> instead of
>
> __syscall(chdir, path);
>
> is only three characters longer and the same amout of lines.
>
Yeah, I do like your version too, it looks consise too, the only not
comfortable part is there are dual calls in one line.
> Otherwise we would have syscall() _syscall() and __syscall() each doing
> different things.
>
Yes, I'm worried about this too, although the compilers may help a
little, but it is too later.
Just brain storming, What about another non-similar name, for example,
__syswrap() or __sysin() ?
Or even convert __sysret() to __sysout() and __syscall() to __sysin(),
do you like it? or even __sysexit(), __sysentry(), but the __sysexit()
may be misused with sys_exit().
/* Syscall return helper, set errno as -ret when ret < 0 */
static __inline__ __attribute__((unused, always_inline))
long __sysout(long ret)
{
if (ret < 0) {
SET_ERRNO(-ret);
ret = -1;
}
return ret;
}
/* Syscall call helper, use syscall name instead of syscall number */
#define __sysin(name, ...) __sysout(sys_##name(__VA_ARGS__))
static __attribute__((unused))
int brk(void *addr)
{
return __sysout(sys_brk(addr) ? 0 : -ENOMEM);
}
static __attribute__((unused))
int chdir(const char *path)
{
return __sysin(chdir, path);
}
If we really want something like __syscall()/__sysret(), I do think they
should be a pair ;-)
> And __syscall does not behave like a regular function.
>
> The rest of the patchset looks great.
>
Thanks for your nice review.
> Maybe Willy can break the tie?
>
If there is no better solution, I think your version is also a first
step to go.
>
> Thomas
>
>
> Note: If we figure out a way to build syscall() without macros I would
> like that also :-)
Yes, but it is not easy to cope with the variable number of arguments
without a macro.
BTW, do you like to convert the my_syscallN() of sys.h to the syscall()
you added? I do worry about it will make the checking of arguments
mismatch, exspecially, the checking of number of them hardly.
Best regards,
Zhangjin
