Re: [PATCH v3 08/49] semihosting: Inline set_swi_errno into common_semi_cb

[Richard Henderson]

On 5/23/22 03:58, Peter Maydell wrote:
> On Sat, 21 May 2022 at 01:04, Richard Henderson
> <richard.henderson@linaro.org> wrote:
> > Do not store 'err' into errno only to read it back immediately.
> > Use 'ret' for the return value, not 'reg0'.
> >
> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> > ---
> >   semihosting/arm-compat-semi.c | 19 ++++++++++---------
> >   1 file changed, 10 insertions(+), 9 deletions(-)
> >
> > diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c
> > index c6bfd4d1ba..b00ed2c6d1 100644
> > --- a/semihosting/arm-compat-semi.c
> > +++ b/semihosting/arm-compat-semi.c
> > @@ -290,28 +290,29 @@ static target_ulong common_semi_syscall_len;
> >
> >   static void common_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
> >   {
> > -    target_ulong reg0 = common_semi_arg(cs, 0);
> > -
> >       if (ret == (target_ulong)-1) {
> > -        errno = err;
> > -        set_swi_errno(cs, -1);
> > -        reg0 = ret;
> > +#ifdef CONFIG_USER_ONLY
> > +        TaskState *ts = cs->opaque;
> > +        ts->swi_errno = err;
> > +#else
> > +        syscall_err = err;
> > +#endif
> >       } else {
> >           /* Fixup syscalls that use nonstardard return conventions.  */
> > +        target_ulong reg0 = common_semi_arg(cs, 0);
>
> This should be "ret = ", right? (Otherwise I think this fails to
> compile. I assume that some later patch has this fix in it.)

Eh?  No, we're extracting argument reg 0, and then switching on it.
Why would it not compile -- I've moved the whole declaration down.


r~


> Otherwise
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
>
> thanks
> -- PMM