Hi Quentin,
On Wed, 19 Mar 2025 at 13:04, Quentin Schulz <quentin.sch...@cherry.de> wrote:
>
> Hi Simon,
>
> On 3/19/25 12:49 PM, Simon Glass wrote:
> > Logging of function return-values is used very frequently in U-Boot now.
> > Add a few helper macros to make it less verbose to use.
> >
> > It turns out that the log_ret() variants are not so useful, since it is
> > not obviously where the error is coming from. So only the log_msg_ret()
> > variants are worthy of these macros.
> >
> > Signed-off-by: Simon Glass <s...@chromium.org>
> > ---
> >
> > include/log.h | 26 ++++++++++++++++++++++++++
> > 1 file changed, 26 insertions(+)
> >
> > diff --git a/include/log.h b/include/log.h
> > index 4f6d6a2c2cf..bdda7af570c 100644
> > --- a/include/log.h
> > +++ b/include/log.h
> > @@ -380,6 +380,32 @@ void __assert_fail(const char *assertion, const char
> > *file, unsigned int line,
> > #define log_msg_retz(_msg, _ret) ((void)(_msg), _ret)
> > #endif
> >
> > +/*
> > + * LOGR() - helper macro for calling a function and logging error returns
> > + *
> > + * Logs if the function returns a negative value
> > + *
> > + * Usage: LOGR("abc", my_function(...));
> > + */
> > +#define LOGR(_msg, _expr) do { \
> > + int _ret = _expr; \
> > + if (_ret < 0) \
> > + return log_msg_ret(_msg, _ret); \
> > + } while (0)
> > +
> > +/*
> > + * LOGZ() - helper macro for calling a function and logging error returns
> > + *
> > + * Logs if the function returns a non-zero value
> > + *
> > + * Usage: LOGZ("abc", my_function(...));
> > + */
> > +#define LOGZ(_msg, _expr) do { \
> > + int _ret = _expr; \
> > + if (_ret) \
> > + return log_msg_retz(_msg, _ret); \
> > + } while (0)
> > +
>
> Mmmm not sure this forced return call is a good idea, this would forbid
> us from performing some unwinding for example.
Yes, it is really only for simple cases. Without the return, there
isn't much value and you may as well not use this macro.
>
> I don't really see how that is better than simply calling
>
> return log_msg_retz("abc", my_function());
That's not the intention. It actually replaces:
ret = my_function();
if (ret)
return_log_msg_ret("abc", ret);
I use this a lot in my code. You can't always just return, since there
may not be an error.
>
> ?
>
> If we were to keep this, I would recommend to rename the macro and fix
> the docstring because it does not only log if the function returns a
> non-zero value. It does actually return.
>
> So something like
>
> LOGZ_AND_RETURN(_msg, _expr)
>
> maybe?
Sure, longer names are easier to learn, but then it is so long I doubt
anyone would use it.
Perhaps LOG_RET() and LOG_RETZ() ? But they might get confused with
log_ret() and log_retz(), which I am actually thinking of deleting.
I would like the shortest possible name to avoid spilling functions
onto the next line all the time.
Regards,
SImon
