Re: [Qemu-devel] [PATCH 06/34] qerror: avoid passing qerr pointer

[Luiz Capitulino <lcapitulino@redhat.com>]

On Thu, 02 Aug 2012 13:23:58 +0200
Markus Armbruster <armbru@redhat.com> wrote:

> Luiz Capitulino <lcapitulino@redhat.com> writes:
> 
> > Helps dropping/modifying qerror functions.
> >
> > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> > ---
> >  qerror.c | 24 ++++++++++++------------
> >  1 file changed, 12 insertions(+), 12 deletions(-)
> >
> > diff --git a/qerror.c b/qerror.c
> > index 5efccec..59025ea 100644
> > --- a/qerror.c
> > +++ b/qerror.c
> > @@ -346,10 +346,10 @@ static QError *qerror_new(void)
> >      return qerr;
> >  }
> >  
> > -static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
> > -                                               const char *fmt, va_list *va)
> > +static QDict *error_obj_from_fmt_no_fail(const char *fmt, va_list *va)
> 
> Elsewhere, we use FOO_nofail() for a variant of FOO() that must not
> fail.
> 
> Call this function just error_obj_from_fmt()?
> 
> Or if you think the name must convey it can't fail:
> error_obj_from_fmt_nofail()?

It's worth it, this function is dropped later on.

> 
> >  {
> >      QObject *obj;
> > +    QDict *ret;
> >  
> >      obj = qobject_from_jsonv(fmt, va);
> >      if (!obj) {
> > @@ -361,9 +361,8 @@ static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
> >          abort();
> >      }
> >  
> > -    qerr->error = qobject_to_qdict(obj);
> > -
> > -    obj = qdict_get(qerr->error, "class");
> > +    ret = qobject_to_qdict(obj);
> > +    obj = qdict_get(ret, "class");
> >      if (!obj) {
> >          fprintf(stderr, "missing 'class' key in '%s'\n", fmt);
> >          abort();
> > @@ -372,8 +371,8 @@ static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
> >          fprintf(stderr, "'class' key value should be a string in '%s'\n", fmt);
> >          abort();
> >      }
> > -    
> > -    obj = qdict_get(qerr->error, "data");
> > +
> > +    obj = qdict_get(ret, "data");
> >      if (!obj) {
> >          fprintf(stderr, "missing 'data' key in '%s'\n", fmt);
> >          abort();
> > @@ -382,9 +381,11 @@ static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
> >          fprintf(stderr, "'data' key value should be a dict in '%s'\n", fmt);
> >          abort();
> >      }
> > +
> > +    return ret;
> >  }
> >  
> > -static void qerror_set_desc(QError *qerr, const char *fmt)
> > +static const QErrorStringTable *get_desc_no_fail(const char *fmt)
> 
> Likewise.
> 
> >  {
> >      int i;
> >  
> > @@ -392,8 +393,7 @@ static void qerror_set_desc(QError *qerr, const char *fmt)
> >  
> >      for (i = 0; qerror_table[i].error_fmt; i++) {
> >          if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
> > -            qerr->entry = &qerror_table[i];
> > -            return;
> > +            return &qerror_table[i];
> >          }
> >      }
> >  
> > @@ -426,8 +426,8 @@ static QError *qerror_from_info(const char *file, int linenr, const char *func,
> >      qerr->file = file;
> >      qerr->func = func;
> >  
> > -    qerror_set_data(qerr, fmt, va);
> > -    qerror_set_desc(qerr, fmt);
> > +    qerr->error = error_obj_from_fmt_no_fail(fmt, va);
> > +    qerr->entry = get_desc_no_fail(fmt);
> >  
> >      return qerr;
> >  }
> 
> Turns side effects on qerr into a nice clean return values.  Good!
>